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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Investigations of wear in sliding friction of WC-Hadfield steel hard alloy against cast tool steel have been carried out in
a broad range of velocities and pressure values. Structural and phase composition variations have been revealed. Friction-affected
zone was found to be 450 μm in depth. Structural γ → α, γ → transformation regions are located within 100 μm of the surface.
These transformations contributed to the total solid solution deformation hardening. 相似文献
992.
993.
This program was supported by the Department of Energy through the Joint Program on Critical Compilation of Physical and Chemical
Data coordinated through the Office of Standard Reference Data, National Bureau of Standards. Additional support was contributed
by: Molycorp, Inc., Union Oil Co. of California, Los Angeles, CA; Reactive Metals and Alloys Corp., West Pittsburg, PA; Ronson
Metals Corp., Newark, NJ; and Santoku Metal Industry Co., Ltd., Kobe, Japan. Literature searched through 1984. Professor Gschneidner
is the ASM/NBS Data Program Category Editor for binary rare-earth alloys. 相似文献
994.
V. V. Gribova A. S. Kleshchev F. M. Moskalenko V. A. Timchenko 《Automatic Documentation and Mathematical Linguistics》2015,49(6):221-231
A model for generation of directed graphs of information by the directed graph of metainformation for a two-level connected directed graph model of information units is described. It can be used as a basis in computer tools for editing information with a complex structure with different levels of abstraction and invariance to technological spaces (subject domains) in a common conceptual framework for carriers of this information, making it unnecessary to organize specialized training for these carriers or to involve professional intermediaries. 相似文献
995.
Computational Visual Media - Pool and billiards are amongst a family of games played on a table with six pockets along the rails. This paper presents an augmented reality tool designed to assist... 相似文献
996.
997.
De Angeli M Castaldo C Ratynskaia S Grosso G Almaviva S Caneve L Colao F Maddaluno G 《The Review of scientific instruments》2011,82(10):106101
The scheme and construction of an electro-optical probe able to collect charge and detect optical emission from expanding dense partially ionized vapour clouds are reported. The instrument can be applied to phenomena such as dust impact ionization and solid target laser ablation. First, results of measurements of expanding plasma cloud formed upon ablating W target are presented. Use of the instrument in different experimental facilities, including tokamak, is discussed. 相似文献
998.
Nuclear magnetic resonance is widely employed in studies of chemical reactions and molecular motions at moderate pressure and temperature, but for CO(2) solutions under supercritical conditions encountered in geological or mineral sequestration (pressures to 150 atm and temperatures to 150 °C) a specialized variable-temperature probe is required. The critical component of such a probe is its pressure chamber, and our working design is presented along with examples of its use in (13)C NMR measurements of bicarbonate and dissolved CO(2) fractions as functions of time, following initial pressurization to 70 atm. Also shown are final, steady-state values of these fractions as functions of temperature from 50 to 125 °C at 70 atm. 相似文献
999.
Arregui-Dalmases C Del Pozo E Stacey S Kindig M Lessley D Lopez-Valdes F Forman J Kent R 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2011,225(7):688-695
While rupture of the aorta is a leading cause of sudden death following motor vehicle crashes, the specific mechanism that causes this injury is not currently well understood. Aortic ruptures occurring in the field are likely due to a complex combination of contributing factors such as acceleration, compression of the chest, and increased pressure within the aorta. The objective of the current study was to investigate one of these factors in more detail than has been done previously; specifically, to investigate the in situ intra-aortic pressure generated during isolated belt loading to the abdomen. Ten juvenile swine were subjected to dynamic belt loads applied to the abdomen. Intraaortic pressure was measured at multiple locations to assess the magnitude and propagation of the resulting blood pressure wave. The greatest average peak pressure (113.6 +/- 43.5 kPa) was measured in the abdominal aorta. Pressures measured in the thoracic aorta and aortic arch were 70 per cent and 50 per cent, respectively, that measured in the abdominal aorta. No macroscopic aortic trauma was observed. To the authors' knowledge the present study is the first one to document the presence, propagation, and attenuation of a transient pressure wave in the aorta generated by abdominal belt loading. The superiorly moving wave is sufficient to generate hydrostatic and intimal shear stress in the aorta, possibly contributing to the hypothesized mechanisms of traumatic aortic rupture. 相似文献
1000.
This study aimed at enhancing knowledge on the fate of diclofenac (DF), together with its main human metabolite 4'-hydroxydiclofenac (4'OHDF), during wastewater treatment by using a laboratory-scale membrane bioreactor (MBR). The reactor was fed continuously with non-radiolabelled diclofenac for a one month period prior to a single pulse of a 14C-radiolabelled solution of DF and 4'OHDF. The solution spike contained approximately 25% 4'OHDF and 65% DF, which corresponds to the ratio observed in municipal sewage, as well as traces of two other metabolites. The radioactivity was monitored for a total of twelve days in the various output streams. The calculation of the complete mass balance in the system demonstrated that the major part of the radioactivity left the reactor with the permeate (88.7%), while 2.1% was recovered in the excess sludge. Negligible amounts were recovered in the off-gas traps and on the membranes. Chromatographic analyses of effluent samples, by means of HPLC-MS coupled in parallel to a radiodetector, displayed a different pattern than the one of the spiked solution. It showed the occurrence of three additional metabolites. 相似文献