The utilization of wind energy for power generation purposes is becoming increasingly attractive and gaining a great share in the electrical power production market worldwide. This research was considered a feasibilit...The utilization of wind energy for power generation purposes is becoming increasingly attractive and gaining a great share in the electrical power production market worldwide. This research was considered a feasibility study of wind energy farm in Bab Al-Hawa, Irbid. The average wind speed in the site is (6.5 m/s). Data have been collected, which includes the average monthly wind speed for 10 years, but by HOMER software to create the hourly wind speed of a representative year is created in order to build Weibull distribution and to calculate the energy generated output of the project. This project contains the construction of 33 wind turbines in 3.11 km square. Each turbine has a capacity of 900 kW rated power and the total rated capacity is 29.7 MW. The capacity factor was found equal to 37.1% which means the amount of utilization of the turbine capacity. The results show that the turbines work 87,286 h/yr, and the total energy generated is 96.548559 GWh/yr. from the 33 wind turbines installed. The initial cost of this project is equal to 80.5243 M$ and the Payback period is 7 years. We have taken into account the environmental impact such as CO2 emissions into consideration. CO2 reductions by using wind energy instead of coal-fired plant are equal to 67124.4 tons, and the CO2 emissions reduction using wind power instead of fuel oil power plant is 5343.4 tons. This research shows that wind farm at Bab Al-Hawa with a capacity of 29.7 MW, 33 wind turbines, 900 kW each has been feasible with a cost of energy 4 cents/kWh.展开更多
In 2013,Chinese President Xi Jinping announced the proposal of a“New Maritime Silk Road”in conjunction with China’s“Silk Road Economic Belt”project or“One Belt and One Road”(OBOR)initiative to support China’s ...In 2013,Chinese President Xi Jinping announced the proposal of a“New Maritime Silk Road”in conjunction with China’s“Silk Road Economic Belt”project or“One Belt and One Road”(OBOR)initiative to support China’s growing economy and to expand the PRC’s economic influence and network across Eurasia on land and at sea.This article examines the Maritime Silk Road initiative and how it aligns with a larger Chinese maritime strategy to expand China’s maritime presence in the Indian Ocean and Middle East for economic,political,and security reasons.It also looks at how China might soon be well positioned to act as an additional stabilizing force for the broader Middle East.Through an in-depth case study,it will examine China’s increased presence and interest in the world’s most strategic chokepoints:the Bab al-Mandeb.China’s navy has been an important contributor to the Combined Task Force 150 counter-piracy exercises off the Horn of Africa and Arabian Sea and this might bode well for a larger footprint in Djibouti and into the Arabian Peninsula.Understanding China’s increased presence in Djibouti and at the Bab al-Mandeb,in addition to new and emerging regional economic and political partnerships with China,is vitally important for our understanding of future regional security and politics.展开更多
A series of Eu3＋ and Dy3＋ doped/co-doped as well as un-doped BaB2Si2Os phosphors were synthesized via solid state reaction method. The PL result showed typical blue and green emission from Dy3＋ and red emission fro...A series of Eu3＋ and Dy3＋ doped/co-doped as well as un-doped BaB2Si2Os phosphors were synthesized via solid state reaction method. The PL result showed typical blue and green emission from Dy3＋ and red emission from Eu3＋. The f-f transitions in- volving the lanthanide ions along with dopant site occupancy were discussed thoroughly. Phonon assisted energy transfer process was observed from Eu3＋ to Dy3＋, which enhanced the emissions of Dy3＋. Combinations of the emissions from Eu3＋ and Dy3＋ showed a possible white to red tuneable emission on the CIE diagram. The white warmth emissions of the phosphor were revealed to be ad- justable through designing the dopant concentration and excitation wavelengths. An unusual energy transfer that originated from Eu3＋ to Dy3＋ was also discovered and the energy transfer mechanism was discussed. Proposed energy transfer mechanism was investigated using luminescence decay lifetime. All the phosphor exhibited efficient excitation in the UV range which matched well with the emissions from GaN-based LED chips. This presented the BaB2Si208 phosphor as a promising candidate for white LED applications. The effects of doping on the structural properties and the optical band gap of BaB2Si208 phosphor were also discussed in this study.展开更多
The formation of macrostep during high-temperature phase of barium meta-borate （^-BaB204） single crystal growth has been investigated by both optical in-situ observation system and atomic force microscopy （AFM）. T...The formation of macrostep during high-temperature phase of barium meta-borate （^-BaB204） single crystal growth has been investigated by both optical in-situ observation system and atomic force microscopy （AFM）. The in- si$u observation results demonstrate that the critical linear size of growing facet exceeding the size that the macrostep generates is significantly anisotropic. The critical linear sizes are around 280 ~m and 620 ~m for {1010} and （T010} planes, respectively. AFM study illustrates that macrostep train with a height of 150 nm^200 nm is one typical morphological feature of the as-grown crystal surface. The riser of each macrostep consists of several straight and parallel sub-steps, indicating the occurrence of step bunching. Additionally, triangular sub-steps with heights of several nanometers on the treads of the macrosteps are found to be another typical feature of surface morphology, which implies a microscopically competitive bunching of sub-steps between various crystallographic orientations.展开更多
The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic ev...The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic evolution of the eastern Paleotethyan Ocean.This study presents systematic stratigraphy,petrology,geochemistry,and detrital zircon U-Pb-Hf isotopic analyses for the Late Carboniferous-Jurassic sedimentary strata on both sides of the Luang Prabang Basin.Based on distinct stratigraphic ages and provenance characteristics,the clastic rock samples can be divided into four groups.The Group 1 Late Carboniferous-Early Permian samples from the western part of the basin yield detrital zircon age-peaks of~348 and~1425 Ma,with correspondingεHf(t)values ranging from-2.0 to+15.5 and+1.5 to+14,respectively.The age spectrum of Group 2 Late Carboniferous-Early Permian samples from the eastern part of the basin shows major age-peaks of~287 and~1860 Ma,withεHf(t)values of-5.9--0.9 and-3.6-+4.2,respectively.Group 3 Late Permian-Triassic samples exhibit age-peaks of~242 and~1853 Ma,along withεHf(t)values of-0.7-+14.4 and-5.4--1.8,respectively.Group 4 Middle-Late Jurassic samples yield agepeaks of~237,~431,~813,~1833,and~2460 Ma,lacking Late Devonian(413-345 Ma)detrital zircons.All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai arc in western Indochina,Group 2 was from the Kontum and Truong Son in eastern Indochina,and Group 3 has a combined provenance of the Sukhothai,Kontum,and Truong Son.Regional comparisons suggest that the Jurassic provenance was mainly derived from South China,which was imported through the northern river system.Our data,combined with the regional angular unconformities between the Jurassic continental strata and pre-Jurassic marine strata,suggest that the Luang Prabang Basin transformed into a superimposed collisional retroforeland basin during the Jurassic,and the closure of the Luang Prabang BAB occurred before the Late Triassic.展开更多
文摘The utilization of wind energy for power generation purposes is becoming increasingly attractive and gaining a great share in the electrical power production market worldwide. This research was considered a feasibility study of wind energy farm in Bab Al-Hawa, Irbid. The average wind speed in the site is (6.5 m/s). Data have been collected, which includes the average monthly wind speed for 10 years, but by HOMER software to create the hourly wind speed of a representative year is created in order to build Weibull distribution and to calculate the energy generated output of the project. This project contains the construction of 33 wind turbines in 3.11 km square. Each turbine has a capacity of 900 kW rated power and the total rated capacity is 29.7 MW. The capacity factor was found equal to 37.1% which means the amount of utilization of the turbine capacity. The results show that the turbines work 87,286 h/yr, and the total energy generated is 96.548559 GWh/yr. from the 33 wind turbines installed. The initial cost of this project is equal to 80.5243 M$ and the Payback period is 7 years. We have taken into account the environmental impact such as CO2 emissions into consideration. CO2 reductions by using wind energy instead of coal-fired plant are equal to 67124.4 tons, and the CO2 emissions reduction using wind power instead of fuel oil power plant is 5343.4 tons. This research shows that wind farm at Bab Al-Hawa with a capacity of 29.7 MW, 33 wind turbines, 900 kW each has been feasible with a cost of energy 4 cents/kWh.
文摘In 2013,Chinese President Xi Jinping announced the proposal of a“New Maritime Silk Road”in conjunction with China’s“Silk Road Economic Belt”project or“One Belt and One Road”(OBOR)initiative to support China’s growing economy and to expand the PRC’s economic influence and network across Eurasia on land and at sea.This article examines the Maritime Silk Road initiative and how it aligns with a larger Chinese maritime strategy to expand China’s maritime presence in the Indian Ocean and Middle East for economic,political,and security reasons.It also looks at how China might soon be well positioned to act as an additional stabilizing force for the broader Middle East.Through an in-depth case study,it will examine China’s increased presence and interest in the world’s most strategic chokepoints:the Bab al-Mandeb.China’s navy has been an important contributor to the Combined Task Force 150 counter-piracy exercises off the Horn of Africa and Arabian Sea and this might bode well for a larger footprint in Djibouti and into the Arabian Peninsula.Understanding China’s increased presence in Djibouti and at the Bab al-Mandeb,in addition to new and emerging regional economic and political partnerships with China,is vitally important for our understanding of future regional security and politics.
基金supported by Fundamental Research Grant Scheme of Malaysia(J130000.2526.03H97)the National Natural Science Foundation of China(51372142)
文摘A series of Eu3＋ and Dy3＋ doped/co-doped as well as un-doped BaB2Si2Os phosphors were synthesized via solid state reaction method. The PL result showed typical blue and green emission from Dy3＋ and red emission from Eu3＋. The f-f transitions in- volving the lanthanide ions along with dopant site occupancy were discussed thoroughly. Phonon assisted energy transfer process was observed from Eu3＋ to Dy3＋, which enhanced the emissions of Dy3＋. Combinations of the emissions from Eu3＋ and Dy3＋ showed a possible white to red tuneable emission on the CIE diagram. The white warmth emissions of the phosphor were revealed to be ad- justable through designing the dopant concentration and excitation wavelengths. An unusual energy transfer that originated from Eu3＋ to Dy3＋ was also discovered and the energy transfer mechanism was discussed. Proposed energy transfer mechanism was investigated using luminescence decay lifetime. All the phosphor exhibited efficient excitation in the UV range which matched well with the emissions from GaN-based LED chips. This presented the BaB2Si208 phosphor as a promising candidate for white LED applications. The effects of doping on the structural properties and the optical band gap of BaB2Si208 phosphor were also discussed in this study.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 50802105)
文摘The formation of macrostep during high-temperature phase of barium meta-borate （^-BaB204） single crystal growth has been investigated by both optical in-situ observation system and atomic force microscopy （AFM）. The in- si$u observation results demonstrate that the critical linear size of growing facet exceeding the size that the macrostep generates is significantly anisotropic. The critical linear sizes are around 280 ~m and 620 ~m for {1010} and （T010} planes, respectively. AFM study illustrates that macrostep train with a height of 150 nm^200 nm is one typical morphological feature of the as-grown crystal surface. The riser of each macrostep consists of several straight and parallel sub-steps, indicating the occurrence of step bunching. Additionally, triangular sub-steps with heights of several nanometers on the treads of the macrosteps are found to be another typical feature of surface morphology, which implies a microscopically competitive bunching of sub-steps between various crystallographic orientations.
基金supported by the National Key Research and Development Program of China(No.2023YFF0803701)the National Natural Science Foundation of China(Nos.42330302 and 42472265)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2023SP239)。
文摘The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic evolution of the eastern Paleotethyan Ocean.This study presents systematic stratigraphy,petrology,geochemistry,and detrital zircon U-Pb-Hf isotopic analyses for the Late Carboniferous-Jurassic sedimentary strata on both sides of the Luang Prabang Basin.Based on distinct stratigraphic ages and provenance characteristics,the clastic rock samples can be divided into four groups.The Group 1 Late Carboniferous-Early Permian samples from the western part of the basin yield detrital zircon age-peaks of~348 and~1425 Ma,with correspondingεHf(t)values ranging from-2.0 to+15.5 and+1.5 to+14,respectively.The age spectrum of Group 2 Late Carboniferous-Early Permian samples from the eastern part of the basin shows major age-peaks of~287 and~1860 Ma,withεHf(t)values of-5.9--0.9 and-3.6-+4.2,respectively.Group 3 Late Permian-Triassic samples exhibit age-peaks of~242 and~1853 Ma,along withεHf(t)values of-0.7-+14.4 and-5.4--1.8,respectively.Group 4 Middle-Late Jurassic samples yield agepeaks of~237,~431,~813,~1833,and~2460 Ma,lacking Late Devonian(413-345 Ma)detrital zircons.All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai arc in western Indochina,Group 2 was from the Kontum and Truong Son in eastern Indochina,and Group 3 has a combined provenance of the Sukhothai,Kontum,and Truong Son.Regional comparisons suggest that the Jurassic provenance was mainly derived from South China,which was imported through the northern river system.Our data,combined with the regional angular unconformities between the Jurassic continental strata and pre-Jurassic marine strata,suggest that the Luang Prabang Basin transformed into a superimposed collisional retroforeland basin during the Jurassic,and the closure of the Luang Prabang BAB occurred before the Late Triassic.
