PDMS-Au复合基底上多环芳烃分子的表面增强拉曼光谱

利用聚二甲基硅氧烷(PDMS)对有机物的富集功能,通过在金纳米粒子单层膜(Au MLF)表面旋涂薄层PDMS膜制备PDMS-Au MLF复合表面增强拉曼光谱(SERS)基底.研究了SERS增强性能与旋涂液浓度及稀释溶剂间的关系,考察了复合基底增强活性的均匀性.研究发现,采用叔丁醇为稀释溶剂,浓度为2%(质量分数)的旋涂液时所得复合基底表面多环芳烃(PAHs)的SERS信号强度最高,且此基底SERS信号强度偏差小于10%.分别以PDMS-Au MLF复合材料和Au MLF作为基底,对比研究了对萘、蒽、菲和芘4种多环芳烃的SERS检测能力.结果表明,PDMS-Au MLF复合基底对以上4种有机物的检出限分别为10~(-6),10~(-7),10~(-8)及10~(-7)mol/L,相比于单一Au MLF基底,其检测限至少降低了1个数量级,这主要源自于PDMS对PAHs的富集作用,且此类复合基底可用于多种多环芳烃混合物的特征识别.     

N-叔丁基-α-苯基硝酮对纤维素超临界乙醇液化产物分布的影响

以N-叔丁基-α-苯基硝酮(PBN)为自由基结合剂,采用间歇式高温高压反应釜对玉米秸秆纤维素进行超临界乙醇液化,考察PBN用量(浓度)和反应温度(活性)对纤维素液化产物及生物油中主要化合物分布的影响。结果表明,在320℃,仅有超临界乙醇作用,生物油收率为37.17%,挥发分收率高达50.08%;随着PBN用量增加到0.4 g,生物油收率最高提升至48.35%,挥发分最低下降到35.65%。在超临界乙醇和PBN作用下,随着反应温度从250℃升高至340℃,纤维素转化率从23.10%急剧增加至88.92%,生物油收率从19.18%上升到最高48.35%(320℃)后略有下降,挥发分也从6.03%急剧上升至50.28%。GC-M S结果显示,酯类、酮类、烃类、醇类、酸类及苯类化合物是生物油的主要成分,各组分的最高相对含量分别为27.91%、15.77%、13.44%、12.42%、16.07%、19.81%。实验结果证实了PBN对纤维素超临界乙醇液化产物及生物油组分分布产生了较明显的影响,尤其能通过与含苯基、乙基等活性碎片结合促进挥发分与生物油之间的转化,且PBN用量及液化温度的改变可以促使生物油中主要化合物发生不同程度的相互转化。     

封隔器卡瓦接触应力研究

封隔器上的卡瓦锚定后起到支撑封隔器、锁定胶皮筒的作用,其性能好坏直接影响到油井的产量和生产安全。卡瓦与套管间的咬合力分布决定了封隔器在使用中的成败。咬合力的分布是否合理,将直接关系到套管的损伤程度及卡瓦的寿命。文中同时应用有限元法和三维光弹性技术对封隔器卡瓦进行了接触应力分析,介绍了实验模型的建立和实验步骤以及计算模型的建立和边界条件的考虑,比较了数值计算与三维光弹实验的结果,分析了造成误差的原因。实验应力分析结果为有限元计算模型的建立及边界条件的确定提供了重要的实验保证。研究工作获得了一些重要的结果,为封隔器卡瓦的优化设计提供了相关的参数。     

Diffraction by a metallic wedge covered with a dielectric material

In the literature, the usual formulation which assumes a constant impedance boundary condition does not permit one to express both the value of the geometrical optics field and the actual excited surface wave, since the impedance associated with the material for the reflection and for the surface wave are generally different. To obtain these elements in the field expression, we replace the notion of constant impedance by a differential operator. The general solution presented here preserves enough degrees of freedom to satisfy the continuity of fields at the internal junction of the two materials which cover each face of the wedge. The numerical calculations are based upon a function, related to the Maliuzhinets function, in a form which is easily computable.     

Low-temperature Heat Capacities and Thermodynamic Properties of the Solid State Complexes(C2H10N2)MCl4(s)(M=Cu and Cd)

The tetrachlorocuprate(II) ethylenediammonium and tetrachlorocadmate(II) ethylenediammonium were synthesized. Chemical analysis, elemental analysis, and X‐ray crystallography were applied to characterize the compositions and crystal structures of the two complexes. The lattice potential energies and the radiuses of the anions of two complexes were calculated to be U_POT[(C₂H₁₀N₂)CuCl₄]=1810.19 kJ·mol^?1, U_POT[(C₂H₁₀N₂)CdCl₄]=1784.39 kJ·mol^?1, r[(CuCl₄)^2?]=0.308 nm, and r[(CdCl₄)^2?]=0.321 nm from the data of the crystal structure, respectively. Low‐temperature heat capacities of the two complexes were measured by a precision automatic adiabatic calorimeter with the small sample over the temperature range from 78 to 400 K, respectively. Two polynomial equations of heat capacities against the temperatures were fitted by least square method: C_p,_m[(C₂H₁₀N₂)CuCl₄, s] =213.553+118.578X?5.816X²+4.392X³+0.276X⁴ and C_p,_m[(C₂H₁₀N₂)CdCl₄, s] =190.927+98.501X?7.931X²+0.657X³+3.834X⁴, in which X= (T?239)/161. Based on the fitted polynomial equations, the smoothed heat capacities and thermodynamic functions of the two complexes relative to the standard reference temperature 298.15 K were calculated at intervals of 5 K.     

反相高效液相色谱法测定一种口腔炎喷雾剂中绿原酸和咖啡酸的含量

取1mL口腔炎喷雾剂样品,用甲醇-水(1+1)溶液定量稀释至10mL,分取此溶液25μL供反相高效液相色谱法测定其绿原酸和咖啡酸含量。采用Shim-packVP-ODS色谱柱分离,以甲醇-0.012mol·L-1磷酸(27+73)混合溶液为流动相,柱温为30℃,流量为0.8mL·min-1,紫外检测器波长为323nm。结果表明:绿原酸在0.51～91.80mg·mL-1,咖啡酸在2.0～360.0mg·mL-1范围内呈线性关系,用标准加入法测定方法的回收率,结果依次在95.9%～97.4%和100.1%～100.9%范围内,检出限(3S/N)依次为0.10,0.40mg·mL-1,测定下限(10S/N)依次为0.36,1.40mg·mL-1。     

纳米ZnO/聚合物器件的制备及应用

近年来,氧化锌(ZnO)由于依赖于尺寸、形状的光电特性而备受关注。纳米ZnO尺寸较小、表面能高,易团聚,使其在光电、生物等方面的应用受到限制。将其与聚合物复合或组装,不但能稳定纳米ZnO,而且可以使纳米ZnO/聚合物复合材料具有优良性能。本文综述了近年来纳米ZnO/聚合物复合材料的制备方法(聚合物辅助、表面接枝、转移分散等法)及纳米ZnO/聚合物器件在电致发光、光伏电池、荧光成像等方面的应用,并对纳米ZnO/聚合物复合材料的发展做了展望。     

Synthesis, characterization and hydrodesulfurization activity of silica-dispersed NiMoW trimetallic catalysts

Silica-dispersed NiMoW trimetallic hydrodesulfurization catalysts were prepared by deposition-precipitation method. For comparative purposes, bulk NiMoW trimetallic catalysts were obtained by co-precipitation. Silica was employed to disperse active metals for full utilization of active components and silica-dispersed NiMoW catalyst had high active metal content. BET analysis showed that silica-dispersed NiMoW trimetallic catalysts had a high surface area (165.1 m²/g) and pore volume (0.27 ml/g). Transmission electron microscopy results proved that active components were well dispersed. Hydrodesulfurization activity of silica-dispersed NiMoW catalysts was much higher than that of comparative catalysts and up to twice greater than those of commercial NiMo alumina-supported systems per gram of catalyst.     

莱克多巴胺免疫亲和柱的制备与应用研究

用多元酸酐与混合酸酐相结合的方法合成了莱克多巴胺(Rac)抗原,免疫动物获得特异性抗体,并以蛋白A柱纯化得到IgG抗体。琼脂糖凝胶(Sepharose 4B)经溴化氰(CNBr)活化后与IgG抗体偶联,制备莱克多巴胺免疫吸附剂。据此建立了尿液中莱克多巴胺的免疫亲和柱净化/液相色谱-荧光法(HPLC-FL)测定的分析方法。免疫制备特异抗体50%抑制浓度(IC50)为5μg/L。Sepharose 4B经CNBr活化后与2 mg抗体的偶联率达87.4%。1 mL吸附剂的柱容量为67.57 ng。尿液中莱克多巴胺的回收率为76%~90%。