大豆异黄酮生理功能的研究进展

大豆异黄酮因具有明显的生物学活性已越来越引起社会和学术界的普遍关注,是近年来科学家研究的热点。研究表明,大豆异黄酮与人类健康密切相关,具有许多生理功能,如抗肿瘤作用、对血管的防护作用、抗氧化活性、类似女性雌激素作用以及抗激素作用等。文中阐述了大豆异黄酮生理功能的研究进展。     

卷烟烟气中稠环芳烃的分析研究

本项研究建立了一种测定卷烟烟气中稠环芳烃的分析方法--气质联用法。优化了方法的前处理过程、仪器分析条件,对分析方法的重复性、回收率、检测限进行了研究。确定了环己烷萃取卷烟烟气总粒相物中的稠环芳烃,萃取液经硅胶固相萃取柱净化,用气相色谱-质谱联用仪定量检测苯并[a]芘、苯并[a]蒽和Chrysene 3种稠环芳烃含量的分析方法。该检测方法设计合理,稳定性和重复性好、准确性和精确性高,具有较好的可操作性和推广性。本项目应用该方法对国内外较有代表性的81种卷烟样品中苯并[a]芘、苯并[a]蒽和Chrysene进行了系统的分析测定,研究了国内外混合型与烤烟型卷烟中苯并[a]芘等稠环芳烃含量分布的规律,讨论了卷烟烟气中苯并[a]芘、苯并[a]蒽和Chrysene之间的含量关系及其与总粒相物、焦油的关系。      

造纸企业能量系统"三环节"模型的建立及应用探讨(Ⅰ)--造纸企业"三环节"能量结构模型的建立

本文对过程能量系统综合优化技术和过程能量结构模型进行了系统的分析和研究;提出已在石化、炼油行业应用成功的"三环节"能量结构理论应用于造纸企业的能量系统综合与优化.根据"三环节"能量结构模型,对造纸企业的能量系统进行了划分,建立了造纸企业能量系统的"三环节"物理结构模型,并给出了各环节的能量平衡(火用)平衡数学方程,为造纸企业能量系统优化提供了科学依据.     

造纸企业能量系统"三环节"模型的建立及应用探讨(Ⅱ)--造纸企业能量系统用能分析与评价

根据"三环节"能量结构模型,对某造纸企业的能量系统进行了热量平衡、(火用)平衡以及能量效率进行了计算和分析,并分别对能量利用环节、能量回收环节和能量转换环节的能量利用、能量回收和能量转换效率进行了评价,分析研究了该厂各环节能量效率低下的因素,指出该厂具有巨大的节能潜力.     

Development and Physicochemical Characterization of New Resistant Citrate Starch from Different Corn Starches

Resistant starch has drawn broad interest for both potential health benefits and functional properties. In this study, a technology was developed to increase resistant starch content of corn starch using esterification with citric acid at elevated temperature. Waxy corn, normal corn and high‐amylose corn starches were used as model starches. Citric acid (40% of starch dry weight) was reacted with corn starch at different temperatures (120–150°C) for different reaction times (3–9 h). The effect of reaction conditions on resistant starch content in the citrate corn starch was investigated. When conducting the reaction at 140°C for 7 h, the highest resistant starch content was found in waxy corn citrate starch (87.5%) with the highest degree of substitution (DS, 0.16) of all starches. High‐amylose corn starch had 86.4% resistant starch content and 0.14 DS, and normal corn starch had 78.8% resistant starch and 0.12 DS. The physicochemical properties of these citrate starches were characterized using various analytical techniques. In the presence of excess water upon heating, citrate starch made from waxy corn starch had no peak in the DSC thermogram, and small peaks were found for normal corn starch (0.4 J/g) and Hylon VII starch (3.0 J/g) in the thermograms. This indicates that citrate substitution changes granule properties. There are no retrogradation peaks in the thermograms when starch was reheated after 2 weeks storage at 5°C. All the citrate starches showed no peaks in RVA pasting curves, indicating citrate substitution changes the pasting properties of corn starch as well. Moreover, citrate starch from waxy corn is more thermally stable than the other citrate starches.     

电位滴定法测定葡萄酒中还原糖含量的研究

根据直接滴定法的原理，应用电位滴定法测定了葡萄酒中的还原糖含量。结果表明，该法检测灵敏度高，方便快捷，测定结果符合葡萄酒中糖含量标准。检测结果的标准偏差为0．09，RSD为4．09％，回收率在92．8％～113.2％之间，平均回收率为102．16％。     

Air-water exchange of polychlorinated biphenyls in the Delaware River

The air-water exchange of polychlorinated biphenyls (PCBs) often results in net volatilization, which is thought to be the most important loss process for PCBs in many systems. Previous investigations of the air-water exchange of PCBs have been hampered by difficulties in treatment of the uncertainty in the calculation of air/water fugacity ratios. This work presents a new framework for the treatment of uncertainty, where uncertainty in physical constants is handled differently from random measurement uncertainty associated with random samples, and it further investigates the sorption of PCBs to colloids (dissolved organic carbon). Simultaneous measurements of PCBs in the air and water of five water quality management zones of the Delaware River were taken in 2002 in support of the total maximum daily load (TMDL) process. Gas-phase concentrations of IPCBs ranged from 110 to 1350 pg m(-3), while dissolved water concentrations were between 420 and 1650 pg L(-1). Shallow slopes of log Koc vs. log Kow plots indicated a colloidal contribution to the apparent dissolved-phase concentrations, such that a three-phase partitioning model was applied. Fugacity ratios for individual congeners were calculated under the most conservative assumptions, and their values (log-transformed) were examined via a single-sample T-test to determine whether they were significantly less than 1 at the 95% confidence level. This method demonstrated that air-water exchange resulted in net volatilization in all zones over all cruises for all but seven high molecular weight congeners. Calculated net fluxes ranged from +360 to +3000 ng m(-2) d(-1) for sigma PCBs. The colloidal correction decreased the volatilization flux of sigma PCBs by approximately 30%. The decachlorinated congener (PCB 209), exhibited unusually high concentrations in the suspended solids, especially in the southern portions of the river, indicating that there is a distinct source of PCB 209 in the Delaware River.     

荆条挥发油中β-丁香烯的提取分离

首次从荆条植物中分离得到β-丁香烯。利用水蒸气蒸馏法提取荆条挥发油,得油率1.2%。经减压精馏、硅胶柱色谱、硝酸银-硅胶柱色谱等分离过程得到产物β-丁香烯,色谱纯度98.2%。通过红外光谱、质谱、核磁共振确认了结构。     

黄酒对实验性铅中毒的拮抗作用研究

为了研究黄酒对小鼠铅水平的影响,建立了小鼠实验性铅中毒模型。将ICR小鼠随机分成空白对照组、模型对照组和黄酒剂量(3个剂量)组。空白对照组饲喂基础饲料,模型对照组连续饲喂高铅饲料,3个剂量组按高、中、低剂量分别饲喂黄酒,并同时饲喂高铅饲料。受试后30d,用等离子体发射光谱法(ICP-AES)测定小鼠血液、肝脏和骨骼的铅含量,结果表明:高、中、低剂量黄酒均能够显著降低小鼠血液和肝脏的铅含量,黄酒对小鼠实验性铅中毒有显著的拮抗作用。     

中国式双尺寸多功能大圆机的设计

1双尺寸多功能大圆机的结构中国式双尺寸多功能大圆机(二代研发产品)外观图如图1所示,从图中可以看出,该大圆机与一般的传统式大圆机外形无差异。