全文获取类型
收费全文 | 177篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 35篇 |
金属工艺 | 29篇 |
机械仪表 | 4篇 |
能源动力 | 1篇 |
轻工业 | 2篇 |
石油天然气 | 1篇 |
无线电 | 26篇 |
一般工业技术 | 37篇 |
冶金工业 | 21篇 |
原子能技术 | 2篇 |
自动化技术 | 25篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1962年 | 3篇 |
排序方式: 共有183条查询结果,搜索用时 15 毫秒
1.
This paper presents an overview of our recent work on the use of soft lithography and two-phase fluid flow to form arrays of droplets. The crucial issues in the formation of stable arrays of droplets and alternating droplets of two sets of aqueous solutions include the geometry of the microchannels, the capillary number, and the water fraction of the system. Glass capillaries could be coupled to the PDMS microchannels and droplets could be transferred into glass capillaries for long-term storage. The arrays of droplets have been applied to screen the conditions for protein crystallization with microbatch and vapor diffusion techniques. 相似文献
2.
V. G. Shengurov S. P. Svetlov V. Yu. Chalkov B. A. Andreev Z. F. Krasil'nik B. Ya. Ber Yu. N. Drozdov 《Inorganic Materials》2003,39(1):3-5
The Ge and Er depth profiles in Si1 – x
Ge
x
layers grown on Si(100) substrates by Si sublimation-source molecular-beam epitaxy in GeH4 were studied by secondary ion mass spectrometry. The results demonstrate that Ge facilitates Er incorporation into the growing Si–Ge layer. The Er dopant profile becomes sharper with increasing Ge content. The Ge profile also has rather sharp boundaries, indicating that there is no Ge surface segregation, which is attributable to the presence of adsorbed hydrogen, acting as a surfactant. 相似文献
3.
In this paper, we consider data analysis methods for knowledge extraction from large water data-sets. More specifically, we try to connect physico-chemical parameters and the characteristics of taxons living in sample sites. Among these data analysis methods, we consider formal concept analysis (FCA), which is a recognized tool for classification and rule discovery on object–attribute data. Relational concept analysis (RCA) relies on FCA and deals with sets of object–attribute data provided with relations. RCA produces more informative results but at the expense of an increase in complexity. Besides, in numerous applications of FCA, the partially ordered set of concepts introducing attributes or objects (AOC poset, for Attribute–Object–Concept poset) is used rather than the concept lattice in order to reduce combinatorial problems. AOC posets are much smaller and easier to compute than concept lattices and still contain the information needed to rebuild the initial data. This paper introduces a variant of the RCA process based on AOC posets rather than concept lattices. This approach is compared with RCA based on iceberg lattices. Experiments are performed with various scaling operators, and a specific operator is introduced to deal with noisy data. We show that using AOC poset on water data-sets provides a reasonable concept number and allows us to extract meaningful implication rules (association rules whose confidence is 1), whose semantics depends on the chosen scaling operator. 相似文献
4.
Leila Sharifi Llorenç Cerdà-Alabern Felix Freitag Luís Veiga 《Journal of Grid Computing》2016,14(2):299-325
The cost of power and its associated delivery are becoming significant factors in the total expenditure of large-scale data centers. Numerous techniques have been proposed to address the energy efficiency issue in cloud systems. Recently, some efforts have been made to decentralize the cloud via distributing data centers in diverse geographical positions, at different scales. In this paper, we elaborate on the energy effectiveness of service provisioning on different cloud architectures, from a mega-data center to a nano data center, which provides the extreme decentralization in terms of cloud architecture, as well as P2P-clouds or community network clouds. We study the energy consumption through an analytical and simulation framework for video streaming and MapReduce applications. 相似文献
5.
6.
Olfa Hammami Leila Dhouibi Patrice Berçot El Mustafa Rezrazi 《Journal of Applied Electrochemistry》2014,44(1):115-121
Zn–Ni composite coatings were obtained by electrochemical co-deposition of TiO2 nano-particles (mean diameter 21 nm). Zn–Ni alloy coating was also produced under the same experimental conditions for comparison. The surface morphology, crystallographic structure, and the grain size of the deposits were investigated, along with the percentage of the embedded nano-particles in Zn–Ni matrix, as a function of concentration of TiO2 nano-particles in the bath. As the titania incorporation percentage is increased, a grain refinement in the nanometer region was revealed followed enhanced microhardness values and an improvement of the content of the nickel in the alloy. Annealing of all coatings at 200 °C revealed the crystallization of the matrix accompanied by a decrease of microhardness followed by stability for 24 h. The corrosion behavior of Zn–Ni/nano-TiO2 composite coatings with various amount of particle content was mainly studied by electrochemical impedance spectroscopy in 3 % NaCl. It was seen that Zn–Ni/nano-TiO2 composite coatings exhibited higher corrosion resistances comparing to Zn–Ni alloy coating and corrosion protection improved with increasing nano-TiO2 in coatings. 相似文献
7.
Karlina L. B. Vlasov A. S. Soshnikov I. P. Smirnova I. P. Ber B. Ya. Smirnov A. B. 《Semiconductors》2018,52(10):1363-1368
Semiconductors - The formation of nanostructures on the surface of GaAs under quasi-equilibrium conditions in a quasi-closed volume from saturated phosphor and indium vapors in the presence of a Au... 相似文献
8.
I. Kharmachi L. Dhouibi P. Berçot M. Rezrazi B. Lakard 《Protection of Metals and Physical Chemistry of Surfaces》2017,53(6):1059-1069
The effect of gelatin on the microstructure, composition and electroplating mechanism of Ni–Co coating synthesized from sulfate media onto carbon steel substrate was investigated using AFM analysis, SEM/EDS and Electrochemical Quartz Crystal Microbalance (EQCM) coupled with chronopotentiometric measurements. The deposition of gelatin in the coating matrix was found to lower the mass of Ni–Co layers. Moreover, the adsorption of this additive seemed to inhibit the initial nucleation of the Ni–Co electrodeposition, showing homogeneous surface and smaller crystallites. Furthermore, the corrosion performance was studied in 3% NaCl solution by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). After a long immersion into chloride solution, Ni–Co–Gelatin (Ni–Co–Gel) coating showed a good stability and a better corrosion resistance. Therefore, the presence of gelatin additive impacted the crystal size, corrosion resistance and Ni–Co deposits morphology. 相似文献
9.
V. V. Zabrodskiy P. N. Aruev V. P. Belik B. Ya. Ber D. Yu. Kazantsev M. V. Drozdova N. V. Zabrodskaya M. S. Lazeeva A. D. Nikolenko V. L. Sukhanov V. V. Filimonov E. V. Sherstnev 《Semiconductors》2013,47(2):213-216
The spatial homogeneity of the photoresponse is studied for silicon photodiodes based on p-n and n-p junctions a year after their irradiation at a wavelength of 121.6 nm and those based on n-p junctions four years after their irradiation with soft X-rays. It is demonstrated that silicon photodiodes based on p-n junctions exhibit a photoresponse recovery effect on being irradiated at a wavelength of 121.6 nm. No recovery effect is observed for silicon photodiodes based on n-p structures. 相似文献
10.
The adsorption of dimethyl ether and tetrahydrofurane has been investigated at 150 °C on macroreticular ion exchangers of the styrene-divinylbenzene type containing SO3H, PO(OH)2 or P(OH)2 groups. Dual site adsorption without dissociation is suggested on the basis of the analysis of adsorption isotherms and the investigation of the effect of the number of acid groups on the initial adsorption values. The adsorption coefficients found can be used to express the acid strength of the ion exchangers interacting with gaseous molecules at elevated temperature; the relative logarithmic values for the ion exchangers, respectively, with SO3H, PO(OH)2 and P(OH)2 groups were 0; ?1.64; and ?2.51 (from dimethyl ether adsorption). These results are consistent with those calculated from ethyl acetate adsorption [Komers and Tomanová, Collect. Czech. Chem. Commun.37, 774 (1972)]. On the basis of the adsorption data, the relative basicities of the adsorbed molecules could also be compared. 相似文献