全文获取类型
收费全文 | 202篇 |
免费 | 3篇 |
专业分类
化学工业 | 27篇 |
金属工艺 | 3篇 |
机械仪表 | 17篇 |
建筑科学 | 9篇 |
能源动力 | 1篇 |
轻工业 | 7篇 |
水利工程 | 2篇 |
无线电 | 32篇 |
一般工业技术 | 21篇 |
冶金工业 | 68篇 |
原子能技术 | 6篇 |
自动化技术 | 12篇 |
出版年
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 11篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 10篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1971年 | 4篇 |
1970年 | 1篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有205条查询结果,搜索用时 15 毫秒
41.
Hansen Nancy Downing; Pepitone-Arreola-Rockwell Fran; Greene Anthony F. 《Canadian Metallurgical Quarterly》2000,31(6):652
How do you as a professional psychologist know if you are competent to treat clients whose cultural origins and values differ from your own? What awareness, knowledge, and skills do you need? With whom should you consult? When should you refer? Adopting an idiographic, inclusive approach, the authors identify 12 minimal multicultural competencies for practice and illustrate their usefulness through 3 case examples. Suggestions for how professional psychologists can augment and evaluate their own multicultural competencies are offered as well as implications for professional psychology educators. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
42.
Beers Annemarie E.W. Hoek I. Nijhuis T.A. Downing R.S. Kapteijn F. Moulijn J.A. 《Topics in Catalysis》2000,13(3):275-280
In the acylation of anisole with octanoic acid, Nafion/silica composites were the most active slurry catalysts, compared to
zeolite catalysts. Monolithic structures were coated successfully with Nafion. Tested in the acylation, these structured catalysts
exhibited similar high activities, eliminating the disadvantages (attrition, filtration, regeneration) of a slurry system
operation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
43.
44.
High resolution images of thin paraffin crystals and of purple membrane (i.e., crystalline bacteriorhodopsin) have been recorded with illumination spots that are confined to a size of 1000 to 2000 A. Images recorded in this way show three to five times greater contrast than do images which are recorded with more conventional flood-beam (ca. 3 micron diameter) illumination. In addition, optical diffraction patterns of small areas of such images show much better preservation of contrast in all directions than is normally the case. Both effects substantiate the idea that beam-induced movement of radiation-sensitive organic specimens has been a major factor which has caused low dose images to be greatly inferior in their quality compared to electron diffraction patterns of the same type of specimens. In spite of the marked improvement that is obtained, we often observe an unexplained degree of contrast variation within the small illuminated area, demonstrating that even further improvement in the quality of low dose images should be possible. 相似文献
45.
A novel varactor diode has been developed for tuning high-power microwave solid-state oscillators. The resulting output power against frequency remains much flatter than conventional high-power varactor-tuned oscillators. 相似文献
46.
Downing John D.; Sekaquaptewa Denise J.; Vargas Patrick T.; Brock Timothy C. 《Canadian Metallurgical Quarterly》1995,50(3):175
Comments that D. Kipnis's (see record 1994-29516-001) examination of present-day social psychology journals and textbooks ignored primary outlets in social psychology, widely taught mainstream texts, and "handbook" and "annual review" treatments. Fair use of these sources would have revealed that only a minor fraction of article titles and chapter topics can reasonably be subsumed under "Power and Behavior Technology." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
47.
CC Luo RG Downing N Dela Torre J Baggs DJ Hu RA Respess D Candal L Carr JR George TJ Dondero B Biryahwaho MA Rayfield 《Canadian Metallurgical Quarterly》1998,14(8):691-694
We developed a method for large-scale screening of HIV-1 genotypic variation based on DNA probe hybridization. Nested PCR amplifications were performed to generate fragments in the env C2-V3 region and also in the gp41 region, which encompasses the immunodominant domain. The proviral DNA sequences were derived from 68 samples and phylogenetically analyzed. For comparison, the C2-V3 fragment was used in DNA probe hybridization to rapidly determine the infecting HIV subtype. The hybridizing probes were designed on the basis of the two most prevalent subtypes in Uganda, A and D. The results were compared to evaluate the feasibility of using this hybridization method for large-scale genotypic screening. Sequence analysis of the 68 amplified PCR fragments showed that 39 were subtype A and 29 were subtype D. The results of DNA hybridization to the amplified products with A and D subtype-specific probes were more than 90% concordant with the subtypes determined by sequence analysis. Our findings suggest that probe hybridization with subtype-specific probes is effective for large-scale screening of HIV-infected populations. Application of this method will significantly reduce the time needed for large, population-based investigations. 相似文献
48.
The letter describes the implementation of a phase-locking scheme described earlier to a 35 GHz Gunn solid-state source (SSS). The CLTF is developed, a loop filter is chosen and the response to a step disturbance is measured. This response is compared to the theoretical response obtained by a Runge-Kutta simulation. 相似文献
49.
N. G. Kanwisher (see record 75:34836; J. Park & N. G. Kanwisher; see record 81:35977) has explained repetition blindness in terms of a distinction in visual perception between type activation and token individuation; repeated items are successfully recognized (matched to stored types) but are less likely than unrepeated items to become individuated as separate perceptual tokens. Whittlesea and colleagues (B. W. A. Whittlesea, M. D. Dorken, & K. W. Podrouzek; see record 83:25355; B. W. A. Whittlesea & K. W. Podrouzek; see record 83:25356) argued that repetition blindness does not reflect different processing of repeated and unrepeated items but is better explained as the result of a combination of separate but nondistinctive processing of repeated items and postlist report biases. However, we argue that none of the results reported by Whittlesea and colleagues are inconsistent with the token-individuation hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
K H Downing 《Ultramicroscopy》1992,46(1-4):199-206
The variation in defocus within an image of a highly tilted specimen can be a serious source of artifact. Spot-scan imaging can be combined with dynamic focusing to greatly reduce this range of defocus. A protocol is described for determining the parameters required for the automatic focus compensation during the recording of a spot-scan image. Images of a gold test specimen demonstrate the efficacy of this procedure in extending the area of the image that contains high-quality data. In case the tilt angle or resolution is high enough that the height difference of the specimen within each small illuminated area is larger than the depth of field, the image must be treated to compensate for the focus variation. The same principle is used as was developed for compensation of conventional images of tilted specimens. 相似文献