淀粉微球合成条件的研究

以可溶性淀粉为原料,环氧氯丙烷为交联剂,Span60为乳化剂,环己烷和三氯甲烷为油相,采用逆相悬浮交联聚合法合成淀粉微球。通过单因素及正交实验探讨了各因素对淀粉微球平均粒径的影响。结果表明,水相用量对淀粉微球粒径影响最大,较小淀粉微球合成的最佳条件为：淀粉乳浓度10％,水相用量4mL,乳化剂用量0．5g,交联剂用量3mL。通过电镜照片表征了淀粉微球的微观结构。     

利用GARCH-M类模型和极值理论对上证综指的研究

金融时间序列具有分布的厚尾性、波动的集聚性等特征,传统的方法难以准确的度量其风险。文中运用一种新的估计VaR和ES的方法,即采取两阶段法。首先用GARCH-M类模型(GARCH-M、EGARCH-M和TGARCH-M)拟和原始收益率数据,得到残差序列;第二步用极值分析的方法分析的尾部,最后得到收益率序列的动态VaR和ES。最后对三个模型的计算结果进行比较。     

高油玉米及其产业化发展

本文主要论述了高油玉米的营养价值、经济价值、发展前景以及高油玉米深加工方向和产业化发展的策略。     

结构脂质及其制备方法

简要介绍了结构脂质的基本概念、生理功能、制备方法和发展前景。     

Consumer preference among fluid milks: low‐fat vs. high‐fat milk consumption in the United States

The present study uses data from the Continuing Survey of Food Intakes by Individuals 1994–1996, 1998 in order to analyse milk consumption by type, specifically high‐fat milk vs. low‐fat milk. Whereas trend analysis displays an overall increase in low‐fat milk consumption over the last few decades in the United States, a number of individuals still consume high‐fat milk varieties, and overall dietary intakes have yet to achieve recommended levels. In light of recent research regarding fat intakes, it is important to understand what factors might cause consumers to purchase high‐fat options given the number of low‐fat options available in the market. Through the use of Logistic regression, key socio‐economic and demographic variables are analysed in order to determine their impacts on the probability of consuming low‐fat milk vs. high‐fat milk. The results indicate that a number of factors do influence probability of low‐fat milk consumption as compared with high‐fat milk consumption. Most notably, probability of low‐fat milk consumption appears to be positively related to age, education level, and income level. African Americans and other minorities had a lower probability of consuming low‐fat milk when compared with White people in the sample population. Also, those respondents designated as low income or living in the South were less likely to consume low‐fat milk.     

ICP-AES法测定土易溶盐中的CaO、MgO、SO4^2-

文章对土易溶盐的传统分析方法进行了一些改进,建立了ICP-AES测定土易溶盐中CaO、MgO、SO4^2-的方法。方法线性范围CaO为0.1～40 mg/L;MgO为0.02～10 mg/L,SO4^2-为0.2～100 mg/L。方法检出限CaO为0.022 4 mg/L,MgO为0.003 8 mg/L,SO4^2-为0.0279 mg/L。精密度（RSD）CaO为0.99%,MgO为1.71%, SO4^2-为1.66%。回收率（R）为96.0%～103.2%。     

水溶纤维的应用研究

利用水溶纤维的可溶水性加上其它性能优势，实现用低支毛纺高支纱的设想。     

Autoregressive Conditional Kurtosis

This article proposes a new model for autoregressive conditionalheteroscedasticity and kurtosis. Via a time-varying degreesof freedom parameter, the conditional variance and conditionalkurtosis are permitted to evolve separately. The model usesonly the standard Student’s t-density and consequentlycan be estimated simply using maximum likelihood. The methodis applied to a set of four daily financial asset return seriescomprising U.S. and U.K. stocks and bonds, and significant evidencein favor of the presence of autoregressive conditional kurtosisis observed. Various extensions to the basic model are proposed,and we show that the response of kurtosis to good and bad newsis not significantly asymmetric.     

山西省榆次区干沉降水溶性阴离子的化学特征

为了解山西省榆次区大气干沉降中水溶性阴离子的化学组成及时间变化特征,采集榆次区2022年4月至2023年3月大气干沉降样品,利用相关性分析及HYSPLIT后向轨迹模式探讨干沉降中水溶性离子的化学特征及来源。结果表明：榆次区干沉降水溶性阴离子月平均浓度为846.158 μg/g,通量日平均值为589.7 μmol/(m2·d),季节变化为冬季＞秋季＞春季＞夏季;PM2.5/PM10和NO2/SO2佐证了扬尘和燃煤对榆次区环境污染及离子浓度的贡献率;干沉降阴离子的浓度变化受到降水及本地气团的影响。     

Agricultural Financial Risks Resulting from Extreme Events

Decision‐makers in the agricultural sector operate in a volatile and risky environment. The statistical assessment of agricultural commodity prices is necessary to deduce the stylised facts of agricultural markets and guide the action of market participants. This article examines the kurtosis values of 60 agricultural commodities and presents evidence that the distributions of their returns are fat‐tailed. We use power‐law distributions to model the tail returns and the possible time‐varying extreme event risks in commodity markets. Our results suggest that the usefulness of the value at risk and expected shortfall as risk management tools is questionable.