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

数字微流控技术及其在生物分析中的应用

数字微流控技术是一种基于微电极阵列来实现离散液滴精确控制的新型液滴操纵技术。这种基于介电润湿现象实现的液滴电操纵体系,相比于传统微流控芯片具有自动化、可寻址、可动态配置、易集成等特点。该文介绍了数字微流控技术液滴驱动原理,总结了芯片的结构和常用的制作方法,举例阐述了现阶段该技术在生物分析化学领域的应用,并对其应用前景做了展望。国家自然科学基金资助项目(21735004,21435004,21775128,21705024,21521004);;长江学者和创新研究团队项目(IRT13036

人死亡受体5全长基因的构建及转染胶质瘤细胞

目的构建人死亡受体5(death receptor5,DR5)全长基因真核细胞表达载体pcDNA3.1/DR5,pcDNA3.1/GFP/DR5,并观察其转染胶质瘤细胞U138的效果。方法通过重叠PCR获得DR5全长编码序列,构建pcDNA3.1/GFP/DR5,pcDNA3.1/DR5表达载体,利用脂质体转染试剂盒,分别将2种质粒pcDNA3.1/GFP/DR5、pcDNA3.1/GFP共转染胶质瘤细胞U138,转染后72h,半定量逆转录聚合酶链反应(RT-PCR)检测DR5mRNA的表达,流式细胞术检测DR5的表达强度、检测Anti-DR5对胶质瘤细胞U138生长的影响。结果获得了DR5全长编码序列,成功瞬时转染U138,RT-PCR、流式细胞术检测结果表明,转染后U138细胞DR5mRNA、蛋白水平的表达明显增加,Anti-DR5可以明显抑制U138细胞的生长。结论获得了DR5全长编码序列,探索到成功转染DR5的最佳方法,为稳定筛选高表达DR5的U138细胞提供依据

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

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

CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties

本课题充分发挥了厦门大学多学科协同研究优势，通讯作者为夏海平教授（合成、表征）、刘刚教授（生物医学应用）和吕鑫教授（理论计算）。合成实验和结构表征由朱从青（第一作者，目前在麻省理工学院、2005年诺贝尔化学奖得主Richard Schrock教授课题组从事博士后研究）完成；生物医学应用由杨彩霞（共同第一作者）、林凎、杨宇惠、王晓勇合作完成；理论计算由朱军、王永恒、朱从青完成。美国NIH的陈小元教授参与了生物医学应用的讨论。该研究工作得到国家自然科学基金委、科技部项目的支持。The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry.the National Basic Research Program of China (nos. 2012CB821600 and 2014CB744503) , the National Science Foundation of China (nos. 21332002, 81422023, 51273165, 21490573, and 21573179)

一种LTE系统内统计切换失败率的实现方案

为了更加准确地反映LTE（长期演进）网络的切换失败率,文章根据LTE控制面信令流程提出了一种统计LTE系统内切换失败率的实现方案。该方案是基于源基站侧的统计,根据LTE系统内切换的类型和切换失败的原因设计切换失败统计流程。该方案可以准确地统计源基站的切换失败次数和切换失败率,并最终将结果显示在OMC（运行维护中心）界面上,从而使网络运营商可以及时了解TD-LTE（分时长期演进）系统内的切换性能

一种LTE系统中的基站内切换实现方案

为了实现LTE（长期演进）系统中的基站内切换,文章从控制面和用户面信令流程的角度出发,提出了一种LTE系统中的基站内切换设计方案。通过基站内各模块的协同工作,可有效实现包含数据转发的基站内切换流程,确保切换过程中不丢包,实现平滑切换。将该方案应用于实际的测试中,进行了基站内切换的组网测试,并给出了实际的切换测试结果

基于载波聚合的PUSCH分配研究

3GPP（第三代合作伙伴计划）在LTE-A（高级长期演进）系统中引入了载波聚合技术,这就允许UE（用户设备）能够同时调用不同的带宽。同时,PUSCH（物理上行共享信道）分配不再限定为只能传输一块连续的频谱资源,所以载波聚合下的PUSCH分配成为一个新的研究课题。而现有方案只是以前技术的复用,不能达到资源的最大化利用。文章在现有方案的基础上提出一种在载波聚合场景下最大化PUSCH资源利用的方案,系统级仿真验证表明,改进后的方案能够实现PUSCH资源利用最大化

一种基于多点协作的上行资源调度方式

介绍了基于多点协作的上行资源调度方式。从边缘用户与中心用户判定、无线资源分配模式选择、天线设置与接收数据处理和系统仿真结果四个方面进行了论述。重点分析了中心用户与边缘用户区分标准的设定和资源分配、频选模式的频选度量值设定以及多点协作方式的联合接收数据处理等问题。仿真结果表明,通过合理设置和调整系统的控制参数,多点协作可以有效地降低系统误码率、提升系统吞吐量