全文获取类型
收费全文 | 2174篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 34篇 |
金属工艺 | 10篇 |
机械仪表 | 20篇 |
建筑科学 | 12篇 |
矿业工程 | 6篇 |
能源动力 | 15篇 |
轻工业 | 26篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 51篇 |
冶金工业 | 1898篇 |
原子能技术 | 21篇 |
自动化技术 | 58篇 |
出版年
2022年 | 3篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 34篇 |
2012年 | 14篇 |
2011年 | 12篇 |
2010年 | 21篇 |
2009年 | 11篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 13篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 80篇 |
1998年 | 634篇 |
1997年 | 364篇 |
1996年 | 230篇 |
1995年 | 123篇 |
1994年 | 81篇 |
1993年 | 133篇 |
1992年 | 15篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 29篇 |
1988年 | 17篇 |
1987年 | 18篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 11篇 |
1981年 | 13篇 |
1980年 | 21篇 |
1978年 | 5篇 |
1977年 | 31篇 |
1976年 | 80篇 |
1975年 | 4篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1956年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有2180条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
Chin-Ming Kuo Daniel P. Miranker James C. Browne 《Journal of Parallel and Distributed Computing》1991,13(4)
This paper presents the performance results of a comprehensive approach to the parallel execution of rule systems. It describes the semantics of a Concurrent Rule Execution Language, CREL, and the architecture of the system that compiles and executes CREL programs. The system has been designed to avoid run-time overhead by performing extensive compile-time analysis and by parallelizing compilation. Static dependency analysis, based on serializability, coupled with a set of optimizing transforms, partitions the program into subsets, called clusters. Clusters execute independently of each other and communicate though asynchronous message passing. At run time two additional sources of parallelism are exploited—run-time consistency checking allowing multiple rules to fire, and match-level parallelism. The CREL system is implemented on a Sequent Symmetry shared-memory computer. This paper presents the results of a factorial experiment that isolates and evaluates each source of parallelism in the CREL system and each possible combination of those methods. The results suggest that multiple-rule firing is the single most important source of parallelism in CREL programs and that the use of static dependency analysis based on serializability is instrumental to effectively exploit parallelism. 相似文献
25.
26.
27.
The role of gender was examined in the process and outcome of therapy in the treatment of depressed outpatients seen in the National Institute of Mental Health Treatment of Depression Collaborative Research Program. Patients received either interpersonal therapy, cognitive-behavioral therapy, imipramine plus clinical management, or placebo plus clinical management. None of the therapist-patient by gender groupings (i.e., therapist gender, therapist-patient gender matching vs. mismatching, or patients' beliefs about whether a male or female therapist would be more helpful) were significantly related to measures of treatment process and outcome, controlling for type of treatment and severity of pretreatment depressive symptoms. Findings were duplicated when examining the effects of gender within only the psychotherapeutic modes of treatment for the groupings of therapist gender and therapist-patient gender matching versus mismatching. 相似文献
28.
MT Dorak HK Machulla M Hentschel KI Mills J Langner AK Burnett 《Canadian Metallurgical Quarterly》1996,65(2):134-139
Goodpasture syndrome is an often fatal autoimmune disease associated with glomerulonephritis and/or pulmonary hemorrhage. The clinical manifestations of this disease correlate well with the presence of circulating antiglomerular basement membrane (GBM) autoantibodies. The primary target antigen in glomerular and alveolar basement membranes is thought to be the alpha 3 chain of type IV collagen. Nearly all that is known about anti-GBM antibodies in humans comes from work on unbound circulating antibody. We recently had the unique and rare opportunity to obtain early postmortem antibody and tissues from a patient who died with catastrophic Goodpasture syndrome. The specificity of circulating, kidney-bound and lung-bound autoantibodies from this patient was evaluated against a variety of purified basement membrane constituents. The results indicate that the primary target for the circulating and tissue-bound autoantibodies is the NC1 domain of the alpha 3(IV) chain of type IV collagen. Additionally, all the antibodies recognize a cryptic epitope/s on the alpha 3(IV)NC1 hexamer. Furthermore, tissue-bound and circulating antibodies compete with one another for overlapping epitopes on the antigen. These findings demonstrate that circulating autoantibodies in Goodpasture syndrome are highly representative of those bound to organ tissues, strengthening the notion that pathogenic autoantibodies are targeted to the alpha 3(IV)NC1 collagen, and that previous reports of findings in the circulation may be applicable to tissue injury. 相似文献
29.
ME Martínez S Medina MT del Campo MJ Sánchez-Cabezudo M Sánchez L Munuera 《Canadian Metallurgical Quarterly》1998,62(5):453-456
BACKGROUND AND STUDY AIMS: Anastomotic leakage is a severe complication in gastric surgery and it is associated with a high rate of mortality. Conservative treatment sometimes is not sufficient to stem the leakages and, even when it is sufficient, it takes a long time. The present study describes the first experience in the treatment of anastomotic leakages with endoscopic clipping. PATIENTS AND METHODS: From May 1995 to December 1996, seven patients with postoperative anastomotic leakages after gastric surgery were prospectively treated in our Endoscopy Service. Metallic endoclips (MD 850, Olympus Corp., Tokyo, Japan) with prongs 12 mm long and 6 mm wide were applied, controlling the closure of the leakage by endoscopy, using radiographs to confirm the closure 24 hours later. RESULTS: Complete closure of the leakage was obtained in all seven cases. A single session of endoscopic clipping was needed for five patients while two other required, respectively, two and three sessions. The median time of leakage closure after endoscopic clipping was 2.3 days (range 1-5 days). The clips spontaneously dislodged within 1 month in five patients and within the second month in the other two patients. CONCLUSION: Endoscopic treatment of anastomotic leakages by metallic clips represents a safe and easily repeated method and, compared to conservative treatment, it seems to offer several time and cost advantages. Further studies involving a larger number of patients are needed to verify this finding. 相似文献
30.