全文获取类型
收费全文 | 2191篇 |
免费 | 194篇 |
国内免费 | 24篇 |
专业分类
电工技术 | 6篇 |
综合类 | 84篇 |
化学工业 | 397篇 |
金属工艺 | 6篇 |
机械仪表 | 29篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 64篇 |
轻工业 | 1695篇 |
水利工程 | 5篇 |
石油天然气 | 12篇 |
武器工业 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 41篇 |
冶金工业 | 16篇 |
原子能技术 | 2篇 |
自动化技术 | 24篇 |
出版年
2024年 | 18篇 |
2023年 | 35篇 |
2022年 | 73篇 |
2021年 | 100篇 |
2020年 | 75篇 |
2019年 | 65篇 |
2018年 | 65篇 |
2017年 | 75篇 |
2016年 | 83篇 |
2015年 | 94篇 |
2014年 | 106篇 |
2013年 | 137篇 |
2012年 | 175篇 |
2011年 | 168篇 |
2010年 | 97篇 |
2009年 | 94篇 |
2008年 | 92篇 |
2007年 | 116篇 |
2006年 | 112篇 |
2005年 | 70篇 |
2004年 | 69篇 |
2003年 | 63篇 |
2002年 | 59篇 |
2001年 | 57篇 |
2000年 | 56篇 |
1999年 | 47篇 |
1998年 | 36篇 |
1997年 | 29篇 |
1996年 | 22篇 |
1995年 | 15篇 |
1994年 | 23篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有2409条查询结果,搜索用时 312 毫秒
141.
142.
Anindita Menon Vetriselvi Pandurangan Maragatham Marcus Samuel Rex Arunraj 《Journal of the science of food and agriculture》2024,104(1):21-31
Agriculture products form the foundation building blocks of our daily lives. Although they have been claimed to be renewable resources with a low carbon footprint, the agricultural community is constantly challenged to overcome two post-harvest bottlenecks: first, farm bio-waste, a substantial economic and environmental burden to the farming sector, and second, an inefficient agricultural processing sector, plagued by the need for significant energy input to generate the products. Both these sectors require extensive processing technologies that are demanding in their energy requirements and expensive. To address these issues, an enzyme(s)-based green chemistry is available to break down complex structures into bio-degradable compounds that source alternate energy with valuable by-products and co-products. α-Galactosidase is a widespread class of glycoside hydroxylases that hydrolyzes α-galactosyl moieties in simple and complex oligo and polysaccharides, glycolipids, and glycoproteins. As a result of its growing importance, in this review we discuss the source of the enzyme, production and purification systems, and enzyme properties. We also elaborate on the enzyme's potential in agricultural bio-waste management, secondary agricultural industries like sugar refining, soymilk derivatives, food and confectionery, and animal feed processing. Insight into this vital enzyme will provide new avenues for less expensive green chemistry-based secondary agricultural processing and agricultural sustainability. © 2023 Society of Chemical Industry. 相似文献
143.
144.
以花生仁、红枣、冰糖为原料,将花生仁、红枣分别制成花生浆和枣浆后按一定比例混合,加入冰糖溶解混匀,接种经驯化的乳酸混合菌进行乳酸发酵,由正交试验筛选出混浆发酵的冰糖添加量、接种量、发酵温度及花生浆与枣浆的质量比,制成具有独特营养与保健功能及风味诱人的饮料. 相似文献
145.
Maggie Smallwood 《Journal of the science of food and agriculture》2006,86(12):1747-1754
The complete sequence of the genomes of two model plants is now available together with technology for the parallel analysis of thousands of genes, the proteins that they encode and the metabolites whose production they control. This review focuses on application of these technologies to engineer output characteristics of crops specifically relevant to non‐food use. Following a brief introduction to the resources available for genomic analysis, some examples are provided of how genomics is enabling both transgenic and non‐GM manipulation of agricultural materials such as carbohydrates, oils, fibres and speciality chemicals for use as industrial feedstocks. Copyright © 2006 Society of Chemical Industry 相似文献
146.
猕猴桃果脯糖液酿酒实验研究 总被引:1,自引:0,他引:1
猕猴桃果肉含有丰富的Vc,用加工猕猴桃果脯剩下的糖液为发酵原液,以酒精活性干酵母为发酵茵种,生产猕猴桃果酒,发酵温度为20~32℃,发酵期为8~10d,调酒精度为7%~8%(v/v),陈贮1月后用JA澄清荆澄清。 相似文献
147.
148.
Alexei Lapin 《Chemical engineering science》2006,61(14):4783-4797
In the present work, an Euler-Lagrange approach has been applied to characterize the behavior of a heterogeneous cell population in a stirred-tank bioreactor with non-ideal mixing. It allows one to describe population behavior as the outcome of the interaction between the intracellular state of its individual cell and the turbulent flow field in the reactor. The modeling approach and the numerical method employed are based on an Euler-Lagrange formulation of the system combined with a fractional-step method to allow for a stable, accurate, and numerically efficient solution of the underlying equations. This strategy permits one to account for the heterogeneity present in real reactors in both the abiotic and biotic phases. The example of sugar uptake (phosphotransferase system, PTS) of E. coli cells growing in a fed-batch culture is used to illustrate the application of the approach. The activity of the uptake system depends on the local concentration of glucose as well as the ratio of the intracellular concentrations of phosphoenolpyruvate and pyruvate, which in turn is a function of the history of the individual cell. The simulation results point to distinct differences in the viability of the cells at different scale of operation. 相似文献
149.
ABSTRACT: Structural and rheological properties have been investigated for an aerated system containing a high content of invert sugar and 2 to 10 wt% egg albumen. The specific gravity and the overrun were found to be influenced by the protein concentration and the whipping time. The systems exhibited rheopexy and shear-thinning at high shear rate, with flow data fitted to a power-law model. At small deformations, viscous character was found to dominate over elastic character over the frequency range 10−2 to 10 Hz. Images taken from confocal microscopy indicated that mean bubble size and concentration varied systematically with protein concentration and whipping time, and that more protein accumulated on the bubble surfaces as whipping proceeded. The study of this model system illustrates how the texture of a high sugar content aerated food depends on protein content and whipping conditions. 相似文献
150.
Influence of Pectinesterase Inhibitor from Jelly Fig (Ficus awkeotsang Makino) Achenes on Pectinesterases and Cloud Loss of Fruit Juices 总被引:1,自引:0,他引:1
ABSTRACT: Citrus and jelly fig achene pectinesterase (PE) (1 U/mL) activity was remarkably inhibited by PE inhibitor (PEI) (2 mg/mL) from jelly fig ( Ficus awkeotsang Makino) achenes, in the absence or presence of 0- to 500-mM salts or 0 to 30% of sugars. Changes in temperature (20 to 40 °C) apparently decreased the activity of citrus PE in PE-PEI reaction mixture. Enzyme-activity curves for jelly fig PE alone and for that in combination with PEI were parallel. Activity of crude PEs (1 U/mL) from tomato, apple, asparagus, and guava was reduced remarkably. Cloud loss of fresh tomato juice, apple juice, and papaya juice was greatly inhibited by PEI (1 mg/mL) during 12-wk storage. 相似文献