Research Progress on the Separation of Alkaloids from Chinese Medicines by Column Chromatography

Alkaloids have a variety of bioactivities and great development value in the fields of pharmaceuticals, cosmetics and health food. Column chromatography is a common method for preparing alkaloids. In this paper, the research status of the separation and purification of alkaloids from Chinese medicines by column chromatography is reviewed, and the factors that influence the refining of alkaloids via a macroporous adsorption resin, ion exchange resin and silica gel are summarized. The thermodynamic and kinetic modeling methods for the static adsorption of adsorbents are also reviewed in this paper. It is suggested that the modeling method of the column chromatography process be deeply studied to establish a more stringent quality control method for sampling liquid and to strengthen the online detection of the chromatography process to improve the refining effect of alkaloids.

The Urgency of Interest-developed Communicative Activities

The article holds that there is an urgent need to implement interest-activated communicative activities in English classes in accordance with the present situation of Shanxi. These activities, as illustrated in the examples, are a means to activate the students＇ interest in English. Moreover, the significance of such activities is mentioned.

Control and Patterning of Various Hydrophobic Surfaces:Insitu Modification Realized by Flexible Atmospheric Plasma Stamp Technique

Wettability plays a vital role in fundamental researches and practical applications.Wettability control and patterning have been widely studied in various fields.Although researches have grown rapidly,the methods are still restricted by limitations including complicated processes,high equipment requirements and shortage of methods to treat complex surfaces.Here we report a simple,low cost,array-based wettability control and patterning method via in-situ modification by flexible plasma stamp.Wettability control and patterning on surfaces of superhydrophobic aluminum,superhydrophobic PDMS and silicon,even plant leaf and fruit are achieved.The relationships between the wettability and the treatment time are investigated.We elucidate that the wetting states can also be reversible.The surface modification mechanism of in-situ plasma treatment is further investigated.Utilizing the step by step treatment,gradient and arbitrary wettability patterning on surfaces have been obtained.Notably,the patterned wettability on the inner surface of a tube has been realized,which has never been reported.Finally,in-situ wettability patterning is applied to achieve microfluidics channels on the inner surface of superhydrophobic tube.This work will bring new insights into the study of wetting field and stimulate more applications on wettability control and patterning.

福建海岛滨海特有植物种–面积关系及物种丰富度决定因素

福建海岛具有丰富的滨海特有植物资源,研究其物种丰富度的分布格局及机制,能够为滨海特有植物资源保护提供依据。本研究探讨了福建53个海岛滨海特有植物的种–面积关系,以及景观、人为干扰和气候3个方面10个环境因子对滨海特有植物物种丰富度的影响。同时还探讨了不同生活型(乔木、灌木、草本)对海岛环境因子的响应。结果表明:滨海特有植物和不同生活型植物的种–面积关系呈现物种丰富度随着面积增加而增加的趋势,滨海特有植物、乔木、灌木和草本的种–面积关系的斜率(z)分别为0.16、0.15、0.15和0.14。景观环境因子中的面积、形状指数和周长面积比是解释福建海岛滨海特有植物及不同生活型植物物种丰富度的主要决定因素,滨海特有植物及各生活型植物物种丰富度随着面积和形状指数的增加而增加,而滨海特有植物、灌木和草本的物种丰富度随着周长面积比的增加而减少。此外,不同生活型植物的物种丰富度对海岛环境因子的响应存在差异,除景观方面的因子外,气候对乔木的解释率最大,达9.82%。综上所述,相比于其他海岛生态系统,福建海岛滨海特有植物及不同生活型植物的物种丰富度与面积密切相关,其较低的斜率(z)表明滨海特有植物对海岛生境的敏感性较弱。景观方面的环境因子相比气候和人为干扰方面贡献了更多的解释率。以往研究发现岛屿环境因子与生境异质性显著相关,如岛屿越大、形状越不规则、周长面积比越低,则生境异质性越高。因此生境异质性的提升可能是解释滨海特有植物丰富度随景观环境因子变化的内在机制。