全文获取类型
收费全文 | 2975篇 |
免费 | 143篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 34篇 |
综合类 | 3篇 |
化学工业 | 658篇 |
金属工艺 | 44篇 |
机械仪表 | 60篇 |
建筑科学 | 111篇 |
矿业工程 | 5篇 |
能源动力 | 65篇 |
轻工业 | 370篇 |
水利工程 | 44篇 |
石油天然气 | 5篇 |
无线电 | 279篇 |
一般工业技术 | 497篇 |
冶金工业 | 604篇 |
原子能技术 | 31篇 |
自动化技术 | 310篇 |
出版年
2023年 | 21篇 |
2022年 | 19篇 |
2021年 | 127篇 |
2020年 | 46篇 |
2019年 | 55篇 |
2018年 | 58篇 |
2017年 | 54篇 |
2016年 | 71篇 |
2015年 | 74篇 |
2014年 | 76篇 |
2013年 | 154篇 |
2012年 | 114篇 |
2011年 | 158篇 |
2010年 | 122篇 |
2009年 | 132篇 |
2008年 | 143篇 |
2007年 | 114篇 |
2006年 | 98篇 |
2005年 | 65篇 |
2004年 | 86篇 |
2003年 | 68篇 |
2002年 | 54篇 |
2001年 | 60篇 |
2000年 | 64篇 |
1999年 | 59篇 |
1998年 | 155篇 |
1997年 | 97篇 |
1996年 | 85篇 |
1995年 | 61篇 |
1994年 | 40篇 |
1993年 | 49篇 |
1992年 | 24篇 |
1991年 | 26篇 |
1990年 | 31篇 |
1989年 | 26篇 |
1988年 | 17篇 |
1987年 | 26篇 |
1986年 | 30篇 |
1985年 | 21篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 18篇 |
1978年 | 17篇 |
1977年 | 25篇 |
1976年 | 46篇 |
1975年 | 15篇 |
1971年 | 14篇 |
排序方式: 共有3120条查询结果,搜索用时 296 毫秒
1.
2.
Casalaro Giuseppina Lucia Cattivera Giulio Ciccozzi Federico Malavolta Ivano Wortmann Andreas Pelliccione Patrizio 《Software and Systems Modeling》2022,21(1):19-49
Software and Systems Modeling - Mobile robots operate in various environments (e.g. aquatic, aerial, or terrestrial), they come in many diverse shapes and they are increasingly becoming parts of... 相似文献
3.
4.
5.
The fission yeast Schizosaccharomyces pombe is an important model organism for the study of fundamental questions in eukaryotic cell and molecular biology. A plethora of cellular processes are membrane associated and/or dependent on the proper functioning of cellular membranes. Phospholipids are not only the basic building blocks of cellular membranes; they also serve as precursors to numerous signaling molecules. In this review, we describe the biosynthetic pathways leading to major S. pombe phospholipids, how these pathways are regulated, and what is known about degradation and turnover of fission yeast phospholipids. This review also addresses the synthesis, regulation and the role of water-soluble phospholipid precursors. The last chapter of the review is devoted to the use of S. pombe for the biotechnological production of value-added lipid molecules. 相似文献
6.
Dipl.-Biol. Michael Gommel Claudia Raichle Patrick Müller Frieder Keller 《Ethik in der Medizin》2005,17(1):21-27
Definition of the problem: Ethical reasoning cannot be enforced. Voluntary understanding is a basic condition for the development of ethical competencies and attitudes. The aim of this survey was to investigate whether the presence of those students who attended our seminars compulsorily would have a negative effect upon the quality of the course. Methods and results: The participants of our small-group seminars in medical ethics were asked to complete a questionnaire on teaching aims, seminar atmosphere, moderation and importance of subjects. One hundred and ninety-two voluntary participants (2001/2) and 293 compulsory participants (2002/3) completed the questionnaire and were statistically compared. There was no significant difference between voluntary and compulsory participants in any of the important items. However, there were considerable differences in some items between male and female participants. Conclusion: We were surprised that there was no difference between the two groups. This leads us to hope that our concept of case-based small-group seminars will prove capable of realising our teaching aims for all students. The difference between male and female participants may have important didactic consequences and will be the subject of further studies. 相似文献
7.
8.
Non-pinched, minimum energy solutions are important class of distillation designs that offer the potential advantage of a better trade-off between capital investment and operating costs. In this paper, two important tasks associated with non-pinched distillation designs are studied. Thus the novel contributions of this work to the literature are
- (1) A comprehensive methodology for finding non-pinched minimum energy designs.
- (2) Understanding of the reasons for the existence of non-pinched distillation designs.
9.
An innovative method for modelling biological processes under anaerobic conditions is presented and discussed. The method is based on titrimetric and off-gas measurements. Titrimetric data is recorded as the addition rate of hydroxyl ions or protons that is required to maintain pH in a bioreactor at a constant level. An off-gas analysis arrangement measures, among other things, the transfer rate of carbon dioxide. The integration of these signals results in a continuous signal which is solely related to the biological reactions. When coupled with a mathematical model of the biological reactions, the signal allows a detailed characterisation of these reactions, which would otherwise be difficult to achieve. Two applications of the method to the enhanced biological phosphorus removal processes are presented and discussed to demonstrate the principle and effectiveness of the method. 相似文献
10.
Energy management for commercial servers 总被引:1,自引:0,他引:1
Servers: high-end, multiprocessor systems running commercial workloads, have typically included extensive cooling systems and resided in custom-built rooms for high-power delivery. Recently, as transistor density and demand for computing resources have rapidly increased, even these high-end systems face energy-use constraints. Commercial-server energy management now focuses on conserving power in the memory and microprocessor subsystems. Because their workloads are typically structured as multiple application programs, system-wide approaches are more applicable to multiprocessor environments in commercial servers than techniques that primarily apply to single-application environments, such as those based on compiler optimizations. 相似文献