Papers by Keyword: Mechanism

Abstract: The complex number method is employed to analyze the planar motion problems of mechanism. The angular velocities and accelerations of connecting rod and rocker are formulated, and the linear velocities and accelerations of key points are also given. The analyzing process and the numerical computation results of the example show the simplicity in comparation with that of the vector method introduced in theoretical mechanics.

Abstract: A vertical-axis tidal turbine was designed in the paper. Modal analysis of the vertical-axis tidal turbine was investigated based finite element software analysis method. Finite element simulation model for modal analysis of the accelerator and the whole tidal turbine were built by appropriate structure simplification. And, the anterior 10 ranks of natural frequencies and corresponding mode shapes were calculated. Modal analysis results show that the natural frequency of the turbine away from the frequencies of tidal current incentive, impeller incentive and generator rotor incentive, so the resonance phenomenon does not exist in the turbine of the paper. Also, the modal analysis results show that the input of the accelerator and leaves of impeller have a large deformation, and the stiffness of the input shaft and spokes and leaves of impeller should be increased.

Abstract: Recent studies [1, 2] were devoted to author's efforts in formalization of conceptual design process based on vast data in mechanical design accumulated over years. The suggested novel method of conceptual design is implying direct dependence of function and a mechanism intending to implement the challenged function, considering a wider interpretation for both categories of mechanism and function. Main aspects of this method relate to formalization of both mechanism and function, formatting of design pages for tracking the concept design process, formalization of synthesis and analyze tools and formation of design models serving different design targets. Effectiveness of those formalization tasks is based on development and usage of specific graph and matrix based mathematical engine, enabling compact presentation of various aspects of conceptual design method. The current study is aiming to disclose the specific conditions of formalization for reconfigurable as categories widely used in mechanism synthesis and analyzes. Formalization of reconfigurable mechanisms will categories is contribute a lot in effectiveness of organization of concept design. An example from design experience is considered to confirm the validity of suggested formalization approach for the case of reconfigurable mechanisms.

Abstract: At present, China is establishing eco-compensation mechanism on the basis of key ecological function zones and ecological factors, but trans-provincial eco-compensation mechanism (especially in river basin) is making slow progress due to its complicated stakeholders involvement. The promulgation of relevant papers, such as Planning on National Main Functional Zones and National Key Ecological Function Zones, provide important basis and new thoughts for implementing eco-compensation mechanism in China. In this paper, we take trans-provincial key ecological function zone as breakthrough point to study trans-provincial river basin eco-compensation mechanism, and take the source area of Dongjiang River in Jiangxi province and Guangdong province as an example to put forward some ideas for trans-provincial river basin eco-compensation mechanism designing based on the key ecological function zones. Taking the study of key ecological function zone as the platform, we propose a framework of river basin eco-compensation plan, which includes particular design in the following aspects: the funding needs, funding sources, financial operation mechanism, monitoring and evaluation, organizational management and compensation security system. Designing River basin eco-compensation mechanism in source areas while based on key ecological function zone, which will increase the scientific nature and rationality of policy making, is more in line with ideas and concepts of payment for ecosystem services (PES) and it will effectively promote scientific and rational development and implementation of river basin eco-compensation. However there are still many inevitable problems in the following aspects: river basin eco-compensation monitoring and evaluation, management of river basin eco-compensation and measures to ensure the long-term effect of river basin eco-compensation policy. With the in-depth understanding of eco-compensation study and practice in China, these problems should be constantly improved and Chinas eco-compensation mechanism will become increasingly complete and rigorous in the future.

Abstract: The effects of multiple injections coupled with medium EGR (25% - 30%) on heavy duty diesel engine were investigated. Injection timing and mass were adjusted with different injection strategies (main-post and pilot-main) to study the influence of these parameters on combustion and emissions. The mechanism of soot emission reduction was discussed. Results indicate that, at fixed total injection quantity and EGR rate, NOx is reduced, while soot is decreased followed by an increasing with increasing post injection quantity; NOx nearly kept constant and soot declined before rising with lager main-post interval. Optimum post injection could accelerate soot oxidation rate. Pilot injection has no positive impact on NOx, while soot decreases with less pilot fuel mass and lager pilot-main interval. Optimum pilot injection could be beneficial for a better mixture property. The acceleration of soot oxidation rate is the basic reason of soot emission reducing by multiple injections.

Abstract: Ammonium sulfate, ammonium bisulfate and ferric oxide are mixed at a molar ratio of 8:5:13 and heated in high temperature muffle furnace or fluidized bed at different temperature. To the sample, the thermal gravimetric (TG) analysis is used, the reaction residue is analyzed by fourier transform infrared spectroscopy (FT-IR) and chemical analysis, the generated gas is qualitatively analyzed as well. The process of thermal decomposition for ammonium sulfate and ammonium bisulfate via addition of Ferric oxide has four stages-the decomposition of ammonium sulfate, the formation of ammonium ferric pyrosulfate, the decomposition of ammonium ferric pyrosulfate, and the decomposition of ferric sulfate. The ammonium ion in sample is completely decomposed at about 500°C. The decomposition ratio of sulfate ion or bisulfate ion is up to 99.8% above 800°C.

Abstract: Since The Bottom of Pyramid Strategy has been put forward, enterprises began to pay close attention to this untapped market with potential. But how to dig the potential of BOP market, design the product that BOP groups really need, and open the BOP market, are problems that should be solved. This paper discussed the mechanism of mining and developing the BOP market with the orientation of value. The results of the study is that the mining and developing of BOP market is essentially the process that enterprises found value, put forward the value proposition, reconstruct the value network ,create value , deliver value and realize value.

Abstract: Along with the thorough research of lithium ion battery, the lithium iron phosphate with the peridot structure becomes a new higher energy power battery anode material. But the charge and discharge mechanism of the modified lithium iron phosphate positive material did not get the unity understanding. In this paper, the carbon coating modification, metal ion doping, particle surfaces coated iron-phosphorus phase network and the nanoparticles of lithium iron phosphate were analyzed from the modified microstructure of the lithium ion phosphate batteries, so as to get the charge and discharge mechanism is the results of the active atoms and lithium ion embedded in the grid work and emergence in the layer structure, leading to the energy changes in lithium iron phosphate microstructure.

Abstract: This paper is the result of research on preparation and properties of foam glazed thermal insulation mortar by means of orthogonal experiment method, the influence of main preparation process parameters on mortar’s dry density and compressive strength, and the optimum combination was obtained. The micro-structure of foam glazed hollow bead insulation mortar was analyzed by scanning electron microscope (SEM), and the mechanism of glazed hollow bead and foaming agent was preliminarily discussed.

Abstract: The interfacial reactions and thermodynamic properties of the emulsion liquid membrane on separation and concentration of chromium (III) were discussed. Interfacial chemical reaction equations of membrane phase with P204 and mass transfer mechanism of ELM system were determined. The extraction reaction enthalpy is 11.41 kJmol¹, while stripping reaction enthalpy is-143.65 kJmol¹, were obtained by investigating reaction temperature on the distribution ratio under two different conditions. So extraction is an endothermic process and stripping is an exothermic process. And the main driving force of the separation system is the concentration gradient of hydrogen ion between external and internal phase interface.