全文获取类型
收费全文 | 14671篇 |
免费 | 658篇 |
国内免费 | 27篇 |
学科分类
工业技术 | 15356篇 |
出版年
2023年 | 135篇 |
2022年 | 280篇 |
2021年 | 491篇 |
2020年 | 301篇 |
2019年 | 333篇 |
2018年 | 478篇 |
2017年 | 432篇 |
2016年 | 535篇 |
2015年 | 408篇 |
2014年 | 542篇 |
2013年 | 1119篇 |
2012年 | 706篇 |
2011年 | 877篇 |
2010年 | 657篇 |
2009年 | 710篇 |
2008年 | 608篇 |
2007年 | 519篇 |
2006年 | 503篇 |
2005年 | 430篇 |
2004年 | 537篇 |
2003年 | 620篇 |
2002年 | 583篇 |
2001年 | 432篇 |
2000年 | 234篇 |
1999年 | 249篇 |
1998年 | 303篇 |
1997年 | 233篇 |
1996年 | 182篇 |
1995年 | 162篇 |
1994年 | 116篇 |
1993年 | 109篇 |
1992年 | 80篇 |
1991年 | 86篇 |
1990年 | 78篇 |
1989年 | 94篇 |
1988年 | 62篇 |
1987年 | 66篇 |
1986年 | 67篇 |
1985年 | 82篇 |
1984年 | 97篇 |
1983年 | 71篇 |
1982年 | 70篇 |
1981年 | 63篇 |
1980年 | 61篇 |
1979年 | 50篇 |
1978年 | 50篇 |
1977年 | 56篇 |
1976年 | 69篇 |
1975年 | 58篇 |
1973年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
I. Budić-Leto T. Lovrić J. Gajdoš Kljusurić I. Pezo U. Vrhovšek 《European Food Research and Technology》2006,222(3-4):397-402
Identification of anthocyanins in the wine made of the Croatian autochthonous grape variety of Babić (Vitis vinifera L.) was carried out and their profile was determined by means of high-performance liquid chromatography with diode array
and mass spectrometric detection. Dependence of anthocyanins content and profile on maceration treatment conditions was investigated.
Statistically significant differences of anthocyanins concentration in wines Babić produced by various maceration treatments
were confirmed by the use of multivariate analysis of variances. The investigation results indicated that the maceration temperature
exerts higher influence on anthocyanins concentration than the duration of maceration. In addition, on the basis of anthocyanin
composition and using different multivariate statistical analyses, differentiation of wines Babić according to maceration
treatments was procured. 相似文献
2.
Jan van Eijck 《Formal Aspects of Computing》1994,6(1):766-787
Presuppositions of utterances are the pieces of information you convey with an utterance no matter whether your utterance is true or not. We first study presupposition in a very simple framework of updating propositional information, with examples of how presuppositions of complex propositional updates can be calculated. Next we move on to presuppositions and quantification, in the context of a dynamic version of predicate logic, suitably modified to allow for presupposition failure. In both the propositional and the quantificational case, presupposition failure can be viewed as error abortion of procedures. Thus, a dynamic assertion logic which describes the preconditions for error abortion is the suitable tool for analysing presupposition. 相似文献
3.
4.
JFC磷酸酯的合成和应用 总被引:2,自引:0,他引:2
详述了JFC磷酸酯的合成工艺路线,以及它在织物前处理精练工艺中的应用。与其它磷酸酯类精练剂性能对比,证明它可作为一种性能优良的精练剂中的添加剂。 相似文献
5.
6.
An extended model and calculus, called RasterCalc, is presented for operations on discrete graphics rasters, including their colour functions. The operations are separated into two main categories: operations on domains, and operations on colour functions. The operations are further classified as local and remote, depending on the correspondence between destination and source pixels. The new raster element or pixel can be a function of a single element from one or more rasters, a function of a small area from other rasters, or a function of entire rasters. Local operations have their main applications in computer graphics, while remote operations are more oriented towards image processing. A mathematically oriented notation is used to define and represent the operations included. RasterCalc has been implemented as a procedure package in Pascal, to be used on a powerful, yet expensive display. Recently a C version has been completed for a personal colour computer with a special chip for raster operations. The work reported in this paper is partially supplied by the Dutch Technical Sciences Foundation, under project number LWI 14.0130: “Facilities for raster graphics in programming languages” 相似文献
7.
Bedich ika Helena Bendov Ivan Macha
《Chemical Engineering and Processing: Process Intensification》2005,44(12):1312-1319
A procedure has been proposed for the estimation of the terminal falling velocity of non-spherical particles moving in a Carreau model fluid in the transition flow region. The procedure is based on a modification of the relationship formerly developed for the fall of spherical particles including the particle dynamic shape factor. The suitability of the proposed procedure has been confirmed by good agreement between experimental and calculated terminal falling velocity data. In the experiments, the terminal falling velocity of short cylinders and rectangular prisms in polymer solutions of different measure of shear thinning and elasticity has been measured. 相似文献
8.
9.
10.
Farzaneh Fayazpour Bart Lucas Roosmarijn E. Vandenbroucke Stefaan Derveaux Jan Tavernier Sam Lievens Joseph Demeester Stefaan C. De Smedt 《Advanced functional materials》2008,18(18):2716-2723
To obtain more biologically relevant data there is a growing interest in the use of living cells for assaying the biological activity of unknown chemical compounds. Density ‘multiplex’ cell‐based assays, where different cell types are mixed in one well and simultaneously investigated upon exposure to a certain compound are beginning to emerge. To be able to identify the cells they should be attached to microscopic carriers that are encoded. This paper investigates how digitally encoded microparticles can be loaded with cells while keeping the digital code in the microcarriers readable. It turns out that coating the surface of the encoded microcarriers with polyelectrolytes using the layer‐by‐layer (LbL) approach provides the microcarriers with a ‘highly functional’ surface. The polyelectrolyte layer allows the growth of the cells, allows the orientation of the cell loaded microcarriers in a magnetic field, and does not hamper the reading of the code. It has further been shown that the cells growing on the polyelectrolyte layer can become transduced by adenoviral particles hosted by the polyelectrolyte layer. It is concluded that the digitally encoded microparticles are promising materials for use in biomedical and pharmaceutical in‐vitro research where cells are used as tools. 相似文献