全文获取类型
收费全文 | 2474篇 |
免费 | 13篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 96篇 |
金属工艺 | 10篇 |
机械仪表 | 20篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 23篇 |
轻工业 | 166篇 |
水利工程 | 7篇 |
石油天然气 | 5篇 |
武器工业 | 1篇 |
无线电 | 61篇 |
一般工业技术 | 161篇 |
冶金工业 | 1797篇 |
原子能技术 | 6篇 |
自动化技术 | 101篇 |
出版年
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 42篇 |
2012年 | 19篇 |
2011年 | 44篇 |
2010年 | 20篇 |
2009年 | 18篇 |
2008年 | 34篇 |
2007年 | 33篇 |
2006年 | 27篇 |
2005年 | 25篇 |
2004年 | 28篇 |
2003年 | 37篇 |
2002年 | 28篇 |
2001年 | 17篇 |
2000年 | 18篇 |
1999年 | 61篇 |
1998年 | 570篇 |
1997年 | 309篇 |
1996年 | 216篇 |
1995年 | 126篇 |
1994年 | 86篇 |
1993年 | 134篇 |
1992年 | 18篇 |
1991年 | 21篇 |
1990年 | 26篇 |
1989年 | 25篇 |
1988年 | 23篇 |
1987年 | 28篇 |
1986年 | 27篇 |
1985年 | 21篇 |
1984年 | 23篇 |
1983年 | 21篇 |
1982年 | 24篇 |
1981年 | 19篇 |
1980年 | 33篇 |
1979年 | 7篇 |
1978年 | 13篇 |
1977年 | 47篇 |
1976年 | 114篇 |
1975年 | 8篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1970年 | 6篇 |
1967年 | 5篇 |
排序方式: 共有2493条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
Z Xu LE Reinstein G Yang S Pai G Gluckman PR Almond 《Canadian Metallurgical Quarterly》1997,24(11):1788-1792
The dose distribution from a 32P source has been measured and calculated in order to evaluate its application in endovascular irradiation. The source dimension was 27 mm in length and 0.3 mm in diameter and was embedded in the end of a Ni-Ti wire. Dose measurements were performed using radiochromic film in several specially designed tissue equivalent phantoms. Loevinger's point dose kernel was used for the calculation. The approximate dose rate at a radial distance of 1.5 mm from the center of the source was found to be 6.75 cGy/s per GBq (0.25 cGy/s per mCi), which allows the delivery of a therapeutic dose in a short time interval with a satisfactory homogeneity without stepping the source. However, the dose rate falls off almost exponentially along the radial distance. Therefore it may not be suitable for treating large diameter vessel from a centrally located source. The effect of a curved 32P wire source on the radial dose distribution was also investigated. The results showed that for a maximum bend of 180 degrees the dose rate was increased by as much as 20% along the inner radial distance but decreased by as much as 20% along the outer radial distance compared to the dose along a straight wire. However, for curvatures normally encountered in a clinical situation, the dose rate was changed less than 5%. 相似文献
25.
The rôle of saponins in the undesirable sensory properties of the dried pea P sativum is reported. The sensory properties of isolated soyasaponin I are defined and described as bitter, astringent and metallic. The distribution of saponin in various air-classified pea flour fractions shows that the protein-rich fraction may contain sufficient saponin to cause undesirable tastes. 相似文献
26.
27.
28.
29.
RB Jones PR Pomrehn RE Mecklenburg EA Lindsay M Manley JK Ockene 《Canadian Metallurgical Quarterly》1993,124(9):92-104; discussion 106-8
The National Cancer Institute's program to help dentists reduce tobacco use among their patients is part of the Community Intervention Trial for Smoking Cessation, a 22-community, randomly controlled trial of an intervention program for smoking cessation. Results of COMMIT baseline surveys of dentists in the 11 intervention communities are presented. 相似文献
30.
A 6-year-old white female was found to have an adenoid cystic carcinoma originating in a lacrimal gland. Eighteen months following diagnosis, the tumor recurred. Conservative surgery has been the sole mode of therapy. To date, after four operations and quadrimenstral imaging surveillance, there is no sign of disease progression. Our purpose is to record the unusual occurrence of an adenoid cystic carcinoma of the lacrimal gland in a child. An interim report, 32 months after diagnosis, is presented. 相似文献