硫化树脂对EPDM性能的影响

文中通过对三元乙丙橡胶化学结构的分析，探讨了多种硫化树脂与EPDM分子中的双键、巯基进行的交联反应，旨在提高EPDM制品的物理机械性能，减少其他配合剂的用量，防止硫化产品喷霜。实验证明，树脂硫化EPDM体系效果良好，在性价比方面国产WS硫化树脂具有较大的市场发展空间。     

枯草杆菌碱性磷酸酶制备的最佳工艺条件及酶促反应动力学性质的研究

以枯草杆菌为菌种液体培养制备碱性磷酸酶，研究确定了培养的最佳工艺条件，并对碱性磷酸酶的酶促反应动力学性质进行了初步探讨。结果表明，枯草杆菌制备碱性磷酸酶的最佳工艺条件为：40℃，pH值7．4振荡培养10h，酶活最高。对碱性磷酸酶的动力学性质研究表明，该酶催化底物磷酸苯二钠水解反应的最适pH值8．8，最适温度52℃，米氏常数Km值为2．94mmol／L。     

Surface morphology and nodule formation mechanism of cellulose acetate membranes by atomic force microscopy

By the use of atomic force microscopy (AFM), formation mechanism of nodular structure in cellulose acetate membranes was systematically investigated. Elementary factors affecting the nodule formation were delineated on the basis of both kinetic and thermodynamic considerations. It was shown that (1) the exact nature of nodular structure is thermodynamic equilibrium glassy state; nodular structure will vanish in the rubbery state; (2) the thermodynamic factor affecting nodule formation is the membrane formation temperature; with the membrane formation temperature decreasing, more chain segments are able to form nodular structures; (3) nodule formation is dependent on the segment rearrangement; variation of the solvent environment is the major kinetic factor affecting the segment rearrangement and nodule formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1328–1335, 2003     

换热器管板厚度的快速计算

在化工生产中，换热器设备是应用最广泛的一种设备，且占主导地位。而在换热器设计过程中，管板厚度设计计算比较复杂。本文的特点是在满足GB151—1999《管壳式换热器》标准要求的前提下，介绍一种快速简便估算管板厚度的计算公式，从而达到快速确定管板厚度的目的。     

Photochemical degradation of glassy polyesters of low softening point

The photodegradation of polyesters prepared by the reaction of o-phthalic, adipic, and “dimer” acids with ethylene glycol has been studied. The polyesters softened at temperatures in the range of 25–50°C. Polymer films were irradiated in air by means of a medium pressure mercury lamp and the extent of formation of COOH groups determined by infrared spectroscopy. The films were also irradiated in vacuo and in air by means of a high-pressure mercury lamp, and the volatile products, consisting mainly of carbon monoxide and carbon dioxide, were determined by gas chromatography. The results are interpreted in terms of simultaneous Norrish type I and type II decompositions of the polyesters. The type I process accounts for the formation of carbon monoxide and carbon dioxide in the absence of air. The enhanced yield of carbon dioxide in irradiations performed in air is ascribed to the formation of hydroperoxide which undergoes further photolysis. The type II process accounts for the formation of COOH groups. The photodegradation of these glassy polyesters parallels that of crystalline poly(ethylene terephthalate) and is relatively unaffected by changes in composition of the aromatic polyester.     

Impacts of new technologies on media usage and social behaviour in domestic environments

Technological infrastructure at home is changing continuously and is becoming increasingly interconnected. Media devices, including the TV set, provide access to the Internet and offer manifold opportunities to consume media on demand. Additionally, personal devices, such as smartphones, also enable flexible consumption and sharing of media. Questions about how these technologies change the user's media usage and how these changes affect the social structure of a household, however, remain largely unanswered. In order to gain insight into the adoption of new technologies into daily routines, we explored these changes in respect of people's media usage in a qualitative long-term Living Lab study. We will present findings regarding personal routines, flexible integration of new devices into existing practices, influences on households as social systems and related issues in device access and collective use. We will highlight potentials and conflicts regarding device shifts and roles; restrictions in device access; social influences in the living room; and individual changes in media consumption.     

试验温度和停放时间对胶料加工性能的影响

研究试验温度和停放时间对胶料加工性能的影响。结果表明，试验温度对胶料的门尼粘度、门尼焦烧时间和硫化特性均有一定影响。门尼粘度测定的试验温度选择100℃；门尼焦烧时间测定的试验温度一般选120℃，SBR胶料可提高至130℃左右，以缩短试验时间；硫化特性测定的试验温度一般选185℃。试验前模腔达到规定温度后再保持15min，以使转子与模腔温度一致。胶料停放时间应控制在2h左右。     

悬浮液进样-火焰原子吸收光谱法测定茶叶中的微量铬

将茶叶悬浮于琼脂胶体中制成悬浮液 ,直接喷入空气 -乙炔火焰 ,用火焰原子吸收光谱法测定茶叶中的微量铬 ,方法简便、快速、灵敏度和精密度高、测定结果与用灰化法处理样品一致 ,检验表明 ,两种样品前处理方法之间无显著性差异。相对标准偏差为 3.4 %～ 6 .1% ,加标回收率为 95 .7%～ 10 3.8 %。     

抗日战争时期的青年心理探析

抗日战争是中华民族历史上的一次大浩劫,中国人民为此承受了太多的痛苦与磨难,特别是对于肩负着国家与民族振兴使命的青年更是如此.分析战时青年的心理变化及原因,指出政府和社会对青年人的心理没有采取恰当的方法进行有效的疏导,提出要总结和吸取历史的经验教训,为我们今天应对大灾难提供借鉴.     

GCr15轴承钢连铸过程中热物性参数的研究

借鉴前人实验数据,采用一定的数学方法,对轴承钢的热物性参数进行了研究.结果表明：GCr15轴承钢的液相线温度为1 465.7℃,固相线温度为1 328.4℃,零强度温度为1 380℃左右,零塑性温度为1 330℃左右;在固相区、液固两相区、液相区分别采用不同的公式进行处理,可使结果更加准确,还避免了奇异性.研究结果可为轴承钢连铸工艺有限元模拟提供基础.