肉桂醛衍生物的分子二阶非线性光学效应的理论研究

采用ＣＮＤＯ／Ｓ—ＣＩ方法结合引入外场的微扰理论．计算了一系列内桂醛衍生物的分子二阶极化率，并且从微观上探讨了该类化合物取代基的电子性质、取代基位置及其取代数目对分子二阶非线性光学系数的影响。结果表明，该类化合物有较高的分子二阶极化率；取代基的电子性质和取代方式对其有明显的影响。     

高密度笼状烃衍生物的合成及热性能

以环戊二烯(CPD)或甲基环戊二烯(MCPD)为原料,通过Diels-Alder反应、[2+2]环加成反应、羰基和含氮试剂的加成反应合成了五环[5.4.0.02,6.03,10.05,9]十一烷、甲基五环[5.4.0.02,6.03,10.05,9]十一烷的腙类衍生物,通过质谱、红外光谱、核磁共振氢谱等确证了产物结构,并通过PDSC研究了部分化合物在高温下的热分解性能。高张力笼状烃衍生物可改善笼状烃的挥发性能,分解过程放热,且分解温度随压力增大略有升高,可用作新型炸药或高能燃料组分。     

The effect of thiophene sequence separation on air-stable organic thin-film transistor materials

The relationship between thiophene sequences and organic thin-film transistor (OTFT) characteristics was studied to determine their effect on ionization potential, molecular orientation, and air stability. Two types of molecular structures were used: continuous sequence and divided sequence thiophenes. The length of thiophene sequence did not affect FET characteristics but did affect ionic potential and air stability. Furthermore, materials with divided thiophene sequences showed no change in OTFT characteristics when exposed to air. These results suggest that separation of thiophene sequences can improve air stability, which is a problem of thiophene-based materials.     

Lithiation MXene Derivative Skeletons for Wide-Temperature Lithium Metal Anodes

Lithium (Li) metal, as an appealing candidate for the next-generation of high-energy-density batteries, is plagued by its safety issue mainly caused by uncontrolled dendrite growth and infinite volume expansion. Developing new materials that can improve the performance of Li-metal anode is one of the urgent tasks. Herein, a new MXene derivative containing pure rutile TiO₂ and N-doped carbon prepared by heat-treating MXene under a mixing gas, exhibiting high chemical activity in molten Li, is reported. The lithiation MXene derivative with a hybrid of LiTiO₂-Li₃N-C and Li offers outstanding electrochemical properties. The symmetrical cell assembling lithiation MXene derivative hybrid anode exhibits an ultra-long cycle lifespan of 2000 h with an overpotential of ≈30 mV at 1 mA cm⁻², which overwhelms Li-based anodes reported so far. Additionally, long-term operations of 34, 350, and 500 h at 10 mA cm⁻² can be achieved in symmetrical cells at temperatures of −10, 25, and 50 °C, respectively. Both experimental tests and density functional theory calculations confirm that the LiTiO₂-Li₃N-C skeleton serves as a promising host for Li infusion by alleviating volume variation. Simultaneously, the superlithiophilic interphase of Li₃N guides Li deposition along the LiTiO₂-Li₃N-C skeleton to avoid dendrite growth.     

二茂铁及其衍生物修饰电极的研究

二茂铁及其衍生物修饰电极在电催化、电分析和生物传感器等方面具有重要的应用前景。本文对二茂铁及其衍生物修饰电极分类、制备、特点及其应用等方面的研究现状作了归纳和评述。提出了今后研究工作的方向。     

Oxidative desulfurization using graphene and its composites for fuel containing thiophene and its derivatives: An update review

Oxidative desulfurization, in which the aromatic sulfur containing compounds are oxidized to their analogical sulfones and subsequently extracted, has assured to be one of the exceedingly effective desulfurization processes for resulting ultra-low sulfur import fuels. The oxidative desulfurization process using graphene oxide has attracted significant interest for sulfur removal from fuels. In this survey, we discussed systematically the techniques of desulfurizations in catalytic oxidation, including the role of graphene as a supported catalyst, the research results of oxidative desulfurization using graphene oxide and provided the factors affecting the desulfurization process. We also debate the challenges counterattack the use of graphene oxide in this view, including their preparation methods and their efficiency and stability as a supported catalyst. Also, there are some of the desulfurization processes currently under investigation such as oxidation, biodesulfurization, and adsorption was outlined in brief. The combustion of fossil fuels containing sulfur compounds emits some of the sulfur oxides which considered a harmful influence on human health and the surrounding environment as well as the economy. It can be concluded that GO remains a kind of ideal supported catalysts to recognize a pure fuel in the near futurity due to their eligible physicochemical characteristics.     

笼形含能化合物热分解研究进展

笼形含能化合物因能量高、密度大而成为当前含能材料领域的研究热点,阐明其热分解机理对于深入研究其爆轰机理及提高热稳定性均有重要意义。以笼形骨架为线索,介绍了金刚烷衍生物、立方烷衍生物和异伍兹烷衍生物三类笼形含能化合物的热分解研究进展,总结了上述三类笼形化合物热分解规律:金刚烷衍生物热分解始于取代基且具有"桥头C"效应,立方烷衍生物热分解通常始于笼形结构的C-C键,多硝基异伍兹烷热分解一般始于脱硝基。后续研究应进一步丰富笼形含能化合物的种类,开展笼形化合物热分解的系统性研究,特别是笼状骨架的热分解机理研究。     

叶绿素及其Cu、Zn衍生物的伪装性能研究

研究了类叶绿素活性颜料在伪装应用中的光谱性能及光稳定性问题。从绿色植被的色素着手,分析了叶绿素的性质及影响其降解的原因,用Cu2+、Zn2+金属离子替代天然叶绿素中的Mg2+,制备了叶绿素衍生物,并通过光谱特性和光稳定性对叶绿素衍生物的特性进行了比较分析。研究结果表明,从光谱性能和稳定性两方面综合考虑,Cu叶绿素更适合作为叶绿素修饰目标来提高颜料的稳定性,从而为新型光学伪装涂料的制备提供材料基础。     

Image structure preserving denoising using generalized fractional time integrals

A generalization of the linear fractional integral equation u(t)=u₀+∂^−αAu(t), 1<α<2, which is written as a Volterra matrix-valued equation when applied as a pixel-by-pixel technique is proposed in this paper for image denoising (restoration, smoothing, etc.). Since the fractional integral equation interpolates a linear parabolic equation and a hyperbolic equation, the solution enjoys intermediate properties. The Volterra equation we propose is well-posed for all t>0, and allows us to handle the diffusion by means of a viscosity parameter instead of introducing nonlinearities in the equation as in the Perona-Malik and alike approaches. Several experiments showing the improvements achieved by our approach are provided.