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1.
针对汽车理论中尚无整车质量分配系数研究的缺憾,考虑垂向和侧向路面激励的复合影响,以14个自由度整车传统物理模型为背景,对簧载质量进行空间动力学分析,借助4个轮系方位与簧载质量质心处的运动学关系,研究车体垂直、侧向、俯仰角、侧倾角和横摆角这五种运动,进而推导得到整车悬架与4个1/4悬架系统间的动力耦合定量关系,发展与完善汽车质量分配系数理论,并为今后汽车悬架系统振动控制、转向与操纵系统平稳性的研究提供新的视角与思路。 相似文献
2.
建立水蒸气蒸馏分离植物挥发油传质过程数学模型．对常规蒸馏器进行改进，加入搅拌装置强化了传质．通过３种植物蒸馏的实验数据，求取了总传质系数值并验证了数学模型，并讨论了搅拌转速对传质系数的影响． 相似文献
3.
Zhong Shao Xiang 《大连大学学报》1995,(4)
根据叶片绕流理论,用保角变换和级数展开的方法推导出由变换系数表示的叶片表面的速度分布,给出了轴流泵可调叶片的水动力矩数学模型及可靠性分析。最后,对某泵可调叶片的水动力矩进行了计算。研究表明,方法是可靠的,结果令人满意。 相似文献
4.
Chemical absorption of CO2 into aqueous slurries of Ca(OH)2 was studied in a stirred thermostatic reactor. The influence of solid loading and stirring speed on absorption rate were investigated experimentally, and the results show that the enhancement factor increases with particle content due to the increase of reactive particles in the gas-liquid interfacial region. The absorption process was controlled by the diffusion of gas molecules in slurry. The influence of stirring intensity on enhancement factor is an integration of gas-liquid and liquid-solid mass transfer variation. A novel prediction model of enhancement factors was proposed with the partition of interface into two various zones, and the prediction values by the presented model are in agreement with the experimental data. 相似文献
5.
用气相色谱归一化法和外标法相结合的定量分析方法,分别测定化工生产技术竞赛原料和蒸馏产品中乙醇的含量。结果表明,原料测定的乙醇线性范围为10%~15%(质量浓度),相关系数达到0.9997。蒸馏产品测定的乙醇线性范围为80%~92%(质量浓度),相关系数达到0.99995。线性关系良好,精密度高,而且测定结果的相对误差小,准确度高。此复合型的定量方法具有简单、快速、准确的优点,尤其适合竞赛,可确保竞赛成绩的公正性。 相似文献
6.
滴状冷凝传热系数的实验研究及分析 总被引：1，自引：1，他引：1
选取管内递推法作为滴状冷凝传热系数的实验测试原理,利用该原理搭建了滴状冷凝传热系数测定和观察的实验台,并完成了实验数据的测定;通过对比性分析后发现不凝性气体会降低滴状冷凝传热系数的测定值,滴状冷凝传热系数与雷诺数Re间的变化关系受到多种外界因素的影响,最后为本实验装置提出了改进与完善建议。 相似文献
7.
A novel ε-type solenoid actuator is proposed to improve the dynamic response of electro-pneumatic ejector valves by reducing moving mass weight. A finite element analysis （FEA） model has been developed to describe the static and dynamic operations of the valves. Compared with a conventional E-type actuator, the proposed ε-type actuator reduced the moving mass weight by almost 65% without significant loss of solenoid force, and reduced the response time （RT） typically by 20%. Prototype valves were designed and fabricated based on the proposed ε-type actuator model. An experimental setup was also established to investigate the dynamic characteristics of valves. The experimental results of the dynamics of valves agreed well with simulations, indicating the validity of the FEA model. 相似文献
8.
基于Jones-Harris方法建立了调心球轴承的动力学模型,应用Newton-Raphson方法对轴承动力学方程组进行了求解,开发了相应的计算程序.完成了该轴承的离心力、陀螺力矩、接触载荷、接触角、径向变形与径向刚度等动态特性参数分析.分析结果表明：转速与载荷是影响接触角大小与接触载荷分布最主要的2个因素;滚子的离心力与陀螺力矩随着转速的上升而增大,在此影响下外圈接触载荷增大而内圈接触载荷减小;受离心力的影响,外圈的接触角减小而内圈的接触角增大,且随着转速的增加,内外圈接触角的差值越来越大;轴承的径向刚度随着转速的上升而下降,而滚道沟曲率系数也对轴承径向刚度有一定程度的影响. 相似文献
9.
Yong-wei Wang Jun Wang Chong Yao Qiu-jun Lu 《Journal of Zhejiang University. Science. B》2009,10(12):883-889
The impact force response of a peach impacting on a metal flat-surface was considered as nondestructive determination of firmness. The objectives were to analyze the effect of firmness, drop height, fruit mass, and impact orientation on the impact force parameters, and to establish a relationship between the impact force parameter and firmness. The effect of fruit firmness, drop height and fruit mass on the impact force parameters (coefficient of restitution, percentage of energy absorbed, and coefficient of force-time) was evaluated. The study found that the coefficient of restitution, percentage of energy absorbed, and force-time impact coefficient were significantly affected by fruit ripeness, but not affected by drop height, impact position (fruit cheek), and mass. The percentage of absorbed energy increased with ripeness, while the force-time impact coefficient and coefficient of restitution decreased with ripeness. Relationships were obtained between the three impact characteristic parameters (force-time impact coefficient, coefficient of restitution, and percentage of energy absorbed) and peach firmness using a polynomial model (R~2=0.932), S model (R~2=0.910), and exponential model (R~2=0.941), respectively. 相似文献
10.
应用G98W程序包中的量子化学密度泛涵（DFT）方法，在B3LYP／6—31G（d）水平上，对51种二苯并呋喃及其衍生物（PCDFs）进行几何构型全优化。优化后所得分子的最高占据轨道能量、二苯并呋喃环上1，2，3，7四个原子静电荷密度作为PCDFa分子结构描述符。应用支持向量机构建多氯代二苯并呋喃logKow的定量构效（QSAR）关系模型，所建模型的预测值与实验值吻合的很好，经留一交叉校检法检验该模型，该模型具有良好的稳健性，有一定的应用价值． 相似文献
11.
边清泉 《绵阳师范学院学报》1999,(5)
用硅酮DC—550的气相色谱填充柱,以碳酸二乙酯为内标,用具有氢焰离子化检测器的气相色谱仪定量分析对溴磷杀虫剂原液和乳油.原液和乳油的标准偏差、平均变异系数和平均回收率三项指标均达到满意效果. 相似文献
12.
十全大补汤的高效液相色谱指纹谱图研究 总被引：2，自引：0，他引：2
基于HPLC方法,本文研究了十全大补处方乙醚萃取液的HPLC指纹谱图和提取工艺稳定性的表征指标。发现了5个色谱峰能够较为稳定地出现在所测样本的色谱图中,它们表现出了相同或极其相近的相对保留时间,因此可以作为指纹谱图的良好的定性特征。对全光谱分别以均值光谱和中位数光谱为标准进行相似性评价,其相关系数和相合系数均具有较强的相似性,大多数表现出85%以上的相似度。表明本文方法可以较为理想地用于复方提取物的质量评价和工艺过程的质量控制。 相似文献
13.
A measurement model based on torsion pendulum was established,in which nonlinear damping and nonlinear restoring force were considered.The calculation method of the moment of inertia was based on Hilbert transform.The motion of torsion pendulum showed the time-frequency characteristics due to the nonlinear factors,which were validated by the experimental data.The analytical signal was formed by Hilbert transform of the angular displacement signal of the test object.The moment of inertia can be computed by the instantaneous undamped natural frequency with Hilbert transform.Prior to the implementation of Hilbert transform,the empirical mode decomposition was used to filter the experimental signal.The moment of inertia of the test object was measured by the torsion pendulum system.The experimental results show that the relative measurement error of the moment of inertia was within 0.7%,which indicated the validity of the measurement method. 相似文献
14.
杨薇 《鞍山师范学院学报》2016,(6):24-26
运用描述统计和回归分析的方法,建立了用于判断陶瓷过滤机是否高效运行的2个主要指标之间的回归模型。通过模型分析可知,给料浓度和利用系数之间有较强的线性关系,为提高陶瓷过滤机的过滤效率以及对机器的更新升级提供依据。 相似文献
15.
采用有限元分析方法考察梁和柱的截面尺寸、角型连接件尺寸、铆钉直径及端距等对节点性能的影响,根据计算得到的弯矩-转角曲线拟合出三参数模型中形状系数n 值的近似计算公式。结果表明,柱翼缘厚度和角型件厚度对节点初始刚度和极限承载力影响显著,梁高和铆钉端距的影响次之。形状系数建议公式计算结果与试验结果吻合较好,可为该类连接节点设计方法提供理论依据。 相似文献
16.
通过有限元软件ANSYS构建非线性数值模型,并利用现有试验数据进行模型准确性验证。分析了板件宽厚比、截面尺寸效应以及是否约束某一主轴方向位移对构件稳定承载力的影响,发现三者影响均可不予考虑。在大规模参数分析的基础上,本文建议对于6061-T6,几何缺陷系数中的两个参数分别取和,对于6061-T4建议取和。对比中、欧规范计算结果发现,该建议与试验及参数分析结果具有更好的吻合性,满足计算精度和安全度的工程设计要求。 相似文献
17.
青蒿素的热稳定行为及气相色谱分析 总被引：1，自引：0，他引：1
以气相色谱法研究了青蒿素的热稳定性、分解行为以及气相色谱分析方法.在色谱图上发现,青蒿素热分解有两个主产物,经推测可能为分解或重排产物.还发现前期流出的产物与青蒿素浓度有线性关系,据此可对青蒿素含量进行分析. 相似文献
18.
Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained. 相似文献
19.
This paper presents a disturbance rejection scheme for walking robots under unknown external forces and moments. The disturbance rejection strategy, which combines the inverse dynamics control with the acceleration projection onto the ZMP （zero moment point）-plane, can ensure the overall dynamic stability of the robot during tracking the pre-computed trajectories. Under normal conditions, i.e., the system is dynamically balanced, a primary inverse dynamics control is utilized. In the case that the system becomes unbalanced due to external disturbances, the acceleration projection control （APC） loop, will be activated to keep the dynamic stability of the walking robot through modifying the input torques. The preliminary experimental results on a robot leg demonstrate that the proposed method can actually make the robot keep a stable motion under unknown external perturbations. 相似文献
20.
结合非参数回归技术分析,通过均匀试验设计方法得到的24组稀硫酸腐蚀掺粉煤灰混凝土试件试验数据,研究pH值、水胶比、水泥用量、粉煤灰用量、坍落度5个因素对混凝土腐蚀量的影响以及相应预测方法。结合试验数据,首先采用Pavlick建议的幂函数模型进行参数回归,获得各组试验的腐蚀系数k与时间指数n,然后在此基础上,采用ACE非参数回归技术分析腐蚀系数k与pH值、水胶比、水泥用量、粉煤灰用量、坍落度5个因素的关系,并建立腐蚀预测模型。结果表明：①幂函数模型能很好地反映腐蚀随时间的增长规律;②按浸泡过程中硫酸钙析出时间点不同,可将k、n值分布特征大致划分为3类,采用ACE回归分别建立不同类预测模型,能获得较好的预测结果。 相似文献