P(AA-AMPS)吸水树脂的制备及高温环境中耐盐性能测定

以四烯丙基氯化铵(TAAC)为交联剂,过硫酸钾(KPS)为引发剂,引入耐盐性单体2-丙烯酰胺基-2-甲基丙磺酸(AMPS),通过水溶液共聚制备了一种适用于高温环境的丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸共聚物[P(AAAMPS)]耐盐性吸水树脂。考察了交联剂和引发剂用量、单体配比对吸水树脂在150℃下1%(wt,质量分数,下同)NaCl盐水中吸液性能的影响。结果表明:耐盐性吸水树脂的最佳聚合条件为:TAAC、KPS和AMPS占丙烯酸的质量分数分别为0.17%、0.12%和20%。在上述条件下制备的吸水树脂150℃下在1%NaCl盐水中吸水倍率可达78g/g,且表现出优异的耐高温性能和耐酸碱性能,拓宽了吸水树脂在高温含盐领域的应用范围。     

丙烯酸与丙烯酰胺共聚制备耐高温吸水树脂

以丙烯酸(AA)、丙烯酰胺(AM)为单体,四烯丙基氯化铵(TAAC)为交联剂,过硫酸钾(KPS)为引发剂,通过水溶液聚合法制备了耐高温吸水树脂。考察了单体配比、引发剂和交联剂用量以及中和度对吸水树脂在200℃下吸水性能的影响,并对吸水树脂在不同温度下吸水后的表面形貌进行扫描电镜分析。结果表明,在最佳条件下合成的吸水树脂耐高温性能良好,200℃下蒸馏水中的吸水倍率为299g/g。且该树脂样品高温下耐盐性能优异,200℃下在1%(质量分数)的NaCl盐水中的吸水倍率为86g/g。     

耐高温聚丙烯酸钠吸水树脂的制备与性能

以三烯丙基氯化铵(TAAC)为交联剂,偶氮二异丁咪唑啉盐酸盐(VA-044)为引发剂,丙烯酸钠为聚合单体,室温(25℃)下通过水溶液聚合法制备了耐高温吸水树脂。考察了交联剂和引发剂用量以及中和度对吸水树脂在200℃下吸水性能的影响。结果表明,最佳条件下合成的吸水树脂200℃下在蒸馏水中的吸液倍率为824 g/g。并且该树脂样品在高温下表现出优异的耐酸碱性和耐盐性。     

耐温耐盐SSS/AMPS/膨润土吸水树脂的制备与表征

以二乙烯苯为交联剂,过硫酸钾和亚硫酸钠为引发剂,采用水溶液聚合法合成对苯乙烯磺酸钠/2-丙烯酰胺基-2-甲基丙磺酸/膨润土(SSS/AMPS/膨润土)吸水树脂。对制备条件进行优化,采用FT-IR对树脂结构进行表征,TG曲线表征树脂的热稳定性。结果表明:当AMPS质量分数为50%、交联剂用量为0.8%、引发剂用量为0.6%、膨润土用量为10%,反应温度为65℃时,在25%模拟水溶液中树脂的吸水倍率可以达到14.71g/g,强度最佳。树脂的耐热性能好,SEM图表明树脂表面呈现多孔状结构。     

耐盐型壳聚糖高吸水树脂的制备及其性能

以天然无毒、可降解性、抑菌性能良好的壳聚糖(CS)为基体,利用自由基接枝聚合法接枝丙烯酸(AA)和2-甲基丙烯酰胺基-2-甲基丙磺酸单体(AMPS),制备了吸水性和耐盐性能良好的CS高吸水树脂。研究了各因素(温度、投料比、引发剂用量和交联剂用量等)对吸水性及耐盐性的影响,并用红外光谱及扫描电镜对高吸水树脂的结构和形貌进行表征。结果表明:在温度60℃、物料比m(CS)∶m(AA)∶m(AMPS)=1∶8∶3、交联剂用量及引发剂用量均为单体质量1%的条件下,合成的高吸水树脂最大吸水率达578.7g/g,吸盐率达114.2g/g;1h基本达到吸水平衡,且重复使用5次后,吸水率变化不大,重复使用性能良好。     

AM类互穿网络结构高吸水性树脂的室温制备与表征

通过水溶液自由基聚合的方法,以丙烯酰胺(AM)、丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料制备了AM类高吸水性树脂。室温条件下,考察了各反应因素对树脂吸水性能的影响,通过正交优化试验确定最佳的合成条件为:单体总浓度35%,单体质量配比5.0∶5.0∶2.0,引发剂浓度0.4%,交联剂浓度0.55%,吸水膨胀倍率高达250g/g之多。采用红外光谱(IR)和扫锚电镜(SEM)分别对合成的高吸水性树脂表征并进行结构分析。     

丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂的制备

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾-亚硫酸氢钠为引发剂,丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,采用水溶液聚合法合成了丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂.考察了交联剂、引发剂、单体的质量比、AA中和度、反应温度、滤渣含量对树脂吸水率的影响.经正交实验制得的高吸水性树脂在24h内吸水达到饱和,吸蒸馏水1397g/g,自来水330g/g,0.225moL/L NaCl溶液79g/g.该树脂具有一定的耐盐性.     

无N2下合成钠基膨润土/P(AA-AM)复合吸水树脂的研制

以N,N'-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,丙烯酸(AA)和丙烯酰胺(AM)为单体,采用水溶液聚合法合成出钠基膨润土复合聚丙烯酸钠-丙烯酰胺复合吸水树脂.研究了钠基膨润土的添加量、交联剂用量、引发剂用量、中和度及AM的用量对吸水倍率的影响.结果表明,钠基膨润土用量为40%,交联剂用量为0.025%,引发剂用量为0.3%,AM用量为12%及AA的中和度为80%时,吸蒸馏水倍率与吸收0.7%NaCl溶液倍率分别为422.28 g/g和65.80 g/g.     

ST-g-PAMPS高吸水性树脂的微波合成与表征

以海泡石黏土(ST)和丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,过硫酸钾(KPS)为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用微波辐射法接枝共聚合成了ST-g-PAMPS耐盐性复合高吸水性树脂,探讨了交联剂、引发剂、ST用量、中和度、微波功率和时间对树脂吸水倍率的影响,用FTIR对树脂官能团进行了表征。实验结果表明:FTIR表明ST和有机单体之间发生了接枝共聚反应,在最佳合成条件下树脂对去离子和生理盐水的吸水倍率分别为1026g/g和110g/g,树脂中引入适量ST能够显著提高复合吸水树脂的吸水能力和耐盐性能。     

淀粉基吸水树脂的制备与性能分析

以淀粉、丙烯酸(AA)和丙烯酰胺(AM)为原料,采用过硫酸铵[(NH_4)_2S_2O_8]作为引发剂,利用N,N-亚甲基双丙烯酰胺(NMBA)进行交联,采用水溶液聚合法制备了AA-AM共聚淀粉吸水树脂。考察了丙烯酸溶液pH、丙烯酸单体用量、引发剂及交联剂用量、反应体系温度与时间对合成树脂性能的影响。通过性能测试和分析得出优化合成条件为:丙烯酸溶液pH=5.5,丙烯酸单体与葡萄糖剩基(AGU)摩尔比为7∶1,过硫酸铵用量为0.35mmol,交联剂用量为0.08571mmol,反应时间为65℃,反应温度为3h。在优化工艺下合成的树脂吸收蒸馏水、0.9%NaCl溶液量分别达到798.6g/g和95.7g/g。采用红外光谱(FT-IR)和热重分析(TG)对合成的树脂进行了表征与分析评价。     

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.