检索结果-南通市图书馆

Handedness-inverted polymorphic helical assembly and circularly polarized luminescence of chiral platinum complexes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2021年第5期64卷 788-799页

作者： zhong-Liang Gong Yu-Wu zhong Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of PhotochemistryCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

Circularly polarized luminescence(CPL)materials have potential applications in three-dimensional(3d)displays,quantum encryption,and optical *** development of single-component CPL materials with polymorphic assembly and handedness inversion remains a significant ***,we present the access of such materials by controlling the underlying assembly pathway of well-designed chiral emitters.A pair of enantiomeric platinum complexes(R)-1 and(S)-1 decorated with a chiralα-methylbenzyl isocyanide ligand were *** using the mixed-solvent(THF/n-hexane,THF=tetrahydrofuran)or high-concentration condition,these complexes were found to assemble via a cooperative or isodesmic pathway with significantly enhanced yellow or red emission,*** aggregate samples obtained via these conditions show efficient CPL(dissymmery factor|glum|>0.02,emission quantum yieldΦ>20%).Interestingly,different assembly pathway leads to helical nanoribbons or nanofibers with opposite handedness from the complex with the same molecular *** has been unambiguously and consistently manifested by circular dichroism and CPL spectral analysis and transmission electron,scanning electron,and atomic force microscope *** work demonstrates an appealing example of constructing polymorphic helical architectures with highly efficient CPL and inverted handedness thanks to the excellent assembly and emission of platinum complexes.

关键词： self-assembly nanostructures circularly polarized luminescence chiral materials platinum complexes

Thermal-flow-electric coupling performance analysis of a liquid-immersed battery thermal management system

在线全文

学校读者我要写书评

暂无评论

Science China Technological Sciences 2025年第1期 157-176页

作者： Qiang GAO Jun TIAN Chujin BAO Yangfan zhong Chengbin ZHANG Yongping CHEN School of Energy and Environment Southeast University Battery Testing Center China North Vehicle Research Institute Zhejiang Immertech Co. Ltd. Alibaba Cloud Computing Co. Ltd.

Ensuring the safety and performance of lithium-ion batteries(LIBs) is a significant challenge for electric *** tackle this issue, an innovative liquid-immersed battery thermal management system(LIBTMS) using bionic baffles with fish-like perforations is developed. The thermal-flow-electric coupling characteristics of LIBTMSs with different baffle structures(no baffle, conventional baffle, baffle with circular perforations and baffle with fish-like perforations) are systematically investigated using experimental and numerical methods. The results indicate that the forced flow scheme exhibits better thermal management performance and voltage equalization than static flow. Moreover, the LIB temperatures and voltage deviations of different LIBTMSs increase quickly with increasing discharge rates. More importantly, the innovative LIBTMS exhibits the best thermoelectric performance due to its excellent thermoelectric equilibrium behavior caused by high electrical and temperature consistency, as well as the best overall performance involving the balance between the pressure loss and heat transfer capacity of the system. Compared with other structures, the innovative LIBTMS using baffles with fish-like perforations exhibits a maximum reduction of 10.1%, 15.2%, 25.8% and 9.0% in LIB maximum temperature, maximum temperature difference, system pressure drop and voltage deviation, respectively, under the same operating ***, for the LIBTMS using baffles with fish-like perforations, the bottom inlet and top outlet configuration and coolant precooling are suggested to enhance cooling performance.

关键词：

Formation of Singularity for Full Compressible Magnetohydrodynamic Equations with Zero Resistivity in Two dimensional Bounded domains

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2023年第4期39卷 990-1008页

作者： Xin zhong School of Mathematics and Statistics Southwest UniversityChongqing 400715China

We are concerned with singularity formation of strong solutions to the two-dimensional(2d)full compressible magnetohydrodynamic equations with zero resistivity in a bounded *** energy method and critical Sobolev inequalities of logarithmic type,we show that the strong solution exists globally if the temporal integral of the maximum norm of the deformation tensor is *** result is the same as Ponce’s criterion for 3d incompressible Euler *** particular,it is independent of the magnetic field and ***,the initial vacuum states are allowed.

关键词： full compressible magnetohydrodynamic equations zero resistivity formation of singularity

HIGH-RESOLUTION SEMI-dISCRETE CENTRAL SCHEME FOR dAM-BREAK PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2005年第5期17卷 585-589页

作者： CHEN Jian-zhong SHI zhong-ke College of Automation Northwestern Polytechnical University Xi＇an 710072 China

A numerical model for simulating the dambreak problems was presented. The model was based on a high-resolution semi-discrete central-upwind difference scheme. In order to reduce spurious oscillation, the uniformly non-oscillatory limiter was employed. A third-order total variation diminishing Runge-Kutta method is used for time integration. The main feature of the presented method is its simplicity. It requires no Riemann solvers, no flux splitting and no flux limiter. It is explicit and does not require dimensional splitting for two dimensions. The Simpson quadrature rule was employed to compute the source term. To verify the effectiveness and accuracy of the proposed method, the 1d dambreak, circular dam-break and partial dam-break problems were simulated. The results are shown to be in good agreement with analytical solution and numerical results obtained by other methods.

关键词： dam-break shallow water equations central-upwind difference scheme

SOLUTION OF 2d SHALLOW WATER EQUATIONS BY GENUINELY MULTIdIMENSIONAL SEMI-dISCRETE CENTRAL SCHEME

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2006年第4期18卷 436-442页

作者： CHEN Jian-zhong, SHI zhong-ke College of Automation Northwestern Polytechnical University Xi＇an 710072 China

A numerical two-dimensional shallow water method was based on method for solving the equations was presented. This the third-order genuinely multidimensional semi-discrete central scheme for spatial discretization and the optimal third-order Strong Stability Preserving （SSP） Runge-Kutta method for time integration. The third-order compact Central Weighted Essentially Non-Oscillatory （CWENO） reconstruction was adopted to guarantee the non-oscillatory behavior of the presented scheme and improve the resolution. Two kinds of source terms were considered in this work. They were evaluated using different approaches. The resulting scheme does not require Riemann solvers or characteristic decomposition, hence it retains all the attractive features of central schemes such as simplicity and high resolution. To evaluate the performance of the presented scheme, several numerical examples were tested. The results demonstrate that our method is efficient, stable and robust.

关键词： 2d shallow water equations semi-discrete central scheme Central Weighted Essentially Non-Oscil]atory (CWENO) reconstruction

Solid-State 13C Nuclear Magnetic Resonance Spectroscopic Characterization of Soil Organic Matter Fractions in a Forest Ecosystem Subjected to Prescribed Burning and Thinning

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2017年第5期27卷 901-911页

作者： thilini d.ranatunga zhongqi he kamala n.bhat junyan zhong department of Biological&Environmental Sciences Alabama A&M UniversityNormal AL 35762(USA) USdA-ARS Southern Regional Research CenterNew 0rlcans LA 70124(USA) department of Physics Chemistry and MathematicsAlabama A&M UniversityNormal AL 35762(USA) College of Sciences 0ld Dominion UniversityNorfolk VA 23529(USA) Intertek Allentown PA 18195(USA)

Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.

关键词： density fractionation forest fires forest management practices forest soils fulvic acids humic acids humin particulateorganic matter

Electrode Modifications for Polymer Light-Emitting Electrochemical Cells

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2006年第A03期35卷 600-602页

作者： Z Y zhong Y d Jiang W Z Li X Yang School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China

The influence of different modification methods on the surface properties of indium-tin-oxide (ITO) electrodes were investigated by measurements of chemical composition,surface roughness,sheet resistance,contact angle and surface free *** results demonstrate that oxygen plasma treatment more effectively optimizes the surface properties of ITO electrodes compared with the other ***,the polymer light-emitting electrochemical cells (PLECs) with the differently treated ITO substrates as device electrodes were fabricated and *** is found that oxygen plasma treatment on the ITO electrode enhances injection current,luminance and efficiency,thereby improves the device characteristics of the PLECs.

关键词： electroluminescene polymer light-emitting electrochemical cells electrode modifications device performance

INTERMETALLICS AS SUBSTITUTES FOR SUPERALLOYS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 463-467页

作者： J. Zhang d. Feng Z. Y. zhong High Temperature Materials division Central Iron and Steel Research Institute Beijing 100081China

The application advances of TiAl, Ti3Al and Ni3Al base aUoys were denumstrated by Central Iron and Steel Research Institute, China. The recent research progresses on improving the reliability of cast TiAI were mainly presented and discussed. The characteristics of the self-oriented lamellar microstructure in cast TiAI were investigated in both as cast and as HlPed states. Based on the mechanical anisotropy of the cast lamellar microstructure, the component specific microstrueture design was proposed for a better performance and reliability of cast TiAl.

关键词： intermetallic application TiAl alloy microstructure design

Full-duplex two-way AF relaying systems with imperfect interference cancellation in Nakagami-m fading channels

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2021年第8期64卷 143-155页

作者： Jianping TONG Caijun zhong College of Science Zhejiang University of Technology department of Information and Communication Engineering Zhejiang University

Full-duplex(Fd) two-way relaying has the potential to substantially improve the spectral efficiency of the system, and is regarded as an enabling technology for the next generation wireless communication systems. Nevertheless, the joint effect of residual interference and channel fading condition on the fundamental performance of Fd two-way relaying systems remains unclear. Motivated by this, this study considers a general Fd two-way amplify-and-forward(AF) relaying system with imperfect interference cancellation in the versatile Nakagami-m fading channels, and presents a detailed analytical investigation on the outage performance of the system. The findings of the paper suggest that the performance of the Fd two-way AF relaying system depends heavily on the residual interference strength, fading condition parameter m, and signal-to-noise ratio(SNR). The Fd scheme outperforms the half-duplex(Hd) two-way relaying counterpart in the low and moderate SNR regime, while becomes inferior in the high SNR regime, owing to strong residual interference. Also, compared to the channel fading condition of the information transmission channels, the impact of the channel fading condition of the interference channel on the system performance is relatively insignificant. Moreover, it is desirable to deploy the Fd scheme when the channel fading condition of the information transmission channels is good, since it can effectively alleviate the detrimental effect of residual interference.

关键词： full-duplex two-way relaying Nakagami-m fading outage probability sum throughput

同方期刊数据库