壳聚糖/聚氨酯树脂的制备及对Cu2+吸附研究

以壳聚糖和聚氨酯预聚体为原料制备了壳聚糖/聚氨酯树脂(CTS/PU),考察了其对铜离子吸附性能。结果表明,CTS/PU树脂表面较粗糙;随预聚体用量增大,树脂吸附量先增加后降低。CTS/PU比例为1∶1时,树脂对Cu2+吸附量可达到优;pH值为6时,树脂对Cu2+吸附量最大。动力学研究表明,树脂对Cu2+吸附过程符合准二次动力学模型。     

多孔壳聚糖树脂对Cu~(2+)吸附研究

以壳聚糖为母体,聚乙二醇2000为致孔剂,采用微波加热方法制备了多孔壳聚糖树脂。研究了搅拌速率、致孔剂浓度和交联剂用量等制备条件对树脂对Cu2+的吸附性能的影响,并采用扫描电镜对树脂的微观结构进行表征。结果表明:交联后的树脂具有多孔结构,较壳聚糖具有更大的比表面积;Shiff碱反应能够保护壳聚糖上的氨基;树脂对Cu2+的吸附量随着树脂中氨基含量的增加而增加;致孔剂浓度、交联剂用量、胺化剂用量及酸处理条件对树脂对Cu2+的吸附性能影响较大,在最优吸附条件下,对Cu2+的吸附量可达3.9mmol/L。     

乙二醛交联壳聚糖树脂对Cu(Ⅱ)吸附研究

以乙二醛为交联剂,由壳聚糖合成了一种交联壳聚糖树脂.研究了不同温度下其对Cu(Ⅱ)的静态吸附性能,测定了不同温度下的吸附曲线,并通过FTIR及XRD对交联壳聚糖树脂产物和吸附Cu(Ⅱ)后的材料结构进行了表征.结果表明,乙二醛交联壳聚糖树脂在40℃时对铜离子的平衡吸附量为78mg/g,不同温度下的吸附过程符合一级动力学模...     

磁性交联壳聚糖微球的制备及对Cu~(2+)的吸附性能

以Fe3O4为磁核,环氧氯丙烷为交联剂,制备了磁性交联壳聚糖微球(MCB),采用FT-IR和VSM对MCB进行表征,结果表明,Fe3O4被壳聚糖包埋,制备的MCB的饱和磁化强度为12.8emu/g。其交联度、溶胀度和含水量分别为85.2%、6.94%和80.1%。同时研究了MCB对Cu2+的吸附性能,研究表明:MCB对Cu2+的吸附的最佳pH值为5,MCB对Cu2+的吸附符合Langmuir方程,为单分子层吸附,最大吸附容量为64.6mg/g;动力学研究表明,MCB对Cu2+的吸附过程符合准二级动力学方程。MCB再生-重复使用8次,其吸附容量没有明显的降低。     

马铃薯淀粉黄原酸酯基高吸水树脂对重金属离子吸附特性的研究

探索了马铃薯淀粉黄原酸酯基高吸水树脂对Ni 2+、Co2+、Zn2+和Cu2+的二元混合溶液的平衡吸附,并对吸附机理进行了初步研究。结果表明:树脂在二元混合溶液中对Cu2+具有较好的选择性吸附能力。当树脂投放量为0.1g、金属离子初始浓度为100mg/L时,马铃薯淀粉黄原酸酯基高吸水树脂对Cu2+的吸附容量可达78.27mg/g。该高吸水树脂对重金属离子的静态吸附过程符合准二级动力学方程,且与高吸水树脂表面的物理吸附有关。     

8-羟基喹啉改性DK110树脂的合成及其对Cu~(2+)的吸附性能

以大孔丙烯酸系弱酸树脂DK110为大分子骨架,通过与5-氯甲基-8-羟基喹啉的接枝反应,合成了带8-羟基喹啉螯合功能基的改性树脂HQDK110。探讨了HQDK110树脂对Cu2+在不同温度、不同pH值、不同浓度等条件下的静态吸附性能、动态吸附性能及脱附性能。结果表明,HQDK110树脂对Cu2+具有良好的吸附作用,实验条件下,25℃时HQDK110树脂对Cu2+的吸附量达2.278 mmol/g。HQDK110树脂对Cu2+的动力学吸附很好地符合了拟二级动力学模型,吸附过程符合Langmuir吸附等温式。树脂对Cu2+的去除率在较宽的浓度范围内达到98%以上,吸附Cu2+后的树脂在0.1 mol/L的盐酸溶液中的脱附率达96.88%。树脂有良好的重复使用性能。     

酚醛树脂骨架的8-羟基喹啉螯合树脂吸附性能的研究

以1,4-二氯甲氧基丁烷为氯甲基化试剂,对酚醛树脂进行氯甲基化,得到氯甲基化酚醛树脂,再与8-羟基喹啉通过Friedel-Crafts反应制得以酚醛树脂为骨架的8-羟基喹啉螯合树脂。探讨了螯合树脂对不同金属离子的吸附量及吸附选择性;用静态吸附法研究了螯合树脂对Cu2+、Pb2+的吸附符合Freundlich模型;对Cu2+、Pb2+的吸附动力学进行了研究,符合Boyd液膜扩散方程,线性相关性较好。在动态条件下,Cu2+、Pb2+分别在第22个床体积、17个床体积出现穿透;用5mol/L的硝酸进行洗脱,在3个床体积的洗脱率均达到96%以上,说明该树脂具有良好的洗脱性能。     

多孔壳聚糖交联树脂的制备及对磷酸盐中磷的吸附

以壳聚糖为原料,二甲苯为分散剂、乙酸乙酯为致孔剂、环氧氯丙烷为交联剂,利用反相悬浮交联法制备了多孔壳聚糖交联树脂;通过红外光谱对树脂结构进行表征并对其性能参数进行了测定;系统考察了该多孔树脂对磷酸盐中磷的吸附特性,结果表明,溶液pH和温度对吸附率的影响较大,在磷酸根浓度为2 mg/L,pH=3,溶液温度为60℃时吸附率达到85.8%;吸附过程符合二级动力学吸附,符合Langmuir吸附模型,吸附为吸热、熵增、自发的过程。在7次吸附解吸循环试验中,相邻2次的吸附量变化不超过0.03 mg/g,说明多孔树脂具有良好的循环吸附稳定性。     

N,O-羧甲基壳聚糖树脂的制备及其对重金属吸附性能研究

通过乳化交联法制备了一种新型的戊二醛交联N,O-羧甲基壳聚糖树脂,用SEM和FT-IR对树脂的表面结构和化学结构进行表征。用树脂吸附水溶液中的Cu(Ⅱ)、Pb(Ⅱ)和Cd(Ⅱ)等重金属离子,研究了不同pH值、接触时间和初始浓度对吸附量的影响。当pH值=5时,树脂对Cu(Ⅱ)的吸附量达到最大值;当pH值=6时,对Pb(Ⅱ)和Cd(Ⅱ)的吸附量达到最大值。利用两种吸附等温线模型对数据进行拟合并对吸附动力学进行研究,实验数据对Langmuir等温线模型具有较高的拟合度,拟合后对Cu(Ⅱ)、Pb(Ⅱ)和Cd(Ⅱ)的最大吸附量分别为156.25、222.22和178.57mg/g,吸附过程符合拟二级反应动力学模型。     

杂原子聚合物冠醚研究Ⅲ.多胺交联甘油双缩水甘油醚树脂的合成及其吸附性能

合成了三乙烯四胺交联的甘油双缩水甘油醚树脂,并研究了该树脂对Cu2+、Ni2+、Zn2+、Co2+的静态吸附性能和吸附机理.结果表明,该树脂对Zn2+、Co2+的吸附是单一吸附机理,而对Cu2+、Ni2+的吸附则为多重吸附机理,对4种离子的等温吸附过程均符合Freundlich方程.对Cu2+、Ni2+、Zn2+、Co2+的吸附容量可分别达0.61、0.32、0.06和0.23 mmol／g.     

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 ...     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.