Discovery of nitric oxide in marine ecological system and the chemical characteristics of nitric oxide

Nitric oxide was discovered in both the lab and the alga culture pond of Daya Bay (1―300 m3) before the growth of alga reached the maximum. The results included: (1) NO was detected before the growth of alga reached the maximum in the case of red tide alga and food alga, and the concentration of NO decreased rapidly after the growth maximum; (2) the curve between NO con-centration and time indicated that the concentration of NO in the daytime was more than that at night, and the maximal concentration of NO appeared in the midday (1―3 pm); (3) the growth of alga reached the maximum in the alga culture pond of Daya Bay in about 8―10 d, and NO was discovered in 5―7 d; (4) the measured NO concentration was 10-9 mol/L, 10-9―10-8 mol/L, and 10-8 mol/L for Haeterosigma akashiwo, mixed alga in Daya Bay and Chaetoceros Curvisetus individually; (5) the relation of illumination with NO production was discussed.     

Investigation of conjugated dinitrones — derivatives of pyrroline oxide

The molecular structure of three derivatives ofbis(2- R- 5,5- dimethyl- 3- oxo- 1- oxide pyrrolin- 1- ylidene- 3),where R =CH ₃ (@#@5a @#@), C ₆H₅ (@#@5b @#@), C(CH ₃)₃ (@#@5c @#@), and of the complex of 5b with copper(II)hexafluoroacetylacetonate [Cu(hfac) ₂ (@#@5b @#@)] was investigated by X- ray diffraction analysis in the framework of our studies of the possible tautomeric equilibrium conjugated dinitrone ? nitroxide biradical. The pyrroline rings of the molecules under analysis are planar (rms deviations of atoms are no more than 0.041 å), and the interplanar angles are 32.01(5), 42.84(9), and 51.45(7)? for 5a,5b,and 5c,respectively. It is established that the bond lengths of the C(2)- C(3) =C(3a)- C(2a) fragment are equalized to C(2)- C(3) 1.42 and C(3)- C(3a) 1.40 å. The N→O bond lengths of the nitrone group are within 1.250(4)- 1.282(4) å) [in Cu(hfac)₂ (5b)]. The geometrical data obtained do not permit us to make an unambiguous choice between the tautomeric structures. The magnetic susceptibility measurements of the Cu(hfac)₂ solid complex (5b) and the absence of paramagnetism in solid compounds 5 indicate that they are diamagnetic.     

Influence of cerium oxide on properties of glass–ceramic sealants for solid oxide fuel cells

The influence of the cerium oxide concentration on the properties of glasses and glass ceramics of the SiO₂–Al₂O₃–CaO–Na₂O–MgO–K₂O–B₂O₃–CeO₂ system as potential adhesive and sealing materials for solid oxide fuel cells was studied. According to the data of differential scanning calorimetry, variation of the CeO₂ concentration does not appreciably influence the glass transition and crystallization temperatures of glasses. As the cerium oxide concentration is increased, the linear thermal expansion coefficient increases for the glasses but decreases for the partially crystalline samples. The gluing temperature of the glass sealants prepared allows their use for joining YSZ solid electrolytes with interconnectors of Crofer22APU type in solid oxide fuel cells..     

Argentic oxide mediated N-dearylation of β-lactams

A method is described for the N-dearylation of N-(4-methoxy- or 4-ethoxyphenyl)-2-azetidinones with argentic oxide. The yields are good-to-excellent and the reaction is simple, efficient, and fast.     

Transformations of sclareol oxide by bromination. Synthesis of driman-8α, l l-diol from sclareol oxide

Depending on reaction conditions, the reaction of sclareol oxide with N-bromosuccinimide affords either 12-bromo- or 12,16-dibromosclareol oxide, whereas the reaction of sclareol oxide with bromine in methanol gives l2-monobromide or (13S)-1 1,12-dibromo-8,13-epoxy-13-methoxy-14,15-bisnorlabdane. Dehydrobromination of the latter with potassium hydroxide in toluene in the presence of polyethylene glycol gives (13S)-12-bromo-8, 13-epoxy-l3-methoxy-14,15-bisnorlabd-11-ene, ozonolysis of which followed by reduction of the ozonide with LiAlH₄ affords drimane-8, 11 I-diol.Translated fromIzvestiya Akademi Nauk. Seriya Khimicheskaya, No. 11, pp.2780–2784, November,1996     

Thermal analysis of the improved Hummers’ synthesis of graphene oxide

Journal of Thermal Analysis and Calorimetry - The improved Hummers’ synthesis of graphene oxide (GO) from graphite is investigated to monitor how the functional groups form during the...     

Facile synthesis of mesoporous magnesium oxide–graphene oxide composite for efficient and highly selective adsorption of hazardous anionic dyes

Mesoporous magnesium oxide–graphene oxide composite (MGC) has been synthesized using a facile post-immobilization method by mixing pre-synthesized magnesium oxide (MgO) with graphene oxide (GO). MgO used for fabrication of the composite has been synthesized using an environment-friendly method involving gelatin as a template. XRD, Raman and EDX analyses have confirmed the presence of MgO and GO in the composite. FTIR and SEM analyses of synthesized MGC have further elucidated the surface functionalities and morphology, respectively. Using N₂ adsorption–desorption isotherm, BET surface area of MGC has been calculated to be 55.9 m² g^?1 and BJH analysis confirmed the mesoporous nature of MGC. The application of synthesized MGC as a selective adsorbent for various toxic anionic dyes has been explored. Batch adsorption studies have been carried out to investigate the influence of different adsorption parameters on the adsorption of two anionic dyes: indigo carmine (IC) and orange G (OG). The maximum adsorption capacities exhibited by MGC for IC and OG are 252.4 and 24.5 mg g^?1, respectively. Plausible mechanism of dye adsorption has been explained in detail using FTIR analysis. In a mixture of cationic and anionic dyes, MGC selectively adsorbs anionic dyes with high separation factors, while in binary mixtures of anionic dyes, both dyes are adsorbed efficiently. Thus, MGC has been shown to be a potential adsorbent for the selective removal of anionic dyes from wastewater.

     

Synthesis of bicyclohomofarnesane compounds by the ozonization of “sclareol oxide”

Ozonolytic pathways for the selective transformation of sclareol oxide (I) with good yield into the bicyclohomofarnesane derivatives (II), (III), (V), and (VII) have been developed.Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 209–214, March–April, 1991.     

Passivation layer–dependent catalysis of zinc oxide nanostructures

Electrochemical and photoelectrochemical catalysis of surface-passivated zinc oxide (ZnO) nanostructures with three different metal oxides were investigated. Initially, vertically aligned ZnO nanorods structures were developed over conductive substrates by a two-step approach and then passivated with an ultrathin zinc hydroxide, that is, Zn(OH)₂, cobalt oxide, that is, CoO, and Zn(OH)₂/CoO as bilayer, by electrochemical deposition. Compared with the pristine ZnO structures, the surface-passivated nanostructures possess slightly rough surfaces, whereas their crystal structure remains unchanged. From electrochemical catalysis studies under dark and illumination, it is noticed that vertically aligned ZnO nanostructures passivated with narrow band-gap CoO layers have a predominant water oxidation performance than that of the structures passivated with other oxide materials. It is mainly attributed to the eradication of surface states present on ZnO nanorods. Interestingly, the structures passivated with bilayers, that is, Zn(OH)₂/CoO, showed significant stability and durability (～103% retention in current density@60^th min) with a continuous oxygen evolution reaction process for long durations.     

The Synthesis of Poly(ethylene oxide)-Block-Polybutylacrylate

ＴｈｅＳｙｎｔｈｅｓｉｓｏｆＰｏｌｙ（ｅｔｈｙｌｅｎｅｏｘｉｄｅ）┐Ｂｌｏｃｋ┐Ｐｏｌｙｂｕｔｙｌａｃｒｙｌａｔｅ＊＊ＳｕｐｐｏｒｔｅｄｂｙｔｈｅＮａｔｉｏｎａｌＮａｔｕｒａｌＳｃｉｅｎｃｅＦｏｕｎｄａｔｉｏｎｏｆＣｈｉｎａａｎｄＤｏｃｔｏｒａｌｆｏ...     

The Review of the Catalyst System of Poly（ethylene oxide）

聚氧化乙烯（PEO）是环氧乙烷经开环聚合而成的一种多功能水溶性聚合物,性能优异,用途广泛。本文简述了聚氧化乙烯的典型特征和国内外研究进展,综述了聚氧化乙烯制备的各类催化剂体系,描述了催化剂聚合环氧乙烷的聚合机理,重点介绍了几种具有工业应用前景的催化剂体系：烷基金属催化剂体系、烷氧基金属催化剂体系和碱土金属氨化物催化痢体系。并对其技术发展和应用进行了展望。     

Nanostructural oxide “memory” of rare earth molybdates

The structural aspects of the acid-base interaction in the course of formation of molybdates in the binary systems Ln₂O₃-MoO₃ have been considered. The structures of rare earth molybdates inherit infinite bands of {[LnO _n ]-[LnO _n ]} dimers from the structures of Ln₂O₃ oxides. The nanostructural oxide “memory” of molybdates implies that the dimers in these bands retain approximately nanometer sizes and predominant mutual orientation despite the fact that, as the Mo formula content increases, the types of polyhedra in the dimers change and the contacts between dimers and, eventually, between the polyhedra in these dimers are lost.     

Enthalpy of mixing in the propylene oxide–dimethylformamide and propylene oxide–ethylene glycol systems

Heat of mixing of propylene oxide with N,N-dimethylformamide and ethylene glycol has been determined by means of microcalorimetry. Theoretically suggested choice of the aprotic solvent as a selective separating agent for the propylene oxide–methanol binary mixture has been experimentally justified.     

Oxidative aromatization of 3,5-disubstituted 2-isoxazolines by nitric oxide

3,5-Disubstituted 2-isoxazolines were oxidized to corresponding isoxazoles by nitric oxide in dichloromethane. The reaction more likely occurred via a one-electron transfer process.     

Preparation and Electrocatalytic Activity of Polyaniline-poly（propylene oxide）

A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FFIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.     

Thermally stimulated dielectric properties of polyvinylidenefluoride–zinc oxide nanocomposites

Thirty-micrometer thick polyvinylidenefluoride (PVDF)–zinc oxide (ZnO) nanocomposite samples in the mass ratio of ZnO (1–6% (w/w)) have been prepared by solution mixing method. The nano- and microstructures of PVDF–ZnO nanocomposite of different mass ratios were characterized by using high-resolution techniques such as atomic force microscopy (AFM) and scanning electron microscopy (SEM). The SEM and AFM images show the presence of different components such as nanoparticles, amorphous and crystalline phases in nanocomposite samples. Dielectric properties of polymer nanocomposite based on PVDF and ZnO of different mass/% compositions have been studied to understand the molecular motion at different frequencies in the temperature range from 300 to 500 K. The permittivity of the nanocomposites decreases with frequency, while increases with the increasing temperature and ZnO content. The loss peak that disappeared at higher frequency is the remarkable result of this study.     

Synthesis of zinc oxide powders in plasma–solution systems

A new method is proposed for the synthesis of powdered zinc oxide with the use of a plasma–solution system. The chemical and phase compositions and the morphology of the synthesized powders have been determined. It has been found that the calcination of powders obtained in the plasma–solution system leads to the formation of ZnO.     

Selective assembly of cyclodextrins on poly(ethylene oxide)–poly(propylene oxide) block copolymers

This paper presents a computational study on the formation of a molecular necklace formed by specific threading of cyclodextrins (CDs) on block copolymers. Structural as well as energetic principles for the selective complexation of - and -cyclodextrin with poly(ethylene oxide)–poly(propylene oxide) block copolymers (PEO–PPO) are elucidated considering a diblock copolymer of equimolecular composition (PEO)4–(PPO)4 as guest. A non-statistical distribution of CDs, i.e. -CDs primarily located on the PEO chain and -CDs on PPO blocks of the polymer, is based on a variety of structural features and energetic preferences considering both potential as well as solvation energies. This selectivity becomes already obvious considering 1:1 complexes between PEO and PPO monomers and the two CDs, but is increasingly evident when calculating higher order ensembles. Besides the host–guest interaction, docking between CDs themselves is an important, also non-statistical, prerequisite for the self-assembly of highly ordered tubes. The formation of intermolecular hydrogen bonds between adjacent CDs in a tubular aggregate gives an important contribution to the overall stability of the molecular necklace. The net effect, based on the preferential interaction between host and guest as well as between the host molecules themselves, results in the formation of a stable, highly ordered macromolecular, multicomponent aggregate.