表面增强拉曼光谱研究吸附态的变化

测量了吡啶分子在电化学处理的银表面和亚甲基蓝分子在硝酸刻蚀银表面的表面增强拉曼光谱（ＳＥＲＳ）．对ＳＥＲＳ谱线的分析结果表明，吡啶分子在较低的表面吸附分子密度时倾向于平躺方式；而在较高的表面分子密度时，则倾向于向垂直吸附态转化．亚甲基蓝分子在较低浓度时主要是平躺吸附，随Ｃｌ－浓度的增加，亚甲基蓝从“平躺”吸附态转向“站立”吸附态．     

2-巯基苯并咪唑保护的铜纳米团簇的制备及银离子检测

以2-巯基苯并咪唑为保护剂,聚乙烯吡咯烷酮为稳定剂,水合肼为还原剂,“一锅法”合成2-巯基苯并咪唑保护的,高稳定性、强荧光、大斯托克斯位移的铜纳米团簇(Cu NCs),并用于检测水样中的银离子含量。采用透射电子显微镜(TEM)和X射线光电子能谱(XPS)对铜纳米团簇的结构进行表征,通过荧光光谱和紫外可见光谱对其光学性能进行研究。研究表明:该铜纳米团簇的最大激发和发射波长分别为340和558 nm,在日光灯和紫外灯下分别为无色和橙色。Cu NCs具有较高的分散性,尺寸大小为2~3 nm。在最佳反应条件下,铜纳米团簇可以选择性地被银离子猝灭,且灵敏度高,线性范围为1~40μmol/L,检测限为0.5μmol/L。该方法用于检测实际水样(自来水、湖水)中银离子的浓度,结果令人满意,表明在环境监测中有非常高的应用价值。     

Eu(Ⅲ)、Tb(Ⅲ)、Ho(Ⅲ)、Tm(Ⅲ)和Lu(Ⅲ)与N,N′-二(邻羟基亚甲基)乙二胺配合物的研究

Dutt曾合成稀土离子与N,N′-二(邻羟基亚甲基)乙二胺的稀土双希夫碱配合物。但未见报道Eu(Ⅲ),Tb(Ⅲ),Ho(Ⅲ),Tm(Ⅲ),Lu(Ⅲ)与双希夫碱N,N′-二(邻羟基亚甲基)乙二胺的配合物。本工作合成了这5种双希夫碱配合物。 所用稀土氧化物纯度大于99.9%(上海跃龙化工厂)。水杨醛(CP,用前经减压蒸馏提纯)。稀土硝酸盐Ln(NO_3)_3·xH_2_由稀土氧化物与硝酸反应制得。其余试剂均为分析纯。 仪器为Perkin-Elmer 240-C元素分析仪;Nicolet-5DX型红外光谱仪,KBr压片;岛津UV-     

Cesium lead halide perovskite nanocrystals for ultraviolet and blue light blocking

Using cesium lead halide perovskite nanocrystals, CsPb(Cl/Br)_3, as a light absorber, we report a highly effective UV and blue light blocking film. The CsPb(Cl/Br)_3 nanocrystals are well dispersed in the ethyl cellulose(EC) matrix to compose a UV and blue light shielding film, and the absorption edge of the film is tunable by adjusting Cl to Br ratio using anion exchange. The CsPbCl_2 Br-EC film exhibits a transmittance of 5% at 459 nm, 90% at 478 nm and 95% in the range of 500–800 nm, which makes it excellent for UV and blue light shielding. In addition, the as-prepared EC-CsPb(Cl/Br)_3 film shows excellent photostability under UV irradiation. Results demonstrate that this EC-CsPb(Cl/Br)_3 based materials with sharp absorbance edges, tunable blocking wavelength, and high photostability can be useful for the applications in UV and blue light blocking and optical filters     

Two novel Co (II)-coordination polymers as bifunctional materials for efficient photocatalytic degradation of dyes and electrocatalytic water oxidation

Two novel Co (II)- coordination polymers (CPs) based on 2,5-bis(4-carboxylpheny)-1,3,4-oxadiazole (bcpo), namely [Co/(bcpo)_0.5(tib)(H₂O)₂]_n (1) and [Co (bcpo)_0.5(bidpe)(H₂O)₂]_n (2) (tib = 1,3,5-tirs(1-imidazolyl)benzene, bidpe = 4,4′-bis (imidazolyl)diphenyl ether) have been synthesized under solvothermal conditions and characterized by powder X-ray diffraction (PXRD), single crystal X-ray diffraction, photochemistry as well as electrochemistry. The investigation of the photo-degradation methyl blue and methyl violet (MB, MV) properties of CPs 1–2 demonstrates that CP 1 shows great performance for the degradation of MB, and CP 2 could efficiently degrade MB/MV. Meanwhile, the possible photo-degradation mechanism has been proposed and explored. Simultaneously, electrochemistry studies show that both CPs 1 and 2 can catalyze water oxidation under an alkaline condition at the potential around 1.20 V vs. NHE with relatively low overpotential of 330–510 mV vs. NHE.     

Synthesis and self-assembly behavior of thermoresponsive triblock copolymer

Block copolymers comprising thermosensitive poly(N-isopropylacrylamide) (PNIPAM) and hydrophobic poly(n-butyl acrylate) (PBA) blocks, were synthesized using the reversible addition-fragmentation chain transfer polymerization (RAFT), their thermosensitive behavior was studied by ultraviolet spectrophotometer (UV) and dynamic light scattering (DLS). The lower critical solution temperature (LCST) was strongly correlated to the hydrophobic/hydrophilic ratio of the copolymers. Their micellization and self-assembly behavior in dilute aqueous solution were studied by surface tension (SFT), DLS and TEM. The resulting block copolymers reversibly formed or deformed micellar assemblies during their LCSTs. The critical micelle concentration (CMC) was controlled by the composition of PBA and PNIPAM, indicating the successful formation of the block copolymers.     

Numerical Simulation of a Multi-Output Radar Orthogonal Waveform Based on a Chaos Optimization Algorithm

Russian Physics Journal - Aiming at problems of low probability of interception and poor anti-jamming performance of the multi-output radar, the numerical simulation based on a chaos optimization...     

铀(Ⅵ)的二溴水杨醛缩二胺类双希夫碱及溶剂三元配合物的合成和表征

Nine new complexes [UO₂(Dbsal-o-Phdn)L][UO₂(Dbsalen)L] and [UO₂(Dbsalpn)L] [Dbsal-o-PhdnH 2=N,N′-o-phenylenebis-(3,5-dibromosalicylideneimine), DbsalenH₂=N,N′-ethylenebis (3,5-dibromosalicylideneimine), DbsalpnH₂=N,N′-1,2-propanylenebis (3,5-dibromosalicylideneimine), L=MeOH, EtOH, py] have been synthesized and characterized by elemental analysis, IR, UV, TG-DTA and molar conductance analysis. These complexes are proposed to have seven coordinate environment.     

Electrochemical and Electrochemiluminescence Determination of Cancer Cells Based on Aptamers and Magnetic Beads

The electrochemical and electrochemiluminescence (ECL) detection of cell lines of Burkitt’s lymphoma (Ramos) by using magnetic beads as the separation tool and high‐affinity DNA aptamers for signal recognition is reported. Au nanoparticles (NPs) bifunctionalized with aptamers and CdS NPs were used for electrochemical signal amplification. The anodic stripping voltammetry technology employed for the analysis of cadmium ions dissolved from CdS NPs on the aggregates provided a means to quantify the amount of the target cells. This electrochemical method could respond down to 67 cancer cells per mL with a linear calibration range from 1.0×10² to 1.0×10⁵ cells mL^?1, which shows very high sensitivity. In addition, the assay was able to differentiate between target and control cells based on the aptamer used in the assay, indicating the wide applicability of the assay for diseased cell detection. ECL detection was also performed by functionalizing the signal DNA, which was complementary to the aptamer of the Ramos cells, with tris(2,2‐bipyridyl) ruthenium. The ECL intensity of the signal DNA, replaced by the target cells from the ECL probes, directly reflected the quantity of the amount of the cells. With the use of the developed ECL probe, a limit of detection as low as 89 Ramos cells per mL could be achieved. The proposed methods based on electrochemical and ECL should have wide applications in the diagnosis of cancers due to their high sensitivity, simplicity, and low cost.     

离子色谱法测定饮用水中6种阴离子

建立生活饮用水中F~–,Cl~–,PO_3^(3–),PO_4^(3–),SO_3^(2–),SO_4^(2–)6种阴离子的离子色谱检测法。采用戴安DX–120型离子色谱仪及Ion Pac AS9–HC(250 mm×4.0 mm)阴离子交换柱,以5.0 mmo L/L Na_2CO_3–0.6 mmo L/L NaHCO_3溶液为淋洗液,流量为1.2 mL/min。6种阴离子的质量浓度与其色谱峰面积呈良好的线性关系,相关系数为0.999 3~0.999 8,检出限为0.026 4~0.741 4μg/mL(S/N=3)。水样的加标回收率为91.3%~110.0%,测定结果的相对标准偏差为1.65%~3.07%(n=6)。该方法具有操作简单,选择性、准确性好等优点,能够满足饮用水中F~–,Cl~–,PO_3^(3–),PO_4^(3–),SO_3^(2–),SO_4^(2–)6种阴离子的测定要求。