全文获取类型
收费全文 | 243篇 |
免费 | 14篇 |
国内免费 | 3篇 |
专业分类
化学 | 145篇 |
数学 | 21篇 |
物理学 | 49篇 |
无线电 | 45篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 39篇 |
2012年 | 39篇 |
2011年 | 5篇 |
2010年 | 1篇 |
2009年 | 14篇 |
2008年 | 11篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1981年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1962年 | 1篇 |
排序方式: 共有260条查询结果,搜索用时 671 毫秒
1.
2.
3.
Stingeder G. Gara S. Pahlke S. Schwenk H. Guerrero E. Grasserbauer M. 《Analytical and bioanalytical chemistry》1989,333(4-5):576-582
Analytical and Bioanalytical Chemistry - VLSI devices are almost exclusively fabricated on Czochralski (CZ) silicon containing high concentrations of interstitially dissolved oxygen ([Oi] ∼... 相似文献
4.
Chunsheng Tian Stefan Gara Gerhard Hobler Gerhard Stingeder 《Mikrochimica acta》1992,107(3-6):161-169
The axial channeling behaviour of boron implants in <100>, <110> and <111> silicon wafers is investigated by SIMS. Large differences of channeling characteristics such as channeled projected range (the projected range of channeled ions or channeling peak) and the fraction of channeled to implanted ions are observed among the three major crystal orientations. Within the critical angle, the channeling behaviour is very sensitive to the incidence beam angle with respect to crystal orientations. SIMS measurements are performed at different positions along several critical directions over a whole wafer. Well channeled profiles with an incidence beam angle to crystal orientations of 0 ° are obtained for each ion implantation energy and orientation. The results are used to test various models of ion implantation by simulation. A 3-parameter model for electronic stopping power of boron in silicon was proposed. 相似文献
5.
Mild treatment of sepiomelanin and biosynthetic eumelanins with NaBH4 in 0.1 N NaOH leads to the isolation of 5,6-dihydroxyindole-2-carboxylic acid (), a component of structural interest which may account for most of the degradation products of melanins so far obtained. 相似文献
6.
7.
Jose′ L. F. C. Lima Antoacutenio O. S. S. Rangel M. Renata S. Souto 《Fresenius' Journal of Analytical Chemistry》1997,358(5):657-662
A flow injection system was developed for the sequential determination of total nitrogen and phosphorus in digests of vegetables
using potentiometric and spectrophotometric detection systems, respectively. A tubular ammonium selective electrode with a
sensor system composed of nonactin/monactin in tris(2-ethylhexyl) phosphate was used. The selectivity limitations of this
electrode were overcome by the inclusion of a gas-diffusion unit in the system that separated ammonium from the rest of the
sample matrix and allowed the determination of total nitrogen and phosphorus by the partition of the sample plug between two
streams.
The results obtained with the developed FIA system were in good agreement with those of the reference methods. Sampling rates
from 40 to 60 samples per hour and relative standard deviations below 3.5% were achieved.
Received: 17 October 1996/Revised: 21 November 1996/Accepted: 27 November 1996 相似文献
8.
9.
10.
Kochetkov K. A. Vasil′eva T. T. Gasanov R. G. Mysova N. E. Bystrova N. A. 《Russian Chemical Bulletin》2019,68(7):1301-1320
Russian Chemical Bulletin - The review systematizes material by key types of reactions promoted by iron carbonyls. The reaction types are subdivided into several principal directions, focusing... 相似文献