全文获取类型
收费全文 | 267篇 |
免费 | 12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 | 82篇 |
金属工艺 | 4篇 |
机械仪表 | 4篇 |
建筑科学 | 3篇 |
矿业工程 | 3篇 |
能源动力 | 23篇 |
轻工业 | 2篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 25篇 |
一般工业技术 | 97篇 |
冶金工业 | 9篇 |
原子能技术 | 1篇 |
自动化技术 | 23篇 |
出版年
2023年 | 3篇 |
2022年 | 24篇 |
2021年 | 18篇 |
2020年 | 10篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 13篇 |
2015年 | 4篇 |
2014年 | 20篇 |
2013年 | 31篇 |
2012年 | 18篇 |
2011年 | 19篇 |
2010年 | 12篇 |
2009年 | 15篇 |
2008年 | 21篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有283条查询结果,搜索用时 0 毫秒
41.
Sergey Kirpotin Yuriy Polishchuk Nataliya Bryksina Anna Sugaipova Alexei Kouraev Elena Zakharova 《The International journal of environmental studies》2013,70(5):603-623
Palsa peatlands occupy extensive areas in Western Siberia which is one of the most paludified flat lowlands of the world. Climatic changes in Western Siberia are more dramatic compared with other northern regions, and changes in palsa landscapes are more notable due to the severe continental climate here. The distribution, peculiarities and climate-indication capacities of West Siberian palsas are poorly known outside Russia. Thus, Western Siberia is one of the most interesting vast natural polygons for studying climate-driven changes in the landscapes. This paper aims to fill the gap in knowledge on West Siberian palsas and their capacity as a climate regulator. We present issues in distribution, typology and cyclic development of palsa peatlands and their actual climate-driven changes. We also analyse the role of palsas in the atmospheric cycle of CO2, and the hydrology of the palsa regions. 相似文献
42.
Ivan Gavrilyuk Martin Hermann Volodymyr Trotsenko Yuriy Trotsenko Alexander Timokha 《Journal of Engineering Mathematics》2010,68(2):165-178
A spectral boundary problem on axisymmetric eigenoscillations of a cupola-shaped shell is considered with emphasis on small shell thickness. The problem deals with a singularly perturbed system of ordinary differential equations. The paper examines analytical properties of the solution and, based on that, constructs an appropriate functional basis for Ritz’ method. Employing this basis provides fast convergence in the C 3-metrics. 相似文献
43.
Yuriy I. Kuzmin 《Journal of Low Temperature Physics》2003,130(3-4):261-286
The effect of the fractal clusters of a normal phase, which act as pinning centers, on the dynamics of magnetic flux in percolative type-II superconductor is considered. The main features of these clusters are studied in detail: the cluster statistics is analyzed; the fractal dimension of their boundary is estimated; the distribution of critical currents is obtained, and its peculiarities are explored. It is found that there is the range of fractal dimension where this distribution has anomalous statistical properties, specifically, its dispersion becomes infinite. It is examined how the finite resolution capacity of the cluster geometric size measurement affects the estimated value of fractal dimension. The effect of fractal properties of the normal phase clusters on the electric field arisen from magnetic flux motion is investigated for the cluster area distribution of different kinds. The voltage-current characteristics of fractal superconducting structures in the resistive state are obtained for an arbitrary fractal dimension. It is revealed that the fractality of the boundaries of the normal phase clusters intensifies the magnetic flux trapping and thereby raises the critical current of a superconductor. 相似文献
44.
Shmaliy YS Arceo-Miquel L 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2008,55(10):2131-2139
This paper addresses an unbiased p-step predictive finite impulse response (FIR) filter of the local clock K-degree time interval error (TIE) polynomial model with applications to the global positioning system (GPS)-based clock synchronization. Generic coefficients are derived for a 2-parameter family of the polynomial filter gains. A generalization is provided for the p-step linear (ramp) gain allowing for close to optimal predictive filtering of the TIE. Basic holdover algorithms are discussed along with their most critical properties. Efficiency of the proposed filter in holdover is demonstrated by simulation and in real applications to GPS-based (sawtooth and sawtoothless) measurements of the TIE of a crystal clock. 相似文献
45.
Sitalo EI Raevski IP Lutokhin AG Blazhevich AV Kubrin SP Raevskaya SI Zakharov YN Malitskaya MA Titov VV Zakharchenko IN 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(9):1914-1919
Dielectric, X-ray, and piezoelectric studies of highly-resistive Li-doped (1-x)PbFe(1/2)Nb(1/2)O(3)-(x)PbTiO(3) (PFN-xPT) ceramics from the 0 ≤ x ≤ 0.2 range fabricated by solid-state synthesis and usual sintering have been carried out. Distinct anomalies of dielectric and piezoelectric parameters, corresponding to the transition between rhombohedral (monoclinic) and tetragonal ferroelectric phases, have been observed in pure PFN and PFN-xPT compositions with PbTiO(3) content up to 8 mol.%. The x,T-phase diagram of the PFN-xPT solid solution system has been constructed using these data. 相似文献
46.
Yuriy M. Bunkov 《Journal of Low Temperature Physics》2004,135(5-6):337-359
This article is dedicated to the memory of Olli Lounasmaa, the physicist, who directed my scientific life along the path of superfluid 3He! In the article I review the results of experimental and theoretical studies of superfluid 3He spin dynamics at ultralow temperatures, where the density of the normal component is virtually zero. I describe our current understanding of the phenomena of catastrophic relaxation, NMR in the Landau field and the surface instability of homogeneous precession. PACS numbers: 67.57.Lm. 相似文献
47.
48.
Alexander D. Pogrebnjak Mariya M. Danilionok Vladimir V. Uglov Nazgul K. Erdybaeva Grigoriy V. Kirik Sergey N. Dub Vyacheslav S. Rusakov Andrey P. Shypylenko Pawel V. Zukovski Yuriy Zh. Tuleushev 《Vacuum》2009
The first results of manufacturing and investigations of a new type of nanocomposite protective coatings are presented. They were manufactured using a combination of two technologies: plasma-detonation coating deposition with the help of plasma jets and thin coating vacuum-arc deposition. We investigated structure, morphology, physical and mechanical properties of the coatings of 80–90 μm thickness, as well as defined the hardness, elastic Young modulus and their corrosion resistance in different media. Grain dimensions of the nanocomposite coatings on Ti–N–Cr base varied from 2.8 to 4 nm. The following phases and compounds formed as a result of plasma interaction with the thick coating surface were found in the coatings: Ti–N–Cr (200), (220), γ-Ni3–Fe, a hexagonal Cr2–Ti, Fe3–Ni, (Fe, Ni)N and the following Ti–Ni compounds: Ti2Ni, Ni3Ti, Ni4Ti, etc. We also found that the nanocomposite coating microhardness increased to H = 31.6 ± 1.1 GPa. The Young elastic modulus was determined to be E = 319 ± 27 GPa – it was derived from the loading–unloading curves. The protective coating demonstrated the increased corrosion resistance in acidic and alkaline media in comparison with that of the stainless steel substrate. 相似文献
49.
Just a few years ago it was generally believed that the NMR properties of superfluid3He far below Tc would not be qualitatively different from those found at higher temperatures. Surprisingly, the strange enhancement of relaxation processes at around 0.4 Tc named catastrophic relaxation, was then found. Recently an extremely long lived induction signal with new dynamical properties was discovered in the region of 100 K. Some of the newly discovered properties can be partly explained, although there are still many unsolved problems. The main aim of this article is to raise new questions for future investigations at the lowest temperatures presently possible. 相似文献
50.
Shkuratov Y Petrov D Videen G 《Journal of the Optical Society of America. A, Optics, image science, and vision》2003,20(11):2081-2092
Using the scale invariance of classical photometry, we develop an approach to finding the photometric function of prefractal structures that form a random topography. The photometric function of the prefractal surfaces is found as the general solution of the resulting differential equation in partial derivatives. The function depends on two parameters: the number of hierarchical levels of the prefractal structures and the roughness parameter of the single-level generation. As a limiting case, the approach includes our previous theory that considered fractoids. 相似文献