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Copper ion-antibiotic complexation inhibits photochemical transformation of fluoroquinolones via electron redistribution and reactivity regulation 认领 引用
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作者 Bo Gong Chang Xu +4 位作者 Shan Zhao Xiao-Min Sun Shu-Guang Wang Xian-Zheng Yuan Chao Song 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第4期584-592,共9页
The photochemical transformation of fluoroquinolones(FQs) represents a crucial environmental phenomenon eliciting growing concern. Nevertheless, the impact and mechanisms of ubiquitously coexisting copper ions, i.e.,... The photochemical transformation of fluoroquinolones(FQs) represents a crucial environmental phenomenon eliciting growing concern. Nevertheless, the impact and mechanisms of ubiquitously coexisting copper ions, i.e.,Cu(Ⅱ), remain elusive. Here, the role of Cu(Ⅱ) in the photochemical transformation of FQs was systematically investigated via experimental characterizations and theoretical simulations. Cu(Ⅱ) markedly inhibited the photolysis of levofloxacin(LEV), a representative FQs model, from 0.0078 to 0.0040 min-1 after a 100-min irradiation under simulated sunlight with the molar ratio of Cu(Ⅱ): LEV at 1:1. The micro-level mechanisms were explored, including the ligand-to-metal charge transfer in complexation, modifications to reactive sites and activities with various reactive species, and higher hole-electron separation extents. In addition, the triplet excited state, singlet oxygen, and hydroxyl radical in LEV and LEV-Cu(Ⅱ) with 1:1 molar ratio played pivotal roles in the transformation, contributing 20.77 %/20.02 %, 13.87 %/14.59 %, and 7.96 %/4.68 %, respectively. Furthermore, considering more FQs models, the inhibition of Cu(Ⅱ) on the transformation was found to universally exist in ciprofloxacin, enoxacin, enrofloxacin, norfloxacin, ofloxacin and pefloxacin, and their multiple molecular descriptors were changed with a same tendency. This work provides a comprehensive understanding of the transformation of antibiotics within complex aqueous matrices, contributing to further estimation of antibiotics removal and ecological risks. 展开更多
关键词 Fluoroquinolones Photochemical transformation Copper complexation Reactivity regulation Molecular mechanism
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Linear relationship between reactivity and the reciprocal of uranium concentration in thermal‑spectrum molten salt reactors 认领 引用
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作者 Chang-Qing Yu Gui-Feng Zhu +7 位作者 Shu-Yang Jia Yang Zou Rui Yan Jian Guo Ya-Fen Liu Bo Zhou Xue-Chao Zhao Xiao-Han Yu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第2期208-222,共15页
Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain... Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of 235 U;similarly,the reciprocal of 235U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors. 展开更多
关键词 Molten salt reactor Reactivity Uranium concentration Cross sections Linear
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Pilot-Ignition Reactivity-Stratification Combustion for Ammonia Fueled Engines 认领 引用
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作者 Yuxiao Qiu Yanyuan Zhang +3 位作者 Yingnan Yang You Zhang Dong Han Zhen Huang 《Engineering》 SCIE EI CSCD 2026年第1期257-266,共10页
Ammonia combustion does not produce carbon dioxide,and has been recognized as one of the promising approaches to achieving carbon neutrality in transportation sector.Due to the slow flame propagation speed and high ig... Ammonia combustion does not produce carbon dioxide,and has been recognized as one of the promising approaches to achieving carbon neutrality in transportation sector.Due to the slow flame propagation speed and high ignition energy requirements,reactive fuel pilot ignition is essential for ammonia combustion in compression ignition engines.The reduction of pilot fuel drives CO2 mitigation by curtailing carbon input,but this has a demand of advanced combustion modulation techniques to sustain engine efficiency.Designed pilot fuel stratification enables an activated in-cylinder environment,overcoming the difficulty in ammonia ignition and combustion,and allowing for a minimal pilot fuel amount to trigger premixed ammonia combustion.The minimum pilot fuel permits 99.1% ammonia energy substitution,accounting for only 1.3% of the CO2 emissions from diesel combustion at the same load condition.Optimized intake organization coupled with improved reactivity stratification also achieves over 46%brake thermal efficiency,and reduces unburned ammonia by over 80% compared to baseline operation. 展开更多
关键词 Ammonia-fueled engine Diesel pilot ignition Reactivity stratification Combustion optimization Maximum ammonia substitution
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Particle-Size-Dependent Reactivity and Graded Utilization of Water-Cooled Ferronickel Slag in Cement-Based Materials 认领 引用
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作者 Yubo Li Zhaolin Xu +4 位作者 Xingyang He Ying Su DingWang Lu Cheng Bohumír Strnadel 《Fluid Dynamics & Materials Processing》 EI 2026年第6期1-23,共23页
The utilization of water-cooled electric furnace ferronickel slag(EFFS)in concrete remains constrained by its intrinsically low pozzolanic reactivity as a supplementary cementitious material(SCM)and its inadequate vol... The utilization of water-cooled electric furnace ferronickel slag(EFFS)in concrete remains constrained by its intrinsically low pozzolanic reactivity as a supplementary cementitious material(SCM)and its inadequate volumetric stability when employed as aggregate.This study systematically investigates the compositional characteristics of this slag across different particle-size fractions and proposes a wet-grinding activation strategy to enhance its pozzolanic performance.In particular,cement pastes incorporating 10%,30%,and 50%ultrafine EFFS derived from three original size fractions are comprehensively evaluated in terms of rheological behavior,compressive strength,hydration characteristics,and microstructural evolution.The results demonstrate pronounced size-dependent differences in phase composition.The amorphous phase content of EFFS particles smaller than 1.0 mm(EFFS0)reaches 54.04%,which is 19.72%higher than that of particles larger than 1.8 mm(EFFS2).The higher amorphous content leads to enhanced pozzolanic activity and improved mechanical performance.Mortars containing 30%ultrafine EFFS0 exhibit favorable strength development,with the 28-day compressive strength reaching 96%of that of the plain cement control and showing a 29%increase relative to the corresponding EFFS2 mixture.Based on these findings,a graded utilization strategy for water-cooled EFFS is proposed:The finer and more reactive fractions are suitable for SCM applications after activation,whereas the coarser fractions are more appropriate for non-cementitious applications,such as aggregate utilization. 展开更多
关键词 Electric furnace ferronickel slag pozzolanic reactivity supplementary cementitious material wet-grinding activation rheological behavior graded utilization strategy
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Effects of Mn doping on the reactivity,elastic,and magnetic properties ofα-Fe2O3based on DFT calculation 认领 引用
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作者 WANG Peng DONG Changqing +4 位作者 XUE Junjie GAO Qi HU Xiaoying ZHANG Junjiao ZHAO Jie 《燃料化学学报（中英文）》 EI CAS CSCD 北大核心 2026年第2期140-152,共13页
Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separ... Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(Evac)from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(Hv/Ev)forα-Fe2O3and an 83.33%reduction for Fe3O4.Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(Ms)of Fe3O4reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability. 展开更多
关键词 oxygen carrier Mn-dopedα-Fe2O3 reactivity elastic properties magnetic properties
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Effect of key parameters on the refueling reactivity coefficient in a pebble-bed high-temperature gas-cooled reactor 认领 引用
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作者 Zhong‑Kai Sheng Bing Xia +3 位作者 Hong‑Wei Wu Ding She Fu Li Zuo‑Yi Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第8期308-318,共11页
Online continuous refueling is one of the main features of a pebble-bed high-temperature gas-cooled reactor(PB-HTR).During the normal operation of a PB-HTR,positive reactivity is mainly introduced through refueling,wh... Online continuous refueling is one of the main features of a pebble-bed high-temperature gas-cooled reactor(PB-HTR).During the normal operation of a PB-HTR,positive reactivity is mainly introduced through refueling,whereas negative reactivity is introduced through depletion.Therefore,evaluating the refueling reactivity coefficient is crucial for the safe and stable operation of PB-HTRs.In this study,the perturbation theory is used to calculate the refueling reactivity coefficient,and the effect of key parameters on the refueling reactivity coefficient is examined based on the HTR-PM equilibrium core.The refueling reactivity introduced into the reactor core is driven by the gradient of the nuclide atomic density,particularly235U.The neutron flux modulates the spatial distribution of the refueling reactivity.The loading fraction of the fresh fuel directly and positively influences the refueling reactivity coefficient.This study provides comprehensive insights into the effect of these parameters on the refueling of PB-HTRs,paving the way for efficient fuel management. 展开更多
关键词 Refueling reactivity coefficient PB-HTR Perturbation theory
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Biochar-assisted gasification of raw biomass:a review on the reactivity and synergistic effect on tar reforming 认领 引用 被引量：1
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作者 Aghietyas Choirun Az Zahra Alahakoon Mudiyanselage Yushani Wimansika Alahakoon +3 位作者 Lianfeng Zhu Tirto Prakoso Abuliti Abudula Guoqing Guan 《Resources Chemicals and Materials》 2025年第3期46-67,共22页
The thermal conversion process known as biomass gasification has the potential to produce environmentally friendly fuels such as hydrogen.However,tar generation during the gasification remains an issue,affecting opera... The thermal conversion process known as biomass gasification has the potential to produce environmentally friendly fuels such as hydrogen.However,tar generation during the gasification remains an issue,affecting operational efficiency and environmental health.Biochar has been confirmed as an inexpensive and efficient catalyst for tar removal.The challenge lies in creating a highly reactive biochar which can be applied for different types of biomass with varying properties.This review discusses the factors that affect biochar’s reactivity as a catalyst for tar reforming.Additionally,incorporating biochar into a gasification scenario with raw biomass offers a practical solution by leveraging the synergistic behavior.However,this synergy could be either positive or negative:the positive synergy enhances tar removal while the negative synergy has the opposite effect.The numerous factors affecting the results of gasification are presented in this review.It is concluded that the positive synergistic effect resulted from the balance between the available reactants from biomass and biochar,the optimal gas flowrate and the active sites on the carbon surface.Understanding these interactions is crucial for optimizing biochar performance for tar removal.Ultimately,this research provides insights into biochar’s role in biomass gasification and suggests improvements for future studies to enhance the feasibility of biomass gasification with the assistance of biochar. 展开更多
关键词 Biochar-based catalyst Biomass gasification Biochar reactivity Synergistic effect Tar reforming
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Interfacial adsorption and reactivity of exact separation of sphalerite and pyrite by ferrophilic inhibitors in EX−Cu(Ⅱ)system 认领 引用
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作者 Wen-chao DONG Run-qing LIU +2 位作者 Chang-tao WANG Zheng-qiang CAO Wei SUN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2025年第5期1662-1678,共17页
Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively sep... Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively separate sphalerite and pyrite under low alkaline conditions.Furthermore,high-quality zinc concentrates with a Zn grade of 58.48%and a recovery of 91.24%through mixed mineral flotation were obtained.The fundamental mechanisms were investigated through surface wettability tests,adsorption capacity tests,LEIS,FTIR,and XPS.The results confirmed that IDS prevents the adsorption of EX on the surface of pyrite,thereby reducing the response and reactivity of pyrite.The introduction of IDS causes the detachment of Cu2+from the Cu-activated pyrite surface.This process allowed IDS to chelate with the Fe sites on the surface of pyrite through the-COO-and N-centered active groups.By contrast,IDS exhibits weaker adhesion on the surface of Cu-activated sphalerite,making it easily displaced by EX through competitive adsorption. 展开更多
关键词 interfacial adsorption reactivity separation sphalerite pyrite tetrasodium iminodisuccinate
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Pressure and temperature effects resulting from impact onto materials of different reactivity 认领 引用 被引量：1
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作者 Andreas Heine Matthias Wickert 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2025年第2期221-230,共10页
The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale setup.This allows deriving qualitative information on the occurrin... The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale setup.This allows deriving qualitative information on the occurring phenomenology as well as quantitative statements about the relative effects sizes as a function of target material and threat.The considered target materials are steel,aluminum,and magnesium.As threats,kinetic energy penetrator,explosively formed projectile,and shaped charge jet are used.For the investigated combinations,the measured overpressures vary by a factor of up to 5 for a variation of the material,by a factor of up to 7 for a variation of the threat,and by a factor larger than 15for a simultaneous variation of both.The obtained results as well as the experimental approach are relevant for the basic understanding of impact effects and risks due to material reactivity.The paper combines two main aims.Firstly,to provide a summary of own prior work in a coherent journal article and,secondly,to review and discuss these earlier results with a new perspective. 展开更多
关键词 Impact effects Pressure Temperature Risk assessment Material reactivity
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The combustion reactivity of core-shell Al/Fluoropolymers and application in RDX-based explosives 认领 引用
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作者 Ting Liu Jian Wang +6 位作者 Jie Chen Cui Nie Yaofeng Mao Fude Nie Ruolei Zhong Wei Cao Jun Wang 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2025年第9期30-39,共10页
Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al2O3)on Al particles limits combustion reactivity and ... Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al2O3)on Al particles limits combustion reactivity and energy efficiency.Fluoride-based surface modification has been developed as an effective approach to address this issue.Here,four classical fluoropolymers(F11,F14,PVDF,PTFE)are employed as coatings to prepare core-shell Al/Fluoropolymer.The combustion experimental results demonstrate that the core-shell Al/PTFE exhibits the highest flame propagation rate(52.88 mm·ms-1)and pressure output(109.02 k Pa)performance.Consequently,core-shell Al/PTFE is selected as a high-energy fuel to prepare RDX/Al/PTFE microspheres via the emulsion and solvent evaporation method,which can enhance the energy performance of RDX.The effects of the core-shell Al/PTFE ratio and RDX content on the combustion heat and pressure output are systematically investigated.The peak pressure reaches a maximum of 187.8 k Pa when the mass ratio of RDX,Al,and PTFE is 60:25:10.Additionally,RDX/Al/PTFE microspheres exhibit significantly higher laser-induced air shock velocities,detonation heat,and detonation pressure than those of pure RDX and RDX/Al.The mechanism underlying the enhanced reactivity and energetic performance is attributed to the ability of PTFE to etch the inert Al2O3shell on the surface of Al particles,thereby improving post-combustion reactions and significantly increasing the overall energy output of RDX explosives.This work offers a novel design strategy for high-energy structural thermobaric explosives for the practical applications. 展开更多
关键词 Core-shell Al/Fluoropolymers RDX/Al/PTFE Microspheres Combustion reactivity Energetic performance
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An Observational Study of the Relationship Between Outcome and Platelet Reactivity in Chinese Patients Undergoing PCI Loading with 600 mg Clopidogrel 认领 引用 被引量：2
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作者 Jing-xiu Li Ling Weng +13 位作者 Xue-qi Li Yang Li Shu-jun Yan Zhao-yan Song Xue-yanZhang Li Cha Lin Lin Tian-shu Yang Wei-jun Lv Ying-nan Dai Ye-ping Chen De-Jun Xia Xin Li En-ze Jin 《Cardiovascular Innovations and Applications》 2020年第3期27-35,共9页
Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneou... Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis. 展开更多
关键词 clopidogrel platelet reactivity PCI VerifyNow assay high on-clopidogrel platelet reactivity
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Improvements in methodology to determine feedback reactivity coefficients 认领 引用 被引量：2
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作者 Faisal Qayyum Muhammad Rizwan Ali +1 位作者 Awais Zahur R.Khan 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2019年第4期91-104,共14页
The reactivity of a nuclear reactor is the most important safety and operating parameter. Due to short reactor period, the Light Water Reactor(LWR) designs require the compensations of rapid unfavorable reactivity inc... The reactivity of a nuclear reactor is the most important safety and operating parameter. Due to short reactor period, the Light Water Reactor(LWR) designs require the compensations of rapid unfavorable reactivity increases. The increase in fuel or moderator temperature leads to compensate the reactivity jumps as inherent safety characteristics. The safe and reliable reactor operation requires the accurate assessment of these reactivity changes. This paper highlights the improvements in the methodology to determine the feedback reactivity changes in IAEA MTR benchmark. This method incorporates the reactivity effects of fuel temperature in moderator regions and vice versa. For this purpose, a detailed 3D model of the IAEA 10 MW MTR benchmark reactor is developed employing OpenMC computer code. OpenMC is a probabilistic computer code for neutronic calculations. This work uses temperature-dependent JEFF 3.2 cross-sectional library. The model is validated against the reference results of eigenvalues for control rods(inserted and in fully withdrawn position), control rod reactivity worth, averaged thermal flux in the central flux trap, and power fraction for each fuel element at beginning of life. The validated model is applied to simulate the feedback reactivity coefficients against the conventional reference results. In order to improve the methodology, the effect of the moderator temperature and void on fuel is incorporated to obtain a more realistic value of the fuel temperature coefficient.Similarly, the moderator temperature coefficient and void coefficient are improved by incorporating the coupling effects of fuel temperature on moderator. This methodology can be applied to improve the LWR designs. 展开更多
关键词 OpenMC MTR benchmark Reactivity feedback coefficients Fuel temperature coefficient Moderator temperature coefficient Void coefficient of reactivity
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Density functional theory study of influence of impurity on electronic properties and reactivity of pyrite 认领 引用 被引量：21
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作者 李玉琼 陈建华 +1 位作者 陈晔 郭进 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1887-1895,共9页
The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by fr... The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods.The cell volume expands due to the presence of impurity.Co and Ni mainly affect the bands near Fermi levels,while As mainly affects the shallow and deep valence bands,and Se and Te mainly affect the deep valence bands.Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms.By frontier orbital calculation,it is suggested that As,Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te.In addition,pyrite containing As,Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te,and pyrite containing Co or Ni has greater interaction with collector.These are in agreement with the observed pyrite practice. 展开更多
关键词 pyrite impurity density functional theory electronic properties reactivity
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Impact of photoneutrons on reactivity measurements for TMSR-SF1 认领 引用 被引量：16
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作者 Rui-Min Ji Ming-Hai Li +1 位作者 Yang Zou Gui-Min Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2017年第6期101-107,共7页
The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MWth test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great int... The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MWth test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great intrinsic safety features and economic advantages.Due to a large amount of beryllium in the coolant salt,photoneutrons are produced by(y,n) reaction,hence the increasing fraction of effective delayed neutrons in the core by the photoneutrons originating from the long-lived fission products.Some of the delayed photoneutron groups are of long lifetime,so a direct effect is resulted in the transient process and reactivity measurement.To study the impact of photoneutrons for TMSR-SF1,the effective photoneutron fraction is estimated using k-ratio method and performed by the Monte Carlo code(MCNP5) with ENDF/B-Ⅶ cross sections.Based on the coupled neutronphoton point kinetics equations,influence of the photoneutrons is analyzed.The results show that the impact of photoneutrons is not negligible in reactivity measurement.Without considering photoneutrons in on-line reactivity measurement based on inverse point kinetics can result in overestimation of the positive reactivity and underestimation of the negative reactivity.The photoneutrons also lead to more waiting time for the doubling time measurement.Since the photoneutron precursors take extremely long time to achieve equilibrium,a "steady" power operation may not directly imply a "real" criticality. 展开更多
关键词 TMSR-SF1 Delayed photoneutrons Coupled neutron-photon point kinetics Reactivity measurement
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Pericytes protect rats and mice from sepsis-induced injuries by maintaining vascular reactivity and barrier function:implication of miRNAs and microvesicles 认领 引用 被引量：10
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作者 Zi-Sen Zhang Yi-Yan Liu +10 位作者 Shuang-Shuang He Dai-Qin Bao Hong-Chen Wang Jie Zhang Xiao-Yong Peng Jia-Tao Zang Yu Zhu Yue Wu Qing-Hui Li Tao Li Liang-Ming Liu 《Military Medical Research》 SCIE CAS CSCD 2024年第1期1-18,共18页
Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity... Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43flox/floxmice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs. 展开更多
关键词 Pericyte Vascular reactivity Vascular permeability Cx43 Microvesicle
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Research on the effect of the heavy nuclei amount on the temperature reactivity coefficient in a small modular molten salt reactor 认领 引用 被引量：6
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作者 Meng-Lu Tan Gui-Feng Zhu +2 位作者 Yang Zou Xiao-Han Yu Ye Dai 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2019年第9期83-93,共11页
Small modular thorium-based graphite-moderated molten salt reactors (smTMSRs), which combine the advantages of small modular reactors and molten salt reactors, are regarded as a wise development path to speed deployme... Small modular thorium-based graphite-moderated molten salt reactors (smTMSRs), which combine the advantages of small modular reactors and molten salt reactors, are regarded as a wise development path to speed deployment time. In a smTMSR, low enriched uranium and thorium fuels are used in once-through mode, which makes a marked difference in their neutronic properties compared with the case when a conventional molten salt breeder reactor is used. This study investigated the temperature reactivity coefficient (TRC) in a smTMSR, which is mainly affected by the molten salt volume fraction (VF) and the heavy nuclei concentration in the fuel salt (HN). The fourfactor formula method and the reaction rate method were used to indicate the reasons for the TRC change, including the fuel density effect, the fuel Doppler effect, and the graphite thermal scattering effect. The results indicate that only the fuel density has a positive effect on the TRC in the undermoderated region. Thermal scattering from both salt and graphite has a significant negative influence on the TRC in the overmoderated region. The maximal effective multiplication factor, which shows the highest fuel utilization, is located at 10% VF and 12 mol% HN and is still located in the negative TRC region. In addition, on increasing the heavy nuclei amount from 2 mol% HN to 12 mol% HN (VF = 10%), the total TRC undergoes an obvious change from - 11 to - 3 pcm/K, which implies that the change in the HN caused by the fuel feed online should be small to avoid potential trouble in the reactivity control scheme. 展开更多
关键词 Molten salt reactor Temperature reactivity coefficient Heavy nuclei amount
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Crystal lattice free volume in a study of initiation reactivity of nitramines:Friction sensitivity 认领 引用 被引量：6
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作者 Svatopluk Zeman Ning Liu +2 位作者 Marcela Jungová Ahmed K.Hussein Qi-long Yan 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2018年第2期132-136,共5页
The relationship between friction sensitivity(FS) and the crystal lattice free space per molecule, △V. of thirteen nitramines is described by a linear equation, divided into a number of the partial relationships with... The relationship between friction sensitivity(FS) and the crystal lattice free space per molecule, △V. of thirteen nitramines is described by a linear equation, divided into a number of the partial relationships with strong limitations by their molecular structure characteristics. Increasing FS due to raising of the △V values is not clearly confirmed. The influence of the △V values on friction sensitivity of nitramines is similar to that of their aza atoms which influence the mutual orientations of nitro groups in neighboring molecules. The dipole-dipole interaction of the oxygen and nitrogen atoms of nitro groups in neighboring nitramine molecules has a major effect on their own FS. In accordance with this interaction, a directly proportional relationship was derived between FS and the intrinsic gas phase molecular volume, Vint, of the nitramines mentioned, which is divided also into several straight lines according to relatively tight molecular structure similarity. The relationships found again confirm a level of disorder in the distribution of the forces in the crystal lattice of the "common" quality of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, in comparison with its reduced sensitivity(RS) or chemically pure analogue. 展开更多
关键词 Crystal lattice Friction Initiation reactivity Nitramines
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Determining an optimal control strategy for anthropogenic VOC emissions in China based on source emissions and reactivity 认领 引用 被引量：8
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作者 Ruipeng Wang Xiaoqi Wang +4 位作者 Shuiyuan Cheng Jiaxian Zhu Xinyu Zhang Long Cheng Kai Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期248-260,共13页
An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018... An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results.Then,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was analyzed.Moreover,priority control routes for VOC emission sources were proposed for different periods.Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main contributors.Industrial protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and SOAFP.Priority in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in China.In addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits. 展开更多
关键词 Volatile organic compounds Anthropogenic emission inventory Reactivity Emission projection Priority control route
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Crystal lattice free volume in a study of initiation reactivity of nitramines:Impact sensitivity 认领 引用 被引量：6
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作者 Svatopluk Zeman Ning Liu +2 位作者 Marcela Jungová Ahmed K. Hussein Qi-Long Yan 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2018年第2期93-98,共6页
More detailed analysis of a mutual relationship of impact sensitivity(detected by sound) and crystal lattice free volume, △V, for the 18 nitramines shows that its course is not unequivocal. For a part of the studied ... More detailed analysis of a mutual relationship of impact sensitivity(detected by sound) and crystal lattice free volume, △V, for the 18 nitramines shows that its course is not unequivocal. For a part of the studied compounds this sensitivity has increased with increase of the AV values, but for fairly big number of nitramines the relationship works in the opposite direction, especially for data of 1,3,5-trinitro-1,3,5-triazinane, 1,3,5,7-tetranitro-1,3,5,7-tetrazocane. and β-and ε-polymorphs of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane. Initiation reactivity of technical ε-polymorph of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane gives the impression by disorderliness in distribution of the actions of forces in its crystal lattice in comparison with its RS(reduced sensitivity) or chemically pure analogue. Limitations of partial shapes of the mentioned relationship by the molecular-structural similarity, and already published information about the decisive factors governing the crystal structure, signalizes a higher influence of the intermolecular interactions in a crystal lattice in comparison with influence of the crystal lattice free volume for initiation of the crystalline EMs. 展开更多
关键词 Crystal lattice Impact Initiation reactivity Nitramines
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Effect of sulfur impurity on coke reactivity and its mechanism 认领 引用 被引量：10
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作者 肖劲 邓松云 +1 位作者 仲奇凡 叶绍龙 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3702-3709,共8页
Effect of sulfur impurity on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and impurities doping. And its mechanism was discussed by X-ray diffraction (XRD), scanning elect... Effect of sulfur impurity on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and impurities doping. And its mechanism was discussed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that sulfur has strong catalysis on both air and CO2 reactivity of coke in the case of no other impurity interference. Its catalysis is probably realized by triggering organic sulfur→H2S→SO2→COS and elemental sulfur (Sx)→SO2 and organic sulfur→H2S→COS→Sx→C2S→COS reaction systems during coke?O2 and coke?CO2 reactions, respectively, which are partly circular with functions of increasing carbon consumption and enlarging coke specific surface area. 展开更多
关键词 coke reactivity sulfur impurity catalysis
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