Spectrum-Splitting Diffractive Optical Element of High Concentration Factor and High Optical Efficiency for Three-Junction Photovoltaics

A spectrum-splitting and beam-concentrating （SSBC） diffractive optical element （DOE） for three-junction pho- tovoltaics （PV） system is designed and fabricated by five-circ/e micro-fabrication. The incident solar light is efficiently split into three sub-spectrum ranges and strongly concentrated on the focal plane, which can be di- rectly utilized by suitable spectrum-matching solar cells. The system concentration factor reaches 12x. Moreover, the designed wavelengths （450nm, 550nm and 65Onto） are spatially distributed on the focal plane, in good agree- ment with the theoretical results. The average optical effic/ency of all the cells over the three designed wavelengths is 60.07%. The SSBC DOE with a high concentration factor and a high optical efficiency provides a cost-effective approach to achieve higher PV conversion efficieneies.

Application of High-pressure Flat Membranes in Coal Chemical Wastewater Treatment

In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the conditions of different concentrations of influent TDS,COD and silicon dioxide.The results showed that when the concentration of influent TDS was 35 000-55 000 mg/L,the economic benefit of high-pressure flat membrane operation was the best,and the concentration ratio of high-pressure flat membranes was stable,varying from 3.3 to 3.6.As the concentration of influent organic matter ranged from 100 to 1 800 mg/L,the removal rate of organic matter ranged from 60% to 79%.In addition,the retention rate of high-pressure flat membranes to silicon dioxide was more than 90%.

Analysis and Comparison of Doping Level Effects on a Crystalline Silicon PV Cell under Both Moderate Light Concentration and Normal Illumination Modes

The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the both illumination modes. The results show for both illumination modes that diffusion parameters decrease with increasing doping level. These results are in agreement with the studies of the current and the voltage which showed for the two illumination modes that doping level increase leads to a decrease in current density and an increase in voltage. It also emerges for the two illumination modes and for the doping range 1013 cm-3 - 1016 cm-3, a decrease of maximum power and conversion efficiency. The results also show that decrease of diffusion parameters is faster under moderate concentration in comparison with normal illumination. These results predict a greater variation rate of the current, the voltage, the maximum power and the conversion efficiency under moderate concentration compared to normal illumination. Contrary to diffusion parameters study, the results show higher variation rates of parameters under normal illumination. This is explained by the fact that under moderate concentration, carriers density is close to doping level: the cell is then in high injection condition. Consequently, under moderate concentration, carriers density is less sensitive to doping level variations. The study confirms that carriers density variation with the doping level is weak under the moderate concentration compared to normal illumination.

Assessment of High Concentrated Photovoltaic/Thermal Collector in Hot Climate

This work investigates the performance of combined hybrid high concentrated photovoltaic/thermal collector (HCPV/T) in Kuwait harsh climate. The proposed system consists of triple junction solar cells (InGaP/InGaAs/Ge) attached to heat source to discharge thermal energy to cooling media. Published HCPV/T models do not consider the effect of shunt resistance which greatly affects the system performance. So, a single diode model employing five parameters including the effect of shunt resistance is adapted to analyze the proposed system. To analyze the thermal performance of the proposed system, a two-dimensional thermal model based on the technique of finite difference is introduced to determine the efficiency of the hybrid HCPV/T system. The present developed subroutines are integrated with other involved codes in TRNSYS software to calculate HCPV/T system efficiency. Electrical and thermal as well as the whole system efficiency at different weather circumstances are evaluated and assessed. The effect of different weather conditions, cell temperature, concentration ratio and the temperatures of the coolant fluid on system performance are studied. Current results indicate that the model of single diode is a reliable one rather than using the two-diode complex model. Compared to measurements provided by high concentrated PV manufacturer, the current results revealed a total root mean square error of approximately 1.94%. Present predictions show that PV cell temperature has logarithmic increase with the rise in concentration ratio but with low values till concentration ratio of 400 suns after that the rise is faster at higher concentration values up to 1500 suns. Results also revealed that hybrid HCPV/T system works effectively specially in severe hot climate where thermal efficiency increases with high surrounding temperature for higher values of concentration ratio. In addition, an increase of approximately 15% in thermal efficiency and 10% in total efficiency can be achieved by utilizing active cooling device in HCPV/T system.

豆浆固形物含量及浆液深度对腐竹生产及品质的影响

目的:确定腐竹高效优质生产适宜的豆浆固形物含量和浆液深度。方法:探究豆浆固形物含量和浆液深度对腐竹得率、成膜速率、营养成分、机械性能、蒸煮损失率和复水比等的影响。结果:当豆浆固形物含量为6%,豆浆浆液深度为6 cm时,腐竹得率(34.68%)和营养物质含量最高,其蛋白质含量为51.05%,脂肪含量为23.42%,且抗拉强度和复水性较好,分别为3.74 MPa和3.80 g/g。结论:综合考虑腐竹得率、成膜速率和食用品质等指标,建议采用豆浆固形物含量6%,豆浆浆液深度6 cm进行腐竹的高效优质生产。

低品位铋多金属精矿加压碱浸分离钼、钨、硫和铋

针对传统铋精矿冶炼原料适应性差、不适于低品位铋精矿、有价金属综合回收率低、火法冶炼产生低浓度SO_(2)治理难、成本高等问题,以柿竹园低品位铋多金属精矿为原料,提出加压氧化碱浸分离钼、钨、硫和铋的新工艺,研究了碱用量、时间、温度、总压及液固比等因素对钼、钨、硫、铋浸出率的影响。在优化工艺条件下,钼、钨、硫的浸出率分别达99.73%、90.81%和97.69%,铋不浸出在渣中富集,实现了低品位铋多金属精矿中钼、钨、硫与铋的高效分离。

基于聚光光伏电池系统热管式换热器的数值研究

针对在高倍聚光下光伏电池效率受表面温度的影响,文章对聚光光伏电池系统中耦合翅片热管散热器进行了数值模拟研究。在水冷、风冷情况下,研究了热管散热器的翅片数量、分布、流体流量对电池效率、温度表面均匀性的影响,并将研究结果与普通散热器进行比较。结果表明:水冷型热管散热器的电池表面温差较低,均匀性和电池效率较高;在流量为0.64 m/s,翅片间距为1.5 mm,翅片厚度为0.4 mm的工况下,电池的综合性能最优,表面温度为314 K,温差小于1 K,均匀性良好,电效率为31.25%,热效率为66.03%。

基于外源排查和工程改造的污水系统提质增效实践

分流制污水管网的外水侵入是造成管网高水位运行、污水浓度低的主要原因之一。针对某污水系统A、B污水厂进水水质浓度降低、污水处理总量波动较大的现象,坚持系统治水,在全面摸查管网的基础上,通过物料平衡法、水量平衡法初步判断进入系统的山水、河涌水、湖水、雨水的外水量和区域,再进行外水点实际踏勘、监测、验证,对外水进行溯源,精准定量、定位。结合4类水特点和基础条件,通过一系列工程实施有力地减少外水入侵,提高了污水厂进水水质浓度。上述研究成果为后续推进污水系统提质增效、营造健康的城市排水保障系统探索出一条实施路径。

基于TiO_(2)的近红外大数值孔径、高聚焦效率、高透射率会聚透镜

利用相位调控原理设计了一种基于TiO_(2)材料的具有非周期同心圆环形高折射率差亚波长光栅结构的会聚透镜,可实现大数值孔径、高聚焦效率、高透射率、低损耗特性,同时具有体积小、易集成的优点。采用时域有限差分法对提出的透镜结构进行仿真和分析,工作波长为850 nm时,该透镜透射率为90.5%,焦距约为10.4μm,焦斑的半高全宽为0.61μm。通过对仿真得到的数据进行分析,可得数值孔径为0.92,聚焦效率高达91.07%,损耗为0.41 dB,平衡了高数值孔径与高聚焦效率之间的矛盾,可在小器件直径下接近衍射极限实现点会聚效果。

某高硫含砷低品位金精矿选矿工艺研究

为提高某高硫含砷低品位难处理金精矿选别指标,分别采用尼尔森离心重选和高效旋流器分级工艺进行金精矿分选试验研究。试验结果表明:在保障金精矿冶炼净返系数等级的基础上,采用试验条件为重力倍数60G、反冲洗水量4 L/min、给矿速度400 g/min的尼尔森离心重选工艺,可获得金品位为30.97 g/t,金回收率为19.97%的重选精矿;采用试验条件为矿浆浓度20%、沉砂口直径22 mm的高效旋流器分级工艺,可获得金品位为26.02 g/t,金回收率为12.50%的溢流。尼尔森离心重选、高效旋流器分级工艺可使最终精矿产品的金回收率分别提高1.6%~1.9%和0.7%~1.0%。考虑到尼尔森离心重选工艺成熟工艺少、后期投资高,故推荐高效旋流器分级工艺进行该金精矿分选试验,以提高该金精矿利用价值。

矿井工业级硫酸钾制备中高浓度盐水的资源化利用

硫酸钾是全球工业领域的重要原料,但其生产过程中产生的高浓度盐水如何有效利用一直是个难题。基于此,提出了一种新的方法,利用矿井产生的高浓度盐水制备硫酸钾。在特定设备和精确参数控制下,实现了高效、环保的硫酸钾制备。实验结果表明,硫酸钾的产量和质量均得到显著提升,处理效率提高了约30%,同时,CO_(2)排放量减少了约40%。新的硫酸钾制备方法具有显著优势和广阔的应用前景,对硫酸钾生产技术的发展有积极影响,对环境保护和资源循环利用具有重要意义。

长江中下游典型污水系统提质增效案例研究

以长江中下游某城市南部污水系统为例,对污水系统外水入侵、高水位运行、进厂水质浓度低等问题进行分析,针对性的提出分片、分区、分阶段提质增效的思路,并给出降水位排查污水管网、市政管网系统整治、排水单元整治、污水管网优化运行等技术措施.先期实施的1#泵站片区通过上述措施,已挤出外水量约为12 708 m3/d,污水厂进水BOD5浓度由69.6 mg/L提升至78.3 mg/L,较整治前提升12.5%,城市污水集中收集率由61.6%提升至69.3%,基本实现了提质增效的阶段目标.

高SO_(2)浓度烟气超低排放治理技术和方法

以石墨化炉高SO_(2)浓度烟气为例,采用石灰-石膏脱硫工艺,优化设计了双塔双循环、低烟气流速、高液气比、增效托盘、高效管束式除雾器等新技术和方法,实现烟气超低排放,为其他行业高SO_(2)浓度烟气超低治理提供了可靠的参考,具有重要的借鉴意义。

新型高效活化剂在氧化金矿浮选中的试验研究

某浮选厂回采处理的高氧化低品位尾渣性质复杂,原矿金品位0.9 g/t,矿石氧化率75%~80%,泥质含量较重,浮选回收难度较大,精矿品位与回收率指标双双偏低。为了使金精矿品位及回收率得到较大地提高,实现效益增收,开展了新型高效活化剂探索试验研究工作,试验表明新型高效活化剂能高效抑制矿泥,活化金矿物,在浮选精选生产实际流程中添加适量的新型高效活化剂,金精矿品位与回收率得到了有效提升,取得了可观的经济效益。

Yb-and Er concentration dependence of the upconversion luminescence of highly doped NaYF_(4):Yb,Er/NaYF_(4):Lu core/shell nanocrystals prepared by a water-free synthesis

High sensitizer and activator concentrations have been increasingly examined to improve the performance of multi-color emissive upconversion(UC)nanocrystals(UCNC)like NaYF_(4):Yb,Er and first strategies were reported to reduce concentration quenching in highly doped UCNC.UC luminescence(UCL)is,however,controlled not only by dopant concentration,yet by an interplay of different parameters including size,crystal and shell quality,and excitation power density(P).Thus,identifying optimum dopant concentrations requires systematic studies of UCNC designed to minimize additional quenching pathways and quantitative spectroscopy.Here,we quantify the dopant concentration dependence of the UCL quantum yield(ΦUC)of solid NaYF_(4):Yb,Er/NaYF_(4):Lu upconversion core/shell nanocrystals of varying Yb3+and Er3+concentrations(Yb3+series:20%‒98%Yb3+;2%Er3+;Er3+series:60%Yb3+;2%‒40%Er3+).To circumvent other luminescence quenching processes,an elaborate synthesis yielding OH-free UCNC with recordΦUC of~9%and~25 nm core particles with a thick surface shell were used.High Yb3+concentrations barely reduceΦUC from~9%(20%Yb3+)to~7%(98%Yb3+)for an Er3+concentration of 2%,thereby allowing to strongly increase the particle absorption cross section and UCNC brightness.Although an increased Er3+concentration reducesΦUC from~7%(2%Er3+)to 1%(40%)for 60%Yb3+.Nevertheless,at very high P(>1 MW/cm^(2))used for microscopic studies,highly Er3+-doped UCNC display a high brightness because of reduced saturation.These findings underline the importance of synthesis control and will pave the road to many fundamental studies of UC materials.

适用于高浓度煤化工废水预处理的新型絮凝剂研究

针对高浓度煤化工废水絮凝沉淀预处理过程中采用传统絮凝剂处理效率不高的问题,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和改性阳离子单体(WA-1)为原料,并引入改性纳米Fe3O4,制备了一种适用于高浓度煤化工废水絮凝预处理的新型磁性复合絮凝剂AFC-Ⅱ。红外光谱和能谱分析结果表明,各种单体均参与了聚合反应。高浓度煤化工废水絮凝处理实验结果表明,当新型磁性复合絮凝剂AFC-Ⅱ加量为800 mg/L、废水pH为8、搅拌速度为120 r/min、搅拌时间为8 min、沉降时间为15 min时,高浓度煤化工废水中COD的去除率最高,可以达到96.74%。在实验条件均相同的情况下,新型磁性复合絮凝剂AFC-Ⅱ对实验用高浓度煤化工废水中COD的去除率明显高于其他几种常用的絮凝剂。研究结果证明,该新型磁性复合絮凝剂AFC-Ⅱ可以有效提高高浓度煤化工废水的絮凝处理效率,为此类废水的后续深度处理奠定良好的基础。

SL离心机从攀西选钛尾矿中分选微细钛铁矿试验

针对攀西地区选钛尾矿中微细钛铁矿难以回收利用的问题,采用SLon-100周期式脉动高梯度磁选机和SL-400离心机开展微细钛铁矿分选试验研究。结果表明,对TiO_(2)品位4.77%的选钛尾矿,采用SLon强磁一粗一扫一精选预富集、钛精矿分级,可得到TiO_(2)品位为18.36%的-0.037 mm微细钛粗精矿;该粒级钛粗精矿采用SL-400离心机一粗一扫-精选、精选尾矿和扫选精矿合并再选的工艺,可以获得作业产率42.39%、TiO_(2)品位30.77%、TiO_(2)作业回收率71.04%的钛精矿,为后续浮选精矿、生产合格钛精矿产品创造了良好的条件。该研究结果说明了SL离心机用于分选攀西地区微细钛铁矿的可行性,对提升攀西地区钛铁矿资源的开发利用提供了一种新的技术思路。

锂金属电池电解液的研究进展

锂离子电池拥有高能量密度和长循环寿命等众多优点,在可移动电子设备、电动汽车和储能等领域得到越来越广泛的应用。锂金属因其最高的能量密度,被认为是负极的终极目标,因此成为研究的前沿热点。由于锂金属负极反应活性很高,传统电解液碳酸酯和其适配性很差,因此亟待开发锂金属电池电解液。本文主要阐述锂金属电池电解液的研究进展,介绍了锂金属电解液的常用表征方法,包括库伦效率测试,负极界面表征,不同类型电池测试等。并对锂金属电池电解液主要开发方向进行了介绍,包括全氟电解液、双盐电解液、高盐电解液、局域高盐电解液等,分析了其性能优劣。随着研究的成熟,未来的研究将基于更加商业化的体系开发电解液,并多方向融合发展,开发新型有机溶剂等。相信通过持续的深入研究和创新,锂金属电池商业化将成为现实。

纯碱软化-高效反渗透在浓盐水处理中的应用

采用纯碱软化-高效反渗透组合工艺对某热电企业反渗透系统产生的高盐度浓水进行处理,产水用作循环冷却水补水。结果表明,纯碱软化法除硬效率高达90.2%,再经弱酸阳床处理后,水中硬度可被完全去除;高效反渗透系统除盐率最高达97.4%,产水率达91.3%,产水水质可满足《城市污水再生利用工业用水水质》(GB/T19923-2005)要求。项目吨水药剂费用为4.7元,其中液碱、盐酸费用占比分别为53.80%、17.28%。该工艺回收了水资源,实现了浓盐水减量化,具有良好的社会效益。

瓦斯治理抽采钻孔修复提浓及配套技术研究

针对钻孔抽采一段时间后,受抽采负压、煤层压力、巷道压力变化等因素影响,可能造成钻孔堵塞、漏气,抽采浓度降低,抽采效率变差,甚至失效的问题,以大众煤矿21上01工作面为研究对象,通过研究钻孔修复、压风疏通、钻孔疏通等技术及配套措施对抽采效果的影响,提出了抽采钻孔修复提浓方案。经研究发现,该方案能够保障抽采钻孔持续高效抽采瓦斯,提升了瓦斯治理效果。