全文获取类型
收费全文 | 246篇 |
免费 | 7篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 47篇 |
金属工艺 | 8篇 |
机械仪表 | 3篇 |
建筑科学 | 7篇 |
能源动力 | 13篇 |
轻工业 | 21篇 |
水利工程 | 4篇 |
无线电 | 18篇 |
一般工业技术 | 38篇 |
冶金工业 | 58篇 |
原子能技术 | 4篇 |
自动化技术 | 24篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 14篇 |
2009年 | 13篇 |
2008年 | 17篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1998年 | 19篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有253条查询结果,搜索用时 15 毫秒
1.
2.
Hybrid techniques are effective for exploring interesting corner cases, coverage holes, invariant variations, and so forth, in the general area of directed functional validation. However, despite the emergence of several effective hybrid validation techniques, several questions still remain. The five articles in this special issue help explain some of the different facets of this area. 相似文献
3.
Phosphatidic acid (PtdOH) and lysophosphatidic acid (lysoPtdOH) have been shown to enhance T-lymphocyte function. However,
the FA preference and influence of acyl-CoA binding proteins on lysoPtdOH and PtdOH biosynthesis are not known. Therefore,
we determined glycerol-3-phosphate acyltransferase (GPAT) and lysophosphatidic acid acyltransferase (LAT) activity in rat
T-lymphocyte and liver membrane preparations in the presence of palmitoyl-CoA and oleoyl-CoA with or without BSA. We found
two different properties of GPAT and LAT in whole T-lymphocyte membrane preparations relative to liver. First, T-lymphocyte
basal GPAT and LAT activities were similar, whereas in liver membranes LAT activity was 10-fold higher than GPAT. Second,
T-lymphocyte LAT, but not GPAT, activity was inducible (fivefold) by the addition of albumin in the presence of palmitoyl-CoA
but not oleoyl-CoA. In contrast, albumin stimulated GPAT, but not LAT, activity in liver membranes in the presence of palmitoyl-CoA.
These results show, for the first time, that T-lymphocyte LAT activity can be increased by the presence of an acyl-CoA binding
protein, which may indicate a new important control mechanism for regulating intracellular lysoPtdOH and PtdOH levels in T-lymphocytes. 相似文献
4.
A series of N-alkylacetonitrilium ions were characterized by IR spectroscopy on an activated H-ZSM-5 sample pretreated by CD3CN with various adsorbed olefins. Two kinds of(CN) band were evidenced according to whether the carbenium ion is secondary (2387 cm–1) or tertiary (2376 cm–1). The method is able to detect the isomerization intermediates of cyclohexene into methyl-cyclopentene. 相似文献
5.
The problem tackled in this article consists in associating perceived objects detected at a certain time with known objects previously detected, knowing uncertain and imprecise information regarding the association of each perceived objects with each known objects. For instance, this problem can occur during the association step of an obstacle tracking process, especially in the context of vehicle driving aid. A contribution in the modeling of this association problem in the belief function framework is introduced. By interpreting belief functions as weighted opinions according to the Transferable Belief Model semantics, pieces of information regarding the association of known objects and perceived objects can be expressed in a common global space of association to be combined by the conjunctive rule of combination, and a decision making process using the pignistic transformation can be made. This approach is validated on real data. 相似文献
6.
Mahendra Nath Roy Bhoj Bahadur Gurung Vikas Kumar Dakua 《International Journal of Thermophysics》2006,27(5):1539-1550
Electrolytic conductivities of potassium halides, KX (X = Cl−, Br−, I−) have been investigated in 10, 20, and 30 mass% glycerol + H2O mixtures at 298.0, 308.0, and 318.0 K. The conductance data have been analyzed by the Fuoss-conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K
A
), and the distance of closest approach of ion (R). The association constant (K
A
) tends to increase in the order: 10 mass% < 20 mass% < 30 mass% glycerol + water mixtures, while it decreases with temperature. Thermodynamic parameters ΔH
0, ΔG
0, and ΔS
0 are obtained and discussed. Also, Walden products (Λ0η) are reported. The results have been interpreted in terms of ion–solvent interactions and structural changes in the mixed solvents. 相似文献
7.
This article, from the Motorola (now Freescale) PowerPC design group, presents an interesting synergy among test, equivalence verification, and constraints. The authors use RTL, gate, and switch models of a design in two different flows one for test and one for functional verification to show that rectifying constraints and merging tests between the-two flows saves significant presilicon debug effort. 相似文献
8.
We report the preparation of polyaniline (PANI) nanoparticles dispersed in polyvinyl alcohol (PVA) matrix. From SEM picture
it is seen that the particle sizes vary from 100–20 nm. Also with increase in PVA content the stability of dispersion is found
to increase. Apart from SEM, spin cast films of PANI in PVA are also characterized through XRD and FTIR. XRD shows increase
in crystallinity with PVA content and FTIR gives evidence of crosslinking between PANI and PVA molecules. In plane electrical
conductivity (in the range of 102 Scm−1) and the exponent of nonlinear I–V are found to decrease with increase of PVA content. There is a good correlation between SEM, XRD, FTIR and electrical properties. 相似文献
9.
Subrata Pandit Pulok K. Mukherjee Kakali Mukherjee Rahul Gajbhiye M. Venkatesh S. Ponnusankar Santanu Bhadra 《Food research international (Ottawa, Ont.)》2012,45(1):69-74
Spices constitute an important group of food which is virtually indispensable in the culinary art. In a view, these spices feared to pose a probability to affect the disposition of conventional pharmaceuticals through inhibition of human cytochrome P450 (CYPs) enzymes. In the present study an approach has been made to evaluate the possible CYP inhibition potential with some Indian spices (Capsicum annuum, Murraya koenigii, Zingiber officinale) and their major bioactive compounds, in combination with pooled microsome; as well as commercially available recombinant human CYP3A4, CYP2D6, CYP2C9 and CYP1A2. Quantification of the bioactive compound was determined through RP-HPLC, in order to standardize the plant material. CYP–carbon monoxide (CYP–CO) complex assay result indicated that all the plants and their bioactive compounds have an interaction potential with CYPs. Fluoregenic assay results indicated that the spice extracts have higher inhibition potential comparing to their single bioactive molecule. The higher enzyme inhibition potential by the extracts may be related to the synergistic effects due to the presence of other constituents in the extract. Capsaicin and C. annuum showed the lowest IC50 value and 6-gingerol and Z. officinale extract showed the highest IC50 value among the entire sample tested. The entire sample showed significantly less (P < 0.001, P < 0.01) interaction potential than known inhibitors. These findings indicate that selected spices are unlikely to cause clinically relevant drug interactions involving the inhibition of major CYP isozymes. 相似文献
10.
Helen M. Snaith Corresponding author Martin Gade Gordon W. Jolly Antoine Mangin Vittorio Barale Ove Rud 《International journal of remote sensing》2013,34(7-8):1341-1347
The Clean Seas project focused on the role that existing Earth observing satellites might play in monitoring marine pollution. Results are presented here from August 1997, for the North Sea test site, using sea surface temperature (SST), colour and synthetic aperture radar (SAR) images in conjunction with a hydrodynamic model. There was good correlation between data sources, e.g. between SST and ERS-2 SAR images. Both datasets showed the development of fine plume structures close to the Rhine outflow, apparently associated with the outflow, and possibly caused by tidal pulsing of the Rhine Plume. The model reproduced general temperature and sediment distributions well, but fine structures were not reproduced. Model sediment distribution patterns were verified using ‘chlorophyll concentration’ data from colour sensors, representative of sediment concentration in turbid water. In conjunction with the visible channels of the Advanced Very High Resolution Radiometer and Along-Track Scanning Radiometer, they give an uncalibrated measure of the sediment load. The model gives a more complete picture of the temporal dispersion of the Rhine Plume over time than is evident from the remotely sensed data alone. 相似文献