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101.
102.
介绍了脱酰胺、脱羟胺型单组分室温硫化(RTV-1)硅橡胶的特点,以及脱酰胺/羟胺型(包括普通型、高粘接性型、耐水性型、超低模量型)、脱羟胺型(包括用含S-H基的硅氧烷或异氰酸酯作羟胺清除剂)、脱酰胺型(快干型、自流平型)及脱酰胺/酮肟型低模量RTV-1硅橡胶的配制。 相似文献
103.
利用多尺度分析的思想,对原始图像进行重复行信号预滤波,把标量小波变换扩展到多小波变换后选取变换出来的低频子带进行水印嵌入。为了保证水印信息的安全性,对水印进行加密置乱处理。然后结合量化索引模数调制(QIMM)的优越性能,根据水印的信息不同选择不同的子块进行嵌入并实现了水印的盲提取。实验证明,算法具有良好的视觉性和鲁棒性,并大大扩展了水印的容量。 相似文献
104.
Selecting a parsimonious subset autoregressive time series model is a valuable objective particularly where there is or may be evidence that a time series may have some form of periodic or quasi-periodic behaviour. An efficient model selection procedure is essential because of the large number of possible alternative models involved. The explanation of an increase in residual variance due to excluding a lag is examined in Hilbert space. As a result, a new statistic, the projection modulus , and its derivatives are developed to assess the significance of any lag in a model. The impact of deleting a lag, as measured by these statistics, helps to produce a selection procedure where true lags have less chance of being removed. We then assess an efficient subset autoregressive model selection procedure employing these statistics. The success of the proposed procedure is illustrated by its efficiency in identifying the true model for simulated and real data. 相似文献
105.
研究了模量增强剂HMZ在轮胎胎面胶和缓冲胶中的应用效果。试验结果表明 ,在胎面胶中加入 1 5份模量增强剂HMZ ,不改变其它组分用量 ;在缓冲胶中加入 2份模量增强剂HMZ ,适当减小炭黑用量 ,可增大硫化胶的3 0 0 %定伸应力、邵尔A型硬度和回弹值 ;胶料的门尼粘度有所下降 ,包辊性好 ,挤出和压延性能有所改善。试制的成品轮胎 6.5 0 -1610PR的耐久性达到 15 5 4h ,速度性能达到 13 0km·h- 1 。 相似文献
106.
107.
108.
Mixtures of polystyrene and high density polyethylene were injection molded from recycled and virgin polymers to generate cocontinuous structures. The mechanical properties of these blends were evaluated to assess their conformance to rule of mixtures behavior in general and to identify areas of synergy or incompatibility in specific. Flexural and tensile data for recycled blends showed that generally the properties are not additive, except in a cocontinuous region of composition near 35/65 PS/HDPE that has been identified previously for recycled materials. Analysis of crystallinity in the HDPE phase of these blends by differential scanning calorimetry indicates a marked reduction in the level of HDPE crystallinity at the 35/65 PS/HDPE composition. Similar blends of virgin PS/HDPE polymer do not show the differing regions of incompatibility and synergy illustrated by the recycled materials, but rather show approximate conformance to the rule of mixtures. Furthermore, the virgin blends show virtually no crystallinity suppression and a more pronounced Tg shift in the polystyrene compared to recycled materials. Detailed characterization of the recycled materials in terms of polymer and particulate impurities should improve understanding of these differences and perhaps provide direction for obtaining enhanced synergistic behavior in virgin polymer blends. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
109.
David?Pérez-Martínez C.?Alvarez-Salas J.?A.?Morales-Rueda J.?F.?Toro-VazquezEmail author M.?Charó-Alonso E.?Dibildox-Alvarado 《Journal of the American Oil Chemists' Society》2005,82(7):471-479
The solid fat content (SFC), Avrami index (n), crystallization rate (z), fractal dimension (D), and the pre-exponential term [log(γ)] were determined in blends of cocoa butter (CB) with canola oil or soybean oil crystallized
at temperatures (T
Cr) between 9.5 and 13.5°C. The relationship of these parameters with the elasticity (G′) and yield stress (σ*) values of the crystallized blends was investigated, considering the equilibrium melting temperature (T
M
o) and the supercooling (i.e., T
Cr
o−T
M
o) present in the blends. In general, supercooling was higher in the CB/soybean oil blend [T
M
o=65.8°C (±3.0°C)] than in the CB/canola oil blend [T
M
o=33.7°C (±4.9°C)]. Therefore, under similar T
Cr values, higher SFC and z values (P<0.05) were obtained with the CB/soybean oil blend. However, independent of T
Cr TAG followed a spherulitic crystal growth mechanism in both blends. Supercooling calculated with melting temperatures from
DSC thermograms explained the SFC and z behavior just within each blend. However, supercooling calculated with T
M
o explained both the SFC and z behavior within each blend and between the blends. Thus, independent of the blend used, SFC described the behavior of G′eq and σ* and pointed out the presence of two supercooling regions. In the lower supercooling region, G′eq and σ* decreased as SFC increased between 20 and 23%. In this region, the crystal network structures were formed by a mixture of
small β′ crystals and large β crystals. In contrast, in the higher supercooling region (24 to 27% SFC), G′eq and σ* had a direct relationship with SFC, and the crystal network structure was formed mainly by small β′ crystals. However, we
could not find a particular relationship that described the overall behavior of G′eq and σ* as a function of D and independent of the system investigated. 相似文献
110.
Based on nonlinearity contact theory and the geological structure of the Xieqiao Coal Mine in the newly developed Huainan coal field, rock movements, mining fissures and deformation of overlying strata were simulated by using the interface unit of FLAC3D to evaluate the pressure-relief gas drainage in the exploitation of super-remote protected seams. The simulation indicates that the height of the water flowing fractured zone is 54 m in the overlying strata above the protective layer. The maximum relative swelling deformation of the C 13 coal seam is 0.232%,while the mining height is 3.0 m and the distance from the B8 roof to the C13 floor is 129 m, which provides good agreement with a similar experiment and in situ results. The feasibility of exploitation of a super-remote protective coal seam and the performance of the pressure-relief gas drainage in a super-remote protected layer are evaluated by comparisons with practice projects. It demonstrates that the relieved gas in the super-remote protected layers could be better drained and it is feasible to exploit the B8 coal seam before the C13 super-remote protected coal seam. The method is applicable for the study of rock movements, mining fissures and deformation of the overburden, using the interface unit to analyze the contact problems in coal mines. 相似文献