苯并18－冠－6与M2[Pt(SCN)6](M=Na,K)配合物的合成、结构

合成了苯并18－冠－6(B18C6)与M2[Pt(SCN)6](M=Na,K)的配合物：{[Na (B18C6)]6[Pt(SCN)6]}[Pt(SCN)6](SCN)2(1),[K(B18C6)]2[Pt(SCN)6]·4H2O(2). 通过元素分析、红外光谱、单晶X射线衍射进行了表征.1为单斜晶系、空间群R3^-, a=b=1.9933(3)nm,c=2.9760(6)nm,α=β=90°,γ=120°,V=10.240(3)nm^3,Z=3, Dcalcd=1.564g/cm^3,F(000)=4908,R1=0.0535,wR2=0.1030.2为三斜晶纱、空间群 P1^-,a=1.1692(3)nm,b=1.1853(4)nm,c=1.2381(5)nm,α=61.419(5)°,β=80.757 (8)°,γ=89.003(5)°,V=1.4836(9)nm^3,Z=1,Dcalcd=1.476g/cm^3,F(000)=666, R1=0.0696,wR2=0.1346.1由{[Na(B18C6)]6[Pt(SCN)6]}^4+配阳离子、[Pt(SCN)6] ^2-配阴离子和SCN^-阴离子组成。相邻{[Na(B18C6)]6[Pt(SCN)6]}^4+通过Na-O键 形成三维网状结构。[Pt(SCN)6]^2-和SCN^-仅起平衡电荷的作用.2由两个[K (B18C6)]^+配阳离子和一个[Pt(SCN)6]^2-配阴离子组成。相邻[K(B18C6)]2[Pt (SCN)6]离子对通过K－O键形成一维链状结构。     

Synthesis and Structural Characterization of One New Polyoxotungstate Connected via Potassium Cations with aThree-dimensional Framework: H_6Na_2K_4(H_2W_(12)O_(42))Cl_2·14H_2O

One new polyoxotungstate complex H_6Na_2K_4(H_2W_(12)O_(42))Cl_2·14H_2O 1 has been prepared in the beaker solution and characterized by elemental analysis and IR spectroscopy. Crystal data: H36Cl2K4W12Na2O56, Mr = 3411.77, monoclinic, space group P21/c, a = 11.5734(16), b = 14.3136(19), c = 15.459(2) , β = 105.601(2)°, V = 2466.5(6)3, Z = 2, Dc = 4.594 g/cm3, F(000) = 3008, μ = 28.447 mm-1, R = 0.0574 and wR = 0.1239 (I > 2σ(I)). Single-crystal X-ray diffraction analysis results reveal that a three-dimensional architecture in the title compound is constructed from the H2W12O4210- units linked by potassium.     

瑞利粒子在贝塞尔光束中的横向受力

为寻找捕获瑞利粒子的最佳光场,利用电磁模型推导了贝塞尔光束捕获粒子的最小半径的表达式,并数值计算了瑞利粒子在贝塞尔光束和高斯光束中所受的横向力和势阱的深度。结果表明:当激光功率为4 W时,贝塞尔光束仅能在光轴处稳定地捕获瑞利粒子;当激光功率达到6 W时,贝塞尔光束能够在光轴和次极大位置捕获瑞利粒子。在相同的激光参数条件下,高斯光束无法克服布朗运动的影响稳定地捕获瑞利粒子,贝塞尔光束更有利于捕获瑞利粒子。     

2-吡嗪羧酸银的合成、晶体结构及热化学性质

以二次蒸馏水为溶剂,合成了2-吡嗪羧酸银(Ag(pyza)(s)),并利用X-射线单晶衍射法表征了其晶体结构.根据晶体结构数据计算得到2-吡嗪羧酸银的晶格能为554.10 kJ/mol.利用TG/DSC热分析技术研究了该化合物的热分解过程;用精密自动绝热热量计测量了其在78~378 K温区的低温热容;通过最小二乘法拟合得到了摩尔热容随折合温度变化的多项式方程,利用此方程计算出该化合物的舒平热容和各种热力学函数.通过设计合理的热化学循环,利用等温环境溶解-反应热量计分别测定了所设计热化学反应的反应物和产物在选定溶剂中的溶解焓,通过计算得到反应的反应焓为:?(31.919±0.526)kJ/mol.利用Hess定律计算出2-吡嗪羧酸银的标准摩尔生成焓为:?(243.659±1.298)kJ/mol.利用紫外-可见光谱仪对反应物和产物溶解所得溶液分别进行测量,从而证实了所设计热化学循环的可靠性.     

硬球势中相对论费米气体的热力学性质

用量子统计与数值模拟相结合的方法,在广义外势中相对论费米系统的热力学量的基础上,研究硬球势中相对论费米气体的热力学性质.得到了考虑相对论效应时系统的内能和热容量的解析表达式,分析了相对论效应对内能和热容量的影响.研究表明:与非相对论比较,相对论费米气体的内能和热容量更高;相对论特征量越大,热容量的转折温度越低;随着温度的升高,特征量越大,内能就越大.     

基于高双折射光纤布拉格光栅的自动增益控制掺铒光纤放大器

掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益,提出了一种新颖的自动增益控制掺铒光纤放大器的结构:即采用高双折射光纤布拉格光栅产生抽运光,其写制光栅的波峰对应的波长分别为1549.3 nm和1549.83 nm,波长间隔为0.53 nm。通过调整偏振控制器,就实现了单激光或双激光的增益控制。这种设计增益控制范围为40 nm(1530~1570 nm),当输入功率在-40~-15 dBm的动态范围内,双激光增益控制的掺铒光纤放大器的平均增益和噪声系数分别约为22.22 dB和8.69 dB,而它们的漂移分别被钳制在0.69 dB和1.51 dB。系统性能测试表明:双激光控制掺饵光纤放大器在稳定性方面比单激光有着明显的优势。     

微米/纳米相结合的三维金属铝图案

利用光刻，反应离子刻蚀以及电化学阳极氧化技术在铝基底上构建出了微米纳米相结合的三维金属铝图案。首先在铝片的表面形成一层具有图案的二氧化硅阻碍层，阳极氧化过程中，在二氧化硅阻碍层之下会形成侧向生长的倾斜孔道和残留的金属铝微结构。形成机制可阐述为：由于表面二氧化硅阻碍层的存在造成局域电场方向的偏折，影响到反应过程中离子的输运，从而导致侧向倾斜孔的形成，而在远离阻碍层的区域孔道则会正常垂直表面向下生长。这种垂直与侧向阳极腐蚀的同时进行导致在二氧化硅阻碍层之下形成了金属铝微结构。     

A Room-Temperature Multiwavelength Erbium-Doped Fibre Laser by Exploiting Polarization Hole Burning

Multiwavelength operation of a linear cavity erbium-doped fibre laser (EDFL) is proposed and demonstrated. A 3-dB fibre loop mirror and a high birefringence (HiBi) fibre loop mirror are utilized as the cavity reflectors. By utilizing the wavelength-dependent polarization rotation induced by the HiBi fibre loop mirror and by using a fibre polarizer to control the intracavity polarization state, the polarization states of different wavelengths are diversified. Therefore, the polarization hole burning (PHB) effect has been greatly enhanced and the homogeneous broadening of erbium-doped fibre is suppressed to a large extent. By simply tuning a polarization controller, we experimentally obtained simultaneous lasing of four and five wavelengths with wavelength spacing of ～1.8nm and less than 2nm at room temperature, respectively. The repeated scans show that all of these lasers have good stability.     

Single-Photon Emission at Liquid Nitrogen Temperature from a Single InAs/GaAs Quantum Dot

We report on the single photon emission from single InAs/GaAs self-assembled Stranski-Krastanow quantum dots up to 80 K under pulsed and continuous wave excitations. At temperature 8OK, the second-order correlation function at zero time delay, g^（2）（0）, is measured to be 0.422 for pulsed excitation. At the same temperature under continuous wave excitation, the photon antibunching effect is observed. Thus, our experimental results demonstrate a promising potential application of self-assembled InAs/GaAs quantum dots in single photon emission at liquid nitrogen temperature.