In this article, we propose methods that increase numerical efficiency of dynamic simulation of spatial multibody systems
described in absolute coordinates. The successive coordinate projection method efficiently stabilizes the system constraints
in the case when a non-minimal set of orientation coordinates is used to describe the orientation of bodies in space. The
new procedure of generation of Newton–Euler equations is shown in detail for systems with the most popular types of joints
(prismatic joint, revolute joint, etc.). The proposed algorithms were tested with models of a governor mechanism and Yamaha
YZF-R1 motorcycle engine. The simulation results show that the successive coordinate projection method is stable and can be
implemented for complex mechanical systems. 相似文献
An important commitment in the UN Framework Convention on Climate Change is to conduct mitigation analysis and to communicate climate change measures and polices. In major part reducing CO2 as well as the other greenhouse gas emissions in Kazakstan can be a side-product of measures addressed to increasing energy efficiency. Since such measures are very important for the national economy, mitigation strategies in the energy sector of Kazakstan are directly connected with the general national strategy of the energy sector development. This paper outlines the main measures and technologies in energy sector of Kazakstan which can lead to GHG emissions reduction and presents the results of current mitigation assessment.
The mitigation analysis addressed to energy production sector. A baseline and six mitigation scenarios were developed to evaluate the most attractive mitigation options, focusing on specific technologies which have been already included in sustainable energy programs. According to the baseline projection, Kazakstan's CO2 emissions will not exceed their 1990 level until 2005. The potential for CO2 emission reduction is estimated to be about 11% of the baseline emission level by the end of considered period (in 2020). The main mitigation options in the energy production sector in terms of mitigation potential and technical and economical feasibility include rehabilitation of thermal power plants aimed to increasing efficiency, use of nuclear energy, and further expansion in the use of hydro energy based on small hydroelectric power plants. 相似文献
The natural lignan hydroxymatairesinol was hydrogenolysed to a potential anticarcinogenic substance matairesinol over different carbon-supported palladium catalysts. The reaction was conducted in 2-propanol at 70 °C under hydrogen flow in a stirred glass reactor. The catalysts were characterised by N2-physisorption, CO pulse chemisorption and pH measurement of aqueous catalyst slurries. The most active catalyst (Degussa-Hüls) gave yields of matairesinol over 90% in 4 h. It was concluded that the acidity of the catalyst had a profound influence on the reaction rate. 相似文献
We have synthesized NiCo2O4 nanoparticles (NCO NPs) using an ascorbic acid-assisted co-precipitation method for the first time. When NCO NPs are used as an anode material for lithium-ion batteries, the cell exhibits superior lithium storage properties, such as high capacity (700 mA h g?1 after 300 cycles at 200 mA g?1), excellent rate capabilities (applied current density range 100–1200 mA g?1), and impressive cycling stability (at 1200 mA g?1 up to 650 cycles). The enhanced electrochemical properties of NCO NPs are due to the nanometer dimensions which not only offers a smooth charge-transport pathway and short diffusion paths of the lithium ions but also adequate spaces for volume expansion during Li storage. Hence, this eco-friendly synthesis approach will provide a new strategy for the synthesis of various nanostructured metal oxide compounds, for energy conversion and storage systems applications. 相似文献
The isothermal section of the Er-Ag-Sn system at 873 K was constructed with the use of scanning electron microscopy, energy-dispersive x-ray microanalysis and x-ray powder diffraction. Two ternary compounds were confirmed at this temperature: ErAgSn (LiGaGe structure type, P63mc, Z = 2, a = 4.6595(2) Å, c = 7.2872(3) Å) and non-stoichiometric phase ErAg1?xSn2+x (Cu3Au structure type, Pm-3m, Z = 1). For the last one homogeneity range was established (0.08 < x < 0.24) and lattice parameters were determined (a = 4.5007(4), 4.5040(2), 4.5107(1), 4.5412(1) Å for the compositions Er25.4Ag23.4Sn51.2, Er25.7Ag23.0Sn51.3, Er25.7Ag21.7Sn52.6, Er25.2Ag18.6Sn56.2 (at.%) respectively). Melting point of the phase Er25.7Ag21.7Sn52.6 (at.%) was determined to be 1199 K by differential thermal analysis. 相似文献