两种沥青炭微观结构和性能的对比研究

将高温煤沥青和浸溃荆沥青在92MPa下炭化，在2500℃下对所得沥青炭进行石墨化处理；测试了所得沥青炭的体积密度、开孔率、比表面积（SBET）；利用扫描电子显微镜（SEM）观察了所得沥青炭的显微结构；利用X射线衍射方法（XRD）检测了所得沥青炭石墨化处理后的石墨化度；测试了所得沥青炭的氧化性能；测试了沥青炭试样的比热容、导热系数、热扩散率和线膨胀系数。结果表明：在92MPa下，两种沥青炭有着相近的密度和开孔率；浸渍剂沥青炭的SBEt高于高温煤沥青炭；浸渍荆沥青炭为流线型结构，高温煤沥青炭为镶嵌型和域型并存的结构；流线型结构沥青炭石墨化度较高；高温煤沥青炭的抗氧化性能要好于浸溃荆沥青炭；随着沥青炭石墨化程度的增大，比热客、导热系数、热扩散率都增大，而线膨胀系数减小。     

丙烯酸酯橡胶柔性电极材料的制备及其性能研究

通过导电炭黑与多壁碳纳米管（MWCNT）并用制备丙烯酸酯橡胶（ACM）柔性电极材料,研究导电炭黑和MWCNT在ACM基体中的分散性及其并用比对柔性电极材料硫化特性、物理性能和导电性能的影响,并分析柔性电极材料与介电弹性体（DE）基体的粘合性能。结果表明：导电炭黑和MWCNT在ACM基体中具有良好的分散性;添加导电炭黑/MWCNT并用体系的ACM柔性电极材料的拉断伸长率远大于200%,满足DE发电机对于大形变的要求,且与仅添加导电炭黑的柔性电极材料相比,其硬度和弹性模量减小,柔韧性提高;随着MWCNT用量的增大,柔性电极材料的导电通路逐渐完善,导电性能提高;导电炭黑/MWCNT并用比为10/10的ACM柔性电极材料与ACM基DE基体共硫化后,两者的粘合强度达到5 N·mm^-1,且粘合稳定性较好。     

Two-dimensional graphitic carbon nitride for membrane separation

Recent years, membrane separation technology has attracted significant research attention because of the efficient and environmentally friendly operation. The selection of suitable materials to improve the membrane selectivity, permeability and other properties has become a topic of vital research relevance. Two-dimensional (2D) materials, a novel family of multifunctional materials, are widely used in membrane separation due to their unique structure and properties. In this respect, as a novel 2D material, graphitic carbon nitride (g-C₃N₄) have found specific attention in membrane separation. This study reviews the application of carbon nitride in gas separation membranes, pervaporation membranes, nanofiltration membranes, reverse osmosis membranes, ion exchange membranes and catalytic membranes, along with describing the separation mechanisms.     

三阶非线性光学玻璃材料的研究进展

评述了三阶非线性光学玻璃材料的种类、制备方法、基本特性及评价体系、非线性现象的起源、基本原理,几种典型非线性光学材料的潜在应用。简要介绍了该领域国内外的最新研究成果,重点阐述了掺杂CdS,PbS,Au等量子点尺寸、量子点玻璃微结构与光学和非线性光学性质的关系。评述了掺CdS、PbS这两种典型半导体量子点玻璃材料在光波导和激光饱和吸收器等领域的研究进展。指出在掺杂易极化金属,如;Pb,Bi,Nb等纳米团簇,掺杂半导体元素,如:Ge,Si等纳米团簇,掺杂Ⅴ-Ⅵ族半导体化合物,如:In_2Se_3,Bi_2S_3等纳米团簇量子点玻璃中,会有大的量子尺寸效应和非线性光学效应。     

北京市富营养化淡水水体中微囊藻毒素的研究进展

微囊藻毒素(Microcystins,MCYSTs,MCs)是富营养化淡水水体中最常见的藻类毒素,它的产生受到藻类遗传因素和环境因素的共同作用。由于其毒性大、分布广、结构稳定,从而成为水环境中的潜在危害物质。本文在总结国内外研览的基础上,主要对北京市不同富营养化程度的河流湖泊中微囊藻毒素的来源、结构性质、产生机理、危害及分析检测方法进行综述,为北京市淡水水体中微囊藻毒素的防治提供科学参考,也为2008年北京"绿色奥运"尽绵薄之力。     

苄·环庚除草剂开发与应用技术研究

近年来大面积推广水稻轻型栽培技术,水稻10-15天秧龄抛秧、地膜秧、工厂秧和直播田面积不断扩大,化除难度增大,草害问题突出,威胁严重.本研究以水稻小苗(抛秧)田和直播田杂草防除为目标,旨在研究开发新型除草剂的应用技术.研究结果表明:苄·环庚除草剂(商品名:谷旺)杀草谱广,对一年生稗草、千金子、异型莎草、丁香蓼、陌上菜、鸭舌草、节节菜等均有较好的防效,对多年生的矮慈姑、野荸荠也有明显的效果,在适时施用,方法适当的前提下,亩用10%苄·环庚可湿性粉剂40-50g,一次用药即能有效地控制水稻全生育期杂草的危害,综合防效达95%左右,且安全性好,农本比施用二氯苄、丁苄、苯苄、龙杀等除草剂降低四分之一,经济效益显著提高.     

Percolation and catalysis effect of bamboo‐based active carbon on the thermal and flame retardancy properties of ethylene vinyl‐acetate rubber

The effect of percolation and catalysis of bamboo‐based active carbon (BAC) on the thermal degradation and flame retardancy of ethylene vinyl‐acetate rubber (EVM) composites with intumescent flame retardants (IFR) consisting of ammonium polyphosphate (APP) and dipentaerythritol (DPER) has been investigated. The vulcanization characteristics were analyzed by a moving die rheometer. Thermogravimetric analysis (TGA) and fire behavior tests such as limiting oxygen index (LOI), vertical burning (UL 94), and cone calorimetry were used to evaluate the thermal properties and flame retardancy of EVM composites. Scanning electron microscopy (SEM) was used to study the morphology of residues of EVM composites. The addition of BAC significantly increased the maximum torque (M_H) of EVM composites and EVM matrices. The combination of IFR with BAC can improve the thermal stability of EVM composites. Moreover, BAC can enhance char residue and promote the formation of a network for IFR. The current EVM/37IFR/3BAC composite achieved an LOI of 33.6% and a UL 94 V‐0 rating. The PHRR, total heat release (THR), and total smoke release (TSR) for EVM/IFR/BAC were greatly reduced as compared to EVM/40IFR. Also, the mechanical properties of the EVMIFR/BAC composites increased with increasing BAC contents. The physical percolation effect between BAC and EVM before and after thermal degradation, and the chemical catalysis effect between BAC and IFR during thermal degradation are responsible for the improved flame retardancy of EVM composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42414.     

The Safety and Anti‐Hypercholesterolemic Effect of Coptisine in Syrian Golden Hamsters

Current work was conducted to evaluate the cholesterol‐lowering effect of coptisine extracted from Rhizomacoptidis in Syrian golden hamsters. The safety results indicated that coptisine was a safe and low‐toxic compound. Coptisine showed a beneficial effect in the abnormal serum lipid levels induced by a high‐fat and high‐cholesterol diet (HFHC): at a concentration of 70.05 mg/kg, coptisine significantly led to a decrease in total cholesterol, triglycerides, and low‐density lipoprotein cholesterol (LDL‐c) levels by 26.70, 15.38, and 22.22 %, respectively, and high‐density lipoprotein cholesterol (HDL‐c) was increased by 41.74 % in serum of hamsters (p < 0.01). In addition, total bile acid (TBA) levels in feces of hamsters were elevated after coptisine administration. Further investigation has suggested that the mRNA and protein expression of 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase (HMGCR) in the liver of hamsters was down‐regulated by high‐dosage coptisine treatment (p < 0.05); mRNA and protein expression of low‐density lipoprotein receptor (LDLR) and cholesterol 7α‐hydroxylase (CYP7A1) were dramatically up‐regulated by coptisine administration. The apical sodium‐dependent bile salt transporter expression was down‐regulated in the coptisine‐treated animals, but showed no significant differences from the HFHC groups. Taken together, our results demonstrate that a high dosage of coptisine could inhibit cholesterol synthesis via suppressing the HMGCR expression and promoting the use and excretion of cholesterol via up‐regulating LDLR and CYP7A1 expression. These findings suggest a critical role for coptisine in anti‐ hypercholesterolemia, and thus it needs to be considered as a potential natural cholesterol lowering agent.     

西部地区化工安全发展存在的问题及对策研究

为切实推进西部地区化工安全发展,基于西部大开发过程中化工生产与安全发展存在的主要问题,从科学制定化工行业发展规划,推进化工园区一体化安全管理;强化"两重点一重大"安全监管;加强危险化学品设计安全管理;全面开展企业安全生产标准化建设;加强危险化学品应急救援体系建设等方面进行探讨。结果表明,只有根据西部地区的实际情况,超前谋划安全发展的政策和措施,才能提升危险化学品领域安全水平和应急处置的能力,为西部地区化工大发展保驾护航。     

二恶唑啉改性酚醛树脂固化动力学研究

采用非等温差示扫描量热(DSC)法探讨了固化剂为六次甲基四胺的酚醛树脂(PF2828)和二恶唑啉(1,3–PBO)固化酚醛树脂(PF)(1,3–PBO 与 PF 质量比为40∶60)在不同量α,α–二溴对二甲苯(质量份数分别为0.5份,1.5份)作用下的固化行为,运用 Kissinger 法和 Ozawa 方法对其固化动力学进行研究,得到了固化反应活化能。结果表明,二恶唑啉和催化剂α,α–二溴对二甲苯的使用,可以加速 PF 的固化反应,降低了 PF 固化反应的活化能;当催化剂用量为1.5份时,最易于改性 PF 固化反应的进行。