全文获取类型
收费全文 | 91篇 |
免费 | 1篇 |
专业分类
综合类 | 3篇 |
化学工业 | 32篇 |
金属工艺 | 17篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
轻工业 | 2篇 |
无线电 | 12篇 |
一般工业技术 | 6篇 |
冶金工业 | 8篇 |
原子能技术 | 1篇 |
自动化技术 | 9篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有92条查询结果,搜索用时 15 毫秒
51.
Anselm K.A. Murtaza S.S. Hu C. Nie H. Streetman B.G. Campbell J.C. 《Electron Device Letters, IEEE》1996,17(3):91-93
We report on the design, fabrication, and performance of a photodiode that combines the advantages of a resonant cavity with a separate-absorption-and-multiplication avalanche photodiode. The device is grown on GaAs using molecular beam epitaxy and is designed to detect light near 900 nm. This photodetector has exhibited the following characteristics: an external quantum efficiency of 70%, a spectral linewidth of less than 7 nm, an avalanche gain in excess of 30, and low dark current. In addition, a low excess noise factor corresponding to 0.2⩽k⩽0.3 has been achieved 相似文献
52.
In-situ production of sodium hypochlorite is one of the oldest electrochemical processes of the chemical industry. During the past twenty years a new “in-situ” hypochlorite industry has developed. Construction and performance of present-day cells are considered in detail. Modern cells are fed with seawater or similar weak brines and yield solutions suitable for disinfection, e. g. in breweries, laundries, etc., or for treatment of municipal sewage. Particular importance attaches to units for chlorination of cooling water for power stations or on board ships, thus hindering growth of organisms leading to operating failures. The article closes by considering development trends. 相似文献
53.
54.
55.
Hardegger LA Kuhn B Spinnler B Anselm L Ecabert R Stihle M Gsell B Thoma R Diez J Benz J Plancher JM Hartmann G Isshiki Y Morikami K Shimma N Haap W Banner DW Diederich F 《ChemMedChem》2011,6(11):2048-2054
In two series of small‐molecule ligands, one inhibiting human cathepsin L (hcatL) and the other MEK1 kinase, biological affinities were found to strongly increase when an aryl ring of the inhibitors is substituted with the larger halogens Cl, Br, and I, but to decrease upon F substitution. X‐ray co‐crystal structure analyses revealed that the higher halides engage in halogen bonding (XB) with a backbone C?O in the S3 pocket of hcatL and in a back pocket of MEK1. While the S3 pocket is located at the surface of the enzyme, which provides a polar environment, the back pocket in MEK1 is deeply buried in the protein and is of pronounced apolar character. This study analyzes environmental effects on XB in protein–ligand complexes. It is hypothesized that energetic gains by XB are predominantly not due to water replacements but originate from direct interactions between the XB donor (Caryl? X) and the XB acceptor (C?O) in the correct geometry. New X‐ray co‐crystal structures in the same crystal form (space group P212121) were obtained for aryl chloride, bromide, and iodide ligands bound to hcatL. These high‐resolution structures reveal that the backbone C?O group of Gly61 in most hcatL co‐crystal structures maintains water solvation while engaging in XB. An aryl? CF3‐substituted ligand of hcatL with an unexpectedly high affinity was found to adopt the same binding geometry as the aryl halides, with the CF3 group pointing to the C?O group of Gly61 in the S3 pocket. In this case, a repulsive F2C? F???O?C contact apparently is energetically overcompensated by other favorable protein–ligand contacts established by the CF3 group. 相似文献
56.
57.
S Kohl I Giddings D Besch E Apfelstedt-Sylla E Zrenner B Wissinger 《Canadian Metallurgical Quarterly》1998,162(2-3):75-84
The effect of a potent endogenous antioxidant, the pineal gland indole melatonin (MLT) on the mutagenicity of twelve well-known mutagens and carcinogens has been investigated using two in vitro tests the Ames test and the single cell gel electrophoresis assay (SCGE assay or COMET assay). The 12 mutagens used were 7, 12-dimethylbenz(a)anthracene (DMBA), benzo(a)pyrene (BP), 2-aminofluorene (AF), 1,2-dimethylhydrazine (DMH), bleomycin, cyclophosphamide (CP), 4-nitroquinoline-N-oxide (NQO), 2,4, 7-trinitro-9-fluorenone (TNF), 9-aminoacridine (AA), N-nitrosomethylurea (NMU), mitomycin C and sodium azide tested in the absence or in the presence of S9 mix. MLT alone turned out neither toxic nor mutagenic in the Ames test and revealed clastogenic activity at the highest concentration tested (100 microM) in the SCGE assay. In four Salmonella typhimurium tester strains TA 97, TA 98, TA 100 and TA 102 MLT significantly reduced the mutagenicity of chemicals which require S9 activation. In the SCGE assay performed on CHO cells, preincubation with MLT led to a strong inhibition of clastogenic activities of DMBA and CP, and in a lesser extent with BP and NMU. With mitomycin C, MLT exacerbated responses in both tests. The possible mechanisms of MLT's inhibitory action are discussed. 相似文献
58.
Yuan P. Anselm K.A. Hu C. Nie H. Lenox C. Holmes A.L. Streetman B.G. Campbell J.C. McIntyre R.J. 《Electron Devices, IEEE Transactions on》1999,46(8):1632-1639
For Part I see R.J. McIntyre, ibid., vol.46, no.8, pp.1623-31 (1999). In Part I, a new theory for impact ionization that utilizes history-dependent ionization coefficients to account for the nonlocal nature of the ionization process has been described. In this paper, we will review this theory and extend it with the assumptions that are implicitly used in both the local-field theory in which the ionization coefficients are functions only of the local electric field and the new one. A systematic study of the noise characteristics of GaAs homojunction avalanche photodiodes with different multiplication layer thicknesses is also presented. It is demonstrated that there is a definite “size effect” for thin multiplication regions that is not well characterized by the local-field model. The new theory, on the other hand, provides very good fits to the measured gain and noise. The new ionization coefficient model has also been validated by Monte Carlo simulations 相似文献
59.
The electropolishing of titanium and its alloys 总被引:2,自引:0,他引:2
Anselm Kuhn 《Metal Finishing》2004,102(6):80-86
60.
Michael D. Birkett Robert L. Clarke Anselm T. Kuhn 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1980,30(1):711-720
The design concepts used in the construction of bipolar parallel plate cells for aqueous electrolysis are critically considered. 相似文献