Optical add-drop multiplexers with low crosstalk

We propose and demonstrate three new optical add-drop multiplexer (OADM) architectures with simple and compact configuration and excellent crosstalk performance. The OADMs use a single multiport optical circulator and either one or two narrow-band fiber Bragg gratings, depending on the crosstalk requirement     

三面内抽芯盒盖注射模设计

介绍三面内抽芯盒盖注射模的模具结构及工艺原理，并指出了该模具的设计要点。     

Axonal damage revealed by accumulation of beta-APP in HIV-positive individuals without AIDS

The presence of neuropsychological disturbances in HIV-positive, pre-symptomatic individuals is a controversial issue. Neuroimaging studies have not shown brain atrophy or hyperintensity in the white matter, whereas proton magnetic resonance spectroscopy has revealed some abnormality of cerebral biochemistry. Using an antibody to beta-amyloid precursor protein (beta-APP), we previously demonstrated frequent and widespread axonal changes in the brains of AIDS patients. In this study, we extended the use of beta-APP to asymptomatic patients in order to establish a possible morphological correlation with neuropsychological disorders. Brain samples from 29 patients were examined. Results showed bundles of beta-APP-positive axons in 8/29 cases (27%). The changes, seen in both superficial and deep white matter, were either focal or diffuse, could not be visualized by silver or ubiquitin stains, and did not coexist with any change in distribution or morphology of astrocytes and microglial cells. We conclude that in HIV-positive asymptomatic individuals, axonal changes: (a) may be related to the state of immune activation with consequent presence of toxic substances, including cytokines, observed in these patients; (b) may represent mild changes that could undergo repair, unless other pathological events, such as the supervening of the AIDS stage and the specific encephalitis, make them permanent.     

表面活性剂在拜耳赤泥过滤中的应用

主要针对赤泥过滤时，添加适宜的表面活性剂，使拜耳赤泥料浆中的液体表面张力下降，从而达到降低过滤后拜耳赤泥浆含水率的目的。文中详细阐述了根据拜耳赤泥的特性，筛选拜耳赤泥过滤适应的表面活性剂，并深入地分析了三种类型的表面活性剂在拜耳赤泥过滤的作用和影响，提出了在拜耳赤泥过滤方面采用阴离子表面活性剂的研究方向。     

Plasma etching optimization of oxide/nitride/oxide interpolydielectric breakdown time in flash memory devices

The breakdown time of flash memory oxide/nitride/oxide (ONO) layer t_bd under positive constant current stressing has been found to be closely related to the cumulative extent of (over)etch of the tungsten silicide, control polysilicon, and ONO layers, i.e., Σ(ΛOE). An empirical first-order relation between t_bd and Σ(ΛOE) has been derived to facilitate the plasma etch recipe optimization. This has led to a four-fold increase in the average t_bd across a 200-mm wafer to 208 s. More importantly, the spread in t_bd has been tightened to ~5%, which is down from ~54%     

Distribution of the carbide phase in the viscoplastic layer during the rotational friction-welding of various steels

The paper presents the viscoplastic phenomena observed during the rotational friction-welding process of high-speed steel M2 (AISI SAE) with carbon steel 1060 (AISI SAE). The structure, phase composition and distribution of the carbide phase in the friction plane and adjoining zones are examined by using optical microscopy (OM) with a system for quantitative analysis, and scanning electron microscopy (SEM) in addition to EDS analysis. The experimentally-checked mathematical relationship is suggested for the calculation of the radial movements of the carbide phase, immediately next to the friction plane. On the basis of qualitative and quantitative evaluation of the microstructural and rheological appearances, a model of carbide phase distribution is also established in the viscoplastic and viscous layers in the area of the friction plane.     

Luminescent and mechanical properties of the epoxy composites doped with europium complex

Reaction of 2,2′,2″-nitrilotris(2,1-ethanediyloxy)tris(benzoic acid) (H₃L) with europium (Eu) perchloride resulted in the ball-like nanoparticles of [EuL]·6H₂O which were characterized by elemental analysis (EA), infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). The prepared precursor was blended into the epoxy resin by different ratio (1, 3, 5 wt.%) to make luminescent nanocomposites. Lifetime measurements suggest that the luminescence of the composite maintains the efficiency of that of the pure complex. Tensile test was carried out to evaluate the mechanical properties of the composites.     

A double-layer composite electrode based on SrSc0.2Co0.8O3−δ perovskite with improved performance in intermediate temperature solid oxide fuel cells

Dual-layer composite electrodes consisting of a layer adjoining to an Sm_0.2Ce_0.8O_1.9 (SDC) electrolyte composed of 70 wt.% SrSc_0.2Co_0.8O_3−δ + 30 wt.% Sm_0.2Ce_0.8O_1.9 (SScC + SDC composite) and a second layer composed of 70 wt.% SrSc_0.2Co_0.8O_3−δ + 30 wt.% Sm_0.5Sr_0.5CoO_3−δ (SScC + SmSC composite) were fabricated and investigated as potential cathodes in intermediate temperature solid-oxide fuel cells. Thermo-mechanical compatibility between the two electrode layers and between the electrode and the electrolyte were examined by SEM, XRD and EIS. After sintering, no clear boundary between SScC + SDC and SScC + SmSC layers was observable by SEM. The repeated thermal cycling didn’t induce the delamination of the electrode from the electrolyte nor the formation of cracks within the electrode. As a result, stable electrode performance was achieved during thermal cycling and long-term operation. Symmetric cell tests demonstrated that the dual-layer electrode with a ∼10-μm SScC + SDC layer and a ∼50-μm SScC + SmSC layer (SScC + SDC/SScC + SmSC (1:5)) had the lowest electrode-polarization resistance among those tested. Anode-supported fuel cells with an SDC electrolyte and SScC + SDC/SScC + SmSC (1:5) cathode were fabricated. Peak power density as high as 1326 mW cm⁻² was achieved at 650 °C, which was higher than for similar fuel cells with a single-layer SScC + SDC or an SScC + SmSC composite electrode.     

低温奥氏体钢的层错能

根据层错及层错能的物理本质和测试层错的依据，明确了层错能和层错形核能的定义。借助计算机处理大量试验结果得到了计算机层错能的表达式。     

Polygonal Single-Crystal Aluminum Borate Microtubes

In this paper we report the synthesis of polygonal single-crystal aluminum borate microtubes by the direct calcination of alumina and boron nitride powders in air. The diameters of the obtained tubes vary between 1 and 15 μm; and the lengths are in the range of tens to hundreds of micrometers. The cross-sections of the microtubes are in the shapes of rectangular, hexagonal, and quasi-circle. A new solid–liquid–solid growth mechanism was proposed to account for the formation of microtubes instead of whiskers.