三维荧光光谱表征饮用水中溶解性有机物研究进展

荧光技术目前已经被广泛地应用于溶解性有机物(DOM)的表征。其中荧光激发发射矩阵光谱(EEM),也称为三维荧光(3D-EEM)或荧光指纹是最主要的方法之一。目前，三维荧光已经被开发并用于表征饮用水处理工艺对有机物的去除效果。该文综述了目前主要的三维荧光分析方法，并总结了三维荧光在饮用水处理工艺中的运用及其存在的问题。     

Sn(Ⅳ)与Fe(Ⅲ)溶液共聚合研究

<正> 引言 随着水污染的加剧,水资源的再生利用已成为一个亟待解决的问题.混凝法是当前国内外众多水处理工艺技术中应用最为广泛的单元操作技术之一.而混凝效能的好坏主要取决于絮凝剂.因此高效絮凝剂的研究开发工作一直是水处理领域的热点.在六、七十年代,人们对聚合氯化铝(PAC)、聚合氯化铁(PFC)进行了较为深入的研究,并得到了广泛的应用.后来又在铁铝共聚合,尤其在加聚某些阴离子方面,作了新的探索.但目前尚未见到加聚Fe~(3+)、Al~(3+)以外的其他金属离子的研究报道。本文正是通过加聚sn~(4+),即含有更高离子化合价的金属离子来提高絮凝剂压缩双电层和电中和能力,进而提高絮凝剂的凝聚性能,以提高水处理效果.     

陶瓷增材制造(3D打印)技术研究进展

高性能陶瓷是现代技术发展和应用不可或缺的关键材料。常规的陶瓷制造技术难以满足对个性化、精细化、轻量化和复杂化的高端产品快速制造的需求。新兴的增材制造技术(3D打印)在高性能陶瓷的成型制造领域具有巨大的发展潜力,有望突破传统陶瓷加工和生产的技术瓶颈,为陶瓷关键零部件的应用开辟新的途径。本文针对陶瓷材料及其快速成型和后处理工艺,重点阐述了三维打印技术、光固化成型技术、选择性激光烧结技术等主流陶瓷增材制造技术的研究现状,并指出了目前存在的问题及发展趋势。     

热塑性聚氨酯(TPU)3D打印研究进展

热塑性聚氨酯(TPU)具有高弹性和生物相容性,在工业和医疗领域中均得到了广泛应用,3D打印技术进一步拓展了TPU材料在医疗领域的应用。但是,热塑性聚氨酯的部分性能特点不利于3D打印成型,在一定程度上限制了其在3D打印中的应用,因此,需要对TPU材料进行改性。从3D打印工艺、工艺参数、专用材料、掺杂改性及先进应用领域研究5个方面,综述了TPU材料3D打印的国内外研究进展。介绍了FDM和SLS 2种可用于TPU材料3D打印的工艺方法,并且对国内外TPU打印材料力学性能与掺杂改性的研究现状进行了总结。同时,分析了TPU材料3D打印在鞋类加工和医学研究领域的应用发展,并且对3D打印TPU在医疗领域的应用前景进行了展望。     

电去离子技术(EDI)在水处理中的应用

主要介绍了电去离子(EDI)技术在水处理方面的应用:简要介绍了EDI技术去离子的原理及其发展情况;介绍了该技术在电镀废水、锅炉补给水、纯水制造以及去除低浓度重金属废水中的应用及研究现状,并简要介绍了ED I技术今后的研究方向。     

吸附天然气(ANG)储存技术吸附剂研究进展

介绍了吸附天然气(ANG)储存技术的基本原理、特征,阐述了高性能天然气吸附剂的研制和优化是天然气储存技术ANG的关键所在,综述了天然气吸附剂研究及其在国内外发展的状况,并介绍和对比了一些高性能的天然气吸附剂,最后总结了ANG技术应用前景与应用中存在的主要问题。     

芳纶表面改性技术进展(一)——物理改性方法

简单介绍了芳纶Ⅱ、芳纶Ⅲ及Technora 3种对位芳纶,并对芳纶表面改性的物理方法进行了概述。综合论述了表面涂层技术、等离子体技术、超声波技术、γ-射线技术在芳纶表面改性过程中的应用过程、反应原理及改性效果。结合应用实践,对相关物理改性技术的应用进行了探讨和展望。     

Al(OH)_3阻燃聚丙烯塑料

本文介绍了阻燃剂Al(OH)_3的阻燃机理及Al(OH)_3阻燃PP塑料的工艺、配方、性能和应用,并对它的技术经济作了评价。     

(Na,K)NbO_3基无铅压电陶瓷的研究进展

本文主要综述近几年来国内外有关(Na,K)NbO3基无铅压电陶瓷体系的加压固相烧结技术、液相助烧致密化技术、掺杂改性、相结构调控以及相关机理研究方面的研究进展和动向,并展望该陶瓷体系在医疗超声换能器技术方面的应用前景。     

自动收(付)费卡技术及应用系统(一)

介绍了地铁自动收 (付 )费卡技术概要及其应用系统，并对射频卡、接触式 IC卡和磁条卡等技术方案在技术上和经济上进行了总结，指出了不同收 (付 )费卡技术的优缺点并进行了全面的比较。     

Synergistic Extraction of Am(III) and Eu(III) by Tris(2‐pyridylmethyl)Amine with Various Anions in 1,2‐Dichloroethane

The extraction equilibria of Am(III) and Eu(III) by using a tripodal ligand, tris(2‐pyridylmethyl)amine (tpa), with various lipophilic anions have been investigated. The extractability of both Am(III) and Eu(III) was increased by the combination of tpa and counteranions due to a synergistic effect. The separation factors between Am(III) and Eu(III) were also increased from 7.6 to 49 by the combination of counteranions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2‐dichloroethane were determined by slope analysis. It was found that three anions and one molecule of the ligand coordinated to Am(III) and Eu(III) was extracted regardless of the anions.     

Interpretation of intrinsic viscosity/temperature data for solutions of poly(phenyl acrylate) and poly(ethylene oxide)

Measured intrinsic viscosities ([η]) at several temperatures (T) within the interval 280–350 K have been found to increase with T for solutions of poly(phenyl acrylate) (PPA) in ethyl lactate. A decrease of [η] with T was observed for aqueous solutions of poly(ethylene oxide) (PEO) at several temperatures within the range 276–358 K. The results have been treated on the basis of eight excluded volume theories, among which the best consistency was afforded by those of Kurata-Stockmayer-Roig, Fixman, and Stockmayer (Padé). These yielded values of ?3.4 × 10^?3 to ?4.7 × 10^?3 deg^?1 and ?0.9 × 10^?3 to ?2.4 × 10^?3 deg^?1 for the temperatur coefficient of the unperturbed dimensions of PPA and PEO, respectively. The derived θ-temperatures were 287 K as the upper critical solution temperature for PPA in ethyl lactate and 365–382 K as the lower critical solution temperature for aqueous PEO.     

可溶性Fas与VEGF及TIMP-1表达在乳腺癌淋巴结转移中的相互关系

目的通过对乳腺癌可溶性Fas浓度与血管内皮生长因子(VEGF)及金属蛋白酶抑制物(TIMP-1)表达之间关系的分析,探讨患者血清中sFas浓度改变对乳腺癌细胞生长、浸润和转移的影响。方法通过S-P免疫组化法和ELISA法,分别检测乳腺癌细胞VEGF和TIMP-1表达及血清sFas浓度,结合VEGF、TIMP-1与乳腺癌临床病理参数,分析浸润、淋巴结转移乳腺癌中VEGF、TIMP-1表达失衡与血清sFas浓度之间的关系。结果①VEGF阳性表达与乳腺癌淋巴结转移呈显著相关,VEGF阳性的肿瘤有淋巴结转移率为56%,明显高于VEGF阳性的肿瘤无淋巴结转移率(7%)。随着乳腺癌TNM分期和组织学分级的进展,VEGF阳性表达率逐渐增加,呈正相关。TIMP-1阳性表达与肿瘤淋巴结转移明显相关。随着TNM分期和组织学分级的进展,TIMP-1阳性表达率逐渐降低,呈负相关。②VEGF阳性表达而TIMP-1阴性表达组发生乳腺癌浸润和淋巴结转移率及血清sFas浓度最高,VEGF阴性表达而TIMP-1阳性表达组发生淋巴结转移率及血清sFas浓度最低,两组比较差异有极显著意义。结论sFas与VEGF及TIMP-1表达之间存在着反馈机理以及相互激活的密切关系。sFas浓度可以间接地反映基质金属蛋白酶(MMPs)和VEGF的表达情况,sFas在乳腺癌中的浓度变化可以反映乳腺癌的生长、局部浸润和转移。     

An inelastic electron tunnelling spectroscopy (IETS) study of poly(vinylacetate) poly(methyl methacrylate) and poly(vinylalcohol) adsorbed on aluminium oxide

IETS is used to investigate the adsorption of poly(vinylacetate) (PVA), poly(methylmethacrylate) (PMMA), and poly(vinylalcohol) (PVOH) on aluminium oxide. These polymers are of interest in the field of adhesion science, and until now synthetic macromolecules have not been studied in this way. Both commercially available polymers and those synthesized in our laboratory have been used. On the basis of IET spectra presented here, and existing i.r. spectra it is believed that PMMA and PVA undergo ester cleavage at the oxide surface leading to their subsequent adsorption. For PMMA this is thought to be via carboxylate anions generated on the polymer side groups, while PVA is expected to be adsorbed as PVOH. Bonding of PVOH to the oxide is not fully understood, but may occur by the formation of an AlOC bridge. Another possibility for the above polymers, that of intermolecular hydrogen bonding between polar polymer side groups, and adsorbed hydroxyl species present on the oxide surface, cannot be ruled out.     

Quantifying Structural and Solid‐State Viscoelastic Properties of Poly(propylene) (PP)/Poly(oxymethylene) (POM) Blend Films

In this study, isotactic poly(propylene) (PP)/poly(oxymethylene) (POM) blend films, including of POM as minor phase in the range of 10–30 wt%, are prepared in a twin screw extruder equipped with a slit‐die and cast film haul‐off unit. It is found that the blend films show characteristic immiscible matrix‐droplet morphology. Short‐term uniaxial tensile creep behaviors of films imply that the introducing of POM significantly improves the elastic modulus and decreases the total creep strain of PP/POM blends. Creep tests are also performed at various temperatures and long‐term deformations of samples are predicted by applying of time‐temperature superposition principle and the Findley model. It is found that the presence of POM domains into PP matrix enhances the creep resistance of PP especially at high temperatures. It is concluded that the PP‐rich PP/POM blend films show much lower short and long‐term creep strains compared to PP.

     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998     

三价铁离子浓度对As(V)-Fe(II)-Fe(III)体系沉淀臭葱石的影响

在常压、95℃、初始pH=1.5的条件下，研究了As(V)–Fe(II)–Fe(III)体系中初始Fe(III)浓度对砷的去除率和臭葱石合成的影响。结果表明，溶液中初始Fe(III)/As(V)摩尔比为0时，沉淀产物为结晶度良好的臭葱石，但砷的去除率仅为24.3%，沉淀浸出砷浓度高于国标规定的浓度限值5 mg/L。溶液中初始Fe(III)/As(V)摩尔比大于0时，在升温过程中生成了无定形砷酸铁，当初始Fe(III)/As(V)摩尔比不超过1.6时，砷酸铁反应8 h后转化为臭葱石；随初始Fe(III)/As(V)摩尔比增大，砷的去除率增大，臭葱石沉淀的结晶度降低、浸出砷浓度降低；其中，初始Fe(III)/As(V)摩尔比为0.8和1.6时，臭葱石沉淀的浸出砷浓度低于5 mg/L，适合安全堆存。当初始Fe(III)/As(V)摩尔比大于1.6时，无定形砷酸铁反应8 h仍不能转化成臭葱石，砷的去除率降低，沉淀浸出砷浓度超标，不适合安全堆存。     

Compatibility of poly(vinylidene fluoride) (PVDF)/polyamide 12 (PA12) blends

Poly(vinylidene fluoride) (PVDF)/polyamide 12 (PA12) blends showed new peaks in XRD profile with increasing PA12 and the crystallinity of PA12 significantly decreased with the addition of PVDF. PVDF showed three relaxation regions at about −40, 40, and 100°C, respectively, and glass transition temperature (T_g ) of PA12 increased in blends (10.8→30.14°C) and α‐relaxation of PVDF decreased from 100.26 to 86.46°C. Complex viscosities (η*) vs. composition curve showed a great positive deviation in PVDF‐rich and a small negative deviation in PA12‐rich blends. The N—H and C=O stretching band of PA12 shifted slightly toward higher wavelength, and from curve‐fitted data the area of hydrogen‐bonded C=O stretching bands of PA12 decreased with the addition of PVDF, especially in the 30/70 blend, implying the existence of interactions between the β‐hydrogen atom of PVDF and amide carbonyl group of PA12 in the blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1374–1380, 2000     

Swelling and morphological properties of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) hydrogels in solution with high salt concentration

Understanding the swelling properties of hydrogels and how they affect the hydrogel's morphology is of fundamental importance in the development of hydrogel-based artificial muscles, bio-actuators, sensors and other devices. In this paper, the swelling behavior of PVA-PAA hydrogel films in saline water and in buffer solutions of different pH values was investigated. It was observed that the swelling factor of the hydrogel decreases when the ionic strength of the solvent solution increases. Scanning Electron Microscopy (SEM) revealed structures with different pore shapes and sizes depending on the type of solution used for hydration. In saline water, Energy Dispersive X-Ray (EDS) analysis indicated the formation of NaCl crystals within the polymeric network. Finally, the PVA-PAA hydrogel was used as an actuator to strain a fiber Bragg grating sensor, thus providing an indirect measurement of the pH value of the surrounding solution.