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挤管用螺旋芯模机头内熔体流动分析 被引量:3
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作者 毛维友 汪映寒 林师沛 《高分子材料科学与工程》 EI CAS CSCD 北大核心 1992年第4期99-107,共9页
本文以B.Procter的简化模型(方法Ⅰ)为基础,考虑流动指数与剪切速率的关系(方法Ⅱ)和垂直于轴的截面上的压力平衡(方法Ⅲ),用迭代法分配计算单元的轴向和沿螺旋流道方向的体积流率。编制了模拟螺旋芯模机头内熔体流量、压力降和剪切速... 本文以B.Procter的简化模型(方法Ⅰ)为基础,考虑流动指数与剪切速率的关系(方法Ⅱ)和垂直于轴的截面上的压力平衡(方法Ⅲ),用迭代法分配计算单元的轴向和沿螺旋流道方向的体积流率。编制了模拟螺旋芯模机头内熔体流量、压力降和剪切速率分布的计算机程序。模拟结果表明,根据漏流分布曲线的特性选择几何参数的螺旋芯模机头对熔体的分配效果不受更换物料和改变机头温度及挤出速率的影响。用高密度聚乙烯进行挤管实验时测定的机头压力降和管材壁厚偏差介于用方法Ⅱ和方法Ⅲ模拟结果之间,实验测定结果与用方法Ⅰ模拟结果的差别最大。高密度聚乙烯管的内、外表层的结晶不同,其差别随挤管时的牵引速度的提高而降低。 展开更多
关键词 模机头 塑料 挤管 熔体 流动
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衣架式机头口模设计公式的修正探讨 被引量:3
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作者 杨广军 朱世杰 +2 位作者 黄醒春 申长雨 陈静波 《塑料科技》 CAS 北大核心 2005年第4期46-50,共5页
基于表征值方法和熔体等压线平行于模唇这一流动模型,对衣架式机头口模进行了流动分析,并发现了文献[1]提出的口模设计公式中的一个缺陷,即计算的扇形狭缝区域与歧管发生了分离,针对该缺陷给出了修正公式。
关键词 挤出 CAE 流道分配系统 衣架式机头
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BMC推出可变形的口模环
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作者 杨中文 《国外塑料》 2005年第7期52-52,共1页
关键词 机头 可变形 BMC 推出 挤出吹塑 生产制造 有限公司 控制器件 优化分布
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微轮廓挤出成型研究 被引量:3
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作者 王洪 傅志红 Yao Donggang 《工程塑料应用》 CAS CSCD 北大核心 2009年第9期49-51,共3页
在毛细管流变仪上对微轮廓的挤出成型过程中的形变进行了实验研究,所采用的微轮廓口模孔分别为三叶形和椭圆形,试验原材料为纤维级聚丙烯。结果表明,在微轮廓的挤出成型中,挤出物轮廓形状发生了明显的变化,微轮廓尺寸随挤出速度的增加... 在毛细管流变仪上对微轮廓的挤出成型过程中的形变进行了实验研究,所采用的微轮廓口模孔分别为三叶形和椭圆形,试验原材料为纤维级聚丙烯。结果表明,在微轮廓的挤出成型中,挤出物轮廓形状发生了明显的变化,微轮廓尺寸随挤出速度的增加而增大,随挤出温度的升高而增大,随拉伸速度的增加而减小;采用水冷却有利于减小形变;三叶形轮廓的叶片在宽度方向的形变要远大于长度方向,椭圆形轮廓的形变在短轴方向大于长轴方向。 展开更多
关键词 微挤出 聚合物微加工 形变 机头
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双螺杆挤出机及其理论基础(连载之三)(连载之四) 被引量:4
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作者 朱复华 《塑料科技》 CAS 1982年第2期23-41,共19页
本部分是全文六个部分中数学概念应用最多的部分,建议对高等数学感到困难的读者,可只着重于理解从数学分析中得到的结论,而不必深究方程的推导过程。
关键词 双螺杆挤出机 漏流 压力梯度 牵引流 压力流 螺棱间隙 螺槽 机头 剪切速率 剪切率
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PVC螺旋管的生产及改进
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作者 王玫瑰 《现代塑料加工应用》 CAS 2003年第6期33-34,共2页
介绍了PVC螺旋管生产的方法及存在的问题 ,通过分析 ,采用了在配方上减少硬料中的外润滑剂、共混改性和机头口模处进行改进的办法 。
关键词 配方 聚氯乙烯螺旋管 生产工艺 原料 润滑剂 机头 粘接强度
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耐高温带状电缆 被引量:1
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作者 钱科 《电线电缆》 2016年第4期25-29,40,共6页
带状电缆,一类是以聚氯乙烯绝缘排线等为代表的普通带状电缆;另一类是以氟塑料绝缘高温排线等为代表的耐高温带状电缆。介绍了带状电缆的基本种类、性能参数,以及目前的研发生产状况。依据挤管式(改进型)一次挤出成型技术研制YDFR系列... 带状电缆,一类是以聚氯乙烯绝缘排线等为代表的普通带状电缆;另一类是以氟塑料绝缘高温排线等为代表的耐高温带状电缆。介绍了带状电缆的基本种类、性能参数,以及目前的研发生产状况。依据挤管式(改进型)一次挤出成型技术研制YDFR系列高温带状电缆的成功经验,着重介绍了YDFR系列高温带状电缆的基本性能,挤出机机头及模芯、模套的设计,生产工艺控制,以及高温带状电缆的相关技术要点。 展开更多
关键词 氟塑料绝缘 耐高温带状电缆 带状电缆性能 机头芯、套设计 工艺控制
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聚醚醚酮的成型加工(下) 被引量:2
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作者 陶国源 《广东塑料》 2006年第3期30-33,共4页
关键词 成型加工 聚醚醚酮 表面光洁度 机头 缝隙式 流线形 熔体 流道
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Numerical simulation of cyclic behavior of double sand lenses and corresponding liquefaction-induced soil settlement 被引量:2
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作者 Y.PASHANG PISHEH S.M.MIR MOHAMMAD HOSSEINI 《Journal of Central South University》 SCIE EI CAS 2010年第3期593-602,共10页
A two-dimensional numerical model was used to explain the liquefaction mechanism of double sand lenses and the corresponding soil deformation due to the cyclic loading. Moreover, in order to investigate the influences... A two-dimensional numerical model was used to explain the liquefaction mechanism of double sand lenses and the corresponding soil deformation due to the cyclic loading. Moreover, in order to investigate the influences of the soil characteristics and input loading data a parametric study was carried out on the essential parameters affecting the soil settlement, and so the variation of these parameters with the corresponding displacements was mainly examined. At last, the results obtained from the numerical analyses of double sand lenses and a continuous sand layer with similar characteristics were compared with those of an estimating method proposed by ISHIHARA and YOSHIMINE. The comparisons show that the settlements due to liquefaction of the continuous sand layer in both numerical and the estimating method are in a good agreement with and are obviously greater than those of double sand lenses. 展开更多
关键词 LIQUEFACTION ground failure cyclic loading double sand lenses DEFORMATION
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浅析塑料型材生产中的弯曲现象
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作者 潘国玉 《塑料挤出》 2002年第4期23-24,共2页
关键词 弯曲现象 塑料异型材 型材生产 挤出工艺 机头 出料 定型 原料配方
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2D Model of Guide Vane for Low Head Hydraulic Turbine: Analytical and Numerical Solution of Inverse Problem 被引量:2
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作者 Romuald Puzyrewski Zbigniew Krzemianowski 《Journal of Mechanics Engineering and Automation》 2014年第3期195-202,共8页
Low-head hydraulic turbines are the subjects to individual approach of design. This comes from the fact that hydrological conditions are not of a standard character. Therefore, the design method of the hydraulic turbi... Low-head hydraulic turbines are the subjects to individual approach of design. This comes from the fact that hydrological conditions are not of a standard character. Therefore, the design method of the hydraulic turbine stage has a great importance for those who may be interested in such an investment. As a first task in a design procedure the guide vane is considered. The proposed method is based on the solution of the inverse problem within the flame of 2D model. By the inverse problem authors mean a design of the blade shapes for given flow conditions. In the paper analytical solution for the simple cylindrical shape of a guide vane is presented. For the more realistic cases numerical solutions according to the axis-symmetrical model of the flow are also presented. The influence of such parameters as the inclination of trailing edge, the blockage factor due to blade thickness, the influence of loss due to dissipation are shown for the chosen simple geometrical example. 展开更多
关键词 Hydraulic turbines inverse problem in a turbomachinery guide vanes design.
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Numerical Simulation of Multi-Directional Random Wave Transformation in a Yacht Port 被引量:3
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作者 JI Qiaoling DONG Sheng +1 位作者 ZHAO Xizeng ZHANG Guowei 《Journal of Ocean University of China》 SCIE CAS 2012年第3期315-322,共8页
This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and break... This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. This numerical model is improved by 1) introducing Wen's frequency spectrum and Mitsuyasu's directional function, which are more suitable to the coastal area of China; 2) considering energy dissipation caused by bottom friction, which ensures more accurate results for large-scale and shallow water areas; 3) taking into account a non-linear dispersion relation. Predictions using the extended wave model are carried out to study the feasibility of constructing the Ai Hua yacht port in Qingdao, China, with a comparison between two port layouts in design. Wave fields inside the port for different incident wave directions, water levels and return periods are simulated, and then two kinds of parameters are calculated to evaluate the wave conditions for the two layouts. Analyses show that Layout I is better than Layout II. Calculation results also show that the harbor will be calm for different wave directions under the design water level. On the contrary, the wave conditions do not wholly meet the requirements of a yacht port for ship berthing under the extreme water level. For safety consideration, the elevation of the breakwater might need to be properly increased to prevent wave overtopping under such water level. The extended numerical simulation model may provide an effective approach to computing wave heights in a harbor. 展开更多
关键词 random wave diffraction energy balance equation numerical simulation yacht port
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THE PHYSICAL MODEL AND MATH MODEL OF CONTACT FAILURE ON SMALL CURRENT CONTACTS UNDER MECHANICAL ACTIONS
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作者 郭凤仪 刘玉珍 +1 位作者 赵然 王其平 《Journal of Coal Science & Engineering(China)》 1998年第2期73-77,共5页
Based on the experimental results of the references [1] and [2], i. e., the contact resistance increases due to the contaminants formed on contact surface with the operating cycles,the physical model and math model of... Based on the experimental results of the references [1] and [2], i. e., the contact resistance increases due to the contaminants formed on contact surface with the operating cycles,the physical model and math model of contact failure on small current contacts under mechanical actions are proposed through deep theoretical analysis in this paper. 展开更多
关键词 contact resistance contact failure CONTAMINANTS physical model and math model fretting CORROSION
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Mechanochemical Coupling of Kinesin Studied with a Neck-Linker Swing Model
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作者 LI Ming SHU Yao-Gen OU-YANG Zhong-Can 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期1143-1148,共6页
A neck-linker swing model has been proposed in this work to investigate the mechanochemical coupling of kinesin. The difference between force-velocity curves given by force clamp and fixed trap respectively has been s... A neck-linker swing model has been proposed in this work to investigate the mechanochemical coupling of kinesin. The difference between force-velocity curves given by force clamp and fixed trap respectively has been satisfactorily interpreted by this model. The study implies that ADP releasing and ATP hydrolysis are much less forcedependent in force clamp experiments than that in fixed trap experiments in the regime of moderate loading force, which might be a consequence of the delayed response of servo system in force clamp experiments. 展开更多
关键词 KINESIN neck-linker swing force clamp fixed trap
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Quantifying of Paraplegic Patient Facial Agitation Based on Fuzzy k-NN
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作者 Muhammad Naufal Bin Mansor Azrini Binti Idris +2 位作者 Sazali Yaacob Ramachandran Nagaraj an Hariharan Muthusamy 《Computer Technology and Application》 2011年第1期24-28,共5页
A non-specific symptom of one or more physical, or psychological processes in which screaming, shouting, complaining, moaning, cursing, pacing, fidgeting or wandering pose risk or discomfort, become disruptive or unsa... A non-specific symptom of one or more physical, or psychological processes in which screaming, shouting, complaining, moaning, cursing, pacing, fidgeting or wandering pose risk or discomfort, become disruptive or unsafe or interfere with the delivery of care are called agitation. Individuals in agitation manifest their condition through "pain behavior", which includes facial expressions. Clinicians regard the patient's facial expression as a valid indicator for pain and pain intensity. Hence, correct interpretation of the facial agitation of the patient and its correlation with pain is a fundamental step in designing an automated pain assessment system. Computer vision techniques can be used to quantify agitation in sedated patients in Intensive Care Unit (ICU). In particular, such techniques can be used to develop objective agitation measurements from patient motion. In the case of paraplegic patients, whole body movement is not available, and hence, monitoring the whole body motion is not a viable solution. Hence in this case, the author measured head motion and facial grimacing for quantifying facial patient agitation in critical care based on Fuzzy k-NN. 展开更多
关键词 AGITATION fuzzy k-NN intensive care unit (ICU) paraplegic.
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A Self-Position Estimation Algorithm for Multiple Mobile Robots Using Two Omnidirectional Cameras and an Accelerometer
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作者 Kosuke Sasahara Akinori Nagano Zhi-Wei Luo 《Journal of Mechanics Engineering and Automation》 2013年第4期189-196,共8页
This paper proposes a self-position estimate algorithm for the multiple mobile robots; each robot uses two omnidirectional cameras and an accelerometer. In recent years, the Great East Japan Earthquake and large-scale... This paper proposes a self-position estimate algorithm for the multiple mobile robots; each robot uses two omnidirectional cameras and an accelerometer. In recent years, the Great East Japan Earthquake and large-scale disasters have occurred frequently in Japan. From this, development of the searching robot which supports the rescue team to perform a relief activity at a large-scale disaster is indispensable. Then, this research has developed the searching robot group system with two or more mobile robots. In this research, the searching robot equips with two omnidirectional cameras and an accelerometer. In order to perform distance measurement using two omnidirectional cameras, each parameter of an omnidirectional camera and the position and posture between two omnidirectional cameras have to be calibrated in advance. If there are few mobile robots, the calibration time of each omnidirectional camera does not pose a problem. However, if the calibration is separately performed when using two or more robots in a disaster site, etc., it will take huge calibration time. Then, this paper proposed the algorithm which estimates a mobile robot's position and the parameter of the position and posture between two omnidirectional cameras simultaneously. The algorithm proposed in this paper extended Nonlinear Transformation (NLT) Method. This paper conducted the simulation experiment to check the validity of the proposed algorithm. In some simulation experiments, one mobile robot moves and observes the circumference of another mobile robot which has stopped at a certain place. This paper verified whether the mobile robot can estimate position using the measurement value when the number of observation times becomes 10 times in n/18 of observation intervals. The result of the simulation shows the effectiveness of the algorithm. 展开更多
关键词 Multiple mobile robots omnidirectional cameras self-position estimation algorithm
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