全文获取类型
收费全文 | 2445篇 |
免费 | 0篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 14篇 |
机械仪表 | 3篇 |
建筑科学 | 1篇 |
轻工业 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 11篇 |
冶金工业 | 2386篇 |
原子能技术 | 1篇 |
自动化技术 | 6篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 84篇 |
1998年 | 809篇 |
1997年 | 481篇 |
1996年 | 251篇 |
1995年 | 158篇 |
1994年 | 125篇 |
1993年 | 139篇 |
1992年 | 15篇 |
1991年 | 15篇 |
1990年 | 24篇 |
1989年 | 29篇 |
1988年 | 23篇 |
1987年 | 23篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 45篇 |
1976年 | 106篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1965年 | 1篇 |
1955年 | 3篇 |
1954年 | 1篇 |
排序方式: 共有2445条查询结果,搜索用时 31 毫秒
991.
992.
993.
TJ Hamblin 《Canadian Metallurgical Quarterly》1997,21(11-12):1025-1026
994.
NJ Horwood J Elliott TJ Martin MT Gillespie 《Canadian Metallurgical Quarterly》1998,139(11):4743-4746
The osteoclastogenic factor of osteoblastic origin has recently been elucidated as a novel Tumor Necrosis Factor (TNF)-ligand family member, termed osteoclast differentiation factor (ODF). Using a semiquantitative RT-PCR approach, we sought to determine the mRNA expression of ODF and its decoy receptor, osteoprotegerin (OPG), in a selection of osteoblastic cell lines and in response to three factors representative of different signal transduction pathways, vitamin D receptor, protein kinase A or gp130. Each osteotropic agent, either 1,25-(OH)2D3, PTH or IL-11, promoted an increase in the ratio of ODF:OPG, with maximal stimulation occurring at 24 h, 4 h, and 8 h, respectively, and furthermore each was shown to act in a dose-dependent manner. This report establishes that osteoblastic cell lines incapable of supporting osteoclast formation have markedly reduced ODF expression and also illustrates the importance of the relative abundance of ODF compared with the levels of OPG for the induction of osteoclastogenesis. 相似文献
995.
Ulcerations may appear on the genitalia in a variety of both infectious and noninfectious conditions. The vast diversity of etiologies, coupled with the often overlapping morphological features, make the diagnosis of genital ulcerations a challenging endeavor. This article highlights the most important clinical manifestations and laboratory findings which aid in the proper diagnosis of genital ulcerations. 相似文献
996.
997.
998.
Bone marrow transplant-associated thrombotic microangiopathy (BMT-TM), usually associated with thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and renal insufficiency, has been reported to occur approximately 5-6 months after BMT. We report a case of relapsed malignant lymphoma complicated by BMT-TM of hyperacute onset, which has never been described in the literature. Our patient, a 52-year-old male, developed MAHA with gross haematuria, thrombocytopenia, lactate dehydrogenase elevation and renal insufficiency 2 days after autologous PBSC transplantation following high-dose chemotherapy. Supportive treatment, ie glucocorticoid, fresh frozen plasma and haemodiafiltration were given, and thereafter the BMT-TM gradually improved. In heavily pretreated patients, caution should be exercised for possible occurrence of the BMT-TM of hyperacute onset. 相似文献
999.
AM Padberg TJ Wilson-Holden LG Lenke KH Bridwell 《Canadian Metallurgical Quarterly》1998,23(12):1392-1400
STUDY DESIGN: This was a retrospective study of 500 patients undergoing corrective surgery between 1987 and 1997 for spinal deformity caused by idiopathic scoliosis. OBJECTIVES: To report the sensitivity and specificity of somatosensory-evoked and neurogenic motor-evoked potentials monitoring and the requirements for an intraoperative wake-up test for all idiopathic scoliosis surgeries at a single institution. SUMMARY OF BACKGROUND DATA: Intraoperative monitoring is recommended for use during corrective spinal surgery. Accepted monitoring standards and requirements for an intraoperative wake-up test are still debated. METHODS: The study group consisted of 500 patients undergoing corrective surgery for idiopathic scoliosis between 1987 and 1997. All patients were monitored using somatosensory-evoked and neurogenic motor-evoked potential techniques, using a standard protocol developed at this institution. RESULTS: The false-positive rate (significant data change without postoperative neurologic deficit) was 0.014% (n = 7). The true-positive rate (degradation of data that met warning criteria, with a corresponding postoperative neurologic deficit) was 0.004% (n = 2). No false-negative results (normal data during with a postoperative neurologic deficit) were seen. The sensitivity of combined somatosensory-evoked and neurogenic motor-evoked potential data in predicting neurologic status was 98.6%, and the specificity of normal data predicting normal findings in a neurologic examination was 100%. CONCLUSION: Combined somatosensory-evoked and neurogenic motor-evoked potentials monitoring during idiopathic scoliosis surgery represents a standard of care that obviates the need for an intraoperative wake-up test when reliable data are obtained and maintained. 相似文献
1000.