庄信万丰发布《铂金2009年年鉴》

据庄信万丰公司最近出版的《PLATINUM 2009》报道,2008年,全球铂金市场出现了11.7t的短缺,铂金的供应量下降了9.5%,达到了185.7t。汽车尾气净化催化剂行业对铂金的需求下降了8.2%,达到了118.3t。除去回收料,全球首饰行业对铂金原材料的需求下降了6.2%,达到了42.5t。     

圆筒式加热炉辐射室分片预制及安装方法

研究了在垂直方向上对圆筒式加热炉辐射室进行分片预制的方法,分析了辐射室分片预制方法的特点。结果表明:这种方法大大减少了现场安装组对工作量,减少了人工,机械的使用量,节约了成本。降低了工作风险,提高了施工进度,保证了工程质量。     

分析GPS在油田井位测量上的应用

我国科学技术的不断发展,推动了我国GPS技术的不断进步,在我国多个领域获得了应用,实现了我国国民经济的快速、高效的增长。GPS在我国油田井位测量中的应用,大大提高了工作人员的工作效率,且保证了油田井位测量结果的准确性。本文先是对GPS全球定位系统进行了概述,又详细阐述了GPS技术在井位测量中的建立,后分析介绍了GPS全球定位系统的其它应用。     

带式过滤机在多品种氢氧化铝生产中的应用

介绍了带式真空过滤机的工作原理及其在多品种氢氧化铝生产方面的应用情况,并对带式真空过滤机使用过程中存在的问题进行了改造。改造之后,提高了洗涤过滤效率,降低了滤饼水分,降低了能耗,提高了产量,确保了产品质量,取得了较好的经济效益。     

中医药院校物理化学教学改革与探索

物理化学是药学专业学生的一门重要基础课。针对中医院校学生的专业特点,我们对物理化学课程的教学内容进行了有针对性的改革,突出了教学的专业特色。通过采用不同的教学形式,活跃了课堂气氛,提高了学生的综合素质。在教学中引入多媒体教学技术,提高了教学效率。与此同时,我们加强了实验教学中学生科研能力的培养,取得了较好的教学效果。     

高庄煤矿供热系统的改造

高庄煤矿针对原锅炉供热系统存在的问题进行了改造,拆除原锅炉,采用邻矿电厂的富余蒸气作热源,安装热交换器组。改造后保证了供热质量,节约了能源、资源,提高了矿区环境质量,降低了运行维护费用,节省了人力资源,减少了占地面积,节约了各项检查检测费用。     

一种基于可编程计数阵列和最小二乘法的模数转换器

设计了一款软硬件结合的八位模数转换器。分析了脉宽调制波形的特性,研究了可编程计数阵列的工作原理,建立了系统实现的理论模型。经过理论分析和实际测试,设计了系统硬件电路。对硬件系统进行了抽样测试,并将抽样数据与理论值进行对比研究。采用最小二乘法对抽样数据进行拟合,对拟合结果进行对比分析研究,建立了优化的模数转换数学模型。在Keilv4平台上,设计了模数转换的软件系统。在某钢化玻璃加热炉上得到应用,系统工作稳定可靠。     

酒瓶顶盖注塑模具设计

分析了酒瓶顶盖的结构,提出了模具设计的关键点,设计了模具的整体结构。根据塑件分型面的位置,设计了推件板和推杆的二次推出机构,在型芯紧固螺钉中心钻孔,解决了推杆的安装问题。多个分型面处采用了锥面配合,解决了导向件磨损的问题,提高了模具的精度,延长了模具的寿命。经过生产验证,该摸具结构合理、动作可靠。     

2010年度工作会议

<正>2010年1月16日—17日,公司召开了2010年度工作会议。会议认真回顾总结了2009年的主要工作,分析了当前的形势和机遇,部署了2010年的工作任务。会上,公司董事长蒋明作了重要讲话,总经理毛绍融作了行政工作报告,党委副书记陈百河作了党委工作报告,副总     

对二甲苯储存输转中的环境风险评估与管控研究

随着工业化的快速发展和化学品使用量的不断增加,对二甲苯储存输转中的环境风险成了一个亟待解决的问题。本文首先介绍了环境风险评估的概念和流程,然后探讨了对二甲苯储存输转中可能存在的环境风险,并阐述了环境风险评估的方法和实现。接着,文章分析了风险管控的基本原则,提出了对二甲苯储存输转中的风险管控策略,并结合实践案例进行了分析。最后,总结了对二甲苯在储存输转中的环境风险评估与管控的现状和不足,并提出了相关改进和建议。     

Adhesion of UV-Cured Laminates of Poly(ethylene-2,6-naphthalate) (PEN) and Poly(ethylene terephthalate) (PET) films

This paper describes the properties of an ultraviolet (UV) curable laminating adhesive system that can be used with PEN, PET and UV-stabilized PET films. The adhesive system that contains (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO) as photoinitiator was optimally cured with a V-bulb fitted ultraviolet irradiator. The laminated structures built with this adhesive system and PEN, PET and UV-stabilized PET films showed a large manufacturing operating window, both in terms of adhesive layer thickness, initial peel strengths above 1500 N/m, V- and D-bulb UV sources and curing speeds from 5– 10 m/min. The 600-h dry heat aging tests indicated that the UV-stabilized PET films underwent less than approximately 1% decrease in light transmission and less than a 1% gain in color. The UV-stabilized PET film and its laminate showed particularly strong retention of optical properties under damp aging and QUV weathering, compared to PEN and non-UV-stabilized PET films. Finally, the peel strengths of the laminates were retained to greater than 1300 N/m for laminate structures of 50 μm film thickness, whereas structures made from thicker films retained approx. 40–60% (700–1100 N/m) of their initial peel strength.     

Eco-Friendly Adhesives Based on Tannin and N,N-Bis(2-Hydroxy-Ethyl) Fatty Amides (HEFAs) from Non-Traditional Oils for Wood Bonding

Abstract

Wood adhesives were formulated using tannin and N,N-bis(2-hydroxyethyl) fatty amides (HEFAs). The natural tannin-based adhesives can be used to replace formaldehyde-based adhesive systems and thereby reduce formaldehyde and volatile organic compound (VOC) emissions from adhesives used for plywoods. Performance properties of the adhesively bonded wood joints viz., tensile strength, impact strength and chemical resistance were measured. N,N-bis(2-hydroxyethyl) fatty amides (HEFAs) from non-traditional oils were mixed with a pure tannin-based adhesive as a crosslinker, and this increased the tensile strength, impact strength and chemical resistance of wood joints. The results revealed that a high performance and eco-friendly adhesive system for wood can be successfully formulated using tannin and HEFA.     

Intensity of singular stress field (ISSF) variation as a function of the Young's modulus in single lap adhesive joints

Employing mixed adhesive joints has been proven to be very useful. This type of joint leads to improved performance by increasing strength and decreasing stresses in critical areas of the joint. In the same way, the use of the Intensity of Singular Stress Field (ISSF) has been shown to be suitable for adhesive joint calculation, since the adhesive strength can be controlled by the ISSF at the interface end. Four finite element models have been created by combining two epoxy adhesives with different mechanical properties, and therefore with different Young's moduli. New mixed adhesive joints have been compared with respect to only-one adhesive joints in terms of the ISSF. The results show a clear improvement with one of the configurations of mixed adhesive joints. A significant decrease of 35.64% in the ISSF is obtained compared to the only-one adhesive configuration.     

Properties and thermal analysis study of modified polyvinyl acetate (PVA) adhesive

Polyvinyl acetate (PVA) adhesive is one of the most common types of adhesives has been used in the wood industry for decades. However, many drawbacks are still associated with this adhesive including low water resistance, poor bond strength, and low viscosity. In this reported study, two additives, sulfanilamide and N,N-dimethylethylenediamine, were used to modify a PVA adhesive to improve its comprehensive practical performance. The prepared adhesive samples were characterized by Fourier transform infrared spectroscopy (FT-IR). Furthermore, the thermal decomposition characteristics of the PVA adhesives were studied using Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry analysis (DSC) combined with the Kissinger method. The experimental results showed that when compared to the pure PVA adhesive, the solid content, viscosity, dry bond strength, and wet bond strength of the modified PVA adhesive (PVA + N,N-dimethylethylenediamine + sulfanilamide) were improved by 34.8, 41.4, 47.0 and 35.2%, respectively. FT-IR analysis indicate that these two additives altered the chemical bond ratio that resulted from the generation of new chemical bonds, which explained the improved performance of the modified PVA adhesive. The pure PVA adhesive possessed two thermal decomposition steps, while the modified PVA adhesive (PVA + N,N-dimethylethylenediamine + sulfanilamide) exhibited only one thermal decomposition step. The thermal decomposition process of the pure PVA adhesive is characterized by a quick thermal decomposition stage and a slow thermal decomposition stage. Since the ΔH > 0, ΔS < 0 and ΔG > 0 in the thermal decomposition process it can be concluded that the decomposition reactions of the PVA adhesive were non-spontaneously endothermic and the entropy decreased during the reaction.     

Analysis of methyl methacrylate adhesive (MMA) relaxation with non-linear stress–strain dependence

One of the problems regarding high strength and stiffness adhesive connections is the concentration of stresses on the edges of the bond. The use of adhesives characterized by high strength but also greater flexibility would avoid this effect and prevent brittle failure. Therefore, the results of a series of laboratory tests are presented in the paper for a semi-rigid methyl methacrylate adhesive (MMA). The research included quasi-static tensile and relaxation tests of the adhesive at a temperature of 23 °C and 50% humidity. Based on the test results, the complex characteristics of the viscoelastic material parameters of the adhesive for different stress levels were determined. The Maxwell model was used to describe the material model of the adhesive during relaxation, for which Prony series were calculated. The work also indicates the approach to numerical modelling using the Finite Element Method (FEM) for selected adhesive, ensuring good convergence of results in the elastic work of the material. Numerical analyses were performed in the ABAQUS software, using material models such as hyperfoam and viscoelasticity. Finally, the relaxation function values obtained during the laboratory tests and numerical analyses were compared and a forecast for longer term function values was presented. The presented results can be used for numerical analysis of adhesive joints with the use of a selected methacrylate adhesive, in the scope of the elastic range subjected to short- or long-term loads.     

Characteristics of simultaneous epoxy-novolac full interpenetrating polymer network (IPN) adhesive

In this investigation, an attempt has been made on the synthesis of epoxy-novolac IPN adhesive simultaneously by using full interpenetrating polymer network (IPN) technique. Novolac resin is mixed in different weight ratios with respect to epoxy resin. Thereafter, both the resins are cross-linked with their respective cross linker agents simultaneously. This epoxy-novolac IPN adhesive is characterized by various studies such as swelling; cross-link density; dynamic mechanical and thermal analysis and fourier transform inferred spectroscopy (FTIR). The swelling study reveals that the epoxy-novolac IPN adhesive is synthesized through full IPN technique successfully. The cross-link density result shows that epoxy- novolac (4:1) IPN adhesive has greater interpenetration than other epoxy-novolac IPN adhesive systems. Dynamic mechanical and thermal analysis (DMTA) result exhibits that epoxy-novolac (4:1) IPN adhesive is stiffer than another epoxy-novolac IPN adhesive system. The result of FTIR proves that epoxy-novolac IPN adhesive undergoes simultaneously. The results of all these characterization techniques conclude that epoxy-novolac IPN adhesive system with 4:1 ratio is considered to be the best IPN adhesive compared to others epoxy-novolac IPN adhesive systems.     

Adhesion at Poly(Butylacrylate)-Poly(Dimethylsiloxane) Interfaces

We present an investigation of the adhesion modulation mechanisms of silica-like nanoparticles (MQ resins) incorporated in polydimethylsiloxane (PDMS) elastomers and acrylic adhesives. The Johnson-Kendall-Roberts (JKR) test has been used to gain information on the both zero velocity and the velocity dependence of the adhesive strength, avoiding as much as possible contributions to the adhesive strength of bulk dissipation in the adhesive (which is not the case with peel tests). As the incorporation of the MQ resins into the elastomers deeply affects their own mechanical properties, the loading and unloading curves of small poly(butylacrylate) (PBA) lenses on either PDMS elastomers, adsorbed PDMS and pure MQ resin layers are compared in a systematic manner. The PBA chains are observed to have a neat affinity for the MQ resin nanoparticles. When MQ resins are present at the interface, they tend to prevent facture propagation, thus producing a larger deformation of the PBA lens. The modulation of adhesion is then dominated by the corresponding dissipation inside the acrylic adhesive.     

低温(一℃)固化环氧树脂胶粘剂的研究

介绍一种能在-15℃条件下固化的环氧树脂胶粘剂的配制,固化条件与力学性能的影响及其应用。     

Pressure-sensitive adhesion in the blends of poly(N-vinyl pyrrolidone) and poly(ethylene glycol) of disparate chain lengths

Adhesive behavior in blends of high molecular weight poly(N-vinyl pyrrolidone (PVP) with a short-chain, liquid poly(ethylene glycol) (PEG) has been studied using a 180° peel test as a function of PVP-PEG composition and water vapor sorption. Hydrophilic pressure-sensitive adhesives are keenly needed in various fields of contemporary industry and medicine, and the PVP-PEG blends, pressure-sensitive adhesion has been established to appear within a narrow composition range, in the vicinity of 36 wt% PEG, and it is affected by the blend hydration. Both plasticizers, PEG and water, behave as tackifiers (enhancers of adhesion) in the blends with glassy PVP. However, PEP alone is shown to account for the occurrence of adhesion, and the tackifying effect of PEG is appreciably stronger than that of sorbed water. Blend hydration enhances adhesion for the systems that exhibit an apparently adhesive type of debonding from a standard substrate (at PEG content less than 36 wt%), but the same amounts of sorbed water are also capable of depressign adhesion in the PEG-overloaded blends, where a cohesive mechanism of adhesive joint failure is typical. The PVP-PEG blend with 36% PEG couples both the adhesive and cohesive mechanisms of bond rupture (i.e., the fibrillation of adhesive polymer under debonding force and predominantly adhesive locus of failure). Blend hydration effect on adhesion has been found to be reversible. The micromechanics of adhesive joint failure for PVP-PEG hydrogels involves the fibrillation of adhesive polymer, followed by fibrils stretching and fracturing as their elongation attains 1000-1500%. Peel force to rupture the adhesive bond of PVP-PEG blends increases with increasing size of the tensile deformation zone, increasing cohesive strength of the material, and increasing tensile compliance of the material, obeying the well-known Kaelble equation, derived originally for conventional rubbery pressure-sensitive adhesives. The major deformation mode upon peeling the PVP-PEG adhesive from a standard substrate is extension, and direct correlations have been established between the composition behaviour of peel strength and that of the total work of viscoelastic strain to break the PVP-PEG films under uniaxial drawing. As a result of strong interfacial interaction with the PET backing film, the PVP-PEG adhesive has a heterogeneous two-layer structure, where different layers demonstrate dissimilar adhesive characteristics.     

PRESSURE-SENSITIVE ADHESION IN THE BLENDS OF POLY(N-VINYL PYRROLIDONE) AND POLY(ETHYLENE GLYCOL) OF DISPARATE CHAIN LENGTHS

Adhesive behavior in blends of high molecular weight poly(N-vinyl pyrrolidone (PVP) with a short-chain, liquid poly(ethylene glycol) (PEG) has been studied using a 180° peel test as a function of PVP-PEG composition and water vapor sorption. Hydrophilic pressure-sensitive adhesives are keenly needed in various fields of contemporary industry and medicine, and the PVP-PEG blends, pressure-sensitive adhesion has been established to appear within a narrow composition range, in the vicinity of 36 wt% PEG, and it is affected by the blend hydration. Both plasticizers, PEG and water, behave as tackifiers (enhancers of adhesion) in the blends with glassy PVP. However, PEP alone is shown to account for the occurrence of adhesion, and the tackifying effect of PEG is appreciably stronger than that of sorbed water. Blend hydration enhances adhesion for the systems that exhibit an apparently adhesive type of debonding from a standard substrate (at PEG content less than 36 wt%), but the same amounts of sorbed water are also capable of depressign adhesion in the PEG-overloaded blends, where a cohesive mechanism of adhesive joint failure is typical. The PVP-PEG blend with 36% PEG couples both the adhesive and cohesive mechanisms of bond rupture (i.e., the fibrillation of adhesive polymer under debonding force and predominantly adhesive locus of failure). Blend hydration effect on adhesion has been found to be reversible. The micromechanics of adhesive joint failure for PVP-PEG hydrogels involves the fibrillation of adhesive polymer, followed by fibrils stretching and fracturing as their elongation attains 1000-1500%. Peel force to rupture the adhesive bond of PVP-PEG blends increases with increasing size of the tensile deformation zone, increasing cohesive strength of the material, and increasing tensile compliance of the material, obeying the well-known Kaelble equation, derived originally for conventional rubbery pressure-sensitive adhesives. The major deformation mode upon peeling the PVP-PEG adhesive from a standard substrate is extension, and direct correlations have been established between the composition behaviour of peel strength and that of the total work of viscoelastic strain to break the PVP-PEG films under uniaxial drawing. As a result of strong interfacial interaction with the PET backing film, the PVP-PEG adhesive has a heterogeneous two-layer structure, where different layers demonstrate dissimilar adhesive characteristics.