全文获取类型
收费全文 | 2464篇 |
免费 | 147篇 |
国内免费 | 13篇 |
专业分类
电工技术 | 31篇 |
综合类 | 17篇 |
化学工业 | 694篇 |
金属工艺 | 40篇 |
机械仪表 | 41篇 |
建筑科学 | 169篇 |
矿业工程 | 29篇 |
能源动力 | 52篇 |
轻工业 | 238篇 |
水利工程 | 22篇 |
石油天然气 | 13篇 |
无线电 | 185篇 |
一般工业技术 | 465篇 |
冶金工业 | 281篇 |
原子能技术 | 11篇 |
自动化技术 | 336篇 |
出版年
2023年 | 16篇 |
2022年 | 36篇 |
2021年 | 63篇 |
2020年 | 54篇 |
2019年 | 51篇 |
2018年 | 48篇 |
2017年 | 45篇 |
2016年 | 88篇 |
2015年 | 86篇 |
2014年 | 121篇 |
2013年 | 133篇 |
2012年 | 112篇 |
2011年 | 133篇 |
2010年 | 88篇 |
2009年 | 118篇 |
2008年 | 101篇 |
2007年 | 98篇 |
2006年 | 79篇 |
2005年 | 79篇 |
2004年 | 68篇 |
2003年 | 61篇 |
2002年 | 51篇 |
2001年 | 35篇 |
2000年 | 34篇 |
1999年 | 46篇 |
1998年 | 89篇 |
1997年 | 54篇 |
1996年 | 61篇 |
1995年 | 37篇 |
1994年 | 42篇 |
1993年 | 39篇 |
1992年 | 28篇 |
1991年 | 39篇 |
1990年 | 29篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 12篇 |
1986年 | 23篇 |
1985年 | 17篇 |
1984年 | 20篇 |
1983年 | 24篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1980年 | 22篇 |
1979年 | 16篇 |
1978年 | 24篇 |
1977年 | 15篇 |
1976年 | 18篇 |
1975年 | 9篇 |
1968年 | 9篇 |
排序方式: 共有2624条查询结果,搜索用时 15 毫秒
1.
Nazir Kizzie‐Hayford Doris Jaros Yvonne Schneider Harald Rohm 《International Journal of Food Science & Technology》2015,50(2):381-388
A standard method for the extraction of tiger nut milk has been introduced. It has been shown that, although milling duration improves the yield of tiger nut milk solids and its nutrient composition, there is a quantifiable loss of nutrient in the pressing residue during milk extraction. Milling duration improved the colloidal stability of the milk against creaming during 16 h of storage. A higher milling intensity resulted in the aggregation of biological polymers which resulted in colloidal destabilisation. Milling improved the lightness and stability and reduced browning rate of the tiger nut milk during storage. This report is important for the production of tiger nut milk of consistent and comparable characteristics. Milling has been introduced as a processing method for the qualitative and quantitative modulation of the properties of tiger nut milk. It is recommended to develop further strategies to improve the colloidal stability of tiger nut milk as a beverage. 相似文献
2.
Sakizadeh Mohamad Mohamed Mohamed M. A. Klammler Harald 《Water Resources Management》2019,33(4):1425-1437
Water Resources Management - Overexploitation of groundwater in the Malayer Plain has resulted in a continuous decline of groundwater levels over recent years with associated risks to water... 相似文献
3.
4.
Symbolic parametrization of curves 总被引:1,自引:0,他引:1
If algebraic varieties like curves or surfaces are to be manipulated by computers, it is essential to be able to represent these geometric objects in an appropriate way. For some applications an implicit representation by algebraic equations is desirable, whereas for others an explicit or parametric representation is more suitable. Therefore, transformation algorithms from one representation to the other are of utmost importance.We investigate the transformation of an implicit representation of a plane algebraic curve into a parametric representation. Various methods for computing a rational parametrization, if one exists, are described. As a new idea we introduce the concept of working with classes of conjugate (singular or simple) points on curves. All the necessary operations, like determining the multiplicity and the character of the singular points or passing a linear system of curves through these points, can be applied to such classes of conjugate points. Using this idea one can parametrize a curve if one knows only one simple point on it. We do not propose any new method for finding such a simple point. By classical methods a rational point on a rational curve can be computed, if such a point exists. Otherwise, one can express the coordinates of such a point in an algebraic extension of degree 2 over the ground field. 相似文献
5.
6.
7.
8.
Ohne Zusammenfassung 相似文献
9.
10.
The special situation of patent information is dealt with against the background of the general problems of information provision. The role of the Patent Department of Siemens as a user of patent information and in the distribution of patent information within the company is discussed. Finally, the present system of current patent information on granted patents and first publications is outlined and an outlook on future developments given. 相似文献