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等熵轻质活塞风洞中活塞质量对匹配压力振荡的影响 被引量:1
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作者 李立人 孔繁琳 《实验力学》 CSCD 北大核心 2003年第4期513-519,共7页
等熵轻质活塞风洞的管道中被压缩的气体是作为实验段的气源.在实验阶段,要求其压力维持恒值,称此压力为匹配压力.这一条件只有在忽略活塞质量的理想情况下才可实现.本文研究在实际情况下,即考虑活塞质量时,质量对匹配压力振荡的影响,从... 等熵轻质活塞风洞的管道中被压缩的气体是作为实验段的气源.在实验阶段,要求其压力维持恒值,称此压力为匹配压力.这一条件只有在忽略活塞质量的理想情况下才可实现.本文研究在实际情况下,即考虑活塞质量时,质量对匹配压力振荡的影响,从而得出活塞质量的选择范围. 展开更多
关键词 等熵轻质活塞 风洞实验 活塞质量 匹配压力 振荡 体积流率
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铝活塞毛坯铸造质量攻关技术服务
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《内燃机配件》 2004年第5期17-17,共1页
关键词 内燃机 活塞 毛坯铸造 活塞质量 加工质量
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活塞压力计稳定性研究 被引量:5
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作者 张国春 李燕华 +2 位作者 闫小克 悦进 王金库 《计量技术》 2007年第12期40-43,共4页
依据活塞压力计工作原理,从活塞和砝码质量的稳定性,活塞有效面积稳定性,重力加速度稳定性三方面分析了其对活塞压力计稳定性影响。研究结果表明:作为活塞压力计,重力加速度量值变化很小,可以忽略;而砝码与活塞质量及其有效面积对活塞... 依据活塞压力计工作原理,从活塞和砝码质量的稳定性,活塞有效面积稳定性,重力加速度稳定性三方面分析了其对活塞压力计稳定性影响。研究结果表明:作为活塞压力计,重力加速度量值变化很小,可以忽略;而砝码与活塞质量及其有效面积对活塞压力计稳定性影响较大。 展开更多
关键词 活塞压力计 稳定性 有效面积 砝码与活塞质量
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多品种变批量柔性活塞生产线的设计与分析
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作者 张宝国 《电子世界》 2018年第20期16-16,21,共2页
导语:文章针对活塞多品种变批量生产模式特点和现有生产线现状,对柔性活塞生产线进行了设计和分析,对柔性活塞生产线的的关键技术和关键参数进行了分析和验证。随着汽车工业的发展,对内燃机活塞品种的需求越来越多,对活塞质量要求也越... 导语:文章针对活塞多品种变批量生产模式特点和现有生产线现状,对柔性活塞生产线进行了设计和分析,对柔性活塞生产线的的关键技术和关键参数进行了分析和验证。随着汽车工业的发展,对内燃机活塞品种的需求越来越多,对活塞质量要求也越来越高,传统活塞加工生产线因身特点的限制,越来越难以适应市场对活塞的需求:多品种、高精度。面对这一新的要求,迫切需要我们改变传统活塞流水线的布线形式、加工方式来快速适应市场的需求。设计一种柔性的能快速适应市场品种、批量变化的生产线及其设备成为活塞制造企业迫切需要解决的问题之一。 展开更多
关键词 加工生产线 活塞质量 多品种 柔性 设计 生产模式 关键参数 汽车工业
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过滤技术在汽车铝活塞金属型铸造生产中的应用 被引量:3
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作者 朱利民 朱祯 《铸造技术》 CAS 北大核心 2008年第4期559-561,共3页
关键词 铸造生产 过滤技术 活塞 金属型 应用 汽车 机械负荷 活塞质量
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铝活塞铸造缺陷分析改进 被引量:2
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作者 王云峰 王剑 +3 位作者 李晓婧 邓士东 商玉猛 高青 《金属加工(热加工)》 2018年第8期71-73,共3页
简要介绍了镶耐磨镶圈活塞无损检测废品率高的原因和影响因素,并以一个典型产品为例说明浇道设计对活塞质量的影响。
关键词 耐磨镶圈 无损检测 浇道设计 活塞质量
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活塞模具的工艺改进
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作者 刘向芹 《金属加工(热加工)》 2015年第17期23-24,共2页
1.概述活塞是发动机的"心脏",作为活塞加工的第一步,铸造质量的好坏直接关系到活塞最终产品质量的结果,模具是活塞成形的前提和基础,模具质量与活塞质量息息相关,模具的制造缺陷极易造成大批量活塞废品损失。因此,控制活塞质量需从铸... 1.概述活塞是发动机的"心脏",作为活塞加工的第一步,铸造质量的好坏直接关系到活塞最终产品质量的结果,模具是活塞成形的前提和基础,模具质量与活塞质量息息相关,模具的制造缺陷极易造成大批量活塞废品损失。因此,控制活塞质量需从铸造开始。为满足轿车活塞质量的严格要求,同时为改变传统手工模具的工作方式,提高生产效率,我公司从德国引进了MG20铸造机,主要用于生产轿车活塞。 展开更多
关键词 活塞模具 工艺 活塞质量 铸造质量 生产效率 活塞加工 产品质量 模具质量
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气动矛性能的计算机仿真研究 被引量:5
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作者 张志兵 刘静 祝世平 《地质与勘探》 CAS CSCD 北大核心 2001年第2期77-79,共3页
运用计算机仿真方法 ,以YH75型气动矛为例 ,对影响气动矛性能的因素进行了分析 ,探讨了气动矛设计参数的选取原则。
关键词 气动矛 计算机仿真 性能分析 系统压力 活塞质量 气垫体积
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基于Matlab/Simulink的直线发动机性能仿真研究 被引量:12
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作者 王哲 叶晓倩 邓俊 《内燃机工程》 EI CAS CSCD 北大核心 2009年第1期69-73,共5页
建立了直线发动机的动力学及燃烧模型,通过Matlab/Simulink建模仿真,研究了直线发动机的运行特性,并定性分析了各主要设计、控制参数对系统性能的影响。研究结果表明:直线发动机的活塞组件质量直接影响系统输出性能,且在3.5~4 kg范围内... 建立了直线发动机的动力学及燃烧模型,通过Matlab/Simulink建模仿真,研究了直线发动机的运行特性,并定性分析了各主要设计、控制参数对系统性能的影响。研究结果表明:直线发动机的活塞组件质量直接影响系统输出性能,且在3.5~4 kg范围内输出功率较高;而对点火位置和喷油量的实时调节则是直线发动机控制的关键。 展开更多
关键词 内燃机 直线发动机 MATLAB/SIMULINK 活塞组件质量 实时调节
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低速射流元件控制的高能液动锤研究 被引量:5
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作者 彭枧明 殷其雷 +1 位作者 赵志强 王维 《石油机械》 北大核心 2010年第3期1-4,89,共4页
为解决常规射流元件受钻井液冲蚀而过早失效问题和满足高效碎岩钻进对冲击功的要求,设计了SC71B型新一代液动锤试验样机,并通过试验和数值模拟研究了活塞冲锤质量对射流元件临界流速的影响。试验结果表明,配用常规质量的活塞冲锤时该低... 为解决常规射流元件受钻井液冲蚀而过早失效问题和满足高效碎岩钻进对冲击功的要求,设计了SC71B型新一代液动锤试验样机,并通过试验和数值模拟研究了活塞冲锤质量对射流元件临界流速的影响。试验结果表明,配用常规质量的活塞冲锤时该低速型射流元件实测临界流速为21.83m/s,不到以往实测最低值的1/2;当活塞冲锤质量较常规增加5倍时,冲击功较常规增加40倍以上,其临界流速仍不大于以往实测最低值。活塞冲锤质量对临界流速和冲击功影响的CFD动态数值模拟分析结果与实测结果吻合。该研究结果对研制油气钻井用长寿命高能射流式液动锤有重要借鉴意义。 展开更多
关键词 液动锤 射流元件 临界流速 工作寿命 活塞冲锤质量 冲击功
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The Pulmonary Embolism Nursing Intervention Implementation
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作者 LiXin Jiye Yangfengli Zhoulichun 《International English Education Research》 2014年第2期64-66,共3页
Objective: Explore the pulmonary embolism nursing intervention implementation.The evaluation of the overall nursing applied to the effect of patients with pulmonary embolism. Methods: A retrospective analysis the da... Objective: Explore the pulmonary embolism nursing intervention implementation.The evaluation of the overall nursing applied to the effect of patients with pulmonary embolism. Methods: A retrospective analysis the data of the nine cases who with pulmonary embolism in our hospital from January 2010 to May 2012, to assess the overall nursing experience. During the period, nurses do a sound basis for nursing, and strengthen the observation close monitoring of adverse reaction and well before discharge health guidance. Results: through the timely diagnosis, standard treatment and careful nursing on a patient ofholistic nursing intervention, thus, reducing the recurrence of pulmonary embolism, to promote the rehabilitation of patients with pulmonary embolism, and effectively reduce mortality. Conclusion: The application of the overall care for patients with pulmonary thromboembolism to provide quality care services, reduce the incidence of acute pulmonary thromboembolism, improve the quality of care and patient satisfaction. Effectively improve patients' quality of life. 展开更多
关键词 Pulmonary embolism Nursing intervention
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FACTORS ASSOCIATED WITH QUALITY OF LIFE IN ACUTE EXACERBATION OF COPD
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作者 曹振英 Ng Tze Pin 《Journal of Shanghai Second Medical University(Foreign Language Edition)》 2005年第2期116-122,共7页
Objective To measure the QOL in patients with AECOPD and the frequency of potential risk factors, and to evaluate the association of risk factors with poor QOL in patients with AECOPD. Methods A study sample of 196 pa... Objective To measure the QOL in patients with AECOPD and the frequency of potential risk factors, and to evaluate the association of risk factors with poor QOL in patients with AECOPD. Methods A study sample of 196 patients with moderate to severe COPD admitted for acute exacerbations to two large general hospitals were studied. The St George QOL (SGQOL) scale, socio-demographic, clinical and patient care characteristics, including depression and spirometry were ascertained in the stable state before discharge and at one-month post discharge. Results There was a high prevalence of current or ex-heavy smokers, depression and consumption of psychotropic drugs, and low prevalence of care giver support, pulmonary rehabilitation and vaccination. The mean scores for the different domains were 55.9 for Symptoms; 65.1 for Activity; 32.9 for Impact; and the mean of overall Total scores was 46.5. Multiple regression analysis showed that CMH, male, depression, previous frequent hospital readmissions and poor therapy compliance were independently related to worse Symptoms Scores. Previous frequent readmissions, depression, severe dyspnea and older age (>72 years) were related to worse Activity Scores of SGQOL. Depression, previous frequent readmissions, severe dyspnea, long COPD duration(≥5years) and severe smoking were related to worse Impact Scores of SGQOL. Depression, previous frequent readmissions, severe dyspnea and long COPD duration(≥5years) were independently related to worse Total Scores of SGQOL. Conclusion Poor QOL in patients with COPD exacerbation was associated with disease severity, psychosocial and health care factors which are modifiable. 展开更多
关键词 COPD exacerbation SGQOL risk factors
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Correlation between lower gastrointestinal tract symptoms and quality of life in patients with stable chronic obstructive pulmonary disease 被引量:10
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作者 Yan Sun Fengjie Zheng +5 位作者 Yuhang Li Ruohan Wu Yuchao Liu Miao Liu Jinchao Zhang Kuo Gao 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2013年第5期608-614,共7页
OBJECTIVE:To explore correlations between the symptoms of constipation and abdominal distention and severity of chronic obstructive pulmonary disease(COPD)in patients with stable disease.METHODS:We studied 191 patient... OBJECTIVE:To explore correlations between the symptoms of constipation and abdominal distention and severity of chronic obstructive pulmonary disease(COPD)in patients with stable disease.METHODS:We studied 191 patients with stable COPD(according to defined criteria)in this cross-sectional study from four three-level class A Chinese medicine hospitals in China.We built an Epidata 3.0 database and performed statistical analysis with SPSS,version 17.0.We analyzed correlations between the frequency of lower gastrointestinal tract symptoms(constipation and abdominal distention)and scores for major pulmonary symptoms(cough,sputum and wheezing)based on the St.George's Respiratory Questionnaire(SGRQ),6-minute walking distance(6MWD)and frequency of acute exacerbations of COPD(AECOPD).RESULTS:In addition to their pulmonary symptoms,39.79%and 40.31%of study patients withstable COPD reported constipation and abdominal distention,respectively.Scores for major pulmonary symptoms(cough,sputum and wheezing),AECOPD and SGRQ values in patients with constipation and abdominal distention were significantly greater,and the 6MWD markedly shorter,than in those without them.According to Pearson's correlation analysis,there were strong correlations between these lower gastrointestinal tract symptoms and scores for pulmonary symptoms,SGRQ,6MWD and AECOPD.CONCLUSION:Lower gastrointestinal tract symptoms such as constipation and abdominal distention can adversely affect pulmonary symptoms,frequency of acute exacerbations and quality of life in patients with stable COPD. 展开更多
关键词 Chronic obstructive pulmonary disease Constipation Flatulence Quality of life Questionnaires
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The effects of Chinese Yam-Epimedium mixture on respiratory function and quality of life in patients with chronic obstructive pulmonary disease 被引量:11
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作者 赵亚玲 宋鸿儒 +5 位作者 费晋秀 梁英 张兵华 刘秋平 王娟 胡平 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2012年第2期203-207,共5页
OBJECTIVE:To examine the clinical effects of a mixture of Chinese Yam and Epimedium in patients with stable moderate or severe chronic obstructive pulmonary disease(COPD).METHODS:Forty-nine patients with COPD were ran... OBJECTIVE:To examine the clinical effects of a mixture of Chinese Yam and Epimedium in patients with stable moderate or severe chronic obstructive pulmonary disease(COPD).METHODS:Forty-nine patients with COPD were randomly allocated to a group whose usual treatment was supplemented with oral Chinese Yam-Epimedium mixture,or a control group given placebo.For each patient,body mass index,airflow obstruction,dyspnea,and exercise capacity were measured and converted into the BODE index before treatment and at one and three months after initiation of treatment.Participants also completed the St George's Respiratory Questionnaire(SGRQ) at the same intervals.RESULTS:After one month,improvements were seen in the BODE index and SGRQ of participants taking Chinese Yam-Epimedium mixture compared to controls.There were statistically significant differences in the SGRQ:three of its components and the total SGRQ scores were significantly decreased(P<0.05),respiratory symptom scores had improved(P<0.01),and the dyspnea component of the BODE index had significantly decreased(P<0.05).Similar improvements were observed after three months of treatment,but exercise tolerance had also improved:the six-minute walking distance had significantly increased(P<0.05) in the treatment group when compared with controls.CONCLUSION:Chinese Yam-Epimedium mixture can significantly improve dyspnea,exercise capacity,and the quality of life of patients with stable moderate or severe COPD. 展开更多
关键词 Pulmonary disease Obstructive Chinese herbal drug BODE index(the body-mass index airflow obstruction DYSPNEA and exercise capacity index) The St George's respiratory questionnaire(SGRQ) Quality of life
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