飞行时间二次离子质谱(TOF-SIMS)结合化学衍生法分析杂环新化合物的结构

飞行时间二次离子质谱(TOF-SIMS)分析了难挥发的杂环新化合物咪唑啉硫氰酸盐及其三种衍生物, 确认出很强的氢离化及银离化准分子离子峰, 通过对各种衍生物谱图的对照分析, 确认出较强的含有结构特征的碎片离子峰, 并对该化合物在离子轰击下的裂解规律作了分析, 支持了对该新化合物结构的鉴定。     

A Plasma Surface Treatment of Polyester Textile Fabrics Used for Reinforcement of Car Tires

Polyester tire cord surfaces have been modified by plasma at low temperature and atmospheric pressure. The surface treatment has been executed by various nonequilibrium discharges, namely by barrier discharge, atmospheric pressure glow discharge and gliding arc. The polymeric multicord sewing threads treated by this procedure have been used in the same form as in industry, i.e., with the protecting oil films on their surface. The surface properties have been investigated by electron spin resonance spectroscopy and by measuring their contact angle with various liquids; partially the zeta potential measurements have been used, too. Further tests have been done at an industrial testing impregnation line using the common technology and conditions, on both plasma treated and untreated fibers. Finally, the standard H-tests and peel-tests have been used to characterize the fiber adhesion to usual testing rubbers.     

3-芳氧基-6-取代哒嗪的合成及其除草活性

合成了系列3-芳氧基-6-取代哒嗪类化合物.化合物结构经¹HNMR、元素分析、IR和MS确证.生物活性测试结果表明,该类化合物具有很好的除草活性,讨论了其结构与除草活性的关系.     

Facile synthesis methodology and characterization studies of silica-decorated hybridized anisotropic nanotubes and nanosheets

Carbonaceous nanomaterials and their derivatives have been inspired tremendous enthusiasm in the scientific community. They have been excogitated as the encouraging attributes and the qualified dispersed phase to develop multi-functional composites. Particularly, graphene and carbon nanotube (anisotropic fillers) have gained substantial research interest owing to their promising characteristics. This highlights an innovative technique to synthesize hybridized nanotube and nanosheet. Initially, parent materials have been synthesized: The pristine CNT has been modified by acid mixture solution, and reduced graphene oxide has been prepared by chemical reduction method. Henceforth, the self-assembly in situ sol–gel technique has been endorsed here. The synthesized nanohybrids have been characterized by different spectroscopic techniques: FTIR, Raman, UV, and XPS to confirm the attachment of multifunctionalities; meanwhile, the composition and stability have been investigated from XRD and TGA plots. The magnitude of surface charge and particle size distribution have been evaluated for the parent and hybridized products; further, morphology of all the samples has been authenticated from FESEM and TEM.     

Curing of an epoxy resin modified with poly(methylmethacrylate) monitored by simultaneous dielectric/near infrared spectroscopies

Simultaneous dielectric and near infrared measurements have been performed in “real-time” to follow polymerisation reactions on blends of a diglycidyl ether of bisphenol-A epoxy resin with 4,4^′-diaminodiphenylmethane hardener and different amounts of poly(methylmethacrylate) as modifier. The effect of the modifier amount on the polymerisation reactions has been studied, as well as that of the curing temperature. Epoxy and amine conversions have been followed by near infrared spectroscopy (NIR), while changes in molecular mobility in the reaction mixture have been analysed by dielectric relaxation spectroscopy (DRS). Evolutions of ionic conductivity and α-relaxation have been analysed and vitrification times have been obtained. The relaxational behaviour has been analysed through curing in the frequency domain, being the change of the main relaxation indicative of the cure reaction advancement. DRS data are also presented as complex impedance Z(ω). Vitrification times, obtained by dielectrometry have been compared with those obtained by rheological measurements and gelation times obtained by NIR have been compared with those obtained by solvent extraction.     

High-performance quantitative thin-layer chromatography of flavonoid glycosides and biflavonoids ofCupressus sempervirens in relation to cypress canker

Summary The flavonoid glycosides and the biflavonoids of cypress leaves have been separted by means of high-performance thin-layer chromatography with quantitation by densitometry. Some flavonoid glycosides and biflavonoids have been identified, other than from their chromatographic characteristics, by means of UV spectra recorded directly on the layer. Different clones, resistant and susceptible to cypress canker, have been analyzed; some differences between these two classes of trees have been found in their biflavonoid content.     

Synthesis of monodisperse spherical nanocrystals

Much progress has been made over the past ten years on the synthesis of monodisperse spherical nanocrystals. Mechanistic studies have shown that monodisperse nanocrystals are produced when the burst of nucleation that enables separation of the nucleation and growth processes is combined with the subsequent diffusion-controlled growth process through which the crystal size is determined. Several chemical methods have been used to synthesize uniform nanocrystals of metals, metal oxides, and metal chalcogenides. Monodisperse nanocrystals of CdSe, Co, and other materials have been generated in surfactant solution by nucleation induced at high temperature, and subsequent aging and size selection. Monodisperse nanocrystals of many metals and metal oxides, including magnetic ferrites, have been synthesized directly by thermal decomposition of metal-surfactant complexes prepared from the metal precursors and surfactants. Nonhydrolytic sol-gel reactions have been used to synthesize various transition-metal-oxide nanocrystals. Monodisperse gold nanocrystals have been obtained from polydisperse samples by digestive-ripening processes. Uniform-sized nanocrystals of gold, silver, platinum, and palladium have been synthesized by polyol processes in which metal salts are reduced by alcohols in the presence of appropriate surfactants.     

Polymer modification to achieve novel properties

Polymers have been modified, by subjecting them to reactions in solution, in the melt and in the solid state. Novel polymers with improved and optimized properties have also been created by copolymerization, chain transfer or by the design of chain termination. Even by manipulating the initiation step in polymerizations, functional and reactive groups have been introduced at the head of the polymer chain. Polymer properties have been modified by influencing physical properties of polymers by orienting, annealing and blending.     

Improved microbiological hydroxylation of sesquiterpenoids: semisynthesis,structural determination and biotransformation studies of cyclic sulfite eudesmane derivatives

Two new cyclic sulfite eudesmane derivatives have been investigated. Their (R) and (S) sulfur configuration and the structural arrangement of their "A" rings have been assigned by means of their 13C and 1H NMR chemical shifts and have been confirmed by single-crystal X-ray analyses. Microbial-transformation of these epimer cyclic sulfites and their dihydroxyeudesmane precursor have been studied using the hydroxylating fungus Rhizopus nigricans. Increased biocatalysis rates and considerable differences in the biotransformation of both cyclic sulfite eudesmanes have been found. Promising 8alpha,11-dihydroxy derivatives have been isolated from the (S)-diastereomer bioconversion.     

硫酸锌与L-亮氨酸配合物行为的研究

锌是生命元素,缺锌引起的各种疾病已引起全世界的共同注意.L-α-氨基酸是人体蛋白质的基本结构单元.α-氨基酸锌作为添加剂在药物、食品和化妆品中有广阔的应用前景[1～3].L-α-亮氨酸(简写为Leu)是人体必需但在人体内又不能合成的氨基酸之一,必须从食物中得到.文献中尚未见亮氨酸锌的报导.本文用半微量相平衡方法[4]研究了ZnSO4-Leu-H2O体系在25℃的相化学行为,发现该体系中未形成新化合物.改进文献方法合成了未见文献报导的Zn(Leu)SO4·12H2O和Zn(Leu)2固态配合物,并研究了它们的物理化学性质.1实验部分1.1试剂与仪器　　Zn…     

Structure formation of sulfonated polyphenylquinoxalines in solution and in the solid state

Sulfonated polyphenylquinoxalines with different content of sulfo groups have been synthesized by polymer analogous reactions under different conditions. The rheological properties of these polymers in Nmethylpyrrolidone have been studied. The mechanical properties of films based on sulfonated polyphenylquinoxalines under uniaxial tension have been measured. The structures of the polymers have been examined by AFM.     

对杂散光测试材料要求的探讨

从分光光度计杂散光测试原理出发,对我国目前在用的几种杂散光测试材料特性进行了分析。通过实验验证,指出了其中的不合理处,并提出了对杂散光测试材料特性的基本要求。 ,     

Vibrational spectra,normal coordinates and infrared intensities of four isotopic phenyl acetates

The i.r. and Raman spectra of phenyl acetate and its deuteromethyl and deuterophenyl derivatives have been recorded. The fundamental frequencies of the four isotopic species have been assigned by referring to the Raman depolarization ratios and isotopic frequency shifts. The normal coordinates have been calculated on the basis of a valence force field. The general valence type force constants have been refined by the least-squares method. The i.r. spectra of the four isotopes have been simulated by using the obtained force field in combination with a suitable set of the atomic charges and their fluxes.     

Layer-by-layer self-assembly of Prussian blue colloids

The adsorption of Prussian blue (PB) colloids within layers of polyelectrolytes has been achieved by a reiterative immersion-rinse approach. Multilayer assemblies consisting of alternate layers of these components have been prepared by the layer-by-layer (LbL) self-assembly technique. Both processes have been carefully monitored by cyclic voltammetry and infrared and UV-visible spectroscopy. Linear increase in the IR and UV-visible light absorbance with the number of deposited layers indicates that well-organized lamellar systems have been elaborated. Size and distribution of Prussian blue nanoparticles in these systems have been investigated by AFM. The effect of the molar concentration of the PB dipping solution on the adsorption process and the distribution of the PB colloids has also been described. Finally, magnetic properties of these assemblies have been studied by low-temperature ESR measurements. Indeed, this new approach of hybrid LbL films opens the way to a new class of nanostructured lamellar compounds.     

Synthesis and properties of sol-gel submicron silica powders doped with partly oxidized iron particles

Magnetic powders based on metallic iron crystallites encapsulated in submicron-sized spherical silica particles have been obtained and investigated. The metallic iron clusters have been produced by the exploding wire method. The silica shells have been prepared via the modified sol-gel Stöber method and the metallic particles have been entrapped by occlusion during the silica powder formation. The entrapped iron particles are partially oxidized due to the nature of the synthetic methods employed. The obtained hybrid materials have been investigated by electron microscopy, X-ray diffraction, magnetic and ζ-potential techniques. Such materials can be employed in such applications as e.g. magnetically-controlled drug vectors or electromagnetic field-shielding.     

Determination of pyrethroids and their degradation productds in indoor air and on surfaces by HRGC-ECD and HRGC-MS(NCI)

Air and surface samples taken following indoor applications of natural pyrethrins and pyrethroids have been analyzed by HRGC-ECD and HRGC-MS using negative chemical ionization (NCI). It has been found that pyrethroids persist on surfaces as long as sixty hours after application. Primary pyrethroid degradation products have been characterized by mass spectrometry; their identities and route of formation by ozonolysis have been verified by degradation studies and NMR.     

Synthetic analogs of natural flavolignans. V. A new synthesis of 6-halogeno-1,3-benzodioxane analogs of silandrin and hydnocarpin

6-Halogeno-1,3-benzodioxane analogs of chalcones have been synthesized by various methods. Flavanone and flavone analogs of silandrin and hydnocarpin have been obtained from them. The structures of the new flavonoids have been shown by their PMR spectra.     

Pt/HM、Pd/HM催化剂上CO氧化反应活性和动力学研究

研究了Pt/HM、Pd/HM催化剂上CO氧化反应的活性,求出了各种催化剂的CO氧化反应动力学方程。考察了不同气氛下CO氧化活性的演变规律和V⁴⁺、Co²⁺离子对Pt、Pd的助催化作用,并用催化剂集团结构适应模型对以上结果作出了解释。     

Electronic structure and hyperfine interactions for hydrazyl radicals

Some aspects of electronic structure and hyperfine interactions for α,α-diphenyl-β-picrylhydrazyl and its derivatives have been studied. High resolution EPR spectra have been obtained and analyzed by the least-quares method in Fourier space. The results obtained are confirmed by NMR experiments. Anisotropic EPR spectra of hydrazyl radicals in frozen solutions and glasses have been recorded. Parameters of hyperfine tensors and g-tensor have been determined by the least-squares method. Spin distributions in radical molecules are calculated by the unrestricted Hartree—Fock method and calculations of isotropic and anisotropic hyperfine interactions have been carried out.     

(Re-)crystallization mechanism of highly oriented Si-microwire arrays by TEM analysis

Novel anodes for Li-ion batteries have been characterized by transmission electron microscopy (TEM). The anodes consist of arrays of ordered silicon microwires obtained from conventional silicon wafers by controlled etching processes. Suitable preparation methods for wires in the micrometer range have been tested, optimized, and subsequently applied. Ex situ TEM measurements have been performed for pristine as well as for electrochemically cycled wires that have been charged and discharged for several times. The influences of cycling rate, an electrolyte additive, as well as elevated temperatures on the anodes’ stability have been investigated.