The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nu...The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators and β-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.展开更多
PyQED is an open-source Python package designed for the numerical simulation of strongly coupled elec-tron-nuclear quantum dynamics,in particular,conical intersection dy-namics.Besides conventional nona-diabatic wavep...PyQED is an open-source Python package designed for the numerical simulation of strongly coupled elec-tron-nuclear quantum dynamics,in particular,conical intersection dy-namics.Besides conventional nona-diabatic wavepacket dynamics methods based on the Born-Huang representation and mixed quantum-classical Ehrenfest dynamics,PyQED implements the geometric quantum dynamics based on the local diabatic representation,which provides a numerically exact framework for nonadiabatic quantum molecular dynamics.It differs from the conven-tional Born-Huang representation in that all non-Born-Oppenheimer effects are accounted for by a single electronic overlap matrix between adiabatic states,therefore removing the sin-gular derivative couplings.The complete workflow for ab initio modeling of conical intersec-tion dynamics is illustrated through the internal conversion dynamics in the H3+cation.PyQED provides a powerful and user-friendly computational platform for first-principles quantum dynamics,with applications to photochemical and photophysical processes.展开更多
为了对案件缴获的合成大麻素前体物质进行结构确认,建立该前体化合物的表征数据,本文基于气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)、超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(ultra high performance liquid c...为了对案件缴获的合成大麻素前体物质进行结构确认,建立该前体化合物的表征数据,本文基于气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)、超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(ultra high performance liquid chromatography quadrupole-orbitrap high resolution mass spectrometry,UPLC-Q Exactive HRMS)、核磁共振波谱(nuclear magnetic resonance spectroscopy,NMR)和红外吸收光谱(infrared spectroscopy,IR)等技术,采用多仪器联合检验、多维度综合分析的方式进行未知物结构表征与解析,确证目标化合物为合成大麻素AB-FUBINACA的前体化学品1-(4-氟苄基)吲唑-3-羧酸。本研究方法科学高效,结果准确可靠,融合发挥不同检测技术在结构表征中的优势,克服标准物质缺失、谱库信息滞后的局限,可为毒品合成前体化学品的结构确证提供新途径。展开更多
The rapid development of high-frequency electronic devices and fifth-generation wireless communication systems has increased the demand for polymer-based materials with both electromagnetic interference shielding and ...The rapid development of high-frequency electronic devices and fifth-generation wireless communication systems has increased the demand for polymer-based materials with both electromagnetic interference shielding and microwave absorption capabilities.In this work,carbon-fiber-reinforced polycarbonate/acrylonitrile-butadiene-styrene composites were prepared by twin-screw melt compounding,and the effects of carbon fiber content,fiber type,and feeding strategy on the mechanical and electromagnetic properties were investigated.Two feeding modes,namely main feeding and side feeding,were compared to regulate the fiber length distribution and conductive-network structure in the PC/ABS matrix.Compared with main feeding,side feeding effectively reduced fiber breakage during extrusion.For example,the number-average fiber length of MC10%-SF reached 165.7μm,whereas that of MC10%prepared by main feeding was only 111.7μm.The retained long fibers promoted the formation of continuous conductive pathways,leading to enhanced dielectric loss and improved electromagnetic attenuation.Among the investigated formulations,MC20%-SF exhibited a maximum reflection loss of-51 dBat 15.5 GHzwith a thickness of 1.7 mmand an effective absorption bandwidth of 4.56 GHz.Meanwhile,it maintained favorable mechanical properties,including a tensile strength of 115 MPaand a flexural modulus of 13,249 MPa.For EMI shielding,HC30%-SF achieved a total shielding effectivenessclose to 55 dBin the X-band.These results indicate that controlling fiber length through side feeding is an effective strategy for balancing mechanical reinforcement,microwave absorption,and EMI shielding performance in PC/ABS-based conductive composites.展开更多
Developing an irradiation embrittlement predictive model for low-Cu reactor pressure vessel steels is essential for extending the life of modern pressurized water reactors.Irradiation-produced dislocation loops are re...Developing an irradiation embrittlement predictive model for low-Cu reactor pressure vessel steels is essential for extending the life of modern pressurized water reactors.Irradiation-produced dislocation loops are recognized as the leading causes of embrittlement,surpassing the mechanism of Cu clustering with a reduction in Cu content in modern steels.Extensive data have been accumulated from surveillance programs on high-Cu steels used in old reactors.The extrapolation of these data to low-Cu systems for embrittlement prediction requires a comprehensive understanding of the interactions between Cu,particularly Cu-rich clusters,and radiation defects.Therefore,in this study,ab initio calculations of vacancy aggregation in solute clusters containing Cu,Ni,Mn,and Si were performed.The interactions between the solute elements and vacancies in the solute clusters and Fe matrix were analyzed.The results demonstrated the occurrence of attractive interactions between the Cu clusters and vacancies.The addition of Si and the synergistic effect between Ni and Mn facilitated vacancy aggregation in the solute clusters.The behavior of Mn correlated with its magnetic state,and the size effects of the solute elements were analyzed.展开更多
All-solid-state battery is a promising solution to make lithium batteries safer while boosting their energy density.Solid polymer electrolytes offer a cheaper alternative to inorganic solid electrolyte.Solid polymer e...All-solid-state battery is a promising solution to make lithium batteries safer while boosting their energy density.Solid polymer electrolytes offer a cheaper alternative to inorganic solid electrolyte.Solid polymer electrolytes even outperform inorganic solid electrolytes in some domains;for example,they are less prone to mechanical failure or to contact loss with electrodes upon cycles.However,there are still a couple of challenges to address,including the solid electrolyte/positive electrode interface degradation.The interface between solid polymer electrolyte and the positive electrode is largely overlooked in favor of that of the negative electrode.Ab initio molecular dynamics was combined with relative bond length change analysis and X-ray photoelectron spectroscopy to study the compatibility of a broad selection of functional groups with two grades of Ni-rich NMC cathode(NMC622,NMC811).The results emphasize the relative reactivity of NMC811 compared to NMC622.It was observed that Li is mostly responsible for triggering chemical degradation by interacting with negatively charged atoms from functional groups.Results revealed that hydroxyl or amine deprotonation is a major mechanism of interface degradation that leads to capacity fading.The role of the electric field during cycling was also investigated,showing how it affects functional group orientation and interactions with the NMC electrode.展开更多
【目的】探究黑龙江林蛙(Rana amurensis)热休克蛋白90α家族B类成员1(heat shock protein 90 alpha class B member 1,HSP90AB1)基因的序列特征,了解其组织表达特性和脂多糖(LPS)诱导下的表达变化。【方法】以黑龙江林蛙脾脏组织cDNA...【目的】探究黑龙江林蛙(Rana amurensis)热休克蛋白90α家族B类成员1(heat shock protein 90 alpha class B member 1,HSP90AB1)基因的序列特征,了解其组织表达特性和脂多糖(LPS)诱导下的表达变化。【方法】以黑龙江林蛙脾脏组织cDNA为模板,通过PCR扩增HSP90AB1基因完整编码区(CDS)序列,使用在线软件对其编码蛋白进行生物信息学分析;利用实时荧光定量PCR和Western blotting检测生理状态下HSP90AB1基因在黑龙江林蛙皮肤、肌肉、心脏、肝脏、脾脏、肺脏、肾脏和胃等组织器官中的表达量,同时对LPS诱导下不同时间点HSP90AB1基因在不同组织器官的转录水平进行检测。【结果】黑龙江林蛙HSP90AB1基因CDS长2178 bp,共编码725个氨基酸。生物信息学分析显示,HSP90AB1蛋白不存在信号肽且无跨膜信号,属于非跨膜蛋白,存在62个潜在磷酸化位点(含33个丝氨酸、19个苏氨酸及10个酪氨酸位点),其二级结构以α-螺旋为主(占47.03%),其次为无规则卷曲(占39.59%)和延伸链(占13.38%)。系统进化树结果显示,黑龙江林蛙与欧洲林蛙亲缘关系最近。在生理状态下,HSP90AB1基因在黑龙江林蛙胃中表达量最高,且显著高于其他组织(P<0.05);在肌肉组织中表达量最低,且显著低于其他组织(P<0.05)。Western blotting结果显示,HSP90AB1蛋白在黑龙江林蛙胃中表达量最高;在心脏中表达量最低,且显著低于其他组织(P<0.05)。LPS诱导后,黑龙江林蛙各组织中HSP90AB1基因表达量随诱导时间延长而呈降低趋势,其中诱导72和96 h表达量均显著低于其他时间点(P<0.05);诱导12、72 h时脾脏中HSP90AB1基因表达量显著高于其他组织(P<0.05);24 h时肌肉和脾脏中HSP90AB1基因表达量显著高于其他组织(P<0.05)。【结论】本研究成功克隆了黑龙江林蛙HSP90AB1基因CDS区序列,并明确了其在不同组织中的表达规律,其中在胃中表达量最高,肌肉组织中表达量最低。LPS诱导可明显抑制HSP90AB1基因在黑龙江林蛙不同组织中的转录水平。本试验结果为深入探究HSP90AB1基因在林蛙生理及应激过程中的功能机制提供了理论依据。展开更多
基金supported by the National Key R&D Program of China under Grant Nos.2024YFA1610900 and 2023YFA1606401the National Natural Science Foundation of China under Grant Nos.12335007 and 12035001。
摘要The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators and β-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.
基金supported by the National Natural Sci-ence Foundation of China(Nos.22473090 and 92356310).
摘要PyQED is an open-source Python package designed for the numerical simulation of strongly coupled elec-tron-nuclear quantum dynamics,in particular,conical intersection dy-namics.Besides conventional nona-diabatic wavepacket dynamics methods based on the Born-Huang representation and mixed quantum-classical Ehrenfest dynamics,PyQED implements the geometric quantum dynamics based on the local diabatic representation,which provides a numerically exact framework for nonadiabatic quantum molecular dynamics.It differs from the conven-tional Born-Huang representation in that all non-Born-Oppenheimer effects are accounted for by a single electronic overlap matrix between adiabatic states,therefore removing the sin-gular derivative couplings.The complete workflow for ab initio modeling of conical intersec-tion dynamics is illustrated through the internal conversion dynamics in the H3+cation.PyQED provides a powerful and user-friendly computational platform for first-principles quantum dynamics,with applications to photochemical and photophysical processes.
摘要为了对案件缴获的合成大麻素前体物质进行结构确认,建立该前体化合物的表征数据,本文基于气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)、超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(ultra high performance liquid chromatography quadrupole-orbitrap high resolution mass spectrometry,UPLC-Q Exactive HRMS)、核磁共振波谱(nuclear magnetic resonance spectroscopy,NMR)和红外吸收光谱(infrared spectroscopy,IR)等技术,采用多仪器联合检验、多维度综合分析的方式进行未知物结构表征与解析,确证目标化合物为合成大麻素AB-FUBINACA的前体化学品1-(4-氟苄基)吲唑-3-羧酸。本研究方法科学高效,结果准确可靠,融合发挥不同检测技术在结构表征中的优势,克服标准物质缺失、谱库信息滞后的局限,可为毒品合成前体化学品的结构确证提供新途径。
摘要The rapid development of high-frequency electronic devices and fifth-generation wireless communication systems has increased the demand for polymer-based materials with both electromagnetic interference shielding and microwave absorption capabilities.In this work,carbon-fiber-reinforced polycarbonate/acrylonitrile-butadiene-styrene composites were prepared by twin-screw melt compounding,and the effects of carbon fiber content,fiber type,and feeding strategy on the mechanical and electromagnetic properties were investigated.Two feeding modes,namely main feeding and side feeding,were compared to regulate the fiber length distribution and conductive-network structure in the PC/ABS matrix.Compared with main feeding,side feeding effectively reduced fiber breakage during extrusion.For example,the number-average fiber length of MC10%-SF reached 165.7μm,whereas that of MC10%prepared by main feeding was only 111.7μm.The retained long fibers promoted the formation of continuous conductive pathways,leading to enhanced dielectric loss and improved electromagnetic attenuation.Among the investigated formulations,MC20%-SF exhibited a maximum reflection loss of-51 dBat 15.5 GHzwith a thickness of 1.7 mmand an effective absorption bandwidth of 4.56 GHz.Meanwhile,it maintained favorable mechanical properties,including a tensile strength of 115 MPaand a flexural modulus of 13,249 MPa.For EMI shielding,HC30%-SF achieved a total shielding effectivenessclose to 55 dBin the X-band.These results indicate that controlling fiber length through side feeding is an effective strategy for balancing mechanical reinforcement,microwave absorption,and EMI shielding performance in PC/ABS-based conductive composites.
基金supported by the National Natural Science Foundation of China(No.12205188)Natural Science Foundation of Shanghai(No.22ZR1428700)China National Nuclear Corporation(No.CNNC-LCKY-202236).
摘要Developing an irradiation embrittlement predictive model for low-Cu reactor pressure vessel steels is essential for extending the life of modern pressurized water reactors.Irradiation-produced dislocation loops are recognized as the leading causes of embrittlement,surpassing the mechanism of Cu clustering with a reduction in Cu content in modern steels.Extensive data have been accumulated from surveillance programs on high-Cu steels used in old reactors.The extrapolation of these data to low-Cu systems for embrittlement prediction requires a comprehensive understanding of the interactions between Cu,particularly Cu-rich clusters,and radiation defects.Therefore,in this study,ab initio calculations of vacancy aggregation in solute clusters containing Cu,Ni,Mn,and Si were performed.The interactions between the solute elements and vacancies in the solute clusters and Fe matrix were analyzed.The results demonstrated the occurrence of attractive interactions between the Cu clusters and vacancies.The addition of Si and the synergistic effect between Ni and Mn facilitated vacancy aggregation in the solute clusters.The behavior of Mn correlated with its magnetic state,and the size effects of the solute elements were analyzed.
基金funding from the Research Foundation-Flanders(FWO,project 1264221N)funding from Flanders Innovation&Entrepreneurship(VLAIO,SBO project HBC.2021.0017)+1 种基金the VSC(Flemish Supercomputer Center),funded by the Research Foundation-Flanders(FWO)the Flemish Government.
摘要All-solid-state battery is a promising solution to make lithium batteries safer while boosting their energy density.Solid polymer electrolytes offer a cheaper alternative to inorganic solid electrolyte.Solid polymer electrolytes even outperform inorganic solid electrolytes in some domains;for example,they are less prone to mechanical failure or to contact loss with electrodes upon cycles.However,there are still a couple of challenges to address,including the solid electrolyte/positive electrode interface degradation.The interface between solid polymer electrolyte and the positive electrode is largely overlooked in favor of that of the negative electrode.Ab initio molecular dynamics was combined with relative bond length change analysis and X-ray photoelectron spectroscopy to study the compatibility of a broad selection of functional groups with two grades of Ni-rich NMC cathode(NMC622,NMC811).The results emphasize the relative reactivity of NMC811 compared to NMC622.It was observed that Li is mostly responsible for triggering chemical degradation by interacting with negatively charged atoms from functional groups.Results revealed that hydroxyl or amine deprotonation is a major mechanism of interface degradation that leads to capacity fading.The role of the electric field during cycling was also investigated,showing how it affects functional group orientation and interactions with the NMC electrode.
摘要【目的】探究黑龙江林蛙(Rana amurensis)热休克蛋白90α家族B类成员1(heat shock protein 90 alpha class B member 1,HSP90AB1)基因的序列特征,了解其组织表达特性和脂多糖(LPS)诱导下的表达变化。【方法】以黑龙江林蛙脾脏组织cDNA为模板,通过PCR扩增HSP90AB1基因完整编码区(CDS)序列,使用在线软件对其编码蛋白进行生物信息学分析;利用实时荧光定量PCR和Western blotting检测生理状态下HSP90AB1基因在黑龙江林蛙皮肤、肌肉、心脏、肝脏、脾脏、肺脏、肾脏和胃等组织器官中的表达量,同时对LPS诱导下不同时间点HSP90AB1基因在不同组织器官的转录水平进行检测。【结果】黑龙江林蛙HSP90AB1基因CDS长2178 bp,共编码725个氨基酸。生物信息学分析显示,HSP90AB1蛋白不存在信号肽且无跨膜信号,属于非跨膜蛋白,存在62个潜在磷酸化位点(含33个丝氨酸、19个苏氨酸及10个酪氨酸位点),其二级结构以α-螺旋为主(占47.03%),其次为无规则卷曲(占39.59%)和延伸链(占13.38%)。系统进化树结果显示,黑龙江林蛙与欧洲林蛙亲缘关系最近。在生理状态下,HSP90AB1基因在黑龙江林蛙胃中表达量最高,且显著高于其他组织(P<0.05);在肌肉组织中表达量最低,且显著低于其他组织(P<0.05)。Western blotting结果显示,HSP90AB1蛋白在黑龙江林蛙胃中表达量最高;在心脏中表达量最低,且显著低于其他组织(P<0.05)。LPS诱导后,黑龙江林蛙各组织中HSP90AB1基因表达量随诱导时间延长而呈降低趋势,其中诱导72和96 h表达量均显著低于其他时间点(P<0.05);诱导12、72 h时脾脏中HSP90AB1基因表达量显著高于其他组织(P<0.05);24 h时肌肉和脾脏中HSP90AB1基因表达量显著高于其他组织(P<0.05)。【结论】本研究成功克隆了黑龙江林蛙HSP90AB1基因CDS区序列,并明确了其在不同组织中的表达规律,其中在胃中表达量最高,肌肉组织中表达量最低。LPS诱导可明显抑制HSP90AB1基因在黑龙江林蛙不同组织中的转录水平。本试验结果为深入探究HSP90AB1基因在林蛙生理及应激过程中的功能机制提供了理论依据。