bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of nano‐sized Co3O4 as anode materials for lithium‐ion batteries
Authors: Huang Feng , Zhan Hui , Zhou Yun‐Hong 
Published: September 2010

AbstractThe structural evolution of the Co3O4 fine powders prepared by rheological phase reaction and pyrolysis method upon different temperature has been investigated using X‐ray diffraction (XRD) topography. The electrochemical performance of Co3O4 electrode materials for Li‐ion batteries is studied in the form of Li/Co3O4 cells. The reversible capacity as high as 930 mAh/g for the Co3O4 sample heat‐treated at 600 °C is achieved and sustained over 30 times charge‐discharge cycles at room temperature. The detailed information concerning the reaction mechanism of Co3O4 active material together with lithium ion is obtained through ex‐situ XRD topography, X‐ray photoelectron spectroscopy (XPS) analysis and cyclic voltammetry (CV) technique. And it is revealed that a “two‐step” reaction is involved in the charge and discharge of the Li/Co3O4 cells, in which Co3O4 active material is reversibly reduced into xCoO(3 ‐ x)CoO and then into metallic Co.
A novel fluorescent aminoacid designed for fluorometric detection of Cu(II)
Authors: Sun Xiang‐Ying , Wen Zhen‐Chang , Jiang Yun‐Bao 
Published: September 2010

AbstractA fluorescent aminoacid was designed for selective and sensitive detection of Cu(II) in aqueous solution. The designing of this Cu(II) fluorescent chemosensing molecule, N ± (1‐naphthyl). aminoacetic acid (NAA), was based on the binding of Cu(II) to aminoacetic acid and the novel charge transfer photophysics of 1‐aminonaphthalenes. The fluorescence of NAA was found quenched by Cu (II) and several other metal ions of similar electronic structure such as Co(II), Ni(II) and Zn(II). The quenching was shown to occur via electron transfer within the metal‐NAA complex, which required an optimal combination of high binding affinity and favorable redox properties of the components in the metal‐NAA complex and hence afforded selective fluorometric detection of Cu(II). The calibration graph obeyed Stern‐Volmer theory and was shown for Cu(II) over the range of 0–2.75 ± 10–4 mol/L. The quenching constant of Cu(II) was measured as 8.0 ± 103 mol/L that was two orders of magnitude higher than those of Co(II), Ni(II) and Zn(II). The 3SD limit of detection for Cu(II) was 8.00 ± 10−6 mol/L with a coefficient of variation of 1.65%. Linear range for quantitative detection of Cu(II) was 2.67 ± 10−5‐2.75 ± 10−4 mol/L. The method was applied to synthetic sample measurements which gave recoveries of 105%‐112%.
Triterpenoid constituents of Huperzia miyoshiana
Authors: Tong Xiao‐Tian , Tan Chang‐Heng , Zhou Hui , Jiang Shan‐Hao , Ma Xiao‐Qiang , Zhu Da‐Yuan 
Published: September 2010

AbstractThirteen triterpenoids, including three new ones, miyoshianols A (1), B (2) and C (3), were isolated from Huperzia miyoshiana. The structures of these new compounds were established as 3‐O‐dihydroferuloyltohogenol (1), 16‐oxo‐3β, 21β‐dihydroxy‐serrat‐14‐en‐24‐ferulate (2) and 16‐oxo‐3α, 21β‐dihydroxyserrat‐14‐en‐24‐ferulate (3), respectively, on the basis of their spectroscopic analysis.
Calix[4] crowns with Methoxynaphthoylmethyl Pendant Groups
Authors: Jin Chuan‐Min , Lu Guo‐Yuan , Zhang Chao‐Zhi , Shi Zheng‐Wei , You Xiao‐Zeng 
Published: September 2010

AbstractThe novel calix [4] crowns with two pendant groups were prepared by the alkylation of calix [4] crowns with 6‐methoxy‐2‐bromoacetylnaphthalene. 1H NMR titration and picrate extraction experiments indicated that they exhibit higher complexing efficiency than their parent compounds and possess obvious selectivity for Na+ or K+, respectively, and that the cation is encapsulated inside the preorganized ionophoric cavity defined by carbonyl oxygens, the crown ether and the phenoxy oxygens. From UV and fluorescent spectra it is revealed that calix [4]‐crown‐4 3a with 6‐methoxy‐2‐naphthoylmethyl pedant groups exhibits remarkable cation‐induced photophysical effects and it could be utilized as a selective fluorescent sensor for Ca2+.
Substituent Effects on the Hydrogen Bonding between 4‐Substituted Phenols and HF, H2O, NH3
Authors: Cheng Yu‐Hui , Fu Yao , Liu Lei , Guo Qing‐Xiang 
Published: September 2010

AbstractDensity function theory UB3LYP/6–31 + g(d) calculations were performed to study the hydrogen bonds between para‐substituted phenols and HF, H2O, or NH3. It revealed that many properties of the non‐covalent complexes, such as the interaction energies, donor‐acceptor distances, bond lengths and vibration frequencies, showed well‐defined substituent effects. Therefore, from the substituent effects not only the mechanism of a certain non‐covalent interaction can be better understood, but also the interaction energies and structures of a certain non‐covalent complex, which otherwise might be very hard or resource‐consuming to estimate, can be easily predicted.
Study of Activation and Inhibition of Certain Metal Ions to Amylase Catalyzed Reaction by Microcalorimetry
Authors: Zhang Hong‐Lin , Yu Xhi‐Fang , Nie Yi , Liu Xiao‐Jing , Zhang Gang 
Published: September 2010

AbstractWith or without activation or inhibition of metal ion, the power‐time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant (K), apparent Michaelis constant (Km), maximum velocity (vm) and apparent maximum velocity (vam) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method.On the basis of data obtained, the following relationships between Km and concentration of metal ion (c) were establishedfor inhibitor of Ni2+Km = 2.9648 × 10−3‐1.3912 × 10−4cR =0.9998for inhibitor of Co2+Km = 1.0227 × 10−3 + 8.2676 × 10−6cR = 0.9955for activator of Ca2+Km = 1.0630 × 10–7c2‐1.8311 × 10−6c + 9.3058 × 10−6R = 0.9999for activator of Li+Km = 5.6300 × 10–8c2‐1.5329 × 10−6c + 1.2662 × 10−5R = 0.9999The Km‐c relationships show a strenuous inhibitory effect for Ni2+ and a strenuous active effect for Ca2+.
QSAR Studies on the COX‐2 Inhibition by 3,4‐Diarylcycloxazolones Based on MEDV Descriptor
Authors: Liu Shu‐Shen , Cui Shi‐Hai , Yin Da‐Qiang , Shi Yun‐Yu , Wang Lian‐Sheng 
Published: September 2010

AbstractSelective inhibition of cyclooxygenase‐2 (COX‐2) might avoid the side effects of current available nonsteroidal antiinflammatory drugs while retaining their therapeutic efficacy. A novel variable selection and modeling method based on prediction is developed to construct the quantitative structure‐activity relationships (QSAR) between the molecular electronegativity distance vector (MEDV) based on 13 atomic types and the biological activities of a set of selective cyclooxygenase‐2 inhibitory molecules, 3,4‐diarylcycloxazolones (DAA) plus indomethacin, naproxen, and celecoxib. Using multiple linear regression, a 5‐variable linear model is developed with the calibrated correlation coefficient of 0.9271 and root mean square error of 0.17 in modeling stage and the validated correlation coefficient of 0.9030 and root mean square error of 0.20 in leave‐one‐out validation step, respectively. To further test the predictive ability of the model, 20 DAA compounds are picked up to construct a training set which is used to build a QSAR model and then the model is employed to predict the biological activities of the balance compounds. The predicted correlation coefficient and root mean square error are 0.9332 and 0.19, respectively.
Synthesis and Liquid Crystal Behaviors of 2,4‐Dioxo‐3‐pentyl 4‐decyloxy Cinnamate Rhodium(I) Complexes
Authors: Han Jie , Zhang Liang‐Fu , Wan Wen 
Published: September 2010

AbstractThe title complexes have been synthesized by the reaction of [RhCl(CO)2]2 or [RhCl(COD)]2 (COD = 1,5‐cyclooctadiene) with the organic ligand 2,4‐dioxo‐3‐pentyl 4‐decyloxy cinnamate 2. The complex 3 based on dicarbonylrhodium(I) shows nematic phase, while the complex 4 containing rhodium(I) bound to a COD ligand is a nonmesogen. The relationship between molecular structures and liquid crystal behavior has also been discussed by means of computer‐aided molecular modeling.
Morphology Control over the Organic Nanoparticles of 1, 3‐Diphenyl‐5‐(9‐anthryl)‐2‐pyrazoline
Authors: Xi Lu , Xiao De‐Bao , Yang Wen‐Sheng , Yao Jian‐Nian , Zhang Bao‐Wen 
Published: September 2010

AbstractThe organic nanoparticles of a blue‐light‐emitting molecule, 1, 3‐diphenyl‐5‐(9‐anthryl)‐2‐pyrazoline, were prepared by reprecipitation method using acetonitrile as the solvent for the molecular precursor. Three morphologies, spherical, doughnut‐shaped and cubic, could be observed on the silicon substrate for the nanoparticles by the volume‐controlled addition of acetonitrile. The evolution of particle morphology as a function of acetonitrile addition was attributed to the variation of the growth habits of the particles in the different environment. The nanoparticles exhibit the novel photoluminescence spectra as compared to those of monomer and the bulk crystals.
Total Synthesis of (‐)‐Kaerophyllin, (‐)‐Hinokinin and (±)‐Isohinokinin
Authors: Xia Ya‐Mu , Liang Qi‐Ren , Wang Xiao‐Long , Cao Xiao‐Ping , Pan Xin‐Fu 
Published: September 2010

AbstractA convenient and rapid approach for the syntheses of (‐)‐kaerophyllin (1), (‐)‐hinokinin (2) and (±)‐isohinokinin (3) was described. The key steps were involved in condensation of aromatic aldehyde and alkylation of the resulting ester to give the complete skeleton of dibenzylbutyrolactone‐lignan. Hydrolysis, followed by resolution with quinine, reduction and when appropriate, oxidation gave the title compound. The asymmetric total synthesis of the kaerophyllin (1) was reported for the first time.
Molecular Dynamics Studies of the Kinetics of Phase Changes in Clusters IV: Crystal Nucleation from Molten (NaCl)256 and (NaCl)500 Clusters
Authors: Li Xiao‐Hua , Huang Jin‐Fan 
Published: September 2010

AbstractMolecular dynamics computer simulation based on the Born‐Mayer‐Huggins potential function has been carried out to study the effects of cluster size and temperature on the nucleation rate of sodium chloride clusters in the temperature range of 580 K to 630 K. Clusters with 256 and 500 NaCI molecules have been studied and the results have been compared with those obtained from 108 molecule clusters. The melting point (MP) of the dusters were observed to increase with the size of the clusters and can be well described by a linear equation MP = 1107(37)‐1229(23)N−1/3(N is the number of molecules in the cluster). The nucleation rate was found to decrease with increasing the cluster size or temperature. Various nucleation theories have been used to interpret the nucleation rates obtained from this molecular dynamics simulation. It is possible to use a constant diffuse interface thickness to interpret the nucleation rate from the diffuse interface theory in the temperature range of this study. However, the interfacial free energy estimated from classical nucleation theory and diffuse interface theory increases too fast with increasing the temperature while that from Gran‐Gunton theory does not change with changing temperatures. The sizes of critical nuclei estimated from all the theories are smaller than those estimated from our simulations.
A New Formulation of the Lindemann Mechanism of Unimolecular Reactions
Authors: Qian Ren‐Yuan 
Published: September 2010

AbstractA new formulation of the Lindemann mechanism of unimolecular reactions in gaseous phase is presented, without the use of steady state hypothesis. It is hereby shown that the nature of applicability of steady state hypothesis in the regime of high reactant gas pressure is different from that in the regime of low gas pressure. In the former case it is an equilibrium approximation, while in the latter case it is a highly reactive intermediate approximation in no connection with a steady state. Furthermore for the latter case it is shown that in the classical formulation of Lindemann mechanism the use of steady state hypothesis is an ad hoc assumption. A highly reactive intermediate in the sense that its concentration is very small during the whole course of reaction is a necessary condition for the applicability of very reactive intermediate approximation. When the two distinctive nature of the applicability of steady state hypothesis is mixed‐up, wrong or useless conclusion may be arrived at. The only possible case of realizing a true steady state in a complex reaction is pointed out.
DAR Assisted Layer‐by‐Layer Assembly of Aromatic Compounds
Authors: Jiang Si‐Guang , Chen Xiao‐Dong , Zhang Li , Liu Ming‐Hua 
Published: September 2010

AbstractA facile DAR (diphenylamine‐4‐diazonium‐formaldehyde resin) assisted layer‐by‐layer (LbL) assembly of ultrathin organic film of aromatic compounds has been investigated. The multilayer of pyrene or anthracene was fabricated through simple dipping of the glass slide into the mixed solution of DAR with the target compounds. In this method, DAR acted as an assistant compound to help the assembling of the aromatic compounds. Such a convenient deposition method not only reserves the advantages of the traditional LbL technique but also simplifies the technique and extends the effectiveness of LbL technique to small molecules without any charge.
On the Importance of CP‐corrected Gradient Optimization in the Study of Hydrogen Bonded Systems
Authors: Wang Wei‐Zhou , Pu Xue‐Mei , Zheng Wen‐Xu , Wong Ning‐Bew , Tian An‐Min 
Published: September 2010

AbstractGeometries, harmonic vibrational frequencies and interaction energies of the water‐hydrogen sulfide dimer, hydrogen fluoride dimer and glycine zwitterion‐water dimer were determined by the counterpoise‐corrected (CP‐corrected) gradient optimization that explicitly corrects for the basis set superposition error (BSSE) and CP‐uncorrected (normal) gradient optimization respectively at the B3LYP and MP2 levels of theory, employing the popular Pople's standard 6–31G(d), 6–31G(d, p) and 6–311 + + G(d, p) basis sets in order to assess the importance of CP‐corrected gradient optimization in the study of hydrogen bonded systems. The normal optimization of these three H‐bonded systems obtained using these popular basis sets all yielded erratic results, whereas use of CP‐corrected gradient optimization led to consistent results with those from larger basis sets. So this CP receipt becomes useful and necessary to correctly describe large systems, where the use of small basis sets may be necessary.
3D‐QSAR Study on Apicidin Inhibit Histone Deacetylase
Authors: Chen Hai‐Feng , Kang Jiu‐Hong , Li Qiang , Zeng Bao‐Shan , Yao Xiao‐Jun , Fan Bo‐Tao , Yuan Shen‐Gang , Panay A. , Doucet J. P. 
Published: September 2010

AbstractFor Histone Deacetylase (HDAC) Inhibitor, four 3D‐QSAR models for four types of different activities, were constructed. The cross‐validated q2 value of CoMFA Model 1 is 0.624 and the noncross‐validated r2 value is 0.939. The cross‐validated q2 value of Model 2 for training set is 0.652 and the noncross‐validated r2 value is 0.963. The cross‐validated q1 value for Model 3 is 0.713, with noncross‐validated r2 value 0.947. The cross‐validated q2 value for Model 4 is 0.566 with noncross‐validated r2 value 0.959. Their predicted abilities were validated by different test sets which did not include in training set. Then the relationship between substituents and activities was analyzed by using these models and the main influence elements in different positions (positions 8 and 14) were found. The polar donor electron group of position 8 could increase the activity of inhibition of HDAC, because it could form chelation with the catalytic Zn. Suitable bulk and positive groups at position 14 are favorable to anti‐HDAC activity. These models could well interpret the relationship between inhibition activity and apicidin structure affording us important information for structure‐based drug design.
Synthesis, Structure and Biological Activities of S‐[a‐(4‐Methoxyphenylcarbonyl)‐2‐(1, 2, 4‐triazole‐1‐yl)] ethyl‐N, N‐dimethyldithiocarbamate
Authors: Xu Liang‐Zhong , Jian Fang‐Fang , Gao Hong‐Rong , Zhu Chong‐Yi 
Published: September 2010

AbstractThe title compound was prepared by reaction of N, N‐dimethyldithiocarbamate sodium with l‐bromo‐l‐(4‐methoxyphenylcarbonyl)‐2‐(1, 2, 4‐triazole‐l‐yl) ethane. Its crystal structure has been determined by X‐ray diffraction analysis.The crystal belongs to triclinic with space group Pī, a = 0.7339(2) nm, b = 1.1032(2) nm, c = 1.1203(2) nm, a = 90.27(3)°, β = 102.03(3)°, γ = 104.91(3)°, Z=2, V = 0.8556(3) nm3, Dc = 1.360 g/cm3, μ =0.325 mm−1, F(000)=368, final R1 =0.0475. The planes of 4‐methoxybenzyl group and triazole ring are nearly perpendicular to each other. The dihedral angle is 83.97°. There is an obvious π‐π stacking interaction between the molecules in the crystal lattice. The results of biological test show that the title compound has fungicidal and plant growth regulating activities.
A Novel Glucose Biosensor Based on Palladium Nanoparticles and Its Application in Detection of Glucose Level in Urine
Authors: Zhang Fen‐Fen , Wan Qiao , Li Chen‐Xin , Zhu Zi‐Qiang , Xian Yue‐Zhong , Jin Li‐Tong , Yamamoto Katsunobu 
Published: September 2010

AbstractA novel glucose biosensor was constructed by electrodeposition of highly dispersed palladium (Pd) nanoparticles on a glassy carbon electrode (GCE). Atomic force microscopy (AFM) was applied to characterize its surface morphology. Electrodeposited Pd nanoparticles exhibited efficiently electrocatalytic oxidation for hydrogen peroxide (H2O2) with relatively high sensitivity and stability, which was studied by CV technique and Raman spectroscopy, respectively. The GC/PdVGOD/Nafion system allowed a low working potential of +0.3 V (vs. SCE). Its signal current was linearly related to the glucose concentration in the range of 1.0 × 10–6‐1.2 × 10–4mol × L−1 with a detection limit of 5.0 × 10–7 mol · L−1. The sensor required no special pretreatment to suppress interference from urate and L‐ascorbate. It was successfully used in detection of glucose level in human urine with high stability, sensitivity and anti‐poisoning ability.
Synthesis of l‐Benzoyl‐3‐aryl‐4‐hydroxy‐4‐phenylimidazolidin‐2‐thiones
Authors: Zeng Run‐Sheng , Zou Jian‐Ping , Mu Xue‐Jun , Shen Qi 
Published: September 2010

Abstract1‐Benzoyl‐3‐aryl‐4‐hydroxy‐4‐phenylimidazolidin‐2‐thiones can be synthesized readily from the cyclization of l‐benzoyl‐3‐arylthioureas with bromine‐acetophenone in the presence of excess triethylamine.
Study on the Phase Equilibrium of the Ternary System Ethanol‐Cesium Carbonate‐Water at 10, 30 and 50 °C
Authors: Zhai Quan‐Guo , Hu Man‐Cheng , Liu Zhi‐Hong , Xia Shu‐Ping 
Published: September 2010

AbstractThe phase diagrams of the CH3CH2OH‐Cs2CO3‐H2O system were determined at 10, 30 and 50 C, respectively. It was found that the effect of the temperature on the phase equilibrium was insignificant within the investigated range. The binodal curves were given using a five‐parameter equation and the tie lines were fitted using the Oth‐mer‐Tobias and Bancroft correlations. Correlation coefficients (R) for all equations exceeded 0.99. Samples of the solid phase at 30 °C were analyzed by TGA showing that it consisted of Cs2CO3. 3.5H2O. The refractive index of the systems was also determined.
Study on Tonghaosu and Its Analogs: Isolation, Structure Identification and Synthesis of Antifeedant B‐ring‐homo‐tonghaosu
Authors: Chen Li , Yin Biao‐Lin , Xu Han‐Hong , Chiu Ming‐Hua , Wu Yu‐Lin 
Published: September 2010

AbstractThe methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay‐guided separation, the active component, B‐ring‐homo‐tonghaosu, 2–(2′.4′‐hexadiynylidene)‐1, 6‐dioxaspiro‐[4, 5]dec‐3‐ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Furthermore new convenient total synthesis methods of B‐ring‐homo‐tonghaosu were also developed to confirm its structure and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.
New Myrsinol Diterpenes from Euphorbia prolifera
Authors: Zhang Wan‐Jin , Chen Dao‐Feng , Hou Ai‐Jun 
Published: September 2010

AbstractFour new myrsinol diterpenes, euphorprolitherins A‐D (1–3, 5), were isolated from the ethanolic extract of the mot of Euphorbia prolifera, along with a known one. SPr5 (4). The structures were elucidated on the basis of their spectroscopic evidences. The structure and relative stereochemistry of 1 were confirmed by X‐ray crystallography.
Synthesis and Luminescent Properties of an Acetylide‐Bridged Dinuclear Platinum(II) Terpyridyl Complex
Authors: Wang You‐Wei , Yang Qing‐Zheng , Wu Li‐Zhu , Zhang Li‐Ping , Tung Chen‐Ho 
Published: September 2010

AbstractAn acetylide‐bridged dinuclear platinum(II) terpyridyl complex, [Pt(4‐p‐tolyl‐terpy)‐i‐phenyl‐=‐(4′‐p‐tolyl‐terpy)Pt](C104)2 (1). has been successfully synthesized and its photophysical properties are reported.
Preparation and Charactrization of Fibrous Crystals of Boron‐containing MTW‐type Zeolite
Authors: Song Mao‐Ying , Zhou Wei‐Zheng , Long Ying‐Cai 
Published: September 2010

AbstractFibrous crystals of boron‐containing MTW‐type zeolite have been hydrothermally synthesized in B2O3‐SiO2‐HF‐H2O gel system at 170 °C in 20 to 28 d by using 1, 4‐diazabicyclo[2.2, 2]octane (DABCO) and methylamine as the co‐template, and characterized with XRD, SEM, TEM, HRTEM and SAED. The results of characterizations show that B atoms are incorporated into the zeolite framework as tetrahedron of B(OSi)4. The fibrous single crystals of 5–50 μm in length and 100–500 nm in width inter‐grow along the c‐axis of the zeolite, and the one dimension 12 oxygen ring channels are perpendicular to the fibber axis.
Thermochemical Properties and Non‐isothermal Decomposition Reaction Kinetics of N‐Guanylurea Dinitramide (GUDN)
Authors: Zhao Feng‐Qi , Chen Pei , Yuan Hong‐An , Gao Sheog‐Li , Hu Rong‐Zu , Shi Qi‐Zhen 
Published: September 2010

AbstractThe constant‐volume combustion energy, ΔcU (GUDN, s, 298.15 K), enthalpy of solution in acetic ether, Δ Hθm and kinetic behavior of the exothermic decomposition reaction of the title compound (GUDN) are determined by a precise rotating bomb calorimeter, a Calvet microcalorimeter and DSC, respectively. Its standard enthalpy of combustion, Δ, Hθm: (GUDN, s, 298.15 K), standard enthalpy of formation, Δ, Hθm (GUDN, s, 298.15 K) and kinetic parameters of the exothermic main decomposition reaction in a temperature‐programmed mode [the apparent activation energy ( Ea ) and pre‐exponential factor (A)] are calculated. The values of ΔcU (GUDN, s, 298.15 K), Δ Hθm (GUDN, s, 298.15 K), Δ, Hθm (GUDN, s, 298.15 K) and Δsol Hθm of GUDN are (‐7068.64×2.37) I‐g (‐1467.66×0.50) kJ · mol−1, (‐319.76×0.58) kJ · mol−1 and (165.737×0.013) kJ·mol−1, respectively. The kinetic model function in integral form and the value of Ea and A of the exothermic main decomposition reaction of GUDN are 220.20 kl · mol−1 and 1021.18 s−1, respectively. The critical temperature of thermal explosion of GUDN is 217.6 °C.