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Science China(Technological Sciences) 2021年第10期64卷 2153-2165页

作者： TONGSH Chasen LIANG YiQi XIE Xu LI LinCai LIU Zhi du qing JIAO Kui State Key Laboratory of Engines Tianjin UniversityTianjin 300350China

The flow field is a pivotal part to manage the transport of water and gas in proton exchange membrane fuel ***,the reported water measurement methods(e.g.,X-ray and electrochemical impedance spectroscopy(EIS))cannot give a comprehensive understanding water distribution in the flow field,resulting in challenges in optimizing the channel design and enhancing fuel cell ***,we propose a water measurement method combining the X-ray radiography with EIS to investigate the effect of different operating conditions on the growth law and distribution of liquid water in parallel and serpentine flow *** attenuation coefficient of liquid water to X-ray is calibrated with constant tube-current and tubevoltage of X-ray ***,the parallel flow field with hydrophobic treatment is *** results show that the water accumulation of the parallel flow field is far more than the serpentine flow field,and the water content of the middle region is higher than that of other regions in the parallel flow ***,operating conditions(cathode inlet gas flow rate,inlet gas humidity,and back pressure)have little effect on the liquid water content of the middle region in the parallel flow *** polarization curve,EIS result,and X-ray radiography show that the performance and water drainage capacity of the hydrophobic parallel flow field are better than the normal one.

关键词： proton exchange membrane fuel cell water management flow field X-ray EIS

Local chemical ordering and its impact on radiation damage behavior of multi-principal element alloys

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Journal of Materials Science & Technology 2023年第4期135卷 13-25页

作者： Leqing Liu Xiongjun Liu qing du Hui Wang Yuan Wu Suihe Jiang Zhaoping Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China

Multi-principal element alloys(MPEAs)have attracted much attention as future nuclear materials due to their extraordinary radiation *** this work,we have elucidated the development of local chemical orderings(LCOs)and their influences on radiation damage behavior in the typical CrFeNi MPEA by hybrid-molecular dynamics and Monte Carlo *** was found that considerable LCOs consist-ing of the Cr-Cr and Ni-Fe short-range orders existed in the ordered configuration with optimized system *** modeling the accumulation cascades up to 1000 recoils,we revealed that the size of de-fect clusters and dislocation loops is smaller in the ordered configuration than those in the random one,although the former formed more Frenkel pairs(i.e.,self-interstitials and vacancies).In addition,the dis-tribution of dislocation loops is relatively more dispersed in the ordered configuration,and the stair-rod dislocations related to irradiation swelling are also smaller,implying that the existence of LCOs is con-ducive to enhancing radiation damage *** understand the underlying mechanism,the effects of LCOs on the formation and evolution of defects and radiation resistance were discussed from the aspects of atomic bonding,migration path,and energy of defect diffusion,which provides theoretical guidance for the design of MPEAs with enhanced radiation resistance.

关键词： Multi-principal element alloys Local chemical ordering Radiation damage Dislocation evolution Molecular dynamics simulation

Design of a Minimally Actuated Lower Limb Exoskeleton with Mechanical Joint Coupling

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Journal of Bionic Engineering 2022年第2期19卷 370-389页

作者： Hui Li Hongliu Yu Yingwei Chen Xinyi Tang duojin Wang Qiaoling Meng qing du Institute of Rehabilitation Engineering and Technology University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Engineering Research Center of Assistive Devices Institute of Rehabilitation Engineering and Technology Shanghai 200093China Key Laboratory of Neural-Functional Information and Rehabilitation Engineering of the Ministry of Civil Affairs Shanghai 200093China Department of Gastroenterology Xinhua Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghai 200092China Department of Rehabilitation Medicine Xinhua Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghai 200092China

Powered lower limb exoskeletons have traditionally used four or more powered joints to provide ambulation assistance for individuals with spinal cord *** with numerous powered joints commonly lost some excellent features of passive orthoses and further decreased utility due to added weight and increased control *** work adopts joints coupling mechanism to design a powered exoskeleton to minimize the number of actuated joints and control *** conventional powered exoskeletons,the joint-coupled-powered exoskeleton only has a single motor-actuated joint for each exoskeleton leg in conjunction with a unique knee coupled system to enable their users to walk,sit,and *** two types of joint coupled systems are designed,respectively,hip-knee coupled and knee-ankle *** joint-coupled-powered exoskeleton system allows a single actuator to power the hip motion,and allows activate knee motion through the coupled motions of the hip or *** specifically,when the mechanical coupled system is activated,the knee joint is unlocked,resulting in synchronized hip-knee or ankle-knee flexion and *** coupling mechanism is switched on and off at specific phases of the gait(the stance phase and the swing phase)to generate the desired *** research work proves that minimal actuated robotic systems with joint coupled could achieve safe and natural walking.

关键词： Powered exoskeleton Minimal actuation Joint coupling Single motor-actuated joint

Echinacoside Alleviates Cognitive Impairment in Cerebral Ischemia Rats through α7nAChR-Induced Autophagy

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Chinese Journal of Integrative Medicine 2022年第9期28卷 809-816页

作者： DING Ling YE Hong GU Long-dian du An-qing YUAN Xin-lu Department of Endocrinology and Metabolic Diseases Shanghai Pudong HospitalFudan University Pudong Medical CenterShanghai201399China

Objectives:To evaluate the effect of echinacoside(ECH)on cognitive dysfunction in post cerebral stroke model ***:The post stroke cognitive impairment rat model was created by occlusion of the transient middle cerebral artery(MCAO).The rats were randomly divided into 3 groups by a random number table:the sham group(sham operation),the MCAO group(received operation for focal cerebral ischemia),and the ECH group(received operation for focal cerebral ischemia and ECH50 mg/kg per day),with 6 rats in each group,The infarct volume and spatial learning were evaluated by triphenyl tetrazolium chloride staining and Morris water *** expression of α7 nAChR in the hippocampus was detected by *** contents of acetylcholine(ACh),malondialdehyde(MDA),glutathione(GSH),superoxide dismutase(SOD),activities of choline acetyltransferase(ChAT),acetylcholinesterase(AChE),and catalase(CAT)were evaluated by enzyme linked immunosorbent *** neural apoptosis and autophagy were determined by TUNEL staining and LC3 staining,***:ECH significantly lessened the brain infarct volume and ameliorated neurological deficit in infarct volume and water content(both Pducing TUNEL-positive cells and also enhanced autophagy in MCAO rats(all P<0.01).Conclusion:ECH treatment helped improve cognitive impairment by attenuating neurological damage and enhancing autophagy in MCAO rats.

关键词： cerebral ischemia cognitive impairment autophagy echinacoside cholinergic activity

Cenozoic potassic volcanic rocks from the Keluo and Wudalianchi volcanic districts,northeast China:origin from the new sub-continental lithospheric mantle(SCLM)metasomatized by potassium-rich fluids from delaminated lower crust

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Frontiers of Earth Science 2022年第4期16卷 989-1004页

作者： Fanchao MENG Yulu TIAN Yaoqi ZHOU Jiaqi LIU Gengchao ZUO qing du School of Geosciences China University of Petroleum(East China)Qingdao 266580China Pilot National Laboratory for Marine Science and Technology(qingdao) Qingdao 266061China Shandong Provincial Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

A series of Cenozoic potassium-rich volcanic rocks developed in the Xiaoguli-Keluo-Wudalianchi-Erkeshan districts,northeast *** source region and potassium-rich mechanism of the potassic rocks remain highly *** this paper,the major elements,trace elements,and Sr-Nd-Pb isotopes of the volcanic rocks in Keluo(KL)and Wudalianchi(WDLC)volcanic districts were analyzed *** results show that the volcanic rocks are characterized by high K2O(4.36wt.%-6.13wt.%),remarkable enrichment in LREEs and LILEs,as well as the strong fractionation of *** isotopic characteristics with high 87Sr/86Sr(0.704990-0.705272),low 143Nd/144Nd(0.512306-0.512417),low 206Pb/204Pb(16.546-17.135)and 207Pb/204Pb(15.002-15.783)of the volcanic rocks suggest the involvement of EM-I-type *** the basis of the geochemical characteristics,the potassium-rich volcanic magma originated from the new SCLM forming after delamination of the ancient SCLM,with metasomatism of the potassium-rich fluids released from the ancient lower crust during the Late *** proposed genetic model assumes the source which represented by a phlogopite-bearing garnet peridotite(with modal garnet in the range of 2%-10%)experienced very low degrees(i.e.,~0.5)of partial *** Cenozoic,the lithosphere in northeast China was affected by the extension and decompression of continental rift,and the metasomatized SCLM underwent low degree partial melting,resulting in the formation of potassium-rich primitive basaltic magma.

关键词： northeast China Keluo-Wudalianchi volcanic districts Cenozoic potassic volcanic rocks petrogenesis sub-continental lithospheric mantle

PLQ:An Efficient Approach to Processing Pattern-Based Log Queries

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Journal of Computer Science & Technology 2022年第5期37卷 1239-1254页

作者： Jia Chen Peng Wang Fan Qiao Shi-qing du Wei Wang School of Computer Science Fudan UniversityShanghai 200082China

As software systems grow more and more complex,extensive techniques have been proposed to analyze the log data to obtain the insight of the system ***,during log data analysis,tedious manual efforts are paid to search interesting or informative log patterns from a huge volume of log data,named pattern-based *** existing log management tools and DMBS systems can also support pattern-based queries,they suffer from a low *** deal with this problem,we propose a novel approach,named PLQ(Pattern-based Log Query).First,PLQ organizes logs into disjoint chunks and builds chunk-wise bitmap indexes for log types and attribute ***,based on bitmap indexes,PLQ finds candidate logs with a set of efficient bit-wise ***,PLQ fetches candidate logs and validates them according to the queried *** experiments are conducted on real-life *** to experimental results,compared with existing log management systems,PLQ is more efficient in querying log patterns and has a higher pruning rate for filtering irrelevant ***,in PLQ,since the ratio of the index size to the data size does not exceed 2.5%for log datasets of different sizes,PLQ has a high scalability.

关键词： pattern query log analysis bitmap index log pattern

Integration of rolling circle amplification and cationic conjugated polymer for the homogeneous detection of single nucleotide polymorphisms

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Chinese Science Bulletin 2011年第31期56卷 3247-3252页

作者： TANG ZhiYuan CHENG YongQiang du qing ZHANG HongXia LI ZhengPing Key Laboratory of Medicine Chemistry and Molecular Diagnosis Ministry of Education College of Chemistry and Environment Science HebeiUniversity Baoding 071002 China

A novel, homogeneous and sensitive assay for the detection of single nucleotide polymorphisms (SNPs) by integration of rolling circle amplification (RCA) and cationic conjugated polymer (CCP) has been developed and tested. Mutant DNA serves as the template for specifically circularizing a padlock probe (PLP) with a sequence that is complementary to the mutant DNA. Afterwards, the mutant DNA directly acts as the primer to initiate the RCA reaction in the presence of phi29 DNA polymerase that generates a long, tandem single-strand DNA product. during the RCA reaction, fluorescein-labeled duTPs are incorporated into the RCA products. When the CCP is introduced, efficient FRET from CCP to fluorescein occurs as a result of the strong electrostatic interactions between the CCP and the DNA produced by RCA. The wild-type DNA contains a single base mismatch with PLP with the result that the PLP is not circularized, RCA is not triggered and inefficient FRET results. By measuring the change of the emission intensities of CCP and fluorescein, it was possible to detect the SNP in a homogeneous manner. The method is sensitive and specific enough to detect 0.1 pmol/L mutant DNA and to determine a mutant allele frequency as low as 2.0%.

关键词：单核苷酸多态性多态性检测共轭聚合物阳离子同质化滚环一体化 DNA序列

A Simplified Nonlinear Model of Vertical Vortex-Induced Force on Box Decks for Predicting Stable Amplitudes of Vortex-Induced Vibrations

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Engineering 2017年第6期3卷 854-862页

作者： Le-Dong Zhu Xiao-Liang Meng Lin-qing du Ming-Chang Ding State Key Laboratory of Disaster Reduction in Civil Engineering & Department of Bridge Engineering College of Civil Engineering & Key Laboratory for Wind Resistance Technology of Bridges of Ministry of Transport Tongji University Shanghai 200092 China Shanghai Urban Construction Municipal Engineering (Croup) Co. Ltd. Shanghai 200065 China Tongji Architectural Design (Group) Co. Ltd. Shanghai 200092 China Highway Planning Survey Design and Research Institute Sichuan Provincial Transport Department Chengdu 610041 China

Wind-tunnel tests of a large-scale sectional model with synchronous measurements of force and vibration responses were carried out to investigate the nonlinear behaviors of vertical vortex-induced forces （VIFs） on three typical box decks （i.e., fully closed box, centrally slotted box, and semi-closed box）. The mechanisms of the onset, development, and self-limiting phenomenon of the vertical vortex-induced vibration （VlV） were also explored by analyzing the energy evolution of different vertical VIF components and their contributions to the vertical VIV responses. The results show that the nonlinear components of the vertical VIF often differ from deck to deck; the most important components of the vertical VIF, governing the stable amplitudes of the vertical VIV responses, are the linear and cubic components of velocity contained in the self-excited aerodynamic damping forces. The former provides a constant negative damping ratio to the vibration system and is thus the essential power driving the development of the VIV amplitude, while the latter provides a positive damping ratio proportional to the square of the vibration velocity and is actually the inherent factor making the VIV amplitude self-limiting. On these bases, a universal simplified nonlinear mathematical model of the vertical VIF on box decks of bridges is presented and verified in this paper; it can be used to predict the stable amplitudes of the vertical VIV of long-span bridges with satisfactory accuracy.

关键词： Box deck of bridge Vertical vortex-induced vibration Vertical vortex-induced force Simplified nonlinear model Wind-tunnel test Large-scale sectional model Synchronous measurement of force and vibration

Application progress of small-scale proton exchange membrane fuel cell

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Energy Reviews 2023年第2期2卷 1-12页

作者： Zixuan Wang Zhi Liu Linhao Fan qing du Kui Jiao State Key Laboratory of Engines Tianjin University135 Yaguan RoadTianjin300350China National Industry-Education Platform of Energy Storage Tianjin University135 Yaguan RoadTianjin300350China

Proton exchange membrane fuel cells(PEMFCs)are promising power sources owing to their high-power/energy densities and low pollution *** the increasing demand for electricity for various low-power devices,small-scale storage of electricity encountered bottle-neck,which provides new opportunities for *** to the high specific energy of PEMFCs,the utilization of this technology for small-scale applications has recently attracted significant *** recent years,considerable effort has been made to advance PEMFC technology and applications,especially in the small-scale PEMFC commercial *** current review provides a holistic overview of the cutting-edge developments of small-scale PEMFCs in the transportation,stationary,and portable power generator *** particular,we examine current literature on the development of small-scale PEMFCs and discuss the operating complexity of PEMFC systems for different ***,we provide a forwardlooking perspective on the strategies for small-scale high-specific-power PEMFC systems.

关键词： Small-scale proton exchange membrane fuel cell Transportation Stationary Portable Applications

Review on regulation of MnS in non-qquenched and tempered steel

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Journal of Iron and Steel Research International 2024年第4期31卷 779-789页

作者： Guo-xing Qiu qing du Feng Lu De-jun Miao Yong-kun Yang Xiao-ming Li School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina Laigang Technique Center Shandong Iron and Steel Group Co.Ltd.Jinan 271104ShandongChina

An overview of the current research status and control methods of MnS in non-quenched and tempered steel was *** a low-melting plastic inclusion,the morphology and distribution of MnS were influenced by various production ***,control of MnS is a systematic problem that must be integrated into the entire production *** on the production process,the factors affecting the morphology and distribution of MnS in steel were *** effects of oxygen activity,manganese,sulfur,and some alloys on MnS inclusion precipitation were summarized,mainly including MnS modification treatment and oxygen-sulfide composite precipitation *** is believed that MnS precipitates during the solidification process of steel,and controlling the solidification cooling rate could effectively regulate the size and morphology of MnS,avoiding the precipitation of ***,by changing the deformation rate,deformation amount,deformation temperature during the hot deformation process,and heating time and temperature during heat treatment,the distribution and morphology of MnS could be *** the fine control of the above process parameters,the number of II-MnS in steel could be effectively reduced,and their morphology could be improved,thereby enhancing the performance of non-quenched and tempered steel and promoting its wider ***,applying laboratory research results to industrial production is an important direction for future research efforts in this field.

关键词： MnS Non-quenched and tempered steel Control technology Process parameter Morphology Distribution