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1.
Ian Skelton 《Housing Studies》1996,11(2):189-206
This paper provides a perspective on the contemporary debate over the production of social housing. Its main focus is on the issue that geographic patterns of service levels may be related to the type of supply program in place. The paper describes the social housing programs in Ontario, Canada over the post‐war period. Two main approaches have been taken: public housing, an essentially centralized program; and locally sponsored, third sector housing provided through non‐profit corporations and co‐operatives. The programs operated in different time periods and the analysis suggests they do have distinctive geographic distributions. The distribution of public housing shows strong correlations with need as defined by the incidence of poor housing conditions and mother‐led families. Provision under the localized program is also strongly correlated with the incidence of mother‐led families; however, the most consistent associations are with measures of socio‐economic status. These results may be partly understood in terms of the changing concept of housing need over the temporal span of the study. Program influences may be that the centralized nature of the public housing program enabled the direction of allocations to high need areas; whereas under the localized program the distribution is more closely related to the social differentiation of leadership roles in service provision under a third sector delivery model. As this approach becomes more prevalent it may be important to examine its potential impacts on service provision. 相似文献
2.
Atomistic Origin of the Enhanced Crystallization Speed and n‐Type Conductivity in Bi‐doped Ge‐Sb‐Te Phase‐Change Materials 下载免费PDF全文
Jonathan M. Skelton Anuradha R. Pallipurath Tae‐Hoon Lee Stephen R. Elliott 《Advanced functional materials》2014,24(46):7291-7300
Phase‐change alloys are the functional materials at the heart of an emerging digital‐storage technology. The GeTe‐Sb2Te3 pseudo‐binary systems, in particular the composition Ge2Sb2Te5 (GST), are one of a handful of materials which meet the unique requirements of a stable amorphous phase, rapid amorphous‐to‐crystalline phase transition, and significant contrasts in optical and electrical properties between material states. The properties of GST can be optimized by doping with p‐block elements, of which Bi has interesting effects on the crystallization kinetics and electrical properties. A comprehensive simulational study of Bi‐doped GST is carried out, looking at trends in behavior and properties as a function of dopant concentration. The results reveal how Bi integrates into the host matrix, and provide insight into its enhancement of the crystallization speed. A straightforward explanation is proposed for the reversal of the charge‐carrier sign beyond a critical doping threshold. The effect of Bi on the optical properties of GST is also investigated. The microscopic insight from this study may assist in the future selection of dopants to optimize the phase‐change properties of GST, and also of other PCMs, and the general methods employed in this work should be applicable to the study of related materials, for example, doped chalcogenide glasses. 相似文献
3.
J. Skelton 《纺织学会志》2013,104(11):533-556
A theoretical investigation of the tensile, flexural and torsional behaviour of crimped filaments has been made; the relationships describing the filament behaviour are presented in graphical and in analytical form, and are verified experimentally. Two results are of particular importance in routine textile testing: it is shown that the Young's modulus of staple fibres measured with a tensile-testing machine is not subject to significant error caused by crimp; and a new expression is proposed which enables the optimum tension for the routine yarn-crimp test to be calculated. 相似文献
4.
Health care providers and purchasers of health services have an opportunity to improve patient care and potentially save costs through the wise purchase of interactive health communication applications for patients and employees. Purchasing decisions based on evaluation and evidence should drive the design and development of new systems. The cycle of evaluation includes a needs assessment before system development, usability testing during development, and studies of use and outcomes in natural settings. This type of evidence is critical to our understanding of how best to provide health information and decision assistance to patients, employees, and others. 相似文献
5.
Dense multichannel recordings of scalp electroencephalogram (EEG) were obtained in the vicinity of primary somatosensory cortex, time-locked to repetitive vibrotactile stimulation of sites on the right index finger of a single human subject. Frequency-domain analysis of cross-trial averages revealed prominent 'driving' responses in the EEG at the frequency of stimulation, which under specific stimulus conditions displayed pronounced changes in amplitude and topographic organization over brief (4 s) durations of stimulus exposure. The changes were systematic and physiologically coherent, evolving toward driving-response topographies observed in the same subject in conjunction with periodic microstimulation of single mechanoreceptive afferents whose receptive fields occupied corresponding positions on the digit. This dynamic process was orderly and reproducible, and could be controlled by manipulating factors such as the amplitude, frequency, and temporal spacing of the stimuli. The results are tentatively interpreted in light of a previously proposed neurophysiological model of stimulus-driven response plasticity in mammalian somatosensory cortex. 相似文献
6.
8.
Instrument precision is characterized by its signal-to-noise ratio, employing a new noise model. In this paper, this measure of precision of each instrument is used to characterize instrumentation, and an integration is achieved by jointly optimizing the feedback control law and the instrument signal-to-noise ratios to meet control system performance requirements. Iterative algorithms are proposed to find locally optimal solutions. Assuming that the signal-to-noise ratio is directly related to the instrumentation cost, this integration provides a systematic procedure to design a low cost control system. More importantly, this procedure identifies the performance-limiting components of a control system, identifies where to spend money on a system, and generates component design requirements from closed loop system performance criteria. 相似文献
9.
The authors compared the extent of development of the germ cells of the human fetus ovaries developing in the organ culture and of control ovaries obtained of fetuses of "equivalent" age. The capacity to enter the meiosis prophase under conditions of the organ culture was expressed by the germ cells of fetuses of 8-9 week of gestation, and older; only individual oocytes reached the leptotene stage in the explants of the ovaries of 7-8 week fetuses. The oocytes at the leptotene, zygotene and pachitene stage appeared in the culture at the same periods as in the organism. However, the percentage of cells of these stages in the explant was as a rule lower than in control ovaries. In case of pulse administration of thymidine-3H into the culture labeled oocytes at the zygotene stage appeared in 4, and at the pachitene stage - in 14 days. 相似文献
10.
W Beischer L Keller M Maas E Scherfer EF Pfeiffer 《Canadian Metallurgical Quarterly》1976,54(15):709-715
Synthetic human C-peptide bearing a Tyrosine group at its amino end is labelled with 125iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results are compared applying both methods. Antiserum to synthetic human C-peptide (without Tyrosine) which was partially compared to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pigs concerning antibody production. The so-called "hook effect" phenomenon is observed in setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated with the anxion exchange resin Amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. 相似文献