全文获取类型
收费全文 | 180篇 |
免费 | 3篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 25篇 |
金属工艺 | 3篇 |
机械仪表 | 4篇 |
建筑科学 | 7篇 |
能源动力 | 3篇 |
轻工业 | 12篇 |
无线电 | 14篇 |
一般工业技术 | 30篇 |
冶金工业 | 55篇 |
原子能技术 | 3篇 |
自动化技术 | 17篇 |
出版年
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1941年 | 2篇 |
1925年 | 1篇 |
排序方式: 共有183条查询结果,搜索用时 15 毫秒
11.
Goff Phillip Atiba; Eberhardt Jennifer L.; Williams Melissa J.; Jackson Matthew Christian 《Canadian Metallurgical Quarterly》2008,94(2):292
Historical representations explicitly depicting Blacks as apelike have largely disappeared in the United States, yet a mental association between Blacks and apes remains. Here, the authors demonstrate that U.S. citizens implicitly associate Blacks and apes. In a series of laboratory studies, the authors reveal how this association influences study participants' basic cognitive processes and significantly alters their judgments in criminal justice contexts. Specifically, this Black-ape association alters visual perception and attention, and it increases endorsement of violence against Black suspects. In an archival study of actual criminal cases, the authors show that news articles written about Blacks who are convicted of capital crimes are more likely to contain ape-relevant language than news articles written about White convicts. Moreover, those who are implicitly portrayed as more apelike in these articles are more likely to be executed by the state than those who are not. The authors argue that examining the subtle persistence of specific historical representations such as these may not only enhance contemporary research on dehumanization, stereotyping, and implicit processes but also highlight common forms of discrimination that previously have gone unrecognized. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
12.
Recent trends of downsizing and miniaturization of components, e.g. in the automotive industry for the manufacturing of fuel injectors or in the medical industry for the production of bone screws or surgical instruments, increase the importance of mechanical deep hole drilling with small diameters. Unfortunately, there are still some open challenges regarding this process. In addition to the unfavorable ratio of the cutting edge rounding to the achievable feed rates and undeformed chip thicknesses which results in significant mechanical tool loads, the control of the chip formation and the removal constitutes a major difficulty. The slender tool dimensions, especially the small cross sections of the chip flutes, necessitate a favorable chip formation to achieve the required process safety and productivity. Therefore, analyses of the chip formation, when machining difficult-to-cut materials provide the means for an effective process design. This analysis, however, is particularly difficult due to the closed operating zone. Quick-stop devices used for the chip formation analyses so far are limited in the tool diameter respectively the revolution speed. Furthermore the informative value is limited, because a quick-stop test takes a significant time to stop and thus the instantaneous cutting conditions during the tool retraction are altered. To overcome these restrictions, a new method for the analysis of the chip formation in small diameter deep hole drilling is presented in this paper. It is based on the utilization of a high-speed camera and tailored material samples. The experimental set-up and the results of first analyses conducted under minimum quantity lubrication are presented. The chip formation process is analyzed for the single-lip gun drilling of the nickel-based alloy Inconel718 and the bainitic steel 20MnCrMo7. 相似文献
13.
F Wolfe M Lassere D van der Heijde G Stucki M Suarez-Almazor T Pincus K Eberhardt TK Kvien D Symmons A Silman P van Riel P Tugwell M Boers 《Canadian Metallurgical Quarterly》1999,26(2):484-489
The minimized energy mapping of annexin V Trp-187 chi1 x chi2 isomerization supports the existence of two preferential rotameric orientations of the Trp side chain upon annexin V binding to membranes, in agreement with the time-resolved fluorescence results. They correspond to the perpendicular trans (-173 degrees, 73 degrees) and g- (-71 degrees, 83 degrees) rotamers and represent 59 and 28% of the population, respectively. The analysis of their local environment makes it possible to assign the trans rotamer to the long component and the g- rotamer to the short component of the biexponential fluorescence decay. The orientation of these rotamers relative to the protein core suggests a dual role for Trp-187, which might be involved both in the interaction with the phospholipid bilayer and in the formation of the annexin V 2-D array at the surface of the membrane. 相似文献
14.
M. S. Levenson D. L. Banks K. R. Eberhardt L. M. Gill W. F. Guthrie H. K. Liu M. G. Vangel J. H. Yen N. F. Zhang 《Journal of research of the National Institute of Standards and Technology》2000,105(4):571-579
The problem of determining a consensus value and its uncertainty from the results of multiple methods or laboratories is discussed. Desirable criteria of a solution are presented. A solution motivated by the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM) is introduced and applied in a detailed worked example. A Bayesian hierarchical model motivated by the proposed solution is presented and compared to the solution. 相似文献
15.
16.
A Huwiler el-S Akool A Aschrafi FM Hamada J Pfeilschifter W Eberhardt 《Canadian Metallurgical Quarterly》2003,278(51):51758-51769
Renal mesangial cells express high levels of matrix metalloproteinase 9 (MMP-9) in response to inflammatory cytokines such as interleukin (IL)-1 beta. We demonstrate here that the stable ATP analog adenosine 5'-O-(thiotriphosphate) (ATP gamma S) potently amplifies the cytokine-induced gelatinolytic content of mesangial cells mainly by an increase in the MMP-9 steady-state mRNA level. A Luciferase reporter gene containing 1.3 kb of the MMP-9 5'-promoter region showed weak responses to ATP gamma S but conferred a strong ATP-dependent increase in Luciferase activity when under the additional control of the 3'-untranslated region of MMP-9. By in vitro degradation assay and actinomycin D experiments we found that ATP gamma S potently delayed the decay of MMP-9 mRNA. Gel-shift and supershift assays demonstrated that three AU-rich elements (AREs) present in the 3'-untranslated region of MMP-9 are constitutively bound by complexes containing the mRNA stabilizing factor HuR. The RNA binding of these complexes was markedly increased by ATP gamma S. Mutation of each ARE element strongly impaired the RNA binding of the HuR containing complexes. Reporter gene assays revealed that mutation of one ARE did not affect the stimulatory effects by ATP gamma S, but mutation of all three ARE motifs caused a loss of ATP-dependent increase in luciferase activity without affecting IL-1 beta-inducibility. By confocal microscopy we demonstrate that ATP gamma S increased the nucleo cytoplasmic shuttling of HuR and caused an increase in the cytosolic HuR level as shown by cell fractionation experiments. Together, our results indicate that the amplification of MMP-9 expression by extracellular ATP is triggered through mechanisms that likely involve a HuR-dependent rise in MMP-9 mRNA stability. 相似文献
17.
We have previously shown that serum concentrations of cartilage oligomeric matrix protein (COMP) are increased early in rheumatoid arthritis (RA) patients who subsequently develop advanced large-joint destruction. A prognostic value for joint damage of serum concentrations of hyaluronan (HA) is also suggested by previous studies. In contrast, serum concentrations of bone sialoprotein (BSP) have not been useful for identifying patients with progressive large-joint destruction. In the present study, we have examined the hypothesis that serum concentrations of these tissue-derived markers are of prognostic value in RA for the development of radiographically detectable joint damage in hands and feet. Serum concentrations of COMP, HA and BSP were quantified in samples obtained from 62 patients within the first year after onset of RA and were related to the development of radiographically detectable damage in these joints after 5 yr. Neither the serum concentrations of COMP nor of BSP at inclusion predicted joint damage in hands and feet after 5 yr, and the concentration of these proteins did not change over the 5 yr period. However, the serum concentration of HA at inclusion correlated with the radiographic score at the 5 yr follow-up (r = 0.425, P < 0.01), but was not a better predictor in this respect than the erythrocyte sedimentation rate or C-reactive protein levels at inclusion. Thus, serum concentrations of the three studied tissue-derived macromolecules were in this study not useful for identifying patients prone to small-joint destruction. 相似文献
18.
19.
Partial discharges (PDs) occur in the air-filled gaps of enameled wires that are touching. They erode the insulation and consequently lead to an interturn breakdown. This paper describes the failure mechanism of low voltage interturn insulation as a consequence of PDs and shows why and how it is influenced by the insulation design, temperature, and the applied voltage. Understanding the failure mechanism leads to better founded maximal permissible stresses and a proper design of the interturn insulation to avoid premature drive failures 相似文献
20.
W Eberhardt H Wilke G Stamatis M Stuschke A Harstrick H Menker B Krause MR Müeller M Stahl M Flasshove V Budach D Greschuchna N Konietzko H Sack S Seeber 《Canadian Metallurgical Quarterly》1998,16(2):622-634
The ability of rats to learn the location of a hidden platform in a swim maze was compared in animals with excitotoxic lesions of the anterior or posterior (retrosplenial) cingulate cortex or radiofrequency lesions of the cingulum bundle or fimbria-fornix. Performance of this allocentric spatial task was unaffected by the posterior cingulate cortex lesions, while anterior cingulate cortex damage produced only a mild acquisition deficit. Transection of the fornix and lesions of the cingulum bundle produced similar patterns of impairment on initial acquisition, but the cingulum bundle lesions had less effect on reversal of the task. The results from the water maze, and from a subsequent T-maze alternation task, indicate that cingulum bundle lesions can produce a spatial deficit that is similar, but milder, to that observed after fornix transection. The results of the excitotoxic lesions suggest that previous studies examining conventional cingulate lesions may have been influenced by damage to adjacent fibre tracts, such as the cingulum bundle. 相似文献