全文获取类型
收费全文 | 817篇 |
免费 | 37篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 2篇 |
综合类 | 1篇 |
化学工业 | 157篇 |
金属工艺 | 20篇 |
机械仪表 | 19篇 |
建筑科学 | 43篇 |
矿业工程 | 4篇 |
能源动力 | 20篇 |
轻工业 | 60篇 |
水利工程 | 10篇 |
无线电 | 75篇 |
一般工业技术 | 190篇 |
冶金工业 | 106篇 |
原子能技术 | 8篇 |
自动化技术 | 143篇 |
出版年
2023年 | 12篇 |
2022年 | 15篇 |
2021年 | 41篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 22篇 |
2017年 | 24篇 |
2016年 | 41篇 |
2015年 | 18篇 |
2014年 | 39篇 |
2013年 | 44篇 |
2012年 | 64篇 |
2011年 | 62篇 |
2010年 | 32篇 |
2009年 | 47篇 |
2008年 | 51篇 |
2007年 | 36篇 |
2006年 | 29篇 |
2005年 | 25篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 27篇 |
1997年 | 14篇 |
1996年 | 22篇 |
1995年 | 12篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有858条查询结果,搜索用时 15 毫秒
101.
This study presents a method to regenerate molecularly imprinted polymers (MIPs) used for the selective removal of endocrine disrupting compounds from aqueous effluents. Regeneration was based on solvent extraction under UV irradiation to regenerate the polymer and the solvent while destroying the contaminants. Acetone was selected as the best solvent for irradiation of estrone (E1), 17beta-estradiol (E2) and ethinylestradiol (EE2) using either UVC (254 nm) or UV-vis. A MIP synthesized with E2 as template was then tested for the extraction of this compound from a 2 microg/L loaded aqueous solution. E2 was recovered by 73+/-11% and 46+/-13% from the MIPs and a non-imprinted control polymer synthesized under the same conditions, respectively, after a single step elution with acetone. The irradiated polymers and acetone were reused for an additional extraction-regeneration cycle and showed no capacity decrease. 相似文献
102.
Alexandre Benoit Laurent Bonnaud Alice Caplier Phillipe Ngo Lionel Lawson Daniela G. Trevisan Vjekoslav Levacic Céline Mancas Guillaume Chanel 《Personal and Ubiquitous Computing》2009,13(1):33-41
This paper presents a driver simulator, which takes into account the information about the user’s state of mind (level of
attention, fatigue state, stress state). The user’s state of mind analysis is based on video data and biological signals.
Facial movements such as eyes blinking, yawning, head rotations, etc., are detected on video data: they are used in order
to evaluate the fatigue and the attention level of the driver. The user’s electrocardiogram and galvanic skin response are
recorded and analyzed in order to evaluate the stress level of the driver. A driver simulator software is modified so that
the system is able to appropriately react to these critical situations of fatigue and stress: some audio and visual messages
are sent to the driver, wheel vibrations are generated and the driver is supposed to react to the alert messages. A multi-threaded
system is proposed to support multi-messages sent by the different modalities. Strategies for data fusion and fission are
also provided. Some of these components are integrated within the first prototype of OpenInterface: the multimodal similar
platform. 相似文献
103.
A Benoit De Coignac C Bisbal B Lebleu T Salehzada 《Canadian Metallurgical Quarterly》1998,209(1-2):149-156
This study was designed to test the hypothesis that the immune changes seen during in vivo whole body hyperthermia are mediated by elevations in the plasma concentrations of either catecholamines, growth hormone or beta-endorphins. Eight healthy volunteers were immersed in a hot water bath (WI; water temperature 39.5 degrees C) for 2 h during which their rectal temperature rose to 39.5 degrees C. In a single blind, randomized, cross-over study the stress hormone effects were blocked one at a time by administration of propranolol, somatostatin or naloxone; the results were compared to those obtained during saline infusion (control). Blood samples were collected before, at the end of 2 h of WI (body temperature 39.5 degrees C), and 2 h later. Hormone blockade did not abolish the hyperthermia-induced recruitment of natural killer (NK) cells to the blood, and no influence was observed on the percentages or concentrations of any other subpopulations of blood mononuclear cells, except that the number of cluster designation (CD)3+ cells slightly increased after hyperthermia only in the propranolol experiment. Furthermore, the NK cell activity, both unstimulated and interferon-alpha or interleukin-2 stimulated, did not differ from the control situation. It is of interest, however, that somatostatin partly abolished the hyperthermia induced increase in the neutrophil number. Based on these data and previous results showing that growth hormone infusion increases the concentration of neutrophils in the blood, it is suggested that growth hormone is at least partly responsible for hyperthermia induced neutrocytosis. 相似文献
104.
Perales A. Goldstein L. Fernier B. Starck C. Lievin J.L. Poingt F. Benoit J. 《Electronics letters》1989,25(20):1350-1352
GaInAs/GaInAsP multi-quantum-well structures emitting at 1.55 mu m have been realised by gas source molecular beam epitaxy (GSMBE) over a large range of growth temperature. Threshold current densities as low as 0.81 kA/cm/sup 2/ have been obtained. The first BH lasers fabricated by GSMBE from these heterostructures exhibit low threshold current (18 mA) and linear DC light-current characteristics up to 20 mW.<> 相似文献
105.
106.
107.
108.
In immunocytes from the mollusc Mytilus galloprovincialis, the major pathway followed by platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 in provoking the release of norepinephrine, epinephrine and dopamine into cell-free hemolymph (serum) is mediated by a corticotropin-releasing hormone-adrenocorticotropin hormone (CRH-ACTH) biogenic amine axis. This axis not only annulled the inhibiting properties of PDGF-AB, it even reversed the latter's effect, while the inducing effect of TGF-beta1 was amplified. These findings show that non-classical immune-neuroendocrine molecules, such as PDGF-AB and TGF-beta1, are involved in building stress response, using the same conserved mechanisms present from invertebrates to vertebrates. 相似文献
109.
110.