浅析一水柠檬酸结晶工艺和设备选型

分析一水柠檬酸的结晶过程及其影响因素,对其结晶工艺进行创新,优化选择结晶设备,并成功地工业化应用且取得了显著的经济效益。     

Influence of filler selection on twin screw foam granulation

The influence of filler selection in wet granulation was studied for the novel case where the binder is delivered as an unstable, semi-rigid aqueous foam to an extrusion process. The work primarily examined the impact of differing concentrations of microcrystalline cellulose (Avicel PH® 101) in a formulation with spray-dried α-lactose monohydrate (Flowlac® 100) in regards to wetting and granule nucleation for this relatively new technique known as continuous foam granulation. Foam stability was varied within the work to change its drainage and coarsening behavior atop these powder excipients, by use of different foamable binding agents (METHOCEL? F4 PLV and METHOCEL? Premium VLV) as well as by adjusting the foam quality. A static bed penetration test was first used to study the foam behavior in wetting these powders without the processing constraints of an extruder which limit possible liquid-to-solids ratios as well as introduce shear which may complicate interpretation of the mechanism. The test found that the penetration time to saturate these powders decreased as their water absorption capacity increased which in turn decreased the size of the formed nuclei. Differences in the stability of the foamed binder had minimal influence on these attributes of wetting despite its high spread-to-soak behavior. The size of granules produced by extrusion similarly demonstrated sensitivity to the increasing water absorption capacity of the filler and little dependency on foam properties. The different liquid-to-solids ratios required to granulate these different formulations inside the extruder highlighted an evolving concept of powder lubricity for continuous foam granulation.     

Effect of water activity and temperature on the stability of creatine during storage

Creatine degradation to creatinine, which has no biological activity, in combinations of glycerol and pH 4.0 buffer solutions followed first-order kinetics up to a point where degradation started to level off, generally beyond the first half-life. Practical data are reported for a wide range of water activity (a_w) values (0.31–0.983) at 4°C, 23°C, and 35°C. Creatine degradation did not exhibit a dilution effect, that is a decrease in rate about an a_w of 0.7, as is found for both microbiological growth and chemical reactions in semisolid food matrix systems. The temperature dependence obeyed the Arrhenius relationship with an energy of activation of about 20 kcal/mol at a_w ≥ 0.68 increasing to 23 kcal/mole below that a_w. In addition, a semilog plot of half-life as a function of a_w at each temperature follows a predicted straight line. The pH and assumed liquid viscosity increase through increased glycerol concentration were not able to completely explain the decrease in rate of degradation as a function of a_w. Furthermore, we confirmed that creatine stability in the crystal form is very high as long as it does not reach the deliquescence state.     

Optical and thermal properties of precursor-controlled graphene–zinc nanocomposites

Graphene, a monolayer two dimensional carbon sheet can be utilized as a support to anchor functional nanomaterials to form novel nanocomposites for a variety of potential applications. We present an approach for the in situ preparation of graphene–zinc oxide nanocomposites through a reflux process in which either zinc acetate or zinc chloride can serve as precursors. The synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray analysis, ultraviolet–visible spectroscopy and thermogravimetry analysis (TGA–DSC) for structural, optical and thermal properties. It has been found that nanocomposites comprise of zinc oxide (ZnO) nanostructures deposited on graphene sheets, and the choice of zinc precursor has a deterministic influence on the morphology, structure and properties of the graphene–ZnO nanocomposites. In addition, the novel structure of zinc acetate based nanocomposite has induced improved absorption and thermal stability of the graphene/ZnO nanocomposite as compared to zinc chloride based nanocomposite and would be promising for future applications in nanotechnology.     

用ADC发泡剂副产十水碳酸钠生产一水碳酸钠的工艺

介绍中平能化集团开封东大化工有限公司ADC发泡剂生产中副产十水碳酸钠的回收利用情况,简述利用回收的副产物十水碳酸钠生产一水碳酸钠或无水碳酸钠的工艺;由于原料价格低,综合利用效果好。     

Hybrid modelling and self-learning system for dextrose crystallization process

This paper deals with the modelling of a continuous cooling column crystallizer. An accurate model of this system is needed for complex process control. The investigated system consists on dextrose monohydrate in aqueous solution. An adaptive hybrid model is presented. The model consists of two parts: the phenomenological model, expressed by a set of differential algebraic equations, and a neural network, based on historical data, developed by the fuzzy ARMAP technique. The empirical part of the hybrid model is aimed at eliminating the deviations of the prediction of the phenomenological model caused mainly by incrustations over the surface of the cooling coils located along the column crystallizer. The model is adaptive since neural network parameters are updated by a self-learning system (SLS) based on the acquired process data storage of the DCS of an industrial plant. Firstly, the hybrid model was implemented by using the data of a three-month campaign of the crystallizer, then the self-learning technique was checked on site in a subsequent campaign.     

2-氨基-7-羟基四氢萘水合物的合成

以7-甲氧基-2-萘满酮为原料合成了2-氨基-7-羟基四氢萘水合物。以苄胺与7-甲氧基-2-萘满酮反应,然后以硼氢化钠还原、盐酸酸化得到苄基保护的胺的盐酸盐,再以Pd/C催化氢解得到2-氨基-7-甲氧基四氢萘盐酸盐。将盐以碱处理得到2-氨基-7-甲氧基四氢萘,于无水乙醇中与扁桃酸反应分离手性异构体。分开的异构体先以NaOH中和,然后分别在48%的氢溴酸存在下水解得到2-氨基-7-羟基四氢萘的溴酸盐,再分别以氨水中和后得到2-氨基-7-羟基四氢萘两手性异构体的水合物。两异构体总收率均达到30%以上。     

The Stability of Theophylline Tablets with a Hydroxypropylcellulose Matrix

The behavior of 40:60 anhydrous theophylline/hydroxypropylcellulose (HPC) direct compression tablets obtained using a variety of hydroxypropylcelluloses with low or medium-high degrees of substitution (L-HPCs and HPCs, respectively) was determined immediately following their preparation and after storage for 6 months at 20°C and a relative humidity (RH) of either 70.4% or 93.9%. The lower relative humidity did not bring about hydration of the active principle in any formulation, but the higher relative humidity totally hydrated the drug in all except one L-HPC formulation, in which hydration remained incomplete. Both relative humidities caused significant tablet swelling, with L-HPC formulations being more affected than HPC formulations. Drug release was slowed by hydration of the active principle, but accelerated with tablet swelling. The lower relative humidity caused significant alteration of drug release characteristics in only two L-HPC formulations, release from which was accelerated, while the higher relative humidities only failed to cause such alterations in two HPC formulations, with release from all except one of the others slowed (in the exceptional formulation, which exhibited incompletely hydrated theophylline and the greatest swelling of all, release was accelerated).     

Nutritional characteristics of emu (Dromaius novaehollandiae) meat and its value-added products

The objectives of the present study were to ascertain the nutritional value (i.e., macro and microconstituents) of emu (Dromaius novaehollandiae, Latham) meat and a value-added product derived therefrom. The contents of creatine, creatinine and phosphocreatine in fresh emu meat and the impact of processing on these bioactives during the production of jerky were of particular interest. For comparative purposes, a beef counterpart was prepared. The proximate compositional data indicated that the macroconstituents of emu meat and the fabricated jerky product were not so different from their beef analogues. Analysis of the microconstituents in emu samples revealed that the levels of a number of nutritionally important oil- and water-soluble vitamins and minerals were typical of those for red meat species. The creatine content in emu meat (29.3 mg/g dry matter) was similar to that of beef; slightly higher creatine levels were detected, however, in the emu jerky (22.8 mg/g dry matter) compared to its beef counterpart, and these were significant (P < 0.01) when the data was analysed on a dry weight basis. This demonstrates a potential for the emu meat snack to be considered as a functional food for athletes looking for performance enhancement, and who are interested in consuming greater quantities of creatine from a natural food source.     

一水肌酸及共轭亚油酸对大鼠肌纤维相关基因和酶活性的影响及机理

本实验旨在研究饲粮中添加一水肌酸（creatine monohydrate,CMH）和共轭亚油酸（conjugated linoleic acid,CLA）对大鼠肌纤维相关基因及酶活性的影响及机理。选择40 只健康雌性Wistar大鼠随机分为5 组：对照组,饲喂基础饲料;CMH低剂量组,饲喂0.5%（以基础饲料质量计,下同）CMH＋基础饲料;CMH高剂量组,饲喂1% CMH＋基础饲料;CLA低剂量组,饲喂0.5% CLA＋基础饲料;CLA高剂量组,饲喂1% CLA＋基础饲料;饲喂4 周。结果表明：与对照组相比,CMH低剂量组大鼠日摄入量显著降低（P＜0.05）,肌球蛋白重链IIa（myosin heavy chain IIa,MyHC IIa）、MyHC IIb、过氧化物酶增殖体激活受体γ辅激活因子1α（peroxisome proliferator-activated receptor γ coactivator 1α,PGC-1α）、肌细胞增强因子2C（myocyte enhancer factor 2C,MEF2C）、葡萄糖转运子4（glucose transporter 4,GLUT4）mRNA相对表达量及琥珀酸脱氢酶（succinate dehydrogenase,SDH）活力显著增加（P＜0.05）;CMH高剂量组大鼠日摄入量显著降低（P＜0.05）,MyHC IIb、MEF2C、GLUT4 mRNA相对表达量显著增加（P＜0.05）。与对照组相比,CLA低剂量组大鼠日摄入量、MyHC IIx mRNA相对表达量显著降低（P＜0.05）,MyHC IIa、PGC-1α mRNA相对表达量显著升高,SDH、苹果酸脱氢酶、一磷酸腺苷活化蛋白激酶（AMP-activated protein kinase,AMPK）活力显著增加（P＜0.05）;CLA高剂量组大鼠日摄入量、乳酸脱氢酶活力、MEF2C mRNA相对表达量显著降低（P＜0.05）,MyHC I、MyHC IIa、PGC-1α、GLUT4 mRNA相对表达量和SDH活力显著增加（P＜0.05）。综上所述,饲粮添加CMH、CLA后,大鼠肌肉组织中AMPK被激活,氧化代谢酶活性增加,通路相关基因PGC-1α、MEF2C、GLUT4 mRNA相对表达量增加,肌肉氧化代谢增强,进而改变肌纤维类型。