Gravitational-wave research with resonant antennas

Summary A brief historical survey of the GW experiments is presented. In particular, the experiments with resonant detectors are illustrated and the problems arising when comparing data of different detectors for the search of coincidences are discussed. The experimental results so far obtained are shown, among them the correlation during the SN1987A with various GW and neutrino detectors. Finally a warning for the long times needed to improve the sensitivity of the GW detectors is given and the improvements expected with spherical resonant detectors are mentioned.     

Preparation and characterization of waterborne poly(urethane urea) with well‐defined hard segments

A series of polyester‐based poly(urethane urea) (PUU) aqueous dispersions with well‐defined hard segments were prepared from polyester polyol, 4,4′‐diphenylmethane diisocyanate, dimethylolpropionic acid, 1,4‐butanediol, isophorone diisocyanate, and ethylenediamine. These anionic‐type aqueous dispersions had good dispersity in water and were stable at the ambient temperature for more than 1 year. For these aqueous dispersions, the particle size decreased as the hard‐segment content increased, and the polydispersity index was very narrow (<1.10). Films prepared with the PUU aqueous dispersions exhibited excellent waterproof performance: the amount of water absorption was as low as 5.0 wt %, and the contact angle of water on the surface of this kind of film was as high as 103° (this led to a hydrophobic surface). The water‐resistant property of these waterborne PUU films could be well correlated with some crystallites and ordered structures of the well‐defined hard segments formed by hydrogen bonding between the urethane/urethane groups and urethane/ester groups, as well as the degree of microphase separation between the hard and soft segments in the PUU systems. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2606–2614, 2005     

Electronic quasiparticles and evolution of Fermi level spin states in thin magnetic layers

Here we report on high-resolution photoemission of iron layers grown on a W(1 1 0) substrate. The evolution of the substrate states upon sub-monolayer adsorption of Fe atoms leads to a shift in surface state binding energy. For thicker (1 1 0) films, sharp metallic surface states are obtained. Their dispersion displays the signature of quasiparticle renormalization due to dressing with excitations. The energy scale is characteristic for the spin wave spectrum in iron, thereby giving evidence of electron-magnon coupling. Furthermore, it is found that quantum well states occur as a function of layer thickness. These modify the spin density of states at the Fermi level in the ferromagnetic film.     

Low temperature transport properties of thin SOI MOSFETs

Fabrication and 4.2 K mobility measurements of silicon-on-insulator (SOI) metal–oxide-field-effect-transistors are reported. The three sets of samples fabricated in this work include devices for which the SOI film thicknesses (t_SOI) are in the ranges of 10–15, 16–19 and 56–61 nm. The peak mobility of the devices that have the SOI film thickness above 16.5 nm is 1.9 m²/V s. The set of devices with thinnest channel (t_SOI=10–15 nm) suggest that the peak mobility decreases with decreasing t_SOI.     

多量子阱波导的传输和色散特性

本文用Floquet理论分析了多量子阱(阱垒数N>>1)波导的传输和色散特性,给出了适用于TE和TM两种偏振态的等效三层平板波导芯子折射率的解析公式,该公式清楚地说明了多量子阱波导的本征双折射行为。     

-na (Department of Lingu

lect, the pronunciation of the characters with entering tone is unique: it has neither the glottal stop nor the characteristic     

在［311］面上直接生长GaAs／AlAs的量子线结构及其光学性质

本文介绍在分子束外延系统中，沿［３１１］面原位生长ＧａＡｓ／ＡＩＡｓ量子线结构的一种简单方法及其拉曼和发光特性。这一方法能克服目前纳米尺度光刻技术的困难，因此，是一种制备低维样品的有希望的方法。     

Semi-empirical likelihood ratio confidence intervals for the difference of two sample means

We all know that we can use the likelihood ratio statistic to test hypotheses and construct confidence intervals in full parametric models. Recently, Owen (1988,Biometrika,75, 237–249; 1990,Ann. Statist.,18, 90–120) has introduced the empirical likelihood method in nonparametric models. In this paper, we combine these two likelihoods together and use the likelihood ratio to construct confidence intervals in a semiparametric problem, in which one model is parametric, and the other is nonparametric. A version of Wilks's theorem is developed.     

多量子阱半导体激光器的交叉增益调制波长转换特性

实验利用光注入多量子陆半导体激光器产生的载流子消耗和带间载流子吸收产生的交叉增益调制效,实现波长转换，转换光的光强变化幅度与偏置电流有关。通过调节偏置电流的大小，能使转换光与注入信号光在同向和反向间进行切换。     

Evaluating alternative system configurations using simulation: A nonparametric approach

The real utility of simulation lies in comparing different alternatives that might represent competing system designs. Conventional statistical techniques are not directly applicable to the analysis of simulation output data in the evaluation of competing alternatives since the usual assumptions of normality and common variance are difficult to justify in simulation experiments. This paper revisits a known nonparametric test whose application has recently become feasible due to considerable increases in computing power:randomization tests assess the significance of the observed value of the test statistic by evaluating different permutations of the data. The procedure only requires invariance of the data under all permutations.