全文获取类型
收费全文 | 2122篇 |
免费 | 70篇 |
国内免费 | 20篇 |
专业分类
电工技术 | 1篇 |
综合类 | 25篇 |
化学工业 | 491篇 |
金属工艺 | 10篇 |
机械仪表 | 53篇 |
建筑科学 | 27篇 |
矿业工程 | 1篇 |
能源动力 | 15篇 |
轻工业 | 1177篇 |
水利工程 | 1篇 |
石油天然气 | 14篇 |
武器工业 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 106篇 |
冶金工业 | 5篇 |
原子能技术 | 35篇 |
自动化技术 | 232篇 |
出版年
2024年 | 3篇 |
2023年 | 19篇 |
2022年 | 25篇 |
2021年 | 39篇 |
2020年 | 36篇 |
2019年 | 31篇 |
2018年 | 22篇 |
2017年 | 62篇 |
2016年 | 49篇 |
2015年 | 53篇 |
2014年 | 106篇 |
2013年 | 186篇 |
2012年 | 134篇 |
2011年 | 201篇 |
2010年 | 138篇 |
2009年 | 163篇 |
2008年 | 143篇 |
2007年 | 175篇 |
2006年 | 140篇 |
2005年 | 53篇 |
2004年 | 87篇 |
2003年 | 47篇 |
2002年 | 52篇 |
2001年 | 35篇 |
2000年 | 27篇 |
1999年 | 26篇 |
1998年 | 25篇 |
1997年 | 17篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有2212条查询结果,搜索用时 15 毫秒
1.
本文对芝麻营养保健成分的提取进行了系统的研究。确定了芝麻营养原液的制取工艺。为充分发挥芝麻的营养保健作用开辟了新的途径。 相似文献
2.
To gain a better understanding of the ultra-high molecular weight polyethylene (UHMWPE) wear mechanism in the physiological environment, the effects of protein and lipid constituents of synovial fluid on the specific wear rate of UHMWPE were examined experimentally. The multidirectional sliding pin-on-plate wear tester was employed to simulate the simplified sliding condition of hip joint prostheses. Bovine serum γ-globulin and synthetic l--DPPC were used as model protein and lipid constituents of synovia, respectively. Results of the wear test indicated that the UHMWPE wear rate primarily depended on the protein concentration of the test lubricant. Lipids acted as a boundary lubricant and reduced polyethylene wear in the low protein lubricants. However, the polyethylene wear rate increased with increasing lipid concentrations if the protein concentration was within the physiological level. Increased interactions between protein and lipid molecules and lipid diffusion to polyethylene surface might be responsible for the increased wear. 相似文献
3.
本文列出影响用凯氏定氮仪测定蛋白质结果的因子,依据测量不确定度评定规范,尝试对测定蛋白质结果不确定度的评价。 相似文献
4.
国际乳业的热点论题:蛋白质标准化 总被引:1,自引:0,他引:1
介绍了蛋白质的标准化这一国际乳品界正热的研究和讨论题目,综述了蛋白质标准化的必要性和世界上目前采用的方法,展望了膜技术在蛋白质标准化上的应用前景。 相似文献
5.
Hong Jin Mohammad S. Uddin Yu L. Huang Wah K. Teo 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,59(1):67-72
High level expression of recombinant human tumour necrosis factor β (rh TNF-β) in Escherichia coli results in the formation of two portions of protein, namely soluble active protein and insoluble protein which is inactive and aggregates in the form of inclusion bodies (IBs). In this study, a procedure for purification and renaturation of rh TNF-β from inclusion bodies has been designed and verified experimentally with a product purity of more than 90% and a recovery of about 30%. The procedure includes washing of IBs with specific wash buffer (Triton X-100/EDTA/lysozyme/PMSF), their solubilization with 8 mol dm?3 alkaline urea, purification with ion-exchange columns, refolding with renaturation buffer and finally concentration and desalination with an ultrafiltration membrane. The characteristics of the renatured protein were identical with those of purified protein from the soluble fraction as demonstrated by (1) SDS-PAGE, (2) cytotoxic activity on mouse L929 cells, (3) N-terminal amino acid sequence, and (4) gel filtration chromatography. 相似文献
6.
7.
8.
大豆蛋白复合材料的研究进展 总被引:4,自引:0,他引:4
对国外近十年来大豆蛋白与聚磷酸盐、玻璃纤维、麦草、苎麻、淀粉、聚乙烯醇、聚己内酯、聚羟基酯醚等的复合材料的制备方法,材料性能特点进行了总结。分析了大豆蛋白复合材料作为可生物降解材料替代某些通用塑料和工程塑料的应用前景,并提出了近期的发展方向。 相似文献
9.
Baumann G.; Froommel C.; Sander C. 《Protein engineering, design & selection : PEDS》1989,2(5):329-334
Hypothetical proteins can be tested computationally by determiningwhether or not the designed sequence-structure pair has thecharacteristics of a typical globular protein. We have developedsuch a test by deriving quantities with approximately constantvalue for all globular proteins, based on empirical analysisof the exposed and buried surfaces of 128 structurally knownproteins. The characteristic quantities that best appear tosegregate badly designed or deliberately misfolded proteinsfrom their properly folded natural relatives are the polar fractionof side chains on the protein surface and, independently, inthe protein interior. Three of the seven hypothetical structurestested here can be rejected as having too many polar side-chaingroups in the interior or too few on the protein surface. Inaddition, a recently designed nutritional protein is identifiedas being very much unlike globular proteins. These database-derivedcharacteristic quantities are useful in screening designed proteinsprior to experiment and may be useful in screening experimentallydetermined (X-ray, NMR) protein structures for possible errors. 相似文献
10.