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基于2018-2022年国家自然科学基金结题项目分析干细胞研究现状

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中国组织工程研究 2025年第19期29卷 4145-4150页

作者：蒋君张玢中国医学科学院医学信息研究所北京市100005

背景:目前大多数研究从国家自然科学基金资助论文和项目申请角度出发,对干细胞某一方面进行深入分析,或者验证某种评价方法,缺乏对干细胞领域国家自然科学基金已结题项目的全面分析。目的:了解2018-2022年干细胞领域国家自然科学基金结... 详细信息

背景:目前大多数研究从国家自然科学基金资助论文和项目申请角度出发,对干细胞某一方面进行深入分析,或者验证某种评价方法,缺乏对干细胞领域国家自然科学基金已结题项目的全面分析。目的:了解2018-2022年干细胞领域国家自然科学基金结题项目资助情况及研究热点,为后续研究提供参考。

关键词：干细胞国家自然科学基金聚类分析研究热点文献计量学

An Effective Numerical Procedure to Determine Saddle-Type Unstable Invariant Limit Sets in Nonlinear Systems

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Chinese Physics Letters 2012年第5期29卷 52-55页

作者： jiang jun State Key Laboratory of Strength and Vibration Xi’an Jiaotong UniversityXi’an 710049

A new technique that can efficiently approximate the attracting set of a nonlinear dynamical system is proposed under the framework of point mapping with the cell reference *** the aid of the approximated attracting set,the difficulties encountered by the PIM-triple method and bisection procedure in finding trajectories on the stable manifolds of chaotic saddles in basins of attraction and on basin boundaries can be overcome *** the basis of this development,an effective method to determine saddle-type invariant limit sets of nonlinear dynamical systems can be *** are presented for the purposes of illustration and to demonstrate the capabilities of the proposed method.

关键词： method. saddle attracting

Theoretical Study on the Structures and Electronic Spectra of the Derivatives of C_(60)-P-2,4,6-Triphenyl Borazinc

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1140-1144页

作者： jiang Qi-jun Department of Chemistry Xiaogan University Xiaogan 432000 China

The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy difference between HOMO and LUMO. It is found that the electron cloud on unoccupied frontier orbital mainly comes from the contribution of C60, while that on occupied frontier orbital mainly concentrates on the side chain. A long-lived charge-separated state may occur in the objective compounds.

关键词： derivatives of C60-P-2,4,6-triphenyl borazinc electronic spectra charge-separated state AM1

Nonlinear Out-of-Plane Mechanical Behaviours of Rectangular Woven Composite Flexible Skin Under Uniform Normal Pressure

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Acta Mechanica Solida Sinica 2023年第5期36卷 672-684页

作者： Di Chen jun-jiang Xiong School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China School of Transportation Science and Engineering Beihang UniversityBeijing 102206China

This paper seeks to investigate nonlinear out-of-plane mechanical behaviours of woven composite flexible skin(WCFS)through experimental and theoretical ***,quasi-static experiments are carried out on rectangular WCFSs with different aspect ratios under uniform normal pressure to measure out-of-plane deformation and failure ***,a new three-parameter geometric model is presented to describe 3D geometry of pressurized WCFS,and thus,a nonlinear mechanical model is deduced for depicting the relationship between pressure and out-of-plane *** application of the aforementioned models for experimental results shows that the new models have adequately and logically depicted deformation geometry and nonlinear mechanical characteristics.

关键词： Woven compositeﬂexible skin Nonlinear performance Uniform normal pressure Geometric model Mechanical model Aspect ratio

New constitutive relation for eddy viscosity models

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航空动力学报 2016年第10期31卷 2485-2492页

作者： jiang Li-jun GAO Ge Hunan Aviation Powerplant Research Institute Aero Engine Corporation of China School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics

A new turbulent constitutive relation was directly derived from Boussinesqs hypothesis and mixing length theory,and then implemented in the standard k-ε *** performance of this constitutive relation was validated in zero pressure gradient flat-plate boundary layer flow,fully-developed turbulent channel flow and separated flow in a plane asymmetric *** investigation demonstrated that,this new constitutive relation gave very accurate results in the former two basic cases and provided significant improvement in prediction of separated and reattachment points in the plane asymmetric *** and reattachment points at x/H =7.5and 29 were calculated accurately in comparison to experimental results,and the static pressure coefficient of 0.82 was very close to large eddy simulation *** results are very encouraging but further verification and extensive application of the new constitutive relation to other two-equation eddy viscosity model are needed.

关键词： constitutive relation turbulence model flat-plate flow channel flow separated flow

Monitoring micro-structural evolution during aluminum sintering and understanding the sintering mechanism of aluminum nanoparticles:A molecular dynamics study

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Journal of Materials Science & Technology 2020年第22期54卷 92-100页

作者： jun jiang Pengwan Chen Weifu Sun State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

In this work, molecular dynamics simulations have been performed to explore the structural evolution and underlying sintering mechanism of aluminum nanoparticles. The structural evolution during sintering was firstly monitored through radial distribution function and atomic migration, and the underlying sintering mechanism was further quantitatively characterized in terms of average displacement, mean squared distance(MSD), radius ratio(i.e., the ratio of the neck radius to the particle radius), shrinkage and radius of gyration, crystalline orientations, particle size, etc. Results show that the surface atoms of nanoparticles are more active than the internal atoms, favoring the mechanical rotation of nanoparticles during sintering. During the sintering process, average displacement, radius ratio and the shrinkage rate have undergone three stages with increasing the temperature:(1) a slow increase and subsequent abrupt hike after reaching the sintering temperature;(2) an almost plateau region over a wide span of temperature;(3) finally a sharp increase again after reaching the melting temperature. In contrast, MSD remains basically unchanged before melting, close to zero, followed by a sudden increase after melting temperature. Although the radius of gyration also experiences three stages, nonetheless it exhibits almost completely contrary trend. It has also been found that both sintering temperature and melting temperature demonstrate an almost linear increase with the increase of nanoparticle size ranging from4.0, 6.0, 8.0 to 10.0 nm in diameter. Finally, we also found that the particle direction has limited effect on neck growth during sintering.

关键词： Molecular dynamics simulation Aluminum nanoparticle Sintering Mechanical contact Microstructural evolution

Passive vibration control of truss-cored sandwich plate with planar Kagome truss as one face plane

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Science China(Technological Sciences) 2011年第5期54卷 1113-1120页

作者： GUO Xu jiang jun MOE Key Laboratory of Strength and Vibration Xi'an Jiaotong University Xi'an 710049 China

Kagome based high authority shape morphing structure is a kind of truss-cored sandwich metal plate with a planar Kagome truss as one of its face plane. The planar Kagome truss can achieve arbitrary in-plane nodal displacements with minimal internal resistance when its rods are deformed. Moreover, the in-plane deflection of the planar Kagome truss may induce the lateral deflection of the whole sandwich plate. In this paper, the feasibility to enhance the damping of the truss-cored sandwich plate through the replacement of a very small portion of rods in the planar Kagome truss by cylindrical viscoelastic dampers is exploited. The Biot model is chosen to simulate the behavior of the viscoelastic material in the dampers, and the fraction of axial modal strain energy of the rods in the planar Kagome truss is adopted as the index to decide the positions of the dampers. Through complex modal analysis and time-domain simulation, it is shown that the passive vibration control approach is very effective for the vibration reduction of this kind of truss-cored sandwich plates.

关键词： truss-cored sandwich plate passive vibration control cylindrical viscoelastic damper modal strain energy

Adsorption of Cr(Ⅲ) from acidic solutions by crop straw derived biochars

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Journal of Environmental Sciences 2013年第10期25卷 1957-1965页

作者： Jingjian Pan jun jiang Renkou Xu State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of Sciences College of Resource and Environment Nanjing Agricultural University

Cr（Ⅲ） adsorption by biochars generated from peanut, soybean, canola and rice straws is investigated with batch methods. Adsorption of Cr（Ⅲ） increased as pH rose from 2.5 to 5.0. Adsorption of Cr（Ⅲ） led to peak position shifts in the FFIR-PAS spectra of the biochars and made zeta potential values less negative, suggesting the formation of surface complexes between Cr^3＋ and functional groups on the biochars. The adsorption capacity of Cr（Ⅲ） followed the order： peanut straw char 〉 soybean straw char 〉 canola straw char 〉 rice straw char, which was consistent with the content of acidic functional groups on the biochars. The increase in Cr^3＋ hydrolysis as the pH rose was one of the main reasons for the increased adsorption of Cr（Ⅲ） by the biochars at higher pH values. Cr（llI） can be adsorbed by the biochars through electrostatic attraction between negative surfaces and Cr^3＋, but the relative contribution of electrostatic adsorption was less than 5%. Therefore, Cr（Ⅲ） was mainly adsorbed by the biochars through specific adsorption. The Langumir and Freundlich equations fitted the adsorption isotherms well and can therefore be used to describe the adsorption behavior of Cr（Ⅲ） by the crop straw biochars. The crop straw biochars have great adsorption capacities for Cr（Ⅲ） under acidic conditions and can be used as adsorbents to remove Cr（Ⅲ） from acidic wastewaters.

关键词： biochar crop straw Cr(Ⅲ) adsorption functional groups zeta potential

After announced carbon neutrality targets,more homework ahead for research

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Advances in Climate Change Research 2022年第2期13卷 157-158页

作者： Ke-jun jiang Energy Research Institute Beijing 100038China

By January 2022,more than 130 countries announced their carbon neutrality target by 2050 or before 2060,with more than 80%of global emissions,making it possible to achieve the Paris Agreement *** on the IEA(2021),COP26 climate pledges could help limit global warming to 1.8℃,but implementing them will be the *** is a big change by looking back the history of human being's action on climate change.

关键词： neutral looking carbon