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亚洲精细农业与计算机农业应用联合大会

作者： Baoguo Wu1 Yan Qi1,2 Chi Ma3 Hongquan Zhang4 (1.beijing Forestry university beijing 100083 2.china agricultural university, beijing 100083 3.beijing Park Service and Afforestation Bureau, beijing 100029 4.Forest Inventory and Planning Institute of Hebei Province 050051.)

The paper is based on the research of forestry experts’ systems funded by "National Tenth-Five-Year 863 Plan". In the context of the collective forest rights system reforms, in order to enhance the technological support to the farmers in the fast-growing and high-yield poplar cultivation and to satisfy the actual needs of related enterprises, the study focuses on the fast-growing and high-yield poplar plantation harvest model and related decision-making criteria. Taking Populus tomentosa Carr as an example, by adopting the age - diameter at breast height growth model, diameter and tree height model, and the dual volume model based on Hebei Province’s data, the age-volume produce model is constructed;by adopting market price of the non-discount method which is relatively easy for farmers, PNW （Present Net Worth） and Le （Land Expectation Value） calculation methods, the economic benefits evaluation model is established. By using the calculation results of these models as a decision-making benchmark, the growth model, evaluation model and an calculation example of Populus tomentosa Carr are obtained. Based on the above-mentioned studies, the components and functions, model base and model resolver algorithm of the system are designed, and the economic benefits forecast process is set. The results of the research is applied to the "National Eleventh-Five-Year Plan" funded program "The research and application of key technologies in fast-growing and high-yield plantation production and management process informatization ". And the application obtains a satisfied result. By using harvest evaluation system to conduct economic benefits analysis of poplar varieties, the farmers and the investors can predict future earnings, and to make decisions in reforestation.

关键词： Fast-Growing Poplar Plantation Harvest Evaluation and Prediction Harvest Model Growth Model Decision Support System Forest Management

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我国稻谷供需平衡与安全研究

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生态经济(学术版) 2010年第2期 147-151页

作者：王蕾张虎中国人民大学商学院中国农业大学

稻谷是我国的主要粮食作物和居民消费口粮,稻谷供需安全在我国具有重要的战略意义。近年来,我国稻谷生产出现恢复性增长,但是供求关系依然紧张。文章构建了四指标加权平均安全系数,选取了稻谷产量波动率、年末库存与消费比、稻谷自给率... 详细信息

稻谷是我国的主要粮食作物和居民消费口粮,稻谷供需安全在我国具有重要的战略意义。近年来,我国稻谷生产出现恢复性增长,但是供求关系依然紧张。文章构建了四指标加权平均安全系数,选取了稻谷产量波动率、年末库存与消费比、稻谷自给率、人均稻谷占有量这四项指标作为稻谷安全评估的基本指标,赋予各项指标不同权重。研究表明:我国稻谷安全系数为0.63,供需形势依然严峻。

关键词：中国稻谷供需平衡安全系数

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草原白蘑菌种分离及菌丝体生长因子试验

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食品科技 2011年第4期36卷 18-21页

作者：马荣山凌岚方蕊卢媛沈阳农业大学食品科学学院沈阳110161 中国农业大学北京100083

草原白蘑是我国宝贵的珍稀食用菌资源,由于草场退化及人为过度采集,产量不断下降。为了保护草原白蘑且对其进行更好的开发利用,现对其生长因子进行研究。结果表明：选取菌褶处的组织进行分离菌丝体,萌发率在35%。草原白蘑的菌丝体生长... 详细信息

草原白蘑是我国宝贵的珍稀食用菌资源,由于草场退化及人为过度采集,产量不断下降。为了保护草原白蘑且对其进行更好的开发利用,现对其生长因子进行研究。结果表明：选取菌褶处的组织进行分离菌丝体,萌发率在35%。草原白蘑的菌丝体生长的最佳碳源为蔗糖;最佳氮源为酵母膏;当碳氮比为20：1~30：1时,菌丝生长较快。最适合菌丝体生长的温度为22~28℃,最适pH为6.5~7.0。Vc、VB6和α-萘乙酸能较好地促进菌丝体的生长。

关键词：草原白蘑菌丝分离生长因子

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改善机井离心泵吸水性能试验研究

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山东农业大学学报（自然科学版） 2004年第4期35卷 577-581页

作者：胡化坤张昕宋学东马庆彬禹海峰万林梅山东农业大学山东泰安271018 中国农业大学北京100083 泰安市水利局山东泰安271000 泰安市高级技工学校山东泰安271000

利用射水器以水泵自身压力水作为动力来提高机井离心泵装置的吸水性能 ,解决超吸程离心泵机井在干旱季节无法正常工作 ,水泵汽蚀严重的问题 ,能使无法上水的离心泵重新上水。同时 ,可使井、泵在不同时期出水量均处于一个合理范围 ,从而... 详细信息

利用射水器以水泵自身压力水作为动力来提高机井离心泵装置的吸水性能 ,解决超吸程离心泵机井在干旱季节无法正常工作 ,水泵汽蚀严重的问题 ,能使无法上水的离心泵重新上水。同时 ,可使井、泵在不同时期出水量均处于一个合理范围 ,从而使井泵安全运行。

关键词：机井干旱季节水作井泵吸程不同时期利用离心泵水泵汽蚀压力水

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超高心墙堆石坝大型振动台模型试验及数值模拟

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水力发电学报 2011年第6期30卷 20-24页

作者：袁林娟刘小生汪小刚赵剑明洪桂标刘启旺陈宁中国水利水电科学研究院北京100044 中国农业大学北京100083 浙江省水利水电勘测设计院杭州310002

我国西南强震区兴建高坝抗震问题非常突出。振动台模型试验是研究土石坝动力反应和震害机理、验证动力计算方法的有效手段。论文以300m级的双江口超高心墙堆石坝为依托,介绍了大型振动台模型试验,并利用等效线性模型对模型坝进行了数值... 详细信息

我国西南强震区兴建高坝抗震问题非常突出。振动台模型试验是研究土石坝动力反应和震害机理、验证动力计算方法的有效手段。论文以300m级的双江口超高心墙堆石坝为依托,介绍了大型振动台模型试验,并利用等效线性模型对模型坝进行了数值计算。通过对试验值和计算值的比较,验证了等效线性模型能较好的模拟坝体的动力反应。两种方法均反映出坝体最危险位置在下游坝坡0.75～0.85H处,且空库比满库的地震反应明显偏大。但是,有限元难以准确模拟松散边坡的表面放大效应,可能导致计算结果偏小;且等效线性方法属于非线性粘弹性模型,不能反映先期振动和坝体破坏过程。

关键词：振动台模型试验心墙堆石坝等效线性法加速度放大倍数

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CONVERGENCE PROPERTIES OF A MODIFIED BFGSALGORITHM FOR MINIMIZATION WITHARMIJO-GOLDSTEIN STEPLENGTHS

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Journal of Computational Mathematics 1999年第6期17卷 645-652页

作者： Nai-yang Deng Zheng-feng Li(Department of Mathematics, beijing agricultural Engineering university, beijing 100083,china) 北京农业工程大学数学系北京 100083 北京农业工程大学数学系北京

The line search strategy is crucial for an efficient unconstrained optimization algorithm. One of the reason why the Wolfe line searches is recommended lies in that it ensures positive definiteness of BFGS updates. When gradient information has to be obtained costly, the Armijo-Goldstein line searches may be preferred. To maintain positive difiniteness of BFGS updates based on the Armijo-Goldstein line searches, a slightly modified form of BFGS update is proposed by I.D. Coope and C.J. Price (Journal of Computational Mathematics, 13 (1995), 156-160), while its convergence properties is open up to now. This paper shows that the modified BFGS algorithm is globally and superlinearly convergent based on the Armijo-Goldstein line searches.

关键词： BFGS methods convergence superlinear convergence

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Nanostructured Sulfide Composite Coating Prepared by Atmospheric Plasma Spraying

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材料工程 2006年第Z1期34卷 281-284页

作者： GUAN Yao-hui~1,XU Yang~1,ZHENG Zhong-yu~2,TONG Xiao-hui~2(1 Engineering College of china agricultural university,beijing 100083,china 2 beijing Research Institute of Mechanical & Electrical Technology,beijing 100083,china) Engineering College China Agricultural University Beijing 100083 China beijing Research Institute of Mechanical and Electrical Technology Beijing 100083 China

Nanostructured FeS-SiC coating was deposited by atmospheric plasma spraying（APS）.The microstructure and phase composition of the coating were characterized with SEM and XRD,*** addition,the size distribution of the reconstituted powders and the porosity of the coating have been *** was found that the reconstitiuted powers with sizes in the range of 20 to 80 μm had excellent flowability and were suitable for plasma spraying *** as-sprayed FeS-SiC composite coating exhibited a bimodal distribution with small grains（30～80nm） and large grains（100～200nm）.The coating was mainly composed of FeS and SiC,a small quantity of Fe1-xS and oxide were also *** porosity of the coating was approximately 19%.

关键词： plasma spraying nanostructured FeS-SiC composite coating

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Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science china(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2, HUANG GuanHua1,2 & QU ZhongYi3 1 Center for Agriculture Water Research, china agricultural university, beijing 100083, china 2 Chinese-Israeli International Center for Research and Training in Agriculture, china agricultural university, beijing 100083, china 3 Water Conservancy and Civil Engineering College, Inner Mongolia agricultural university, Hohhot 010018, china Center for Agriculture Water Research China Agricultural University Beijing China Chinese-Israeli International Center for Research and Training in Agriculture China Agricultural University Beijing China Water Conservancy and Civil Engineering College Inner Mongolia Agricultural University Hohhot China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic Information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

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Flotation Separating Rutile from Calcium and Silicon Gangue Minerals

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Rare Metals 2001年第4期20卷 205-208页

作者： Hao Ding1, HaiLin 2 1) beijing Academy of Building Materials, beijing 100041, china 2) university of Science and Technology beijing, beijing 100083, china 北京建筑材料研究院北京 100041 北京科技大学北京 100083

Rutile separation from calcite, apatite and quartz by flotation was investigated. The results show that the rutile separation from calcium and silicon gangue minerals can be realized with alkyl-imino-bismethylene phos... 详细信息

关键词： rutile calcium and silicon gangue minerals flotation separate alkyl-imino-bismethylene phosphoric acid sodium hexametaphosphate

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Decisive influence of the ionization strength of cosmic rays on the cavitation characteristics of pure water

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Science china(Technological Sciences) 2009年第6期52卷 1804-1808页

作者： CHANG JinShi College of Water Conservancy & Civil Engineering,china agricultural university,beijing 100083,china College of Water Conservancy & Civil Engineering China Agricultural University Beijing China

The experiment result in this article shows that the initial and critical cavitation pressure of pure water are both increasing along with the increase of height above sea level,and the ionization strength of cosmic rays in the lower aerosphere is the crucial factor which influences the cavitation pressure of pure *** author concludes the relationship between the cavitaion pressure of pure water and the height above sea ***,air particles in water caused by the radiation of cosmic rays can exist in the water for a long time and will not escape.

关键词： initial cavitaiton pressure critical cavitation pressure ionization strength of cosmic rays height above sea level

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