On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country...On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country's high-speed locomotive traction gears. The measures include the fol- lowing five aspects : optimally selecting the material and heat treatment process , optimally designing the tooth profile . reasonably choosing the manufacture accuracy and technique , optimally choosing the lubricant and the way of lubrication and seal , improving the dynamic feature of the gearing. In the respect of the tooth profile , a hob with optimal cutter angles is designed to make root thickness on the dangerous section as large as possible and the stress concentration as small as possible. Ad- dendum modification coefficient is optimized to minimize the maximum flash temperature in the course of meshing. Finally . finite element analysis method is used to calculate the deformation and the stress of teeth accurately. And on this basis , optimal profile correction and axial modification have been designed with regard to the start , continuious running and high speed travel of the loco- motive .展开更多
In the morning of August 20,Heilongjiang Zijin Copper Project formally signed agreement at Fularji District in Qiqihar City.This also signals that the copper smelting project with a total investment of 4 billion yuan,...In the morning of August 20,Heilongjiang Zijin Copper Project formally signed agreement at Fularji District in Qiqihar City.This also signals that the copper smelting project with a total investment of 4 billion yuan,a project under planning since 2011,has formally landed in Qiqihar City.展开更多
With the depletion of fossil fuel and climate change,multi-energy systems have attracted widespread attention in buildings.Multi-energy systems,fuelled by renewable energy,including solar and biomass energy,are gain-i...With the depletion of fossil fuel and climate change,multi-energy systems have attracted widespread attention in buildings.Multi-energy systems,fuelled by renewable energy,including solar and biomass energy,are gain-ing increasing adoption in commercial buildings.Most of previous capacity design approaches are formulated based upon conventional operating schedules,which result in inappropriate design capacities and ineffective operating schedules of the multi-energy system.Therefore,a two-stage capacity optimization approach is pro-posed for the multi-energy system with its optimal operating schedule taken into consideration.To demonstrate the effectiveness of the proposed capacity optimization approach,it is tested on a renewable energy fuelled multi-energy system in a commercial building.The primary energy devices of the multi-energy system consist of biomass gasification-based power generation unit,heat recovery unit,heat exchanger,absorption chiller,elec-tric chiller,biomass boiler,building integrated photovoltaic and photovoltaic thermal hybrid solar collector.The variable efficiency owing to weather condition and part-load operation is also considered.Genetic algorithm is adopted to determine the optimal design capacity and operating capacity of energy devices for the first-stage and second-stage optimization,respectively.The two optimization stages are interrelated;thus,the optimal design and operation of the multi-energy system can be obtained simultaneously and effectively.With the adoption of the proposed novel capacity optimization approach,there is a 14%reduction of year-round biomass consumption compared to one with the conventional capacity design approach.展开更多
Opened to traffic in August 2004,the RionAntirion Bridge crosses the Gulf of Corinth near Patras in western Greece.It consists of an impressive multi cablestayed span bridge connected to the land by two approaches.An ...Opened to traffic in August 2004,the RionAntirion Bridge crosses the Gulf of Corinth near Patras in western Greece.It consists of an impressive multi cablestayed span bridge connected to the land by two approaches.An exceptional combination of physical conditions made this project quite unusual:high water depth,deep strata of weak soil,strong seismic activity and fault displacements.In addition a risk of heavy ship collision had to be taken into account.The structure has been designed in view of challenging severe earthquakes and ensuring the everyday serviceability of the link as well.To make the bridge feasible,innovative techniques had to be developed:The strength of the in situ soil has been improved by means of inclusions;the bridge deck has been suspended on its full length,and therefore isolated as much as it can be.展开更多
文摘On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country's high-speed locomotive traction gears. The measures include the fol- lowing five aspects : optimally selecting the material and heat treatment process , optimally designing the tooth profile . reasonably choosing the manufacture accuracy and technique , optimally choosing the lubricant and the way of lubrication and seal , improving the dynamic feature of the gearing. In the respect of the tooth profile , a hob with optimal cutter angles is designed to make root thickness on the dangerous section as large as possible and the stress concentration as small as possible. Ad- dendum modification coefficient is optimized to minimize the maximum flash temperature in the course of meshing. Finally . finite element analysis method is used to calculate the deformation and the stress of teeth accurately. And on this basis , optimal profile correction and axial modification have been designed with regard to the start , continuious running and high speed travel of the loco- motive .
文摘In the morning of August 20,Heilongjiang Zijin Copper Project formally signed agreement at Fularji District in Qiqihar City.This also signals that the copper smelting project with a total investment of 4 billion yuan,a project under planning since 2011,has formally landed in Qiqihar City.
文摘With the depletion of fossil fuel and climate change,multi-energy systems have attracted widespread attention in buildings.Multi-energy systems,fuelled by renewable energy,including solar and biomass energy,are gain-ing increasing adoption in commercial buildings.Most of previous capacity design approaches are formulated based upon conventional operating schedules,which result in inappropriate design capacities and ineffective operating schedules of the multi-energy system.Therefore,a two-stage capacity optimization approach is pro-posed for the multi-energy system with its optimal operating schedule taken into consideration.To demonstrate the effectiveness of the proposed capacity optimization approach,it is tested on a renewable energy fuelled multi-energy system in a commercial building.The primary energy devices of the multi-energy system consist of biomass gasification-based power generation unit,heat recovery unit,heat exchanger,absorption chiller,elec-tric chiller,biomass boiler,building integrated photovoltaic and photovoltaic thermal hybrid solar collector.The variable efficiency owing to weather condition and part-load operation is also considered.Genetic algorithm is adopted to determine the optimal design capacity and operating capacity of energy devices for the first-stage and second-stage optimization,respectively.The two optimization stages are interrelated;thus,the optimal design and operation of the multi-energy system can be obtained simultaneously and effectively.With the adoption of the proposed novel capacity optimization approach,there is a 14%reduction of year-round biomass consumption compared to one with the conventional capacity design approach.
文摘Opened to traffic in August 2004,the RionAntirion Bridge crosses the Gulf of Corinth near Patras in western Greece.It consists of an impressive multi cablestayed span bridge connected to the land by two approaches.An exceptional combination of physical conditions made this project quite unusual:high water depth,deep strata of weak soil,strong seismic activity and fault displacements.In addition a risk of heavy ship collision had to be taken into account.The structure has been designed in view of challenging severe earthquakes and ensuring the everyday serviceability of the link as well.To make the bridge feasible,innovative techniques had to be developed:The strength of the in situ soil has been improved by means of inclusions;the bridge deck has been suspended on its full length,and therefore isolated as much as it can be.