全文获取类型
收费全文 | 48篇 |
免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 16篇 |
金属工艺 | 1篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 3篇 |
水利工程 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 10篇 |
原子能技术 | 5篇 |
自动化技术 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 1篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 1篇 |
1994年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有49条查询结果,搜索用时 15 毫秒
1.
Gintautas Dundulis Eugenijus Uspuras Ronald F. Kulak Algirdas Marchertas 《Nuclear Engineering and Design》2007,237(8):848-857
Stress corrosion cracks have been discovered in Group Distribution Headers (GDH) at the Ignalina and Chernobyl Nuclear Power Plants. This increases the probability that a guillotine pipe break can occur that creates a whipping pipe (GDH) with the potential to damage surrounding structures—i.e. adjacent GDH and its attached piping or adjacent reinforced concrete compartment wall. The GDH is the most important component for reactor safety in case of an accident. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the ECSS into the GDH.Presented in this paper is the transient analysis of a Group Distribution Header following a guillotine break at the blind end of the header. Using a very conservative force loading function, the transient response of a whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is obtained using finite element methodology.The results of the study, assuming that the impacted GDH does not suffer stress corrosion cracking, indicate that the structural integrity of the compartment should be maintained and failure should not propagate from GDH to GDH. 相似文献
2.
This paper focuses on the development of fishery and fishculture in Lithuania. It provides a brief review of fishery evolution in the Baltic Sea and World Ocean and focuses on Lithuania's inner waters, with a particular emphasis on fishculture in Soviet (1945–90) and post-Soviet (1990–2007) Lithuania. Data for the paper were obtained from statistical yearbooks, state and enterprises' reports, direct contact with institutions and personnel and field survey work. During the Soviet period, more than 20 large state fishculture enterprises were established, each with 500–1000 ha of fishponds. These enterprises also owned 4000–7000 ha of farmland, which were used for rearing ducks and geese, stockbreeding and arable farming. In the Soviet period fishculture was a profitable business because it was partly subsidized by the state and the cost of energy and fish fodder were artificially low, not corresponding to their real value. After Lithuania declared its independence, state support of fishculture ceased, fishponds were privatized and the costs of energy and fodder increased significantly. As a result, fishculture enterprises barely manage to survive in free market economic conditions. Energy costs can be up to 50% of the fishculture enterprises' expenditure. Therefore, it is necessary to look for methods to improve fishculture practices in Lithuania. 相似文献
3.
One of the main challenges in today's solid oxide fuel cell (SOFC) technology is the reduction of their operating temperature. New types of oxygen ion conducting materials are currently under investigation to overcome the problems which SOFC faces at high temperatures. Samarium doped ceria oxide (SDC) was the material of investigation in this work. Optical quartz (SiO2) and Fe–Ni–Cr alloy (Alloy 600) were the two types of chosen substrates onto which SDC thin films were deposited by e-beam evaporation technique. The bias voltage was applied to the substrate during film growth. It had an influence on film formation, its microstructure and density because of the ionized particles presence in the SDC vapor stream. Changes in crystallite size and surface morphology were determined from X-ray diffraction data and scanning electron microscopy images. Influence of bias voltage on porosity of formed SDC thin films on optical quartz were calculated from transmittance spectra data by using Swanepoel method. The porosity decreases up to 12% by decreasing bias voltage from 0 to ?150 V. 相似文献
4.
Arturas Kaklauskas Andrej Vlasenko Vidas Raudonis Edmundas Kazimieras Zavadskas Renaldas Gudauskas Mark Seniut Algirdas Juozapaitis Ieva Jackute Loreta Kanapeckiene Silva Rimkuviene Gabrielius Kaklauskas 《Engineering Applications of Artificial Intelligence》2013,26(1):35-50
Students and lecturers would like to know how well students have learned the study materials being taught. A formal test or exam would cause needless stress for students. To resolve this problem, the authors of this article have developed an Intelligent Pupil Analysis (IPA) System. A sufficient amount of studies worldwide prove an interrelation between pupil size and a person's cognitive load. The obtained research results are comparable with the results from other similar studies. The original contribution of this article, compared to the research results published earlier, is as follows: the IPA System developed by the authors is superior to the traditional pupil analysis research due to the integration of pupil analysis with subsystems of decision support, recommender and intelligent tutoring systems and innovative Models of the Model-base, which permit a more detailed analysis of the knowledge attained by a student. This article ends with a case study to demonstrate the practical operation of the IPA System. 相似文献
5.
Algirdas Vaškelis Aldona Jagminien? Loreta Tamašauskait?-Tamašiūnait? Remigijus Jušk?nas 《Electrochimica acta》2005,50(23):4586-4591
The preparation of nano-size Ag particles and their application for forming nanostructured catalysts on various surfaces are described. Silver colloid solutions were prepared by reduction of Ag(I) salt by tin(II) and characterized by electron microscopy, X-ray diffraction and light absorption spectra. Depending on the colloid preparation conditions metal particles of 5-100 nm size were obtained. According to XRD data, the colloid particles contain Ag and SnO2 phases and no metallic Sn. The Ag nanoparticles were found to be efficient electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. The catalytic activity of a glassy carbon electrode with Ag surface coverage of 0.3-1 μg cm−2 is similar or even exceeds that of the metallic electrode. The silver particles were used for the initiation of the electroless copper deposition process on dielectrics; for that 1-2 μg cm−2 Ag is needed. 相似文献
6.
Vidmantas Dikinis Violeta Rėzaitė Irina Demčenko Algirdas Seiskis Tauras Bernatavičius 《金属精饰学会汇刊》2013,91(3-4):98-104
The influence of the components of an acidic solution: Cr(III) nitrate-malonic acid-Co(II) salt and treatment conditions on zinc dissolution and formation of Chromate films as well as on their decorative and protective properties have been studied using the analytical, XPS, structural and accelerated corrosion test methods. An organic acid is the main component, which has an essential influence on zinc dissolution and formation of Chromate films as well as their decorative and protective properties. The influence of organic acid is directly related with the state of the Cr3+ ions in chromating solution. When the Cr3+ ions are in the form of hexaaquaions, the organic acid increases the quantities of the zinc dissolved and the Cr(III) deposited on the zinc surface (especially at 60°C). It also predetermines the formation of a thick, porous Chromate film with large cracks at 60°C. Its decorative and protective properties are rather poor. When Cr3+ ions are in the form of a complex with organic acid, the quantities of the zinc dissolved and the Cr(III) deposited on the zinc surface significantly decrease and thinner Chromate films with an even surface, good decorative appearance and high corrosion resistance are formed Decorative blue-bright Cr(VI)-free films with a slight iridescent tint, obtained in solution, containing Cr(III) nitrate (0.2), malonic acid (0.3) and Co(II) nitrate (0.02) mol dm?3, at p H 1.6-2.0 at room temperature over 30–60 s, possess corrosion resistance (192–240 h in a salt spray chamber) similar to that of iridescent Chromate films, obtained in acidic Cr(VI) solution. 相似文献
7.
Adsorption of anionic dyes on the cross-linked with epichlorohydrin starches containing quaternary ammonium groups (CCS) was
investigated and compared with that of modified starches containing only quaternary ammonium groups (CS). The adsorption of
anionic dyes on CS and CCS closely follows the Langmuir model of adsorption. The computed Langmuir saturation capacity Q
o increases with increasing degree of substitution (DS) of CS or CCS and has the value from 0.81 mol/kg to 3.22 mol/kg for
CCS and from 0.88 mol/kg to 1.87 mol/kg for CS. The effectiveness of the cationic groups in dye binding was about 1 mol/equiv
for CSS with DS from 0.47 to 0.62 and all the cationic groups had attached one anionic groups of the dye. Increasing DS of
CS decreases the effectiveness of dye binding due to the increase in solubility of CS, and the soluble part of CS binds the
dye as a typical soluble polyelectrolyte. CCS are more suitable than CS for the anionic dye adsorption from a textile dyeing
solution. DS of CCS should be about 0.5–0.6. They adsorb the anionic dyes in few minutes and acts in the wide range of pH
of the solutions. The Langmuir saturation capacity Q
o and the effectiveness of the cationic groups in dye binding increase with an increase of the adsorption temperature. The
positive values of the enthalpy and entropy suggest that the adsorption is endothermic and during the adsorption of the anionic
dye on CCS the randomness of the system increases. 相似文献
8.
9.
K. K. Éidukyavichus V. R. Matseikene V. V. Balkyavichus A. A. Shpokauskas A. A. Laukaitis L. Yu. Kunskaite 《Glass and Ceramics》2004,61(3-4):77-80
The results of studying the possibility of using cullet of different chemical compositions accumulated at dumping grounds for foam glass production are described. It is established that sodium silicate introduced into cullet in the form of water glass partly destroys milled cullet and homogenizes the chemical composition of the batch and its most significant technological properties. Due to the chemical reaction between water glass and the surface of milled cullet particles, silicates are formed containing bound water, which is released at high temperatures (600 – 620°C) and facilitates frothing of foam glass. Water glass in a batch increases the quantity of the vitreous phase and decreases the propensity of glass for crystallization. 相似文献
10.
Vilius Poderys Marija Matulionyte Algirdas Selskis Ricardas Rotomskis 《Nanoscale research letters》2011,6(1):9-6
Semiconductor nanoparticles (quantum dots) are promising fluorescent markers, but it is very little known about interaction of quantum dots with biological molecules. In this study, interaction of CdTe quantum dots coated with thioglycolic acid (TGA) with bovine serum albumin was investigated. Steady state spectroscopy, atomic force microscopy, electron microscopy and dynamic light scattering methods were used. It was explored how bovine serum albumin affects stability and spectral properties of quantum dots in aqueous media. CdTe–TGA quantum dots in aqueous solution appeared to be not stable and precipitated. Interaction with bovine serum albumin significantly enhanced stability and photoluminescence quantum yield of quantum dots and prevented quantum dots from aggregating. 相似文献