全文获取类型
收费全文 | 1417篇 |
免费 | 35篇 |
国内免费 | 28篇 |
专业分类
电工技术 | 40篇 |
综合类 | 62篇 |
化学工业 | 64篇 |
金属工艺 | 189篇 |
机械仪表 | 60篇 |
建筑科学 | 32篇 |
矿业工程 | 1篇 |
能源动力 | 16篇 |
轻工业 | 302篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 56篇 |
一般工业技术 | 193篇 |
冶金工业 | 359篇 |
原子能技术 | 20篇 |
自动化技术 | 79篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 10篇 |
2020年 | 4篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 44篇 |
2013年 | 166篇 |
2012年 | 79篇 |
2011年 | 105篇 |
2010年 | 60篇 |
2009年 | 82篇 |
2008年 | 49篇 |
2007年 | 37篇 |
2006年 | 55篇 |
2005年 | 25篇 |
2004年 | 33篇 |
2003年 | 20篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 12篇 |
1999年 | 16篇 |
1998年 | 126篇 |
1997年 | 118篇 |
1996年 | 62篇 |
1995年 | 44篇 |
1994年 | 36篇 |
1993年 | 27篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 4篇 |
1989年 | 17篇 |
1988年 | 8篇 |
1987年 | 17篇 |
1986年 | 12篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 14篇 |
1976年 | 31篇 |
1975年 | 6篇 |
1967年 | 2篇 |
1960年 | 2篇 |
排序方式: 共有1480条查询结果,搜索用时 15 毫秒
31.
BACKGROUND: Like other areas of health care, critical care faces increasing pressure to improve the quality while reducing the cost of care. Strategies drawn from the literature and the authors' experiences are presented. STRATEGIES AND OPPORTUNITIES FOR IMPROVEMENTS: Ten process- or structure-related areas are targeted as strategically important focuses of improvement: (1) restructuring administrative lines to better suit key processes; (2) physician leadership in critical care units; (3) management training for critical care managers; (4) triage; (5) multidisciplinary critical care; (6) standardization of care; (7) developing alternatives to critical care units; (8) timeliness of care delivery; (9) appropriate use of critical care resources; and (10) tracking quality improvement. TIMELINESS OF CARE DELIVERY: Whatever the root cause(s) of unnecessary delays, the result is inefficient use of critical care resources-and ultimately either a need for more resources or longer wait times. Innovations designed to reduce wait times and waste, such as the establishment of a microchemistry stat laboratory, may prove valuable. APPROPRIATE USE OF CRITICAL CARE RESOURCES: Possible strategies for the appropriate use of critical care resources include better selection of well-informed patients who undergo procedures. Reduction in variation among physicians and organizations in providing therapies will also likely lead to a reduction in some high-risk procedures offering little or no benefit, and therefore a reduction in need for critical care services. Better preparation of patients and families should also make end-of-life decisions easier when questions of "futility" arise. Better information on outcomes and cost-effectiveness and consensus on withdrawal of critical care treatments represent two additional strategies. 相似文献
32.
33.
提出了一种计算公式,定量地计算了既有氢氧化物沉淀又有氢氧配离子形成的化学反应体系中的金属离子的分布,考察了影响沉淀和配离子形成的各种因素.基于提出的公式,计算了锌、镉、铜、镍、铁(Ⅲ)、铁(Ⅱ)、铝、钙、镁的沉淀率,理论计算与实验结果一致. 相似文献
34.
35.
36.
A weight function-critical plane approach for low-cycle fatigue under variable amplitude multiaxial loading 总被引:1,自引:0,他引:1
X. CHEN D. JIN K. S. KIM 《Fatigue & Fracture of Engineering Materials & Structures》2006,29(4):331-339
Low‐cycle fatigue data of type 304 stainless steel obtained under axial‐torsional loading of variable amplitudes are analyzed using four multiaxial fatigue parameters: SWT, KBM, FS and LKN. Rainflow cycle counting and Morrow's plastic work interaction rule are used to calculate fatigue damage. The performance of a fatigue model is dependent on the fatigue parameter, the critical plane and the damage accumulation rule employed in the model. The conservatism and non‐conservatism of predicted lives are examined for some combinations of these variables. A new critical plane called the weight function‐critical plane is introduced for variable amplitude loading. This approach is found to improve the KBM‐based life predictions. 相似文献
37.
38.
With the development of modern science and technology, the importance of small structures or microstructures (such as the fluidic nanostructure or microreactor[1], the in- tegrate circuit in microelectronics[2], the factory in a chip[3,4], etc.) has been incarnated day by day in the fields of microelectronics, micro-optical systems, microanalytical sys- tems, microelectromechanical systems and cytobiology. And the fabrication technique (microfabrication) of the small structures has become the h… 相似文献
39.
40.
A new controller for linear multivariable ordinary systems is suggested in which distributed delays are included in the feedback loop. A general design approach to obtain this type of controller is suggested. It is shown that the resulting closed-loop system is asymptotically stable under some sufficient conditions. Sufficient conditions are derived under which the disturbance attenuation, the robustness against parameter variations, and the time-delay stability margins are improved by the proposed controller. The state feedback tracking controller and the dual-state observer are obtained by modification of the proposed controller. 相似文献