大孔吸附树脂纯化芹菜黄酮的研究

研究6种大孔吸附树脂对芹菜黄酮类物质的吸附和解吸性能,筛选出吸附率较高的XAD-16树脂,并对XAD-16树脂静态吸附和动态吸附解吸工艺做了研究。优化出XAD-16树脂纯化芹菜黄酮的最佳工艺参数为：室温下吸附;上样流速4 BV/h,在上样浓度0.55 mg/mL下,上样体积为15倍柱床体积;洗脱溶剂采用体积分数50%的乙醇,洗脱流速为6 BV/h,洗脱液量为4倍柱床体积。     

大孔吸附树脂对喜树叶中喜树碱的纯化工艺研究

研究通过静态吸附/解吸实验对大孔吸附树脂进行筛选,优选AB-8大孔吸附树脂作为层析柱填料,并对其进行喜树碱纯化工艺研究;研究表明AB-8树脂对喜树碱的静态吸附率为95.31%;体积分数95%的乙醇静态解吸率为92.4%;最佳吸附条件为:上样液质量浓度为0.175mg/mL,上样液不调pH值,吸附流速为2BV/h,平衡吸附5h;最佳洗脱条件:体积分数95%乙醇,洗脱流速1BV/h,洗脱体积为8BV。在该工艺条件下,洗脱物中喜树碱质量分数为7.43%,洗脱率为83.1%。     

八角莲中黄酮类化合物的分离纯化工艺研究

研究了八角莲中黄酮类化合物的分离纯化工艺。考察各种因素对树脂吸附和洗脱效果的影响,确定了AB-8型大孔树脂分离纯化八角莲中黄酮类化合物的最佳工艺参数。最佳工艺参数为:静态吸附,树脂与样液比为1:20 g/m L、吸附时间为3 h,静态解吸过程解吸液(乙醇)体积分数为70%、树脂与解吸液的比例为1∶50 g/m L;动态吸附中动态流速为0.5 m L/min、静置时间为80 min,动态解吸中洗脱液(乙醇)的体积分数为60%、树脂与洗脱液的比例为1∶40 g/m L。     

大孔吸附树脂纯化东北岩高兰总黄酮

依据东北岩高兰总黄酮的吸附和解吸能力,采用静态吸附和解吸实验对8种型号的大孔吸附树脂进行筛选。结果显示,AB-8型大孔吸附树脂对东北岩高兰总黄酮具有较好的吸附和解吸性能。经HPLC分析提取出的东北岩高兰主要有5种成分。进一步探究了总黄酮的纯化工艺,得到5种成分的最佳静态吸附解吸条件为:吸附平衡时间1.0 h,解吸溶剂为体积分数95%的乙醇,解吸平衡时间1.5 h。不同温度(25、30、35℃)下,AB-8型大孔吸附树脂对东北岩高兰不同成分的吸附等温线均符合Freundlich模型和Langmuir模型。5种成分的最佳动态吸附洗脱工艺条件为:上样液质量浓度为5 g/L,最大上样量400 mL,5倍柱体积(BV)的体积分数为20%的乙醇洗脱杂质,5倍BV的体积分数为95%的乙醇洗脱成分,洗脱流速3m L/min。在最佳实验条件下,东北岩高兰总黄酮的质量分数由纯化前的49.16%提高到纯化后的89.59%,表明AB-8型大孔吸附树脂能够有效纯化东北岩高兰。     

大孔吸附树脂分离纯化胡芦巴中总皂苷工艺

通过对11种大孔吸附树脂对比研究,筛选出了一种对胡芦巴中总皂苷具有最佳吸附解吸性能的树脂,并对该树脂的静态和动态吸附性能进行了研究,确定了树脂纯化总皂苷的工艺参数。结果表明,HPD-400A型树脂对总皂苷有良好吸附分离性能,Freundlich等温吸附模型较Langmuir模型更适宜描述树脂对胡芦巴总皂苷的吸附;吸附分离总皂苷的工艺条件:树脂柱径高比为1∶10,上柱液质量浓度为1.358 mg/mL,流速为2 BV/h,解吸流速1 BV/h,解吸液为体积分数60%的乙醇,洗脱剂用量为1.5 BV。经大孔树脂纯化前总固物中总皂苷质量分数为11.38%,纯化后总固物中总皂苷质量分数为42.76%,纯度提高了近4倍。     

大孔树脂纯化萼翅藤总黄酮工艺

筛选纯化萼翅藤总黄酮的最佳树脂,并对影响这种树脂分离的主要因素进行研究,确定大孔树脂纯化总黄酮的最佳工艺参数。选择4种大孔树脂分别对萼翅藤总黄酮进行静态与动态吸附性能研究,考察影响分离的各种因素如上样液pH值、上样液质量浓度、上样量和洗脱剂体积分数等。HPD-450树脂分离效果最好,Langmuir等温吸附模型较Freundlich模型更适宜描述树脂对萼翅藤总黄酮的吸附,其吸附分离萼翅藤总黄酮的最佳工艺为:上样液pH值为5,质量浓度为0.6—0.8 mg/mL,上样量为3 BV(树脂床体积),洗脱液为体积分数70%的乙醇,洗脱剂用量为3 BV。经HPD-450树脂吸附分离后,总固物中总黄酮质量分数从20.23%提高到75.86%,纯度提高了3倍多,回收率为62.65%。     

大孔吸附树脂分离纯化猪毛菜总黄酮及其抗氧化活性

采用不同大孔吸附树脂分离纯化猪毛菜总黄酮,并对纯化后的总黄酮进行体外抗氧化活性测试。通过考察影响树脂静态和动态吸附与洗脱的主要因素,确定猪毛菜总黄酮分离纯化优化工艺条件。静态吸附实验表明,AB-8树脂分离纯化效果较好,并且吸附符合Langmuir和Freundlich方程。动态吸附和解吸的最佳工艺条件为:上样液质量浓度1.25 g/L、p H=4.5、上样流速2 m L/min、上样量2.5 BV(BV指树脂柱内装载树脂的体积)、洗脱剂为体积分数80%的乙醇溶液、洗脱流速1.0 m L/min,洗脱剂用量4 BV。所得洗脱液中黄酮质量分数从纯化前10.20%增加到纯化后51.89%,回收率为84.43%。体外实验表明,纯化后的黄酮可以清除羟自由基和超氧阴离子自由基,并有较好的还原力。纯化后的黄酮可以作为一种潜在的天然抗氧化剂。     

大孔树脂分离纯化沙芥黄酮的工艺研究

用大孔吸附树脂分离纯化沙芥总黄酮,比较了7种大孔树脂对沙芥总黄酮的静态吸附动力学特性,优选出D-4020型大孔吸附树脂分离纯化沙芥总黄酮,并对其进行动态吸附实验。结果表明,D-4020纯化沙芥总黄酮的最佳工艺参数为：上样液浓度0.4 mg/mL,pH值5,上样流速2 mL/min;使用4BV用量95%的乙醇作为洗脱剂,洗脱流速为2 mL/min。采用该工艺分离纯化沙芥总黄酮含量达40.91%。     

大孔树脂分离纯化沙芥黄酮的工艺研究

用大孔吸附树脂分离纯化沙芥总黄酮,比较了7种大孔树脂对沙芥总黄酮的静态吸附动力学特性,优选出D-4020型大孔吸附树脂分离纯化沙芥总黄酮,并对其进行动态吸附实验。结果表明,D-4020纯化沙芥总黄酮的最佳工艺参数为:上样液浓度0.4 mg/mL,pH值5,上样流速2 mL/min;使用4BV用量95%的乙醇作为洗脱剂,洗脱流速为2 mL/min。采用该工艺分离纯化沙芥总黄酮含量达40.91%。     

响应面法优化箬叶总黄酮的大孔树脂纯化工艺

采用大孔树脂纯化箬叶总黄酮。由静态吸附与解吸实验筛选出最佳树脂,在动态吸附与解吸单因素实验的基础上,运用响应面法实验优化箬叶总黄酮的大孔树脂纯化工艺条件。结果表明:HPD-800树脂对箬叶总黄酮的吸附容量最大,上样液pH值为9,上样液浓度为2.3 mg·mL~(-1),上样流速为1.0 mL·min~(-1),用4 BV 80%乙醇以3 BV·h~(-1)速度洗脱,解吸率为84.62%。     

预分解窑窑头和窑尾参数的分析与控制

新型干法水泥是目前水泥行业的发展趋势,中央控制室是新型干法水泥生产线的控制指挥中心。预分解窑系统需要控制的参数较多,综合考虑各参数的变化将有利于窑系统的稳定运行。窑头和窑尾参数是准确判断窑系统运行状况的重要参数,包括窑尾的温度、压力,窑头的温度、压力,窑尾的气体分析等,在操作中应引起操作员的重视。     

西玛津在甘蔗及土壤中的残留消解动态

为了探明西玛津使用后在甘蔗及其土壤中的残留降解规律,采用气相色谱法研究了西玛津90%水分散粒剂在甘蔗及其土壤中的残留消解降解动态和最终残留实验。结果表明:西玛津在甘蔗和土壤中的降解动态方程分别为Ct=19.157e-0.0587t和Ct=1.689 8e-0.036t,半衰期分别为11.8 d和19.3 d;以1 647 g a.i./hm2和2 470.5 g a.i./hm2的剂量在甘蔗田进行喷雾处理,收获期甘蔗和土壤中的最终残留量分别小于0.01 mg/kg和0.02 mg/kg。     

欧盟对农药的重新评定与我国除草剂品种发展

评述了欧盟评定的农药名单中禁用的除草剂品种及我国今后除草剂的开发与使用。     

咪鲜胺在粤浙两地水稻和土壤中残留动态

为了评价咪鲜胺在水稻上使用后的残留动态及环境安全性，在广东、浙江两地同时进行了咪鲜胺在水稻上的残留动态试验。结果表明：在广东地区，咪鲜胺在植株中的半衰期为2．59d，在土壤中的半衰期为2．46d，在稻田水的半衰期为0．46d；在浙江地区，咪鲜胺在植株中的半衰期为3．08d，在土壤中的半衰期为1．89d，在稻田水的半衰期为1．52d。收获的水稻糙米中咪鲜胺最终残留量均低于0．5mg／kg。     

Preparation and characterization of porous microspheres and applications in controlled-release of abamectin in water and soil

Porous microspheres with different sizes were prepared through solvent evaporation method with ethylcellulose as a matrix material and abamectin as a core material. The abamectin-loaded microspheres were characterized through scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The chemical structure of the microspheres was determined through FTIR. DLS analysis showed that the diameter of the microspheres range from 10 to 100 μm. SEM analysis revealed that the inner structure of the microspheres is characterized by a porous network. TGA revealed that the microspheres are thermally stable below 125 °C. The controlled release of abamectin from the microspheres into water and soil was also investigated. Abamectin was released from microspheres into water through diffusion. The release of abamectin into soil was mainly caused by erosion, a result that was verified through SEM.     

Evaluation and characterization of vector fluids and peroxides in a process of in situ compatibilization of polyethylene and polystyrene

An organic functional silane was found to be the most efficient among several vector fluids in reactive blend compatibilization of the polyethylene (PE) / polystyrene (PS) / peroxide / vector fluid system. This paper involves further analysis of this reactive blending system. Surface tension data was used to calculate spreading coefficients which were compared to the amount of PE-PS copolymer formed during blending. A good correlation between a computed spreading coefficient and the degree of grafting of PS onto PE was found. The results suggest that the pattern of distribution of the vector fluid in PE / PS blends is the key factor leading to effective results. Furthermore, different peroxides were evaluated in PE / PS blends, in order to determine the dependence of PE / PS interfacial grafting reaction on the structure of the peroxide.     

生物表面活性剂在日化行业的研究及应用进展

综述了生物表面活性剂在日化行业的研究进展和用于日化行业的生物表面活性剂新产品,探讨了生物表面活性剂在日化行业的应用优势及限制因素,指出了应对措施并对其在日化行业的应用前景进行了展望。     

Phosphodiesterases and Compartmentation of cAMP and cGMP Signaling in Regulation of Cardiac Contractility in Normal and Failing Hearts

Cardiac contractility is regulated by several neural, hormonal, paracrine, and autocrine factors. Amongst these, signaling through β-adrenergic and serotonin receptors generates the second messenger cyclic AMP (cAMP), whereas activation of natriuretic peptide receptors and soluble guanylyl cyclases generates cyclic GMP (cGMP). Both cyclic nucleotides regulate cardiac contractility through several mechanisms. Phosphodiesterases (PDEs) are enzymes that degrade cAMP and cGMP and therefore determine the dynamics of their downstream effects. In addition, the intracellular localization of the different PDEs may contribute to regulation of compartmented signaling of cAMP and cGMP. In this review, we will focus on the role of PDEs in regulating contractility and evaluate changes in heart failure.     

表面活性剂在宾馆／酒店厨房、餐具保洁中的应用

本文简述了在宾馆／酒店厨房、餐具保洁中应用的表面活性剂的主要类型,并且仅限于对环境及物品的清洁。     

Morphology and microstructure of autoclaved clinker and slag-lime pastes in presence and in absence of silica sand

Development of microstructure in four hydrothermal reactions has been undertaken using scanning electron microscopy. These are clinker, clinker-sand, slag-lime and slag-lime-sand hydrothermal reactions. The microstructure of clinker hydration products displayed crumpled foils and tabular masses of calcium silicate hydrates; few cubic crystals of hydrogarnet appeared only during the initial stage of the reaction. In clinker-sand mixture the C-S-H phase was the only product identified. In slag-lime hydration the microstructure displayed both of the hydrogarnet crystals and the C-S-H phase. The hydration of slag-lime-sand mixture (an optimum composition) was associated with the formation of ill-crystallized tobermorite and crystalline 11A tobermorite as the main products.