The title compound [Cu(dafone)2(DMF)2]?2ClO4 1 (dafone = 4,5-diazafluoren- 9-one, dmf = N,N?-dimethyl formamide) was synthesized by the reaction of Cu(ClO4 )2 and dafone in DMF solution at room temperature with pH = 3...The title compound [Cu(dafone)2(DMF)2]?2ClO4 1 (dafone = 4,5-diazafluoren- 9-one, dmf = N,N?-dimethyl formamide) was synthesized by the reaction of Cu(ClO4 )2 and dafone in DMF solution at room temperature with pH = 3.0. The single-crystal X-ray analysis has revealed that 1 crystallizes in monoclinic, space group P21/n with a = 8.4853(8), b = 13.1520 (14), c = 14.3866(12) ?, β = 102.629(3)o, V = 1566.7(3) ?3, C28H26Cl2CuN6O12, Mr = 773.00, Z = 2, Dc = 1.639 g/cm3 , F(000) = 790, μ = 0.942 mm-1, the final R = 0.0438 and wR = 0.1214 for 3165 obser- ved reflections with I > 2σ(I). X-ray analysis shows that compound 1 has unsymmetric chelation of dafone with one Cu–N bond being much longer than the other. Coordination geometry of Cu is a highly distorted octahedron and the whole structure is stabilized by π-π stacking and static attractive forces from [ClO4]- anions. Based on the crystal data, quantum chemistry calculation at the DFT/ B3LPY level was used to reveal the electronic structure of 1.展开更多
A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacill...A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacillus sp.B26 by 16S rDNA(ribosomal DNA) sequencing.Phylogenic analysis showed that the strain was most similar to Bacillus sp.enrichment culture clone SYW5(FJ601635.1) and Bacillus cereus strain FM-4(EU794727.1).Efforts were made to further improve HPA-production and PGA-tolerance by UV irradiation and UV-LiCl cooperative mutagenesis.Among viable mutants,B.sp.UV-38 and B.sp.ULi-11 exhibited better productivities than the wild type.Comparisons of HPA production and time course among wild strain and two mutants showed that B.sp.ULi-11 was more competent than B.sp.UV-38.HPA production was increased by 39.1% with B.sp.ULi-11(yield,65.4%) compared to that with B.sp.B26(yield,47.0%) when cultured in fermentation broth(pH 7.2) at 32℃ with an agitation speed of 180 r·min-1 and PGA final concentration of 15 mmol·L-1 for 25 h.展开更多
N, O-carboxymethyl chitosan (NOCC) composite nanofiltration (NF) membranes were prepared by coating and cross-linking. The fermentation effluent from a wine factory was treated with the resulting NOCC/polysulfone ...N, O-carboxymethyl chitosan (NOCC) composite nanofiltration (NF) membranes were prepared by coating and cross-linking. The fermentation effluent from a wine factory was treated with the resulting NOCC/polysulfone (PSF) composite NF membranes. The permeate flux and the removal efficiencies of the resulting NF membranes for the color, chemical oxygen demand (CODcr), total organic carbon (TOC), and conductivity of the fermentation effluent were investigated in relation to the driving pressure, the feed flow, and the operation time. The permeate flux and the removal efficiencies were found to increase with the increase of the driving pressure or the feed flow. At 0.40 MPa and ambient temperature the removal efficiencies were 95.5%, 70.7%, 72.6%, and 31.6% for color, CODcr, TOC, and conductivity, respectively. The membrane was found to be stable over a 10-h ooeration for the fermentation effluent treatment.展开更多
Determination of the optimal model parameters for biochemical systems is a time consuming iterative process. In this study, a novel hybrid differential evolution (DE) algorithm based on the differential evolution te...Determination of the optimal model parameters for biochemical systems is a time consuming iterative process. In this study, a novel hybrid differential evolution (DE) algorithm based on the differential evolution technique and a local search strategy is developed for solving kinetic parameter estimation problems. By combining the merits of DE with Gauss-Newton method, the proposed hybrid approach employs a DE algorithm for identifying promising regions of the solution space followed by use of Gauss-Newton method to determine the optimum in the identified regions. Some well-known benchmark estimation problems are utilized to test the efficiency and the robustness of the proposed algorithm compared to other methods in literature. The comparison indicates that the present hybrid algorithm outperforms other estimation techniques in terms of the global searching ability and the con- vergence speed. Additionally, the estimation of kinetic model parameters for a feed batch fermentor is carried out to test the applicability of the proposed algorithm. The result suggests that the method can be used to estimate suitable values of model oarameters for a comolex mathematical model.展开更多
New lithium fast ion conductors of Li1.2 + x - y Yx Ti1.9 - x Al0.1Si0. 1Wy P2.9 - y O12 based on LiTi2(PO4)3 were prepared by high temperature solid state reaction using refined natural kaolinite as a starting mat...New lithium fast ion conductors of Li1.2 + x - y Yx Ti1.9 - x Al0.1Si0. 1Wy P2.9 - y O12 based on LiTi2(PO4)3 were prepared by high temperature solid state reaction using refined natural kaolinite as a starting material. X-ray powder diffraction analysis indicates that a phase with Nasieon-like structure exists together with other phases in the composition range of x =0.1, y≤0.2 and x =0.2,y ≤0.2. AC impedance measurements show that the initial composition with x = 0.10, y = 0.10 possesses the highest ionic conductivity of 1.65 × 10^-5 S·cm^-1 at room temperature, while the sample with initial composition of x =0.20, y =0.10 has the best ionic conductivity of 6. 53 × 10^-3S·cm^-1 at 573 K and decomposes at 3.0 V.展开更多
Ag^+ -doped ZnS nanocrystals surface-capped with thiourea (expressed as ZnS: Ag/thiourea) were synthesized through sol-gel method with thiourea as a surface modifier and characterized by X-ray diffraction(XRD), ...Ag^+ -doped ZnS nanocrystals surface-capped with thiourea (expressed as ZnS: Ag/thiourea) were synthesized through sol-gel method with thiourea as a surface modifier and characterized by X-ray diffraction(XRD), transmission electron microscope(TEM), X-ray fluorescence spectrum(XRF), infrared spectrum (IR), UV-Vis absorption spectrum( UV-Vis), and photoluminescence spectrum(PL). The results show that Ag^+ ions are doped in ZnS nanocrystals, and the sulfur atoms in thiourea molecules coordinate with metal ions on the surface of the nanocrystals. The spherical ZnS: Ag/thiourea nanocrystals with an average diameter of 5 nm have good fluorescent characteristics, and therefore have great potential for use in molecular assembly and novel luminescence materials.展开更多
A novel coordination polymer [(C8H20N)(Ag2I3)]n ([C8H20N]+ = tetraethyl ammo- nium (TEA)) was synthesized by the reaction of AgI and C8H20NI at room temperature with pH = 6.5, and structurally characterized by means o...A novel coordination polymer [(C8H20N)(Ag2I3)]n ([C8H20N]+ = tetraethyl ammo- nium (TEA)) was synthesized by the reaction of AgI and C8H20NI at room temperature with pH = 6.5, and structurally characterized by means of X-ray single-crystal diffraction. It crystallizes in orthorhombic, space group Pna21 with a = 7.3323(9), b = 18.250(2), c =12.5294(15) ?, C6.33H16.16NAg2I3, Mr = 702.76, V = 1676.6(4) ?3, Z = 4, Dc = 2.784 g/cm3, F(000) = 1256.6, μ(MoKα) = 7.828 mm-1, the final R = 0.0529 and wR = 0.1586 for 1189 observed reflections with I > 2σ(I). X-ray analysis shows that the [Ag2I3]n- chain is built up by AgI4 tetrahedron and in combination with quaternary ammonium cations ([C8H20N]+) by static attractive forces to form the so-called organic-inorganic hybrid material.展开更多
A new iodoplumbate polymer incorporating copper iodide complex cation {[Cu(Ⅱ)(bipy)2I][PbI3](H2O)2}n 1(bipy = 2,2'-bipyridine) has been synthesized and structurally determined.It crystallizes in the triclini...A new iodoplumbate polymer incorporating copper iodide complex cation {[Cu(Ⅱ)(bipy)2I][PbI3](H2O)2}n 1(bipy = 2,2'-bipyridine) has been synthesized and structurally determined.It crystallizes in the triclinic system,space group P1 with a = 7.979(4),b = 14.538(11),c = 15.853(8),α = 110.77(2),β = 97.955(18),γ = 104.88(2)°,V = 1607.3(17)3,Z = 2,C20H16CuI4N4O2Pb,Mr = 1122.72,Dc = 2.320 g/cm3,F(000) = 1006,μ(MoKα) = 9.753,the final R = 0.0627 and wR = 0.1741 for 4846 observed reflections with Ⅰ 〉 2σ(Ⅰ).Structural analysis indicates that 1 consists of 2-D {[Cu(Ⅱ)(bipy)2I]}nn+ cation layers(based on π-π interaction and hydrogen bonds) and [PbI3]nn-polyanions.The C-H···I hydrogen bonds between {[Cu(Ⅱ)(bipy)2I]}nn+ cation layers and [PbI3]nn-polyanions lead to the formation of an interesting 3-D network.Optical absorp-tion spectrum indicates that 1 is a semiconductor,which is further validated by DFT calculation.Its electronic structure is also discussed.展开更多
Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulate...Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.展开更多
A new nonlinear optical crystal of sodium terbium borate (Na2.67Tb2.11B3O9, Mr = 573.14) was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solut...A new nonlinear optical crystal of sodium terbium borate (Na2.67Tb2.11B3O9, Mr = 573.14) was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was deter- mined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a = 5.0744(10), b = 10.990(2), c = 6.9078(14) A, V = 385.24(13) A3, Dc = 4.941 g/cm3, F(000) = 250, Z = 2, μ= 9.205 mm-1, the final R = 0.0253 and wR = 0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na(1)O8, Na(2)O6, Na(3)O6 and Tb(1)O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic (μj = 7.04 μb). The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.展开更多
Synthesis of polycrystalline Nd:Sr0.95Ba0.05WO4 by means of liquid-and solid-phase reaction was reported.X-ray powder diffraction results showed that the as-grown Sr0.95Ba0.05WO4 and Nd:Sr0.95Ba0.05WO4 single crysta...Synthesis of polycrystalline Nd:Sr0.95Ba0.05WO4 by means of liquid-and solid-phase reaction was reported.X-ray powder diffraction results showed that the as-grown Sr0.95Ba0.05WO4 and Nd:Sr0.95Ba0.05WO4 single crystals belonged to tetragonal system and I41/a space group.Transparent Nd:Sr0.95Ba0.05WO4 single crystal could be obtained along c-axis by Czochralski method from the synthesized polycrys-talline material.As the transmittance of Sr0.95Ba.005WO4 single crystal could reach 80%, Nd3+ ion was adopted to be doped into the single crystal.Spontaneous Raman spectrums of polycrystalline material and single crystal were measured by RERKZN-ELMER2000 and JY-HR800.By using X-ray fluorescence method, the effective segregation coefficients of Nd, Ba, Sr, and W elements in Sr0.95Ba.005WO4 single crystal were estimated as 0.844(0.745), 0.44, 1.09, and 0.95, respectively.The segregation coefficients of Nd in Sr0.95Ba0.05WO4 were higher than that in BaWO4, and this is as better as a Raman laser crystal.展开更多
Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the sur...Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the surface of androgen receptor by using molecular docking with computational investigation. The energy was calculated respectively based on the QM (quantum mechanics) and MM (molecular mechanics) methods. The result shows that the allosteric modulation of androgen receptor plays an important role in the binding process between androgens and receptor. The open state receptor is less stable than the close state one, but the latter is more favorable for binding with androgens. It is worthy of note that when the androgen receptors binding or without binding with androgen are in close state, they are difficult to return to their open state. This phenomenon is an exception of the well known two-state model theory in which the two states are reversible. Whether the internal of close state androgen receptor has a combination of androgen or not, the androgen receptor surface can be combined with another androgen, and their surface binding energies could be very close. The result is consistent with the experimental observations, but this phenomenon of continuous combination from open state is also an exception of the two-state model theory.展开更多
A new borophosphate compound Cd3 BPO7(Mr = 490.98) has been successfully synthesized by conventional high temperature solid state reaction for the first time and its structure was determined by single-crystal X-ray ...A new borophosphate compound Cd3 BPO7(Mr = 490.98) has been successfully synthesized by conventional high temperature solid state reaction for the first time and its structure was determined by single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group Pna21, with a = 13.247(3), b = 8.8217(18), c = 5.0792(10), V = 593.56(20)3, Z = 4, Dc = 5.494 g/cm3, λ(CuKα) = 1.5406, F(000) = 880, the final R = 0.0212 and wR = 0.0513 for 1287 observed reflections(I 〉 2σ(I)). In the crystal structure of Cd3 BPO7, the Cd(II) forms a slightly distorted octahedral geometry, BO3 3- and PO4 3- ions linking adjacent Cd(II) ions to form a 3D network. The second harmonic generation(SHG) on powder samples was measured using Kurtz and Perry technique. The result indicates that Cd3 BPO7 exhibits a SHG response 2.2 times larger than that of potassium dihydrogen phosphate(KDP) and is phase-matchable.展开更多
The adsorption and decomposition of N2O on the InN (0001) surface have been explored employing density functional theory method. To study the most favorable N2O adsorption model, ten typical adsorption cases (four ...The adsorption and decomposition of N2O on the InN (0001) surface have been explored employing density functional theory method. To study the most favorable N2O adsorption model, ten typical adsorption cases (four for the parallel style and six for the vertical style) were proposed. The calculated results indicate that the parallel models are energetically preferred over the vertical models. The parallelly adsorbed N2O prefers to be dissociated on the surface, the dissociated O atom is combined at the fcc site, and the N-N piece is desorbed from the surface and forms N2 molecules. The comparison of the density of states of InN (0001) surface before and after N2O adsorption is analyzed in detail. Through the searching for transition state of decomposition reaction, a very low energy barrier of 45.0 KJ/mol is derived.展开更多
Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in th...Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in the crystal was measured by the ICP method. The absorption and emission spectra were also measured. On the basis of the spectra, the absorption cross-sections, emission spectrum FWHM and fluorescence lifetime of the crystal were calculated. From the properties mentioned above.展开更多
A novel coordination polymer {[Cu(en)2][Ag2I4]}, (en = ethylenediamine) was synthesized by the reaction of NaAgI2 and Cu(en)2(NO3)2·2H2O at room temperature with pH = 6.0, and the structure was characteri...A novel coordination polymer {[Cu(en)2][Ag2I4]}, (en = ethylenediamine) was synthesized by the reaction of NaAgI2 and Cu(en)2(NO3)2·2H2O at room temperature with pH = 6.0, and the structure was characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group C2/m, with a=10.646(2), b = 13.304(3), c = 6.8445(14) ,A°, β = 118.95(3)°, C4H16N4CuAg2I4, Mr = 907.10, V= 848.3(4) A°^3, Z= 2, Dc = 3.551 g/cm^3, F(000) = 806, μ(MoKa) = 10.787 mm^-1, the final R1 = 0.0256 and wR2 = 0.0654 for 900 observed reflections with I 〉 2σ(I). According to structural analysis, the title compound consists of template cation [Cu(en)2]^2+ and inorganic chain [Ag2I4]n^2-. The polymeric negative chain [Ag2I4]n^2- is built up from pairs of AgI4 tetrahedron by sharing one edge. Through N-H…I hydrogen-bonding interactions, the whole structure represents a quasi-two dimensional arrangement. Electrostatic attraction exists between organic cations and inorganic chains, leading to a so-called organic-inorganic hybrid structure.展开更多
An efficient and recyclable cadmium removal adsorbent was prepared by molding and sintering of ultrafine silica powder produced from ferroalloy plant as the main raw materials, with the addition of a certain amount of...An efficient and recyclable cadmium removal adsorbent was prepared by molding and sintering of ultrafine silica powder produced from ferroalloy plant as the main raw materials, with the addition of a certain amount of AI(OH)3 and CaO for modification. XRD and SEM were used to characterize the crystal phases and microstructures of the adsorbent. The influences of different pH, initial cadmium concentration and contacting time on the cadmium adsorption capacity were investigated. The results show that the cadmium removal capacity is up to 0.239 mg/g at the initial Cd2+ concentration of 5 g/L, pH value of 7 and contacting time of 120 rain when the optimum, mass ratio is 70(ultrafine silica powder):30(Al(OH)3 and CaO mixture). The corresponding adsorbent has a porous structure with main crystalline phases of CazAI2SiO7 and CaSiO3. Cadmium is adsorbed and removed mainly by physical adsorption, assisted by chemical adsorption.展开更多
CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray phot...CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to characterize the products. It was found that the crystallographic structure and optical property of the products synthesized at different temperature were almost the same. The SBEX of CdIn2S4 products decreased when the synthesized temperature increased, and the largest SBET was 33.16 m2 g-1 (120 ℃ sample). The degradation of methyl orange (MO) under the visible-light irradiation had been used as a probe reaction to investigate the photocatalytic activity of the as-prepared CdIn2S4, which showed that the CdIn2S4 sample synthesized at 120 ℃ presented the best photocatalytic activity for MO degradation.展开更多
One novel organically templated zincophophate (CsN2HI4).[Zn3(OH2)(POn)2(HPO4)] has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction together with elemental a...One novel organically templated zincophophate (CsN2HI4).[Zn3(OH2)(POn)2(HPO4)] has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction together with elemental analysis, infrared spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/n, with a = 9.7904(11), b = 14.0287(14), c = 11.8651(13) A, β= 104.690(3)°, V= 1576.4(3) A^3, Z= 4, T= 296(2) K, Mr = 601.31 and Dc = 2.533 g/cm^3. The compound consists of a macroanionic [Zn3(OH2)(PO4)2(HPO4)]^2- framework and (C5N2H14)^2+ cations, and its structure is built up from ZnO3(OH2), ZnO4, HPO4 and PO4 tetrahedral units that result in 4, 8 and 10-ring channels.展开更多
A new iodiplumbate polymer [(ipq)2(pea)(Pb3I9)-DMF]n 1 (ipq = N-(isopentyl)- quinolinium, pea = protonated ethylamine) was synthesized by self-assembly reaction of ipq·I, PbI2 with ethylamine and struct...A new iodiplumbate polymer [(ipq)2(pea)(Pb3I9)-DMF]n 1 (ipq = N-(isopentyl)- quinolinium, pea = protonated ethylamine) was synthesized by self-assembly reaction of ipq·I, PbI2 with ethylamine and structurally characterized. 1 crystallizes in the triclinic system, space group P1 with α= 1.0731(4), b = 1.2560(4), c = 2.0785(7) nm, α = 96.378(5), β= 91.132(2), γ= 100.303(5)°, V= 2.7369(16) nm^3, Z= 2, Dc = 2.770 g/cm^3,μ = 14.307 mm^-1, F(000) = 2014, R = 0.0588 and wR = 0.1345. 1 features its hybrid structure concertedly templated by two kinds of organic cations, which exhibits interesting semiconductor property. In 1, the [Pb2I6]^2 n infinite chains shape the sketch of the title compound constructed from face-sharing of ideal and distorted PbI6 octahedra. Based on the crystal structure data, quantum chemistry calculation with DFT was used to reveal the electronic structure of 1.展开更多
基金This work was supported by the Foundation of Education Committee of Fujian Province (JB04016, JB04017)
文摘The title compound [Cu(dafone)2(DMF)2]?2ClO4 1 (dafone = 4,5-diazafluoren- 9-one, dmf = N,N?-dimethyl formamide) was synthesized by the reaction of Cu(ClO4 )2 and dafone in DMF solution at room temperature with pH = 3.0. The single-crystal X-ray analysis has revealed that 1 crystallizes in monoclinic, space group P21/n with a = 8.4853(8), b = 13.1520 (14), c = 14.3866(12) ?, β = 102.629(3)o, V = 1566.7(3) ?3, C28H26Cl2CuN6O12, Mr = 773.00, Z = 2, Dc = 1.639 g/cm3 , F(000) = 790, μ = 0.942 mm-1, the final R = 0.0438 and wR = 0.1214 for 3165 obser- ved reflections with I > 2σ(I). X-ray analysis shows that compound 1 has unsymmetric chelation of dafone with one Cu–N bond being much longer than the other. Coordination geometry of Cu is a highly distorted octahedron and the whole structure is stabilized by π-π stacking and static attractive forces from [ClO4]- anions. Based on the crystal data, quantum chemistry calculation at the DFT/ B3LPY level was used to reveal the electronic structure of 1.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (20103514110002)the Science and Technology Key Project of Fujian Province (2009N0046)
文摘A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacillus sp.B26 by 16S rDNA(ribosomal DNA) sequencing.Phylogenic analysis showed that the strain was most similar to Bacillus sp.enrichment culture clone SYW5(FJ601635.1) and Bacillus cereus strain FM-4(EU794727.1).Efforts were made to further improve HPA-production and PGA-tolerance by UV irradiation and UV-LiCl cooperative mutagenesis.Among viable mutants,B.sp.UV-38 and B.sp.ULi-11 exhibited better productivities than the wild type.Comparisons of HPA production and time course among wild strain and two mutants showed that B.sp.ULi-11 was more competent than B.sp.UV-38.HPA production was increased by 39.1% with B.sp.ULi-11(yield,65.4%) compared to that with B.sp.B26(yield,47.0%) when cultured in fermentation broth(pH 7.2) at 32℃ with an agitation speed of 180 r·min-1 and PGA final concentration of 15 mmol·L-1 for 25 h.
基金the Special Funds for Major State Basic Research Program of China(2003CB615706)
文摘N, O-carboxymethyl chitosan (NOCC) composite nanofiltration (NF) membranes were prepared by coating and cross-linking. The fermentation effluent from a wine factory was treated with the resulting NOCC/polysulfone (PSF) composite NF membranes. The permeate flux and the removal efficiencies of the resulting NF membranes for the color, chemical oxygen demand (CODcr), total organic carbon (TOC), and conductivity of the fermentation effluent were investigated in relation to the driving pressure, the feed flow, and the operation time. The permeate flux and the removal efficiencies were found to increase with the increase of the driving pressure or the feed flow. At 0.40 MPa and ambient temperature the removal efficiencies were 95.5%, 70.7%, 72.6%, and 31.6% for color, CODcr, TOC, and conductivity, respectively. The membrane was found to be stable over a 10-h ooeration for the fermentation effluent treatment.
基金Supported by the National Natural Science Foundation of China (60804027, 61064003) and Fuzhou University Research Foundation (FZU-02335, 600338 and 600567).
文摘Determination of the optimal model parameters for biochemical systems is a time consuming iterative process. In this study, a novel hybrid differential evolution (DE) algorithm based on the differential evolution technique and a local search strategy is developed for solving kinetic parameter estimation problems. By combining the merits of DE with Gauss-Newton method, the proposed hybrid approach employs a DE algorithm for identifying promising regions of the solution space followed by use of Gauss-Newton method to determine the optimum in the identified regions. Some well-known benchmark estimation problems are utilized to test the efficiency and the robustness of the proposed algorithm compared to other methods in literature. The comparison indicates that the present hybrid algorithm outperforms other estimation techniques in terms of the global searching ability and the con- vergence speed. Additionally, the estimation of kinetic model parameters for a feed batch fermentor is carried out to test the applicability of the proposed algorithm. The result suggests that the method can be used to estimate suitable values of model oarameters for a comolex mathematical model.
文摘New lithium fast ion conductors of Li1.2 + x - y Yx Ti1.9 - x Al0.1Si0. 1Wy P2.9 - y O12 based on LiTi2(PO4)3 were prepared by high temperature solid state reaction using refined natural kaolinite as a starting material. X-ray powder diffraction analysis indicates that a phase with Nasieon-like structure exists together with other phases in the composition range of x =0.1, y≤0.2 and x =0.2,y ≤0.2. AC impedance measurements show that the initial composition with x = 0.10, y = 0.10 possesses the highest ionic conductivity of 1.65 × 10^-5 S·cm^-1 at room temperature, while the sample with initial composition of x =0.20, y =0.10 has the best ionic conductivity of 6. 53 × 10^-3S·cm^-1 at 573 K and decomposes at 3.0 V.
基金Supported by the Science Foundation of Education Department of Fujian Province(JA03043)the Science Foundation ofDepartment of Science and Technology of Fujian Province(2005 K011).
文摘Ag^+ -doped ZnS nanocrystals surface-capped with thiourea (expressed as ZnS: Ag/thiourea) were synthesized through sol-gel method with thiourea as a surface modifier and characterized by X-ray diffraction(XRD), transmission electron microscope(TEM), X-ray fluorescence spectrum(XRF), infrared spectrum (IR), UV-Vis absorption spectrum( UV-Vis), and photoluminescence spectrum(PL). The results show that Ag^+ ions are doped in ZnS nanocrystals, and the sulfur atoms in thiourea molecules coordinate with metal ions on the surface of the nanocrystals. The spherical ZnS: Ag/thiourea nanocrystals with an average diameter of 5 nm have good fluorescent characteristics, and therefore have great potential for use in molecular assembly and novel luminescence materials.
基金This work was supported by the Foundation of Education Committee of Fujian Province (JB03053, JB04016)
文摘A novel coordination polymer [(C8H20N)(Ag2I3)]n ([C8H20N]+ = tetraethyl ammo- nium (TEA)) was synthesized by the reaction of AgI and C8H20NI at room temperature with pH = 6.5, and structurally characterized by means of X-ray single-crystal diffraction. It crystallizes in orthorhombic, space group Pna21 with a = 7.3323(9), b = 18.250(2), c =12.5294(15) ?, C6.33H16.16NAg2I3, Mr = 702.76, V = 1676.6(4) ?3, Z = 4, Dc = 2.784 g/cm3, F(000) = 1256.6, μ(MoKα) = 7.828 mm-1, the final R = 0.0529 and wR = 0.1586 for 1189 observed reflections with I > 2σ(I). X-ray analysis shows that the [Ag2I3]n- chain is built up by AgI4 tetrahedron and in combination with quaternary ammonium cations ([C8H20N]+) by static attractive forces to form the so-called organic-inorganic hybrid material.
基金Supported by the National Natural Science Foundation of China (No. 20901017)Innovation Fund for Young Scientist of Fujian Province (2007F3049)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education of China (20093514120003)Sci. & Tech. Promotion Foundation of Fuzhou University (2009-XQ-08)
文摘A new iodoplumbate polymer incorporating copper iodide complex cation {[Cu(Ⅱ)(bipy)2I][PbI3](H2O)2}n 1(bipy = 2,2'-bipyridine) has been synthesized and structurally determined.It crystallizes in the triclinic system,space group P1 with a = 7.979(4),b = 14.538(11),c = 15.853(8),α = 110.77(2),β = 97.955(18),γ = 104.88(2)°,V = 1607.3(17)3,Z = 2,C20H16CuI4N4O2Pb,Mr = 1122.72,Dc = 2.320 g/cm3,F(000) = 1006,μ(MoKα) = 9.753,the final R = 0.0627 and wR = 0.1741 for 4846 observed reflections with Ⅰ 〉 2σ(Ⅰ).Structural analysis indicates that 1 consists of 2-D {[Cu(Ⅱ)(bipy)2I]}nn+ cation layers(based on π-π interaction and hydrogen bonds) and [PbI3]nn-polyanions.The C-H···I hydrogen bonds between {[Cu(Ⅱ)(bipy)2I]}nn+ cation layers and [PbI3]nn-polyanions lead to the formation of an interesting 3-D network.Optical absorp-tion spectrum indicates that 1 is a semiconductor,which is further validated by DFT calculation.Its electronic structure is also discussed.
基金Supported by the National Natural Science Foundation of China(21376053)
文摘Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.
基金supported by the National Natural Science Foundation of China (91022025, 51072036)the Natural Science Foundation of Fujian Province (2010J01284)
文摘A new nonlinear optical crystal of sodium terbium borate (Na2.67Tb2.11B3O9, Mr = 573.14) was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was deter- mined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a = 5.0744(10), b = 10.990(2), c = 6.9078(14) A, V = 385.24(13) A3, Dc = 4.941 g/cm3, F(000) = 250, Z = 2, μ= 9.205 mm-1, the final R = 0.0253 and wR = 0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na(1)O8, Na(2)O6, Na(3)O6 and Tb(1)O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic (μj = 7.04 μb). The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.
基金supported by the National Natural Science Foundation of China (0041814161)
文摘Synthesis of polycrystalline Nd:Sr0.95Ba0.05WO4 by means of liquid-and solid-phase reaction was reported.X-ray powder diffraction results showed that the as-grown Sr0.95Ba0.05WO4 and Nd:Sr0.95Ba0.05WO4 single crystals belonged to tetragonal system and I41/a space group.Transparent Nd:Sr0.95Ba0.05WO4 single crystal could be obtained along c-axis by Czochralski method from the synthesized polycrys-talline material.As the transmittance of Sr0.95Ba.005WO4 single crystal could reach 80%, Nd3+ ion was adopted to be doped into the single crystal.Spontaneous Raman spectrums of polycrystalline material and single crystal were measured by RERKZN-ELMER2000 and JY-HR800.By using X-ray fluorescence method, the effective segregation coefficients of Nd, Ba, Sr, and W elements in Sr0.95Ba.005WO4 single crystal were estimated as 0.844(0.745), 0.44, 1.09, and 0.95, respectively.The segregation coefficients of Nd in Sr0.95Ba0.05WO4 were higher than that in BaWO4, and this is as better as a Raman laser crystal.
基金supported by the National Natural Science Foundation of China (No. 21073034)the State Key Laboratory of Structural Chemistry (No. 20090060)+1 种基金the Natural Science Foundation of Fujian Province (X0650070)the Science and Technology Development Foundation of Fuzhou University (2010-XY-9)
文摘Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the surface of androgen receptor by using molecular docking with computational investigation. The energy was calculated respectively based on the QM (quantum mechanics) and MM (molecular mechanics) methods. The result shows that the allosteric modulation of androgen receptor plays an important role in the binding process between androgens and receptor. The open state receptor is less stable than the close state one, but the latter is more favorable for binding with androgens. It is worthy of note that when the androgen receptors binding or without binding with androgen are in close state, they are difficult to return to their open state. This phenomenon is an exception of the well known two-state model theory in which the two states are reversible. Whether the internal of close state androgen receptor has a combination of androgen or not, the androgen receptor surface can be combined with another androgen, and their surface binding energies could be very close. The result is consistent with the experimental observations, but this phenomenon of continuous combination from open state is also an exception of the two-state model theory.
文摘A new borophosphate compound Cd3 BPO7(Mr = 490.98) has been successfully synthesized by conventional high temperature solid state reaction for the first time and its structure was determined by single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group Pna21, with a = 13.247(3), b = 8.8217(18), c = 5.0792(10), V = 593.56(20)3, Z = 4, Dc = 5.494 g/cm3, λ(CuKα) = 1.5406, F(000) = 880, the final R = 0.0212 and wR = 0.0513 for 1287 observed reflections(I 〉 2σ(I)). In the crystal structure of Cd3 BPO7, the Cd(II) forms a slightly distorted octahedral geometry, BO3 3- and PO4 3- ions linking adjacent Cd(II) ions to form a 3D network. The second harmonic generation(SHG) on powder samples was measured using Kurtz and Perry technique. The result indicates that Cd3 BPO7 exhibits a SHG response 2.2 times larger than that of potassium dihydrogen phosphate(KDP) and is phase-matchable.
基金Supported by the National Natural Science Foundation of China (No. 21073034)the State Key Laboratory of Structural Chemistry (No. 20090060)
文摘The adsorption and decomposition of N2O on the InN (0001) surface have been explored employing density functional theory method. To study the most favorable N2O adsorption model, ten typical adsorption cases (four for the parallel style and six for the vertical style) were proposed. The calculated results indicate that the parallel models are energetically preferred over the vertical models. The parallelly adsorbed N2O prefers to be dissociated on the surface, the dissociated O atom is combined at the fcc site, and the N-N piece is desorbed from the surface and forms N2 molecules. The comparison of the density of states of InN (0001) surface before and after N2O adsorption is analyzed in detail. Through the searching for transition state of decomposition reaction, a very low energy barrier of 45.0 KJ/mol is derived.
文摘Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in the crystal was measured by the ICP method. The absorption and emission spectra were also measured. On the basis of the spectra, the absorption cross-sections, emission spectrum FWHM and fluorescence lifetime of the crystal were calculated. From the properties mentioned above.
基金This work was supported by the Fondation of Education Committee of Fujian Province(JB04016, JB04017)
文摘A novel coordination polymer {[Cu(en)2][Ag2I4]}, (en = ethylenediamine) was synthesized by the reaction of NaAgI2 and Cu(en)2(NO3)2·2H2O at room temperature with pH = 6.0, and the structure was characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group C2/m, with a=10.646(2), b = 13.304(3), c = 6.8445(14) ,A°, β = 118.95(3)°, C4H16N4CuAg2I4, Mr = 907.10, V= 848.3(4) A°^3, Z= 2, Dc = 3.551 g/cm^3, F(000) = 806, μ(MoKa) = 10.787 mm^-1, the final R1 = 0.0256 and wR2 = 0.0654 for 900 observed reflections with I 〉 2σ(I). According to structural analysis, the title compound consists of template cation [Cu(en)2]^2+ and inorganic chain [Ag2I4]n^2-. The polymeric negative chain [Ag2I4]n^2- is built up from pairs of AgI4 tetrahedron by sharing one edge. Through N-H…I hydrogen-bonding interactions, the whole structure represents a quasi-two dimensional arrangement. Electrostatic attraction exists between organic cations and inorganic chains, leading to a so-called organic-inorganic hybrid structure.
基金Supported by the National Natural Science Foundation of China (No. 21201035)
文摘An efficient and recyclable cadmium removal adsorbent was prepared by molding and sintering of ultrafine silica powder produced from ferroalloy plant as the main raw materials, with the addition of a certain amount of AI(OH)3 and CaO for modification. XRD and SEM were used to characterize the crystal phases and microstructures of the adsorbent. The influences of different pH, initial cadmium concentration and contacting time on the cadmium adsorption capacity were investigated. The results show that the cadmium removal capacity is up to 0.239 mg/g at the initial Cd2+ concentration of 5 g/L, pH value of 7 and contacting time of 120 rain when the optimum, mass ratio is 70(ultrafine silica powder):30(Al(OH)3 and CaO mixture). The corresponding adsorbent has a porous structure with main crystalline phases of CazAI2SiO7 and CaSiO3. Cadmium is adsorbed and removed mainly by physical adsorption, assisted by chemical adsorption.
基金financially supported by the Natural Science Foundation of Fujian Province (2011J05024)
文摘CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to characterize the products. It was found that the crystallographic structure and optical property of the products synthesized at different temperature were almost the same. The SBEX of CdIn2S4 products decreased when the synthesized temperature increased, and the largest SBET was 33.16 m2 g-1 (120 ℃ sample). The degradation of methyl orange (MO) under the visible-light irradiation had been used as a probe reaction to investigate the photocatalytic activity of the as-prepared CdIn2S4, which showed that the CdIn2S4 sample synthesized at 120 ℃ presented the best photocatalytic activity for MO degradation.
基金Supported by the Science and Technology Development Foundation of Fuzhou University(No.2004-xq-05)
文摘One novel organically templated zincophophate (CsN2HI4).[Zn3(OH2)(POn)2(HPO4)] has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction together with elemental analysis, infrared spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/n, with a = 9.7904(11), b = 14.0287(14), c = 11.8651(13) A, β= 104.690(3)°, V= 1576.4(3) A^3, Z= 4, T= 296(2) K, Mr = 601.31 and Dc = 2.533 g/cm^3. The compound consists of a macroanionic [Zn3(OH2)(PO4)2(HPO4)]^2- framework and (C5N2H14)^2+ cations, and its structure is built up from ZnO3(OH2), ZnO4, HPO4 and PO4 tetrahedral units that result in 4, 8 and 10-ring channels.
基金Supported by the Natural Science Foundation of Fujian Province (E0710008)Innovation Fund for Young Scientist of Fujian Province (2007F3049)+2 种基金Fund of Education Committee of Fujian Province (JA07018)the Special Foundation for Young Scientists of Fuzhou University (XRC-0644)Science & Technology Promotion Foundation of Fuzhou University (XJJ-0605)
文摘A new iodiplumbate polymer [(ipq)2(pea)(Pb3I9)-DMF]n 1 (ipq = N-(isopentyl)- quinolinium, pea = protonated ethylamine) was synthesized by self-assembly reaction of ipq·I, PbI2 with ethylamine and structurally characterized. 1 crystallizes in the triclinic system, space group P1 with α= 1.0731(4), b = 1.2560(4), c = 2.0785(7) nm, α = 96.378(5), β= 91.132(2), γ= 100.303(5)°, V= 2.7369(16) nm^3, Z= 2, Dc = 2.770 g/cm^3,μ = 14.307 mm^-1, F(000) = 2014, R = 0.0588 and wR = 0.1345. 1 features its hybrid structure concertedly templated by two kinds of organic cations, which exhibits interesting semiconductor property. In 1, the [Pb2I6]^2 n infinite chains shape the sketch of the title compound constructed from face-sharing of ideal and distorted PbI6 octahedra. Based on the crystal structure data, quantum chemistry calculation with DFT was used to reveal the electronic structure of 1.