Degradation Behavior of 850 nm AlGaAs/GaAs Oxide VCSELs Suffered from Electrostatic Discharge

The effect of forward and reverse electrostatic discharge (ESD) on the electro‐optical characteristics of oxide vertical‐cavity surface‐emitting lasers is investigated using a human body model for the purpose of understanding degradation behavior. Forward ESD‐induced degradation is complicated, showing three degradation phases depending on ESD voltage, while reverse ESD‐induced degradation is relatively simple, exhibiting two phases of degradation divided by a sudden distinctive change in electro‐optical characteristics. We demonstrate that the increase in the threshold current is mainly due to the increase in leakage current, nonradiative recombination current, and optical loss. The decrease in the slope efficiency is mainly due to the increase in optical loss.     

三则技改及其效果

<正>1窑尾锅炉回灰系统的工艺改进1.1原系统组成及存在问题某公司5000t/d新型干法熟料水泥生产线窑尾锅炉回灰系统由闸阀、下料器、膨胀节及螺旋输送机1(规格型号GLS500×7650)和螺旋输送机2(规格型号GLS500×9500)组成(见图1),锅炉收集的窑灰经此系统输送到增湿塔送灰用的链式输送机(规格型号FU350×21500)后,最终被输送到均化库再利用。图1中,螺旋输送机1,2两端是滚动轴承,中间     

A Novel Function of TET2 in CNS: Sustaining Neuronal Survival

DNA dioxygenases Ten-Eleven Translocation (TET) proteins can catalyze the conversion of 5-methylcytosine (5mC) of DNA to 5-hydroxymethylcytosine (5hmC), and thereby alter the epigenetic state of DNA. The TET family includes TET1, TET2 and TET3 members in mammals. Recently, accumulative research uncovered that TET1–3 occur abundantly in the central nervous system (CNS), and their biological functions have just begun to be investigated. In the present study, we demonstrated that mRNA and protein of TET2 were highly expressed in the cerebral cortex and hippocampus along the whole brain-development process. Further studies showed that TET2 was expressed in various types of cells, especially in most neurons. Subcellular distribution pattern implicated that TET2 is localized in both nucleus and cytoplasm of neurons. Down-regulation of TET2 in cultured cortical neurons with RNA interference implied that TET2 was required for cell survival. In all, our results indicate that neuronal TET2 is positively involved in the regulation of cell survival.     

Surface functionalization of SBA-15 particles for ibuprofen delivery

We have synthesized SBA-15 particles and functionalized their surface with different functional groups (amine, diamine, and sulfonic acid groups) to use them as carrier materials in drug delivery. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption, and zeta potential measurements were used to characterize the synthesized particles. After surface functionalization, the surface of the sulfonic acid-functionalized particles was more acidic than that of the other particles. Using ibuprofen as a model drug, we found that the release rate increased at higher pH. Furthermore, the particles with the sulfonic acid groups exhibited higher release rate than those with the amine and diamine groups. We explained the difference in the release rate using different electrostatic interaction between drug and particle surface that was caused by the surface functionalization. These results should enable design of drug carrier materials based on the SBA-15 particles with the desired release rate.     

Characteristics of Y3Al5O12:Ce phosphor powders prepared by spray pyrolysis from ethylenediaminetetraacetic acid solution

Nanometer and submicron-sized YAG:Ce phosphor powders were prepared by spray pyrolysis from the spray solutions with ethylenediaminetetraacetic acid (EDTA). The precursor powders with hollow and thin wall structure turned to the fine-sized YAG:Ce phosphor powders after post-treatment at high temperatures of 1400 and 1500 °C. The mean size of the phosphor powders post-treated at a temperature of 1500 °C was 0.72 μm. The white LEDs formed from the YAG:Ce phosphor powders post-treated at 1400 and 1500 °C showed (0.2781, 0.2871) and (0.2731, 0.2795) on the CIE chromaticity diagram, and about 78.20 and 79.04 of Ra. The luminous efficiency of the white LED formed from the commercial YAG:Ce phosphor powders was 84.36 lm/W. However, the luminous efficiencies of the white LEDs formed from the YAG:Ce phosphor powders post-treated at 1400 and 1500 °C were 47.74 and 76.64 lm/W.     

Cholesterol Removal from Squid Liver Oil by Crosslinked β-Cyclodextrin

The present study was designed to optimize the different conditions for β-cyclodextrin (β-CD) crosslinked by adipic acid on cholesterol removal from squid liver oil. Different factors were concentrations of crosslinked β-CD, mixing temperature, ratio of squid liver oil to distilled water, mixing time and mixing speed. It was found that cholesterol removal from squid liver oil was significantly affected by concentrations of crosslinked β-CD, mixing temperature, ratio of squid liver oil to distilled water, mixing time and mixing speed. In a recycling study, cholesterol removal from the squid liver oil with recycled crosslinked β-CD in the first recycling trial was 81.05%, which was slightly lower than that with new crosslinked β-CD (87.06%). In up to three time trials, over 70% of cholesterol removal was observed. The present study indicated that the optimum conditions for cholesterol removal from squid liver oil using crosslinked β-CD were a 1:3 ratio of squid liver oil to distilled water, 25% (crosslinked β-CD/distilled water, w/v) crosslinked β-CD concentration, 20 min mixing time, 800 rpm mixing speed and 55 °C mixing temperature with about 87% cholesterol removal.     

复合陶瓷料浆分散剂在电瓷干法生产中的应用

分析了瓷绝缘子的等静压干法生产中回料循环使用后,分散剂引入的氧化钠的增长趋势;试验了复合分散剂对泥浆性能的影响,考虑了生产成本等因素,确定了复合分散剂的组成并应用于生产,解决了产品拉伸、针孔、开裂、掉头等缺陷,大幅度提高了产品合格率并稳定在较高的水平,探讨了复合分散剂对坯料性能的影响。     

农村公路排水设施的重要性

在分析现今农村公路破坏形式的基础上,指出了缺乏必要的排水设施是造成路面损坏的重要原因,探讨了排水设施被忽视的原因及因其出现的混凝土板断裂的严重路损情况,从而应加强排水设施的建设,以期减少公路破坏,提高公路质量。     

Dehydration of methanol over Nordstrandite based catalysts for dimethyl ether synthesis

This study focused on the investigation of Nordstrandite as a catalyst for dehydration of methanol to dimethyl ether synthesis. The structure phase of Nordstrandite has been changed to boehmite and γ-Al₂O₃ in sequence via calcinations at various temperatures. Moreover, the properties of the samples have been varied significantly with heat treatment. The number of acid sites of Nordstrandite was much higher than the other aluminas. However, the catalytic activity of Nordstrandite was comparable to the other catalysts with fewer amounts of acid sites. This means that structure phase is one of the most important factors for catalytic performance in this reaction.