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Science China(Technological Sciences) 2024年第2期67卷 395-407页

作者： ZHANG JieXin nie PingYun ZHANG bo State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction ***,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure *** method ensures the tracking error converges in a finite time,even when the system faces *** method also preserves the passivity of the ***,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity *** observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation *** particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot *** effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.

关键词： motion control elastic joint robot finite-time convergence high-order system state estimation physical human-robot interaction

A study of antineutrino spectra from spent nuclear fuel at Daya Bay

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Chinese Physics C 2012年第1期36卷 1-5页

作者： ZHOU Bin RUAN Xi-Chao nie yang-bo ZHOU Zu-Ying AN Feng-Peng CAO Jun Science and Technology on Nuclear Data Laboratory China Institute of Atomic EnergyBeijing 102413China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Northwest Institute of Nuclear Technology Xi’an 710024China

The Daya Bay Reactor Antineutrino Experiment is designed to determine the as yet unknown neutrino mixing angle,θ13,by measuring the disappearance of electron antineutrinos from several nuclear reactor *** projected sensitivity in sin2（2θ13） of better than 0.01 at a 90% CL should be achieved after three years of *** emitted from spent nuclear fuel （SNF） distort the soft part of the energy *** this article,a calculation of the antineutrino spectra from the long-life isotopes in SNF is performed.A non-equilibrium generation of long half-life isotopes during the running time of the reactor is also ***,we show that the antineutrino event rate contribution from SNF,which has been stored in the SNF pool for several years,may be non-negligible.

关键词： spent nuclear fuel antineutrino spectrum non-equilibrium event rate

Processing,microstructure,and properties of porous ceramic composites with directional channels

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Journal of Materials Science & Technology 2024年第1期168卷 1-15页

作者： bo Zhang yang yang Xueling Fan Key Laboratory of Service Performance and Protection Technology in Extreme Environments Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China

Porous ceramic composites with directional microchannels from micrometer to dozens of micrometer levels have attracted more and more attention in various fields including aerospace,biomedicines,and thermal insulation due to their excellent fluid permeability,mechanical properties,*** this article,we summarize the recent directional porous ceramics developments including their main processing routes and respective ***,the properties get from different processing routes have been com-pared and analyzed in terms of microstructures,mechanical properties,and *** has been given to the deeper understanding which can allow one to control the microstructural features of these porous ceramic composites to obtain the desired *** work can provide a useful reference for the development and application of porous ceramic composites with directional microchan-nels.

关键词： Porous ceramic composites Directional microchannels Processing routes Permeability

Programming molecular switches in water and ethanol via thermo-sensitive polymers for phase control in energetic crystals

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Defence Technology（防务技术） 2024年第8期38卷 75-88页

作者： Xinru yang Yushi Wen Congmei Lin Feiyan Gong Zhijian yang Fude nie Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China

The practical application of energetic materials, particularly 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20), is frequently impeded by phase transition challenges. In this study, we propose a novel strategy to enhance the stability of CL-20 by employing a thermo-sensitive polymer,poly(N-isopropylacrylamide)(PNIPAM), to modulate its phase transitions. Our approach involves the use of an in-situ polymerized polydopamine(PDA) shell as a platform for surface grafting through atom transfer radical polymerization, yielding a core-shell structured CL-20@PDA-PNIPAM. Through comprehensive characterization, the successful grafting of PNIPAM is confirmed, significantly enhanced the phase stability of CL-20. Notably, our core-shell structure exhibits a 13℃ increase in phase transition temperature compared to raw CL-20, thereby delaying the ε→a phase transition by over 80 min under combined thermal and solvent conditions. The enhanced stability is attributed to the hydrophobic nature of PNIPAM above its low critical solution temperature in water, which effectively shields the CL-20 crystal. These findings provide new insights into enhancing the stability and safety of energetic materials in complex environments, highlighting the potential of our molecular switch mechanism.

关键词： 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20) Phase stability Polydopamine(PDA) Poly-N-Isopropylacrylamide(PNIPAM) Thermal and solvent effects

Deflagration and detonation induced by shock wave focusing at different Mach numbers

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Chinese Journal of Aeronautics 2024年第2期37卷 249-258页

作者： Zezhong yang Jun CHENG bo ZHANG School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Shock wave focusing is an effective way to create a hot spot or a high-pressure and hightemperature region at a certain place,showing its unique usage in detonation initiation,which is beneficial for the development of detonation-based *** flame propagation behavior after the autoignition induced by shock wave focusing is crucial to the formation and self-sustaining of the detonation *** this study,wedge reflectors with two different angles(60°and 90°)and a planar reflector are employed,and the Mach number of incident shock waves ranging from 2.0 to 2.8 is utilized to trigger different flame propagation *** pressure transducers and the high-speed schlieren imaging system are both employed to investigate the shock-shock collision and ignition *** results reveal a total of four flame propagation modes:deflagration,DDT(Deflagration-to-Detonation Transition),unsteady detonation,and direct *** detonation wave formed in the DDT and unsteady detonation mode is only approximately 75%-85%of the Chapman-Jouguet(C-J)speed;meanwhile,the directly induced detonation wave speed is close to the C-J *** waves,which are strong evidence for the existence of detonation waves,are discovered in *** usage of wedge reflectors significantly reduces the initial pressure difference ratio needed for direct detonation *** also provide a practical method for differentiating between detonation and deflagration modes,which involves contrasting the speed of the reflected shock wave with the speed of the theoretically nonreactive reflected shock *** findings should serve as a reference for the detonation initiation technique in advanced detonation propulsion engines.

关键词： Deflagration Detonation Hydrogen Ignition Shock wave focusing

Pressure effects on metal/covalent-organic frameworks:structural and optical properties

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Science China Chemistry 2024年第9期67卷 2890-2903页

作者： Yixuan Wang Yunfeng yang Xinyi yang bo Zou Synergetic Extreme Condition High-Pressure Science Center State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)with highly ordered porous structure,tunable bandgap,large specific surface area and structural diversity,provide an appealing platform for the development of stimulus response,sensing,imaging and *** various tuning methods,pressure engineering using the diamond anvil cell is a highly powerful in-situ technique,which can efficiently modulate the structural and optical properties of MOFs/*** is beyond the realization of traditional chemical *** review outlines the research progress in the experimentoriented discovery of new phases or unique properties under high pressure,including phase transition,abnormal compression,photoluminescence(PL)discoloration and ***,the improvement of PL quantum yield in MOFs could be achieved by pressure-treated engineering and hydrogen-bonding cooperativity *** also propose and establish the relationship between structure and optical properties under high ***,the challenge and outlook of the current fields are *** hope that this review will supply guidance for comprehending the development of high-pressure MOF/COF-related research fields,and offer novel strategies for designing more high-performance MOF/COF materials to ultimately expand their applications.

关键词： metal/covalent-organic frameworks pressure engineering phase transition abnormal compressive behaviors piezochromic behaviors emission enhancement

Mechanism of Qili Qiangxin Capsule for Heart Failure Based on miR133a-Endoplasmic Reticulum Stress

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Chinese Journal of Integrative Medicine 2024年第5期30卷 398-407页

作者： JI Xiao-di yang Ding CUI Xi-yuan LOU Li-xia nie bo ZHAO Jiu-li ZHAO Ming-jing WU Ai-ming Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine Key Laboratory of Chinese Internal Medicine of Ministry of Education and BeijingBeijing 100700China Department of Traditional Chinese Medicine Fuwai HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100037China

Objective:To investigate the pharmacological mechanism of Qili Qiangxin Capsule(QLQX)improvement of heart failure(HF)based on miR133a-endoplasmic reticulum stress(ERS)***:A left coronary artery ligation-induced HF after myocardial infarction model was used in this *** were randomly assigned to the sham group,the model group,the QLQX group[0.32 g/(kg·d)],and the captopril group[2.25 mg/(kg·d)],15 rats per group,followed by 4 weeks of *** function such as left ventricular ejection fraction(EF),fractional shortening(FS),left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),the maximal rate of increase of left ventricular pressure(+dp/dt max),and the maximal rate of decrease of left ventricular pressure(–dp/dt max)were monitored by echocardiography and *** and eosin(HE)and Masson stainings were used to visualize pathological changes in myocardial *** m RNA expression of mi R133a,glucose-regulated protein78(GRP78),inositol-requiring enzyme 1(IRE1),activating transcription factor 6(ATF6),X-box binding protein1(XBP1),C/EBP homologous protein(CHOP)and Caspase 12 were detected by *** protein expression of GRP78,p-IRE1/IRE1ratio,cleaved-ATF6,XBP1-s(the spliced form of XBP1),CHOP and Caspase 12 were detected by Western *** T-mediated d UTP nick-end labeling(TUNEL)staining was used to detect the rate of ***:QLQX significantly improved cardiac function as evidenced by increased EF,FS,LVSP,+dp/dt max,-dp/dt max,and decreased LVEDP(P<0.05,P<0.01).HE staining showed that QLQX ameliorated cardiac pathologic damage to some *** staining indicated that QLQX significantly reduced collagen volume fraction in myocardial tissue(P<0.01).Results from RT-PCR and Western blot showed that QLQX significantly increased the expression of mi R133a and inhibited the m RNA expressions of GRP78,IRE1,ATF6 and XBP1,as well as decreased the protein expressions of GRP78,cleave

关键词： heart failure Qili Qiangxin Capsule miR133a endoplasmic reticulum stress apoptosis

Intersection theory rules symbology

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 93-104页

作者： Jiaqi Chen bo Feng Lilin yang Beijing Computational Science Research Center Beijing 100084China Zhejiang Institute of Modern Physics School of PhysicsZhejiang UniversityHangzhou 310027China Peng Huanwu Center for Fundamental Theory Hefei 230026China

We propose a novel method to determine the structure of symbols for any family of polylogarithmic Feynman *** the d log-bases and simple formulas for the leading order and next-to-leading contributions to the intersection numbers,we give a streamlined procedure to compute the entries in the coefficient matrices of canonical differential equations,including the symbol letters and the rational *** also provide a selection rule to decide whether a given matrix element must be *** symbol letters are deeply related to the poles of the integrands and also have interesting connections to the geometry of Newton *** method can be applied to many cutting-edge multi-loop *** simplicity of our results also hints at the possible underlying structure in perturbative quantum field theories.

关键词： scattering amplitude Feynman integral symbology

Soil type and wetting intensity control the enhancement extent of N_(2)O efflux in soil with drought and rewetting cycles

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International Soil and Water Conservation Research 2024年第1期12卷 137-144页

作者： Panpan Jiao Lei yang Zhongwu Li Peng Zheng Xiaodong nie School of Geographical Sciences Hunan Normal UniversityChangsha 410081China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau The Research Center of Soil and Water Conservation and Ecological EnvironmentChinese Academy of Sciences and Ministry of EducationYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

Climate change alters the intensity and frequency of drought and rewetting(D/W)events;however,the influence patterns of D/W on soil N_(2)O efflux in the water-limited area were not fully ***,the impacts of D/W cycles varying in different extent of rewetting and frequency to N_(2)O efflux in two kinds of soil on the Loess Plateau were *** incubation conditions consisted of 1)D/W treatments with four 7-day cycles from 10%water holding capacity(WHC)to 60%WHC or 90%WHC,2)constant moisture of 60%WHC and 90%*** pulse of N_(2)O efflux rate under 10-60%WHC treatment was higher than that under 10-90%WHC treatment in calcic cambisols,while opposite trend was observed in earth-cumuli-orthic ***,the pulse of N_(2)O efflux rate decreased as cycle number increased for different wetting intensities and soil *** direct N_(2)O efflux under 10-60%WHC and 10-90%WHC treatments were 5.49 and 1.89μg N_(2)O-N g^(-1)soil in calcic cambisols,with those being 1.92 and 10.85μg N_(2)O-N g^(-1)soil in earth-cumuli-orthic anthrosols,*** N loss in earth-cumuli-orthic anthrosols was approximately 5.74 times greater than that in calcic cambisols under 10-90%WHC treatment,whereas the N loss under 10-60%WHC treatment was about 2.86 times greater in calcic cambisols than that in earth-cumuli-orthic *** study suggested that extreme rainfall events can enhance the N_(2)O efflux and N loss in agricultural soils on the Loess Plateau in terms of soil type and wetting intensity,which should not be ignored in the N fertilizer management.

关键词： Drought/rewetting cycles N_(2)O efflux Wetting intensity Microbial biomass N Dissolved organic N Loess plateau

A strategy to synthesize phosphorus-containing nickel phyllosilicate whiskers to enhance the flame retardancy of epoxy composites with excellent mechanical and dry-friction properties

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 39-50页

作者： Shibin nie Zongquan Zhao Yuxuan Xu Wei He Wenli Zhai Jinian yang School of Public Security and Emergency Management Anhui University of Science and TechnologyHefei231131China School of Safety Science and Engineering Anhui University of Science and TechnologyHuainan232001China School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan232001China Institute of Energy Hefei Comprehensive National Science CenterHefei230000China

To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthrene as the organic *** impacts of FP-NiPS on the thermal stability,flame retardancy,and mechanical and tribological properties of EP composites were *** findings demonstrated that 5 wt%FP-NiPS elevated the limiting oxygen index of the EP composite from 23.8%to 28.4%,achieving a V-0 rating during vertical burning ***-NiPS could enhance the thermal stability of epoxy resin(EP)and facilitate the development of a dense and continuous carbon layer,thereby significantly improving the fire safety of the EP *** FP-NiPS led to an 8.2%increase in the tensile strength and a 38.8%increase in the elastic modulus of the EP composite,showing outstanding mechanical ***,FP-NiPS showed remarkable potential in enhancing the wear resistance of *** wear rate of 1 wt%FP-NiPS is 2.34×10^(−5) mm^(3)·N^(−1)·m^(−1),a decrease of 66.7%compared to *** work provides a novel promising modification method to enhance the fire safety,mechanical and wear resistance properties of EP.

关键词： nickel phyllosilicate epoxy resin flame retardant wear resistance mechanical property