基于DOPO的阻燃剂合成及其对不同高分子材料的阻燃效率(英文)

由于环境可持续性的需要,在过去的几十年,无卤含磷阻燃剂的重要性越来越受到社会的关注。9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)及其衍生物作为一种无卤含磷阻燃剂,在聚合物中主要以气相阻燃的机理而表现出优异的阻燃性能。相比于卤系阻燃剂,DOPO及其衍生物在燃烧过程中所释放出的腐蚀性和毒性气体很少,因此许多反应型和添加型的DOPO衍生物得到学术界和工业界的青睐,品种越来越多。DOPO中的P-H键具有较强的反应活性,可以与含活泼双键的化合物(如苯醌、丙烯酸酯、醛类和环氧衍生物等)反应制备出反应型或添加型阻燃剂。反应型DOPO衍生物阻燃剂主要应用于热固性环氧树脂化合物(EP)的阻燃,包括基于DOPO的环氧单体和基于DOPO的胺基和酸酐固化剂,通常这类阻燃剂在环氧树脂中的磷含量达到1.5%以上就可以达到UL 94 V-0级。添加型DOPO衍生物阻燃剂主要是将DOPO中的P-H键转化为P-C,P-O或P-N键的DOPO衍生物,包括基于DOPO的三聚氰胺盐和锌盐以及将P-H键烷基化的DOPO衍生物等,通常这类阻燃剂在聚合物(如EP,PU,PA,PBT和PET等)中的磷含量达到1.0%以上就可以达到UL 94 V-0级。

The inhibitory effect of dihydroartemisinin on the growth of neuroblastoma cells

Objective:To evaluate the inhibitory effect of dihydroartemisinin on neuroblastoma cell line SH-SY5 Y,explore the possible mechanism of dihydroartemisinin against neuroblastoma cells.Methods:The cell viability of dihydroartemisinin treated SH-SY5 Y cells was examined by MTT assay and morphology of cells was observed by using inverted microscope.Cell cycle was examined with flowcytometry assay,then cyclin D1 and caspase-3 proteins expression was detected by ELISA and western blotting assay.Results:MTT analysis results showed that cell viability significantly decreased after exposure to 0.05,0.50,5.00 and 50.00 mmol/L dihydroartemisinin in a dose-dependent manner,and the lower density of cells was observed in treated groups.The number of cells in sub-G1 phase was increased after treatment with different doses of dihydroartemisinin compared with the control group.The expression of cyclin D1 protein was decreased,while the expression of caspase-3 protein was increased in treated group.Conclusions:Dihydroartemisinin could inhibit the proliferation through stopping the cell cycle and inducing the apoptosis in neuroblastoma SH-SY5 Y cells.

Estimation and Long-term Trend Analysis of Surface Solar Radiation in Antarctica: A Case Study of Zhongshan Station

Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R^2 of 0.984,root-mean-square error of 1.377 MJ m^(-2),and mean absolute error of 0.828 MJ m^(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.

山地与极地冰川表面生态系统DNA病毒的多样性与功能

冰川覆盖了地球表面的10%,是典型的极端环境.病毒在冰川表面生态系统中丰富且活跃,在控制微生物群落中发挥关键作用.然而,我们对冰川表面生态系统病毒及其对下游生态系统的潜在影响了解非常有限.本研究构建了冰川表面生态系统DNA病毒基因组数据集(SgVG),将已有冰川DNA病毒基因组数量扩展了15倍.数据集包含了来自全球38个山地和极地冰川,涵盖雪、冰、融水和冰尘的10,840个DNA病毒物种.冰川表面DNA病毒特异性高,但对公众健康的潜在风险极低.冰川表面病毒群落结构主要受生境影响,且冰尘病毒最为活跃.裂解性病毒在所有生境中普遍存在,而雪和冰中溶源性病毒的相对比例较高.此外,冰川表面病毒可侵染冰川中83%的门或纲的原核微生物,并且能够编码具有促进宿主代谢和协助宿主适应寒冷环境等功能的多种辅助代谢基因.本研究系统地描述了山地和极地冰川表面生态系统DNA病毒的多样性和功能,为评估冰川DNA病毒的生态功能、安全风险及构建区域生态模型提供了重要科学依据.