水泥-聚苯乙烯轻质材料的准静态压缩力学行为

根据Gibson-Ashby模型中的多孔材料力学行为理论,对水泥-聚苯乙烯轻质材料的准静态压缩应力-应变曲线进行了预测,并通过试验对其进行验证,分析了纤维、乳胶粉、压缩比及养护方式对应力-应变曲线的影响.讨论了脆性抗压强度的变化规律,根据Gibson模型的强度理论拟合、分析了抗压强度与密度的关系.结果表明:材料的压缩应力-应变曲线可根据Gibson理论中弹性多孔材料和弹脆性多孔材料的应力-应变曲线进行复合,预测结果与实验结果基本一致;纤维、乳胶粉、压缩比和养护方式对曲线的线弹性、平台、密实化三个阶段均有一定的影响,也影响材料的脆性抗压强度;纯水泥组、加纤维组和高压缩比组脆性抗压强度的拟合相关性较高,而由于乳胶粉和蒸汽养护影响了孔壁的破坏强度,所以该两组的拟合相关性较低.     

河蚬(Corbicula fluminea)对氧化石墨烯和全氟辛烷磺酸类物质(PFOS)联合胁迫的生理生化响应

为了探索碳纳米材料氧化石墨烯(GO)和全氟辛烷磺酸类物质(PFOS)在淡水底栖贝类体内的联合毒性效应, 以河蚬为研究对象, 考察 1 mg/L GO和500 ng/L PFOS单独及联合暴露28天后对河蚬体长、体重、滤食率、活性氧水平、抗氧化系统酶活性和丙二醛含量的影响, 并采用优化的综合生物标志物响应指数(EIBR)进行整体评估。结果表明, 暴露结束后, 河蚬的体长和体重没有明显的变化。与空白对照组和溶剂对照组相比, GO和PFOS的单独暴露组及联合暴露组的滤食率均显著下降。在河蚬的鳃和内脏团中, GO和PFOS的胁迫都会引起抗氧化系统酶活性响应的显著变化, 且两器官中变化趋势一致。EIBR结果表明, 鳃和内脏团中联合暴露组的毒性比 PFOS或GO单独暴露组的毒性更强。     

Flame spread over the surface of thermal insulation materials in different environments

Experiments were conducted in a plateau area in Lhasa and a plain area in Hefei China to investigate the flame spread characteristics on thermal insulation materials under different environmental conditions (pressure and oxygen concentration).Molded polystyrene foam (EPS) and extruded polystyrene foam (XPS) samples were placed horizontally on a small-scale flame spread experimental bench.Changes in the average length of the pool fire,flame spread speed,average flame height,and length of preheating zone were used to determine the effect of the plateau and plain environments on flame spread characteristics.These parameters were all larger in Hefei than in Lhasa,which indicates the fire hazard in Hefei will be higher than that in Lhasa if insulation materials of the same size are used.     

水样中Cr（Ⅵ）的测定

铬及其化合物在工业中应用广泛,对环境造成了较大的污染,是环境污染监测中的必测项目之一.在酸性溶液中,通过用Fe2＋标准溶液滴定Cr（Ⅵ）,使其还原成Cr3＋,以二苯胺磺酸钠作指示剂,根据Fe2＋标准溶液所消耗的体积,计算出水中Cr（Ⅵ）的含量（mg L）.本实验操作简单,快速,通过对实际样品的测量,结果令人满意.     

水样中Cr（Ⅵ）的测定

铬及其化合物在工业中应用广泛,对环境造成了较大的污染,是环境污染监测中的必测项目之一.在酸性溶液中,通过用Fe2＋标准溶液滴定Cr（Ⅵ）,使其还原成Cr3＋,以二苯胺磺酸钠作指示剂,根据Fe2＋标准溶液所消耗的体积,计算出水中Cr（Ⅵ）的含量（mg L）.本实验操作简单,快速,通过对实际样品的测量,结果令人满意.     

弱碱石油磺酸盐提高采收率技术室内实验研究

碱/表活剂/聚合物(ASP)三元复合驱是目前提高采收率效果较好的一项技术,但强碱会带来较为严重的结垢现象。为完善三元复合驱技术,开展了弱碱石油磺酸盐提高采收率技术研究,通过界面活性范围、界面张力稳定性、乳化、吸附和室内岩心驱油实验较系统地评价了弱碱石油磺酸盐体系。研究显示,所评价三元体系界面活性范围很宽,且45℃恒温90天仍可达到超低界面张力;0.4%表活剂+1.2%Na2CO3三元体系具有较好的抗吸附能力;人造岩心可提高采收率27.55%,贝雷岩心可提高24.11%。     

PS/PC共混膜的干燥动力学

高分子共混物薄膜产品中的残余溶剂量与干燥过程密切相关,是影响高分子涂膜性能的重要因素之一。将石英晶体微天平（QCM）与自制强制空气对流干燥装置相结合,研究了不同共混比的聚苯乙烯（PS）/聚碳酸酯（PC）共混物的二氯甲烷铸膜液在不同热空气流速和温度下的干燥过程,并应用蠕变传递模型关联了干燥动力学实验数据。研究结果表明：高...     

Preparation of three-dimensionally ordered macroporous perovskite materials

In this paper,we use La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 as examples to demonstrate a preparation method for threedimensionally ordered macroporous(3DOM) perovskite thermochromic materials.Polystyrene spheres with an average diameter of 220 nm were self-assembled into a three-dimensionally ordered colloidal crystal template.A mixed metal nitrate solution prepared using La(NO3) 3·6H2O,Ca(NO3) 2·4H2O,Sr(NO3) 2,Mn(CH3COO) 2·4H2O and an ethanol precursor was used to fill the interstitial voids of the polystyrene colloidal crystal templates.3DOM La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 materials were then obtained after the sphere templates were removed via drying and calcination.The results show that the framework of the 3DOM materials can have different thicknesses and pore shrinkage rates by varying the filling times.In addition,the Curie temperatures of the 3DOM and bulk La0.8Sr0.2MnO3 materials can be varied by altering the preparation method.     

Serum levels of perfluorinated compounds in the general population in Shenzhen, China

Perfluorinated compounds (PFCs) have been detected in many environmental matrices, biota, and nonoccupationally exposed populations in China recently. However, little is known about the distribution and levels of various PFCs in the general population living in areas where there is PFC exposure. In the present study, the levels and prevalence of ten target PFCs were determined in 227 serum samples from a population of nonoccupationally exposed individuals in Shenzhen, China. Results indicated that human exposure to PFCs was prevalent in Shenzhen. Perfluorooctanoate (PFOA) was the dominant PFC contaminant in the serum samples, with a median concentration of 6.72 ng/mL, followed by perfluorooctane sulfonate (PFOS) with a median concentration of 2.07 ng/mL. Other PFCs were detected at much lower concentrations, with median concentrations ranging from 0.02 to 0.87 ng/mL. Statistically, no significant (P>0.05) gender differences were observed for any of the PFCs. Significant (P<0.01) positive correlations were found between age and serum concentrations of the target PFCs, except for perfluorobutane sulfonate (R = 0.16, P = 0.01), perfluorohexanoic acid (R = 0.08, P = 0.22), and perfluoroheptanoic acid (R = 0.11, P = 0.10). Based on the one-compartment pharmacokinetic model, the total daily intakes of PFOA and PFOS for the general population in Shenzhen were calculated as 0.63 and 0.20 ng/kg body weight/day, respectively.     

电荷稳定分散聚合制备光活性聚苯乙烯微球

采用苯乙烯磺酸钠电荷稳定分散聚合体系,在甲醇/水混合溶剂中,通过后滴加功能单体4-烯丙氧基-2-羟基苯甲酮（BP-OH）,制备出表面带有二苯甲酮光引发基团的聚苯乙烯（PS）微球。研究了功能单体BP-OH的补加时间及总反应时间对微球形貌及功能基团结合量的影响,并将所制备的功能性PS微球在紫外光辐照下引发荧光单体7-甲基丙烯酰氧乙基-4-甲基香豆素（MCMA）反应;并通过场发射扫描电子显微镜（FESEM）、傅里叶变换红外光谱（FT-IR）、紫外可见光谱（UV-Vis）及荧光显微镜（FM）对微球进行测试表征。结果表明,所制备的微球具有光引发活性。