全文获取类型
收费全文 | 1137篇 |
免费 | 72篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 279篇 |
金属工艺 | 7篇 |
机械仪表 | 17篇 |
建筑科学 | 45篇 |
能源动力 | 41篇 |
轻工业 | 139篇 |
水利工程 | 18篇 |
无线电 | 113篇 |
一般工业技术 | 184篇 |
冶金工业 | 180篇 |
原子能技术 | 16篇 |
自动化技术 | 152篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 36篇 |
2021年 | 62篇 |
2020年 | 30篇 |
2019年 | 26篇 |
2018年 | 36篇 |
2017年 | 31篇 |
2016年 | 32篇 |
2015年 | 35篇 |
2014年 | 58篇 |
2013年 | 69篇 |
2012年 | 65篇 |
2011年 | 52篇 |
2010年 | 49篇 |
2009年 | 52篇 |
2008年 | 52篇 |
2007年 | 35篇 |
2006年 | 37篇 |
2005年 | 29篇 |
2004年 | 33篇 |
2003年 | 33篇 |
2002年 | 27篇 |
2001年 | 19篇 |
2000年 | 10篇 |
1999年 | 28篇 |
1998年 | 57篇 |
1997年 | 36篇 |
1996年 | 31篇 |
1995年 | 17篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1974年 | 2篇 |
排序方式: 共有1209条查询结果,搜索用时 46 毫秒
991.
Investigation of inflammatory and allergic responses to common mold species: Results from in vitro experiments,from a mouse model of asthma,and from a group of asthmatic patients
下载免费PDF全文
![点击此处可从《Indoor air》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Vincent P. Percier S. De Prins K. Huygen G. Potemberg E. Muraille M. Romano O. Michel O. Denis 《Indoor air》2017,27(5):933-945
Most studies on molds focus on Alternaria alternata and Aspergillus fumigatus. Here, we report on inflammatory and allergenic properties of more typical indoor species Aspergillus versicolor, P. chrysogenum, C. cladosporioïdes, and C. sphaerospermum that were compared to A. alternata and A. fumigatus. In a mouse model, after intranasal instillation, A. alternaria, A. versicolor, and C. sphaerospermum induced the early recruitment of neutrophils and the strong expression of inflammatory markers in the bronchoalveolar lavages fluids. A. fumigatus also induced the early accumulation of neutrophils but with lower levels of inflammatory markers. Chronic treatment induced variable response according to species: P. chrysogenum and A. fumigatus appeared strong pro‐allergenic inducers compared to A. alternata and C. sphaerospermum while A. versicolor and C. cladosporioides induced a mixed pro‐allergenic/pro‐inflammatory response. In mold‐sensitized asthmatics, mold‐specific Immunoglobulin E (IgE) were detected with an in‐house dot‐blot assay. A. fumigatus and A. alternata were the most frequent sensitizers. Altogether, P. chrysogenum, P. brevicompactum, C. sphaerospermum, and C. cladosporïoides were the “major sensitizer” (defined as the strongest response against a single mold species) for almost 30% of the asthmatics. These results show that, not only A. alternata and A. fumigatus, but also indoor species have strong inflammatory and allergic properties and a harmful potency. 相似文献
992.
Electrical properties (permittivity and conductivity) of vegetable oils were determined in the frequency range from 20 Hz to 2 MHz. Commercial samples of corn, sunflower, soybean, grapeseed, cottonseed, olive, canola and chia oils were measured at temperatures between 300 K and 343 K (stabilized within 0.1 K). The calibration uncertainty in the measuring system was below 1%. 相似文献
993.
A combined concentrating solar power system and a geothermal binary plant based on an Organic Rankine Cycle (ORC) is analyzed. Given a supercritical ORC, designed for the optimal utilization of an intermediate enthalpy geothermal source, a solar parabolic trough field was included in the plant, introducing an additional high temperature heat source for the cycle and increasing power production. The off-design performance analysis of the power cycle was performed first. An hour-by-hour simulation was then carried out to estimate the yearly production using a detailed solar field model. Finally, a differential economic analysis was performed to determine the cost of the additional electricity generated with the solar source. On the basis of the current cost of solar collectors, levelized costs of electricity of 145-280 €/MWh were obtained depending on the location of the plant: a competitive value with respect to large, stand-alone concentrating solar power plants. 相似文献
994.
995.
996.
997.
998.
Claudia Crocini Raffaele Coppini Cecilia Ferrantini Ping Yan Leslie M. Loew Corrado Poggesi Elisabetta Cerbai Francesco S. Pavone Leonardo Sacconi 《International journal of molecular sciences》2016,17(9)
Alterations of the β-adrenergic signalling, structural remodelling, and electrical failure of T-tubules are hallmarks of heart failure (HF). Here, we assess the effect of β-adrenoceptor activation on local Ca2+ release in electrically coupled and uncoupled T-tubules in ventricular myocytes from HF rats. We employ an ultrafast random access multi-photon (RAMP) microscope to simultaneously record action potentials and Ca2+ transients from multiple T-tubules in ventricular cardiomyocytes from a HF rat model of coronary ligation compared to sham-operated rats as a control. We confirmed that β-adrenergic stimulation increases the frequency of Ca2+ sparks, reduces Ca2+ transient variability, and hastens the decay of Ca2+ transients: all these effects are similarly exerted by β-adrenergic stimulation in control and HF cardiomyocytes. Conversely, β-adrenergic stimulation in HF cells accelerates a Ca2+ rise exclusively in the proximity of T-tubules that regularly conduct the action potential. The delayed Ca2+ rise found at T-tubules that fail to conduct the action potential is instead not affected by β-adrenergic signalling. Taken together, these findings indicate that HF cells globally respond to β-adrenergic stimulation, except at T-tubules that fail to conduct action potentials, where the blunted effect of the β-adrenergic signalling may be directly caused by the lack of electrical activity. 相似文献
999.
Detailed analyses based on mass and energy balances of lignite‐fired air‐blown gasification‐based combined cycles with CO2 pre‐combustion capture are presented and discussed in this work. The thermodynamic assessment is carried out with a proprietary code integrated with Aspen Plus® to carefully simulate the selective removal of both H2S and CO2 in the acid gas removal station. The work focuses on power plants with two combustion turbines, with lower and higher turbine inlet temperatures, respectively, as topping cycle. A high‐moisture lignite, partially dried before feeding the air‐blown gasification system, is used as fuel input. Because the raw lignite presents a very low amount of sulfur, a particular technique consisting of an acid gas recycle to the absorber, is adopted to fulfill the requirements related to the presence of H2S in the stream to the Claus plant and in the CO2‐rich stream to storage. Despite the operation of the H2S removal section representing a significant issue, the impact on the performance of the power plant is limited. The calculations show that a significant lignite pre‐drying is necessary to achieve higher efficiency in case of CO2 capture. In particular, considering a wide range (10–30 wt.%) of residual moisture in the dried lignite, higher heating value (HHV) efficiency presents a decreasing trend, with maximum values of 35.15% and 37.12% depending on the type of the combustion turbine, even though the higher the residual moisture in the dried coal, the lower the extraction of steam from the heat recovery steam cycle. On the other hand, introducing the specific primary energy consumption for CO2 avoided (SPECCA) as a measure of the energy cost related to CO2 capture, lower values were predicted when gasifying dried lignite with higher residual moisture content. In particular, a SPECCA value as low as 2.69 MJ/kgCO2 was calculated when gasifying lignite with the highest (30 wt.%) residual moisture content in a power plant with the advanced combustion turbine. Ultimately, focusing on the power plants with the advanced combustion turbine, air‐blown gasification of lignite brings about a reduction in HHV efficiency equal to almost 1.5 to 2.8 percentage points, depending on the residual moisture in the dried lignite, if compared with similar cases where bituminous coal is used as fuel input. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
1000.
The dynamic response to oxidation of a hot-pressed ZrB2 + 15 vol%. SiC ceramic composite was studied under aero-thermal heating using a high enthalpy supersonic flow of a N2/O2 gas mixture in plasma wind tunnel. Microstructural features of the reaction scale developed upon oxidation were analyzed and correlated to test conditions through Computational Fluid Dynamics simulations. The significant heat flux and temperature gradients of the sample’s surface exposed to the highly energized N2/O2 gas stream led to the formation and evolution of distinct layered oxide sub-scales. The diffusion of oxidants through silica-rich 3D glassy network was proposed as the rate governing factor for oxidation. 相似文献