检索结果-南通市图书馆

A Knowledge Model System for Wheat Production Management

Pedosphere 2007年第2期17卷 172-181页

作者： ZHU Yan CAO Wei-Xing DAI Ting-Bo TIAN Yong-Chao YAO Xia hi-tech Key Laboratory of Information Agriculture of Jiangsu Province Nanjing Agricultural University Nanjing 210095 （China）. Key Laboratory of Crop Growth Regulation of Ministry of Agriculture Nanjing Agricultural University Nanjing 210095 （China）

A knowledge model with temporal and spatial characteristics for the quantitative design of a cultural pattern in wheat production, using systems analysis and dynamic modeling techniques, was developed for wheat management, as a decision-making tool in digital farming. The fundamental relationships and algorithms of wheat growth indices and management criteria to cultivars, ecological environments, and production levels were derived from the existing literature and research data to establish a knowledge model system for quantitative wheat management using Visual C^＋＋. The system designed a cultural management plan for general management guidelines and crop regulation indices for timecourse control criteria during the wheat-growing period. The cultural management plan module included submodels to determine target grain yield and quality, cultivar choice, sowing date, population density, sowing rate, fertilization strategy, and water management, whereas the crop regulation indices module included submodels for suitable development stages, dynamic growth indices, source-sink indices, and nutrient indices. Ewluation of the knowledge model by design studies on the basis of data sets of different eco-sites, cultiwrs, and soil types indicated a favorable performance of the model system in recommending growth indices and management criteria under diverse conditions. Practical application of the knowledge model system in comparative field experiments produced yield gains of 2.4% to 16.5%. Thus, the presented knowledge model system overcame some of the difficulties of the traditional wheat management patterns and expert systems, and laid a foundation for facilitating the digitization of wheat management.

关键词： expert system knowledge model quantitative decision-making regulation index wheat

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two alternative modes for diffuse pollution control in Wuhan City Zoo

引用

Journal of Environmental Sciences 2007年第9期19卷 1067-1073页

作者： CHEN Qing-feng SHAN Bao-qing YIN Cheng-qing HU Cheng-xiao State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of Sciences Beijing 10085 China College of Resources and Environment Huazhong Agriculture University Wuhan 430050 China.

Pollution in urban zoos arises from diffuse and small point sources. However, its control has received little attention in past decades. Online and ofttine modes of ecological engineering technology were designed to control pollution from small point and diffuse sources in Wuhan City Zoo, China. Their characteristics and performances were investigated in sixteen runoff events from 2003 to 2005. The results showed that the two modes both improved runoff water quality and had high retention rates for water and pollutants. In the outflows, the event mean concentrations （EMCs） of total suspended solids （TSS）, chemical oxygen demand （COD）, total nitrogen （TN） and total phosphorus （TP） were reduced by 88%, 59%, 46% and 71% for the online mode, and those were 77%, 42%, 50% and 66% for the ofttine mode. The annual retention rates of pollutant loads for the online mode were 94.9%-98.5% in the three study years; those for the ofitine mode were 70.5%-86.4%. Based on calculation, the online mode was able to store the runoff of 66.7 mm rainfall completely, and the ofttine mode could store that of 31.3 mm rainfall. In addition, the online mode can provide an effective way for rainwater utilization and good habitats for aquatic wildlives, and has an excellent aesthetics value for recreationsal pastimes. The ofiline mode can save land resources and may be an effective and economical measure for diffuse pollution control in urban areas.

关键词： eutrophication runoff stormwater wetland zoo

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation of compaction and sintering behavior of SiC powder after ultra-fine treatment

引用

Journal of Zhejiang University Science 2004年第8期5卷 950-955页

作者：郭兴忠杨辉 CenterofNano-Science＆Nano-technology ZhejiangUniversityHangzhou310027China

Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as raw materials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of SiC ceramics were investigated. The results showed that the compacts had higher density and microstructure homogeneity when the sintering temperature of the compact was decreased; and that the surface microstructure, densification and mechanical properties of the sintered body could be ameliorated obviously.

关键词： SiC ceramic Ultra-fine treatment Compaction efficiency Sintering behavior

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Using Greedy algorithm: DBSCAN revisited II

引用

Journal of Zhejiang University Science 2004年第11期5卷 1405-1412页

作者：岳士弘李平郭继东周水庚 InstituteofIndustrialProcessControl ZhejiangUniversityHangzhou310027China YiliTeacher＇sCollege Yining835000China

The density-based clustering algorithm presented is different from the classical Density-Based Spatial Clustering of Applications with Noise (DBSCAN) (Ester et al., 1996), and has the following advantages: first, Greedy algorithm substitutes for R*-tree (Bechmann et al., 1990) in DBSCAN to index the clustering space so that the clustering time cost is decreased to great extent and I/O memory load is reduced as well; second, the merging condition to approach to arbitrary-shaped clusters is designed carefully so that a single threshold can distinguish correctly all clusters in a large spatial dataset though some density-skewed clusters live in it. Finally, authors investigate a robotic navigation and test two artificial datasets by the proposed algorithm to verify its effectiveness and efficiency.

关键词： DBSCAN algorithm Greedy algorithm Density-skewed cluster

来源：

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

Plasma-Neutral Gas Structure in a Magnesium Cathodic Arc Operating at Oxygen Gas with Experimental Comparison

引用

Plasma Science and technology 2013年第11期15卷 1116-1121页

作者：朱道云郑昌喜陈弟虎何振辉 Experiment Teaching Department Guangdong University of Technology State Key Laboratory of Optoelectronic Materials and technologies School of Physics andEngineering Sun Yat-sen University

The plasma-neutral gas structure generated in a magnesium cathodic arc operated with oxygen gas at a constant current of 50 A has been investigated by employing a simplified one-dimensional fluid model. The model includes elastic collisions and charge-exchange reactions between metallic particles and gas molecules, and also generation and recombination of gaseous ions by electron impact. The distribution profiles of density and velocity of species along the axial direction were obtained at different background gas pressures （in the range of 0.7-3.0 Pa） by this model. A comparison with the experiments was made. At lower gas pressures, the depositing particles were mainly the metallic ions with a larger kinetic energy. As the gas pressure increased, the magnesium atoms with smaller kinetic energy acted as the dominant depositing species. Determined by the minimization of the system＇s total energy, MgO（100） or/and MgO（110） orientation appeared easily in the MgO films at lower gas pressures, and at higher gas pressures, the film preferred orientation was MgO（111）.

关键词： cathodic arc plasma-neutral gas structure one-dimensional model MgO films

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reduction of nitrobenzene by the catalyzed Fe/Cu process

引用

Journal of Environmental Sciences 2008年第8期20卷 915-921页

作者： XU Wenying LI Ping FAN Jinhong The National Engineering research Center for Urban Pollution Control Tongji University Shanghai 200092 China

The polarization behavior of the couple Fe/Cu in 100 mg/L nitrobenzene aqueous solution was studied using Evans coupling *** results indicated that the iron corrosion was limited by both anodic and cathodic half-cell reactions under the neutral conditions,and cathodically controlled under the alkaline *** experiments were performed to study the effect of solution pH,reaction duration,concentration,type of electrolyte,and dissolved oxygen(DO)on the reduction of nitrobenzene by the catal...

关键词： nitrobenzene Evans coupling diagram reduction mechanisms influencing factors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dissolution kinetics of copper from multi-metal copper alloy roasted in oxygen

引用

Journal of Central South University 2017年第2期24卷 335-340页

作者：卢伟红尹周澜丁治英刘洋 College of Chemistry & Chemical Engineering Central South University Changsha 410083 China

A kinetic study on the sulfuric acid leaching of multi-metal oxide, which is the product of multi-metal copper alloy with iron trioxide roasted in oxygen, was carried out. The effects of leaching time, stirring speed, sulfuric acid concentration, reaction temperature, and particle size of the multi-metal oxide on the kinetics and mechanism of copper extraction were studied. It was found that the reaction kinetic model about the copper extraction from multi-metal oxide follows the mixed kinetic shrinking core mode： 1/31n（1-X）＋（1-X）-l/3-1=680.5C（H2SO4）0.4297dp0.75115exp（-Ea/RT）t.

关键词： leaching kinetic multi-metal copper alloy roasting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the technology of Ni-P Electroless Plating on the Mg Alloy

引用

稀有金属材料与工程 2012年第S1期41卷 472-474页

作者： Liu Yihan Sun Huawei Jiang Yanan Northeastern Univ Shenyang 110004 Peoples R China Shenyang Second high Sch Shenyang 110016 Peoples R China

Base on the analysis for the corrosion mechanism of the Mg alloys,the technology of Ni-P directly electroless plating on the Mg-10Li-1Zn alloys was *** effects of the pre-treatment on the morphologies of substrate and plating films were investigated,The result shows that Ni-P electroless plating could be divided two steps:the induction period and the rapid deposition *** Ni-P film is amorphous structure:A excellent Ni-P coating can be obtained under the optimal *** Ni-P coating can obviously improve the corrosion resistance of Mg alloy in variety environment.

关键词： Mg alloy electroless plating Ni-P coating corrosion protection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A bioaugmentation failure caused by phage infection and weak biofilm formation ability

引用

Journal of Environmental Sciences 2009年第8期21卷 1153-1161页

作者： FU Songzhe FAN Hongxia LIU Shuangjiang LIU Ying LIU Zhipei State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100039 China Institute of Oceanology Chinese Academy of Sciences Qingdao 266701 China

Two biological aerated filters （BAF） were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization （FISH） with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved differently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9-18.

关键词： marine culture water circulation ammonia removal Lutimonas sp. hiO nitrification breakdown fluorescent in situhybridization (FISH)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tensile property of Al-Si closed-cell aluminum foam

引用

Transactions of Nonferrous Metals Society of China 2006年第6期7卷 1335-1340页

作者：尉海军姚广春刘宜汉 School of Materials and Metallurgy Northeastern University

Al-Si closed-cell aluminum foams of different densities were prepared by molten body transitional foaming *** tensile behavior of Al-Si closed-cell aluminum foam was studied and the influence of relative densities on the tensile strength and elastic modulus was also *** results show that the fracture surfaces of Al-Si closed-cell aluminum foam display quasi-cleavage fracture consisting of brittle cleavages and ductile *** tensile strength and elastic modulus are strictly affected by the relative density of Al-Si closed-cell aluminum *** increasing relative density,the tensile strength increases and the strain at which the peak strength is measured also increases;in addition,the elastic modulus increases with increasing relative density.

关键词： Al-Si aluminum foam closed-cell tensile property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：