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Optimization Design and Performance Analysis of Vehicle Powertrain Mounting System 被引量:7
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作者 Han Zhou Hui Liu +1 位作者 Pu Gao Chang-Le Xiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期76-88,共13页
The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, th... The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6?degrees?of?freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system. 展开更多
关键词 mounting system Optimization algorithm Vibration simulation analysis Topological structure Acceleration response Vibration transmissibility
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Simulation and Optimization Design Based on Adams Engine Mounting System 被引量:1
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作者 Xie Jianxin Wang Xiaole Liu Chao 《International Journal of Technology Management》 2014年第7期152-154,共3页
The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software f... The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software for simulation. It studies the isolation vibration of the engine mounting system and conducts goal optimization for fixed frequency. This paper uses two methods for optimization. One is to use the rational allocation of fixed frequency to optimize the fixed frequency, and the other is to use energy decoupling method to optimize the fixed frequency. It uses Adams software for simulation of the optimized fixed frequency and conducts comparison of simulated results. The simulated results show that the optimized energy distribution situation almost achieves 90%. Compared with original data, decoupling degree also has a very great improvement, illustrating that the optimized data has greater effect for the isolated vibration of engine, in order to further verify the feasibility of optimization design method. 展开更多
关键词 engine mounting system optimization design SIMULATION ADAMS
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Decoupling Analysis for a Powertrain Mounting System with a Combination of Hydraulic Mounts 被引量:7
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作者 HU Jinfang CHEN Wuwei HUANG He 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第4期737-745,共9页
The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally ... The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally varying stiffness and damping characteristics, and the influence of the spectrally-varying properties of the hydraulic mounts on the powertrain system cannot be ignored. To overcome the deficiency, an analytical quasi-linear model of the hydraulic mount and the coupled properties of the powertrain and hydraulic mounts system are formulated. The influence of the hydraulic mounts on the TRA decoupling of a powertrain system is analytically examined in terms of eigensolutions, frequency, and impulse responses, and then a new analytical axiom is proposed based on the TRA decoupling indices. With the experimental setup of a fixed decoupler hydraulic mount in the context of non-resonant dynamic stiffness testing procedure, the quasi-linear model of the hydraulic mount is verified by comparing the predictions with the measurement. And the quasi-linear formulation of the coupled system is also verified by comparing the frequency responses with the numerical results obtained by the direct inversion method. Finally, the mounting system with a combination of hydraulic mounts is redesigned in terms of the stiffness, damping and mount locations by satisfying the new axiom. The frequency and time domain results of the redesigned system demonstrate that the torque roll axis of the redesigned powertrain mounting system is indeed decoupled in the presence of hydraulic mounts (given oscillating torque or impulsive torque excitation). The proposed research provides an important basis and method for the research on a powertrain system with spectrally-varying mount properties, especially for the TRA decoupling. 展开更多
关键词 hydraulic mount coupled quasi-linear system motion control TRA decoupling
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Hybrid uncertainties-based analysis and optimization design of powertrain mounting systems 被引量:7
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作者 CAI BoHao SHANGGUAN Wen-Bin +1 位作者 LÜHui BO Tao 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2020年第5期838-850,共13页
In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters w... In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters with sufficient data are treated as random variables,while those with limited information are defined as interval variables.Then,an uncertainty-based analysis method called as hybrid interval-random perturbation-central difference method(HIRP-CDM),is proposed to compute the hybrid interval-random outputs of the inherent characteristics of the PMS in concerned directions.In addition,the hybrid interval-random-Monte Carlo method(HIR-MCM)is developed to verify the computational accuracy of HIRP-CDM.Next,an optimization model mixed uncertainties is built up for the PMS design based on HIRP-CDM,in which the hybrid intervalrandom outputs of the concerned inherent characteristics are adopted to construct the design objective and constrains.The complex optimization problem can be effectively settled by means of HIRP-CDM.The effectiveness of the presented method is verified by a numerical example. 展开更多
关键词 powertrain mounting system hybrid uncertainties uncertainty analysis optimization design
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Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem
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作者 HAO Aihua LUO Zhengming CHEN Xiaojiang 《Journal of Mountain Science》 SCIE CSCD 2024年第1期146-159,共14页
Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradient... Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(P<0.05), and the percentage of increasing temperature and decreasing moisture both gradually raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(P<0.01) and Shannon-Weiner index(P<0.05) at low elevational gradients but significantly decreased belowground biomass(P<0.05) at a depth of 0–10 cm at three elevational gradients. Warming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatment(P<0.05). The warmed aboveground biomass had a significant nonlinear response to soil temperature and significant linear responses to soil moisture(P<0.05). This study provided evidence that altitude is a factor in sensitivity to climate warming, and these different parameters(e.g., plant species richness, Shannon-Weiner index, soil temperature, soil moisture, SOC, and TN) can be used to measure this sensitivity. 展开更多
关键词 Warming effect Plant diversity pattern Community structure change Elevation gradient Alpine meadow ecosystem Mount Wutai
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The Applicability and Productiveness of a Systematic Literature Review Methodology in Volcanology Research: Case of the Magma Pathway at the Mount Cameroon Volcano
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作者 Caroline Neh Ngwa Fru Vitalis Akuma Benoît Joseph Mbassa 《International Journal of Geosciences》 CAS 2024年第10期792-808,共17页
The presented research illustrates the applicability and productiveness of the systematic literature review methodology, a non-empirical methodology in the geological sciences, particularly volcanology. The systematic... The presented research illustrates the applicability and productiveness of the systematic literature review methodology, a non-empirical methodology in the geological sciences, particularly volcanology. The systematic literature review methodology is a replicable, rigorous, and transparent methodology for synthesizing existing literature to answer questions on a specific topic. The synthesis allows for knowledge consolidation, such as identifying knowledge gaps. In our illustration of this methodology, we focused on the expanding knowledge about the magma pathway at Mount Cameroon, one of Africa’s active volcanoes. Our synthesis of the relevant international geoscience research literature is based on the framework of knowledge about the magma pathway beneath a typical basaltic volcano. The framework has three primary components: magma supply, storage, and transport to erupting vents. Across these components is a total of twelve secondary components. The result is a previously non-existent and fragmented overall understanding of the magma pathway at Mount Cameroon. The gaps in the understanding (such as in the magma supply rates, timescales of chamber processes, and magma ascent rates) may be addressed in future research. Another key implication of the presented research lies in the proof of concept of the systematic literature review methodology as an applicable qualitative research methodology in the study of volcanoes. 展开更多
关键词 systematic Literature Review VOLCANOLOGY Magma Pathway Mount Cameroon Volcano
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Conceptual design of automobile engine rubber mounting composite using TRIZ-Morphological chart-analytic network process technique 被引量:10
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作者 A.M.Noor Azammi S.M.Sapuan +1 位作者 M.R.Ishak Mohamed T.H.Sultan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第4期268-277,共10页
An engine rubber mounting is one of the important parts of a vehicle. It is a function to isolate or absorb and to reduce vibration to the vehicle body thus to the passenger itself. Due to the engine compartments envi... An engine rubber mounting is one of the important parts of a vehicle. It is a function to isolate or absorb and to reduce vibration to the vehicle body thus to the passenger itself. Due to the engine compartments environment such as heat and massive vibration due to road conditions, the engine rubber mountings lifespan has been reduced. Thus several studies have been conducted to upgrade the material lifespan to make it more reliable and better engine mounting components. This paper presents the conceptual design of kenaf fiber polymer as automotive engine rubber mounting composites using the integration of Theory of Inventive Problem Solving(TRIZ). In this early stage, the solution is generated using 40 inventive principles and TRIZ contradiction method. The solution parameter for the specific design character is the selected using the morphological chart to develop a systematic conceptual design for the component. Four(4) innovative design concepts were produced and Analytic Network Process(ANP)methods were utilized to perform the multi-criteria decision-making process of selecting the best concept design for the polymer composite engine rubber mounting component. 展开更多
关键词 TRIZ ANP MORPHOLOGICAL Automotive composites component Engine rubber COMPOSITE mounting
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Hierarchical planning for a surface mounting machine placement 被引量:4
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作者 曾又姣 马登哲 +1 位作者 金烨 严隽琪 《Journal of Zhejiang University Science》 EI CSCD 2004年第11期1449-1455,共7页
For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarc... For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance. 展开更多
关键词 Printed circuit board Surface mounting machine Hierarchical planning Feeder assignment Placement sequence
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The Study of SMT Product Manufacturing Grid System 被引量:1
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作者 李春泉 余涛 《上海交通大学学报》 EI CAS CSCD 北大核心 2007年第S2期131-138,共8页
Surface mount technology product manufacturing grid(SMT-MG) is a typical application which grid technology was applied to SMT product manufacturing.In this paper,for SMT-MG system,conception and intension of SMT-MG we... Surface mount technology product manufacturing grid(SMT-MG) is a typical application which grid technology was applied to SMT product manufacturing.In this paper,for SMT-MG system,conception and intension of SMT-MG were analyzed.Then six-layer architecture of SMT-MG was constructed and mesh three-dimensional matrix organization mode of SMT-MG was studied.Operation mechanism of SMT-MG was discussed emphatically which include adaptive evolution mechanism,PUSH/PULL driving mechanism,cooperation game mechanism,feedback,regulation and control mechanism,coordination mechanism and impetus mechanism.The study of SMT-MG must be useful for developing of electronic product manufacturing. 展开更多
关键词 SURFACE MOUNT technology(SMT) MANUFACTURING GRID system design
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OPTIMUM DESIGN AND NON-LINEAR MODEL OF POWERPLANT HYDRAULIC MOUNT SYSTEM 被引量:1
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作者 ShiWenku MinHaitao DangZhaolong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第3期237-240,共4页
6-DOF non-linear mechanics model of powerplant hydraulic mount system isestablished. Optimum design of the powerplant hydraulic mount system is made with the hydraulicmount parameters as variables and with uncoupling ... 6-DOF non-linear mechanics model of powerplant hydraulic mount system isestablished. Optimum design of the powerplant hydraulic mount system is made with the hydraulicmount parameters as variables and with uncoupling of energy, rational disposition of naturefrequency and minimum of reactive force at mount's location as objective functions. And based on theoptimum design, software named ODPHMS (optimum design of powerplant hydraulic mount system) used inpowerplant mount system optimum design is developed. 展开更多
关键词 Powerplant Hydraulic mount OPTIMIZATION SOFTWARE
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An improved loopless mounting method for cryocrystallography
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作者 齐建勋 江凡 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第1期212-221,共10页
Based on a recent loopless mounting method, a simplified loopless and bufferless crystal mounting method is developed for macromolecular crystallography. This simplified crystal mounting system is composed of the foll... Based on a recent loopless mounting method, a simplified loopless and bufferless crystal mounting method is developed for macromolecular crystallography. This simplified crystal mounting system is composed of the following components: a home-made glass capillary, a brass seat for holding the glass capillary, a flow regulator, and a vacuum pump for evacuation. Compared with the currently prevalent loop mounting method, this simplified method has almost the same mounting procedure and thus is compatible with the current automated crystal mounting system. The advantages of this method include higher signal-to-noise ratio, more accurate measurement, more rapid flash cooling, less x-ray absorption and thus less radiation damage to the crystal. This method can be extended to the flash-freeing of a crystal without or with soaking it in a lower concentration of cryoprotectant, thus it may be the best option for data collection in the absence of suitable cryoprotectant. Therefore, it is suggested that this mounting method should be further improved and extensively applied to eryocrystallographic experiments. 展开更多
关键词 CRYOPROTECTANT crystal mounting data collection flash cooling
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Monochrome HUD’s Imaging Projector Based on Laser-DMD System 被引量:1
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作者 Sayed Sajjad Mousavi Fard Masood Kavosh Tehrani Mehrdad Mehrani 《Journal of Modern Physics》 2016年第10期1138-1149,共12页
Design and tolerance of a new head up display’s projector system is reported. It is based on laser-micro display modules. We designed optical diffraction limited modules and some of our novelties were compactness, us... Design and tolerance of a new head up display’s projector system is reported. It is based on laser-micro display modules. We designed optical diffraction limited modules and some of our novelties were compactness, using common material and spherical lenses in optical design, easy and economical manufacturing process, uniform intensity and minimum aberrations of final image, economical and repairable designed system. Projector magnification is 10.0X and diagonal of image plane is 76.2 mm. ZEMAX software is employed for optical design and tolerance. 展开更多
关键词 Head-Up Display (HUD) Head Mounted Display (HMD) Deformable Micro Mirror Displays (DMD) Polarizer Beam Splitter (PBS)
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Application of A New Anchor Cable Mounting Rod in the Lower Soft Coal Seam of Splitting and Merging Coal
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作者 XIONG Lijun ZHA Wenhua 《Journal of Landscape Research》 2017年第6期25-28,共4页
To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological ... To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological conditions. This paper is based on the splitting and merging of 7_1 coal and 7_2 coal in Huaibei Mining(Group) Co., Ltd., and analyzes properties of the roof andcoal in the 7_2 coal of the lower coal seam of bifurcation area, and calculates the damage depth of the floor in the process of 7_1 coal mining. The multi-point displacement meter installation is often challenged by hole collapse, stuck pole and broken installation rod in 7_2 coal of the soft coal seam of bifurcation area, as a result, the base points can't be installed in the specified location. In view of this, this paper adopts a new anchor cable mounting rod which can install the whole base points to the specified location without stuck pole or broken mounting stem. All the basic displacement data can be obtained, and the law of mine pressure appearance in stope and tunnel can be accurately controlled, which can be used to maintain the stability of roadway and the safety of stope. 展开更多
关键词 Deep displacement Multi-point displacement meter Splitting and merging Lower coal seam New anchor cable mounting rod
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Clinical observation of Hot Compress and Mounting Medicine Method
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作者 Zhang Lide(Physiotherapy Dept.of Yangzhou Mineral Bureau General Hospital,Shandong Province) 《中国针灸》 CAS CSCD 北大核心 1995年第S2期336-336,共1页
ClinicalobservationofHotCompressandMountingMedicineMethod¥ZhangLide(PhysiotherapyDept.ofYangzhouMineralBurea... ClinicalobservationofHotCompressandMountingMedicineMethod¥ZhangLide(PhysiotherapyDept.ofYangzhouMineralBureauGeneralHospital,... 展开更多
关键词 Clinical observation of Hot Compress and mounting Medicine Method
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Image-Based Methods for Interaction with Head-Worn Worker-Assistance Systems
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作者 Frerk Saxen Omer Rashid +3 位作者 Ayoub Al-Hamadi Simon Adler Alexa Kernchen Rüdiger Mecke 《Journal of Intelligent Learning Systems and Applications》 2014年第3期141-152,共12页
In this paper, a mobile assistance-system is described which supports users in performing manual working tasks in the context of assembling complex products. The assistance system contains a head-worn display for the ... In this paper, a mobile assistance-system is described which supports users in performing manual working tasks in the context of assembling complex products. The assistance system contains a head-worn display for the visualization of information relevant for the workflow as well as a video camera to acquire the scene. This paper is focused on the interaction of the user with this system and describes work in progress and initial results from an industrial application scenario. We present image-based methods for robust recognition of static and dynamic hand gestures in realtime. These methods are used for an intuitive interaction with the assistance-system. The segmentation of the hand based on color information builds the basis of feature extraction for static and dynamic gestures. For the static gestures, the activation of particular sensitive regions in the camera image by the user’s hand is used for interaction. An HMM classifier is used to extract dynamic gestures depending on motion parameters determined based on the optical flow in the camera image. 展开更多
关键词 HEAD Mounted DISPLAY GESTURE Recognition Mobile ASSISTANCE system
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Software Engineering in Photo Electricity Orient System
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作者 Zhang Jianyong and Dong Chengfu 《IMP & HIRFL Annual Report》 2001年第1期107-107,共1页
We have designed a photo electricity orient system to control nuclei physics experiments.In this paper I will introduce its software.This photo electricity orient systemic software is designed by C language.Exploitati... We have designed a photo electricity orient system to control nuclei physics experiments.In this paper I will introduce its software.This photo electricity orient systemic software is designed by C language.Exploitation environment is Turbo C of Borland Inc.Help design instrument is PlayCase.The block diagram of this software is given in Fig.1. 展开更多
关键词 ORIENT ELECTRICITY BORLAND instrument NUCLEI execute contrary ELEMENTARY MOUNT
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Investigation of Self Excited Torsional Vibrations of Different Configurations of Automatic Transmission Systems during Engagement
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作者 Eid O. A. Abd Elmaksoud E M. Rabeih +1 位作者 N A Abdel-halim S M. El Demerdash 《Engineering(科研)》 2011年第12期1171-1181,共11页
The vehicle drive line system is subjected to torsional vibration from different sources of the system such as;engine fluctuating torque, Hook’s joint and the final drive. However, the essential source is the frictio... The vehicle drive line system is subjected to torsional vibration from different sources of the system such as;engine fluctuating torque, Hook’s joint and the final drive. However, the essential source is the friction torque induced in the friction elements, during their engagement. In the automatic transmission system, the planetary gear set includes several friction elements such as;clutch, band brakes, and one way clutch. During the engagement, severe torsional vibration is induced by friction which is noticeable by the passengers in the form of what so called vehicle shunt. In present paper, a torsional vibration model for Drive Line (DL) system includes three different configurations of automatic transmission is constructed. A computer program using MATLAB subroutines is implemented to obtain the system response. Effect of system parameters on the dynamic behavior and stability has been investigated. The system damping and the trend of the friction coefficient have an essential effect on the dynamic behavior and stability of the system. The system response is now predictable with change of the system parameters which opens up the opportunity in future to control the vibration level. 展开更多
关键词 SELF EXCITED Torsional Vibration Computer Simulation Ravigneaux PLANETARY GEAR SET Compound PLANETARY GEAR SET Longitudinally Mounted AUTOMATIC Transmission
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Soil Organic Carbon Stock and Soil Quality under Four Major Agroecosystems in the Eastern Flank of Mount Bambouto (West-Cameroon)
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作者 Ade Linda Wijungbwen Cedrick Nguemezi +1 位作者 Duchel Ivilin Voulemo Djeuhala Paul Tematio 《Journal of Geoscience and Environment Protection》 2023年第9期40-53,共14页
Assessing soil organic carbon stock (SOCS) and soil quality (SQ) helps design better agricultural practices to improve environmental sustainability and productivity. The purpose of the study is to assess SOCS and soil... Assessing soil organic carbon stock (SOCS) and soil quality (SQ) helps design better agricultural practices to improve environmental sustainability and productivity. The purpose of the study is to assess SOCS and soil quality SQ in the main agroecosystems (AES) of the eastern flank of Mount Bambouto (West, Cameroon). Using multiple statistics tests and principal component analysis (PCA), SOCS and Soil Quality Index (SQI) were computed for each AES. SOCS and SQI were computed based on soil chemical properties and analysis of variance. Topsoil samples (0 - 30 cm) were collected in a different AES and analyzed in the laboratory. The four AES identified and selected are cultivated land (CL), forest areas (FA), mixed areas (MA), and bush areas (BA). Further, multiple comparison tests were used to compare soils from different AES. PCA was used to select the most appropriate indicators that control SOCS and SQ. Several soil properties showed high to very high coefficient of variation within the AES. Organic matter (OM) was significantly high in FA. SOCS and SQ differ significantly (p = 0.000) between the AES. The study further indicates that the main variables controlling SQ within the eastern flank of Mount Bambouto are OM, pHw, N, C/N, and CEC. While the main soil parameters controlling SOCS are OM, OC, BD, C/N, S, and pHKCl. 展开更多
关键词 Soil Organic Carbon Stock Soil Quality AGROECOsystemS Principal Component Analysis Mount Bambouto
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HQ-61 Surf ace-to-Air Missile System
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作者 Tang Zhlliang 《Aerospace China》 1992年第1期24-26,共3页
This paper describes China’s HQ 61 surface-to-air missile system, especially the main tactical and technical performances, missile aerodynamic configuration, propulsion system, warhead, guidance and electric system. ... This paper describes China’s HQ 61 surface-to-air missile system, especially the main tactical and technical performances, missile aerodynamic configuration, propulsion system, warhead, guidance and electric system. The paper also briefs the weapon’s launching facilities and operation process. 展开更多
关键词 MISSILE PROPULSION WEAPON LAUNCHING facilities guidance aerodynamic antenna HEXAGONAL mounted
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The Art of Chinese Painting and Calligraphy Mounting
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作者 Chen Weiguo 《China & The World Cultural Exchange》 2009年第12期39-41,共3页
The history of Chinese painting and calligraphy mounting can date back to the Warring States period(475-221 BC).This unique craftsmanship saw its heydays in
关键词 The Art of Chinese Painting and Calligraphy mounting
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