Chromaticity-tunable remote LuYAG: Ce phosphor-in-glass film on regular textured glass substrate for white light emitting diodes

All inorganic remote phosphor-in-glass film exhibits excellent properties in high power white light-emitting-diodes (WLEDs) thanks to their easy fabrication and thermal stability. Herein, fabrication of (Lu, Y)₃Al₅O₁₂: Ce³⁺ (LuYAG: Ce)phosphors embedded in borosilicate glass film by the conventional solid state reaction and spin coating technology has been reported. The introduction of Y³⁺ ions reduces the difference of relative growth rate along some directions in growth of LuYAG microparticles, yielding a finer grain with smooth edges. By adjusting the molar concentration of Y³⁺ ions in LuAG phosphor, a series of tunable broadband emission from green to yellow region is observed and maintains excellent thermal stability. Meanwhile, the decay curves of samples with different Y³⁺ are almost same. SEM images show that phosphor particles are homogenously distributed within the glass matrix and keep their original morphology, suggesting the phosphor-in-glass films were synthesized as expected. Finally, a simple WLEDs based on the films was constructed using the commercial blue chip. The correlated color temperature ranging from 4853K to 4627K and high color rendering index from 81.4–79.7 were obtained. Upon the different driving current, the chromaticity coordinates of as-fabricated film exhibit good light color stability. These results bring an inspiring insight to tune the luminescent performance for remote WLEDs.     

粉煤灰-酒糟混合基质的植物生长试验研究

利用粉煤灰和酒糟的理化特性,将二者按照一定比例配成混合基质,通过白花三叶草的盆栽试验,分析种植前后混合基质的理化特性及三叶草的生长情况,并检测基质和植株中的重金属含量.结果表明:当粉煤灰与酒糟的质量比为4:1时,基质最适合三叶草的生长,而且基质和植株体内的重金属含量均未超出国家标准.因此,可以将该基质作为矿区塌陷地的复垦基质.     

多层喷射沉积板坯设备的优化设计

将原始多层喷射沉积板坯设备改为由计算机控制，步进电机驱动，钢丝卷筒结构传动，介绍了该设备的设计思路，实际生产应用表明，优化后的设备操作简单平稳，工作环境良好，制备出的板坯形貌平整，厚薄均匀。     

A/O复合式生物膜工艺缺氧段的动力学模型

对A/O复合式生物膜工艺的缺氧段进行了深入研究,并以物料平衡理论为基础,结合莫诺方程和Fick定律,建立了相应的底物降解和微生物增殖的动力学模型.算例结果表明,理论值与试验所得数据有相似的变化趋势,但两者间存在一定的偏差,而且随着进水有机物浓度的增加,其偏差逐渐加大,不过最大偏差率仅为13%,说明模型与实际情况符合较好,比较准确地预测了缺氧段的运行效果,这为该工艺的设计、运行和控制提供了较好的理论基础.     

Effects of substrate concentrations on the growth of heterotrophic bacteria and algae in secondary facultative ponds

This paper presents the effect of substrate concentration on the growth of a mixed culture of algae and heterotrophic bacteria in secondary facultative ponds (SFPs) utilizing settled domestic sewage as a sole source of organic carbon. The growth of the mixed culture was studied at the concentrations ranging between 200 and 800 mg COD/l in a series of batch chemostat reactors. From the laboratory data, the specific growth rate (micro) was determined using the modified Gompertz model. The maximum specific growth rate ( micro(max)) and half saturation coefficients (K(s)) were calculated using the Monod kinetic equation. The maximum observed growth rate ( micro(max)) for heterotrophic bacteria was 3.8 day(-1) with K(s) of 200 mg COD/l. The micro(max) for algal biomass based on suspended volatile solids was 2.7 day(-1) with K(s) of 110 mg COD/l. The micro(max) of algae based on the chlorophyll-a was 3.5 day(-1) at K(s) of 50mg COD/l. The observed specific substrate removal by heterotrophic bacteria varied between the concentrations of substrate used and the average value was 0.82 (mg COD/mg biomass). The specific substrate utilization rate in the bioreactors was direct proportional to the specific growth rate. Hence, the determined Monod kinetic parameters are useful for the definition of the operation of SFPs.     

潮湿基面处理剂的研制及应用

介绍了潮湿基面处理剂的组成、配方、性能及应用。     

Operating characteristics of the aerated submerged fixed-film (ASFF) bioreactor

A multi-stage fixed-film reactor was developed in which a stationary submerged biofilm is attached to ceramic tiles under diffused aeration. Tracer studies revealed that the reactor's hydraulic regime is described by a CSTR-in-series model. Reactor performance at 20 °C was examined using sucrose wastewaters with organic strength up to 900 mg l⁻¹ COD, at hydraulic loadings up to 0.1 m³ m⁻²d⁻¹ and organic loadings up to 90 g CODm⁻² d⁻¹. The reactor demonstrated the capability of achieving 97% soluble COD removals at low loadings and exhibited efficient and stable performance at high hydraulic and organic loadings. Even at application rates near the rate-limiting mass loadings, there was only a 9% loss in efficiency. Reactor operation at high loadings appears to be advantageous since organic substrate removal rates and attached biomass per unit surface area increased with the increase in organic loading. This can be attributed to the good oxygen transfer and the considerable quantity and type of attached biomass attained. Staging of the reactor proved to be effective in eliminating short circuiting and damping excessive loadings, although the majority of COD removal occurs in the first stage which retains the greatest quantity of attached biomass. A good quality effluent was produced.     

Chemical characterisation of natural organic substrates for biological mitigation of acid mine drainage

The current approach of the biological treatment of acid mine drainage by means of a passive remediation system involves the choice of an appropriate organic substrate as electron donor for sulphate reducers. Nowadays this selection is one of the critical steps in the performance of such treatment, as this depends to a great extent on the degradability of the organic substrate. Thus, a prior characterisation of the organic substrate predicting its biodegradability would be desirable before embarking on an extensive large-scale application. The aim of this study was to correlate the chemical composition (lignin content) of four different natural organic substrates (compost, sheep and poultry manures, oak leaf) and their capacity to sustain bacterial activity in an attempt to predict biodegradation from chemical characterisation. The results showed that the lower the content of lignin in the organic substrate, the higher its biodegradability and capacity for developing bacterial activity. Of the four organic materials, sheep and poultry manures and oak leaf evolved reducing conditions and sustained active sulphidogenesis, which coupled with the decrease in sulphate concentration indicated bacterial activity. Sheep manure was clearly the most successful organic material as electron donor (sulphate removal >99%), followed by poultry manure and oak leaf (sulphate removal of 80%). Compost appeared to be too poor in carbon to promote sulphate-reducing bacteria activity by itself. Column experiments emphasised the importance of considering the residence time as a key factor in the performance of continuous systems. With a residence time of 0.73 days, sheep manure did not promote sulphidogenesis. However, extending residence time to 2.4 and 9.0 days resulted in an increase in the sulphate removal to 18% and 27%, respectively.     

键合法制备硅基1.55μm InP-InGaAsP量子阱激光器

在硅基上成功地制备出了1.55μm InP-InGaAsP量子阱激光器.设计并生长了适合于键合的量子阱激光器结构材料,通过直接键合技术,将Si衬底与InP-InGaAsP外延片键合到一起.剥离去掉InP衬底后,在5～6μm的薄膜上制备出20μm条形边发射激光器.室温下,阈值电流160mA(电流密度为2.7kA/cm2),功率可达10mW以上(在约350mA电流下),实现了1.55μm长波长边发射激光器与Si的集成.目前,该结果国际上还未见报道.     

4 500 V沟槽栅IGBT芯片的设计与研制

为提升IGBT单芯片的电流密度,掌握高压沟槽栅IGBT技术,进行4500 V沟槽栅IGBT芯片的研制。使用TCAD仿真软件,对4500 V沟槽栅IGBT的衬底材料、载流子储存层设计、沟槽宽度、沟槽深度、假栅结构等方面进行研究和仿真分析,明确各方面设计与芯片性能的关系。根据总体设计目标,确定相应的芯片结构和工艺参数,并对4500 V沟槽栅IGBT芯片进行流片验证。验证结果显示：4500 V沟槽栅IGBT芯片的测试结果符合设计预期,芯片的额定电流、导通压降、开通损耗和关断损耗等关键参数相比平面栅IGBT芯片有明显优化。