超声辅助法制备黄姜淀粉醋酸酯及其产物表征

通过比较未施加超声场和超声强化对醋酸酯淀粉取代度的影响,结合扫描电镜(SEM)、X射线衍射(XRD)、热重法(TG)和差热分析(DTA)技术对所制得的黄姜醋酸酯淀粉的形貌,颗粒大小,结晶性及热稳定性进行的表征,探讨超声辅助法制备黄姜淀粉醋酸酯的特点及产物特性。实验结果表明,在制备醋酸酯淀粉的过程中,超声强化可以缩短反应时间,减少催化剂用量。根据SEM、XRD、TG和DTA分析结果说明,超声强化作用引起淀粉降解,破坏了淀粉的非结晶区,增加了乙酰剂与淀粉颗粒的接触位点;对淀粉的结晶区影响甚微,所以超声强化对产品的热稳定性影响较小。     

响应面法优化高取代度黄姜醋酸酯淀粉的制备

以浓硫酸作催化剂,黄姜淀粉为原料,冰醋酸和醋酸酐为改性剂,合成了高取代度的黄姜淀粉醋酸酯。运用响应面法优化了制备工艺,结果表明制备黄姜醋酸酯淀粉的最佳反应条件为反应温度70℃,反应时间2.5h,0.20mL H2SO4作催化剂,醋酸酐与醋酸体积比为32∶68,取代度为1.70     

机械活化木薯淀粉制备低取代度醋酸酯淀粉的研究

以机械活化0.5h的木薯淀粉和木薯原淀粉为原料,以醋酸酐为酯化试剂,氢氧化钠为催化剂,制备低取代度木薯淀粉醋酸酯。以淀粉醋酸酯的取代度和反应效率为评价指标,分别研究反应温度、反应时间、醋酸酐用量、pH各因素对其取代度和反应效率的影响。实验结果表明,反应温度、反应时间、醋酸酐用量、pH对木薯淀粉醋酸酯的取代度和反应效率均有影响。机械活化能显著提高木薯淀粉醋酸酯化反应的取代度和反应效率。通过试验得到制备低取代度木薯淀粉醋酸酯的较佳工艺条件为:反应温度为30℃,反应时间为40min,醋酸酐用量为0.15mL,pH为8.5时,在此条件下制备的醋酸酯淀粉的取代度为0.075、反应效率为87.45%。并用红外光谱对醋酸酯淀粉进行分析。     

氧化醋酸酯淀粉的制备及其在表面施胶中的应用

介绍了氧化醋酸酯淀粉的制备方法与表面施胶性能,重点探讨了醋酸乙烯酯的用量、pH值、反应时间和反应温度对氧化醋酸酯淀粉的取代度及反应效率的影响,并利用IR和SEM对氧化醋酸酯淀粉的结构进行了表征。结果表明,以水为反应介质,在醋酸乙烯酯用量8%、pH值9～10、反应温度30℃、反应时间60min时,可得到取代度为0.104的氧化醋酸酯淀粉。表面施胶实验发现,取代度为0.051～0.104的氧化醋酸酯淀粉表现出比氧化淀粉更好的表面施胶性能,同时还可改善纸张的物理性能指标。     

醋酸酯支链淀粉的制备及其性能

摘要： 研究醋酸酯支链淀粉的制备与性能。以玉米淀粉为原料,以醋酸酐为酯化剂,采用干法制备醋酸酯支链淀粉。以透光率、糊化温度和取代度为指标,采用正交实验确定了制备醋酸酯化支链淀粉的最佳条件。测定并分析了醋酸酯支链淀粉的取代度、IR图谱和X-衍射光谱。测定并比较了醋酸酯支链淀粉与玉米淀粉、支链淀粉、醋酸酯淀粉的浆纱强伸性、透光率、糊化温度、黏度、黏度热稳定性。实验结果表明：醋酸酯支链淀粉与支链淀粉的X-衍射光谱基本相同,为无定型晶体结构;与玉米淀粉、支链淀粉和醋酸酯淀粉比较,醋酸酯支链淀粉具有黏度低、糊化温度低、取代度高、透明度高、黏度热稳定性高等特点,是一种比醋酸酯淀粉更好的纺织浆料。     

超声波预处理制备磷酸酯淀粉的研究

为探索新工艺路线,提高磷酸酯淀粉的取代度,将超声波技术引入其制备工艺,对木薯淀粉进行预处理,结合半干法制备磷酸酯淀粉,分别研究超声处理时间、超声处理功率、分散介质种类及分散介质浓度对磷酸酯淀粉取代度和黏度的影响。结果表明,超声波对木薯淀粉磷酸化有显著强化作用,20％乙醇作分散介质,功率为300W的超声波作用2．5min可制得磷酸酯淀粉的取代度比相同反应条件下未经超声处理制得样品提高25％;超声处理使磷酸酯淀粉的黏度发生较大程度降低,原因是超声波破坏了淀粉颗粒结晶区,直链淀粉含量增加,导致淀粉的聚合度下降。     

超声波辅助制备醋酸酯多孔淀粉

以玉米多孔淀粉为原料,研究超声辅助处理对制备醋酸酯多孔淀粉的影响,以及对醋酸酯多孔淀粉吸油率的影响。实验结果表明,超声波辅助处理对多孔淀粉的醋酸酯化反应作用明显,在超声功率为200 W,超声时间为150 min时取代度和吸油率分别能达到0.055 9和89.1%,跟未经过超声的醋酸酯化多孔淀粉相比,取代度提高了64.4%,吸油率提高了13.9%,在此超声处理条件下酯化后多孔淀粉的蜂窝状孔洞未被破坏,相对结晶度与多孔淀粉原料相比,下降16.1%。     

机械活化固相化学反应制备木薯醋酸酯淀粉

为获得制备醋酸酯淀粉的新工艺,采用机械活化固相化学反应法制备木薯醋酸酯淀粉。以醋酸酯淀粉的取代度为评价指标,分别探讨醋酸酐用量、NaOH用量、球磨温度、球磨时间、搅拌速度、球磨介质的堆体积等因素对木薯淀粉醋酸酯反应的影响,并对影响因素进行了正交优化。结果表明:在醋酸酐质量分数60%、NaOH质量分数2.0%、球磨温度60℃、球磨时间60 min、搅拌速度380 r/min、球磨介质堆体积500 mL的反应条件下,制备得到的木薯醋酸酯淀粉的取代度为0.263 2,反应效率为25.57%。并采用红外光谱(FTIR)、X-射线衍射(XRD)对木薯醋酸酯淀粉的结构进行了表征。机械活化对淀粉发生酯反应有显著的强化作用。     

取代度对醋酸酯淀粉结构与性能的影响

取代度的大小对醋酸酯淀粉的性能有重要的影响。利用相同的制备工艺获取3种不同取代度的醋酸酯淀粉,采用红外光谱仪对淀粉的分子构成做出表征分析,在扫描电镜(SEM)下观察不同取代度醋酸酯淀粉颗粒的表面及内部的微观结构与原淀粉进行对比分析,并对浆液的凝沉性及淀粉的成膜性进行测试。结果表明,取代度较低的醋酸酯淀粉颗粒表面发生的变化较小,浆液的凝沉性及成膜性与原淀粉相差不大,浆膜较脆硬;高取代度的醋酸酯淀粉中酯基含量较明显,淀粉颗粒的网状结构突出,浆膜的吸湿率较低,保湿性较差。     

3种马铃薯改性淀粉的理化性质及结构分析

以马铃薯淀粉为材料,制备氧化淀粉、醋酸酯淀粉、氧化醋酸酯淀粉,比较其理化性质,并通过红外光谱(FT-IR)、电子扫描显微镜(SEM)等对其结构进行分析。结果表明:氧化淀粉、醋酸酯淀粉、氧化醋酸酯淀粉比原淀粉透明度高、流动性好、附着力强、涂抹性好。FT-IR实验表明氧化淀粉有羧基的特征吸收峰,而氧化醋酸酯淀粉酯化改性过程中有醋酸酯基团的生成。SEM扫描实验显示氧化淀粉的外形比较规整多为球状或椭球状,表面较光滑;醋酸酯淀粉颗粒形状未发生大的改变,但规整度很差;氧化醋酸酯淀粉颗粒完整,表面粗糙,低取代度的酯化反应仅发生在淀粉颗粒表面。     

蛋白质水解度测定方法综述

对目前国内外常用的蛋白质水解度测定方法进行了综述，其中pH—state方法是通过滴定水解过程中释放的质子测定DH；OPA、TNBS及国内常用的水合茚三酮和甲醛等测定方法是利用游离氨基的反应测定DH。     

SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.     

BASIS OF STABILITY OF AMINE SALTS OF LINOLEIC ACID

SUMMARY— The mechanism and generality of the known stabilization against autoxidation conferred on linoleic acid by certain basic amino acids, such as lysine and arginine, was investigated. Basic amino acids were the only class of compounds found to confer the effect. However, the smallest basic amino acid, 2,3-diaminopropionic acid, was not effective, nor was αβω-diaminc acid, 3,6-diaminohexanoic acid, although a simple isomer of lysine. The stabilization was observed only in the solid phase. Inclusion of sodium chloride in the solid matrix was deleterious to the effect. A large number of physical and chemical observations were made and correlated but it has not been possible to draw detailed conclusions about the mechanism of stabilization, nor can a detailed structure of the stabilized complex be suggested. The cause of the phenomenon appears to be closely associated with the physical arrangement of the ions in the crystal lattice.     

聚多元羧酸盐的合成及应用

研究了聚多元羧酸盐的合成方法及反应机理,将其应用于洗涤剂和PVC制品中分别代替三聚磷酸钠和邻苯二甲酸二丁酯,证明有良好效果。     

百年风尚

一场流光溢彩、赏心悦目的展览,一段百年风尚演进的传奇旅程,一次东西方文化艺术的完美对话。2013年9月13日,“博萃臻艺一中西方珍宝艺术展”在辽宁省博物馆举行了隆重的开幕仪式,法兰西共和国驻华大使白林女士、辽宁省文物局局长丁辉先生、辽宁省博物馆馆长马宝杰先生、卡地亚全球总裁兼首席执行官邓阁仕先生、卡地亚区域行政总裁（北亚洲）陆慧全先生、卡地亚中国区首席执行官陆意斯先生、辽宁省文物店总经理张春鹰先生,以及众多文化界与文博界的贵宾齐聚一堂,共同见证了这场文化艺术盛事。     

STABILITY OF AQUEOUS EMULSIONS OF THE ESSENTIAL OIL OF HOPS

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

DEVELOPMENT OF CHAINS OF CELLS OF SACCHAROMYCES CEREVISIAE DURING FERMENTATION

The lengths of chains of cells of Saccharomyces cerevisiae were studied during fermentation. Pitching yeast generally contained about half of the total number of cells as two-celled chains. The chain lengths varied during the subsequent fermentation and the variations were characteristic of the strain. Electronic counting assessments of chain length were unreliable.     

ANALYTICAL CHARACTERIZATION OF THE PRODUCTS OF NONENZYMATIC GLYCOSYLATION OF LYSOZYME

The quantitative analysis of the reaction products of the water activity dependent nonenzymatic glycosylation of lysozyme was not straightforward. Difficulties arose in the determination of the number of bound glucose molecules because glycosylation leads to glucose mediated protein aggregation, and the likely presence of a mixture of relatively labile Schiff-base intermediates, and the more stable ketoamine products generated by Amadori rearrangement. Polyacrylamide gel electrophoresis was used to monitor protein aggregation; periodate oxidation, nuclear magnetic resonance (NMR), and oxalic acid hydrolysis combined with HPLC, emerged as the most promising methods to quantitate the degree of glycosylation. Possible interpretations are advanced to explain the apparent discrepancies in degree of glycosylation suggested by the different analytical methods evaluated.     

矩阵乘积的行式,列式

给出了ｍ×ｍ矩阵与ｍ×ｎ矩阵的行（列）式的表达式．若Ａ＝ａ１１ａ１２…ａ１ｍａ２１ａ２２…ａ２ｍ……ａｍ１ａｍ２…ａｍｍＢ＝ｂ１１ｂ１２…ｂ１ｎｂ２１ｂ２２…ｂ２ｎ……ｂｍ１ｂｍ２…ｂｍｎ分别是ｍ×ｍ，ｍ×ｎ矩阵，则｜Ａ｜｜Ｂ｜＝｜ＡＢ｜＋∑ｉ１＜ｉ２＜…＜ｉｔｊ１＜ｊ２＜…＜ｊｔ１≤ｔ≤ｍｎ－ｔ≥ｍＮＢｉ１ｉ２…ｉｔｊ１ｊ２…ｊｔＮＡＢ１…ｍ（－１）ｓｔ＋１ｊｔ＋１…（－１）ｓｎｊｎ其中ｉ１，ｉ２，…，ｉｔ是１，２，…，ｍ中ｔ个数码；ｊ１，ｊ２，…，ｊｔ，ｊｔ＋１，…，ｊｎ是１，２，…，ｎ的一个排列；ｓｒ＝π（ｊ１，ｊ２，…，ｊｔ，ｊｒ）（ｒ＝１，２，…，ｎ）是排列ｊ１，ｊ２，…，ｊｔ，ｊｒ的反序数．