Dietary fatty acids regulate cholesterol induction of liver CYP7α1 expression and bile acid production

In the present study we investigated the effects of dietary fats containing predominantly PUFA, monounsaturated FA (MUFA), or saturated FA (SFA) on lipid profile and liver cholesterol 7α-hydroxylase (CYP7α1) mRNA expression and bile acid production in C57BL/6J mice. The animals (n=75) were randomly divided into five groups and fed a basic chow diet (AIN-93G) (BC diet), a chow diet with 1g/100g of cholesterol (Chol diet), a chow diet with 1g/100g of cholesterol and 14g/100g of safflower oil (Chol+PUFA diet), a chow diet with 1g/100g of cholesterol and olive oil (Chol+MUFA diet), or a chow diet with 1g/100g of cholesterol and myristic acid (Chol+SFA diet) for 6 wk. The results showed that the Chol+SFA diet decreased CYP7α1 gene expression and bile acid pool size, resulting in increased blood and liver cholesterol levels. Addition of PUFA and MUFA to a 1% cholesterol diet increased the bile acid pool production or bile acid excretion and simultaneously decreased liver cholesterol accumulation despite decreased CYP7α1 mRNA expression. The results indicate that the decreased bile acid pool size induced by the SFA diet is related to inhibition of the liver CYP7α1 gene expression, but an increased bile acid pool size and improved cholesterol homeostasis are disassociated from the liver CYP7α1 gene expression.     

电极沥青粘结剂性能评价参数相关性的研究

以两个国外电极沥青粘结剂产品为参考样，选用典型国产原料以热化学改质法和调和法制备出工业分析指标与参考样处于同一水平的两组煤沥青粘结剂试样；对各组粘结剂试样和相应的参考样的元素组成、流变学性质、热动态行为、平均分子量及其分布以及各评价参数间的相关性进行了研究；就引入与其应用性能直接相关的评价因子的可能性进行了探索。     

聚丙烯/超高摩尔质量聚乙烯共混物的结构与性能研究

研究了不同物料比和加工工艺对聚丙烯（PP）／超高摩尔质量聚乙烯（UHMWPE）共混体系性能的影响。结果表明，PP／UHMWPE共混体系具有比音一组分更高的冲击性能，当体系中UHMWPE的质量分数为60％时，共混物的冲击强度高达101kJ/m^2，分别是PP的1．8倍和UHMWPE的1．3倍，将UHMWPE加入PP中可明显降低PP的摩擦系数，提高其耐磨性，而适量UHMWPE加入PP中，对UHMWPE的耐磨性能无不良影响，对以PP为连续相的共混体系，混炼方式对共混物的性能影响大，偏光显微镜分析表明，当PP／UHMWPE共混体系中UHMWPE的质量分数大于40％时，就很难观察到明显的PP大球晶结构，DSC分析显示，PP／UHMWPE共混物出现了两纯组分熔点的结晶熔融峰，PP／UHMWPE为热力学不相容体系。     

湘潭电厂粉煤灰在建筑工程中的应用

本文首先简述湘潭电厂除、排灰情况，粉煤灰加工工艺和品质，然后较详细地用文字和图表表述该粉煤灰在水工工程、泵送砼工程、路面工程、砂浆及轻质砼中的应用。     

改性耐磨涂料研究进展

从环氧树脂改性耐磨涂料、陶瓷耐磨涂料以及纳米技术在耐磨涂料中的应用等几方面对改性耐磨涂料进行综述.     

Polydispersity effect on transient flow behavior of polystyrene solution

Summary The transient flow behavior of the binary blend of monodisperse polystyrene fractions is measured by a flow birefringence method. Both of the shear stress and first normal stress difference are obtained simultaneously in time by using a PMFB technique. The entanglements of the polymer chains significantly affect the rheological property of the binary blend in flow region. Especially, the entanglements of the high molecular weight fractions with themselves is proven to be the main source to the growth of first normal stress differences.     

双道原子荧光光谱法测定水中痕量Hg、As、Se、Sb

介绍了应用双道原子荧光光谱法测定水中的汞、砷、硒、锑等痕量元素的原理、过程，并讨论测定条件的优化、干扰的去除方法。     

一体化复合式膜生物反应器除磷研究

本文通过对比实验，研究了不同工艺组合条件下一体化复合式膜生物反应器（HCMBR）的除磷效果，研究表明，在无厌氧段的情况下，反应器内保持好氧状态的同时，填料内部存在厌氧环境，TP的去除率为22％，在有厌氧段（A／O）的情况下，TP的去除率可达70％，采用化学方法时，TP去除率可达82．1％，但过高的n(Al^3 )/n(TP)值将会影响污泥的活性，并且HCMBR对NH3－N，CODCr,TN等污染物有十分良好的去除效果。     

预测控制约束边界效应与解决方法研究

约束预测控制（Constrained model predictive control,CMPC）中,因约束的存在,优化过程中最优控制作用可能会在可行域的边界取值,也就是说会 有一个或多个变量饱和,即约束边界效应. 而过程控制中操纵变量饱和是我们不希望出现的. 对此,首先基于稳态模型,对期望值位于可行域内时最优解必在期望值处达到给出证明;同时证明了期望值在可行域外时最优解可转化为期望值到可行域的投影. 其次,针对变量在动态及稳态过程中饱和的情况提出了改善控制性能的措施——调整目标函数;终端约束的加入,为预测控制系统稳定性提供了保障. 通过对包含约束的连续搅拌釜式反应器（Continuous stirred tank reactor,CSTR）系统进行仿真实验,验证了所提方法的正确性,并说明了对目标函数进行适当调整,可有效改善系统的控制性能.     

Electrodeposition of Ni-transition alloys for the oxygen evolution reaction

The oxygen evolution reaction (OER) is the anodic reaction in several industrial electrolytic processes. The objective of this work was to develop a new electrocatalytic material for long-lasting and economical high performance electrodes. New electrodes were prepared by electrodeposition of nickel, nickel-ruthenium and nickel-iridium alloys. They were then activated by anodic polarization at 100 mA cm^–2 to form an oxide layer. The electrocatalytic activity was characterized for the OER in 5M KOH solution. The results show that nickel-iridium alloys provide greater electrocatalytic activity for the OER and better corrosion resistance than nickel-ruthenium in alkaline solution. The effects of transition elements on improving the performance of the nickel electrode are then discussed.Notation b Tafel slope - i _ex exchange current density - i _dp electrodeposition current density - i _OER oxygen evolution reaction current density - C _dl double-layer capacity - o₂ oxygen overpotential