全文获取类型
收费全文 | 1217篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
化学工业 | 7篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 5篇 |
轻工业 | 6篇 |
一般工业技术 | 5篇 |
冶金工业 | 1191篇 |
自动化技术 | 4篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2017年 | 1篇 |
2013年 | 3篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2005年 | 3篇 |
2003年 | 4篇 |
2000年 | 1篇 |
1999年 | 42篇 |
1998年 | 384篇 |
1997年 | 206篇 |
1996年 | 146篇 |
1995年 | 76篇 |
1994年 | 69篇 |
1993年 | 71篇 |
1992年 | 4篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 16篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1978年 | 5篇 |
1977年 | 28篇 |
1976年 | 68篇 |
1975年 | 10篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有1221条查询结果,搜索用时 46 毫秒
21.
22.
23.
BS Reddy A Mastromarino C Gustafson M Lipkin EL Wynder 《Canadian Metallurgical Quarterly》1976,38(4):1694-1698
Fecal neutral steroids and bile acids were measured in patients with familial polyposis, family controls who are immediate relatives of patients, and controls other than relatives. All subjects were consuming a mixed Western diet at the time of collection of stool specimens. Although the total fecal neutral sterol concentrations were not different between the groups, the patients with familial polyposis excreted a high amount of cholesterol and low levels of coprostanol and coprostanone compared with other groups. Patients with familial polyposis excreted levels of total bile acids in their feces comparable to those excreted by controls; lithocholic acid excretion was decreased in patients with familial polyposis. These findings suggest that analysis of stools for cholesterol and its metabolites be useful in screening the siblings of polyposis families for latent disease. 相似文献
24.
Four cases of intrauterine fetal demise in term infants are presented. From these cases and other published reports, a sequence of fetal heart rate changes preceding intrapartum death is presented. Late or variable decelerations, if unrelieved or uncorrected, lead to baseline heart rate changes of tachycardia and loss of variability reflecting loss of fetal reserve and fetal distress. This is followed by an unstable heart rate, a sinusoidal pattern, or a rapidly changing fetal heart rate. The final event is a profound bradycardia just prior to fetal demise. 相似文献
25.
26.
27.
Gray scale B-scans in renal sinus lipomatosis show a variety of features which must be differentiated from clinically significant pathological processes. Normal kidneys show dense homogeneous central echoes. In renal sinus lipomatosis, however, the central echoes are divided and become more sparse (Type I), interspersed with small relatively echo-free areas (Type II), or outline a single relatively echo-free area resembling a mass (Type III). In contrast to similar features in hydronephrosis or multiple cysts, the relatively echo-free areas in lipomatosis are ill-defined and do present several weak internal echoes. 相似文献
28.
29.
30.
J Barrette R Bellwied P Braun-Munzinger WE Cleland T Cormier G Dadusc G David J Dee O Dietzsch M Fatyga SV Greene JV Germani JR Hall TK Hemmick N Herrmann RW Hogue B Hong K Jayananda D Kraus BS Kumar R Lacasse D Lissauer WJ Llope TW Ludlam R Majka SK Mark JT Mitchell M Muthuswamy E O'Brien C Pruneau FS Rotondo da Silva NC J Simon-Gillo U Sonnadara J Stachel H Takai EM Takagui TG Throwe L Waters C Winter D Wolfe CL Woody N Xu Y Zhang Z Zhang C Zou 《Canadian Metallurgical Quarterly》1995,52(5):2679-2683