bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Elucidation on Different Lipid‐Oxidation Potentials of Aminoxyl Antioxidants
Authors: Wang Lan‐Fen , Zhang Hong‐Yu 
Published: September 2010

AbstractTo elucidate the different lipid‐oxidation potentials of aminoxyl antioxidants, a kind of combined density functional theory (DFT) method was employed to calculate CH bond dissociation enthalpies (BDEs) of a model linoleic acid (LH) and OH BDEs of hydrogenated aminoxyls. The higher the OH BDE is, the more potent the aminoxyl to abstract the H‐atom from LH and the stronger the LH‐oxidation potential. Accordingly, the prooxidant activity differences of aminoxyls were elucidated by the different OH BDEs of hydrogenated aminoxyls, which were further clarified in terms of distinct electronic effects of the substituents.
Thermodynamic Investigation of the Azeotropic Mixture Composed of Water and Benzene
Authors: Nan Zhao‐Dong , Tan Zhi‐Cheng 
Published: September 2010

AbstractThe molar heat capacity of the azeotropic mixture composed of water and benzene was measured by an adiabatic calorimeter in the temperature range from 80 to 320 K. The phase transitions took place in the temperature range from 265.409 to 275.165 K and 275.165 to 279.399 K. The phase transition temperatures were determined to be 272.945 and 278.339 K, which were corresponding to the solid‐liquid phase transitions of water and benzene, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.
Tailor and Control of Acidic Strength in Ordered Mesoporous Aluminosilicates by Using Preformed Zeolite Precursors
Authors: Lin Sen , Wang Li‐Feng , Han Yu , Yu Yi , Di Yan , Wang Run‐Wei , Jiang Da‐Zhen , Xiao Feng‐Shod 
Published: September 2010

AbstractThe acidic strength of ordered mesoporous aluminosilicates of MAS‐2, MAS‐3, MAS‐7 and MAS‐9 and microporous crystals of Y. L, beta, and ZSM‐5 zeolites was systemically investigated by temperature‐programmed desorption of ammonia (NH3‐TPD). Due to the use of preformed zeolite precursors of Y. L, beta and ZSM‐5, the ordered mesoporous aluminosilicates with distinguished acidic strength were obtained. being dependent on the type of preformed zeolite precursors. Therefore, the acidic strength of these mesoporous aluminosilicates could be tailored and controlled.
Kinetics of the First Order Autocatalytic Decomposition Reaction of Nitrocellulose (13.86% N)
Authors: Guo Peng‐Jiang , Hu Rong‐Zu , Ning Bin‐Ke , Yang Zheng‐Quan , Song Ji‐Rong , Shi Qi‐Zhen , Lu Gui‐E , Jiang Jin‐You 
Published: September 2010

AbstractThe kinetics of the first order autocatalytic decomposition reaction of nitrocellulose (NC, 13.86% N) was studied by using DSC. The results show that the DSC curve for the initial 508 of conversion degree of NC can be described by the first order autocatalytic equation magnified image and that for the latter 50% conversion degree of NC described by the reaction equations magnified image.
Theoretical Study on the Mechanism of the Cycloaddition Reaction between Alkylidene Carbene and Ethylene
Authors: Lu Xiu‐Hui , Zhai Li‐Min , Wu Wei‐Rong 
Published: September 2010

AbstractThe mechanism of cycloaddition reaction between singlet alkylidene carbene and ethylene has been investigated with second‐order Moller‐Plesset perturbation theory (MP2). By using 6–31G* basis, geometry optimization, vibrational analysis and energetics have been calculated for the involved stationary points on the potential energy surface. The results show that the title reaction has two major competition channels. An energy‐rich intermediate (INT) is firstly formed between alkylidene carbene and ethylene through a barrier‐free exothermic reaction of 63.62 kJ/mol, and the intermediate then isomerizes to a three‐membered ring product (Pl) and a four‐membered ring product (P2) via transition state TS1 and TS2, in which energy barriers are 47.00 and 51.02 kl/mol. respectively. PI is the main product.
Application of Ultrasonic Attenuation Measurements in the Studies on Macromolecular Conformational Behaviors —Phase Behavior of the Aqueous Solution of Poly(vinyl methyl ether) Sensitive to Temperature and the Modification of the Behavior by Using Poly(acrylic acid)
Authors: Wang Gong‐Zheng , Fang Yu , Shang Zhi‐Yuan , Zhang Mng , Hu Dao‐Dao 
Published: September 2010

AbstractThe phase behavior of the aqueous solution of poly(vinyl methyl ether) (PVME) sensitive to temperature and the modification of the behavior by using poly(acrylic acid) (PAA) have been studied by ultrasonic attenuation measurements and fluorescence probe techniques. It has been observed that PVME solution is transparent at mom temperature and becomes turbid upon heating. The solution turns clear again as smn as the temperature is decreased to room temperature. The heating and cooling process can be repeated for many times. The phase behavior of the solution sensitive to temperature is attributed to the conformational changes of the polymer. PVME may adopt an open coil conformation at mom temperature. With this conformation, the polymer is well miscible with the solvent, water, and thereby the system is a real solution. The polymer may adopt a compact coil conformation when the temperature is higher than a specific value. which is called the LCST (the lower critical solution temperature) of PVME. In this case, the polymer tangles to each other and forms various aggregates, which can scatter incident light and ultrasonic waves greatly. resulting in the phase separation, Introduction of PAA decreases the temperature sensitivity of the phase behavior of the polymer. The nature of the inhibition is attributed to the complexation of PAA with PVME and the strong hydrophilicity of PAA. Results from fluorescence probe studies are in accordance with those from ultrasonic attenuation measurements, indicating again that the ultrasonic attenuation method can be successfully used for the qualitative studies of polymer conformations and complexation between polymers.
Preparation and Characterization of Divanadium Pentoxide Nanowires inside SBA‐15 Channels
Authors: Zhu Ka‐Ke , Yue Bin , Xie Song‐Hai , Zhang Si‐Yi , Zhang Biao , Jin Song‐Lin , He He‐Yong 
Published: September 2010

AbstractOne‐dimensional V2O5 nanowires have been synthesized inside the channels of mesoporous silica SBA‐15 through chemical approach, which involves aminosilylation of silanol groups on the silica surface, anchoring of isopoly acid, H6V10O28. by neutralization of basic amine groups, and thermal decomposition. The formation and physicochemical properties of the nanowires were monitored and studied by TG‐DTA, variable temperature in situ XRD, TEM, N2 sorption measurements and UV‐Vis DRS. The results indicate that V2O5 nanowires formed within SBA‐15 channels belong to orthorhombic polycrystal domains. The oxygen‐to‐metal charge transfer band of V2O5 nanowires shows a blue shift in comparison with bulk V2O5, which clearly exhibits the quantum size effect of nanowires.
Synthesis and Crystal Structure of the Copper Complex of 7,16‐Bis(2‐hydroxy‐5‐methylbenzyl)‐1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane
Authors: Ma Shu‐Lan , Zhu Wen‐Xiang , Guo Qian‐Ling , Liu Ying‐Chun , Xu Miao‐Qiong 
Published: September 2010

AbstractA lariat crown ether ligand 7.16‐bis (2‐hydroxy‐5‐methylbenzyl)‐1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane (Ll) has been prepared via one‐pot Mannich reaction. Its copper(II) complex Cu‐Ll was synthesized and characterized by elemental analysis, IR and UV‐visible spectroscopy. The crystal structure of the complex has been determined by X‐ray diffraction analysis. The result shows that the copper(II) ion is six‐coordinated by two nitrogen and four oxygen atoms, two from the crown ether and the other two from the deprotonated phenolate anions, forming an elongated octahedral complex. Electrochemical study indicates that the complex undergoes reversible reduction in DMF solution.
Crystal Structures and Characterizations of Bis(1‐benzoyl‐methyl‐benzotriazole‐N3)dichoro Metal(ll) Complex: [MCl2‐‐(CsH4N3CH2COPh)2] [M=Zn(ll), Co(ll)]
Authors: Jian Fang‐Fang , Sun Ping‐Ping , Xiao Hai‐Lian , Jiao Kui 
Published: September 2010

AbstractThe structures of [MCl2(C6H4B3CH2COPh)2] [M=Zn(II) (1), Co(II) (2)] have been determined by X‐ray crystallography. They were characterized by elemental analysis, IR spectrum, electronic spectrum and thermogravimetric‐differential thermal analysis. They all crystallize in the triclinic system, space pup Pi, with lattice parameters a=0.9449(2) nm, b=1.1291(2) nm, c=1.3637(3) nm, α=111.70(3)°, β= 94.33(3)°, y=90.97(3), Z=2 for compound 1; a=0.9437(2) nm, b= 1.1277(2) nm, c= 1.3650(3) nm, a=111.76(3)°, β=94.50(3)°, y=90.80(3)°, Z=2 for compound 2. The metal ions are all coordinated by two C1−‐ anions and two nitrogen atoms of 1‐benzoylmethyl‐bentriazole ligands. forming the distorted tetrahedral geometry. The Zn—Cl and Zn—N bond lengths are 0.2209(2), 0.2210(2) nm and 0.2059(4), 0.2067(4) nm. respectively. The CO‐Cl 3 and Co–N bond lengths are 0.2215(2). 0.2222(2) nm and 0.2028(5), 0.2045(5) nm. respectively. The thermogravimetric (TG) data indicate that they are nearly similar in TG curve, and there are not structural transitions in the two compounds. They all have a high thd stability. But, there is little difference in DTG (differential thermogravimetric) curves of those two compounds. Elemental analysis, electronic and IR spectra are in agreement with the structural data.
Synthesis, Structure and Biological Activity of Zn(ll) Complex with Tris(benzimidazol‐2‐yl‐methyl)amine Ligand
Authors: Liu Xiao‐Lan , Zhao Ru , Liu Xiao‐Hong , Yue Jun‐Jie , Yin Yu‐Xin , Sun Yun , Sun Ming 
Published: September 2010

AbstractA new Zn(II) mononuclear complex with tris(benzimidazol‐2‐yl‐methyl)amine (NTB) was synthesized with stoichiometry of [Zn(NTB)NO3]NO3 · DIPY · DMF (DIPY : 4,4′‐dipyridyl). The complex was characterized by elemental analysis, UV and IR spectra. The crystal structure was determined by using X‐ray diffraction analysis. The crystal structure indicates that four N atoms and one O atom coordinate to zinc ion to construct a distorted trigonal‐dipyramid configuration. Three nonprotonated N atoms from imidazole groups are in the equatorial plane, one alkylamino N atom and one O atom from NO3−‐ in the axial directions. The biological activity assay shows that this complex presents certain biological activity by means of pyrogallol autoxidation and it can be called a model compound of superoxide dismutase (SOD).
Fluorescence Quenching of Poly[2‐methoxy‐5–(2′‐ethylhexoxy)‐p‐phenylene vinylene] (MEH‐PPV) in Solutions
Authors: Li Sha‐Yu , Xiong Fei , Zhang Hai‐Rong , Lu Xue‐Fang , Li Yi , Yang Guo‐Qiang 
Published: September 2010

AbstractFluorescence quenching processes of poly[2‐methoxy‐5–(2′ethyl‐hexoxy)‐p‐phenylene vinylene] (MEH‐PPV) in solution by electron acceptors, O2 and acid, have been studied. Static quenching of the fluorescence from MEH‐PPV by an electron acceptor (DDQ or TCNE) occurs due to electron transfer from MEH‐PPV to the electron acceptor and this electron transfer quenching can be promoted by chloroform. Photooxidation takes place in the MEH‐PPV solution and singlet oxygen is an intermediate in the photooxidation. according to the results of ESR spectroscopy. Acid also plays an important role in the fluorescence quenching process of MEH‐PPV, by the protonation of the alkoxy groups in the molecular chain.
Studies on Synthesis and Photochromism of a Novel Class of Fulgimide: (Z)‐4‐Oxazolylfulgimide
Authors: Xiao Jun‐Ping , Han Yong , Chen Yi , Li Wen , Fan Mei‐Gong 
Published: September 2010

AbstractA novel class of fulgimide, (Z)‐4‐oxazolylfulgimide ((Z)‐1‐benzyl‐4–isopropylidene‐3–[1–(2–aryl‐5–methyl‐oxazolyl)ethylidene]tetrahydropyrrole‐2, 5–dione), was synthesized by the reaction of (Z)‐4–oxazolyl fulgide (4–isopropylidene‐3–[1–(2–aryl‐5–methyloxazolyl)ethylidene]tetrahydrofuran‐2, 5–dione) with benzyl amine. Photochromic property of (Z)4–oxazolylfulgimide was studied. Compared with (Z)‐4–oxazolylfulgide, the absorption maximum of the colored form of (Z)‐4–oxazolylfulgimide is bathochromic‐shifted. Substituents on the aryl ring affect the absorption maximum of the open form and the colored form of (Z)‐4‐oxazolylfulgimide.
Michael‐Addition Reaction of Malononitrile with α,β‐Unsaturated Cycloketones Catalyzed by KF/Al2O3
Authors: Wang Xiang‐Shan , Shi Da‐Qing , Tu Shu‐Jiang 
Published: September 2010

AbstractA series of KF/Al2O3catalyzed Michael‐addition reactions between malononitrile and α,β‐unsaturate cycloketones in DMF solution were studied. At room temperature, 2‐cyano‐3‐aryl‐3–(1, 2, 3, 4‐tetrahydronaphthalen‐1‐one‐2‐yl) propionitrile derivatives were synthesized by the reaction between 2‐arylmethylidene‐1, 2, 3, 4‐tetra‐hydronaphthalen‐l‐one and malononitrile. However, if the temperature was increased to 80 C, 2‐amino‐3‐cyano‐4‐aryl‐4H‐benzo[h]chromene derivatives were obtained in high yields. When the α,β‐unsaturated ketones were replaced by 2, 6‐biarylmethylidenecyclohexanone or 25‐biarylmethylidenecyclopentanone, another series of 2‐amino‐3‐cyano‐4H‐pyran derivatives was isolated successfully. The structures of the products were confirmed by X‐ray diffraction analysis.
Synthesis of Zeolite ZSM‐2 Using Zeolite NaX as Seeds
Authors: Yi Hong‐Jiang , Wu Tai‐Liu , Wang Li‐Ping , Sun Yao‐Jun 
Published: September 2010

AbstractA method is presented for the synthesis of zeolite ZSM‐2 by adding zeolite X as seeds in the synthetic mixture containing both lithium and sodium. At the presence of zeolite X seeds, highly crystalline zeolite ZSM‐2 with composition of (0.3–0.7)Li2O·(0.7–0.3)Na2O·A12O3, · (2.5–4.0)SiO2 a nH2O can be obtained in a wide range of SiO2/Al2O3 ratios from 2.5 to 16, and the optimum Li2O/(Li2O+Na2O) fraction is between 0.3 and 0.7. The ZSM‐2 products were characterized by XRD. SEM, IR. 29Si MAS NMR and DTA/TG analysis etc. By 29Si MAS NMR spectroscopy, it was found that ZSM‐2 contained nearly equal FAU and EMT phase, and the Si/Al ratios in FAU were slightly lower than those in EMT domains in most cases. The lithium form zeolite ZSM‐2 has comparable N2 adsorption capacity with LiX.
Adsorption Study of Methane on Activated Meso‐carbon Microbeads by Density Functional Theory
Authors: Shao Xiao‐Hong , Huang Shi‐Ping , Shen Zhi‐Gang , Chen Jian‐Feng 
Published: September 2010

AbstractA combined method of density functional theory (DFT) and statistics integral equation (SIE) for the determination of the pore size distribution (PSD) is developed based on the experimental adsorption data of nitrogen on activated mesocarbon microbead (AMCMB) at 77 K. The pores of AMCMB are described as slit‐shaped with PSD. Based on the PSD, methane adsorption and phase behavior are studied by the DR method. Both nitrogen and methane molecules are modeled as Lennard‐Jones spherical molecules. and the well‐known Steele's 10–4–3 potential is used to represent the interaction between the fluid molecule and the solid wall. In order to test the combined method and the PSD model, the Intelligent Gravimetric Analyzer (IGA‐003) was used to measure the adsorption of methane on the AMCMB. The DFT results are in good agreement with the experimental data. Based on these facts, we predict the adsorption amount of methane, which can reach 32.3 w at 299 K and 4 MPa. The results indicate that the AMCMBs are a good candidate for adsorptive storage of methane and natural gas. In addition, the capillary condensation and hysteresis phenomenon of methane are also observed at 74.05 K.
Simulations of Metal Cu in Heating Process
Authors: Zhang Tao , Wu Ai‐Ling , Guan Li , Qi Yuan‐Hua 
Published: September 2010

AbstractBased on the Finnis‐Sinsclair (FS) many‐body potential model, the melting process of a system, which consists of 500 Cu atoms, controlled by period boundary condition has been simulated. The means of pair correlation function, mean square displacement and Honeycutt‐Anderson bonded pair have been used to characterize the melting behavior of Cu at different heating rates. The simulation indicates that melting point of metal Cu is 1444 K during a continuous heating process, and the calculated diffusion constant at the melting point is 4.31×10−‐9/s. These results are better than those from the EAM method, showing that the FS potential model works well in some disordered systems.
Analysis and Protection of One Thousand Hand Buddha in Dazu Stone Sculptures
Authors: Wang Li‐Qin , Dang Gao‐Chao , Wang Xiao‐Qi , Xi Zhou‐Kuan , Liang Guo‐Zheng 
Published: September 2010

AbstractThe components of the rock, the pigments, the gold foils and the adhesive of One Thousand Hand Buddha in Dazu stone sculptures, Chongqing. China, have been analyzed by X‐ray diffraction (XRD). X‐ray fluorescence (XW. infrared spectroscopy (IR), energy dispersive X‐ray analysis (EDX) and fiber optics reflectance spectroscopy (FORS). Furthermore, the weathering and degeneration of One Thousand Hand Buddha have been discussed and the protective methods have been provided. In this work some useful information to study on conservation of stone relics is given.
Highly Stereoselective Synthesis of Phenylseleno‐ and p‐Tolylsulfonyl Substituted 1,3‐Dienes from Functionalized Allyl Alcohols
Authors: Xie Mei‐Hua , Huang Xian 
Published: September 2010

AbstractPhenylseleno‐ and p‐tolylsulfonyl substituted 1,3‐dienes were conveniently prepared with high stereoselectivity by the elimination reaction of phenylseleno‐ and p‐tolylsulfonyl substituted allyl alcohols in the presence of BF3 · Et2O in acetic anhydride. The products were characterized by 1H NMR, MS, IR and elemental analysis. The single crystal structure of 2a was determined by X‐ray diffraction analysis.
Three New Diterpenoids from Euphorbia wallichii
Authors: Wang Huan , Zhang Xiao‐Feng , Cai Xiang‐Hai , Ma Yun‐Bao , Luo Xiao‐Dong 
Published: September 2010

AbstractThree new abietane diterpene lactones, 3α‐hydroxyjolkinolide A (1), ent‐8α, 14β‐dihydroxy‐ 13(15)‐ene‐16(12α)‐abietanolide (2) and ent‐8α, 14α‐dihydroxy‐13(15)‐ene‐16(12α)‐abietanolide (3) as well as a known abietane diterpene jolkinolide A (4) were isolated from the roots of Euphorbia wallichii. Their structures were elucidated on the basis of spectroscopic analysis.
Asymmetric Hydroformylation of Olefins Catalyzed by a Chiral Diphosphite‐Rhodium Complex
Authors: Yan Ming , Li Xing‐Shu , Chan‐Chi Albert Sun 
Published: September 2010

AbstractA C2‐symmetrical aryl diphosphite derived from chiral binaphthol was prepared and its rhodium complex was used as catalysts in the asymmetric hydroformylation of olefin. High catalytic activity and good regioselectivity were observed. Up to 31.2% ee and 38.1% ee were achieved for the hydroformylation of 4‐fluoro‐styrene and vinyl acetate respectively. The influences of ligand‐to‐metal ratio, reaction temperature and the pressure of syn‐gas on the enantioselectivity and regioselectivity were also studied.
Electrodeposition, Structure and Corrosion Resistance of Nanocrystalline Ni‐W Alloy
Authors: Yang Fang‐Zu , Guo Yi Fei , Huang Ling , Xu Shu‐Kai , Zhou Shao‐Min 
Published: September 2010

AbstractNi—W alloy was electrodeposited from the electrolyte solution containing sodium tungstate, nickel sulfate and ammonium citrate. The electrodeposition, heat treatment, structure, surface morphology and corrosion resistance in w=0.03 NaCl solution, of Ni—W alloys were studied by means of DSC, XRD, SEM and electrochemical techniques. The results showed that the obtained Ni—W alloy electrodeposit with W weight content (ww=0.471) was presented in more typical nanocrystalline. After heat treatment at 400 C for 1 h, the phase structure of the deposits was not obviously changed whereas the agglomerate for the reunion of tiny grains on deposit surface caused the granule in a more smooth morphology, the microhardness was slightly increased and the corrosion resistance was enhanced.
Li3AIB2O6: Synthesis, Crystal Structure, and Its Luminescence Property Compared with LiSrBO3
Authors: Wang Hai‐Xia , Cheng Wen‐Dan , Chen Da‐Gui , Zhang Hao , Wu Dong‐Sheng , Gong Ya‐Jin 
Published: September 2010

AbstractThe synthesis and crystal structure of Li3AlB2O6 with different cell parameters are reported and these cells are transformed each other from the confirmation of crystallographic structural analyses. The absorption spectrum, luminescence and lifetimes of the Li3AlB2O6 and LiSrBO3 solid compounds are measured and the comparisons are made between them. It is shown that the absorption edges are at about 400 run (or band gap 3.1 eV) and there is one of absorption peaks at about 350 run for the Li3AlB2O6 and LiSrBO3. The emission band (530 nm) makes a red shift and fluorescence decay time (24.39 ns) of the Li3AIB2O6 becomes smaller compound with the emission band (480 nm) and lifetime (93.16 ns) of the LiSrBO3 at the visible region. The transition energies and oscillator strengths of the clusters (Li3AlB2O6)2 and (LiSrBO3)2 lying at low excited states are calculated by the time‐dependent Har‐tree‐Fock method. The obtained results arc used to model the photophysical properties and discuss the origin of spectral bands of the Li3AlB2O6 and LiSrBO3.
Nanostructure Pt Electrode Obtained via Self‐assembly of Nanoparticles on Conductive Oxide‐coated Glass Substrate
Authors: Wang Wei‐Bo , Luo Zhen , Xiao Xu‐Rui , Lin Yuan 
Published: September 2010

AbstractSelf‐assembly of platinum nanoparticles were applied to fabrication of counter electrode for dye‐sensitized solar cells on conductive oxide‐coated glass substrate. The present Pt electrode exhibits high exchange current density of 220 mA/cm2, which is comparable to those prepared by electrodeposition. magnetron sputtering or thermal decomposition of platinum chloride. After analysis by transmission electron microscopy (TEM). atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS), it was found that the catalyst was structurally characterized as nanosized platinum metal clusters and was continuously arranged on electrode surface. The present nanostructure electrode had high electrocatalytic activity for the reduction of iodine in organic solution.
Molten Salt Synthesis, Crystal Structure and Optical Properties of a Novel Quaternary Metal Selenide, K2AgIn3Se6
Authors: Guo Hong‐You , Wang Zhi‐Xia , Shu Gui‐Ming , Wang Ru‐Ji , Zhang Li‐Dan , Wang Ping 
Published: September 2010

AbstractK2AgIn3Se6 was synthesized by a molten‐salt (alkali‐metal polyselenide flux) reaction at 500 C. The orange red granular crystal crystallizes in monoclinic space group C2/c with cell parameters, a =1.16411(7) nm, b= 1.16348(8) nm, c=2.14179(12) nm, V=2.8740(9) nm3, and Z=8. The crystal has a new two‐dimensional structure containing 2‐−[AgInSe6]2‐− anionic layers separated by K+ cations and the 2‐−[AgIn3Se6]2‐− layer is constructed with comer‐shared [AgSe4] and [InSe4] tetrahedra. The optical band gap of K2AgIn3Se6 was determined to be ca. 2.9 eV by UV/vis/NIR diffuse reflectance spectra.