全文获取类型
收费全文 | 424篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 53篇 |
金属工艺 | 4篇 |
机械仪表 | 5篇 |
建筑科学 | 22篇 |
矿业工程 | 1篇 |
能源动力 | 17篇 |
轻工业 | 44篇 |
水利工程 | 1篇 |
无线电 | 28篇 |
一般工业技术 | 64篇 |
冶金工业 | 141篇 |
原子能技术 | 5篇 |
自动化技术 | 46篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 15篇 |
2012年 | 11篇 |
2011年 | 22篇 |
2010年 | 20篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 45篇 |
1997年 | 25篇 |
1996年 | 18篇 |
1995年 | 10篇 |
1994年 | 18篇 |
1993年 | 15篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1978年 | 2篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1968年 | 2篇 |
1967年 | 3篇 |
排序方式: 共有434条查询结果,搜索用时 15 毫秒
101.
In the last decade, a range of drivers within the seafood sector have incentivized the application of traceability to issues beyond food safety and inventory management. Some of the issues motivating the expanded use of traceability within the global seafood sector include: increased media attention on the legal and social risks within some seafood supply chains, governmental traceability requirements, private‐sector sustainability commitments, and others. This article begins with an overview of these topics in the seafood industry, and why many nongovernment organizations (NGOs), companies, and government actors have turned to traceability as a tool to address them. We discuss how traceability connects to key requirements of environmental sustainability and social responsibility. Later, we review the range of traceability services, tools, software solutions, and the due diligence measures that are currently being leveraged within the seafood sector. The paper concludes with a discussion of several NGO‐ and industry‐led traceability initiatives that are examples of seafood traceability improvements. 相似文献
102.
Sally K. Abell Barbora De Courten Jacqueline A. Boyle Helena J. Teede 《International journal of molecular sciences》2015,16(6):13442-13473
Understanding pathophysiology and identifying mothers at risk of major pregnancy complications is vital to effective prevention and optimal management. However, in current antenatal care, understanding of pathophysiology of complications is limited. In gestational diabetes mellitus (GDM), risk prediction is mostly based on maternal history and clinical risk factors and may not optimally identify high risk pregnancies. Hence, universal screening is widely recommended. Here, we will explore the literature on GDM and biomarkers including inflammatory markers, adipokines, endothelial function and lipids to advance understanding of pathophysiology and explore risk prediction, with a goal to guide prevention and treatment of GDM. 相似文献
103.
The advent of high-throughput phenotyping installations signals a need for plant biology to use pattern analysis and recognition techniques, especially when analysis is done via digital images. Such installations also provide an opportunity to computer vision. We describe one such application at the UK National Plant Phenomics Centre, in which historically measurements have been made in a labour-intensive manual manner. We develop an estimator of tiller number in growing wheat which, when exploiting per-day averaging, temporal interpolation and dynamic programming, delivers measurements of finer-grain and no less accuracy than manually, and provides observations on plant treatments hitherto difficult or impossible to obtain. The approach developed lends itself to reuse for any similar imaging setup, and plants with tillering characteristics similar to wheat. We consider the work a useful exemplar for co-operation between biologists and computer scientists in such installations. 相似文献
104.
Thomas M. Connolly Elizabeth A. Boyle Ewan MacArthur Thomas Hainey James M. Boyle 《Computers & Education》2012
This paper examines the literature on computer games and serious games in regard to the potential positive impacts of gaming on users aged 14 years or above, especially with respect to learning, skill enhancement and engagement. Search terms identified 129 papers reporting empirical evidence about the impacts and outcomes of computer games and serious games with respect to learning and engagement and a multidimensional approach to categorizing games was developed. The findings revealed that playing computer games is linked to a range of perceptual, cognitive, behavioural, affective and motivational impacts and outcomes. The most frequently occurring outcomes and impacts were knowledge acquisition/content understanding and affective and motivational outcomes. The range of indicators and measures used in the included papers are discussed, together with methodological limitations and recommendations for further work in this area. 相似文献
105.
Vegetarianism is a dynamic and fluid lifestyle that can be described as unique for each person who practices. Vegetarianism traditionally falls outside of the accepted eating patterns in Western nations; furthermore, the meat-free lifestyle can be classified as a form of positive deviance. Semistructured interviews were conducted with self-described vegetarians regarding eating patterns and motivations within the initial adoption of the lifestyle. Vegetarian vocabularies of motive were categorized according to established deviance theory referred to as accounts. This newly practicing, or developmental, stage of vegetarianism was more likely to fall on the less strict side of the vegetarian continuum for eating patterns and the motives had a propensity to be monothematic. 相似文献
106.
107.
Maarten van Ham Lee Williamson Peteke Feijten Paul Boyle 《Journal of Housing and the Built Environment》2013,28(1):129-146
Part of the political argument in favour of the right to buy (RTB) was that it would stimulate the economy by encouraging the inter-regional mobility of those in public sector housing. This is the first study to examine whether RTB-owners are indeed more mobile than those in social housing. Using longitudinal data from the British household panel survey and panel regression models we show that the probability of a RTB-owner making a long distance move falls between that of social renters and owner occupiers. However, the difference between RTB-owners and homeowners or social renters is not significant. Social renters are significantly less likely to move over long distances than traditional owners. The results also suggest that RTB-owners are less likely than traditional owners to move for job related reasons, but more likely than social renters. 相似文献
108.
Megan A. Boyle Andrew L. Samaha Andrew M. Rodewald Audrey N. Hoffmann 《Computers in human behavior》2013
Data extraction programs are used to obtain approximations of raw data from published graphs. Quantitative syntheses of single-subject data require that researchers have access to valid and reliable data extraction programs. We analyzed the reliability and validity of a data extraction program, GraphClick. Three independent coders extracted data from 191 graphs from the Journal of Applied Behavior Analysis (JABA) and 15 graphs of hypothetical data. Results showed that GraphClick is both reliable and valid with nearly perfect correlations for all analyses. Suggestions are included for researchers and authors to improve the accuracy of data extraction techniques. 相似文献
109.
Objective
Some crashes result in drivers experiencing (or sustaining) a traumatic brain injury (TBI) while other crashes involve drivers that have already experienced a TBI. The objective of this study is to examine the factors that influence these two TBI crash groups.Methods
Data from the Iowa Department of Public Health's Brain Injury Registry and Department of Transportation's crash records were linked together and used in logistic regression models to predict the likelihood of a driver sustaining a TBI in a crash and those who drive after a TBI.Results
Between 2001 and 2006, there were 2382 crashes in which an individual sustained a TBI. As expected, a higher likelihood of sustaining a TBI was observed for motorcycle drivers who did not wear a helmet and in crashes that resulted in total or disabling vehicle damage. Focusing specifically on the post-TBI drivers (and not occupants), 1583 were involved in crashes. These post-TBI drivers were less likely to wear seatbelts or have passengers in the vehicle at the time of the crash, and were more likely to crash at night. Post-TBI drivers were also involved in significantly more multiple crashes (about 14%) when compared to drivers who have not experienced a TBI (about 10%) during the study period. When controlling for gender, date of injury, and severity of TBI (using Glasgow Coma Scale), individuals that sustained a TBI when they were younger were more likely to be involved in multiple crashes.Conclusions
Different factors influence the crash likelihood for those that sustain a TBI in a crash and those that crash following a TBI. In general, post-TBI drivers have a higher occurrence of multiple crashes and this should be further explored to guide driver rehabilitation, evaluation, and training. 相似文献110.
Hydrodynamic dispersion of particle agglomerates occurs whenever the applied shear stresses can break the interparticle bonds responsible for the cohesivity of the agglomerate. Various mechanisms of hydrodynamic dispersion have been demonstrated for silica agglomerates infiltrated to different extents by the suspending fluid. In some cases, hydrodynamic forces are sufficient to induce the removal of incompletely infiltrated fragments from the parent agglomerate (dry cohesive failure) or the breakage of wetted fragments from the infiltrated portion of the parent agglomerate (wet cohesive failure). Dispersion can also occur such that a portion of the fracture surface originates at the interface between the infiltrated periphery of the agglomerate and its dry core (adhesive failure). To elucidate the tendencies for dispersion via various modes, a hydrodynamic analysis of the forces acting on and within the agglomerate has been performed for both uninfiltrated and partially infiltrated structures. This analysis reveals that the size of the region on which the hydrodynamic stress bears is sensitive to the degree of infiltration, which is consistent with the observed shifts in dispersion mechanism. 相似文献