Ping PENG
,
Caixing ZHENG
,
Shaochang HAN
,
Zhaohui JIN
,
Rui YANG
,
Zhuangqi HU
材料科学技术（英文）
The interfacial binding covalent bond density (CBD) and the local environmental total bond order (LTBO) of the Ni/Ni3Al interface with different lattice misfits (δ) were calculated by using first-principles discrete variation Xα method. It was found that the effects of lattice misfits on the electronic structures of incoherent Ni/Ni3Al interface were very obvious. On one hand, less than -0.6% negative lattice misfit can promote the binding strength of γ/ interface. On the other hand, the total bonding strength ofγ/ interface decreases with increasing δ. Therefore, the magnitude and sign of lattice misfit must be carefully controlled for balancing the high temperature creep strength of Ni-base single crystal superalloy and the structural stability ofγ/ interface when one designs a new Ni-base single crystal superalloy.
关键词:
γ/ interface
,
null
,
null
,
null
林鸿
,
段远源
工程热物理学报
利用密度平移的方法对Peng-Robinson状态方程计算的液相密度进行了修正,给出了其描述平移量的关联式.对22种卤代烃纯物质的计算结果表明,修正后的PR方程能够很好地计算液相密度,并且能很好地再现纯物质的临界压缩因子,计算精度可以满足工程应用的需要.
关键词:
PR状态方程
,
密度漂移
,
卤代烃
,
临界压缩因子
林鸿
,
段远源
工程热物理学报
利用比容平移修正后的Peng-Robinson状态方程和密度梯度理论建立了简单流体和烷烃的表面张力的理论模型,并提出了适合于这一类纯物质的作用因子通用关联式.对3种简单流体和21种烷烃的表面张力的计算结果表明,利用新的作用因子关联式结合梯度理论模型能在广泛温度范围内高精度地再现纯物质的表面张力,总的平均绝对偏差为0.19 mN·m-1,计算精度可以满足工程应用的需要.
关键词:
表面张力
,
梯度理论
,
PR状态方程
,
简单流体
,
烷烃
段远源
,
林鸿
,
张庆麟
,
张秋芳
工程热物理学报
目前国际上已商业化使用或提出的潜在的环保工质,大多数为氢氟烃(HFC)混合物,利用状态方程描述混合工质热力性质时,交互作用系数是重要参数之一.本文应用Peng-Robinson状态方程对多种HFC二元混合物的气液相平衡(vapor-liquid equilibrium,VLE)实验数据进行了回归,得到了相应混合物的交互作用系数.提出了交互作用系数新关联式,结果表明所得到的交互作用系数能很好的应用于描述HFC混合物气液相平衡性质,计算精度可以满足工程应用的需要.
关键词:
氢氟烃(HFC)
,
混合物
,
气液相平衡(VLE)
,
二元交互作用系数
,
PR状态方程
Journal of Physics-Condensed Matter
This research purposes to investigate the atomic and electronic structures of the Al/TiC(001) interface with lattice misfit using the ab initio pseudopotential approach. A detailed analysis of the relaxed atomic structure reveals that the atoms over the initial unfavourable sites relax to the favourable sites along the lateral plane. The properties of the semicoherent interface can be taken as averages over the different coherent sites. In addition, the interface atoms in relatively favourable regions are dragged near to the interface, while those in unfavourable regions are pushed away from the interface. Therefore, a large war-ping near the interface is made perpendicular to the lateral plane. The calculated adhesions explain the different wetting results from the viewpoint of structural transition. The subsequent analysis of electronic properties demonstrates that adhesions dominate mainly via the strong Al-C covalent bond.
关键词:
first-principles;1st principles;adhesion;surfaces;misfit;1st-principles;wettability;al
X. Q. Yang
,
L. X. Huo
,
Y. F. Zhang and J. X. Yan (School of Material Science and Engineering
,
Tianjin University
,
Tianjin 300072
,
China)
金属学报(英文版)
The buckling formation and influence factors during welding thin - plated structures were investigated based on finite element methods, An engineering treatment method for prdicating the buckling distor- tion was proposed in here. It was used the equivalent applied thermal - load to simulate the welding residual stress,therefore the calculation of complex welding distoriton can be transformed into 3D elas- tic structural applied- load analyses, which can reduce the quantities of calculating works effectively. The validation of the method was verified by comparison of the numerical simulation and experimental results. The simulation of buckling distorition for side - walled structrues of paseenger train was per- formed and the calculation was in agreement with measuring results in general. It was shown that the main factors for producing the buckling were the intermittent fillet and ping the during welding the stiffened beams and columns to the panel.The existence of the free edge of panels would reduce the crit- ical buckling stress and enlarge the deflection obviously,but the continuous weld in closed frames didn' t degrade the buckling situation.
关键词:
welding buckling distortion
,
null
,
null
闵琪
,
林鸿
,
段远源
,
宋艺新
工程热物理学报
表面张力是非常重要的物性参数之一,特别对于沸腾和凝结换热的计算是必不可少的.但目前的研究成果主要集中于纯物质,对有重要工程应用前景的混合工质研究还很少.本文应用密度梯度理论,结合比容平移后的Peng-Robinson方程建立了混合物的表面张力模型,该模型不含有任何需要表面张力实验数据回归确定的经验可调系数.计算结果表明,本文建立的模型具有很好的通用性和计算精度,能在广泛的温度范围内较好地再现一般流体混合物和含超临界组元混合物的表面张力数据.
关键词:
表面张力
,
密度梯度理论
,
二元混合物
,
状态方程
闵琪
,
段远源
,
林鸿
,
宋艺新
工程热物理学报
表面张力是重要的物性参数之一,与人们的生产生活密切相关.醇类及其混合物具有重要的工业应用价值.含醇混合物作为特殊的缔合体系,由于氢键的存在,性质复杂.本文应用密度梯度理论结合比容平移后的Peng-Robinson状态方程,回归了醇、水纯净物的作用因子关联式系数,建立了混合物的表面张力预测模型,计算了含醇二元缔合体系的表面张力,该模型不含有任何需要混合物表面张力实验数据回归确定的经验可调参数,对绝大多数含醇混合物具有很好的通用性和计算精度.
关键词:
表面张力
,
密度梯度理论
,
二元混合物
,
醇
,
水
Z.L. Ding
,
Y.C. Fan
,
H.B. Qi
,
D.L. Ren
,
J.B. Guo and Z.Q. Jiang Shijiazhuang Railway Institute
,
Shijiazhuang 050043
,
China
金属学报(英文版)
The SiC_p/Al-alloy composite front broke rotors designed for SHANGHAI SANTANA cars were prepared by semi-solid stirring+liquid for ping process. The properties of the composite rotors were examined. The composite brake rotors were subjected to dynamometer tests on a SCHENCK broke testing system, referring to TLll0 standard of VOLKSWAGEN Company. The friction coefficient and thermal response during fade testing and the wear performance of the composite rotors were studied as the function of various parameters, such as braking pressures, initial speeds, initial temperatures, torque and decelerations, and compared with that of conventional cast iron rotors. The results showed that the properties of SiC_p,/Al-alloy composite rotors can achieve the requirements of commercial cast iron rotor.s. The results also suggested that the friction coefficients of composite rotors under different broking conditions are within the deviation band specified by the TLll0 standard, and the temperature rise of the composite rotors at the cud of each fade stop is lower than that of the cast iron rotors. The wear resistance of composite rotors was higher than that of cast iron rotors. The friction and wear mechanism are analyzed.
关键词:
SiC_p/Al-alloy composite
,
null
,
null
,
null
钱鹏
,
李兴华
量子电子学报
doi:10.3969/j.issn.1007-5461.2015.06.008
基于量子信道加密原理,结合Ping-Pong协议控制模式和信息模式的概念,提出了一个量子安全直接通信协议.在此协议中,发送者和接收者用n对Bell态作为量子信道,发送者用controlled-Not操作将单粒子纠缠入量子信道,接收者用controlled-Not操作将单粒子与量子信道解纠缠.通信双方依次执行控制模式和信息模式,控制模式检测窃听,信息模式发送秘密信息.控制模式和信息模式均不会对已建立的量子信道造成破坏,因此建立量子信道的过程仅需执行一次,此后通信双方可以反复进行控制模式和信息模式,从而不断进行窃听检测和秘密信息传输.
关键词:
量子光学
,
量子安全直接通信
,
信道加密
,
窃听检测
