全文获取类型
收费全文 | 459篇 |
免费 | 18篇 |
专业分类
电工技术 | 23篇 |
综合类 | 2篇 |
化学工业 | 83篇 |
金属工艺 | 11篇 |
机械仪表 | 17篇 |
建筑科学 | 21篇 |
矿业工程 | 1篇 |
能源动力 | 4篇 |
轻工业 | 36篇 |
水利工程 | 1篇 |
无线电 | 33篇 |
一般工业技术 | 117篇 |
冶金工业 | 98篇 |
原子能技术 | 1篇 |
自动化技术 | 29篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 12篇 |
2013年 | 22篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 12篇 |
2008年 | 15篇 |
2007年 | 20篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 14篇 |
1998年 | 25篇 |
1997年 | 23篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1989年 | 5篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1971年 | 6篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1932年 | 4篇 |
1929年 | 3篇 |
1928年 | 3篇 |
排序方式: 共有477条查询结果,搜索用时 31 毫秒
1.
2.
3.
Summary
This article reports the synthesis of novel hydrophilic end-branched poly(ethylene glycol)s, in aqueous media by atom transfer
radical polymerization (ATRP). Poly(ethylene glycol)s with molecular weights 10,000 and 16,000 were end-functionalized and
used as bifunctional initiators for the polymerization of a poly(ethylene glycol) macromonomer with a molecular weight of
2,000 (PEGMA), either by aqueous ATRP or in a watedmethanol (l/l V/V) mixture. For both macroinitiators a DP of 10 was the
target, giving an average of 5 branches in each end. The rates of polymerization were of the same order of magnitude when
the polymerizations were initiated by either of the two macroinitiators in watedmethanol (l/l V/V). When a bifunctional oligo(ethy1ene
glycol) initiator (Mn = 600) was used to study the polymerization of PEGMA in water/methanol a reduction in the rate of polymerization was observed
indicating an influence of the molecular weight of the initiator on the rate of polymerization.
Received 25 Maich 2002/Revised 8 November 2002/Accepted 8 November 2002
Correspondence to Jorgen Kops 相似文献
4.
5.
6.
Biological membranes are often poorly visible with the electron microscope after high‐pressure freezing and freeze‐substitution. The water content of the sample and of the substitution medium is one factor among others that strongly influences membrane visibility. In order to investigate this effect, high‐pressure frozen yeast cells, rat‐pancreas tissue and arthropod tissue were freeze‐substituted with and without adding water to the substitution medium. The visibility of the biological membranes was generally improved if the substitution medium contained 1–5% water. The effect was especially pronounced in yeast cells, where membrane visibility was poor after freeze‐substitution with water‐free medium but good after addition of 5% water to the substitution medium. 相似文献
7.
Definition of the problem
The concept of “ethics” has recently been incorporated into both the 2014 Model Professional Code for Dentists and the current version of the “National Competence-Based Catalog of Learning Objectives in Dental Medicine” (NKLZ, Nationaler Kompetenzbasierter Lernzielkatalog Zahnmedizin). The study presented here addresses the question which relevance this has for the relevance of the new concept accomplished for the dental profession and society.Arguments
To this end, the societal processes that are related to the autonomous freedom of action of the dental profession are discussed. Therefore the sociological fields of discourse such as profession (and the effect of its constitutive antinomies), trust, education, expertise, practice of treatments and sanction are reviewed for their potential of having connections to each other and serving as a structural frame concerning an ethically reflected acting of the professional. The basis of the professional freedom of action is the trust of society and the individual patient in the professionally acting dentist.Conclusion
The study arrives at the conclusion that it was a serious omission for many decades not to make young dentists aware of the ethical foundations of dental activity on an institutionally established basis and thus failing to encourage them to constantly reflect their professional expertise in relation to the problems to be solved. This deficit has now been identified. It is absolutely essential to implement an institutionalized structure dealing with ethical questions within the scope of dental medicine.8.
Bodo Walther 《Datenschutz und Datensicherheit - DuD》2016,40(9):598-604
9.
10.