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Characterization of a Novel Rice Metallothionein Gene Promoter:Its Tissue Specificity and Heavy Metal Responsiveness

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Journal of Integrative Plant Biology 2010年第10期52卷 914-924页

作者： Chun-juan Dong Yun Wang shi-shi Yu Jin-Yuan Liu Laboratory of Molecular Biology and MOE Laboratory of Protein Science School of Life Sciences Tsinghua University Beijing 100084China

The rice （Oryza sativa L.） metallothionein gene OsMT-I-4b has previously been identified as a type I MT gene. To elucidate the regulatory mechanism involved in its tissue specificity and abiotic induction, we isolated a 1 730 bp fragment of the OsMT-I-4b promoter region. Histochemical /^-glucuronidase （GUS） staining indicated a precise spacial and temporal expression pattern in transgenic Arabidopsis. Higher GUS activity was detected in the roots and the buds of flower stigmas, and relatively lower GUS staining in the shoots was restricted to the trichomes and hydathodes of leaves. No activity was observed in the stems and seeds. Additionally, in the root of transgenic plants, the promoter activity was highly upregulated by various environmental signals, such as abscisic acid, drought, dark, and heavy metals including Cu2＋, Zn2~, Pb2~ and Al3＋. Slight induction was observed in transgenic seedlings under salinity stress, or when treated with Co2＋ and Cd2＋. Promoter analysis of 5＇-deletions revealed that the region -583/-1 was sufficient to drive strong GUS expression in the roots but not in the shoots. Furthermore, deletion analysis indicated important promoter regions containing different metal- responsive c/s-elements that were responsible for responding to different heavy metals. Collectively, these findings provided important insight into the transcriptional regulation mechanisms of the OsMT-I- 4b promoter, and the results also gave us some implications for the potential application of this promoter in plant genetic engineering.

关键词： Mechanization Mechanics Genes Heavy metals Imports Shoots Plants Planting Metals Transgenics

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Numerical and Experimental Investigation on the Performance of Lean Burn Catalytic Combustion for Gas Turbine Application

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Journal of Thermal Science 2015年第2期24卷 185-193页

作者： juan YIN Yi-wu WENG jun-qiang ZHU Institute of Engineering Thermophysics Chinese Academy of Sciences Shanghai Jiao Tong University

This manuscript presents our numerical and experimental results regarding the performance characteristics of lean bum catalytic combustion for gas turbine application. The reactant transport was assumed to be controlled by both bulk diffusion as well as surface kinetics, implemented by means of an approximate reaction rate equation and empirical coefficients to incorporate reaction mechanism. Experimental and numerical results were compared to examine the effects of methane mole fraction, inlet temperature, operating pressure, velocity and hydrogen spe- cies on combustion intensity. The results indicate that inlet temperature is the most significant parameter that im- pacts operation of the catalytic combustor and the most effective methods for improving the methane conversion are increasing the inlet temperature and increasing the methane mole fraction. Simulations from ID heterogene- ous plug flow model can capture the trend of catalytic combustion and describe the behavior of the catalytic mo- nolith in detail. The addition of hydrogen will provide heat release by the exothermie combustion reaction so that the reactants reach a temperature at which methane oxidation can light-off.

关键词： Lean burn catalytic combustion performance gas turbine

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Construction of n-sided polygonal spline element using area coordinates and B-net method

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Acta Mechanica Sinica 2010年第5期26卷 685-693页

作者： juan Chen Chong-jun Li Wan-Ji Chen School of Mathematical Sciences Dalian University of Technology 116024 Dalian China State Key Laboratory for Structural Analysisof Industrial Equipment Dalian University of Technology116024 Dalian China Institute for Structural Analysis of Aerocraft Shenyang Institute of Aeronautical Engineering110136 Shenyang China

In general, triangular and quadrilateral elements are commonly applied in two-dimensional finite element methods. If they are used to compute polycrystalline materials, the cost of computation can be quite significant. Polygonal elements can do well in simulation of the materials behavior and provide greater flexibility for the meshing of complex geometries. Hence, the study on the polygonal element is a very useful and necessary part in the finite element method. In this paper, an n-sided polygonal element based on quadratic spline interpolant, denoted by PS2 element, is presented using the triangular area coordinates and the B-net method. The PS2 element is conforming and can exactly model the quadratic field. It is valid for both convex and non-convex polygonal element, and insensitive to mesh distortions. In addition, no mapping or coordinate transformation is required and thus no Jacobian matrix and its inverse are evaluated. Some appropriate examples are employed to evaluate the performance of the proposed element.

关键词： Finite element method n-sided polygonalelement - Bivariate spline interpolation The second ordercompleteness

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Two lower order nonconforming quadrilateral elements for the Reissner-Mindlin plate

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Science China Mathematics 2008年第11期51卷 2097-2114页

作者： HU jun shi ZhongCi LMAM and School of Mathematical Sciences Peking UniversityBeijing 100871China Institute of Computational Mathematics Chinese Academy of SciencesBeijing 100080China

This paper generalizes two nonconforming rectangular elements of the Reissner-Mindlin plate to the quadrilateral mesh. The first quadrilateral element uses the usual conforming bilinear element to approximate both components of the rotation, and the modified nonconforming rotated Q1 element enriched with the intersected term on each element to approximate the displacement, whereas the second one uses the enriched modified nonconforming rotated Q1 element to approximate both the rotation and the displacement. Both elements employ a more complicated shear force space to overcome the shear force locking, which will be described in detail in the introduction. We prove that both methods converge at optimal rates uniformly in the plate thickness t and the mesh distortion parameter in both the H1-and the L2-norms, and consequently they are locking free.

关键词： Reissner-Mindlin plate bilinear element rotated Q 1 element locking-free 65N30

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Effect of cerium on microstructure,eutectic carbides and Laves phase in electroslag remelted 15Cr-22Ni-1Nb austenitic heat-resistant steel

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Journal of Iron and Steel Research International 2023年第2期30卷 338-349页

作者： Xin Zhu Cheng-bin shi shi-jun Wang Peng Lan Jing Li State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing(USTB)Beijing100083China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China

The dendrites,eutectic carbides,Laves phase and microsegregation of alloying element in electroslag remelted 15Cr-22Ni-1Nb austenitic heat-resistant steel with varying cerium contents were *** liquidus and solidus temperatures of the steel were determined to reveal the effect of cerium on solidification temperature interval and local solidification time of the *** secondary dendrite arm spacing decreases from 57.10 to 40.18μm with increasing the cerium content from 0 to 0.0630 wt.%.The eutectic NbC and Laves phase in as-cast ingots exhibit blocky and honeycomb morphology,*** area fractions and sizes of eutectic NbC and Laves phase in as-cast ingots decrease with the increase in cerium *** atomic percentage of Laves phase-forming element(Ni,Nb,Cr,Mo and Si)decreases with the increase in cerium content of the *** microsegregation of Mo,Ni,Si,Cr and Nb decreases with increasing the cerium content,which is favorable to reducing both the amount and sizes of eutectic NbC and Laves phase in as-cast *** solidification temperature interval and local solidification time of the steel decrease as the cerium content is increased from 0 to 0.0630 wt.%,which inhibits the growth of dendrites,eutectic NbC and Laves phase.

关键词： Heat-resistant steel Rare earth cerium Eutectic NbC Laves phase Microsegregation Solidification characteristics

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Nanolubricant additives: A review

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Friction 2021年第5期9卷 891-917页

作者： jun ZHAO Yiyao HUANG Yongyong HE Yijun shi College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Division of Machine Elements LuleåUniversity of TechnologyLuleå97187Sweden

Using nanoadditives in lubricants is one of the most effective ways to control friction and wear,which is of great significance for energy conservation,emission reduction,and environmental *** the scientific and technological development,great advances have been made in nanolubricant additives in the scientific research and industrial *** review summarizes the categories of nanolubricant additives and illustrates the tribological properties of these *** on the component elements of nanomaterials,nanolubricant additives can be divided into three types:nanometal-based,nanocarbon-based,and nanocomposite-based *** dispersion stabilities of additives in lubricants are also discussed in the review *** affecting factors and effective dispersion methods have been investigated in ***,the review summarizes the lubrication mechanisms of nanolubricant additives including tribofilm formation,micro-bearing effect,self-repair performance,and synergistic *** addition,the challenges and prospects of nanolubricant additives are proposed,which guides the design and synthesis of novel additives with significant lubrication and antiwear properties in the future.

关键词： nanolubricant additive dispersion stability tribological properties lubrication mechanism

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Neural learning control for discrete-time nonlinear systems in pure-feedback form

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Science China(Information Sciences) 2022年第2期65卷 124-138页

作者： Min WANG Haotian shi Cong WANG jun FU School of Automation Science and Engineering South China University of Technology State Key Laboratory of Synthetical Automation for Process Industries Northeastern University School of Control Science and Engineering Shandong University

This study focuses on state-feedback and output-feedback neural learning control problems for discrete-time nonlinear systems in the pure-feedback form. First, an extended result for the exponential stability for a class of discrete-time linear time-varying(LTV) systems with n-step delays is proposed to verify the exponential convergence of estimated weights. Subsequently, both state-feedback and outputfeedback adaptive neural network(NN) controllers are constructed by combining the classical n-step and n-step input-output predictors. After ensuring convergence of the system output to a recurrent reference signal, the radial basis function subvector of NN is verified to satisfy the persistent exciting condition using the system state equation and the implicit function theorem. By combining the extended stability corollary of an LTV system, the estimated weights are verified to exponentially converge to their optimal values. By constructing "learning rules" and using a "mod" function, the estimated weights with a convergent sequence are synthetically represented and stored as the experience knowledge, which is reused to construct neural learning controllers. The proposed neural learning controllers not only accomplish similar control tasks but also reduce the burden of online computation compared with the conventional adaptive NN ***, simulation results are presented to demonstrate the effectiveness of the presented schemes.

关键词： discrete-time nonlinear systems pure-feedback systems learning control neural networks persistent excitation

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Optimization of Fuel In-Situ Reduction(FISR)Denitrification Technology for Cement Kiln using CFD Method

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Journal of Thermal Science 2023年第6期32卷 2256-2272页

作者： shi Chaoting CAI jun REN Qiangqiang WU Huixing Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Dalian National Laboratory for Clean Energy Dalian116023China

Nitrogen oxides(NO_(x))from cement industry have drawn more and more attention and the existing denitrification technologies can hardly meet the increasingly stringent emission requirements in *** our previous work,fuel in-situ reduction(FISR)method was proposed to cut cement NO_(x)*** the pilot-scale precalciner in the previous experiment as objection,optimization of FISR method was conducted using CFD *** results demonstrated that NO_(x)emission decreased by 69.86%after adopting FISR *** effects of initial concentrations of NO and O_(2)in kiln gas,feeding location of the first-stage tertiary(tertiary air-I)and cement raw meal(CRM)were further *** increasing initial NO concentration,NO_(x)emission increased linearly,while the reduction rate of NO in kiln gas maintained above 80%.When O_(2)content in kiln gas is more than 4%,oxygen would more significantly promote the formation of NO_(x)and inhibit the reduction of *** dimensionless locations of tertiary air-I and CRM were *** simulation results showed that the optimal dimensionless locations are 0.6 and 1.6 for tertiary air-I and CRM,*** outputs achieved in this study will provide a strong support for the practical application of FISR method in cement industry.

关键词： cement industry precalciner pretreated fuel NO_(x)emission denitrification

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Rectangling irregular videos by optimal spatio-temporal warping

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Computational Visual Media 2022年第1期8卷 93-103页

作者： Jin-Liang Wu jun-Jie shi Lei Zhang The 54th Research Institute of CETC Shijiazhuang 050050China School of Computer Science Beijing Institute of TechnologyBeijing 100081China.

Image and video processing based on geometric principles typically changes the rectangular shape of video frames to an irregular shape. This paper presents a warping based approach for rectangling such irregular frame boundaries in space and time, i.e., making them rectangular again. To reduce geometric distortion in the rectangling process, we employ contentpreserving deformation of a mesh grid with line structures as constraints to warp the frames. To conform to the original inter-frame motion, we keep feature trajectory distribution as constraints during motion compensation to ensure stability after warping the frames. Such spatially and temporally optimized warps enable the output of regular rectangular boundaries for the video frames with low geometric distortion and jitter. Our experiments demonstrate that our approach can generate plausible video rectangling results in a variety of applications.

关键词： rectangling warping content-preserving

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A survey of safety separation management and collision avoidance approaches of civil UAS operating in integration national airspace system

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Chinese Journal of Aeronautics 2020年第11期33卷 2851-2863页

作者： Xiangmin GUAN Renli LYU Hongxia shi jun CHEN Department of General Aviation Civil Aviation Management Institute of ChinaBeijing 100102China General Aviation Institute of Zhejiang JianDe Hangzhou 311600China School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUnited Kingdom

Recent years have witnessed a booming of the industry of civil Unmanned Aircraft System(UAS).As an emerging industry,the UAS industry has been attracting great attention from governments of all countries and the aviation *** are highly digitalized,informationized,and intelligent;therefore,their integration into the national airspace system has become an important trend in the development of civil ***,the complexity of UAS operation poses great challenges to the traditional aviation regulatory system and technical *** to prevent collisions between UASs and between UAS and manned aircraft to achieve safe and efficient operation in the integrated operating airspace has become a common challenge for industry and academia around the *** recent years,the international community has carried out a great amount of work and experiments in the air traffic management of UAS and some of the key *** paper attempts to make a review of the UAS separation management and key technologies in collision avoidance in the integrated airspace,mainly focusing on the current situation of UAS Traffic Management(UTM),safety separation standards,detection system,collision risk prediction,collision avoidance,safety risk assessment,etc.,as well as an analysis of the bottlenecks that the current researches encountered and their development trends,so as to provide some insights and references for further research in this ***,this paper makes a further summary of some of the research highlights and challenges.

关键词： Air transportation Collision avoidance Safety Separation control Unmanned aircraft system

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