全文获取类型
收费全文 | 265篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 18篇 |
金属工艺 | 26篇 |
机械仪表 | 38篇 |
建筑科学 | 2篇 |
矿业工程 | 10篇 |
能源动力 | 1篇 |
轻工业 | 7篇 |
水利工程 | 2篇 |
石油天然气 | 6篇 |
无线电 | 10篇 |
一般工业技术 | 49篇 |
冶金工业 | 37篇 |
原子能技术 | 39篇 |
自动化技术 | 27篇 |
出版年
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2017年 | 13篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 15篇 |
2012年 | 14篇 |
2011年 | 10篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1973年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1966年 | 2篇 |
1957年 | 2篇 |
排序方式: 共有273条查询结果,搜索用时 31 毫秒
1.
N. Mitchell A. Alekseev R. Gallix D. Holland R. Meyder A. Panin M. Shimada F. Wong E. Zapretelina 《Journal of Fusion Energy》1997,16(1-2):25-35
The ITER magnet system consists of structurally linked sets of toroidal (TF) and poloidal (PF) field coils, central solenoid (CS), and various support structures. The coils are superconducting, force flow Helium cooled with a Kapton-Glass-Epoxy multilayer insulation system. The stored magnetic energy is about 100GJ in the TF system and 20GJ in the PF-CS. Coils and structure are maintained at 4 K by enclosing them in a vacuum cryostat. The cryostat, comprising an outer envelope to the magnets, forms most of the second radioactivity confinement barrier. The inner primary barrier is formed by the vacuum vessel, its ports and their extensions. To keep the machine size within acceptable bounds, it is essential that the magnets are in close proximity to both of the nuclear confinement barriers. The objective of the magnet design is that, although local damage to one of the barriers may occur in very exceptional circumstances, large scale magnet structural or thermal failure leading to simultaneous breaching of both barriers is not credible. Magnet accidents fall into three categories: thermal (which includes arcing arising from insulation failure and local overheating due to discharge failure in the event of a superconductor quench), structural (which includes component mechanical failure arising from material inadequacies, design errors and exceptional force patterns arising from coil shorts or control failures), and fluid (Helium release due to cooling line failure). After a preliminary survey to select initial faults conceivable within the present design, these faults are systematically analyzed to provide an assessment of the damage potential. The results of this damage assessment together with an assessment of the reliability of the monitoring and protective systems, shows that the magnets can operate with the required safety condition. 相似文献
2.
Conclusion In the optimization problem [f
0(x)│hi(x)<-0,i=1,…,l] relaxation of the functionf
0(x)+Nh+(x) does not produce, as we know [6, 7], αk=1 in Newton's method with the auxiliary problem (5), (6), whereF(x)=f
0′(x). For this reason, Newton type methods based on relaxation off
0(x)+Nh+(x) are not superlinearly convergent (so-called Maratos effect). The results of this article indicate that if (F(x)=f
0′(x), then replacement of the initial optimization problem with a larger equivalent problem (7) eliminates the Maratos effect
in the proposed quasi-Newton method. This result is mainly of theoretical interest, because Newton type optimization methods
in the space of the variablesx ∈R
n are less complex. However to the best of our knowledge, the difficulties with nonlocal convergence arising in these methods
(choice of parameters, etc.) have not been fully resolved [10, 11]. The discussion of these difficulties and comparison with
the proposed method fall outside the scope of the present article, which focuses on solution of variational inequalities (1),
(2) for the general caseF′(x)≠F′
T(x).
Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 78–91, November–December, 1994. 相似文献
3.
4.
In the present work it was directly demonstrated that increased acetylation level of histones causes the decompactization of 30 nm chromatin fiber, as revealed by low-percentage agarose gel electrophoresis. In the light of obtained results the possible molecular mechanism of the decompactization of acetylated fiber is discussed. 相似文献
5.
6.
Postoperative feeding with a special-purpose foodstuff Ovolact proved superior to tube feeding in patients on after treatment following surgical correction of congenital jaw defects. This was evident from assessment of anthropometric and protein metabolism parameters. Nitrogen metabolism underwent positive changes reflecting the product value for maintenance of protein status of the above patients. Therefore, Ovolact can make more effective postoperative rehabilitation in jaw reconstruction. 相似文献
7.
The main technical measures for increasing the nominal safety of the No. 5 unit of the Kursk nuclear power plant are presented:
optimization of the neutron-physical characteristics of the core, adoption of a comprehensive monitoring, control, and protection
system, switching to cluster-type control rods, adoption of a system for limiting radioactive emissions during anticipated
accidents with pipeline rupture outside the containment system.
__________
Translated from Atomnaya énergiya, Vol. 100, No. 4, pp. 320–327, April, 2006. 相似文献
8.
M. A. Medkov P. A. Storozhenko A. M. Tsirlin N. I. Steblevskaya E. S. Panin D. N. Grishchenko G. S. Kubakhova 《Inorganic Materials》2007,43(2):162-166
Zirconia coatings have been produced on Hi-Nicalon fibers via pyrolysis of zirconium oxalates extracted into amine-benzene solutions. X-ray diffraction and electron probe x-ray microanalysis results demonstrate that the pyrolysis of extracts is a viable approach to producing thin zirconia coatings on coreless silicon carbide fibers and that further research is needed to optimize the microstructure of zirconia coatings. 相似文献
9.
Evaluation of dynamic fracture toughness parameters of locomotive axle steel by instrumented Charpy impact test
下载免费PDF全文
![点击此处可从《Fatigue & Fracture of Engineering Materials & Structures》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. P. Sorochak P. O. Maruschak O. P. Yasniy T. Vuherer S. V. Panin 《Fatigue & Fracture of Engineering Materials & Structures》2017,40(4):512-522
The analysis of the energy of fracture of specimens from steel OSL, which is widely used for the manufacture of railway axles under shock loading, is performed. The nature and quantitative parameters of the typical stages of the processes of plastic and brittle fracture, depending on the test temperature and stiffness of the stress state at the tip of the crack‐like defect, are established. It is shown that impact loading at 20 °C leads to the formation of the local zone of plasticity and ductile–brittle fracture of the material. An increased stiffness of the stress state at the tip of the defect at ?40 °C causes brittle fracture. An approach is developed, which is based on using the size of shear lips as a quantitative parameter of fracture under normal and low temperatures, similar in its physical essence to deformation approaches of nonlinear fracture mechanics. Based on this approach and the quantitative analysis of specimen fracture zones, the physical and mechanical scheme of specimen fracture is proposed in the presence of localized plasticity and in its absence near the tip of the concentrator. 相似文献
10.
P. O. Maruschak S. V. Panin F. Stachowicz I. M. Danyliuk I. V. Vlasov R. T. Bishchak 《Acta Mechanica》2016,227(1):151-157
The evaluation of crack initiation and growth at microscopic scale is a crucial issue for the safety assessment of macroscopical fractures. In the present paper, the crack propagation in 17Mn1Si steel macroscale is investigated by taking into account the microstructural damage accumulation in polycrystalline solids. The revealed regularities are in good agreement with the concept of physical mesomechanics, which allows obtaining a generalized view of the material deformation and the failure process in the vicinity of the concentrator, which fulfills the limiting, initial and physical conditions and allows obtaining the generalized regularities in deformation and failure of 17Mn1Si steel. 相似文献