全文获取类型
收费全文 | 2798篇 |
免费 | 224篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 3023篇 |
出版年
2024年 | 8篇 |
2023年 | 34篇 |
2022年 | 25篇 |
2021年 | 142篇 |
2020年 | 118篇 |
2019年 | 134篇 |
2018年 | 115篇 |
2017年 | 118篇 |
2016年 | 129篇 |
2015年 | 98篇 |
2014年 | 144篇 |
2013年 | 254篇 |
2012年 | 194篇 |
2011年 | 225篇 |
2010年 | 184篇 |
2009年 | 165篇 |
2008年 | 126篇 |
2007年 | 134篇 |
2006年 | 114篇 |
2005年 | 84篇 |
2004年 | 65篇 |
2003年 | 60篇 |
2002年 | 56篇 |
2001年 | 31篇 |
2000年 | 31篇 |
1999年 | 20篇 |
1998年 | 20篇 |
1997年 | 24篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1970年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有3023条查询结果,搜索用时 15 毫秒
71.
72.
Belén A. Acevedo María G. Chaves María V. Avanza Eduardo S. Dellacassa 《International Journal of Food Science & Technology》2014,49(2):423-428
The use of freeze‐drying for concentrating lime Rangpur juice was investigated. This procedure allowed obtaining concentrated Rangpur lime juices between 23 and 51.3 °Brix, without affecting their organoleptic and nutritional characteristics. The efficiency of the procedure was inversely related to the film thickness of the matrix to be lyophilised. The sublimation speed per unit area diminished with the reduction in the residual moisture content of the juice. The mathematical model that fitted to the concentration procedure allowed to predict the time required for concentrating Rangpur lime by freeze‐drying starting from samples of different thickness. When compared with other citric juices evaluated, the Rangpur lime juice was the most suitable for freeze‐drying concentration. The results could be used to devise optimal industrial freeze‐drying cycles for processing Rangpur lime juices at different concentrations. 相似文献
73.
Dan Raviv Eduardo Bayro-Corrochano Ramesh Raskar 《International Journal of Computer Vision》2017,124(2):132-144
We present a novel algorithm for generating the mean structure of non-rigid stretchable shapes. Following an alignment process, which supports local affine deformations, we translate the search of the mean shape into a diagonalization problem where the structure is hidden within the kernel of a matrix. This is the first step required in many practical applications, where one needs to model bendable and stretchable shapes from multiple observations. 相似文献
74.
Birzabith Mendoza-Novelo Diego I. Alvarado-Castro José L. Mata-Mata Juan V. Cauich-Rodríguez Arturo Vega-González Eduardo Jorge-Herrero Francisco J. Rojo Gustavo V. Guinea 《Materials science & engineering. C, Materials for biological applications》2013,33(4):2392-2398
The present study investigates the potential use of non-catalyzed water-soluble blocked polyurethane prepolymer (PUP) as a bifunctional cross-linker for collagenous scaffolds. The effect of concentration (5, 10, 15 and 20%), time (4, 6, 12 and 24 h), medium volume (50, 100, 200 and 300%) and pH (7.4, 8.2, 9 and 10) over stability, microstructure and tensile mechanical behavior of acellular pericardial matrix was studied. The cross-linking index increased up to 81% while the denaturation temperature increased up to 12 °C after PUP crosslinking. PUP-treated scaffold resisted the collagenase degradation (0.167 ± 0.14 mmol/g of liberated amine groups vs. 598 ± 60 mmol/g for non-cross-linked matrix). The collagen fiber network was coated with PUP while viscoelastic properties were altered after cross-linking. The treatment of the pericardial scaffold with PUP allows (i) different densities of cross-linking depending of the process parameters and (ii) tensile properties similar to glutaraldehyde method. 相似文献
75.
This paper focuses on the design of time-homogeneous fully observed Markov decision processes (MDPs), with finite state and action spaces. The main objective is to obtain policies that generate the maximal set of recurrent states, subject to convex constraints on the set of invariant probability mass functions. We propose a design method that relies on a finitely parametrized convex program inspired on principles of entropy maximization. A numerical example is provided to illustrate these ideas. 相似文献
76.
Abstract Musicians have long been interested in using iterative processes to aid the composition of musical forms (macrostructure) and to synthesize sounds (microstructure). This paper introduces a new sound synthesis method exploring the non-linear behaviour of two iterative cross-coupled digital oscillators. It begins with a brief introduction to iterative systems followed by background information on previous attempts at using them for synthesizing sounds (e.g. feedback frequency and amplitude modulations). Next, it introduces our synthesis method and briefly explains how it has been implemented in a system for real-time composition and performance. The paper concludes with a discussion on how the system has been put into practice to compose and perform a number of works. 相似文献
77.
Jose Luz Silveira Wendell de Queiroz Lamas Celso Eduardo Tuna Iraides Aparecida de Castro Villela Laura Siso Miro 《Renewable & Sustainable Energy Reviews》2012,16(5):2894-2906
This work aims with an approach for cogeneration plants evaluation based on thermoeconomic functional diagram analysis. The second law of thermodynamics is used to develop a methodology to analyse cogeneration systems, based on exergoeconomics evaluation. The thermoeconomic optimisation method developed is applied to allow a better configuration of the cogeneration plant associated to a university hospital. Also ecological efficiency is evaluated. The method was efficient and contributes for thermoeconomics modelling and analysis and can be applied to any sort of thermal system, especially those with combined heat and power in thermal parity. 相似文献
78.
Valério Rosset Pedro F. Souto Paulo Portugal Francisco Vasques 《Computer Standards & Interfaces》2012,34(3):281-291
We present reliability models for a group membership protocol designed for TDMA networks such as FlexRay, a protocol that is likely to become the de facto standard for next generation automotive networks. The models are based on discrete-time Markov chains and consider a comprehensive set of fault scenarios. Furthermore, they are parametric allowing for a sensitivity analysis. The results, obtained by a numeric solution of the models using the PRISM model-checker, show that they are computationally practical for realistic configurations and that the GMP can achieve reliability levels in the range required for safety critical applications. 相似文献
79.
Fernanda Arboite de Oliveira Ana Paula Pasqualotto Wladimir Padilha da Silva Eduardo Cesar Tondo 《Food research international (Ottawa, Ont.)》2012,45(2):1000-1003
This study aimed to characterize Salmonella Enteritidis (SE) isolated from blood (n = 12) and feces (n = 68) of salmonellosis victims in Southern Brazil. All isolates were submitted to antimicrobial susceptibility testing, PCR-ribotyping, and XbaI macrorestriction Pulsed-Field Gel Eletrophoresis (PFGE). Results demonstrated high levels of ampicillin and nalidixic acid resistance, and strains isolated in different geographic regions were clustered together, presenting a common resistance profile. All strains demonstrated similar and related PCR-ribotyping patterns (R1, R2, and R3); being that the predominant profile R1 grouped 47.5% of the strains. PFGE profile P1 grouped the majority of the strains (96.25%), suggesting a clonal relationship among the strains or inability of molecular typing methods to discriminate strains of this serovar. Results suggested on an increase in antimicrobial resistance and that strains of S. Enteritidis with similar PFGE and PCR-ribotyping profiles were involved in several salmonellosis outbreaks in Southern Brazil. 相似文献
80.
Given a wide amount of possible ratios available for constructing a LOGIT model for forecasting bankruptcy, this paper provides a computational search methodology, only guided by data, for selecting the financial ratios employed in the model. This procedure is based on genetic algorithms which are used to explore the universe of models made available by all possible existing financial ratios (with very redundant information). This search process of the correct model is guided by the Schwarz information criterion. As an empirical illustration, the methodology is applied to forecasting the failure of firms in the Spanish building industry using annual public accounting information. 相似文献