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681.
目的应用弱阳离子交换纳米磁珠(WCX-MB)分离血清蛋白并联合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)技术,对比分析临床上难治复发与治疗敏感的多发性骨髓瘤(MM)患者血清蛋白质组的差异,以期为阐明多发性骨髓瘤的耐药机制提供线索。方法选择临床确诊的19例MM患者,按实际疗效分为难治复发组(11例)和治疗敏感组(8例),以WCX-MB捕获各自的血清蛋白质组分,MALDI-TOF-MS检测蛋白质谱,再利用ClinprotoolsTM 2.2软件进行数据分析,筛选出与耐药相关的差异蛋白质分子。结果在分子量0.7~10ku的范围内,共得到59个有统计学意义的差异多肽峰(P<0.05);与治疗敏感组相比,难治复发组MM患者的血清多肽峰有34个表达上调,有25个表达下调;将区分难治复发组与治疗敏感组MM患者能力最强的10个质谱峰建成了一个诊断GA模型,其灵敏度及特异性均为100%。结论利用CLINPROT系统筛选血清差异表达蛋白能够为研究多发性骨髓瘤的耐药机制和临床预后判定提供有价值的线索。  相似文献   
682.
Compared with the extensive research on logistics network infrastructures (LNIs) in the developed world, empirical research is still scarce in China. In this paper the theory of LNIs is firstly overviewed. Then a new evaluation index system for LNIs is set up which contains factors that reflect the economic development level, transportation accessibility and turnover volume of freight traffic. An empirical study is carried out by using data envelopment analysis (DEA) and principal component analysis (PCA) approach to classify LNIs into 4 clusters for 25 cities in the Yangtze River Delta Region of China. According to the characteristics of the 4 clusters, suggestions are proposed for improving their LNIs. Finally, after comparing different LNIs of 25 cities in the Yangtze River Delta Region of China, this paper proposes that different LNIs including hub, central distribution center or cross docking center, regional distribution center or distribution center should be built reasonably in order to meet the customer’s requirement in the four different cluster cities.  相似文献   
683.
This paper presents a fault detection and diagnosis (FDD) method to enhance the reliability and safety for longitudinal control of an autonomous all-terrain vehicle (ATV). An integrated approach using decentralized and centralized FDD is proposed to optimize the tradeoff between sensitivity and robustness. While the decentralized approach is suitable for detecting faults in actuators and sensors directly connected to a single processor, it is sensitive to noises and disturbances and thus may result in false alarms. On the other hand, the centralized approach is based on information communicated between multiple processors, and it detects and diagnoses faults through analyzing concurrent computations of multiple hardware modules. However, its performance is still limited to isolating faults specifically in terms of components in the single hardware. To incorporate the advantages of both FDD approaches, a two-layered structure integrating both decentralized and centralized FDD is proposed and allows us to perform more robust fault detection as well as more detailed fault isolation. Finally, the proposed method is validated experimentally via field tests of an ATV.  相似文献   
684.
The concept of Low Temperature Combustion (LTC) has been advancing rapidly because it may reduce emissions of NOx and soot simultaneously. Various LTC regimes that yield specific emissions have been investigated by a great number of experiments. To accelerate the evaluation of the spray combustion characteristics of LTC, to identify the soot formation threshold in LTC, and to implement the LTC concept in real diesel engines, LTC is modeled and simulated. However, since the physics of LTC is rather complex, it has been a challenge to precisely compute LTC regimes by applying the available diesel combustion models and considering all spatial and temporal characteristics as well as local properties of LTC. In this paper, LTC regimes in a constant-volume chamber with n-Heptane fuel were simulated using the ECFM3Z model implemented in a commercial STAR-CD code. The simulations were performed for different ambient gas O2 concentrations, ambient gas temperatures and injection pressures. The simulation results showed very good agreement with available experimental data, including similar trends in autoignition and flame evolution. In the selected range of ambient temperatures and O2 concentrations, soot and NOx emissions were simultaneously reduced.  相似文献   
685.
FMECA (Failure Modes, Effects and Criticality Analysis) is a procedure used to identify potential failure modes, determine causes and effects of failure modes and mitigate or remove its effects on system functional performance. For the last several decades, FMECA has been widely used in industry, and specialized versions of FMEA have been developed for several industrial sectors. For instance, MIL-1629a, SAE-J1739 and IEC-60812 have been mainly used in the military, automotive and electronics industries, respectively. However, there is no specialized FMECA method for the railroad industry yet, despite a need for highly reliable systems. Thus, in this study three specifications, MIL-1629a, SAE-J1739 and IEC-60812, were analyzed and compared with one another, and characteristics and requirements of railroad systems were summarized. Then a specialized FMECA procedure for railroad systems was proposed based on the processes documented in the specifications, characteristics and requirements of railroad systems. Finally, the procedure was applied to a railroad system in order to validate its applicability.  相似文献   
686.
Improving the durability of an automotive V-belt pulley, which is commonly used in an automotive powertrain to transfer power to other parts, is discussed. Fatigue life of the original V-belt pulley is predicted based on damage analysis by finite element analysis (FEA). Stress history of the pulley during operation was found by performing consecutive static analyses on the pulley as the pulley rotates. Assembly load (due to the tightening of the bolts) and operation load were considered to describe the actual load conditions in a durability test. The contact condition from the belt was calculated and applied to the surface of the pulley. Static analyses at 36 different positions of the pulley, every ten degrees of rotation, were performed to determine the stress history of the pulley during operation. Using stress history data calculated from FE analysis, damage over one rotation of the pulley was calculated and fatigue life, in number of rotations to failure, was estimated. An improvement to the durability of the pulley was investigated by modifying the design of the pulley using FE analysis results. Durability tests for the pulleys used in the analysis were carried out to verify the analytical results. Comparison between analysis and experimental results showed that analytical results correlated with the experimental results closely.  相似文献   
687.
钢板弹簧离散梁动力学参数反求   总被引:3,自引:0,他引:3  
针对采用多体动力学方法创建钢板弹簧动力学模型中所需的对钢板弹簧进行简化处理(用少片等效模拟多片钢板弹簧)时确定离散梁动力学参数的困难,引入遗传算法.利用遗传算法来反求对弹簧刚度影响最大的离散梁的动力学参数(绕3个轴的转动惯量),从而可快速准确地建立钢板弹簧仿真模型.最后,用某车型前桥的钢板弹簧离散梁动力学参数反求算例中仿真与试验结果的对比,验证了该方法的有效性.  相似文献   
688.
The vibrational characteristics of automotives during idling were studied experimentally by considering the axial forces of the drive shaft and the spider positions in a constant-velocity joint. The generated forces, such as PF (plunging force) and GAF (generated axial force) in the assembly of the drive-shaft module, were measured directly by an experimental apparatus. Measurements of the GAF and PF did not show the same trends as the joint angles. They depended instead on the types of CV joints. In addition, the relationship between the offset values of the shaft and the spider positions in the tulip of the constant-velocity joint were studied. As a result, the idle vibration characteristics were affected by the variation of the spider positions and the vibrational characteristics in the axial direction of the shaft, including the amplitude and the harmonic periods.  相似文献   
689.
Unlike an actual vehicle, a vehicle driving simulator (VDS) has limited kinematics, workspace, and bounded dynamic characteristics making it very difficult to simulate dynamic motions of an actual vehicle. To solve these problems, a washout algorithm was developed. The developed algorithm restricts the workspace of the VDS to within the kinematic limit and makes the person driving the VDS perceive movement of an actual vehicle. However, the classic washout algorithm contains several problems, such as time delay and the generation of a wrong motion signal caused by characteristics of the filters. So the driver feels “simulator sickness,” such as fatigue, nausea, headache and so on because of differences between the sense of movement of the VDS and that of a real vehicle. In this paper, a partial range scaling method based washout algorithm, including a tilt coordination system, is developed to enhance the perception of motion and reduce simulator sickness. It is verified by a simulation, a survey, and a bio signal analysis using an electrocardiogram (ECG).  相似文献   
690.
In this paper, a simple design method for improving the performance of an interior permanent magnet synchronous motor (IPMSM), for driving the air-conditioning compressor used in hybrid electric vehicles, is presented. There are many design methods that optimize the IPMSM. Each method deals with a variety of design factors, such as slot opening, pole arc, and rotor shape. However, as the number of design variables increases, a lot of modeling and analysis time is needed in order to improve the characteristics of an IPMSM. This paper demonstrates that the optimization of a double-layer IPMSM, satisfying the given design conditions, is possible with only a flux barrier shape design. Then, response surface methodology is applied as the optimization method, and the validity of the design approach is verified by comparison with test results.  相似文献   
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