锂铬基金属氧化物贮备式电池激活性能研究

为满足锂贮备电池高比能、高功率和快激活性能同时兼顾的要求,开发了新型锂铬基金属氧化物贮备电池,并开展了正极、负极、隔膜、电解液、真空度和激活时间对激活性能的影响研究。采用多孔导电剂、高孔隙率无纺布基隔膜和低粘度高润湿电解液等新型材料和改进设计,可显著提升新型锂贮备电池在较短激活时间下的大倍率放电能力。基于改进后的方案制备了贮备式锂铬基金属氧化物电池模块,在激活时间1 min的条件下,1 C放电比能量达264.49 Wh/kg,并具备5 C持续放电5 min的大倍率放电能力。

氧化银电极中镀银泡沫镍的性能研究

本文通过恒电阻放电测试方法,对铝氧化银电池中采用镀银泡沫镍为集流体的激活初期倍率性能进行研究。实验结果表明镀银泡沫镍为基体的氧化银电极在放电过程中电化学极化较银网为基体的氧化银电极较低,利用率较高。镀银泡沫镍为基体的氧化银电极在620m A/cm^2的电流密度下,放电截止电压为1.4V时的平均电压为1.65V,比银网为基体的氧化银电极的平均电压高70m V,利用率高近5%。

Electrochemical properties of magnesium alloy anodes discharged in seawater

Magnesium alloys can be developed as anode materials for seawater activated batteries. The electrochemical properties of AZ31, AP65 and Mg-3%Ga-2%Hg alloy anodes discharged in seawater were studied. The potentiodynamic polarization shows that the Mg-3%Ga-2%Hg alloy provides more negative corrosion potentials than AZ31 or AP65 alloy. The galvanostatic discharge results show that the Mg-3%Ga-2%Hg alloy exhibits good electrochemical properties as anodes in seawater. And the EIS studies reveal that the magnesium alloy anode/seawater interfacial process is determined by an activation controlled reaction. The Mg3Hg and Mg21Ga5Hg3 phases in Mg-3%Ga-2%Hg alloy improve its electrochemical properties better than the Mg17（Al,Zn）12 phase in AZ31 and Mg（Pb） solid solution phase in AP65 alloys.

Preparation and properties of Ni_(68.6)W_(17.9)B_(13.5) metallic glass

A novel Ni-based metallic glass, i.e., Ni68.6W17.9B13.5（mole fraction, %）, was prepared using melt spinning method. The results showed that the element B has much effect on the glass forming ability of the Ni-W-B metallic glass. Ni-W-B metallic glass could not be fabricated with lower content of B, whereas a higher content of 13.5% B could easily lead to the fully amorphous structure. The glass transition temperature and the onset temperature of crystallization are as high as 768 K and 781.5 K, respectively, and the crystallization activation energy calculated by Ozawa model is（637±60） k J/mol, which showed strong thermal stability of Ni68.6W17.9B13.5 metallic glass. This novel Ni-based metallic glass also exhibited good mechanical properties with the tensile strength of about 2331 MPa. The results indicate that this metallic glass should have a promising application in high strength material.

汽油具有一定毒性 要少吸少闻油蒸气

汽车是现代生活中最便捷的交通工具，汽油性质对汽车发动机影响极大，为适应各种不同车型及环保的要求，良好的汽油品质必需具备下列各种条件：(1)抗震爆性能良好、(2)激活性能良好、(3)暖车迅速、(4)加速能力强、(5)耗油量少、(6)引擎运转平稳、(7)防止气障、(8)抗腐蚀性良好、(9)不易变质或生胶、

Microstructure and remarkably improved hydrogen storage properties of Mg_2Ni alloys doped with metal elements of Al, Mn and Ti

Mg2Ni0.7M0.3(M=Al,Mn and Ti)alloys were prepared by solid phase sintering process.The phases and microstructure of the alloys were systematically characterized by XRD,SEM and STEM.It was found that Mg3MNi2intermetallic compounds formed in Mg2Ni0.7M0.3alloys and coexisted with Mg and Mg2Ni,and that radius of M atoms closer to that of Mg atom was more beneficial to the formation of Mg3MNi2.The hydrogen storage properties and corrosion resistance of Mg2Ni0.7M0.3alloys were investigated through Sievert and Tafel methods.Mg2Ni0.7M0.3alloys exhibited remarkably improved hydrogen absorption and desorption properties.Significantly reduced apparent dehydriding activation energy values of-46.12,-59.16and-73.15kJ/mol were achieved for Mg2Ni0.7Al0.3,Mg2Ni0.7Mn0.3and Mg2Ni0.7Ti0.3alloys,respectively.The corrosion potential of Mg2Ni0.7M0.3alloys shifted to the positive position compared with Mg2Ni alloy,e.g.there was a corrosion potential difference of0.110V between Mg2Ni0.7Al0.3alloy(-0.529V)and Mg2Ni(-0.639V),showing improved anti-corrosion properties by the addition of Al,Mn and Ti.

Is kinase activity essential for biological functions of BRI1？

Brassinosteroids （BRs） are a major group of plant hormones that regulate plant growth and development. BRI1, a protein localized to the plasma membrane, functions as a BR receptor and it has been proposed that its kinase activity has an essential role in BR-regulated plant growth and development. Here we report the isolation and molecular characterization of a new allele of bril, bril-301, which shows moderate morphological phenotypes and a reduced response to BRs under normal growth conditions. Sequence analysis identified a two-base alteration from GG to AT, resulting in a conversion of 989G to 9891 in the BRI1 kinase domain. An in vitro assay of kinase activity showed that bril-301 has no detectable autophosphorylation activity or phosphorylation activity towards the BRI1 substrates TTL and BAK1. Furthermore, our results suggest that bril-301, even with extremely impaired kinase activity, still retains partial function in regulating plant growth and development, which raises the question of whether BRI1 kinase activity is essential for BR-mediated growth and development in higher plants.

Influence of different solution methods on microstructure, precipitation behavior and mechanical properties of Al-Mg-Si alloy

The effects of different solution methods on microstructure, mechanical properties and precipitation behavior of Al-Mg-Si alloy were investigated by scanning electron microscope, transmission electron microscope, tensile test, and differential scanning calorimetry. The results revealed that the recrystallized grains of the alloy after the solution treatment with hot air became smaller and more uniform, compared with solution treatment with electrical resistance. The texture of the alloy after two solution treatment methods was different. More rotated cube components were formed through solution treatment with electrical resistance, which was better for improving the drawability of the alloy. The strength of the alloy under the solution treatment with hot air was higher before stamping, because of the small uniform grains and many clusters in the matrix. The alloy solution treated with hot air also possessed good bake hardenability, because the transformation occurred on more clusters in the matrix.

Effect of Cistanoside Compounds on Oxidative Stress and Immunity

Cistanoside compounds were studied as the scavengers of hydroxyl and superoxide anion free radicals with spin trapping ESR method in vitro. Low-temperature ESR technique, experimental technique of immunotoxicology and biochemical method were used to detect the level of reactive oxygen radicals in kidney tissue of rats and SOD level and GSH-Px activity in rat serum. The results indicated that cistanoside compounds could inhibit reactive oxygen free radicals in vitro and prevent and repair the free radical damages for diabetic nephropathy. The experimental data of 揷arbon-particle detection in mouse serum?showed that cistanoside compounds could improve the phagocytotis index of macrophages (Mj) in mice blood and increase the weights of immune organs of mice.

Effect of Chemical Doping and Ion Implantation on Cond uctivity of Poly(p-phenylene vinylene) Derivatives

The surface conductivity of poly [ 2-methoxy-5-（3＇-methyl） butoxy]-p-phenylene vinylene （PMOMBOPV） films doped with FeCl3 and H2SO4 by chemical method and implanted by N^＋ ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N^＋ ions were in the rang 15～35 keV and 3. 8×10^15～9. 6×10^16 ions/cm^2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N^＋ ions. For example, the conductivity of PMOMBOPV film was 3. 2×10^-2S/cm when ion implantation was performed with an energy of 35 keV at a dose of 9. 6 × 10^14 ions/cm^2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV.

Grain growth and thermal stability of nanocrystalline Ni-TiO_2 composites

The grain growth and thermal stability of nanocrystalline Ni-TiO2composites were systematically investigated.Thenanocrystalline Ni-TiO2composites with different contents of TiO2were prepared via electroplating method with the variation ofTiO2nano-particles concentration.The effect of TiO2content on the grain size,phase structure and microhardness was investigatedin detail.The corresponding grain growth and diffusion mechanisms during the heating process were also discussed.The optimalmicrohardness of HV50270was achieved for the composite with addition of20g/L TiO2nano-particles after annealing at400°C for90min.The calculation of the activation energy indicated that lattice diffusion dominated at high temperatures for thenanocrystalline Ni-TiO2composites.It was indicated that the increase of TiO2nano-particles content took effect on restricting thegrain growth at high temperatures by increasing the grain growth activation energy.

Structural Performance and Characterization of Polyimide Doped Activated Carbon Fibers for Mercury Adsorption

Structure characteristics about activated carbon fibers (ACF) and polyimide (P84) doped ACF modified by HNO3 solution were studied to apply in mercury removal in coal-fired flue gases. The P84, which was always used in the non-woven fabric for bag filter, was intermingled with polyacrylonitrile-based ACF (PAN-ACF) in the weight ratio of 1∶1 in order to make the doped ACF with P84 (doped-ACF-P84). Then the doped-ACF-P84 fibers were modified by HNO3 solution. The structure and morphology of doped-ACF-P84 were characterized and compared with those of ACF and doped-ACF-P84 modified by HNO3solution. The results show that the modified doped-ACF-P84 fibers have almost the same pore structure and specific surface area comparing with the original one. However, contrasted with the original PAN-ACF, the doped-ACF-P84 fibers modified by HNO3 solution have more oxygen-containing groups used for mercury removal. In particular, they have more lactone and carboxyl groups.

Effect of processing parameters on flow behaviors and microstructure during high temperature deformation of GH4586 superalloy

The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy.

Active control of structural vibration by piezoelectric stack actuators

This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the model to achieve vibration control of flexible structures, and dynamic characteristics are also investigated. Mobility technique is used to derive the governing equations of the system. The power flow transmitted into the foundation is solved and considered as a cost function to achieve optimal control of vibration isolation. Some numerical simulations revealed that the analytical model is effective as piezoelectric stack actuators can achieve substantial vibration attenuation by selecting proper value of the input voltage.

Properties of fluoride film and its effect on electroless nickel deposition on magnesium alloys

The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.

Effects of pre-deformation on microstructure and tensile properties of Al-Zn-Mg-Cu alloy produced by modified strain induced melt activation

The effects of Al-8B grain refiner on microstructure and tensile properties of an Al-12Zn-3Mg-2.5Cu alloy produced by modified strain induced melt activation process were investigated. Pre-deformation of 60% was used by hot working at 300 ℃. After pre-deformation, the samples were heated to a temperature above the solidus and below the liquidus point and maintained in the isothermal conditions at three different temperatures（500, 550 and 590 ℃） for varying time（10, 20 and 40 min）. It was observed that strain induced melt activation has caused the globular morphology of α（Al） grains. Microstructural study was carried out on the alloy by using optical microscope and scanning electron microscope in both unrefined and B-refined conditions. The results showed that for the desired microstructures of the alloy during SIMA process, the optimum temperature and time are 550 ℃ and 10 min, respectively. After the T6 heat treatment, the average tensile strengths increased from 278 to 585 MPa and 252 to 560 MPa for samples refined with 3.75% Al-8B before and after SIMA process, respectively. The ultimate strength of SIMA specimens is lower than that of B-refined specimens.

Synthesis and Luminescence Properties of Tb^3＋-Activated Silicate Oxyapatite Phosphor

A green-emitting phosphor Ca（Tb1-xLax）4（SiO4）3O （CTLS） was synthesized by a solid state reaction. X-ray diffraction, photoluminescence （PL） spectroscopy, reflectance spectra and chromaticity coordinates were carried out in this study. The CaTb4（SiO4）3O host has been known to crystallize in a hexagonal structure with disordering found in the Ca2＋ and Tb3＋ cation sites. The phosphors exhibited highly green-emitting band centered at 541 nm under ultraviolet excitation, which corresponds to the 5D4→7F5 transition. The optimal doping concentration of Tb3＋ was observed to be at 20 mol%, and the PL intensity was found to decline dramatically when the content of Tb3＋ exceeds 20m01% due to concentration quenching. Based on the results, we are currently evaluating the potential application of Ca（Tb,La）4（SiO4）30 as a new green-emitting near-UV LED convertible phosphor.

Storage and Subsequent Reactivation of Phosphate-Accumulating Aerobic Granules

Phosphate-accumulating aerobic granules cultivated in a sequencing batch reactor were composed of inner rod-shaped bacteria aggregates and outer twining filamentous bacteria. The influence of two-month storage under dif- ferent conditions on the storage and subsequent reactivation performance of aerobic granules was investigated. After two-month storage the granules sealed at 4 ~C in distilled water or normal saline （named granules A and granules B, respectively） could maintain their characteristics as before, while the granules idled in the reactor at room temperature （named granules C） exhibited decreased properties. During reactivation, granules A and granules B presented almost identical recovery performance, faster than granules C, in terms of phosphorus removal efficiency, mixed liquor sus- pended solids （MLSS）, phosphate release and accumulating ability. The results suggest that hermetical storage at low temperature promoted the maintenance of the granular properties and the reviving behaviors of phosphateaccumulating aerobic granules, and storage medium had little influence on the storage and recovery perfomlance.

Ultrasonic-assisted plastic flow in a Zr-based metallic glass

Ultrasonic vibration can be used for the micro-molding of metallic glasses(MGs)due to stress-softening and fast surface-diffusion effects.However,the structural rearrangement under ultrasonic vibration and its impact on the mechanical response of metallic glasses remain a puzzle.In this work,the plastic flow of the Zr35Ti30Cu8.25Be26.75 metallic glass with the applied ultrasonic-vibration energy of 140 J was investigated by nanoindentation.Both Kelvin and Maxwell-Voigt models have been adopted to analyze the structural evolution during the creep deformation.The increase of the characteristic relaxation time and the peak intensity of relaxation spectra can be found in the sample after ultrasonic vibration.It effectively improves the activation energy of atomic diffusion during the glass transition(Eg)and the growth of the crystal nucleus(Ep).A more homogenous plastic deformation with a weak loading-rate sensitivity of stress exponent is observed in the ultrasonic-vibrated sample,which coincides with the low pile-up and penetration depth as shown in the cross profile of indents.The structural rearrangement under resonance actuation demonstrated in this work might help us better understand the defect-activation mechanism for the plastic flow of amorphous systems.

Purely organic optoelectronic materials with ultralong-lived excited states under ambient conditions

The exponential growth of utilizing synthetic organic molecules in optoelectronic applications poses strong demands for rational control over the excited states of the materials. The manipulation of excited states through molecular design has led to the development of high-performance optoelectronic devices with tunable emission colors, high quantum efficiencies and efficient energy/charge transfer processes. Recently, a significant breakthrough in lifetime tuning of excited states has been made;the purely organic molecules were found to have ultralonglived excited state under ambient conditions with luminescence lifetimes up to 1.35 s, which are several orders of magnitude longer than those of conventional organic fluorophores. Given the conceptual advance in understanding the fundamental behavior of excited state tuning in organic luminescent materials, the investigations of organic ultralong room-temperature phosphorescence(OURTP) should provide new directions for researches and have profound impacts on many different disciplines. Here, we summarized the recent understandings on the excited state tuning, the reported OURTP molecules and their design considerations,the spectacular photophysical performance, and the amazing optoelectronic applications of the newly emerged organic optoelectronic materials that free of heavy metals.