热处理对激光增材In718/316L功能梯度材料组织和性能的影响

研究1 080 ℃ (HT1)和980 ℃ (HT2)固溶温度的固溶双时效处理对激光定向能量沉积(Laser directed energy deposition, LDED)的In718/316L功能梯度材料(Functionally gradient material, FGM)微观组织的影响，以揭示热处理诱导的微观组织演变对In718/316L FGM硬度和拉伸性能的影响机理。结果表明，随着In718粉末含量的增加，In718/316L FGM的微观组织沿增材方向呈现由等轴晶向柱状晶的转化，固溶双时效热处理后，In718/316L FGM中的铁素体含量降低，同时在靠近In718的区域析出大量的γ′、γ″和δ强化相。HT2试样的晶粒比HT1试样的更细。随着In718粉末含量的增加，In718/316L FGM的硬度呈现出先减后增的趋势，热处理后，随着γ′和γ″等强化相的析出，In718/316L FGM的整体显微硬度、抗拉强度和塑性得到显著提高。热处理前后试样都以韧性断裂为主，但热处理后韧性特征更为显著。相比之下，HT2热处理后In718/316L FGM的强塑性配比更佳。     

Phase methods for piezoelectric resonator measurements: New proposals

In the paper two new computerized phase transmission methods for piezoelectric resonator measurement are presented. In both methods new ways of determining the reference phase, which is the tuning criterion, are utilized. In the first method this phase is calculated using predicted values of resonator motional resistance and shunt capacitance. In the second one the mean value of the minimum and maximum phase values (obtained during sweeping the test signal frequency in the resonance area) is used as a reference.     

求解模糊控制表的方法

在模糊控制装置中,往往采取用查表的方法取代模糊推理语句以及进行模糊决策,这将极大地减轻软件制作的工作量。本文介绍的是一种求解模糊控制表的方法。     

面向群组基于身份加密及门限解密技术的可行性研究

每个群组都有区别于其他群组的‘身份’,所以基于身份加密的方案中,可以认为发送方、接受方都可以是一个群组。事实上,有时也很需要以一个群组的身份去加密一个信息传给一个群组或者个人,同时希望是该组织的一些人一起才能共同解密这个信息。文中提出了面向群组的基于身份加密方案中的门限解密思想。     

Bat intelligence search with application to multi-objective multiprocessor scheduling optimization

In this paper, we present the bat intelligence search for the first time. Bat intelligence is a novel and unique heuristic that models two major prey hunting behaviors of bats: (a) utilization of echolocation to observe the environment and (b) employment of constant absolute target direction approach to pursue preys. In order to illustrate the performance of bat intelligence, we implement this heuristic to solve two types of multiprocessor scheduling problems (MSP): single objective MSP and multi-objective MSP. In single objective MSP, we independently solve for minimization of makespan and minimization of tardiness. In multiple objective MSP, these two objectives are optimized simultaneously. In the single objective MSP, on average, the bat intelligence outperformed the list algorithm and the genetic algorithm by 11.12% when solving for minimization of makespan and by 23.97% when solving for the minimization of tardiness. In comparison to the genetic algorithm, the bat intelligence produces better results for the same computational effort. In multiple objective MSP, bat intelligence is combined with normalized weighted additive utility function to generate a set of efficient solutions by varying the weights of importance. The results demonstrate that the bat intelligence finds a set of Pareto optimal solutions on bi-objective optimization of MSP.     

新环保冷媒R410A型高效直流变频压缩机

近年来,空调的使用时间变得越来越长,空调使用中的实际能耗情况越来越受重视.日本在2006年大幅修改空调标准,确定从2010年开始对所有空调采用年度运行效率APF(Annual Per_formance Factor)进行考核.介绍一款适用于高APF空调的新环保冷媒R410A型高效直流变频压缩机.     

基于曲柄摇杆机构的新型六足爬行机器人的设计

六足爬行机器人在理论上可以实现向前向后稳定行走.对驱动足采用了曲柄摇杆机构,将腿放在四杆机构的摇杆上,实现了腿前后摇摆行走.此外,由于是通过连杆曲线图谱选择腿部运动轨迹,从连杆曲线图谱上可以看到,整条曲线都是很平滑的,因此,机器人在行走过程中也会非常稳定,而不至于出现冲击载荷.对六足机器人的行进机构、运动设计与分析、机器人的运动轨迹和六足机器人的控制系统进行了详细阐述.     

Mass spectrometry and natural variations of iron isotopes

Although the processes that govern iron isotope variations in nature are just beginning to be understood, multiple studies attest of the virtue of this system to solve important problems in geosciences and biology. In this article, we review recent advances in the geochemistry, cosmochemistry, and biochemistry of iron isotopes. In Section 2, we briefly address the question of the nucleosynthesis of Fe isotopes. In Section 3, we describe the different methods for purifying Fe and analyzing its isotopic composition. The methods of SIMS, RIMS, and TIMS are presented but more weight is given to measurements by MC-ICPMS. In Section 4, the isotope anomalies measured in extraterrestrial material are briefly discussed. In Section 5, we show how high temperature processes like evaporation, condensation, diffusion, reduction, and phase partitioning can affect Fe isotopic composition. In Section 6, the various low temperature processes causing Fe isotopic fractionation are presented. These involve aqueous and biologic systems.     

星点像二维光强分布的定量测定

本文介绍了测试显微物镜星点像二维光强分布的实验方法、内容有实验原理、用微机进行二维快速离散傅立叶变换。数据拟合及软件系统的设计;并讨论了如何选择测量的方位数及二维离散傅立叶变换的抽样间隔。     

ASC-Ⅱ型自动轴类校直机

本文概述了校直机的应用与其在国内发展过程，介绍了ASC-Ⅱ型自动轴类校直机的开发背景和技术特点。重点叙述自动校直机的工作原理、系统组成以及各部分的功能，并提及自动校直机今后的发展方向。     

分级权限管理在数据库应用系统中的实现

在分布式数据库应用系统中,用户众多又往往采用集中的用户权限管理方式。这种管理方式管理员工作量大,不符合实际的分级管理的工作制度。这里设计了一种分级权限管理的方案,并给出了Delphi7下的实现方法。     

Adaptive Noise Detection and Removal Algorithm Using Local Statistics for Salt-and-Pepper Noise

In this paper,an adaptive noise detection and removal algorithm using local statistics for salt-and-pepper noise are proposed.In order to determine constraints for noise detection,the local mean,variance,and maximum value are used.In addition,a weighted median filter is employed to remove the detected noise.The simulation results show the capability of the propsed algorithm removcs the noise effectively.     

A frequency response model matching method for PID controller design for processes with dead-time

In this paper, a PID controller design method for the integrating processes based on frequency response matching is presented. Two approaches are proposed for the controller design. In the first approach, a double feedback loop configuration is considered where the inner loop is designed with a stabilizing gain. In the outer loop, the parameters of the PID controller are obtained by frequency response matching between the closed-loop system with the PID controller and a reference model with desired specifications. In the second approach, the design is directly carried out considering a desired load-disturbance rejection model of the system. In both the approaches, two low frequency points are considered for matching the frequency response, which yield linear algebraic equations, solution of which gives the controller parameters. Several examples are taken from the literature to demonstrate the effectiveness and to compare with some well known design methods.     

电热烘箱温度控制系统设计

介绍一种主要由镍铬丝加热丝、接触器、铂热电阻和温度控制器构成的电热烘箱温度控制系统。镍铬丝采用星形连接,属于接触器控制。此系统控制精度高,故障率低。     

Auxiliary input design for stochastic subspace-based structural damage detection

This paper considers the problem of auxiliary input design for subspace-based fault detection methods. In several real applications, particularly in the damage detection of mechanical structures and vibrating systems, environment noise is the only input to the system. In some applications, white noise produces low quality output data for the subspace-based fault detection method. In those methods, a residual is calculated to detect the fault based on the output information. However, some modes of the system may not influence the outputs and the residual appropriately if the input is not exciting enough for those modes. In this paper, the method of “rotated inputs” is implemented to excite the system modes. In addition to produce a residual more sensitive to the weak modes, it is possible to detect system order changes due to the fault using the rotated inputs. Simulation results demonstrate the efficiency of injecting the auxiliary input to improve the subspace-based fault detection methodology.     

一种星空背景的运动补偿方法

运动背景补偿技术是提高运动星空背景下弱小目标检测精度的关键技术之一。本文提出了一种基于块匹配与质心提取法相结合的星空背景运动补偿技术。该方法在样本运动参数估计阶段直接剔除异常点;为了减少块匹配过程中每个待匹配位置的运算次数,保持块匹配的精度,又引入了连续排除算法,降低了计算复杂度。实验验证了该方法的有效性和优越性,证明了该方法能有效地提高目标的信噪比并且降低差分残余图像灰度均值。     

基于VB的滚动轴承型号选择设计

在机械设计中需要根据工作条件选用合适的滚动轴承类型和型号,进行组合设计。但在具体设计计算时,其计算量大,过程复杂。鉴于此开发了基于VB的滚动轴承型号选择程序来辅助设计,该程序具有强大的数据处理能力,减少了工作量,提高了工作效率。     

计算机辅助进货质量管理

在一个制造企业的生产制造质量中，包含着相当部分的供应商制造质量。所以企业要确保产品质量，一定要重视对进货的质量管理和控制。本文首先分析了ＩＳＯ９０００国际质量标准对进货质量控制的要求，然后介绍了用ＯＲＡＣＬＥ数据库系统开发的符合ＩＳＯ９０００标准的计算机辅助进货质量管理系统。     

粘结叠片工件外圆加工参数选取的可视化算法

针对粘结叠片工件的结构特点,分析了粘结叠片工件的外圆加工特性,对粘结叠片工件加工过程中的切削用量参数进行理论分析,建立以生产效率为目标的函数模型,应用可视化算法在各种约束条件下寻找其最优的加工参数,使粘结叠片工件能够在加工过程中实现快速而准确地定量各切削用量参数,从而缩短加工时间。以硅钢片黏结叠片工件为例,应用可视化算法,成功加工出了符合要求的圆柱体粘结叠片工件。     

Design of RCS measurement system based on hardgating

In accordance with the measurement requirements of radar cross section(RCS) in the nonstandard outdoor field,a RCS measurement system based on hardware gating was designed.In this paper,firstly the principle of hardware gating based on pulse measurement was introduced.Subsequently,the scheme of RCS measurement system and the design of out-door environment were presented.In the end,measurement results in an outer field were demonstrated.