硬段结构对分子链含亲水基团的聚氨酯形状记忆性能的影响

采用自乳化法,用聚酯二元醇、二苯基甲烷二异氰酸酯(MDI)或异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)、乙二胺(EDA)、三羟甲基丙烷(TMP)等单体合成了分子链含亲水基团的聚氨酯.用FTIR对聚氨酯进行了结构表征,并测试了胶膜力学性能和形状记忆性能.主要探讨了硬段结构与质量分数,回复温度和多次拉伸-回复对聚氨酯形状回复率的影响.结果表明,聚氨酯分子链内引入苯环或化学交联结构,可以改善材料的力学性能和形状记忆性能;聚氨酯的硬段质量分数有一最佳值,达到此值形状回复率最大;不同硬段结构的聚氨酯达到最大形变回复率的临界硬段质量分数不同,硬段的结构越稳定,其在形状记忆聚氨酯中的质量分数越低.多次拉伸-回复可以提高形状记忆性能.     

多级加砂压裂工艺技术现场应用及效果评价

对于较薄,有底水边水的低渗储层油藏来说,多级加砂压裂工艺能够有效的控制缝高,增加裂缝的延伸深度,最大限度的提高油井压后形成裂缝导流能力,从而提高油井产量。从实践验证理论方面出发,讲述了该工艺的原理,使用三维压裂软件模拟预测裂缝形态,设计施工排量和加砂程序,3口井现场应用与施工评价,压后效果分析,最后客观的总结出了三口实验井的成功之处和不足,对今后该区块以及同类区块科学使用多级加砂压裂工艺技术具有指导意义。     

超声波条件下除油技术的研究

在超声波条件下,研究确定了除油技术的清洗介质配方及运行条件,并对超声波、化学(声化)协同除油机理进行了分析讨论.研究结果表明,在声化条件下,研究确定的低浓度的碱性除油介质可在较低温度下,快速有效去除试样表面的油污;升高清洗液温度,可提高除油效率.     

Cu、Zn对Mg晶粒尺寸以及微观组织影响

通过向镁熔体中单独和复合添加一定量的Cu及Zn元素,探究了Cu、Zn对镁晶粒尺寸和微观组织的影响并阐释了其细化机理;同时深入表征了Cu、Zn单独及复合添加后合金的物相组成。结果表明：向纯Mg中加入Cu、Zn和Cu、Zn复合添加后,晶粒依次由柱状晶转变为等轴晶。单独加Cu、单独加Zn和Cu、Zn复合添加后,平均晶粒尺寸由纯Mg的1270μm分别减小至470、120和85μm。单独加Zn对Mg的晶粒细化机理主要为Zn元素的溶质效应;单独加Cu对Mg的晶粒细化机理主要为Cu元素的溶质效应和CuMg2相对晶界的钉扎作用;Cu、Zn复合添加后细化效果更好主要是因为Cu、Zn元素的复合溶质效应及第二相对晶界的钉扎作用更为强烈。此外,单独加Zn后,第二相呈颗粒状分布于基体中,合金中的物相组成为α-Mg+MgZn;单独加Cu后,第二相形貌呈网状,合金中的物相组成为α-Mg+CuMg2;Cu、Zn复合添加后,Mg-5Cu-3Zn晶界上的第二相呈现出两种不同的形貌,经鉴定,连续的块状第二相为CuMg2相,不连续的鱼骨状第二相为CuMgZn相。     

炭黑填充聚合物基PTC导电复合材料及制品的研究进展

介绍了PTC效应的几种主要机理,讨论了不同基体、填充物和加工工艺对此类复合材料PTC效应的影响,NTC效应产生的主要原因以及减缓或推迟NTC效应的方法,并对其商业推广应用进行了较为深入的探讨.     

The characteristics of metallocene/Ziegler-Natta hybrid catalysts supported on the recrystallized MgCl2

A metallocene catalyst or a metallocene/Ziegler-Natta hybrid catalyst supported on MgCl₂ was studied for application to the commercial slurry phase process and to the control of MWD of the polymer produced. The MgCl₂ support was prepared by the recrystallization method with different solvents: alcohols and H₂O. The recrystallized MgCl₂ support was pretreated with triisobutylaluminum (TiBAL) or trimethylaluminum (TMA), methylaluminoxane (MAO), to give different supporting environments. Metallocene/Ziegler-Natta hybrid catalysts on MgCl₂ were prepared by first supporting the metallocene catalyst, followed by the Ziegler-Natta catalyst after pretreatment with an alkylaluminum compound. The type of solvent plays a role in providing a suitable environment in the support for impregnating catalysts. The hybrid catalyst, whose support was recrystallized in n-propanol (n-PrOH) and pretreated with TiBAL, showed the highest molar ratio of Zr/Ti= 1/2.71. But the hybrid catalyst, whose support was recrystallized in H₂O and pretreated with MAO, showed the best hybrid effect showing a variety of bimodal peaks in proportion to the ratio of MAO/TEA in GPC analysis. This effect might be due to steric factor and polarity of solvent, as well as the pretreatment material. It is concluded that the MWD of polyethylene produced by metallocene/Ziegler-Natta hybrid catalyst that is supported on MgCl₂ can be controlled by regulating the amounts of MAO and TEA added as cocatalysts and by the use of different solvents and pretreatment materials.     

双节距齿形输送链的设计及其横向波动分析

为了减小链式输送机的横向波动量,增强输送的平稳性与准确性,基于齿形链啮合理论及设计方法,设计了一款新型的双节距齿形输送链,给出了设计参数方法,分析了其分时啮合机理以及横向振动产生的原因,基于Adams多体动力学软件建立了双节距齿形输送链与双节距滚子链的横向波动量对比仿真试验,提取仿真结果并进行处理,分析结果显示:与双节距滚子链相比,双节距齿形输送链的横向波动量明显降低。可见,双节距齿形输送链的设计具有实用价值。     

不同表面活性剂体系对去血渍复合酶活性的影响研究

以碱性蛋白酶的相对活性作为衡量指标,研究了3种类型8种常用表面活性剂LAS,K12,AES,AOS,TX-10,6501,CAB以及AE09在不同体系下对去血渍复合酶活性的影响,表面活性剂质量浓度设定为0．8g／L。结果表明：在实验室考察条件下,8种单一表面活性剂中除了LAS有较大抑制作用外,其他的表面活性剂均能与去血渍复合酶较好配伍;LAS与其他7种表面活性剂按质量比1：1配伍后可不同程度的减少它对酶活的影响,其中LAS／TX-10,LAS／AE09以及LAS／CAB3组复配体系表现的最为明显,且复配比例在1：4～3：2之间时效果较佳。     

Soft measurement of pulp suspension flow velocity based on wavelet transform

A soft measurement technique is presented, which the pulp suspension flow velocity (PSFV) can be obtained by analysis of pulp fibre consistency signal without using the flow sensor or flow meter. Doppler Effect in pulp fibre consistency signal, which is caused by the relative motion between pulp suspension flowing in pulp pipe and consistency sensor fixed in the pipe, is discovered on the basis of studying the structure of pulp suspension and the properties of pulp fibre consistency signal, and it is proved by wavelet transform (WT) in this paper. WT are used to analyse pulp fibre consistency signal based on Doppler Effect. PSFV can be determined by the average period of WT which is used to analyse pulp fibre consistency signal based on Doppler Effect. The corresponding tests indicate that the measurement technique is feasible with high precision and better dynamic characteristics.     

环鄱阳湖风沙区风电场工程水土保持措施及建议 --以老爷庙风电场为例

风力作为一种清洁能源,近年来越来越得到国家的重视.环鄱阳湖风沙区风电场在建设过程中不可避免地会对土壤及植被造成一定程度的破坏,人为地加剧了水土流失.本文以老爷庙风电场工程为例,结合项目区具体特点,分区合理配置工程措施、植物措施和临时措施,有效地防治了水土流失.