Effect of Hot Carrier on Amplitude Modulation and Demodulation of Gaussian High Power Helicon Wave in Homogeneous Longitudinally Magnetized Strain Dependent Dielectric Material

In the present communication, the hydrodynamic model is used to investigate the amplitude modulation as well as demodulation of an electromagnetic wave of high power helicon pump wave into another helicon wave in strain dependent dielectric material incorporating carrier heating (CH) effects. The consideration of CH in modulation and demodulation is prime importance for the adding of new dimension in analysis of amplification of acoustic helicon wave. By using the dispersion relation, threshold pump electric filed and growth rate of unstable mode from the modulation and demodulation of the high power helicon wave well above from the threshold value will be discussed in the present analysis. The numerical analysis is applied to a strain dependent dielectric material, BaTiO3 at room temperature and irradiated with high power helicon wave of frequency 1.78 × 1014 Hz. This material is very sensitive to the pump intensities, therefore during studies, Gaussian shape of the helicon pump wave is considered during the propagation in stain dependent dielectric material and opto-acoustic wave in the form of Gaussian profile (ω0,κ0) is induced longitudinally along the crystallographic plane of BaTiO3. Its variation is caused by the available magnetic field (ωc), interaction length (z) and pulsed duration of interaction (τ). From the analysis of numerical results, the incorporation of CH effect can effectively modify the magnitude of modulation or demodulation of the amplitude of high power helicon laser wave through diffusion process. Not only the amplitude modulation and demodulation of the wave, the diffusion of the CH effectively modifies the growth rate of unstable mode of frequency in BaTiO3. The propagation of the threshold electric field shows the sinusoidal or complete Gaussian profile, whereas this profile is found to be completely lost in growth of unstable mode. It has also been seen that the growth rate is observed to be of the order of 108 - 1010 s-1 but from diffusion of carrier heating, and that its order is enhanced from 1010 - 1012 s-1 with the variation of the magnetized frequency from 1 to 2.5 × 1014 Hz.

Synthesis and Electrochemical Characterization of Li₂MnSiO₄with Different Crystal Structure as Cathode Material in Lithium Rechargeable Batteries

Li2MnSiO4 with different crystal structure was synthesized by solid state reaction method. Their crystal structure and electrochemical properties have been characterized by X-ray diffraction and charge-discharge test. The material prepared at 900oC in N2 atmosphere had γ-phase and its crystal structure changed to β-phase by post-heating at 400oC in air after 900oC sintering. In electrochemical measurement, two materials (γ- and β-phase) showed ~3 and ~45mAh/g, respectively. The different capacities of these two materials might be due to the change of crystal structure.

Repair of Rat Segmental Defects with Mineralized Collagen Grafts Combined with or without Mesenchymal Stem Cells and BMP-2

The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （control defects） or implanted with （1） nano-hydroxyapatite/collagen/PIA （nHAC/PIA） composite, （2） nHAC/ PIA composite added with bone marrow mesenchymal tem cells （ BMSCs ）, （ 3 ） nHAC/ PIA composite added with bone morphogenetic protein 2 （ BMP- 2）. Radiographs of the defects were taken weekly post-surgery. After 1 or 2 months, the rats were eathaaized. Histologic analyses were performed on the harvested tissue. nHAC/ PIA composite could enhance the repair of rat tibia segmental defects. Addition of BMSCs or BMP- 2 to nHAC/ PIA led to an increase in osteogenesis, nHAC/ PIA composite could be an Meal alternative bone-grafi material and it could also be used as an Meal carrier of BMSCs or BMP- 2.

Feasibility of Substituting Cerium-Rich Metal by La-Pr-Ce Alloy in Magnesium Alloy

In magnesium alloy ZM3, using cheap Lanthanum-praseodymium-cerium (LPC) rare earth as a substitute for rich-cerium rare earth was studied. The experimental results show that when the adding amount of LPC is between 2.53% and 3.33%, the tensile strength increases as the adding amount of LPC increases; when the amount of RE is 2.53% and 3.33%, the average tensile strength is 142.35, 153.65 MPa respectively. The results show that LPC rare earth replacing rich Ce rare earth is feasible for the tensile strength of ZM3.

Improvement of Gold to Reducibility of La-Ce-Mn Catalyst under Lean Combustion

The effect of Au on the reducibility of La Ce Mn catalyst was studied in the synthetic exhaust gas mixture containing 10% oxygen. The characteristics of samples were analyzed by BET, SEM, XRD and activity evaluation. The results show that, in lean combustion, the performance of perovskite type catalysts is evidently enhanced through adding Au, and specially a satisfying reducibility for NO x is demonstrated between 300～500 ℃. The catalytic activity of samples increases with the loading amount of Au, and the maximum conversion rate for NO x decomposition reaches up to 47% in 360～400 ℃. Moreover, the dispersivity and uniformity of the surface distribution of perovskite with Au have an important influence on the catalytic activity.

Properties of Ultra-Thin Hafnium Oxide and Interfacial Layer Deposited by Atomic Layer Deposition

Ultra-thin hafnium-oxide gate dielectric films deposited by atomic layer deposition technique using HfCl4 and H2O precursor on a hydrogen-terminated Si substrate were investigated. X-ray photoelectron spectroscopy indicates that the interface layer is Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. The Hf-silicate interfacial layer partially changes into SiOx after high temperature annealing, resulting in a complex HfO2-silicate-SiOx dielectric structure. Electrical measurements confirms that HfO2 on Si is stable up to 700 ℃ for 30 s under N2 ambient.

Preparation and Characterization of Nano-hydroxyapatite/polyvinyl Alcohol Gel Composites

Nano-hydroxyapatite reinforced poly（vinyl alcohol） gel（nano-HA/PVA gel） composites has been proposed as a promising biomaterial,especially used as an articular cartilage repair biomaterial.In this paper,nano-HA/PVA gel composite was prepared by in situ synthesis method and incorporation with freeze-thaw cycle process.The microstructure and morphology were investigated by X-ray diffraction,TEM,SEM and FTIR.The results showed that the size of HA particles synthesized in PVA solution was on the nanometer scale.Both the size and crystallinity of HA particles synthesized in PVA solution decreased compared with that of HA synthesized in distilled water.The nano-HA particles were distributed in PVA matrix uniformly due to the effect of PVA solution as a dispersant while low content of HA particles in the composites.On the contrary,with high content of nano-HA particles in the composites,the particles tended to aggregate.The result of FT-IR analysis indicated that the chemical bond between nano-HA particles and PVA matrix existed.The conformation and degree of tacticity of PVA molecule changed because of the addition of HA particles.Furthermore,the interfacial strength of the composites was improved due to the interaction between nano-HA particle and PVA matrix and this was beneficial to improving the mechanical properties of the composites.

Dynamic Oxygen Storage Capacity Measurements on Ceria-Based Material

Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of 0.1 Hz with the inlet gas-flow sequence CO （5S）→O2（5S）→CO→O2 and a flow rate of 300 ml·min^-1. Under this condition, similar regular square wave in the inlet and outlet of the reactor was obtained to guarantee the reliability of the dynamic OSC results. The dynamic OSC performance of the CeO2 and Ce0.67Zr0.33O2 mixed oxide prepared using the citric sol-gel method was studied at the optimum measurement condition with focus on both quantitative and qualitative analyses, The results reveal distinctly that Ce0.67Zr0.33O2 had better dynamic OSC performance because of its higher oxygen migration rate than CeO2. Under dynamic conditions, two CO2 production peaks occurred corresponding to the CO pulse and the O2 pulse, respectively, during the entire cycle. The intensity and ratio between the two CO2 productions were highly influenced by temperature and frequency indicating complex surface phenomena during the oxygen storage/release process, As a result, this set-up can be applied to the evaluation of ceria-based material on the OSC performance.

Study on the characteristics of mineral matter in Huainan coals by computer controlled scanning electron microscope (CCSEM)

The mineral features, ash composition, ash fusion temperature of Huainan coals were investigated by CCSEM, X-ray fluorescence (XRF) and JIS (Japan Industrial Standard) ash cone melting method respectively. The mineral matter is characterized by higher aluminosilicate clay minerals contents (more than 60% of the total mineral matter in coal) with quartz, which accounts for the higher ash flow temperatures, frequently higher than1 500℃. The contents of calcite and dolomite in Huainan coals range from 0.16% to about 11.57%. Another important non-silicate mineral matter, pyrite, ranges from 0.73% to 12.25%. Low amount of kaolinite-type clays and high amount of calcite and pyrite in the HN115 and XM coals are beneficial to ash melting. It is suggested that the high content of kaolinite in Huainan coals shows the high ash fusion temperature. CCSEM results also provide the size distribution of the minerals in Huainan coals. Generally, the mineral has bimodal size distribution in 6 Huainan coals.

Influence of Thickness and Annealing Temperature on the Optical Properties of Spin-Coated Photoactive P3HT:PCBM Blend

Influence of annealing temperature and thickness on the optical characteristics of the blend of poly (3-hexylthiophene) (P3HT) and Phenyl C61 butyric acid methylester (PCBM) layer has been investigated in this report. Photoactive polymer material (P3HT:PCBM) was deposited on indium tin oxide (ITO) substrate by spin-coating. The morphology of P3HT:PCBM composite layer was investigated by Atomic Force Microscope (AFM). The surface roughness was found to reduce after heat treatment. The absorption of the composite layer was found to increase with its number of layer (thickness). On the other hand, the photoluminescence (PL) quenching, which indicates efficient charge separation in the bulk heterojunction, was found higher for the thinner layer. Absorption was also found to increase with the annealing temperature. Therefore, to optimize the thickness of the P3HT:PCBM photoactive layer that will provide best absorption while providing efficient charge separation, annealing at optimized temperature might be an effective tool.

An Experimental Study of Microstructure through SEM and AFM by Interaction from High Power Femtosecond Laser Wave with BaTiO3

This paper deals with the interaction of femtosecond laser with strain dependent high dielectric material. For this investigation, ferroelectric material like BaTiO3 has been chosen because of centrosymmetric structure. Due to irradiation of laser light, the micro-structure of BaTiO3 is found to change along the direction of heat propagation. SEM and AFM tools have been used to detect the morphology and roughness of the femotosecond laser treated BaTiO3. The change of morphology and surface behavior depends upon the laser fluence and intensity of laser light. The maximum change in morphology has been observed at a higher laser fluence.

Ti-Mo-Sn合金显微组织、力学性能和形状记忆性能（英文）

研究Mo作为β相稳定元素,对Ti-Mo-Sn合金相组成、显微组织、力学性能和形状记忆性能的影响。通过电弧熔炼法制备不同成分的Ti-xMo-3Sn(x=2,4,6,摩尔分数,%)合金,并制备二元合金Ti-6Mo作为对照组。Ti-xMo-3Sn合金具有硬度低和韧性高(厚度可减少90%)的特点,而Ti-6Mo合金则表现出脆性行为,硬度高、韧性差。场发射扫描电镜(FESEM)下发现圆形的无热ω(ωath)析出相。X射线衍射结果也证实铸态和固溶处理-淬火态的样品中均存在ωath相。光学显微镜和FESEM结果显示,由于发生β→ω相变,淬火过程中形成的马氏体数量随着Mo含量的增加而降低。硬度的变化趋势也证实ωath相的存。Ti-6Mo-3Sn合金的形状记忆效应(SME)最高,为9%。合金SME较低是由于形成ωath相;然而,SME随着Mo含量的增加而增加,这是由于ωath相的逆相变和由压力引起的马氏体相变所致。另外,设计一种新的、非常简单的测量形状记忆效应的方法。

Tempering Behavior of Ductile 1700 MPa Mn-Si-Cr-C Steel Treated by Quenching and Partitioning Process Incorporating Bainite Formation

We obtained a good combination of strength and ductility in a 0.4C-2.0Mn-1.7Si-0.4Cr（wt%） steel,namely,;.7 GPa of ultimate tensile strength and;6% of elongation,by conducting a Q-P-T（quenching-partitioning- tempering） process incorporating the formation of carbide-free bainite. The tempering behavior of this steel was discussed by using experimental finding(scanning electron microscopy,X-ray diffraction（XRD）,transmission electron microscopy and dilatometer) and CCE（constrained carbon equilibrium） modeling. The XRD results combined with CCE calculation prove that carbon partitioning from martensite to austenite occurs during tempering. Consequently,the thermodynamic stability of retained austenite is enhanced. This idea can be utilized to design novel Q-P-T processes in future.

In situ synthesis of chemically bonded NaTi2（PO4）3/rGO 2D nanocomposite for high-rate sodium-ion batteries

A phase-pure NaTi2（PO4）3/reduced graphene oxide （rGO） nanocomposite was prepared using a microwave-assisted one-pot method and subsequent heat treatment. The well-crystallized NaTi2（PO4）3 nanoparticles （30-40 nm） were uniformly precipitated on rGO templates through Ti-O-C bonds. The chemical interactions between the NaTi2（PO4）3 nanoparticles and rGO could immobilize the NaTi2（PO4）3 nanoparticles on the rGO sheets, which might be responsible for the excellent electrochemical performance of the nanocomposite. The NaTi2（PO4）B/rGO nanocomposite exhibited a specific capacity of 128.6 mA-h.g-1 approaching the theoretical value at a 0.1 C-rate with an excellent rate capability （72.9% capacity retention at 50 C-rate） and cycling performance （only 4.5% capacity loss after 1,000 cycles at a high rate of 10 C）. These properties were maintained even when the electrodes were prepared without the use of an additional conducting agent. The excellent sodium storage properties of the NaTi2（PO4）B/rGO nanocomposite could be attributed to the nano-sized NaTi2（PO4）3 particles, which significantly reduced the transport lengths for Na＋ ions, and an intimate contact between the NaTi2（PO4）3 particles and rGO due to chemical bonding.

MnHCF/MnO_2 Core-shell Nanostructures as Cathode Material for Supercapacitors with High Energy Density

A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.

Effect of Phosphor Addition on Intergranular Exchange Coupling of Co-Pt Thin Films

In this paper, ternary Co-Pt-P thin films were prepared by Co-P chips pasted on the cobalt target. The structure magnetron sputtering with platinum and home-made and magnetic properties were investigated by X-ray diffraction （XRD） and vibrating sample magnetometer （VSM）, respectively. With increasing phosphor content, the coercivities of Co-12 at.% Pt-P films increase from 1034 to 1525 Oe owing to the exchange decoupling among magnetic grains. The decrease of inter-granular exchange coupling was confirmed by delta-M curve measurement and magnetic force microscopy （MFM）. Transmission electronic microscopy （TEM） with nano- beam composition analysis shows that phosphor segregated at cobalt-based grain boundaries is responsible for the exchange decoupling. It is thus suggested that the phosphor addition is effective to tune the exchange coupling of magnetic grains, particularly for perpendicular recording media.

Inclusions in Runner Steel During Ingot Casting

This paper reported the observation of inclusions in the steel of an ingot runner. Thermodynamic modeling was performed to study the formation mechanism and sources of inclusions. CFD modeling on fluid flow, heat transfer, solidification of molten steel was carried out and the entrapment of inclusions in runner steel was predicted and compared with the measurement. Al2O3-based inclusions were the main ones in the steel samples. MgO?Al2O3 mainly stemmed from the lining refractory. The high MnO inclusions in the runner steel came from the runner slag. The effect of natural convection was very important for the cooling and solidification of the steel in the runner. Both the observation and the modeling show that 】 50μm inclusions more accumulated on the upper area in the runner and 【 50μm inclusions dispersed well and more accumulated on the lower area of the runner.