The effects of Nd or Zr addition on microstructure and mechanical properties of casting Mg-Zn-RE alloy have been investigated. The results indicate that the optimum contents of Nd and Zr are 0.5% and 0.3% respectively. The less or higher contents all increase grain size and accelerate the formation of shrinkage porosity, and thus decrease tensile properties and change fracture regime from transgranular mode to intergranular mode during tensile tests. The Mg-Zn-RE ternary phases transform from W (Mg 3 Zn 3 (Nd,Y) 2 ) in turn into W + Z (Mg 12 Zn(Nd,Y)) and Z as the Nd content increases and their distribution gradually changes from small discontinuous lath form to continuous network form. The grain bonding strength of an alloy with a certain amount of W phase that distributes in a discontinuous form is high than that of the alloy with the Z phase, and thus the W phase is an ideal strengthening phase. The alloy with 0.5 Nd and 0.3% Zr, named ZW21 alloy, has the smallest grains and highest grain bonding strength, and so has the highest comprehensive mechanical properties.

With the construction of smart grid and centralized data center, traditional information technology management mode already cannot meet the requirements on the timeliness and flexibility. Cloud computing technology can solve the complicated calculation, mass data processing, and network dynamic migration issues for electric power business, but when in the face of different business applications demand, due to the heterogeneous resources variety of applications bottleneck will be produced, difficult to achieve real "smart". In view of the smart grid application scenarios, heterogeneous resources adaptation method is given respectively for computing, storage and network resources. Makes the heterogeneous resources can be shared centrally, allocate resources on demand, unified managing, dynamic scheduling, and loaded balancing, form heterogeneous resource pool. Based on heterogeneous resource pool, build the heterogeneous cloud service model, and carried out preliminary design implementation, the availability of the model was verified.

The existing sample selection methods are inadequate in the determination of defect sample set, and lacking necessary metrics or evaluation methods of the defect sample set. This paper determines the typical defect sample set according to the selecting principles and proposes a metrics method of defect sample set to measure whether the defect sample set is representative of the defect library. At present, defect sample selection mainly depends on brainstorming and expert experiences in the electric system. However, for those organizations which have no experiences orfor large databases, there are significant difficulties on sample selection. The proposed defect sample selection framework and measurement criteria can effectively improve the situation and ensure that the selected sample set can well represent the defect library.

Bone thickness, bone mineral content and bone density in the midshaft and bone length of the amounts of fluoride in their drinking water than the urban residents. The amount of fluorine accumulated in bone and absorbed into the body decreased with the ingestion of water containing lower levels of fluoride.