以Cu(II)为光谱探针离子分光光度法测定异烟肼的新方法

以Cu(II)为光谱探针建立了一种高选择性、高灵敏度测定异烟肼的新方法。试验表明：在pH 6.0时，Cu(II)可被异烟肼还原生成Cu(I)，反应生成的Cu(I) 与SCN-反应生成CuSCN白色乳状沉淀，在硝酸钠的存在下该沉淀可被浮选至水相表面。通过测定水相中剩余Cu(II)的量，可以间接测定异烟肼的含量。已反应Cu(II) 的量与异烟肼的浓度呈良好的线性关系，线性范围为0.050-4.50 µg mL-1，检出限为0.048 µg mL-1。该法已经成功的用于药物样品和病人尿液样品中异烟肼含量的测定。     

Fabrication of monodispersed nickel flower-like architectures via a solvent-thermal process and analysis of their magnetic and electromagnetic properties

Monodispersed Ni flower-like architectures with size of 1–2 μm were synthesized through a facile solvent-thermal process in 1,2-propanediol solution in the presence of polyethylene glycol (PEG) and sodium alkali for electromagnetic absorption application. The Ni architectures are composed of nanoflakes, which assemble to form three dimensional flower-like structure, and the thickness of nanoflakes is about 10–40 nm. A possible formation mechanism for Ni flower-like architectures was proposed and it was confirmed by the control experiments. The Ni architectures exhibited a saturation magnetization (M_s) of 47.7 emu/g and a large coercivity (H_cj) of 332.3 Oe. The epoxy resin composites with 20 vol% Ni sample provided good electromagnetic wave absorption performance (reflection loss <−20 dB) in the range of 2.8–6.3 GHz over absorber thickness of 2.6–5.0 mm.     

TiO2 Nanobelts Decorated with In2S3 Nanoparticles as Photocatalysts with Enhanced Full‐Solar‐Spectrum (UV–vis–NIR) Photocatalytic Activity toward the Degradation of Tetracycline

Herein, ultradispersed In₂S₃ nanoparticle (NP)/TiO₂ nanobelt (NB) heterostructures with an intimate interfacial coupling effect are synthesized from the consideration of combining the visible/near‐infrared photoabsorption property of In₂S₃ with the excellent UV photocatalytic property of TiO₂. In this process, the 1D TiO₂ NBs not only perform as the support to form the heterostructure, but are also employed as a dispersant to confine the aggregation of In₂S₃ NPs. As expected, the obtained In₂S₃ NP/TiO₂ NB heterostructure gives rise to a prominently strong optical absorption in the full solar region of 300–1800 nm, and thus displays a desired photocatalytic degradation of tetracycline in full utilization of all solar energy, compared with that of pristine In₂S₃ and TiO₂. Besides, the In₂S₃ NP/TiO₂ NB heterostructure photocatalysts have no selectivity and can effectively degrade other different kinds of organic pollutants, including cationic dyes (methyl blue and rhodamine B) and colorless chemical pollutants (phenol and salicylic acid). The exceptional photocatalytic enhancement is due to the synergistic interactions of heterojunction with the strong interfacial coupling effect, the In₂S₃ extended light absorption, efficient photogenerated e^?/h⁺ pair separation, and fully exposed reactive sites induced by uniform packing of the ultrasmall In₂S₃.     

裂纹转子的振动响应研究

本文研究了裂纹转子的振动响应。文章首先通过应力强度因子积分得到含裂纹轴单元的刚度矩阵；建立了裂纹转子的运动微分方程。进而研究了裂纹转子的振动响应，得出了裂纹转子的振动响应随裂纹位置和深度的变化关系。为工程上早期诊断微小裂纹提供了理论根据。     

Steric Considerations in Supramolecular Inclusion of Modified β-cyclodextrins with Triton X-100 and α-bromonaphthalene

Supramolecular inclusion of modified β-cyclodextrin (β-CD) with Triton X-100 (TX) and α-bromonaphthalene (BN) was studied by fluorescence and phosphorescence measurements. Major differences were observed in the magnitude of the apparent stability constants and quenching constants of the inclusion complexes. Methyl substitution on the rims of β-CD increased the binding of TX with β-CD but was unfavorable to the protection of the phenyl group of TX from fluorescence quenching and further accommodation of BN for steric considerations. According to the overall molecular size of β-CD, TX and BN, further inclusion of BN in the cavity of β-CD occupied by TX may force the flexible tert-octyl chain of TX to deform to a greater extent and close packing complexes were obtained. Phosphorescence of BN arising from intermolecular energy transfer between BN and the phenyl group of TX was observed when the phenyl group of TX was irradiated. In the case of heptakis(2,6-di-O-methyl)-β-CD, BN failed to penetrate into the cavity because of the steric hindrance of the methyl substituents at the rim of the β-CD cavity.     

In situ growth and phenyl functionalization of titania nanoparticles coating for solid-phase microextraction of ultraviolet filters in environmental water samples followed by high performance liquid chromatography–UV detection

Based on TiO₂-nanoparticles coating fabricated by a one-step anodization method on titanium wire substrate, a novel phenyl functionalized solid-phase microextraction (SPME) fiber coating was prepared by simple and rapid in situ chemical assembling technique between the fiber surface titanol groups and trichlorophenylsilane reaction. The as-fabricated fiber exhibited good extraction capability for some UV filters and was employed to determine the ultraviolet (UV) filters in combination with high performance liquid chromatography–UV detection (HPLC–UV). The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the developed method was applied to detect several UV filters at trace concentration levels with only 8 mL of sample volume. They were determined in the range from 0.005 to 25 μg L⁻¹ with detection limits (S/N = 3) from 0.1 to 50 ng L⁻¹. The relative standard deviations (RSDs) for single fiber repeatability varied from 4.6 to 6.5% (n = 5) and fiber-to-fiber reproducibility (n = 5) ranged from 5.5 to 9.1%. The linear ranges spanned two-four magnitudes with correlation coefficients above 0.9990. Five real water samples including four Yellow River water samples and one rain water sample were determined sensitively with good recoveries ranging from 86.2 to 105.5%. The functionalized fiber coating performed good reproducible manner, high mechanical strength, good stability and long service life. Moreover, this study proposed an efficient sample pretreatment method for the determination of UV filters from environmental water samples.     

Comparative study on fluorescence enhancement and quenching of europium and terbium chelate anions in cationic micelles

Fluorescence enhancement and quenching of water soluble chelates of terbium (Tb3+) with Tiron, salicylic acid (SA), 4-sulfonyl salicylic acid (SSA) and acetylacetone (AA) and sparingly soluble chelates of europium (Eu3+) with beta-diketones were comparatively examined in the presence of cetyltrimethyl ammonium bromide (CTMAB) and cetylpyridinium chloride (CPC). By the composition of the complexes, surface tension measurements and spectral analysis, the binding mode of chelate anions to the micellar surface of cationic surfactants was discussed in terms of ion-exchange model. Quenching effect of CPC on the fluorescence of association complexes seems to arise from the charge transfer from a fluorescent ligand to pyridinium cation. In the case of the chelates of Eu3+ with beta-diketones, however, pyridinium ion is only capable of overlapping the aromatic ring of beta-diketones to less extent since the poorly soluble charged chelates have a weak affinity for the highly polar surface of pyridinium cationic micelles. Efficient charge transfer between the excited aromatic beta-diketone and pyridinium cation fails to be established. CPC also shows enhanced effect on fluorescence like CTMAB.     

Mesostructured cellular foam solid‐phase microextraction coating for the highly sensitive recognition of polychlorinated biphenyls in water samples

We herein presented a mesoporous cellular foam solid‐phase microextraction coating that showed highly sensitive recognition for weakly polarity polychlorinated biphenyls in water samples. The mesoporous cellular foam coater fiber was for the first time prepared by a simple sol‐gel method. The main experimental parameters including extraction temperature, extraction time, desorption time, stirring rate, and ionic strength were investigated by high‐efficiency orthogonal array design, a L₁₆ (4⁴) matrix was applied for the identification of optimized extraction parameters, and the optimized method was successfully applied to the analysis of environmental water sample. The novel mesoporous cellular foam coated fibers exhibited sensitive limits of detection (0.07–0.28 µg/L), wide linearity (5–3000 µg/L), and good reproducibility (3.5–8.3% for single fiber, and 4.9–8.7% for fiber‐to‐fiber) for polychlorinated biphenyls. The home‐made coating was successfully used in the analysis of polychlorinated biphenyls in real environmental water samples. These results indicate that the synthesized mesoporous cellular foams are promising materials for adsorption and separation applications in sample pretreatment.     

新型含吡啶酮(吡唑)结构的A2a/A2b双靶点腺苷受体拮抗剂的合成及生物活性研究

设计并合成了具有吡啶酮或吡唑结构的6个新型双靶点(A_2a和A_2b)腺苷受体拮抗剂。其结构经¹H NMR、¹³C NMR和HR-MS(ESI)表征。采用cAMP法评价了目标化合物(11a～11f)对A_2a和A_2b受体的抑制活性。活性测试结果表明：该系列化合物对A_2a和A_2b受体均有较好的抑制活性。其中化合物11e抑制活性最强,抑制A_2a和A_2b受体的IC₅₀值分别为8.188 nM和15.22 nM,11e对A_2bR受体的抑制活性优于阳性对照药AB928(IC₅₀=36.48 nM)。此外,利用分子对接研究了化合物11e与A_2a和A_2b靶点的结合情况,结果表明：化合物11e与A_2a和A_2b靶点具有较好的亲和作用。     

计算机处理三组分重叠峰法在高效液相色谱法中的应用——钐、钆、镝的同时测定

本文以二甲酚橙为显色剂、甲醇-水(含CTMAB和缓冲溶液)为流动相,利用可编辑的时间程序求得某一保留时间和波长处的电频值对Sm、Gd、Dy混合组分体系进行了考察,提出了一种处理三组分重叠峰法的计算机程序。试验结果表明,该程序简单、快速,计算结果准确度较高。