今夏首选高度耐水防晒液

在四季不太分明的南方，春天还蹒跚着不肯离去，夏天已抖擞着英姿盛装而来，渴望着以炎热和明媚拥抱大地。面对即将来临的夏季，为使雪白的肌肤不受到伤害、众爱美人士纷纷展开防晒、护肤行动。

Study on the preparation and properties of sunscreen O/W/Si multiple emulsion

To solve the greasiness and irritation risks brought about by organic sun-screening agents in sunscreen emulsions,in this work,a sunscreen O/W/Si multiple emulsion was prepared by two-step emulsification method,in which the outer oil phase was silicone oil and the inner oil phase was solid lipid nanoparticles coated with organic sun-screening agent.Several influencing factors on the formation and stability of the emulsion were analyzed,including inorganic salts,the volume fraction of outer oil phase(silicone oil),and the dosage of W/O emulsifier.The in vitro sunscreen performance,water resistance and skin permeability of different types of sunscreen emulsions were further studied.The results showed that the sunscreen O/W/Si multiple emulsion containing 22.5%silicone oil,2.5%emulsifier and 0.2%NaCl had the best stability under the experimental conditions.The SPF value and water resistance of sunscreen O/W/Si multiple emulsion were slightly higher than those of sunscreen W/O emulsion,but significantly higher than those of sunscreen O/W emulsion.Compared with sunscreen W/O emulsion,the in vitro transdermal permeability of organic sun-screening agent in sunscreen O/W/Si multiple emulsion was reduced by approximately 60%,indicative of higher safety and good application prospect in sunscreen cosmetics.

对二甲氨基苯甲酸的合成研究

用硫酸二甲酯在碱性条件下将对氨基苯甲酸甲基化;在浓氨水存在下,将经甲基化的混合物在152℃水解8h;用 稀硫酸中和水解产物,得到对二甲氨基苯甲酸,产率为82.1％。

人民公社体制下盐业社会的变迁——以东江盐区“沙改”为中心的考察

20世纪50至70年代,东江盐区经历了一场名为"沙改"的盐业技术变革。它不仅是一场生产技术变革,更成为盐区社队群众广泛参与的运动。在人民公社体制下,盐业生产、盐区建设和盐民生活等方面都发生了深刻变化。盐业生产逐步走向合作化、集体化。盐民专门从事盐业生产,同时国家为盐民的生活必须提供保障。气象站、纳潮站等配套设施的兴建也专门服务于盐田生产。"沙改"带来了一种集约化的生产方式,同时也收到一定成效。但是随着国家经济体制的转变,东江盐区盐田又出现大面积丢荒或转产。东江盐区盐业的兴衰正是国家经济社会变迁的一个缩影。

泉州市2007—2009年桶装水卫生质量监测结果分析

[目的]了解泉州市桶装水卫生状况及其主要的污染因素,为企业改善卫生质量和相关部门的监督管理提供科学依据。[方法]监督抽检2007—2009年泉州市本地企业生产的桶装水,并分类比较。[结果]2007—2009年桶装水抽检结果合格率分别是66.7%、68.0%、70.8%;3年总计纯净水、饮用水、矿泉水合格率分别为63.5%、68.4%、79.2%;抽检项目显示不合格的主要是菌落总数、大肠菌群、霉菌和酵母、电导率、耗氧量和亚硝酸盐等。[结论]桶装水菌落总数、霉菌及酵母等微生物指标和理化指标中电导率出现超标的现象较为常见。应加强卫生监督管理,引导规范生产,提高桶装水的卫生质量。