柏林中央火车站

在曾为选帝侯冯伯兰登堡狩猎场的洪堡港以西,一个集长途交通、地区交通及短途交通于一身的欧洲最大的火车站:新的柏林中央火车站,已竣工于它的历史故址.东西向呈弧线的铁道线与地下南北向的新城际快车线交汇于此;2个方向上的轻轨和连接南北的地铁也在此相交.南北向的轨道线通向地下15m的隧道,向前横穿施普雷河和提尔加藤区.这里被建设成一个地下的长途火车站,它拥有8条长途交通轨道,4个为长途车次和区域间车次设置的站台.在与东面的长途轨道相平行位置,地铁U5线的新地铁站也成形于此.东两向的轨道线相对于街面被抬高10m,与现有的铁轨持平.在4条新的市内铁路桥上总共建设了4条长途交通轨道和2条轻轨轨道.预计到2010年,进出柏林的长途客流量将达到5000万人次,而包括周边地区在内的区域间交通流量将达到8500万人次.对于柏林中央火车站来说,这意味着年客流量3000万人次,或者每天2.5万人次的客流量.     

Characterization of epitaxial Bi2Sr2CaCu2O8+δ thin films

We report a dc sputtering method for the fullin situ preparation of Bi₂Sr₂CaCu₂O₈₊ thin films on SrTiO₃ and LaAlO₃.T _c values of more than 90 K can be achieved by oxidizing annealing below the melting point, followed by a reducing anneal at 500°C. The structural properties of the films are revealed by X-ray diffraction in Bragg-Brentano geometry (strongc-axis orientation with FWHM (0 0 10)=0.3) and also by scans (epitaxy within the substrate plane). Rutherford backscattering and channeling confirmed the correct composition of the cations while the minimum yield, _min, is 23%. Depth profiles by SNMS show a very homogeneous distribution of the cations with no detectable loss of bismuth near the surface. The surface morphology of the films was studied by SEM and by STM. Patterning of the films in lateral geometry can be performed by photolithographic techniques without degradation ofT _c .     

Chirped gratings for DFB laser diodes using bent waveguides

The authors propose a method capable of providing arbitrarily chirped DFB (distributed feedback) gratings using bent waveguides on homogeneous grating fields and report the first realization as well as preliminary experimental results     

AlGaInAs/InP 1.5 μm MQW DFB laser diodes exceeding 20 GHzbandwidth

Buried mushroom multiquantum well DFB laser diodes with compressively strained GaInAs quantum wells and asymmetric confinement layer design are fabricated with a combined MBE/MOCVD technology. Packaged devices exhibit high -3 dB IM bandwidths for very low bias levels and a record bandwidth for this material system of 21 GHz     

Characterization of epitaxial Bi2Sr2CaCu2O8+δ thin films

We report a dc sputtering method for the fullin situ preparation of Bi₂Sr₂CaCu₂O_8+δ thin films on SrTiO₃ and LaAlO₃.T _c values of more than 90 K can be achieved by oxidizing annealing below the melting point, followed by a reducing anneal at 500°C. The structural properties of the films are revealed by X-ray diffraction in Bragg-Brentano geometry (strongc-axis orientation with FWHM (0 0 10)=0.3) and also byΦ scans (epitaxy within the substrate plane). Rutherford backscattering and channeling confirmed the correct composition of the cations while the minimum yield,χ _min, is 23%. Depth profiles by SNMS show a very homogeneous distribution of the cations with no detectable loss of bismuth near the surface. The surface morphology of the films was studied by SEM and by STM. Patterning of the films in lateral geometry can be performed by photolithographic techniques without degradation ofT _c .     

INITIALIZING THE KALMAN FILTER FOR NONSTATIONARY TIME SERIES MODELS

Abstract. The problem of initializing the Kalman filter for nonstationary time series models is considered. Ansley and Kohn have developed a 'modified Kalman filter' for use with nonstationary models to produce estimates from what they call a 'transformation approach'. We show that the same results can be obtained with a suitable initialization of the ordinary Kalman filter. Assuming there are d starting values for the nonstationary series, we initialize the Kalman filter using data through time d with the transformation approach estimate of the state vector and its associated error covariance matrix at time d . We give details of the initialization for ARIMA models, ARIMA component models and dynamic linear models. We present an example to illustrate how the results may differ from results obtained under more naive initializations that have been suggested.     

An enhanced quasi-monolithic integration technology for microwave and millimeter wave applications

A new technology for integration of high frequency active devices into low cost silicon substrate has been introduced. The novel fabrication process gives excellent advantages such as extremely low thermal resistance, and a much lower thermo-mechanical stress than the earlier quasimonolithic integration technology (QMIT) concept . This highly improves the packaging lifetime and electrical characteristics of the active devices. The fabrication process is simple and compatible with fabrication of high-Q passive elements. Successful integration of high-Q passive elements on low resistivity silicon substrate in this technology has been possible for the first time. In comparison to the earlier concept of QMIT, elimination of air-bridges in this technology not only reduces the parasitic elements but also enables the fabrication of the rest of the circuit after measuring the microwave characteristics of the embedded active devices. This makes very accurate microwave and millimeter-wave designs possible. Using the new fabrication process, microwave and millimeter-wave circuits (with both coplanar and microstrip lines) containing power devices have for the first time been possible. Furthermore, the enhanced QMIT can be considered as an organic deposited multi chip module (MCM-D), which is a potential candidate for integration an system on a package (SOP) at microwave and millimeterwave frequencies.     

Identification, authoritarian defensiveness, and self-esteem.

It was hypothesized that if one individual identifies with another with regard to 1 trait, the possession of a 2nd trait by the one with whom S identifies will lead S to assume the possession of even the 2nd trait. The opposite was also hypothesized, i.e., that if a person is made to perceive that he is opposite to a model with regard to a given trait, he will perceive that he is opposite the other trait. The degree of self-esteem will also influence this process; the higher the self-esteem the lower the assumption of similarity. After performing on 4 tasks (identifying associated nouns, finding antonymns, letter-number substitution, making words formed from other words), Ss were presented with material to structure identification or distinction from another S who performed the same or opposite tasks, describing this S in terms of intellectual level. Results supported the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigations of thermal crosstalk in laser arrays for WDMapplications

Our studies on the thermal crosstalk of laser arrays with integrated thin-film heaters involved theoretical as well as experimental investigations. Comparing the effects of intentional geometrical variations of the device design, we found that the relative thermal crosstalk depends critically on the distance between the active area and the film heater. The most striking result is that a minimization of the thermal resistivity of the device does not always lead to a reduced thermal crosstalk. We demonstrate that an additional heat barrier close to the active region and/or an improved heat transfer between the submount and the heat sink may reduce the relative thermal crosstalk, a result completely unexpected from intuitive considerations