全文获取类型
收费全文 | 206篇 |
免费 | 17篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 2篇 |
综合类 | 3篇 |
化学工业 | 51篇 |
金属工艺 | 8篇 |
机械仪表 | 8篇 |
建筑科学 | 2篇 |
能源动力 | 5篇 |
轻工业 | 22篇 |
石油天然气 | 1篇 |
无线电 | 24篇 |
一般工业技术 | 41篇 |
冶金工业 | 44篇 |
原子能技术 | 3篇 |
自动化技术 | 12篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 15篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 20篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1991年 | 2篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1954年 | 1篇 |
1939年 | 1篇 |
排序方式: 共有226条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The large-angle convergent beam electron diffraction (LACBED) technique is used for determining the crystal polarity of GaP and GaAs single crystals from < 1 1 0 > cross-sectional samples. The method which is based on an earlier approach using convergent beam electron diffraction (CBED) evaluates the polarity-sensitive contrast of high odd-index Bragg-lines in [0 0 2] dark-field patterns. The polarity is determined by application of a simple contrast rule as well as by direct comparison with dynamical simulations. For the two materials the ranges of applicability are determined by a detailed analysis of the Bragg-line contrast as a function of the sample thickness. The coexistence of the Bragg-line pattern and the of shadow image of the defect in correct rotational relationship to each other makes the analysis straightforward and free from possible sources of errors. As an example, the crystal polarity of GaP is related to the morphology of facetted voids. The LACBED method is shown to be suitable for relating the analysis of extended crystal defects. The advantages and the disadvantages of the LACBED method are discussed in comparison with the corresponding CBED method and with a recent method based on the analysis of bend contours. 相似文献
5.
Erdmann N Betti M Kollmer F Benninghoven A Grüning C Philipsen V Lievens P Silverans RE Vandeweert E 《Analytical chemistry》2003,75(13):3175-3181
The resonance and nonresonant laser ionization of uranium atoms sputtered from thin metal films and individual micrometer-size uranium oxide particles, respectively, was studied to evaluate a new setup for the analysis of actinide-containing micrometer-size particles. Experiments using nonresonant (193-nm) ionization of atoms and molecules sputtered from micrometer-size uranium oxide particles have shown that the uranium detection efficiencies for sputtered neutral atoms are approximately 2 orders of magnitude higher than for secondary ions. In uranium particles of 0.5-microm diameter, 6 x 10(6) atoms of 235U were easily detected and the isotopic ratio of 235U/238U = 0.0048 +/- 4.6% is in excellent agreement with the certified value. The use of two-color, two-step resonance ionization of the sputtered neutral uranium atoms from thin films was investigated. Several excitation schemes were tested, and a significant population of several low-lying metastable states after ion sputtering was observed. Autoionizing states for double-resonant ionization were determined, and the high selectivity of ionization schemes involving these autoionizing states was illustrated by comparing the flight-time distributions of different sputtered species obtained both by resonance and nonresonant multiphoton (355-nm) laser postionization. Ideally, the options for resonance as well as nonresonant ionization would be combined in a single setup, to obtain a large gain in sensitivity and selectivity. Thus, information about the main components as well as specific isotopic information of a trace element could be obtained from the same single particle. 相似文献
6.
D. Spiecker 《Zeitschrift für Jagdwissenschaft》1967,13(3):122-123
Ohne Zusammenfassung 相似文献
7.
8.
D. Spiecker 《Zeitschrift für Jagdwissenschaft》1967,13(1):39-40
Ohne Zusammenfassung 相似文献
9.
Back Cover: [3H]UR‐DE257: Development of a Tritium‐Labeled Squaramide‐Type Selective Histamine H2 Receptor Antagonist (ChemMedChem 1/2015)
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
10.
Jürgen Fuhrmann André Fiebach Manfred Uhle Andreas Erdmann Charles R. Szmanda Chi Truong 《Microelectronic Engineering》2009,86(4-6):792-795
Pattern doubling by cross-linking of a spacer triggered by residual acid diffusion from a previously developed primary structure into the spacer is a possible option to create the necessary structure widths for the 32 nm node with current exposure technology by pattern doubling. A particular advantage of this process step would be the self-alignment to the primary structure, which would render a second exposure step unnecessary. In the paper, we present a new prototypical model of the bake step of this process and discuss the dependency of the desired behavior on parameters of the model. 相似文献