共查询到20条相似文献，搜索用时 578 毫秒
1.
固定阴极电化学射孔的成型规律研究 总被引：1，自引：0，他引：1
根据电场理论,提出了一种研究固定阴极电化学射孔成型规律的更为严密的处理方法, 且基于这种思路分析了该加工方式下阴极表面电荷密度及加工区电场强度、电流密度、加工速度等在加工过程中的变化规律,建立了加工中间隙变化的数学模型,并给出了相关的实验结果,为这种简易加工方式的合理应用提供了理论依据.,A kind of new idea based on electromagnetic theory is presented, and it is used in research of the shaping law of electrochemical perforation with fixed cathode. The changing laws of the electric field vectors at certain point on the surface of the anode workpiece with machining time, such as the electric field intensity E, the current density j and so on, are introduced. The mathematical model of the perforating velocity is presented, moreover, the experimental result to verify it is given at the end of the paper. 相似文献
2.
To investigate the activities of typical night-migrating birds under the light with various spectral compositions during autumn migration,23 Siberian Rubythroat Luscinia calliope were tested under colorful LED lights with different wavelengths and mixed white at 100 lx.Using behavior response as an indicator,the quantitative relationship between the activity level of test birds and illumination stimulation duration was acquired.It was found that the visible light sensitivity of Siberian Rubythroat was the highest for the 478 nm turquoise and decreased towards the 622 nm red. 相似文献
3.
In this work, a novel morphing machining strategy （MMS） is proposed. In the method, the workpiece is progressively carved out from the stock. Pitfalls in conventional iso-height strategy, such as sharp edges and unevenly distributed left-over materials, are overcome. Moreover, to calculate different levels in the MMS, an energy-based morphing algorithm is proposed. Finally, the proposed strategy is employed in the machining of artificial bone represented by a T-spline surface. The excellent properties of T-spline, such as expressing complex shapes with a single surface, have been well adopted to artificial bone fabri- cation. Computer simulation and the actual machining of the middle finger bone show the feasibility of the proposed strategy. 相似文献
4.
计算机及其网络的发展在改变着人们的经济模式和文化观念,同时对英语教学也产生了巨大的影响,任何一种传统的英语教学方法都是无法同它相比的.过去的英语教学,除了教师在课堂上使用授语外,虽也借助其它手段,如图片、录音带、录象带等,但效果都不理想,而借助计算机(软件)及其网络进行教学则可大大弥补其不足.计算机辅助语言学习已成为或将要成 相似文献
5.
计算机及其网络的发展在改变着人们的经济模式和文化观念,同时对英语学习也产生了巨大的影响。计算机辅助语言学习已成为或将要成为一种新的英语学习模式。一、计算机及其网络在语言学习上的应用计算机辅助教学 CAI(Computer Aided Instruction)是计算机非常重要的应用领域之一,其中计算机辅助语言学习 CALL(Computer Assisted Language 相似文献
6.
《韩山师范学院学报》1996,(4)
《五镇的安娜》是本世纪初英国小说家阿诺德·本内特(Arnold Bennett,1867—1931)的“五镇”系列小说之一。书中叙述了女主公安娜·特尔莱特在与亨利·迈那斯和威利·普赖斯的接触中渐渐地找到了真爱,但最终却履行义务般地选择她自己并不爱的亨利作丈夫。本文着重探讨安娜对这两个男人的感情的双重性以及它所隐含的现实意义。 相似文献
7.
从因特网上,可以获得大量的英语学习和教学方面的信息.为了帮助上网的英语教师和学习英语的学生以及英语爱好者找到并利用好这些信息,笔者对这方面的资源进行了搜寻查找,整理分类,并对网址给予解释说明,以及如何通过电子邮件参加英语学习和教学专题讨论等. 相似文献
8.
The Ethernet passive optical network (EPON) is the next generation of broad-band network technique. A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units (ONUs). This article provides a novel dynamic bandwidth allocation algorithm, i.e. threshold dynamic bandwidth allocation (TDBA), which is based on adaptive threshold, to increase resource utilization. The algorithm uses ONU data-transmitting rate to adjust optical line terminal (OLT) receiving data threshold from an ONU. Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a 10G EPON system. 相似文献
9.
本文在对中小院校Internet应用与需求分析的基础上,给出了适合中小院校的Internet网络教室解决方案。 相似文献
10.
苏丽娜 《广西大学梧州分校学报》1999,(2)
在听力技能的教学中,我们的目的是提供能被学生理解、以内容为中心的、训练目的明确的听力练习,以便提高学生的听力能力。本文提出在选择听力理解练习前应考虑五个方面的内容。 相似文献
11.
高速加工是一种先进制造技术,它可以大大缩短制造周期,提高生产效率;本文重点介绍了高速加工的基本原理,加工特点及主要优势,详细介绍了其在模具工业中的重要作用;并列举实例说明了在模具制造业中该方法是一种值得广泛推广的制造技术。 相似文献
12.
在数控铣削加工中,常遇到工件加工尺寸大于机床加工行程的情况,利用移位加工法可以在一定程度上解决这个问题。以冰箱发泡模为例,对移位加工法在使用中的移位方法选择、加工坐标系设置、零件模型构建、刀具路径设置及加工操作中涉及的关键问题进行了分析研究,并提出了一套实用性较高的加工方案,为中、小企业的数控铣削加工中的具体应用提供相应的指导。 相似文献
13.
This paper proposes novel multiple-mobile-robot collision avoidance path planning based on cooperative co-evolution, which can be executed fully distributed and in parallel. A real valued co-evolutionary algorithm is developed to coordinate the movement of multiple robots in 2D world, avoiding C-space or grid net searching. The collision avoidance is achieved by cooperatively co-evolving segments of paths and the time interval to pass them. Methods for constraint handling, which are developed for evolutionary algorithm, make the path planning easier. The effectiveness of the algorithm is demonstrated on a number of 2D path planning problems. 相似文献
14.
在数控加工过程中,粗加工往往要占去大部分的加工时间.因此,研究基于测量数据点的数控粗加工刀具路径生成方法对于缩短加工时间、提高加工效率具有重要意义.对基于测量数据点的数控粗加工刀位轨迹生成技术的研究状况进行了概括和总结,阐述了直接由点云数据生成粗加工刀位轨迹的关键技术,并指出了各种方法的优缺点. 相似文献
15.
16.
刀具结构创新是实现高效加工的有效途径之一 总被引：1，自引：1，他引：0
徐进 《广东轻工职业技术学院学报》2008,7(4):7-10
刀具结构创新是提高切削效率,实现高效加工的有效手段之一。以切削变形和切削摩擦两个基本问题为出发点,对刀具几何结构进行创新改造,使第Ⅲ变形区中材料的延展变形实现向着低应力区域的多维塑性流动。对外圆车削试件的已加工表面和对刀具检测表明,创新刀具能够有效地降低工件表面粗糙度,提高尺寸精度,使已加工表面层中保持残余压应力;减轻刀具的磨损,提高刀具耐用度。 相似文献
17.
18.
对模具自由曲面数控加工工艺的规划方法进行研究,建立了适于模具自由曲面数控加工的工艺规划。针对某模具的自由曲面,根据工艺规划得到的自由曲面加工工艺参数,在UG NX 8.0中设定各项参数,生成刀具加工路径,进行仿真加工,获得其数控加工代码。实例加工证明,该规划方法使模具加工工艺信息得到了最大程度地有效利用,降低了模具设计的工作量,提高了生产效率,降低了设计成本。 相似文献
19.
Calculation method of ship collision force on bridge using artificial neural network 总被引：1，自引：0，他引：1
Ship collision on bridge is a dynamic process featured by high nonlinearity and instantaneity. Calculating ship-bridge collision force typically involves either the use of design-specification-stipulated equivalent static load, or the use of finite element method （FEM） which is more time-consuming and requires supercomputing resources. In this paper, we proposed an alternative approach that combines FEM with artificial neural network （ANN）. The radial basis function neural network （RBFNN） employed for calculating the impact force in consideration of ship-bridge collision mechanics. With ship velocity and mass as the input vectors and ship collision force as the output vector, the neural networks for different network parameters are trained by the learning samples obtained from finite element simulation results. The error analyses of the learning and testing samples show that the proposed RBFNN is accurate enough to calculate ship-bridge collision force. The input-output relationship obtained by the RBFNN is essentially consistent with the typical empirical formulae. Finally, a special toolbox is developed for calculation effi- ciency in application using MATLAB software. 相似文献
20.
针对目前磨料流加工存在的问题,本文设计了一种新型的细孔磨料流加工机床.从浆料流变学的角度,推导出磨料流加工中壁面剪应力的数学表达式.结合数学表达式对其加工原理进行了分析,得出新型磨料流加工机床研磨内孔的3种主要方式.相比只存在粘性剪应力的研磨加工,新型研磨机床采用复合粘性剪应力和雷诺剪应力的工作方式,其加工效率得到明显提高.最后给出细孔磨料流加工机床在喷油器体内孔研磨加工的应用实例. 相似文献