微波消解-ICP-MS法测定金银花和白芷中5种有害重金属元素

选取了不同产地及不同等级的10批次金银花和白芷进行测定,并建立了微波消解-ICP-MS法测定中药材中5种有害元素含量的分析方法,各元素的线性关系良好,灵敏度(cps/ng/mL)959～18116,相关系数0.999992～1.000000,定量限0.03～0.3ng/mL,线性范围0～100ng/mL.因其低检出限及高灵敏度,该方法能满足中药材样品质量控制中5种有害元素的测定要求.为中药材中该5种有害元素的准确测定提供参考.     

离子色谱法在饮用水溴酸盐分析中的应用

采用抑制电导离子色谱法(IC)检测饮用水中的痕量溴酸盐.对样品中高浓度的干扰组分氯离子进行了处理,避免其对测定的影响.溴酸盐浓度在5ng/mL～100ng/mL范围内具有良好的线性关系,相关系数为0.9999,方法的定量限为2ng/mL(S/N=10),样品加标回收率大于91.6%.该方法经试验,成功地试用于各种饮用水中溴酸盐含量的测定.     

电感耦合等离子体质谱法测定硅铁中痕量铌、砷、锑

在高锰酸钾存在下,采用硝酸-氢氟酸溶解样品,建立电感耦合等离子体质谱法(ICP-MS)测定硅铁中铌、砷、锑含量的方法。根据丰度高和无干扰的原则来选择93Nb、75As、121Sb为测量同位素;对仪器工作条件进行优化,确定功率为1 300 W,载气流量为1.00 L/min,采样深度为1.3×104μm;以钇、铑、铟为内标元素对仪器信号漂移和基体效应进行校正试验,选择10 ng/mL铑为内标。在标准模式下与碰撞/反应池(CCT)模式下砷的测定结果一致,该方法标准模式下测定砷没有受到56Fe19F的干扰。该方法铌、砷、锑的检出限分别为0.087,0.313,0.069 ng/mL;测定下限分别为0.291,1.042,0.229 ng/mL。可作为测定硅铁中痕量铌、砷、锑元素含量的分析方法。     

ICP-MS测定食品原料中微量硒

建立基于同位素77Se、乙醇基体改进电感耦合等离子体质谱法(ICP-MS)直接测定食品原料中微量硒的方法。实验以2%(V/V)乙醇作为基体改进剂,采用Y元素作内标补偿基体效应,选择同位素77Se测定样品中的硒,方法检出限为0.87 ng/g,精密度(RSD,n=6)5%,回收率为98.1%~106.0%。该方法具有简便、快速、灵敏、准确、消耗小等优点,可为食品原料中微量硒的测定提供参考。     

LC-MS/MS测定猪尿中盐酸克伦特罗不确定度的评定

建立了液相色谱-串联质谱法(LC-MS/MS)测定猪尿中盐酸克伦特罗残留量的不确定度评定数学模型,分析了影响样品测定结果的不确定度的主要来源,并计算出了各影响因素的不确定度分量.当猪尿中盐酸克伦特罗残留量的测定结果为3.6ng/mL时,其扩展不确定度为0.4ng/mL.     

动物组织中新霉素残留快速检测方法

以兔抗新霉素多抗为包被抗体,以新霉素-HRP连接物为标记物,TMB为显色底物,三氯乙酸提取法为样品前处理方法,建立了一种适用于动物组织中新霉素残留量的竞争性直接酶联免疫快速检测方法.该方法可测定新霉素残留的线性范围为0.6~50.0 ng/mL,线性方程为y=-0.412 7x+1.185 9,相关系数为0.993 6,半抑制率IC50为5.0 ng/mL,板内变异系数小于5.6%,板间变异系数小于5.3%,检出限为0.6 ng/mL,回收率在80%~120%之间.     

ICP-MS测定土壤和水系沉积物中的微量银

样品经三酸(HF+HNO3+H2SO4)完全分解后采用ICP-MS测定银时,锆会产生强烈干扰。为消除这种干扰,提高结果准确度,建立离线干扰校正方法。通过测试4件水系沉积物及9件土壤国家标准物质,选择最适测定条件:溶液酸度为1.0%,内标为10 ng/m L Rh、In,采用94Zn消除锆对107Ag干扰。实测结果表明该方法检出限为5.8 ng/g,精密度为5.80%,测试值与推荐值吻合,误差在标准物质允许范围内。该方法具有简便、快捷、准确的优点,还能实现多元素同时测定。     

大田软海绵酸荧光偏振免疫分析方法研究

设计使用荧光试剂PDAM与大田软海绵酸单(OA)反应合成了荧光标记物,并在OA单克隆抗体的基础上建立TOA荧光偏振免疫(FPIA)检测方法.该FPIA方法检测限为4.6 ng/mL,检测范围为7.0-88.7 ng/mL.IC(50)为24.9 ng/mL.本方法操作简单、稳定,有望应用于高通量筛查牡蛎样品中OA含量.     

微波消解-原子荧光法测定食品中的砷

目的:建立测定食品中砷的微波消解原子荧光法。方法:采用微波消解处理样品,原子荧光法分析测定。结果:砷标准系列浓度在(0~8.0)ng/ml范围内线性关系良好。本方法检出限为0.11 ng/ml样品中砷回收率为88.0%~93.2%,具有简便、快速、灵敏、准确的特点。结论:本方法测定结果令人满意,具有一定的实用价值。     

牛奶中抗生素的液相芯片检测方法研究

利用悬液芯片系统建立了一种快速、多成份、高灵敏、高通量的抗生素残留的检测方法.使用表面具有羧基的微球作为固相载体,将人工合成的抗生素全抗原键合到微球上作为捕获抗原,与样品中的抗生素竞争体系中抗生素的单克隆抗体,使用藻红蛋白标记的二抗作为荧光探针,构建间接竞争反应体系.反应体系经悬液芯片系统可对荧光探针进行测定并对包被不同抗原的不同型号微球进行分类识别,实现抗生素的高通量检测.以检测牛奶中头孢氨苄、卡那霉素为例,头孢氨苄、卡那霉素的检测限分别为13.98 ng/mL、23.44 ng/mL,50%抑制的质量浓度(IC50)分别为56.88 ng/mL、190.09 ng/mL.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...