全文获取类型
收费全文 | 1784篇 |
免费 | 62篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
综合类 | 3篇 |
化学工业 | 320篇 |
金属工艺 | 38篇 |
机械仪表 | 15篇 |
建筑科学 | 30篇 |
矿业工程 | 3篇 |
能源动力 | 22篇 |
轻工业 | 47篇 |
石油天然气 | 2篇 |
无线电 | 118篇 |
一般工业技术 | 404篇 |
冶金工业 | 741篇 |
原子能技术 | 15篇 |
自动化技术 | 79篇 |
出版年
2023年 | 9篇 |
2022年 | 14篇 |
2021年 | 19篇 |
2020年 | 20篇 |
2019年 | 17篇 |
2018年 | 21篇 |
2017年 | 14篇 |
2016年 | 29篇 |
2015年 | 15篇 |
2014年 | 30篇 |
2013年 | 46篇 |
2012年 | 33篇 |
2011年 | 57篇 |
2010年 | 37篇 |
2009年 | 51篇 |
2008年 | 42篇 |
2007年 | 45篇 |
2006年 | 53篇 |
2005年 | 36篇 |
2004年 | 41篇 |
2003年 | 46篇 |
2002年 | 35篇 |
2001年 | 43篇 |
2000年 | 17篇 |
1999年 | 47篇 |
1998年 | 229篇 |
1997年 | 138篇 |
1996年 | 99篇 |
1995年 | 57篇 |
1994年 | 49篇 |
1993年 | 40篇 |
1992年 | 18篇 |
1991年 | 26篇 |
1990年 | 32篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 16篇 |
1986年 | 10篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1983年 | 14篇 |
1982年 | 16篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 13篇 |
1977年 | 30篇 |
1976年 | 57篇 |
1974年 | 10篇 |
1969年 | 9篇 |
排序方式: 共有1847条查询结果,搜索用时 147 毫秒
1.
2.
3.
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
4.
5.
6.
A new comprehensive framework for narrative understanding has been developed. Its centerpiece is a new situational logic calledEpisodic Logic (EL), a knowledge and semantic representation well-adapted to the interpretive and inferential needs of general NLU. The most distinctive features of EL is its natural language-like expressiveness. It allows for generalized quantifiers, lambda abstraction, sentence and predicate modifiers, sentence and predicate reification, intensional predicates (corresponding to wanting, believing, making, etc.), unreliable generalizations, and perhaps most importantly, explicit situational variables (denoting episodes, events, states of affairs, etc.) linked to arbitrary formulas that describe them. These allow episodes to be explicitly related in terms of part-whole, temporal and causal relations. Episodic logical form is easily computed from surface syntax and lends itself to effective inference. 相似文献
7.
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
8.
9.
J Macas J Dolezel G Gualberti U Pich I Schubert S Lucretti 《Canadian Metallurgical Quarterly》1995,19(3):402-4; 407-8
A protocol for primed in situ DNA labeling (PRINS) was optimized for pea (Pisum sativum L.) and field bean (Vicia faba L.) chromosomes attached to coverslips. Cloned DNA or synthetic oligonucleotides were used as probes for repetitive DNA sequences (rDNA, Fok-element) and different reaction conditions were tested to achieve the highest specific signal-to-background ratio. A procedure based on direct labeling by fluorescein-dUTP was compared with an indirect one using digoxigenin detected by fluorescently labeled antibody. Under optimal conditions, strong and specific signals were obtained exclusively on chromosome regions known to contain respective DNA sequences. Compared to the direct labeling, significantly stronger signals were obtained when the indirect procedure was used. Both types of labeling were successfully applied to chromosomes in suspension and were shown to produce signals comparable to that obtained with chromosomes attached to coverslips. It is expected that primed in situ DNA labeling en suspension (PRINSES) will provide a basis for flow-cytometric discrimination and sorting of otherwise indistinguishable chromosomes according to their specific fluorescent labeling. 相似文献
10.
FR Margolin 《Canadian Metallurgical Quarterly》1992,1(1):1-10
The capability of high-quality mammography to discover early, preclinical breast cancer has demanded the development of a new relationship between radiologists, surgeons, and pathologists. It is only through mutual understanding and appreciation of the technical requirements and interpretive difficulties involved in the successful identification, preoperative localization, and excision of these lesions that the full benefits of this method of early cancer detection can be brought to all of our patients. 相似文献