Preparation of Thermal Insulation Ceramics Using Felsic Tailings as Main Raw Material and Soda-ash Dregs as Flux

Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,Al_(2)O_(3)and CaO content on the pore structure and crystal phase of porous ceramics.The effect of Ca^(2+)in soda-ash dregs on the preparation of quartz-feldspar based porous ceramics was studied.The results showed that the contribution of Ca^(2+)to the preparation of porous ceramics in this system was mainly to accelerate the Si-O bond fracture and reduce the sintering temperature at the initial stage of sintering,which destroyed the needle-like feldspar in the high temperature melt and reduced the melt viscosity,thus reduced the foaming resistance and promoted the porous products with uniform pore size distribution.The Ca^(2+)content on the high side can participate in the formation of crystals in sintering.The generated needle-like diopside and augite,which have small length-diameter ratio,will negligibly change in the viscosity of melt at high temperatures,and their inhibition effect on pores is not as good as that of feldspar with large length-diameter ratio,resulting in the merger and collapse of pores.But the increase of diopside and augite can improve the compressive strength of porous products to some extent.Porous ceramic products containing needle-like feldspar phase can be prepared by using two kinds of solid waste,which can improve the compressive strength of the products and reduce the raw material cost and energy consumption while comprehensively utilizing the double solid waste.The optimal product has a bulk density of 0.45 g/cm^(3),a compressive strength of 3.17 MPa,and a thermal conductivity of 0.11 W/(m·K).

DFT Studies on Thermal Stabilities,Electronic Structures,and ^(13)C Chemical Shifts of C_(24)O_2 Based on Fullerene C_(24)(D_6)

Quantum chemical calculations on some possible equilibrium geometries of C24O2 isomers derived from C24 （D6） and C24O have been performed using density functional theory （DFT） method. The geometric and electronic structures as well as the relative energies and thermal stabilities of various C24O2 isomers at the ground state have been calculated at the B3LYP/6-31G（d） level of theory. And the 1,4,2,5-C24O2 isomer was found to be the most stable geometry where two oxygen atoms were added to the longest carbon-carbon bonds in the same pentagon from a thermodynamic point of view. Based on the optimized neutral geometries, the vertical ionization potential and vertical electron affinity have been obtained. Meanwhile, the vibrational frequencies, IR spectrum, and 13C chemical shifts of various C24O2 isomers have been calculated and analyzed.

Quantum-chemical Investigations of Structures and Stabilities of Ethynyl-or Ethenyl-expanded [n]-Prismanes

Quantum-chemical calculations on some derivatives of [n]-prismanes expanded by ethynyl or ethenyl groups have been performed using density functional theory （DFT） method.Their geometric structures,electronic structures,vertical ionization potentials and vertical electron affinities have been obtained at the B3LYP/6-31G＊＊ level of theory.Meanwhile,the total strain energy has been investigated in detail and compared with [n]-prismane and other derivatives.The present paper has also computed the enthalpies of formation for different isomers so as to evaluate their thermal stabilities.

Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalyst and Optimal Synthesis Conditions of the Support Prepared by Sol-gel Method

The support of catalyst for the direct synthesis of diphenyl carbonate （DPC） by heterogeneous catalytic reaction was prepared by the sol-gel method. Compared with activated charcoal, molecular sieve, porous ceramics, hopcalite, the support prepared by the sol-gel method has higher activity. The characterization of the support by X-ray diffraction （XRD） and transmission electron microscope （TEM） show that the mare crystal phase is Co2MnO4 and the average particle diameter is about 40 nm. The optimum conditions for synthesis of the support were determined by orthogonal experiments, which indicate that the proportion of Cu, Mn, and Co is the first important factor influencing the yield and selectivity of DPC. Temperature of calcination is the second one. The optimum conditions are： molar proportion of Cu, Mn, and Co being 1 ： 1 ： 1, temperature of calcination 700℃, drying at 100~C, temperature of water bath 85~C. The yield and selectivity of DPC in the process can reach 38% and 99% in the batch operation, respectively. The copper cobalt manganese mixed oxides chosen as the support contribute more to the high catalytic activity than the sol-gel method.

Syntheses, Crystal Structures and Magnetic Properties of Ni(Ⅱ) and Mn(Ⅱ) Coordination Polymers Constructed from 5-(2'-Carboxylphenyl) Nicotate and 2,2'-Biimidazole

Two coordination polymers, namely {[Ni（cpna）（H2biim）（H2O）]·H2O}n （1） and {[Mn（cpna）（H2biim）]·H2O}n （2） （H2cpna = 5-（2＇-carboxylphenyl） nicotic acid, H2biim = 2,2＇- biimidazole）,have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. Compound 1 exhibits a one- dimensional （1D） step-like chain structure, which further builds a three-dimensional （3D） supramolecular architecture via O–HAAAO and N–HAAAO hydrogen-bonding and π-π stacking interactions. Compound 2 possesses a one-dimensional （1D） double chain structure, which is further assembled into a 3D supramolecular framework by N–HAAAO hydrogen bonding and π-π stacking interactions. Magnetic susceptibility measurement indicates that compound 1 shows a weak antiferromagnetic coupling between the nearest Ni（II） centers, with g = 2.11 and J = –1.87 cm^-1.

Preparation and drug releasing property of magnetic chitosan-5-fluorouracil nano-particles

In order to synthesize the targeting drug carrier system,magnetic chitosan-5-fluorouracil nano-particles were prepared by using 5-fluorouracil(5-Fu)as model drug,Fe3O4 nano-particles as kernel,chitosan as enveloping material and glutaraldehyde as cross linking agent through ultrasonic technique.The morphology of the magnetic chitosan-5-Fu nano-particles was observed with a transmission electron microscope(TEM).The results showed that magnetic chitosan-5-Fu nano-particles were prepared in spherical structure with a size range of 50-60 nm.The delivering capacity and drug releasing properties of magnetic chitosan-5-Fu nano-particles were investigated by UV-vis spectrum analysis.The results showed that the loading capacity was 13.4%and the cumulative release percentage in the phosphate buffer(pH=7.2)solutions was 68%in 30 h.These data indicate that the wrapped drug of magnetic chitosan-5-Fu nano-particles was slowly-released.The magnetic response of magnetic chitosan-5-Fu nano-particles was studied by UV-vis spectrometer to detect the changes of solution absorbance.Without external magnetic field,the nano-particle deposition rate was slow.When being subjected to 8 mT magnetic field,the particle sedimentation rate was increased rapidly.The results showed that magnetic chitosan-5-Fu nano-particles have a magnetic stability and strong targeting characteristics.

Extraction and Purification of Depigmenting Agents from Chinese Plants

Depigmenting agents were solvent-extracted and purified by preparative and analytical HPLC from three Chinese plants; Chrysanthemum morifolium Ramat（ Xizang Caijuhua）, Rhodiola sachalinensis, and Terminalia chebula Retzius. Four fractions obtained from the ethyl ether layer of C. m. Rama and two fractions from the ethyl acetate layer of Rhodiola salientness show depigmenting effects. At 8 200, the ethyl acetate layers of Chrysanthemum morifolium Ramat, Rhodiola sachalinensis and the methanol extract of Terminalia chebula Retzius, can inhibit the melanin production of mouse B16 melanoma cells by 92%, 60% and 90%, respectively, whereas 46% inhibition was observed by commercially available depigmenting agents（arbutin）. These results show the potential of these three Chinese plants as a novel resource for depigmenting agents in the cosmetic industry.

Decomposition kinetics of dimethyl methylphospate(chemical agent simulant) by supercritical water oxidation

Supercritical water oxidation （SCWO） has been drawing much attention due to effectively destroy a large variety of high-risk wastes resulting from munitions demilitarization and complex industrial chemical. An important design consideration in the development of supercritical water oxidation is the information of decomposition rate. In this paper, the decomposition rate of dimethyl methylphosphonate（DMMP）, which is similar to the nerve agent VX and GB（Sarin） in its structure, was investigated under SCWO conditions. The experiments were performed in an isothermal tubular reactor with a H2O2 as an oxidant. The reaction temperatures were ranged from 398 to 633℃ at a fixed pressure of 24 MPa. The conversion of DMMP was monitored by analyzing total organic carbon （TOC） on the liquid effluent samples. It is found that the oxidative decomposition of DMMP proceeded rapidly and a high TOC decomposition up to 99.99% was obtained within 11 s at 555℃. On the basis of data derived from experiments, a global kinetic equation for the decomposition of DMMP was developed. The model predictions agreed well with the experimental data.

Magnetic resonance imaging of the pancreas in streptozotocin-induced diabetic rats: Gadofluorine P and Gd-DOTA

AIM: To investigate the performance of Gadofluorine P-enhanced magnetic resonance imaging(MRI) on the diagnosis of diabetes in a streptozotocin(STZ)-induced diabetic rat model.METHODS: Fischer 344 rats were treated with STZ.Rats not treated with STZ served as controls. T1-weighted MRI was performed using a 3T scanner before and after the injection of Gd-DOTA or Gadofluorine P(6 diabetic rats, 5 controls). The normalized signal intensity(SI) and the enhancement ratio(ER) of the pancreas were measured at each time point, and the values were compared between the normal and diabetic rats using the Mann-Whitney test. In addition,the values were correlated with the mean islet number.Optimal cut-off values were calculated using a positive test based on receiver operating characteristics.Intrapancreatic Gd concentration after the injection of each contrast media was measured using laser ablation-inductively coupled plasma-mass spectrometry in a separate set of rats(4 diabetic rats, 4 controls for Gadofluorine P; 2, 2 for Gd-DOTA).RESULTS: The normalized SI and ER of the pancreas using Gd-DOTA were not significantly different between diabetic rats and controls. With Gadofluorine P, the values were significantly higher in the diabetic rats than in the control rats 30 min after injection(P < 0.05). The area under the receiver operating characteristic curve that differentiated diabetic rats from the control group was greater for Gadofluorine P than for Gd-DOTA(0.967 vs 0.667, P = 0.085). An increase in normalized SI 30 min after Gadofluorine P was correlated with a decrease in the mean number of islets(r 2 = 0.510, P = 0.014). Intra-pancreatic Gd was higher in rats with Gadofluorine P injection than Gd-DOTA injection(Gadofluorine P vs Gd-DOTA, 7.37 vs 0.00, P < 0.01). A significant difference in the concentration of intrapancreatic Gd was observed between the control and diabetic animals that were sacrificed 30 min after Gadofluorine P injection(control vs diabetic, 3.25 ng/g vs 10.55 ng/g, P < 0.05)CONCLUSION: In this STZ-induced diabetes rat model,Gadofluorine P-enhanced MRI of the pancreas showed high accuracy in the diagnosis of diabetes.

Comparative analysis of volatile constituents between herbal pair flos lonicerae-caulis lonicerae and its single herbs

Gas chromatography-mass spectrometry(GC-MS) and the chemometric resolution method(alternative moving window factor analysis,AMWFA) were used for comparative analysis of volatile constituents in herbal pair(HP) flos lonicerae-caulis lonicerae(FL-CL) and its single herbs.The temperature-programmed retention index(PTRI) was also employed for the identification of compounds.In total,44,39,and 50 volatile chemical components in volatile oil of FL,CL and HP FL-CL were separately determined qualitatively and quantitatively,accounting for 87.22%,94.54% and 90.08% total contents of volatile oil of FL,CL and HP FL-CL,respectively.The results show that there are 32 common volatile constituents between HP FL-CL and single herb FL,33 common volatile constituents between HP FL-CL and single herb CL,and 10 new constituents in the volatile oil of HP FL-CL.

Syntheses,Crystal Structures and Luminescent Properties of Lead(Ⅱ) and Cadmium(Ⅱ) Coordination Polymers Constructed from Biphenyl-2,5,3′-tricarboxylate

Two coordination polymers, namely [Pb（Hbtc）（phen）]n（1） and {[Cd3（btc）2（H2O）4]·2H2O}n（2, H3btc = biphenyl-2,5,3＇-tricarboxylic acid, phen = 1,10-phenanthroline）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a zigzag chain 1D coordination network, which is further extended into a 3D supramolecular architecture via O–H···O hydrogen bonds and π-π packing interactions. Compound 2 features a 3D open framework based on a tricadmium（II） subunit, generating a trinodal 4,4,6-connected net with the 4,4,6T24 topology defined by the point symbol of（44·62）3（46·69）2. Thermal stability and luminescent properties of both compounds were studied and discussed.

Preparation of Thin Palladium Composite Membranes and Application to Hydrogen/Nitrogen Separation

Thin palladium composite membranes were prepared by modified electroless plating method on a-alumina supports and a dense Pd/α-Al2O3 composite membrane with high hydrogen flux, good selectivity for hydrogen was obtained. It was tested in a single gas permeation system for hydrogen permeance and hydrogen selectivity over mtrogen. The hydrogen permeance of the corresponding membrane was ashigh as 2.45×10^-6mol·m^-2·s^-1.Pa^-1 and H2/N2 selectivityover700 at 623K and a pressure difference of 0.1MPa. The-main resistance of the composite membrane to H2 permeation lies in the aluminum ceramic support rather than the thin Pd layer.

Synthesis and Crystal Structure of 2-Hydroxybenzoic Acid [1-(3,5-Dibromo-2-hydroxyphenyl)methylidene]hydrazide Methanol

A new Schiff base compound, 2-hydroxybenzoic acid [1-（3,5-dibromo-2-hydroxyphenyl） methylidene]hydrazide methanol （C14H10Br2N2O3·CH3OH）, has been synthesized by the condensation of equimolar 3,5-dibromosalicylaldehyde and 2-hydroxybenzoic acid hydrazide in a methanol solution. The compound was characterized by elemental analysis, IR spectra, and singlecrystal X-ray diffraction. The compound consists of a Schiff base moiety 2-hydroxybenzoic acid [1-（3,5-dibromo-2-hydroxyphenyl）methylidene]hydrazide and a lattice methanol molecule. The crystal belongs to the monoclinic system, space group P21/n with a = 7.183（1）, b = 15.673（2）, c = 15.001（2） A, β = 98.345（2）°, Z = 4, V = 1670.9（4） A^3, Dc = 1.773 g/cm^3, Mr = 446.10, λ（MoKα） = 0.71073 , μ = 4.872 mm^-1, F（000） = 880, R = 0.0458 and wR = 0.0963. A total of 3445 unique reflections were collected, of which 2236 with I 〉 2σ（Ⅰ） were observed. As expected, the molecule adopts a trans configuration about the C=N double bond. The two benzene rings are nearly coplanar （mean deviation from the combined plane is 0.061（4） ）, with the dihedral angle of 7.9（3）°. The preliminary biological tests show that the compound has moderate antibacterial activities.

In vitro degradation resistance of glucose and L-cysteine-bioinspired Schiff-base anodic Ca−P coating on AZ31 magnesium alloy

A Schiff base(a compound containing a C=N bond)induced anodic Ca−P coating was prepared on AZ31 Mg alloy in a mixed solution of CaCl_(2) and KH_(2)PO_(4) at 60℃ in the presence of glucose and L-cysteine.The microstructure and chemical composition of the coatings were characterized using FE-SEM,FT-IR,XRD,and XPS.The in vitro degradation resistance of the coated samples was evaluated via potentiodynamic polarization(PDP),electrochemical impedance spectroscopy(EIS),and hydrogen evolution test.The experimental results show that the Ca−PSchiff base coating is composed of CaHPO_(4)(DCPA)and hydroxyapatite(HA),whereas HA is not present in the Ca−P coating.The Ca−P_(Schiff base) coating thickness is about 2 times that of Ca−P coating(Ca−P coating:(9.13±4.20)μm and Ca−P_(Schiff base):(18.13±5.78)μm).The corrosion current density of the Ca−P_(Schiff base) coating is two orders of magnitude lower than that of the Ca−P coating.The formation mechanism of the Ca−P_(Schiff base) is proposed.

Syntheses, Crystal Structures, and Magnetic Properties of the Cobalt(Ⅱ) and Nickel(Ⅱ) Coordination Polymers Constructed from 5-Halonicotinate and 2,2ˊ-Biimidazole

Two coordination polymers, namely [Co（5-Clnic）2（H2biim）]n 1 and {[Ni（5-Clnic）（Hbiim）]·H2O}n 2（5-Clnic H = 5-halonicotinic acid, H2 biim = 2,2ˊ-biimidazole）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a 1D chain coordination network, which is further extended into a 3D supramolecular architecture via N–H…O hydrogen bonds and π-π packing interactions. Compound 2 features a 1D chain structure based on the hexanuclear macrocycles. The adjacent 1D chains are held together into a 3D supramolecular framework via N–H…O and O–H…O hydrogen bonding interactions. Thermal stability and magnetic properties of both compounds were studied and discussed.

Syntheses, Crystal Structures and Luminescent and Magnetic Properties of Cerium(Ⅲ) and Zinc(Ⅱ) Coordination Compounds Constructed from 3,5-Dibromobenzoic Acid

Two coordination compounds, namely [Ce（3,5-Br2BC）3（3,5-HBrzBC）]n （1） and [Zn（3,5-Br2BC）2（phen）] （2, 3,5-HBr2BC = 3,5-dibromobenzoic acid, phen = 1,10-phenanthroline）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a ID chain coordination network, which is further extended into a 3D supramolecular architecture via Br..＇Br and Br＇＂O halogen bonding. Compound 2 consists of a mononuclear molecule, which is assembled to a 3D supramolecular framework through C-H..-O hydrogen bond, π-π stacking interactions and Br..π halogen bonding. Luminescent and magnetic properties of both compounds have also been studied.

Synthesis, Crystal Structure, and Magnetic Properties of a Co Metal-organic Framework with Mixed Dicarboxylate and Tricarboxylate Ligands

One new mixed-ligand coordination polymer,namely[Co2（btc）（bpdc）（0.5）（py）3]n（1）,was hydrothermally synthesized using biphenyl-2,4,4＇-tricarboxylic acid（H3btc） as a main building block,along with two auxiliary ligands（H2bpdc = 2,2＇-bipyridine-5,5＇-dicarboxylic acid and py =pyridine）.The product 1 was characterized by IR spectroscopy,elemental,thermogravimetric,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction studies show that compound 1 possesses an intricate 3D metal-organic framework based on tetracobalt（Ⅱ） units.Magnetic susceptibility measurement indicates that compound 1 shows an antiferromagnetic coupling between the Co（Ⅱ） ions.

Synthesis, Crystal Structure and Luminescent Properties of a Novel 2D Sheet Cd(Ⅱ) Coordination Polymer [Cd(Cpna)(Py)]_n

A coordination polymer, [Cd（cpna）（py）]n （H2cpna = 5-（2＇-carboxylphenyl） nicotic acid, py -- pyridine） 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectra and single-crystal X-ray diffraction. Colorless crystals crystallize in the monoclinic system, space group P21/c with a = 8.589（2）, b = 13.047（3）, c = 14.940（4） A, fl = 96.001（2）°, V = 1664.9（7） A3, C18H12CdN204, Mr = 432.70, Dc = 1.726 g/cm3, F（000） = 856, Z = 4, p（MoKa） = 1.337 mm^-1, the final R = 0.0396 and wR = 0.0891 for 2422 observed reflections （1 〉 2a（I））. Complex I exhibits a two-dimensional （2D） sheet structure, which further builds a three-dimensional （3D） supramolecular architecture via C-H...O hydrogen-bonding interactions.

Syntheses, Crystal Structures and Magnetic Properties of Cobalt(Ⅱ) and Manganese(Ⅱ) Coordination Polymers Constructed from 5-(Pyridin-4-yl)Isophthalate Ligands

Two coordination polymers, namely {[Co（L）（H2O）]·H2O}n （1） and [Mn（L）（phen）]n （2, H2L = 5-（pyridin-4-yl）isophthalic acid, phen = 1,10-phenanthroline）, have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. 1 belongs to the triclinic system, space group Pī with α = 7.2188（7）, b = 10.0835（8）, c = 10.2069（7） ？, α = 113.713（7）, β = 99.490（7）, γ = 104.516（8）o, V = 628.24（9） ？3, C13H11NCoO6, Mr = 336.16, Z = 2, Dc = 1.777 Mg/m3, μ（MoKα） = 1.395 mm–1, F（000） = 342, S = 1.041, the final R = 0.0381 and wR = 0.0819 for 3744 observed reflections （I 〉 2σ（I）） and R = 0.0448 and wR = 0.0874 for all data. 2 belongs to the monoclinic system, space group P2/c with α = 12.9185（3）, b = 10.4343（2）, c = 31.7650（6） ？, β = 101.282（2）o, V = 4199.08（13） ？3, C50H30N6Mn2O8, Mr = 952.68, Z = 4, Dc = 1.507 Mg/m3, μ（MoKα） = 5.447 mm–1, F（000） = 1944, S = 1.128, the final R = 0.1003 and wR = 0.1052 for 8247 observed reflections （I 〉 2σ（I）） and R = 0.2595 and wR = 0.2625 for all data. Single-crystal X-ray diffraction studies show that compound 1 features a 2D sheet structure based on a dicobalt（II） subunit, which is further extended into a 3D metal-organic supramolecular framework by O–H… hydrogen bond. Compound 2 also possesses a 2D sheet, which is held together into a 3D supramolecular architecture via C–H… hydrogen bond and π-π stacking interactions. Magnetic studies for compound 2 show antiferromagnetic coupling between the adjacent metal centers, with J = –11.8 cm–1 and g = 2.12 for 2.