A Study of Hydrometallurgical Purification Boron unit for Preparing Solar-Grade Silicon with metallurgical route

湿法提纯作为冶金法路线制备太阳能级硅前处理工序，可去除大部分铁铝等碱金属及硼杂质，提高最终产品收率。其中，太阳能级多晶硅中硼杂质含量在相当程度上影响了产品价格。因此，世界各国都竞相开发低成本、低能耗的除硼工艺与技术。 实验筛选了适合湿法提纯冶金级硅的浸出剂，考察主要工艺因素：浸出剂浓度、温度、时间、搅拌等对产品纯度的影响，采用场发射扫描电子显微镜（FSEM），电感耦合等离子光谱仪（ICP）等对产品进行表征。实验表明：当采用硝酸—硫酸混合酸为浸出剂时，c（HNO3）=6.5mol/L，c（H2SO4）=6mol/L，反应温度120℃，反应时间4h为最优浸出条件。在该工艺条件下，可使液固分离后杂...As a pre-treatment unit for preparing solar-grade silicon (SG-Si), hydrometallurgical route could remove not only alkali metal like Iron and Aluminum but also most impurity “Boron” in metallurgical-grade silicon (MG-Si) and increase final product yield. Among the impurities, impurity “Boron”, to a considerable extent, affected the price of the solar grade. Therefore, all countries are competing to...学位：工学硕士院系专业：化学化工学院化学工程与生物工程系_化学工程学号：2062007115087

研究图书馆数字资源建设的转型与发展——以中国科学院文献情报系统为例

[目的/意义]旨在对研究图书馆数字资源建设转型与发展，特别是开放资源触发的第二次转型与发展进行总结，以探索研究图书馆数字资源建设的未来发展方向。[方法/过程]以中国科学院文献情报系统为例，梳理其数字资源建设实践与成效，并对今后发展做出预期&mdash;&mdash;以综合科技资源、开放资源建设为转型基础，以细粒化的知识关联与呈现为发展目标。[结果/结论]研究图书馆在数字资源建设转型时会遇到诸多问题，提出以下建议：①制定明确的数字资源建设方案；②合理投入经费、人力和技术；③明确开放资源使用权益，积极推动开放获取；④加强开放资源建设的馆际合作与共享；⑤加强知识资源组织的跨界合作。</p

不同脂肪源对异育银鲫的生长、体组成和肌肉脂肪酸的影响

配制了十种等氮等能的饲料饲喂3.53 g的异育银鲫幼鱼12周,探讨异育银鲫对不同脂肪源的利用效果。十种饲料中分别添加8%的鱼油(FO)、椰子油(CNO)、玉米油(CO)、亚麻油(LO)、大豆油(SO)、菜籽油(RO)、1∶1鱼油-椰子油(FCNO)、1∶1鱼油-玉米油(FCO)、1∶1鱼油-亚麻油(FLO)和1∶1∶1∶1鱼油-椰子油-玉米油-亚麻油混合油(MIX)。每组饲料三个平行,每个平行30尾。实验在循环水养殖系统中进行,水温控制在(24±1)℃。结果表明,在单一脂肪源中,豆油组和椰子油组的增重率最高,其次是菜籽油组,鱼油、玉米油和亚麻油组的增重率最低。与相应的单一脂肪源相比,饲料中鱼油与椰子油、玉米油或亚麻油1∶1混合后使用提高了异育银鲫的生长。摄食不同脂肪源饲料的异育银鲫血清生化指标、各组织的水分和脂肪含量差异不明显(P>0.05)。肌肉脂肪酸与饲料脂肪源呈明显正相关。摄食豆油和菜籽油饲料的鱼体肌肉中20:4n-6较高,而摄食亚麻油饲料的鱼则含有较高的20:5n-3和22:6n-3,表明异育银鲫具有转化18:2n-6和18:3n-3为高不饱和脂肪酸的能力。从实验可以看出,豆油、椰子油和菜籽油是异育银鲫饲料中良好的脂肪源

Study on the Characteristics of Loss Ratio and Loading-unloading Response Ratio before Rock Failure

以多种岩石循环加卸载声发射试验为基础,针对岩石损耗比和加卸载响应比特性进行了研究,探索岩石在受载过程中的内部损伤演化和破坏前兆特性。结果表明,在; 循环加卸载下角岩等三种岩石损耗比变化特性一致:低应力水平阶段损耗比较大,呈明显下降趋势;中等应力水平阶段比值下降趋势较平缓;高等应力水平阶段比值; 趋于稳定,在0.08 ~; 0.10时,试样破坏。而钨钼矿等三种岩石加卸载响应比变化特性一致:低应力水平阶段卸载时几乎没有声发射,加卸载响应比较大;中等应力水平阶段卸载时声; 发射较活跃,比值下降至1左右;高等应力水平阶段卸载时声发射很活跃,当比值重新大于1时,试样破坏。试验结果都体现了岩石内部损伤从很小到稳定扩展再到; 不稳定扩展的过程。可见,损耗比和加卸载响应比的变化特性均可用于评价岩石损伤情况,也可用作岩石破坏预测的参考依据。On the basis of the acoustic emission for rock under cyclic loading and; unloading,the characteristics for the loss ratio and loading-unloading; response ratio of rocks is studied,and the evolution of the internal; damage in the course of loading and the precursor characteristics of; failure are explored. The results show that the variation; characteristics of loss ratio of three kinds of rocks like hrnfelswere; are consistent under loading and unloading conditions; The loss ratio is; relatively large in the low stress level stage,and it shows a clear; downward trend. After entering the medium stress level,the ratio; decreases with a relatively flat trend. In higher stress level,the ratio; tends to be stable,and the specimen fails at 0.08~ 0.10. At the same; time,the variation characteristics of loading-unloading response ratio; of three kinds of rocks like tungsten and molybdenum ores are; consistent. There were almost no acoustic emission at the unloading; stage in the low stress level stage,and the loading-unloading response; ratio were relatively large. Acoustic emission was more active at the; unloading stage in the medium stress level,and the ratio dropped to; about 1. In higher stress level,acoustic emission was very active at; unloading stage,and the specimen failed when the ratio increased over 1; again. The results reflect the process of rock internal damage from; small to steady expansion and then to unstable expansion. So the; variation characteristics of loss ratio and loading-unloading response; ration can be used to evaluate the damage of rock,and also can be used; as a reference for prediction of rock failure.国家十二五科技支撑计划项

Improvement of n-butanol recycling technique in industrialized production of silicon dioxide as flatting agent

针对福建某工厂现有工艺生产二氧化硅消光剂过程,采用间歇蒸馏方式回收正丁醇存在时间长、效率低等问题,提出使用双塔精馏工艺进行改进以缩短正丁醇回收时间和提高回收效率。对改进后的工艺使用流程模拟软件进行模拟计算,获得了新的工艺条件参数。改进后,冷凝分层温度为85℃,精馏塔一塔釜液中正丁醇质量分数为99.62%,精馏塔二塔釜中正丁醇质量分数为0.31%。在此基础上搭建了实验室规模精馏装置并进行了验证试验,试验结果与模拟计算值接近,相对平均偏差为5.4%,表明模拟计算的结果可信。模拟计算结果为工业装置的优化提供了依据。改进后,正丁醇回收率将大幅提高,生产周期由原来的10 H缩短为5 H,能耗显著降低。采用此工艺生产二氧化硅消光剂可大幅降低过程成本。In order to reduce time cost and increase efficiency in n-butanol recycling,a double-column distillation process was suggested to replace the existing batch process due to its high time consumption and low efficiency.The improved process was simulated with flow simulation software.The calculated results show that in the improved process,condensing temperature is 85 ℃,the mass fraction of n-butanol at the bottom of Column 1 and Column 2 is 99.62% and 0.31% respectively.The verification tests on lab-scale distillation device were carried out.It shows that the calculated results are close to the tested results,and the average relative deviation is 5.4%,which indicates the calculated results are credible,and can provide a basis for optimization in industrialized plants.Now,n-butanol recycling efficiency increases largely and production cycle is reduced from 10 h to 5 h and energy consumption drops remarkably,so production cost can be largely reduced

饲喂不同浓度黄曲霉毒素B_1饲料对异育银鲫成鱼的生长和毒素积累的影响

以含不同浓度黄曲霉毒素B1(AFB1)的配合饲料饲喂异育银鲫(Carassius auratus gibelio)成鱼56d,研究异育银鲫成鱼[(122.3±0.7)g]生长、生理反应、肝脏组织学变化、卵巢发育以及鱼体各组织中的AFB1的毒素积累状况。实验分为5个实验组,不同实验组饲料中AFB1含量分别为0、5、20、50、500μg/kg饲料(实测值分别为2.59、4.12、12.39、46.23、454.07μg/kg饲料),每个处理3个平行。在整个实验过程中各实验组均未表现出外部形态和行为异常,各组存活率均达到100%。各实验组异育银鲫成鱼终末体重、摄食率(FR)、特定生长率(SGR)和饲料效率(FE)均无显著差异。饲料AFB1水平对异育银鲫血清总胆固醇(TC)含量、血清谷丙转氨酶(GPT)、谷草转氨酶(GOT)和碱性磷酸酶(AKP)活性均无显著影响。各毒素组血清超氧化物岐化酶(SOD)活性与对照无显著差异。各毒素组肝脏和卵巢均未见明显的组织学病理变化。肌肉和性腺中的AFB1积累量低于FDA食品安全限定标准(5μg/kg)。肝胰脏中的AFB1积累和饲料中的AFB1水平呈对数关系。饲喂AFB1≥50μg/kg饲料使异育银鲫成鱼肝脏AFB1积累超过安全限量标准。结果表明,异育银鲫成鱼至少可耐受AFB1含量达500μg/kg饲料(实测值:454.07μg/kg饲料)56d

Study on removal boron from solargrade silicon with hydrometallurgy

湿法提纯作为冶金法制备太阳能级硅的前处理工序,可以去除大部分金属和硼杂质。研究了以氢氟酸-硫酸混合酸为浸出剂,有机溶剂甲醇作为后处理剂,去除硅粉中硼杂质的方法。采用电感耦合等离子体发射光谱仪(ICP)等对产品进行表征。酸浸过程优化工艺条件:硫酸质量分数为55%,氢氟酸质量分数为7%,酸浸温度为70℃、酸浸时间为4 H、液固质量比为8∶1。酸浸后可使硅粉中的硼杂质质量分数由6.893x10-6降至3.867x10-6,去除率为41.9%。在酸浸基础上采用有机溶剂甲醇作为后处理剂,杂质硼质量分数降至3.84x10-6,去除率为44.29%。从硼酸浸后形成的产物入手探索提高硼去除率的方法,实验验证了该方法的可行性,为研究湿法冶金预处理太阳能级硅提供了新的参考。As a pretreatment unit for preparing solargrade silicon(SG-Si) by metallurgic method,wet purification could remove most metallic impurities and nonmetallic impurities,such as boron.Experiment researched a new method to remove boron from SG-Si with mixed hydrofluoric acid-sulfuric acid as leaching agent and with organic solvent methanol as posttreatment agent.Samples were characterized by ICP and other analysis methods.When SG-Si powder had been leached at optimized conditions as follows:mass fraction of sulfuric acid was 55%,mass fraction of hydrofluoric acid was 7%,reaction temperature was 70 ℃,reaction time was 4 h,and liquid-solid mass ratio 8∶1,it was found that mass fraction of impurity boron in SG-Si was reduced to 3.867×10-6 from 6.893×10-6 and the removal rate was 41.9% after acid leaching;on the basis of the former procedure,mass fraction of impurity boron was reduced to 3.84×10-6 and the removal rate was 44.29% when treated with organic solvent.Experiment proved the feasibility of the method and provided a new reference for researching on the pretreatment of SG-Si by hydrometallurgy

催化裂解法制备碳纳米管中试反应器优化研究

对催化裂解法(CVD)间歇制备多壁碳纳米管(CNTs)的中试流化床反应器的结构进行优化研究,以期简化结构、改变出料方式、实现半连续化操作。实验结果表明:床层内置加热器开启,CNTs产量下降15%,床层阻力增加67%;预热层高度为零,反应4h,产率最高为9.2g/g;催化剂量为100g,最佳匣钵高度是35cm;将间歇操作调整为半连续操作,生产周期将从24.0h降为8.5h

在线客户粘性研究综述

随着信息技术的发展,在线购物与服务已经成为社会主要的商业行为,而在线客户粘性是网络经济成功的重要因素,本文主要回顾了以往对在线客户粘性的研究文献,对其定义、测量方法、形成机制、影响因素进行了分析,并在总结文献的基础上展望未来的研究方向

用于水污染生物检测的恒流稀释装置

本文提出一种用于水污染生物检测的恒流稀释装置,介绍装置的运转原理、结构及其评价。本装置的浓度变异系数在3.05&mdash;11.76%之间,与国外同类产品接近,由于结构简单,运转可靠,不需电力,本装置可广泛用于水生生物毒性试验,特别适于长期的亚致死和慢性毒性试验