The X-HPD—conceptual study of a large spherical hybrid photodetector

We present the results of a conceptual study demonstrating the feasibility of a large spherical hybrid photodetector with central anode. A prototype tube with 208 mm diameter and an anode in form of a metallic cube has been fabricated. In the final version of the so-called X-HPD concept the anode will be a scintillator cube with plated faces and a small photodetector to readout the bottom. The bialkali photocathode covers three quarters of the sphere surface. Combined use of this cathode in transmissive and reflective mode leads to effective quantum efficiency values exceeding those obtained in conventional hemispherical PMT designs. Further features of the concept are a photoelectron collection efficiency approaching 100% and a photon amplification in the scintillator crystal leading to a distinct single photoelectron signal.

Using a custom built electron accelerator based on a CsI transmissive photocathode, LSO and YAP block crystals in geometries adapted to the anode of an X-HPD have been tested with single photoelectrons in the 10–30 keV energy range. The scintillation light was readout with a conventional PMT or a Si-PM. More than 30 photoelectrons per incident electron could be detected with the PMT.     

Bayesian assessing for a repairable system with standby imperfect switching and reboot delay

System performance measures of a repairable system are studied from a Bayesian viewpoint with different types of priors assumed for unknown parameters, in which the system consists of two active components and one warm standby. There is a failure probability q that switches from standby state to active state. Time-to-failure of components is assumed to be an exponential distribution. The reboot time and repair time are also exponential distributions. When time-to-failure, time-to-repair and reboot time are with uncertain parameters, a Bayesian assessing is adopted to evaluate system performance measures. Monte Carlo simulation is used to derive the posterior distribution for the steady-state availability and the mean time-to-system failure. Some numerical experiments are performed to illustrate the results derived in this article.     

利用数字光通信技术实现计算机视频信号长距离传输

介绍了如何采用数字光通信技术实现计算机视频信号的长距离传输;介绍了数字显示接口(DVI)标准的相关知识,通过项目实施解决了其中的关键技术,项目成果达到了实用化程度.     

谐波保护器及其在智能建筑中的应用

随着科技的进步,智能建筑中广泛使用高灵敏度的现代化用电设备和装置.高次谐波污染往往导致这些电子系统运行错误乃至损坏.通过谐波保护器能够净化电源,保护用电设备和功率因数补偿设备,防止保护装置误跳闸,从而保证设备安全、高效地运行.     

Default Bayesian Priors for Regression Models with First-Order Autoregressive Residuals

Abstract. The objective of this paper is to develop default priors when the parameter of interest is the autocorrelation coefficient in normal regression models with first-order autoregressive residuals. Jeffreys' prior as well as reference priors are found. These priors are compared in the light of how accurately the coverage probabilities of Bayesian credible intervals match the corresponding frequentist coverage probabilities. It is found that the reference priors have a definite edge over Jeffreys' prior in this respect. Also, the credible intervals based on these reference priors seem superior to similar intervals based on certain divergence measures.     

On stochastic optimization: Taguchi Methods™ demystified; its limitations and fallacy clarified

The intent of this paper is to clarify and straighten out important misperceptions. Recently, the need for Stochastic Optimization in Design and Manufacturing Engineering has received increased recognition. The only technique belonging in the realm of Stochastic Optimization that has been practiced somewhat in industry is Taguchi Methods™. (Taguchi Methods™ and Robust Design™ are registered trademarks of the American Supplier Institute for Taguchi methodology. In this paper, Taguchi Methods or methodology is used in the singular and without the trademark symbol, and mostly its acronym, TM, is used.) However, Taguchi Method (TM) has been incorrectly promoted by many as THE work process for attaining “a robust design,” thus the use of Robust Design™ to stand for TM! This has caused great confusion since much else is needed for designing a robust product. More serious is that simple mathematical fundamentals behind TM have not been fully clarified so that its limitations and deficiencies would be obvious. Thus even greater confusion exists amongst people who “learn” or hear of TM or are intended practitioners. Because of our extensive work on HPD (Holistic Probabilistic Design), which holistically treats Stochastic Optimization and thus includes comprehensively and rigorously addressing robustness, we have gone beyond TM capabilities. As byproducts, we can now demystify TM in a simple manner, show its limitations clearly, and clarify TM's fallacy which essentially invalidates it as a technique!     

脉冲激光光敏疗法医治中晚期癌症156例

采用脉冲激光光敏疗法医治中晚期癌症,有效率91.6％,总缓解率42.8％。讨论了疗效与输出功率、光照时间的关系,适应症的选择,综合治疗及重复治疗的时间等。     

精细积分法分析流引起粘弹输液曲管的稳定性

将精细积分法用于分析输液曲管的动力稳定性是一个新的尝试．首先将输液曲管的控制方程写成状态向量的形式，通过精细积分法高精度地计算出传递矩阵，再由边界条件得到输液曲管的特征方程，解此方程就可确定失稳对应的临界流速．在此基础上，还研究了管材的粘阻系数对管稳定性的影响．结果表明，它能降低管的振动频率，加快振幅衰减，但对屈曲临界流速没有影响．     

Identification of novel and conserved functional and structural elements of the G1 cyclin Cln3 important for interactions with the CDK Cdc28 in Saccharomyces cerevisiae

Regions of the budding yeast G1 cyclin Cln3 were characterized using mutational analysis and viability assays to identify functionally relevant and novel mutant alleles of CLN3. Cyclin proteins are conserved, and Cln3 contains a region with homology to the cyclin box, which is thought to mediate physical interactions with the cyclin-dependent kinase. CLN3 was found to have characteristics similar to the conserved cyclin fold found in higher eukaryotic cyclin boxes, which consist of five alpha-helices. Peptide linker sequences inserted within helices 1, 2, 3 and 5 resulted in a loss of Cln3 function, showing cyclin fold structure similar to that previously observed for the G1 cyclin Cln2. A clustered-charge-to-alanine scan mutagenesis revealed two regions of Cln3 important for Cln3-dependent viability. The first region encompasses the conserved cyclin box. The second region is identified with alanine substitutions located well past the cyclin box, just prior to the C-terminal region of Cln3 important for protein stability. Cln3 with mutational changes in each of these regions are expressed at steady-state levels higher than wild-type Cln3, and show some defect in binding to Cdc28. The conserved hydrophobic patch domain (HPD) of cyclins is present within the first helix of the cyclin box. Alanine substitutions introduced into the HPD of Cln3 and Cln2 show functional defects while maintaining physical interaction with Cdc28 as measured by co-immunoprecipitation assay.