刍议市政道路养护机械优化配置评价指标体系构建

市政府道路是城市道路的主要组成部分。通过对市政府道路养护的必要性、养护机械配置的问题以及如何构建合理的评价指标体系等进行阐释,为市政府道路养护工作提供相应的参考意见。     

剑麻纤维／酚醛树脂复合材料研究

本文采用碱处理、硅烷偶联剂处理、化学接枝和热处理等物理化学方法，对剑麻纤维进行改性。研究了改性后短剑麻纤维／酚醛树脂复合材料的弯曲性能、无缺口冲击强度和布氏硬度，借助扫描电子显微镜观察了复合材料的弯曲断口形貌，并研究了剑麻纤维的不同处理方法对复合材料耐水浸泡性的影响。结果表明：剑麻纤维经硅烷偶联剂处理后，能有效改善刚性的剑麻纤维与脆性的酚醛树脂基体之间的粘结，从而提高了复合材料的综合力学性能，剑麻     

壳聚糖固定化脲酶生物传感器选择性测定铜离子

基于重金属对脲酶的抑制作用,研制了用于测定铜离子的生物传感器。该生物传感器的制备以壳聚糖为载体,将脲酶固定于pH电极表面。由于壳聚糖对Cu2+的富集,该生物传感器展现出高灵敏度。在样品溶液中加入5 mmol/L NaI,可以消除Hg2+和Ag+的干扰,从而实现Cu2+的选择性检测。在0.005～0.5μg/mL的浓度范围内,脲酶活性的抑制率与Cu2+浓度的对数呈良好的线性响应关系,其检出限为0.002μg/mL。将使用后的生物传感器浸泡于0.5 mmol/L的EDTA溶液再生5 min,被Cu2+抑制的脲酶的活性可以得到恢复。     

基于移动平台的校园资讯系统设计与实现

为了让高校师生可以快捷方便地获取到校园各类资讯,摆脱时间和空间的限制,设计了一种基于移动平台的校园资讯系统。该系统在PC平台上采用Asp.Net和SQL Server 2005技术,基于B/S的三层网络结构设计,在移动平台上基于C/S模式设计并开发了一个具备相应功能的Android手机客户端应用[1]。该系统具有查询课程、查询教室、查询考试安排、学生交友、发布商品、查询商品等基本功能。该移动平台系统界面友好,操作方便,资讯丰富,极大地方便了高校师生的学习、工作和生活。     

Effects of reaction and cure temperatures on morphology and properties of poly(ester‐urethane)

Poly(ester‐urethane) was synthesized from poly(ethylene glycol adipate) (PEG) and 2,4‐toluene diisocyanate (TDI) to study the effects of reaction temperature and cure temperature on the crystallization behavior, morphology, and mechanical properties of the semicrystalline polyurethane (PU). PEG as soft segment was first reacted with TDI as hard segment at 90, 100, and 110°C, respectively, to obtain three kinds of PU prepolymers, coded as PEPU‐90, PEPU‐100, and PEPU‐110. Then the PU prepolymers were crosslinked by 1,1,1‐tris (hydroxylmethyl) propane (TMP) and were cured at 18, 25, 40, 60, and 80°C. Their structure and properties were characterized by attenuated total reflection Fourier transform infrared, wide‐angle X‐ray diffraction, scanning electron microscopy, dynamic mechanical analysis, and tensile testing. With an increase of the reaction temperature from 90 to 100°C, the crystallinity degree of soft segment decreased, but interaction between soft and hard segments enhanced, leading to the increase of the glass transition temperature (T_g) of soft domain and tensile strength. When the cure temperature was above 60°C, miscibility between soft and hard segments of the PEPU films was improved, resulting in relatively low crystallinity and elongation at break, but high soft segment T_g and tensile strength. On the whole, all of the PEPU‐90, PEPU‐100, and PEPU‐110 films cured above 60°C possessed higher tensile strength and elongation at break than that of the films cured at other temperatures. The results revealed that the reaction temperature and cure temperature play an important role in the improvement of the crosslinking structure and mechanical properties of the semicrystalline PU. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 708–714, 2006     

微波烧结Al2O3-TiC复合材料的研究

以纳米级TiC、Al2 O3 为原料 ,用微波烧结制备Al2 O3 -TiC复合材料 ,并与常规烧结比较。分析了两种烧结方法对制备试样的力学性能的影响 ,并探讨了添加剂对Al2 O3 -TiC复合材料烧结性能的影响     

间歇窑窑墙温度场图形仿真研究

本文利用有限差分法求解间歇窑窑墙中的温度分布，并用Ｃ语言设计了窑墙温度场图形仿真软件。输入窑墙厚度和材料的物性参数等，系统可进行窑墙温度场分布的实时仿真及窑炉结构与操作的优化     

甲缩醛空气氧化制甲醛催化剂的研制和工艺条件探讨

考察了铁钼催化剂对甲缩醛空气氧化制甲醛的催化性能。制备了多种不同钼铁比和第三、第四组分的催化剂,进行了活性评价和筛选,探讨了适宜的工艺条件范围。对于所选定的催化剂(钼铁比为1.82～1.88;铬铁比为0.1～0.38)在适宜的工艺条件(甲缩醛进料浓度4.5～5.5％;甲缩醛和氧气进料比1:2.0±0.2;空速12000～22000h~(-1);热点温度370～390℃)下,甲醛收率可达85％左右。     

果胶杂质对苎麻纤维及其复合材料性能的影响

研究了苎麻纤维中的果胶杂质对苎麻纤维及其复合材料性能的影响，根据苎麻复合材料综合性能，确定了最佳果胶杂质含量为6．6％。     

Effect of montmorillonite on properties of styrene–butadiene–styrene copolymer modified bitumen

Clay/styrene–butadiene–styrene (SBS) modified bitumen composites were prepared by melt blending with different contents of sodium montmorillonite (Na‐MMT) and organophilic montmorillonite (OMMT). The structures of clay/SBS modified bitumen composites were characterized by XRD. The XRD results showed that Na‐MMT/SBS modified bitumen composites may form an intercalated structure, whereas the OMMT/SBS modified bitumen composites may form an exfoliated structure. Effects of MMT on physical properties, dynamic rheological behaviors, and aging properties of SBS modified bitumen were investigated. The addition of Na‐MMT and OMMT increases both the softening point and viscosity of SBS modified bitumens and the clay/SBS modified bitumens exhibited higher complex modulus, lower phase angle. The high‐temperature storage stability can also be improved by clay with a proper amount added. Furthermore, clay/SBS modified bitumen composites showed better resistance to aging than SBS modified bitumen, which was ascribed to barrier of the intercalated or exfoliated structure to oxygen, reducing efficiently the oxidation of bitumen, and the degradation of SBS. POLYM. ENG. SCI., 47:1289–1295, 2007. © 2007 Society of Plastics Engineers