氢化苯乙烯热塑性弹性体发展展望

氢化苯乙烯类热塑性弹性体是一种重要的热塑性弹性体,在常温下具有橡胶的高弹性,在高温下表现出热塑性树脂的流动性,可以直接加工成型,广泛应用于国民生产的各行各业。文中从国内外弹性体的政策法规和市场需求入手,介绍了国内氢化苯乙烯热塑性弹性体的总体发展状况和未来市场需求,并从氢化苯乙烯热塑性弹性体下游应用产品阐述了氢化苯乙烯热塑性弹性体制品发展现状及特点。

A Table That Produces Elements

How do elements originate, how atoms are formed, and what are the laws? According to the unified logic of “Tong Yi Lun Thought”, combined with the elements’ attributes and the atomic composition that have been discovered now, after determining that the mechanism of increasing yang in the atomic system is the increase of proton number, the Bian Zheng relationship among proton, neutron and electron determines that there are only 128 kinds of elements in the atomic system. At the same time, element atoms have corresponding logical relations when they are generated.

Detrital-Zircon Evidence for the Origin of the Late Quaternary Loess in Qingzhou,Shandong Province and Its Implications for the Evolution of the Yellow River

The loess depositions in Shandong Province are important parts of loess records in eastern China,but their origin and genetic linkage between the Yellow River and the Chinese Loess Plateau are still unclear.This paper presents the detrital-zircon evidence for the origin and provenance evolution of the Qingzhou loess in Shandong Province.The results show that:(1) the Qingzhou loess was sourced from the sandy lands within the North China Plain that were fed by the silty materials from the Chinese Loess Plateau,the mountainous region in central Shandong Province,and the Yanshan and Taihang Mountains;(2) the Qingzhou loess was mainly sourced from the loess materials transported by the Yellow River,and the basal age of the Qingzhou loess indicates the timing of intensified aridification of the North China Plain and integration of the Yellow River was not later than 0.5 Ma;and(3) the provenance and grain-size of the Qingzhou loess underwent a significant transition at ~0.22 Ma,which was related to the expansion of the sandy land within the North China Plain.Our results indicate that the origin of the loess on the North China Plain are obviously different from the loess on the Chinese Loess Plateau,and the increase of grain-size and accumulation rate in the loess records on the North China Plain at ~0.22 Ma was due to the environmental deterioration of the eastern China.

Overestimate of remediation efficiency due to residual sodium persulfate in PAHs contaminated soil and a solution

Oxidation remediation is a commonly used technology for PAHs contaminated soil presently,but the overestimate of efficiency due to ongoing remediation by residual oxidants during extraction and testing has not been paid enough attention.In this study,persulfate was activated by Fe(Ⅱ)to investigate the effects of residual oxidants on PAHs removal during detection process and the elimination effects of adding Na_(2)SO_(3) and extending sampling time on residual oxidants.Results verified that the residual oxidants removed PAHs in extraction process,making the results lower than the actual values:the detection recovery rate η of ΣPAHs and 3-6 ring PAHs ranged from 24.3%(25%Na_(2)S_(2)O_(8)treatment)to 87.4%(5%Na_(2)S_(2)O_(8)+4/4Fe^(2+) treatment),20.1%-99.0%,28.9%-87.9%,20.8%-89.4%,and 1.8.6%-76.9%,respectively.After adding Na_(2)SO_(3),the accuracy of detection results increased significantly:the η of ΣPAHs and 3-6 ring PAHs increased to 64.1%-96.5%,58.8%-95.5%,73.8%-114.4%,60.6%-95.6%,and 45.4%-77.1%,respectively.After 49 days of adding oxidants,residual oxidants had no considerable effect on the detection of PAHs,indicating it was appropriate to start soil remediation verification sampling49 days after the remediation was completed.The observed results will help scientific evaluation of the remediation effects of chemical oxidation on or-ganic contaminated soil.