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Light(Science & Applications) 2018年第1期7卷 1063-1071页

作者： Min-song wei Fei Xing Zheng You Department of Precision Instrument Tsinghua UniversityBeijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering University of CaliforniaBerkeleyCA 94720USA

A small and weak target detection method is proposed in this work that outperforms all other methods in terms of real-time *** is the first time that two-dimensional(2D)images are processed using only one-dimensional1D structuring elements in a morphology-based approach,enabling the real-time hardware implementation of the whole image processing method.A parallel image readout and processing structure is introduced to achieve an ultra-low latency time on the order of nanoseconds,and a hyper-frame resolution in the time domain can be achieved by combining the row-by-row structure and the electrical rolling shutter *** results suggest that the expected target can be successfully detected under various interferences with an accuracy of 0.1 pixels(1σ)under the worst sky night test condition and that a centroiding precision of better than 0.03 pixels(1σ)can be reached for static *** real-time detection method with high robustness and accuracy is attractive for application to all types of real-time small target detection systems,such as medical imaging,infrared surveillance,and target measurement and tracking,where an ultra-high processing speed is required.

关键词： high robustness and accuracy 1D morphology-based approach row-by-row structure real-time detection method small and weak target detection and positioning

High Speed Sintering:Assessing the Influence of Energy Input on Microstructure and Mechanical Properties of Polyether Block Amide(PEBA)Parts

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Chinese Journal of Polymer Science 2024年第5期42卷 675-682,I0004,I0010页

作者： Jiang-Tao Sun Zhi-Yong Fan Yi-wei Mao wei Li wei Zhu Dao-Sheng Cai Qing-song wei State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430074China National Engineering Research Centre for High Efficiency Grinding Hunan UniversityChangsha410082China Wuhan EasyMFG Technology CO. LTDWuhan430074China

High speed sintering,a new powder-bed fusion additive manufacturing technology,utilizes infrared lights(IR)to intensely heat and melt polymer *** presence of defects such as porosity,which is associated with particle coalescence,is highly dependdent on the level of energy *** study investigate the influcence of energy input on porosity and its subsequent effects on the mechanical properties and microstructures of PEBA *** parts were manufactured with a variety of lamp powers,resulting in a range of energy input levels spanning from low to ***,they underwent testing using Archimedes’method,followed by tensile *** porosity,mechanical characteristics,and energy input exhibit a strong correlation;inadequate energy input was the primary cause of pore *** the reduced IR light power resulted in the following outcomes:porosity,ultimate tensile strength,and elongation of 1.37%,7.6 MPa,and 194.2%,*** the energy input was further increased,the porosity was reduced to as low as 0.05%and the ultimate tensile strength and elongation were increased to their peak values of 233.8%and 9.1 MPa,respectively.

关键词： High speed sintering Additive manufacturing Energy input Powder bed fusion PEBA

Thermodynamic Properties of Nanograin Boundary and Thermal Stability of Nanograin Structure

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Journal of Materials Science & Technology 2009年第4期25卷 475-478页

作者： Jun wei Xiaoyan song Qingchao Han Lingmei Li College of Materials Science and Engineering Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology Bcijing 100124 China

The thermal features of the nanograin boundary were described by a developed thermodynamic model. Using the nanocrystalline Cu as an example, the pressure, the bulk modulus, and the volume thermal expansion coef- ficient were calculated to characterize the thermodynamic properties of the grain boundaries on the nanoscale. Based on the parabola-type relationship between the excess free energy and the excess volume of the nanograin boundary, the thermal stability, as well as its evolution characteristics, was analyzed. The experimental re- sults of the temperature-varying grain growth in the nanocrystalline Cu, which exhibited the discontinuous nanograin growth behavior, verified the thermodynamic predictions. In addition, the quantitative relationships correlating the excess volume and the lattice expansion with the nanograin size were discussed.

关键词： Thermodynamic properties Thermal stability Nanograin growth Excess volume

Diagnosis and treatment of tubal endometriosis in women undergoing laparoscopy:A case series from a single hospital

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World Journal of Clinical Cases 2022年第33期10卷 12136-12145页

作者： Hai-Ning Jiao wei song wei-wei Feng Hua Liu Department of Obstetrics and Gynecology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China

BACKGROUND Tubal endometriosis(TEM)is a category of pelvic endometriosis(EM)that is characterized by ectopic endometrial glands and/or stroma within any part of the fallopian *** fallopian tubes may be a partial source of ovarian endometriosis(OEM).TEM is difficult to diagnose during surgery and is usually detected by pathology after *** To provide a clinical basis for the diagnosis and treatment of *** In this study,the data of 30 patients who underwent laparoscopic salpingectomy due to various gynecological diseases and had pathological confirmation of TEM at our hospital were retrospectively analyzed,and the clinical basis for the diagnosis and treatment of TEM was *** Among 1982 surgical patients,30 met the study *** those,6 patients had a history of infertility,12 patients had a history of artificial abortion,13 patients had a history of cesarean section,1 patient had a history of tubal ligation,4 patients had an intrauterine device,and 22 patients had *** patients(53.33%)conceived naturally and gave birth to healthy *** showed that only 2 patients had TEM without any other gynecological diseases,while the others all had simultaneous diseases,including 26 patients with EM at other pelvic *** The final diagnosis of TEM depends on pathological examination since there are no specific clinical *** rate of TEM combined with EM(especially OEM)was higher than that of other gynecological diseases,which indicates that TEM is related to OEM.

关键词： Endometriosis Fallopian tubes Ovary Laparoscopy Infertility Pathology

Online Optimization of Physical-Layer Secure Computation Offloading in Dynamic Environments

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China Communications 2020年第10期17卷 19-30页

作者： Chenshan Ren wei song Lizhi Zhao Xiaobing Zhao School of Information Engineering Minzu University of ChinaBeijing 100081China

Mobile edge computing can provide powerful computation services around the ***,given the broadcast nature of wireless transmissions,offloading the computation tasks via the uplink channels would raise serious security *** paper proposes an online approach to jointly optimize local processing,transmit power,and task offloading decisions without the a-priori knowledge of the dynamic *** proposed approach can guarantee the secure offloading and asymptotically minimize the time-average energy consumption of devices while maintaining the stability of the ergodic secrecy queues and task *** exploiting the Lyapunov optimization,the local processing,transmit power,and task offloading variables can be decoupled between time *** subproblems on local processing and computation offloading can be solved *** optimization and graph matching can be used to solve the computation offloading *** show that the performances of the proposed approach are superior to other popular approaches.

关键词： mobile edge computing physical-layer security Lyapunov optimization ergodic secrecy queue

Experimental investigation on degradation mechanism of membrane electrode assembly at different humidity under automotive protocol

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Chinese Journal of Chemical Engineering 2023年第4期56卷 70-79页

作者： Jiajun Wang Wenbin Yang Jiangtao Geng Zhigang Shao wei song Fuel Cell System and Engineering Laboratory Key Laboratory of Fuel Cells and Hybrid Power SourcesDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100039China

Humidity can affect the attenuation of MEA(membrane electrode assembly), however, the relationship between humidity and MEA decays is complex and ambiguous in realistic application. Herein, we design a simulating automotive protocol, performed on five single fuel cells under RH(relative humidity) 100%,RH 80%, RH 64%, and RH 40%, RH 10%, respectively, to study the relationship of MEA decays and humidity and suggest optimized humidity range to extend the durability. With the electrochemical impedance spectroscopy, cyclic voltammetry, X-ray fluorescence, X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, the four degradation mechanisms about catalyst layer, including Pt dissolution, Pt coarsening, carbon corrosion and ionomer degradation, are observed. Pt coarsening and carbon corrosion are accelerated by higher water content at high humidity. Ionomer degradation and Pt dissolution are enhanced in low humidity. With the linear sweep voltammetry, ion chromatography,nuclear magnetic resonance, tensile test and scan electron microscope, chemical and mechanical degradation in proton exchange membrane are all observed in these five fuels. Chemical degradation, characterized by membrane thinning and more fluoride loss, occurred markedly in RH 10%. Mechanical degradation, characterized by the non-uniformity thickness and bad mechanical properties, is more pronounced in RH 100%, RH 80%, RH 64%. These two degradations are in a moderate level in RH 40%. The research suggests that the RH range from 64% to 40% is conductive to mitigate the degradation of MEAs operated in automotive applications.

关键词： Fuel cell Simulating automotive protocol Relative humidity Degradation Membrane

Thiourea crystal growth kinetics,mechanism and process optimization during cooling crystallization

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Chinese Journal of Chemical Engineering 2024年第9期73卷 62-69页

作者： Zhongxiang Ding wei song Tong Zhou weihua Cui Changsong Wang State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing Tech UniversityNanjing 211816China Yifeng New Material Co. Ltd.Binzhou 256600China

In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine *** investigation delves into the growth kinetics and mechanisms governing thiourea crystals during the cooling crystallization *** fitting results indicate that the crystal growth rate coefficient,falls within the range of 10^(-7)to 10^(-8)m·s^(-1).Moreover,with decreasing crystallization temperature,the growth process undergoes a transition from diffusion-controlled to surface reaction-controlled,with temperature primarily influencing the surface reaction process and having a limited impact on the diffusion *** the crystal growth rate,and the diffusion-limited growth rate,at different temperatures,it is observed that the crystal growth process can be broadly divided into two *** temperatures above 25℃,1/qd(qd is diffusion control index)approaches 1,indicating the predominance of diffusion ***,at temperatures below 25℃,1/qd increases rapidly,signifying the dominance of surface reaction *** address these findings,process optimization was *** the high-temperature phase(35-25℃),agitation was increased to reduce the limitations posed by bulk-phase diffusion in the crystallization *** the low-temperature phase(25-15℃),agitation was reduced to minimize crystal *** optimized process resulted in a thiourea crystal product with a particle size distribution predominantly ranging from 0.7 to 0.9 mm,accounting for 84%of the *** study provides valuable insights into resolving the issue of excessive fine crystals in the thiourea crystallization process.

关键词： Thiourea Crystallization Growth kinetics Process optimization Diffusion Surface reaction

In situ facile loading of noble metal nanoparticles onpolydopamine nanospheres via galvanic replacement reaction for multifunctional catalysis

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Science China Chemistry 2017年第9期60卷 1236-1242页

作者： Fang wei Jian Liu Ya-Nan Zhu Xiao-Shi Wang Chang-Yan Cao wei-Guo song Laboratory of Molecular Nanostructures and Nanotechnology Institute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Noble metal nanoparticles(Pd,Ag,Pt,Au) with small and relatively uniform sizes were loaded on polydopamine nanospheres through in situ galvanic replacement reaction in aqueous *** additional reductant,surfactant or organic solvent was needed.X-ray photoelectron spectroscopy results revealed that the amount of quinone increased,while the amount of phenolic hydroxyl decreased on PDA nanospheres,indicating that the galvanic displacement reaction occurred between catechol groups and noble metal *** as-prepared PDA/Pd exhibited high catalytic activity and excellent stability in styrene ***,PDA spheres retains the photo-thermal effect to serve as a nano-sized heater to accelerate the catalytic reactions under near-infrared illumination.

关键词： polydopamine, noble metal, facile loading, multifunctional catalysis

Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics

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Chinese Journal of Chemical Engineering 2021年第10期34卷 132-144页

作者： Zhaoxiang Zhang Fei Guo wei song Xiaohong Jia Yuming Wang State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Joint Research Center for Rubber and Plastic Seals Tsinghua UniversityBeijing 100084China State Key Laboratory of Advanced Forming Technology&Equipment China Academy of Machinery Science&TechnologyBeijing 100044China Tianding Sealing Technology(Beijing)Co. Ltd.Beijing 100072China

Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been *** make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were *** types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate,and two types of correction methods are *** model was explained and verified using published experimental data of different polymer thermal reaction systems,and its effectiveness and wide adaptability were *** the given kinetic model,only one parameter needs to be *** proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process.

关键词： Thermal reaction Polymer processing Reaction kinetics Mathematical modeling Empirical correction

Multi-scale simulation model of air system based on cross-dimensional data transmission method

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Chinese Journal of Aeronautics 2023年第5期36卷 157-174页

作者： Lei WANG Junkui MAO song wei Longfei WANG Jin PAN AECC Aeroengine Control System Institute Wuxi 214063China College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The Secondary Air System(SAS)plays an important role in the safe operation and performance of *** traditional 1D-3D coupling method loses information when used for secondary air systems,which affects the calculation *** this paper,a Cross-dimensional Data Transmission method(CDT)from 3D to 1D is proposed by introducing flow field uniformity into the data ***,a uniformity index was established to quantify the flow field parameter distribution characteristics,and a uniformity index prediction model based on the locally weighted regression method(Lowess)was established to quickly obtain the flow field ***,an information selection criterion in 3D to 1D data transmission was established based on the Spearman rank correlation coefficient between the uniformity index and the accuracy of coupling calculation,and the calculation method was automatically determined according to the established ***,a modified function was obtained by fitting the ratio of the 3D mass-average parameters to the analytical solution,which are then used to modify the selected parameters at the 1D-3D *** a typical disk cavity air system as an example,the results show that the calculation accuracy of the CDT method is greatly improved by a relative 53.88%compared with the traditional 1D-3D coupling ***,the CDT method achieves a speedup of 2 to 3 orders of magnitude compared to the 3D calculation.

关键词： Air system Data transmission Disk cavity Multi-scale simulation 1D-3D coupling