bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on False Peak Phenomena in On‐line Sweeping Technique in MEKC
Authors: Yang Geng‐Liang , Li Bao‐Hui , Wang De‐Xian , Chen Yi 
Published: September 2010

AbstractIn this paper, several {actors that could lead to the appearance of false peak were investigated by using on‐line sample sweeping technique under different experimental conditions. The tested analytes were buflomedil hydrochloride, ephedrine hydrochloride, benzyl alcohol, vanillin, p‐hydroxybenzaldehyde and m‐methylphenol. Results showed mat among the six compounds, three of them, i.e., buflomedil hydrochloride, ephedrine hydrochloride and benzyl alcohol will cause false peaks to appear when sample injection time is long, sodium dodecyl sulfate (SDS) concentration is high and there is pH gradient between cathode and anode. In order to avoid the appearance of false peak, the pH gradient should be avoided.
Second‐order Nonlinear Optical Properties of a Series of Benzothiazole Derivatives
Authors: Xiao‐Juan Liu , Ji‐Kang Feng , Ai‐Min Ren , Xin Zhou , Wei‐Nan Leng 
Published: September 2010

AbstractThe second‐order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO‐SOS method. These chromophores are formed by a donor‐π‐bridge‐acceptor system, based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl‐functional amino group as the donor. For the purpose of comparison, we also designed molecules in which nitrobenzene is an acceptor. The calculation results indicate that benzothiazole derivatives exhibit larger second‐order polarizabilities than nitrobenzene derivatives. In order to clarify the origin of the NLO response of these chromophores, their electron properties were investigated as well. The benzothiazole derivatives are good candidates for application in electro‐optical device due to their high optical nonlinearities, good thermal and photonic stability.
Crystal Structures and Characterizations of Bis (pyrrolidinedithiocarbamato) Cu(II) and Zn(II) Complexes
Authors: Fang‐Fang Jian , Ting Xue , Kui Jiao , Shu‐Sheng Zhang 
Published: September 2010

AbstractThe structures of [Cu (S2CN (CH2)4)2] (1) and [Zn2(S2CN‐(CH2)4)4] (2) have been determined by X‐ray crystallography analysis. They are all isomorphous and triclinic, space group of P1−, with Z = 1. The lattice parameters of compound 1 is: a = 0.63483(2) nm, b = 0.74972(3) nm, c=0.78390(1) mn, α = 75.912(2)°, β = 78.634(2)° and γ = 86.845(2)°; compound 2: a = 0.78707(6) nm, b=0.79823(6) nm, c = 1.23246(9) nm, α = 74.813(2)°, β = 73.048(2)° and γ = 88.036(2)°. The copper atom is located on a crystallographic inversion center and zinc atom lies across centers of symmetry. The Cu(II) ion has a square‐planar geometry while Zn(II) has a distorted tetrahedral geometry. The thermal gravity (TG) data indicate that no structural transitions in the two compounds were abserved and the decomposition products can adsorb gas. Also they all have a high thermal stability.
Study on Lead Dioxide Modified Electrode and Its Application in Detection of Phenols
Authors: Shi‐Yun Ai , Meng‐Nan Gao , Qi Cai , Zheng‐Dong Sun , Li‐Tong Jem 
Published: September 2010

AbstractThe conditions for the preparation of PbO2 modified Pt rotation disc electrode in solutions containing HC104 and Pb(II) were studied, and the morphology and composition of the obtained PbO2 film were characterized by SEM and XRD techniques, respectively. The results show that the modification process of PbO is dependent on the rotation velocity of the electrode and the concentrations of HCIO4 and Pb(II). And it was observed that the obtained PbO2 film was rutile β‐PDO2 structure. At a certain positive potential, HO· and HO2· radicals can be generated on the surface of the modified PbO2/Pt electrode and then oxidize phenols. According to the change of the responding anodic current, the determination of phenols was realizable and good results were obtained.
FeCl3‐Mediated Reaction of 1,4‐Dilithio‐1,3‐dienes with Alkynes Affording Benzene Derivatives
Authors: Guo‐Tao Li , Hong‐Yun Fang , Zhi‐Ping Li , Zhen‐Feng Xt 
Published: September 2010

AbstractUnactivated alkynes reacted with 1,4‐dilithio‐1,3‐diene derivatives in the presence of FeCl3 affording substituted benzene derivatives via a formal [4 + 2] cycloaddition.
QSAR Study and VolSurf Characterization of Human Intestinal Absorption of Drugs
Authors: Gui‐Xiang Hu , Zhi‐Cai Shang , Jian‐Wei Zou , Guo‐Ming Yang , Qing‐Sen Yu 
Published: September 2010

AbstractThe prediction of human intestinal absorption is a major goal in the design, optimization, and selection of candidates for the development of oral drugs. In this study, a computerized method (VolSurf with GRID) was used as a novel tool for predicting human intestinal absorption of test compound, and for determining the critical molecular properties needed for human intestinal absorption. The tested molecules consisted of 20 diverse drug‐like compounds. Partial least squares (PLS) discriminate analysis was used to correlate the experimental data with the theoretical molecular properties of human intestinal absorption. A good correlation (r2 = 0.95, q2 = 0.86) between the molecular modeling results and the experimental data demonstrated that human intestinal absorption could be predicted from the three‐dimensional (3D) molecular structure of a compound. Favorable structural properties identified for the potent intestinal absorption of drugs included strong imbalance between the center of mass of a molecule and the barycentre of its hydrophilic and hydrophobic regions and a definitive hydrophobic region as well as less hydrogen bonding donors and acceptors in the molecule.
Abnormal Fluorescence Behavior of Pyrene Functionalized Chitosan Films to Some Quenchers
Authors: Shu‐Juan Zhang , Yu Fang , Dao‐Dao Hu , Gai‐Ling Gao 
Published: September 2010

AbstractInvestigation of the fluorescence behavior of a pyrene functionalized chitosan film (PSC‐CS) to some quenchers, including KI, CH3NO2 and Cu(NO3)2, has revealed that the monomer emission from the PSC‐CS film increased rather than decreased, whereas the excimer emission decreased with the increase of time of duration after addition of KI or Cu(NO3)2. Both the increasing and decreasing processes could last as long as 20 min to 40 min. Unlike that observed in the system containing KI or Cu(NO3)2, for CH3NQ2 system, both the monomer emission and the excimer emission increased with introduction of the quencher, but the excimer emission only started to increase after an hour‐long induction period. The position of the excimer emission of the PSC‐CS film did not change very much with addition of KI or Cu(NO3)2. However, addition of CH3NO2 made the excimer emission blue shifted for at least 20 nm indicating formation of distorted excimers or partially overlapped excimers. The fluorescence response of the film to external additions is sensitive but is low in selectivity. This property may make the film use as a novel sensing material for monitoring the purity of water.
Low‐valent Titanium Induced Intramolecular Reductive Coupling of Keto‐enamines: A Facile Synthesis of 2,3,5‐Trisubstituted Pyrroles
Authors: Xue‐Sen Fan , Xin‐Ying Zhang , Yong‐Min Zhang 
Published: September 2010

AbstractPromoted by low‐valent titanium reagent which was generated in situ from Sm/TiCl4 system, keto‐enamine derivatives underwent efficient intromolecular deoxygenative coupling reactions and afforded the corresponding 2,3,5‐trisubstituted pyrroles in moderate to good yields under mild reaction conditions.
Investigation of the Crystallization Kinetics of Zn(Leu)SO4·0.5H2O in Mixing Solvent by Microcalorimetry
Authors: San‐Ping Chen , Yan Fang , Sheng‐Li Gao , Rong‐Zu Hu 
Published: September 2010

AbstractThe crystal growth process of Zn(Len)SO4·0.5H2O from water and acetone was investigated using a Calvet microcalorimeter. The heat and the rate of heat production during the crystal growth process at 293.15 K, 295.15 K, 298.15 K and 300.15 K were measured. On the basis of experimental and calculated results, the rate constant and the kinetic parameters (the activation energies, the pre‐exponential) during the crystal growth process were obtained. The results show that the crystal growth process accorded with the Burton‐Cabrera‐Frank dislocation theory.
Extended Network via #±# Interaction and Hydrogen Bond Linkages of ID Copper(II) Coordination Polymer: Synthesis, Crystal Structure and Characterization of [Cu(4,4′‐bpy) (2‐pzc)‐(H2O)] CIO4 · H2O (2‐pzc = 2‐pyrazine‐5‐carboxylate; 4,4′‐bpy = 4, 4′‐bipyridine)
Authors: Jun‐Hua Luo , Rui‐Hu Wang , Rong Cao , Lei Han , Jia‐Bao Weng , Zheng‐Zhong Lin , Li‐Hua Chen , Mao‐Chun Hong 
Published: September 2010

AbstractA penta‐coordinated Cu(II) complex with mixed ligands 4, 4′‐bipyridine (4,4′‐bpy) and 2‐pyrazine‐5‐carboxylate anion (2‐pzc), [Cu(4,4′‐bpy)(2‐pzc)(H2O)]CIO4·HzO (1), has been solvothermally synthesized and characterized. Complex 1 crystallizes in the monoclinic space group P21/n with a = 0.82996(2) nm, b = 1.58156(5) nm, c = 1.53837(1) nm, β = 103.536(2)°, V = 1.96322(8) nm3, Mr = 478.30, Z = 4, Dc = 1.618 g/cm3, final R = 0.0544 and wR = 0.1487. The Structure of 1 indicates that the central Cu(II) atom is penta‐coordinated by two N atoms from two 4,4′‐bpy ligands, and one N atom and one oxygen atom of the 2‐pzc ligand in the equatorial plane, and one oxygen atom of the coordinated water molecule at the axial position. The coordination geometry of Cu(II) atom could be considered as a slightly distorted square‐pyramidal environment. The 4, 4′‐bpy ligands bridge the Cu(II) centers to form a one‐dimensional chain, and 2‐pzc acts as a terminal chelated ligand, and #±# interaction between the pyrazine rings of 2‐pzc ligands of adjacent chains links the chains into a 2D sheet. Furthermore, the hydrogen bonds among the oxygen atoms of the uncoordinated water molecules and the N atoms and O atoms of 2‐pzc ligands and the oxygen atoms of the coordinated water molecules link the sheets into the ultimate 3D network of complex 1.
Photophysical and Photoelectric Properties of 2‐{[4‐(N‐Hexadecyl‐N‐methylamino) phenyl] methylene}‐propanedinitrile
Authors: Di Liu , Kui‐Wang Wu , Xue‐Song Wang , Yuan‐Jun Hou , Bao‐Wen Zhang , Yi Cao 
Published: September 2010

Abstract2‐{[4‐(N‐Hexadecyl‐N‐methylamino) phenyl] methylene}‐propanedinitrile (HMAPN) with typical donor‐#‐acceptor (D‐#‐A) structure was synthesized. It could be easily assembled into stable films by LB technique. The photophysical properties of HMAPN were investigated in solution and on LB films. The photoelectric properties of HMAPN were examined and the anodic photocurrent of the ITO electrode modified by the monolayer LB film of HMAPN was measured as 835 nA/cm2 under the white light of 218.2 mW/cm2 without bias voltage. The effects of light intensity, bias voltage on the photocurrent were discussed. The possible mechanism of the photocurrent formation was given.
Preparation and Thermal Chemical Property of Complexes of Zinc Nitrate with Trytophan
Authors: San‐Ping Chen , Sheng‐Li Gao , Xu‐Wu Yang , Qi‐Zhen Shi 
Published: September 2010

AbstractThe solubility property of Zn (NO3)2‐Try‐H2O system at 25 °C in whole concentration range has been investigated by the semimicro phase equilibrium method. The corresponding phase diagrams and refractive index diagrams were constructed. Under the guidance of the phase equilibrium results, the incongruently soluble compounds of Zn (Try) (NO3)2 · 2H2O (F) and Zn‐(Try)2(NO3)2·H2O (G), which have not been reported previously, were synthesized and characterized by IR, XRD, TG‐DTG, as well as chemical and elemental analyses. The constant‐volume combustion energies of the compounds, δcE, determined by a precision rotating bomb calorimeter at 298.15 K, were (‐13518.98±4.99) Jg−1 and (− 17690.85 ± 4.88) J. g−1, respectively. The standard enthalpies of combustion for these compounds, δc47, were calculated to be (− 5802.36 ± 2.14) kJ·mol−1 and (− 10891.59 ± 3.01) kJ·mol−1 when the standard enthalpies of formation, δtH⊖ were (− 1161.18 ± 2.61) kJ·mol−1 and (− 1829.71 ± 4.20) kJ·mol−1. The enthalpies of solution in condition of simulating human gastric juice (37 °C, pH = 1, the solution of hydrochloric acid), which were also measured by a microcalorimeter, were (14.55 ± 0.04) kJ·mol−1and (10.58±0.06) kJ·mol−1, respectively.
Syntheses and Crystal Structure of a New 3D Ag (I)‐Fumaric Acid Framework, [Ag (hmt) (fma)1/2 · 2H2O]n
Authors: Wen‐Hua Bi , Dao‐Feng Sun , Rong Cao , Xing Li , Qian Shi , Mao‐Chun Hong 
Published: September 2010

AbstractA new silver (I) coordination polymer, [Ag(hmt) (fma)1/2 · 2H2O]n (1), (hmt = hexamethylenetetramine, fma = furmaric acid), was obtained by self‐assembly of hmt, fma and AgNO3 in the mixed solvent of methanol, dichloromethane and water (CH3OH:CH2Cl2:H2O = 5:5:1), and characterized by X‐ray diffraction analysis. Complex 1 belongs to orthorhombic space group Pbcn with cell parameters a = 1.72043(5) nm, b=1.19704(2) nm, c = 1.11685(3) nm, V = 2.30007(10) nm3, Z = 8, CCDC number: 194381. In complex 1, each hmt ligand acts as a μ3‐bridge to link three Ag(I) atoms and in turn every Ag(I) ion attaches to three hmt ligands to produce a 2D honeycomb network, which is further linked by the bidentate fma ligands to form a 3D noninterpenetrating open framework with one‐dimensional channels being filled by guest molecules.
Effects of Ethylene Oxide Spacer Length on Solution Properties of Water‐Soluble Fluorocarbon‐Containing Hydrophobically Associating Poly (Acrylic Acid‐co‐Rf‐PEG Macromonomer)
Authors: Li‐Bin Du , Dong‐Qing Zhuang , Shou‐Ping Liu , Yun‐Xiang Zhang 
Published: September 2010

AbstractPoly (acrylic acid)s (PAAs) modified with a series of fluorocarbon group (Rf) end‐capped Poly(ethylene glycol) (PEG) macromonomers (number of ethylene oxide unit: 1, 9, 23, 45) and corresponding copolymers without fluorocarbon end groups were synthesized. It was found that the effect of the hydrophobic association of fluorocarbon groups on the solution viscosity prevailed over that of the hydrogen bond between grafted PEG and the backbone. Rheological measurement on the aqueous solutions of these poly (acrylic add‐co‐RrPEG macromonomer)s demonstrated that the best thickening performance was shown when the number of ethylene oxide unit (EO number) was 23.
Heck Reaction Catalyzed by Palladacycle in Neat Water
Authors: Hou Jian‐Jun , Yang Liang‐Ru , Cui Xiu‐Ling , Wu Yang‐Jie 
Published: September 2010

AbstractCyclopalladated ferrocenylimine has been found to be a type of excellent phosphine‐free catalyst for Heck reactions in neat water with both higher yields and turnover numbers than those reported in the literature up to now. Some commercial emulsifying agents, including the commonly used quaternary ammonium salts, have been proved to be excellent additives in the catalysis of the reactions. Not only aromatic iodide, but also aromatic bromide could be coupled with the olefins. All reactions were able to be conducted in air under refluxing condition.
Synthesis and Antitumor Activity of Tanshinone Analogues
Authors: Akber Aisa, Haji , Lu Wd , Cai Jun‐Chao 
Published: September 2010

Abstract8,8‐Dimethyl‐5,6,7,8‐tetrahydrophenanthrene‐3,4‐dione (3) and 8,8‐dimethyl‐2‐(l‐hydroxy ethyl)‐5,6,7,8‐tetrahydrophenanthrene‐3,4‐dione (4), two analogues of the antitumor active tanshinone, were synthesized from anisole. The synthesized compounds 3 and 4 were shown to be highly active against leukemia P‐388 cell line as assayed by in vitro MTT method.
Spectral and Electrochemical Investigation of Intercalations of Adrenaline and CT‐DNA
Authors: Zheng Sai‐Jing , Lin Xiang‐Qin 
Published: September 2010

AbstractA strong interaction between double stranded calf‐thymus DNA (ds‐DNA) and adrenaline in solution, but no interaction between single stranded calf‐thymus DNA (ss‐DNA) and adrenaline was observed by the use of UV‐visible spectroscopy and voltametric techniques. It is suggested that the interaction leads to an intercalation of adrenaline molecules into the groove of ds‐DNA and the formation of ds‐DNA (adrenaline), complex. The binding site size of the interaction of adrenaline with CT‐DNA in nucleotide phosphate [NP] has been determined as 25. The interaction of different concentration adrenaline with DNA modified GCE shows that the DNA modified GCE can be a good tool to detect lower concentration a‐drenaline.
Syntheses of Chiral Calix [4] arene Derivatives Bearing Amino Acid Residue
Authors: Zhang Wen‐Chun , Zheng Yan‐Song , Wang Wen‐Guang , Zheng Qi‐Yu , Huang Zhi‐Tang 
Published: September 2010

AbstractThe syntheses of chiral calix[4]arene derivatives bearing amino acid residue at the lower rim or upper rim by three different methods were reported.
Ion Exchange Extraction of Boron from Aqueous Fluids by Amber‐lite IRA 743 Resin
Authors: Ying‐Kai Xiao , Bu‐Yong Liao , Wei‐Guo Liu , Yun Xiao , George H. Swihart 
Published: September 2010

AbstractThe ion exchange characteristics of Amberlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that Amberlite IRA 743 resin, a boron‐specific ion exchange resin, can quantitatively extract boron as the B(OH)−4 species from weakly basic solution. Some exchangeable anions such as Cl−and SO24 are present, resulting in an increase in pH value of the loaded solution within the column, and the boron in natural aqueous fluids with low pH is also extracted by Amberlite IRA 743 resin. However, the volume of loaded solution must be restricted. The maximum volume of loaded solution giving quantitative extraction of boron decreases for sample solutions of lower pH value. Warm HG solution is more effective than room temperature HC1 solution for eluting boron from Amberlite IRA 743 resin.
Cell volume effect on the ferroelectric stability of perovskite oxides pbtio3 and batio3 from first principle calculation
Authors: Wang Yuan‐Xu , Wang Chun‐Lei 
Published: September 2010

AbstractElectronic structure of ferroelectric PbTiO3 and BaTiO3 is calculated by the full potential linearized augmented plane wave method. The total energy as a function of the displacement of Ti‐cation is obtained for PbTiO3 and BaTiO3 at different cell volumes. At experimental cell volume, Ti‐displacement lowers the total energy and the ferroelectricity is stable. When the cell volume is reduced to 90%, total energy is increased with Ti‐displacement and ferroelectricity will disappear. The cell volume effect is also confirmed by comparison of the density of states of Ti and O at different cell volumes.
Studying flocculation mechanism of chitosan with pyrene‐fluorescence probe method
Authors: Chen Liang , Chen Dong‐Hui , Wu Chong‐Liang 
Published: September 2010

AbstractA peak/ratio in pyrene‐fluorescence spectrum was employed to measure the polarity of micro‐environment of chitosan adsorbing pyrene molecules. The authors have in the first time detected the pyrene‐fluorescence spectrum of chitosan with different degrees of deacetylation (D. D.), and found the relationship between the flocculation of bentonite colloid by chitosan and the peak/ratio values of different molecular weight (M.W.) and D.D. of chitosan. We find that M.W. plays a key role in the flocculation, but D. D. has limited effect on it. From micro‐environmental structure of view, it can be proved that the inter‐particle bridging rather than charge neutralization dominates the flocculation with chitosan.
Ring‐opening polymerization of ε‐caprolactone by lanthanide tris (2, 6‐dimethylphenolate) s
Authors: Zhang Li‐Fang , Shen Zhi‐Quan , Yu Cui‐Ping 
Published: September 2010

AbstractLanthanide tris (2,6‐dimethylphenolate)s [Ln(ODMP)3] were used as initiators for ring‐opening polymerization of s‐caprolactone (CL) for the first time. The influence of different rare earth elements and solvents was investigated. 1H NMR spectral data of polycaprolactone (PCL) obtained showed that the polymerization mechanism is in agreement with the coordination‐insertion mechanism and the selective cleavage of the acyl‐oxygen bond of CL.
Surface modification of nano‐SiO2 by grafting PMMA/PBA
Authors: Yu Hai‐Yin , Gu Jia‐Shan , Guan Ming‐Yun , Wu Zheng‐Cui , Sun Yi‐Min , Du Jun 
Published: September 2010

AbstractThe surface of nano‐SiO2 was modified by being encapsulated with hydroxy‐propyl‐methyl cellulose (HPMC), and then cografted with acrylates. The grafting conditions, such as pH of the medium, and initiator concentration have been studied. The modified nano‐SiO2 particles were characterized by TEM, DSC and FT‐IR spectra. TEM images show that the surface of the nano‐particles has been successfully modified by a thick layer of film‐like polymer in this way. The DSC results show that the decomposition temperature of modified nano‐particles of SiO2 is 90 °C higher than that of grafted‐on polymer. According to the FT‐IR spectra, it is convinced that poly‐methyl methacrylate (PMMA) and poly‐acrylic butyl‐ester (PBA) were co‐grafted onto the surface of nano‐SiO2.
A Novel Diterpenoid from the Soft Coral Sarcophyton crassocaule
Authors: Xu Xiao‐Hua , Kong Chui‐Hua , Lin Chang‐Jiang , Wang Xin , Zhu Ying‐Dong , Yang Hai‐Shen 
Published: September 2010

AbstractA novel hydroperoxide cembrane‐type diterpenoid was isolated from the soft coral Sarcophyton crassocaule collected from the Xisha Islands in the South China Sea. The structure of 3 was established by spectroscopy and X‐ray diffraction analysis, named as sarcophyocrassolide A. It exhibited strong cytotoxicity against the P‐388 cell line with IC50 value of 0.1 μg/mL.
Imprinted Polymeric Film‐Based Sensor for the Detection of Dopamine Using Cyclic Voltammetry
Authors: Guo Hong‐Sheng , He Xi‐Wen , Li Yi‐Jun 
Published: September 2010

AbstractThe imprinted polymeric film was synthesized on the glass‐carbon electrodes directly. The response to the template molecule‐dopamine and other molecules with similar structure was measured by cyclic voltammetry. The response of dopamine on imprinted electrode was much higher than that of other molecules, because of the existing of micro‐cavities in polymeric film fitting with the size and shape of dopamine in the imprinted polymer. Experimental results showed that dopamine can be enriched by the imprinted film, therefore increasing the sensitivity of the sensor. The imprinted film could also efface the interference of ascorbic acid, indicating that dopamine can be determined with a large excess of ascorbic acid.
Synthesis and Biological Activities of 4‐Arylmethylidene‐l‐aryl‐2‐(selenomorpholin‐4‐yl)‐2‐imidazolin‐5‐one
Authors: Hu Li‐Ming , Feng Ju‐Hong , Chen Zhi‐Yuan , Liu Zhao‐Jie , Xu Han‐Sheng 
Published: September 2010

AbstractIn a search for novel agrochemical with high activity and low toxicity, a series of substituted 4, 5‐dihydro‐imidazol‐5‐one containing selenomorpholine group were synthesized by a three‐step synthetic route starting from 2‐azido‐3‐aryl‐acrylic add ethyl ester. The structures of title compounds were confirmed by lH NMR, IR, mass spectroscopy and elemental analysis. The preliminary bioassay against Gibberella zeae, Fusarium oxysporum, Pellicularia sasakii, Physalospora piricola and Cercospora beticola indicated that most title compounds displayed fungicidal activity at the concentration of 50 ppm and compounds 41, 4n, 4o were found to have particularly high activities against Physalospora piricola. A further in vivo test showed that compounds 41, 4n and 4o possessed better fungicidal activity against Physalospora piricola at a concentration of 100 ppm than Carbendazim. To our knowledge, this is first report that 4, 5‐dihydro‐imidazol‐5‐one containing selenomorpholine group display fungicidal activity against Physalospora piricola.