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Journal of Thermal Science 2021年第1期30卷 191-200页

作者： YANG zheng CHENG xu zheng Xinghua CHEN Haisheng Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China Institute for Applied Thermofluidics Karlsruhe Institute of TechnologyKarlsruhe 76131Germany

Supercritical fluid has been widely applied in many industrial *** traditional Reynolds-averaged Navier-Stokes(RANS)equations are directly applied for turbulent flow and heat transfer of the supercritical fluid,ignoring turbulent effect of the thermal physical properties due to the intense *** paper deduces a set of Reynolds-averaged Navier-Stokes equations for supercritical fluid(SCF-RANS equations)to depict turbulent flow and heat transfer of the supercritical fluid taking all the physical parameters as *** SCF-RANS equations include many new correlation terms due to fluctuation of the thermal physical *** methods for the new correlation term have been discussed for closing the SCF-RANS *** of them have relatively mature models,while others are completely new and need profound physical theoretical analysis for proposing reasonable *** paper provides referable information for these new correlations as far as authors *** SCF-RANS equations not only provide the formulation special for flow and heat transfer of the supercritical fluid,but also represent the most sophisticate form of the RANS equations,for every involved physical property has been considered as variable without any simplification.

关键词： SCF-RANS equations supercritical fluid turbulence Reynolds-averaged Navier-Stokes equations

An in-plane low-noise accelerometer fabricated with an improved process flow

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第10期10卷 1413-1420页

作者： xu-dong zheng Zhong-he jin Yue-lin WANG Wei-jun LIN Xiao-qi ZHOU Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow,by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure electrode for the sensing *** improved flow greatly lowers the footing effect during deep reactive ion etching(DRIE),and increases the proof mass by 54% compared to the traditional way,resulting in both improved device quality and a higher yield *** in the X direction is sensed capacitively by varying the overlapped area of a differential capacitor pair,which eliminates the nonlinear behavior by fixing the parallel-plate *** damping coefficient of the sensing motion is low due to the slide-film damping.A large proof mass is made using DRIE,which also ensures that dimensions of the spring beams in the Y and Z directions can be made large to lower cross axis coupling and increase the pull-in *** theoretical Brownian noise floor is 0.47 μg/Hz1/2 at room temperature and atmospheric *** tested frequency response of a prototype complies with the low damping design *** data for input acceleration from ?1 g to 1 g are recorded by a digital multimeter and show very good *** tested random bias of the prototype is 130 μg at an averaging time of around 6 s.

关键词： MEMS accelerometer, Deeo reactive ion etchin (DRIE), Footin effect, Canacitive sensing

Adsorption thermodynamics and kinetic investigation of aromatic amphoteric compounds onto different polymeric adsorbents

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Journal of Environmental Sciences 2007年第11期19卷 1298-1304页

作者： WANG Hal-ling FEI zheng-hao CHEN jin-long ZHANG Quan-xing xu Yan-hua College of Environment Nanjing University of Technology Nanjing 210009 China Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection Yancheng 224002 China State Key Laboratory of Pollution Control and Resources Reuse School of Environment Nanjing University Nanjing 210093 China

The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.

关键词： aromatic amphoteric compound aminobenzoic acid polymeric adsorbents adsorption thermodynamics kinetics

Organic photovoltaic cells:Novel organic semiconducting materials and molecular arrangement engineering

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Chinese Science Bulletin 2012年第32期57卷 4143-4152页

作者： WANG Zixuan ZHANG FuJun WANG jin xu XiaoWei WANG Jian LIU Yang xu zheng Key Laboratory of Luminescence and Optical Information(Ministry of Education) School of ScienceBeijing Jiaotong UniversityBeijing 100044China

Organic photovoltaic cells(OPVs) have attracted more and more attention due to its highly potential application to solve the energy crisis considering its advantages,such as low cost and ease of large area *** power conversion efficiency(PCE) of OPVs has undergone a more than nine-fold increase from ～1.0% by Tang in 1986 to 9.2% in 2010 announced by Mitsubishi *** major challenges of obtaining high efficiency OPVs are the synthesis of new narrow band gap materials,controlling molecular arrangement,designing novel configuration cells for better photon harvesting in the active *** the article,we summarized the recent progress of novel narrow band gap photovoltaic materials and the effective methods to control the morphology of donor and acceptor in the blend films for high performance of OPVs.

关键词：有机光伏电池分子排列有机半导体材料工程功率转换效率带隙材料大面积生产能源危机

Modeling and noise analysis of a fence structure micromachined capacitive accelerometer system

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第12期11卷 1009-1015页

作者： Xia ZHANG Hao WANG xu-dong zheng Shi-chang HU Zhong-he jin Department of lnformation Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Beijing Institute of Aerospace Control Devices Beijing 100854 China

We analyze the effects of possible noise sources on a fence structure micromachined capacitive accelerometer system by modeling and simulation to improve its performance. Simulation results show that a mismatch between the two initial sensing capacitors of the accelerometer or a mismatch between the two capacitance-voltage conversion circuits has a great effect on the output noise floor. When there is a serious mismatch, the noise induced by a sinusoidal carrier is the major noise source. When there is no or only a slight mismatch, the differential capacitance-voltage conversion circuits become the main noise source. The simulation results were validated by experiments and some effective approaches are proposed to improve the system resolution.

关键词： Capacitive accelerometer Micro-electromechanical system (MEMS) Noise Modeling Simulation

Dynamic defenses in cyber security:Techniques,methods and challenges Author links open overlay panel

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Digital Communications and Networks 2022年第4期8卷 422-435页

作者： Yu zheng zheng Li Xiaolong xu Qingzhan Zhao School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044JiangsuChina Key Laboratory for Novel Software Technology Nanjing UniversityNanjing210023JiangsuChina College of Information Science and Technology Shihezi University Geospatial Information Engineering Research CenterChina

Driven by the rapid development of the Internet of Things,cloud computing and other emerging technologies,the connotation of cyberspace is constantly expanding and becoming the fifth dimension of human ***,security problems in cyberspace are becoming serious,and traditional defense measures(e.g.,firewall,intrusion detection systems,and security audits)often fall into a passive situation of being prone to attacks and difficult to take effect when responding to new types of network attacks with a higher and higher degree of coordination and *** constructing and implementing the diverse strategy of dynamic transformation,the configuration characteristics of systems are constantly changing,and the probability of vulnerability exposure is ***,the difficulty and cost of attack are increasing,which provides new ideas for reversing the asymmetric situation of defense and attack in ***,few related works systematically introduce dynamic defense mechanisms for cyber *** related concepts and development strategies of dynamic defense are rarely analyzed and *** bridge this gap,we conduct a comprehensive and concrete survey of recent research efforts on dynamic defense in cyber ***,we firstly introduce basic concepts and define dynamic defense in cyber ***,we review the architectures,enabling techniques and methods for moving target defense and mimic *** is followed by taxonomically summarizing the implementation and evaluation of dynamic ***,we discuss some open challenges and opportunities for dynamic defense in cyber security.

关键词： Cyber security Dynamic defense Moving target defense Mimic defense

Advances and Prospects in Breeding Japonica Rice for Super High Yield inthe Northern China

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Agricultural Sciences in China 2007年第10期6卷 1157-1165页

作者： CHEN Wen-fu xu zheng-jin ZHANG Wen-zhong Rice Research Institute Shenyang Agricultural University Shenyang 110161 P.R.China

In this paper, advances and prospects in breeding japonica rice for super high yield in the northern China were analyzed comprehensively in terms of breeding theories, techniques and practices. The author holds that developing and spreading super rice is an important way to enhance the overall yielding ability of japonica rice and attaining immense expansion of rice production. After theories and technical guidelines for super rice breeding were formulated, which involved the creation of new plant morphology and strong hybrid vigor through crossing indica with japonica subspecies, the optimization of combination of desirable traits via multiple crossing or backcrossing, the assemblage of favorable genes and the integration of ideal plant morphology with the utilization of vigor-major breakthroughs have been made in conventional breeding of japonica super rice. A batch of new super rice varieties marked by superior rice quality and high disease resistance, such as Shennong 265, Shennong 606, and Jijing 88, etc., have been developed and released. In comparison with the advancement in conventional breeding ef super rice, progress in hybrid japonica super rice breeding is slower because of climatic and ecological constraint in northern China. Therefore, solving the contradictions between vigor and growth duration, between yield and rice quality, and boosting vastly seed production are still serious challenges for breeders of hybrid japonica rice. Physiological and genetic problems in japonica super rice breeding are also discussed in this paper.

关键词： rice ideal plant morphology japonica super rice

Ecological Species Groups and Interspecific Association of Dominant Tree Species in Daiyun Mountain National Nature Reserve

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Journal of Mountain Science 2015年第3期12卷 637-646页

作者： SU Song-jin LIU jin-fu HE Zhong-sheng zheng Shi-qun HONG Wei xu Dao-wei Fujian Agriculture and Forestry University Fujian Sanming Forest School Cross-Strait Nature Reserve Research Centre Fujian Agriculture and Forestry University

Abstract： Research on the ecological species groups and interspecific association of plant species are helpful to discover species coexistence processes and mechanisms, and to more fully understand plant community structure, function, and its taxonomy. However, little is known about the ecological species groups （ESG） and the interspecific association of dominant species in Daiyun Mountain National Nature Reserve of Fujian Province, China. Therefore, the main goal of this paper is to explore the ESG using maximal tree, and to analyze interspecific associations of 32 dominant species selected from lo2 sample plots using the chi-square test. The results show that：（1） 32 dominant species have a significant overall positive interspecific association, which indicates that the natural forest in Daiyun Mountain National Nature Reserve is stable, （a） The species pairs with weak associations, non-associations and positive associations account for lo.88%, 29.64% and 59.48% of the total 496 species pairs respectively, which suggests that the population distributions of the dominant species investigated are relatively independent, （3） The following species pairs may be useful for practical application, 〈Pinus taiwanensis, Rhododendron farrerae〉, 〈Castanopsis carlesii, Altingia chinensis〉, 〈C. carlesii, Castanopsis fargesii〉, 〈Castanopsis eyrei, C. fargesii〉, 〈P. taiwanensis, Fagus lucida〉 , 〈Machilus thunbergii, Castanopsis nigrescens〉, and （4） The results of clustering analysis based on the maximal tree method indicates that the 32 dominant species can be divided into 3 ESGs when A at o.6o, that is ESG I {Pinus massoniana, Cunning hamia lanceolata}, ESG II {P. taiwanensis, R. farrerae, Enkianthus quinqueflorus}, ESG III {C. carlesii, A. chinensis, C. eyrei, Castanopsis fabri, C. fargesii, Schima superba, Machilus thunbergii, Rhododendron latoueheae}. The results may be used for the selection of afforestation tree species in South China Forest Areas and guide the natural manag

关键词： Ecological Species Groups InterspecificAssociation Daiyun Mountain National NatureReserve Maximal Tree

Single-crystal structure of coordination polymer [Nd_(2)(C_(8)H_(5)NO_(4))_(3)·4H_(2)O]_∞

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Chinese Science Bulletin 2003年第11期48卷 1111-1114页

作者： YANG Ruyi zheng Nengwu xu Haitao LI zhengquan jin Xianglin Department of Chemistry University of Science and Technology of ChinaDepartment of Chemistry University of Science and Technology of ChinaDepartment of Chemistry University of Science and Technology of ChinaDepartment of Chemistry University of Science and Technology of ChinaDepartment of Chemistry Peking University Hefei 230026 China Hefei 230026 China Hefei 230026 China Hefei 230026 ChinaBeijing 100871 China

The single-crystal structure of the coordination polymer [Nd2(C8H5NO4)3 · 4H2O]∞with rhombus-channels is reported in this paper. There are two crystallographically independent Nd(III) ions, and each Nd(III) ion is in the eight-coordinated environment. Seven of eight oxygen atoms are from six 5-aminoisophthalic acid ligands, the other oxygen atom is given by coordination water. Carboxyl groups link two Nd(III) ions using η1,1 and η1,3 modes. Two carboxyl groups from ligands chelate Nd(III) ion to form fourmembered rings. Crystal data: Triclinic, space group P1,a = 1.03680(5) nm,b = 1.66934(15) nm,c = 0.88221(14) nm, α = 99.754(2)β, β = 111.169(4)°, γ = 85.400(4)°. Some ligands linking metal Nd(III) ions parallel toab plane form molecular ladders, and the others linking molecular ladders result in rhombus channels alongc-axis. These coordinated water molecules and amino groups are pendent in the channels.

关键词： [Nd2(C8H5NO4)3·4H2O]∞ 单晶结构离子调和聚合物配位

Revolutionizing plasmonic platform via magnetic field-assisted confined ultrafast laser deposition of high-density,uniform,and ultrafine nanoparticle arrays

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International Journal of Extreme Manufacturing 2024年第3期6卷 428-438页

作者： jin xu Lingfeng Wang Peilin Yang Haoqing Jiang Huai zheng Licong An Xingtao Liu Gary J Cheng School of Industrial Engineering Purdue UniversityWest LafayetteIN 47906United States of America Institute of Technological Sciences Wuhan UniversityWuhanHubei 430072People’s Republic of China

The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant ***,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their *** address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in *** precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)*** profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and *** the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering *** enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)***,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of ***,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS *** study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy *** outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,ph

关键词： magnetic field manipulation laser deposition metasurface SERS