The study was conducted to ascertain the views on piracy among marine engineering students and marine officers who had encountered piracy on international waters thereby suggesting threats to international peace. The ...The study was conducted to ascertain the views on piracy among marine engineering students and marine officers who had encountered piracy on international waters thereby suggesting threats to international peace. The respondents of the study were 50, specifically distributed to thirty （30） onboard marine engineering students enrolled for the current school year 2014-2015 and twenty （20） marine officers who had experienced piracy at Somalia and other places. The researchers employed quantitative-qualitative research method design. The questionnaire on ＂Piracy at Sea＂ was validated by experts in research, statistics, qualitative research, and maritime international conventions. To test the reliability, this same instrument was pilot-tested among marine officers and students who had been on board international ships. Qualitative data were captured through interviews by using open-ended questions. Frequency count, percentage, and rank were used in this study for descriptive-quantitative statistics. The data were analyzed using appropriate statistics through computer-processed software （SPSS）. Qualitative analysis was employed to determine the views of the respondents on piracy so that mitigation measures were elicited for protection of life at sea leading towards international peace among identified HRAs （high-risk areas）. Results revealed that seafarers were familiar of piracy. They were aware that piracy usually happens in areas like Somalia water sand other threatening territories. To combat piracy, the participants have pointed out the role of the international community in their concerted effort to help seafarers safeguard their lives specifically during these hard times. Somalia also needs to effectively check their organization by whether or not strict implementation of the Anti Piracy Law was being observed. Full knowledge of piracy, techniques for avoiding it, and surviving pirate attacks are necessary among seafarers. Satellite system called shiplock allows shipping companies to monitor location of ships particularly useful during pirate attacks, hijacks, or ship theft. They also install non-lethal electrical fences around a ship＇s perimeter to protect them during these times. IMO regulations require ships to send distress signals and warnings covertly in case of pirate attacks.展开更多
In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data proc...In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data processing,the phase space reconstruction method based on Hilbert transform,the mode analysis,and the development of feedback kicker cavity.展开更多
The effect of twist angle on the hydrogenation of bilayer graphene （BLG） is systematically explored by density functional theory （DFT） calculations. We found that a twist between the upper and lower layers of the ...The effect of twist angle on the hydrogenation of bilayer graphene （BLG） is systematically explored by density functional theory （DFT） calculations. We found that a twist between the upper and lower layers of the graphene BLGs, either big or small, interferes with the formation of inter-layer C-C covalent bonds and this leads to strong resistance to hydrogenation. In addition, the electronic properties of stable, hydrogenated twisted BLG with different twist angles and degrees of H coverage were investigated. This study paves the way to the selective functionalization of BLG for various applications.展开更多
Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosp...Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosphere and its changing pattern is very important. Although atmospheric scientists have developed a variety of means to measure precipitable water vapor(PWV) using remote sensing data that have been widely used, there are some limitations in using one kind satellite measurements for PWV retrieval over land. In this paper, a new algorithm is proposed for retrieving PWV over land by combining different kinds of remote sensing data and it would work well under the cloud weather conditions. The PWV retrieval algorithm based on near infrared data is more suitable to clear sky conditions with high precision. The 23.5 GHz microwave remote sensing data is sensitive to water vapor and powerful in cloud-covered areas because of its longer wavelengths that permit viewing into and through the atmosphere. Therefore, the PWV retrieval results from near infrared data and the indices combined by microwave bands remote sensing data which are sensitive to water vapor will be regressed to generate the equation for PWV retrieval under cloud covered areas. The algorithm developed in this paper has the potential to detect PWV under all weather conditions and makes an excellent complement to PWV retrieved by near infrared data. Different types of surface exert different depolarization effects on surface emissions, which would increase the complexity of the algorithm. In this paper, MODIS surface classification data was used to consider this influence. Compared with the GPS results, the root mean square error of our algorithm is 8 mm for cloud covered area. Regional consistency was found between the results from MODIS and our algorithm. Our algorithm can yield reasonable results on the surfaces covered by cloud where MODIS cannot be used to retrieve PWV.展开更多
文摘The study was conducted to ascertain the views on piracy among marine engineering students and marine officers who had encountered piracy on international waters thereby suggesting threats to international peace. The respondents of the study were 50, specifically distributed to thirty （30） onboard marine engineering students enrolled for the current school year 2014-2015 and twenty （20） marine officers who had experienced piracy at Somalia and other places. The researchers employed quantitative-qualitative research method design. The questionnaire on ＂Piracy at Sea＂ was validated by experts in research, statistics, qualitative research, and maritime international conventions. To test the reliability, this same instrument was pilot-tested among marine officers and students who had been on board international ships. Qualitative data were captured through interviews by using open-ended questions. Frequency count, percentage, and rank were used in this study for descriptive-quantitative statistics. The data were analyzed using appropriate statistics through computer-processed software （SPSS）. Qualitative analysis was employed to determine the views of the respondents on piracy so that mitigation measures were elicited for protection of life at sea leading towards international peace among identified HRAs （high-risk areas）. Results revealed that seafarers were familiar of piracy. They were aware that piracy usually happens in areas like Somalia water sand other threatening territories. To combat piracy, the participants have pointed out the role of the international community in their concerted effort to help seafarers safeguard their lives specifically during these hard times. Somalia also needs to effectively check their organization by whether or not strict implementation of the Anti Piracy Law was being observed. Full knowledge of piracy, techniques for avoiding it, and surviving pirate attacks are necessary among seafarers. Satellite system called shiplock allows shipping companies to monitor location of ships particularly useful during pirate attacks, hijacks, or ship theft. They also install non-lethal electrical fences around a ship＇s perimeter to protect them during these times. IMO regulations require ships to send distress signals and warnings covertly in case of pirate attacks.
文摘In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data processing,the phase space reconstruction method based on Hilbert transform,the mode analysis,and the development of feedback kicker cavity.
文摘The effect of twist angle on the hydrogenation of bilayer graphene （BLG） is systematically explored by density functional theory （DFT） calculations. We found that a twist between the upper and lower layers of the graphene BLGs, either big or small, interferes with the formation of inter-layer C-C covalent bonds and this leads to strong resistance to hydrogenation. In addition, the electronic properties of stable, hydrogenated twisted BLG with different twist angles and degrees of H coverage were investigated. This study paves the way to the selective functionalization of BLG for various applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.4147130541405036&41301653)+1 种基金the Sichuan Youth Science Foundation(Grant No.2015JQ0037)the Chongqing Meteorological Bureau Open Fund(Grant No.KFJJ-201402)
文摘Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosphere and its changing pattern is very important. Although atmospheric scientists have developed a variety of means to measure precipitable water vapor(PWV) using remote sensing data that have been widely used, there are some limitations in using one kind satellite measurements for PWV retrieval over land. In this paper, a new algorithm is proposed for retrieving PWV over land by combining different kinds of remote sensing data and it would work well under the cloud weather conditions. The PWV retrieval algorithm based on near infrared data is more suitable to clear sky conditions with high precision. The 23.5 GHz microwave remote sensing data is sensitive to water vapor and powerful in cloud-covered areas because of its longer wavelengths that permit viewing into and through the atmosphere. Therefore, the PWV retrieval results from near infrared data and the indices combined by microwave bands remote sensing data which are sensitive to water vapor will be regressed to generate the equation for PWV retrieval under cloud covered areas. The algorithm developed in this paper has the potential to detect PWV under all weather conditions and makes an excellent complement to PWV retrieved by near infrared data. Different types of surface exert different depolarization effects on surface emissions, which would increase the complexity of the algorithm. In this paper, MODIS surface classification data was used to consider this influence. Compared with the GPS results, the root mean square error of our algorithm is 8 mm for cloud covered area. Regional consistency was found between the results from MODIS and our algorithm. Our algorithm can yield reasonable results on the surfaces covered by cloud where MODIS cannot be used to retrieve PWV.
