检索结果-南通市图书馆

A New Approach to the Level Function

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 237-240页

作者： Yaosong CHEN &Jiangfa LIN (Dept.of Mech.,Peking Univ.,Beijing1 0 0 871 ) Department of Mechanics and Engineering Science Peking Univesity Beijing 100871 China

This article devores to design a hybrid Level Set Method which compromises the advantages of the level functions designed in[2 ]and[3].

关键词： boundary fitting two phase flow level set

Numerical Computation of High Dimensional Solitons Via Darboux Transformation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 248-252页

作者： Zixiang ZHOU (Institute of Mathematics,Fudan University,Shanghai 2 0 0 433,China) E- mail:zxzhou@*** Institute of Mathematics Fudan University Shanghai 200433 China

Darboux transformation gives explicit soliton solutionsof nonlinear partial differential equations. Using numerical computation in each step of constructing Darboux transformation,one can get the graphs of the solitons ***(n 3) , this method greatly increases the speed and deduces the memory usage of computation comparing to the software for algebraic computation. A technical problem concerning floating overflow is discussed.

关键词： Darboux transformation numerical computation

Video learning based image classification method for object recognition

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2013年第9期20卷 2399-2406页

作者： LEE Hong-ro SHIN Yong-ju Department of NTIS Center Korea Institute of Science & Technology Information

Automatic image classification is the first step toward semantic understanding of an object in the computer vision *** key challenge of problem for accurate object recognition is the ability to extract the robust features from various viewpoint images and rapidly calculate similarity between features in the image database or video *** order to solve these problems,an effective and rapid image classification method was presented for the object recognition based on the video learning *** optical-flow and RANSAC algorithm were used to acquire scene images from each video *** the selection of scene images,the local maximum points on comer of object around local area were found using the Harris comer detection algorithm and the several attributes from local block around each feature point were calculated by using scale invariant feature transform （SIFT） for extracting local ***,the extracted local descriptor was learned to the three-dimensional pyramid match *** results show that our method can extract features in various multi-viewpoint images from query video and calculate a similarity between a query image and images in the database.

关键词： image classification multi-viewpoint image feature extraction video learning

Market Status Quo and Production Technology of CPP Film in China

在线全文

学校读者我要写书评

暂无评论

中国塑料 2004年第6期 8+10-8+10页

作者： CHENYing1,2 ( 1.SchoolofChemistryandChemicalTechnology ,ShanghaiJiaotongUniversity ,Shanghai 2 0 0 0 3 0 ,China 2 .WuxiHuanyaPackagingMaterialsCo .,Ltd .,Wuxi 2 14 0 2 8,China) School of Chemistry and Chemical Technology， Shanghai Jiaotong University， Shanghai 200030， China Wuxi Huanya Packaging Materials Co.， Ltd.，Wuxi 214028，China

1 Production capacity and annual demand of CPP 1.1 Situation of production and market of CPP The production of CPP originated from the eighties of the twenty-century in China. With 20 years' development, now there are... 详细信息

关键词： CPP Market Status Quo and Production Technology of CPP Film in China

Effects of Plant Residue Decomposition on Soil N Availability,Microbial Biomass and β-Glucosidase Activity During Soil Fertility Improvement in Ghana

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2019年第5期29卷 608-618页

作者： Samuel T. PARTEY robert B. Z0UGM0RE Naresh V. THEVATHASAN Richard F. PREZIOSI CGI AR CCAFS West Africa ProgramInternational Crops Research Institute for the Semi-Arid Tropics (ICRISAT)Bamako B.P. Box 320 (Mali) School of Environmental Sciences University of GuelphGuelph NIG 2W1 (Canada) Faculty of Life Sciences The University of ManchesterManchester M13 9PL (UK)

With limited use of inorganic fertilizers on smallholder farms,plant residues could be viable alternatives for soil fertility *** study was conducted to determine how residue quality and decomposition of nine plant species influence soil N availability,microbial biomass,andβ-glucosidase activity during soil fertility *** differences in N concentration were found among the species,ranging from 12.2 g kg-1 in Zea mays to 39.2 g kg-1 in Baphia *** C/N ratio was the highest in ***(34.4),whereas lignin and polyphenol concentrations were the greatest in Acacia *** highest decomposition rate(0.251%per day)occurred in Tithonia diversifolia,and the lowest in ***,Albizia zygia,***,and ***,with the half-lives of 28-56 *** 80%and 89%of N,P,K,Ca,and Mg were released from *** in 7 d,compared with over 70%retention in ***,***,and *** decomposition and nutrient release half-lives of Gliricidia sepium,Leucaena leucocephala,Azadirachta indica,and Senna spectabilis were less than 14 *** mineral N,microbial biomass,andβ-glucosidase activity increased under all treatments,with *** having the greatest *** N mineralization occurred in all of the species throughout the experiment,an initial N immobilization was recorded in the ***,***,***,and *** treatments for up to 14 *** and nutrient release rates,mineral N,soil microbial biomass,andβ-glucosidase activity were dependent on residue quality,and P and lignin levels,the lignin/N ratio,and the(lignin+polyphenol)/N ratio had the most significant effects(P≤0.05).

关键词： leguminous species litter quality microbial activity N mineralization nutrient release organic matter

Effects of the susceptibility of rice varieties to Sogatella furcifera on nymphal development and reproduction of Microvelia horvathi through a food chain

在线全文

学校读者我要写书评

暂无评论

Insect Science 2007年第4期14卷 317-321页

作者： TIE-GUANG XIA0 JIANG-XIA TANG Institute of Insect Ecology Hunan Agricultural UniversityChangshaChina

The effects of four rice varieties highly susceptible （ Xiang-Zao-Xian31 and Jia-Yu 164 ）, moderately susceptible （ Wei-You402 ）, and resistant （ Zhu-Liang-You02 ） to the whitebacked planthopper Sogatellafurcifera on the nymphal development, reproduc- tion and survival of Microvelia horoathi were investigated through a food chain using SogateUafurcifera as herbivore prey. Significant longer nymphal developmental time were observed in the 1 st, 4th, 5th instar and whole nymphal stage of M. horvathi raised on S. furcifera fed ZLY02 and WY402 than those of the other two varieties. M. horvathi raised on S. furcifera fed resistant ZLY02 showed a significant lower survival of whole nymphal stage than those fed other three susceptible varieties. Moreover, M. horvathi raised on S. furcifera fed resistant ZLY02 had shorter female longevity and lower lifetime fecundity than those of on susceptible XZX3l. Our results suggest that the S. furcifera- resistant rice variety ZLY02 had a negative effect on the growth and development of the predator M. horvathi through a food chain.

关键词： development food Microvelia horoathi rice variety Sogatellafurcifera,tritrophic interaction

BASIC FORMULATION OF STATIC AND DYNAMIC BEHAVIOURS OF SOIL AND OTHER POroUS MEDIA

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

Applied Mathematics and Mechanics(English Edition) 1982年第4期3卷 457-468页

作者： 0.C.Zienkiewicz University of Wales. Swansea. U. K. Department of Civil Engineering

This paper treats the soil and rock or concrete as a two-phasemedium composed of a solid skeleton and an interstitial ***-der the unsaturated condition of interstitial fluid,the thirdphase is taken into consideration. In this paper. we consider theconstitutive relation,dynamic and kinematic relations,and also va-rious approximations with their limits of *** thoseof most practical engineering situations such as the consolidationproblem and the undrained behaviour. The finite element discreti-zation and the time dependent solution of various classes of soilproblem are also discussed.

关键词： BASIC FORMULATION OF STATIC AND DYNAMIC BEHAVIOURS OF SOIL AND OTHER POroUS MEDIA

Synthesis and photocurrent response of porphyrin-containing conjugated polymers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第11期51卷 1287-1295页

作者： ZHAO Jinling LI Binsong B0 Zhishan State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

Porphyrin-containing conjugated poly- mers with fluorene or carbazole as spacer groups were prepared by Sonogashira cross-coupling reac- tions. The polymers were of high molecular weight and the flexible alkyl chains on fluorene or carbazole units made the conjugated polymers soluble in common organic solvents, such as THF and methyl- ene chloride. The polymers could form high quality durable films from solution casting. Their optical and photocurrent responsive properties were investigated. It was found that the photocurrent response was di- rectly proportional to the content of porphyrin. The incorporation of carbazole units into the polymer chains also gave positive contribution to the photo- current generation in some extent.

关键词：卟啉共轭聚合物光电流响应合成

Entry qualifications and academic performance of architecture students in Nigerian Polytechnics： Are the admission requirements still relevant？

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2014年第1期3卷 69-75页

作者： Peter 0 Adewale Olasunmbo Bolanle Adhuze Department of Architectural Technology The Federal Polytechnic Ado-Ekiti Ekiti-State Nigeria

The competence of fresh graduates of architecture has been continuously criticized by the industry for inadequate knowledge. This is often blamed on the poor standard of education evidenced by poor performances in professional and degree/diploma examinations conducted by various schools of architecture in the country. Although, factors responsible for the scenario are wetl documented in the literature, most of these works are based on testimonial and circumstantial evidences relating to management of architectural education only. The aim of this paper is to investigate the relationship between entry qualifications and the performance of architecture students in Nigerian Polytechnics with a view to determining the relevance of current admission policy to architectural education in Nigeria. Data were obtained from official records in the Department of Architecture in four randomly selected polytechnics in the southwestern part of Nigeria. Pearson Product Moment Corretation （r） was used to test the hypotheses. Findings reveal weak relationship between the two variables （physics and mathematics）. This is contrary to the expectations of most schotars and policy makers who opine that studentst proficiency in these subjects would enhance their performance at higher LeveLs. The paper traces the contradiction to the poor handling of public examinations and misconception of architecture as being pure science. It holds that if these requirements are still relied upon for the admission of students into schools of architecture, wrong candidates wouldcontinue to gain entry into the profession. The paper concludes by recommending certain measures that are capable of reversing the trend.

关键词： Academic perfor-mance Admission criteria Architecture Arts Education Science