高效液相色谱直接进样法测定水中氨基甲酸酯

采用直接进样-高效液相色谱-荧光检测,Waters Carbamate Analysis3．9×150mm色谱柱,以水-甲醇-乙腈为流动相,激发波长为339nm,发射波长为445nm定量测定水中的氨基甲酸酯。结果表明本方法的标准偏差在0．02-0．12μg／L之间,变异系数在1．07％-7．24％之间,平均回收率在89．5％-100．5％之间,检出限在0．06-0．36μg/L之间。     

舒肝宁注射液中黄芩苷和栀子苷的含量测定技术

目的：建立高效液相色谱法测定舒肝宁注射液中黄芩苷和栀子苷含量。方法：AtiantisTMdC18柱,4．6×150mm,5μ;黄芩苷流动相为0．01mol／L磷酸盐缓冲液（pH2．8）甲醇（60：40）,流速1ml／min,检测波长280nm;栀子苷流动相为甲醇水冰醋酸（20：80：0．5）,流速1ml／min,检测波长238nm。结果：黄芩苷和栀子苷线性范围分别为30-100μg／ml,30-150μg／ml,平均回收率分别为99．68％、99．66％。结论：该法简便快速、结果准确,适合舒肝宁注射液的质量控制。     

高效液相色谱法定量分析化妆品中对羟基苯甲酸酯

建立了用高效液相色谱测定化妆品中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯4种防腐剂的方法。以甲醇与水作为流动相,DAD检测器的检测波长254nm,流速为1．0mL／min,柱温30℃。方法检出限分别为对羟基苯甲酸甲酯0．18μg、对羟基苯甲酸乙酯0．20μg、对羟基苯甲酸丙酯0．20μg、对羟基苯甲酸丁酯0．21μg。4种防腐剂在0～100mg／L呈现良好的线性关系。样品的加标回收率为101.3％～102.5％,相对标准偏差为0．13％～O．21％     

高效液相色谱法测定设备淋洗液中氨苄西林残留含量

目的测定设备淋洗液中氨苄西林残留量。方法采用十八烷基硅烷键合硅胶为填充剂,以12%醋酸溶液-0．2mol／L磷酸二氢钾溶液-乙腈-水（0．5：50：50：900）为流动相A,以12％醋酸溶液-0．2mol／L磷酸二氢钾溶液-乙腈-水（0．5：50：400：550）为流动相B,流动相A-流动相B（85：15）,检测波长254nm,流速1．0mL／min,柱温40℃,进样量20？L,结果氨苄西林在0．005106mg／mL～0．01191mg／mL范围有良好的线性关系（r为0．9995）,检测限为5．106×10-5mg／mL,平均回收率为98．5％;RSD为0．69％。结论该方法简便,重现性好,专属性强,为检测设备淋洗液中氨苄西林残留含量提供了可靠的方法。     

茶叶中镁含量分析方法研究

本文研究了刚果红分光光度法测定茶叶中镁含量的方法。结果表明：在一定条件下,镁离子含量在0～45μg／25mL范围内遵守朗伯比尔定律,检测限为3．8p,g／L,方法的表观摩尔吸光度为1．27×10^4L·mol^-1·cm^-1,方法的精密度（RSD）小于2．5％,样品加标回收率在96％-103％之间,结果令人满意。     

锌酸盐镀锌液中杂质元素的质谱分析

利用带八极杆碰撞／反应池（ORS）和屏蔽炬技术的电感耦合等离子体质谱（ICP-MS）可同时直接测定锌酸盐镀锌液中Mg，V，Cr，Mn，Co，Ni，Cu，Cd，Sb，Pb杂质元素。通过向碰撞池中引入氢气和氦气消除多元素分子、离子的干扰，以50μg／Lsc，Ge，In，Tb为内标元素校正基体干扰和漂移，确定了仪器的最佳工作参数。结果表明：各元素在0～500．0μg／L内均有良好的线性关系，相关系数均在0．9995以上；10种杂质元素的检出限在0．001～0．034μg／L，回收率为95．2％～107．4％，相对标准偏差（R肋）小于2．90％。     

RP—HPLC法同时测定罗非鱼血浆中DMP和DEP含量

方法：血浆样品经液-液萃取,以乙腈水=40 60（V／V）为流动相,流速1．0mL·min,采用SHIMADZUODS柱（150mm×4．6mm;i．d．,5μm）色谱柱分离。测定罗非鱼经口暴露后血浆中邻苯二甲酸二甲酯和邻苯二甲酸二乙酯的浓度。结果：标准曲线线性范围为0．01-10．0μg·mL,线性关系良好（r〉0．99）,定量限为0．01μg·mL^-1,回收率90％以上,日内变异系数和日间变异系数均低于10％。经口暴露48h内罗非鱼血浆中均能检测到邻苯二甲酸二甲酯和邻苯二甲酸二乙酯的残留。     

离子色谱法测定面粉中的溴酸盐

采用离子色谱法测定面粉中的溴酸盐,选用Metmhm861型离子色谱仪,Metmsep Asupp 5—250阴离子分析柱,以3．2mmol／LNaCO3＋1．0mmol／LNaHCO3溶液为淋洗液（流动相）。标准曲线的线性范围为0．2～1．2mg／L（r=0．999807）,BrO3^-的检出限为0．02mg／L（进样阵积20μL）,相对标准偏差为1．173％,厢本方法测定面粉样品,加标回收率在91．9％以上。实验表明,本方法快速、准确,灵敏,重复性较好,结果令人满意。     

稀土铬复合电镀层的制备方法及应用

电镀层由混合稀土铬基相与硫酸盐和碳酸盐第二相组成。电镀工序由电镀前期、中期、后期3阶段构成，电镀时间均为4h，每个阶段内均进行反相与正相的交替操作；3阶段内正相操作时间分别为30，40，50min，反相操作时间除首次为1min外，其余均为3min；稀土铬镀层的厚度为0．3—0．4mm。镀液为：CrO3140-170g／L，H2SO41．5—2．0g／L，以混合稀土氧化物为主的可溶稀土添加剂2．0—2．5g／L，     

微波消解-原子荧光法测定螺旋藻中的硒

以微波消解对样品进行消解,以盐酸为还原剂,用氢化物原子荧光法测定螺旋藻中硒元素的含量;在最佳仪器条件下,该方法在浓度范围为。-10μg／L内,一次线性拟合回归方程为If=45．924X＋0．3045,R=0．9996,检出限是0．217μg／L,RSD为4．731％,加标回收率为98％-109．5％。     

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.     

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...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.