全文获取类型
收费全文 | 9222篇 |
免费 | 48篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 33篇 |
化学工业 | 331篇 |
金属工艺 | 32篇 |
机械仪表 | 22篇 |
建筑科学 | 39篇 |
矿业工程 | 2篇 |
能源动力 | 28篇 |
轻工业 | 256篇 |
水利工程 | 7篇 |
石油天然气 | 4篇 |
无线电 | 247篇 |
一般工业技术 | 374篇 |
冶金工业 | 7608篇 |
原子能技术 | 34篇 |
自动化技术 | 256篇 |
出版年
2022年 | 18篇 |
2021年 | 32篇 |
2020年 | 17篇 |
2019年 | 25篇 |
2018年 | 32篇 |
2017年 | 31篇 |
2016年 | 30篇 |
2015年 | 23篇 |
2014年 | 37篇 |
2013年 | 107篇 |
2012年 | 57篇 |
2011年 | 82篇 |
2010年 | 53篇 |
2009年 | 66篇 |
2008年 | 78篇 |
2007年 | 52篇 |
2006年 | 73篇 |
2005年 | 66篇 |
2004年 | 42篇 |
2003年 | 57篇 |
2002年 | 40篇 |
2001年 | 53篇 |
2000年 | 44篇 |
1999年 | 272篇 |
1998年 | 2527篇 |
1997年 | 1435篇 |
1996年 | 916篇 |
1995年 | 494篇 |
1994年 | 404篇 |
1993年 | 493篇 |
1992年 | 91篇 |
1991年 | 71篇 |
1990年 | 83篇 |
1989年 | 76篇 |
1988年 | 90篇 |
1987年 | 88篇 |
1986年 | 85篇 |
1985年 | 70篇 |
1984年 | 23篇 |
1983年 | 37篇 |
1982年 | 52篇 |
1981年 | 52篇 |
1980年 | 82篇 |
1978年 | 37篇 |
1977年 | 160篇 |
1976年 | 322篇 |
1975年 | 40篇 |
1973年 | 17篇 |
1972年 | 15篇 |
1970年 | 14篇 |
排序方式: 共有9273条查询结果,搜索用时 31 毫秒
61.
The coagulation system plays a major role in the formation of the infected endocardial vegetation in bacterial endocarditis. Since monocytes can express tissue factor (TF) on their surfaces, they are thought to be responsible for the extrinsic activation of the coagulation cascade during this disease. The present study used an in vitro model in which fibrin plates, isolated adherent monocytes, and Streptococcus sanguis were used as an analog for endocardial vegetations. Adherence to fibrin by itself was found to stimulate TF expression on the monocytes, but stimulation by S. sanguis significantly increased TF expression, which was found to be maximal at a bacterium-to-monocyte ratio of 9 or more. 相似文献
62.
63.
64.
Resisting care is defined as any patient behavior which prevents or interferes with the care provider performing or assisting with ADLs for the patient, including bathing, eating, toileting, dressing and grooming. Significant consequences of resisting care include malnutrition, skin breakdown, dehydration, constipation and weight loss. Creativity, flexibility and patience are key components of any intervention. Due to the lability of the person with cognitive impairment, a plan that works perfectly one day may never work again. 相似文献
65.
We present a case where a Wiktor intracoronary stent was inserted for 'poor angiographic result' following balloon angioplasty. Despite appropriate positioning and repeated dilation of the stent a suboptimal result was achieved because of plaque herniation through the stent. The case emphasizes that the choice of stent used is important and will become more so as the number of choices available increases. 相似文献
66.
67.
68.
Pulmonary surfactant is a complex mixture of lipids and proteins that functions to keep alveoli from collapsing at the end of expiration. Dipalmitoylphosphatidylcholine has been identified as the most important component for lowering surface tension at the air-liquid interface. Hydrophobic surfactant apoproteins, SP-B and SP-C, play essential roles in the biophysical functions of the surfactant phospholipids. Hydrophilic surfactant apoproteins (SP-A and SP-D) that are members of C-type lectin superfamily, interact with phospholipids and glycolipids and modulate host defense functions in the lung. SP-A also plays an important role in regulating phospholipid homeostasis in the alveolar spaces. Recent advances in genetics and molecular biology have clarified the structure-function relationship of surfactant apoproteins. 相似文献
69.
70.
Online monitoring by dynamically refining imprecise models 总被引:1,自引:0,他引:1
Rinner B. Weiss U. 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2004,34(4):1811-1822
Model-based monitoring determines faults in a supervised system by comparing the available system's measurements with a priori information represented by the system's mathematical model. Especially in technical environments, a monitoring system must be able to reason with incomplete knowledge about the supervised system, to process noisy and erroneous observations and to react within a limited time. We present MOSES, a model-based monitoring system which is based on imprecise models where the structure is known and the parameters may be imprecisely specified by numerical intervals. As a consequence, only bounds on the trajectories can be derived with imprecise models. These bounds are computed using traditional numerical integration techniques starting from individual points on the external surface of the model's uncertainty space. When new measurements from the supervised system become available, MOSES checks the consistency of this new information with the model's prediction and refutes inconsistent parts from the uncertainty space of the model. A fault in the supervised system is detected when the complete model's uncertainty space has been refuted. MOSES bridges and extends methodologies from the FDI and DX communities by refining the model's uncertainty space conservatively through refutation, by applying standard numerical techniques for deriving the trajectories of imprecise models and by exploiting the measurements as soon as possible for online monitoring. The performance of MOSES is evaluated based on examples and by online monitoring a complex heating system. 相似文献