4-(5-氯-2-吡啶)-偶氮-1,3-二氨基苯光度法测定电镀废水中的微量镍(Ⅱ)

4-(5-氯-2-吡啶)-偶氮-1,3-二氨基苯(5-Cl-PADAB)可与镍发生灵敏的显色反应,生成稳定的配位化合物。基于此建立了一种测定电镀废水中微量镍的光度法。结果表明:在2.0 mol/L HCl介质中,5-Cl-PADAB与Ni(Ⅱ)反应生成摩尔比2∶1的稳定配位化合物,其最大吸收波长为565 nm,表观摩尔吸光系数为6.42×104 L/(mol.cm),Ni(Ⅱ)含量在0～1.0 mg/L内符合比尔定律;该方法用于测定电镀废水中微量镍,结果与催化-分光光度法相符,相对标准偏差小于4.0%,加标回收率为98.5%～101.8%。     

胶束光度法测定非晶态FeNiCr合金中的镍

在pH =8 .0、HCl tris缓冲溶液和Tween80胶束介质中 ,研究了 1 亚硝基 2 萘酚 (NN)与Ni(Ⅱ )的显色反应。建立了胶束光度法测定微量Ni(Ⅱ )的新方法。结果表明 ,Ni(Ⅱ ) NN配合物的最大吸收波长为 4 5 5nm ,摩尔吸光系数为1.0 1× 10 4 L/ (mol·cm) ,检出限为 0 .0 4mg/L ,有色溶液的吸光度与Ni(Ⅱ )量在 0 .2～ 1.0mg/L范围内符合比耳定律 ,加标回收率为 96 .2 %～ 10 3.1% (n =6 )。测定了非晶态FeNiCr合金钢中的镍。     

用5-氯-苯骈噻唑偶氮苯甲酸光度法测定电镀废水中的微量铜

研究了5-氯-苯骈噻唑偶氮苯甲酸(5-Cl-BTAEB)与铜的显色反应.在pH值为3.5的HAc NaAc缓冲溶液中,在乳化剂OP存在下,5-Cl-BTAEB与Cu(Ⅱ)生成2:1稳定配合物,最大吸收波长为655nm,表观摩尔吸光系数为5.17×104L/(mol·cm),由此建立了一种新的Cu(Ⅱ)测定方法.铜含量在0～480.0μg/L内符合比尔定律,该方法用于测定电镀废水中微量铜,结果与萃取-催化褪色光度法相符.实际样品分析结果的相对标准偏差小于4%,加标回收率为98.0%～103.5%.     

8-羟基喹啉显色光度法测定电镀废水中的微量铝(Ⅲ)

为了准确测定电镀废水中的微量铝(Ⅲ),利用8-羟基喹啉与铝(Ⅲ)的显色反应,建立了一种新的分光光度法。在pH值5.0的CH3COOH-CH3COONa缓冲溶液中,8-羟基喹啉与铝(Ⅲ)反应生成摩尔比2∶1的稳定配位化合物。使用三氯甲烷(CHCl3)萃取,配位化合物最大吸收波长为395 nm,表观摩尔吸光系数为2.31×104L/(mol·cm)。铝(Ⅲ)含量在0~4.0 mg/L内符合比尔定律。本法应用于电镀废水中微量铝的测定,结果与原子吸收光度法相符;实际样品6次测定值的相对标准偏差小于3%,加标回收率为98.6%~102.5%。     

电镀废水中镍(Ⅱ)的6-氯-苯并噻唑偶氮苯甲酸显色光度法测定

在pH值为5.0的HAc-NaAc缓冲溶液中,在乳化剂OP存在的条件下,利用6-氯-苯并噻唑偶氮苯甲酸(6-Cl-BTAEB)与镍的显色反应测定电镀废水中的镍含量.结果表明:反应生成的配合物中的Ni(Ⅱ)与6-Cl-BTAEB摩尔比为1:2;镍含量低于400μg/L时符合比尔定律,表观摩尔吸光系数为1.59×10~5L/(mol·cm);该法用于测定电镀废水中的微量镍,结果与催化-分光光度法相符,相对标准偏差小于5.0%,加标回收率为97.6%～105.5%.     

黄铜镀液中锌的快速测定

研究了二甲酚橙与锌形成配合物的条件及其光度性质.结果表明,在pH值为5.7～6.0的醋酸-醋酸盐缓冲介质中,锌(Ⅱ)与二甲酚橙形成紫红色配合物,其最大吸收波长位于570 nm,锌浓度介于0～2 μg/mL,遵守比尔定律,表观摩尔吸光系统ε'570=1.48×104 L/(mol·cm).用硫代硫酸钠作掩蔽剂,大量铜(Ⅱ)共存无干扰,应用于黄铜镀液中锌的测定,方法简便快速,准确度和精密度高,能满足生产要求.     

1-偶氮苯-3-(6-甲氧基-2-苯骈噻唑)-三氮烯显色光度法测定镀镍液中微量铜

研究了1-偶氮苯-3-(6-甲氧基-2-苯骈噻唑)-三氮烯(AMBT)与铜的显色反应,在pH=10.0的Na2CO3-NaHCO3缓冲溶液中,在Triton X-100存在下,AMBT与Cu2 反应生成2:1稳定配合物,其最大吸收波长为560 nm,表观摩尔吸光系数为5.36×104 L/(mol·cm).铜含量在0～12 μg/25 mL内符合比尔定律,方法用于测定镀镍液中微量铜,结果与原子吸收法(AAS)相符,6次测定值相对标准偏差＜2%.     

苯芴酮光度法快速测定镀银溶液中的微量锑

利用苯芴酮与锑(Ⅲ)的显色反应,对镀银溶液中的锑进行光度测定.试验结果表明,在乳化剂OP存在下的0.09～0.18 mol/L硫酸介质中,显色体系的最大吸收波长位于560 nm.表明摩尔吸光系数为5.85×104L/(mol·cm),锑浓度介于0.14～1.40μg/mL,遵守比尔定律.加标回收率97.3%～104.7%,本方法简便快速,且具有良好的选择性.     

用分光光度法测定电镀废水中的微量铅(Ⅱ)

在OP乳化剂存在下,研究了Pb2 和双硫腙的配位显色反应.试验结果表明,在pH=5.0的HAc-NaAc缓冲溶液中,有色溶液的最大吸收波长为500 nm,摩尔吸光系数为4.8×104 L/(mol·cm),Pb2 浓度在0～1.2 mg/L范围内符合比耳定律,加标回收率为98.5%～102.1%之间.本法用于测定处理电镀废水中的微量铅,方法简单易行,结果可靠.     

镀铜废水中Cu2+含量的5,6-二氯-苯并噻唑偶氮苯甲酸显色光度法测定

利用5,6-二氯-苯并噻唑偶氮苯甲酸(5,6-diCl-BTAEB)与铜的显色反应,在pH值为5.0的NH4OAcHOAc缓冲溶液中,在乳化剂OP存在下,使5,6-diCl-BTAEB与Cu2+反应生成2:1稳定的配合物,可实现对Cu2+的测定.其最大吸收波长为650 nm,表观摩尔吸光系数为5.57×104L/(mo...     

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.……     

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.     

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.     

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.     

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.     

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.