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《化学研究与应用》2016,(7)
采用水溶液聚合方法制备两种两性高分子絮凝剂p(DMDAAC-co-FA)和p(DMC-co-DMAEMA-coAMPS)。对两种共聚合产物进行了傅里叶红外光谱(FT-IR)结构表征。用两种絮凝剂对印染废水进行絮凝试验的结果显示,絮凝剂p(DMDAAC-co-FA)在pH~7、投加量120 mg·L~(-1)时,CODCr去除率79.2%,色度去除率95.0%;絮凝剂p(DMC-co-DMAEMA-co-AMPS)在pH~7、投加量140 mg·L~(-1)时,CODCr去除率75.3%,色度去除率92.0%。通过对絮凝试验的絮体进行电镜扫描分析,采用非线性数学分形理论盒子法计算絮体形貌的空隙分维数Df,结果表明,絮体形貌的空隙分维数理论计算值与试验结果相符。 相似文献
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以壳聚糖改性凹凸棒土作为普通小球藻Chlorella vulgaris的絮凝剂,CaCl2为助凝剂,研究了絮凝采收小球藻的工艺条件。结果表明,最佳絮凝条件为:絮凝剂0.4g/L、壳聚糖/凹凸棒土为1∶12、助凝剂CaCl2为0.2g/L、溶液的pH为9.0,此条件下小球藻絮凝率达到95%以上。絮凝剂的扫描电镜图和BET比表面积(BET)数据显示,改性后的凹凸棒土以一定的空间结构状吸附连接壳聚糖,有效增加了絮凝剂的比表面积,有利于小球藻的吸附。研究采用的原料价格低廉、安全环保,絮凝剂的制备简单且絮凝效率高,可广泛用于工业化生产中微藻的采收。 相似文献
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采用PFSS絮凝-膜分离法处理炼油废水.通过对PAC、PFS和PFSS的除油、CODcr、SS性能比较,确定了PFSS为较好的絮凝剂,探讨了絮凝剂用量、絮凝时间对絮凝效果的影响.通过对膜材料的分析,确定了聚氯乙烯-聚丙烯腈膜对炼油废水有较好的处理效果,探讨了进料流量、操作压力、温度对膜通量的影响.结果表明:当PFSS用量为50-70mg/L、反应时间为8min、进料流量为60L·h-1、操作压力为1.6Mpa、温度为40℃时,通过絮凝沉降、膜分离处理过程,炼油废水中的油、CODcr、SS的去除率分别达到98%、95%、93%以上.出水水质达到国家一级排放标准. 相似文献
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TiO2纳米酶絮凝动力学 总被引:1,自引:0,他引:1
以聚丙烯酰胺(PAM)为絮凝剂,纳米TiO2为固定化酶载体材料,木瓜蛋白酶为酶模型制备纳米絮凝酶.结合粒度分析、SEM、EDS等表征手段,考察PAM种类、加量及体系pH对高分子凝胶絮凝与沉降动力学的影响.结果表明通过氢键、静电吸附和架桥等作用,纳米酶和PAM间产生有效的絮凝.TiO2纳米酶的絮凝沉降速度、体系浊度、絮团大小和紧实程度随PAM用量不同而改变.适量的PAM产生高沉降速度,低浊度,稳定、大絮团的强絮凝,其中nPAM絮凝酶的沉降速度最快,絮团最大.过量的絮凝剂导致絮团脱稳.调控体系酸碱度亦可有效调控PAM絮凝动力学行为.比较nPAM和cPAM,发现nPAM絮凝体对pH有较高稳定性,cPAM絮凝体受pH影响显著.故可以根据酶结构与特性,调节絮凝剂加量和体系酸碱度设计出微纳尺度可调的固定化酶. 相似文献
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壳聚糖对药液絮凝作用的研究 总被引:14,自引:0,他引:14
以壳聚糖为絮凝剂,研究了它对丹参水提液的絮凝情况。比较了絮凝剂加入量不同和分子量不同时,絮凝物的沉降速率,从而考察了它们对絮凝效果的影响以及所得产品的质量。 相似文献
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多环芳二酐型聚酯亚胺膜的透气性能李悦生,丁孟贤,徐纪平(浙江大学高分子科学与工程研究所,杭州,310027)(中国科学院长春应用化学研究所)关键词聚醚酰亚胺,聚酯酰亚胺,膜,透气性通常的聚酰亚胺加工性能较差,在芳环二酐的苯环间引入醚键等柔性基团后,其... 相似文献
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Wenbi Guan 《International journal of environmental analytical chemistry》2013,93(6):679-691
A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg?1, the maximum residue level of European Union for quizalofop-p-ethyl). 相似文献
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微量元素与疾病诊断治疗的研究现状及展望 总被引:8,自引:0,他引:8
对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述,包括:微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。 相似文献
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Prof. Inmaculada García‐Moreno Lu Wang Prof. Angel Costela Dr. Jorge Bañuelos Prof. Iñigo López Arbeloa Prof. Yi Xiao 《Chemphyschem》2012,13(17):3923-3931
Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission. 相似文献
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The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R2UPh type and -thioureas of the R2TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments. 相似文献
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Charles Manzi-Nshuti 《Polymer Degradation and Stability》2007,92(10):1803-1812
In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer. 相似文献
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Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB5型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。 相似文献
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Ling Yun Wang 《European Polymer Journal》2006,42(2):322-327
Neutral nickel(II) and palladium(II) complexes bearing β-ketoiminato ligand have been synthesized. The two complexes have been investigated as catalyst for the polymerization. Using methylaluminoxane (MAO) as a cocatalyst, both complexes produce vinyl-addition polynorbornenes, but palladium(II) complex displays much higher activity up to 8.0 × 107 g/(molPd h). Furthermore, both Ni(II) and Pd(II)/MAO system can efficiently copolymerize norbornene and 5-norbornene-2-yl acetate (NB-OCOMe) in moderate yields and in relatively high molecular weights. The analyses of the product by FTIR, 1H NMR and 13C NMR spectra give the verification of vinyl addition copolymer. The copolymers show narrow molecular weight distribution and good solubility in common organic solvents. 相似文献