Effect of grain size on high-temperature oxidation behavior of Cu-80Ni alloy

1　INTRODUCTIONTheoxidationofunalloyedcopperandnickelhasalreadybeenstudiedindetail.Whilethehigh tem peratureoxidationofCu Nialloys ,alsostudiedanumberoftimestodate[13] ,isanexampleofarela tivelysimpleclassofscalingofbinaryalloysbyasin gleoxidant,becausethemetalsformacontinuousse riesofsolidsolutions ,whiletheiroxides ,CuO ,Cu2 OandNiO ,exhibitsmallmutualsolubilitiesandshowsignificantdifferencesinthethermodynamicstabilityandparabolicgrowthrates .Thus ,copper richalloysformexternalscales…     

Stress－rupture Property and Microstructure of Yttria Dispersion Strengthened Alloy MA956

Ｓｔｒｅｓｓ－ｒｕｐｔｕｒｅＰｒｏｐｅｒｔｙａｎｄＭｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆＹｔｔｒｉａＤｉｓｐｅｒｓｉｏｎＳｔｒｅｎｇｔｈｅｎｅｄＡｌｌｏｙＭＡ９５６ＳｈａＷｅｉ（沙维）（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌＦｎｇｉｎｅｅｒｉｎｇ，ＴｈｅＱｗｅ...     

Sr对高铁Al-Si合金组织和性能的影响

研究了Sr元素（加入量分别为0．03％、0．06％、0．09％、0．12％和0．18％）对含Fe量为1．2％的ZL102合金的组织和性能的影响。研究发现，随着Sr元素的加入，合金中粗大的针状Fe相开始出现断裂分叉现象，同时针状Fe相的长度也随Sr元素加入量的增加而减小，但Sr对Fe相的针状形貌没有明显改变。随着Sr元素加入量逐渐增加，合金的抗拉强度和伸长率均呈现出先增后减的变化趋势。当Sr元素加入量达到0．12％时，合金材料的综合力学性能最佳。     

基于梯形图方法的全气动装弹机械手设计

介绍了基于梯形图设计方法的全气动装弹机械手的设计,重点探讨了在设计中考虑气缸运行位置检测、手动及自动切换、急停处理等实用问题.采用两位三通阀扩充方法来解决单一行程阀多次切换分区条件的难题,利用梭阀实现手动和自动操作的配合,通过增加一个中继阀来实现急停处理.     

Rh(Ⅲ)—钍试剂—高碘酸钾新体系催化光度法测定痕量铑

在pH3.9醋酸盐缓冲溶液中及加热条件下,Rh(Ⅲ)对高碘酸钾氧化钍试剂这一褪色反应有强烈的催化作用,可藉自来水冷却中止反应,研究了催化光度测定痕量铑的影响因素,建立了一个检出限和测定范围分别为0.06ng/ml和0.12～4.5ng/ml铑的催化光度新方法。     

Performance of positive and negative electrodes in amorphous manganese oxide supercapacitor

Using potassium permanganate and acetic manganese as the reactants, amorphous manganese oxide was prepared with mechanochemical method. XRD was used for microstructure characterization, while cyclic voltammetry and constant current charge-discharge were used for electrochemical performance testing. The positive electrode （PE） and negative electrode （NE） were investigated respectively in amorphous manganese oxide supercapacitor, aiming to find their different performances in charging-discharging. The results show that the crystalline structure is destroyed in both the PE and NE material during charge-discharge process. Thereinto, the NE suffers a bit more seriously. When cycling, the PE potential scope diminishes while the NE potential scope enlarges. The increased inner resistance makes the NE curves almost bended to be a right angle, but not the PE curves. The cell＇s equivalent series resistance （ESR） is more dependent on the NE, and the capacitance is mainly determined by the rapid descent of the NE potential range. The capacitances of the NE are highly rate-dependent, decreasing from 121.3 to 53.1 F/g, by 56.2%, over the range of 5-25 mV/s. However, the PE appears to be weakly dependent and its capacitance is only dropped by 22.1%.     

A THERMODYNAMIC INVESTIGATION ON SPINODAL DECOMPOSITION BOUNDARY IN Cu－Ti ALLOYS

ＡＴＨＥＲＭＯＤＹＮＡＭＩＣＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＳＰＩＮＯＤＡＬＤＥＣＯＭＰＯＳＩＴＩＯＮＢＯＵＮＤＡＲＹＩＮＣｕ－ＴｉＡＬＬＯＹＳ￥ＷｅｉＹｉｎｇｈｕｉ；ＷａｎｇＸｉａｏｔｉａｎ（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎ...     

Redundancy filtering and fusion verification for video copy detection

Multimedia Systems - Recently, the frame fusion based video copy detection scheme provides a possibility to detect copies in a continuous query video stream. However, its computational complexity...     

L波段微波功率合成技术研究

无人机机载功率放大器的性能一直是限制无人机技术发展的主要因素,为此提出了将功率合成技术应用于无人机数据系统的方法解决上述问题。利用微带线技术结合系统性的电路调试方法,辅以Advanced Design System仿真软件优化设计,同时采用实频技术法进行宽带功放设计,成功研制了频段在1.3 GHz~1.7 GHz的功率放大器,单路功率放大器采用级联的技术输出功率为8 W,两路合成后,实测总输出功率为15.67 W,合成效率达97%,性能稳定,达到实用水平。