全文获取类型
收费全文 | 427篇 |
免费 | 12篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 131篇 |
金属工艺 | 3篇 |
机械仪表 | 7篇 |
建筑科学 | 26篇 |
能源动力 | 12篇 |
轻工业 | 28篇 |
水利工程 | 3篇 |
无线电 | 33篇 |
一般工业技术 | 68篇 |
冶金工业 | 37篇 |
原子能技术 | 4篇 |
自动化技术 | 82篇 |
出版年
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 22篇 |
2011年 | 26篇 |
2010年 | 27篇 |
2009年 | 28篇 |
2008年 | 27篇 |
2007年 | 10篇 |
2006年 | 18篇 |
2005年 | 11篇 |
2004年 | 15篇 |
2003年 | 19篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 1篇 |
1998年 | 9篇 |
1997年 | 15篇 |
1996年 | 9篇 |
1995年 | 11篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有439条查询结果,搜索用时 15 毫秒
21.
This article concerns the functionalization of polypropylene (PP) with oxazoline functionality by melt free radical grafting along with a low degree of degradation of PP in a batch mixer. A low volatile oxazoline, ricinoloxazoline maleinate (OXA), was used as the monomer. The grafting yield of OXA ranged from about 0.5 phr up to 1.5 phr (grams per 100 grams of PP) when its initial concentration and that of the peroxide ranged from 1.5 to 6.0 phr and 0.1 to 0.7 phr, respectively. The corresponding conversion of OXA to grafted OXA ranged from about 15 to 50%. Addition of styrene (St) as the comonomer did not enhance the grafting yield of OXA but markedly reduced the PP degradation. Also, little homo-and/or copolymers of OXA and/or St were found in the grafting system. This agrees with our finding that OXA and St did not copolymerize easily. The potential of using an OXA modified PP (PP-g-OXA) as the compatibilizer precursor in PP/PBT blends was examined as well. The presence of PP-g-OXA reduced the particle size of the dispersed phase (PBT) along with improved cohesion between the PP and PBT phases. This is consistent with a model kinetic study, which showed that the reaction between oxazoline and carboxylic functionalities was very fast. © 1996 John Wiley & Sons, Inc. 相似文献
22.
23.
Peetu Nieminen Salvador Esque Ali Muhammad Jouni Mattila Jukka Vyrynen Mikko Siuko Matti Vilenius 《Fusion Engineering and Design》2009,84(7-11):1420-1424
Department of Intelligent Hydraulics and Automation (IHA) of Tampere University of Technology has been involved in the European Fusion program since 1994 within the ITER reactor maintenance activities. In this paper we discuss the design and development of a six degrees of freedom water hydraulic manipulator with a force feedback for teleoperation tasks. The manipulator is planned to be delivered to Divertor Test Platform 2 (DTP2) during year 2008. The paper also discusses the possibility to improve the fail safe and redundant operation of the manipulator. During the design of the water hydraulic manipulator, special provisions have been made in order to meet the safety requirements such as servo valve block for redundant operation and safety vane brakes for fail safe operation. 相似文献
24.
Five silane blends were evaluated as experimental adhesion-promoter primers. First, five organosilane monomers (silicon esters),
3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, tetrakis-(2-ethyloxyethoxy)silane and bis-[3-(triethoxysilyl)propyl]tetrasulfide, were diluted to 1% (v/v) and blended with a non-functional cross-linking silane, 1,2-bis-(triethoxysilyl)ethane (1%), in 95% ethanol. After activation, each blend was applied to silica-coated Ti coupons. A resin
based on bis-phenol-A-diglycidyldimethacrylate was then bonded and photo-polymerized as stubs to the pretreated Ti coupons. Half of the
specimens were stored in dry conditions and half were artificially aged by thermo-cycling. The primers containing 3-acryloxypropyltrimethoxysilane
and 3-methacryloxypropyltrimethoxysilane produced significantly higher shear bond strength values than the control silane,
a standard pre-activated product used in clinical dentistry. 相似文献
25.
The sorption of Si may decisively influence the P dynamics in surface sediment through competitive ligand exchange mechanisms. Many aspects of the process, such as the impact of Si dissolving from diatoms, are both insufficiently known and difficult to monitor by quantitative analyses due to the ubiquitousness of Si in sediment. Since the radioactive isotopes of Si have impractical half-times, the applicability of 68Ge as a tracer for Si additions in both inorganic and biogenic form to freshwater sediment (Lake Vesij?rvi, Southern Finland) was studied in a 24-h laboratory experiment. The 68Ge-label was added to the sediment with either inorganic Si (940mg l(-1)) or diatoms (3.2 x 10(6) cellsl(-1)), and the distributions of the 68Ge-label and the different forms of added Si between the interstitial water and sequentially extracted, solid-phase sediment pools were critically examined. The inorganic Si addition significantly increased the amount of Si in the interstitial water and in the reversibly bound fraction, while the diatom addition had no discernible effects. The relative distribution of Si and 68Ge between the various sediment pools indicated that the first sorption phase of the added inorganic Si was similar to that reported for P. The high concentration of diatom-derived 68Ge-labelled Si in the interstitial water and in the easily soluble, reversibly bound pool indicated rapid dissolution of the added diatoms. The comparable distributions of the diatom-derived and inorganic Si-derived 68Ge-label within the studied pools indicated that the sorption of Si dissolving from diatoms in surface sediment closely resembles that of an inorganic addition of Si. Caution about the chemical speciation of the 68Ge-label is, however, advisable in sediment environments. Fractionation procedures designed for e.g. P may also be of limited use when applied to a different element, such as Si. 相似文献
26.
Anu Kärkkäinen Panu Pekko James Dekker Nadine Pesonen Mika Suhonen Aarne Oja Jukka Kyynäräinen Heikki Seppä 《Microsystem Technologies》2005,12(1-2):169-172
We have designed and manufactured a micromachined moving plate capacitor to be used as an AC voltage reference in electrical metrology. The reference is based on the characteristic AC current–voltage curve of the component having a maximum, the value of which ideally depends only on the geometry of the component and material properties of single crystalline silicon. The electrode surface stability is essential in this application and hence a new fabrication process has been developed to metallize both surfaces of an electrostatically actuated micromachined structure. The stability of the AC reference voltage at a frequency of 100 kHz and an RMS voltage value 6.4 V was measured to be ±60 ppm over 14 h. 相似文献
27.
Jukka J.A. Lempi?inen 《Wireless Personal Communications》2000,15(3):247-248
Volume Contents
Volume contents 相似文献28.
29.
This paper presents practical experience in planning, implementing, and adopting a Quality Management System (QMS) for embedded systems development at VTT Electronics. The main objective for the development of the QMS was to make it practical for real-life embedded systems research and development (R&D) projects. We have applied the ISO 9001 standard and ISO 9000–3 guidelines in building the quality system. From our personnel's point of view, the most important parts of the system have been document skeletons and plan templates that were made accessible to everyone. One of the major quality improvement resulting from the use of the QMS has been the enhanced predictability of R&D projects. This makes it possible for the organization to concentrate on essential matters. From our clients' point of view, we have clearly improved the quality of our R&D services in terms of the customer satisfaction index. Based on QMS auditing activities, we have been able to evaluate and tune our R&D procedures in a systematic manner. We have decided to use Total Quality Management and Quality Award frameworks in the further development of the QMS. Customer service and human resources management are examples of important areas for further quality improvement. 相似文献
30.
Davydenko SG Juselius JK Munder T Bogengruber E Jäntti J Keränen S 《Yeast (Chichester, England)》2004,21(6):463-471
We describe here a screening procedure devised for searching new genes involved in protein secretion in Saccharomyces cerevisiae. The screening procedure takes advantage of yeast strains constructed within the EUROFAN project, in which the promoters of the novel essential genes were replaced by the doxycycline-regulated tetO(7)-CYC1 promoter. This promoter is active in normal growth medium but results in downregulation of the gene in the presence of doxycycline. The yeast cells were grown in the presence or absence of doxycycline, and both the growth and secretion of the heat shock protein, Hsp150p, into the culture medium were determined. In seven strains there was a specific effect on protein secretion. In a strain in which the RPN5 gene was downregulated, the level of secreted Hsp150p was increased compared to the control culture. When RER2 was downregulated, cells secreted Hsp150p that was not of the mature size. In five strains, secretion was more severely reduced than cell growth. One of these downregulated genes, YGL098w, was recently reported to encode an ER-located t-SNARE, USE1. Four of the genes detected, NOG2, NOP15, RRP40 and SDA1, encode proteins involved in ribosome assembly, suggesting a possible new signalling pathway between ribosome biogenesis and production of secreted proteins. The results obtained here indicate that the present screen could be successfully used in larger scale to identify novel secretion-related genes. 相似文献