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81.
82.
The high density steam flash-explosion (HDSFE) was used to extract protein from soybean meal. Soybean meal samples were treated at 1.3 MPa and 1.8 MPa for 60 s, 120 s and 180 s, respectively. After HDSFE treatment at 1.8 MPa for 180 s, the extraction yield of protein was increased from 50.50% to 65.66% compared with untreated soybean meal. The emulsification properties and fat-binding capacity of soy protein isolate (SPI) extracted from soybean meal treated by HDSFE were all improved compared with SPI extracted from untreated soybean meal and white flakes. Molecular weight distribution analysis of SPI showed that after HDSFE treatment the peak with molecular weight about 504 kDa and 43.3 kDa disappeared and the peak with molecular weight about 669 kDa increased indicating protein aggregation. Gel electrophoresis showed that high molecular weight aggregates of protein have been formed by covalent bond. 相似文献
83.
绿豆分离蛋白功能特性研究 总被引:6,自引:0,他引:6
研究了绿豆分离蛋白的功能特性,探讨了pH值、温度、离子强度、蛋白质质量分数诸因素对绿豆分离蛋白溶解性、吸水性与吸油性、起泡性与起泡稳定性、乳化性与乳化稳定性、黏度的影响.结果表明,在pH=8的溶液中,绿豆分离蛋白的乳化性最好(45.2);在c(NaCl)=0.6 mol/L的溶液中,绿豆分离蛋白表现出较好的起泡性(160%);当w(绿豆分离蛋白)=9%时,起泡性和起泡稳定性最佳(分别为270%,77.8%~100%);当w(绿豆分离蛋白)=10%时,绿豆分离蛋白溶液的黏度可达7050 mPa·s. 相似文献
84.
目的 探索定量评价大黄鱼新鲜度的方法。方法 在整鱼背部采集近红外光谱, 将原始光谱预处理后分别与挥发性盐基氮(TVB-N)、菌落总数建立偏最小二乘(PLS)模型、区间偏最小二乘(iPLS)模型、向后区间偏最小二乘(biPLS)模型和联合区间偏最小二乘(siPLS)模型。结果 biPLS模型的精度最高、预测性能最佳。TVB-N的biPLS模型的校正集和预测集相关系数分别为0.8371和0.7652; 菌落总数的biPLS模型的校正集和预测集相关系数分别为0.878和0.7009。结论 大黄鱼的近红外光谱信息与其TVB-N、菌落总数间都存在较高的相关性, 所建模型可以快速、无损地定量评价大黄鱼的新鲜度。 相似文献
85.
M. Alireza Sadeghi 《LWT》2006,39(8):911-917
A process for the preparation of mustard protein isolate, comprising steps such as dispersion of defatted meal in 0.1 mol/l NaCl solution, incubation, extraction at alkaline pH, followed by treatment of the protein solution with activated carbon was developed. The protein, coagulated by steam injection, was subjected to separation by centrifugation, washing and spray drying. The parameters evaluated were protein yield, purity, presence of antinutritional factors and nutritional quality of proteins. The protein yield was 58-60%. The purity of the protein isolate was 95%. The hydrolysed products of glocosinolates like isothiocyanates and oxazolidine thione levels, phenolics and phytic acid levels were low in the protein isolate. The in vitro digestibility of the protein isolate was 92.4% compared to 80.6% of the meal. Chemical score of the meal and protein isolate were similar; isoleucine was the first limiting amino acid. The calculated nutritional indices, essential amino acid index, biological value, nutritional index and C-PER of protein isolate were higher compared to meal. The protein quality as indicated by amino acid profile and PDCAAS scores for 10-12-years old and adults were 100. 相似文献
86.
以大豆分离蛋白为原料,添加瓜尔胶多糖,通过共混改性制备生物材料溶液,探讨了混合体系在不同pH、不同蛋白、盐和瓜尔胶浓度条件下表面疏水值的变化。结果表明:瓜尔胶多糖加入到单组分大豆分离蛋白体系后,会使体系表面疏水值降低;未加盐时pH=8.0条件下,体系可溶性蛋白的表面疏水值最大,加入盐后pH=10.0时混合体系表面疏水值明显大于纯水条件;且pH=10.0条件下,当盐浓度小于0.1mol/L时,体系表面疏水值随盐浓度的增大而增大,反之减小。此研究为大豆分离蛋白-瓜尔胶生物材料的成膜机理解释奠定了理论基础。 相似文献
87.
88.
Electrostatic interactions between polysaccharides and proteins at oil–water interfaces alter the physicochemical properties and stability of emulsions. In this research, we studied the influence of chitosan addition on the properties of oil-in-water emulsions containing whey protein-coated lipid droplets. Experiments were carried out under conditions where the protein and polysaccharide had similar charges (pH 3.0) or opposite charges (pH 6.5). At pH 3.0, chitosan addition (0–0.025%) had little influence on droplet charge, aggregation, creaming stability or shear viscosity of whey protein emulsions, which was attributed to the fact that the cationic chitosan molecules did not adsorb to the cationic droplet surfaces due to electrostatic repulsion. At pH 6.5, chitosan addition caused a decrease in particle negative charge, an increase in particle size, a decrease in creaming stability, and an increase in viscosity. These effects were attributed to droplet aggregation caused by charge neutralization and bridging resulting from attraction of cationic chitosan molecules to anionic patches on the protein-coated droplet surfaces. Addition of cationic polyelectrolytes to protein-stabilized emulsions may be utilized to control their physicochemical properties, stability and biological fate, which may be useful for developing commercial products with novel or improved functional properties. 相似文献
89.
酰化对芸豆分离蛋白热学特性的影响研究 总被引:1,自引:0,他引:1
从参与酰化反应基团的视角,运用热分析(DSC)技术,研究了不同酰化阶段芸豆分离蛋白热学性质的变化规律。芸豆分离蛋白(KPI)的酰化过程存在两个主要的酰化阶段,酸酐-蛋白比为0~0.1(乙酰化)和0~0.2(琥珀酰化)g/g,为ε-氨基(Lys)酰化阶段(N-酰化);再增加酸酐与蛋白比,ε-氨基酰化基本完成,反应进入羟基(Thr,Ser)酰化阶段(O-酰化)。在N-酰化阶段,琥珀酰化诱导KPI的热稳定性增加,而焓变(ΔH)略有降低,乙酰化不影响KPI的热稳定性和焓变(ΔH);羟基酰化阶段,酰化导致KPI变性温度(Td)降低,伴随焓变(ΔH)急剧下降。 相似文献
90.