Effects of the Composition of Electrodeposited Fe-Ni-P Alloy on the Thermostability and Magnetic Properties

The magnetic properties, structure defects of electrodeposited Fe-Ni-P alloys with various compositions and the thermostability at amorphous state have been studied by DSC, positron annihilation and electronic integrating instrument methods. The results show that the thermostability of amorphous Fe-Ni-P alloys increases with Fe content. Emergence and recrystallization of stable phases defer as the P content of the coating increases. The minimum H-c, B-r and P-h occur at 9.4 P (wt pet) content. Maximum H-c, B-r and P-h occur at the weight ratio of Fe to Ni equaling to 1/9.

Thermal Effects on Composition of Rearranged Hopanes in Hydrocarbon Source Rocks

Objective The distribution characteristics and formation mechanism of rearranged hopanes in hydrocarbon source rocks are affected by various geological conditions.Among these geological conditions,thermal action has an important influence on the formation of rearranged hopanes,which has been however little documented previously.

Composition Dependence and Irradation Effects on Residual Resistivity in Cu-Al Alloys

Residual electrical resistivity due to short-range order has been calculated for Cu100-xAlx (x=9.13,13.56, 14.5 and 14.76 in at pct) alloys using pseudopotential approach, and the results have been discussed in the light of experimental studies of the local-order structure of these alloys. In case of Cu85.5Al14.5, change in the total residual electrical resistivity due to neutron-irradiation effects has been estimated by including contributions from the short-range order and static atomic displacement correction. Our results show a decrease in the residual resistivity in the irradiated Cu-Al solid solution as compared to the unirradiated sample. This is in accordance with the experimental results

Experimental Study on the Effect of Sediment Composition Ratio on Shallow Water Delta

1 Introduction Shallow water delta in the middle-newborn Stratum Widely developed with huge oil and gas in China(Hu Shengwu et al.,2013).The control factors on the deltadevelopment like Climate,sea level,tectonic subsidence,sediment supply(flow,type),the geometric characteristics of the upstream river,the energy(wave,

Lattice Constants of R-Co Permanent Magnet Alloys

The lattice constants of Sm-Co permanent magnet alloy have been determined by means of X-ray diffraction measurement. The lattice constants of R-Co alloy systems (R = rare earth) have been investigated with Bragg-williams (B-W) approximation and their expressions are given. It is pointed out that the lattice constants of RCo5 phase depend only on the alloy composition, and that the lattice constants of R2Co17 phase are related to the order parameter as well as the alloy composition. In this paper the relationship between the lattice constants of RCo5 and those of R2Co17 is discussed, and the values calculated by the expressions are compared with experimentally determined for Sm-Co alloys.

Effects of Zr and Y on the Mechanical Properties and the Microstructure of Ti-Al-Sn-Nb-Mo-Si Alloy

In the present paper the effects of additions of Zr and Y on the microstructure and mechanical properties for Ti-(6.0 approximately 6.5)Al-(2.0 approximately 3.0)Sn-(1.5 approximately 6.0)Zr-(0.8 approximately 1.0)Mo-1.0Nb-0.25Si alloys are reported. The experimental results shows that: with increasing of Zr content, tensile strength and creep resistance of the alloys increase, and reduction in area and thermal stability of the alloys decrease. Decrease in thermal stability of the alloys mainly caused by surface thermal unstability. After heat treatment Y addition can make grain size of the alloys refine. The reduction in area and thermal stability of the alloys with Y addition are improved, and tensile strength slightly decreases and creep resistance is essentially the same as the alloy without Y addition. These phenomena are explained in brief.

The Composite Effect of Nanometer MnO_2 Mixed with the Electrolytic MnO_2

The nanometer MnO2 has outstanding electrochemical performance theoretically, but it is not suitable for actual utilization, which may result in capacity decrease and resource waste. In this study we have utilized the characterizations of the nanometer material, synthesized a type of nanometer α-MnO2 through KMnO4 and KNO3 with hydrothermal method, and mixed the products into micron electrolytic manganese dioxide （EMD） to enhance the electrochemical performance of the electrode.The cyclic voltammogram and galvanostatical discharge measurements of the samples were investigated. It is found that the 50﹪ nanometer MnO2 mixed electrode has the best electrochemical performance. The electrochemical performance improvement mechanism of the sample nanometer MnO2 mixed into micron EMD was discussed. With the existence of electrolyte, the nanometer MnO2 particles filled into the interspaces of the micron EMD particles, the mass and charge transfer conditions of the electrode reaction were improved, and the electrode polarization was diminished.

SEM in-situ Fracture Observation and the Reinforcing Effect of Composite SiC_p/ZA22

The strengthening effect of a Zn alloy reinforced by SiC particulate was examined. Based on the results of SEM in-situ fracture observation and stress field analysis by finite element method, it is believed that the reinforcing effect of this composite is due to the combination of strain and stress hardening in the matrix.

The effects of radiation damage on power VDMOS devices with composite SiO_2-Si_3N_4 films

Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films.

Tunable Band Gap in Piezoelectric Composite Rod Based on the Inter-Coupling Effect

The longitudinal wave propagating in one-dimensional periodic piezoelectric composite rod with inter-coupling between different piezoelectric segments is investigated. The analytical formulae for such a structure are shown and the dispersion relation is calculated. The results show that, by introducing the inter-coupling between the different piezoelectric segments, which is accomplished by serially connecting every n piezoelectric segment into supercells, some tunable Bragg band gaps can accordingly be opened in the low frequency region. The investigation could provide a new guideline for the tunable phononic crystal under passive control.

Effects of Breaking Waves on Composite Backscattering from Ship-Ocean Scene

The existence of the sea surface is bound to affect the electromagnetic （EM） scattering from marine targets. When dealing with the composite scattering from targets over a sea surface by applying high-frequency EM theories, the total scattering field can be decomposed into three parts in low sea states, namely, the direct scattering from the sea surface, the direct scattering from targets and the coupling scattering between the sea surface and targets. With regard to high sea states, breaking waves make the direct scattering from the sea surface and the coupling scattering more complicated. To solve this issue, a scattering model is proposed to analyze the composite scattering from a ship over a rough sea surface under high sea states. To consider the effect of breaking waves, a three dimensional geometric model is adopted together with Ufimtsev＇s theory of edge waves for the scattering from a breaker. In addition, the coupling scattering between targets and breaking waves is taken into account by considering all possible scattering paths. The simulated results indicate that the influence of breaking waves on the scattering field from the sea surface and on the coupling field is non-negligible, and the numerical results also show the effectiveness of the proposed scattering model.

ANISOTROPIC EFFECTS OF QUASI-ISOTROPIC COMPOSITES(I)──MODELLING

Experimental obseryations show that quasi-isotropic materials, such as N-axial fibre-reinforced composites and woven materials . exhibit various degrees of anisotrpy in elasticity and strength, and the anisotropy in strengty is normally stronger than that in elasticity.In view of some available experimental data and based on the general formulation of the constitutive equations and .failure criteria of quasi-isotropic materials established by using the theory of repesentations for tensor functions, we postulate several applicable models of the constitutive equations and strength for 3and 4-axial quasi-isotropic materials to reveal the anisotropic effects In a continued work (Part II) the anisotropic effect in strength of an infintely large plate with a single elliptical hole or crack is studied. and the proposed stiffness and strength modelsare verified in terms of micro-mechanical analyses.

Effects of Positron Diffusion and Its Application in Composite System

The effects of positron diffusion on the measured S parameter have been investigated by a point-source diffusion model and a δ function method. Firstly, the theoretical analyses of the effects are presented for the samples of a homogeneous semi-infinite medium and a film of definite thickness. Then the results are used to analyze the S parameters in several composite systems and interface models.

Effect of the implant composite of poly lactide-co-glycolide and bone mesenchymal stem cells modified by basic fibroblast growth factor on injured spinal cord in rats

Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.Methods Two hundred and

Protective Effect of Effective Composite of Chinese Medicine Prescription Naodesheng(脑得生) against Focal Cerebral Ischemia in Rats

Objective： To study the effects and possible mechanisms of effective composite of Naodesheng （脑得生, NDS） on permanent cerebral ischemia-induced injury in rats. Methods： Male Sprague-Dawley rats with middle cerebral artery occlusion （MCAO） were established with the modified suture method, and they were randomly divided into the following groups： the sham-operated group, the model group, the Nimodipine group （0.012 g/kg）, the NDS group （1.075 g/kg）, the total extracts group （0.23 g/kg）, the high-dose NEC group （0.07 g/kg）, the middle-dose NEC group （0.02 g/kg）, and the low-dose NEC group （0.007 g/kg）. The aforesaid medicines were administered at the 2nd, 4th, and 24th h after focal cerebral ischemia, and the infarction size and water content in the brain were evaluated at the 26th h after MCAO. Then, after oral administration once daily for 7 successive days, the changes in the degree of neurological deficit, oxidative stress, and apoptosis were measured on the 7th day. Results： NEC could significantly reduce the infarction size after focal cerebral ischemia, and slightly relieve water content in the brain, significantly alleviate neurological function impairment, increase the levels of superoxide dismutase （SOD） and adenosine triphosphate enzyme （ATPase） activity, and decrease the content of malondialdehyde （MDA）. NEE; could also extenuate Bax and caspase-3 expression in the hippocampus tissue of the ischemic region. As compared with the three NEE; treated groups, the highdose NEC showed better efficacy. Conclusions： NEE; could significantly reduce brain injury induced by ischemia; its mechanism was closely associated with hindering oxidative stress and apoptosis. The effective compositeguided methodology is a feasible tool to improve the neuro-protective properties of the Chinese medicine prescription NDS against focal cerebral ischemia in rats.

Composition-dependent dynamic precipitation and grain refinement in Al-Si system under high-pressure torsion

Understanding composition effects is crucial for alloy design and development. To date, there is a lack of research comprehensively addressing the effect of alloy composition on dynamic precipitation, segregation and grain refinement under severe-plastic-deformation processing. This research investigates Al-x Si alloys with x = 0.1, 0.5 and 1.0 at.% Si processed by high pressure torsion(HPT) at room temperature by using transmission electron microscopy, transmission Kikuchi diffraction and atom probe tomography. The alloys exhibit interesting composition-dependent grain refinement and fast dynamic decomposition under HPT processing. Si atoms segregate at dislocations and Si precipitates form at grain boundaries(GBs) depending on the Si content of the alloys. The growth of Si precipitates consumes most Si atoms segregating at GBs, hence the size and distribution of the Si precipitates become predominant factors in controlling the grain size of the decomposed Al-Si alloys after HPT processing. The hardness of the Al-Si alloys is well correlated with a combination of grain-refinement strengthening and the decomposition-induced softening.

The effect of Bi composition on the electrical properties of InP1-xBix

Ⅲ-ⅤSemiconductors containing a small amount of Bi,known as dilute bismides,have attracted great interest in recent years,due to the large band-gap reduction and other unique properties[1,2].Previous studies have been primarily focused on the growth and optical properties of the GaAs-based bismuthides[3],while the properties of other dilute bismides are less well understood.Berding et al.[4]theoretically predicted that InPBi is expected to be

Temperature and metal composition dependence of lateral photovoltaic effect in Al-Alq_3/SiO_2/Si structures

A series of Al=-（Alq3）l-x granular films is prepared on Si wafer with native oxide layer using co-evaporation technique. Large lateral photovoltaic effect （LPE） is observed, with an optimal LPV sensitivity of 75 mV/mm in x=0.35 sample. The dependence of LPE on temperature and A1 composition is investigated, and the possible mechanism is discussed.

Strengthening in Al-,Mo-or Ti-doped CoCrFeNi high entropy alloys:A parallel comparison

In the current work,a parallel comparison of the influence of Al,Mo and Ti,on the microstructure and strengthening of the CoCrFeNi alloy was conducted.To achieve this,inconsistencies on variables including the extent of alloying,thermomechanical processing and property-evaluation method were avoided.Microstructurally,following cold-rolling,annealing of the 4 at.%Al-doped alloys at 800-1000℃ did not result in phase separation;nevertheless,that of the 4 at.%Mo-and Ti-doped alloys led to the respective formation ofσandηphase and,consequently,caused extra strengthening through the Orowan dislocation bypassing mechanism.Our systematic qualitative analysis and DFT calculations showed that Al and Ti are more effective than Mo in reducing the stacking fault energy(SFE)of the CoCrFeNi alloy,because they can induce more considerable deformation of electronic density,making the gliding of atomic layers easier.Following identical thermomechnical processing,Al-,Mo-,and Ti-doping causes different extent of solid solution strengthening and grain boundary strengthening.Mo causes the most pronounced solid solution strengthening but does not benefit the grain boundary strengthening;in contrast,the effectiveness of grain boundary strengthening is boosted by the doping Al and Ti.Current analyses support that Labusch instead of Fleischer mechanism is applicable to explain the differences in solid solution strengthening,and the observed differences in grain boundary strengthening arise from the different tendency of Al,Mo and Ti to reduce the SFE of CoCrFeNi.In addition,we determined the value of the dimensionless parameter f in the Labusch model for CoCrFeNi-based alloys and observed a close relation between Hall-Petch slope and SFE.Although more in-depth studies are needed to provide full and mechanistic understandings,both these findings in fact presents significant values toward designing novel singlephase high-strength CoCrFeNi-based alloys through manipulating the solid solution and grain boundary strengthening by compositional tuning.

Flame-retardant Wrapped Ramie Fibers towards Suppressing “Candlewick Effect” of Polypropylene/Ramie Fiber Composites

In this work, a flame-retardant polypropylene（PP）/ramie fiber（RF） composite was prepared. The ramie fibers were wrapped chemically by a phosphorus- and nitrogen-containing flame retardant（FR） produced via in situ condensation reaction so as to suppress their candlewick effect. Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS） and scanning electron microscopy（SEM） demonstrated that the ramie fibers wrapped chemically by FR（FR-RF） were obtained successfully. Thermogravimatric test showed that the PP/FR-RF composite had more residue and better thermal stability at high temperatures than the PP/RF composite. Cone calorimeter（CC） results indicated that the peak of heat release rate（PHRR） and total heat release（THR） correspondingly decreased by 23.4% and 12.5% compared with the values of neat PP/RF. The PP/FR-RF composite created a continuous and compact char layer after the combustion. Combining FTIR analysis of char residue after CC test with heat conduction coefficient results, it could be concluded that the charring of FR on RF greatly weakened the candlewick effect of RF, and more char residue in the RF domain facilitated the formation of more continuous and compact char layer in the whole combustion zone, consequently protected PP composites during combustion, resulting in the better flame retardancy of PP/FR-RF composite than that of PP/RF composite.