板坯结晶器铜板锥度的研究

以实测结晶器铜板温度计算的热流量作边界条件,采用有限元方法,建立结晶器内凝固传热方程,对凝固传热方程进行了离散化,利用ANSYS商业软件进行求解,得到凝固坯壳的应力、应变情况,探讨影响结晶器锥度的因素。     

机械密封环隔离体法有限元分析

针对动静环整体建模繁琐及求解计算量大的缺点,采用隔离体法思路对动静环分开建模、加载和计算,将计算结果通过数值方法加以整合,并从中找到与实际整体运行过程中相符的计算结果以便于进行推断,具有较好的可行性和可取性。     

一种通用的微波六端口反射计研究

在微波阻抗与网络参量测量方面,反射计应用举足轻重;在通过对反射计的S参数进行分析的基础上,介绍了一个六端口反射计的通用设计方案,并确立了设计指标;依据设计指标,利用LSBRM方法、频移法、渐变线分割的方法和数值积分等算法完成了六端口反射计的设计;最后通过实际的反射计测量检验验证其满足设计指标的要求.     

Self-Efficacy and Compliance With Benzodiazepine Taper in Older Adults With Chronic Insomnia.

Better understanding of compliance with BZD taper is warranted. Compliance with a taper program and perceived self-efficacy (SE) in being able to comply with hypnotic reduction goals was monitored weekly in 52 older adults (mean age: 63.0 years) with chronic insomnia (average duration: 21.9 years) who underwent a 10-week physician-supervised medication tapering. One group received cognitive- behavior therapy for insomnia during discontinuation, whereas the other did not. Compliant patients showed higher SE ratings at Weeks 6, 8, 9, and 10. Medication-free patients at the end of the treatment also reported higher mean SE ratings at those 4 weeks. Differences remained significant when withdrawal symptoms and sleep efficiency were controlled for. These results have important clinical implications because SE may indicate key time points when patients are experiencing more difficulty during discontinuation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

弧齿锥齿轮冷挤压齿形凹模使用寿命

分析了弧齿锥齿轮冷挤压齿形的主要失效形式和失效原因,针对不同的失效形式,从模具材料、结构、热处理方法和加工方法等方面提出相应的解决措施,有效延长了模具使用寿命。     

大锥度薄壁铝罐成形技术研究

大锥度铝罐是指铝罐口部半锥角大于40°.根据大锥度铝罐成形特点,提出了以多道次圆弧缩口和滚压加工相结合的成形工艺,开发了与工艺相应的新型模具.该工艺根据零件壁薄、半锥角大的特点,采用在圆锥模口部引进圆弧的结构.试验结果表明,该工艺是有效的,能够加工出合格的零件.     

"穿地龙"机器人总体方案分析与研究

通过对国内外地下管线非开挖技术发展的分析,设计了应用于中、小管线铺设的“穿地龙”机器人,根据总体方案的要求,确定由气动二冲击机构、转向机构测试部件组成的本体方案,分析锥形钻头的旋转空间,针对机器人在土中的实际运行,确定机器人位置姿态、温度及压力等物理量的测量方案,最后,采用微机操作实现自动控制。     

激光靶光电探测系统优化设计

介绍了一种新颖的激光光幕靶弹丸速度测量系统.系统由半导体激光光源准直、扩束形成原向反射屏反射后形成一定直径的反射光斑,光斑经用以扩大接收面积的光纤光锥会聚后由光电探测器接收.给出了苏格兰片反射率测试的方法和测试结果以及3 mm飞行物体的过靶波形.试验结果表明,采用原向反射屏和光纤光锥构成的光电探测系统具有较高的信噪比和灵敏度.     

Relationship between rheological manufacturing process and optical performance of optical fiber coupler

Through theoretical analysis and experiments, the viscoelastic mechanical model of optical fiber coupler in the process of fused biconical taper was established, and the numerical analysis in non-uniform temperature field was made. The results show that the rheological parameters, such as drawing speed and fused temperature, have a tremendous influence on stress distribution and performance of optical fiber coupler, especially the influence of fused temperature. The change of fused temperature by 5 ℃ can lead to the change of the maximum stress by 30% and stress difference by 20% in the same cross section. The change of temperature gradient by 3% can result in the change of stress difference by 90%. In the present condition of rheological technology, rheological defects such as crystallizations and microcracks are easy to generate in the optical fiber coupler.     

240Mbit/s直线运动型无线光通信系统研究

详细分析了直线轨道上运动通信的特点,设计和研制了一种具有双向收发功能的直线运动型无线光通信系统。该系统主要包括1 550 nm半导体激光器、高灵敏度PIN光探测器、球面单透镜式光发射天线和实心光锥耦合式光接收天线等关键部件。130 m运动工作距离的系统性能测试结果表明,在3.5 m/s最高运动速度、240Mbit/s通信传输速率下,运动中的数据丢帧率为零,以太网和视频指标均满足实际应用要求,系统适用于存在直线运动轨道的无线光通信场合。