超临界CO2萃取丹参酮ⅡA提取工艺

采用超临界CO2萃取法提取了丹参酮ⅡA,讨论了压力、温度、时间、乙醇流量对丹参酮ⅡA提取收率的影响.得出最佳条件为:萃取压力25 MPa,萃取温度40℃,萃取时间2h,乙醇流量1.0 mL/min,并与乙醇提取法进行对比.结果表明,超临界CO2萃取法优于乙醇提取法.而后用液质联机分析得到其结构式.     

输水线路一干郭河与沙坡河倒虹吸工程地质评价

经过张峰水库输水线路一干工程地质勘测,就输水线路一干郭河与沙坡河倒虹吸工程地质条件进行了分析与评价。     

苯乙炔封端含萘环的聚酰亚胺树脂

将二胺单体1,3 双（4 氨基苯氧基）苯（1,3,4-APB）、3,4 二氨基二苯醚（3,4-ODA）分别与3,3′,4,4′-联苯四酸二酐（s-BPDA）和1,4,5,8 萘四甲酸二酐（NTDA）进行缩聚反应，并在两种不同合成条件下合成三种苯乙炔苯酐（PEPA）封端的聚酰亚胺低聚（PI1、PI2、PI3）。结果表明，含六元酸酐环的NTDA与二胺反应不仅形成酰亚胺结构，而且还形成异酰亚胺结构，并且酸性条件下更有利于酰亚胺结构的形成。这三种以苯乙炔苯酐封端的低聚物均具有良好的加工性能和热性能，有很宽的加工窗口，5%热失重温度均5300℃以上。萘环的引入使低聚物固化前后的玻璃化转变温度均有所提高，但也使得低聚物黏度上升。     

企业纳税筹划成本收益分析

从实施成本和风险成本两个方面论述了企业纳税筹划的成本,在此基础上分析了企业纳税筹划的收益。     

一类线性不确定切换系统的鲁棒镇定

考虑一类标称系统存在统一Lyapunov函数的线性不确定切换系统的鲁棒镇定问题,在不确定项满足一定限定条件下,利用完备性条件和统一Lyapunov函数方法,设计出鲁棒状态反馈控制器,使闭环系统仍然具有统一Lyapunov函数,从而在任意的切换策略下,确保闭环系统在其平衡点处是渐近稳定的. 仿真结果表明所设计的控制器是有效的.     

落实会计实践教学应把握的几个要素

会计专业进行实践教学是现实的客观要求,也是该学科本身的内在要求。本文主要从会计教师,实践课程体系设置,实践教学条件,教学组织等实践教学的几个要素进行了探讨。     

综采综放采区地质条件综合评价系统研究

综采综放采区地质条件综合评价的目的是根据评价单元条件对相关开采工艺的适应程度进行综合评价。该评价系统的指标体系包括地质条件（煤层、煤质、地质构造和岩浆岩）和开采技术条件（工程地质条件、水文地质条件等），评语集可按评价因素的分级来确定。因评价指标体系具有层次性和模糊性的特点，多级模糊综合评价法是较为适用的评价计算方法。因素的权重可采用专家调查法与层次分析法相结合的方法确定。文中利用上述模型建立了综采综放地质条件综合评价系统，并对即将开拓的某矿5^#，7^#采区进行评价计算。结果表明，5^#采区能进行综采综放开采，7^#采区较适合综采综放开采。从而为煤炭资源高产高效、安全开采提供了科学指导。     

厂商利润最大化理论之经济哲学透视

MR(边际收益)=MC(边际成本)是完全竞争市场上厂商实现利润最大化的均衡条件。这一理论在当今主流经济学家眼里是不可动摇的金科玉律。然而,这一理论的科学性甚至是经济学的科学性仍受到一些人的质疑。针对此,以经济哲学和科学哲学的视角,对这一理论的科学品格问题进行了全面审视。     

Optimizing Conditions of Enhancing Granule Sludge Concentration and Performance

An expanded granular sludge bed （EGSB） reactor was adopted to study the influence factors and rule of enhancing granular sludge concentration and performance. The experiment was performed at 33 ℃, pH 6.0-8.0 with continuous flow by adding proper quantity of nutritional trace elements. The results show that SLR was the key of steady operation of EGSB reactor. The increment of the granular sludge was influenced by volume loading rate （VLR）, liquid up-flow velocity and sludge loading rate （SLR）. Concentration of granular sludge increased rapidly when liquid up-flow velocity was over 0.94 m · h^-1 with SLR being at 1.0-2.0 d ^-1. With the propriety parameters： liquid up-flow velocity 2.52 m · h^-1, SLR 1.0-2.2 d^-1 and VLR 8.2-13.1 kg · m ^3 · d^-1, 23 days＇ continuous operation resulted in an increment by over 80% of granular sludge concentration in the EGSB reactor, plus good granular sludge property.     

Determining method and conditional factors of electrochemical fingerprint of Chinese traditional medicine

The thermodynamic systems and kinetic model suitable for the electrochemical token of the compo-nent throng in Chinese traditional medicines have been analyzed. It has been indicated that the damp oscillatory reactions in the non-equilibrium close system and open system without the supplement of dissipative substance have important significance for the throng token and analysis of chemical com-ponents in Chinese traditional medicines. Various factors influencing the electrochemical fingerprint,such as reactant species and their concentrations,electrode types,temperature,stir rate,the kind,dosage and granularity of Chinese traditional medicines,have amply been researched by the B-Z os-cillatory reaction which used malonic acid as a main dissipative substance. In addition,the quantitative information about the chemical components in Chinese traditional medicines has been discussed in detail. The method and its conditions for determining the electrochemical fingerprint used in scientifi-cally distinguishing and evaluating Chinese traditional medicines have successfully been put forward.