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排序方式: 共有199条查询结果,搜索用时 15 毫秒
151.
This article focuses on the problems of application of artificial intelligence to represent legal knowledge. The volume of legal knowledge used in practice is unusually large, and therefore the ontological knowledge representation is proposed to be used for semantic analysis, presentation and use of common vocabulary, and knowledge integration of problem domain. At the same time some features of legal knowledge representation in Ukraine have been taken into account. The software package has been developed to work with the ontology. The main features of the program complex, which has a Web-based interface and supports multi-user filling of the knowledge base, have been described. The crowdsourcing method is due to be used for filling the knowledge base of legal information. The success of this method is explained by the self-organization principle of information. However, as a result of such collective work a number of errors are identified, which are distributed throughout the structure of the ontology. The results of application of this program complex are discussed in the end of the article and the ways of improvement of the considered technique are planned. 相似文献
152.
Volodymyr Hutsaylyuk 《先进材料力学与结构力学》2020,27(14):1246-1255
AbstractThe results of a study of the influence of low-cycle loading of the aluminum alloy D16ChATV, after a previous combined loading, on its plasticity. The previous combined load (PCL) was applied with the help of a short-term external force impulse superimposed on the main monotonic load by stretching. The residual fatigue strength of the material after the PCL is estimated using the deformation and energy criteria. The peculiarities of the changes in the micro-pattern of the surface of fracture of the material are analyzed to identify the main mechanisms of micro-deformation and fracture of materials. 相似文献
153.
Edyta Adrian Duana Treov Elena Filov Marta Kumorek Volodymyr Lobaz Rafal Poreba Olga Janoukov Ognen Pop-Georgievski Igor Lacík Dana Kubies 《International journal of molecular sciences》2021,22(21)
Long-term delivery of growth factors and immunomodulatory agents is highly required to support the integrity of tissue in engineering constructs, e.g., formation of vasculature, and to minimize immune response in a recipient. However, for proteins with a net positive charge at the physiological pH, controlled delivery from negatively charged alginate (Alg) platforms is challenging due to electrostatic interactions that can hamper the protein release. In order to regulate such interactions between proteins and the Alg matrix, we propose to complex proteins of interest in this study - CXCL12, FGF-2, VEGF - with polyanionic heparin prior to their encapsulation into Alg microbeads of high content of α-L-guluronic acid units (high-G). This strategy effectively reduced protein interactions with Alg (as shown by model ITC and SPR experiments) and, depending on the protein type, afforded control over the protein release for at least one month. The released proteins retained their in vitro bioactivity: CXCL12 stimulated the migration of Jurkat cells, and FGF-2 and VEGF induced proliferation and maturation of HUVECs. The presence of heparin also intensified protein biological efficiency. The proposed approach for encapsulation of proteins with a positive net charge into high-G Alg hydrogels is promising for controlled long-term protein delivery under in vivo conditions. 相似文献
154.
Volodymyr Bushlya Jinming Zhou Pajazit Avdovic Jan-Eric Ståhl 《The International Journal of Advanced Manufacturing Technology》2013,66(9-12):2013-2021
Inconel 718, an efficient superalloy for energy and aerospace applications, is currently machined with cemented carbide tools at low speed (v c?≈?60 m/min) due to its unfavorable mechanical and thermal properties. The article presents results of a study of superalloy machinability with whisker-reinforced alumina, uncoated and coated polycrystalline cubic boron nitride (PCBN) tools. Turning of age-hardened Inconel 718 (45 HRC) was done under high-speed machining conditions (v c?=?250…350 m/min). Aspects of tool life, tool wear, and generated surface quality were studied. Application of uncoated PCBN tools resulted in surface quality and force level superior to other tool materials. Considerable sideflow of workpiece material was found to affect surface quality, especially for coated PCBN and ceramic tools. It was found that protective function of the coating, which increases the tool life up to 20 %, is limited only to low cutting speed range. EDX and AFM analyses suggested dominance of chemical and abrasive wear mechanisms. EDX mapping of worn tools pointed absence of diffusional wear for PCBN tools and intensive degradation of whisker reinforcement in ceramic tools due to diffusion of Ni, Fe, and Cr. 相似文献
155.
目的 为了解决选区激光熔化增材再制造时出现的首层铺粉粉层厚度不均的问题,研究首层粉层厚度为400μm时选区激光熔化成形工艺.方法 采用倾斜基板预置楔形粉层,在粉层上进行不同激光功率的激光扫描实验,研究楔形粉层对沉积的影响规律.然后在水平放置的基板上分别预置50、100、200、300、400μm厚度粉层,在粉层上进行激... 相似文献
156.
Direct observation of liquid crystals using cryo‐TEM: Specimen preparation and low‐dose imaging 下载免费PDF全文
Min Gao Young‐Ki Kim Cuiyu Zhang Volodymyr Borshch Shuang Zhou Heung‐Shik Park Antal Jákli Oleg D. Lavrentovich Maria‐Gabriela Tamba Alexandra Kohlmeier Georg H. Mehl Wolfgang Weissflog Daniel Studer Benoît Zuber Helmut Gnägi Fang Lin 《Microscopy research and technique》2014,77(10):754-772
Liquid crystals (LCs) represent a challenging group of materials for direct transmission electron microscopy (TEM) studies due to the complications in specimen preparation and the severe radiation damage. In this paper, we summarize a series of specimen preparation methods, including thin film and cryo‐sectioning approaches, as a comprehensive toolset enabling high‐resolution direct cryo‐TEM observation of a broad range of LCs. We also present comparative analysis using cryo‐TEM and replica freeze‐fracture TEM on both thermotropic and lyotropic LCs. In addition to the revisits of previous practices, some new concepts are introduced, e.g., suspended thermotropic LC thin films, combined high‐pressure freezing and cryo‐sectioning of lyotropic LCs, and the complementary applications of direct TEM and indirect replica TEM techniques. The significance of subnanometer resolution cryo‐TEM observation is demonstrated in a few important issues in LC studies, including providing direct evidences for the existence of nanoscale smectic domains in nematic bent‐core thermotropic LCs, comprehensive understanding of the twist‐bend nematic phase, and probing the packing of columnar aggregates in lyotropic chromonic LCs. Direct TEM observation opens ways to a variety of TEM techniques, suggesting that TEM (replica, cryo, and in situ techniques), in general, may be a promising part of the solution to the lack of effective structural probe at the molecular scale in LC studies. Microsc. Res. Tech. 77:754–772, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
157.
Volodymyr Pavlyuk Grygoriy Dmytriv Ihor Chumak Oliver Gutfleisch Inge Lindemann Helmut Ehrenberg 《International Journal of Hydrogen Energy》2013
The existence of Li-rich super-lightweight intermetallics in the Li–Mg–Si ternary system has attracted attention for high capacity hydrogen storage materials. The hydrogenation properties of the alloys were studied by thermogravimetric analysis, differential scanning calorimetry in H2 atmosphere and X-ray diffraction. The Li-rich alloy absorbs the highest amount of hydrogen (8.8% w/w for Li70Mg10Si20), while the Mg-rich alloy (Li30Mg40Si30) absorbs 6.0% w/w H2 and shows the first experimental evidence for LiMgH3 formation with LiNbO3-type structure during hydrogenation. 相似文献
158.
Dhawan A Taurozzi JS Pandey AK Shan W Miller SM Hashsham SA Tarabara VV 《Environmental science & technology》2006,40(23):7394-7401
Stable aqueous suspensions of colloidal C60 fullerenes free of toxic organic solvents were prepared by two methods: ethanol to water solvent exchange (EthOH/nC60 suspensions) and extended mixing in water (aqu/nC60 suspensions). The extended mixing method resulted in the formation of larger (dp approximately 178 nm) and less negatively charged (zeta approximately -13.5 mV) nC60 colloids than nC60 prepared by ethanol to water solvent exchange (dp approximately 122 nm, zeta approximately -31.6 mV). Genotoxicity of these suspensions was evaluated with respect to human lymphocytes using single-cell gel electrophoresis assay (Comet assay). The assay demonstrated genotoxicity for both types of suspensions with a strong correlation between the genotoxic response and nC60 concentration, and with genotoxicity observed at concentrations as low as 2.2 microg/L for aqu/nC60 and 4.2 microg/L for EtOH/nC60. The Olive tail moments (OTM) for these two concentrations were 1.54 +/- 0.24 and 1.34 +/- 0.07, respectively, which in comparison to the negative control OTM of 0.98 +/- 0.17 is statistically different with a p value of at least 0.05. Aqu/nC60 suspensions elicited higher genotoxic response than EthOH/nC60 for the same nC60 concentration. The results represent the first genotoxicity data for colloidal fullerenes produced by simple mixing in water. 相似文献
159.
The work is devoted to the implementation of the hydrodynamic laws to the head-on heavy ion collisions within the energy range 50-100 MeV/A. The hydrodynamic mechanisms of the bubble and ring structures formation are investigated. It is shown that there is a possible hydrodynamic explanation of the different structures being formed in the case of soft (K=200 MeV) and stiff (K=400 MeV) equations of state. Within the suggested approach the final geometry of the system is defined in the initial stage of the collision and is very dependent on the sound velocity in the nuclear matter. The obtained results are in a good correspondence with the Boltzmann-like transport theory calculations and the experimental data for the selected energy range. 相似文献
160.
Roman V. Denys Andrey A. Poletaev Jan Petter Maehlen Jan Ketil Solberg Boris P. Tarasov Volodymyr A. Yartys 《International Journal of Hydrogen Energy》2012
Recently, the present authors [17] have reported dramatic improvements in the hydrogenation behaviours of nanostructured LaMg11Ni prepared by Rapid Solidification, caused by modifications of the microstructure and crystal structure. The aim of the present work was to study the mechanism and kinetics of the hydrogen interaction with rapidly solidified LaMg11Ni by employing in situ synchrotron X-Ray diffraction studies of hydrogen absorption–desorption processes in hydrogen gas or in vacuum. 相似文献