全文获取类型
收费全文 | 616篇 |
免费 | 78篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 203篇 |
金属工艺 | 10篇 |
机械仪表 | 57篇 |
建筑科学 | 3篇 |
能源动力 | 25篇 |
轻工业 | 73篇 |
武器工业 | 2篇 |
无线电 | 107篇 |
一般工业技术 | 124篇 |
冶金工业 | 23篇 |
原子能技术 | 6篇 |
自动化技术 | 58篇 |
出版年
2024年 | 2篇 |
2023年 | 12篇 |
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 27篇 |
2019年 | 40篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 32篇 |
2015年 | 27篇 |
2014年 | 39篇 |
2013年 | 41篇 |
2012年 | 31篇 |
2011年 | 47篇 |
2010年 | 31篇 |
2009年 | 37篇 |
2008年 | 23篇 |
2007年 | 28篇 |
2006年 | 19篇 |
2005年 | 15篇 |
2004年 | 15篇 |
2003年 | 18篇 |
2002年 | 9篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有694条查询结果,搜索用时 15 毫秒
261.
262.
Yeong Shin Jeong Eric Cervi Antonio Cammi Hisashi Ninokata In Cheol Bang 《国际能源研究杂志》2020,44(5):3934-3953
The strongly coupled behaviors between neutronics and thermal-hydraulics of liquid-fueled molten salt reactors make it difficult to evaluate system behaviors, due to the transport of precursors along moving fuel. Extending an adjoint-based method on the multiphysics approach, different assumptions on temperature dependencies of nuclear and thermophysical properties of salt are included in the local sensitivity analysis of a circulating liquid fuel system. Local sensitivity of various types of system response in steady-state is analyzed for 39 parameters including coupling models, reactor design values, and kinetic constants of delayed neutron and decay heat precursors for a simplified 1D model of molten salt fast reactor. Extended adjoint-based sensitivity analysis method for MSR is successfully validated achieving 1.38% deviation on average between a recalculation and adjoint method, comparing local sensitivities to all parameters. Also, it takes 66.3 times less in computational time compared with the recalculation method for evaluating the sensitivity of the same type of system response. The importance of all the parameters to the system response is analyzed according to the assumptions on temperature dependencies to nuclear data and salt properties. The most influencing ones are fission energy-related terms, and their importance increases when temperature dependencies are taken into account, compared with constant properties. Changes of influences on the sensitivity are investigated from the relative changes of the parameter values in various system response types, and it implies the importance to consider the multiphysics modeling on the local sensitivity analysis. 相似文献
263.
Pandey Sudhanshu Park Yong Gap Ha Man Yeong 《Journal of Mechanical Science and Technology》2020,34(8):3457-3470
Journal of Mechanical Science and Technology - The present study deals with an unsteady laminar free convection inside the annuli confined between an outer square enclosure and an inner circular... 相似文献
264.
265.
266.
One of the greatest challenges of modern separation technology is separating isotope mixtures in high purity. The separation of hydrogen isotopes can create immense economic value by producing valuable deuterium (D) and tritium (T), which are irreplaceable for various industrial and scientific applications. However, current separation methods suffer from low separation efficiency owing to the similar chemical properties of isotopes; thus, high‐purity isotopes are not easily achieved. Recently, nanoporous materials have been proposed as promising candidates and are supported by a newly proposed separation mechanism, i.e., quantum effects. Herein, the fundamentals of the quantum sieving effect of hydrogen isotopes in nanoporous materials are discussed, which are mainly kinetic quantum sieving and chemical‐affinity quantum sieving, including the recent advances in the analytical techniques. As examples of nanoporous materials, carbons, zeolites, metal–organic frameworks, and covalent organic frameworks are addressed from computational and experimental standpoints. Understanding the quantum sieving effect in nanospaces and the tailoring of porous materials based on it will open up new opportunities to develop a highly efficient and advanced isotope separation systems. 相似文献
267.
268.
Han Sol Lee Sam Park June Yeong Lim Sanghyuck Yu Jongtae Ahn Do Kyung Hwang Yumin Sim Je‐Ho Lee Maeng‐Je Seong Sehoon Oh Hyoung Joon Choi Seongil Im 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(38)
Band‐like transport behavior of H‐doped transition metal dichalcogenide (TMD) channels in field effect transistors (FET) is studied by conducting low‐temperature electrical measurements, where MoTe2, WSe2, and MoS2 are chosen for channels. Doped with H atoms through atomic layer deposition, those channels show strong n‐type conduction and their mobility increases without losing on‐state current as the measurement temperature decreases. In contrast, the mobility of unintentionally (naturally) doped TMD FETs always drops at low temperatures whether they are p‐ or n‐type. Density functional theory calculations show that H‐doped MoTe2, WSe2, and MoS2 have Fermi levels above conduction band edge. It is thus concluded that the charge transport behavior in H‐doped TMD channels is metallic showing band‐like transport rather than thermal hopping. These results indicate that H‐doped TMD FETs are practically useful even at low‐temperature ranges. 相似文献
269.
Offshore wind energy has been growing up as a promising renewable energy source. Recently, tripod suction bucket foundation is rapidly expanding as a foundation system supporting the offshore wind turbine. In offshore environment, wind turbine foundation structures should be designed considering cyclic loading which can lead to permanent deformation of structure, tilting problem, and overall degradation of soil stiffness. However, it is technically difficult to predict the cyclic behavior of the tripod accurately because the cyclic behaviors of the tripod bucket can be inferred from vertical pullout and compression behaviors of each single bucket elements. In this paper, a series of model tests was performed by applying cyclic vertical compression and extension loadings to a single bucket element that is one element of the tripod foundation. Loading directions, level, and rate were controlled for investigating of cyclic behavior of tripod foundation. On the basis of testing results, the permanent deformation and cyclic stiffness response of tripod suction caisson were discussed. Based on the test results, it was confirmed that the cyclic behavior of the single bucket is affected by the load level and rate. In addition, the behavior showed quite different trends with the loading directions: compression, pullout, and two‐way. 相似文献
270.
Woo Minji Kim Mijeong Noh Jeong Sook Park Chan Hum Song Yeong Ok 《Food science and biotechnology》2018,27(1):211-218
Food Science and Biotechnology - This study investigated the effect of kimchi on hepatic lipid metabolism and inflammatory response. Low-density lipoprotein receptor knockout mice fed high... 相似文献