基于本体理论的关系数据库存储模式

通过分析借鉴现有本体在关系数据库中的存储模式的优势与不足,提出面向查询的基于本体理论的关系数据库新型存储模式.分析关系数据库概念模型与OWL本体表述之间的关系,实现OWL本体描述关系数据库概念模型,将本体映射到POJO对象模型,利用ORM技术将对象模型映射到关系模型中,形成新型的关系数据库存储模式.该存储模式支持数据库概念模型的灵活演变与更新,实验验证了其有效性.     

N,N,N-三甲基-2,3-二(硬脂酰氧基)丙基氯化铵(CDESA)的生物降解性

采用活性环氧中间体失水甘油基三甲基氯化铵合成了一种阳离子双酯表面活性剂——N,N,N-三甲基-2,3-二(硬脂酰氧基)丙基氯化铵(CDESA),来代替传统的难降解的表面活性剂型柔软剂,如目前国内仍在大量使用的双十八烷基二甲基氯化铵(D1821)。对CDESA的好氧降解性能进行了研究:以天然环境中的生活沉降污泥作为微生物源,用河水稀释,经培养、驯化后用于测试降解时间和半衰期,并与D1821的好氧降解性能作了对比。结果表明,CDESA的半衰期为3 d,容易降解,而D1821半衰期为7 d,较难降解,CDESA生物降解性能优于D1821。     

全球蛋氨酸市场现状分析

目前全球蛋氨酸市场由少数几家公司控制 ,其中Novus、Degussa、Adiesso公司分别占有 3 4%、3 0 %和 2 8%的市场份额 ,国内迄今尚未有一套规模型生产装置。而亚洲地区蛋氨酸供应紧张 ,中国作为世界第二大饲料生产国 ,对蛋氨酸的需求更高 ,目前我国主要依靠进口解决需求问题 ,2 0 0 1～ 2 0 0 3年每年进口量均在 5万t/a以上。     

脲类杀菌剂戊菌隆的合成

以对氯氯苄为原料，先与六甲基次胺进行胺化反应制得对氯苄胺；然后在Raney Ni催化剂存在下。在高压釜中与环戊酮进行缩合反应，同时加氢还原，得到N-对氯苄基-N-环戊胺；最后N-对氯苄基-N-环戊胺与苯基异氰酸酯在50℃的甲苯溶液中缩合，处理后得到戊菌隆。产品戊菌隆含量95％，以对氯氯苄计总收率67．3％。     

膨胀阻燃聚丙烯复合体系的研究

采用聚磷酸铵（APP）和Deflam（敌火龙）分别对聚丙烯（PP）进行了填充改性，研究了两者对PP力学性能、阻燃性能、结晶性能的影响。结果表明：在PP中分别加入APP和Deflam，都可改善PP的阻燃性能，并且添加后者比添加前者对PP的阻燃效果要好。在阻燃性能改善的同时，复合体系的弯曲模量和弹性模量明显提高，但拉伸强度和冲击强度降低。APP和Deflam在PP中都具有成核剂作用，可使PP的结晶过程在较高温度下进行，但Deflam对PP的成核效果不如APP。     

环氧氯丙烷中有机杂质组分的气相色谱法测定

介绍了在环氧氯丙烷国家标准制定过程中对环氧氯丙烷中有机杂质组分测定方法的改进。通过采用毛细管柱气相色谱法,对分离条件、毛细管柱选择等进行了试验和讨论。试验结果表明,采用毛细管柱气相色谱法,选用N2作为载气,分流比50∶1,并采用程序升温:柱初温40℃(保持5 min)→10℃/min→180℃(保持30 min)的条件下可获得更好的分离效果及准确度,该方法测得各杂质组分的相对标准偏差为0.0113%~0.0377%,回收率为93.3%~102.9%。能满足生产中质量控制和产品出厂分析的需要,保证了国家标准分析方法的先进性。     

风险型多指标决策分析方法研究

根据风险型多指标决策问题的特点,利用确定型多指标决策和单目标风险型决策理论,提出了三种风险型多指标决策分析方法,并以实例验证.     

SnO2和SiO2用于PVC的阻燃消烟及协同作用

研究了二氧化锡和二氧化硅对软PVC阻燃消烟性的影响。通过对极限氧指数、剩炭率、烟密度的测定和DTATG曲线的分析证明,添加8g二氧化锡/二氧化硅复合阻燃剂的PVC的氧指数和剩炭率比未添加的分别增高5.5个单位和4.1%,烟密度降低16.4%,降解活化能分别降低38kJ/mol和23.1kJ/mol,从而证明二氧化锡/二氧化硅复合阻燃剂对于PVC是一种很好的阻燃消烟剂,二氧化锡和二氧化硅有很好的协同作用。同时证明这种复合阻燃剂能代替三氧化二锑,使产品的成本进一步降低。     

Reactive blending of thermoplastic polyurethane in situ with poly(vinyl chloride)

In this study, a novel reactive blending process was developed for producing poly(vinyl chloride)/thermoplastic polyurethane (PVC/TPU) blends. An alternative to melt or solution blending, the advantages to such a blending technique are fewer processing steps and less cost, no solvent removal, reduced PVC degradation, and the potential for producing otherwise unobtainable blend morphologies and properties. Using an internal mixer, PVC was compounded and plasticized with the polyol and chain extender of a polyester‐based TPU. Then, upon addition of the stoichiometric amount of TPU diisocyanate, a high molecular weight TPU was polymerized in situ with PVC. Because of reaction‐induced phase separation, the resulting partially miscible PVC/TPU blends were characterized by heterogeneous, multiphase morphologies. In addition, they exhibited excellent tensile properties intermediate between that of neat PVC and TPU. POLYM. ENG. SCI., 45:876–887, 2005. © 2005 Society of Plastics Engineers     

Effects of ion group content and polyol molecular weight on physical properties of HTPB‐based waterborne poly(urethane‐urea)s

A series of waterborne poly(urethane‐urea)s, WPUUs, based on using nonpolar hydroxyl‐terminated polybutadiene (HTPB) as the soft segment, were successfully synthesized in this article. The effects of the COOH group content and soft‐segment molecular weight (Mn_s) on the dispersion, morphology, and physical properties were investigated. Variations of the particle size, viscosity, and zeta potential were first governed by the hydrophilicity of the polymer chain, and then by the swelling derived from water. Fourier transfer infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) indicated that the degree of phase separation decreased as the COOH group content increased or as Mn_s decreased. However, the hydrogen bonding between the soft and hard segments and the two‐phase mixing could not occur in this nonpolar HTPB‐based WPUU system, indicating that the hard segments tended to form smaller domains and to pack more loosely. It was attributed to the fact that the presence of bulky ionic salt groups destroyed the ordered arrangement of the hard segments. In this case, the increases of the interface area between the soft and hard phases resulted in that the present behaviors were similar to the phase mixing. In tensile properties, HTPB‐based WPUUs exhibited higher tensile stress, elongation at break, and modulus as the COOH group content decreased or as Mn_s decreased. In thermal degradation, the introduction of HTPB polyol improved the thermal stability of WPUU. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007