A New Manganese Coordination Polymer Based on Azobenzene Tetracarboxylate and Auxiliary Pyridine Ligand: Synthesis,Crystal Structure and Magnetic Property

A new manganese coordination polymer(CP)has been synthesized under hydrothermal conditions.It’s formula is{Mn2(Oaobtc)(bpe)(H₂O)₄]}n,where H4Oobtc represents oxide azobenzene 2,2',3,3'-tetracarboxyl acid,and bpe is 1,2-bis(4-pyridine)ethylene.It was characterized by elemental analysis,infrared spectrum and X-ray single-crystal diffraction.The coordination polymer crystallizes in the monoclinic system,space group P2₁/c.The central ion was coordinated with H₄Oobtc ligands using bridging model,and carboxylic group connects two adjacent Mn(Ⅱ)ions into dimer units.The oxygen from carboxylates connect these dimer units into a one-dimensional(1D)chain,and N atoms from the bpe further expanded them into three-dimensional(3D)supramolecular edifice,eventually.Variable-temperature magnetic measurements of CP 1 indicate the presence of weak antiferromagnetic exchange between two nearest Mn(Ⅱ)ions with J=–0.367 cm^-1.     

MEASUREMENT OF NON-UNIFORM RESIDUAL STRESSES BY COMBINED MOIRE INTERFEROMETRY AND HOLE-DRILLING METHOD： THEORY, EXPERIMENTAL METHOD AND APPLICATIONS

Hole-drilling method is one of the most convenient methods for engineering residual stress measurement. Combined with moiré interferometry to obtain the relaxed whole-field displacement data, hole-drilling technique can be used to solve non-uniform residual stress problems, both in-depth and in-plane. In this paper, the theory of moiré interferometry and incremental hole-drilling (MIIHD) for non-uniform residual stress measurement is introduced. Three dimensional finite element model is constructed by ABAQUS to obtain the coefficients for the residual stress calculation. An experimental system including real-time measurement, automatic data processing and residual stresses calculation is established. Two applications for non-uniform in-depth residual stress of surface nanocrystalline material and non-uniform in-plane residual stress of friction stir welding are presented. Experimental results show that MIIHD is effective for both non-uniform in-depth and in-plane residual stress measurements. The project supported by the FRAMATOME ANP     

冲蚀与气蚀复合磨损试验研究

通过改造MCF-30型冲蚀腐蚀试验机,建立了水、沙、气三相流冲蚀磨损试验装置;试验研究了水、沙混合流场中试样的磨损特征,通过扫描电子显微镜观测了三相流冲蚀磨损表面,并借助计算机模拟分析水、沙混合条件下产生气蚀破坏的条件.结果表明:合理的设计可以实现冲蚀与气蚀的复合磨损模拟试验;形成三相流共同作用下的冲蚀与气蚀复合磨损重要条件为介质中含有较多气体,并且在试样中有气泡溃灭.三相流磨损模拟试验与仿真为进一步开展三相流气蚀与冲蚀磨损研究奠定了基础.     

超声回波参数估计的初值选取方法

针对超声回波参数估计中,初值随机选取带来的收敛速度慢,搜索效率低,易受噪声影响等问题,对回波参数估计的初值选取进行了探讨。理论上研究了超声回波信号的包络和能量与信号参数的关系,阐明了从信号自身选取参数初值的可行性。在此基础上,利用希尔伯特变换和傅里叶变换提取有效信息,为回波参数估计提供合适的初值,从而减少估计过程的迭代次数、提高参数估计速度。实验结果表明,与传统参数估计方法相比,该方法在不同信噪比情况下都可获得较高的估计精度,而且参数估计的收敛速度较快。      

Impact of the self-steepening effect on soliton spectral tunneling in PCF with three zero dispersion wavelengths

This work presents a numerical investigation of the self-steepening(SS) effect on the soliton spectral tunneling(SST) effect in a photonic crystal fiber(PCF) with three zero dispersion wavelengths. Interestingly, the spectral range and flatness can be flexibly tuned by adjusting the SS value. When the SS coefficient increases, the energy between solitons and dispersion waves is redistributed, and the red-shifted soliton forms earlier in the region of long wavelength anomalous dispersion. As a consequence, the SST becomes more obvious. The findings of this work provide interesting insights in regard to the impact of the SST effect on tailored supercontinuum generation.     

简易旋转倒立摆及控制装置的系统设计

采用ATmega128作为本旋转倒立摆控制装置的主控芯片,通过直流电机对旋转臂进行控制,实现对摆杆的旋转控制。用编码器对摆杆旋转角度进行测量,将旋转位移转换成数字脉冲实现控制。通过对编码器设定零点,运用PID算法实现精确控制摆杆的摆动角度与状态。测试结果表明,该简易旋转倒立摆及控制装置的系统设计方法科学,具有性能稳定、抗干扰能力强、控制精确,可靠性高,节能环保等优点。     

基于腔辅助相互作用的远距离信息传递

提出了一种基于腔辅助相互作用的远距离信息传递的方案.在该方案中,通过让一束相干光和一个囚禁在腔里面的原子进行相互作用,可以使相干光产生一个可控的相位偏移.用这种腔辅助相互作用完成了原子态和光场态之间信息的相互转移.最后我们演示了远距离信息传递方案,该方案在当前实验条件下是可行的,并且在理想条件下,成功的概率几乎为1.     

荧光光谱法研究双醋瑞因与人血清白蛋白的相互作用

在模拟人体生理条件下（pH=7.40）,采用荧光光谱法研究双醋瑞因与人血清白蛋白的相互作用。 采用2种方法计算不同温度下其结合常数KA、结合位点数n,同时对2种计算方法进行了比较;并根据热力学参数确定了双醋瑞因与人血清白蛋白之间的作用力类型。 根据Forster非辐射能量转移原理,确定了双醋瑞因与人血清白蛋白相互结合时供能体 受能体间的作用距离和能量转移效率,并用同步荧光光谱研究了双醋瑞因对人血清白蛋白构象的影响。 结果表明,双醋瑞因与人血清白蛋白之间主要是以静态猝灭为主;结合距离r=2.88 nm,能量转移效率E=0.273 8,二者主要凭借氢键和范德华力进行结合。     

疏水缔合聚丙烯酰胺与双子表面活性剂的相互作用

制备了一种脂肪酸酯双磺酸盐型双子表面活性剂, 利用粘度法、界面张力法和原子力显微镜研究了疏水缔合聚丙烯酰胺与双子表面活性剂在溶液中的相互作用. 实验结果表明: 疏水缔合聚丙烯酰胺在溶液中能够通过自组装形成疏水微区并发展成网络结构, 疏水微区与表面活性剂在溶液中能形成混合胶束; 当一定量的表面活性剂加入时, 对疏水缔合聚丙烯酰胺的自组装起促进作用, 而过多双子表面活性剂的加入又会对聚合物分子的自组装起抑制作用, 从而显著影响疏水缔合聚丙烯酰胺的溶液性质, 随着表面活性剂浓度的增加, 聚合物溶液粘度先增加、再降低; 同时, 疏水缔合聚丙烯酰胺对双子表面活性剂的界面性能也有较大影响, 聚合物的加入使双子表面活性剂降低油/水界面张力的能力下降, 油/水界面张力达到平衡所需时间延长.     

纳米SiO2/HPAM/SDS分散体系稳定性的改进及其对驱油性能的影响

分析了60℃、1. 0×104mg/L氯化钠盐水和模拟地层水中纳米SiO2/HPAM/SDS分散体系的浊度实验及Zeta电位,发现Ca2+、Mg2+离子是体系失去稳定性的主要原因。根据沉降实验及Zeta电位分析仪探讨了降低p H值和添加络合剂对模拟地层水中纳米SiO2/HPAM/SDS体系稳定性的改善效果及机理,同时利用流变仪及界面张力仪分析了两种方法对体系驱油性能的影响。结果表明,p H值降低,体系的Zeta电位绝对值降低,但SiO2周围H+保护层的形成及水化作用力的增强改善了体系的稳定性;络合剂Na2EDTA、ATM P和Na4EDTA均能增强体系的稳定性,Na2EDTA和ATM P络合Ca2+、Mg2+的同时降低了体系的p H值,而体系的黏度随p H值的降低急剧下降; Na4EDTA加入后,体系的p H值增大,稳定配位化合物的形成使体系的Zeta电位绝对值、黏度、储能模量和损耗模量增加,降低界面张力的能力增强。因此,在SiO2质量分数为0. 5%的体系中加入质量分数为0. 4%的Na4EDTA(最佳质量分数),采收率提高了3. 1%。