全文获取类型
收费全文 | 1187篇 |
免费 | 5篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 46篇 |
金属工艺 | 20篇 |
机械仪表 | 65篇 |
建筑科学 | 49篇 |
矿业工程 | 18篇 |
能源动力 | 3篇 |
轻工业 | 1篇 |
水利工程 | 12篇 |
石油天然气 | 30篇 |
无线电 | 22篇 |
一般工业技术 | 109篇 |
冶金工业 | 754篇 |
原子能技术 | 43篇 |
自动化技术 | 12篇 |
出版年
2022年 | 7篇 |
2021年 | 13篇 |
2018年 | 26篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 8篇 |
2014年 | 19篇 |
2013年 | 25篇 |
2012年 | 18篇 |
2011年 | 26篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 22篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 24篇 |
2004年 | 14篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 24篇 |
1998年 | 153篇 |
1997年 | 86篇 |
1996年 | 86篇 |
1995年 | 64篇 |
1994年 | 43篇 |
1993年 | 35篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1986年 | 7篇 |
1985年 | 12篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1978年 | 9篇 |
1977年 | 46篇 |
1976年 | 84篇 |
1975年 | 14篇 |
1973年 | 8篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 7篇 |
1968年 | 7篇 |
1966年 | 6篇 |
1959年 | 6篇 |
排序方式: 共有1192条查询结果,搜索用时 15 毫秒
1.
2.
3.
VN Bhattathiri L Bindu P Remani B Chandralekha CA Davis MK Nair 《Canadian Metallurgical Quarterly》1996,41(2):139-142
The role of the propeptide sequence and a disulfide bridge between sites 1 and 122 in chymotrypsin has been examined by comparing enzyme activities of wild-type and mutant enzymes. The kinetic constants of mutants devoid of the Cys1-Cys122 disulfide-linked propeptide show that this linkage is not important either for activity or substrate specificity. However this linkage appears to be the major factor in keeping the zymogen stable against non-specific activation. A comparison of zymogen stabilities showed that the trypsinogen propeptide is ten times more effective than the chymotrypsinogen propeptide in preventing non-specific zymogen activation during heterologous expression and secretion from yeast. This feature can also be transferred in trans to chymotrypsinogen; i.e. the chymotrypsin trypsin propeptide chimera forms a stable zymogen. 相似文献
4.
5.
6.
Translated from Atomnaya Énergiya, Vol. 73, No. 5, pp. 350–354, November, 1992. 相似文献
7.
The ARM-Uchet computerized system is considered, which is intended for accounting, planning, and monitoring for metrological support to an organization and has been implemented on an IBM PC AT. Schemes are given for the basic modes of operation and for the software suites, as well as the database structure.Translated from Izmeritel'naya Tekhnika, No. 7, pp. 70–71, July, 1994. 相似文献
8.
The contrasting agent Gd-DTPA (Magnevist, Schering AG, Germany) was tested when used in magnetic resonance tomography using extra-low (0.04 T) magnetic field intensity in 68 patients with various brain and spine tumors. The agent was injected intravenously in a dose of 0.1 mmol/kg. No complications were found. The tests showed its high efficiency in the diagnosis of brain neoplasms (particularly in malignant intracerebral disorders, meningiomas and neurinomas). Benign astrocytomas induced no noticeable signal intensification on post-contrasting T1-weighed tomograms. In all cases of spinal tumors, the application of Gd-DTPA could specify the extent of tumor invasions, the presence of cysts and identify accessory tumor nodes in one case. 相似文献
9.
10.
VN Dobrovolsky OV Lagutin TV Vinogradova IS Frolova VP Kuznetsov OA Larionov 《Canadian Metallurgical Quarterly》1993,319(1-2):181-184
Transgenic mice carrying a hybrid gene consisting of ovine beta-lactoglobulin gene sequences and human gamma-interferon (hIFN-g) cDNA were produced. hIFN-g expression in the mammary gland of two lactating transgenic founder females was found. The concentration of active hIFN-g in the milk was estimated as being ca. 1800 IU/ml. The hIFN-g ability to express in the mammary gland was found in the progeny of transgenic founder male. 相似文献