Investigation of the structural, electronic and mechanical properties of CaO–SiO_(2) compound particles in steel based on density functional theory

CaO–SiO_(2)compounds compromise one of the most common series of oxide particles in liquid steels, which could significantly affect the service performance of the steels as crack initiation sites. However, the structural, electronic, and mechanical properties of the compounds in CaO–SiO_(2)system are still not fully clarified due to the difficulties in the experiments. In this study, a thorough investigation of these properties of CaO–SiO_(2)compound particles in steels was conducted based on first-principles density functional theory. Corresponding phases were determined by thermodynamic calculation, including gamma dicalcium silicate(γ-C2S), alpha-prime(L) dicalcium silicate(αL′-C2S), alpha-prime(H) dicalcium silicate(αH′-C2S), alpha dicalcium silicate(α-C2S), rankinite(C3S2), hatrurite(C3S), wollastonite(CS), and pseudowollastonite(Ps-CS). The results showed that the calculated crystal structures of the eight phases agree well with the experimental results. All the eight phases are stable according to the calculated formation energies, and γ-C2S is the most stable. O atom contributes the most to the reactivity of these phases. The Young’s modulus of the eight phases is in the range of 100.63–132.04 GPa. Poisson’s ratio is in the range of0.249–0.281. This study provided further understanding concerning the CaO–SiO_(2)compound particles in steels and fulfilled the corresponding property database, paving the way for inclusion engineering and design in terms of fracture-resistant steels.

Impacts of Changes in Structure of Rural Land Property Rights on Agricultural Performance

In the reform process of the rural land property rights system,the incentive mechanism of the rural land property rights system has a crucial impact on the production activities of rural economic entities.Due to the different rights structures of the property rights system in different social and economic development stages,the land rights and interests enjoyed by rural economic subjects are different,and the degree of incentives for farmers is also different.This difference in incentives affects farmers investment in agricultural production factors,which in turn affects agricultural performance.This paper analyzes the incentive impacts of the structure of rural land property rights on the changes of farmers land rights and agricultural performance since the founding of the People s Republic of China,in order to further deepen the reform of the land system,protect the rights and interests of farmers,promote the modernization of agriculture and rural areas,and explore the realization form and operation mechanism of the rural collective land system in the new era.

Effects of Different Drying Methods on the Functional and Structural Properties of Dietary Fiber from Peanut Shell

[Objectives] This study was conducted to investigate the drying methods,functional and structure properties of dietary fiber( DF) from peanut shells.[Methods]Peanut shells were used as a raw material to prepare peanut shell dietary fiber( DF) by hot air drying( HA) and vacuum freeze drying( VF),respectively,and their functional and structural characteristics were compared in detail. [Results]The solubility,water holding capacity,oil holding capacity and swelling capacity of HA-DF and VF-DF were 2. 15 %,7. 63 g/g,7. 73 g/g,10. 35 ml/g and 3. 85 %,14. 98 g/g,15. 25 g/g,15. 85 ml/g,respectively. The total phenol contents were 2. 623 and 5. 173 mg GAE/g,respectively. The IC(50) values of ·OH,O2^-· and DPPH free radicals were 4. 16 and 4. 09 mg/ml,7. 90 and 3. 32 mg/ml,and 3. 19 and 3. 09 mg/ml,respectively. The molecular weight of VF-DF was smaller,and it had narrow molecular weight distribution and denser particles. Electron microscopy showed that VF-DF had a porous network like honeycomb and swelled structure. [Conclusions]This study can provide a theoretical basis for the functional modification and comprehensive utilization of peanut shell dietary fiber.

Structure,electronic,and nonlinear optical properties of superalkaline M_(3)O(M=Li,Na)doped cyclo[18]carbon

Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm.

Effects of N_2 Pressure on the Structural and Electrical Properties of TiN Films Deposited by Laser Molecular Beam Epitaxy

Titanium nitride （TiN） films were deposited on Si（100） substrates by laser molecular beam epitaxy（LMBE）,and their properties of structure and resistivity with varying N2 pressure were investigated.The results showed that atomically flat TiN films with layer-by-layer growth mode were successfully grown on Si（100） substrates,and （200） was the preferred orientation.With the increasing of N2 pressure,the N/Ti ratio gradually increased and the diffraction peak progressively shifted towards lower diffraction angle.At pressure of 0.1 Pa,stoichiometric TiN film was formed which exhibited the characteristic diffraction angle of （200） plane.All films showed high reflectance to infrared spectrum and the films with overstoichiometry and understoichiometry had a higher resistivity owing to the surface particles and lattice distortion,while the stoichiometric TiN film depicted the minimum resistivity,around 19 μΩ·cm.

STRUCTURAL PROPERTIES INVESTIGATION ON MICROCRYSTALLINE SILICON FILMS DEPOSITED WITH VHF-PECVD TECHNIQUE

Raman scattering spectroscopy and scanning electron microscopy (SEM) techniques were used to determine the structural properties of two typical series of microc rystalline silicon (μc-Si:H) films deposited at different VHF plasma power and different working gas pressure by very high frequency plasma enhanced chemical v apor deposition (VHF-PECVD) technique. Raman spectra measurements show that both crystalline volume fraction Xc and average grain size d of μc-Si : H films ar e strongly affected by the two deposition conditions and are more sensitive to w orking gas pressure than VHF plasma power. SEM characterizations have further co nfirmed that VHF plasma power and working gas pressure could clearly enhance the surface roughness of μc-Si : H films ascribing to polymerization reactions, w hich is also more sensitive to working gas pressure than VHF plasma power.

Unusual structural properties of polymers confined in a nanocylinder

Structural properties of polymers confined in nanocylinders are investigated by Monte Carlo simulation, which is successfully used to consider the conformational property of constrained polymers. The conformational properties of the polymers close to the walls exhibit different features. The density profiles of polymers are enhanced near the wall of the nanocylinder, which shows that the packing densities differ near the wall and far from the wall. The highest densities near the wall of the nanocylinder decrease with increasing radius of the nanocylinder. Furthermore, the density excess is not only near the wall of the nanocylinder, but also shifts to the center of the nanocylinder at lower temperatures. The radius of gyration and the bond length of polymers in the nanocylinder show that the polymer chains tend to extend along the axis of the nanocylinder in highly confined nanocylinder and contract at lower temperature. Our results are very helpful in understanding the packing induced physical behaviors of polymers in nanocylinders, such as glass transition, crystallization,etc.

Influence of oxygen gas content on the structural and optical properties of ZnO thin films deposited by RF magnetron sputtering at room temperature

Zinc oxide （ZnO） thin films were deposited on sapphire （0001） substrates at room temperature by radiofrequency （RF） magnetron sputtering at oxygen gas contents of 0%, 25%, 50% and 75%, respectively. The influence of oxygen gas content on the structural and optical properties of ZnO thin films was studied by a surface profile measuring system, X-ray diffraction analysis, atomic force microscopy, and UV spectro- photometry. It is found that the size of ZnO crystalline grains increases first and then decreases with the increase of oxygen gas content, and the maximum grain size locates at the 25% oxygen gas content. The crystalline quality and average optical transmittance （〉90%） in the visi- ble-light region of the ZnO film prepared at an oxygen gas content of 25% are better than those of ZnO films at the other contents. The obtained results can be attributed to the resputtefing by energetic oxygen anions in the growing process.

Synthesis, Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd（Ⅱ） coordination polymer, namely, [Cd（1,3-bip）（3,5-pdc）]n （1,3-bip = 1,3-bis（imidazol）propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid） has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178（7）, b = 1.72502（12）, c = 1.41635（6） ran, β = 92.653（4）°, V = 3.4212（3） nm3, Z = 4, C16HIsCdNsO4, Mr = 453.73, Dc = 1.762 g/cm3, F（000） = 1808,μ = 1.310 mm1, R = 0.0899 and wR = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd（lI） ions and each Cd（Ⅱ） attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.

Structural Characterization and Octanol/water Partition Coefficients(LogP) Prediction for Oxygen-containing Organic Compounds

New descriptors were constructed and structures of some oxygen-containing organic compounds were parameterized. The multiple linear regression（MLR） and partial least squares regression（PLS） methods were employed to build two relationship models between the structures and octanol/water partition coefficients（LogP） of the compounds. The modeling correlation coefficients（R） were 0.976 and 0.922, and the ＂leave one out＂ cross validation correlation coefficients（R（CV）） were 0.973 and 0.909, respectively. The results showed that the structural descriptors could well characterize the molecular structures of the compounds; the stability and predictive power of the models were good.

Synthesis and measurement of structural and magnetic properties of K-doped LaCoO_3 perovskite materials

Polycrystalline La1-xKxCoO3 （0≤ x ≤ 0.2） rare earth cobaltates have been synthesized by a solution combustion method using glycine as a fuel. The synthesized ceramic materials were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR）, and magnetic measurements and studied for physical properties, such as photoeatalytic activity. FTIR measurements in conjunction with XRD showed that phases beyond 10% K doping are accompanied by small amounts of impurities. Chemical titrations show the presence of Co^4＋ and account for the Co^3＋-Co^4＋ mixed-valency of the system. The parent LaCoO3 shows spin-glass transition at low temperatures, whereas doped samples show transition from spin-glass behavior to paramagnetic ordering on progressive doping of K. ＂Mixed-conductor＂ nature of these ceramics positions them as viable candidates for solid oxide fuel cell （SOFC） applications.

Effects of （LiCe） co-substitution on the structural and electrical properties of CaBi2Nb209 ceramics

The piezoelectric, dielectric, and ferroelectric properties of the （LiCe） co-substituted calcium bismuth niobate （CaBi2Nb209, CBNO） are investigated. The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan 5 decreased. This makes poling using （LiCe） co-substitution easier. The ceramics （where represents A-site Ca2＋ vacancies, possess a pure layered structure phase and no other phases can be found. The Cao.ss（LiCe）0.04[]0.04Bi2Nb209 ceramics possess optimal piezoelectric properties, with piezoelectric coefficient （d33） and Curie temperature （Tc） found to be 13.3 pC/N and 960 ℃ respectively. The dielectric and piezoelectric properties of the （LiCe） co-substituted CBNO ceramics exhibit very stable temperature behaviours. This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.

Effects of Sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PSZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2＋concentration increases in the PZT-PMN ceramics.

Magnetic and Structural Properties in Co/Cu/Co Sandwiches with Ni and Cr Buffer Layers

The magnetic and structural properties in Co/Cu/Co sandwiches with Ni and Cr buffer layers were investigated. It was found that the coercivity in Ni layer buffered samples decreases with increasing Ni layer thickness, while that in Cr layer buffered ones increases with increasing Cr layer thickness, leading to a large difference in field sensitivity of their giant magnetoresistance (GMR) properties. X-ray diffraction and high resolution transmission electron microscope images exhibited that there is a strong fcc (111) texture in the samples with Ni buffer layer. But there are only randomly oriented potycrystalline grains in Cr buffered sandwiches. According to atomic force microscope topography, the surface roughness of Cr buffered sandwiches is smaller than that of Ni buffered ones. It is demonstrated that buffer layer influences both magnetic and structural properties in Co/Cu/Co sandwiches as well as their GMR characteristics.

Structural, microstructural, and thermal characterizations of a chalcopyrite concentrate from the Singhbhum shear zone, India

The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The con- centmte powder was composed mainly of free chalcopyrite and low quartz in about 3：1 weight ratio. The particle size was about 100 μm. Spectroscopic studies （FTIR, Raman, UV-visible） of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the con- centrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ-mol 1, and two successive structural changes of silica at 848 K and 1145 K.

Structure and Property of AgLaY Alloy

The structure of RE-Ag alloy was observed and analyzed using electron probe. The property changes of the alloy containing two rare earth elements AgLaY during cold forming and the high temperature softening-resistance during annealing were studied using Vickers hardness tester. The distribution and action of the rare earth elements in Ag-alloy were also analyzed. Experimental results show that AgLaY alloy has more remarkable work-hardening effect than AgLa and pure silver, and it also has better thermal-resistance. The effects of RE elements, La and Y, on the properties of Ag-alloy are attributable to their symbiotic distribution and complementary function. Because of the common properties of La and Y as RE elements, they have the completely similar distribution in Ag-alloy. At the same time, La and Y make full use of complementary role in the alloy since they belong to different periods in periodic table and have differences in atomic structure and properties.

Synthesis,Structure and Fluorescent Property of a New Isolated Zn6Co9 Heteronuclear Cluster Constructed by Four Kinds of Ligands

A novel zero-dimensional heteronuclear cluster based on N-（phosphonomethyl）imi- no-diacetic acid （H4PMIDA） and Phen （1,10-phenanthroline）, [Zn6Co9（PMIDA）6（Phen）6（NO3）4（H2O）6]·2NO3·16H2O, has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectrum, thermal analysis, and single-crystal X-ray diffraction. The isolated 15- nuclearity cluster [Zn6Co9（PMIDA）6（Phen）6（NO3）4（H2O）6]^2＋ was constructed by four kinds of ligands, and its charges are balanced by NO3^–. Each isolated cluster is further extended into a 3D supramolecular network through π？？？π interaction and C–H…O hydrogen bonds. Moreover, the solid-state fluorescent property of this complex has also been investigated at room temperature.

Synthesis,Structure,and Property of a Three-dimensional Channel Quaternary Compound:Cs_(0.75(6))Er_(4.43(5))In_(3.32(6))S_(12)

A new quaternary rare-earth sulfide, Cs0.75（6）Er443（5）In3.32（6）S12 （1）, is discovered by high temperature solid state reactions with a slight excess of CsCI flux. The structure is characterized by single-crystal X-ray diffraction data, while crystallizes in hexagonal space group P63/m （No. 176） with a = 12.0329（6）, c = 3.8693（5）A, V= 485.18（7） A3, Z = 1, Mr = 1606.57, Dc = 5.499 g/cm3,μ = 25.457 mm-1, F（000） = 752, the final R = 0.0337 and wR = 0.0904 for 328 observed reflections with I 〉 2σ（I）. Its structure features a three-dimensional framework with hexagonal channels that are centered by Cs cations. Such channels are formed by double chains of edge-sharing M（1）S6 （M（1） = Er（1）/In（1）） octahedra and single chains of Er（2）S6 triprism interconnected by corner-sharing. The syntheses, single-crystal analyses, optical band gap and magnetic property are reported.

A new method to test rock abrasiveness based on physico-mechanical and structural properties of rocks

A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.

A Quantum Chemistry Study on Structural Properties of Petroleum Resin

The geometries of resins with single-layer （SG）, double-layer （DG） and triple-layer （TG） were calculated with the quantum chemistry method. The geometries and net charges of atoms were obtained. The calculated average distances between layers were 0.5348 nm and 0.5051 nm and the action energies were -9.6355 kJ/mol and -32.2803 kJ/mol for resins DG and TG, respectively. Higher electronegative polar atoms can easily form hydrogen bonds with hydrogen atoms of other resin molecules, resulting in resin aggregates. The minimum cross-sectional diameters of resin molecules are too large to enter the pores of zeolite, so they are likely to crack on the surface of zeolite.