Preparation and Anti-oxidative Effects of Corn Peptides

Corn peptides(CP) were prepared from zein via proteolysis by means of a type of alkaline protease, Alcalase, at 50 ℃ and pH 8.0. The anti oxidative activity of the hydrolysate was examined. It was found that the anti oxidative activity reached the maximum at the fourth hour of the hydrolysis and then decreased. The effect of the enzyme dosage on the solubility of corn protein, the dependence of hydrolysis time on the degree of the hydrolysis(DH) and molecular weight distribution were examined respectively. 30% DH was controlled on the basis of anti oxidative activity. The hydrolysate was fractionated on a Sephadex G 15 column. The anti oxidative activities were examined for all the fractions. The main fraction for anti oxidative activity was collected and characterized by the methods of amino acid analysis, the measurement of average chain length and etc .. The main M W distribution of the main fraction was 300-600 Daltons. The anti oxidative properties of the small peptides in vitro were studied. It was found that they could inhibit the auto oxidation of pyrogallol and the oxidation of hemoglobin. The hemolysis degree of erythrocyte caused by hydroxyl free radicals was decreased greatly, indicating a protective effect of the anti oxidative peptides on the cell membrane damage of erythrocyte.

Oxide Thickness Effects on n-MOSFETs Under On-State Hot-Carrier Stress

Hot carrier induced (HCI) degradation of surface channel n MOSFETs with different oxide thicknesses is investigated under maximum substrate current condition.Results show that the key parameters m and n of Hu's lifetime prediction model have a close relationship with oxide thickness.Furthermore,a linear relationship is found between m and n .Based on this result,the lifetime prediction model can be expended to the device with thinner oxides.

Ligand Size Effect on PdLn Oxidative Addition with Aryl Bromide： A DFT Study

The process and mechanism of the ligand volume controlled Pd（PR3）2 （PR3=PH3, PMe3, and PtBu3） oxidative addition with aryl bromide were investigated, using density functional theory method with the conductor-like screening model. Association pathway and dissocia-tion pathway were investigated by the comparison of several energies. The cleavage energy of Pd（PR3）2 complex was calculated, as well as the oxidative addition reaction barrier energy of Pd（PR3）n （n=1,2） with aryl bromide in N,N-dimethylformamide solvent. This study proved that the ligands volume possessed a great impact on the mechanism of oxidative addition： less bulky ligand palladium associated with aryl bromide via two donor ligands,but larger bulky ligand palladium coordinated via monoligand.

Oxidation Effects on the Electronic Properties of Hydrogenated Silicon Clusters

The geometric and electronic properties of some hydrogenated silicon clusters in the presence of oxygen on the surface have been investigated.The density functional theory with generalized gradient approximation functional was applied in our calculations.By calculating the total energy,the double bond Si=O is shown to be more stable than the bridge bond Si-O-Si for large size oxidized clusters.The results of Mulliken population analysis indicate that a so-called passivation effect is enhanced by oxidization effects.From the energy band structures and density of states,we find that some localized states are induced by the p-orbital of O atom mainly and reduce the energy gaps substantially.

Oxidative Stress and Role of Natural Plant Derived Antioxidants in Animal Reproduction

The experimental knowledge on the role of oxidative stress,and beneficial and detrimental effects of plant derived antioxidants in male and female animal reproduction are reviewed in this article.Free radical-induced oxidative stress in animal reproduction causes great loss to livestock industry.Antioxidant therapy has been implicated to be effective in preventing diseases resulted from oxidative stress.Considering the advantages of lower side effects of natural antioxidants than those of synthetic antioxidants,plants or their extracts have been extensively utilized in animals.Although many advances have been gained on application of plant derived antioxidants in alleviating oxidative stress,debatable issues still exist.Because many opposite effects were observed even using plant extracts containing similar bioactive substances in the same animal species.Therefore,plant derived antioxidants,like free radicals,are ＂double-edged swords＂ in animal reproduction,representing that they may exhibit beneficial or detrimental effects in animal reproduction,including spermatogenesis,semen functions,estrous cycles,ovulation,ovary functions,endometrium,embryo development,and pregnancy.Besides dose-dependent manner as an explanation of plant extracts＇ dual function,future studies are needed to investigate the mechanism of double-edged actions of plant derived antioxidants in different animal reproduction systems.

EFFECTS OF NEODYMIUM ON OXIDATION BEHAVIOUR OF Ti-11Al ALLOY

The oxidation behaviours of pure 77,Ti-11 at% Al and Ti-11 at% Al-Nd alloys in air at the tempera- ture range 800～1000℃ have been investigated in the present paper.Their oxidation kinetics follows substantially the parabolic rate law.The activation energies of oxidation processes are 103 and 91 kcal/mole for Ti-11 Al and Ti-11 Al-Nd alloys,respectively.The platinum wire tagging tests have shown that oxygen atoms diffuse into the substrate during oxidation of pure Ti and that Ti,Al and Nd atoms diffuse across a scale of oxides outwards during oxidations of these alloys.Nd addition promotes the selective oxidation of aluminium.The addition of Al and Nd decreases the extent of penetration of oxygen atoms into the Ti substrate.The X-ray diffraction analysis confirms that the oxide scales of the alloys consist of TiO_2 and α-Al_2O_3,or TiO_2,α-Al_2O_3 and a small amount of Nd_2O_3 for Ti-11 Al and Ti-11 Al-Nd alloys, respectively.

Efficient oxidation of cinnamon oil to natural benzaldehyde over β-cyclodextrin-functionalized MWCNTs

We have designed and prepared β-cyclodextrin （β-CD）-functionalized multi-walled nanotubes （MWCNTs-g-CD） for the oxidation of cinnamon oil to natural benzaldehyde under aqueous condi- tions. The synergistic effect of combining MWCNTs with β-CD led to a remarkable increase in the performance of the MWCNTs-g-CD for the catalytic oxidation of cinnamaldehyde, which exhibited 95% cinnamaldehyde conversion and 85% selectivity to natural benzaldehyde with a short reaction time of 10 rain. The MWCNTs-g-CD also exhibited outstanding recyclability with good stability, showing no discernible decrease in their catalytic activity over five reaction cycles.

Enhanced CO oxidation over potassium-promoted Pt/Al_2O_3 catalysts:Kinetic and infrared spectroscopic study

A series of K-promoted Pt/Al2O3 catalysts were tested for CO oxidation. It was found that the addition of K significantly enhanced the activity. A detailed kinetic study showed that the activation energies of the K-containing catalysts were lower than those of the K-free ones, particularly for catalysts with high Pt contents （51.6 k）/mol for 0.42K-2.0Pt/Al2O3 and 6：3.6 kJ/mol for 2.0Pt/Al2O3 ）. The CO reaction orders were higher for the K-containing catalysts （about -0.2） than for the K-free ones （about -0.5）, with the former having much lower equilibrium constants for CO adsorption than the latter. In situ Fourier-transform infrared spectroscopy showed that surface CO desorption from the 0.42K-2.0Pt/Al2O3 catalyst was easier than from 2.0Pt/Al2O3. The promoting effect of K was therefore caused by weakening of the interactions between CO and surface Pt atoms. This decreased coverage of the catalyst with CO and facilitated competitive O2 chemisorption on the Pt surface, and significantly lowered the reaction barrier between chemisorbed CO and O2 species.

The Genetic Mechanism of Inertinite in the Middle Jurassic Inertinite- Rich Coal Seams of the Southern Ordos Basin

also an important geological information carrier of coal forming environments.In the southern section of the Ordos Basin,the No.4 inertinite-rich coal seam of the Middle Jurassic Yan’an Formation in the Binchang Coal field was selected as an example to study the genetic mechanism of the inertinite.In this study,the results obtained from experimental tests of coal rock,including principal and trace elements,stable carbon isotopes,scanning electron microscopy,inertinite reflectance,sporopollen and free radical retorting methods,were analyzed.Then,the findings were combined with the previous understanding of the oxygen content in the atmosphere and ground fire characteristics,in order to discuss the genesis mechanism of inertinite in the No.4 coal seam.The obtained research results were as follows:(1)During the coal forming period of the No.4 coal seam,the overall climate had been relatively dry.There were four relatively dry-wet climate cycles in the No.4 coal seam,which were controlled by the eccentricity astronomical period.The inertinite content were relatively high during the dry periods;(2)The temperature range suitable for microorganism activities during the oxidation processes was between 0 and 80℃.The simulation results of the free radical concentrations showed that the maximum temperature of fusain in the No.4 coal seam during the process of coalification had not exceeded 300℃,which was significantly higher than the temperature range of microorganism activities.Therefore,these were not conducive to the activities of microorganism and formation of inertinite during the coal-forming period;(3)The genesis temperature of the inertinite in the No.4 coal seam was calculated according to the reflectance of the inertinite,which was lower than 400℃.This result supported the cause of wildfire of the inertinite and reflected that the type of wildfire was mainly ground fire,along with partially surface fire.Moreover,the paleogeographic location,climatic conditions,atmospheric oxygen concentration,etc.of the study area showed that the conditions for wildfire events were in fact available;(4)There were dense and scattered fusinite observed in the No.4 coal seam,and the thickness of cell walls were found to differ.It was speculated that this was related to the type of wildfire,combustion temperatures,combustion timeframes,and different initial conditions of the burned objects during the coal forming periods.

Base-free aerobic oxidation of glycerol on TiO_2-supported bimetallic Au–Pt catalysts

The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au-Pt, Au- Pd and Pt-Pd catalysts on TiO2 were examined under base-free conditions. Pt exhibited a superior activity relative to Pd, and Au-Pd and Pt-Pd while Au was essentially inactive. The presence of Au on the Au-Pt/TiO2 catalysts led to their higher activities （normalized per Pt atom） in a wide range of Au/Pt atomic ratios （i.e. 1/3-7/1 ）, and the one with the Au/Pt ratio of 3/1 exhibited the highest activity. Such promoting effect is ascribed to the increased electron density on Pt via the electron transfer from Au to Pt, as characterized by the temperature-programmed desorption of CO and infra-red spectroscopy for CO adsorption. Meanwhile, the presence of Au on Au-Pt/TiO2, most like due to the observed electron transfer, changed the product selectivity, and facilitated the oxidation of the secondary hydroxyl groups in glycerol, leading to the favorable formation of dihydroxyacetone over glyceraldehyde and glyceric acid that were derived from the oxidation of the primary hydroxyl groups. The synergetic effect between Au and Pt demonstrates the feasibility in the efficient oxidation of glycerol to the targeted products, for example, by rational tuning of the electronic properties of metal catalysts.

Doping Effect of CuO on CeO_2 for CO Oxidation

Cu-Ce-O catalysts, prepared by the amorphous citrate precursor (ACP) method, wereinvestigated by ICP, XRD and ndcro-reactor techniques. At low copper content of Cu-Ce-Ocatalysts, fluorite structures formed at low calcining temperatures, and Cuo doped into the CeO2matrix; at high copper content, in addition to the fluorite structure, crystalline monoclinic phaseCuO formed as well at high calcining temperatures. There was no other phase formed even calcinedat 1000℃. The results show that only a little CuO dopes into the CeO2 matrix to form complexoxide, which promotes the catalytic activity of CO oxidation greatly. The optimum Cu-Ce-Ocatalyst is composed of 15% copper by Cu/(Ce+Cu) atomic ratio, and calcined at 700℃ for 4h. Thephase compositions include the crystalline CuO and the active complex oxide with fluoritestructure. The formulation of the active complex oxide is Cu0.06Ce0. 94O1.94.

Recovery of PMOSFET NBTI under different conditions

Negative bias temperature instability（NBTI） has become a serious reliability issue, and the interface traps and oxide charges play an important role in the degradation process. In this paper, we study the recovery of NBTI systemically under different conditions in the P-type metal–oxide–semiconductor field effect transistor（PMOSFET）, explain the various recovery phenomena, and find the possible processes of the recovery.

Effect of Current Density on Al Alloy Microplasma Oxidation

The microplasma oxidation process of LY 12 Al alloy in Na2SiO3-KOH-NaAL2 system has been studied. The voltage-time curve of oxidation process is changed with the variation of current densities. The voltage breakdown and hardness of coating increase with increasing current density. The phase composition, morphologies, element and the distribution of ceramic coating are investigated by XRD, EPMA.

Effect of Sputtered TiAlCr Coatings on Oxidation and Hot Corrosion Resistance of Ti-24Al-14Nb-3V

The effect of sputtered Ti-50Al-10Cr and Ti-50A1-20Cr coatings on both isothermal and cyclic oxidation resistance at 800-900℃ and hot corrosion resistance at 850℃ of Ti-24Al-14Nb-3V was investigated. Results indicated that Ti-24Al-14Nb-3V alloys exhibited poor oxidation resistance due to the formation of Al2O3+TiO2+AlNbO4 mixed scales in air at 800-900℃ and poor hot corrosion resistance due to the spoliation of scales formed in Na2SO4+K2SO4 melts at 850℃. Both Ti-50Al-10Cr and Ti-50Al-20Cr coatings remarkably improved the oxidation and hot corrosion resistance of Ti-24Al-14Nb-3V alloy.

Advance in Matrix Effect Study of LA-MC-ICPMS U-Pb Dating on U-Bearing Oxide Minerals

Objective With the development of analytic technologies, in-situ dating on U-bearing oxide minerals （e.g., cassiterite, rutile and baddeleyite） has been widely used in geological chronological researches and has attracted remarkable attention to explore evolution of the earth and obtain age information of various geological processes. Matrix effect related studies are especially important during in-situ U- Pb dating based on Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry （LA-MC- ICPMS）. However, to our knowledge, only few thorough and systematical matrix effect study of U-bearing oxide minerals has been reported. In this study, we systematically analyzed the matrix effect of U-bearing oxide minerals in order to take place the standards which are difficult to prepare with available standards.

TIME-DEPENDENT FATIGUE AND ITS MICROMECHANISM OF SUPERALLOY GH169 UNDER OXIDATION

The time-dependent fatigue and its micromechanism of superalloy GH169 at 650℃ have been studied.Under the same stress and duration,its cyclic life in Ar is shorter than that in air.The damage mechanism is mainly of the interaction between high temperature oxidation and fa- tigue.The fracture surface of GH169 specimen oxidized at 650℃ in air is revealed to be cov- ered with a dense and even oxide film,but in Ar,with uncontinuous oxide particles.As the time prolonged,the Cr_2O_3 content in the surface oxides increases in air and decreases in Ar.

Investigation of gate current in nano-scale MOSFETs by Monte Carlo solution of quantum Boltzmann equation

This paper investigates gate current through ultra-thin gate oxide of nano-scale metal oxide semiconductor field effect transistors （MOSFETs）, using two-dimensional （2D） full-band self-consistent ensemble Montc Carlo method based on solving quantum Boltzmann equation. Direct tunnelling, Fowler-Nordheim tunnelling and thermionic emission currents have been taken into account for the calculation of total gate current. The 2D effect on the gate current is investigated by including the details of the energy distribution for electron tunnelling through the barrier. In order to investigate the properties of nano scale MOSFETs, it is necessary to simulate gate tunnelling current in 2D including non-equilibrium transport.

Model of hot-carrier induced degradation in ultra-deep sub-micrometer nMOSFET

The degradation produced by hot carrier （HC） in ultra-deep sub-micron n-channel metal oxide semiconductor field effect transistor （nMOSFET） has been analyzed in this paper. The generation of negatively charged interface states is the predominant mechanism for the ultra-deep sub-micron nMOSFET. According to our lifetime model of p-channel MOFET （pMOFET） that was reported in a previous publication, a lifetime prediction model for nMOSFET is presented and the parameters in the model are extracted. For the first time, the lifetime models of nMOFET and pMOSFET are unified. In addition, the model can precisely predict the lifetime of the ultra-deep sub-micron nMOSFET and pMOSFET.

Novel attributes and design considerations of effective oxide thickness in nano DG MOSFETs

Impacts of effective oxide thickness on a symmetric double-gate MOSFET with 9-nm gate length are studied, using full quantum simulation. The simulations are based on a self-consistent solution of the two-dimensional （2D） Poisson equation and the Schr6dinger equation within the non-equilibrium Green＇s function formalism. Oxide thickness and gate dielectric are investigated in terms of drain current, on-off current ratio, off current, sub-threshold swing, drain induced barrier lowering, transconductance, drain conductance, and voltage. Simulation results illustrate that we can improve the device performance by proper selection of the effective oxide thickness.

Analytical Modeling of Quantum Mechanical Tunneling in Germanium Nano-MOSFETS

A simple analytical model has been developed to study quantum mechanical effects （QME） in a germanium substrate MOSFET （metal oxide semiconductor field effect transistor）, which includes gate oxide tunneling considering the energy quantization effects in the substrate. Some alternate high dielectric constant materials to reduce the tunneling have also been studied. By comparing with the numerically reported results, the results match well with the existing reported work.