纳米Zn-Co铁氧体的固相合成及电磁损耗特性研究

采用NH₄HCO₃与FeCl₃·6H₂O，Zn(NO₃)₂·6H₂O，Co(NO₃)₂·6H₂O进行室温固相反应制得前驱物，经微波加热处理后，进而热分解分别制得复合氧化物ZnFe₂O₄、CoFe₂O₄和Co_0.5Zn_0.5Fe₂O₄。由激光粒度分析仪、XRD和SEM表征：获得了颗粒分布比较均一、平均粒度为65 nm左右、立方晶系尖晶石结构的纳米铁氧体粉体。经测试样品的相对介电常数和相对磁导率后，研究了它们的电磁损耗特性。结果表明：Co_0.5Zn_0.5Fe₂O₄在100～1 800 MHz内比另外两种铁氧体具有更好的电磁损耗特性。     

滂胺天蓝-氨基糖苷类抗生素的显色反应及其分析应用

在 pH2.0～7.0的条件下 ,滂胺天蓝(PSB)与硫酸卡那霉素(KANA)、硫酸庆大霉素(GEN)和硫酸新霉素(NEO)等氨基糖苷类抗生素反应生成蓝色离子缔合物 ,最大显色波长位于686～690nm ,线性范围分别为0～14.0、0～12.5、0～14.0mg/L ,摩尔吸光系数(ε)分别为1.53×104、1.12×104、1.47×104L/(mol·cm) ;最大褪色波长位于620～622nm ,线性范围分别为0～14.0、0～12.0、0～14.0mg/L ,摩尔吸光系数(ε)分别为1.41×104、1.43×104、2.42×104L/(mol·cm) ;当用双波长叠加法测定时 ,ε值分别为2.94×104、2.55×104、3.89×104L/(mol·cm) ;探讨了适宜的反应条件 ;该法用于市售药物中氨基糖苷类抗生素含量的测定 ,结果令人满意     

碳铂类似物的合成,表征及对大鼠W—256肉瘤的抑制作用

合成了十八种〔PtA_2X〕·yH_2O,其中A分别为NH_3、CH_3NH_2、1/2乙二胺和1/2(2,3-二甲基-2,3-丁二胺),X分别为1,1-环丙烷二羧酸根(CPrDCA)、2-甲-1,1-环丙烷二羧酸根(2-M-CPrDCA)、2-甲-1,1-环丁烷二羧酸根(2-M-CBDCA)、1,2-环戊烷二羧酸根(CPDCA)和1,1-环已烷二羧酸根(CHDCA),并进行了表征。测定了配合物抑制大鼠W-256肉瘤的活性,发现配合物〔Pt(NH_3)_2X〕系列按X不同有以下的活性次序:CPrDCA>2-M-CPrDCA>CPDCA>CBDCA(碳铂)≥2-M-CBDCA。     

测接触角法确定偶联剂的最佳用量

偶联剂是一类能在无机填料和聚合物基材之间形成“分子桥”、改善两者之间相容性或提高两者之间相互作用能力的化合物。将经偶联剂改性的无机填料填充到聚合物中可以制得成本低、性能好的复合材料。由于偶联剂用量多少将对复合材料的性能产生较大影响,因此建立一种准确、简便地确定偶联剂最佳用量的方法有着十分重要的理论和实际应用意义。     

芳亚甲基丙二腈、芳亚甲基氰乙酰胺的固相合成

芳醛和丙二腈、氰乙酰胺在NH4Ac催化下经固相反应高产率的得到芳亚甲基丙 二腈和芳亚甲基氰乙酰胺。     

Oxidative coupling of methane over Na-Mn-W/SiO2 catalyst at higher pressure

Na-Mn-W/SiO₂ catalysts were prepared and their catalytic performance for oxidative coupling of methane (OCM) was evaluated in a stainless-steel microreactor at elevated pressure. The results show that a CH₄ conversion of 15.1% with a C₂₊ selectivity of 71.8% was obtained under 750^oC, 1.0×10⁵h^-1 GHSV, CH₄/O₂ ratio of 8 and 1.0 MPa. Moreover, 17.3% CH₄ conversion with 51.6% C₂ selectivity and 23.6% C₃-C₄ selectivity was obtained under 750^oC, 2.0×10⁵h^-1 GHSV, CH₄/O₂ ratio of 8 and 1.0 MPa.     

冠醚化二苯甲酮的合成及其光物理行为

本文报道采用在多聚磷酸中酰化的方法,合成了冠醚化二苯甲酮1～8。它们与叔胺类共用可能被用作光引发剂。为此,用紫外光谱详细研究了这些化合物及其络合后的光物理行为。还提及化合物3和4作为紫外吸收剂的可能性。     

Fabrication of ultrathin films with large third-order nonlinear optical properties.

An ultrathin composite film containing anionic Ag-His complexes (His: L-Histidine) and oppositely charged BH-PPV was fabricated by means of the electrostatic layer-by-layer self-assembly technique. UV/Vis spectra showed a continuous deposition process of Ag-His complexes and BH-PPV. The film structure was characterized by using small-angle X-ray diffraction, AFM, and SEM. The nonlinear optical properties of the ultrathin film were studied by using the Z-scan technique with a laser duration of 8 ns at a wavelength of 532 nm. The film sample exhibited a strong nonlinear saturated absorption, with an alpha2 value of -3.9 x 10(-5) mW(-1) and a self-defocusing effect with an n2 value of -4.78 x 10 (-12) m2W(-1).     

New fluorescent probes for the detection of mixed sodium and potassium metal ions

A new fluorescent probe 2 is developed that is capable of measuring the concentration of a mixture of sodium and potassium ions in the solution. This probe contains a fluorophore that is utilized in two ways depending on the pH of the solution.     

Nonequilibrium Monte Carlo simulation of lattice block copolymer chains subject to oscillatory shear flow

This paper has extended nonequilibrium Monte Carlo (MC) approach to simulate oscillatory shear flow in a lattice block copolymer system. Phase transition and associated rheological behaviors of multiple self-avoiding chains have been investigated. Stress tensor has been obtained based upon sampled configuration distribution functions. At low temperatures, micellar structures have been observed and the underlying frequency-dependent rheological properties exhibit different initial slopes. The simulation outputs are consistent with the experimental observations in literature. Chain deformation during oscillatory shear flow has also been revealed. Although MC simulation cannot account for hydrodynamic interaction, the highlight of our simulation approach is that it can, at small computing cost, investigate polymer chains simultaneously at different spatial scales, i.e., macroscopic rheological behaviors, mesoscopic self-assembled structures, and microscopic chain configurations.