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CSEE Journal of Power and Energy Systems 2024年第2期10卷 746-755页

作者： Zhiyun Han Qingmin Li Yujin Guo Tao liu Guojing Dong Hanwen ren State Key Laboratory of Alternate Electrical Power System with renewable Energy Sources North China Electric Power UniversityBeijing 102206China Electric Power Research Institute Beijing 100085China Inner Mongolia Electric Economy and Technology Academy Hohhot 010020China

Accelerated insulation aging problems under high frequency repetitive impulses in power electronic transformers are drawing more and more attention in modern power systems. Partial discharge (PD) characteristics including discharge inception voltage, phase distribution and statistical characteristics on polyimide (PI) surface under different impulse waveforms and the insulation life of PI films are studied in this paper. We carry out experiments based on PD and insulation lifetime test systems, using five different types of repetitive impulses, including three bipolar waves and two unipolar waves. The experimental results show that there is little variation in discharge inception voltage under different waveforms, but great variation in phase distribution and statistical characteristics of PD. In addition, insulation life is approximately the same under different waveforms with the same polarity, and the aging rate under bipolar waveforms is larger than that under unipolar waveforms. We explain the differences between the bipolar and unipolar waveforms on insulation life, which can be concluded that the surface charge under unipolar waveform accumulates more significnatly compared with bipolar waveform and decreases the electric filed strength in discharging the air gap and inhibits surface discharge from occurring.

关键词： Insulation life polyimide film power electronic transformer repetitive impulse surface discharge characteristics

AP assembled on ultrafine aluminum particle and its application to NEPE propellant

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Defence Technology（防务技术） 2024年第6期36卷 20-29页

作者： Huixin Wang Qiang Li Hui ren Liangjun Xie Tingting liu Zhihong Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Inner Mongolia Institute of Synthetic Chemicals Hohhot 010010China

Coating modification is an important way to enhance the reactivity of aluminum *** this paper,ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition *** particles with AP as shell and ultrafine aluminum powder as the core(Al@AP)were *** micromorphology results show that the coated particles are about 5μm,and the coating layer is evenly distributed on the outer surface of aluminum powder,indicating a complete *** energetic microunits were implanted into the nitrate ester plasticizing adhesive system(NEPE)as solid phase *** effect of filler on the rheological properties,safety,mechanical properties,thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum *** test results show that the rheological properties,mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant *** with Al based propellant,the mechanical sensitivity and thermal sensitivity are decreased,the safety is better,and the explosion heat of the propellant is increased by 7.8%.The engine test shows that the specific impulse is increased by 1.2 ***@AP can improve the energy output and safety of NEPE propellant,and has potential application prospects in high-energy propellants.

关键词： Aluminum powder Coating NEPE propellant Energy output Applied research

Copper coordination-driven self-assembly and encapsulation of PCR reagents

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Chinese Chemical Letters 2024年第3期35卷 189-192页

作者： Chang Lu Jinkai zheng Juewen liu Institute of Food Science and Technology Chinese Academy of Agricultural SciencesBeijing 100193China Department of Chemistry Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooONN2L 3G1Canada

Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic *** storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are *** this paper,we report using metal ions to form coordination nanomaterials with the intrinsic components of the PCR reagents including dNTP,DNA primers and DNA polymerase as an integrated PCR reaction *** complete PCR reactions,users need only to dissolve the coordination nanomaterials with a buffer and add template DNA.A few transition metal ions were screened and Cu^(2+)was found to be the most effective metal ion for this *** the encapsulation efficiency of PCR reagents was measured,which can reach close to 100%for the primers and DNA polymerase,but only 10%for dNTP because dNTP was *** study also exhibited this integrated PCR reaction system can be used for DNA detection with a similar detection limit to the normal PCR,and showed good stability of encapsulated PCR nanomaterial after storage for a week.

关键词： Metal ions Coordination Encapsulation PCR Storage

Fermi level tuning in Sn_(1-x)Pb_(x)Te/Pb heterostructure via changing interface roughness

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 118-125页

作者： Tengteng liu Zhaoxia Yi Bangjin Xie Weiyan zheng Dandan Guan Shiyong Wang Hao zheng Canhua liu Hao Yang Yaoyi Li Jinfeng Jia Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Tsung-Dao Lee InstituteSchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Shanghai Research Center for Quantum Sciences Shanghai 201315China Hefei National Laboratory Hefei 230088China

Superconducting SnTe-type topological crystalline insulators(TCIs)are predicted to host multiple Majorana zero modes(MZMs)which can coexist in a single *** level(FL)close to the Dirac points of topological surface states is helpful for detecting ***,the TCI SnTe is a heavily p-type semiconductor which is very difficult to modify to n-type via doping or *** this work,we fabricate the atomically flat Sn_(1-x)Pb_(x)Te/Pb heterostructure by molecular beam epitaxy,and make the p-type Sn_(1-x)Pb_(x)Te become n-type through changing the interface *** scanning tunnelling microscope,we find the Dirac points of Sn_(1-x)Pb_(x)Te/Pb heterostructure are always above the FL due to the Fermi level pinning(FLP)induced by topological surface states at atomically flat *** increasing the interface roughness,the FLP effect is suppressed and then the Dirac points of p-type Sn_(1-x)Pb_(x)Te can be tuned very close to or even below the *** work provides a new method for tuning the FL of SnTe-type TCI which has potential application in novel topological superconductor device.

关键词： topological crystalline insulator superconductor heterostructure Fermi level pinning interface roughness

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin Zou Di-wei liu Jian liu Hong-cheng Zuo Yin-huan zheng Hao Xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

Review on research and development of oxy-coal burner for carbon capture

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Science China(Technological Sciences) 2024年第3期67卷 647-672页

作者： GUO JunJun liu JingZhang ZHANG Tai HU Fan LI PengFei liu ZhaoHui zheng ChuGuang State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and Technology Wuhan 430074China CCRC King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Kingdom of Saudi Arabia Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China National Key Laboratory of High Efficiency and Low Carbon Utilization of Coal Beijing 100049China Institute of Energy Research Jiangxi Academy of SciencesNanchang 330096China Carbon Neutrality Research Center of Jiangxi Province Nanchang 330096China Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China National Energy Research and Development Center of Clean and Low Carbon Coal-based Power Generation Technologies Wuhan 430074China

In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.

关键词： carbon capture oxy-fuel combustion oxy-fuel burner pulverized coal compatible design

70 Gbps PAM-4850-nm oxide-confined VCSEL without equalization and pre-emphasis

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Journal of Semiconductors 2024年第5期45卷 5-7页

作者： Anjin liu Bao Tang Zhiyong Li Wanhua zheng Key Laboratory of Optoelectronic Materials and Devices Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Accelink technologies co. LtdWuhan 430205China Key Laboratory of Solid-State Optoelectronics Information Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Directly modulated 850-nm vertical-cavity surface-emitting lasers(VCSELs)with the advantages of low cost,high modulation speed,good reliability,and low power consumption,are the key sources in the optical interconnects with multimode fibers for the supercomputers,data centers,and machine learning applications[1−3].Typically,non-return-tozero(NRZ)modulation format is used.

关键词： return confined fibers

In silico off-target profiling for enhanced drug safety assessment

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Acta Pharmaceutica Sinica B 2024年第7期14卷 2927-2941页

作者： Jin liu Yike Gui Jingxin Rao Jingjing Sun Gang Wang Qun ren Ning Qu Buying Niu Zhiyi Chene Xia Sheng Yitian Wang Mingyue zheng Xutong Li College of Pharmaceutical Sciences Zhejiang UniversityHangzhou 310058China Drug Discovery and Design Center State Key Laboratory of Drug ResearchShanghai Institute of Materia Medica Chinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China Nanjing University of Chinese Medicine Nanjing 210023China School of Pharmaceutical Science and Technology Hangzhou Institute for Advanced StudyHangzhou 330106China

Ensuring drug safety in the early stages of drug development is crucial to avoid costly failures in subsequent ***,the economic burden associated with detecting drug off-targets and potential side effects through in vitro safety screening and animal testing is *** off-target interactions,along with the adverse drug reactions they induce,are significant factors affecting drug *** assess the liability of candidate drugs,we developed an artificial intelligence model for the precise prediction of compound off-target interactions,leveraging multi-task graph neural *** outcomes of off-target predictions can serve as representations for compounds,enabling the differentiation of drugs under various ATC codes and the classification of compound ***,the predicted off-target profiles are employed in adverse drug reaction(ADR)enrichment analysis,facilitating the inference of potential ADRs for a *** the withdrawn drug Pergolide as an example,we elucidate the mechanisms underlying ADRs at the target level,contributing to the exploration of the potential clinical relevance of newly predicted off-target ***,our work facilitates the early assessment of compound safety/toxicity based on off-target identification,deduces potential ADRs of drugs,and ultimately promotes the secure development of drugs.

关键词： Drug safety Off-target prediction Adverse drug reactions Toxicity Molecular representation Artificial intelligence

Effect of solvent on the initiation mechanism of living anionic polymerization of styrene:A computational study

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Chinese Journal of Chemical Engineering 2024年第5期69卷 135-142页

作者： Shen Li Yin-Ning Zhou Zhong-Xin liu zheng-Hong Luo School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

For living anionic polymerization(LAP),solvent has a great influence on both reaction mechanism and *** this work,by using the classical butyl lithium-styrene polymerization as a model system,the effect of solvent on the mechanism and kinetics of LAP was revealed through a strategy combining density functional theory(DFT)calculations and kinetic *** terms of mechanism,it is found that the stronger the solvent polarity,the more electrons transfer from initiator to solvent through detailed energy decomposition analysis of electrostatic interactions between initiator and solvent ***,we also found that the stronger the solvent polarity,the higher the monomer initiation energy barrier and the smaller the initiation rate ***,initiation is more favorable at lower temperatures based on the calculated results ofΔG_(TS).Finally,the kinetic characteristics in different solvents were further examined by kinetic *** is found that in benzene and n-pentane,the polymerization rate exhibits first-order ***,slow initiation and fast propagation were observed in tetrahydrofuran(THF)due to the slow free ion formation rate,leading to a deviation from first-order kinetics.

关键词： Living anionic polymerization Solvent effect Reaction kinetics Computational chemistry Mathematical modeling Kinetic modeling

Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment

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China Foundry 2024年第4期21卷 343-351页

作者： Yuan-hang Jiang Hui-ting zheng Fei liu Hai-dong Zhao National Engineering Research Center of Near-net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical *** this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn *** characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was *** results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging *** number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 *** precipitates with the highest density and smallest size are observed after pre-aging for 4 *** pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关键词： high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging