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31.
Jack Silver Robert Withnall George R.Fern Paul G Harris Terry G.Ireland Anthony Lipman 《电子器件》2008,31(1):161-165
文章介绍了两种移植和可控纳米沉积荧光粉颗粒和纳米铁电体颗粒的载体.第一种载体是一种可以悬浮和沉积合成的具有亚微米级尺寸大小的荧光粉颗粒的油墨.解决了该油墨的聚集和沉降问题,并发现该油墨具有良好的液流学性能,从而可用于印刷高分辨率的荧光粉.测量了相关的单个象素的阴极发光密度以评定这种丝网印刷油墨的可重复性.第二种载体是一种粘结剂,这种粘结剂不仅可以携带 30 μm 以及更大的尺寸的电致发光的荧光粉,还可以携带纳米铁电体颗粒.这种新型的粘结剂可应用于不需要额外的绝缘反射层的低造价的 EL 显示器.从衬底按要求将发射层剥下来就形成了柔性薄膜,将该薄膜置于两电极之间,仍可保持其电致发光的活性.该粘结剂薄膜可以很容易地印刷和定型制成显示屏. 相似文献
32.
In this paper, recent results of Weibull slopes, area scaling factors, and breakdown behaviors observed for both soft breakdown and hard breakdown are discussed. These results would help to shed light on the breakdown mechanism of HfO2 gate dielectrics. The Weibull slope β of the hard breakdown for both the area dependence and the time-to-dielectric-breakdown distribution was found to be β=2, whereas that of the soft breakdown was about 1.4 (EOT=14 Å). We also integrated the time-to-breakdown characteristics of HfO2 under unipolar AC voltage stress on MOS capacitors. The results show that longer lifetime of HfO2 has been observed when compared to constant voltage stress. Higher frequency and lower duty cycle in the AC stress resulted in longer lifetime. As thickness decreases, the amount of lifetime enhancement decreases. The enhancement of unipolar tBD is attributed to less charge trapping during the “on time”, ton and charge detrapping during the off time, toff. It is proposed that time (τin) for charge to be trapped in HfO2 is longer than ton of unipolar stress under high frequency. In addition to experimental results, possible solutions are discussed. 相似文献
33.
In many developing countries such as Saudi Arabia the adoption of cloud computing is still at an early stage. This research aims to investigate the influencing factors in the decision to adopt cloud computing in the private sector. An integrated model is proposed incorporating critical factors derived from a literature review, along with other factors (such as physical location) that have not been examined in previous studies as main factors in the organisation’s decision to adopt cloud services. Data were collected from 300 IT staff in different organisations in the private sector in Saudi Arabia, in order to test the cloud adoption model and explore factors that were positively or negatively associated with cloud adoption. The most influential determinants of cloud adoption were found to be quality of service and trust. However, security and privacy concerns still prevent cloud adoption in this country. This study also showed that the effect of these variables differed according to organisation size and in adopter and non-adopter companies. Overall, these research findings provide valuable guidelines to cloud providers, managers, and government policy makers on ways of encouraging the spread of cloud computing in Middle Eastern countries and increasing its implementation, particularly in Saudi Arabia. 相似文献
34.
The production of consistent high purity materials is critical for improvement in performance and sensitivity of II-VI photovoltaic
and photoconductive devices. Information regarding the energy band structure and impurity or defect levels present in the
material is essential to understand and enhance the performance of current detectors along with the development of future
novel devices. Secondary ion mass spectrometry (SIMS) is capable of providing information of purity, junction depths, dopant
distribution, and stoichiometry in the material. SIMS techniques can achieve high detection sensitivities in very small analytical
volumes and for a wide range of elements (almost the entire periodic table). SIMS analysis also provides unique capabilities
for localizing atomic distribution in two and three dimensions. Ion images can be obtained by registering the positions of
mass selected ions formed in the sputtering process. The combination of excellent detection sensitivity, high mass resolution,
depth profiling capability, and high resolution image acquisition on a wide spectrum of elements by a SIMS instrument is not
matched by any other instrumentation technique. 相似文献
35.
Mandayam Narayan B. Chen Pi-Chun Holtzman Jack M. 《Wireless Personal Communications》1998,7(2-3):135-146
Traditionally, outage for CDMA cellular systems has been defined as the signal level (or, more precisely, the signal-to-interference ratio (SIR)) falling below a required threshold. In real cellular environments, it is not the instantaneous drop of the signal strength below the threshold that determines outage. It is, in fact, the duration of time below a threshold that determines outage for cellular systems. Moreover, the static analysis of outage precludes the time correlation in the signals which is important in real systems owing to mobility, fading and power control. In this paper, we analyze minimum duration outages for such systems, where outage is defined as an excursion of the SIR below a level for a certain minimum duration. We formulate the outage condition as a level crossing problem and extend asymptotic results from the theory of level crossings to derive analytical results for the probability of outage. This method enables us to include the time correlation of signals in the analysis as well. The validity of the asymptotic results is verified using some exact results as well as simulations. These minimum duration outages have implications in redefining user capacity and handoff performance. 相似文献
36.
Pan J.S. McInnes F.R. Jack M.A. 《Vision, Image and Signal Processing, IEE Proceedings -》1996,143(1):67-71
A bound for a Minkowski metric based on Lp distortion measure is proposed and evaluated as a means to reduce the computation in vector quantisation. This bound provides a better criterion than the absolute error inequality (AEI) elimination rule on the Euclidean distortion measure. For the Minkowski metric of order n, this bound contributes the elimination criterion from the L1 metric to L n metric. This bound can also be an extended quadratic metric which can be a hidden Markov model (HMM) with a Gaussian mixture probability density function (PDF). In speech recognition, the HMM with the Gaussian mixture VQ codebook PDF has been shown to be a promising method 相似文献
37.
The modified test of NBU-ness given by Green and Tiwari (1) related to more general null and alternative hypotheses than the corresponding test given by Hollander and Proschan (2). The Green and Tiwari test used an upper bound for the basic of the basic criterion, resulting in the test not being very powerful. In this revised test, suitable estimate of the variance is used instead of an upper bound. This is appropriate because a large sample size is assumed. The resulting test is more powerful than the earlier Green-Tiwari test, and more generally applicable than the Hollander-Proschan test. 相似文献
38.
Hollander and Proschan (1972) gave a test of NBU-ness of a distribution F, but it was pointed out by Green and Tiwari (1989) that the test more appropriately related to much wider null and alternative hypotheses than those stated, and provided suitable critical values. Similarly, Hollander, Park and Proschan (1986) later provided a test that a distribution is NBU-to and a modified test was given by Ebrahimi and Habibullah (1990). However, a similar criticism may be levelled against these tests and a modified test is here provided for appropriate, more general, hypotheses. 相似文献
39.
Allie E. Auld Fabian Mueller Keyue Ma Smedley Scott Samuelsen Jack Brouwer 《Journal of power sources》2008
Adding distributed generation (DG) is a desirable strategy for providing highly efficient and environmentally benign services for electric power, heating, and cooling. The interface between a solid oxide fuel cell (SOFC), typical loads, and the electrical grid is simulated in Matlab/Simulink and analyzed to assess the interactions between DG and the electrical grid. A commercial building load profile is measured during both steady-state and transient conditions. The load data are combined with the following models that are designed to account for physical features: a One-Cycle Control grid-connected inverter, a One-Cycle Control active power filter, an SOFC, and capacitor storage. High penetration of DG without any power filter increases the percentage of undesirable harmonics provided by the grid, but combined use of an inverter and active power filter allows the DG system interconnection to improve the grid tie-line flow by lowering total harmonic distortion and increasing the power factor to unity. 相似文献
40.
Derek Pletcher Hantao Zhou Gareth Kear C.T. John Low Frank C. Walsh Richard G.A. Wills 《Journal of power sources》2008
The structure of lead deposits (approximately 1 mm thick) formed in conditions likely to be met at the negative electrode during the charge/discharge cycling of a soluble lead-acid flow battery is examined. The quality of the lead deposit could be improved by appropriate additives and the preferred additive was shown to be the hexadecyltrimethylammonium cation, C16H33(CH3)3N+, at a concentration of 5 mM. In the presence of this additive, thick layers with acceptable uniformity could be formed over a range of current densities (20–80 mA cm−2) and solution compositions. While electrolyte compositions with lead(II) concentrations in the range 0.1–1.5 M and methanesulfonic acid concentrations in the range 0–2.4 M have been investigated, the best quality deposits are formed at lower concentrations of both species. Surprisingly, the acid concentration was more important than the lead(II) concentration; hence a possible initial electrolyte composition is 1.2 M Pb(II) + 5 mM C16H33(CH3)3N+ without added acid. 相似文献