Managing nutrient losses from rural point sources and urban environments

Nutrient loss from rural point sources and urban environments need to be minimised as part of strategies to overcome declining water quality on the Swan Coastal Plain and in the Peel-Harvey estuary in Western Australia. This paper discusses the management of nutrient losses from domestic effluent, urban stormwater runoff, domestic gardens and public open space, intensive animal industries and intensive irrigated agriculture. Measures to minimise nutrient losses from these sources are outlined, using cooperative, technological and regulatory approaches.     

基于多判据的散乱点云特征点提取算法

为了有效获取散乱点云中的尖锐特征点和边界特征点,提出一种利用多判据融合的特征点提取算法。首先利用一种改进的k-d tree构建点云拓扑,搜索样点的K局部邻域;然后利用法向夹角判定准则、核密度判定准则、场力和判定准则分别求取各个样点局部邻域的三个特征参数,最后通过加权计算特征参数得到每个样点的特征值与全局判定阈值,特征值比阈值大的点即为特征点。实验证明,该算法能有效的获取散乱点云中边沿特征点与尖锐特征点。     

聚酯高效催化剂缩聚反应动力学研究

研究了常规的Sb2 O3 、复合催化剂和C - 94三种催化剂对于PET缩聚反应的宏观动力学。结果表明 ,在相同条件下复合催化剂和C - 94的催化活性明显高于常规的Sb2 O3 催化剂 ;C -94的表观活化能明显高于复合催化剂和常规催化剂 ,其催化PET缩聚反应过程的温度效应显著 ;在有效搅拌条件下 ,三种催化剂在高真空阶段仍有较高的催化活性 ,过程是化学反应控制的。     

阴极电泳涂料用高固体分丙烯酸树脂的合成

采用甲基丙烯酸异冰片酯(IBOMA)、甲基丙烯酸二甲胺乙酯(DMAEMA)等(甲基)丙烯酸酯类单体合成阴极电泳涂料用高固体分自交联型丙烯酸树脂。研究发现,引入低表面张力、带非极性多环酯基的IBOMA可降低树脂的黏度,提高合成树脂的固体质量分数到75%甚至更高;当单体的滴加时间控制在3～3 5h,采用m(偶氮二异丁腈)∶m(过氧化苯甲酸叔戊酯)=1∶(0 3～0 5)的混合引发剂,w(混合引发剂)=2%～4%时,能获得相对分子质量大小及分布适宜的水溶性高固体分自交联聚合物;研究聚合物水溶性和涂膜交联性的影响因素发现,w(DMAEMA)=16%、w(甲基丙烯酸羟乙酯)=15%、w(N 丁氧甲基丙烯酰胺)=6%时,树脂的水溶性较佳,涂膜的交联度可达90%;引入了丙烯酸作为共聚物自交联的潜催化剂,差示扫描式量热法(DSC)分析表明,w(丙烯酸)=1%时,可显著降低树脂的固化反应温度。     

Measurement of Fiber/Matrix Interfacial Shear Stress at Elevated Temperatures

An apparatus for measurement of the fiber/matrix interfacial shear stress at temperatures up to 1100° is described. Equipment was used to measure interfacial properties as a function of temperature in two ceramic-matrix composites and one metal-matrix composite. In the composites where the thermal expansion of the matrix was higher than that of the fiber, the interfacial shear stress decreased with temperature. The opposite trend was observed in a system with low matrix thermal expansion. The change of the interfacial shear stress with temperature of all the composites studied can be fully explained by considering the fiber/matrix expansion differences.     

高纯盐酸的合理生产

介绍了“三合一”石墨炉法生产高纯盐酸工艺的改进,确定了最佳工艺流程。结合生产实际提出了注意事项和操作要点。     

方型状态方程在高压相平衡中的研究及应用

对近年来状态方程的研究及其在高压相平衡计算中的应用状况作了综述分析。以ＰＲＳＶ方程为基础，通过实际计算考察和评价不同混合规则在复杂体高压汽液平衡、超临界流体／固体体系相平衡计算中的性能     

有机溶剂下盐酸环丙沙星的荧光特性研究

本文在几种有机试剂(乙醇，甲醇，丙酮)条件下，对盐酸环丙沙星产生的荧光特性进行了初步的研究，并初步探讨了有机溶剂下温度对其荧光强度的影响。     

Effects of branching upon some surfactant properties of sulfated alcohols

A study was undertaken to determine the surfactant properties of various sulfated alcohols. Most notably, the Krafft point and the ability to emulsify decane were studied. A series of sulfated Guerbet alcohol and Guerbet alcohol alkoxylate sulfates with 16 carbon atoms and an analogous series based upon cetyl alcohol, a linear C₁₆, were studied as hydrophobes.     

Effect of polymer density on polyethylene hollow fiber membrane formation via thermally induced phase separation

Microporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004