低能离子束表面改性对聚碳酸酯(PC)粘接性能的影响

利用氩氧混合低能离子束对双酚A型聚碳酸酯(PC)透明材料进行表面改性,并用自制丙烯酸酯胶黏剂表征了改性前后的粘接性能.结果表明:改性后的PC与丙烯酸酯胶黏剂的压剪强度得到了明显的改善.经分析,粘接性能的改善是由于低能离子束表面改性后的PC表面润湿性能的改善、表面活性的提高、表面弱电层的剥蚀和表面微交联层的生成引起的.     

凹凸棒石改性及在酚醛胶黏剂中的应用

利用硅烷偶联剂A-1160(γ-脲基丙基三乙氧基硅烷)改性凹凸棒石(ATP),并制备了改性凹凸棒石/酚醛树脂复合胶黏剂。通过FTIR、热重分析和TEM等技术对改性凹凸棒石以及酚醛树脂复合胶黏剂进行了表征。探讨了酚醛树脂合成工艺条件和改性凹凸棒石(A1160-ATP)用量等对胶黏剂剪切强度、游离甲醛含量和耐热性等性能的影响。结果表明:在甲醛与苯酚物质的量比为1.5∶1,氢氧化钠与苯酚物质的量比为1∶4,A1160-ATP用量为总质量的5%时,改性凹凸棒石/酚醛树脂复合胶黏剂的剪切强度提高到4.64MPa,游离甲醛含量降低到0.10%,A1160-ATP的加入有利于提高酚醛树脂胶黏剂固化后的耐热性能。     

端氨基液体丁腈橡胶/环氧树脂绝缘胶黏剂的制备与性能EI北大核心CSCD

介绍了一种端氨基液体丁腈橡胶(ATBN)增韧改性环氧树脂(EP)的绝缘胶黏剂;借助红外光谱表征胶黏剂固化前后的分子结构变化;通过拉伸与T剥离强度测试表征胶黏剂的黏接性能,借助弯曲与冲击强度测试及冲击断面扫描电镜照片进一步解释胶黏剂的黏接特性;通过击穿场强、体积电阻率以及介电性能测试考核胶黏剂的绝缘性能。研究发现,ATBN分子结构中的活性基团参与了胶黏剂的固化反应;当ATBN添加量为EP的20%时,胶黏剂的拉伸和T剥离强度达到4.92 MPa和9.87 N/mm,分别较纯EP体系提高77%和98%;在此添加量下弯曲强度为113 MPa,冲击强度为18.73kJ/m^2,体积电阻率为1.54×10^(14)Ω·m,击穿场强为25 kV/mm,工频下介电常数为4.53,介电损耗为0.0148。     

端氨基液体丁腈橡胶/环氧树脂绝缘胶黏剂的制备与性能

介绍了一种端氨基液体丁腈橡胶(ATBN)增韧改性环氧树脂(EP)的绝缘胶黏剂;借助红外光谱表征胶黏剂固化前后的分子结构变化;通过拉伸与T剥离强度测试表征胶黏剂的黏接性能,借助弯曲与冲击强度测试及冲击断面扫描电镜照片进一步解释胶黏剂的黏接特性;通过击穿场强、体积电阻率以及介电性能测试考核胶黏剂的绝缘性能。研究发现,ATBN分子结构中的活性基团参与了胶黏剂的固化反应;当ATBN添加量为EP的20%时,胶黏剂的拉伸和T剥离强度达到4.92 MPa和9.87 N/mm,分别较纯EP体系提高77%和98%;在此添加量下弯曲强度为113 MPa,冲击强度为18.73kJ/m~2,体积电阻率为1.54×10~(14)Ω·m,击穿场强为25 kV/mm,工频下介电常数为4.53,介电损耗为0.0148。     

铁锚101胶在粘接结构中的老化机理

以铁锚101胶为粘接剂,工业三乙醇胺为固化剂,制备了橡胶-玻璃纤维粘接结构。同一温度下对粘接结构进行加速老化试验,测定不同老化时间后粘接结构中胶黏剂的180°剥离强度,对粘接结构的剥离界面进行宏、微观观察,并通过红外(IR)、示差扫描量热(DSC)等对胶黏剂进行表征,研究粘接结构中胶黏剂的微观形貌、失效模式和活性官能团结构随老化时间的变化。     

氧化淀粉胶黏剂的交联改性及其性能研究

用玉米淀粉与过硫酸铵反应制备了氧化淀粉胶黏剂,再与二羟甲基双氰胺(DMDCD)进行交联反应,制备了一种交联改性氧化淀粉胶黏剂。采用红外光谱对样品进行了表征,并讨论了交联改性对氧化淀粉胶黏剂耐水性和贮存稳定性的影响。实验结果表明:DMDCD改性提高了淀粉胶黏剂的耐水性与贮存稳定性;当过硫酸铵质量分数为淀粉质量的1.5%,DMDCD质量分数为淀粉质量的3%时,交联改性氧化淀粉胶黏剂的贮存稳定性在45 d以上,其耐水时间、黏度分别为102 h和1680 mPa.s;红外分析证实了DMDCD与氧化淀粉发生了交联反应。     

淀粉/酚醛预聚物共缩聚胶黏剂的制备

以玉米淀粉为原料,采用次氯酸钠进行氧化改性,并以聚乙烯醇为接枝剂进行接枝改性,再与酚醛预聚物进行共缩聚反应,制得淀粉/酚醛预聚物(S/PFO)共缩聚胶黏剂。讨论了淀粉/酚醛预聚物比例、共缩聚温度和共缩聚时间对S/PFO共缩聚胶黏剂固体含量、黏度、固化时间、干状胶合强度和湿状胶合强度的影响。结果表明,淀粉/酚醛预聚物比例为15/120,共缩聚温度为90℃,共缩聚时间为2.0 h时,所制得的S/PFO共缩聚胶黏剂综合性能最佳。采用同步热分析和扫描电子显微镜对S/PFO共缩聚胶黏剂的固化性能和胶合界面进行了表征。相比于酚醛树脂胶黏剂,S/PFO共缩聚胶黏剂固化温度和固化焓值均降低,能够有效降低生产能耗。S/PFO共缩聚胶黏剂能将木材表面的孔隙均匀填满,形成一层薄薄的且连续的胶膜,有利于提高其胶接强度和耐水性能。     

聚氨酯交联改性工业明胶木材胶黏剂的制备与性能

首先以异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃(PTMG)和2,4-二羟基苯甲醛(DBA)为原料制备了水性聚氨酯(DBA-WPU),再以此为交联剂,通过其分子链上的醛基与废弃皮革中提取的工业明胶(INGE)的氨基发生Schiff碱交联反应制得木材胶黏剂INGE/DBA-WPU。紫外光谱(UV-vis)、傅里叶变换红外光谱(FT-IR)和核磁分析(~1H-NMR)表明成功地将DBA引入到水性聚氨酯分子主链上,利用DBA分子链上的羟基与聚氨酯预聚体上的异氰酸酯基反应制备DBA-WPU交联剂。通过FT-IR、X射线衍射(XRD)、接触角、热重分析(TGA)和湿剪切强度对INGE/DBA-WPU黏合剂进行性能检测和结构表征。结果表明,DBA-WPU与INGE发生交联反应,使得胶黏剂的接触角和热稳定性提高。应用试验结果表明,当DBA-WPU用量为30%时,胶黏剂的湿剪切强度高达1.1 MPa,满足GB/T 9846.3-2004中Ⅱ类胶合板的使用要求(≥0.7 MPa),表明引入DBA-WPU可以提高INGE木材黏合剂的耐水性。     

木材胶黏剂仿生改性研究进展

目前,利用无醛胶黏剂替代醛类树脂胶黏剂制备人造板产品成为木材胶黏剂研究热点,符合国家可持续发展和“双碳”战略。生物仿生为木材胶黏剂的改性和性能提升提供了设计灵感,是一种新兴且有效的改性策略。通过仿生设计与改性,无醛木材胶黏剂的耐水性、防霉性、涂布预压性等得到显著提升的同时可以赋予胶黏剂功能性,是木材工业研究热点之一。本文综述了无醛木材胶黏剂仿生改性研究进展,按照仿生原理分为生物化学仿生木材胶黏剂(包括灵感来源于贻贝湿态黏附或模拟生物矿化、细胞壁构筑和重组键合网络过程等)以及结构仿生木材胶黏剂(包括灵感来源于壁虎脚趾微纳刷状结构、蜘蛛丝微相分离结构、珍珠层“砖和砂浆”结构、墨鱼骨多孔结构、弹簧螺旋结构等)。重点介绍了仿生原理、配方设计、胶黏剂性能和潜在应用价值,以期为木材胶黏剂的开发与高附加值利用提供参考。     

废弃PET资源化低聚物多元醇制备聚氨酯胶黏剂性能研究

目的 采用预处理后的废弃PET降解产物作为扩链剂,制备不释放甲醛、附着力强、耐久性好、具有一定力学性能的胶黏剂,以替代传统甲醛基胶黏剂。方法 将废弃PET降解得到的低聚物多元醇进行洗脱预处理,再与异氰酸酯通过逐步聚合反应制得新型聚氨酯胶黏剂(PUa)。结果 在低温/室温环境下,PUa对纸张、玻璃、木材等基材的黏附强度超过126 kPa;经过黏附-解黏附-黏附38次循环黏结后,仍保留至少39.2%的黏附性,具有优良的重复黏结性能。结论 利用废弃PET制备的新型聚氨酯胶黏剂的热稳定性和黏结性能较好,环境适应性好,在轻质缓冲包装领域具有巨大的潜在应用价值。该研究可为塑料废弃物资源化利用提供高附加值的解决方案,还可以为缓解石油资源短缺和胶黏剂行业的可持续发展提供新的思路。     

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