Painlevé Analysis,Soliton Collision and B?cklund Transformation for the (3+1)-Dimensional Variable-Coefficient Kadomtsev–Petviashvili Equation in Fluids or Plasmas

In this paper, we investigate a(3+1)-dimensional generalized variable-coefficient Kadomtsev–Petviashvili equation, which can describe the nonlinear phenomena in fluids or plasmas. Painlev′e analysis is performed for us to study the integrability, and we find that the equation is not completely integrable. By virtue of the binary Bell polynomials,bilinear form and soliton solutions are obtained, and B¨acklund transformation in the binary-Bell-polynomial form and bilinear form are derived. Soliton collisions are graphically discussed: the solitons keep their original shapes unchanged after the collision except for the phase shifts. Variable coefficients are seen to affect the motion of solitons: when the variable coefficients are chosen as the constants, solitons keep their directions unchanged during the collision; with the variable coefficients as the functions of the temporal coordinate, the one soliton changes its direction.     

染料敏化太阳能电池器件的研究进展

染料敏化太阳能电池（dye-sensitized solar cells,DSCs）作为一种新型的薄膜太阳能电池,是目前光伏电池领域的一个研究热点.文章首先介绍此类电池的基本结构、工作原理、影响电池性能的关键材料及其最新研究进展,而后重点分析了器件集成的设计模式,并对各种模式的研究进展与存在的问题进行了探讨.     

开口箭属植物甾体皂苷成分及13C NMR波谱特征

对开口箭属植物近20年的甾体皂苷类成分的结构及波谱学研究内容进行综述. 目前已从开口箭属植物中分离鉴定了53个新甾体皂苷,其中27个螺甾烷型甾体皂苷,24个呋甾烷型甾体皂苷,2个变形螺甾烷型甾体皂苷. 不同类型的甾体皂苷其¹³C NMR波谱在骨架类型、取代基类型及位置等方面均具有其特征性. 通过总结开口箭属甾体皂苷¹³C NMR波谱特征规律,对进一步鉴定该类化合物结构以及进行波谱数据的归属都起着重要的作用.     

密度渐变多层碳气凝胶靶型的制备

 以间苯二酚-甲醛为原料,结合自制活动式微模具成型工艺制备不同厚度和密度的碳气凝胶薄片,采用密度为10 mg·cm^-3的SiO₂溶胶为“粘合剂”,获得单元薄片厚度在100～580 μm,密度在50～400 mg·cm^-3范围内变化的5层密度渐变碳气凝胶靶型。重点研究了该特殊靶型内部C/SiO₂气凝胶层间界面情况。采用场发射扫描电镜（FESEM）,X射线相衬成像仪等对靶型整体结构及碳气凝胶单元薄片表面和内部微观结构进行了表征。结果表明：胶粘层SiO₂气凝胶厚度约为15 μm,厚度一致,远小于碳气凝胶层厚度且与碳气凝胶薄片的胶粘程度较好,界面平整,靶结构均匀。     

两个含2-(2-吡啶基)咪唑衍生物的铜(Ⅱ)配合物的合成、晶体结构及发光性质

通过自然挥发法,合成了2个配合物[Cu(DMPM)₂(Bz)][Cu(DMPM)(Bz)₃]·2H₂O(1)和[Cu(PMA)Cl₂](2)(DMPM=4,5二甲基2(2吡啶基)咪唑,PMA=[2(2吡啶基)咪唑1基]乙酸乙酯,Bz=苯甲酸根),并对其荧光、热稳定性及电子自旋共振光谱进行了研究。结构分析结果表明化合物1属于三斜晶系,P1空间群;化合物2属于单斜晶系,P2₁/c空间群。化合物1通过氢键的作用形成了三维超分子框架,化合物2通过氢键作用形成了二维的层状结构。     

基于二乙醇胺配体的[Dy2Co8]型配合物的合成、晶体结构和磁性分析

以二乙醇胺为配体合成了一种具有[Dy₂Co₈]核结构的配合物[Dy₂Co₈（L）₄（HL）₄（HCOO）₄（OH）₂Cl₂（CH₃OH）₂]Cl₂·4CH₃OH·2H₂O（1）（H₂L=二乙醇胺）,并对其进行了X射线单晶衍射、红外光谱、元素分析和磁性表征。该配合物属于三斜晶系,P1空间群。晶体学数据：a=1.160 4（8）nm,b=1.322 7（9）nm,c=1.465 3（9）nm,α=71.181（7）°,β=67.638（7）°,γ=65.939（7）°。在晶体结构中,每一个Dy（Ⅲ）都是九配位,而每一个Co（Ⅱ）均为六配位。     

Synthesis and Crystal Structure of a New [Mn_2Ni_2] Cubane Complex

A new Mn2Ni2 cubane complex has been synthesized and characterized by single-crystal X-ray diffraction,FT IR spectra and elemental analysis.The title compound [MnIII2NiII2(hmp)4(N3)4(O2CR)2](hmp-is the anion of 2-pyridinemethanol and O2CR-is α-na-phthaleneacetate)crystallizes in the monoclinic system,space group P21/c with a = 10.519(5),b = 22.109(10),c = 23.235(9),β = 106.096(17)o,C48H42Mn2N16Ni2O8,Mr = 1198.28,V = 5192(4)3,Dc = 1.533 g/cm3,F(000)= 2448,μ = 1.258 cm1,Z = 4,the final R = 0.0875 and wR = 0.2020 for 3398 reflections with I > 2σ(I).X-ray diffraction analysis reveals that each Mn(III)center is octahedrally coordinated by two nitrogen atoms of azide anions and three oxygen atoms from three 2-pyridinemethanol anion ligands together with one oxygen atom from naphthaleneacetate.Each Ni(II)is octahedrally coordinated by two nitrogen atoms of 2-pyridinemethanol anion ligands as well as three oxygen atoms from three 2-pyridinemethanol anion ligands and one oxygen atom from naphthaleneacetate.     

Ca掺杂的Ba2Al2Si10N14O4:Eu2+荧光粉发光性能

通过固相反应制备了系列Ca掺杂的Ba2Al2Si10M14O4:Eu2+色荧光粉,发现当半径较大的Ba被Ca取代后导致了晶格的收缩,通过X射线衍射(XRD)测量和Unitcell软件计算发现Ca的最大掺杂量在20％.Ca掺人Eu0.4Ba1.6Al2Si10N14O4荧光粉后,可有效地提高光转换性能,并使激发光谱发生一定程度的红移和宽化,从而被近紫外宽波段光有效激发,与近紫外LED的发射光谱匹配.同时Ca的掺杂也使发射光谱发生了可控的红移,可以由520 nm的绿光红移至548 nm的黄光区域.进一步发现Eu2+的淬灭浓度随着20％ Ca的掺入而降低,这是由于Ca掺入导致的晶格收缩使Eu2+离子间距离减小.最后在CIE色度图中对不同Ca,Eu浓度的荧光粉的色坐标位置进行比较,发现可通过Ca,Eu浓度的变化在很大范围内调制荧光粉的发光性能.     

Simulating the resonance-mediated (1+2)-three-photon absorption enhancement in Pr3+ ions by a rectangle phase modulation

Enhancing the upconversion luminescence of rare earth ions is crucial for their applications in the laser sources, fiber optic communications, color displays, biolabeling, and biomedical sensors. In this paper, we theoretically study the resonance-mediated (1+2)-three-photon absorption in Pr³⁺ ions by a rectangle phase modulation. The results show that the resonance-mediated (1+2)-three-photon absorption can be effectively enhanced by properly designing the depth and width of the rectangle phase modulation, which can be attributed to the constructive interference between on-resonant and near-resonant three-photon excitation pathways. Further, the enhancement efficiency of resonance-mediated (1+2)-three-photon absorption can be affected by the pulse width (or spectral bandwidth) of femtosecond laser field, final state transition frequency, and absorption bandwidths. This research can provide a clear physical picture for understanding and controlling the multi-photon absorption in rare-earth ions, and also can provide theoretical guidance for improving the up-conversion luminescence.     

电动机与发电机二合一原理演示仪

介绍一款电动机与发电机二合一原理演示仪,借用直流电动机线圈转动的动力带动发电线圈在磁场中转动发电,并用引入单片机等电子控制和电子显示装置.