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11.
Barbara K. Reck Robert B. Gordon 《JOM Journal of the Minerals, Metals and Materials Society》2008,60(7):55-59
Nickel and chromium are essential ingredients in alloys increasingly important for energy-efficient, environmentally friendly
modern technology. Quantitative assessment of the flows of these metals through the world economy from resource extraction
to final disposal informs resource policy, energy planning, environmental science, and waste management. This article summarizes
the worldwide technological cycles of nickel and chromium in 2000. Stainless steel is the major use of these metals, but they
serve numerous other special needs, as in superalloys for high-temperature service, as plating materials, and in coinage.
Because they are used primarily in alloys, novel recycling issues arise as their use becomes more widespread.
“... the great New York and St. Louis double track, nickel plated railroad...”
— Norwalk, Ohio, Chronicle 10 March 1881 announces arrival of surveyors for the future Nickel Plate Railway
“Later [1911] I formed an alloy of Iron and Chromium, which showed remarkable resistance to rust and tarnish ... [It was]
rediscovered by an Englishman named Brearley, in 1914.”
—Elwood Haynes to Stephen F. Roberts, 17 January 1925 相似文献
12.
Sarason Barbara R.; Shearin Edward N.; Pierce Gregory R.; Sarason Irwin G. 《Canadian Metallurgical Quarterly》1987,52(4):813
To obtain a clearer picture of what constitutes social support, we conducted three studies to compare measures of different conceptions of social support. Relations of these instruments to various personality measures were also investigated. Subdividing the construct into discrete functions did not add to the sensitivity of the indices. Measures of received support and support networks were not strongly related to most of the perceived available support measures. Interview and questionnaire approaches were similar in the information they evoked about close supportive relationships. The results suggest that measures of perceived available support, regardless of the way the instruments attempt to break down the construct, generally assess the extent to which an individual is accepted, loved, and involved in relationships in which communication is open. Psychometric characteristics of the measures were associated with differential sensitivity over the range of supportive relationships. The theoretical implications of the findings are discussed with emphasis on the common core underlying social support indices. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
14.
On July 24, 2010, 21 people died and more than 500 were injured in a stampede at the Loveparade, a music festival, in Duisburg, Germany. Although this tragic incident is but one among many terrible crowd disasters that occur during pilgrimage, sports events, or other mass gatherings, it stands out for it has been well documented: there were a total of seven security cameras monitoring the Loveparade and the chain of events that led to disaster was meticulously reconstructed.In this paper, we present an automatic, video-based analysis of the events in Duisburg. While physical models and simulations of human crowd behavior have been reported before, to the best of our knowledge, automatic vision systems that detect congestions and dangerous crowd turbulences in real world settings were not reported yet. Derived from lessons learned from the video footage of the Loveparade, our system is able to detect motion patterns that characterize crowd behavior in stampedes. Based on our analysis, we propose methods for the detection and early warning of dangerous situations during mass events. Since our approach mainly relies on optical flow computations, it runs in real-time and preserves privacy of the people being monitored. 相似文献
15.
The definite trend towards the use of large-diameter rebars and the introduction of high-strength steels (f
y=500 to 600 MPa) make it necessary to study the effects of longitudinal splitting on the steel-to-concrete bond. The study
of splitting effects requires firstly basic tests to be performed in order to gather experimental information on bond and
confinement stresses acting at the bar-to-concrete interface. For this purpose, three series of tests were recently carried
out at the Politecnico di Milano. The results make it possible to ascertain a few basic properties of the bond after concrete
splitting, and to formulate empirical constitutive laws regarding the stresses and the displacements (bar slip and opening
of the splitting crack). All specimens consisted of a short deformed bar embedded in a concrete block, which had a preformed
splitting crack in the plane passing through the bar axis: twelve specimens (Tests A and C) were fitted up with a round deformed
bar having crescent-shaped lugs (Db=18 mm); seven specimens (Tests B) were fitted up with a specially machined deformed bar having a rectangular cross-section
and straigth, lugs, so that concrete deterioration close to the bar could be investigated at the surface of the specimen,
by means of the moiré technique. The tests were carried out at constant slip rate, up to very large slip values (
); both the ascending and the descending branches of the stress-slip curves were measured, for four different values of the
opening of the splitting crack. The agreement among the results of the three series is generally satisfactory and often very
good: consequently, constitutive laws regarding the four main variables (crack opening and bar slip, shear and confinement
stresses) can be worked out, as will be shown in a companion paper on constitutive relationships and on concrete deterioration
at the bar-to-concrete interface. 相似文献
16.
A new approach is presented for the characterization of particle motion in fluid-solid systems based on dynamic imaging with a gamma scintillation camera. A two-dimensional spouted bed of 200-500 micron diameter anion exchange resin beads was used as a test system. One or several beads were radiolabeled with the 140 keV gamma emitting radionuclide 99m-Tc pertechnetate, and particle velocity, panicle path, the spatial distribution of particle residence times, and local bed density were determined from the measured temporal and spatial distributions of particle activity. While care must be exercised in the interpretation of data when the scale for changes in the spatial distribution of activity approaches the limits of camera resolution, the method is quantitative, non-invasive, and well suited to the study of systems having symmetry in one spatial dimension. 相似文献
17.
This study investigated what sources were relied on to find out about Osama bin Laden's death and whether perceptions of credibility and political party affiliation influenced these media choices. The most striking difference in media reliance for bin Laden news was that whatever sources Tea Partiers relied on and thought credible were those that Democrats did not rely on or see as credible. Despite the clamor about how quickly news flows through social network sites and Twitter, only about 5% of respondents first heard about bin Laden through these sources and a slightly larger percentage spread the news via these tools. Moreover, social network sites and Twitter were the least relied on about the aftermath of bin Laden's death. 相似文献
18.
Barbara Porter 《计算机与网络》2014,(15):77-77
<正>长期以来,Emulex I/O解决方案的价值一直为全球电信公司所公认。如今,Emulex宣布推出计划中的高级功能,使用这些功能,电信公司能够更快速地开发优质网络服务提供给客户。新增功能包括增强了Emulex OneConnect OCe14000系列10Gb和40Gb以太网(10/40GbE)网络以及融合网络适配器(CNA)的数据包处理并提高了可编程性。使用这些新增功能,电信设备制造商(TEM)和电信运营商可以加快网络功能虚拟化(NFV)解决方案的部署。Emulex已经与6WIND建立合作伙伴关系,共同开发了Emulex轮询模式驱动程序(PMD),以增强数据平面开发工具包 相似文献
19.
A method for isolation and quantitation of cellular free fatty acid has been developed. When this method was used to quantitate
the free fatty acid content of various cells and tissues, their levels of free fatty acids were found to vary over a wide
range. In comparing tissue culture cells having different levels of free fatty acid, it was demonstrated that the conditions
of culture and the type of serum in the medium are not responsible for the difference in levels. Isotopic studies have shown
that the cellular free fatty acid is not biosynthesized, but is derived from the free fatty acid of the medium. Preliminary
studies on the fate of the intracellular free fatty acid and a discussion of possible factors controlling the level of this
compound in cells are presented. 相似文献
20.