全文获取类型
收费全文 | 528篇 |
免费 | 65篇 |
国内免费 | 36篇 |
专业分类
电工技术 | 8篇 |
综合类 | 106篇 |
化学工业 | 61篇 |
金属工艺 | 16篇 |
机械仪表 | 12篇 |
建筑科学 | 120篇 |
矿业工程 | 31篇 |
能源动力 | 4篇 |
轻工业 | 32篇 |
水利工程 | 42篇 |
石油天然气 | 7篇 |
武器工业 | 2篇 |
无线电 | 18篇 |
一般工业技术 | 44篇 |
冶金工业 | 45篇 |
自动化技术 | 81篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 17篇 |
2020年 | 12篇 |
2019年 | 17篇 |
2018年 | 21篇 |
2017年 | 25篇 |
2016年 | 17篇 |
2015年 | 20篇 |
2014年 | 38篇 |
2013年 | 41篇 |
2012年 | 33篇 |
2011年 | 38篇 |
2010年 | 34篇 |
2009年 | 30篇 |
2008年 | 29篇 |
2007年 | 28篇 |
2006年 | 33篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 30篇 |
2002年 | 11篇 |
2001年 | 20篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1982年 | 1篇 |
1970年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有629条查询结果,搜索用时 16 毫秒
1.
Benhui Hu Christopher Berkey Timothy Feliciano Xiaohong Chen Zhuyun Li Chao Chen Shahrouz Amini Mui Hoon Nai Qun-Li Lei Ran Ni Juan Wang Wan Ru Leow Shaowu Pan Yong-Qiang Li Pingqiang Cai Ali Miserez Shuzhou Li Chwee Teck Lim Yun-Long Wu Teri W. Odom Reinhold H. Dauskardt Xiaodong Chen 《Advanced materials (Deerfield Beach, Fla.)》2020,32(12):1907030
Bacterial infections remain a leading threat to global health because of the misuse of antibiotics and the rise in drug-resistant pathogens. Although several strategies such as photothermal therapy and magneto-thermal therapy can suppress bacterial infections, excessive heat often damages host cells and lengthens the healing time. Here, a localized thermal managing strategy, thermal-disrupting interface induced mitigation (TRIM), is reported, to minimize intercellular cohesion loss for accurate antibacterial therapy. The TRIM dressing film is composed of alternative microscale arrangement of heat-responsive hydrogel regions and mechanical support regions, which enables the surface microtopography to have a significant effect on disrupting bacterial colonization upon infrared irradiation. The regulation of the interfacial contact to the attached skin confines the produced heat and minimizes the risk of skin damage during thermoablation. Quantitative mechanobiology studies demonstrate the TRIM dressing film with a critical dimension for surface features plays a critical role in maintaining intercellular cohesion of the epidermis during photothermal therapy. Finally, endowing wound dressing with the TRIM effect via in vivo studies in S. aureus infected mice demonstrates a promising strategy for mitigating the side effects of photothermal therapy against a wide spectrum of bacterial infections, promoting future biointerface design for antibacterial therapy. 相似文献
2.
Our empirical analysis focuses on the effect of regional policies on migration attraction factors in Europe. We employ a regression discontinuity design to assess the causal relationship between the reception of large amounts of public funds and migration flows in the EU-15 regions. In highly-subsidised regions, we find a large increase in the share of foreign citizens from less-developed countries when compared to low-subsidised regions with similar pre-treatment characteristics. The analysis shows that such an increase is due to the positive impact of the European regional policy on job market opportunities as well as the improvement of public goods supply. 相似文献
3.
Andreas Faludi 《Planning Perspectives》2018,33(4):507-522
ABSTRACTThis paper explains the limited success of the European Spatial Development Perspective pointing to fault lines in the institutional architecture of European integration and the view that the EU has no business in national spatial planning. So, along with the experts at the Commission, the EU has been sidelined. Spending departments at both national as well as at EU level have more clout than planning anyhow. Later, the EU did obtain a competence, if not for spatial planning, then for territorial cohesion. In anticipation, member states adopted their own Territorial Agenda of the European Union. Neither it, nor EU territorial cohesion policy proper went far. Part of EU Cohesion policy, European Territorial Cooperation serves as a substitute. The continuing primacy which the EU institutional architecture gives to member states explains why. But this implies that European space is conceptualized as the sum of state jurisdiction, a view challenged by a fluid, dynamic spatial reality. 相似文献
4.
The last few years have seen many studies of large post-Second World War housing estates. At present they are often the most deprived areas of European cities. The turnover of the population on these estates is characteristically rapid, leading to considerable socio-economic and socio-cultural changes and a multi-ethnic neighbourhood. Such areas often have to contend with severe physical, social and economic problems and the consequent dissatisfaction of the residents. This combination of rapid and selective population turnover and increasing numbers of problems may well affect aspects of social cohesion within these neighbourhoods, particularly the social networks. This process is regrettable, because social cohesion is regarded in a positive light, something that enhances the quality of life. Stimulating social cohesion is therefore an important objective of many policies that focus on large post-Second World War housing estates. The authors have found it interesting to discover how important social cohesion is in the opinions and the lives of the inhabitants rather than the policy makers. In their opinion, urban policies focus on social cohesion while the inhabitants' views of its relevance are unknown. On the basis of this paper, certain aspects of social cohesion in large post-Second World War housing estates appear to be valued, but housing market behaviour, such as residential moves, is hardly affected by aspects of social cohesion. Other aspects, such as moving to a better house, are much more relevant. The results may put into doubt the stress placed in urban policies on social cohesion. 相似文献
5.
堤防工程生态固坡浅析 总被引:8,自引:0,他引:8
阐述了堤防工程中生态固坡技术的一般性原理,着重分析了生态固坡的岩土力学效应。参照树根桩计算的力学模式,把根系考虑为摩擦桩,根据加固后边坡中的力学平衡条件建议了深粗根加固坡体计算的本构模型。介绍了几种生态固坡新技术。 相似文献
6.
加筋挡土墙长期工作性能的黏弹塑性有限元分析 总被引:2,自引:1,他引:2
随着工程上的广泛应用,作为设计中的关键技术问题之一,土工合成材料加筋挡土墙长期工作性能的合理评价日益得到重视,对此必须考虑加筋材料的非线性蠕变效应。对于加筋挡土墙,采用黏弹塑性流变模型和黏弹性本构模型分别考虑填土与土工合成材料的非线性蠕变性,合理考虑筋材与填土、填土与面板及面板之间的相互作用效应,同时在计算中反映逐层填筑过程,采用增量一初应变迭代法,对土工合成材料加筋挡土墙结构的工作性能评价发展了二维有限元数值分析方法。基于Denver黏性土试验挡土墙的试验结果确定计算参数,利用所建议的分析方法对Denver黏性土试验挡土墙进行了数值计算与分析,通过与实测结果及与常规方法的对比分析,论证了所建议的有限元数值分析方法的合理性及其可靠性。 相似文献
7.
碳纤维增强复合材料(CFRP)与黏土砖界面的粘结性能是外贴CFRP加固技术的关键,为了解CFRP-黏土砖界面粘结性能在硫酸盐侵蚀下的退化规律,对硫酸盐干湿循环不同周期下的加固试件进行了单面剪切试验,结果表明:硫酸盐侵蚀对CFRP片材与浸渍胶性能影响并不明显,但对CFRP-黏土砖界面粘结性能影响较大,CFRP-黏土砖界面剪应力、承载力均随循环次数呈先小幅上升后明显下降的趋势;在试验基础上,根据已有的理论,提出硫酸盐干湿循环作用下CFRP-黏土砖界面粘结-滑移模型,通过与试验值对比分析发现,模型能够很好地反映CFRP-黏土砖界面的粘结性能退化规律。基于ABAQUS软件,利用内聚力本构关系模型对界面力学行为进行数值模拟,结果表明,内聚力模型可以很好地模拟界面的非线性力学行为,数值模拟值与试验值吻合较好。 相似文献
8.
为研究工艺参数对物料抛圆整形的影响,基于Abaqus仿真软件和内聚元法,对物料碰撞壁面过程进行数值模拟,研究颗粒在不同速度及结合能碰撞后的效果。结果表明:随速度增大,颗粒碰撞过程中剥落区增大,且在较高速度下(≥3 m/s),颗粒形貌变化较大。相同碰撞速度下,随颗粒结合能增大,颗粒剥落区减小。在碰撞速度为3 m/s,结合能为0.04J时,碰撞后颗粒的形貌更好,物料造粒效果较好。 相似文献
9.
《Soils and Foundations》2021,61(5):1475-1479
A growing number of slope hazard and engineering case studies have shown that only one safety factor (SF) can predict landslide occurrence, but cannot identify potentially dangerous landslides, which is the major source of the most destructive landslides. To solve the problem, a safety factor of cohesion (SFc) is proposed, and an improved slope stability analysis based on two safety factors is presented. Taking a sloping rock mass as a case study, the results showed that when SFc was less than 1 and the ratio of the cohesive force to the sliding resistance force drops to less than 100%, the slope became a potential landslide. The study suggests a new method for quantitative identification of potential landslides and provides a more reliable safety evaluation index, thus can solve the difficulty of adjustment of potential landslides and provide a more reliable safety evaluation index for engineering. 相似文献
10.
Nikolaos Gavanas Efthimios Moutsiakis Anastasia Tasopoulou Eleni Verani Vasilios Fourkas 《影响评估与项目评价》2018,36(4):294-307
Territorial Impact Assessment (TIA) is proposed as a critical tool in order to investigate the way policies affect spatial development and hence territorial cohesion. The paper introduces a TIA methodological model in relation to transport sector. The design of the methodological model is based on a quantitative evaluation framework that comprises a set of selected indicators applied in a cross-border area of southeast Europe, influenced by the operation of the Greek motorway system of Egnatia and its vertical axes. The indicators are grouped into three main fields of TIA, i.e. transport intermodality, polycentric spatial organization and cross-border territorial cooperation. The TIA’s indicators are approximated by quantitative analysis. The procedure concludes to an overall composite indicator measuring the ‘level of territorial cohesion’ along with some core results and the expected added value. It also highlights some key technical aspects about the routines used and proceeds to suggestions for further refinement. 相似文献