碱性蛋白酶对拉伸细化羊毛纤维性能的改善

为去除拉伸细化羊毛表面影响其产品服用性能的鳞片突出部分,改善细化羊毛纤维表面的光滑程度,使纤维在形态上更接近羊绒纤维,使用碱性蛋白酶Savinase对拉伸细化后的毛条进行处理。通过观察纤维表面形态,测定纤维减量率、摩擦因数、断裂强度和断裂伸长率,证明酶处理吞蚀去除翘起鳞片的可行性。实验结果表明：蛋白酶用量为1.6%(o.w.f),时间为40min的处理工艺,对纤维的处理效果最好。     

γ-聚谷氨酸吸附金属离子性能的研究

研究了γ-聚谷氨酸的阻垢性能以及对六价铬离子的吸附性。试验表明,在pH8、温度为60℃、γ-聚谷氨酸的含量为0.32 mg/mL的条件下,吸附钙离子24 h,可达到最高阻垢率77.07%;pH6、温度为60℃,γ-聚谷氨酸的量为0.04 mg/mL条件下,γ-聚谷氨酸对24μg/mL铬离子液中六价铬的吸附率可达72.50%。     

3-十二烷氧基-2-羟基丙基三甲基氯化铵的合成及性质研究

本文以十二醇、环氧氯丙烷（EPIC）与三甲胺盐酸盐合成了阳离子表面活性剂3-十二烷氧基-2-羟基丙基三甲基氯化铵（DPAC）。实验得出了最佳合成条件：中间体十二烷基缩水甘油醚：n（脂肪醇）∶n（EPIC）=1∶1.8,反应时间4 h,温度50℃,碱的浓度为50%,四丁基溴化铵作催化剂;DPAC的合成：n（十二烷氧基缩水甘油醚）∶n（三甲胺盐酸盐）=1∶1,温度30℃,反应3 h。DPAC的收率可达96%。使用红外、核磁共振对产品进行了定性分析,并研究了其界面、抗菌、抑菌性质。     

紧性的非标准定义及其性质

在非标准扩大模型和拓扑的非标准定义基础之上, 对拓扑空间中紧性的概念及相关结论进行了描述和刻画.一方面, 这种新的定义与一般的紧性定义是一致的;另一方面, 这种新的定义方法简化了原有的概念和结论, 使它们的本质特性更为清晰, 因而在一定程度上发展了拓扑空间中原有的紧性理论.     

新型纺织空调喷淋室的设计与应用

探讨新型纺织空调喷淋室的设计及应用效果.通过分析目前常用喷淋室的结构及缺陷,设计了新型纺织空调喷淋室.新型纺织空调喷淋室由两排至五排喷淋排管构成,并按照一定方式组合使用.通过喷淋室高密度水雾横喷、逆喷等方法,可以提高空气与水热湿交换效率及空气质量.以五排喷淋排管喷淋室为例对比说明:五排喷淋排管喷淋室能够实现冷却、加湿等多种功能,同时高效环保,是一种理想的纺织空调喷淋室.     

不同生态尺度烟区烤烟香型风格的初步研究

采用烟叶香型指数的方法,研究了我国5个不同生态尺度烟区烤烟香型风格及相关香气成分的变化。结果表明,云南大理和福建三明的烤烟为＂清香型＂风格,但二者之间香型指数差异明显;贵州黔南和广西河池烤烟为＂中间香型＂风格;河南南阳烤烟为＂浓香型＂风格。生态条件差异大是影响烟叶香型风格的主导因素,在同一烤烟产区不同产烟县,生态条件差异较小对相关香气成分有影响,但不会改变烟叶的香型风格。     

Analytical Methods for Quantification of Modified Fatty Acids and Sterols Formed as a Result of Processing

Fats and oils are often submitted to technological treatments before being consumed. Some treatments like refining, hydrogenation, and frying often lead to the formation of modified fatty acids such as cyclic fatty acid monomers (CFAM), geometrical fatty acid isomers, and/or oxidized fatty acids and sterols (cholesterol and phytosterols). Both cholesterol oxidation products (COP) and phytosterol oxidation products (POP), may be present in foods. As some of the newly formed components may present some adverse effects upon consumption, methods have been developed to analyze these compounds in food products and biological samples. Gas liquid chromatography (GC) on long polar columns (100m) is a good choice to quantify trans mono- and poly-unsaturated fatty acids. In some cases a pre-fractionation step using silver nitrate thin layer chromatography (AgNO₃-TLC) may be necessary to avoid GC overlapping of cis and trans isomers. Analysis of CFAM usually involves transformation of the sample in fatty acid methyl esters (FAME) which after addition of an internal standard (IS) are further hydrogenated. An enrichment step using reverse phase high performance liquid chromatography (RP-HPLC) permits to obtain a fraction which consists of a mixture of CFAM and the IS. This fraction is further analyzed by GC on a polar column. The analysis of oxidized triacylglycerol monomers (oxTG) as a group was feasible by a combination of adsorption and size-exclusion chromatography. Quantification in used frying fats and oils around the limit of rejection for human consumption (25% polar compounds) has shown that the amount of oxTG range 5.9–9.4% expressed on fat or oil weight. In foods and biological tissues, the level of oxidized sterols (SOP) is often a very small fraction of their unoxidized forms. Analysis of SOP involved extraction of lipids, saponification or transesterification, enrichment, and subsequent qualitative and quantitative determination by GC and GC-MS, or HPLC and HPLC-MS. In addition, enrichment of SOP requires complete separation from the unoxidized sterols in order to separate these compounds even by high resolution GC capillary columns.     

Extraction and characterisation of pectin methylesterase from black carrot (Daucus carota L.)

This study was carried out to determine some of the biochemical properties of pectin methylesterase (PME) from black carrot. The enzyme showed very high activity in a broad pH range of 6.5–8.5, with the optimum pH occurring at 7.5. The optimum temperature for maximal PME activity was found to be 55 °C. NaCl enhanced PME activity, particularly at 0.2 M. K_m and V_max values for black carrot PME using apple pectin as substrate were found to be 2.14 mg/ml (r² = 0.988) and 3.75 units/ml, respectively. The enzyme was stable between the temperatures of 30–50 °C/5 min whereas it lost nearly all of its activity at 70 °C/5 min. E_a and Z values were found to be 196.8 kJmol⁻¹ (r² = 0.996) and 2.16 °C (r² = 0.995), respectively.     

产谷胱甘肽酵母菌株培养基优化

目的筛选对谷胱甘肽产量影响显著的碳源和氮源,考察其浓度对产量的影响。方法通过单因素实验和正交试验确定最佳碳源、氮源和无机盐浓度。结果最佳培养基的基本组成：2．5％葡萄糖,1％酵母粉,0．3％硫酸铵,0．03％硫酸镁,1．2g／L磷酸氢二钾和1．8g／L磷酸二氢钾。结论确定了最优培养基组成。     

yankee烘缸与高温热风气罩结合用于纸幅干燥节约能量、提高质量和增加产量

该文论述新颖热风气罩与传统yankee烘缸,联合使用于生活用纸纸幅干燥取得很好效果,在提高热风温度25%～30%的情况下使过程的干燥速率加快30%～50%。运种新颖热风气罩是在老式平台的基础上对其结构设计和材料强度进行优化和改进而成,从而能突破传统干燥过程里空气受到温度限制,从而在作业过程里实现节约能量、提高质量和增加产量。