The objective of this study is to estimate the vehicle kilometer traveled（VKT） and on-road emissions using the traffic volume in urban. We estimated two VKT; one is based on registered vehicles and the other is base...The objective of this study is to estimate the vehicle kilometer traveled（VKT） and on-road emissions using the traffic volume in urban. We estimated two VKT; one is based on registered vehicles and the other is based on traffic volumes. VKT for registered vehicles was 2.11 times greater than that of the applied traffic volumes because each VKT estimation method is different. Therefore, we had to define the inner VKT is moved VKT inner in urban to compare two values. Also, we focused on freight modes because these are discharged much air pollutant emissions. From analysis results, we found middle and large trucks registered in other regions traveled to target city in order to carry freight, target city has included many industrial and logistics areas. Freight is transferred through the harbors,large logistics centers, or via locations before being moved to the final destination. During this process, most freight is moved by middle and large trucks, and trailers rather than small trucks for freight import and export. Therefore, these trucks from other areas are inflow more than registered vehicles. Most emissions from diesel trucks had been overestimated in comparison to VKT from applied traffic volumes in target city. From these findings, VKT is essential based on traffic volume and travel speed on road links in order to estimate accurately the emissions of diesel trucks in target city. Our findings support the estimation of the effect of on-road emissions on urban air quality in Korea.展开更多
Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a prac...Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a practical system.This achievement set a world record for long-distance stable transmission,demonstrating a rate of 2.38 kbps at a distance of 104.8 km over 168 hours.展开更多
On Aug.21,the 2024 Trans-Himalaya Cycling Race kicked off in Lhasa,the Xizang Autonomous Region.The five-day event,with three stages in Lhasa.Nyingchi,and Xigaze,covered a total distance of over 310 kilometers and ran...On Aug.21,the 2024 Trans-Himalaya Cycling Race kicked off in Lhasa,the Xizang Autonomous Region.The five-day event,with three stages in Lhasa.Nyingchi,and Xigaze,covered a total distance of over 310 kilometers and ranged from 2,988 to 4,034 meters above sea level.22 domestic and international teams with over 150 athletes participated in the race.展开更多
话题激活。阅读以下文字,请先总结出文章中关于科技发展的话题表达,再与同学交流你的成果,并完成文后的练习。World's largest electric motorcycle未来电动车:速度与里程的完美结合。Pitched as a near‑future electric touring bi...话题激活。阅读以下文字,请先总结出文章中关于科技发展的话题表达,再与同学交流你的成果,并完成文后的练习。World's largest electric motorcycle未来电动车:速度与里程的完美结合。Pitched as a near‑future electric touring bike,the Felo TOOZ has a top speed of 125 mph,and a range of 720 kilometers per charge.展开更多
针对车用发动机机械零部件在设计阶段的B10可靠寿命计算问题,分析车用发动机机械零部件的特点及其寿命建模方法,研究基于应力-强度干涉的车用发动机机械零部件失效行为表达方法;以车辆行驶里程为寿命度量指标,建立车用发动机机械零部件...针对车用发动机机械零部件在设计阶段的B10可靠寿命计算问题,分析车用发动机机械零部件的特点及其寿命建模方法,研究基于应力-强度干涉的车用发动机机械零部件失效行为表达方法;以车辆行驶里程为寿命度量指标,建立车用发动机机械零部件的B10可靠寿命计算模型,推导机械零部件的可靠度函数、失效率函数、寿命累积分布函数和寿命概率密度函数以及平均失效里程(Mean kilometer to failure,MKTF)计算模型。研究表明,运用建立的方法及模型,能够结合车用发动机的工作剖面,利用零部件的应力、强度等参数,计算出车用发动机机械零部件的B10可靠寿命、可靠度与失效率随寿命变化规律、寿命概率分布特征以及平均失效里程,可以更好地指导发动机机械零部件的设计、试验、使用等。展开更多
To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation...To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation and accident rate per 100,000,000 vehicle kilometers by regression analysis. The model shows that the more discrete is the speed distribution, the higher is the accident rate, which provides theoretical gist for speed limit on freeway. It is suggested that speed limit should be set according to 85th percentile speed obtained by the relationship between 85th percentile speed and RCCs (curvature change rate of single circular curve), and different speed limits should be set for cars and trucks. Through analyzing spot speed data of eight freeways in China, regression models were established between 85th percentile speed and RCCs and 15th percentile speed and RCCs. Reasonable speed limit suggestion values are put forward through these models.展开更多
Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span section...Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections,but also generates vortex induced vibration (VIV),which can lead to fatigue issues. The phenomenon,if not predicted and controlled properly,will negatively affect pipeline integrity,leading to expensive remediation and intervention work. Span analysis can be complicated by:long span lengths,a large number of spans caused by a rough seabed,and multi-span interactions. In addition,the complexity can be more onerous and challenging when soil uncertainty,concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a'state-of-the-art' finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.展开更多
Adygea(or Adygeya), one of the seven autonomous republics of Russian Federation, is situated in the northern part of Caucasus. With the 7800 square kilometer's area, the Adygh Republic has a population of 446,000;...Adygea(or Adygeya), one of the seven autonomous republics of Russian Federation, is situated in the northern part of Caucasus. With the 7800 square kilometer's area, the Adygh Republic has a population of 446,000; its rural and urban population is almost equally divided into 242,600 and 207,900 respectively. In the north Caucasus region there are three language families: Ibero- Caucasian, Ataic and Indo- European. The Ibero- Caucasian consists of three groups: Northeast Caucasian group,Northwest Caucasian Group and Central Caucasian. Adyge is one of the Circassian languages and belongs to the Northwest Caucasian group. The other two Circassian languages are Cherkess and Kabardian(Lazarev & Pravikova, 2005). This paper mainly analyzed the sociolinguistic situation of the Republic of Adygea from three perspectives: past, present and future.展开更多
As main transportation and communication facilities,automo-biles contribute much convenience for people all over the world.However,they also bring about serious problem of pollution,espe-cially in urban areas where pe...As main transportation and communication facilities,automo-biles contribute much convenience for people all over the world.However,they also bring about serious problem of pollution,espe-cially in urban areas where people are jeopardized in health by theheavy noise and the toxic substances in the exhaust gas from them.Early in 1966,air pollution investigation made by USA pointed outthat 61% of total air pollution originated from automobiles.In 1981,West Germany studied and analysed the detrimental substancesexhausted from sedans,trucks and buses per kilometer travel dis-tance,as shown in the following table:展开更多
THE Zigong Lantern Festivalis a well-established traditionin Sichuan Province.It has,in fact,become so famous through-out China that it has been takenabroad several times,where it hasbeen an enormous success The fes-t...THE Zigong Lantern Festivalis a well-established traditionin Sichuan Province.It has,in fact,become so famous through-out China that it has been takenabroad several times,where it hasbeen an enormous success The fes-tival combines traditional workman-ship and modern science and tech-nology in its brilliant display of lan-terns.展开更多
It didn’t take long to travel the seven kilometers from Kashgar city center to the renowned“Folk Instrument Village.”At the center of the village square is a three-meter-tall colored sculpture of Gijak(fiddle).The ...It didn’t take long to travel the seven kilometers from Kashgar city center to the renowned“Folk Instrument Village.”At the center of the village square is a three-meter-tall colored sculpture of Gijak(fiddle).The main gate is a Uygur-style structure supported by 12 columns symbolizing the 12 Muqam(the 12-section classic music of the Uygurs).A variety of folk instruments are painted on the walls on both sides.展开更多
China's Zhurong Travels 1.9 km on Mars The Mars fover Zhurong has traveled more than 1.9 kilometers since it first set its wheels on the surface of the planet of Mars inMay last year,according to the latest data,r...China's Zhurong Travels 1.9 km on Mars The Mars fover Zhurong has traveled more than 1.9 kilometers since it first set its wheels on the surface of the planet of Mars inMay last year,according to the latest data,released by the Lunar Exploration and Space Program Center of the China National Space Administration.展开更多
基金supported by the Korea Transport Institute,Republic of Koreasupported by Technology Development to evaluate GHG Emissions Indices of Mobiles and Municipal Sustainability(Transport logistics project 14TLRP-CO84940-01) commissioned from KAIA
文摘The objective of this study is to estimate the vehicle kilometer traveled（VKT） and on-road emissions using the traffic volume in urban. We estimated two VKT; one is based on registered vehicles and the other is based on traffic volumes. VKT for registered vehicles was 2.11 times greater than that of the applied traffic volumes because each VKT estimation method is different. Therefore, we had to define the inner VKT is moved VKT inner in urban to compare two values. Also, we focused on freight modes because these are discharged much air pollutant emissions. From analysis results, we found middle and large trucks registered in other regions traveled to target city in order to carry freight, target city has included many industrial and logistics areas. Freight is transferred through the harbors,large logistics centers, or via locations before being moved to the final destination. During this process, most freight is moved by middle and large trucks, and trailers rather than small trucks for freight import and export. Therefore, these trucks from other areas are inflow more than registered vehicles. Most emissions from diesel trucks had been overestimated in comparison to VKT from applied traffic volumes in target city. From these findings, VKT is essential based on traffic volume and travel speed on road links in order to estimate accurately the emissions of diesel trucks in target city. Our findings support the estimation of the effect of on-road emissions on urban air quality in Korea.
文摘Recently,Long et al.[1]at the Beijing Academy of Quantum Information Sciences,in collaboration with the partners,proposed the theory of oneway quantum secure direct communication(QSDC)and successfully developed a practical system.This achievement set a world record for long-distance stable transmission,demonstrating a rate of 2.38 kbps at a distance of 104.8 km over 168 hours.
文摘On Aug.21,the 2024 Trans-Himalaya Cycling Race kicked off in Lhasa,the Xizang Autonomous Region.The five-day event,with three stages in Lhasa.Nyingchi,and Xigaze,covered a total distance of over 310 kilometers and ranged from 2,988 to 4,034 meters above sea level.22 domestic and international teams with over 150 athletes participated in the race.
文摘话题激活。阅读以下文字,请先总结出文章中关于科技发展的话题表达,再与同学交流你的成果,并完成文后的练习。World's largest electric motorcycle未来电动车:速度与里程的完美结合。Pitched as a near‑future electric touring bike,the Felo TOOZ has a top speed of 125 mph,and a range of 720 kilometers per charge.
文摘针对车用发动机机械零部件在设计阶段的B10可靠寿命计算问题,分析车用发动机机械零部件的特点及其寿命建模方法,研究基于应力-强度干涉的车用发动机机械零部件失效行为表达方法;以车辆行驶里程为寿命度量指标,建立车用发动机机械零部件的B10可靠寿命计算模型,推导机械零部件的可靠度函数、失效率函数、寿命累积分布函数和寿命概率密度函数以及平均失效里程(Mean kilometer to failure,MKTF)计算模型。研究表明,运用建立的方法及模型,能够结合车用发动机的工作剖面,利用零部件的应力、强度等参数,计算出车用发动机机械零部件的B10可靠寿命、可靠度与失效率随寿命变化规律、寿命概率分布特征以及平均失效里程,可以更好地指导发动机机械零部件的设计、试验、使用等。
基金Special Research Fund for Doctoral Program of Higher Education of China(Grant No.20030213030)
文摘To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation and accident rate per 100,000,000 vehicle kilometers by regression analysis. The model shows that the more discrete is the speed distribution, the higher is the accident rate, which provides theoretical gist for speed limit on freeway. It is suggested that speed limit should be set according to 85th percentile speed obtained by the relationship between 85th percentile speed and RCCs (curvature change rate of single circular curve), and different speed limits should be set for cars and trucks. Through analyzing spot speed data of eight freeways in China, regression models were established between 85th percentile speed and RCCs and 15th percentile speed and RCCs. Reasonable speed limit suggestion values are put forward through these models.
文摘Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections,but also generates vortex induced vibration (VIV),which can lead to fatigue issues. The phenomenon,if not predicted and controlled properly,will negatively affect pipeline integrity,leading to expensive remediation and intervention work. Span analysis can be complicated by:long span lengths,a large number of spans caused by a rough seabed,and multi-span interactions. In addition,the complexity can be more onerous and challenging when soil uncertainty,concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a'state-of-the-art' finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.
文摘Adygea(or Adygeya), one of the seven autonomous republics of Russian Federation, is situated in the northern part of Caucasus. With the 7800 square kilometer's area, the Adygh Republic has a population of 446,000; its rural and urban population is almost equally divided into 242,600 and 207,900 respectively. In the north Caucasus region there are three language families: Ibero- Caucasian, Ataic and Indo- European. The Ibero- Caucasian consists of three groups: Northeast Caucasian group,Northwest Caucasian Group and Central Caucasian. Adyge is one of the Circassian languages and belongs to the Northwest Caucasian group. The other two Circassian languages are Cherkess and Kabardian(Lazarev & Pravikova, 2005). This paper mainly analyzed the sociolinguistic situation of the Republic of Adygea from three perspectives: past, present and future.
文摘As main transportation and communication facilities,automo-biles contribute much convenience for people all over the world.However,they also bring about serious problem of pollution,espe-cially in urban areas where people are jeopardized in health by theheavy noise and the toxic substances in the exhaust gas from them.Early in 1966,air pollution investigation made by USA pointed outthat 61% of total air pollution originated from automobiles.In 1981,West Germany studied and analysed the detrimental substancesexhausted from sedans,trucks and buses per kilometer travel dis-tance,as shown in the following table:
文摘THE Zigong Lantern Festivalis a well-established traditionin Sichuan Province.It has,in fact,become so famous through-out China that it has been takenabroad several times,where it hasbeen an enormous success The fes-tival combines traditional workman-ship and modern science and tech-nology in its brilliant display of lan-terns.
文摘It didn’t take long to travel the seven kilometers from Kashgar city center to the renowned“Folk Instrument Village.”At the center of the village square is a three-meter-tall colored sculpture of Gijak(fiddle).The main gate is a Uygur-style structure supported by 12 columns symbolizing the 12 Muqam(the 12-section classic music of the Uygurs).A variety of folk instruments are painted on the walls on both sides.
文摘China's Zhurong Travels 1.9 km on Mars The Mars fover Zhurong has traveled more than 1.9 kilometers since it first set its wheels on the surface of the planet of Mars inMay last year,according to the latest data,released by the Lunar Exploration and Space Program Center of the China National Space Administration.
