Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick ...Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick films and integrating them on the silicon substrate as electronic and MEMS devices is a very attractive research area and challenging. In this paper, we report our research works on ferroelectric MEMS and ferroelectric films for electronic device applications. Pyroelectric thin film infrared sensors have been made, characterized, and a 32×32 array with its size of 1cm×1cm has been obtained on Si membrane. Ferroelectric thin films in amorphous phase have been applied to make silicon based hydrogen gas sensors with the metal/amorphous ferroelectric film/metal device structure, and its turn-on voltage of about 4.5V at ～1000 ppm in air is about 7 times of the best value reported in the literature. For the application of electron emission flat panel display, ferroelectric BST thin films with excess Ti concentrations have been coated on Si tips, the threshold voltage of those ferroelectric film coated tips has been reduced about one order from ～70 V/μm to 4～10 V/μm for different Ti concentrations, and however, the electron emission current density has been increased at least 3～4 order for those coated tips compared to that of the bare Si tips. To fulfill in the thickness gap between thin film of typical ～1 μm made by PVD/CVD and polished ceramic wafer of ～50 μm from the bulk, piezoelectric films with thickness in a range of 1～30 μm have been successfully deposited on Si substrate at a low temperature of 650oC by a novel hybridized deposition technique, and piezoelectric MEMS ultrasonic arrays have been very recently obtained with the sound pressure level up to ～120 dB. More detailed results will be presented and mechanisms will be discussed.展开更多
Capacity building is a key issue for the implementation of climate adaptation measures in urban planning processes. For successful capacity building, it is important to define the relevant stakeholders and tailor the ...Capacity building is a key issue for the implementation of climate adaptation measures in urban planning processes. For successful capacity building, it is important to define the relevant stakeholders and tailor the adaptation strategies first to (the position of) these stakeholders and next to the specific urban conditions and issues. In addition, scientific insights and tools can be of assistance, and the use of climate maps can help to create a common language. Thomas Hartmann and Tejo Spit’s research work on capacity building was published in American Journal of Climate Change, 3, 245-252, 2014 [1]. In June 2015, Thomas Hartmann and Tejo Spit’s research work [1] was cited by Nature Geoscience as one of six important papers in the field of capacity building [2], in detail, please see: http://www.nature.com/ngeo/journal/v8/n7/full/ngeo2465.html.展开更多
The city of Manaus (Brazil) is located in the central part of the largest tropical forest in the world, the Amazon rainforest, and has a population of approximately 2 million inhabitants. Osmar Pinto Jr., Iara Regina ...The city of Manaus (Brazil) is located in the central part of the largest tropical forest in the world, the Amazon rainforest, and has a population of approximately 2 million inhabitants. Osmar Pinto Jr., Iara Regina Cardoso de Almeida Pinto, and Osmar P. Neto showed that the lightning activity in Manaus is larger than that in the regions around the city and it has been increasing in the last four decades with the increasing of the urban area of the city. These results suggest that these spatial and time variations are related to the Urban Heat Island effect, since it is believed that the Urban Heat Island effect influences thunderstorm formation and evolution and, in consequence, the lightning activity. Therefore, they suggest that the replacement of the forest by urban areas tends to increase the lightning activity in the Amazon region. These results were published in American Journal of Climate Change in December 2013 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300390030003700300031003600360033000000 . In March 14, 2014, BBC News reported Osmar Pinto Jr. et al.’s results. The title of news report is “Enlightened forest”, in detail, please find at? http://www.bbc.com/news/science-environment-26554974.展开更多
Pinhas Alpert’s team studies recent decadal trends of aerosol optical depth (AOD) over megacities around the world by using three NASA space aerosol sensors: MODIS-Terra, MODIS-Aqua and MISR. Results from these three...Pinhas Alpert’s team studies recent decadal trends of aerosol optical depth (AOD) over megacities around the world by using three NASA space aerosol sensors: MODIS-Terra, MODIS-Aqua and MISR. Results from these three satellites clearly show a rise in air pollution levels in the megacities of the Middle East, India and North China (see Figure 1). At the same time, Alpert et al.’s study also reveals some positive trends. Megacities in Europe, northeastern United States and South-East Asia indicate a decrease in air pollution from 2002 to 2010 (see Figure 1). These cities have taken active steps to reduce the amount of contaminants in the air. Alpert hopes that these greener cities will serve as an example to the rest of the world, inspiring those who have yet to clean up their communities to push for environmental reforms.展开更多
The situation and status of the research work on the next higher transmission voltage for Northwest Power Grid in China are briefly presented in this paper. It has been preliminarily determined that 750 kV will be ado...The situation and status of the research work on the next higher transmission voltage for Northwest Power Grid in China are briefly presented in this paper. It has been preliminarily determined that 750 kV will be adopted as the next higher transmission voltage to the 330 kV being used. In consideration of the temporary slowing down of the growth of electric power industry in Northwest China and the advance of the.research work on nation--wide interconnection, the authors put forward their views on this problem.展开更多
From Nov. 5 to 6, 2013, the China Society for Human Rights Studies （CSHRS）held the Fifth National Meeting for the Exchange of Work Experience Among Human Rights Research Institutions at Wuhan University. More than 1...From Nov. 5 to 6, 2013, the China Society for Human Rights Studies （CSHRS）held the Fifth National Meeting for the Exchange of Work Experience Among Human Rights Research Institutions at Wuhan University. More than 100 experts and scholars, focusing on empirical human rights studies and their contribution to building a society based on the rule of law, shared their work experience and discussed effective strategies. CSHRS President Luo Haocai, who served as vice chairman of the 10th National Committee of the Chinese People＇s Political Consultative Conference,展开更多
文摘Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick films and integrating them on the silicon substrate as electronic and MEMS devices is a very attractive research area and challenging. In this paper, we report our research works on ferroelectric MEMS and ferroelectric films for electronic device applications. Pyroelectric thin film infrared sensors have been made, characterized, and a 32×32 array with its size of 1cm×1cm has been obtained on Si membrane. Ferroelectric thin films in amorphous phase have been applied to make silicon based hydrogen gas sensors with the metal/amorphous ferroelectric film/metal device structure, and its turn-on voltage of about 4.5V at ～1000 ppm in air is about 7 times of the best value reported in the literature. For the application of electron emission flat panel display, ferroelectric BST thin films with excess Ti concentrations have been coated on Si tips, the threshold voltage of those ferroelectric film coated tips has been reduced about one order from ～70 V/μm to 4～10 V/μm for different Ti concentrations, and however, the electron emission current density has been increased at least 3～4 order for those coated tips compared to that of the bare Si tips. To fulfill in the thickness gap between thin film of typical ～1 μm made by PVD/CVD and polished ceramic wafer of ～50 μm from the bulk, piezoelectric films with thickness in a range of 1～30 μm have been successfully deposited on Si substrate at a low temperature of 650oC by a novel hybridized deposition technique, and piezoelectric MEMS ultrasonic arrays have been very recently obtained with the sound pressure level up to ～120 dB. More detailed results will be presented and mechanisms will be discussed.
文摘Capacity building is a key issue for the implementation of climate adaptation measures in urban planning processes. For successful capacity building, it is important to define the relevant stakeholders and tailor the adaptation strategies first to (the position of) these stakeholders and next to the specific urban conditions and issues. In addition, scientific insights and tools can be of assistance, and the use of climate maps can help to create a common language. Thomas Hartmann and Tejo Spit’s research work on capacity building was published in American Journal of Climate Change, 3, 245-252, 2014 [1]. In June 2015, Thomas Hartmann and Tejo Spit’s research work [1] was cited by Nature Geoscience as one of six important papers in the field of capacity building [2], in detail, please see: http://www.nature.com/ngeo/journal/v8/n7/full/ngeo2465.html.
文摘The city of Manaus (Brazil) is located in the central part of the largest tropical forest in the world, the Amazon rainforest, and has a population of approximately 2 million inhabitants. Osmar Pinto Jr., Iara Regina Cardoso de Almeida Pinto, and Osmar P. Neto showed that the lightning activity in Manaus is larger than that in the regions around the city and it has been increasing in the last four decades with the increasing of the urban area of the city. These results suggest that these spatial and time variations are related to the Urban Heat Island effect, since it is believed that the Urban Heat Island effect influences thunderstorm formation and evolution and, in consequence, the lightning activity. Therefore, they suggest that the replacement of the forest by urban areas tends to increase the lightning activity in the Amazon region. These results were published in American Journal of Climate Change in December 2013 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300390030003700300031003600360033000000 . In March 14, 2014, BBC News reported Osmar Pinto Jr. et al.’s results. The title of news report is “Enlightened forest”, in detail, please find at? http://www.bbc.com/news/science-environment-26554974.
文摘Pinhas Alpert’s team studies recent decadal trends of aerosol optical depth (AOD) over megacities around the world by using three NASA space aerosol sensors: MODIS-Terra, MODIS-Aqua and MISR. Results from these three satellites clearly show a rise in air pollution levels in the megacities of the Middle East, India and North China (see Figure 1). At the same time, Alpert et al.’s study also reveals some positive trends. Megacities in Europe, northeastern United States and South-East Asia indicate a decrease in air pollution from 2002 to 2010 (see Figure 1). These cities have taken active steps to reduce the amount of contaminants in the air. Alpert hopes that these greener cities will serve as an example to the rest of the world, inspiring those who have yet to clean up their communities to push for environmental reforms.
文摘The situation and status of the research work on the next higher transmission voltage for Northwest Power Grid in China are briefly presented in this paper. It has been preliminarily determined that 750 kV will be adopted as the next higher transmission voltage to the 330 kV being used. In consideration of the temporary slowing down of the growth of electric power industry in Northwest China and the advance of the.research work on nation--wide interconnection, the authors put forward their views on this problem.
文摘From Nov. 5 to 6, 2013, the China Society for Human Rights Studies （CSHRS）held the Fifth National Meeting for the Exchange of Work Experience Among Human Rights Research Institutions at Wuhan University. More than 100 experts and scholars, focusing on empirical human rights studies and their contribution to building a society based on the rule of law, shared their work experience and discussed effective strategies. CSHRS President Luo Haocai, who served as vice chairman of the 10th National Committee of the Chinese People＇s Political Consultative Conference,
