全文获取类型
收费全文 | 1255篇 |
免费 | 26篇 |
国内免费 | 32篇 |
专业分类
电工技术 | 31篇 |
综合类 | 43篇 |
化学工业 | 140篇 |
金属工艺 | 41篇 |
机械仪表 | 39篇 |
建筑科学 | 70篇 |
矿业工程 | 4篇 |
能源动力 | 8篇 |
轻工业 | 64篇 |
水利工程 | 15篇 |
石油天然气 | 31篇 |
武器工业 | 2篇 |
无线电 | 33篇 |
一般工业技术 | 39篇 |
冶金工业 | 711篇 |
原子能技术 | 7篇 |
自动化技术 | 35篇 |
出版年
2022年 | 6篇 |
2021年 | 9篇 |
2019年 | 4篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 6篇 |
2015年 | 24篇 |
2014年 | 69篇 |
2013年 | 49篇 |
2012年 | 30篇 |
2011年 | 96篇 |
2010年 | 27篇 |
2009年 | 53篇 |
2008年 | 32篇 |
2007年 | 42篇 |
2006年 | 29篇 |
2005年 | 12篇 |
2004年 | 16篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 19篇 |
1998年 | 199篇 |
1997年 | 123篇 |
1996年 | 81篇 |
1995年 | 60篇 |
1994年 | 34篇 |
1993年 | 43篇 |
1992年 | 12篇 |
1991年 | 8篇 |
1990年 | 15篇 |
1989年 | 16篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1978年 | 6篇 |
1977年 | 24篇 |
1976年 | 42篇 |
1975年 | 4篇 |
1970年 | 2篇 |
1968年 | 4篇 |
1961年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有1313条查询结果,搜索用时 609 毫秒
41.
42.
甲磺酸倍他司汀经氧瓶燃烧后用吸收液吸收,结构中的硫氧化成硫酸根,采用离子色谱法测定,并根据甲磺酸倍他司汀化学式的计量关系求出样品中有效药物的含量.结果硫在0.02~60 μg·m<'-1>浓度范围内线性关系良好,平均回收率为98.8%,RSD为0.15%. 相似文献
43.
44.
通过分析国内外转子振动控制技术,提出了自感式电磁阻尼器的转子横向振动主动控制的设计构思,并以前置滤波器的引入来实现系统功能,同时进行对模型的仿真研究,论证了自感式电磁阻尼器的可行性,具有结构简单,经济实用的特点。 相似文献
45.
46.
硝胺推进剂用聚合物键合剂的研究进展 总被引:1,自引:0,他引:1
综述了硝胺推进剂产生"脱湿"现象的原因及改善力学性能的方法,介绍了目前国内外用于改善硝胺推进剂力学性能的三种聚合物键合剂的作用机理和效果。 相似文献
47.
48.
49.
MJ Clemons E Marshall J Dürig K Watanabe A Howell D Miles H Earl J Kiernan A Griffiths K Towlson P DeTakats NG Testa M Dougal MG Hunter LM Wood LG Czaplewski A Millar TM Dexter BI Lord 《Canadian Metallurgical Quarterly》1998,92(5):1532-1540
BB-10010 is a variant of the human form of macrophage inflammatory protein-1alpha (MIP-1alpha), which has been shown in mice to block the entry of hematopoietic stem cells into S-phase and to increase their self-renewal capacity during recovery from cytotoxic damage. Its use may constitute a novel approach for protecting the quality of the stem cell population and its capacity to regenerate after periods of cytotoxic treatment. Thirty patients with locally advanced or metastatic breast cancer were entered into the first randomized, parallel group controlled phase II study. This was designed to evaluate the potential myeloprotective effects of a 7-day regimen of BB-10010 administered to patients receiving six cycles of 5-fluorouracil (5-FU), adriamycin, and cyclophosphamide (FAC) chemotherapy. Patients were randomized, 10 receiving 100 microgram/kg BB-10010, 11 receiving 30 microgram/kg BB-10010, and nine control patients receiving no BB-10010. BB-10010 was well-tolerated in all patients with no severe adverse events related to the drug. Episodes of febrile neutropenia complicated only 4% of the treatment cycles and there was no difference in incidence between the treated and nontreated groups. Studies to assess the generation of progenitor cells in long-term bone marrow cultures were performed immediately preceding chemotherapy and at the end of six dosing cycles in 18 patients. Circulating neutrophils, platelets, CD 34(+) cells, and granulocyte/macrophage colony-forming cell (GM-CFC) levels were determined at serial time points in cycles 1, 3, and 6. The results showed similar hemoglobin and platelet kinetics in all three groups. On completion of the six treatment cycles, the average pretreatment neutrophil levels were reduced from 5.3 to 1.7 x 10(9)/L in the control patients and from 4.3 to 1.9 and 4.5 to 2.5 x 10(9)/L in the 30/100 microgram/kg BB-10010 groups, respectively. Relative to their pretreatment values, 50% of the patients receiving BB-10010 completed the treatment with neutrophil values significantly higher than any of the controls (P = .02). Mobilization of GM-CFC was enhanced by BB-10010 with an additional fivefold increase over that generated by chemotherapy alone, giving a maximal 25-fold increase over pretreatment values. Bone marrow progenitor assays before and after this standard regimen of chemotherapy indicated little long-term cumulative impairment to recovery from chemotherapy. Despite the limited cumulative damage to the bone marrow, which may have minimized the protective value of BB-10010 during this regimen of chemotherapy, better recovery of neutrophils in the later treatment cycles with BB-10010 was indicated in a number of patients. 相似文献
50.