二氯喹啉酸在玻碳电极上的伏安行为及测定

应用循环伏安法(CV)和微分脉冲溶出伏安法(DPSV)在玻碳电极(GCE)上对二氯喹啉酸进行了研究,发现二氯喹啉酸在pH一=的B-R(Britton-Robinson)缓冲底液中于 0.954 V(vs.SCE)左右产生一个尖锐的阳极氧化峰.实验考察了pH值、富集时间、扫速、静止时间的影响.该法二氯喹啉酸在1.0×10-6～1.0×10-4 mol/L范围内与峰电流呈线性关系(r=0.998 8),检出限为6.0×10-7mol/L.用该方法对二氯喹啉酸进行了实际测定;对二氯喹啉酸的电极反应机理进行了初步探讨.     

泛昔洛韦与牛血清白蛋白相互作用的伏安行为研究

在pH 7的B-R缓冲底液中,应用循环伏安法和微分脉冲法在玻碳电极上对泛昔洛韦与牛血清白蛋白相互作用进行了研究,与相同浓度单独存在于溶液中泛昔洛韦相比,峰电位基本不变,峰电流有所降低,讨论了pH、反应时间、扫速、富集时间、静止时间对二者作用的影响,建立了对牛血清白蛋白浓度的检测方法.计算了泛昔洛韦加入BSA前后转移的质子数和电子数不变,扩散系数变小,推测泛昔洛韦进入BSA的疏水空腔内,使游离药物浓度变小.     

Z型Ag-Cu2O/BiVO4光催化剂的光催化还原CO2性能

利用简单的化学还原沉积法将 Cu₂O纳米球和 Ag纳米颗粒均匀包裹在十面体 BiVO₄表面,成功构建了一种具有高效电荷载流子分离/转移特性的Z型异质结光催化剂Ag-Cu₂O/BiVO₄。Ag-Cu₂O/BiVO₄在可见光下光催化CO₂还原为CO的产率可达5.37 μmol·g^-1·h^-1,分别是纯 BiVO₄和 Cu₂O的 35.80倍和 6.30倍。通过 X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、X射线能谱(EDS)、紫外可见漫反射光谱(UV-Vis DRS)、光致发光(PL)光谱、瞬态光电流响应(TPC)和电化学阻抗谱(EIS)对 Ag-Cu₂O/BiVO₄的晶体结构、形貌、组成、能带结构和吸光能力等进行了系统表征分析,并提出了其光催化体系还原CO₂的催化机理。     

退火温度对旋涂法制备SnO_2薄膜性能的影响

采用旋涂法在玻璃基底上制备SnO_2薄膜,通过原子力显微镜(AFM)、X射线反射(XRR)、傅氏转换红外线光谱仪(FT-IR)、X射线衍射(XRD)、紫外-可见分光光度计、四探针、开尔文探针系统对薄膜的表面形貌、结构及光学特性、电学特性进行分析,探讨了退火温度对薄膜质量的影响及作用机制。研究发现:随着退火温度升高,薄膜厚度和有机成分杂质减小,薄膜密度递增,但薄膜表面粗糙度有所上升;当退火温度升高至500℃时,薄膜结构由非晶转变为结晶,其主要晶面为氧化锡的(110)、(101)和(211)晶面。旋涂法制备的氧化锡薄膜在可见光区域的平均透光率在90%以上,随着退火温度上升,薄膜在400～800 nm波段的透光率先减小后增大,薄膜的带隙宽度分别为3. 840 eV(沉积态薄膜)、3. 792 eV(100℃)、3. 690 eV(300℃)和3. 768eV(500℃);薄膜的电导率也随着退火温度升高而增加,在500℃时电导率高达916 S/m;薄膜的功函数先增大后减小,分别为(4. 61±0. 005) eV(沉积态薄膜)、(4. 64±0. 005) eV(100℃)、(4. 82±0. 025) eV(300℃)、(4. 78±0. 065) eV(500℃)。     

离子液体在萃取和液膜过程中的应用研究新进展

介绍了近几年离子液体在萃取和液膜分离过程中研究应用的新进展,并展望了离子液体在分离科学应用的前景和发展方向。引用文献56篇。     

微波辅助无催化剂高效串联环化合成吡啶[2,3⁃d]嘧啶衍生物

建立了一种吡啶[2,3-d]嘧啶类化合物的高效合成方法. 以α,β?不饱和酮类化合物和1,3-二甲基-6-氨基脲嘧啶为原料, 在微波辅助无催化剂条件下, 于5~15 min内高效串联环化合成了28个具有分子多样性的吡啶[2,3-d]嘧啶类化合物, 其中21个化合物未见文献报道. 该方法具有原料简单易得、 高效绿色、 成键效率高及后处理简单等优点.     

基于相关系数指标筛选法的油田集输泵机组用能评价体系研究

针对不同油田泵机组的用能情况不同而导致的泵机组评价指标种类和权重产生差异的问题,提出一种确定指标的方法,根据西北油田泵机组的实际工况,采用相关系数法筛选评价指标,再结合主成分分析法与灰色关联法综合评价泵机组的用能情况.结果表明筛选出了5个评价指标,按权重大小排序依次为泵机组效率、节流损失率、外输负载率、集输单耗、功率因数.通过关联度的计算,找到了能量损失严重的泵机组,并分析判断出其薄弱环节.     

Measurement of the linear electro-optic tensor of cubic boron nitride single crystals

The transverse electro-optic(EO)modulation system is built based on cubic boron nitride(cBN)single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of the system includes two parts that can be measured respectively and the value of elements in the linear EO tensor of the cBN crystal can be obtained.This method does not need to measure the absolute light intensity.All of the surfaces of the tiny cBN crystals whose hardness is next to the hardest diamonds are{111}planes.The rectangular parallelepiped cBN samples are obtained by cleaving along{110}planes and subsequently grinding and polishing{112}planes of the tiny octahedral cBN flakes.Three identical non-zero elements of the EO tensor of the cBN crystal are measured via two sample configurations,and the measured results are very close,about 3.68 and 3.95 pm/V,respectively,which are larger than the linear EO coefficients of the general III-V compounds.     

Metamaterial inspired terahertz devices: from ultra-sensitive sensing to near field manipulation

We present a review of terahertz plasmonic metamaterial devices that have functionalities and applications ranging from sensing, enhanced electromagnetic fields, and near field manipulation. Metamaterials allow the properties of light propagation to be manipulated at will by using a combination of appropriately designed geometry and suitable materials at the unit cell level. In this review, we first discuss the sensing aspect of a planar plasmonic metamaterial and how to overcome its limitations. Conventional symmetric metamaterials are limited by their low Q factor, thus we probed the symmetry broken plasmonic metamaterial structures in which the interference between a broad continuum mode and a narrow localized mode leads to the excitation of the sharp Fano resonances. We also discuss the near field mediated excitation of dark plasmonic modes in metamaterials that is caused by a strong coupling from the bright mode resonator. The near field coupling between the dark and bright mode resonances leads to classical analogue of electromagnetically induced transparency in plasmonic systems. Finally, we discuss active switching in terahertz metamaterials based on high temperature superconductors that holds the promise of reducing the resistive losses in these systems, though it fails to suppress the radiation loss in plasmonic metamaterial at terahertz frequencies.     

硅材料的场致线性电光效应

从经典的极化理论出发,分析了直流电场、低频调制电场和光波电场共同存在时硅材料折射率的变化,从理论上揭示了场致线性电光效应的物理实质.以近本征硅材料为样品,采用金属-绝缘体-半导体样品结构,搭建了由塞纳蒙(Senarmont)补偿器改进成的横向电光调制系统.在硅材料空间电荷区内观测到显著的线性电光调制效应,系统的半波电压小于170 V,从实验上直接证实了硅材料中内建电场诱导的场致线性电光效应的存在.此外还观测到由克尔效应引起的二次电光凋制信号.以及由场致光整流效应引起的、随线偏振光的方位角的二倍余弦变化的电信号.实验结果与经典极化理论的预期完全一致,也间接证实了硅材料中场致线性电光效应的存在.