Thermoluminescence of Vitreous Germanium Oxide Containing the Impurity Aluminum

The introduction of between 0 and 5% alumina into vitreous germanium oxide produces a thermoluminescence phenomenon after excitation by ultraviolet radiation which is characterized by (1) a peak position between 50° and 70° C. and (2) a peak height increasing with increase in the alumina introduced into the GeO₂ glass.     

MICROBIOLOGICAL AND SENSORY EVALUATION OF SIX OHMICALLY HEATED STEW TYPE FOODS

Presented are the results of a Natick RD&E Center study of microbiological and sensory evaluation of six commercially produced ohmically heated stew type products before and after three years' storage at 27C. All six products were commercially sterile and had no post processing contamination and, in general, had excellent retention of sensory quality, as determined by sensory measurement of color, appearance, flavor, texture and integrity attributes and overall quality ratings. These studies indicated that ohmic heating technology has the potential to provide shelf-stable foods closely equivalent to those prepared from scratch. It was also evident that reformulation of the entree items presented and development of new items is needed to take full advantage of this technology.     

Generalized Wigner distributions,moments and conditional correspondence rules

Methods are presented to generate conditional moments for all quasi-probability distributions, and explicit expressions for all conditional moments are given. In analogy to the generalized characteristic function operator, which generates all joint quasi-distribution functions, the conditional characteristic function operator which generates all conditional quasi-distributions is defined. This allows one to introduce the concept of conditional correspondence rules; formulations are given for all such rules.     

Phase Relations at Low Temperatures in the Fe-Mg-O System

Even when magnesiowustite is rapidly cooled in a reducing atmosphere, a small volume fraction of spinel forms. These results provide a basis for understanding the large discrepancies in M-H curves and the observed quadrupole splitting in Moessbauer spectra reported by various workers. In addition, it is shown that, with modern monochromatic X-ray diffraction techniques, a volume percent <0.10 can readily be measured.     

生物可降解聚丁二酸己二酸丁二醇共聚酯的合成

通过控制1,4-丁二醇(B)与丁二酸(S)和己二酸(A)的投料比,经过酯化和缩聚制备了高摩尔质量的聚丁二酸己二酸丁二醇共聚酯.通过研究缩聚反应的时间、温度和催化剂用量对反应酯化率的影响,确定了制备聚丁二酸己二酸丁二醇共聚酯的最佳工艺.在最佳的反应条件下,反应酯化率最高为96.2%,PBSA(Mn=40 280g/mol,Mw/Mn=1.056 640).红外光谱的结果表明PBSA为一个高摩尔质量的聚酯.     

Tobacco commerce on the internet: a threat to comprehensive tobacco control

Although internet use continues to increase and e-commerce sales are expected to exceed US$1 trillion by the end of 2001, there have been few assessments in the literature regarding the implications of this medium for tobacco control efforts. This commentary explores the challenges that the internet may pose to the key components of a comprehensive tobacco control strategy, and pinpoints potential approaches for addressing these challenges. Four key challenges that the internet presents for tobacco control are identified: unrestricted sales to minors; cheaper cigarettes through tax avoidance and smuggling; unfettered advertising, marketing and promotion; and continued normalisation of the tobacco industry and its products. Potential strategies for addressing these challenges include international tobacco control agreements, national and state regulation, and legal remedies.     

挂串密度对晾房干燥吐鲁番无核白葡萄干品质的影响

为了探讨无核白葡萄晾房干燥挂串密度对无核白葡萄干品质指标的影响。以产自新疆吐鲁番的无核白葡萄作为研究对象,分别以1:0.5、1:0.75、1:1的密度进行晾房干燥挂串,对无核白葡萄干成品的外观、果粒均匀度、破损果粒率、干燥时间、总糖、V_C等6项指标进行分析,探究挂串密度对晾房干燥吐鲁番无核白葡萄干品质的影响。结果表明:1:0.5密度挂串的葡萄干外观、果粒均匀度达到一级要求的概率分别为83%、85%,破损果粒率为11.5%,干燥时间为26 d,总糖平均含量为701.9 mg/g,V_C平均含量为7.05 mg/100 g;1:0.75密度挂串的葡萄干外观、果粒均匀度达到一级要求的概率分别为85%、86%,破损果粒率为12.0%,干燥时间为26 d,总糖平均含量为702.4 mg/g,V_C平均含量为7.34 mg/100 g;1:1密度挂串的葡萄干外观、果粒均匀度达到一级要求的概率分别为80%、85%,破损果粒率为17.3%,干燥时间为28 d,总糖平均含量为691.5 mg/g,V_C平均含量为7.21 mg/100 g。其中1:0.5及1:0.75密度挂串的干燥速率显著高于1:1密度(p<0.05);1:0.75密度挂串的葡萄干平均糖度含量及平均V_C含量显著高于1:0.5密度及1:1密度(p<0.05)。根据无核白葡萄干成品的6项指标的综合考虑,确定1:0.75的葡萄晾房挂串密度为最佳晾房干燥挂串密度。     

EFFECTS OF CATHEPTIC ENZYMES FROM SPLEEN ON THE MICROSTRUCTURE OF BOVINE SEMIMEMBRANOSUS MUSCLE

Fresh bovine semimembranosus muscle was treated with catheptic enzymes derived from bovine spleen and examined by light and scanning electron microscopy. The results indicate that the degree of microstructural changes in both the muscle fibers and the tissue surrounding the sarcolemma was related to the concentration of the enzyme. The structural changes in the myofibrils were restricted to the region of the Z bands.     

尿素嵌入法生产纤维素氨基甲酸酯新工艺

以纤维素浆粕及尿素为原料,在二甲苯体系中于135～140℃反应制取纤维素氨基甲酸酯。通过实验考察了各种工艺参数,结果显示:当原料活化用氢氧化钠溶液浓度为14%～16%,活化温度为40～50℃,活化时间为30～40 min,尿素与纤维素的质量比为2～3︰1,合成反应时间为2～3h时,产品纤维素氨基甲酸酯可在氢氧化钠溶液中形成良好的稳定的溶液且具有良好的过滤性和可纺性。