Investigation of the cross-reaction mechanism of C<Subscript>6</Subscript>H<Subscript>5</Subscript>F-HNO<Subscript>2</Subscript> aqueous solution irradiated at 355 nm by transient absorbance spectrum technique

The transient absorption spectrum technique was employed to investigate the cross-reaction mechanism of C6H5F-HNO2 aqueous solution irradiated at 355 nm. The characteristic and the kinetic parameters of transient species were also detected. Hydroxyl radical derived from the photolysis of HNO2 was added to monofluorobenzene with a second-order rate constant of （5.83±0.17）×10^9 L·mol^-1·s^-1 to form an adduct, C6H5F…OH, which was able to react with HNO2 as the main reaction pathway with a rate constant of （8.3±0.1）×10^7 L·mol^-1·s^-1. The C6F6…OH adduct can also be decayed by elimination of H2O to yield monofluorophenyl radical C6H4F-. By GC-MS technique, the final products were identified to be monofluorophenol, nitro-monofluorobenzene, nitro-monofluorophenol and para-fluorobiphenyl.     

Two-dimensional crystallization and preliminary electron crystallographic result of partially purified F<Subscript>0</Subscript> from porcine mitochondria

After removal of cytoplasmic sector F₁ from submitochondrial particles of F₀F₁-ATP synthase complex with guanidine hydrochloride, the transmembrane sector F₀ was specifically extracted from the stripped membranes in the presence of detergent CHAPS and partially purified. Two-dimensional crystals were produced by the reconstitution of the partially purified F₀ into asolectin and microdialysis. The obtained crystals are able to diffract to 2 nm. The projection map of the negatively stained crystal shows that the crystal has p42₁2 symmetry, lattice constant, a=b=14.4 nm. A unit cell contains four F₀ molecules.     

Research on C<Subscript>3</Subscript>N<Subscript>4</Subscript> superhard compound thin film and its application

By combination of DC reactive magnetron sputtering with multiple arcplating, the alternating C₃N₄/TiN compound film is deposited onto HSS. The core level binding energy and the contents of carbon and nitrogen are characterized by X-ray photoelectron spectrum. X-ray diffraction (XRD) shows that compound thin film contains hard crystalline phases of α-C₃N₄ and β-C₃N₄. The Knoop microhardness in the load range of 50, 5–54, 1 GPa is measured. According to acoustic emission scratch test, the critical load values for the coatings on HSS substrates are in the range of 40–80 N. The metal coated with C₃N₄/TiN compound films has a great improvement in the resistance against corrosion. Many tests show that such a coating has a very high wearability. Compared with the uncoated and TiN coated tools, the C₃N₄/TiN coated tools have a much longer cutting life. Foundation item: Supported by the National Natural Science Foundation of China (19875037) Biography: Wu Da-we( (1941-), male, Professor, research direction; thin film and its application.     

Compression behavior and equation of state of Ni77P23 amorphous alloy

The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation source. The equation of state is determined by fitting the experimental data accord- ing to Birch-Murnaghan equation: -ΔV/V0=0.08606P-3.2×10-4P2 5.7×10-6P3. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa.     

Giant magneto-optical faraday effect of nanometer Fe-In<Subscript>2</Subscript>O<Subscript>3</Subscript> granular films

The giant magneto-optical Faraday effect of nanometer ferromagnetic metal-semiconductor matrix Fe-ln2O3 granular films prepared by the radio frequency sputtering are studied. The result shows that the Faraday rotation angle θF value of the granular film samples with Fe volume fraction x = 35% is of the order of 10^5（°）/cm at room temperature. Temperature dependence of the Faraday rotation angle θF of Fe0.35（In2O3）0.65 granular films shows that θF value below 10 K increases rapidly with the decrease of the temperature, and when T= 4.2 K, θF value is 106（°）/cm. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that when the temperature decreases to a critical point Tp = 10 K, the transformation of state from ferro-agnetic to spin-glass-like occurs in Fe0.35（In2O3）0.65 granular films. The remarkable increase of the Faraday rotation angle θF value of Fe0.35（In2O3）0.65 granular films below 10 K seems to arise from the sp-d exchange interaction of the granular film samples in the spin-glass-like state.     

Electronic structures and nonlinear optical properties of XAuPH<Subscript>3</Subscript>

The studies on model systems XAuPH3(X-H,F,Cl,Br,I,CN,CH3)have been carried out by using ab intiol HF and DFT B3LYP methods at pseudopotential and double-zeta LANL2DZ level.The results are compared with those of MP2,The properties of the models.i.e.the atomic net charge populations.the frontier molecular orbitals and nonlinear optical(NLO)properties have been investigated under an applied electric field on the basis of optimized structures.The computational results show that for these models characterized as electron acceptor-metal-electron donor(A-M-D)system,the NLO properties are due to intramolecular charge-transfer interaction between the acceptor and the donor.The more charges transfer gives,the better NLO properties.In the selected model systems,IAuPH3 has the biggest βvec and γof 1184.1942 a.u.and 17341.9214 a.u.,whereas IC6H4PH3^ ,A TYPICAL a-π-D organic conjugated system,has βvec and γof 710.7697 and 11664.1405 a.u.respectively.In comparison.IAuPH3 has significant NLO properties.     

Synthesis,Structure and Antitumor Activities of [Ni（dien）2][Ni（CN）4] Complex

Ni(II)-dien complex was prepared and characterized by X-ray diffraction. The crystal belongs to triclinic system, space group P-1, with crystallographic parametersa=0.888 13(18) nm,b=0.890 10(18) nm,c=1. 591 8(3) nm, α=77.71(3)°, β=89.12(3)°, γ=61.24(3)°,Z=2. The two dien molecules coordinate to the central Ni atom, the six nitrogen atoms form a distorted octahedron. Preliminary pharmacological tests showed this complex had antitumor activity against HepG₂ and HL-60 cell linesin vitro. Foundation item, Supported by the National Natural Science Foundation of China (29972034) Biography: Li Tao (1976-), male, Ph. D candidate, research direction: ophthalmology and chemicalbiology.     

Theoretical study on the lithium bond interaction of furan homologues C4H4Y （Y=O,S） with LiCH3 via DFT and MP2

The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y （Y=O, S） and CHiLi have been calculated at the B3LYP/6-311＋＋G^＊＊ and MP2/6-311＋＋G^＊＊ levels. Three complexes were obtained. Abnormally, the calculations showed that all the C10--Li14 bond lengths increased obviously but the blue-shift of C10-Li14 stretching frequency occurred after formed complexes. The calculated binding energy with basis set super-position error （BSSE） and zero-point vibrational energy corrections of complexes I-III is -45.757, -35.700 and -39.107 kJ·mol^-1, respectively. The analyses on the combining interaction with the atom-in-molecules theory （AIM） also showed that a relatively strong lithium bond interaction presented in furan homologues C4H4Y-LiCH3 systems. Natural bond orbital theory （NBO） analysis has been performed, and the results revealed that the complex I is formed with n-σ type lithium bond interaction between C4H40 and LiCH3, complex II is formed with TT-s type lithium bond interaction between C4H4O and LiCH3, and complex III is formed with TT-s and n-s type lithium bond interactions between C4H4S and LiCH3, respectively.     

Effects of Yb^3＋ codoping on visible and near infrared emissions of Er^3＋-Yb^3＋ codoped Al2O3 powders by the sol-gel method

The 0.1 mol% Er^3＋ and 0-2 mol% Yb^3＋ codoped Al2O3 powders were prepared by the sol-gel method, and the phase structure, including only two crystalline types of doped Al2O3 phase, γ-（Al,Er, Yb）2O3 and θ-（Al,Er, Yb）2O3, was detected at the sintering temperature of 1000℃. The visible and near infrared emissions properties depended strongly on the Yb^3＋ codoping, and the corresponding maximal peak intensities centered at about 523, 545, 660 and 1533 nm were obtained respectively for the 0.1 mol% Er^3＋ and 0.5 mol% Yb^3＋ codoped Al2O3 powders, which were composed of θ-（Al,Er,Yb）2O3 and a small amount of γ-（Al,Er, Yb）2O3 phases. The two-photon absorption process was responsible for the visible up-conversion emissions, and the one-photon absorption process was involved in the near infrared emissions of the Er^3＋-yb^3＋ codoped Al2O3 powders.     

Doping effect on thermoelectric properties of nonstoichiometric AgSbTe<Subscript>2</Subscript> compounds

Nonstoichiometric ternary thermoelectric materials Ag_0.84Sb_1.15M_0.01Te_2.16 (M=Ce, Yb, Cu) were prepared by a direct melt-quench and hot press process. The carrier concentration of all the samples increased after doping. Thermoelectric properties, namely electrical conductivity, Seebeck coefficient, and thermal conductivity, were measured from 300 to 673 K. The phase transition occurring at about 418 K representing the phase transition from β-Ag₂Te to α-Ag₂Te influenced the electrical transport properties. The electrical conductivities of Ce and Yb doped samples increased after doping from 1.9×10⁴ to 2.5×10⁴ and 2.3×10⁴ S·m⁻¹, respectively, at 673 K. Also, at room temperature, the Seebeck coefficient of the Ce doped sample relatively increased corresponding to the high carrier concentration due to the changes in the band structure. However, all the thermal conductivities increased after doping at low temperature. Because of the higher thermal conductivity, the dimensionless figure of merit ZT of these doped samples has not been improved.     

Surface tension and specific heat of liquid Ni<Subscript>70.2</Subscript>Si<Subscript>29.8</Subscript> alloy

The thermophysical properties of liquid alloys in me-tastable state are of importance for liquid-solid phase transformation under nonequilibrium conditions[1―10]. Sur-face tension and specific heat, two of the most important thermophysical properties, have significant influences on the process of crystal nucleation and growth. Furthermore, it is necessary to obtain these data so as to perform quan-titative research on rapid solidification[3―10]. The tradi-tional measurement methods, however,…     

Analysis of the characteristics of the harmonics coefficient <Emphasis Type="Italic">J</Emphasis><Subscript>2</Subscript> of the Earth’s gravity field in different periods

The characteristics of the geopotential coefficient J2 in different periods are analyzed using satellite laser ranging data spanning the last 27 years.The satellites used in the analysis are Lageos1 and Lageos2.The variations in J2 are obtained by determining the dynamic orbit.The results show that there are strong seasonal and long-term variations.For different data spans,the seasonal variations agree well in terms of both amplitude and phase.Using all the data,the amplitude and phase of the annual term are 2.5 10-10 and 127°,respectively,while the amplitude and phase of the semiannual term are 0.94 10-10 and 213°,respectively.In the case of long-term variation,the secular variation in J2(J2) is-2.2 10-11 a-1 from 1984 to 2010.J2 differs for the different periods because of interannual variations,such as the "1998 anomaly".Another anomaly may have taken place during 2007-2010.Although the cause of the anomaly is unknown,it is an important observational constraint on the shape of the Earth.     

Structure properties for the superconductor MgCNi<Subscript>3</Subscript> under high pressure with synchrotron radiation

In situ high pressure energy dispersive X-ray diffraction measurements on cubic-perovskite superconductor MgCNi₃ under pressure up to 22 GPa have been performed by using diamond anvil cell with synchrotron radiation. We have investigated its crystal structure and compressibility. The results show that the structure of MgCNi₃ is stable under pressure up to 22 GPa. According to Birch-Murnaghan state equation, when we assume B ₀′ = 4, we get B₀ = 267.8 ± 7.2 GPa.     

Microwave sintering of Ca<Subscript>0.6</Subscript>La<Subscript>0.2667</Subscript>TiO<Subscript>3</Subscript> microwave dielectric ceramics

Ca_0.6La_0.2667TiO₃ ceramics were prepared by conventional and microwave sintering techniques and their sinterability, microstructure, and microwave dielectric properties were investigated in detail for comparison. Densified Ca_0.6La_0.2667TiO₃ ceramics were obtained by microwave sintering at 1350°C for 30 min and by conventional sintering at 1450°C for 4 h. An unusual phenomenon was found that some larger grains (grain size range: 8–10 μm) inclined to assemble in one area but some smaller ones (grain size range: 2–4 μm) inclined to gather in another area in the microwave sintered ceramics. The microwave dielectric properties of Ca_0.6La_0.2667TiO₃ ceramics prepared by microwave sintering at 1350°C were as follows: dielectric constant (ɛ _r) = 119.6, quality factor (Qf) = 17858.5 GHz, and temperature coefficient of resonant frequency (τ _f) = 155.5 ppm/°C. In contrast, the microwave dielectric properties of the ceramics prepared by conventional sintering at 1450°C were ɛ _r = 117.4, Qf = 13375 GHz, and τ _f = 217.2 ppm/°C.     

Kinetic investigation of <Emphasis Type="Italic">in situ</Emphasis> growth of CdMoO<Subscript>4</Subscript> nano-octahedra

CdMoO₄ nano-octahedra were grown in situ at room temperature by reverse-microemulsion. Energy evolution from this growth process was monitored using microcalorimetry. The microcalorimetric heat flow (MCHF) curve showed a characteristic endothermic peak for the initial reaction, and double discontinuous exothermic peaks for the subsequent crystal growth. Combined with complementary characterization techniques, the evolution of morphology and size of the CdMoO₄ nano-octahedra were correlated with the MCHF peaks. Calculations based on the microcalorimetric results at 298.15 K provided rate constants of 7.56×10⁻⁵ s⁻¹ for the reaction and nucleation process and 1.59×10⁻⁴ s⁻¹ for the crystallization process.     

<Emphasis Type="Italic">In situ</Emphasis> synthesis of TiC reinforced Cu<Subscript>47</Subscript>Ti<Subscript>34</Subscript>Zr<Subscript>11</Subscript>Ni<Subscript>8</Subscript> bulk metallic glass composites

In situ synthesized TiC particles and β-Ti dendrites reinforced Cu47Ti34Zr11Ni8 bulk metallic glass (BMG) composite ingots were prepared by the suction casting method.The ingots with diameters from 1 up to 4mm were successfully obtained. It was shown that introducing TiC micro-sized particles into the amorphous matrix did not disturb the glass forming ability (GFA) of the matrix,while the yield strength and ductility could be well improved.The phase constitution, microstructure and elements distribution in the composites were studied by OM, XRD, SEM and EDS.It was shown that the in situ synthesized TiC particles acting as heterogeneous nucleation sites promoted the precipitation of β-Ti dendrites, resulting in the formation of the TiC particles and β-Ti dendrites co-reinforced BMG composites. The compressive tests were employed to probe the yield strength and ductility of BMG composites.     

Comparative analysis of the dissolution kinetics of galena in binary solutions of HCl/FeCl<Subscript>3</Subscript> and HCl/H<Subscript>2</Subscript>O<Subscript>2</Subscript>

A comparative study of the dissolution kinetics of galena ore in binary solutions of FeCl₃/HCl and H₂O₂/HCl has been undertaken. The dissolution kinetics of the galena was found to depend on leachant concentration, reaction temperature, stirring speed, solid-to-liquid ratio, and particle diameter. The dissolution rate of galena ore increases with the increase of leachant concentration, reaction temperature, and stirring speed, while it decreases with the increase of solid-to-liquid ratio and particle diameter. The activation energy (E _a) of 26.5 kJ/mol was obtained for galena ore dissolution in 0.3 M FeCl₃/8.06 M HCl, and it suggests the surface diffusion model for the leaching reaction, while the E _a value of 40.6 kJ/mol was obtained for its dissolution in 8.06 M H₂O₂/8.06 M HCl, which suggests the surface chemical reaction model for the leaching reaction. Furthermore, the linear relationship between rate constants and the reciprocal of particle radius supports the fact that dissolution is controlled by the surface reaction in the two cases. Finally, the rate of reaction based on the reaction-controlled process has been described by a semiempirical mathematical model. The Arrhenius and reaction constants of 11.023 s⁻¹, 1.25×10⁴ and 3.65×10² s⁻¹, 8.02×10⁶ were calculated for the 0.3 M FeCl₃/8.06 M HCl and 8.06 M H₂O₂/8.06 M HCl binary solutions, respectively.     

<Emphasis Type="Italic">Ab initio</Emphasis> study of the effects of Ag/Mn doping on the electronic structure of LiFePO<Subscript>4</Subscript>

Based on density functional theory （DFT） of the first-principle for the cathode materials of lithium ion battery, the electronic structures of Li（Fe1-x）PO4 （Me = Ag/Mn, x = 0-0.40） are calculated by plane wave pseudo-potential method using Cambridge serial total energy package （CASTEP） program. The calculated results show that the Fermi level of mixed atoms Fe1-xAgx moves into its conduction bands （CBs） due to the Ag doping. The Li（Fe1-xAgx）PO4 system displays the periodic direct semiconductor characteristic with the increase of Ag-doped concentration. However, for Fe1-xMnx mixed atoms, the Fermi level is pined at the bottom of conduction bands （CBs）, which is ascribed to the interaction between Mn（3d） electrons and Fe（4s） electrons. The intensity of the partial density of states （PDOS） near the bottom of CBs becomes stronger with the increase of Mn-doped concentration. The Fermi energy of the Li（Fe1-xMnx）PO4 reaches maximum at x = 0.25, which is consistent with the experimental value of x = 0.20. The whole conduction property of Mn-doped LiFePO4 is superior to that of Ag-doped LiFePO4 cathode material, but the structural stability is reverse.     

Synthesis, Characterization and Calorimetry of Ni（C4H8N2O3）2Cl2

A coordination complex was synthesized from NiCl2 and dipeptide glycylglycine（GG）. It was characterized by element analysis, NMR and TG methods, and then was determined to be Ni（C4HsN2O3）2Cl2. Using an isoperibolic reaction calorimeter, the standard molar enthalpy of formation of Ni（GG）2Cl2（solid） has been determined to be -（1 674.66±2.02） kJ · mol^-1 at 298.15 K.     

3,4-dichlorotoluene ammoxidation to 3,4-dichlorobenzonitrile over VPO/SiO<Subscript>2</Subscript> catalyst

Ammoxidation of 3,4-dichlorotoluene (DCT) to prepare 3,4-dichlorobenzonitrile (DCBN) over silica supported vanadium phosphorus oxide catalysts has been studied. On the VPO/SiO₂ catalyst, the influence of the reaction temperature, the molar ratio of air/DCT, the molar ratio of NH₃/DCT in the feed gas and the space velocity (v ₁) on the conversion, yield and selectivity was observed. The most appropriate reaction condition is: reactionT=673 K,n(DCT):n(NH₃):n(air)=1:7:30 andv ₁=250 h⁻¹. At this optimum reaction condition, the conversion of DCT is 97.8%; the molar yield of DCBN is 67.4%. It was found that the addition of element phosphorus can improve the yield of DCBN compared with VO/SiO₂ catalyst. Foundation item: Supported by Youth Chen-Guang Project of the Committee of Science and Technology of Wuhan (20015005042) Biography: Huang Chi(1972-), male, Ph D, Lecture, research direction: ammoxidation.