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Characterization of laser cooling in microgravity via long-term operations in TianGong-2 space lab

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National Science Review 2023年第4期10卷 69-75页

作者： De-Sheng Lü wei Ren Yuan Sun Tang Li Qiu-Zhi Qu Bin Wang Lin Li Jian-Bo Zhao Xin Zhao jing-wei Ji Mei-Feng Ye jing-Feng Xiang wei-Biao Chen Yu-Zhu Wang Liang Liu CAS Key Laboratory of Quantum Optics and Center of Cold Atom Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Aerospace Laser Engineering Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

The invention of laser cooling has fundamentally influenced the research frontier of atomic physics and quantum physics, and recently an intense focus has been on the studies of cold atom physics in microgravity environments. Herein, we report the results of our laser cooling experiment in Tian Gong-2 space lab, which operated for 34 consecutive months in orbit. Over such an extended operation time, the quality of laser cooling did not experience any significant decline, while the properties of laser cooling in orbital microgravity were systematically studied. In particular, we demonstrate magneto-optical trapping and polarization-gradient cooling in orbit and carefully examine their performances. A comparison of the in-orbit and on-ground results indicates that a higher cooling efficiency exists in microgravity, including a smaller loss rate during the trapping and cooling process and lower ultimate temperature of laser-cooled atoms. Our progress has laid the technical foundations for future applications of cold atoms in space missions with operation times of the order of years.

关键词： laser cooling polarization-gradient cooling orbital microgravity space lab

发育性髋关节发育不良患者固液双相纤维增强软骨的力学性能

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中国组织工程研究 2025年第21期29卷 4439-4444页

作者：高永昌陈鹏飞陈瑱贤魏晶董哲李辉张志峰长安大学工程机械学院公路养护装备国家工程实验室陕西省西安市710064 内蒙古医科大学第二附属医院关节外科内蒙古自治区呼和浩特市010020 西安市红会医院关节外科陕西省西安市710054

背景:发育性髋关节发育不良由于髋臼、股骨头存在结构、大小及方向等方面的畸形,患者长时间活动或站立会引起腹股沟疼痛,如果得不到有效的治疗,患者的正常活动将严重受限。目的:基于FEBio建立具有固液双相纤维增强软骨的球-窝髋关节有... 详细信息

背景:发育性髋关节发育不良由于髋臼、股骨头存在结构、大小及方向等方面的畸形,患者长时间活动或站立会引起腹股沟疼痛,如果得不到有效的治疗,患者的正常活动将严重受限。目的:基于FEBio建立具有固液双相纤维增强软骨的球-窝髋关节有限元模型,探究发育性髋关节发育不良患者和正常人髋关节软骨的生物力学特性。方法:对1名发育性髋关节发育不良患者和1名正常志愿者进行髋关节建模,模型包含左盆骨、左股骨及附着其上的软骨。验证正常髋关节固液双相纤维增强软骨模型有效性后,建立髋关节发育不良患者髋关节有限元模型,对比两者在单腿站立时(2 130 N静态载荷)软骨的接触应力、流体压力、固相等效应力和流体支撑率的差异。结果与结论:(1)与正常髋关节相比,载荷加载完成后1 s(承载初期),发育性髋关节发育不良患者髋臼软骨出现明显的边缘接触,且峰值接触应力(3.86 MPa)和峰值流体压力(3.76 MPa)均大于正常髋关节软骨;(2)1 500 s(承载稳定)后,2个模型软骨峰值接触应力和峰值流体压力均减小,但发育性髋关节发育不良患者软骨接触位置由软骨边缘向中心移动,流体支撑率由97.41%下降到91.08%,正常髋关节软骨流体支撑率下降了0.58%,由95.24%下降到94.66%;(3)提示单腿站立生理载荷下,发育性髋关节发育不良患者软骨出现明显的边缘载荷,其峰值接触应力、流体压力和流体支撑率的下降幅度均大于正常软骨,考虑软骨的固液双相纤维增强特性对于评估髋关节发育不良患者髋关节软骨的生物力学性能、理解髋关节发育不良病理生理机制和制定术前计划具有重要的临床意义。

关键词：发育性髋关节发育不良软骨固液双相纤维增强有限元分析生物力学

Separation of tryptophan enantiomers with molecularly imprinted polypyrrole electrode column

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Chinese Chemical Letters 2010年第3期21卷 353-356页

作者： Chen, Zhi Dong wei, jing Xuan Wang, Wen Chang Kong, Yong Jiangsu Polytech Univ Fac Chem & Chem Engn Changzhou 213164 Peoples R China

In this study,we have fabricated molecularly imprinted polypyrrole(PPy) packed electrode columns and investigated their effects on separation of tryptophan(Trp) enantiomers by using potential *** results indicate that the imprinted PPy electrode columns could efficiently enhance the L-Trp uptake and separate Trp enantiomers effectively,implying the great potential for the enantioselective recognition of other amino acids enantiomers.

关键词： Polypyrrole Electrode column Molecular imprinting Tryptophan enantiomers

An easy route to exotic 9-epimers of 9-amino-(9-deoxy) cinchona alkaloids with(8S,9R) and(8R,9S)-configurations through two inversions of configuration

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Chinese Chemical Letters 2014年第4期25卷 557-560页

作者： jing-wei Wan Xue-Bing Ma Rong-Xing He Ming Li College of Chemistry and Chemical Engineering Southwest University

Four exotic chiral organocatalysts, 9-amino-（9-deoxy） cinchona alkaloids with （8S, 9R） and （8R, 9S）- configurations, were conveniently synthesized for the first time in 27-72% total yields through two conversion... 详细信息

关键词： Cinchona alkaloids 9-Amino-(9-deoxy) cinchona alkaloids Synthesis Inversion of configuration

Association of cholesterol with risk of pancreatic cancer:A meta-analysis

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World Journal of Gastroenterology 2015年第12期21卷 3711-3719页

作者： Jia Wang wei-jing Wang Long Zhai Dong-Feng Zhang Department of Epidemiology and Health Statistics Qingdao University Medical College

AIM: To evaluate the effect of dietary cholesterol and serum total cholesterol(TC) on the risk of pancreatic cancer. METHODS: A literature search was performed up to June 2014 in Pub Med, EMBASE, China National Knowledge Infrastructure and China Biology Medicalliterature database for relevant articles published in English or Chinese. Pooled relative risks(RRs) with 95% confidence intervals(CIs) were calculated with a random-effects model. RESULTS: We included 14 published articles with 439355 participants for dietary cholesterol, and 6 published articles with 1805697 participants for serum TC. For the highest vs lowest category of dietary cholesterol, the pooled RR(95%CI) of pancreatic cancer was 1.308(1.097-1.559). After excluding two studies(RR > 3.0), the pooled RR(95%CI) was 1.204(1.050-1.380). In subgroup analysis stratified by study design, the pooled RRs(95%CIs) were 1.523(1.226-1.893) for case-control studies and 1.023(0.871-1.200) for cohort studies. The association of dietary cholesterol with the risk of pancreatic cancer was significant for studies conducted in North America [1.275(1.058-1.537)] and others [2.495(1.565-3.977)], but not in Europe [1.149(0.863-1.531)]. No significant association [1.003(0.859-1.171)] was found between the risk of pancreatic cancer and serum TC. CONCLUSION: Dietary cholesterol may be associated with an increased risk of pancreatic cancer in worldwide populations, except for Europeans. The results need to be confirmed further.

关键词： Dietary cholesterol Serum total cholesterol Pancre

Advancing high-speed train gearbox durability:enhanced bearing load and contact stress through transition from helical to herringbone gears

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Railway Engineering Science 2024年第4期32卷 461-479页

作者： Hao Wu jing wei Pingbo Wu Fansong Li Yayun Qi School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610034China School of Mechanotronics and Vehicle Engineering Chongqing Jiaotong UniversityChongqing 400074China

High-speed trains typically utilize helical gear transmissions,which significantly impact the bearing load capacity and fatigue service performance of the gearbox *** paper focuses on the gearbox bearings,establishing dynamic models for both helical gear and herringbone gear transmissions in high-speed *** modeling particularly emphasizes the precision of the bearings at the gearbox's pinion and gear *** this model,a comparative analysis is conducted on the bearing loads and contact stresses of the gearbox bearings under uniform-speed operation between the two gear *** findings reveal that the helical gear transmission generates axial forces leading to severe load imbalance on the bearings at both sides of the large gear,and this imbalance intensifies with the increase in train ***,this results in a significant increase in contact stress on the bearings on one *** adoption of herringbone gear transmission effectively suppresses axial forces,resolving the load imbalance issue and substantially reducing the contact stress on the originally biased side of the *** study demonstrates that employing herringbone gear transmission can significantly enhance the service performance of high-speed train gearbox bearings,thereby extending their service life.

关键词： High-speed train Herringbone gear Helical gear Gearbox bearings Contact stress

Nanocavity enriched CuPd alloy with high selectivity for CO_(2) electroreduction toward C_(2)H_(4)

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Rare Metals 2024年第4期43卷 1513-1523页

作者： Ze-Yu Zhang Hai-Bin Wang Fei-Fei Zhang jing-wei Li Xin-Zhuo Hu Si-wei Yan Yi-Ming Bai Xun Zhang Gu-Rong Shen Peng-Fei Yin jing Yang Cun-Ku Dong jing Mao Hui Liu Xi-Wen Du Institute of New-Energy Materials School of Materials Science and EngineeringTianjin UniversityTianjin300350China

Electrocatalysis of CO_(2)reduction reaction is an effective way to convert CO_(2)into high value-added products,but the selectivity of Cu-based catalysts for C2+products needs to be improved due to the high energy barrier of C-C ***,a viable catalyst design strategy to decrease energy barrier of C-C coupling should be put ***,a nanocavity-enriched CuPd single atom alloy(CuPd SAA)catalyst is designed to promote CC coupling *** faradaic efficiency of CuPd SAA for ethylene and C_(2+)reaches 75.6%and 85.7%at-0.7 V versus reversible hydrogen electrode(RHE),*** on the results given by in situ characterization,the porous hollow structure dramatically increases the ratio of the linear-bond*CO,thus enhancing the faradaic efficiency for *** functional theory(DFT)calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C-C coupling,further improving the faradaic *** work provides a new idea for designing catalyst with high selectivity for ethylene.

关键词： Adsorption configuration C-C coupling CO_(2) electrocatalysis Ethylene Single atom alloy

Room-temperature thermoelectric materials: Challenges and a new paradigm

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Journal of Materiomics 2022年第2期8卷 427-436页

作者： Zhijia Han jing-wei Li Feng Jiang Jiating Xia Bo-Ping Zhang jing-Feng Li weishu Liu The Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing100083China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen518055China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices Southern University of Science and TechnologyShenzhenGuangdong518055China

Room-temperature thermoelectric materials provide promising solutions for energy harvesting from the environment,and deliver a maintenance-free power supply for the internet-of-things(IoTs).The currently available Bi_(2)Te_(3) family discovered in the 1950s,still dominates industrial applications,however,it has serious disadvantages of brittleness and the resource shortage of tellurium(1×10^(-3) ppm in the earth's crust).The novel Mg_(3)Sb_(2) family has received increasing attention as a promising alternative for room-temperature thermoelectric *** this review,the development timeline and fabrication strategies of the Mg 3 Sb 2 family are ***,an insightful comparison between the crystal-linity and band structures of Mg_(3)Sb_(2) and Bi_(2)Te_(3) is *** outlook is presented to discuss challenges and new paradigms in designing room-temperature thermoelectric materials.

关键词： Thermoelectric materials Mg_(3)Sb_(2) Bi_(2)Te_(3) Chemical bond engineering

Microstructure and stability of SrCe_(0.9)Yb_(0.1)O_(3-α)ceramics in H_(2)/H_(2)O/CO_(2)supercritical environment

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Rare Metals 2023年第5期42卷 1460-1464页

作者： Jia-Chen Wang wei-jing Wang Yu-Mei Ren Qing-He Yu College of Bioscience and Resources Environment Beijing University of AgricultureBeijing102206China School of Materials Science and Engineering Northeastern UniversityShenyang110819China National Engineering Research Center of Nonferrous Metals Materials and Products for New Energy China GRINM Group Co.LtdBeijing100088China GRIMAT Engineering Institute Co. LtdBeijing101407China General Research Institute for Nonferrous Metals Beijing100088China Great Wall Motor Company Limited Hebei Automotive Technology Innovation CenterBaoding071000China

SrCe_(0.9)Yb_(0.1)O_(3-α)ceramic samples were obtained by dry pressing and sintering of powders prepared by solid reaction method.X-ray diffraction(XRD)and the field-emission scanning microscope(SEM)were used for phase and microstructure analysis of *** results showed that the ceramics sintered in the air were pure perovskite *** results revealed that the average grain size of ceramics increased from 2 to 10μm when the sinteringtemperature increased from 1400 to 1500℃.

关键词： ceramics ceramic Microstructure