Low-temperature solution combustion synthesis of high performance LiNi0.5Mn1.5O4

High-voltage LiNi_0.5Mn_1.5O₄ spinels were synthesized by a low temperature solution combustion method at 400 °C, 600 °C and 800 °C for 3 h. The phase composition, structural disordering, micro-morphologies and electrochemical properties of the products were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and constant current charge–discharge test. XRD analysis indicated that single phase LiNi_0.5Mn_1.5O₄ powders with disordered Fd-3m structures were obtained by the method at 400 °C, 600 °C and 800 °C. The crystallinity increased with increasing preparation temperatures. XRD and FTIR data indicated that the degree of structural disordering in the product prepared at 800 °C was the largest and in the product prepared at 600 °C was the least. SEM investigation demonstrated that the particle size and the crystal perfection of the products were increased with increasing temperatures. The particles of the product prepared at 600 °C with ~200 nm in size are well developed and homogeneously distributed. Charge/discharge curves and cycling performance tests at different current density indicated that the product prepared at 600 °C had the largest specific capacity and the best cycling performance, due to its high purity, high crystallinity, small particle size as well as moderate amount of Mn³⁺ ions.     

微藻制备生物柴油的技术进展

生物柴油是一种新型的可再生能源,是石化柴油的替代品。微藻种类多、光合作用效率高、生长速度快、生物产量大、含油量高,已成为发展生物柴油产业的最有潜力的原料之一。综述了微藻制备生物柴油的优点及研究进展。针对目前微藻生物柴油存在的瓶颈问题和实际需求,指出未来研究和发展的主要方向。     

Combustion, performance and emission characteristics of a DI diesel engine fueled with ethanol-biodiesel blends

In this study, Euro V diesel fuel, biodiesel, and ethanol-biodiesel blends (BE) were tested in a 4-cylinder direct-injection diesel engine to investigate the combustion, performance and emission characteristics of the engine under five engine loads at the maximum torque engine speed of 1800 rpm. The results indicate that when compared with biodiesel, the combustion characteristics of ethanol-biodiesel blends changed; the engine performance has improved slightly with 5% ethanol in biodiesel (BE5). In comparison with Euro V diesel fuel, the biodiesel and BE blends have higher brake thermal efficiency. On the whole, compared with Euro V diesel fuel, the BE blends could lead to reduction of both NO_x and particulate emissions of the diesel engine. The effectiveness of NO_x and particulate reductions increases with increasing ethanol in the blends. With high percentage of ethanol in the BE blends, the HC, CO emissions could increase. But the use of BE5 could reduce the HC and CO emissions as well.     

The influence of n-butanol/diesel fuel blends utilization on a small diesel engine performance and emissions

Nitrogen oxides and smoke emissions are the most significant emissions for the diesel engines. Especially, fuels containing high-level oxygen content can have potential to reduce smoke emissions significantly. The aim of the present study is to evaluate the influence of n-butanol/diesel fuel blends (as an oxygenation additive for the diesel fuel) on engine performance and exhaust emissions in a small diesel engine. For this aim five-test fuels, B5 (contains 5% n-butanol and 95% diesel fuel in volume basis), B10, B15, B20 and neat diesel fuel, were prepared to test in a diesel engine. Tests were performed in a single cylinder, four stroke, unmodified, and naturally aspirated DI high speed diesel engine at constant engine speed (2600 rpm) and four different engine loads by using five-test fuels. The experimental test results showed that smoke opacity, nitrogen oxides, and carbon monoxide emissions reduced while hydrocarbon emissions increased with the increasing n-butanol content in the fuel blends. In addition, there is an increase in the brake specific fuel consumption and in the brake thermal efficiency with increasing n-butanol content in fuel blends. Also, exhaust gas temperature decreased with increasing n-butanol content in the fuel blends.     

无卤膨胀阻燃长玻纤增强聚丙烯性能研究*

利用无卤膨胀阻燃剂(IFR)阻燃长玻纤增强聚丙烯(LGFPP)复合材料,研究IFR的添加量对复合材料阻燃性能、热稳定性能、燃烧性能和力学性能的影响。结果表明,加入IFR使复合材料燃烧后生成了具有阻燃作用的炭层,显著提高了复合材料的阻燃性能。随IFR添加量的增加,复合材料的极限氧指数(LOI)逐渐提高,热释放速率峰值及其平均值、总热释放速率和生烟速率逐渐降低,力学性能略有下降。当IFR质量分数为20%时,复合材料的LOI和垂直燃烧等级分别达到了24.4%和UL 94 V-0级。     

低阶煤低温干馏炉中低温燃烧室温度场分布模拟及结构优化

用CFD Fluent 6.3软件对自主研发的与增收低温焦油炭化室相配套的褐煤热解旋流式低温燃烧室（1500 mm×200 mm×1500 mm）内温度场分布进行了模拟研究和结构优化,结果表明：在燃烧室内坐标为（?25,550,0）和（25,?550,0）处设计两个关于燃烧室中央轴对称半径为100 mm的130°圆弧形挡板,燃烧室内平均温度（755 ℃）满足褐煤低温热解需求（500～650 ℃）;Realizable k-ε湍流模型、P-1辐射模型和非预混燃烧模型适用于计算焦炉煤气和空气低温燃烧室内温度场分布,模拟计算结果与实验结果基本吻合,误差波动幅度为50～70 ℃,满足工业要求。     

TRIZ创新理论在工作的实际应用——纯氧助燃技术在浮法玻璃熔窑上的应用研究

通过TRIZ创新理论,对传统玻璃行业节能减排、提高玻璃质量进行创新性研究。纯氧助燃技术的开发应用,改变了传统浮法玻璃窑炉的火焰特性,大大地降低了玻璃熔窑能耗及玻璃窑炉烟气中的NOx排放,提高了玻璃质量,对我国浮法玻璃技术的提高具有现实意义。     

电磁场强度对层流火焰和NO生成特性的影响

在液化气与空气燃烧的层流火焰两侧施加放电磁场,测定磁场强度,采用双铂铑热电偶和综合烟气分析仪检测层流自由射流火焰温度和NO浓度,分析了不同磁场强度下层流自由射流火焰特性和NO生成特性. 结果表明,在电磁场作用下火焰长度变短,火焰下部直径增大;随磁场强度增大,火焰面下部温度提高. 电磁场可减少火焰中N, HCN, CN等离子和离子团与氧的碰撞几率,导致NO浓度降低,最大下降值为4.26 mg/m3,最大降幅为78.60%.     

全氧燃烧技术在高硼硅浮法玻璃窑炉上的应用探讨

介绍了全氧燃烧技术的特点和高硼硅玻璃的生产现状,探讨了全氧燃烧高硼硅浮法玻璃窑炉的结构特点,指出了全氧燃烧技术在高技术玻璃生产上的应用前景。     

复合改性双基推进剂燃烧性能研究

采用近距摄影、扫描电镜、电子能谱、X-射线衍射等多种技术,对CMDB（复合改性双基）、Al-CMDB、Mg／Al-CMDB推进剂燃速和火焰结构进行了研究。结果表明,在CMDB推进剂中添加A1、Mg／A1等金属燃料,改变了火焰结构;Mg／Al合金可提高金属燃料Al粉的燃烧效率。