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Three-dimensional computed tomography mapping of posterior malleolar fractures

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World Journal of Clinical Cases 2020年第1期8卷 29-37页

作者： Qi-Hang Su Juan Liu Yan Zhang jun tan Mei-jun Yan Kai Zhu jin Zhang Cong Li Department of Orthopedics Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of the First Clinical Medical School Shanxi Medical UniversityTaiyuan 030000Shanxi ProvinceChina Department of Orthopedics Pinghu Second People’s HospitalPinghu 314200Zhejiang ProvinceChina Department of Trauma Surgery Shanghai East HospitalTongji University School of MedicineShanghai 200120China

BACKGROUND Posterior malleolar fractures have been reported to occur in<40%of ankle *** To reveal the recurrent patterns and characteristics of posterior malleolar fractures by creating fracture maps of the posterior ... 详细信息

BACKGROUND Posterior malleolar fractures have been reported to occur intanding of ankle fracture as well as increase opportunities for follow-up research and aid clinical decision-making.

关键词： Three-dimensional imaging Maps Ankle fractures Computed tomography

Towards automatic freeform optics design: coarse and fine search of the three-mirror solution space

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Light(Science & Applications) 2021年第4期10卷 660-670页

作者： Benqi Zhang Guofan jin jun Zhu State Key Laboratory of Precision Measurement Technology and Instruments Departm ent of Precision InstrumentTsinghua UniversityBeijing 100084China

Design of an optical system,whether classic or novel,in the past or the present,requires significant effort from the *** addition to design methods and theories,the designer’s skills and experience in optical system design are particularly important,which may require years of practice to *** diversity and variety of results are limited because of the difficulty,time,and labor costs *** this article,we propose an automatic design method for freeform optics that can achieve a diverse range of three-mirror *** optical specifications and the design constraints are the only inputs required,and a variety of results can be obtained *** output results have various structures and various optical power distributions with high imaging *** implementing the design method,designers can not only realize an overview of the solution space of the three-mirror freeform system,but can also focus on specific designs.

关键词： mirror optics system

Distributed Penalized Modal Regression for Massive Data

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Journal of Systems Science & Complexity 2023年第2期36卷 798-821页

作者： jin jun LIU Shuangzhe MA Tiefeng College of Mathematical Sciences Yangzhou UniversityYangzhou 225002China Faculty of Science and Technology University of CanberraACT 2601Australia School of Statistics Southwestern University of Finance and EconomicsChengdu 661130China

Nowadays,researchers are frequently confronted with challenges from massive data computing by a number of limitations of computer primary *** regression(MR)is a good alternative of the mean regression and likelihood based methods,because of its robustness and high *** this end,the authors extend MR to massive data analysis and propose a computationally and statistically efficient divide and conquer MR method(DC-MR).The major novelty of this method consists of splitting one entire dataset into several blocks,implementing the MR method on data in each block,and deriving final results through combining these regression results via a weighted average,which provides approximate estimates of regression results on the entire *** proposed method significantly reduces the required amount of primary memory,and the resulting estimator is theoretically as efficient as the traditional MR on the entire data *** authors also investigate a multiple hypothesis testing variable selection approach to select significant parametric components and prove the approach possessing the oracle *** addition,the authors propose a practical modified modal expectation-maximization(MEM)algorithm for the proposed *** studies on simulated and real datasets are conducted to assess and showcase the practical and effective performance of our proposed methods.

关键词： Asymptotic distribution divide and conquer massive data modal regression multiple hypothesis testing

Size effects on the mixed modes and defect modes for a nano-scale phononic crystal slab

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Applied Mathematics and Mechanics(English Edition) 2023年第1期44卷 21-34页

作者： jun jin Ningdong HU Hongping HU Department of Mechanics School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment Huazhong University of Science and TechnologyWuhan 430074China

The size-dependent band structure of an Si phononic crystal(PnC)slab with an air hole is studied by utilizing the non-classic wave equations of the nonlocal strain gradient theory(NSGT).The three-dimensional(3D)non-classic wave equations for the anisotropic material are derived according to the differential form of the *** on the the general form of partial differential equation modules in COMSOL,a method is proposed to solve the non-classic wave *** bands of the in-plane modes and mixed modes are *** in-plane size effect and thickness effect on the band structure of the PnC slab are *** is found that the thickness effect only acts on the mixed *** relative width of the band gap is widened by the thickness *** effects of the geometric parameters on the thickness effect of the mixed modes are further studied,and a defect is introduced to the PnC supercell to reveal the influence of the size effects with stiffness-softening and stiffness-hardening on the defect *** study paves the way for studying and designing PnC slabs at nano-scale.

关键词： band structure phononic crystal(PnC) nonlocal strain gradient theory(NSGT) size effect

Numerical Investigation of the Load Distribution between the Main Blade and the Splitter Blade in a High-Loading Centrifugal Compressor

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Journal of Thermal Science 2022年第5期31卷 1682-1695页

作者： OU jun jin Donghai GUI Xingmin Aeroengine Simulation Research Center School of Energy and Power EngineeringBeihang UniversityBeijing100191China Jiangxi Research Institute of Beihang University Nanchang330096China

In the traditional design of the centrifugal compressor,the splitter blade and the main blade always keep the same ***,to enable high efficiency of the high-loading centrifugal compressor,the matching of design parameters of the splitter blade and the main blade needs to be *** this paper,the influence of the load distribution between the main blade and the splitter blade on the aerodynamic performance,the flow field,and the internal vortices of a high-loading centrifugal compressor were studied by means of CFD *** cases with different values of the variable CR which is defined as the load-ratio of splitter blade to main blade were set *** each case,the splitter blade and the main blade were shaped according to different laws of circulation distribution(_(r)V_(u))while the average circulation of the splitter blade and the main blade at any meridional position were consistent with that of the *** results showed that a proper reduction of the load-ratio of splitter blade to main blade is beneficial to suppress the leakage vortex of the splitter blade and reduce the scale of the wake in the channel near the suction-side of the splitter blade,which consequently improves the flow uniformity at the impeller outlet and enhances the aerodynamic performance of both the stage and the *** stage isentropic efficiency of the optimal case was found to be 0.7%higher than that of the prototype and the stage total pressure ratio was also *** optimal value of CR,which in this investigation is 94%,is supposed to be the result of the trade-off between the development of the wake and the leakage vortices in adjacent two *** optimization of the load distribution between the main blade and the splitter blade provides an opportunity to further improve the high-loading centrifugal compressor performance.

关键词： high-loading centrifugal compressor load distribution performance flow uniformity wake leakage vortex

Preparation and performance of dye-sensitized solar cells based on ZnO-modified TiO_2 electrodes

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International Journal of Minerals,Metallurgy and Materials 2010年第1期17卷 92-97页

作者： Sheng-jun Li Yuan Lin Wei-wei tan jing-bo Zhang Xiao-wen Zhou jin-mao Chen Zeng Chen College of Physics and Electrics He＇nan University Kaifeng 475004 China Beijing National Laboratory for Molecular Sciences Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The ZnO-modified TiO2 electrode was prepared by adding Zn（CH3COO）2·2H2O to the TiO2 colloid during the sol-gel production process, and was used in dye-sensitized solar cells （DSCs）. The open circuit voltage （Voc） and fill factor （if） of the cells were improved sig- nificantly. The performances of the ZnO-modified TiO2 electrode such as dark current, transient photocurrent, impedance, absorption spectra, and fiat band potential （Vfb） were investigated. It is found that the interface charge recombination impedance increases and Vfb shifts about 200 mV toward the cathodic potential. The effect mechanism of ZnO modification on the performance of DSCs may be that ZnO occupies the surface states of the TiO2 film.

关键词： dye-sensitized solar cells TiO2 electrode modification photoelectrochemical properties

Microstructure and mechanical properties of 2219 aluminum alloy VPTIG welds during cyclic thermal treatment

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Rare Metals 2022年第10期41卷 3539-3545页

作者： Di-Yao Su Hui-jin jin Su-jun Wu School of Materials Scienceand Engineering Beihang UniversityBeijing 100191China

In this study,the effect of the cyclic thermal treatment(CTT) on the microstructure and mechanical properties of the 2219 Al alloy welds fabricated using variable polarity tungsten inert gas(VPTIG) arc welding method were investigated by optical microscope(OM),transmission electron microscope(TEM),and low-temperature tensile tests,with emphasis on precipitation evolution and property variation in different areas of the *** of the microhardness profile across the weld reveals that there are maximum and minimum hardness values in the heat-affected zone(HAZ) adjacent to the fusion boundary(FB).It is found that the maximum hardness value increases with the temperature cycles of the cyclic thermal treatment due to the formation of GuinierPreston(GP) zones,while the microhardness at other positions remains *** results show that the CCT results in an increase in the yield strength,but a decrease in the ductility of the weld joint.

关键词： 2219 aluminum alloy VPTIG weld Microstructure Microhardness

Pyrene partition behavior to the NOM:Effect of NOM characteristics and its modification by ozone preoxidation

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Frontiers of Environmental Science & Engineering 2009年第1期3卷 56-61页

作者： jin GUO jun MA School of Environmental and Energy Engineering Beijing University of TechnologyBeijing 100124China School of Municipal and Environmental Engineering Harbin Institute of TechnologyHarbin 150090China

Hydrophobic organic contaminants(HOCs)—pyrene,and natural organic matters(NOM)from different sources were taken as the test compounds to investigate the impact of physicochemical characteristics of NOM on HOCs’partition to the NOM in this *** effects of solution property,NOM characteristics,and modification by ozone preoxidation on pyrene partition to NOM were systematically *** to the fluorescence quenching method,the partition coefficient K_(oc) of pyrene to NOM was calculated,which was found to have a great relationship with the aromatic structures and hydrophobic functional groups of the *** NOM characteristic modification corresponding to solution property could influence the interactions between the NOM and *** could destroy the aromatic or hydrophobic structures of the NOM and decrease K_(oc) of pyrene.

关键词： natural organic matters(NOM) pyrene partition coefficient ozone

3D-Printed Monolith Metallic Ni-Mo Electrodes for Ultrahigh Current Hydrogen Evolution

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Energy & Environmental Materials 2024年第5期7卷 224-233页

作者： Yanran Xun Hongmei jin Yuemeng Li Shixiang Zhou Kaixi Zhang Xi Xu Win Jonhson Shuai Chang Teck Leong tan jun Ding Department of Materials Science and Engineering National University of SingaporeSingapore 117574Singapore Institute of High Performance Computing(IHPC) Agency for ScienceTechnology and Research(A^(*)STAR)1 Fusionopolis Way#16-16 ConnexisSingapore 138632Singapore Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this work,we reported a series of monolithic 3D-printed Ni-Mo alloy electrodes for highly efficient water splitting at high current density(1500 mA cm^(-2))with excellent stability,which provides a solution to scale up Ni-Mo catalysts for HER to industry *** possible Ni-Mo metal/alloy phases were achieved by tuning the atomic composition and heat treatment procedure,and they were investigated through both experiment and simulation,and the optimal NiMo phase shows the best *** functional theory(DFT)calculations elucidate that the NiMo phase has the lowest H2O dissociation energy,which further explains the exceptional performance of *** addition,the microporosity was modulated via controlled thermal treatment,indicating that the 1100℃sintered sample has the best catalytic performance,which is attributed to the high electrochemically active surface area(ECSA).Finally,the four different macrostructures were achieved by 3D printing,and they further improved the catalytic *** gyroid structure exhibits the best catalytic performance of driving 500 mA cm^(-2)at a low overpotential of 228 mV and 1500 mA cm^(-2)at 325 mV,as it maximizes the efficient bubble removal from the electrode surface,which offers the great potential for high current density water splitting.

关键词： 3D-printed electrode Ni-Mo catalyst phase tuning ultra-high current density HER