几种不同品种淀粉及羟丙基产物糊液性质比较研究

以薯类淀粉(木薯,马铃薯)及禾谷类淀粉(普通玉米、蜡质玉米、高直链玉米及糯米)为原料,以环氧丙烷为醚化剂。制备了羟丙基变性淀粉。反应条件:淀粉乳质量分数40%、反应温度40℃、无水Na_2SO_4添加量12%(以淀粉干基计)、NaOH添加量1.2%、环氧丙烷添加量12%、反应时间18h。分别对原淀粉及在相同的反应条件下制备的羟丙基变性淀粉糊性质做了对比研究。不同品种淀粉糊性质存在很大差别。经过羟丙基改性。淀粉糊液粘度性质、冻融稳定性、透光率、都有不同程度的改善,但凝沉性质不能准确反映羟丙基化对蜡质玉米淀粉和糯米淀粉糊液性质的改善。

阳离子淀粉的合成及糊液粘度的研究

合成了阳离子淀粉并对其糊液粘度进行了测定。探讨了阳离子淀粉的糊液粘度与其取代度和性能的相互关系。提出了糊液粘度的测定可作为阳离子淀粉生产控制的一种简便方法。

冷水溶解度对玉米淀粉糊液性质的影响研究

采用乙醇-碱法制备冷水可溶(CWS)玉米淀粉。以糊液表观黏度、糊液粘附强力和糊液透明度为指标对不同冷水溶解度的CWS玉米淀粉的糊液性质进行研究,并与工厂常用的氧化淀粉进行比较分析。目的是研究冷水溶解度对玉米淀粉糊液性质的影响规律,提高玉米淀粉的使用效果。结果表明:随着冷水溶解度的增加,CWS玉米淀粉糊液的表观黏度逐渐减小,对纯棉纱的粘合强力略微下降,透明度及抗老化性能上升。当CWS玉米淀粉的冷水溶解度为95.48%时,淀粉糊液能够克服氧化淀粉在低温环境下粘合强力急剧下降的缺陷。

不同的水对熟胶粉的糊液粘度的影响研究

研究了不同的水对熟胶粉糊液粘度的影响。结果表明:在固定粉液比、溶解搅拌时间等条件下,不同的水对熟胶粉糊液的粘度是有影响的;在相同温度下,用不同的水配制的熟胶粉糊液其粘度不同,杂质越少、水质越纯的水所配制的熟胶粉糊液其粘度越高,试验的3种水所配制的熟胶粉糊液的粘度依次为:蒸馏水>自来水>地下水;对于同一种水,水的温度越高则所配制的熟胶粉糊液的粘度越低,反之。

种子乳液法聚氯乙烯糊树脂粒径的影响因素

探讨了种子乳液法聚氯乙烯糊树脂生产中乳化剂、引发剂、熟化温度及时间对胶乳粒径的影响,以及干燥温度和物料在干燥塔内的停留时间对二次粒子粒径的影响。

超声波处理对木薯淀粉糊理化性质的影响

利用超声波对木薯淀粉糊液进行处理,研究超声作用对糊液特性的影响。结果表明:超声波处理降低了木薯淀粉糊液的粘度,提高了抗剪切作用能力,处理5 min效果最明显;短时间的超声作用能有效改善淀粉糊液的透明度,处理1.5 min透明度最高,由原来的10.05上升到38.5;超声处理能延缓淀粉糊液的凝沉趋势,加强凝沉的强度,处理时间超过1.5 min后,效果接近。超声波处理可以作为一种有效的改变淀粉糊液特性的途径应用于淀粉的变性处理中。

几种复合变性方式对淀粉性质的影响

淀粉的性质直接决定了其使用的效果,不同的各种糊液性质应用于不同的生产领域。本文主要探讨了部分复合变性方式对淀粉性质的影响,论述了淀粉性质方面存在的一些问题,并结合了部分复合变性淀粉的成果,分析了复合变性对淀粉性质存在的一些影响,希望可以为今后的淀粉性质的研究提供参考和借鉴,使变性淀粉得到更好的利用。

Application of Fuzzy Modification Strategy in MRAC

Based on a simplified model reference adaptive control(SMRAC) algorithm a parameter modification algorithm according to fuzzy laws is proposed in this paper. The method makes the adaptive parameters in SMRAC only rely on the status of performance error. Thus it eliminates the influences of gain coefficients in SMRAC and the amplitude of input signal on the dynamic characteristics. Experiments on various step amplitudes and loads show that the performances of SMRAC are improved by incorporating fuzzy modification method.

Fuzzy iterative learning control of electro-hydraulic servo system for SRM direct-drive volume control hydraulic press

A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM(switched reluctance motor) driving technology is developed.Considering that the serious dead zone and time-variant nonlinearity exist in the volume control electro-hydraulic servo system,the ILC(iterative learning control) method is applied to tracking the displacement curve of the hydraulic press slider.In order to improve the convergence speed and precision of ILC,a fuzzy ILC algorithm that utilizes the fuzzy strategy to adaptively adjust the iterative learning gains is put forward.The simulation and experimental researches are carried out to investigate the convergence speed and precision of the fuzzy ILC for hydraulic press slider position tracking.The results show that the fuzzy ILC can raise the iterative learning speed enormously,and realize the tracking control of slider displacement curve with rapid response speed and high control precision.In experiment,the maximum tracking error 0.02 V is achieved through 12 iterations only.

Measurement and correlation of solubility of diosmin in four pure solvents and β-cyclodextrin solution at 298.15K to 333.15K

The aim of present study was to measure and correlate the solubility of poorly water-soluble flavonoid diosmin in water, ethanol, isopropyl alcohol （IPA）, polyethylene glycol-400 （PEG-400） and β-cyclodextrin （β-CD） aqueous solution （0.02 mol·L^-1 ）. The solubility of diosmio was measured using the shake flask method from （298.15 to 333.15） K at atmospheric pressure. The experimental solubilities of diosmin were regressed by the modified Apelblat model with a relative deviation in the range of 0.048% to 5.940%. The correlation coefficients were observed in the range of 0.9957 to 0.9995. The solubility of diosmin was found to be increased with temperature in all sample matrices investigated. The mole fraction solubility of diosmin was found to be higher in 5-CD aqueous solution and PEG-400 as compared to water, ethanol and IPA. Based on solubility data of present study, diosmin was considered as practically insoluble in water, insoluble in ethanol ＆ IPA and soluble in PEG- 400 and β-CD aqueous solution.

加热温度对粮食糊化液粘度的影响

粮食是一种具有丰富的淀粉、脂肪、蛋白质、糖类等多种成份的特殊物质，是人体营养需求的主要来源。粮食粘度的测定，是检验粮食品质好坏的重要指标之一，是了解粮食陈化程度、确保储粮安全的一项重要的科学依据。世界上许多国家把粮食粘度作为进出口检验的重要项目和评价粮食品质的重要依据。我国在《粮食储藏技术规范》中也明确规定，粮食的运动粘度是检验粮食储藏变化的重要指标。

Direct detection of tryptophan enantiomers in urine using the chiral recognition of cyclodextrin by capillary electrophoresis

Racemic tryptophan was separated with resolution 1.3 by CE. In 10 mM H2PO4 containing triethanolamine salt of pH2.8 ahnost saturated α-CD was used as chiral reagent. For the first time L- and D-tryptophan enantiomers in human urine can be detected in 20 minute without pretreatment.

Effects of Storage and Heating on Serum Viscosity of Commercial Hot Break Tomato Paste

Samples of hot break tomato paste were collected from commercially produced aseptic totes after 6-11 months of storage at ambient temperature. Serum viscosity of the hot break tomato paste samples was analyzed at each sampling time and compared to the initial serum viscosity measured at the time of tomato paste manufacturing. As storage time increased, the serum viscosity of hot break tomato paste significantly decreased. After 7 months of storage, 16%-27% reduction of serum viscosity was observed in the hot break tomato paste. To evaluate effects of a heating on the serum viscosity of hot break tomato paste, the paste samples were reconstituted with water to 10° Brix, similar level of tomato solids in typical tomato sauce products. Diluted tomato paste was heated and held at 95℃ for 3 minutes and its serum viscosity was measured. After the heating, the serum viscosity of hot break tomato paste was slightly increased up to 5% of initial value, however the recovery was not significant （p 〈 0.05）.

The Application of Synthetic Fuzzy Assessing Method in Measurement and Control System of Plating Solution Evaporator

The synthetic fuzzy assessing method is usually applied to sensory evaluation. The method has simple and reliable virtue, and it is consistent with objective evaluation results. Using this method, system status of plating solution evaporator is evaluated, and the result is applied to compensate a fuzzy controller. Experimental results have shown the correctness and the validity of the proposed approach.

Fuzzy Logic Based Approach in an Enterprise Resource Planning System for Hydraulic Cylinders Assembly

Trends in modern industry show a tendency towards demassovization of production as a response to the customers＇ specific needs for unique and personalized products. This provokes significant changes in the processes of manufacturing, assembly, and testing The cost of such a type of production can be reduced by employing highly productive reconfigurable equipment with proper software to enable optimization. This paper presents a decision support extension for directing of hydraulic cylinders to assembly-testing lines using fuzzy logic in the Enterprise Resource Planning system of a small size production in a factory in Bulgaria. Different assembly-testing lines are flexibly assigned to the specific cylinder＇s parameters by the developed fuzzy system on the basis of the overlapping of parameters in the hydraulic cylinders classification. The final decision on the line assigned in case of alternatives is made through accounting for the minimal cylinder delay time. The effectiveness of the approach is assessed by simulation. It leads to an increase of the efficiency of the assembly-testing flow lines, a reduction of the time needed for hydraulic cylinders assembling and testing and balanced loading of the modules.

Fuzzy NN based predictive control and its application to green liquor system

The fuzzy NN predictive control algorithm introduced in this paper uses fuzzy neural network to model the nonlinear MIMO process. Its training method that integrates LS and BP algorithm brings quick convergence. GPC algorithm is used as the predictive component. The fuzzy neural network has six layers, including input layer, output layer and four hidden layers. An application to a MIMO nonlinear process(green liquor system of the recovery system in a pulp factory shows that this algorithm has better performance than normal PID algrithm.

A Large Conformational Change of a Bridged b-Cyclodextrin Dimer in Aqueous Solution

A novel bridged b-CD dimer in which two b-cyclodextrins were linked by a naphthalene at positions 2 and 7 has been synthesized. 1H and 13CNMR measurements showed that a large change in the conformation of the dimer occurred in aqueous solution. The dimer interacted with methyl and ethyl orange to form stable inclusion complexes via 搃nduced fit?mechanism.

Effect of β-Cyclodextrin Upon the Sol-gel Transition of Methylcellulose Solutions in the Presence of Sodium Dodecyl Sulfate

The sol-gel transition temperature of methylcellulose （MC） solution in the presence of sodium dodecyl sulfate （SDS） as well as the mixtures of SDS and β-cyclodextrin （β-CD） was mea- sured, and the effect of the two competing interactions, the hydrophobic interaction between SDS and MC and the inclusion interaction between SDS and β-CD, upon the sol-gel transition of MC solution was studied. It has been found that the inclusion interaction between SDS and β-CD is much greater than the hydrophobic interaction between SDS and MC. As a result, in the coexistence of SDS and β-CD, the sol-gel transition temperature of MC solution keeps the same value, independent of the concentration of SDS in solution on con- dition that the concentration of SDS is less than β-CD. Our experimental results not only suggest that the effect of SDS upon the sol-gel transition of MC solution can be screened by β-CD completely but also indicate the inclusion ratio of SDS to β-CD can be determined quantitatively by using rheological measurement. The inclusion ratio of SDS to β-CD is 1：1, which is in good agreement with the inclusion ratio of SDS to β-CD in the presence of poly（vincyl pyrrolidone） determined by the viscosity measurement but is critically different from the inclusion ratio of SDS to β-CD in the presence of the oppositely charged polyelec-trolyte by using the rheological measurement, mainly due to the reason that the mechanism of the interaction between SDS and MC is critically different from the mechanism of the interaction between SDS and the oppositely charged polyelectrolyte.

Equilibrium Studies on Liquid-Liquid Reactive Extraction of Phenylsuccinic Acid Enantiomers Using Hydrophilicβ-CD Derivatives Extractants

This paper deals with the enantioseparation of phenylsuccinic acid(H2A)enantiomers by liquid-liquid reactive extraction usingβ-CD derivatives as aqueous selectors.Cyclodextrin and its derivatives can interact with guest molecules selectively to form complexes with different stabilities.Cyclodextrin derivatives are not soluble in organic liquids,but highly soluble in water.In this work,hydroxypropyl-β-cyclodextrin(HP-β-CD),hydroxyethyl- β-cyclodextrin(HE-β-CD)and methyl-β-cyclodextrin(Me-β-CD)were selected as chiral selectors in aqueous phase for the reactive extraction of phenylsuccinic acid enantiomers from organic phase to aqueous phase.The results show that the efficiency of the extraction depends,often strongly,on a number of process variables,including the types of organic solvents andβ-CD derivatives,the concentrations of the extractants and H2A enantiomers,pH and temperature.HP-β-CD,HE-β-CD and Me-β-CD have stronger recognition abilities for R-phenylsuccinic acid than for S-phenylsuccinic acid.Among the three kinds ofβ-CD derivatives,HP-β-CD has the strongest separation ability. Excellent enantioseparation was achieved under the optimal conditions of pH of 2.5 and temperature of 5°C with a maximum enantioselectivity(a)of 2.38.Reactive extraction of enantiomers with hydrophilicβ-CD derivatives is of strong chiral separation ability and can be hopeful for separations of various enantiomers at a large-scale.