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排序方式: 共有641条查询结果,搜索用时 15 毫秒
1.
J.A. Bakken L. Barone D. Braun M. Caillat C. Dionisi C. Dor H. Elmamouni F. Ferroni G.L. Grazer J.T. He R. Herbiet B. Ille P. Lecomte E. Longo P.F. Loverre Y.S. Lu J.P. Martin U. Micke R.P. Mount P.A. Pirou H.-G. Sander D. Schmitz M. Schneegans D.P. Stickland R.L. Sumner K.L. Tung E. Valente M. Vivargent 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1985,228(2-3):294-302
A calorimeter of 25 bismuth germanate (BGO) crystals equipped with silicon photodiode readout has been tested at the CERN SPS in the energy range 1–50 GeV. The response for electrons has been shown to be linear in this energy range and the rms resolution obtained (
) is approximately 1%, for E > 4 GeV. The electron/pion separation was found to be better than 1:500 in the energy range 1–20 GeV. Data on lateral and longitudinal shower development were compared with the results of a Monte Carlo simulation using the SLAC-EGS program and found to be in good agreement. 相似文献
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Summary In this study we describe the evolution of weakly non-linear shallow water waves in a rectangular channel of 16 m length which aregenerated by a moving boundary. We present a detailed comparison of computaticnal and observational waveheight-time series and thus verify the theoretical model as presented by Villeneuve and Savage [27].Three different types of wave generating devices were used: pistons with vertical and inclined frontal faces, submerged boxes and a rotating plate. Waveheight-time series are recorded at eight different positions along the channel by electrical resistivity gauges, and velocity profiles are determined at certain selective cross sections. Data of many wave experiments are presented in nondimensional form. This representation reveals that the initial wave forms depend upon a Froude number of the motion of the wave generator, the slope angle of the wedge-type pistons and on the dimensionless displaced volume. Evolving waveheight-time series that are recorded at the various gauges are compared with those obtained from computations by use of equations which generalize the Boussinesq equations to include time variations of the boundaries.The method of inverse scattering is applied both, experimental and numerical waveheight-time series are prescribed as initial data. Results are tested relative to two different observers one fixed in time the other fixed in space. Deviations are shown to be small in all cases. 相似文献
3.
R. Kornhuber R. Krause O. Sander P. Deuflhard S. Ertel 《Computing and Visualization in Science》2008,11(1):3-15
The purpose of the paper is to apply monotone multigrid methods to static and dynamic biomechanical contact problems. In space,
a finite element method involving a mortar discretization of the contact conditions is used. In time, a new contact-stabilized
Newmark scheme is presented. Numerical experiments for a two body Hertzian contact problem and a biomechanical application
are reported.
This work was supported by the DFG Research Center Matheon. 相似文献
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Recently some heat-shock proteins have been linked to functionsof chaperoning protein folding in vivo. Here currentexperimental evidence is reviewed and possible requirementsfor such an activity are discussed. It is proposed that onemode of chaperone action is to actively unfold misfolded orbadly aggregated proteins to a conformation from whkh they couldrefold spontaneously; that improperly folded proteins are recognizedby excessive stretches of solvent-exposed backbone, rather thanby exposed hydrophobic patches; and that the molecular mechanismfor unfolding is either repeated binding and dissociation (plucking)or translocation of the protein backbone through a binding cleft(threading), allowing the threaded chain to refoldspontaneously. The observed hydrolysis of ATP would providethe energy for active unfolding. These hypotheses can be appliedto both monomeric folding and oligomeric assembly and are sufficientlydetailed to be open to directed experimental verification. 相似文献
7.
Production of a combustible for coal-fired power stations based on sewage sludge . This article describes various means of achieving more extensive mechanical dewatering of sewage sludges. The heat content of the sludge solids can become available for combustion processes. The sludge filter cakes obtained by the “CarboSed” process can be disposed of with minimum energy consumption by fluidized bed combustion or be used after appropriate work-up as a combustible in coal-fired power stations with full exploitation of their heat content for generation of steam and electric current. Partial substitution of primary energy sources such as coal and fuel oil by sludge filter cake is feasible in all cases. The processes thus make a contribution to the saving of energy resources and the disposal of sludge. 相似文献
8.
As the National Library of Medicine expands access to its products and services by making them available on the Internet, more accurate information about current and future access in medical libraries is needed. The National Network Office of the National Library of Medicine conducted a survey of all network member libraries to determine the extent of connectivity and the barriers preventing 100% connectivity. Respondents called a toll-free number and, using interactive voice technology, answered questions concerning Internet access in their library. Seventy-eight percent of the network member libraries responded. Four percent of academic libraries, 27% of hospital libraries, and 10% of "other" libraries reported that they were not connected. Computer cost, lack of in-house expertise, and lack of management support were the highest ranked barriers to connecting. The National Library of Medicine and the Regional Medical Libraries will use information from this survey to develop strategies to help all member libraries achieve full connectivity. 相似文献
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Jurjen Jansen Sander Veenstra Renske Zuurveen Wouter Stol 《Behaviour & Information Technology》2016,35(5):368-379
Information technology is becoming increasingly important for entrepreneurs. Protecting their technical infrastructure and stored data is, therefore, also becoming more vital. Nevertheless, research into the safety and security of entrepreneurs in general, and online threats targeted at entrepreneurs in particular, is still limited. This study investigates to what extent self-employed entrepreneurs protect themselves against online threats, and what motivates them to do so. Based on secondary analyses on data collected from 1622 Dutch entrepreneurs, we observe that the majority implement technical and personal coping measures. By adopting protection motivation theory as a theoretical basis for our study, we found that coping appraisal explains the adoption of protective measures. Entrepreneurs are likely to implement protective measures when they believe a measure is effective, when they are capable of using internet technology, when their attitude towards online protection is positive and when they believe they are responsible for their own online security. Although the secondary analysis provides some limitations, this study offers new insights into the usage of protective measures and the motivation for taking them. These insights can help to improve information security campaigns. 相似文献