UV光引发丙烯酰胺反相微乳液聚合研究

采用光引发聚合技术,选取合适的光引发剂进行丙烯酰胺(AM)反相微乳液聚合。用UV光引发AM/水/白油/(Span80+OP-10)体系聚合,所得聚合物粘均相对分子质量可达10⁶。考察了光引发剂类型及质量分数、单体质量分数、乳化剂质量分数和聚合时间等对聚合反应的影响,得到了光引发合成聚合物的较优工艺条件。通过红外光谱法鉴定出所得聚合物为聚丙烯酰胺(PAM)。     

芬顿污泥颗粒特性及煅烧回收利用研究

为了解决芬顿污泥产量大、难处理的难题,探索其资源化途径,提出以煅烧法处理焦化废水芬顿污泥,并对芬顿污泥颗粒特性及煅烧过程中的铁相变化进行了分析,最后探讨了煅烧产物的资源化途径。结果表明：1）芬顿污泥主要成分为羟基氧化铁(FeOOH)和α型氧化铁(α-Fe₂O₃),铁元素质量分数为48.3%,含有丰富的羟基和羧基等含氧基团,有氧煅烧铁相转化过程为FeOOH→α-Fe₂O₃→Fe₃O₄→α-Fe₂O₃;2）500 ℃有氧煅烧产物为Fe₃O₄,可直接出售实现经济收益;3）酸改性后的350 ℃缺氧煅烧产物(AFS350)可有效吸附去除水中95%以上的锑和砷,480 ℃缺氧煅烧产物（FS480）对水中的铅和铊有较高的吸附容量;4）AFS350对Sb(Ⅴ)和FS480对Tl(I)的吸附符合准二级动力学及Freundlich等温吸附模型,AFS350和FS480表面均有异质性分布的饱和吸附位点,2个吸附过程均是以表面非均相吸附为主的多层化学吸附。煅烧法处理芬顿污泥,方法简单,产物回收率高且用途广,为芬顿污泥资源化提供了可行途径。     

聚噻吩修饰纳米结构TiO2膜电极光电性能研究

用光电流作用谱、光电流-电势图等光电化学方法研究了聚噻吩(PTh)膜和纳米结构TiO₂/聚噻吩(ITO/TiO₂/PTh)复合膜的光电转换性质。结果表明,PTh膜的禁带宽度为2.02eV,价带位置为-5.86eV,导带位置为-3.84eV。在ITO/TiO₂/ PTh复合膜电极中存在p-n异质结,在一定条件下异质结的存在有利于光生电子-空穴对的分离,PTh修饰ITO/TiO₂电极可使光电流产生波长发生明显红移,从而提高了宽禁带半导体的光电转换效率。在实验条件下,单色光的光电转换效率最高可达到13%。     

不动点集为RP1(2m)∪RP2(2m)∪RP(3)的带有对合的光滑流形

设(M^r,T)是一个具有对合T的r(r>2m+4)维光滑闭流形,它的不动点集为F。本文给出了F=RP₁(2m)∪RP₂(2m)∪RP(3)时对合的协边类(其中m为奇数),RP表示实射影空间。     

羧甲基壳聚糖-Cu2+配合物催化分解H2O2的研究

研究羧甲基壳聚糖-Cu²⁺配合物对H₂O₂分解的催化活性及影响因素。以壳聚糖为原料,制备水溶性羧甲基壳聚糖(CMC),再以其为配体制备CMC-Cu²⁺配合物,并将CMC-Cu²⁺配合物应用于催化H₂O₂分解的反应,考察了w(CMC)/w(CuCl₂)、体系pH值对H₂O₂分解的影响。结果表明:温度为25℃,w(CMC)/w(CuCl₂)为5∶1时形成的CMC-Cu²⁺配合物,在pH值为7附近,对质量分数为5%的H₂O₂的分解率12h为92.5%,24h为99.5%,说明CMC-Cu²⁺配合物对H₂O₂分解有良好的催化作用。     

注射用甲硫氨酸维生素B1的细菌内毒素检查

为考察注射用甲硫氨酸维生素B₁的细菌内毒素检查法的可行性,采用《中华人民共和国药典》(2005年版)细菌内毒素检查法。结果得知,注射用甲硫氨酸维生素B₁质量浓度为0.25mg/mL的稀释液可用灵敏度为0.25EU/mL的鲎试剂进行细菌内毒素检查,实验中3个批号的注射用甲硫氨酸维生素B₁经检查均符合规定。     

Cu-11Fe-4Cr原位复合材料在HSO-3和/或Cl-介质中的耐蚀性

采用选择腐蚀技术,提取了Cu-11Fe-4Cr原位复合材料中Fe-Cr纤维,并测定了其电极电位。通过间歇式盐水喷雾实验和极化曲线测定,研究了Cu-11Fe-4Cr原位复合材料在HSO-₃和/或Cl-介质中的腐蚀行为。用扫描电镜对腐蚀产物和腐蚀表面进行分析。结果表明, Cu-11Fe-4Cr原位复合材料中,E(Cu)3+NaCl)和 NaHSO₃介质中的E(Fe-Cr) －E(Cu)显著高于NaCl 介质中的E(Fe-Cr)－E(Cu),Cu-11Fe-4Cr原位复合材料在NaCl介质中的腐蚀失重最小,在NaCl介质中具有良好的耐蚀性。     

高固含量乳液制备工艺的优化及实验结果的SAS分析

在一系列单因素试验的基础上,确立了6个主要影响因素,将直接试验设计方法用于高固含量乳液苯乙烯/丙烯酸丁酯/丙烯酸(St/BA/AA)制备工艺的优化,对实验结果利用SAS软件进行了回归分析,建立了乳液的影响因素与乳液主要性能间的最优回归方程模型,并通过实验对该模型赋予的优化值进行了检验。结果表明:乳液固含量、引发剂与功能单体浓度的交互作用、乳化剂用量、软单体BA含量与反应温度的交互作用对乳胶粒粒径有明显的影响。     

石家庄市冬防期细颗粒物污染特征及源解析

为了探究石家庄市冬防期细颗粒物（PM_2.5）的主要污染来源,推动石家庄市环境空气质量持续改善,采用在线单颗粒气溶胶质谱仪（SPAMS）捕集的PM_2.5粒子信息,结合自适应共振神经网络分类方法（ART-2a）和石家庄市污染源谱图信息,对2017年10月1日—2018年3月31日、2019年10月1日—2020年3月31日、2021年10月1日—2022年3月31日的石家庄市PM_2.5污染物来源进行解析。结果表明：1）石家庄市冬防期PM_2.5主要受燃煤源、机动车尾气源、工业工艺源共同作用的影响,3种污染源对PM_2.5浓度的贡献率超过60%;2）第3阶段与前2个阶段相比,在不同月份和污染时段机动车尾气源对PM_2.5贡献率占比均升高9个百分点以上,贡献占比最大,机动车尾气源逐渐取代工业工艺源成为PM_2.5首要污染源;3）受春节影响,2月份机动车尾气源对PM_2.5贡献率明显降低;4）第3阶段燃煤源和工业工艺源对PM_2.5浓度的影响降低,但2个污染源对PM_2.5浓度的贡献率仍然较大,贡献占比超过30%。研究结果为石家庄市进一步加强对机动车尾气源的管控提供了依据,同时对未来石家庄市提前采取针对性污染源管控,减缓大气污染的发生提供了数据支撑。     

AM/DAAM/SAS/DMDAAC四元共聚物的合成

以AM、SAS、DMDAAC和DAAM为单体,采用水溶液聚合法合成了AM/DAAM/SAS/DMDAAC共聚物,通过正交实验探究出最佳合成条件:m(AM):m(SAS):m(DMDAAC):m(DAAM)=5.8:2.6:1.2:0.4,w(引发剂)=0.5%,pH=6,引发温度为50℃。     

2-丙烯酰胺基-2-甲基丙磺酸接枝改性瓜尔胶的制备与性能研究

为改善瓜尔胶与其他组分的相容性及耐盐性,以可生物降解的瓜尔胶为原料,过硫酸钾和亚硫酸钠为氧化还原引发体系,将2-丙烯酰胺基-2-甲基丙磺酸(AMPS)接枝到瓜尔胶分子上。研究AMPS用量、引发剂用量、引发剂滴加时间、反应时间、反应温度、分散剂与瓜尔胶的质量比(浴比)、分散剂中乙醇质量分数等因素对接枝反应的影响,确定较佳反应条件。制得的磺酸基瓜尔胶衍生物胶液稳定,黏度较高,在质量分数为2%的KCl盐水溶液中黏度下降很小,具有良好的耐盐性。将其按一定比例与牙膏成分进行混合,其与牙膏组分的相容性好,膏体稳定且改善了脱尾现象,满足作为水性膏体黏结剂的要求。     

二甲基二烯丙基氯化铵与丙烯酸或丙烯酸羟乙酯共聚反应动力学研究

以过硫酸钾-亚硫酸氢钠为引发剂,研究了二甲基二烯丙基氯化铵(DMDAAC)分别与丙烯酸(AA)及丙烯酸羟乙酯(HEA)的水溶液自由基共聚合反应。采用膨胀计法测定共聚反应速率,考察了引发剂浓度、单体浓度、反应温度对共聚反应速率的影响。结果表明,随着引发剂浓度、单体浓度和反应温度的提高,共聚反应速率增大。建立DMDAAC与AA共聚反应的动力学关系式为RP∝[I]0.690 2[M]1.336e-8 244/T,测得该共聚反应表观活化能为68.54 kJ/mol;DMDAAC和HEA共聚反应的动力学关系式为RP∝[I]1.089 0[M]0.833e-12 255/T,该共聚反应的表观活化能Ea为101.89 kJ/mol。     

丙烯/丁烯-1无规共聚产品的工业化开发

在聚丙烯中试装置上采用本体聚合方法合成了丁烯-1质量分数不同的丙烯/丁烯-1无规共聚物,对其力学性能、透明性及共聚物中正己烷提取物的质量分数进行了研究,并在聚丙烯生产装置上实现了工业化生产。当丁烯-1的质量分数达到一定值时,丙烯/丁烯-1无规共聚聚丙烯与丙烯/乙烯无规共聚聚丙烯的透明性相似,但前者综合力学性能更好,正己烷提取物的质量分数更低,可广泛运用于食品包装行业。     

Black and White Preferences for Neighborhood Racial Composition

The research investigates the existence, nature and magnitude of the preferences of races to voluntarily "self-segregate" into particular areas of urban housing markets. Housing market theory is employed to develop a model showing how housing price variations within a group can provide unambiguous evidence of their preferences for neighborhood racial composition. The model is operationalized in a multiple regression specification wherein the variations in a given racial group's housing prices become a function of the dwelling's attributes and the attributes of the neighborhood (including quality, status, stability and density) as well as housing submarket location and racial composition. The size and statistical significance of the coefficient of the last attribute provides the evidence sought.
The regressions are estimated using two micro-household data bases from St. Louis (1967) and Wooster, Ohio (1975), and results compared. Results show that St. Louis black owners had an aversion to larger black proportions within black submarket neighborhoods, with .7% lower housing prices associated with a 1% higher percentage black. Racial effects for black owners in preponderantly white areas and for black renters in all areas were statistically insignificant. St. Louis whites of both tenures did not demonstrate aversion to neighborhoods with higher percentages of blacks as long as they remained 25% black or less. In areas 25–50% black, however, white prices were 1.5% lower for owners and 3.2% lower for renters per 1% higher proportion black. Such associations continued in majority-black areas, although the magnitudes of the price effect became progressively smaller. Wooster whites showed an aversion to living in neighborhoods having even a few percent of blacks, with prices 11% lower for owners and 7% lower for renters in such areas compared to all-white ones.     

The anatomy of an acrylic acid runaway polymerization

The details of an unscheduled polymerization of acrylic acid initiated by indirect heating have been characterized by in-depth analysis of the polymer, kinetic and thermodynamic calculations, and heat and material balances on the system. The data fit together to give a consistent picture of the polymerization scenario. The fact that the acrylic acid polymerization was not violent was primarily due to the presence of about 10 ppm phenothiazine, which delayed the onset of free radical polymerization until about 2 to 3 hours after the monomer had reached its boiling point. Since much of the acrylic acid was converted to dimer during this induction period, the ultimate energy release was greatly limited. Other moderating factors were a relatively slow heatup of the tank contents in the external heat exchange recycle loop, free vapor venting, and the incursion of fire monitor water into the tank.     

水溶性超支化聚丙烯酸酯乳液的制备

超支化聚合物是一类非线性聚合物,具有高度支化结构和大量可改性端基,其反应活性高、溶解性好、黏度低,是目前研究的热点之一。本研究以顺丁烯二酸酐和多元醇经开环半酯化反应,得到以多元醇为核的水溶性超支化聚酯型单体,用其与作为反应单体的甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸进行乳液聚合,制备得到粒径为70～110nm的纳米级超支化聚丙烯酸酯乳液,其后用FTIR、DSC、SEM对其性能进行表征。重点讨论了支化单体配比及单体滴加顺序、链转移剂类型等对乳液聚合的影响,并对乳液的固含量、粒径、稳定性以及胶膜的形貌及胶膜的吸水性进行实验分析。结果表明：超支化聚丙烯酸酯类乳液的黏度较低,稳定性较高,所得胶膜平滑光整;且制备成本较低、工艺简单,因此具有较好的应用前景。     

Non-customers as initiators of radical innovation

Customers who initiate innovation is a topic frequently discussed in the marketing literature. However, the literature largely ignores non-customers – individuals or firms not using products in the category – as potential initiators of innovation in general and of radical innovation in particular. We argue that non-customers have high knowledge of their own needs, but their knowledge of technology is insufficient to self-generate an innovation. By approaching a potential supplier with a high knowledge of technology but an insufficient knowledge of the need, a unique dyad is created, characterized by a bilateral knowledge gap that stimulates increased learning and co-creation of a potentially radical innovation. We use an historical approach to examine the technological and social antecedents and consequences of three innovations initiated by non-customers: air-conditioning, the pill, and the jeep. We contend that non-customers can initiate innovations that may potentially change industries, create new markets, and have long-term social and economic effects.     

单体对UV固化体系流变行为的影响

本研究采用流变动力学来表征UV固化体系的固化性能,使用装有UV固化配件的流变仪,实时监测光固化过程中UV固化体系动态弹性模量G＇的变化,考察了单体的种类、含量对固化体系性能的影响。并将流变转化率β与体系动态弹性模量G＇关联起来,进一步推导出可以描述固化反应的非线性动力学方程。结果表明：UV体系固化过程中,单体官能度越大,样品G＇值越快达到平衡,固化速率越快;单体含量越高,G＇达到平衡状态所需时间越长;实验推导出的非线性动力学方程使用流变转化率β表征UV固化体系固化反应进行的程度,使用dβ/dt表征UV固化体系的固化速率,通过实时红外测试验证了该方程的可行性。