Blood lead, behaviour and intelligence test performance in preschool children

A variety of measures of behaviour and cognitive performance were taken on a group of preschool children together with a sample of venous blood. The relationship between blood lead and intelligence was small and statistically non-significant after controlling for other factors influencing cognitive performance.     

1—20MeV中子与^59Co核的相互作用：全套核数据的理论计算

对1—20MeV中子与~(59)Co核相互作用各反应道的反应截面用光学模型和统计理论进行了计算。统计理论包括带宽度涨落修正的豪斯-费许巴哈理论和予平衡发射理论。计算结果与评价过的实验数据进行了比较,除~(59)Co(n,p)反应道的高能段稍偏低外,其他计算结果均与实验值符合很好。最后给出了最佳拟合的光学模型参数。     

多坐标系设置在墙板类零件加工中的应用

加工中心机床是实现多品种、小批次零件生产的理想设备,零件的一次装夹可完成多种工序的连续自动加工。工件坐标系的合理设置是实施自动加工前须认真考虑的重要问题,而充分利用数控系统的坐标系功能和机床工作台整个区域来实现零件的自动化加工,是提高自动加工效率的措施之一。文章主要讨论了利用多坐标系设置的方法来提高加工中心机床的墙板加工效率的具体措施和步骤,并实现仅在一套程序控制下的自动加工,同时给出了墙板类零件加工程序,实践检验结果表明该方法较单组零件一套程序加工提高效率一倍以上,具有一定应用价值。     

B变质对HPb59-1黄铜组织细化的影响

研究了B变质处理及其变质处理后不同的保温时间对HPb59-1黄铜的组织与力学性能的影响。结果表明,HPb59-1黄铜中加入一定量的B可以细化HPb59-1黄铜的组织,改变α和β相组织的分布状态,提高合金的力学性能。细化效果随着B的含量的增加而增强,当B加入量范围在0·008%~0·015%时细化效果较好。变质处理后随熔体保温时间的延长,B细化变质效果存在衰退现象,保温10min后浇注,晶粒细化变质效果最好。     

供应态HPb59-1黄铜超塑性压缩的试验研究

对供应状态的HPb59-1黄铜棒材进行了超塑性等温压缩试验,分析了压缩变形过程,研究了试样尺寸对压缩变形过程的影响,确定其最佳超塑压缩变形工艺参数,本试验结果为压缩类成形零件提供了较佳的工艺参数。     

热处理工艺轿车同步器齿环用HMn59-2-1-0.5合金磨损性能的影响

制定了国产HMn59-2-1-0.5合金同步器齿环的热处理工艺, 对比了该合金齿环和进口齿环的磨损性能, 分析了HMn59-2-1-0.5合金的磨损机理.结果表明: 国产HMn59-2-1-0.5合金同步器齿环耐磨性优于进口同步器齿环或与之相当, 磨损机理主要是磨粒磨损, 热处理后形成的"硬质点 软基体"和"软质点 硬基体"的典型多相复合耐磨组织使合金具有良好的摩擦特性.     

Cubic structures applied to ideals of BCI-algebras

The notions of cubic a-ideals and cubic p-ideals are introduced, and several related properties are investigated. Characterizations of a cubic a-ideal are established. Relations between cubic p-ideals, cubic a-ideals and cubic q-ideals are discussed. The cubic extension property of a cubic a-ideal is discussed.     

Solving model kinetic equations on GPUs

We present an algorithm specifically tailored for solving model kinetic equations onto Graphics Processing Units (GPUs). The efficiency of the algorithm is demonstrated by solving the one-dimensional shock wave structure problem and the two-dimensional low Mach number driven cavity flow. Computational results show that it is possible to cut down the computing time of the sequential codes of two order of magnitude. The algorithm can be easily extended to more general collision models.     

Path multicoloring with fewer colors in spiders and caterpillars

We study a recently introduced path coloring problem with applications to wavelength assignment in all-optical networks with multiple fibers. In contrast to classical path coloring, it is, in this setting, possible to assign a color more than once to paths that pass through the same edge; the number of allowed repetitions per edge is given and the goal is to minimize the number of colors used. We present algorithms and hardness results for tree topologies of special interest. Our algorithms achieve approximation ratio of 2 in spiders and 3 in caterpillars, whereas the best algorithm for trees so far, achieves an approximation ratio of 4. We also study the directed version of the problem and show that it admits a 3-approximation algorithm in caterpillars, while it can be solved exactly in spiders.      

Numerical simulation of temperature and concentration distributions in fluidized beds with liquid injection

In this paper a numerical simulation study of dynamic behavior of a fluidized bed with liquid injection is presented. A continuum model has been developed taking into account the mass and energy balances of solid, gas as well as liquid to describe the temperature and concentration distributions in gas-solid-fluidized beds. The model considers the deposition efficiency of the liquid droplets as well as the influence of the spray nozzle region. For solving the non-linear partial differential equations with discrete boundary conditions a finite element method is used. Numerical computations have been done with two different schemes of time integration, a fully implicit and a semi implicit scheme. The complex correlations of mass and liquid flow rates, mass and heat transfer, drying, and transient two-dimensional air humidity, air temperature, particle wetting, liquid film temperature and particle temperature were simulated. The model was validated with transient measurements of the air temperature and air humidity at the outlet of a fluidized bed with water injection.