全文获取类型
收费全文 | 523篇 |
免费 | 27篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 105篇 |
金属工艺 | 13篇 |
机械仪表 | 8篇 |
建筑科学 | 29篇 |
矿业工程 | 2篇 |
能源动力 | 16篇 |
轻工业 | 57篇 |
水利工程 | 1篇 |
无线电 | 56篇 |
一般工业技术 | 76篇 |
冶金工业 | 29篇 |
原子能技术 | 5篇 |
自动化技术 | 136篇 |
出版年
2023年 | 10篇 |
2022年 | 12篇 |
2021年 | 15篇 |
2020年 | 15篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 13篇 |
2014年 | 19篇 |
2013年 | 28篇 |
2012年 | 15篇 |
2011年 | 37篇 |
2010年 | 35篇 |
2009年 | 34篇 |
2008年 | 32篇 |
2007年 | 29篇 |
2006年 | 23篇 |
2005年 | 14篇 |
2004年 | 17篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1974年 | 3篇 |
1943年 | 2篇 |
1941年 | 3篇 |
1936年 | 2篇 |
1924年 | 3篇 |
1909年 | 4篇 |
1908年 | 4篇 |
1905年 | 2篇 |
1904年 | 2篇 |
1901年 | 6篇 |
1898年 | 2篇 |
排序方式: 共有550条查询结果,搜索用时 531 毫秒
111.
Jørn A. Holme Elisabeth Øya Anani K. J. Afanou Johan Øvrevik Wijnand Eduard 《Indoor air》2020,30(4):662-681
A number of epidemiological studies find an association between indoor air dampness and respiratory health effects. This is often suggested to be linked to enhanced mold growth. However, the role of mold is obviously difficult to disentangle from other dampness-related exposure including microbes as well as non-biological particles and chemical pollutants. The association may partly be due to visible mycelial growth and a characteristic musty smell of mold. Thus, the potential role of mold exposure should be further explored by evaluating information from experimental studies elucidating possible mechanistic links. Such studies show that exposure to spores and hyphal fragments may act as allergens and pro-inflammatory mediators and that they may damage airways by the production of toxins, enzymes, and volatile organic compounds. In the present review, we hypothesize that continuous exposure to mold particles may result in chronic low-grade pro-inflammatory responses contributing to respiratory diseases. We summarize some of the main methods for detection and characterization of fungal aerosols and highlight in vitro research elucidating how molds may induce toxicity and pro-inflammatory reactions in human cell models relevant for airway exposure. Data suggest that the fraction of fungal hyphal fragments in indoor air is much higher than that of airborne spores, and the hyphal fragments often have a higher pro-inflammatory potential. Thus, hyphal fragments of prevalent mold species with strong pro-inflammatory potential may be particularly relevant candidates for respiratory diseases associated with damp/mold-contaminated indoor air. Future studies linking of indoor air dampness with health effects should assess the toxicity and pro-inflammatory potential of indoor air particulate matter and combined this information with a better characterization of biological components including hyphal fragments from both pathogenic and non-pathogenic mold species. Such studies may increase our understanding of the potential role of mold exposure. 相似文献
112.
113.
Eduard Spaeth 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1908,15(8):472-484
Ohne Zusammenfassung 相似文献
114.
115.
Muljadi Eduard Schiferl Rich Lipo Thomas A. 《Industry Applications, IEEE Transactions on》1985,(3):669-678
High inrush currents and unbalanced supply voltages are two of the major causes for failure of polyphase induction machines. While thyristor voltage controllers, sometimes called static starters, are in widespread use to limit damaging inrush currents, little attention has been paid to the use of these controllers to balance the phases voltages of the machine. The technical feasibility of unsymmetric control to limit unbalanced currents is explored. A substantial reduction in losses is shown to be possible for two specific types of unbalance. 相似文献
116.
Die Verfahrensparameter für die heißisostatische Pulververdichtung des Warmarbeitsstahles X 40 CrMoV 5 1 (Werkstoffnummer 1.2344) werden aus der Beurteilung der mechanischen Festigkeitswerte sowie des Bruch- und Schliffgefüges festgelegt. Hierbei erweist sich die Schlagbiegearbeit der ungekerbten Probe als besonders kritische Meßgröße zur Optimierung der einzelnen Prozeßschritte. Die am PM-Stahl ermittelten statischen und dynamischen Festigkeitswerte werden den Werten der konventionellen SM-Legierung gegenübergestellt. 相似文献
117.
Manchili Swathi K. Wendel Johan Zehri Abdelhafid Liu Johan Hryha Eduard Nyborg Lars 《Metallurgical and Materials Transactions A》2020,51(9):4890-4901
Metallurgical and Materials Transactions A - A promising method of improving the densification of powder metallurgical steel components is to blend nanopowder with the otherwise typically used... 相似文献
118.
During the last decades, anatomy has become an interesting topic in education—even for laymen or schoolchildren. As medical imaging techniques become increasingly sophisticated, virtual anatomical education applications have emerged. Still, anatomical models are often preferred, as they facilitate 3D localization of anatomical structures. Recently, data physicalizations (i.e., physical visualizations) have proven to be effective and engaging—sometimes, even more than their virtual counterparts. So far, medical data physicalizations involve mainly 3D printing, which is still expensive and cumbersome. We investigate alternative forms of physicalizations, which use readily available technologies (home printers) and inexpensive materials (paper or semi-transparent films) to generate crafts for anatomical edutainment. To the best of our knowledge, this is the first computer-generated crafting approach within an anatomical edutainment context. Our approach follows a cost-effective, simple, and easy-to-employ workflow, resulting in assemblable data sculptures (i.e., semi-transparent sliceforms). It primarily supports volumetric data (such as CT or MRI), but mesh data can also be imported. An octree slices the imported volume and an optimization step simplifies the slice configuration, proposing the optimal order for easy assembly. A packing algorithm places the resulting slices with their labels, annotations, and assembly instructions on a paper or transparent film of user-selected size, to be printed, assembled into a sliceform, and explored. We conducted two user studies to assess our approach, demonstrating that it is an initial positive step towards the successful creation of interactive and engaging anatomical physicalizations. 相似文献
119.
Aleksandr Amirkhanov Ilona Kosiuk Peter Szmolyan Artem Amirkhanov Gabriel Mistelbauer M. Eduard Grller Renata G. Raidou 《Computer Graphics Forum》2019,38(7):191-202
Mathematical models of ordinary differential equations are used to describe and understand biological phenomena. These models are dynamical systems that often describe the time evolution of more than three variables, i.e., their dynamics take place in a multi‐dimensional space, called the phase space. Currently, mathematical domain scientists use plots of typical trajectories in the phase space to analyze the qualitative behavior of dynamical systems. These plots are called phase portraits and they perform well for 2D and 3D dynamical systems. However, for 4D, the visual exploration of trajectories becomes challenging, as simple subspace juxtaposition is not sufficient. We propose ManyLands to support mathematical domain scientists in analyzing 4D models of biological systems. By describing the subspaces as Lands, we accompany domain scientists along a continuous journey through 4D HyperLand, 3D SpaceLand, and 2D FlatLand, using seamless transitions. The Lands are also linked to 1D TimeLines. We offer an additional dissected view of trajectories that relies on small‐multiple compass‐alike pictograms for easy navigation across subspaces and trajectory segments of interest. We show three use cases of 4D dynamical systems from cell biology and biochemistry. An informal evaluation with mathematical experts confirmed that ManyLands helps them to visualize and analyze complex 4D dynamics, while facilitating mathematical experiments and simulations. 相似文献
120.
Premixed conical CH4-air flames were studied experimentally and numerically under normal straight, reversed gravity conditions and microgravity. Low-gravity experiments were performed in Drop tower. Classical Bunsen-type burner was used to find out features of gravity influence on the combustion processes. Mixture equivalence ratio was varied from 0.8 to 1.3. Wide range of flow velocity allows to study both laminar and weakly turbulized flames. High-speed flame chemoluminescence video-recording was used as diagnostic. The investigations were performed at atmospheric pressure. As results normalized flame height, laminar flame speed were measured, also features of flame instabilities were shown. Low- and high-frequency flame-instabilities (oscillations) have a various nature as velocity fluctuations, preferential diffusion instability, hydrodynamic and Rayleigh-Taylor ones etc., that was explored and demonstrated. 相似文献