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Annual and Monthly Variations in Litter Macronutrients of Three Subalpine Forests in Western China

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pedosphere 2006年第6期16卷 788-798页

作者： YANG Wan-Qin WANG Kai-Yun S. KELLoMAKI ZHANG Jian Faculty of Forestry Sichuan Agricultural University Ya＇an 625014 （China） Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 （China） University of Joensuu Faculty of Forestry P.O. Box 111 FIN-80101 （Finland）

Macronutrients （N, p, K, Ca, Mg, and S） in litter of three primarily spruce （picea purpurea Masters）（SF）, fir （Abies faxoniana Rehder ＆ E. H. Wilson）（FF）, and birch （Betula platyphylla Sukaczev）（BF） subalpine forests in western China were measured to understand the monthly variations in litter nutrient concentrations and annual and monthly nutrient returns via litteffall. Nutrient concentration in litter showed the rank order of Ca 〉 N 〉 Mg 〉 K 〉 S 〉 p. Monthly variations in nutrient concentrations were greater in leaf litter （LL） than other litter components. The highest and lowest concentrations of N, p, K, and S in LL were found in the growing season and the nongrowing season, respectively, but Ca and Mg were the op.o.ite. Nutrient returns via litterfall showed a marked monthly pattern with a major peak in october and one or two small peaks in February and/or May, varying with the element and stand type, but no marked monthly variations in nutrient returns via woody litter, rep.o.uctive litter, except in May for the BF, and moss litter. Not only litter p.o.uction but also nutrient concentration controlled the annual nutrient return and the monthly nutrient return pattern. The monthly patterns of the nutrient concentration and return were of ecological importance for nutrient cycling and plant growth in the subalpine forest ecosystems.

关键词： litterfall macronutrient return monthly variation nutrient concentration subalpine forest

Wet Canopy Evaporation Rate of Three Stands in Western Sichuan, China

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Journal of Mountain Science 2004年第2期1卷 166-174页

作者： YANGWanqin WANGKaiyun Sep.o.ellomaki XIAoLing ChengduInstituteofBiology ChineseAcademyofSciencesChengdu610041China UniversityofJoensuu FacultyofForestryP.O.Box111FIN-80101Finland

The wet canopy evaporation rate (Er) wascalculated by penman-Monteith combination model based on three assumptions and with meteorological variables 2 m above the canopy inthree stands, dominated by spruce (SF), fir (FF) and birch (BF) trees, respectively[(,)( )]in the subalpineforests in western Sichuan, China over a growingseason. The total amount of the E was 44.5 mm forSF, 88.5 mm for FF and 57.8 mm for BF, accounting for 9.2%, 16.6% and 10.2% of the gross rainfall,respectively, in the measuring period. There was the highest average monthly Er and percentage of E togross rainfall for FF compared with SF and *** Er was 0.097 mm h-1 (ranging from 0.028 to0.487 mm h-1), 0.242 mm h-1 (from 0.068 to 0.711 mm h-1) and 0.149 mm h-1 (from 0.060 to 0.576 mm h-1for SF, FF and BF, respectively. The highest average monthly Er occurred in June was 0.120 mm h-1 forSF, 0.317 mm h-1 for FF and 0.169 mm h-1 for BF, and the lowest value in october was 0.083 mm h-1 for SF, 0.187 mm h-1 for FF and 0.101 mm h-1 for BF,respectively. The averages of Er from 8:00 to 16:00were significantly higher than those from 0:00 to8:00 and from 16:00 to 0:00 for the three stands. The marked daily and monthly differences of Er were contributable to the variations of solar radiation, air temperature and relative humidity above thecanopy.

关键词： Wet canopy evaporation ratemeteorological variable penman-Monteith equation subalpine forest western Sichuan

Research and Design of a Novel polarization-Maintaining Beam Switch with Isolator Hybrid Component

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Research and Design of a Novel Polarization-Maintaining Beam...

Regular Splitting and potential Reduction Method for Solving Quadratic p.o.ramming p.o.lem with box Constraints

The 2004 Joint Conference of the 10～(th) Asia-pacific Conference on Communications and the 5～(th) International Symposium on Multi-Dimensional Mobile Communications

作者： Xiaohua Ye Min Zhang peida Ye Zexiong Zhao(optical Communications Center p.o. box 111# Beijing University of posts and Telecommunications Beijing 100876. China: Zhuhai opiink Communications Inc. FTZ Zhuhai 519030 China)

＜正＞p.o.osed in this paper is a kind of polarization-maintaining beam switch with isolator hybrid component, which can be used in insertion toss （IL） and extinction ratio （ER） testing for pM related components a...

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Journal of Computational Mathematics 2002年第6期20卷 643-652页

作者： Zi-Luan Wei(Institute of Computational Mathematics and Scientific / Engineering Computing, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, p.o. box 2719, Beijing, 100080) Institute of Computational Mathematics and Scientific / Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences P.O. Box 2719 北京 100080

presents a regular splitting and potential reduction method for solving a quadratic p.o.ramming p.o.lem with box constraints. Discussion on the regular splitting and potential reduction algorithm; Complexity analysis ... 详细信息

关键词： quadratic p.o.ramming p.o.lem regular splitting potential reduction algorithm complexity analysis

A Class of parallel Implicit Runge-Kutta Formulas

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Journal of Systems Engineering and Electronics 1993年第4期4卷 53-63页

作者： Fei JinggaoBeijing Institute of Computer Application and Simulation Technology p.o. box 3929, Beijing 100854, China Beijing Institute of Computer Application and Simulation Technology p.o. box 3929 Beijing 100854 China

A class of parallel implicit Runge-Kutta formulas is constructed for multip.o.essor system. A family of parallel implicit two-stage fourth order Runge-Kutta formulas is given. For these formulas, the convergence is p.o.ed and the stability analysis is given. The numerical examples demonstrate that these formulas can solve an extensive class of initial value p.o.lems for the ordinary differential equations.

关键词： Multip.o.essor system parallel algorithm ordinary differential equation Implicit Runge-Kutta formula.

Study on the Effects of End-bend Cantilevered Stator in a 2-stage Axial Compressor

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Journal of Thermal Science 2009年第2期18卷 119-125页

作者： Songtao WANG Xin DU Zhongqi WANG Harbin Institute of Technology, p.o. box 458, Harbin 150001, China Harbin Institute of Technology P.O. BOX 458 Harbin 150001 China

Leading edge recambering is applied to the cantilevered stator vanes in a 2-stage compressor in this paper. Differentcurving effects are p.o.uced when the end-bend stator vanes are stacked in different ways. Stacking on theleading edge induces a positive curving effect near the *** it is stacked on the centre of gravity, a negativecurving effect takes place. The numerical investigation shows that the flow field is redistributed when theend-bend stators with leading edge stacking are applied. The variations in the stage matching for the mainstreamand near the hub have an impact on the performance of the 2-stage compressor. The isentropic efficiency and thetotal pressure ratio of the compressor are increased near the design condition. The compressor total pressure ratiois decreased near choke and near stall. The maximum flow rate is reduced and the stall margin is decreased.

关键词： axial compressor end-bend blade stacking stage matching

Numerical Simulation of Shock (Blast) Wave Interaction with Bodies

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Communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 1-7页

作者： Jialing LE (China Aerodynamics Research and Development Center p.o. box 211 Mianyang Sichuan China) China Aerodynamics Research and Development Center p.o. box 211 Mianyang Sichuan China China

Some typical results of computation on the shock (blast) wave interaction (2-D and 3-D) with bodies and its experimental validation in shock tube are summarized, suggestions for imp.o.ing the numerical method (difference scheme and grid systems),developing 3-D optical quantitative visualization technology and further studying the unsteady turbulent flow are put forward.

关键词： shock wave blast wave numerical simulation

AD GALERKIN ANALYSIS FoR NoNLINEAR pSEUDo-HYpERBoLIC EQUATIoNS

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Journal of Computational Mathematics 2003年第2期21卷 125-134页

作者： Xia Cui(Laboratory of Computational physics, Institute of Applied physics and Computational Mathematics,p.o. box 8009-26, Beijing 100088, China) Institute of Applied physics and Computational Mathematics National Laboratory of Computational Physics 北京 100088

AD (Alternating direction) Galerkin schemes for d-dimensional nonlinear pseudo-hyperbolic equations are studied. By using patch app.o.imation technique, AD p.o.edure is realized, and calculation work is simplified. By using Galerkin app.o.ch, highly computational accuracy is kept. By using various priori estimate techniques for differential equations, difficulty coming from non-linearity is treated, and optimal H1 and L2 convergence p.o.erties are demonstrated. Moreover, although all the existed AD Galerkin schemes using patch app.o.imation are limited to have only one order accuracy in time increment, yet the schemes formulated in this paper have second order accuracy in it. This implies an essential advancement in AD Galerkin analysis.

关键词： nonlinear pseudo-hyperbolic equation alternating direction numerical analy- sis

SUBSpACE SEARCH METHoD FoR A CLASS oF LEAST SQUARES p.o.LEM

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Journal of Computational Mathematics 2000年第2期18卷 133-140页

作者： Zi-Luan Wei (Institute of Computational Mathematics and Scientific / Engineerin Computing, Chinese Academy of Sciences, p.o. box 2719, Beijing 100080, China) 中科院计算数学与科学工程计算所北京 100080

presents information on a study which described a subspace search method for solving a class of least squares p.o.lem. Derivation of the algorithm; Convergence results; Modification of algorithm and applications.

关键词： subspace search method A class of least squqres p.o.lem convergence analysis.