{110}晶面暴露的BiOCl制备及光催化活性研究

利用溶剂热法可控制备了{110}晶面暴露的Bi OCl纳米微球并以甲基橙染料为目标污染物考察其光催化性能.利用XRD和SEM对纳米微球的晶体结构及形貌进行表征.通过与共沉淀法制备氯氧铋的光催化性能对比发现,在降解甲基橙溶液的过程中,高能晶面{110}暴露的Bi OCl纳米微球在紫外光和可见光下都展示出较高的光催化活性.     

高校物理系天体物理导论的教学

针对目前国内高校物理系本科段天体物理导论教学开展不充分的现状,从物理系通常的课程设置,天体物理导论教学目的、教材的选择、教学方法与考核等方面,简要介绍了在高校物理系如何开展本科段天体物理教学.     

Synthesis, supramolecular structures and luminescent properties of quinacridone derivatives bearing carbazole groups

The syntheses of three carbazyl-containing quinacridone derivatives, N,N’-di((N-carbazyl)-n-butyl) quinacridone (DCBQA), N,N’-di((N-carbazyl)-n-hexyl)quinacridone (DCHQA) and N,N’-di((N-carbazyl)-n-octyl)quinacridone (DCOQA), are reported, and the photoluminescent (PL) characteristics are pre- sented. The single crystal X-ray structures of DCBQA, DCHQA and DCOQA are investigated. The crystal of DCBQA is characterized by intermolecular π…π interactions between quinacridone cores and carbazole moieties result...     

Sign series entropy analysis of short-term heart rate variability

Complexity and nonlinearity approaches can be used to study the temporal and structural order in heart rate variability （HRV） signal, which is helpful for understanding the underlying rule and physiological essence of cardiovascular regulation. For clinical applications, methods suitable for short-term HRV analysis are more valuable. In this paper, sign series entropy analysis （SSEA） is proposed to characterize the feature of direction variation of HRV. The results show that SSEA method can detect sensitively physiological and pathological changes from short-term HRV signals, and the method also shows its robustness to nonstationarity and noise. Thus, it is suggested as an efficient way for the analysis of clinical HRV and other complex physiological signals.     

大麻杆活性炭对染料吸附性能的研究

以天然大麻杆为原料,采用磷酸活化法制备大麻杆活性炭。利用低温氮吸附对样品的比表面积与孔结构进行了表征,并利用亚甲基蓝与甲基橙两种染料对活性炭在液相中的吸附行为进行了研究。结果表明,样品的比表面积与中孔孔容随着活化温度的升高而增大,在500℃时达到最大值1325.73m2/g,随后由于磷酸过度活化导致结构坍塌致使各参数有所降低;在25℃下,大麻杆活性炭对亚甲基蓝与甲基橙的吸附等温线均遵循Langmu ir方程,单层吸附量分别达到471.698mg/g和363.64mg/g,吸附量主要受微孔孔容、染料分子尺寸及染料分子与活性炭表面作用力三者的共同影响。吸附动力学能够很好的符合准二级动力学方程,且亚甲基蓝的吸附速率高于甲基橙。     

磷酸活化汉麻布活性炭纤维的孔结构

以汉麻布为原料,采用磷酸活化法制备了汉麻布活性炭纤维,并利用低温氮气吸附和密度泛函理论(DFT)对样品的孔结构进行了分析。结果表明,随着活化温度的升高,磷酸活化的汉麻布活性炭纤维的BET比表面积和总孔容都呈现先增大后减小的变化趋势。不同方法计算得到的样品比表面积值呈相同的变化规律。样品的孔分布集中在2 nm以下的微孔范围内,既有极微孔又有超微孔,只有少量中孔,基本没有大孔。所有样品的孔径在微孔范围内都呈现多峰分布,孔径≤1 nm和1~2 nm的范围内分别都出现了2个峰值孔径。微孔孔容基本上随活化温度的升高而增加,而中孔孔容的数值则整体上变化不大。样品表面能量分布较宽,并呈现有多个不连续峰值的多峰分布,宽的孔径分布导致宽的表面能量分布和较多的能量峰值,并使吸附位的种类也随之增多。     

基于博弈论集对分析模型的机坪管制运行风险评价

考虑大型机场机坪管制运行风险评价因素的不确定性,提出了基于博弈论集对分析模型的机坪管制运行风险评价模型。根据机坪管制运行的业务流程,构建了涵盖“人、机、环、管”四个方面的机坪管制运行风险评价指标体系。基于博弈论思想将层次分析法得到的主观权重和熵权法得到的客观权重进行最优组合来确定各指标权重;根据集对分析理论的同异反模型来计算样本的综合联系度,由此确定机坪运行风险等级和发展趋势,并提出合理的安全建议。最后通过实例验证,得到各样本评价结果与实际情况基本相符,证明了该评价模型的可靠性。     

麦草制浆造纸的利弊及对策

为了解决我国广泛采用的麦草制浆造纸生产中存在的许多问题,如易糊网、断头等,从原料特性入手,分析了造成这些问题的原因并提出了一些解决措施,也简单介绍了国内外用麦草制浆造纸的技术成果,还对选用适宜的工艺流程与设备提出了一些建议。     

Three-dimensional analysis of a thick FGM rectangular plate in thermal environment

The thermal behavior of a thick transversely isotropic FGM rectangular plate was investigated within the scope of three-dimensional elasticity. Noticing many FGMs may have temperature-dependent properties, the material constants were further considered as functions of temperature. A solution method based on state-space formulations with a laminate approximate model was proposed. For a thin plate, the method was clarified by comparison with the thin plate theory. The influences of material inhomogeneity and temperature-dependent characteristics were finally discussed through numerical examples.     

Formation of superthick Al-based amorphous ribbon

The Al-Ni-La-Ce-Pr-Nd amorphous ribbon with a super-thickness of 140μm has been produced by the melt spinning technique.The thickness is as twice as that achieved by the melt spinning technique in the corresponding period (the largest thickness of 65μm）.The crystallization was characterized by using a differential scanning calorimetry.The activation energies are calculated based on the Kissinger equation and the effects of the La,Ce,Pr and Nd on the glass forming ability of Al-based alloy are discussed in the paper.