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热塑性淀粉制备的化学与物理机制及方法
热塑性淀粉 制备 机制 方法
2021/11/20
淀粉是一大类来源丰富、可再生、可完全生物降解及价格低廉的天然高分子,广泛应用于食品、降解塑料、包装和医药等领域。然而,淀粉内部的结晶和半晶结构使其熔融温度大于分解温度,因而不能热塑加工,这一问题严重制约了其在各领域的应用与发展。因此,研究制备热塑性淀粉过程中所涉及的化学与物理机制及具体方法是影响和拓宽其应用的关键科学问题之一。本文以此为出发点,系统总结了近年来国内外该领域的相关研究工作和进展,将制...
利用阳离子型可聚合离子液体1-丙烯酰氧乙基-3-甲基咪唑四氟硼酸盐与丙烯酰胺的反相微乳液共聚合,制备了阳离子型咪唑类离子液体-丙烯酰胺共聚物缓蚀剂,并探讨了其缓蚀性能。 研究了不同阳离子度、不同浓度聚合物溶液的缓蚀性能以及吸附时间对盐酸腐蚀碳钢速率的影响,并初步讨论了缓蚀机理。 研究表明,该种阳离子型缓蚀剂的缓蚀效率可达90%以上;缓蚀剂的缓蚀能力不仅取决于缓蚀剂的阳离子度,还取决于该种缓蚀剂的相...
一步乳液聚合法制备高溶解性导电聚苯胺
聚苯胺 丙烯酰胺-甲基丙磺酸 乳液聚合 溶解性 导电性
2017/2/28
报道了一种高溶解性导电聚苯胺(PANI)的制备方法,以聚2-丙烯酰胺-2-甲基丙磺酸(PAMPS)作为掺杂酸和乳化剂,利用其特有的长链、亲水性及强酸性基团效应,通过乳液聚合法一步合成出具有较高溶解性的导电聚苯胺。 利用核磁共振光谱仪(NMR)、傅里叶红外光谱仪(FT-IR)和扫描电子显微镜(SEM)等技术手段对产物结构和性能进行了表征分析。 结果表明,在m(苯胺)∶m(AMPS)∶m(APS)=1...
高效液相色谱-飞行时间质谱联用法分析人参及人参皂苷与山楂配伍过程中的水解行为
高效液相色谱-飞行时间质谱 人参皂苷 配伍 水解
2016/12/28
利用高效液相色谱-飞行时间质谱联用的方法,分别对人参配伍山楂前后人参皂苷的变化进行分析,同时对人参皂苷Re、Rg1、Rb1、Rd与山楂配伍的水解规律进行系统研究,并与单独煎煮液、仿山楂配伍pH值煎煮液的水解产物进行比较,结果发现人参与山楂配伍后人参皂苷Rg1、Rb1含量明显减少,而人参皂苷Re、Rd、Rg2、Rg3、F2、Rh1含量明显增加,其中人参皂苷Re与山楂配伍后水解产物为人参皂苷20(R)...
Excited-State Energy Transfer Pathways in Photosynthetic reaction Centers:5.Oxidized and Triplet Excited Special Pairs as Energy Acceptors
triplet state spin-orbit coupling primary donor intersystem crossing g-anisotropy high-field EPR temperature dependence
2016/5/24
In bacterial photosynthetic reaction centers, ultrafast singlet excited-state energy transfer occurs from the monomeric bacteriochlorophylls, B, and bacteriopheophytins, H, to the homodimer special pa...
Protein Relaxation Dynamics in Human Myoglobin
Protein Relaxation Dynamics Human Myoglobin
2016/5/23
Transient absorption spectra in the Soret region have been measured following the photolysis of human MbCO in 75%(w/w) glycerol:water at 250, 270, and 290 K. The peak of the transient difference spect...
Structure-Based Analysis of the Initial Electron Transfer Step in Bacterial Photosynthesis: Electric Field Induced Fluorescence Anisotropy
Fluorescence Electric fields Electron transfer Transfer reactions Anisotropy
2016/5/20
The fluorescence intensity from randomly oriented, immobilized Rb. sphaeroides reaction centers at 77 K increases in the presence of an externally applied electric field. We have proposed that this in...
Nonphotochemical Holeburning in a Protein Matrix: Chlorophyllide in Apomyoglobin
Proteins Polymers Temperature measurement Amorphous metals Dephasing
2016/5/20
Nonphotochemical holeburning spectroscopy has been used to study a chlorophyllide chromophore substituted for heme in apomyoglobin. The observed holewidths were compared with those found for the same ...
Contribution of Spin-Spin Interactions to the Magnetic Field Dependence of the Triplet Quantum Yield in Photosynthetic Reaction Centers
Spin-Spin Interactions Magnetic Field Triplet Quantum Yield Photosynthetic Reaction Centers
2016/5/20
Contribution of Spin-Spin Interactions to the Magnetic Field Dependence of the Triplet Quantum Yield in Photosynthetic Reaction Centers.
TiO2纳米颗粒在单晶硅表面的吸附
TiO2纳米颗粒 超光滑表面 单晶硅表面 化学吸附 紫外光诱导纳米颗粒胶体射流加工
2016/3/10
为了实现亚纳米级超光滑表面的加工，建立了紫外光诱导纳米颗粒胶体射流加工系统，同时研究了加工过程中纳米颗粒与工件表面间的相互作用机理。首先，对实验所用锐钛矿TiO2纳米颗粒及单晶硅工件表面进行表征测量。然后，用第一性原理的平面波赝势计算方法研究了纳米颗粒胶体射流加工中TiO2分子团簇在单晶硅表面化学吸附的表面构型结构及其体系能量。最后，开展了TiO2纳米颗粒及单晶硅工件表面间的吸附实验。实验结果表明...
Chemical cross-linking/mass spectrometry targeting acidic residues in proteins and protein complexes.
Chemical cross-linking/mass spectrometry targeting acidic residues proteins protein complexes.
2015/12/11
The study of proteins and protein complexes using chemical cross-linking followed by the MS identification of the cross-linked peptides has found increasingly widespread use in recent years. Thus far,...
Electrostatically Driven Aggregation of B-Lactoglobulin (BLG) and Effects of Added Polyelectrolytes
electrostatically driven aggregation polyelectrolytes B-Lactoglobulin
2015/1/9
The aggregation rate of B-Lactoglobulin (BLG) was studied using turbidimetry and dynamic light scattering in the range 5.8
Enhanced Detection Strategies Accomplished Through Metal Binding and Miniature Mass Spectrometry
Metal binding Miniaturization Multiplexed MS/MS
2014/11/20
A multiplexed method for performing MS/MS on multiple ions simultaneously in a miniature rectilinear ion trap (RIT) mass spectrometer has been developed. This method uses an ion encoding procedure tha...
新型光电离离子迁移谱及其应用
试剂分子辅助光电离源 离子迁移谱 反应试剂离子 爆炸物
2014/6/4
离子迁移谱被广泛应用于爆炸物毒品等现场检测。离子源是离子迁移谱的核心部件，它与离子迁移谱最终的灵敏度和选择性密切相关。近年来，以光电离技术为代表的非放射电离源成为研究热点。本文介绍基于VUV 灯的新型光电离源，重点综述近年来试剂分子辅助电离正离子源负离子源的进展，分析这些新型光电离离子迁移谱在环境污染物爆炸物等检测的应用。