全文获取类型
收费全文 | 1382篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
化学工业 | 7篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
轻工业 | 3篇 |
石油天然气 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 2篇 |
冶金工业 | 1363篇 |
自动化技术 | 2篇 |
出版年
2020年 | 1篇 |
2018年 | 2篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2001年 | 1篇 |
1999年 | 37篇 |
1998年 | 385篇 |
1997年 | 226篇 |
1996年 | 166篇 |
1995年 | 78篇 |
1994年 | 76篇 |
1993年 | 65篇 |
1992年 | 18篇 |
1991年 | 24篇 |
1990年 | 21篇 |
1989年 | 8篇 |
1988年 | 14篇 |
1987年 | 23篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 50篇 |
1976年 | 105篇 |
1975年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有1386条查询结果,搜索用时 15 毫秒
21.
MD Adams JT Earnhardt BR Martin LS Harris WL Dewey RK Razdan 《Canadian Metallurgical Quarterly》1977,33(9):1204-1205
Abnormal-delta8-tetrahydrocannabinol (ABN-delta8-THC) failed to elicit central nervous system and cardiovascular effects in laboratory animals. Abnormal-cannabidiol (ABN-CBD) was also devoid of overt behavioral effects but produced marked hypotension with only slight bradycardia in anesthesized dogs. 相似文献
22.
23.
RB Belshe LS Richardson TJ Schnitzer DA Prevar E Camargo RM Chanock 《Canadian Metallurgical Quarterly》1977,24(1):8-12
ts-2, a temperature-sensitive and plaque morphology mutant of respiratory syncytial virus and sole representative of complementation group B, was compared with members of the other complementation groups of respiratory syncytial virus (group A [ts-1] and group C [ts-7]). ts-2 was found to be 10- to 1,000-fold more restricted in growth and ability to spread at restrictive temperatures (37, 38, and 39 degrees C) than at the permissive temperature (32 degrees C). In temperature shift-up experiments, the ts defect of ts-1 and other members of complementation group A was found to effect a late function that was required for at least 13 h in the replicative cycle. The ts lesion of ts-7 affected a function early in the replication cycle. In contrast, ts-2 was not temperature sensitive when studied by the shift-up technique. The discrepancy between the ts plaque property and failure to detect temperature sensitivity during the shift-up experiment was resolved when it was shown that ts-2 had a defect in adsorption or penetration or both at the restrictive temperature. Clonal analysis of revertant ts-2 showed a coordinate restoration of ts+ phenotype ans syncytium-forming capacity. It appears that ts-2 has a defect in a protein that is involved in adsorption and/or penetration of virus and is also responsible for cell fusion activity. 相似文献
24.
25.
Sixty cats which underwent an ovariohysterectomy were randomly allocated into four treatment groups. One group (controls) received no analgesics postoperatively, and the others received either a single dose of buprenorphine (0.006 mg/kg) intramuscularly, or pethidine (5 mg/kg) intramuscularly, or ketoprofen (2 mg/kg) subcutaneously. The analgesia obtained after each treatment was assessed by three measures. There were significant differences between the groups both for the requirement for intervention analgesia (P = 0.0008) and for the overall clinical assessment (P = 0.0003) with ketoprofen requiring least intervention analgesia and having the best overall clinical assessment, followed by buprenorphine then pethidine. The control group required the most intervention analgesia and had the worst overall clinical assessment. Visual analogue scale scoring for pain produced significant differences between the groups from one hour after the operation, with the cats which were given ketoprofen tending to have lower pain scores than the other groups. 相似文献
26.
Although thoracoscopic sympathectomy or sympathicotomy is the best treatment for hyperhidrosis palmaris, a new approach of clipping only without transection of T2-sympathetic trunk is just as effective. Aside from the guaranteed cure of hyperhidrosis, this new method has fewer complications and has the advantage of recovery of the sympathetic tone in the hands if the procedure is reversed by the removal of the clips. Between March 18 and September 30 of 1996, 326 patients (190 female and 136 male with a mean age of 20.5 years) underwent thoracoscopic T2-sympathetic block by clipping to treat hyperhidrosis. Good results and few complications were noted during follow up six months to one year postoperatively. Five of the 326 patients, all female, had the operation reversed because of intolerable compensatory sweating. Three recovered from the compensatory sweating within two months and had less palmar sweating than before their sympathetic block; the fourth achieved relief of compensatory sweating after nine months, and the fifth reported no improvement. 相似文献
27.
28.
29.
30.