【摘 要】
：
Every year,millions of people travel to high-elevation regions(≥2500 m above sea level) for sightseeing,mountaineering,trek-king,skiing or commercial and scientific research activities.As the largest and highest plateau of the world,the Qinghai-Tibet Pla-
【机 构】
：
State Key Laboratory of Surface Processes and Resource Ecology,Beijing Normal University,Beijing 100
论文部分内容阅读
Every year,millions of people travel to high-elevation regions(≥2500 m above sea level) for sightseeing,mountaineering,trek-king,skiing or commercial and scientific research activities.As the largest and highest plateau of the world,the Qinghai-Tibet Pla-teau (QTP) is one of the most attractive tourist destinations because of its multiple splendid sceneries.High-altitude illnesses occur when the rate of ascent to a high altitude overcomes the abil-ity of the individual to acclimatize.Chronic mountain sickness(CMS) is one of the most important high-altitude pathologies in most high-altitude regions over the world.Its hallmark sign is excessive erythrocytosis.In more advanced and severe stages,high-elevation pulmonary hypertension appears frequently,along with related remodeling of pulmonary arterioles and right ventric-ular hypertrophy [1].In 2017,life expectancies in Tibet and Qing-hai were 69.99 and 73.47 years,respectively,which are 7.19 and 3.71 years lower than China\'s average of 77.18 years [2].In addi-tion to relatively poor medical conditions,the high-altitude hypoxic environment may play an important role in such dispari-ties in life expectancy.
其他文献
近来,欧盟发起先进产业技术项目(ATI),旨在加强先进产业技术的技术监测、政策分析与数据库建设,以服务产业政策制定.欧盟对先进技术的定义与颠覆性技术有相似之处,即“被认为将在最近或未来实质性改变商业和社会环境的技术”.以此为标准,欧盟选定了16种先进产业技术,开展前瞻性技术监测,加强分析性政策跟踪,探索建立由“技术”“领域”“国家”构成的三维指标评估体系与相应数据库,主要包括:“国家”“技术”“领域”三维数据一览表、技术监测报告、领域监测报告、产品监测报告、政策简报、国际报告和欧盟报告.
毕达哥拉斯(Pythagorean)模糊集(PFS)不仅是传统直觉模糊集的一种推广,而且它能在更广泛的区域上处理多属性模糊信息的决策问题,尤其是通过正、负理想值的投影更能有效地发挥作用.本文首先回顾了 Pythagorean模糊数(PFN)的基本定义和相关运算,并基于PFN和最小元(0,1)的距离作比较提出PFN、PFS的模和投影概念,进而讨论该模的基本性质.其次,针对传统VIKOR决策方法的缺陷(只考虑正理想值刻画模糊信息)引入正、负理想值的双向投影概念,并根据双向投影给出新的群体效用值、个体遗憾值、折
Soil heterotrophic respiration (Rh) is the flux of CO2 that microbes and soil fauna release to the atmosphere by extracting the energy of organic molecules that they break down [1].Rh closes the terrestrial carbon cycle by recycling more than 70％ of the a
This manuscript presents a study of three-dimensional magnetohydrodynamic Maxwell nanofluid flow across a slendering stretched surface with Joule heating.The impact of binary chemical reactions,heat generation,thermal radiation,and thermophoretic effect i
本文给出一种新的双论域上的直觉模糊粗糙集模型,定义的近似算子能够保证被近似集与其上、下近似处于同一论域上.首先,在双论域近似空间中,定义三种直觉模糊集的上、下近似,并研究它们之间的关系.其次,在双论域直觉模糊近似空间中,给出由两个论域上直觉模糊二元关系诱导的单个论域上的直觉模糊二元关系,并进一步给出直觉模糊近似算子的构造性定义及其性质.最后,讨论所定义的近似算子与已有定义的近似算子的联系.
清楚地记得,那是一天的下午1点20分,我提前10分钟到达吴院士所住的家属楼楼道口.怕打扰院士休息,我就看着表,准备在1点27分按电梯上楼.时间一到,我冲上楼门口台阶,恰好看到一位长者出电梯正往楼门口走来.虽然没有看清楚,但我觉得他就是吴院士.真的是他.一股暖流融入心田.吴院士已是耄耋之年,但工作日志仍然安排得满满的;对于时间,他保持一贯的敏感度,从不耽搁一分一秒.我想,正是几十年如一日的惜时如金,最终成就了这位航天领域的科学家.
For ground-state singly charmed baryons,the Λ+c,Ξ+c and Ξ0c form an antitriplet representation and they all decay weakly.TheΩ0c,Ξ1+c,Ξ1+c and ∑++,+,0c form a sextet representation;among them,only Ω0c decays weakly.
光的自旋-轨道相互作用是指光的自旋角动量和轨道角动量之间的相互作用,它存在于反射、折射、散射、衍射、聚焦等基本的光学过程中.在传统大尺度量级的经典光学中可以忽略自旋-轨道相互作用的影响,但在亚波长尺度下,自旋和轨道角动量之间会发生强耦合.对光的自旋-轨道相互作用的基本起源和重要应用进行了综述.首先,介绍了光的自旋-轨道相互作用的两个重要基本概念:光子角动量和几何相位理论.其次,分别介绍了自旋-内禀轨道角动量和自旋-外禀轨道角动量两种相互作用的基本原理.然后,重点介绍了光自旋-轨道相互作用的研究进展以及代表
The nuclear history of the Universe started shortly after the Big Bang.Through nuclear reactions,the ashes from the primordial explosion were transformed to hydrogen,helium and trace of other light elements,and to heavier products from rich variety of nuc