气流超微粉碎对马铃薯淀粉颗粒形貌及理化性质的影响

为探讨气流超微粉碎对马铃薯淀粉颗粒形貌及理化性质的影响,以马铃薯淀粉为原料,利用流化床气流粉碎机在不同分级转速条件下制备超微粉,采用扫描电子显微镜、激光粒度分析仪、X射线衍射仪、快速黏度分析仪、差示扫描量热仪等研究气流超微粉碎对马铃薯淀粉颗粒形貌、颗粒大小及分布、晶体结构、糊化特性、热力学特性、溶解度、膨胀度和冻融稳定性等性质的影响。结果表明,马铃薯淀粉经气流超微粉碎后,淀粉颗粒表面粗糙且有棱角和裂纹,颗粒形状变的不规则,粒度减小且尺寸分布不均,在分级转速3000r/min时颗粒平均粒径由39.75μm减小至13.38μm;粉碎后淀粉粉体松装密度和振实密度降低,压缩度增大;粉碎没有改变淀粉的晶体结构,但结晶度降低;粉碎降低了淀粉糊的衰减黏度和回生黏度,淀粉的热糊及冷糊稳定性较好,降低了淀粉糊化温度和热吸收焓,提高了淀粉溶解度和膨胀度,改变了淀粉冻融稳定性。研究结果为淀粉干法物理改性技术研究和马铃薯淀粉深加工与高值化利用提供理论依据及参考。     

《化学通报》网络版(Chemistry Online)2002年第2期论文摘要

[Ｗ 0 0 9]淀粉的结晶性与非晶性研究进展ＰｒｏｇｒｅｓｓｏｆＲｅｓｅａｒｃｈｏｎｔｈｅＣｒｙｓｔａｌｌｉｎｉｔｙａｎｄＮｏｎ ｃｒｙｓｔａｌｌｉｎｉｔｙｏｆＳｔａｒｃｈ梁　勇　张本山　高大雄　杨连生 (华南理工大学轻化所　广州　 5 1 0 640 )从淀粉结晶的类型、结晶度的测定、结晶的熔融及影响因素等方面着重介绍了淀粉结晶的研究和发展状况。与此同时 ,对淀粉的非晶性的研究现状、今后的发展进行了展望。Ｔｈｉｓｐａｐｅｒｍａｉｎｌｙｉｎｔｒｏｄｕｃｅｓｔｈｅｒｅｓｅａｒｃｈａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅｃ…     

《化学通报》网络版2003年第4期论文摘要

[Ｗ 0 2 5 ]淀粉酯的制备及性质ＰｒｅｐａｒａｔｉｏｎａｎｄＰｒｏｐｅｒｔｙｏｆＳｔａｒｃｈＥｓｔｅｒａｎｄｉｔｓＤｅｖｅｌｏｐｍｅｎｔＰｒｏｇｒｅｓｓ王书军　于九皋 (天津大学理学院　天津　 3 0 0 0 72 )详细综述了近年来淀粉酯的制备方法及制备过程中反应参数如温度、浓度、介质的ｐＨ和反应时间等对酯化反应的影响 ,并对淀粉脂肪酸酯的性质如疏水性、热稳定性 ,糊粘度等性质进行了概括。文章总结了淀粉脂肪酸酯制备的现状 ,并展望了未来的发展趋势。Ｓｅｖｅｒａｌｐｒｅｐａｒａｔｉｏｎｍｅｔｈｏｄｓｏｆｓｔａｒｃｈｅ…     

色谱法在辜负原蛋白分离、分析中的应用(Ⅱ)

介绍了国外研究者利用凝胶过滤、离子交换和反相色谱等技术分离、分析胶原溴化氰肽的研究进展以及毛细管电泳法在分离、分析胶原α 链和溴化氰肽等中的应用情况。Ａｄｖａｎｃｅｉｎｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｃｈｒｏｍａｔｏｇｒａｐｈｙｉｎｔｈｅｓｅｐａｒａｔｉｏｎａｎｄａｎａｌｙｓｉｓｏｆｃｅｌｌａｇｅｎａｎｄｉｔｓｃｙａｎｏｇｅｎｓｂｒｏｍｉｄｅｆｒａｇｍｅｎｔｓｗａｓｒｅｖｉｅｗｅｄ .Ｉｎａｄｄｉｔｉｏｎ ,ｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｃａｐｉｌｌａｒｙｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓｉｎｔｈｅｓ…     

微细化交联木薯淀粉醋酸酯的制备与研究

本文以三偏磷酸钠为交联剂,醋酸酐为酯化剂,采用先交联、后酯化,先酯化、后交联,两种方案对木薯淀粉进行改性,并对木薯淀粉醋酸酯进行微细化处理。利用IR、SEM、XRD和TGA对合成产物进行表征;并对其冷热粘度进行了研究。结果表明,理想合成路线为:先酯化,后交联合成交联木薯淀粉醋酸酯。通过机械球磨,能有效地将木薯淀粉颗粒微细化,并可通过球磨时间控制淀粉颗粒的粒度和形貌。测试表明,微细化交联木薯淀粉醋酸酯的耐热性下降、结晶度下降;冷粘度增高,但热粘度性质有所下降。     

马铃薯淀粉磷酸酯的物理化学特性

通过与玉米淀粉和马铃薯淀粉相比较,研究了马铃薯淀粉磷酸酯（PEPS）的理化特性,包括粘度的测定,热糊与冷糊的稳定性,不同pH值及电解质（NaCl)和非电解质（蔗糖）存在下的粘度曲线,凝胶强度及冻融稳定性,结果表明,马铃薯淀粉磷酸酯比玉米淀粉和马铃薯淀粉具有更优良的热糊与冷糊的稳定性,电解质(NaCl）和非电解质（蔗糖）的存在,对其热糊与冷糊的稳定性基本元影响,凝胶强度高,冻融稳定性好,尤其是耐酸性能强。     

多孔马铃薯淀粉对亚甲基蓝的吸附行为研究

以天然马铃薯淀粉为原料,N,N-亚甲基双丙烯酞胺(MBA)为交联剂,K_2S_2O_8和NaHSO_3作为引发体系中的氧化剂和还原剂,通过微波辅助制备了一种多孔马铃薯淀粉。分别采用扫描电子显微镜(SEM)、傅里叶变换红外变换光谱仪(FT-IR)和X射线衍射仪(XRD)对天然马铃薯淀粉和多孔马铃薯淀粉的形貌与性能进行表征,探究了交联前后的结构差异。实验结果表明,多孔马铃薯淀粉粒径增大,反应后出现了新的酰胺基,原有的结晶区被破坏,证明分子链之间发生了交联。以亚甲基蓝(MB)为吸附对象,在一定实验条件下,吸附过程符合Langmuir等温吸附方程;在温度为298K时,最大吸附量为140.845mg/g,并且契合准二阶动力学方程,表明吸附是化学吸附而并非分子扩散。这些结果为染液废水的处理提供了有益的帮助。     

气流超微粉碎对蜡质玉米淀粉结构及理化性质的影响

为探究气流超微粉碎对蜡质玉米淀粉结构及性质的影响,采用扫描电镜、激光粒度分析仪、X-射线衍射仪、红外光谱仪、差示扫描量热仪、快速黏度分析仪等分析手段研究经微细化处理后蜡质玉米淀粉颗粒形貌、晶体结构和理化性质。结果表明,淀粉粒径明显变小,微细化蜡质玉米淀粉粒度中位径减小到6.43μm,粉碎后淀粉颗粒仍为A型结构,颗粒结晶结构被破坏,由多晶态向无定形态转变,粉碎过程淀粉无新的基团产生;热焓值、糊化温度均降低,热糊稳定性好;持水能力增加,冻融稳定性好,微细化蜡质玉米淀粉具有较好的热糊稳定性和冷糊力学稳定性。     

球磨处理对碳纳米管吸附苯胺的影响

探讨了机械球磨处理后碳纳米管的微观结构变化,并研究了球磨时间对其吸附苯胺的影响.实验结果表明,通过机械球磨可获得大量不同长度的开口碳纳米管,且球磨时间越长,碳纳米管的长度越短,开口程度越明显.球磨处理后碳纳米管中堆积孔孔径明显变小,管内孔孔径基本保持不变.处理后的碳纳米管与处理前相比,其对苯胺的吸附量显著增加,管内发生的毛细凝聚在吸附中起到了重要的作用.     

羧甲基淀粉与烷基二甲基苄基氯化铵的相互作用研究

通过电导法、荧光法、粒度法等方法研究了羧甲基淀粉与3种不同碳数烷基二甲基苄基氯化铵之间的相互作用。结果表明,羧甲基淀粉与长链烷基二甲基苄基氯化铵在小于单纯表面活性剂临界胶束浓度（cmc）1～2个数量级的浓度下发生复合,并产生沉淀。当表面活性剂烷基链增加且浓度增大时,表面活性剂长碳链间的疏水作用及与羧甲基淀粉间的疏水作用...     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.