This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Sim...This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Simulation by Ansoft high frequency structure simulator(HFSS)10.0 shows that the in-band impedances are quite stable and satisfactory.Rejected narrow frequency bands are further obtained within the wideband width by inserting U-shaped slots into the fed line of the antennas.The antennas have a dimension of 50mm by 40mm by 1.5mm.The simulation and measurement results show that the proposed antennas have stable directional radiation patterns,very low profile and low fabrication cost,which are suitable for the UWB system.展开更多
Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand cu...Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.展开更多
To the Editor One of the most significant demographic changes in our cotmtry is the increase in the elderly population. In China Mainland, the population aged 60 and older was 194 million in 2012, accounting for 14.3%...To the Editor One of the most significant demographic changes in our cotmtry is the increase in the elderly population. In China Mainland, the population aged 60 and older was 194 million in 2012, accounting for 14.3% of the total population. However, by 2053, it is estimated that the number of elderly will reach 487 million, representing 34.8% of the total population. Elderly patients represent an everncreasing populace in emergency medicine who often present with atypical signs and symptoms as well as eomorbidities that can complicate diagnoses and treatment.Ell The geographic factors and the developmental status of the country can influence the spectrum of common geriatric emergencies. Thus, this study presents a retrospective analysis of common causes of geriatric emergencies involving 9,628 elderly patients from Jan. 2008 to Dec. 2013 in an emergency department in Beijing, China.展开更多
基金Supported by the National High Technology Research and Development Programme of China(No.2007AA01Z261,2009AA01Z228)the National Science and Technology Major Special Project(No.2009ZX03007-001-01)
文摘This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Simulation by Ansoft high frequency structure simulator(HFSS)10.0 shows that the in-band impedances are quite stable and satisfactory.Rejected narrow frequency bands are further obtained within the wideband width by inserting U-shaped slots into the fed line of the antennas.The antennas have a dimension of 50mm by 40mm by 1.5mm.The simulation and measurement results show that the proposed antennas have stable directional radiation patterns,very low profile and low fabrication cost,which are suitable for the UWB system.
文摘Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.
文摘To the Editor One of the most significant demographic changes in our cotmtry is the increase in the elderly population. In China Mainland, the population aged 60 and older was 194 million in 2012, accounting for 14.3% of the total population. However, by 2053, it is estimated that the number of elderly will reach 487 million, representing 34.8% of the total population. Elderly patients represent an everncreasing populace in emergency medicine who often present with atypical signs and symptoms as well as eomorbidities that can complicate diagnoses and treatment.Ell The geographic factors and the developmental status of the country can influence the spectrum of common geriatric emergencies. Thus, this study presents a retrospective analysis of common causes of geriatric emergencies involving 9,628 elderly patients from Jan. 2008 to Dec. 2013 in an emergency department in Beijing, China.
