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951.
The direct polycondensation of isophthalic acid with a mixture of 1,3‐phenylenediamine (m‐PDA) and 3,4′‐diaminodiphenyl ether (3,4′‐ODA) could be successfully performed in the bulk to afford the expected co‐aramids for the first time. The co‐aramids with low molecular weights and 3,4′‐ODA contents higher than 50 mol% display excellent thermoplasticity and melt‐drawing property. Indeed, several meters long filaments with 12 μm diameter could be produced. In addition, the environmentally friendly method for the preparation of aramid materials as well as the demonstration of their filament formation will open up the new possibility to prepare aramid fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   
952.
At the glassy state of polymers, the reptation-type molecular motion should be frozen-in and the relaxation should be only by local motions, such as rotation, vibration, and torsion. Such local motions would not depend on molecular weight. This may be current understanding of the polymer glass. By contrast, we found that the rate of enthalpy relaxation in polycarbonate at 100 °C (50 °C below Tg) clearly depends on molecular weight. Deterioration of impact strength was also found to depend on molecular weight. The surprising results are presented in this letter.  相似文献   
953.
To clarify the effects of food sediments on ultraviolet-C (254 nm) sanitation in food-related environments, we examined the resistance of pathogenic bacteria (Salmonella Typhimurium and Staphylococcus aureus) cells, in wet and dried suspensions adhered with 1.5-15% w/v egg albumen, 1.5-15% yolk or 3.0-30% whole egg solutions, against UV-C irradiation. Bacterial suspensions (0.1 ml of 8 log CFU/ml) were put on 47 mmφ glass dishes and dried at room temperature (20-24 °C) for 180 min in a bio safety cabinet with ventilation. Viable S. Typhimurium and S. aureus cells in distilled water decreased during the drying period from 7.2 to 3.2 and from 8.0 to 6.5 log CFU/dish, respectively,. On the other hand, the bacteria cells were protected from drying by egg compounds, even by the lowest concentration. The UV-C treatment (0.16 mW/cm2 for 10 min) showed a clear bactericidal effect in the absence of egg compounds. However, the bactericidal effect was inhibited by 15% yolk and 30% whole egg. Results in this study suggested that the small food sediment protect bacteria on the surfaces from dryness and UV-C irradiation and it might introduce cross contamination.  相似文献   
954.
The development of the corpus luteum (CL), which secretes large amounts of progesterone to establish pregnancy, is accompanied by active angiogenesis, vascularization, and lymphangiogenesis. Negative feedback regulation is a critical physiological mechanism. Vasohibin-1 (VASH1) was recently discovered as a novel endothelium-derived negative feedback regulator of vascularization. We therefore investigated the expression of VASH1 in the bovine CL. Expression of VASH1 mRNA and protein was predominantly localized to luteal endothelial cells (LECs). VASH1 expression in the CL was constant through the early to late luteal phases and decreased during CL regression relating with the action of luteolytic prostaglandin F(2)(α) in vivo. To investigate the role of VASH1, we determined whether VASH1 treatment affects angiogenesis and/or lymphangiogenesis using LECs and lymphatic endothelial cells (LyECs) in vitro. Vascular endothelial growth factor A (VEGFA) stimulated the expression of VASH1 in LECs but not in LyECs, and VASH1 completely blocked VEGFA-induced formation of capillary-like tube structures of LECs and LyECs in vitro. In summary, VASH1 is predominantly located on LECs in the bovine CL and inhibits the angiogenic and lymphangiogenic actions of VEGFA. Bovine CL therefore has a VEGFA-VASH1 system that may be involved in regulation of luteal function, especially in the development of the CL. The results indicate that VASH1 has the potential to act as a negative feedback regulator of angiogenesis and lymphangiogenesis in the CL in cows.  相似文献   
955.
The aim of this study was to evaluate the changes in endogenous bifidobacteria and administered Bifidobacterium animalis subsp. lactis (B. lactis) GCL2505 (GCL2505) in the intestine after administration of GCL2505 by means of a randomized, placebo-controlled double-blind, cross-over study. An increase in the number of total bifidobacteria (the sum of B. bifidum, B. breve, B. longum subsp. longum, B. adolescentis, B. anglatum, B. catenulatum, B. pseudocatenulatum, B. dentium, B. longum subsp. infantis and B. lactis) in the feces were observed after administration of GCL2505 using species- and subspecies-specific real-time polymerase chain reaction analysis. However, the number of endogenous bifidobacteria species (excluding B. lactis) remained unchanged. B. lactis also became the predominant bifidobacterial species. Taking into account the number of GCL2505 administered, the findings further suggested that GCL2505 proliferated in the intestine. In addition, the defecation frequency increased during GCL2505 administration compared with the placebo. Moreover, a single administration study (n=17) clearly demonstrated that GCL2505 successfully reached the intestine before proliferating at least 10-fold. This is the first report to show an increase in intestinal bifidobacteria, with no changes to the endogenous species, and improvements in constipation following proliferation of administered bifidobacteria.  相似文献   
956.
By using first-principles cluster calculations, we identified that Ta or W substitution for V is useful for decreasing the lattice thermal conductivity of the Fe2VAl Heusler alloy without greatly affecting the electron transport properties. It was clearly confirmed that the Fe2(V1?x Ta x )Al0.95Si0.05 (x?=?0, 0.025, 0.05), Fe2(V0.9?x Ta x Ti0.1)Al (x?=?0, 0.10, 0.20), and Fe2(V0.9?2x W x Ti0.1+x )Al (x?=?0, 0.05, 0.10) alloys indeed possessed large Seebeck coefficient regardless of the amounts of substituted elements, while their lattice thermal conductivity was effectively reduced. As a result of partial substitution of Ta for V, we succeeded in increasing the magnitude of the dimensionless figure of merit of the Heusler phase up to 0.2, which is five times as large as the Ta-free compound.  相似文献   
957.
The role of the competence protein ComEA in DNA uptake during transformation of competent Bacillus subtilis was analyzed by lysed-protoplast transformation (LP transformation). A comEA deletion mutant was constructed by a fusion polymerase chain reaction. Transformants of the mutant were obtained by LP transformation at a frequency of 1.1 × 10(2) transformants per μg DNA, representing a low relative efficiency of transformation [RET (mutant/wild type)] of 2.7 × 10(-6). This implied an important role of the protein during DNA uptake. When analyzing LP transformation of comEA with a plasmid (5.7 kb), a similar RET (mutant/wild type) of 5.6 × 10(-5) was obtained. Following addition of DNA into the comEA mutant culture, the number of transformants increased at a rate of 0.5 transformants/min, which was very low compared with the wild-type (6.9×10(4) transformants/min). However, even in the comEA mutant, DNA uptake began immediately after addition of DNA. Using co-transformation analysis of the comEA mutant, short linkages at distances of 2-156 kb could be detected, but not long linkages at distances of 671-1662 kb. Taken together, the results indicate that ComEA plays an important role in the transfer of transforming DNA into the DNA channel and in controlling the rate of DNA uptake.  相似文献   
958.
The ability of 13 strains of multi-stress-tolerant Issatchenkia orientalis yeast to produce ethanol was examined under different stress conditions, including conditions of elevated H2SO4 and Na2SO4 concentrations and increased heat. The MF-121 strain produced a significant amount of ethanol after the incubation in acidic media containing high concentrations of salt, e.g., 50 g/l Na2SO4 at pH 2.0, or at high temperatures, e.g., 43°C, when compared with other strains.  相似文献   
959.
960.
The development of a methodology to forecast accurately the power produced by photovoltaic systems can be an important tool for the dissemination and integration of such systems on the public electricity grids. Thus, the objective of this study was to forecast the power production of a 1‐MW photovoltaic power plant in Kitakyushu, Japan, using a new methodology based on support vector machines and on the use of several numerically predicted weather variables, including cloudiness. Hourly forecasts of the power produced for 1 year were carried out. Moreover, the effect of the use of numerically predicted cloudiness on the quality of the forecasts was also investigated. The forecasts of power production obtained with the proposed methodology had a root mean square error of 0.0948 MW h and a mean absolute error of 0.058 MW h. It was also found that the forecast and measured values of power production had a good level of correlation varying from 0.8 to 0.88 according to the season of the year. Finally, the use of numerically predicted cloudiness had an important role in the accuracy of the forecasts, and when cloudiness was not used, the root mean square error of the forecasts increased more than 32%, and the mean absolute error increased more than 42%. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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