全文获取类型
收费全文 | 1332篇 |
免费 | 51篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 372篇 |
金属工艺 | 19篇 |
机械仪表 | 35篇 |
建筑科学 | 63篇 |
矿业工程 | 2篇 |
能源动力 | 39篇 |
轻工业 | 140篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 115篇 |
一般工业技术 | 193篇 |
冶金工业 | 73篇 |
原子能技术 | 11篇 |
自动化技术 | 299篇 |
出版年
2023年 | 16篇 |
2022年 | 47篇 |
2021年 | 60篇 |
2020年 | 24篇 |
2019年 | 27篇 |
2018年 | 33篇 |
2017年 | 33篇 |
2016年 | 57篇 |
2015年 | 30篇 |
2014年 | 39篇 |
2013年 | 97篇 |
2012年 | 82篇 |
2011年 | 93篇 |
2010年 | 68篇 |
2009年 | 74篇 |
2008年 | 61篇 |
2007年 | 65篇 |
2006年 | 62篇 |
2005年 | 48篇 |
2004年 | 49篇 |
2003年 | 37篇 |
2002年 | 36篇 |
2001年 | 19篇 |
2000年 | 17篇 |
1999年 | 16篇 |
1998年 | 27篇 |
1997年 | 30篇 |
1996年 | 15篇 |
1995年 | 18篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1963年 | 1篇 |
1903年 | 1篇 |
排序方式: 共有1388条查询结果,搜索用时 15 毫秒
41.
Sandra Keller Franziska Tschan Guido Beldi Anita Kurmann Daniel Candinas Norbert K. Semmer 《Ergonomics》2016,59(12):1541-1552
Noise peaks are powerful distractors. This study focuses on the impact of noise peaks on surgical teams’ communication during 109 long abdominal surgeries. We related measured noise peaks during 5-min intervals to the amount of observed communication during the same interval. Results show that noise peaks are associated with less case-relevant communication; this effect is moderated by the level of surgical experience; case-relevant communications decrease under high noise peak conditions among junior, but not among senior surgeons. However, case-irrelevant communication did not decrease under high noise level conditions, rather there was a trend to more case-irrelevant communication under high noise peaks. The results support the hypothesis that noise peaks impair communication because they draw on attentional resources rather than impairing understanding of communication. As case-relevant communication is important for surgical performance, exposure to high noise peaks in the OR should be minimised especially for less experienced surgeons.
Practitioner Summary: This study investigated whether noise during surgeries influenced the communication within surgical teams. During abdominal surgeries, noise levels were measured and communication was observed. Results showed that high noise peaks reduced the frequency of patient-related communication, but did not reduce patient-irrelevant communication. Noise may negatively affect team coordination in surgeries. 相似文献
42.
43.
Axel Haarmann Lena Zimmermann Michael Bieber Christine Silwedel Guido Stoll Michael K. Schuhmann 《International journal of molecular sciences》2022,23(13)
In large vessel occlusion stroke, recanalization to restore cerebral perfusion is essential but not necessarily sufficient for a favorable outcome. Paradoxically, in some patients, reperfusion carries the risk of increased tissue damage and cerebral hemorrhage. Experimental and clinical data suggest that endothelial cells, representing the interface for detrimental platelet and leukocyte responses, likely play a crucial role in the phenomenon referred to as ischemia/reperfusion (I/R)-injury, but the mechanisms are unknown. We aimed to determine the role of endoglin in cerebral I/R-injury; endoglin is a membrane-bound protein abundantly expressed by endothelial cells that has previously been shown to be involved in the maintenance of vascular homeostasis. We investigated the expression of membranous endoglin (using Western blotting and RT-PCR) and the generation of soluble endoglin (using an enzyme-linked immunosorbent assay of cell culture supernatants) after hypoxia and subsequent reoxygenation in human non-immortalized brain endothelial cells. To validate these in vitro data, we additionally examined endoglin expression in an intraluminal monofilament model of permanent and transient middle cerebral artery occlusion in mice. Subsequently, the effects of recombinant human soluble endoglin were assessed by label-free impedance-based measurement of endothelial monolayer integrity (using the xCELLigence DP system) and immunocytochemistry. Endoglin expression is highly inducible by hypoxia in human brain endothelial monolayers in vitro, and subsequent reoxygenation induced its shedding. These findings were corroborated in mice during MCAO; an upregulation of endoglin was displayed in the infarcted hemispheres under occlusion, whereas endoglin expression was significantly diminished after transient MCAO, which is indicative of shedding. Of note is the finding that soluble endoglin induced an inflammatory phenotype in endothelial monolayers. The treatment of HBMEC with endoglin resulted in a decrease in transendothelial resistance and the downregulation of VE-cadherin. Our data establish a novel mechanism in which hypoxia triggers the initial endothelial upregulation of endoglin and subsequent reoxygenation triggers its release as a vasoactive mediator that, when rinsed into adjacent vascular beds after recanalization, can contribute to cerebral reperfusion injury. 相似文献
44.
Kaan
cal Michael U. Gutmann Guido Sanguinetti Ramon Grima 《Journal of the Royal Society Interface》2022,19(192)
Estimating uncertainty in model predictions is a central task in quantitative biology. Biological models at the single-cell level are intrinsically stochastic and nonlinear, creating formidable challenges for their statistical estimation which inevitably has to rely on approximations that trade accuracy for tractability. Despite intensive interest, a sweet spot in this trade-off has not been found yet. We propose a flexible procedure for uncertainty quantification in a wide class of reaction networks describing stochastic gene expression including those with feedback. The method is based on creating a tractable coarse-graining of the model that is learned from simulations, a synthetic model, to approximate the likelihood function. We demonstrate that synthetic models can substantially outperform state-of-the-art approaches on a number of non-trivial systems and datasets, yielding an accurate and computationally viable solution to uncertainty quantification in stochastic models of gene expression. 相似文献
45.
Emna B. Saafi‐Ben Salah Guido Flamini Amira El Arem Manel Issaoui Samia Dabbou Leila BenYahia Ali Ferchichi Mohamed Hammami Lotfi Achour 《International Journal of Food Science & Technology》2012,47(9):1903-1908
This paper reports a discrimination study based on the physico‐chemical characteristics, fatty acids and profile of volatile compounds of the seeds from seven date palm varieties (Phoenix dactylifera L.) grown in Tunisia. Date seeds contained 10.49–14.76% moisture; 6.28–11.2% fat (on a dry weight basis); 2.67–12.85% protein; 0.91–6.06% reducing sugar; 0.61–2.98% sucrose and 0.97–1.17% ash. Gas liquid chromatography revealed that the oil fraction of the date palm seeds contained eighteen fatty acids, with oleic acid (30.77–42.50%) and lauric acid (18.51–27.48%) as the main unsaturated and saturated ones. Volatile profile showed differences among varieties. In total, forty‐five compounds were identified, mainly alcohols, aldehydes and unsaturated hydrocarbons ones. This study provides evidence that the seeds of date may be a potential source of valuable nutrients with interesting functionality. 相似文献
46.
47.
The crushing behaviour of sinter from blast furnace operations is known to depend on its temperature. In order to characterize it, hot sinter was subject to single particle tests in a very basic drop weight tester. Additionally, a laboratory jaw crusher was sacrificed to work the same feed material. As the results regarding net energy input were not consistent, two common rocks were tested in comparison with both the drop weight and the jaw crusher. Although some discrepancies remained, the results with the rocks can basically be considered as consistent. This investigation illustrates some of the difficulties that can arise when established test methods are applied on material with deviant properties. 相似文献
48.
Enhancing the temporal resolution of satellite-based flood extent generation using crowdsourced data for disaster monitoring 总被引:1,自引:0,他引:1
Remote-sensing satellite data are routinely used during disasters for damage assessment and to coordinate relief operations. Although there is a plethora of satellite sensors able to provide actionable data about an event, their temporal resolution is limited by their revisit time, presence of clouds, and errors in the reception of data. These limitations do not allow for an uninterrupted monitoring, which is crucial during disasters and emergencies. This research presents an approach that leverages the increased temporal resolution of crowdsourced data to partially overcome the limitations of satellite data. The proposed approach focuses on the geostatistical analysis of a combined satellite and Twitter data to help delineate the flood extent on a daily basis. The crowdsourced data are used to augment satellite imagery from Advanced Land Imager instrument on Earth Observating One (EO-1) satellite, Landsat 8, WorldView-2, and WorldView-3. The proposed methodology was applied to estimate the daily flood extents in Charleston, South Carolina, caused by the October 2015 North American storm complex. The results of the proposed methodology indicate that the user-generated data can be utilized adequately to both bridge the temporal gaps in the satellite-based observations and also increase the spatial resolution of the flood extents. 相似文献
49.
Guglielmo Barone Antonello d’Alessandro Guido de Blasio 《Papers in Regional Science》2019,98(5):1893-1902
National policies may have heterogeneous effects at the regional level. When coming to programmes aimed at increasing human capital, worker mobility from poorer to richer regions can reduce the benefits of the policy for the former areas. We focus on Italy and estimate the impact of education on the probability of migrating from a lagging area to a leading one. Endogeneity is addressed by exploiting an increase in the minimum school-leaving age in an instrumental variable framework. We find that one additional year of education increases the probability to migrate by 1.7 percentage points (9% of the average migration rate). 相似文献
50.