层层组装界面聚合制备聚酰胺复合正渗透膜研究

以聚丙烯腈(PAN)为支撑膜材料,利用相转化法制得PAN基膜,水解改性后作为支撑层,通过界面聚合法制备聚酰胺正渗透复合膜.考察了界面聚合次数对复合膜表面形貌结构、粗糙度、亲水性及正渗透性能、反渗透性能的影响.实验结果表明,膜表面粗糙度和亲水性随着界面聚合次数的增加而增大,而反渗透水通量随着界面聚合次数的增加而减小,盐截留率随之而增大,而正渗透性能测试中水通量和盐逆向通量随界面次数的增加而减小.综合得知,经过2次界面聚合后,复合膜表面粗糙度和亲水性较好,正渗透水通量达到16.97L/(m~2·h),盐逆向通量为6.02g/(m~2·h).     

正渗透膜材料与驱动体系的研究

报道课题组在正渗透膜材料及高效易回收驱动液方面的研究进展.在膜材料方面,我们研究了准双皮层的三乙酸纤维素正渗透膜,得到的膜性能优于商业化HTI正渗透膜.在驱动溶质方面,研究了以乙二胺四乙酸和树枝状聚合物以及具有响应性能的纳米材料为代表的大尺寸驱动体系,验证了大分子驱动溶质可以有效降低内浓差极化.研究结果表明,膜与驱动液在正渗透研究中都非常重要.     

正渗透技术应用于污废水处理的研究进展

随着我国污废水处理市场和规模的进一步扩大,同时膜材料生产成本下降,促进了膜技术在废水处理领域的迅速发展.不同于传统施加外压的压力驱动膜处理技术,正渗透以其低能耗、低污染和高截留能力的特点引起了广泛关注.本文从正渗透技术原理出发,介绍了膜材料、汲取液种类和浓差极化3个主要影响因素;其次,分析了正渗透技术及组合工艺在废水处...     

界面聚合技术在材料制备中的应用

界面聚合技术作为一种新型的聚合反应已广泛应用于各个领域.界面聚合技术在材料制备中的应用显示出重要作用,采用界面聚合技术可以制备膜材料、微胶囊材料、纤维粒子及新型材料等.介绍并分析了近几年来界面聚合技术在材料制备中的应用,指出了今后的研究方向.     

正渗透过程参数对渗透性能的影响

正渗透是新的非热能驱动膜过程。采用界面聚合的方法制备了中空纤维复合膜。以Na2SO4、MgSO4、NaCl和Mg-Cl2水溶液作为驱动液进行了正渗透实验。实验表明,正渗透通量随着驱动液浓度的增加而增加,其中Na2SO4、MgCl2水溶液的渗透通量大于MgSO4、NaCl水溶液的。驱动液中无机盐向原水中扩散的渗透速率随无机盐浓度的增加而增加,且MgCl2>NaCl>Na2SO4>MgSO4。原水流速对正渗透通量的影响极小,而驱动液流速对正渗透通量的影响较大。     

界面聚合反渗透复合膜材料及其表面修饰

针对我国反渗透复合膜材料研究领域存在的膜材料品种单一、膜性能相对较差、膜产品缺乏核心竞争力等现状,重点开展了界面聚合反渗透复合膜材料及其表面修饰方面的研究工作.从功能单体与制备工艺入手,研究开发高性能反渗透复合膜材料;采用表面改性技术,对界面聚合反渗透复合膜材料进行表面功能化修饰,研究开发界面聚合反渗透复合膜材料的表面改性实用技术;以期为我国反渗透复合膜材料及其产业的发展提供核心材料和先进制备技术.     

PVA基交联杂化膜的制备与道南渗析性能研究

道南渗析是浓度梯度驱动的选择性膜过程,可用于去除水溶液中的重金属离子Cu~(2+).适合道南渗析用膜的开发是目前道南渗析技术的瓶颈.先由单体聚合制备含有离子交换基团的共聚物,然后通过溶胶-凝胶法制备了一系列不同共聚物含量的PVA基交联有机-无机杂化阳离子交换膜,并采用红外光谱、扫描电镜、离子交换容量和水含量测量等进行性质表征和开展道南渗析去除Cu~(2+)实验.通过考察Cu~(2+)渗透通量,探讨杂化膜共聚物含量和接受液中H~+浓度对杂化膜去除Cu~(2+)效果的影响,并与商品阳离子膜进行比较.结果发现,杂化膜的渗透通量随着共聚物含量的增加而增大,随H~+浓度的增加先增加后基本保持不变;在相同条件下,杂化膜的最高渗透通量约为商品阳离子膜的3倍.这表明,制备的PVA/SiO_2杂化阳离子交换膜在道南渗析法去除废水中Cu~(2+)方面具有潜在的应用前景.     

界面聚合正渗透膜结构参数的调控

<正>渗透过程是以渗透压差为驱动力的膜过程.其中膜的结构参数是决定膜的传质阻力和水通量的关键因素.本文系统介绍了本课题组在调控界面聚合正渗透膜材料结构参数方面的研究进展.利用共混亲水高分子材料调节基膜的亲水性,利用双层刮膜技术调节基膜的孔结构.结果表明利用亲水基膜和具有贯通孔结构的基膜获得FO膜具有更低的膜结构参数,其正渗透性能也更高.     

醋酸纤维素正渗透膜的制备及其性能研究

以醋酸纤维素(CA)作为成膜材料,以聚酯筛网作为支撑材料,利用相转化法制备正渗透膜,考察了正渗透膜制备过程中的影响因素,包括铸膜液中聚合物浓度以及制膜过程中环境湿度、凝胶浴温度及热处理温度对正渗透膜性能(水通量和截盐率)的影响规律。并利用SEM表征了膜表面和断面的形貌。结果表明,在原料液为0.1mol/L NaCl,汲取液为4mol/L葡萄糖,原料液面向分离层,室温的测试条件下,当聚合物浓度为10.4%、在60℃下热处理、凝胶浴温度为15℃、环境湿度为90%时所制备的正渗透膜通量为9.7～10.3L/(m2.h),截盐率在93%以上。     

构建高性能复合正渗透膜及其在果汁浓缩中的应用

传统果汁浓缩技术存在营养损失大和口感差,以及设备管理成本高等缺点.近年来,正渗透技术因其可以弥补传统浓缩技术的缺陷,受到越来越多的关注.但浓缩过程中由于缺乏高性能的正渗透膜,大大限制了其应用推广.通过在聚砜支撑层背面构建碳纳米管(CNT)抗污染层,在支撑层表面界面聚合制备高性能聚酰胺复合正渗透膜,并应用于果汁浓缩.通过扫描电子显微镜的表征、支撑层盐扩散系数及TFC膜的水通量和反向盐通量的测定等方法,考察了CNT层对TFC膜结构及性能的影响.随后考察在实际果汁浓缩时TFC膜的通量衰减和恢复情况.结果表明,当抽滤CNT分散液的体积为20mL时,TFC膜性能最佳,浓缩果汁时膜通量显著优于未含CNT的对照膜.运行4 200min进行果汁浓缩时,膜通量衰减率和恢复率均明显优于对照膜.     

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.     

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.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to