Subscript textNd can obviously improve the mechanical properties of spray deposited 1%Nd, 2%Nd extruded and heat treatment alloy. Nd solid solution in α-Mg matrix lead to the hardness of 2%Nd spray deposited magnesium alloy extruded is higher than that of after heat treatment. A large number of Al2Nd particles precipitation is the key factor to the highest hardness value(139.4Hv) in 2%Nd magnesium alloy after 370°C/3h+205°C/24h heat treatment. Moreover, the precipitation of Al2Nd accompany with Al2Ca and Al-Mn phase increased.

Too much experience is relied on by traditional method to refine equipment,and other problems may be also caused by changes in one part of the equipment.The process of equipment modification is time-consuming and expensive,and sometimes it needs several repeat to reach the goal.By using the idea of reverse design,combined with virtual prototyping technology,a new method which could accomplish the equipment modification was put forward.By an example of modification to coil car of copper strip,the technique to build a CAD model of this equipment quickly,method to deal with constrains of a model to achieve a more precise result and strategy to choose the best optimal value were introduced.Rationality of this model is verified.

Magnesium alloy of 6% Ca and 9% Ca, produced by spray deposited method, was heat treated at different solid-solution and the same aging treatment. The microstructure and hardness were analyzed by SEM, XRD and HV tester. The experimental results showed that Ca can make the spray deposited magnesium matrix grains refine uniformly, the second phase particle Al2Ca and CaZn are formed and the hardness value increase. With the rise of solution temperature, the hardness of 6%Ca and 9%Ca magnesium alloy rise firstly and then fall, and the hardness value of 6%Ca increase to the highest 121Hv and 9%Ca increase to the highest 128Hv after 370°C/3h+205°C/24h.

The structure and dynamic performance of printing cylinder has very important influence on working characteristics of printing machine.In order to improve the quality of printing machine,modal analysis of the printing cylinder was carried out in two different cases by ANSYS on the basis of the existing optimized design.The intrinsic frequency and vibration model of printing cylinder was obtained.The purpose was to provide reliable reference for further structure analysis of the printing cylinder.

Mg-Al-Zn alloys of 2% Nd and without Nd, which produced by spray deposited method, were heat treated at different solid-solution and the same aging treatment. The microstructure and hardness were analyzed by SEM , XRD and HV tester. The experimental results showed that Nd can make the spray deposited magnesium matrix grains tiny evenly, formed the second phase particle Al3Nd, and increased the hardness value. With the rise of solution temperature, the hardness of without Nd magnesium alloy show that rise firstly and then fall rapidly, but the 2%Nd magnesium alloy hardness increase all the time with the rising of solution temperature, and the hardness value increase sharply to the highest 181Hv after 448°C/3h+205°C/24h.

A new motion function scheme of CNC grinding machine is proposed in this paper in order to satisfy processing requirements for different surface of the work-piece.The paper,firstly,analyzes the motion function of CNC grinding machine,and establishes the morphological matrix of it to get some different structure scheme.Then,the optimal structure scheme is obtained by applying the fuzzy comprehensive evaluation method.

Ball screw is an important part in the machine tool feeding system. This paper researches on the ball screw, establishes the 3D virtual numerical model by Pro/engineer. Modal analysis of ball screw is carried out in three different cases by ANSYS, then gets the intrinsic frequency and vibration model of ball screw. It provides reliable reference for further structure analysis of ball screw.

A measurement method of the large-aperture aspheric surfaces with the ronchi wonderful legal quantity the new technology was proposed. The large-aperture aspheric surfaces mirror's processing surface was taken as the example of study. The large-aperture aspheric surfaces examination system was designed. This system was composed by the CCD camera, the He-Ne laser, the ronchi grating, the microcomputer. By using the large aperture aspheric surfaces examination system, the face shape was measured, when the apex radius of curvature was 638. 69 mm, the half light culiker was 315 mm. The optical element standard deviation and the valley value measurement were presented. The results show that based on the geometry priciple of the Ronchi, the method by using the CCD photograpg system to measure the large aperture aspheric surface has the advantage of high precision.

<正>鄂尔多斯军分区党委机关组织开展作风纪律教育整顿,引导机关干部围绕过分依赖网络指导、忽视深入一线帮建的问题开展大讨论,使机关干部进一步强化了岗位意识、责任意识,激发了抓基层建基层的积极性和创造性。(王继东)河北承德县人武部在当地政府电子政务网开设了国防教育网页,并在县广播站、电视台开设国防教育专题栏目,宣传国防知识、法规和关心支持国防建设的先进典型,推动了全民国防教育的深入开展。(李显富)

Ground holding strategy is the main component of air traffic flow management(ATFM),it can contribute for saving flight costs and improving safety level.A multi-index integer programming model is presented for the static ground-holding policy problem in air traffic network,which consists of two indices: minimizing the total delay time and the total delay cost of all the flights.The capacity of specific airspace and the maximum delay time of each flight are taken as the constraints of the model.Considering the computational complexity for solving the mathematical model,simulated annealing algorithm based on the natural principle is employed to find the nearly-optimal solution of the ground-holding policy problem.A numerical example is given to demonstrate the accuracy,feasibility and effectiveness of analysis method.

系统形式化分析(system formal analysis)是近些年在航空系统研发中所应用的一种安全评价方法.原理是运用数学建模,对研发航空软件系统所有假设条件下的输入集元素的有效性及系统算法逻辑性进行验证,其本质是假设合理性及算法正确性的数学检验,可弥补传统的模拟、试飞等安全评价手段的局限性,并将逐步成为未来航空系统研发中安全评价的重要步骤和手段.介绍了系统形式化分析在机载横向间隔信息系统(AILS)研发中的安全评价应用,通过假设检验、建模验证AILs告警算法等,给出了该系统的安全性论断并提出了相关建议.

未来10年,全球空管系统将引入更多自动化技术已成为不争的事实。目前,空管自动化正处在一个多元化的发展阶段,自动化技术在空管领域能走多远,我们将拭目以待。

This paper used the DORA methodology to estimate the sector capacity.This method was based on the quantification of the workload of a radar controller position. It was possibly through time measuring of all observed action categories.