裂蹄木层孔菌总黄酮含量的测定及其抗氧化活性研究

利用体积浓度为70%的乙醇提取裂蹄木层孔菌中的黄酮类物质,以芦丁为对照品,利用紫外分光光度法测定裂蹄木层孔菌中的总黄酮含量,并研究了裂蹄木层孔菌中黄酮类化合物对DPPH自由基、超氧阴离子自由基、羟基自由基的清除作用.结果表明:在510 nm处,芦丁浓度在0.002～0.040 mg/mL范围内线性关系良好(r=0.998 5),裂蹄木层孔菌中总黄酮含量为38.2 mg/g; 裂蹄木层孔菌中的黄酮类化合物对清除自由基有一定的作用,其清除效果在一定范围内随着总黄酮质量浓度的增加而增强.     

Effect of Flotation Reagents on the Cake Moisture of Copper Concentrate

The effect of reagents used in separating chalcopyrite from pyrite on the cake moisture of the copper concentrate at Daye Iron Mine Mineral Processing Plant was investigated. The results showed that the dosage of lime used for depressing pyrite was the main factor that increased the filter cake moisture of copper concentrate. With increasing the dosage of lime, the cake moisture of copper concentrate increased sharply. The cause was concluded to be the addition of lime to the pulp, which resulted in the formation of floc and a high pH value. The collector Z-200#, used for collecting chalcopyrite, had, as well, an adverse effect on the cake moisture of copper concentrate, but its effect was inferior in respect to that of lime. The cake moisture of copper concentrate can be decreased by changing the method with which lime is added and the pH value of pulp is regulated. The experiment results showed that the sulfuric acid was the best regulator. When the clarified liquor of lime was used as a depressant and the pH value of the pulp was regulated to 6.5?7.0 by adding sulfuric acid, the cake moisture of copper concentrate was reduced from 15.49% to 13.13%. The examination of chalcopyrite surface by using ESCA (Electron Spectroscopy for Chemical Analysis) showed that calcium sulfate and iron hydroxide had formed on the surface of chalcopyrite when lime was added to the pulp. The formation of calcium sulfate and iron hydroxide on its surface increased the hydrophilicity of chalcopyrite so that its cake moisture increased. The addition of sulfuric acid to the pulp not only removed the calcium sulfate, but also reduced the concentration of iron hydroxide on the surface of chalcopyrite so that the cake moisture of copper concentrate was decreased.     

A/O+BAF组合工艺在炼油废水处理中的应用

随着原油劣质化趋势的不断加剧,炼油废水水质日趋复杂,传统的活性污泥法、生物膜法以及A/O法等单一的生化处理工艺已不能满足国家污水排放标准的要求。利用A/O工艺除碳脱氮效能显著和BAF工艺处理微污染水性能突出的优点,中油庆阳石化新厂炼油废水处理采用A/O+BAF组合工艺以应对这一趋势,实现炼油废水处理连续稳定达标,确保回用水处理装置长周期平稳运行。     

溶出峰电位相近元素铅、铊和镉的微分电位溶出分析法测定

在许多支持电解质中,Pb,T1和Cd的溶出电位相近,特别是Cd和T1的溶出电位很接近,在同时存在时,难于用电位溶出分析法测定。本文对Pb、T1和Cd在二十多种支持电解质中的微分电位溶出法进行了比较研究。选定0.06mol·dm~(-3)HAc—0.05mol·dm~(-3)KAc缓冲液作支持电解质,对T1的微分电位溶出法进行了较详细的研究。在T1含量小时,在此介质中测定Cd和Pb,然后加入EDTA掩蔽Cd、Pb而测定微量的T1。测定了人发中的Pb和T1。     

长白红景天提取物抗氧化活性的研究

为研究长白红景天的抗氧化活性,采用正交方法确定了长白红景天的最佳提取条件,在最佳条件下提取物的总黄酮含量为3.74%.对提取物进行DPPH、超氧负离子和羟基自由基清除测试显示,长白红景天提取物对DPPH、超氧负离子和羟基自由基均有较好的清除能力,并且在一定浓度范围内其清除效果优于Vc、TBHQ 和BHT; 因此,长白红景天是一种天然的优良抗氧化植物.     

Effect of Partial Recrystallization on Microstructure and Mechanical Properties for Cross-rolled Molybdenum Sheet

The paper presented here reports an appropriate static heat tretment and analyses the microstructure with different partially recrystallized annealing temperatures of cross-rolled molybdenum sheet in order to improve mechanical property of this type of materials and reduce anisotropy at the same time for perspective application. Five different temperature ranges are chosen in this experiment. The samples of a cross-rolled molybdenum sheet are obtained through powder metallurgy, forged ingots and hot or cold rolled sheet. A period of first-stage annealing at 800℃ for one hour is not qualified for the further processing because of bad plasticity, working hardening and crack on the surface. The appropriate second-stage annealing temperature at 950℃ for one hour is chosen for improving the elongation and reduces yield strength. The results show that this appropriate partially recrystallized annealing treatment has achieved the ideal grain size and mechanical properties when it is compared with the other four different temperatures with the same second-stage annealing conditions.     

肿瘤药物甲氨蝶呤在悬汞电极表面电化学吸附性质的研究

本文用线性扫描伏安法研究了甲氨蝾呤(MTX)在悬汞电极表面的吸附性质。测定了MTX的表面浓度、饱和吸附量、一个MTX分子的覆盖面积、吸附平衡常数和吸附自由能。证明了MTX的吸附基本上符合Frumkin吸附等温式。     

野生与种植灵芝中灵芝酸和总黄酮的提取及其含量测定

采用回流的方法从野生及种植灵芝中提取灵芝酸和总黄酮,用紫外分光光度法测定其含量．测得野生及种植灵芝中灵芝酸含量分别为0．366％和0．871％,相对标准偏差（RSD,n=4）分别为1．07％和0．81％,平均回收率为99．65％;野生及种植灵芝中总黄酮含量分别为0．507％和0．551％,RSD（n=4）分别为1．31％和1．10％,平均回收率为99．39％．     

基于数值模拟的天津市地下水严重超采区演变分析

天津市是华北地区典型的水资源短缺城市,地下水的长期超采已引发地面沉降等环境问题。为科学分析地下水开采现状,并预测压采条件下的地下水严重超采区演化趋势,本文采用基于有限差分原理的MODFLOW软件,建立了天津市平原区地下水流动的三维非稳定流数值模型,经识别和校正过的模型能准确反映人工开采引起的各承压层地下水位波动。基于该...