微波消解氢化物发生-ICP-AES测定广豆根中砷锑铋锡

建立了微波消解-氢化物发生-电感耦合等离子体发射光谱联用技术测定中药广豆根中砷、锑、铋和锡的方法,对微波消解、氢化物发生条件、电感耦合等离子体原子发射光谱工作条件进行了优化,预还原剂L-半胱胺酸浓度进行了选择。在最佳工作条件下,砷、锑、铋和锡的检出限分别为0.0055μg.g-1、0.0088μg.g-1、0.0026μg.g-1和0.005 4μg.g-1;相对标准偏差分别为5.6%、2.0%、2.9%和2.6%(n=11);加标回收率分别为100%、90%、90%和110%。     

等离子体处理对聚四氟乙烯微孔薄膜界面粘结性能的影响

以XPS、动态接触角分析仪和扫描电镜等为手段,研究了不同条件下低温等离子体对聚四氟乙烯微孔薄膜界面粘结性能的影响。结果表明：等离子体处理功率对薄膜界面粘结性能的影响．因等离子体种类的不同而有明显的差别。等离子体处理时间对薄膜界面粘结性能的影响,因等离子体种类和处理功率的不同而有一定的差别。不同的等离子体,对薄膜界面粘结性能的改善效果,因等离子体处理功率的不同而有较明显的不同。     

Improved protocol for plasma microRNA extraction and comparison of commercial kits

IntroductionMicroRNAs are small, non-coding RNA molecules that are becoming popular biomarkers in several diseases. However, their low abundance in serum/plasma poses a challenge in exploiting their potential in clinics. Several commercial kits are available for rapid isolation of microRNA from plasma. However, reports guiding the selection of appropriate kits to study downstream assays are scarce. Hence, we compared four commercial kits to evaluate microRNA-extraction from plasma and provided a modified protocol that further improved the superior kit’s performance.Materials and methodsWe compared four kits (miRNeasy Serum/Plasma, miRNeasy Mini Kit from Qiagen; RNA-isolation, and Absolutely-RNA MicroRNA Kit from Agilent technologies) for quality and quantity of microRNA isolated, extraction efficiency, and cost-effectiveness. Bioanalyzer-based Agilent Small RNA kit was used to evaluate quality and quantity of microRNA. Extraction efficiency was evaluated by detection of four endogenous control microRNA using real-time-PCR. Further, we modified the manufacturer’s protocol for miRNeasy Serum/Plasma kit to improve yield.ResultsmiRNeasy Serum/Plasma kit outperformed the other three kits in microRNA-quality (P < 0.005) and yielded maximum microRNA-quantity. Recovery of endogenous control microRNA i.e. hsa-miR-24-3p, hsa-miR-191-5p, hsa-miR-423-5p and hsa-miR-484 was higher as well. Modification with the inclusion of a double elution step enhanced yield of microRNA extracted with miRNeasy Serum/Plasma kit significantly (P < 0.001).ConclusionWe demonstrated that miRNeasy Serum/Plasma kit outperforms other kits and can be reliably used with a limited plasma quantity. We have provided a modified microRNA-extraction protocol with improved microRNA output for downstream analyses.     

A direct measurement method of quantum relaxation time

The quantum relaxation time of electrons in condensed matters is an important physical property, but its direct measurement has been elusive for a century. Here, we report a breakthrough that allows direct determination of quantum relaxation time at zero and non-zero frequencies using optical measurement. Through dielectric loss function, we connect bound electron effects to the physical parameters of plasma resonance and find an extra term of quantum relaxation time from inelastic scattering between bound electrons and conduction electrons at non-zero frequencies. We demonstrate here that the frequency-dependent inelastic polarization effect of bound electrons is the dominant contribution to quantum relaxation time of conduction electrons at optical frequencies, and the elastic polarization effect of bound electrons also dramatically changes the plasma resonance frequency through effective screening to charge carriers.     

金刚石膜的制备方法及应用

简单介绍了金刚石膜的化学气相沉积的主要方法、应用及其最新进展,并对各种方法的优缺点作了简要说明。     

喷嘴-筒式放电极负高压脉冲放电协同二氧化钛光催化对偶氮类染料酸性橙Ⅱ的处理

脉冲放电过程在产生放电等离子体的同时,产生高能电子、紫外光．O3等多因素,可综合作用于水中或大气中的污染物。本文把脉冲放电等离子体和TiO2光催化相结合,对我们设计的喷嘴一筒式反应器中的喷嘴放电极进行二氧化钛镀膜,利用脉冲放电过程中的紫外光实现对二氧化钛的催化．增加放电过程以羟基为主的活性自由基的数量。以偶氮类染料酸性橙Ⅱ为研究对象,对比了放电极二氧化钛镀膜对放电等离子体技术对污染物降解效率的影响。研究了镀膜前后分别脉冲峰值电压,溶液初始浓度、溶液pH值、电导率等因素对偶氮类染料酸性橙Ⅱ液降解率的影响。     

宇宙天体的带电性

从理论的观点考察了宇宙天体的电性,并由此推测天体的初始磁场的起源。     

ICP-AES法测定建筑物基础周边水和土壤易溶盐中的五种离子

提出了使用电感耦合等离子体原子发射光谱同时测定建筑物基础周边水和土壤易溶盐中的钙、镁、钾、钠、硫酸根五种离子分析方法。取少量过滤后不浑浊的样品溶液,不需处理直接在选定的仪器工作条件下进行测定,样品中杂质元素的干扰轻微,不影响本法的测定。各离子的测定检出限为0.025～0.42μg/mL,相对标准偏差(RSD,n=5)为1.6%～4.3%。经比对试验证明,本法测定值与其它方法测定值相符合。     

基于模糊控制的单神经元PID配浆浓度控制

配浆浓度控制过程具有大干扰、强滞后的特点,针对这一对象,本文提出一种基于模糊控制的单神经元PID配浆浓度控制算法.该算法采用双闭环控制,外环为弥补系统滞后利用模糊控制器,进行智能控;内环根据浓度变化的预测值,采用单神经元PID模块对稀释水流量进行调节,抑制系统干扰.实际应用效果证明该算法的有效性.