CPP-g-MAH/BA高弹乳液的合成研究与应用

以酯溶性的CPP-g-MAH、丙烯酸丁酯(BA)、丙烯酸乙酯(EA)和β-羧乙基丙烯酸酯(β-CEA)为共聚单体,烯丙氧基壬基酚丙醇聚氧乙烯(10)醚硫酸铵(DNS-86)为反应型乳化剂,采用乳液聚合法制备出一种高弹乳液。结果表明:当m(BA)∶m(CPP-g-MAH)=7∶3、w(DNS-86)=3.0%、w(过硫酸铵)=0.6%、反应温度为80~82℃和反应时间为5h时,制得的高弹乳液,具有环保,成本低,其黏度、耐沾污性、耐水性、拉伸强度俱佳。其制造的弹性涂料性价比高,具有广阔的市场应用前景。     

壳聚糖/阿拉伯胶复凝聚鱼油微胶囊的制备及性质研究

研究以壳聚糖(chitosan,CS)和阿拉伯胶(acacia gum,GA)作为包裹鱼油的壁材,通过复凝聚反应制备CS/GA复凝聚鱼油微胶囊。首先通过单因素分析法,对复凝聚行为的影响因素进行研究。结果表明,当m(CS)∶m(GA)为1∶6,1∶7,壁材总浓度为3%,4%,5%,pH值为4.0,4.5,5.0,反应温度为20℃,反应时间为30min时,CS与GA具有较好的复凝聚效果。以此为基础,在保证较好的复凝聚效果的前提下,确定了CS/GA复凝聚鱼油微胶囊的最佳制备工艺:CS/GA壁材总浓度为5%,m(CS)∶m(GA)为1∶7,芯壁比为1∶2,pH值为4.5,反应温度为20℃,复凝聚反应时间为30min。在最佳制备工艺下制备的CS/GA复凝聚鱼油微胶囊呈规整的球形,分散性良好;粒径分布均匀,平均粒径为16.3μm;对鱼油的包埋率和壁材的利用率分别为75.33%和81.01%。     

聚苯乙烯交联微球的氯甲基化方法研究

以异戊醇、多聚甲醛及氯化亚砜为主要原料,合成了氯甲基化试剂氯甲基异戊醚。并采用原位法对聚苯乙烯交联微球进行氯甲基化。利用傅里叶红外光谱仪对产物结构进行了表征,以莫尔滴定法对氯球的氯含量进行了测定。考察了各物料配比、反应时间对氯甲基化反应的影响规律。获得最佳反应条件为:异戊醇∶多聚甲醛∶氯化亚砜∶聚苯乙烯∶四氯化锡∶二氯甲烷(均为物质的量比)=1∶2.4∶2.4∶7.2∶0.8∶7.2,氯甲基异戊醚合成阶段反应温度为3~5℃,反应时间为7h;氯甲基化合成阶段反应温度为15~20℃,反应时间为12h,总计反应时间为19h。制得的氯球的氯含量可达18%(wt,质量分数)。     

酸性离子液体水溶液中壳聚糖的氧化降解EI北大核心CSCD

筛选出对壳聚糖溶解具有良好性能的磺酸型离子液体[MIMBS]HSO4,以该离子液体水溶液为反应介质,在均相体系中进行了壳聚糖的氧化降解反应。考察了离子液体用量、H2O2与壳聚糖单元摩尔比、反应温度和反应时间对该氧化降解反应的影响。利用黏度法测定壳聚糖的相对分子质量,采用X射线衍射和红外光谱对原料和再生壳聚糖的结构进行表征。X射线衍射分析结果表明,溶解过程中壳聚糖的晶体结构遭到破坏,结晶度下降。随着离子液体溶液浓度的增加、H2O2用量的增大、反应温度的升高以及反应时间的延长,氧化降解反应进行得更加彻底。在最佳反应条件(8%离子液体水溶液、底物摩尔比5、反应温度80℃、反应时间3 h)下,再生壳聚糖的收率为74%,其黏均相对分子质量为21.2×103。     

羧甲基壳聚糖降尘剂的制备及性能研究

以氯乙酸改性壳聚糖制备羧甲基壳聚糖(CMCS)降尘剂的最佳反应条件为m(壳聚糖)/m(NaOH)=1.0,m(氯乙酸)/m(壳聚糖)=1.25,50℃下反应7h;用IR、XRD表征了CMCS;CMCS投加量0.8g/L,在pH值为3.5、温度21℃时,对于煤尘的去除率高达95.3%,且具有低残留、易降解、无污染等独特优点,在降尘领域中有着良好的应用前景。     

非均相碱脱乙酰法制备壳聚糖

研究的目的是讨论采用非均相碱脱乙酰法制备壳聚糖时，反应时间及反应温度对壳聚糖脱乙酰度（DD）及分子质量（MW）的影响，并建立合适的反应条件，制备具有适当脱乙酰度及分子量的壳聚糖产品。甲壳素是从红虾的残渣中提取的。DD和MW分别由红外光谱及静态光散射仪测定。甲壳素的DD值及MW的测量结果分别为31．9％、5637kDa。实验结果表明壳聚糖的DD值随反应时间、反应温度的增加而增加。反应温度为140℃时制备的壳聚糖的DD值比反应温度为99℃时制备的壳聚糖DD值高。反应温度为99、140℃制备的壳聚糖的加最大值分别92．2％、95．1％。壳聚糖的DD值在反应初期增长较快，随着时间的延长，增长变慢。脱乙酰反应的反应速率及速率常数随反应物DD值的增加而减少。壳聚糖的分子量随脱乙酰反应时间的延长而减小。反应温度为140℃时制备的壳聚糖的分子量比反应温度为99℃时制备的壳聚糖的分子量小。反应初期壳聚糖的分解速率为43．6％／h，随着时间的延长其值减小到20％／h，在反应后期，分解反应速率常数增加。     

新型双交联羧甲基木薯淀粉的合成与表征

以木薯淀粉为主要原料,经环氧氯丙烷交联,采用一氯乙酸进行羧甲基化,制得交联羧甲基木薯淀粉(CC-MS)。然后采用双交联工艺,经乙二醛二次交联制得黏度高达16000mPa.s的双交联羧甲基木薯淀粉(DCCMS)。通过优化条件实验,考察了乙二醛与交联羧甲基淀粉反应过程中诸因素对黏度的影响。确定了较佳的合成工艺条件:交联温度35℃,交联时间60min,m(NaOH)∶m(CCMS)=0.08∶1,m(乙二醛)∶m(CCMS)=0.28∶1,V(乙醇)∶V(水)=11∶1。产物通过红外光谱、X-射线衍射和扫描电镜进行了表征。     

壳聚糖接枝共聚制备高吸水性树脂的研究

以壳聚糖(CTS),丙烯酸(AA),丙烯酰胺(AM)为原料,N,N-亚甲基双烯酰胺(MBAM)为交联剂,NaH-SO3/K2S2O8氧化还原体系为引发剂,通过接枝共聚合反应制备高吸水性树脂。较佳制备条件为:m(CTS)∶m(AA)∶m(AM)为1∶3∶1,丙烯酸的中和度为70%,引发剂用量4%,交联剂用量0.04%,反应温度45℃。研究表明,此条件下所得树脂吸水率为402g/g,吸盐水(浓度0.9%)率为102g/g,并最后采用红外光谱、扫描电镜表征分析了树脂的结构。     

响应面法优化HTCC/Na_2SiO_3/ECH杂化膜催化制备生物柴油

以环氧氯丙烷(ECH)为连接剂,将硅酸钠(Na2SiO3)化学固定于壳聚糖季铵盐(HTCC)分子链上,制得一种硅酸钠/壳聚糖季铵盐有机无机杂化膜(HTCC/Na2SiO3/ECH),作为固体碱催化剂催化大豆油和甲醇进行酯交换反应制备生物柴油,该膜显示出良好的重复使用性,并根据中心组合响应面法对影响生物柴油转化率的条件(反应温度、反应时间、醇油质量比以及催化剂用量)进行优化,确定催化膜催化酯交换反应制备生物柴油的二阶多项式模型和反应因素影响显著性顺序.结果表明:反应温度55℃,醇油摩尔量比6∶1,催化膜含量为油重的质量分数4%,反应时间60min,预测转化率为98.0%,实际值为97.1%,与实际值基本相符,表明优化模型有效可靠.     

磷酸铬铝粘结剂的制备及其热处理中的相变

以Al(OH)3、H3PO4、CrO3和CH3OH为原料制备磷酸铬铝,通过对反应体系粘度及其吸潮率、热失重率的监测,确定反应的物质的量比、温度及反应时间。采用DTA-TG、IR和XRD分析研究了体系的固化特性和耐热性能。结果表明,反应的最佳条件为:反应温度80℃,n(Al(OH)3)∶n(H3PO4)∶n(CrO3)=3∶9∶1,反应时间为1h。磷酸铬铝粘结剂在300～1000℃时是非晶相,1100℃时是Cr(PO3)3和AlPO4两种晶型,1200℃时是Cr4(P2O7)3和AlPO4两种晶型。     

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.     

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.     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from