全文获取类型
收费全文 | 1317篇 |
免费 | 56篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 14篇 |
综合类 | 2篇 |
化学工业 | 393篇 |
金属工艺 | 50篇 |
机械仪表 | 53篇 |
建筑科学 | 47篇 |
矿业工程 | 3篇 |
能源动力 | 30篇 |
轻工业 | 94篇 |
水利工程 | 15篇 |
石油天然气 | 8篇 |
无线电 | 74篇 |
一般工业技术 | 287篇 |
冶金工业 | 85篇 |
原子能技术 | 17篇 |
自动化技术 | 206篇 |
出版年
2023年 | 6篇 |
2022年 | 52篇 |
2021年 | 84篇 |
2020年 | 31篇 |
2019年 | 38篇 |
2018年 | 68篇 |
2017年 | 69篇 |
2016年 | 63篇 |
2015年 | 52篇 |
2014年 | 56篇 |
2013年 | 95篇 |
2012年 | 68篇 |
2011年 | 80篇 |
2010年 | 54篇 |
2009年 | 64篇 |
2008年 | 68篇 |
2007年 | 61篇 |
2006年 | 33篇 |
2005年 | 27篇 |
2004年 | 19篇 |
2003年 | 17篇 |
2002年 | 29篇 |
2001年 | 10篇 |
2000年 | 18篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 5篇 |
1996年 | 14篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1975年 | 11篇 |
1974年 | 3篇 |
1973年 | 11篇 |
1972年 | 4篇 |
排序方式: 共有1378条查询结果,搜索用时 718 毫秒
121.
E. N. Korshunova V. P. Mal’tsev A. D. Shatrov 《Journal of Communications Technology and Electronics》2011,56(8):953-956
The effect (earlier discovered) of penetration of an electromagnetic-field power flux into a wall exhibiting perfect mixed
anisotropic conductivity is considered in more detail. It is shown that the power transmitted into the screen through the
nodes of conductivity lines and through resonance-length closed contours can be regarded as the limit value of the power absorbed
in a wall characterized by an anisotropic impedance when the absorbing impedance approaches the values corresponding to the
case of perfect mixed conductivity. 相似文献
122.
Marcel Karabín Alena Rýparová Lukáš Jelínek Thomas Kunz Philip Wietstock Frank‐Jürgen Methner Pavel Dostálek 《Journal of the Institute of Brewing》2014,120(3):212-219
One of the critical issues regarding the quality of beer is the change in its chemical composition that occurs during storage. Decomposition of iso‐α‐acids results in an undesirable decrease in bitterness as well as a deterioration in the sensory profile of the beer. These changes are caused by the susceptibility of iso‐α‐acids to degradation owing to the influence of reactive oxygen species and light. The aim of this study was to investigate the influence of storage conditions (temperature, light) on the degradation of iso‐α‐acids during aging, with the main focus on monitoring the relationship between the turnover of iso‐α‐acids, the sulphur dioxide content and the antioxidative potential of stored beer as measured by electron spin resonance spectroscopy. In agreement with previous investigations, a significant decrease in the content of bitter compounds (up to 18 % relative to the original level, depending on storage conditions) was observed. A significant decrease in the antioxidant potential of beer was recorded simultaneously and the data confirmed a strong correlation between these parameters. The decline in beer bitterness could become a marker for estimating oxidative damage during storage. Copyright © 2014 The Institute of Brewing & Distilling 相似文献
123.
124.
125.
The capabilities of existing ultrasonic nondestructive evaluation (NDE) methods for the strength-related properties of bonds in structural components is reviewed. The severe limitations of conventional NDE methods in yielding quantitative results are indicated. Some recent results of a joint theoretical and experimental program of research using leaky Lamb waves (LLW) in laboratory specimens are presented. The LLW technique is shown to have several advantages over conventional techniques. Potential applications of the technique to determine non-destructively the quality of bonds in a variety of models are discussed. 相似文献
126.
In this paper we focus on appearance features describing the manual component of Sign Language particularly the Local Binary
Patterns. We compare the performance of these features with geometric moments describing the trajectory and shape of hands.
Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model
combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual
features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary
Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer
dependent tests and 57.54% for signer independent tests. 相似文献
127.
P. Vašek P. Svoboda V. Novák M. Cukr Z. Výborný V. Jurka J. Stuchlík M. Orlita D. K. Maude 《Journal of Superconductivity and Novel Magnetism》2010,23(6):1161-1163
The angular dependence of the magnetoresistance has been studied for two sets of samples: annealed and hydrogenated, respectively.
Different behavior of magnetoresistance anisotropy has been discussed in terms of change of scattering rate and/or introduction
of strain during treatment. 相似文献
128.
This paper describes a solution of CT arteriography vessel segmentation using a combination of methods for segmentation of
image data. Computer tomography (CT) is one of the most useful approaches for investigating the arterial system and its pathologies.
There are three ways for segmenting the vessels from the CT image — manually, fully automatically and with a user interaction.
We considered the (semi)automatic approaches, because the manual way is too time-consuming and human-dependent. We used a
combination of three segmentation techniques: thresholding, edge detection and region growing. Results of this method were
consulted then with a medicine expert. None of these techniques can be used separately, but a combination of them brought
very good results, which can be used in medicine. 相似文献
129.
An uncommon electrolyte, based on sulphosalicylic acid, was used for nickel-cobalt deposition. Some mechanical properties (internal stress and microhardness) and structural properties of the deposits have been presented. High microhardness (nearly 800 HM) with simultaneous low internal stress (about 50 MPa) can be reached. 相似文献
130.
A. P. Sorokin A. D. Efanov E. F. Ivanov D. E. Martsinyuk G. P. Bogoslovskaya K. S. Rymkevich V. L. Mal’kov 《Atomic Energy》1999,87(5):801-807
The physics of the processes, the characteristics, and the stability of different regimes, of boiling (nucleate, projectile,
disperse-ring), which are observed in experiments investigating the boiling of liquid-metal coolant in a model of a fuel assembly
for a fast-neutron reactor in the emergency cooldown regime with low circulation velocity, are analyzed. The experimental
setup, the, methods for performing measurements, and the experimental data on the boiling of a liquid metal are described.
A mathematical model of the process of boiling of a liquid-metal, coolant in a natural-circulation loop is described, and
the results of test calculations for regimes with an increase in heating and with sharp pressure drop are prresented. 7 figures,
12 references.
State Science Center of the Russian Federration–A. I. Leipunskii Physics and Power Engineering Institute. Translated from
Atomnaya énergiya, Vol. 87, No. 5, pp. 337–342, November, 1999. 相似文献