RDX/RF纳米结构复合含能材料的孔结构研究

在黑索今(RDX)/间苯二酚-甲醛树脂(RF)纳米结构复合含能材料制备的基础上,研究了RF气凝胶和RDX/RF纳米结构复合含能材料的孔结构,计算了含10%、30%、50%、70%、80%RDX的复合材料RDX/RF的比表面积、总孔体积、平均孔径,并对RF气凝胶和不同复合材料的吸附脱附等温线、中孔分布和微孔分布进行了比较。用扫描电子显微镜(SEM)对其微观形貌进行了表征,利用X射线粉末衍射仪(XRD)对复合材料中RDX颗粒的晶粒度进行了研究,在34~38 nm之间。研究表明:RDX/RF复合材料的孔径在50 nm以下,随RDX含量的增加,比表面积、总孔体积变小,平均孔径则变大;通过RF气凝胶和RDX/RF纳米复合含能材料的吸附脱附等温线、中孔、微孔分布以及中孔微分总孔体积、微孔微分总孔体积的变化比较,认为RDX的填充对气凝胶的中孔影响较大。     

9种土样高吸力下的持水特征

持水特征曲线(SWRC)是非饱和土重要的本构关系.大部分SWRC由轴平移方法获得,其所能控制的吸力范围较小;然而工程实践中相对湿度常低于95％(吸力高于7.1 MPa);因此采用动态露点法测定Wyoming膨润土、宁明膨胀土、荆门黄褐色膨胀土、Denver黏土岩、荆门棕褐色膨胀土、武汉黏土、三门峡粉质黏土、郑州粉土、开...     

Drying kinetics and quality changes during drying of red pepper

A mathematical model is proposed to simulate the process of drying of individual pieces of red pepper under constant external conditions and to predict changes in some nutritional and organoleptic attributes of the product. The model was solved numerically to obtain moisture content and temperature as well as ascorbic acid and carotenoids concentration in the product as a function of time. A good agreement between predictions and experimental data at different drying temperatures was obtained.Water sorption isotherms of red pepper were determined in the range 20-50 °C and represented by two different sorption equations. Drying kinetics were represented by a diffusive model, the effective moisture diffusivity ranging from 5.01 to 8.32×10⁻¹⁰ m²/s with an activation energy of 23.35 kJ/mol. Degradation kinetics for ascorbic acid and total carotenoids were measured in the range 50-70 °C and modelled as first-order reactions. The rate constants increased with temperature and product moisture content. Average activation energies for carotenoids and vitamin C degradation were 50.1 and 26.9 kJ/mol, respectively.     

Effects of nanorod-rich ZnO on rheological,sorption isotherm,and physicochemical properties of bovine gelatin films

The effects of nanorod-rich zinc oxide (ZnO–nr) on the flow properties of bovine gelatin solution and on the sorption isotherm, antimicrobial, and physchochemical properties of gelatin films were investigated. ZnO–nr was incorporated into gelatin solutions at different concentrations (0.01, 0.02, 0.03, and 0.05 g/g dried gelatin). The introduction of low ZnO–nr concentrations (0.05 g/g dried gelatin) to gelatin solutions significantly increased the viscosity of the solution from 9 to 11.9 mPa s and decreased the permeability of the films to water vapor from 8.9 × 10⁻¹¹ to 1.78 × 10⁻¹¹ (g m⁻¹ s⁻¹ Pa⁻¹). Solubility in water decreased from 30% to 20%, and monolayer water content of the films decreased from 0.13 to 0.10 (g water/g dried solid), whereas their contact angle increased from 45° to 85° with increasing ZnO–nr concentration from 0 to 0.05 g/g dried gelatin. The ZnO–nr gelatin films had very low UV transmittance and were able to absorb more than 50% of the near-infrared spectra. These films showed excellent antimicrobial activity against Staphylococcus aureus. These properties suggest that ZnO–nr can be potentially used as fillers in gelatin-based films for active packaging materials in the pharmaceutical and food packaging industries.     

液相色谱技术在染整中的若干应用

液相色谱技术作为重要的提纯与分析手段,对染整行业的检测方法开发、印染机理研究都有不可替代的作用。综述了液相色谱技术在染整学科中的发展历程;列举了该技术在染整研究中的应用,包括染化料的定性定量分析、纤维对染料吸附的热力学研究、以及不同染料配伍值的计算。另一方面,也综述了纺织材料作为新型色谱填料的相关研究。液相色谱技术与印染技术的结合,不但可以丰富纺织材料的研究手段,揭示小分子化学品与纤维材料之间的相互作用规律,还可以开发性能独特、具有生物相容性的新型纤维形态色谱填料,用于蛋白质、糖以及其它化学品的分离。     

桑皮纤维直接染料染色动力学和热力学研究

采用直接染料对桑皮纤维进行染色动力学和热力学研究。研究结果表明:直接大红4BS的标准曲线方程符合朗伯-比耳定律,吸光度值与染料质量浓度成正比关系。桑皮纤维染色的初始阶段上染迅速,上染量与染色时间几乎呈直线关系,而且纤维的吸附速度随温度的升高而增加。随着染色温度的升高,直接大红4BS染桑皮纤维的染色常数逐渐增大,半染时间逐渐减小。直接染料4BS上染桑皮纤维的吸附等温线符合佛莱因德利胥(Freundlich)吸附。     

Experimental Determination and Modeling of Sorption Isotherms of Tropical Fruits: Banana,Mango, and Pineapple

Abstract

Sorption isotherms of banana, mango, and pineapple have been experimentally found at 40, 50, and 60°C by use of the salt method for a range of water activities from 0.056 to 0.85. The sorption capacity of these fruits increases with the temperature for a given water activity. The experimental curves have been simulated by the GAB and BET models. The BET model ensures a better representation of the experimental results for water activity lower than 0.35 with maximum deviation of 1.0, 1.5, and 2.0 kgw · kgdm^?1 for respectively banana, mango and pineapple. On the contrary, the GAB model enables the representation of the whole desorption isotherms and the estimation of the water content corresponding to monolayer saturation and of the isosteric heat of sorption. It also takes into account the temperature effect. The isosteric sorption heat of the three studied products are deduced from experimental results and empirical correlations are proposed leading to a satisfactorily representation.     

DRYING OF WASTE SLUDGES IN A FLUIDIZED BED DRYER WITH A MIXER

ABSTRACT

Sludge wastes are a very attractive source of many valuable compounds such as nitrogen, phosphorus and organic matter. One of the interesting methods of sludge utilization is dewatering and drying. In this paper some problems of drying of two types of sludge wastes of different form and origin are presented. One of the sludges—a brewery by-product— contains spent grain suspension of brewer's yeast and diatomaceous earth. The second one is a by-product of a biotechnological process which contains mainly lime, protein, many microelements and some microorganisms. Moisture content of both sludges is about 65–70% w/w. The laboratory experiments of sludge drying in the fluidized bed dryer with a mixer, fluidized bed hydrodynamics, and the effects and advantages of sludge drying are shown.     

H103树脂吸附废水中苯胺

１前言生产多亚甲基多芳基异氰酸酯（简称ＰＡＰＩ）时有大量苯胺废水排放,严重污染环境。我们采用国产Ｈ１０３大孔吸附树脂吸附,使排放废水中苯胺浓度达３ｍｇ．ｃｍ－’以下,吸附效果优于美国ＡｍｂｅｒｌｉｔＸＡＤ－４树脂（图互）,又以５０～６０ｏＣ稀盐酸或工业酒精脱附,苯胺回收率＞９０％,回收苯胺可用于ＰＡＰＩ生产中‘’－’１。固定吸附床放大设计的方法有多种：传质模型法Ｉ‘］、改良设计法、工作吸附量法和Ｂｏｂ］．Ａｄａｍｓ［５］法。经小试及放大试验装置实测比较,认为溶液在床层内停留时间了Ｚ吸附达到平衡所…     

壳聚糖对天冬酰胺的吸附性能研究

采用壳聚糖对水溶液中天冬酰胺的吸附性能进行初步研究。采用粒内扩散模型、准一级动力学模型和准二级动力学模型对壳聚糖吸附天冬酰胺的动力学数据进行拟合,并采用Langmuir等温方程和Freundlich等温方程对其吸附等温线数据进行结果拟合。试验表明,当天冬酰胺的初始浓度分别为50、100、150 mg/L时,壳聚糖对天冬酰胺的吸附过程均符合准二级动力学方程(R^2=0.985 7～0.993 2)。壳聚糖对天冬酰胺的吸附等温线符合Langmuir等温吸附模型(R^2=0.978 8),其饱和吸附量为87.72 mg/g。壳聚糖对天冬酰胺具有一定的吸附能力。