Existing State and Partitioning of Rare Earth on Weathered Ores

The existing state and partitioning of rare earth （RE） on weathered ores in Longnan County（LN）, Xingfeng County（XF） and Ninghua County（NH） were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases： （a） water soluble, （b） ion-exchangeable, （c） colloidal sediment （oxides）, （d） minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE, with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2 %. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce^3＋ is oxidized into Ce^4＋ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.     

非线性函数的自适应分区多神经网络学习及仿真实验

根据BP神经网络学习非线性函数的精度与所学函数的区间大小及变化率等有关，提出了一种非线性函数的自适应分区多神经网络学习方法，这种方法根据学习精度的要求，自适应地把所学函数分成若干区间，分别用一个BP神经网络去学习，从而使学习精度大大提高，最后，给出了学习一维函数和多维函数的仿真实例，其结果表明分区学习的精度可提高10倍以上。     

Post-pass partitioning of signal processing programs

Symmetric multiprocessor systems are increasingly common, not only as high-throughput servers, but as a vehicle for executing a single application in parallel in order to reduce its execution latency. This article presents Pedigree, a compilation tool that employs a new partitioning heuristic based on the program dependence graph (PDG). Pedigree creates overlapping, potentially interdependent threads, each executing on a subset of the SMP processors that matches the thread’s available parallelism. A unified framework is used to build threads from procedures, loop nests, loop iterations, and smaller constructs. Pedigree does not require any parallel language support; it is post-compilation tool that reads in object code. The SDIO Signal and Data Processing Benchmark Suite has been selected as an example of real-time, latency-sensitive code. Its coarse-grained data flow parallelism is naturally exploited by Pedigree to achieve speedups of 1.63×/2.13× (mean/max) and 1.71×/2.41× on two and four processors, respectively. There is roughly a 20% improvement over existing techniques that exploit only data parallelism. By exploiting the unidirectional flow of data for coarse-grained pipelining, the synchronization overhead is typically limited to less than 6% for synchronization latency of 100 cycles, and less than 2% for 10 cycles. This research was supported by ONR contract numbers N00014-91-J-1518 and N00014-96-1-0347. We would like to thank the Pittsburgh Supercomputing Center for use of their Alpha systems.     

多探头 K 分割编码结构及循环码编码器研究

针对增量型数字编码器提出了一种多探头Ｋ分割编码结构及与之相应的一种增量型循环码编码器的基本结构，并研究了这种Ｋ分割方式下编码状态的特征及规律，确立了一种以二进制循环码为特征标志的编码方式．尤其是这种基于Ｋ分割编码结构原理的循环码编码器，在改进码盘结构及提高编码器综合性能方面具有显著的效果．     

Hierarchical Partitioning Techniques for Structured Adaptive Mesh Refinement Applications

This paper presents the design and preliminary evaluation of hierarchical partitioning and load-balancing techniques for distributed structured adaptive mesh refinement (SAMR) applications. The overall goal of these techniques is to enable the load distribution to reflect the state of the adaptive grid hierarchy and exploit it to reduce synchronization requirements, improve load-balance, and enable concurrent communications and incremental redistribution. The hierarchical partitioning algorithm (HPA) partitions the computational domain into subdomains and assigns them to hierarchical processor groups. Two variants of HPA are presented in this paper. The static hierarchical partitioning algorithm (SHPA) assigns portions of overall load to processor groups. In SHPA, the group size and the number of processors in each group is setup during initialization and remains unchanged during application execution. It is experimentally shown that SHPA reduces communication costs as compared to the Non-HPA scheme, and reduces overall application execution time by up to 59%. The adaptive hierarchical partitioning algorithm (AHPA) dynamically partitions the processor pool into hierarchical groups that match the structure of the adaptive grid hierarchy. Initial evaluations of AHPA show that it can reduce communication costs by up to 70%.     

Compact Mathematical Formulation for Graph Partitioning

The graph partitioning problem consists of dividing the vertices of a graph into clusters, such that the weight of the edges crossing between clusters is minimized. We present a new compact mathematical formulation of this problem, based on the use of binary representation for the index of clusters assigned to vertices. This new formulation is almost minimal in terms of the number of variables and constraints and of the density of the constraint matrix. Its linear relaxation brings a very fast computational resolution, compared with the standard one.Experiments were conducted on classical large benchmark graphs designed for comparing heuristic methods. On one hand, these experiments show that the new formulation is surprisingly less time efficient than expected on general k-partitioning problems. On the other hand, the new formulation applied on bisection problems allows to obtain the optimum solution for about ten instances, where only best upper bounds were previously known.     

含柔性多状态开关的配电网分区方法

柔性多状态开关是一种新型智能配电装置。结合柔性多状态开关的功能特点,提出了含柔性多状态开关的配电网分区条件。以多层图分割理论框架为基础,提出了由粗化、分区和还原阶段构成的分区方法。在粗化过程中,提出了基于最短电气距离的粗化方法,使用贪婪图生长算法完成初始分区,并在还原阶段提出了基于路径搜索的还原方法。分区方法不仅能够优化配电网的运行指标,还能够提高配电网的可控性和灵活性。通过IEEE 118节点配电网算例对所述分区方法进行了说明和验证,并结合柔性多状态开关的调控对分区效果进行了进一步分析。结果表明,该方法能够改善配电网的日均馈线负载均衡度,并能够和柔性多状态开关的调控相配合,进一步改善配电网每一时刻的馈线负载均衡度和电压分布。     

An ultrahigh strength steel produced through deformation-induced ferrite transformation and Q&P process

In this work,DIFT technology and Q&P process were combined in order to introduce ultrafine-grained ferrite into the matrix of martensite and retained austenite to develop a new kind of advanced high strength steel,and two kinds of steels were investigated by this novel combined process.The newly designed process resulted in a sophisticated microstructure of a large amount of ferrite(about 5 m in diameter),martensite and a considerable amount of retained austenite for TRIP 780 steel.The ultimate tensile strength can reach about 1200 MPa with elongation above 16% for TRIP 780,that is much higher than the one solely treated by Q&P process.Tensile tests showed that both steels with the novel combined process achieved a good combination of strength and ductility,indicating that the new process is promising for the new generation of advanced high strength steels.     

基于数据分区的连续属性整体离散化方法研究

实际问题中经常涉及连续的数值属性,然而许多归纳学习算法却是针对离散属性空间的.因此,对数据进行预处理的离散化算法一直受到人们的重视.兼顾所有属性间关系的整体离散化是一个重要方法,该文提出基于数据分区的整体离散化算法,它首先对例子集合在各个连续属性上的取值进行统一的放大处理,选出包含最多聚类信息的属性,将整个例子集合粗略的划分为多个分区;然后在各个分区中分别进行聚类、合并.该方法改进了基本的整体离散化算法,并利用农业专家系统中的土壤分类数据对算法进行了验证.     

Elemental Partitioning Characteristics of Equilibrium Phases in Inconel 718 Alloy at 600-1100 ℃

 The optimization of heat treatment and chemical composition for Inconel 718 alloy has been investigated uninterruptedly because of its excellent mechanical properties and metallurgical workability. The species, chemical compositions and content of equilibrium phases of Inconel 718 alloy in the temperature range of 600-1100 ℃ were calculated by using thermodynamic software “Thermo-Calc” and the latest relevant datebase of Ni-base superalloys. A concept of elemental partitioning fraction was used to study the partitioning characteristics of alloying elements in each equilibrium phase at different temperatures, such as Ni, Cr, Fe, Nb, Mo, Al, Ti and C, and some calculation results were confirmed under a scanning transmission electron microscope (STEM). The results showed that the elemental partitioning characteristics with the change of temperature revealed the selective partitioning characteristic of alloying elements in equilibrium phases at different temperatures, such as Nb was mainly distributed in δ and γ′ phase, C in carbides, Al and Ti in γ′ phase and Cr, Mo in Laves phase. At the same time, the effect of the change of component and quantity for each precipitated phase on matrix phase can be helpfully understood, which provided a theoretic foundation to optimize the chemical composition and heat treatment in different environments for Inconel 718 alloy.