清末丁宝桢四川盐政改革及启示

盐业作为支撑四川经济的重要产业,盐政的优劣直接关乎国计民生的大计。道光、咸丰以来,四川盐政废坏,岸区倒悬,私盐泛滥,税课亏损,积弊重重。作为封疆大吏、中兴名臣之一的丁宝桢,在1876年升任四川总督后,针对川省当时的盐政积弊,深入调查官场民情,在任其间,雷厉风行地在四川推行盐政改革,实行官运商销制度,成效显著,表现出难能可贵的创新求实精神,给我们以重要的启示。     

Determination of Dextrose Equivalent Value and Number Average Molecular Weight of Maltodextrin by Osmometry

ABSTRACT:  Dextrose equivalent (DE) value is the most common parameter used to characterize the molecular weight of maltodextrins. Its theoretical value is inversely proportional to number average molecular weight ( M_n ), providing a theoretical basis for correlations with physical properties important to food manufacturing, such as: hygroscopicity, the glass transition temperature, and colligative properties. The use of freezing point osmometry to measure DE and M_n  was assessed. Measurements were made on a homologous series of malto-oligomers as well as a variety of commercially available maltodextrin products with DE values ranging from 5 to 18. Results on malto-oligomer samples confirmed that freezing point osmometry provided a linear response with number average molecular weight. However, noncarbohydrate species in some commercial maltodextrin products were found to be in high enough concentration to interfere appreciably with DE measurement. Energy dispersive spectroscopy showed that sodium and chloride were the major ions present in most commercial samples. Osmolality was successfully corrected using conductivity measurements to estimate ion concentrations. The conductivity correction factor appeared to be dependent on the concentration of maltodextrin. Equations were developed to calculate corrected values of DE and M_n  based on measurements of osmolality, conductivity, and maltodextrin concentration. This study builds upon previously reported results through the identification of the major interfering ions and provides an osmolality correction factor that successfully accounts for the influence of maltodextrin concentration on the conductivity measurement. The resulting technique was found to be rapid, robust, and required no reagents.     

山东昌乐蓝宝石砂矿中磁铁矿的宝石矿物学特征研究

采用常规宝石学鉴定方法、反光显微镜、X射线粉末衍射仪(XRD)、电子探针X射线显微分析仪(EPMA)、傅里叶变换红外光谱仪(FTIR)等测试方法,对山东昌乐蓝宝石砂矿中的一种副矿物样品进行了常规的宝石学、矿物学、谱学特征研究。肉眼观察,这种副矿物样品呈黑色、不透明,具有强磁性,摩氏硬度大于小刀。在反光显微镜下,该样品为钢灰色,呈现不透明的四边形颗粒状。X射线粉末衍射及电子探针成分分析的结果表明,该副矿物样品为富含Ti的磁铁矿,其晶体结构中类质同象替代广泛,但未见对人体有害的微量元素。该样品的红外光谱与磁铁矿的标准红外光谱基本一致。     

不同密度级高硫煤质量分布状况

以北宿、洛阳等两地高硫煤为样品按照国标（GB／T478—2001）进行了浮沉试验,并对两煤样进行了不同密度级煤的质量（灰分、比磁化率、硫分）状况的测定;结果表明随着密度级的增加,煤的灰分和比磁化率均逐渐增大,而硫分在各密度级的分布同煤种有关,缺乏普遍规律可循,与低密度级相比高密度级高硫煤的煤质普遍较差。     

Disinfection of Biologically Treated Municipal Wastewater using Electrochemical Process

The present study demonstrates the application of Al-Al electrode combination for electrochemical disinfection of biologically treated municipal wastewater (BTMW) of Sewage Treatment Plant. A glass chamber of 2 liter volume was used for the Electrochemical (EC) process using two electrode plates of aluminum (Al-Al) with DC power supply at different operating conditions of current density (CD), operating time (OT), inter electrode distance (IED), electrode area (EA), initial pH, and settling time (ST). The maximum removal of total coliforms (TC) (99.99%) and total bacteria (TB) (99.87%) from BTMW was achieved with the optimum operating conditions of CD (2.65 A/m²), OT (40 mins.), IED (0.5 cm), EA (160 cm²), initial pH (7.5), and ST (60 min.). The efficiency of the EC process for disinfection of BTMW was strongly affected by the CD, OT, IED, EA, pH, and ST. These effects can be explained by the formation of the reactive species such as OH^?, and ClO₂^?·during the electrochemical process. Under optimal operating conditions, the operating cost was found to be 1.01 $/m³ in terms of the electrode consumption (23.71 x 10^?5 kg Al/m³) and energy consumption (101.76 kwh/m³).     

钙盐调凝剂对硅酸盐水泥水化性能的影响

本文研究了硫酸钙和氯化钙两种钙盐在不同的掺量下对硅酸盐水泥水化性能的影响,试验发现随着两种钙盐掺量的增大,水泥标准稠度值呈现先减小后增大的趋势,且氯化钙的流动度保持效果没有硫酸钙好,但是氯化钙对水泥强度的发展贡献更大,而掺硫酸钙随着掺量达到2‰后,28 d强度出现倒缩.     

The Importance of G Protein-Coupled Receptor Kinase 4 (GRK4) in Pathogenesis of Salt Sensitivity,Salt Sensitive Hypertension and Response to Antihypertensive Treatment

Salt sensitivity is probably caused by either a hereditary or acquired defect of salt excretion by the kidney, and it is reasonable to consider that this is the basis for differences in hypertension between black and white people. Dopamine acts in an autocrine/paracrine fashion to promote natriuresis in the proximal tubule and thick ascending loop of Henle. G-protein receptor kinases (or GRKs) are serine and threonine kinases that phosphorylate G protein-coupled receptors in response to agonist stimulation and uncouple the dopamine receptor from its G protein. This results in a desensitisation process that protects the cell from repeated agonist exposure. GRK4 activity is increased in spontaneously hypertensive rats, and infusion of GRK4 antisense oligonucleotides attenuates the increase in blood pressure (BP). This functional defect is replicated in the proximal tubule by expression of GRK4 variants namely p.Arg65Leu, p.Ala142Val and p.Val486Ala, in cell lines, with the p.Ala142Val showing the most activity. In humans, GRK4 polymorphisms were shown to be associated with essential hypertension in Australia, BP regulation in young adults, low renin hypertension in Japan and impaired stress-induced Na excretion in normotensive black men. In South Africa, GRK4 polymorphisms are more common in people of African descent, associated with impaired Na excretion in normotensive African people, and predict blood pressure response to Na restriction in African patients with mild to moderate essential hypertension. The therapeutic importance of the GRK4 single nucleotide polymorphisms (SNPs) was emphasised in the African American Study of Kidney Disease (AASK) where African-Americans with hypertensive nephrosclerosis were randomised to receive amlodipine, ramipril or metoprolol. Men with the p.Ala142Val genotype were less likely to respond to metoprolol, especially if they also had the p.Arg65Leu variant. Furthermore, in the analysis of response to treatment in two major hypertension studies, the 65Leu/142Val heterozygote predicted a significantly decreased response to atenolol treatment, and the 65Leu/142Val heterozygote and 486Val homozygote were associated in an additive fashion with adverse cardiovascular outcomes, independent of BP. In conclusion, there is considerable evidence that GRK4 variants are linked to impaired Na excretion, hypertension in animal models and humans, therapeutic response to dietary Na restriction and response to antihypertensive drugs. It may also underlie the difference in hypertension between different geographically derived population groups, and form a basis for pharmacogenomic approaches to treatment of hypertension.     

钴盐粘合增进剂的生产与需求分析

简述钻盐粘合增进剂品种的发展,介绍新癸酸钻和硼酰化钴的制备工艺。概述世界和我国钴盐粘合增进剂的供需情况,2012年世界钴盐粘合增进剂需求量约1．8万t;根据我国子午线轮胎的产量测算,2012年我国钴盐粘合增进剂的产能已达到1万t,消费量超过6000t。我国钴盐粘合增进剂企业应重视钴盐粘合增进剂产品的升级换代。     

熔盐合成法制备片状氧化铝的初步研究

片状氧化铝具有优良的物理化学性能,如耐磨、抗氧化、抗化学腐蚀以及良好的附着力与反射光线能力,被广泛用于颜料、化妆品、填料和磨料等领域.本文以化学纯Al2(SO4)3和MgCO3为原料,KCl为熔盐,利用熔盐合成法在1050 ℃×4 h制得粒径3～10 μm厚度0.2～0.4 μm的片状氧化铝.     

Nonparametric Autoregression with Multiplicative Volatility and Additive mean

For over a decade, nonparametric modelling has been successfully applied to studying nonlinear structures in financial time series. It is well known that the usual nonparametric models often have less than satisfactory performance when dealing with more than one lag. When the mean has an additive structure, however, better estimation methods are available which fully exploit such a structure. Although in the past such nonparametric applications had been focused more on the estimation of the conditional mean, it is equally if not more important to measure the future risk of the series along with the mean. For the volatility function, i.e. the conditional variance given the past, a multiplicative structure is more appropriate than an additive structure, as the volatility is a positive scale function and a multiplicative model provides a better interpretation of each lagged value's influence on such a function. In this paper we consider the joint estimation of both the additive mean and the multiplicative volatility. The technique used is marginally integrated local polynomial estimation. The procedure is applied to the deutschmark/US dollar daily exchange returns.