基于Ga As单片集成电路工艺,对接收通道的关键元器件低噪声放大器和电调衰减器进行了芯片化设计。采用基于多层高温共烧陶瓷埋线工艺设计的金属化陶瓷外壳,对接收通道进行了微组装。测试结果表明,该S波段接收通道接收动态范围大于60 d B...基于Ga As单片集成电路工艺,对接收通道的关键元器件低噪声放大器和电调衰减器进行了芯片化设计。采用基于多层高温共烧陶瓷埋线工艺设计的金属化陶瓷外壳,对接收通道进行了微组装。测试结果表明,该S波段接收通道接收动态范围大于60 d B,增益大于95 d B,噪声系数小于1.3 d B,本振抑制大于30 d Bc,中频信号的谐波抑制大于30 d Bc。当中频自动增益控制电路起控时,接收通道输出功率稳定在(2±0.5)d Bm。该接收通道采用+5 V供电,工作电流小于250 m A。整个接收通道的尺寸仅为20 mm×13.8 mm×5.75 mm,其性能优异且集成度非常高,小型化优势非常明显。展开更多
Abstract The principles of reduction, stabilization, harmlessness, resource utilization and low carbonization for sludge treatment and disposal were stated, and the ad- vantages and disadvantages of different sludge t...Abstract The principles of reduction, stabilization, harmlessness, resource utilization and low carbonization for sludge treatment and disposal were stated, and the ad- vantages and disadvantages of different sludge treatment methods were analyzed, from which it concluded that sludge treatment should be acted according to the practical circumstances but not blindly followed, by choosing the appropriate way of sludge treatment. Key words Sludge; Sludge treatment; Landfill; Incineration; Digestion; Land use展开更多
To improve the ablation resistance of carbon/carbon(C/C)composites,a SiC/ZrC-ZrB2 double layer coating was fabricated by pack cementation and slurry-sintering method.The ablation resistance of the SiC/ZrC-ZrB2 coating...To improve the ablation resistance of carbon/carbon(C/C)composites,a SiC/ZrC-ZrB2 double layer coating was fabricated by pack cementation and slurry-sintering method.The ablation resistance of the SiC/ZrC-ZrB2 coating was tested under plasma flame above 2300°C.The results indicate that the SiC/ZrC-ZrB2 double layer coating exhibits superior ablation resistance than the ZrC-ZrB2 single layer coating.After being ablated under the plasma flame for 20 s,the mass and linear ablation rates of the ZrC-ZrB2 coating are 0.89 mg/s and 15.3μm/s,while those for SiC/ZrC-ZrB2 coating are 0.09 mg/s and 24.15μm/s,respectively.During ablation,the SiC inner layer can generate SiO2 glass and result in the formation of ZrO2-SiO2 molten film.Compared with the ZrO2 molten film formed on the ZrC-ZrB2 coating surface,the ZrO2-SiO2 molten film with lower oxygen diffusion rate and viscosity enables the SiC/ZrC-ZrB2 coating to have better self-healing ability.Therefore,the enhanced ablation resistance of the SiC/ZrC-ZrB2 coating can be attributed to the formation of dense ZrO2-SiO2 molten film under the plasma flame.展开更多
The influence of calcination temperature on TiO2 nanotubes＇ catalysis for TiO2/UV/03 was investigated. TiO2 nanotubes （TNTs） were prepared via the sol-gel method and calcined at 300--700 ℃, which were labeled as T...The influence of calcination temperature on TiO2 nanotubes＇ catalysis for TiO2/UV/03 was investigated. TiO2 nanotubes （TNTs） were prepared via the sol-gel method and calcined at 300--700 ℃, which were labeled as TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700, respectively. TNTs were characterized by transmission electron microscopy （TEM） and X-ray diffraction （XRD）. It is found that TNTs calcined at 400 ℃ showed the best thermal stability. When the calcination temperature increased from 400 ℃ to 700 ℃, the special structure of tubes was destroyed and gradually converted into nanorods and/or particles. The transformation from anatase to rutile occurred at 600 ℃, and the rutile phase was enhanced when the calcination temperature was increased to over 600 ℃. The calcina- tion temperature＇s influence on TNTs＇ adsorption activity for for TiO2/UV/O3 was investigated in landfill leachate solution chemical oxygen demand （COD） and catalytic activity In landfill leachate solution, the adsorption activity of COD decreased in the reduced order of TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700. In photocatalytic ozonation, TNTs-400 showed the best catalytic activity while TNTs-700 exhibited the worst. In other three processes, the COD removal of TNTs-300/UV/O3 was higher than those of TNTs-500/UV/O3 and TNTs-600/UV/O3 in the first 20 rain, and then became close to those of the latter two in the following 40 rain. Compared with TNTs-300 and TNTs- 400, TNTs-600 had the best anti-fouling activity, while TNTs-500 and TNTs-700 had lower anti-fouling activity than the former three. In photocatalytic ozonation, the calcination temperature of 400 ℃ was appropriate when TNTs were obtained at the synthesis temperature of 105 ℃.展开更多
Helsinki Environmental Services Authority HSY ,Ammaissuo waste management centre consists of two landfill sites. The old land filling area was established in 1987 and closed in 2007. The landfilling at the new landfil...Helsinki Environmental Services Authority HSY ,Ammaissuo waste management centre consists of two landfill sites. The old land filling area was established in 1987 and closed in 2007. The landfilling at the new landfill section started in November 2007. Until spring 2014 the main treatment method for source separated MSW （municipal solid＇waste） collected from Helsinki Metropolitan area households was landfilling. Approximately 250,000 tonnes of MSW was landfilled annually. From April 2014 on all of the MWS has been utilized in heat and electricity production at new Waste to Energy plant owned and operated by energy company Vantaa Energy Ltd. The landscaping of the landfills is currently ongoing. The construction of the landfill gas collection system was started in 1994 and from 1996 on landfill gas from old landfill area was recovered and burned in torches to reduce the greenhouse gas effect caused by methane in landfill gas. In the end of year （2004） new landfill gas utilisation system was taken in use Gas was used as a fuel in HOB （heat only boiler） to generate district heating for nearby community as well as commercial and industrial sites. The capacity of the system was 7,000 Nm3/h that corresponded to app. 30 MW of heat. Since district heat was mainly needed only during the cold season of the year only about half of the landfill gas produced by the landfill was able to utilize and rest of the gas was still flared leading to relatively low utilization rate of the gas. The construction work of the new 15 MW ＋ 1.2 MW electricity power plant started in spring 2009. The power plant consists of four gas engines and generators and organic rankine cycle process utilizing thermal oil for heat transfer from exhaust gas and steam turbine with hexamethyldisiloxane （silicone oil） as a medium agent. The ORC （Organic Rankine Cycle）-process was commissioned in August 2011 and the operational experiences have been very good. Based on current knowledge the HSY power plant is the biggest landfill gas fired power plant in Europe and probably even in the whole world. Also the combined engine and ORC-process is unique for landfill gas power plants. The third phase of the biogas utilization took place in summer 2015 when the anaerobic digestion biowaste treatment plant was introduced. At the moment the product gas from digestion plant is utilized at landfill gas power plant. In the future gas will be used as a fuel for new power plant process consisting two gas engines and ORC process. Commissioning of the new power plant will take place in October 2016. This paper presents detailed description of the landfill gas utilization system of HSY waste treatment centre and information on operational experiences of landfill gas fired power plant process.展开更多
文摘基于Ga As单片集成电路工艺,对接收通道的关键元器件低噪声放大器和电调衰减器进行了芯片化设计。采用基于多层高温共烧陶瓷埋线工艺设计的金属化陶瓷外壳,对接收通道进行了微组装。测试结果表明,该S波段接收通道接收动态范围大于60 d B,增益大于95 d B,噪声系数小于1.3 d B,本振抑制大于30 d Bc,中频信号的谐波抑制大于30 d Bc。当中频自动增益控制电路起控时,接收通道输出功率稳定在(2±0.5)d Bm。该接收通道采用+5 V供电,工作电流小于250 m A。整个接收通道的尺寸仅为20 mm×13.8 mm×5.75 mm,其性能优异且集成度非常高,小型化优势非常明显。
基金Supported by the Science and Technology Planning Project of Chongqing Municipality(cstc2011pt-gc80019)the Plan for the Construction of Technical Research and Development Base of Chongqing Municipality(cstc2014gjhz20001)the International Science&Technology Cooperation Program of China(2015DFR70390)~~
文摘Abstract The principles of reduction, stabilization, harmlessness, resource utilization and low carbonization for sludge treatment and disposal were stated, and the ad- vantages and disadvantages of different sludge treatment methods were analyzed, from which it concluded that sludge treatment should be acted according to the practical circumstances but not blindly followed, by choosing the appropriate way of sludge treatment. Key words Sludge; Sludge treatment; Landfill; Incineration; Digestion; Land use
基金Project(51304249)supported by the National Natural Science Foundation of ChinaProject(14JJ3023)supported by the Science Foundation of Hunan Province,China。
文摘To improve the ablation resistance of carbon/carbon(C/C)composites,a SiC/ZrC-ZrB2 double layer coating was fabricated by pack cementation and slurry-sintering method.The ablation resistance of the SiC/ZrC-ZrB2 coating was tested under plasma flame above 2300°C.The results indicate that the SiC/ZrC-ZrB2 double layer coating exhibits superior ablation resistance than the ZrC-ZrB2 single layer coating.After being ablated under the plasma flame for 20 s,the mass and linear ablation rates of the ZrC-ZrB2 coating are 0.89 mg/s and 15.3μm/s,while those for SiC/ZrC-ZrB2 coating are 0.09 mg/s and 24.15μm/s,respectively.During ablation,the SiC inner layer can generate SiO2 glass and result in the formation of ZrO2-SiO2 molten film.Compared with the ZrO2 molten film formed on the ZrC-ZrB2 coating surface,the ZrO2-SiO2 molten film with lower oxygen diffusion rate and viscosity enables the SiC/ZrC-ZrB2 coating to have better self-healing ability.Therefore,the enhanced ablation resistance of the SiC/ZrC-ZrB2 coating can be attributed to the formation of dense ZrO2-SiO2 molten film under the plasma flame.
基金Supported by Tianjin Science and Technology Development Plan Project (No.06YFGZSH06700)
文摘The influence of calcination temperature on TiO2 nanotubes＇ catalysis for TiO2/UV/03 was investigated. TiO2 nanotubes （TNTs） were prepared via the sol-gel method and calcined at 300--700 ℃, which were labeled as TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700, respectively. TNTs were characterized by transmission electron microscopy （TEM） and X-ray diffraction （XRD）. It is found that TNTs calcined at 400 ℃ showed the best thermal stability. When the calcination temperature increased from 400 ℃ to 700 ℃, the special structure of tubes was destroyed and gradually converted into nanorods and/or particles. The transformation from anatase to rutile occurred at 600 ℃, and the rutile phase was enhanced when the calcination temperature was increased to over 600 ℃. The calcina- tion temperature＇s influence on TNTs＇ adsorption activity for for TiO2/UV/O3 was investigated in landfill leachate solution chemical oxygen demand （COD） and catalytic activity In landfill leachate solution, the adsorption activity of COD decreased in the reduced order of TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700. In photocatalytic ozonation, TNTs-400 showed the best catalytic activity while TNTs-700 exhibited the worst. In other three processes, the COD removal of TNTs-300/UV/O3 was higher than those of TNTs-500/UV/O3 and TNTs-600/UV/O3 in the first 20 rain, and then became close to those of the latter two in the following 40 rain. Compared with TNTs-300 and TNTs- 400, TNTs-600 had the best anti-fouling activity, while TNTs-500 and TNTs-700 had lower anti-fouling activity than the former three. In photocatalytic ozonation, the calcination temperature of 400 ℃ was appropriate when TNTs were obtained at the synthesis temperature of 105 ℃.
文摘Helsinki Environmental Services Authority HSY ,Ammaissuo waste management centre consists of two landfill sites. The old land filling area was established in 1987 and closed in 2007. The landfilling at the new landfill section started in November 2007. Until spring 2014 the main treatment method for source separated MSW （municipal solid＇waste） collected from Helsinki Metropolitan area households was landfilling. Approximately 250,000 tonnes of MSW was landfilled annually. From April 2014 on all of the MWS has been utilized in heat and electricity production at new Waste to Energy plant owned and operated by energy company Vantaa Energy Ltd. The landscaping of the landfills is currently ongoing. The construction of the landfill gas collection system was started in 1994 and from 1996 on landfill gas from old landfill area was recovered and burned in torches to reduce the greenhouse gas effect caused by methane in landfill gas. In the end of year （2004） new landfill gas utilisation system was taken in use Gas was used as a fuel in HOB （heat only boiler） to generate district heating for nearby community as well as commercial and industrial sites. The capacity of the system was 7,000 Nm3/h that corresponded to app. 30 MW of heat. Since district heat was mainly needed only during the cold season of the year only about half of the landfill gas produced by the landfill was able to utilize and rest of the gas was still flared leading to relatively low utilization rate of the gas. The construction work of the new 15 MW ＋ 1.2 MW electricity power plant started in spring 2009. The power plant consists of four gas engines and generators and organic rankine cycle process utilizing thermal oil for heat transfer from exhaust gas and steam turbine with hexamethyldisiloxane （silicone oil） as a medium agent. The ORC （Organic Rankine Cycle）-process was commissioned in August 2011 and the operational experiences have been very good. Based on current knowledge the HSY power plant is the biggest landfill gas fired power plant in Europe and probably even in the whole world. Also the combined engine and ORC-process is unique for landfill gas power plants. The third phase of the biogas utilization took place in summer 2015 when the anaerobic digestion biowaste treatment plant was introduced. At the moment the product gas from digestion plant is utilized at landfill gas power plant. In the future gas will be used as a fuel for new power plant process consisting two gas engines and ORC process. Commissioning of the new power plant will take place in October 2016. This paper presents detailed description of the landfill gas utilization system of HSY waste treatment centre and information on operational experiences of landfill gas fired power plant process.
