期刊文献+
共找到35,741篇文章
< 1 2 250 >
每页显示 20 50 100
Thermodynamic feasibility of nickel and cerium oxides as versatile oxygen carriers in chemical looping reforming of methane-rich feedstocks 认领 引用
1
作者 Marie-Nour Kaydouh Elie Chalhoub +1 位作者 Ahmed S.Al-Fatesh Nissrine El Hassan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2026年第3期206-217,共12页
Chemical Looping Reforming is an innovative methane-to-syngas conversion process offering high thermal efficiency,flexibility and H2/CO ratio of 2.This study investigates novel NiO-CeO2oxygen carrier combination... Chemical Looping Reforming is an innovative methane-to-syngas conversion process offering high thermal efficiency,flexibility and H2/CO ratio of 2.This study investigates novel NiO-CeO2oxygen carrier combination to leverage their individual benefits while exploring possible synergistic effects.Thermodynamic simulations using Aspen Plus show that NiO-CeO2mixtures promote partial oxidation,suppress carbon formation,and prevent total oxidation,improving cold gas efficiency(CGE),syngas purity,and exergy efficiency.This contrasts with single oxides:excessive NiO induces complete oxidation and CeO2alone suffers from carbon deposition.The optimal composition of 3 kmol·h-1NiO and 1 kmol·h-1CeO2provides enhanced syngas production,limited carbon deposition,92%CGE,and 91%exergy efficiency,causing better temperature control and limited airflow requirements in the oxidation reactor.This supports experimental setups that typically use high MeO/CH4 ratios.The mixture tolerates CO2in methane feed in proportions suitable for natural gas and biogas,promoting CO2utilization and reducing emissions. 展开更多
关键词 Chemical looping reforming Sustainability Syngas Thermodynamic analysis Biogas Carbon dioxide
暂未订购 下载PDF
Enhanced coke resistance of Fe-based garnets by in-situ formed CuFe alloy for chemical looping partial oxidation of methane 认领 引用
2
作者 Teng Zong Xing Zhu +5 位作者 Ming Tian Chaojie Wang Nanxin Wang Jiachen Yang Shu Liu Xiaodong Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2026年第5期399-408,I0010,共10页
It remains a grand challenge to inhibit coke formation for Fe-based oxygen carriers with extensive reduction due to the mismatch between the CH4decomposition rate on metallic Fe(Fe~0)and the rate of the lattice oxy... It remains a grand challenge to inhibit coke formation for Fe-based oxygen carriers with extensive reduction due to the mismatch between the CH4decomposition rate on metallic Fe(Fe~0)and the rate of the lattice oxygen migration to the surface for carbon oxidation,which led to unsatisfactory syngas selectivity and productivity for chemical looping partial oxidation of methane(CLPOM).Herein,Cu-modified Febased garnets(Y3Fe3CuxAl2-xO12abbreviated as Fe3CuxAl2-x,x equals 0,0.01,and 0.05)were designed,which exhibited boosted carbon-resistance with both CH4conversion and CO selectivity of 94%and extraordinary syngas productivity of almost 8 mmol g-1for Fe3Cu0.05Al1.95,surpassing most of the state-of-the-art Fe-based oxygen carriers in CLPOM.This could be attributed to the in-situ formation of a CuFe alloy under reaction conditions,which remarkably decreased the activity of CH4decomposition over Fe~0 sites to generate carbon and thus allowed lattice oxygen migration to the surface timely for the oxidation of coke formed. 展开更多
关键词 Chemical looping oxidation of methane In-situ formed CuFe alloy Carbon resistance C-H activation Fe-based garnet
暂未订购 下载PDF
Novel plastic loop topologies in pure Mg and orientation-dependent fracture ofβ-Mg17Al12 precipitates under shallow scratching 认领 引用
3
作者 Saurav Goel Gaurav Goel +1 位作者 Rajab Alsayegh Jaya Verma 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2026年第6期268-283,共16页
Understanding how microstructural heterogeneity governs nanoscale deformation under surface-dominated loading is a fundamental challenge in lightweight alloy design.Here,large-scale molecular dynamics simulations reve... Understanding how microstructural heterogeneity governs nanoscale deformation under surface-dominated loading is a fundamental challenge in lightweight alloy design.Here,large-scale molecular dynamics simulations reveal a previously unreported plasticity regime in Mg andβ-Mg17Al12-containing substrates under shallow nanoscratching,uncovering deformation mechanisms inaccessible to conventional mechanical testing or bulk atomistic loading geometries.In pure Mg,surface-mediated stresses generate deeply penetrating,curved,multi-segment dislocation loops reaching∼14.9 nm which far exceed the 2 nm scratch depth and are fundamentally distinct from classical prismatic half-loops reported in previous indentation studies.This establishes a new class of surface-nucleated dislocation topology in HCP metals.In precipitate-strengthened Mg,precipitate orientation is shown for the first time to act as the primary determinant of subsurface deformation mode:scratching along theβ-Mg17Al12alignment triggers cleavage-dominated fracture of the intermetallic crystallite,representing the first atomistic evidence of orientation-dependent precipitate fracture under sliding contact,while transverse scratching instead confines plasticity to a high-stress(∼4.4 GPa),barrier-controlled regime without fracture.These two orientations produce mechanistically distinct responses,with peak von Mises stresses,dislocation loop depths and friction coefficients all varying systematically and explicably with precipitate geometry.These findings establish shallow nanoscratching as a effective atomistic probe of incipient plasticity and interfacial fracture,directly informing the microstructural design of Mg alloys for improved machinability,wear resistance and surface integrity in aerospace,automotive and biomedical applications. 展开更多
关键词 Molecular dynamics simulation Magnesium alloys β-Mg17Al12 precipitates Nanoscratching Dislocation loop topology
暂未订购 下载PDF
Sensorless estimation of surface-mounted permanent magnet synchronous motors based on polar-corrected feedforward quadrature phase-locked loop 认领 引用
4
作者 HAN Kun YU Chen LI Wei 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第3期1473-1486,共14页
The sensorless control of surface-mounted permanent magnet synchronous motor(SPMSM)usually uses quadrature phase-locked loop(QPLL)to extract the phase information of the back electromotive force to realize the rotor a... The sensorless control of surface-mounted permanent magnet synchronous motor(SPMSM)usually uses quadrature phase-locked loop(QPLL)to extract the phase information of the back electromotive force to realize the rotor angle estimation.However,the traditional QPLL has a convergence deviation of 180°when the motor is reversed,and the angle estimation error is obvious when the motor is accelerated and decelerated.To solve these problems,an enhanced QPLL(EQPLL)with polarity correction and high precision angle feedforward compensation is proposed.Firstly,the traditional phase discriminator is improved based on the two-phase stationary coordinate system,and the polarity correction function is designed by the error component of the improved phase discriminator to realize the non convergent deviation angle estimation under the forward and reverse switching conditions of the motor.In addition,the error component of the improved phase discriminator is used as the feedforward compensation signal,and the enhanced generalized integrator is used to filter it,so as to realize the angle error compensation with low delay and low noise.Finally,the proposed scheme is verified by experiment on the motor platform,and compared with the existing scheme.The experimental results show that the proposed scheme can realize the polarity correction and angle error elimination,and at the same time,the noise mean square error is reduced by 24.33%compared with the existing angle feedforward compensation scheme. 展开更多
关键词 surface-mounted permanent magnet synchronous motor sensorless control quadrature phase-locked loop polarity correction error compensation
暂未订购 下载PDF
依赖于c-Myc的R-loops结构对胶质瘤细胞增殖、侵袭和迁移的调控作用 认领 引用 被引量:1
5
作者 林家汉 陈彩燕 +2 位作者 陈申波 叶富跃 杨堃 《中华神经外科疾病研究杂志》 CAS 2026年第2期16-22,共7页
目的探讨转录因子c-Myc的R-loops结构及其对胶质瘤细胞恶性生物学行为的调控作用。方法采用DNA-RNA免疫沉淀PCR(DNA-RNA immunoprecipitation PCR,DRIP-PCR)法检测胶质瘤细胞(U251和U87-MG)中c-Myc的R-loops结构。分别将空载质粒、c-My... 目的探讨转录因子c-Myc的R-loops结构及其对胶质瘤细胞恶性生物学行为的调控作用。方法采用DNA-RNA免疫沉淀PCR(DNA-RNA immunoprecipitation PCR,DRIP-PCR)法检测胶质瘤细胞(U251和U87-MG)中c-Myc的R-loops结构。分别将空载质粒、c-Myc过表达质粒、RNASEH1过表达质粒转染至U251和U87-MG细胞,设立对照组(CTRL组)、核糖核酸内切酶H1(RNASEH1)过表达组(RNASEH1-OE组)、c-Myc过表达组(c-Myc-OE组)及共转染c-Myc与RNASEH1共转染组(c-Myc-OE+RNASEH1-OE组)。采用细胞计数试剂盒-8(CCK-8)、5-乙炔基-2'-脱氧尿苷(EdU)实验检测细胞增殖能力;通过细胞划痕实验和Transwell实验评估细胞迁移和侵袭水平;利用蛋白印迹法(Western blot)检测RNASEH1和c-Myc的蛋白表达水平。结果转录因子c-Myc在胶质瘤细胞中存在R-loops结构(P<0.05)。过表达RNASEH1可清除c-Myc依赖的R-loops结构,从而抑制胶质瘤细胞的增殖、侵袭和迁移(P<0.05)。c-Myc的过表达可提高核糖核酸内切酶H1(RNASEH1)的表达,从而挽救其R-loops结构,促进胶质瘤细胞侵袭和迁移能力的影响(P<0.05)。结论转录因子c-Myc可能通过其R-loops结构促进胶质瘤细胞的增殖、侵袭和迁移等恶性生物学行为。 展开更多
关键词 c-Myc 核糖核酸内切酶H1 R环 胶质瘤 增殖 侵袭 迁移
暂未订购 下载PDF
6G Space-Air-Ground Integrated Networks for Unmanned Operations:Closed-Loop Model and Task-Oriented Approach 认领 引用
6
作者 Xinran Fang Wei Feng +3 位作者 Yunfei Chen Ning Ge Shi Jin Shiwen Mao 《Engineering》 SCIE EI CSCD 2026年第1期79-86,共8页
In the upcoming sixth-generation(6G)era,supporting field robots for unmanned operations has emerged as an important application direction.To provide connectivity in remote areas,the space-air-ground integrated network... In the upcoming sixth-generation(6G)era,supporting field robots for unmanned operations has emerged as an important application direction.To provide connectivity in remote areas,the space-air-ground integrated network(SAGIN)will play a crucial role in extending coverage.Through SAGIN connections,the sensors,edge platforms,and actuators form sensing-communication-computing-control(SC3)loops that can automatically execute complex tasks without human intervention.Similar to the reflex arc,the SC3loop is an integrated structure that cannot be deconstructed.This necessitates a systematic approach that takes the SC3loop rather than the communication link as the basic unit of SAGINs.Given the resource limitations in remote areas,we propose a radio-map-based task-oriented framework that uses environmental and task-related information to enable task-matched service provision.We detail how the network collects and uses this information and present task-oriented scheduling schemes.In the case study,we use a control task as an example and validate the superiority of the task-oriented closedloop optimization scheme over traditional communication schemes.Finally,we discuss open challenges and possible solutions for developing nerve system-like SAGINs. 展开更多
关键词 Radio map Sensing-communication-computing-control(SC3)loop Space-air-ground integrated network Sixth-generation(6G)communication Task-oriented communication
暂未订购 下载PDF
Regulation of neuronal transcription by RNA-binding proteins via R-loop dynamics 认领 引用
7
作者 Shruti Singh Kakan Ximena Corso-Díaz 《Neural Regeneration Research》 SCIE CAS CSCD 2026年第10期4878-4879,共2页
Neuronal cells require precise and stable control of gene expression throughout their extended lifespan,which presents numerous challenges for gene transcription.While traditional studies of transcriptional regulation... Neuronal cells require precise and stable control of gene expression throughout their extended lifespan,which presents numerous challenges for gene transcription.While traditional studies of transcriptional regulation have primarily focused on canonical DNA-binding factors,there is an increasing recognition of the role of regulatory RNAs and RNA-binding proteins(RBPs)in modulating this process. 展开更多
关键词 transcriptional regulation neuronal transcription RNA binding proteins regulatory rnas gene expression r loop dynamics
暂未订购 下载PDF
DNA-based one-pot rapid biosensing platform integrating turn-back loop primer-accelerated LAMP and Pyrococcus furiosus Argonaute for meat visual authentication 认领 引用
8
作者 Sheng DING Jing LI +4 位作者 Minglong YANG Yujia SONG Xiangke NIU Mei LI Yao LUO 《Journal of Zhejiang University-SCIENCE B》 SCIE CAS CSCD 2026年第7期775-787,I0020-I0033,共13页
Meat adulteration is a significant global food safety challenge,creating a pressing need for rapid and on-site detection technologies.Herein,we present an intelligent one-pot biosensing platform termed one-pot TLAMP-P... Meat adulteration is a significant global food safety challenge,creating a pressing need for rapid and on-site detection technologies.Herein,we present an intelligent one-pot biosensing platform termed one-pot TLAMP-PfAgo assay(OTPA)that integrates the rapid amplification of turn-back loop primer-accelerated loop-mediated isothermal amplification(LAMP)(TLAMP)with the sequence-specific detection of Pyrococcus furiosus Argonaute(PfAgo).This system features a clever heat-activatable design using microcrystalline wax to spatially separate reactions within a single tube,enabling contamination-free and streamlined operation.The OTPA assay achieves sensitive and specific detection,with limits of detection as low as 3×10-4 ng/μL for pork DNA and 2×10-4 ng/μL for beef DNA within 30 min.It successfully enables duplex target identification and has been validated with commercial meat products,showing perfect concordance with standard polymerase chain reaction(PCR)-based qualitative detection.Notably,the result can be directly visualized under blue light,underscoring the substantial potential of this costeffective and simple platform for point-of-care testing(POCT)and intelligent biosensing in food safety surveillance. 展开更多
关键词 Loop-mediated isothermal amplification(LAMP) Turn-back loop primer-accelerated LAMP(TLAMP) Pyrococcus furiosus Argonaute(PfAgo) Meat authentication One-pot assay Point-of-care testing(POCT)
暂未订购 下载PDF
Tamed loops:a way to obtain finite loop results without UV divergences 认领 引用
9
作者 Lian-Bao Jia 《Communications in Theoretical Physics》 SCIE CAS CSCD 2026年第1期71-79,共9页
For loops with UV divergences,assuming that the physical contributions of loops from UV regions are insignificant,a UV-free scheme method described by an equation is introduced to derive loop results without UV diverg... For loops with UV divergences,assuming that the physical contributions of loops from UV regions are insignificant,a UV-free scheme method described by an equation is introduced to derive loop results without UV divergences in the calculations,i.e.,a route of the analytic continuationTF→TPbesides the traditional route∞−∞in the mathematical structure.This scheme provides a new perspective to an open question of the hierarchy problem of Higgs mass,i.e.,an alternative interpretation without fine-tuning within the standard model. 展开更多
关键词 UV divergence loop calculation UV-free scheme Higgs mass hierarchy problem
暂未订购 下载PDF
利用loop区域理性设计策略提升硫酸软骨素裂解酶ABC的热稳定性 认领 引用 被引量:1
10
作者 杨颖 李春青 +5 位作者 张靖 曾艳 滕玉鸥 黎明 朱玥明 孙媛霞 《生物工程学报》 EI CAS CSCD 北大核心 2026年第3期1188-1199,共12页
硫酸软骨素裂解酶ABC(chondroitinase ABC,ChABC)在生物医药及多糖结构解析等领域具有重要应用价值,但其较差的热稳定性严重限制了该酶的工业化生产及应用。本研究针对来源于普通变形杆菌(Proteus vulgaris)的PvChABC的多结构域特征,以... 硫酸软骨素裂解酶ABC(chondroitinase ABC,ChABC)在生物医药及多糖结构解析等领域具有重要应用价值,但其较差的热稳定性严重限制了该酶的工业化生产及应用。本研究针对来源于普通变形杆菌(Proteus vulgaris)的PvChABC的多结构域特征,以该酶N端结构域与核心催化结构域之间的loop区域为靶点,采用计算机辅助的理性设计策略对其进行分子改造,获得稳定性显著提升的优势突变体M3。该突变体在45℃下的半衰期达到(48.12±1.85)h,是野生型的13.7倍,且其比酶活为野生型的110.5%,没有表现出酶活性的损失。分子动力学模拟揭示,loop区域的突变通过引入关键疏水相互作用与氢键网络,增强了结构域间的结合能力,从而稳定了整体蛋白构象。此外,PvChABC热稳定性的提升有助于异源表达该酶的工程菌株在37℃下发酵产酶,该温度下M3的产量较野生型提高14.84倍,更适合工业化生产应用。本研究不仅为PvChABC的工业生产和应用奠定了基础,也为其他多结构域蛋白的分子改造提供了思路。 展开更多
关键词 硫酸软骨素裂解酶 loop区域 理性设计 热稳定性 多结构域蛋白
暂未订购 下载PDF
基于D-loop和Cyt-b基因的黑线姬鼠种群遗传结构与汉坦病毒感染关联性分析 认领 引用
11
作者 熊亚茹 何方玲 +7 位作者 刘荣娇 王娟 贾华云 湛志飞 戴志辉 杨子琪 陈生宝 蔡亮 《中国人兽共患病学报》 CAS CSCD 北大核心 2026年第3期276-284,共9页
目的探究湖南地区黑线姬鼠种群的遗传结构及汉坦病毒感染与宿主遗传变异的关联性。方法以黑线姬鼠肺组织总DNA为模板,基于其线粒体D-loop区及Cyt-b基因的保守区设计引物进行PCR扩增,并对扩增产物进行测序。利用MEGA 6.0和DnaSP 5.0软件... 目的探究湖南地区黑线姬鼠种群的遗传结构及汉坦病毒感染与宿主遗传变异的关联性。方法以黑线姬鼠肺组织总DNA为模板,基于其线粒体D-loop区及Cyt-b基因的保守区设计引物进行PCR扩增,并对扩增产物进行测序。利用MEGA 6.0和DnaSP 5.0软件分析序列特征及遗传多样性,并采用邻接法(NJ)和最大似然法(ML)构建系统发育树,以揭示种群遗传分化及其与汉坦病毒感染关联性。结果D-loop区(658 bp)和Cyt-b基因(871 bp)的A+T含量分别为60.9%和60.7%,均高于C+G含量;检测到变异位点分别为38个和40个,对应11种和9种单倍型,单倍型多样性(H)分别为0.956和0.912,核苷酸多样性(π)为0.01278和0.00951,Tajima's D值为-1.44626和-1.55571。系统发育分析显示,浏阳种群(除LY-029-HTAA-7、LY-031-HTAA-9外)形成单系分支,双峰种群SF-014-HTAA-7独立分布;未感染样本LY-03-UAA-6与感染样本LY-016-HTAA-6在Cyt-b树中紧密聚类。结论湖南黑线姬鼠种群具有一定程度的遗传多样性,但汉坦病毒感染与线粒体基因组变异无直接关联,提示后续研究需整合宿主生态行为与环境因素,从而解析病毒传播机制。 展开更多
关键词 汉坦病毒 遗传多样性 共进化 D-loop Cyt-b基因
暂未订购 下载PDF
基于D-loop片段及COI基因鉴别狗肾及其混淆品 认领 引用
12
作者 谭颖仪 杨志业 吴跃丽 《中国医药导报》 CAS 2026年第18期15-20,共6页
目的研究采用D-loop片段的狗肾PCR鉴别方法及COI基因分析鉴别狗肾及其混淆品。方法通过比较不同退火温度、变性/退火时间、循环次数、正反向引物加入量、DNA模板加入量对PCR结果的影响,确定狗肾PCR扩增体系及反应条件。以D-loop引物为... 目的研究采用D-loop片段的狗肾PCR鉴别方法及COI基因分析鉴别狗肾及其混淆品。方法通过比较不同退火温度、变性/退火时间、循环次数、正反向引物加入量、DNA模板加入量对PCR结果的影响,确定狗肾PCR扩增体系及反应条件。以D-loop引物为扩增引物,对27批狗肾样品进行鉴定。以COI基因通用引物为扩增引物,对27批狗肾样品PCR鉴别检测结果进行确认。结果PCR反应总体积为25μl,反应条件为95℃预变性5 min,循环反应30次(95℃30 s,56℃30 s),延伸(72℃)5 min。22批狗肾样品为正品,扩增得到200~300 bp的单一条带,基原物种为犬Canis familiaris L.。结论本研究建立的狗肾PCR鉴别方法简单、快速、准确,可用于狗肾真伪鉴别;同时发现以欧亚野猪鞭作为狗肾混淆品的情况,为狗肾药材的质量控制提供技术支持。 展开更多
关键词 狗肾 D-loop片段 COI基因 鉴别
暂未订购 下载PDF
基于SSR和D-loop序列评估安徽青鱼养殖群体的遗传多样性和遗传结构 认领 引用
13
作者 胡玉婷 周华兴 +4 位作者 段国庆 凌俊 汪焕 潘庭双 江河 《安徽农业大学学报》 CAS CSCD 2026年第1期38-47,共10页
【目的】旨在探讨安徽青鱼(Mylopharyngodon piceus)养殖群体的遗传背景,解析其种质资源的遗传组成现状。【方法】对来自安徽省内安庆市宜秀区(YX)、池州市贵池区(GC)、铜陵市枞阳县(ZY)、芜湖市无为市(WW)、芜湖市湾沚区(WZ)、滁州市... 【目的】旨在探讨安徽青鱼(Mylopharyngodon piceus)养殖群体的遗传背景,解析其种质资源的遗传组成现状。【方法】对来自安徽省内安庆市宜秀区(YX)、池州市贵池区(GC)、铜陵市枞阳县(ZY)、芜湖市无为市(WW)、芜湖市湾沚区(WZ)、滁州市南谯区(NQ)、蚌埠市淮上区(HS)、蚌埠市怀远县(HY)的8个青鱼主要养殖群体,共240尾个体,采用10对微卫星(SSR)标记和线粒体D-loop序列两种分子标记,开展其遗传多样性和遗传结构分析。【结果】微卫星标记分析显示,10个微卫星位点均表现出高遗传多样性(Na=7~37,PIC=0.576~0.934);除YX群体外,其余各群体也表现出较高的遗传多样性(He=0.622~0.787,PIC=0.565~0.742)。D-loop序列分析结果显示,所有群体的单倍型多样性差异较大(Hd=0.000~0.830),而核苷酸多样性偏低(Pi=0.0000~0.0166)。两种分析结果均表明,YX群体的遗传多样性最低,NQ群体的遗传多样性最高。群体遗传分化指数(FST)和分子方差分析(AMOVA)结果显示,成对群体间存在不同程度的遗传差异(-0.002~0.223,-0.015~0.767),部分群体间的遗传分化显著(FST>0.05)。瓶颈效应分析显示,除NQ和WZ群体外,其余群体均显著偏离突变—漂移平衡。基于微卫星标记的群体间UPGMA(unweighted pair-group method with arithmetic means)和NJ(neighbor-joining)系统发育树与遗传结构分析结果相似,8个群体被划分为5个理论群,HS和HY群体、YX和ZY群体、NQ和WW群体间的亲缘关系均较近,而GC和WZ群体遗传上较独立。而基于D-loop序列构建的群体间两种系统进化树(UPGMA tree和NJ tree)具有完全相同的拓扑结构。8个青鱼群体明显聚为两大进化支,YX、ZY、WW和WZ 4个群体聚为一支,其余群体聚为另一支,其中YX和ZY群体的亲缘关系较近。【结论】综合分析表明,安徽省8个青鱼养殖群体中,多数养殖群体的遗传多样性水平依然较高,具有一定的选育潜力;群体间存在显著遗传分化和明显遗传结构,其中多数相同或相近地区的青鱼养殖群体具有相似的遗传组成,地理距离可能是影响相互引种或野生亲本采集的重要因素。本研究可为青鱼种质遗传改良及新品种培育等提供科学依据。 展开更多
关键词 青鱼 微卫星 D-loop 遗传多样性 养殖群体
暂未订购 下载PDF
基于线粒体DNA Cyt b、12S rRNA和D-loop序列的铜鱼养殖群体遗传多样性分析 认领 引用
14
作者 吴斌 贺刚 +3 位作者 陶志英 邓勇辉 郭怿宁 袁嘉欣 《渔业研究》 2026年第2期181-189,共9页
【目的】本研究分别利用线粒体DNA Cyt b、12S rRNA和D-loop序列对铜鱼(Coreius heterodon)养殖群体进行遗传多样性分析,初步了解其遗传多样性。【方法】采用已报道的特异性引物对线粒体DNA Cyt b、12S rRNA和D-loop序列进行聚合酶链式... 【目的】本研究分别利用线粒体DNA Cyt b、12S rRNA和D-loop序列对铜鱼(Coreius heterodon)养殖群体进行遗传多样性分析,初步了解其遗传多样性。【方法】采用已报道的特异性引物对线粒体DNA Cyt b、12S rRNA和D-loop序列进行聚合酶链式反应(PCR)扩增,并采用双脱氧测序法(Sanger)对扩增产物进行测序。遗传多样性参数由DNASP 6.12软件计算;采用MEGA 11.0软件分析DNA序列的碱基组成和变异位点;利用Kimura双参数模型计算单倍型间的遗传距离,采用邻接法(NJ)和最大似然法(ML)构建D-loop全序列单倍型系统进化树。【结果】用于分析的线粒体DNA Cyt b、12S rRNA和D-loop序列长度分别为1110~1147、425~445和972~1023 bp,平均长度分别为1122.77、430.00和1000.47 bp,中位数长度分别为1122、429和1001 bp。在线粒体DNA Cyt b、12S rRNA和D-loop序列中,分别检测出8、1和14个变异位点,以及22、19和30种单倍型,单倍型间遗传距离分别为0~0.004、0~0.005和0~0.007。基于线粒体DNA Cyt b、12S rRNA和D-loop序列的平均单倍型多样性(Hd)分别为0.547±0.0105、0.186±0.0078和0.885±0.0013;平均核苷酸多样性(Pi)分别为0.00076、0.00044和0.00258;平均核苷酸差异数(k)为0.830、0.186和2.432。同时,歧点分布分析图谱呈现单峰型,在中性检验中Tajima’s D(D=-1.040,P>0.01)为负值,但统计结果为不显著(P>0.01)。【结论】铜鱼养殖群体遗传多样性相对较低,且单倍型间存在广泛的基因交流,但铜鱼养殖群体的种群数量下降。因此,建立起遗传多样性丰富的铜鱼人工繁殖的基础亲鱼群体,解决铜鱼亲本培育问题,持续壮大铜鱼养殖群体规模是首要任务。 展开更多
关键词 铜鱼 Cyt b 12S rRNA D-loop序列 遗传多样性
暂未订购 下载PDF
AutoINF:Path-Sensitive Invariant Inference for Multipath Loops 认领 引用
15
作者 Abeer S.Hadad Fahman Saeed +1 位作者 Adeeb A.Ahmed Jiangbin Zheng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第7期1011-1042,共32页
Loop invariant inference is fundamental to program verification,yet it remains particularly challenging for multipath loops,where different execution paths may exhibit incompatible behaviors across feasible executions... Loop invariant inference is fundamental to program verification,yet it remains particularly challenging for multipath loops,where different execution paths may exhibit incompatible behaviors across feasible executions.In such settings,invariants that are both sound and sufficiently precise often require disjunctive forms,whose automatic inference remains difficult.This paper presents an efficient,path-sensitive,counterexample-guided framework for automated loop invariant inference.Our approach leverages a Path Dependency Automaton(PDA)to systematically decompose the semantics of multipath loops by modeling feasible execution paths independently.Building on this decomposition,we introduce a localized,path-guided Counterexample-Guided Invariant Refinement(CEGIR)process that validates candidate invariants against individual path semantics and uses targeted counterexamples to refine disjunctive and nonlinear polynomial invariant templates only where violations occur.We implement the proposed framework in AutoINF,an automated invariant inference tool for C programs containing multipath loops.The experimental evaluation on a diverse benchmark suite,including programs with complex control flow and nonlinear arithmetic,demonstrates that AutoINF infers sound and expressive invariants for challenging multipath loops. 展开更多
关键词 Numerical loop invariant multipath loops counterexample-guided refinement program analysis and verification software reliability disjunctive invariants
暂未订购 下载PDF
Chemical-looping methane hydrogen production performance of Cu,La,Ce modified Fe2O3/Al2O3oxygen carrier 认领 引用
16
作者 YANG Liangnuo LI Yilong +6 位作者 ZHOU Zheng DENG Chunhuan MA Hao DING Zisheng LI Guoliang LI Ming GU Zhenhua 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2026年第4期82-95,共14页
Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome t... Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome the limitations of single ironbased oxygen carriers,including poor cycling stability,low reactivity and susceptibility to sintering,this study employed a dipcoating method to modify Fe2O3/Al2O3oxygen carriers by incorporating three distinct metal additives:Cu,La and Ce.The composite oxygen carriers were systematically characterized and evaluated under redox conditions to investigate the structure-activity relationships between the physicochemical properties,reactivity,and hydrogen production performance.Results revealed that the spinel-phase CuFe2O4exhibited higher reactivity than the perovskite-phase LaFeO3and CeO2,promoting the deeper reduction of Fe2O3.Fe58Cu2Al exhibited an oxygen storage capacity as high as 6.5 mmol/g.During the CH4 reaction stage,Fe58Cu2Al achieved the highest oxygen loss of 12.1 g/100 g oxygen carrier,accompanied by a syngas yield of 5.15 mmol/g-1.33 times and 1.59 times greater than that of Fe60Al.In the hydrogen production stage,the 2%Cu-modified oxygen carrier demonstrated optimal performance,yielding 5.13 mmol/g of hydrogen,which was 1.51 times that of the pristine sample.Even after ten cycles,the H2yield remained at 3.61 mmol/g,surpassing the single-cycle output of the pristine sample and the H2 purity consistently exceeded 98%. 展开更多
关键词 chemical looping iron-based oxygen carrier metal promoter hydrogen purity
暂未订购 下载PDF
Optimization of chemical looping hydrogen generation process via Aspen Plus——Machine learning integration 认领 引用
17
作者 Xinyu Li Yiwen Song +2 位作者 Shenglong Teng Dewang Zeng Jingxin Xu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2026年第4期257-269,共13页
Chemical looping hydrogen generation(CLHG)utilizes the cyclic operation of oxygen carriers to independently convert fuel and steam,providing advantages such as low energy demand for decarbonization and a simplified pr... Chemical looping hydrogen generation(CLHG)utilizes the cyclic operation of oxygen carriers to independently convert fuel and steam,providing advantages such as low energy demand for decarbonization and a simplified process.However,conventional optimization of CLHG using Aspen Plus generally relies on sequential simulations of individual process parameters,such as reactor temperature,pressure,and feed ratio,which is both time-consuming and inefficient.This study develops an optimization framework that couples Aspen Plus with machine learning algorithms,where the latter serves as a surrogate model to rapidly predict the impact of operational conditions on hydrogen yield and fuel conversion efficiency in CLHG process,thereby avoiding repeated full-scale simulations and accelerating process optimization.The results demonstrate that temperature is the most influential factor,with shapley additive explanations(SHAP)values ranging from-40 to 30.The feed ratio and pressure have relatively weaker impacts,with SHAP values of-10 to 10 and near zero,respectively.Verified through literature data,the model achieves an accuracy rate of approximately 93.8%.This method can rapidly and efficiently optimize the chemical looping hydrogen production process and can be extended to the optimization of other chemical looping applications. 展开更多
关键词 Chemical looping hydrogen production Machine learning Process systems Numerical simulation Mathematical modeling
暂未订购 下载PDF
Osteoblastic sclerostin loop3-LRP4 interaction required by sclerostin to inhibit bone formation 认领 引用
18
作者 Luyao Wang Xiaohui Tao +23 位作者 Hewen Jiang Shijian Ding Ning Zhang Xin Yang Shenghang Wang Yihao Zhang Nanxi Li Haitian Li Zhanghao Li Xiaoxin Wen Meiheng Sun Chuanxin Zhong Heiwa So Jin Liu Yuanyuan Yu Hua Yue Xianghang Luo Péter Ferdinandy Tao Zhang Shu Zhang Zhenlin Zhang Aiping Lu Baoting Zhang Ge Zhang 《Bone Research》 SCIE CAS CSCD 2026年第3期949-962,共14页
Sclerostin negatively regulates bone formation.The marketed antibody against sclerostin loop2 promoted bone formation but may have caused severe cardiovascular events in clinical use.In our published studies,sclerosti... Sclerostin negatively regulates bone formation.The marketed antibody against sclerostin loop2 promoted bone formation but may have caused severe cardiovascular events in clinical use.In our published studies,sclerostin loop3 was found to be involved in inhibitory effects of sclerostin on bone formation,whereas cardiovascular protective effects of sclerostin in mice were independent of loop3.It is necessary to investigate how sclerostin loop3 participates in the inhibitory effects of sclerostin on bone formation to facilitate developing precise strategies that promote bone formation without increasing cardiovascular risk.In this study,sclerostin loop3 was identified to bind to LRP4,thereby facilitating binding of sclerostin to LRP6 in osteoblasts.Blockade of sclerostin loop3-LRP4 interaction by both Lrp4 mutation(Lrp4m)and blocking peptide(LRP4-Pep)diminished the antagonistic effect of sclerostin on Wnt/β-catenin signaling in osteoblasts in vitro.Consistently,Lrp4m promoted bone formation in Lrp4m mice in vivo.Mechanistically,osteoblast-conditional correction of Lrp4m to wild-type Lrp4 resulted in significantly lower bone formation than Lrp4m mice,indicating that the promotive effects of Lrp4m on bone formation acted in osteoblasts in vivo.Moreover,re-expression of sclerostin dramatically inhibited bone formation in sost−/−mice,whilst the inhibitory effects of sclerostin were significantly weaker in sost−/−.Lrp4m mice.Pharmacologically,LRP4-Pep diminished the inhibitory effects of sclerostin on bone formation in SOSTki mice.Taken together,osteoblastic sclerostin loop3-LRP4 interaction,as an anchor,was required by sclerostin to bind to LRP6,thereby inhibiting bone formation.Translationally,blockade of sclerostin loop3-LRP4 interaction in osteoblasts would provide precise therapeutic strategies to promote bone formation without increasing cardiovascular risk. 展开更多
关键词 Wnt catenin signaling osteoblastic interaction sclerostin loop bone formation LRP cardiovascular risk
暂未订购 下载PDF
High‑throughput screening of SrxA1−xFeyB1−yO3 perovskites for low‑temperature chemical looping air separation using graph neural networks 认领 引用
19
作者 ZHAO Jie DONG Changqing +2 位作者 XUE Junjie HU Xiaoying ZHANG Junjiao 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2026年第7期270-282,共13页
Low‑temperature Chemical Looping Air Separation(CLAS)is a promising technology for producing oxygen‑enriched gas streams.It utilizes the redox properties of solid oxygen carriers to selectively capture and release oxy... Low‑temperature Chemical Looping Air Separation(CLAS)is a promising technology for producing oxygen‑enriched gas streams.It utilizes the redox properties of solid oxygen carriers to selectively capture and release oxygen from the air.Oxygen vacancy formation energy(Eovf)can be used to evaluate the ease of oxygen release by the oxides.In this study,the applicable range of Eovffor CLAS oxygen carriers was determined to be<2.3 eV using the thermodynamic calculations.A graph neural network(GNN)was trained and used to predict the Eovf.By predicting Eovfwith the GNN model,a screening from the 3649 compositions of SrxA1−xFeyB1−yO3perovskites was conducted to discover the CLAS oxygen carriers.The prediction results indicate that the doping of Ba and Ca ions at the A site and Co ions at the B‑site can effectively reduce the Eovfof the perovskite structure.The feasibility of screening the CLAS oxygen carriers using the Eovfmethod was validated through the rediscovery of some known materials.These results support the effectiveness of GNNs in accelerating the discovery of CLAS oxygen carriers. 展开更多
关键词 chemical looping air separation oxygen vacancy formation energy graph neural network material discovery
暂未订购 下载PDF
上一页 1 2 250 下一页 到第
在线咨询 使用帮助 返回顶部 意见反馈