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Chinese Physics Letters 1997年第9期14卷 690-693页

作者： YIN Min LOU Li-ren fu Zhu-xi Structure Research Laboratory University of Science and Technology of China and Chinese Academy of SciencesHefei 230026 Department of Physics University of Science and Technology of ChinaHefei 230026

A new method for metalorganic chemical vapor deposition(MOCVD)of GaAs on Si substrates is *** of the usual high temperature surface cleaning treatment for Si substrate,the new method uses room temperature HF vapor polishing in the preparation chamber in the MOCVD system as the first step of the *** crystal GaAs layers with mirror-like surfaces were obtained.

关键词： MOCVD polishing mirror

Quality of service aware admission control in cognitive device-to-device network

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 22-29,36页

作者： fu Zi-xi HU Chun-jing PEng Tao LU Qian-xi WAng Wen-bo Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

A hybrid system of cellular mode and device-to-device （D2D） mode is considered in this paper, where the cellular resource is reused by the D2D transmission. With the objective of capacity maximization, the power optimization of D2D sub-system is considered, taking into account quality of service （QoS） requirement. The power optimization problem is divided into two stages： The first stage is the admission control scheme design based on the QoS requirement of D2D users, and the second is power allocation to maximize aggregate throughput of admissible D2D users. For the D2D admission control problem, a heuristic sorting-based algorithm is proposed to index the admissible D2D links, where gain to Interference ratio （GIR） sorting criterion is used. Applying an approximate form of Shannon capacity, the power allocation problem can be solved by convex optimization and geometric programming tools efficiently. Based on the theoretical analysis, a practical algorithm is proposed. The precision can reach a trade-off between complexity and performance. Numerical simulation results confirm that combining with GIR sorting method, the proposed scheme can significantly improve the D2D system＇s capacity and fairness.

关键词： cognitive radio QoS power control geometric programming sorting-based algorithm

Yield and Quality Response of Cucumber to Irrigation and Nitrogen Fertilization Under Subsurface Drip Irrigation in Solar Greenhouse

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Agricultural Sciences in China 2011年第6期10卷 921-930页

作者： ZHAng He-xi CHI Dao-cai WAng qun FAng Jun FAng xiao-yu College of Water Resources Shenyang Agricultural University Shenyang 110161 P.R. China Guizhou Academy of Hydraulic Sciences Guiyang 550002 P.R.China

The aims of this research were to compare subsurface drip irrigation scheduling and nitrogen fertilization rates in cucumber, and evaluate yield and quality of cucumber fruit, water （WUE）, irrigation water （IWUE）, and nitrogen use （NUE） efficiencies in the solar greenhouse in Southwest China. The irrigation water amounts were determined based on the 20 cm diameter pan （Ep） placed over the crop canopy, and cucumber plant was subjected to three irrigation water levels （I1, 0.6 Ep; I2, 0.8 Ep; and I3, 1.0 Ep） in interaction with three nitrogen fertilization levels （N1, 300 kg ha-1; N2, 450 kg ha-1; and N3, 600 kg ha-1）. The results showed that the cucumber fruit yield increased with the improvement of irrigation water. Irrigation water increased yields by increasing the mean weight of the fruits, and also by increasing fruit number. But the highest values of IWUE and WUE were obtained from I2 treatment. NUE significantly decreased with the improvement of N application, but increased by irrigating more water. The quality of cucumber fruit decreased with the improvement irrigation water and nitrogen fertilization. In conclusion, the optimum irrigation level and nitrogen fertilizer application level for cucunber under subsurface drip irrigation in the solar greenhouse in Southwest China were 0.8 Ep and 450 and 600 kg ha-1, respectively.

关键词： subsurface drip irrigation cucumber water use efficiency nitrogen use efficiency fruit quality

Sedimentary Environment and Mineralization of the Black Shale Polymetallic Layer in the Early Cambrian,SW China:Constraints from in situ LA-ICP-MS Analysis of Pyrite

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 416-429页

作者： YAng Zhen fu Yong LI Chao CAI xi GUO Chuan College of Eco-Environmental Engineering Guizhou Minzu UniversityGuiyang 550025China College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Karst Georesources and the Environment Ministry of EducationGuizhou UniversityGuiyang 500025China National Research Center for Geoanalysis Chinese Academy of Geological SciencesBeijing 100037China

A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou *** mineral that makes up the polymetallic layer is related to the sedimentary *** analyze the differentiation mechanism between polymetallic deposits(Ni-Mo and V),the Zhijin Gezhongwu profile located in the outer shelf and the Sansui Haishan V deposit located in the lower slope are selected to study the in situ sulfur isotopes and trace elements of *** results show that δ^(34)S values of pyrite vary widely from−7.8‰to 28‰in the Gezhongwu profile,while the δ^(34)S values are relatively uniform(from 27.8‰to 38.4‰)in the Haishan *** isotopic S composition is consistent with the transition that occurs in the sedimentary phase from the shelf to the deep sea on the transgressive Yangtze platform;this indicates that the δ^(34)SO_(4)^(2−)values in seawater must be differently distributed in depositional *** sulfur in the Ni-Mo layer is produced after the mixing of seawater and hydrothermal fluid,while the V layer mainly originates from ***,the Ni-Mo and V deposits have been differentiated primarily on the basis of the combined effect of continental weathering and hydrothermal fluid.

关键词： sedimentary environment black shale polymetallic layer pyrite early Cambrian

Quantum Logic Networks for Probabilistic Teleportation of an Arbitrary Three-Particle State

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Communications in Theoretical Physics 2005年第4X期44卷 611-614页

作者： QIAN Xue-Mir FAng Jian-xing ZHU Shi-qun xi Yong-Jun School of Physical Science and Technology Suzhou University Suzhou 215006 China

The scheme for probabilistic teleportation of an arbitrary three-particle state is proposed. By using single qubit gate and three two-qubit gates, efficient quantum logic networks for probabilistic teleportation of an... 详细信息

关键词： probabilistic teleportation arbitrary three-particle state quantum logic networks

Computational design of BC_(3)N_(2) based single atom catalyst for dramatic activation of inert CO_(2) and CH4 gasses into CH_(3)COOH with ultralow CH_(4) dissociation barrier

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Chinese Chemical Letters 2023年第1期34卷 493-498页

作者： Chenxu Zhao Menghui xi Jinrong Huo Chaozheng He Ling fu Institute of Environment and Energy Catalysis School of Materials Science and Chemical EngineeringXi’an Technological UniversityXi’an 710021China School of Sciences Xi’an Technological UniversityXi’an 710021China College of Resources and Environmental Engineering Tianshui Normal UniversityTianshui 741001China

The production of CH_(3)COOH from CO_(2)and CH_(4) has stimulated much interest due to the high energy density of C2 *** kinds of catalysts have been developed while the high dissociation barrier of CH_(4) and low selectivity still hinders the efficiency of the *** have herein proposed a novel catalyst with single metals loaded on 2D BC_(3)N_(2) substrate(M@2D-BC_(3)N_(2))based on density functional *** numerous candidates,Pt@2D-BC_(3)N_(2) possesses the most favorable reactivity with an ultralow barrier of CH_(4) splitting(0.26 e V),which is due to the efficient capture ability of CH_(4) on Pt ***,the selectivity for CH_(3)COOH is also very high,which mainly stems from the unique electronic properties of molecules and substrate:The degenerated states,including s,px,pyand pz,in CO_(2)reflects the existence of delocalizedπbonds between C and *** can interact with states of Pt(s),Pt(pz),Pt(dxz),Pt(dyz),and Pt(z2)in Pt@2D-BC_(3)N_(2).The kinetics model also proves that our system can promote CH_(3)COOH production via simply increasing the temperature or the coverage of CH_(4) and CO_(2).Our results provide a reasonable illustration in clarifying mechanism and propose promising candidates with high reactivity for further study.

关键词： Density functional theory CO_(2)/CH4 coactivation 2D BC_(3)N_(2)substrate CH_(3)COOH production

FINITE ELEMENT NONLINEAR GALERKIN COUPLIngMETHOD FOR THE EXTERIOR STEADY NAVIER-STOKESPROBLEM

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Journal of Computational Mathematics 1999年第6期17卷 595-608页

作者： Yin-nian He Kai-tai Li fu-hai Gao(College of Science, xi’an Jiaotong University, xi’an 710049, China) xian Jiao Tong Univ Coll Sci Xian 710049 Peoples R China

In this paper we represent a new numerical method for solving the steady Navier-Stokes equations in three dimensional unbounded domain. The method consists in coupling the boundary integral and the finite element nonlinear Galerkin methods. An artificial smooth boundary is introduced seperating an interior inhomogeneous region from an exterior one. The Navier-Stokes equations in the exterior region are approximated by the Oseen equations and the approximate solution is represented by an integral equation over the artificial boundary. Moreover, a finite element nonlinear Galerkin method is used to approximate the resulting variational problem. Finally, the existence and error estimates are derived.

关键词： Navier-Stokes equations Oseen equations boundary integral finite element nonlinear Galerkin method

A surrogate-based optimization algorithm for network design problems

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Frontiers of Information Technology & Electronic Engineering 2017年第11期18卷 1693-1704页

作者： Meng LI xi LIN xi-qun CHEN Department of Civil Engineering Tsinghua University Beijing 100084 China College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China

Network design problems （NDPs） have long been regarded as one of the most challenging problems in the field of transportation planning due to the intrinsic non-convexity of their bi-level programming form. furthermore, a mixture of continuous/discrete decision variables makes the mixed network design problem （MNDP） more complicated and difficult to solve. We adopt a surrogate-based optimization （SBO） framework to solve three featured categories of NDPs （continuous, discrete, and mixed-integer）. We prove that the method is asymptotically completely convergent when solving continuous NDPs, guaranteeing a global optimum with probability one through an indefinitely long run. To demonstrate the practical performance of the proposed framework, numerical examples are provided to compare SBO with some existing solving algorithms and other heuristics in the literature for NDP. The results show that SBO is one of the best algorithms in terms of both accuracy and efficiency, and it is efficient for solving large-scale problems with more than 20 decision variables. The SBO approach presented in this paper is a general algorithm of solving other optimization problems in the transportation field.

关键词： Network design problem Surrogate-based optimization Transportation planning Heuristics

Notes and correspondence on ensemble-based three-dimensional variational filters

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第8期14卷 634-641页

作者： Hong-ze LEng Jun-qiang SOng fu-kang YIN xiao-qun CAO College of Computer National University of Defense Technology

Several ensemble-based three-dimensional variational (3D-Var) filters are compared. These schemes replace the static background error covariance of the traditional 3D-Var with the ensemble forecast error covariance, but generate analysis ensemble anomalies (perturbations) in different ways. However, it is demonstrated in this paper that they are all theoretically equivalent to the ensemble transformation Kalman filter (ETKF). furthermore, a new method named EnPSAS is presented. The analysis shows that EnPSAS has a small condition number and can apply covariance localization more easily than other ensemble-based 3D-Var methods.

关键词： 3D-Var Ensemble Kalman filter (EnKF) Ensemble transformation Kalman filter (ETKF) Physical space analysis system (PSAS) Ensemble data assimilation

Hardware-in-loop adaptive neural control for a tiltable V-tail morphing aircraft

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Defence Technology（防务技术） 2023年第4期22卷 197-211页

作者： fu-xi.ng Qiao Jing-ping Shi xiao-bo Qu Yong-xi Lyu School of Automation Northwestern Polytechnical UniversityXi'an710129China Shaanxi Province Key Laboratory of Flight Control and Simulation Technology Xi'an710129China

This paper proposes an adaptive neural control(ANC)method for the coupled nonlinear model of a novel type of embedded surface morphing aircraft which has a tiltable V-tail.A nonlinear model with sixdegrees-of-freedom is *** first-order sliding mode differentiator(FSMD)is applied to the control scheme to avoid the problem of“differential explosion”.Radial basis function neural networks are introduced to estimate the uncertainty and external disturbance of the model,and an ANC controller is proposed based on this design *** stability of the proposed ANC controller is proved using Lyapunov theory,and the tracking error of the closed-loop system is semi-globally uniformly *** effectiveness and robustness of the proposed method are verified by numerical simulations and hardware-in-the-loop(HIL)simulations.

关键词： Morphing aircraft Back-stepping control Adaptive control Neural networks Radial basis function