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AN AB INITIO SORBIE-MURREL pOTENTIAL ENERGY SURFACE OF CARBON DISULFIDE

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Chinese Chemical Letters 1995年第5期6卷 411-414页

作者： Yu Bin WANG Xin Ji HONG Zhen Yi WEN(institute of modern physics, Northwest University, Xian 710069) NW Univ Xian Inst Modern Phys Xian 710069 Peoples R China

In this letter ab initio electronic structure calculations are performed for extensive geometries Of CS2. A newly written program is used to fit the computed energies into the Sorbie-Murrel function, whose contour plo... 详细信息

关键词： AB AN AB INITIO SORBIE-MURREL pOTENTIAL ENERGY SURFACE OF CARBON DISULFIDE

Hybrid HMX multi-level assembled under the constraint of 2D materials with efficiently reduced sensitivity and optimized thermal stability

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Defence Technology（防务技术） 2024年第9期39卷 123-132页

作者： Xiaomin Song Longjin Huang Rufang peng Qi Huang Jinjiang xu Jie Sun institute of Chemical Materials China Academy of Engineering PhysicsMianyang621900China State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive ***,screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major *** this work,HMX-pEI/rGO/g-C_(3)N_(4)(HprGC)composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C_(3)N_(4).The g-C_(3)N_(4) used for desensitization has a richπ-conjugated system and shows outstanding ability in reducing friction *** hierarchical structure of HprGC formed by electrostatic self-assembly andπ-πstacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution,thus exhibiting a prominent synergistic desensitization effect on *** results show that rGO/gC_(3)N_(4) coating has no effect on the crystal structure and chemical structure of *** importantly,the perfect combination of g-C_(3)N_(4) and rGO endows HprGC with enhanced thermal stability and ideal mechanical sensitivity(IS:21 J,FS:216 N).Obviously,the new fabrication of HprGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.

关键词： HMX-pEI/rGO/g-C_(3)N_(4) Electrostatic self-assembly π-πstacking Synergistic desensitization

Advancing space-based gravitational wave astronomy: Rapid parameter estimation via normalizing flows

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Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 20-33页

作者： Minghui Du Bo Liang He Wang peng xu Ziren Luo Yueliang Wu Center for Gravitational Wave Experiment National Microgravity LaboratoryInstitute of MechanicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Gravitational Wave precision Measurement of Zhejiang province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China International Centre for Theoretical physics Asia-pacific University of Chinese Academy of SciencesBeijing 100049China Taiji Laboratory for Gravitational Wave Universe(Beijing/Hangzhou) University of Chinese Academy of SciencesBeijing 100049China Lanzhou Center of Theoretical physics Lanzhou UniversityLanzhou 730000China Hangzhou institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China institute of Theoretical physics Chinese Academy of SciencesBeijing 100190China

Gravitational wave(GW) astronomy is witnessing a transformative shift from terrestrial to space-based detection, with missions like Taiji at the forefront. While the transition brings unprecedented opportunities for exploring massive black hole binaries(MBHBs), it also imposes complex challenges in data analysis, particularly in parameter estimation amidst confusion *** this gap, we utilize scalable normalizing flow models to achieve rapid and accurate inference within the Taiji environment. Innovatively, our approach simplifies the data's complexity, employs a transformation mapping to overcome the year-period time-dependent response function, and unveils additional multimodality in the arrival time parameter. Our method estimates MBHBs several orders of magnitude faster than conventional techniques, maintaining high accuracy even in complex backgrounds. These findings significantly enhance the efficiency of GW data analysis, paving the way for rapid detection and alerting systems and enriching our ability to explore the universe through space-based GW observation.

关键词： Taiji program gravitational wave detection parameter estimation machine learning

Solving the subset sum problem by the quantum Ising model with variational quantum optimization based on conditional values at risk

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Science China(physics,Mechanics & Astronomy) 2024年第8期67卷 43-55页

作者： Qilin Zheng Miaomiao Yu pingyu Zhu Yan Wang Weihong Luo ping xu institute for Quantum Information and State Key Laboratory of High performance Computing College of Computer Science and TechnologyNational University of Defense TechnologyChangsha 410073China Hefei National Laboratory Hefei 230088China

The subset sum problem is a combinatorial optimization problem,and its complexity belongs to the nondeterministic polynomial time complete(Np-Complete)*** problem is widely used in encryption,planning or scheduling,and integer *** accurate search algorithm with polynomial time complexity has not been found,which makes it challenging to be solved on classical *** effectively solve this problem,we translate it into the quantum Ising model and solve it with a variational quantum optimization method based on conditional values at *** proposed model needs only n qubits to encode 2ndimensional search space,which can effectively save the encoding quantum *** model inherits the advantages of variational quantum algorithms and can obtain good performance at shallow circuit depths while being robust to noise,and it is convenient to be deployed in the Noisy Intermediate Scale Quantum *** investigate the effects of the scalability,the variational ansatz type,the variational depth,and noise on the ***,we also discuss the performance of the model under different conditional values at *** computer simulation,the scale can reach more than nine *** selecting the noise type,we construct simulators with different QVs and study the performance of the model with *** addition,we deploy the model on a superconducting quantum computer of the Origin Quantum Technology Company and successfully solve the subset sum *** model provides a new perspective for solving the subset sum problem.

关键词： subset sum problem quantum Ising model conditional values at risk variational quantum optimization

Dual in-situ observation of tribochemical and morphological evolution of single-layer WS_(2)and multi-layer WS_(2)/C coatings

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Friction 2024年第7期12卷 1580-1598页

作者： Yuzhen LIU Jae-Ho HAN Shusheng xu Young Chan JUNG Dae-Eun KIM State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Department of Mechanical Engineering Yonsei UniversitySeoul03722Republic of Korea Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264000China Yantai Zhongke Research institute of Advanced Materials and Green Chemical Engineering Yantai 264000China

The outstanding tribological performance of transition metal dichalcogenides(TMDs)is attributed to their unique sandwich microstructure and low interlayer shear *** advantageous structure allows TMDs to demonstrate exceptional friction reduction ***,the incorporation of TMDs and amorphous carbon(a-C)in multi-layer structures shows excellent potential for further enhancing tribological and anti-oxidation *** carbon,known for its high ductility,chemical inertness,and excellent wear resistance,significantly contributes to the overall performance of these multi-layer *** gain an in-depth understanding of the tribological mechanism and evolution of TMDs’multi-layer coatings,a dual in-situ analysis was carried out using a tribometer equipped with a 3D laser microscope and a Raman *** innovative approach allowed for a comprehensive evolution of the tribological,topographical,and tribochemical characteristics of both single-layer WS_(2)and multi-layer WS_(2)/C coatings in real *** findings from the dual in-situ tribotest revealed distinct failure characteristics between the single-layer WS_(2)coating and the multi-layer WS_(2)/C *** single-layer WS_(2)coating predominantly experienced failure due to mechanical removal,whereas a combination of mechanical removal and tribochemistry primarily influenced the failure of the multi-layer WS_(2)/C *** tribological evolution process of these two coatings can be classified into four stages on the basis of their tribological behavior:the running-in stage,stable friction stage,re-deposition stage,and lubrication failure *** stage represents a distinct phase in the tribological behavior of the coatings and contributes to our understanding of their behavior during sliding.

关键词： In-situ analysis multi-layer coating tribology tribochemistry

Si/TiO_(2) carbon fiber core encapsulated in hierarchical multiple MXene@Co-MoS_(2) shells for constructing a free-standing anode of lithium storage

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Rare Metals 2024年第9期43卷 4222-4233页

作者： Xian-ping Du Ying Huang Jia-ming Wang Zhen-he Feng xu Sun MOE Key Laboratory of Material physics and Chemistry Under Extraordinary Conditions School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shanghai institute of Space power-Sources Shanghai 200245China Ningbo institute of Northwestern polytechnical University Ningbo 315103China

Silicon-based(Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion during cycling seriously limit their development. The optimum solution is to select specific materials to establish an exceptionally conductive and volume buffer structure,which can assist Si materials in developing their excellent lithium storage properties. In this study, Si particles were confined in TiO_(2)carbon fibers(TiO_(2)CFs) via electrospinning, after which they were encapsulated with MXene and Co-MoS_(2)(CMS) nanosheets to fabricate hierarchical ST-2@MXene@CMS films. TiO_(2)CF, MXene and CMS were employed to establish a coherent conductive network with one-, two-and three-dimensional electronic pathways to permit the unimpeded flow of electrons inside the electrode material. TiO_(2)CF, MXene and CMS acted precisely as multilayered buffers to ameliorate the volume change of Si particles during cycling. In addition, the CMS nanosheets were involved in lithium storage, contributing to the final electrochemical performance. Ultimately, the ST-2@MXene@CMS films served as free-standing electrodes, avoiding the impact of inactive interfaces on the electrochemical performance and fulfilling the lightweight requirement for new energy storage devices.

关键词： Si particles MXene Co-MoS_(2)nanosheets Hierarchical structure Lithium-ion batteries

Carbon-based nanomaterials cause toxicity by oxidative stress to the liver and brain in Sprague-Dawley rats

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Nuclear Science and Techniques 2024年第6期35卷 54-64页

作者： Ying-Ying xu Chan Jin Meng Wu Jian-Ye Zhou Hui-Ling Wei Department of Gastroenterology China-Japan Friendship HospitalBeijing 100029China Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China institute of particle and Nuclear physics College of PhysicsHenan Normal UniversityXinxiang 453007China

Carbon-based nanomaterials have important research significance in various disciplines,such as composite materials,nanoelectronic devices,biosensors,biological imaging,and drug ***,the human and ecological risks associated with carbon-based nanomaterials have received increasing ***,the biological safety of carbon based nanomaterials has not been systematically *** this study,we used different types of carbon materials,namely,graphene oxide(GO),single-walled carbon nanotubes(SWCNTs),and multiwalled carbon nanotubes(MWCNTs),as models to observe their distribution and oxidative damage in *** results of Histopathological and ultrastructural examinations indicated that the liver and lungs were the main accumulation targets of these ***-μ-XRF analysis revealed that SWCNTs and MWCNTs might be present in the *** shows that the three types of carbon-based nanomaterials could cross the gas-blood barrier and eventually reach the liver *** addition,SWCNTs and MWCNTs could cross the blood-brain barrier and accumulate in the cerebral *** increase in ROS and MDA levels and the decrease in GSH,SOD,and CAT levels indicated that the three types of nanomaterials might cause oxidative stress in the *** suggests that direct instillation of these carbon-based nanomaterials into rats could induce ROS *** addition,iron(Fe)contaminants in these nanomaterials were a definite source of free ***,these nanomaterials did not cause obvious damage to the rat brain *** deposition of selenoprotein in the rat brain was found to be related to oxidative stress and Fe *** information may support the development of secure and reasonable applications of the studied carbon-based nanomaterials.

关键词： Carbon-based nanomaterials Oxidative stress Trace element distribution TEM SR-μ-XRF

Experimental test of a new neutron threshold detector and its application

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Nuclear Science and Techniques 2002年第3期13卷 149-155页

作者： LI Gui-Sheng, ZHANG Tian-Mei, SU You-Wu, LI Shu-Wei(institute of modern physics, the Chinese Academy of Sciences, Lanzhou 730000) institute of modern physics the Chinese Academyo f Sciences Lanzhou 730000 institute of modern physics the Chinese Academyo f Sciences Lznahou 730000

The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 209Bi, 115In, 27A1, 19F and 12C samples.

关键词：阈探测器中子谱实验

Structures and aromaticity of the planar Al_2p_2^(n-) (n=1―4) clusters

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Science China Chemistry 2009年第12期52卷 2237-2242页

作者： xu WenGuo,ZHANG YuanChun & ZHAI Lei institute of Chemical physics,Beijing institute of Technology,Beijing 100081,China institute of Chemical physics Beijing Institute of Technology Beijing China

Clusters Al2p2n-(n = 1―4) were theoretically investigated using density functional theory (DFT) methods at the B3LYp/6-311+G* and B3pW91/6-311+G* levels of theory. The calculated results showed that the planar structure (D2h symmetry) of Al2p2n-(n = 1―4) species was the global minimum. And the negative nucleus-independent chemical shift (NICS) value of Al2p2n-(n = 1―4) species indicated the existence of a ring current in the planar structure (D2h symmetry). A detailed molecular orbital (MO) analysis revealed that the planar structures (D2h symmetry) had π aromaticity,which further exhibited the strongly aromatic character for Al2p2n-(n = 1―4) species.

关键词： DFT calculation geometric structure nucleus-independent chemical shift molecular orbital