全文获取类型
收费全文 | 7601篇 |
免费 | 30篇 |
专业分类
电工技术 | 14篇 |
综合类 | 3篇 |
化学工业 | 167篇 |
金属工艺 | 14篇 |
机械仪表 | 41篇 |
建筑科学 | 85篇 |
能源动力 | 27篇 |
轻工业 | 95篇 |
水利工程 | 18篇 |
石油天然气 | 2篇 |
无线电 | 101篇 |
一般工业技术 | 168篇 |
冶金工业 | 6736篇 |
原子能技术 | 12篇 |
自动化技术 | 148篇 |
出版年
2021年 | 14篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2014年 | 17篇 |
2013年 | 72篇 |
2012年 | 41篇 |
2011年 | 36篇 |
2010年 | 42篇 |
2009年 | 37篇 |
2008年 | 38篇 |
2007年 | 36篇 |
2006年 | 31篇 |
2005年 | 37篇 |
2004年 | 26篇 |
2003年 | 42篇 |
2002年 | 26篇 |
2001年 | 28篇 |
2000年 | 28篇 |
1999年 | 229篇 |
1998年 | 2096篇 |
1997年 | 1144篇 |
1996年 | 826篇 |
1995年 | 442篇 |
1994年 | 362篇 |
1993年 | 400篇 |
1992年 | 56篇 |
1991年 | 103篇 |
1990年 | 73篇 |
1989年 | 90篇 |
1988年 | 98篇 |
1987年 | 80篇 |
1986年 | 79篇 |
1985年 | 63篇 |
1984年 | 16篇 |
1983年 | 34篇 |
1982年 | 39篇 |
1981年 | 51篇 |
1980年 | 75篇 |
1979年 | 30篇 |
1978年 | 27篇 |
1977年 | 158篇 |
1976年 | 346篇 |
1975年 | 22篇 |
1974年 | 11篇 |
1973年 | 9篇 |
1972年 | 9篇 |
1955年 | 9篇 |
排序方式: 共有7631条查询结果,搜索用时 46 毫秒
81.
LB Corbeil RP Gogolewski I Kacskovics KH Nielsen RR Corbeil JL Morrill R Greenwood JE Butler 《Canadian Metallurgical Quarterly》1997,61(3):207-213
AIMS/BACKGROUND: To characterise clinically a large kindred segregating retinitis pigmentosa and sensorineural hearing impairment in an autosomal dominant pattern and perform genetic linkage studies in this family. Extensive linkage analysis in this family had previously excluded the majority of loci shown to be involved in the aetiologies of RP, some other forms of inherited retinal degeneration, and inherited deafness. METHODS: Members of the family were subjected to detailed ophthalmic and audiological assessment. In addition, some family members underwent skeletal muscle biopsy, electromyography, and electrocardiography. Linkage analysis using anonymous microsatellite markers was performed on DNA samples from all living members of the pedigree. RESULTS: Patients in this kindred have a retinopathy typical of retinitis pigmentosa in addition to a hearing impairment. Those members of the pedigree examined demonstrated a subclinical myopathy, as evidence by abnormal skeletal muscle histology, electromyography, and electrocardiography. LOD scores of Zmax = 3.75 (theta = 0.10), Zmax = 3.41 (theta = 0.10), and Zmax = 3.25 (theta = 0.15) respectively were obtained with the markers D9S118, D9S121, and ASS, located on chromosome 9q34-qter, suggesting that the causative gene in this family may lie on the long arm (q) of chromosome 9. CONCLUSIONS: These data indicate that the gene responsible for the phenotype in this kindred is located on chromosome 9 q. These data, together with evidence that a murine deafness gene is located in a syntenic area of the mouse genome, should direct the research community to consider this area as a candidate region for retinopathy and/or deafness genes. 相似文献
82.
83.
84.
85.
86.
87.
88.
MG Narducci L Virgilio JB Engiles AM Buchberg L Billips A Facchiano CM Croce G Russo JL Rothstein 《Canadian Metallurgical Quarterly》1997,15(8):919-926
In human leukemias and lymphomas nonrandom chromosomal rearrangements cause changes in cell growth and/or survival in such a way as to promote malignancy. The detailed study of the biochemical and genetic pathways altered in human cancer requires the identification or development of models to allow the study and manipulation of cancer gene function. Recently, the breakpoint gene TCL1, involved in chromosome translocations observed mostly in mature T-cell proliferations and chronic lymphocytic leukemias (CLL), was isolated and characterized, and showed to be part of a new gene family of proteins involved in these tumors. The murine Tcl1 gene, is similar in sequence to the murine and human MTCP1 gene also involved in T cell leukemias. The murine Tcl1 gene was shown to reside on mouse chromosome 12 in a region syntenic to human chromosome 14. Furthermore, we show that the murine Tcl1 gene is expressed early in mouse embryonic development and demonstrates expression in fetal hematopoietic organs as well as in immature T and B cells. Characterization of the murine Tcl1 gene will help in developing a mouse model of CLL and would provide the best opportunity to study and decipher the role of TCL1 in malignant transformation. 相似文献
89.
The International Water Management Institute (IWMI) has made important changes in the thrust of its research programmesince 1995. These new thrusts include attention to the implications of increasing water scarcity at the global level; the adoption of a river basin paradigm leading to new insights into opportunities for water conservation and productivity; application of new information technologies and quantitative analytical techniques; and a stronger focus on policy, institutional issues, health and environment, and social inequities in access to water. This paper describes these changes and provides an overview of the remaining papers in this special issue of Water Resources Development. 相似文献
90.
Recent data indicate that rheumatoid arthritis is more often systemic, progressive, and disabling than benign, and that it reduces life expectancy. The new evidence argues for a dramatic alteration in pharmacologic management. If several months of rest, exercise, and anti-inflammatory therapy are ineffectual, aggressive treatment with disease-modifying antirheumatic and immunosuppressive agents may be in order. 相似文献