Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Structures and Spectroscopic Properties of NaAs4 and Its Anions and Cations

The equilibrium geometries, vibrational frequencies, atomization energies, adiabatic electron separations, adiabatic detachment energies （ADE）, and adiabatic ionization potentials of the low-lying electronic states for the NaAs4 clusters and its ions were investigated employing the DFT method, and then compared with the photoelectron spectra. According to the computed results, reasonable assignments for the photoelectron spectra of NaAs4^- were suggested.     

离子的极化和形变

离子的极化和形变是无机化学教学中的一对重要概念,这对概念可以用于解释化合物的结构及许多物理和化学性质。然而一些教科书在介绍这对概念时,大都把极化作用限于阳离子,把形变作用限于阴离子,而忽略了阴离子的极化作用和阳离子的形变作用。同时,在应用这对概念解释化合物结构和性质时,条理上也不十分清晰,甚至还出现自相矛盾的情况,使得学生在学习这对概念时感到困惑。本文介绍了离子的极化和形变这对概念的基本含义,讨论了影响极化能力和形变程度的因素,分析了一些化合物的结构以及溶解度、颜色和热稳定性等物理和化学性质。特别是对一些教学中有争议的问题给出了合理解释。在分析小分子结构时,极化和形变概念的运用可以弥补杂化轨道理论和价层电子对互斥理论的不足。     

Molecular structure and vibrational raman and infrared spectra of bromochlorofluoromethane and its silicon and germanium analogs: quantum-mechanical DFT and MP2 calculations

DFT(B3LYP) and MP2 calculations with the 6-311G(2d, 2p)-type basis set have been carried out for the prediction of molecular parameters (bond distances, bond angles, rotational constants, and dipole moments) and vibrational Raman and infrared spectra (harmonic wavenumbers, absolute intensities, Raman scattering activities, and depolarization ratios) of bromochlorofluoromethane (HCBrCIF) and its silicon and germanium analogs (HSiBrClF and HGeBrCIF). The predicted geometry and vibrational Raman and infrared spectra of HCBrClF agree well with the available experimental data for this molecule and their deuterated derivatives. This agreement allows one to believe that the predicted molecular parameters and vibrational spectra of HSiBrClF, HGeBrClF, and their deuterated derivatives will guide their future experimental studies.     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Analytical nanoscience and nanotechnology today and tomorrow

This article discusses the mutual impact of nanotechnology and analytical science and illustrates how this technical trend can be expected to strengthen the role of analytical chemists. To this end, it defines the limits of actual nanotechnological approaches and uses selected examples to illustrate the three major relationships between nanotechnology and analytical science, namely: the design and use of nanodevices; the use of nanoparticles (and nanostructures) in analytical processes; and the extraction of accurate chemical information from the nanoworld. Finally, the future of analytical nanotechnology in the short and medium term is briefly addressed.     

ZnO和TiO2粒子的光催化活性及其失活与再生

 利用XRD，TEM，BET和UV－Vis等测试技术对商品的ZnO及TiO2和纳米ZnO及TiO2粒子进行了表征．无论是商品的还是纳米的，在光催化氧化降解气相n－C7H16和SO2及液相苯酚的反应中，TiO2均表现出比ZnO高的光催化活性，并从光腐蚀性和表面电荷两方面分析了其原因．在光催化氧化降解n－C7H16的反应中，ZnO粒子易失活，而TiO2粒子不易失活．但是，在光催化氧化降解SO2的反应中，ZnO和TiO2粒子均易失活．SPS和XPS测试结果表明，光催化剂表面的导电类型由反应前的n型变成了失活后的p型．这主要是由于反应产物发生吸附所致．失活后的光催化剂可以通过浸洗和干燥再生．     

Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D

Incorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional-group interconversions, the use of enzymatic C−C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel–Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure–activity relationship studies of [7.7]paracyclophane natural products.     

Preparation and photochromic properties of dye-doped aluminosilicate and ORMOCER gels and coatings

Aluminosilicate and ORMOCER gels and coatings containing photochromic dyes, 1, 3-dihydro-1, 3, 3-trimethylspiro-[2H-indole-2, 3-[3H]-naphth-[2, 1-b][1, 4]-oxazine] (SO) and 1, 8a-dihydro-2, 3-dimethoxycarbonyl-spiro [fluorene-9, 1-indolizine] (DHI), were prepared by the sol-gel method and the photochromic activity was monitored in the course of the sol-wetgel-xerogel transformation. The photochromic activity of the aluminosilicate gels decreases rapidly and even vanishes in the wetgel-xerogel stage while that of ORMOCER gels and coatings levels off in the early wetgel-xerogel stage at a reasonably high photochromic intensity with the colour-fading speed similar to that in ethanol and the photostability being considerably improved. The experimental results are discussed in terms of the matrix effect on photochromism of organic dyes.     

Photocatalytic and Electrochemical Borylation and Silylation Reactions

Due to their high versatility borylated and silylated compounds are inevitable synthons for organic chemists. To escape the classical hydroboration/hydrosilylation paradigm, chemists turned their attention to more modern and green methods such as photoredox chemistry and electrosynthesis. This account focuses on novel methods for the generation of boryl and silyl radicals to forge C−B and C−Si bonds from our group.     

Synthesis and characterization of thorium and uranium cyanoacetates and their coordination compounds

Tetracyanoacetates of thorium and uranium, M(NCCH₂COO)₄ (where M = Th or U) and dioxouranium (VI) dicyanoacetate [UO₂(NCCH₂COO)₂H₂O] and their coordination complexes with dimethyl sulphoxide (DMSO), dimethyl formamide (DMF), 1,10 phenanthroline (Phen) and 2,2′-bipyridyl (Bipy) have been synthesised and characterised by elemental analysis, molecular weight determination, molar conductance measurements, X-ray diffraction and infrared spectroscopic studies (4000–200cm⁻¹). Structural aspects of the compounds and the sites of bonding of the ligands to the central metal atom have been discussed in the light of shifts in thev(C ≡ N),v(COO),v(UO₂) and the metal-ligand stretching vibrations. Thermogravimetric analysis of the compounds have been carried out to study thermal decomposition modes.     

Antioxidant Properties of Fruit and Vegetable Whey Beverages and Fruit and Vegetable Mousses

The study assesses the antioxidant activity, total phenolic content, total flavonoids content and lipophilic pigments (β-carotene, chlorophyll a, chlorophyll b) content in homemade and marketed fruit and vegetable whey beverages and fruit and vegetable mousses. All of the tests were performed using spectrophotometric methods. The highest polyphenol content was found in the homemade green whey beverage W1G (541.95 mg/100 g) and the lowest in the market green whey beverage W2G (46.18 mg/100 g). In the fruit and vegetable mousses under study, the highest content of polyphenolic compounds was determined in the red mousse R3 (76.41 mg/100 g). The highest content of flavonoids was observed in the homemade orange whey beverage W1O (63.06 mg/100 g) and in the green mousse G2 (69.80 mg/100 g). The values of the antioxidant activity of whey beverages and mousses varied depending on the composition. The highest content of β-carotene was identified in homemade orange whey beverage (4.36 mg/100 g) and in orange mousses (in range 1.10–2.24 mg/100 g), while chlorophylls a and b—in homemade green whey beverage W1G (3.00 mg/100 g and 1.31 mg/100 g respectively) and in green mousses (chlorophyll a in range 0.54 to 1.42 mg/100 g and chlorophyll b in range 0.13 to 0.32 mg/100 g).     

Radicals and Anions of Siloles and Germoles

The synthesis of persistent sila- and germacyclopentadienyl (silolyl- and germolyl-) radicals by careful stoichiometric reduction of the corresponding halides with potassium is reported. The radicals were characterized by EPR spectroscopy and trapping reactions. The reduction of tris(trimethylsilyl)silyl-substituted halides was successful while smaller substituents (i. e., t-Butyl, Ph) gave the corresponding dimers. The EPR spectroscopic parameter of the synthesized tetrolyl radicals indicate only small spin delocalization to the butadiene unit due to cross-hyperconjugation. Silolyl- and germolyl anions are unavoidable byproducts and are isolated in the form of their potassium salts and characterized by X-ray crystallography. The comparison of the molecular structures of two closely related potassium silolides provided an example for different coordination of the potassium cation to the silolyl anion (η¹ vs. η⁵ coordination) that triggers the switch between delocalized and localized states.     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.