氧化钴纳米管的制备和模板剂多孔氧化铝的孔洞结构

以草酸电解液制备的多孔氧化铝作为模板,采用硝酸钴溶液浸润法,合成出氧化钴纳米管．通过对分叉氧化钴纳米管成因研究,指出氧气气泡的作用是形成多孔氧化铝纳米孔洞结构的主要驱动力．     

一类非线性项前系数可变号的高阶Duffing方程的周期解存在性问题

利用Fourier级数理论,伯努利数理论和重合度理论研究了一类具偏差变元的高阶泛函微分方程$x^{(m)}(t)+\beta (t)g(x(t-\tau(t)))=p(t)$的周期解问题,得到了周期解存在性的新结论,有意义的是非线性项前的系数$\beta(t)$可变号,但是,周期解先验界估计方法与已有工作不同.     

PID control for chaotic synchronization using particle swarm optimization

In this paper, we attempt to use the proportional-integral-derivative (PID) controller to achieve the chaos synchronization for delayed discrete chaotic systems. Three PID control gains can be optimally determined by means of using a novel optimization algorithm, called the particle swarm optimization (PSO). The algorithm is motivated from the organism behavior of fish schooling and bird flocking, and involves the social psychology principles in socio-cognition human agents and evolutionary computations. It has a good numerical convergence for solving optimization problem. To show the validity of the PSO-based PID control for chaos synchronization, several cases with different initial populations are considered and some simulation results are shown.     

Porous and free-standing Ti_3C_2T_x-RGO film with ultrahigh gravimetric capacitance for supercapacitors

MXene-based electrode materials exhibit favorable supercapacitor performance in sulfuric acid due to praised pseudocapacitance charge storage mechanism.However,self-stacking of conventional MXene electrodes severely restricts their electrochemical performance,especially at high loading.Herein,a flexible cross-linked porous Ti_3C_2T_x-MXene-reduced graphene oxide(Ti_3C_2T_x-RGO) film is skillfully designed and synthesized by microscopic explosion of graphene oxide(GO) at sudden high te mperature.The generated chamber structure between layers could hold a few of electrolyte,leading to a close-fitting reaction at interlayer and avoiding complex ions transmission paths.The Ti_3C_2T_x-RGO film displayed a preferable rate performance than that of pure Ti_3C_2T_x film and a high capacitance of 505 F/g at 2 mV/s.Furthermore,the uniform intralayer structure and unique energy storage process lead to thicknessindependenct electrochemical performances.This work provides a simple and feasible improvement approach for the design of MXene-based electrodes,which can be spread other electrochemical systems limited by ions transport,such as metal ions batteries and catalysis.     

Hydrothermal synthesis, structure and thermal property of a 2-dimensional network: sodium sulfate [Ni(H2O)6(NaSO4)2]

The title compound of [Ni(H₂O)₆(NaSO₄)₂] has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in space group P2₁/c of the monoclinic system in a cell at 293.2 K of a=6.1820(12) Å, b=12.316(3) Å, c=9.0890(18) Å, β=106.03(3)°, and V=665.1(2) Å³. In the title compound, each SO₄ tetrahedron coordinates with three Na(I) ions and each Na(I) connects to three SO₄ tetrahedrons. Such a coordinate model makes up a two-dimensional network having two different kinds of rings and, in the bigger rings, the [Ni(H₂O)₆]²⁺ ions are located. In the solid state, some hydrogen bonds connect the title compound to form three-dimensional networks, stabilizing the crystal structure. Thermogravimetric analysis shows that there are three steps of weight loss from the beginning of 110 °C and the residue may be the mixtures of NiO₂ and Na₂O.     

大孔树脂对对硝基苯胺的吸附行为及其应用研究

研究了溶液中无机盐、pH值对氨基修饰超高交联大孔树脂NDA-99、氧修饰超高交联大孔树脂NDA-150和大孔树脂XAD-4吸附对硝基苯胺的影响。结果表明,无机盐对吸附影响不大;NDA-99、NDA-150在中性范围吸附量最大,XAD-4的吸附量随pH增大而增大;3种树脂的吸附等温线都能很好的利用Freundlich方程进行拟合,吸附皆为放热反应且为优惠吸附;3种树脂的饱和吸附量大小依次为NDA-150>NDA-99>XAD-4。依据上述结论,采用NDA-150处理对硝基苯胺生产母液废水,每批次处理量为40BV,废水中对硝基苯胺浓度由2130mg/L降至9.6mg/L,去除率达99.5%,吸附后的树脂采用95%的乙醇可完全再生,高浓度对硝基苯胺乙醇再生溶液经蒸馏可回收对硝基苯胺和脱附剂,实现了废水治理与资源化的统一。     

具有叶绿素-a碳架的(细菌)卟吩衍生物的合成及其共轭区域变化对光谱性能的影响

以脱镁叶绿酸-a甲酯(MP-a) (1)为起始原料, 通过四氧化锇和高碘酸钠的氧化给出3-位乙烯基和13²-位α-氢的氧化产物2和3, 再用四氧化锇继续氧化卟吩醛2则得到细菌卟吩醛4. 经脱甲酸甲酯和硝酸铊氧化, MP-a (1)转化为焦脱镁叶绿酸衍生物5, 将其进一步用四氧化锇氧化则形成细菌卟吩缩醛6. 卟吩醛2在碱性条件下转化为卟吩e₆三甲酯7, 2与烷基溴化镁的格氏反应给出脱镁叶绿酸醇9, 选择高钌酸四丙基铵(TPAP)和N-甲基吗啉N-氧化物将3-位羟基氧化成羰基, 所生成的卟吩二酮10在酸性条件下脱去甲酸甲酯生成焦脱镁叶绿酸衍生物11, 用四氧化锇对7和11实施氧化, 则分别转化为细菌卟吩衍生物8和12. 同时, 讨论了叶绿素衍生物的共轭区域变化对其光谱性能的影响. 所合成的新卟吩和细菌卟吩衍生物均经UV, IR, ¹H NMR及元素分析证明其结构.     

Investigation of disused artificial zeolite on the properties of metakaolin-based geopolymer

Artificial zeolite deactivated after repeated utilization and the properties compromised formed disused zeolite. In the past, disused artificial zeolite landfilled after incineration and results in environmental pollution and resource waste. This work synthesized a new type of a new metakaolin-based geopolymer prepared by using disused artificial zeolite and metakaolin. The influence of disused artificial zeolite on the performance and pore structure of the final products was investigated. The bulk density and compressive strength of the samples were approximate 457 kg/m³ and 1.3 MPa, respectively. Moreover, disused artificial zeolite has good mesoporosity and strong foaming performance. The incorporation of disused artificial zeolite generated more pores with smaller diameters and pronounced pore grading, adjust the pore structure of the samples, forming multiscale pore structured structures. This study described one application method of disused artificial zeolite in geopolymers, synthesized a new metakaolin-based geopolymer, which is significant for exploring the potential utilization value of disused artificial zeolite.     

非晶态硅酸盐介观团粒结构模型及其参数

非晶态硅酸盐是典型的近程有序,远程无序的准稳定态体系,采用分数维理论与X射线小角散射(SAXS)、拉曼光谱(RS)、透射电子显微镜(TEM)等分析技术相结合,对高温熔融法和溶胶凝胶法合成的CaO-Al2O3-SiO2及Na2O-Al2O3-SiO2系列低维非晶硅酸盐试样进行了网络分数维、微粒微孔分数维、网络自相似比、回旋半径、微孔体积百分率、团粒尺度和微孔尺度等介观参数群的定量测定及研究,获得了低温硅酸盐凝胶、高温硅酸盐熔体(仿岩浆熔体)之淬火玻璃相均具有纳米级(几个nm至几十nm)统计性自相似团粒结构的结论,进而建立了介观团粒结构模型,揭示了该结构模型内各介观参数与其宏观参量的相关性,从而为非晶硅酸盐提供了一整套介观定量结构参数,确定了岩浆熔体是准稳定的、可演变的分数维体系,对探索自然界岩浆的地球化学特征以及低维复合材料结构性能的改进具有重要的理论和实用意义.     

钴岛膜上对巯基苯甲酸的表面增强红外吸收光谱

通过置换反应在金属铝表面制备了表面没有任何保护剂且具有红外增强作用的钴岛膜,用SEM、XRD和表面增强红外光谱对其形貌和性质进行表征。 结果表明,铝片上沉积出的钴呈岛状结构,钴岛膜由二次钴粒子和一次钴粒子通过密堆积的方式构成;首次发现具有这种特殊结构的钴对吸附于其表面的有机分子的红外吸收光谱有较大的增强作用,用此钴岛膜对1 mmol/L的对巯基苯甲酸的红外光谱研究时得到很好的红外增强信号,使得表面增强红外光谱可以用于痕量分析、检测。