全文获取类型
收费全文 | 2021篇 |
免费 | 37篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 177篇 |
综合类 | 3篇 |
化学工业 | 445篇 |
金属工艺 | 34篇 |
机械仪表 | 54篇 |
建筑科学 | 44篇 |
矿业工程 | 3篇 |
能源动力 | 192篇 |
轻工业 | 161篇 |
水利工程 | 24篇 |
石油天然气 | 1篇 |
无线电 | 187篇 |
一般工业技术 | 304篇 |
冶金工业 | 280篇 |
原子能技术 | 44篇 |
自动化技术 | 107篇 |
出版年
2022年 | 23篇 |
2021年 | 22篇 |
2020年 | 10篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 19篇 |
2016年 | 35篇 |
2015年 | 25篇 |
2014年 | 45篇 |
2013年 | 95篇 |
2012年 | 53篇 |
2011年 | 103篇 |
2010年 | 91篇 |
2009年 | 82篇 |
2008年 | 97篇 |
2007年 | 94篇 |
2006年 | 77篇 |
2005年 | 76篇 |
2004年 | 76篇 |
2003年 | 74篇 |
2002年 | 64篇 |
2001年 | 49篇 |
2000年 | 45篇 |
1999年 | 43篇 |
1998年 | 130篇 |
1997年 | 79篇 |
1996年 | 76篇 |
1995年 | 43篇 |
1994年 | 39篇 |
1993年 | 35篇 |
1992年 | 27篇 |
1991年 | 31篇 |
1990年 | 27篇 |
1989年 | 16篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 17篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 15篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 14篇 |
1972年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有2060条查询结果,搜索用时 15 毫秒
101.
Suzuki Y Tsujimoto Y Matsui H Watanabe K 《Journal of Bioscience and Bioengineering》2006,102(2):73-81
Hard-to-degrade animal proteins are ubiquitously present throughout animal bodies. Enormous numbers of these proteins generated in the meat industry are converted to industrial wastes, the disposal of which is tremendously difficult. Most hard-to-degrade animal proteins are currently disposed of by incineration; however, this method has ecological disadvantages in terms of an apparent energy loss and the production of a large amount of carbon dioxide. As a result, an innovative solution to these problems has been sought. In this review, we focus on the degradation of three hard-to-degrade animal proteins (extracellular matrix proteins, collagen in particular, keratin, and prion proteins) and discuss the decomposing capability of thermophilic bacteria. These proteins are strongly resistant to proteinases because of their structural features; therefore, new approaches employing bacterial proteases with strong activity and broad specificity are required for practical application. 相似文献
102.
Makoto Shiota Toshiaki Uchida Taishi Oda Hiroshi Kawakami 《Journal of food science》2006,71(3):C120-C123
ABSTRACT: We investigated the oxidative stability of soybean oil and fish oil fortified with iron solubilized by lactoferrin (FeLF). Oxidative stability was evaluated by measuring the induction period of the Rancimat test. The induction time of soybean oil added FeCl3 was decreased; however, that of added FeLF was not. This effect of lactoferrin was also observed in the iron-catalyzed oxidation offish oil at temperatures ranging from 50°C to 120°C, and at concentrations of iron ranging from 0 to 500 ppm. Thus, lactoferrin is considered useful as a natural iron stabilizer for food products containing polyunsaturated fatty acids. 相似文献
103.
Chitra N Wendakoon Yutaka Shimizu Toshiaki Yada 《Journal of the science of food and agriculture》1991,54(2):295-304
To elucidate the factors affecting the variation in the gel forming ability of fish muscle within a species, the effect of starvation and diet on the proximate composition and gelling property of tilapia muscle was examined. Starvation resulted in a decrease in protein and lipid contents coupled with an increase in water content. Protein depletion, mainly in the myofibrillar fraction, in the starved fish caused a lowering of the gel forming ability of their muscle. The myosin-degrading activity at 65°C was not affected by starvation for 56 days. Tilapia (Oreochromis niloticus L) fed on either fishmeal or krillmeal did not differ in their proximate composition. Phytoplankton-fed fish had a slightly higher lipid content and had the greatest gel forming ability. There was no significant difference in the gel strength between the fish fed fishmeal and the fish fed krill or 58 days. Compared with the phytoplankton, however, prolonged feeding of fishmeal seemed to increase the myosin-degrading activity of the muscle. 相似文献
104.
105.
106.
Xing-Zheng Wu Toshiaki Nakaoka Tomomi Inoue Haruo Inoue 《Sensors and actuators. A, Physical》2009,155(2):241-245
Optical sensing of materials movements across a plant surface with a probe beam is reported. It is based on monitoring of deflection of a probe beam passing through a vicinity of the plant surface. The deflection of the probe beam was caused by concentration gradients of chemical species involved in the materials moments in physiological activities of the plant. Typha angustifolia L. was used as a model plant. The beam deflection at different locations of both leaves and roots in respiration process were monitored and compared. It is found that deflection signals changed with time and locations. Experimental results showed that the beam deflection method could be used for noninvasive sensing and monitoring of materials movements across the plant surface. 相似文献
107.
108.
K Nasu N Matsui H Narahara Y Tanaka N Takai I Miyakawa Y Higuchi 《Canadian Metallurgical Quarterly》1998,122(9):836-841
BACKGROUND: Uterine endometrial stromal sarcoma is a rare neoplasm with a morphology that closely resembles that of the proliferative endometrial stroma. To understand its pathologic characteristics, we established a novel cell line, MaMi, from a primary culture of an endometrial stromal sarcoma obtained from a 65-year-old Japanese woman. METHODS: We observed the morphology of MaMi cells and performed immunohistochemical analysis on the primary tumor and transplants in nude mice. Prolactin, insulin-like growth factor-binding protein-1, interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, E-selectin, vascular cell adhesion molecule-1, and fibronectin production in the culture medium of MaMi cells were also examined. RESULTS: MaMi cells were shown to exhibit a fibroblast-like morphology in vitro, and they adopted a more elongated appearance in response to 12-O-tetradecanoyl phorbol-13-acetate (TPA). On injection into nude mice, the cells gave rise to subcutaneous tumors. Immunohistologically, both the primary tumor and MaMi cell-induced tumors stained positively with antibodies to neuron-specific enolase or vimentin. MaMi cells constitutively produced IL-6, IL-8, and monocyte chemoattractant protein-1 in vitro. Interleukin-1beta, (100 pmol/L), tumor necrosis factor-alpha (1 nmol/L), and lipopolysaccharide (1 microg/mL) each increased the release of IL-6, IL-8, and monocyte chemoattractant protein-1 by MaMi cells. TPA (10 nmol/L) also stimulated the production of IL-6 and IL-8 by these cells, but inhibited that of monocyte chemoattractant protein-1. CONCLUSIONS: We demonstrated that MaMi cells closely resemble proliferative endometrial stromal cells not only morphologically, but also functionally. This cell line may prove valuable in understanding the role of cytokines produced by tumor cells in the pathogenesis of endometrial stromal sarcoma and may also be useful as an in vitro model of functioning endometrial stromal cells. 相似文献
109.
Toshiaki Shimizu Mitsuo Yazawa Tsuneo Hirao Narihiko Arai 《Journal of chemical ecology》1993,19(11):2501-2512
We isolated glucosides from the royal fern,Osmunda japonica, which elicit a deterrent response in larvae ofBombyx mori. These compounds were absent in taro (Colocasia antiquorum) and castor-oil plant (Ricinus communis) leaves and did not evoke responses of sensory cells in the lateral and medial sensilla styloconica ofSpodoptera litura. This glucoside extract of the royal fern leaves stimulates receptors generally associated with deterrent. It is also possible that this compound may act as a behavioral deterrent, and from actual feeding tests, it is suggested that this compound may prevent feeding in some monophagous insects, such asBombyx mori. The deterrent glucoside possesses a noncyclic aglycon. 相似文献
110.
Hitoshi Maruyama Tohei Moritani Toshiyuki Akazawa Toshiaki Sato 《Polymer International》1988,20(4):345-351
Poly(vinyl alcohol) (PV-OH), prepared from poly(viny) acetate), is used widely in many industries. Various grades have been produced, with different degree of polymerization and degree of hydrolysis. Recently, novel modified (PV-OH)s with anion, cation, silanol or hydrophobic groups have been studied and developed. They have new properties in addition to those of ordinary PV-OH and have new applications. The methods of modification and the characteristics and some applications of the modified polymers are described. 相似文献