全文获取类型
收费全文 | 1454篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 52篇 |
金属工艺 | 13篇 |
机械仪表 | 4篇 |
建筑科学 | 19篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 57篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 43篇 |
一般工业技术 | 67篇 |
冶金工业 | 1110篇 |
原子能技术 | 1篇 |
自动化技术 | 78篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2013年 | 19篇 |
2012年 | 8篇 |
2011年 | 14篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 23篇 |
2002年 | 15篇 |
2001年 | 12篇 |
2000年 | 19篇 |
1999年 | 39篇 |
1998年 | 320篇 |
1997年 | 208篇 |
1996年 | 131篇 |
1995年 | 66篇 |
1994年 | 71篇 |
1993年 | 80篇 |
1992年 | 17篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 17篇 |
1987年 | 11篇 |
1986年 | 16篇 |
1985年 | 19篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 22篇 |
1978年 | 9篇 |
1977年 | 34篇 |
1976年 | 77篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1968年 | 4篇 |
1965年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有1460条查询结果,搜索用时 8 毫秒
1.
2.
3.
4.
WS McDougal 《Canadian Metallurgical Quarterly》1997,157(4):1335-1336
5.
BA Cunningham PJ Quinn DH Wolfe W Tamura-Lis LJ Lis O Kucuk MP Westerman 《Canadian Metallurgical Quarterly》1995,1233(1):68-74
A questionnaire survey was carried out to examine the attitudes and practices of Australian and New Zealand intensivists with regard to brain death and organ donation. A return rate of 82.5% was achieved. Fifty-eight per cent had written evidence of their own wishes to donate organs and 94% would agree to donation from a dependent. At least one intensivist is involved in certifying brain death on 95% of occasions. Intensivists are involved in the request for organ donation over 90% of the time although one-third do not believe that it is their role to request organ donation. Although two-thirds believe that the family should always be approached for organ donation, another 52 out of 254 indicated that it was their (the intensivist's) role to decide if families should be asked for organ donation. Possible reasons for not requesting are language or other communication problems, perceptions of cultural differences and degrees of family distress. Twenty per cent of respondents do not provide haemodynamic support before brain death confirmation. Australian and New Zealand intensivists overwhelmingly support the concept of brain death, current methods of confirmation of brain death, organ donation and transplantation. Possible reasons behind loss of potential donors include decisions not to resuscitate both before and after brain death is confirmed. Perceptions of family grief and cultural differences clearly inhibit requests for organ donation. A very few units have an effective policy on approaching families about organ donation. Intensivists have almost exclusive control over requests for organ donation and thus bear a full professional responsibility for this element of hospital practice. 相似文献
6.
7.
WS Ahn J Yoo SW Huh CK Kim JM Lee SE Namkoong SM Bae IP Lee 《Canadian Metallurgical Quarterly》2003,12(5):383-390
We investigated clinical efficacy of green tea extracts (polyphenon E; poly E and (-)-epigallocatechin-3-gallate [EGCG]) delivered in a form of ointment or capsule in patients with human papilloma virus (HPV) infected cervical lesions. Fifty-one patients with cervical lesions (chronic cervicitis, mild dysplasia, moderate dysplasia and severe dysplasia) were divided into four groups, as compared with 39 untreated patients as a control. Poly E ointment was applied locally to 27 patients twice a week. For oral delivery, a 200 mg of poly E or EGCG capsule was taken orally every day for eight to 12 weeks. In the study, 20 out of 27 patients (74%) under poly E ointment therapy showed a response. Six out of eight patients under poly E ointment plus poly E capsule therapy (75%) showed a response, and three out of six patients (50%) under poly E capsule therapy showed a response. Six out of 10 patients (60%) under EGCG capsule therapy showed a response. Overall, a 69% response rate (35/51) was noted for treatment with green tea extracts, as compared with a 10% response rate (4/39) in untreated controls (P<0.05). Thus, the data collected here demonstrated that green tea extracts in a form of ointment and capsule are effective for treating cervical lesions, suggesting that green tea extracts can be a potential therapy regimen for patients with HPV infected cervical lesions. 相似文献
8.
1. Occupational health nurses need a general knowledge of psychiatric medications to work effectively with clients and their off site health providers. 2. Acquiring an understanding of the major classes of medications--anti-psychotic, anti-anxiety, anti-depressant, and antimanic--is important. 3. It is helpful to understand under what conditions and with which conditions psychotropic medications are helpful. 相似文献
9.
10.
A method for simultaneously engineering multiple properties of a protein, based on the observed additivity of effects of individual mutations, is presented. We show that, for the gene V protein of bacteriophage f1, effects of double mutations on both protein stability and DNA binding affinity are approximately equal to the sums of the effects of the constituent single mutations. This additivity of effects implies that it is possible to deliberately construct mutant proteins optimized for multiple properties by combination of appropriate single mutations chosen from a characterized library. 相似文献