Effect of Bio-Based Cobalt Alginate on the Fire Safety and Mechanical Properties for Epoxy Resin

There is a growing demand to develop epoxy resins (EP) with smoke suppression as well as satisfactory flame retardancy. Herein, bio-based cobalt alginate is successfully fabricated and incorporated into EP to prepare EP/Cobalt Alginate composites with better fire safety performance. The addition of cobalt alginate reduces the thermal-decomposition rate, temperature at maximum weight-loss rate of EP, whereas obviously improves the thermal stabilities at a higher temperature range. Furthermore, the addition of cobalt alginate substantially reduces the fire hazard of EP, resulting in 56.2% reduction in peak heat release rate, as well as 17.8% and 56.3% reduction in total smoke production and peak smoke production rate, respectively, compared with EP matrix. Moreover, the presence of cobalt alginate increases smoke-suppressant properties, according to the smoke density test. Additionally, the incorporation of cobalt alginate has no obviously destructive effect on the mechanical properties of EP, while EP/Cobalt Alginate-3 exhibits a 27.0% improvement in impact strength. In prospective, this study may provide a significant method for producing eco-friendly flame retardant EP.     

Effect of SiC nanowhisker addition on microstructure and mechanical properties of regenerated cemented carbides by low-pressure sintering

The hardness and toughness of regenerated cemented carbides, in general, are contradictory. Therefore, it is critical to explore regenerated cemented carbides with both high hardness and high toughness. In this study, regenerated WC-8-wt% Co cemented carbide with SiC nanowhisker were prepared by low-pressure sintering. The influence of SiCw contents on the microstructure and mechanical properties of regenerated WC-8-wt% Co cemented carbide was investigated. The results indicated that the hardness, density, flexural strength, and fracture toughness of regenerated cemented carbide first increased and then decreased with the addition of SiCw. The Vickers hardness, density, flexural strength, and fracture toughness could reach 1575 HV, 14.6 g/cm³, 2204 MPa, 16.85 MPa·m^1/2, respectively, with SiCw content 0.5 wt%, which were increased by 14.4%, 0.7%, 12.2%, and 17.3%, respectively, when compared with the regenerated cemented carbide without SiCw. The lowest friction coefficient and the best wear resistance could be also reached when 0.5-wt% SiCw was added. The fracture mechanism of the regenerated cemented carbide contained both transgranular and intergranular fracture through the microscopic observation of fracture surface via scanning electron microscope.     

Adsorption Mechanism and Electrochemical Properties of Methyl Blue onto Magnetic CoxCu(1–x)Fe2O4 Nanoparticles Prepared via an Alcohol Solution of Nitrate Combustion and Calcination Process

Journal of Inorganic and Organometallic Polymers and Materials - Magnetic CoxCu(1–x)Fe2O4 nanoparticles were prepared via an alcohol solution of nitrate combustion and calcination process....     

喷气燃料微生物ATP荧光检测酶反应体系研究

荧光素酶反应体系是利用ATP生物荧光法检测喷气燃料微生物污染的关键.为了获得最佳的酶反应体系,本研究以ATP标准物质为研究对象,考察了荧光素酶、荧光素和Mg2+的最佳使用量.结果表明:荧光素酶、荧光素和Mg2+的最佳使用量依次为0.05 mg·mL-1、0.08 mg·mL-1和5 mmol·L-1.通过考察Mg2+与ATP相互作用对荧光反应的影响发现,ATP在与荧光素酶之前预先与Mg2+结合,可以提高荧光反应的效率,使相对发光强度有所增加.相比于传统的培养法和HY-LITE JET A1燃料试验,优化的荧光素酶-荧光素反应体系提高了检测效率、大幅度降低了检测成本.     

不同晶型纳米二氧化锰制备及对亚甲基蓝吸附性能

以高锰酸钾（KMnO₄）为氧化剂、硫酸亚铁铵[（NH₄）₂Fe（SO₄）₂]为还原剂,用水热氧化还原反应制备了层状δ-二氧化锰和隧道型α-二氧化锰纳米材料。用X射线衍射（XRD）、扫描电镜（SEM）和氮气吸-脱附技术对产物的晶型、形貌及孔结构进行了表征。实验结果表明,δ-二氧化锰呈花状微球形貌,具有介孔结构（平均孔径为3.4 nm）,BET比表面积为219 m²/g;α-二氧化锰呈纳米线束形貌,具有部分介孔结构（平均孔径为35.7 nm和154.6 nm）,BET比表面积为26 m²/g。研究了不同晶型纳米二氧化锰对亚甲基蓝的吸附性能。实验结果表明,在相同条件下α-二氧化锰的吸附性能优于δ-二氧化锰,且在碱性环境下吸附效果较好。当反应时间达到120 min时,α-二氧化锰和δ-二氧化锰对亚甲基蓝的去除率分别为84.4%和82.9%。     

无机超细粉体改性锂离子电池隔膜的研究进展

综述了近年来无机超细粉体改性锂离子电池隔膜的研究进展,首先介绍了已在锂电隔膜改性上商业应用的Al₂O₃和AlOOH对传统聚烯烃膜和新型静电纺丝膜的改性方法和改性效果,随后又对常规无机材料TiO₂和SiO₂粉体对锂电隔膜的改性进行了叙述,最后对BN等非常规隔膜改性无机材料进行了简介;总结和讨论了无机材料改性后隔膜的组分、结构和性能对锂离子电池综合性能的影响,并对其无机材料改性锂电池隔膜的未来发展趋势进行了展望。     

非贵金属电解水催化剂改性研究进展

氢能作为理想的二次能源,具有能量密度高、清洁无污染等特点,在能源转型过程中将发挥极为重要的作用。电解水制氢被认为是获取氢能最有潜力的绿色工艺,而高效电催化剂是制约电解水制氢快速发展的关键。贵金属催化剂具有优良的电催化性能,但由于成本和储量问题严重限制其推广应用,因而开发低成本高活性的非贵金属催化剂逐渐成为研究热点。为提高非贵金属催化剂的电催化性能,需要对其进行一系列的改性优化工作。综述了近几年国内外非贵金属电解水催化剂的改性研究进展,详细介绍了几何构造（一维、二维、三维结构）和电子调控（组成优化、晶面调控、缺陷构造、杂原子掺杂等）两种非贵金属催化剂的改性方法,并对今后非贵金属电解水催化剂改性发展方向进行了展望。     

AutoCAD系统中实现电子图档模糊查寻的方法

本文讨论了在AutoCAD2000系统中通过图纸标题栏和明细表的少数信息模糊查寻电子图档文件的方法及VBA编程思路，介绍了图档标题栏和明细表数据库的结构，给出了标题栏和明细表信息与图档的路径及文件名之间的查寻关系。     

建筑环境中有机磷酸酯污染特征和控制技术研究进展

有机磷酸酯（Organophosphate esters, OPEs）作为一类阻燃剂和增塑剂,在建筑材料和室内装修材料中广泛使用。由于该类物质主要以物理添加而非化学键合的方式加入到材料中,因此易在使用过程中进入环境。研究表明OPEs普遍存在于室内环境中,并且浓度较高,人体长期暴露在高浓度OPEs的室内环境中,可能存在一定的健康风险。本文在综述了常见OPEs的性质、应用和生物毒性的基础上,总结了其在建筑环境中的污染特征、环境行为和暴露水平,介绍了建筑环境中OPEs的源汇特性、控制技术与人体暴露风险,并对未来研究方向进行了展望。      

GM模型的几何性质及统计检验

以空间向量几何理论为基础，详细地分析了Ｇａｕｓｓ－Ｍａｒｋｏｖ线性模型的几何性质；在实现了模型图形化描述的基础上，利用各解向量的几何及统计性质构造出了不同情形下的统计检验方法和相应的检验统计量，为全面、深入地研究和灵活运用该模型提出了一种简洁直观的数学方法