全文获取类型
收费全文 | 575篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
综合类 | 6篇 |
化学工业 | 47篇 |
金属工艺 | 3篇 |
机械仪表 | 5篇 |
建筑科学 | 4篇 |
能源动力 | 3篇 |
轻工业 | 23篇 |
石油天然气 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 47篇 |
冶金工业 | 416篇 |
自动化技术 | 8篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 21篇 |
2012年 | 5篇 |
2011年 | 9篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 21篇 |
2007年 | 14篇 |
2006年 | 15篇 |
2005年 | 15篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 11篇 |
1998年 | 119篇 |
1997年 | 54篇 |
1996年 | 26篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 27篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 10篇 |
1976年 | 21篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有579条查询结果,搜索用时 15 毫秒
31.
为解决网络入侵检测问题,提高检测准确率和降低误报率,提出一种基于深度迁移学习的网络入侵检测方法,该方法使用非监督学习的深度自编码器来进行迁移学习,实现网络的入侵检测。首先对深度迁移学习问题进行建模,然后对深度模型进行迁移学习。迁移学习框架由嵌入层和标签层实现编/解码,编码和解码权重由源域和目标域共享,用于知识的迁移。嵌入层中,通过最小化域之间的嵌入实例的KL散度来强制源域和目标域数据的分布相似;在标签编码层中,使用softmax回归模型对源域的标签信息进行编码分类。实验结果表明,该方法能够实现网络入侵检测,且性能优于其他入侵检测方法。 相似文献
32.
33.
34.
35.
36.
DO Freedman DA Plier A de Almeida J Miranda C Braga MC Maia e Silva J Tang A Furtado 《Canadian Metallurgical Quarterly》1999,162(3):1756-1764
To investigate the hypothesis that T cells recognizing specific Ags localize to the site of disease activity in human bancroftian filariasis, we have compared the repertoire of TCR Vbeta gene segments in lesions vs blood in individual patients by RT-PCR ELISA. Vbeta14 and Vbeta24 were overrepresented (5% greater in tissue compared with PBMCs and/or tissue/PBMC ratios in the highest 5% of all tissue/PBMC ratios for all Vbetas for all subjects) in 50% and 40% of study subjects, respectively. Overrepresentation of these two Vbetas did not occur in any control subject. In comparing three patient groups, the proportion of individuals meeting at least one criterion for Vbeta14 overrepresentation was shown to increase in tandem with our current concepts of disease progression (asymptomatic filariasis = 25%; clinical filariasis with active infection = 60%; clinical filariasis without active infection = 71%). In 6 of the 10 individuals with Vbeta14 overrepresentation, Vbeta14 represented >20% of the entire lesional Vbeta repertoire. All but one of the 20 study subjects had at least one Vbeta gene segment that was overrepresented in tissue compared with PBMCs. Only a small number of Vbetas, usually three or less, were overrepresented in any single filariasis patient. However, in the same tissue, no differences between patient groups were found when IFN-gamma, TNF-alpha, IL-4, IL-5, and IL-12 mRNA expression were examined. Taken together, these findings suggest that, in principle, in essentially all patients, whether with subclinical or with clinical filariasis, distinct and limited T cell populations are concentrated in affected tissue. 相似文献
37.
The aim of this study was to investigate the expression and distribution patterns of the inducible isoform of nitric oxide synthase (iNOS) in rat placenta during gestation and term labour. The expression of iNOS isoform was assessed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with monoclonal antibodies. Two specific bands were detected corresponding to 135 and 124 kDa in all placenta samples. The upper band (135 kDa) was identified as iNOS due to its correspondence with the band obtained with mouse macrophages (positive control). Compared with its concentrations on day 16, iNOS decreased steadily toward the end of gestation to approximately 37% on day 20, 20% on day 22 before labour and 12% during labour (p < 0.01). The lower band (124 kDa) drastically increased (to almost double) from day 16 to day 18 but returned to initial values on day 22, during delivery. Immunohistochemical staining of placentae at day 16 and 22 using rabbit polyclonal anti-iNOS antibody revealed labelling specifically concentrated in the trophospongial cell layer, at the fetal-maternal interface. The most conspicuous iNOS staining was associated with islands of cells referred to as vacuolated 'glycogen cells'. Staining was greatly decreased during labour. The changes in placental iNOS expression suggest a 'paracrine' role for NO in regulating uterine contractility, blood flow and immunosuppression required for pregnancy maintenance. NO withdrawal at term may also be involved in the initiation of labour. 相似文献
38.
L Lang L Aloj DO Kiesewetter E Jagoda JT Lee CH Paik JA Carrasquillo WC Eckelman 《Canadian Metallurgical Quarterly》1996,23(6):669-672
We have developed three biochemical probes to determine if they are sensitive probes of early biochemical change in a tumor. All three probes appear to have the appropriate properties for in vivo imaging, but must now be evaluated as probes for the sensitive detection of changes in early malignant disease. 相似文献
39.
With the rabies vaccine presently available for preexposure prophylaxis, 20% of all individuals do not have seroconversion following routine immunizations, and 5% are allergic to this vaccine. Two experimental rabies vaccines of cell culture origin offering greater purity and potency were evaluated by means of a double-blind experiment. Thirty-one volunteers who did not have seroconversion or who were allergic to duck embryo rabies vaccine received rabies vaccine produced in either human diploid cell culture (WI-38), or hamster kidney-cell culture. All volunteers had seroconversion within 14 days of receiving a single injection of other experimental vaccine. Clinical side effects were only minor. 相似文献
40.
Ömer N. DOĞAN G. M. Michal H. -W. Kwon 《Metallurgical and Materials Transactions A》1992,23(8):2121-2129
The growth behavior of austenite grains in the presence of A1N precipitates varies with the temperature and time of anneal.
To study this behavior, two iron alloys, (in weight percent) a 0.1 carbon base chemistry with 0.03A1/0.01N and 0.09A1/0.04N,
respectively, were annealed between 1000 °C and 1200 °C for times of up to 180 minutes. Using optical microscopy, as many
as 1000 austenite grains per heat-treatment condition were measured. Conditions of sup- pressed, abnormal, and uniform grain
growth were observed. Using an extraction replica tech- nique, the size, shape, and distribution of the A1N particles were
determined using transmission electron microscopy (TEM). The largest grain boundary curvatures calculated, using the Hellman-
Hillert pinning model, were in close agreement with independent calculations of curvatures using the grain size data. The
largest grains in the lognormal size distribution of austenite grains were found to be the ones with the potential to grow
to abnormally large sizes. 相似文献