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Chinese Geographical Science 2011年第1期21卷 27-35页

作者： GAO Junqin ouyang hua LEI Guangchun XU Xingliang ZHANG Mingxiang Beijing Forestry University Beijing 100083 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Wetland stores substantial amount of carbon and may contribute greatly to global climate change debate. However, few researches have focused on the effects of global climate change on carbon mineralization in Zoige alpine wetland, Qinghai-Tibet Plateau, which is one of the most important peatlands in China. Through incubation experiment, this paper studied the effects of temperature, soil moisture, soil type （marsh soil and peat soil） and their interactions on CO2 and CH4 emission rates in Zoige alpine wetland. Results show that when the temperature rises from 5℃ to 35℃, CO2 emission rates increase by 3.3-3.7 times and 2.4-2.6 times under non-inundation treatment, and by 2.2-2.3 times and 4.1-4.3 times under inundation treatment in marsh soil and peat soil, respectively. Compared with non-inundation treatment, CO2 emission rates decrease by 6%-44%, 20%-60% in marsh soil and peat soil, respectively, under inundation treatment. CO2 emission rate is significantly affected by the combined effects of the temperature and soil type （p 〈 0.001）, and soil moisture and soil type （p 〈 0.001）, and CH4 emission rate was significantly affected by the interaction of the temperature and soil moisture （p 〈 0.001）. Q10 values for CO2 emission rate are higher at the range of 5 ℃-25℃ than 25 ℃-35℃, indicating that carbon mineralization is more sensitive at low temperature in Zoige alpine wetland.

关键词： alpine wetland carbon mineralization marsh soil peat soil soil moisture Qinghai-Tibet Plateau

Visible Light-Induced Methoxycarbonyldifluoromethylation of Trime-thylsilyl Enol Ethers and Allyltrimethylsilanes with FSO2CF2CO2Me

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Chinese Journal of Chemistry 2018年第11期36卷 1024-1030页

作者： Wei Yu Yao ouyang Xiu-hua Xu Feng-Ling qing Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecules Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Science 345 Lingling Lu Shanghai 200032 China Key Laboratory of Science and Technology of Eco-Textiles Ministry of Education College of Chemistry Chemical Engineering and Biotechnolo- gy Donghua University 2999 North Renmin Lu Shanghai 202620 China

A photocatalytic methoxycarbonyldifluoromethylation of trimethylsilyl enol ethers with FSO2CF2CO2Me in the presence of fac‐Ir(ppy)3 was developed. This reaction provided a practical strategy for the construction of various α‐CF2CO2R aromatic ketones, which are difficult to access by other methods. Furthermore, a series of methoxycarbonyldifluoromethylated allylic compounds could also be obtained from allyltrimethylsilanes using the same strategy. The resulting CF2CO2R‐containing products are useful building blocks and potentially valuable in medicinal chemistry and material sciences.

关键词： methoxycarbonyldifluoromethylation silyl enol ether allylsilane ketones allylic compounds radical reactions

RF tuning and beam commissioning of CW RFQ for China-ADS Injector-I

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Nuclear Science and Techniques 2018年第10期29卷 182-190页

作者： hua Shi huafu ouyang Shengchang Wang Ningchuang Zhou Gang Wu Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy Physics Chinese Academy of Sciences

A 325-MHz continuous-wave(CW) four-vane radiofrequency quadrupole(RFQ) is employed in Injector-I of the China Accelerator-Driven Subcritical System. The radiofrequency tuning and beam commissioning were performed from January 2014 to January 2017. In a cold test, a stability study showed that the design of the segmented resonantly coupling and dipole stabilizer rods can shift the harmful quadrupole and dipole mode from the fundamental mode to above 2.6 MHz. We also found a simplified tuning method for the field unflatness, involving changing the inserted length of a few plug tuners. For achieving CW-beam commissioning, two full-size RFQs were constructed successively. The commissioning results indicate that the beam transmission rate decreased by approximately 3% as the normalized field unflatness decreased by 1%. A 10-MeV CW proton beam with an average beam current of 2.1 m A was achieved at the target of Injector-I, and the output beam energy of the RFQ was3.18 MeV.

关键词： RFQ RF tuning CW-beam commissioning beam transmission rate

Modeling soil conservation, water conservation and their tradeoffs: A case study in Beijing

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Journal of Environmental Sciences 2012年第3期24卷 419-426页

作者： Yang Bai Zhiyun ouyang hua Zheng Xiaoma Li Changwei Zhuang Bo Jiang State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Institute of Applied Ecology Shanghai Academy of Environmental SciencesShanghai 200233China Nanjing Institute of Environmental Sciences Ministry of Environmental ProtectionNanjing 210042China

Natural ecosystems provide society with important goods and services. With the rapid increase in human populations and excessive utilization of natural resources, humans frequently enhance the production of some services at the expense of the others. Although the need for tradeoffs between conservation and development is urgent, the lack of efficient methods to assess such tradeoffs has impeded progress. Three land use strategy scenarios （development scenario, plan trend scenario and conservation scenario） were created to forecast potential changes in ecosystem services from 2007 to 2050 in Beijing, China. GIS-based techniques were used to map spatial and temporal distribution and changes in ecosystem services for each scenario. The provision of ecosystem services differed spatially, with significant changes being associated with different scenarios. Scenario analysis of water yield （as average annual yield） and soil retention （as retention rate per unit area） for the period 2007 to 2050 indicated that the highest values for these parameters were predicted for the forest habitat under all three scenarios. Annual yield/retention of forest, shrub, and grassland ranked the highest in the conservation scenario. Total water yield and soil retention increased in the conservation scenario and declined dramatically in the other two scenarios, especially the development scenario. The conservation scenario was the optimal land use strategy, resulting in the highest soil retention and water yield. Our study suggests that the evaluation and visualization of ecosystem services can effectively assist in understanding the tradeoffs between conservation and development. Results of this study have implications for planning and monitoring future management of natural capital and ecosystem services, which can be integrated into land use decision-making.

关键词： ecosystem services tradeoffs scenario management

Design and Synthesis of Chiral Molecular Tweezers Based on Deoxycholic Acid

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Chinese Chemical Letters 2001年第5期12卷 413-416页

作者： Cui hua XUE Qi Ming MU shu hua CHEN The Faculty of chemistry Sichuan UniversityChengdu 610064

A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.

关键词： Molecular tweezers synthesis deoxycholic acid recognition.

Quantum Dynamics of a Single Trapped Ion Interacting with Standing Laser Pulses

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Communications in Theoretical Physics 2004年第4X期42卷 599-604页

作者： LIFei HAIWen-hua CHONGGui-shu XIEQiong-Tao DepartmentofPhysics HunanNormalUniversityChangsha410081China

A classically chaotic system consisting of a Paul trapped ion and a sequences of standing laser pulses is treated quantum-mechanically. Under the circumstance of time-dependence, we derive the transition probability from the ion's motional state n to n', and find, in the first-order approximation, the classically chaotic character *** analysis and numerical calculations show that by regulating the phase parameter φ we can control the transition probability. When φ reaches some specific values, the transition from the state n to n' is forbidden and, for some laser periods, resonance occurs, which leads to the corresponding transitions between different motional states.

关键词：离子俘获量子动力学高斯激光束量子器件标准激光脉冲相位参数

Grassmannian precoding MU-MIMO scheme

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 105-109,117页

作者： FANG shu LI Li-hua ZHANG Ping Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, a Grassmannian precoding multiuser multiple-input multiple-output （MU-MIMO） scheme for downlink transmission is proposed. The proposed MU-MIMO scheme will perform scheduling and precoding simultaneously at the base station, to obtain both the multiuser diversity gain and the precoding gain, to maximize the system capacity. The precoding method is related to Grassmannian precoding, which extends the point-to-point single-user Grassmannian precoding to point-to-multipoint multiuser Grassmannian precoding. It provides further significant system capacity enhancement than the single user MIMO （SU-MIMO） system and also outperforms the block dia^onalization （BD） algorithm under the same simulation environment.

关键词： multiuser MIMO cochannel interference Grassmannian precoding

Aluminum-zinc alloy squeeze casting technological parameters optimization based on PSO and ANN

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China Foundry 2007年第3期4卷 202-205页

作者： shu Fu-hua College of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 4.40070 Hubei China

This paper presents a kind of ZA27 squeeze casting process parameter optimization method using artificial neural network (ANN) combined with the particle swarm optimizer (PSO). Regarding the test data as samples and using neural network create ZA27 squeeze casting process parameters and mechanical properties of nonlinear mapping model. Using PSO optimize the model and obtain the optimum value of the process parameters. Make full use of the non-neural network mapping capabilities and PSO global optimization capability. The network uses the radial direction primary function neural network,using the clustering and gradient method to make use of network learning,in order to enhance the generalization ability of the network. PSO takes dynamic changing inertia weights to accelerate the convergence speed and avoid a local minimum.

关键词： aluminum-zinc alloy squeeze casting process parameters ANN PSO

Observation of Two-Photon Induced Excited-State Absorption Phenomena in C_(60) and C_(70) Derivatives

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Chinese Physics Letters 2012年第8期29卷 247-249页

作者： ouyang Xin-hua LU Liang GE Zi-Yi Ningbo Institute of Material Technology and Engineering Chinese Academy of SciencesNingbo 315201

Four fullerene dyads with different cabazole units,named a,b,c,d,were studied by using a femtosecond laser with 780 nm wavelength using Z-scan ***,all of them show strong two-photon induced excited-state absorption behaviors,which were observed firstly in femtosecond *** values of their excited-state absorption cross-section were up to 6.07×10^(-18),7.27×10^(-18),3.86×10^(-18) and 4.51×10^(-18) cm^(-1) for a,b,c,and d,respectively.

关键词： femtosecond methods excited

Synthesis of Tin Oxide Through Thermal Decomposition of Sn_2(NH_4)_2(C_2O_4)_3 and Its Gas Sensing Property

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Chemical Research in Chinese Universities 2005年第6期21卷 641-645页

作者： SHI Juan WU Shi-hua WANG shu-rong School of Materials Science and Chemical Engineering Tianjin Polytechnic University Tianjin 300160 P. R. China Department of Chemistry Nankai University Tianjin 300071 P. R. China

Nanocrystalline tin oxide samples were prepared by using Sn2 （NH4 ）2 （C2O4）3 as the precursor. The thermal decompositions were respectively conducted at 250,450 and 650 ℃. TG-DTA, XRD, TEM, FTIR were used to characterize the samples. The indirect heating sensors by using these materials as sensitive bodies were fabricated on an alumina tube with Au electrodes and platinum wires. Sensing properties of these sensors were investigated. It was found that the tin oxide sample obtained by thermal decomposition at 450 ℃ has a higher sensitivity to C2H5OH and a higher selectivity to hexane and ammonia than those obtained via the conventional precipitate method and the working temperatures needed were greatly decreased.

关键词： Tin dioxide Thermal decomposition Gas sensing property Selectivity