全文获取类型
收费全文 | 1747篇 |
免费 | 45篇 |
专业分类
电工技术 | 6篇 |
综合类 | 5篇 |
化学工业 | 298篇 |
金属工艺 | 32篇 |
机械仪表 | 11篇 |
建筑科学 | 22篇 |
能源动力 | 8篇 |
轻工业 | 117篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 101篇 |
一般工业技术 | 177篇 |
冶金工业 | 916篇 |
原子能技术 | 9篇 |
自动化技术 | 81篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 19篇 |
2020年 | 19篇 |
2019年 | 12篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 23篇 |
2014年 | 20篇 |
2013年 | 35篇 |
2012年 | 36篇 |
2011年 | 52篇 |
2010年 | 39篇 |
2009年 | 40篇 |
2008年 | 33篇 |
2007年 | 37篇 |
2006年 | 40篇 |
2005年 | 23篇 |
2004年 | 24篇 |
2003年 | 33篇 |
2002年 | 34篇 |
2001年 | 33篇 |
2000年 | 31篇 |
1999年 | 53篇 |
1998年 | 276篇 |
1997年 | 168篇 |
1996年 | 120篇 |
1995年 | 73篇 |
1994年 | 49篇 |
1993年 | 56篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 24篇 |
1989年 | 23篇 |
1988年 | 20篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 7篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 30篇 |
1976年 | 52篇 |
1975年 | 6篇 |
1966年 | 7篇 |
排序方式: 共有1792条查询结果,搜索用时 97 毫秒
1.
2.
3.
4.
5.
The purpose of this study was to identify the optimal knot construction for interrupted dermal sutures. A synthetic braided absorbable suture, sizes 3-0 and 5-0, was selected for this evaluation. With reproducible mechanical performance tests, we determined that the construction of secure knots without ears required one additional throw as compared with secure knots with 3-mm ears. The direction of applied tension did not alter knot security, with the exception of granny knots, which required an extra throw when tension was applied parallel to the suture loop. Because interrupted dermal knot construction is accomplished without knot ears and with an applied tension parallel to the wound, one additional throw must be added to the knot to ensure knot security. 相似文献
6.
7.
Biodegradation of monoaromatic hydrocarbons in aquifer columns amended with hydrogen peroxide and nitrate 总被引:1,自引:0,他引:1
The ability of indigenous microorganisms to degrade benzene, toluene, ethylbenzene and xylenes (BTEX) in laboratory scale flow-through aquifer columns was tested separately with hydrogen peroxide (110 mg/l) and nitrate (330 mg/l as NO3−) amendments to air-saturated influent nutrient solution. The continuous removal of individual components from all columns relative to the sterile controls provided evidence for biodegradation. In the presence of hydrogen peroxide, the indigeneous microorganisms degraded benzene and toluene (> 95%), meta- plus para-xylene (80%) and ortho-xylene (70%). Nitrate addition resulted in 90% removal of toluene and 25% removal of ortho-xylene. However, benzene, ethylbenzene, meta- and para-xylene concentrations were not significantly reduced after 42 days of operation. Following this experiment, low dissolved oxygen (< 1 mg/l) conditions were initiated with the nitrate-amended column influent in order to mimic contaminated groundwater conditions distal from a nutrient injection well. Toluene continued to be effectively degraded (> 90%), and more than 25% of the benzene, 40% of the ethylbenzene, 50% of the meta- plus para-xylenes and 60% of the ortho-xylene were removed after several months of operation. 相似文献
8.
J.-P. Han S.M. Koo E.M. Vogel E.P. Gusev C. DEmic C.A. Richter J.S. Suehle 《Microelectronics Reliability》2005,45(5-6):783
Anomalous threshold voltage roll-up behavior, commonly referred as reverse short channel effect (RSCE), has been observed in high-k (HfO2 on SiON buffer, Al2O3 on SiON buffer) gated submicron nMOSFETs, while the SiO2 or SiON control samples show normal short channel effect (SCE) behavior. The possible causes such as inhomogeneous channel doping profile and gate oxide thickness variation near S/D ends have been ruled out. The results indicate that interface trap density that dependents on channel length is the main cause of the RSCE observed here. In addition, oxide charge also plays a role. 相似文献
9.
10.
WI Bensinger KS Schiffman L Holmberg FR Appelbaum R Maziarz P Montgomery E Ellis S Rivkin P Weiden K Lilleby S Rowley S Petersdorf JP Klarnet W Nichols A Hertler R McCroskey CH Weaver CD Buckner 《Canadian Metallurgical Quarterly》1997,19(12):1183-1189
The purpose of this study was to determine the outcome of patients with metastatic breast cancer treated with high-dose busulfan (Bu), melphalan (Mel) and thiotepa (TT) followed by peripheral blood stem cell (PBSC) infusion. Fifty-one patients with chemotherapy refractory (n = 32) or responsive (n = 19) metastatic breast cancer received Bu (12 mg/kg), Mel (100 mg/m2) and TT (500 mg/m2) followed by PBSC collected after chemotherapy and growth factor (n = 43) or growth factor alone (n = 8). The 100 day treatment-related mortality was 8% including one death from cytomegalovirus pneumonia, one from aspiration pneumonia and two from regimen-related toxicity (RRT). Seven of 28 refractory (25%) and 5/7 (71%) responsive patients with evaluable disease achieved a complete response of all measurable disease or all soft tissue disease with at least improvement in bone lesions (PR*). Fifteen of 51 patients (29%) are alive and progression-free a median of 423 days (range 353-934) after treatment, 5/32 (16%) with refractory disease and 10/19 (53%) with responsive disease. The probabilities of progression-free survival (PFS) at 1.5 years for the patients with refractory (n = 32) and responsive (n = 19) disease were 0.24 and 0.53, respectively. These preliminary data suggest that high-dose Bu/Mel/TT has significant activity in patients with advanced breast cancer and may be superior to some previously published regimens. 相似文献