检索结果-南通市图书馆

Evaluation Method of Web Site Structure Based on Web Structure Mining

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2003年第3A期8卷 791-796页

作者： Li Jun\|e 1 , Zhou Dong\|ru 2 1. Computer center,wuhan university, wuhan 430072, Hubei, china 2. School of Computer,wuhan university, wuhan 430072, Hubei,china wuhan university Computer Center Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) wuhan university School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The structure of Web site became more complex than before. During the design period of a Web site, the lack of model and method results in improper Web structure, which depend on the designer's experience. From the point of view of software engineering, every period in the software life must be evaluated before starting the next period's work. It is very important and essential to search relevant methods for evaluating Web structure before the site is completed. In this work, after studying the related work about the Web structure mining and analyzing the major structure mining methods (Page\|rank and Hub/Authority), a method based on the Page\|rank for Web structure evaluation in design stage is proposed. A Web structure modeling language WSML is designed, and the implement strategies for evaluating system of the Web site structure are given out. Web structure mining has being used mainly in search engines before. It is the first time to employ the Web structure mining technology to evaluate a Web structure in the design period of a Web site. It contributes to the formalization of the design documents for Web site and the improving of software engineering for large scale Web site, and the evaluating system is a practical tool for Web site construction.

关键词： web structure mining page\|rank web structure evaluation modeling language for web structure

Fabrication and characterization of electrospun TiO2/CuS micro-nano-scaled composite fibers

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2012年第1期22卷 59-63页

作者： Delong Li,Chunxu Pan School of Physics and Technology,center for electron microscopy and MOE Key Laboratory of Artificial Micro-and Nano-structures,wuhan university,wuhan 430072,china School of Physics and Technology Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures Wuhan University Wuhan 430072 China

A process to fabricate a kind of novel micro-nano scaled TiO2 /CuS composite fibers by electrospinning technique and chemical precipitation method was developed in the present *** microstructures and photoelectronic properties of the fibers were characterized using SEM,FT-IR,UV-vis and fluorescence *** results revealed that the TiO2 portion in the composite fibers was a mixture rutile and anatase phases while TiO2 and CuS had been fully *** fibers had smooth surface with a diameter of 50-300 *** with pure TiO2 fiber,the TiO2 /CuS micro-nano-scaled composite fibers exhibited a strong absorption in the visible light region and the efficiency of photo-induced charge separation were *** composite system is of widely potential applications in the areas such as solar cells,supercapacity,photocatalysis,etc.

关键词： Electrospinning TiO 2 CuS Composite fiber

CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

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 Journal of Polymer Science 2002年第4期20卷 369-375页

作者： Yun Chen Xiao-peng Xiong Guang Yang Li-na Zhang Sen-lin Lei Hui Liang electron Microscope Lab of Medical School, wuhan university wuhan 430072, china College of Chemistry and Molecular Sciences, wuhan university, wuhan 430072, china wuhan Univ Coll Chem & Mol Sci Wuhan 430072 Peoples R China wuhan Univ Sch Med Electron Microscope Lab Wuhan 430072 Peoples R China

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

关键词： hydrolysis cellulose acetate thermal stability regenerated cellulose membrane pore size solvent-resistance SEM

Seabed Classification Using BP Neural Network Based on GA

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2003年第4期22卷 523-531页

作者： Yang Fanlin1, Liu Jingnan2 1. GPS Engineering Research center, wuhan university, wuhan 430079, china. 2. Presidential Secretariat, wuhan university, wuhan 430079, china wuhan Univ GPS Engn Res Ctr Wuhan 430079 Peoples R China

Side scan sonar imaging is one of the advanced methods for seabed study. In order to be utilized in other projects, such as ocean engineering, the image needs to be classified according to the distributions of different classes of seabed materials. In this paper, seabed image is classified according to BP neural network, and. Genetic Algorithm is adopted in train network in this paper. The feature vectors are average intensity, six statistics of texture and two dimensions of fractal. It considers not only the spatial correlation between different pixels, but also the terrain coarseness. The texture is denoted by the statistics of the co-occurrence matrix. Double Blanket algorithm is used to calculate dimension. Because a uniform fractal may not be sufficient to describe a seafloor, two dimensions are calculated respectively by the upper blanket and the lower blanket. However, in sonar image, fractal has directivity, i. e. there are different dimensions in different direction. Dimensions are different in acrosstrack and alongtrack, so the average of four directions is used to solve this problem. Finally, the real data verify the algorithm. In this paper, one hidden layer including six nodes is adopted. The BP network is rapidly and accurately convergent through GA. Correct classification rate is 92.5 % in the result.

关键词： BP network co-occurrence matrix fractal classification genetic algorithin

electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第3期47卷 232-238页

作者： LIU Xiangwen1,2, YANG Guangming2, ZOU Huamin3, QU Jing1 & ZHAO Wenxia4 1. Graduate School, china university of Geosciences, wuhan 430074, china 2. Test center, china university of Geosciences, wuhan 430074, china 3. Physics and Technology College, wuhan university, wuhan 430072, china 4. Test center, Zhongshan university, Guangzhou 510275, china china Univ Geosci Grad Sch Wuhan 430074 Peoples R China china Univ Geosci Test Ctr Wuhan 430074 Peoples R China wuhan Univ Phys & Technol Coll Wuhan 430072 Peoples R China Zhongshan Univ Test Ctr Guangzhou 510275 Peoples R China

Sakhaite specimens from an endogenous borate deposit in Hunan Province, china have been studied in detail by means of transmission electron microscopy (TEM). The selected area electron diffraction (SAED) patterns obtained with different crystal zone axes show that the crystal system is cubic, with a = 1.463 nm. The convergent beam electron diffraction (CBED) patterns indicate that the point group and space group of sakhaite is m3m and Fd3m, respec-tively. The space group of synthetic sakhaite determined by Chichagov (1974) is F4132. The possible reasons why the space groups of the natural and the synthetic sakhaites are different are discussed.

关键词： sakhaite, space group, convergent beam electron diffraction (CBED).

Modification of Fluorgypsum as Cement Retarder

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of Technology(Materials Science) 2007年第4期22卷 745-748页

作者：王锦华 School of Materials Science and Engineering Wuhan University of Technology

The chemical composition and mineral structure of fluorgypsum as well as its harm to application in cement were elaborately analyzed. The primary fluorgypsum was modified and its applications in cement＇s production were studied. The technological flow chart of preparing modified fluorgypsum was given. Experimental results indicate that hydration ratio the modified fluorgypsum through adding compound additive for 14d is about 70%. The modified fluorgypsum as cement retarder has certain stimulation to fly ash and increases the strength of compound cement. In addition, its adding amount is lower than that of natural gypsum. The modified fluorgypsum is a good substitute for natural gypsum.

关键词： fluorgypsum industry waste modification cement retarder

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2002年第1期7卷 107-112页

作者： Zheng Hua 1 , Du Yu-min 2 1. Department of Chemical Engineering, wuhan university of Technology, wuhan 430070, Hubei, china 2. College of Chemistry and Molecular Sciences, wuhan university, wuhan 430072, Hubei, china wuhan university of Technology Department of Chemical Engineering Wuhan Hubei China (GRID:grid.162110.5) (ISNI:***) wuhan university College of Chemistry and Molecular Sciences Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2%(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

关键词： Key words chitosan carboxymethylated konjac glucomannan blend films structure characterization

Fractal Dimension of Voice-Signal Waveforms

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2002年第4期7卷 399-402页

作者： Xie Yu qiong, Wen Zhi xiong Non linear Science center , wuhan university,wuhan 430072,Hubei,china wuhan university Non-linear Science Center Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The fractal dimension is one important parameter that characterizes waveforms. In this paper, we derive a new method to calculate fractal dimension of digital voice-signal waveforms. We show that fractal dimension is an efficient tool for speaker recognition or speech recognition. It can be used to identify different speakers or distinguish speech. We apply our results to Chinese speaker recognition and numerical experiment shows that fractal dimension is an efficient parameter to characterize individual Chinese speakers. We have developed a semiautomatic voiceprint analysis system based on the theory of this paper and former researches.

关键词： Key words fractal dimension voiceprint analysis speaker recognition speech recognition biometric authentication

中国政治经济学年度发展报告（2023）（下）

在线全文

学校读者我要写书评

暂无评论

政治经济学评论 2024年第3期 90+207-208页

作者： center for Studies of Contemporary Political Economy,Research Institute for 21st-Century Marxism,Nankai university·university of Chinese Academy of Social Science center for Teaching and Research on Capital,Renmin university of china National Institute of Socialist Political Economy with Chinese Characteristics,Renmin university of china 南开大学·中国社会科学院大学21世纪马克思主义研究院当代政治经济学研究中心中国人民大学《资本论》教学与研究中心中国人民大学全国中国特色社会主义政治经济学研究中心

编者按2023年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，...

编者按2023年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，取得系列代表性成果。为准确刻画学界研究进展和轨迹，推动中国经济学理论体系的构建和完善，本刊精选议题如期奉上《中国政治经济学年度发展报告（2023）》。自2010年起，本刊连续十四年发布《中国政治经济学年度发展报告》，“年度发展报告”专栏已成为本刊标志性特色栏目。2023年报告聚焦12个专题，分为（上）（下）两篇，其中专题1—6于报告（上）篇刊登，专题7—12由报告（下）篇刊登。2023年报告（下）选题如下：

关键词：