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951.
通过扫描获取不同碾白时间下的大米图像,提取大米图像信息,分析大米图像信息与糙出白率和碾白率之间的相关性。结果表明:B平均值同糙出白率、H平均值同碾白率的相关系数较高,分别为-0.984 6、-0.986 1;然后建立B平均值同糙出白率、H平均值同碾白率的回归方程,分别为y=-0.302 5x+135.733,R2=0.965 6;y=-0.132 9x+105.401,R2=0.968 9。用建立的回归方程预测糙米糙出白率和碾白率,通过F检验和t检验表明,预测的糙出白率和碾白率与实际检测值是一致的. 相似文献
952.
A bipolar membrane combined with ferric iron reduction as an efficient cathode system in microbial fuel cells 总被引:2,自引:0,他引:2
Ter Heijne A Hamelers HV De Wilde V Rozendal RA Buisman CJ 《Environmental science & technology》2006,40(17):5200-5205
There is a need for alternative catalysts for oxygen reduction in the cathodic compartment of a microbial fuel cell (MFC). In this study, we show that a bipolar membrane combined with ferric iron reduction on a graphite electrode is an efficient cathode system in MFCs. A flat plate MFC with graphite felt electrodes, a volume of 1.2 L and a projected surface area of 290 cm2 was operated in continuous mode. Ferric iron was reduced to ferrous iron in the cathodic compartment according to Fe(3+) + e(-) --> Fe2+ (E0 = +0.77 V vs NHE, normal hydrogen electrode). This reversible electron transfer reaction considerably reduced the cathode overpotential. The low catholyte pH required to keep ferric iron soluble was maintained by using a bipolar membrane instead of the commonly used cation exchange membrane. For the MFC with cathodic ferric iron reduction, the maximum power density was 0.86 W/m2 at a current density of 4.5 A/m2. The Coulombic efficiency and energy recovery were 80-95% and 18-29% respectively. 相似文献
953.
Helena M. Moreno José Carballo A. Javier Borderías 《Innovative Food Science and Emerging Technologies》2010,11(2):394-400
Changes in physicochemical properties of raw-appearing restructured models made from hake (Merluccius capensis) muscle, using cold gelation technology by addition of sodium alginate and microbial transglutaminase (MTGase), were studied during frozen storage at ? 15 °C.Among the more interesting results, addition of MTGase produced more protein aggregation in models processed by muscle homogenization and thus the protein network that formed in the gel was better than in samples with added sodium alginate. All samples presented enhanced changes in mechanical properties such as gel strength in the course of frozen storage. The protein network that formed was better organized as shown by the ultrastructure analysis and by protein aggregation data from the beginning of storage, and as a result Water Binding Capacity was greater in restructured models processed by muscle homogenization. Some of the models studied presented lipid oxidation during frozen storage, slightly more in the ones with MTGase added.Industrial RelevanceThe industrial relevance of the present work is to establish bases for using fish fillet trimmings and minced muscle to prepare restructured products that can be commercialized in a raw state and that could also support frozen storage in order to prolong the self-life in the market. The models studied here are not final products but the base with which to prepare them. One possibility of them is to process this kind of products with technologies normally used in whole fish muscle such as smoked fish fillets, carpaccios or marinated products. In addition, these raw restructured products can be commercialized to be cooked as a normal fresh fish fillet or pieces of fillet in a variety of preparations, and also products that contain a high amount of salt. Samples elaborated by binding larger muscle fragments imitate well the original fibrousness of the muscle so that it could be used to elaborate products similar to hamburgers or others that will be fried in batter. 相似文献
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Verwaal R Paalman JW Hogenkamp A Verkleij AJ Verrips CT Boonstra J 《Yeast (Chichester, England)》2002,19(12):1029-1038
In the yeast Saccharomyces cerevisiae, hexose transporter (Hxt) proteins transport glucose across the plasma membrane. The Hxt proteins are encoded by a multigene family with 20 members, of which Hxt1-4p and Hxt6-7p are the major hexose transporters. The remaining Hxt proteins have other or unknown functions. In this study, expression of HXT5 under different experimental set-ups is determined. In glucose-grown batch cultures, HXT5 is expressed prior to glucose depletion. Independent of the carbon source used in batch cultures, HXT5 is expressed after 24 h of growth and during growth on ethanol or glycerol, which indicates that growth on glucose is not necessary for expression of HXT5. Increasing the temperature or osmolarity of the growth medium also induces expression of HXT5. In fed-batch cultures, expression of HXT5 is only observed at low glucose consumption rates, independent of the extracellular glucose concentration. The only common parameter in these experiments is that an increase of HXT5 expression is accompanied by a decrease of the growth rate of cells. To determine whether HXT5 expression is determined by the growth rate, cells were grown in a nitrogen-limited continuous culture, which enables modulation of only the growth rate of cells. Indeed, HXT5 is expressed only at low dilution rates. Therefore, our results indicate that expression of HXT5 is regulated by growth rates of cells, rather than by extracellular glucose concentrations, as is the case for the major HXTs. A possible function for Hxt5p and factors responsible for increased expression of HXT5 upon low growth rates is discussed. 相似文献
956.
Chemical and microbiological quality of sugar cane juice influences the concentration of ethyl carbamate and volatile congeners in cachaça 下载免费PDF全文
Aline Marques Bortoletto Giovanni Casagrande Silvello André Ricardo Alcarde 《Journal of the Institute of Brewing》2015,121(2):251-256
The aim of this study was to assess the influence of heat treatment of sugar cane juice, supplementation with urea and double distillation on the concentration of volatile congeners (acetic aldehyde, ethyl acetate, n‐propyl, isobutyl and isoamyl alcohols and acetic acid) and contaminants (methanol, 1‐propyl and 2‐butyl alcohols, copper, and ethyl carbamate) in cachaça. Samples of fresh sugar cane juice, sugar cane juice submitted to heat treatment and contaminated sugar cane juice were supplemented (or not) with urea and fermented. The washes so obtained underwent single and double distillation. Supplementation with urea stimulated ethyl carbamate formation. The distilled products that originated from contaminated worts presented higher concentration of acetic acid and ethyl carbamate. Double distillation reduced the concentration of contaminants. The best quality pot still cachaça was obtained employing heat treatment of sugar cane juice, nonsupplementation with urea and double distillation. Copyright © 2015 The Institute of Brewing & Distilling 相似文献
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本实验以百香果果皮为原料,采用超声提取工艺,探索乙醇浓度、料液比、提取时间、提取温度、超声功率这五个实验因素对黄酮提取率的影响。在单因素实验结果的基础上,采用响应面建立了提取百香果果皮中黄酮的二次多项数学模型,并进一步验证了该模型的有效性,同时利用响应面分析法对提取工艺进行优化。结果表明:在乙醇浓度60%、提取时间40 min、提取温度50℃,料液比(g/mL)1∶50,超声功率250 W条件下,测得黄酮得率为19.2124 mg/g,该工艺提取量稳定,方法简单、可靠。 相似文献
960.
Shu Yang Xue-Ying Mao Fei-Fei Li Dan Zhang Xiao-Jing Leng Fa-Zheng Ren Guo-Xin Teng 《European Food Research and Technology》2012,235(1):91-97
Although whey protein hydrolysate (WPH) possesses good physiological functionality, its bitter taste and hygroscopic property limit its direct utilization as food ingredient. The aim of this work was to encapsulate whey protein hydrolysate by spray drying using maltodextrin or maltodextrin/??-cyclodextrin mixture as wall materials to attenuate the bitter taste and enhance the stability of whey protein hydrolysate. Hygroscopicity, glass transition temperature, bitter taste, and morphology of non-encapsulated WPH and encapsulated WPH were evaluated. Solubility, particle size, bulk density, and moisture content were also measured. Compared with the non-encapsulated WPH, the encapsulated WPH exhibited significantly lower hygroscopicity and higher glass transition temperature. The bitterness of both maltodextrin-encapsulated WPH and maltodextrin/??-cyclodextrin-encapsulated WPH was significantly lower than that of the original non-encapsulated WPH. Morphological analysis by scanning electron microscopy showed that the microcapsules of the spray-dried encapsulated WPH were matrix-type with less link bridge and had a continuous wall with many concavities. In addition, encapsulation process did not exert negative effect on the solubility of whey protein hydrolysate. The results indicated that encapsulation with maltodextrin and ??-cyclodextrin as carriers was helpful to attenuate the bitter taste and enhance the stability of whey protein hydrolysate. 相似文献