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Why are COVID-19 travel bubbles a tightrope walk?An investigation based on the Trans-Tasmanian case

Communications in Transportation Research 2023年第1期3卷 37-43页

作者： Xiaoqian sun Sebastian Wandelt Anming Zhang National Key Laboratory of CNS/ATM School of Electronic and Information EngineeringBeihang UniversityBeijing100191China Sauder School of Business University of British ColumbiaVancouverBCCanada

The COVID-19 pandemic has hit the transportation sector hard;particularly air transportation,as a major mode of long-distance transportation,has been affected *** the dawn of COVID-19,politicians and policy makers have discussed the idea of introducing travel bubbles between countries(or counties),to allow for a continued exchange of people and *** eponymous Trans-Tasmanian travel bubble is a major example,involving quarantine-free travel between Australia and New *** both countries have tried to form a travel bubble various times,recurring setbacks and difficulties were *** October 2021,this ambitious project presumably has come to an end,with both countries announcing the essential capitulation of their COVIDZero strategies and a planned opening towards broader international *** this study,we perform a close investigation of the history behind the Trans-Tasmanian travel bubble as an on-off relationship,identifying a set of drivers for the serious problems involving a sustainable setup and *** develop a framework which represents important factors for successful travel bubbles and believe that the satisfaction of all factors at once is extremely *** results and insights are not specific to the Trans-Tasmanian case only,although it is taken as a running example,but can be generalized to various scales and *** hope that our study contributes to the literature by improving our understanding of the highly buzzed travel bubble concept,while providing empirical evidence for the troubles that inherently make such bubbles a tightrope walk.

关键词： COVID-19 Travel bubble Australia New Zealand

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Predicted Pressure-Induced High-Energy-Density Iron Pentazolate Salts

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Chinese Physics Letters 2022年第8期39卷 47-52页

作者： Chuli sun Wei Guo Yugui Yao Frontiers Science Center for High Energy Material(MOE) Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE) School of PhysicsBeijing Institute of TechnologyBeijing 100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Metal-pentazolate compounds as candidates for novel high-energy-density materials have attracted extensive attention in recent ***,dehydrated pentazolate salts of transition metal iron are rarely *** predict two new iron pentazolate salts Fdd2-FeN10 and P1(No.1)-FeN10 using a constrained crystal search method based on first-principles *** propose that the stable Fdd2-FeN_(10) crystal may be synthesized from FeN and N_(2) above 20 GPa,and its formation enthalpy is lower than the reported iron pentazolate salt(marked as P1(No.2)-FeN_(10)).Crystal P1(No.1)-FeN_(10) is composed of iron bispentazole *** enthalpy,phonon spectrum and ab initio molecular dynamics calculations are performed to show their thermodynamic,mechanical and dynamic ***,the high energy density(3.709 kJ/g,6.349 kJ/g)and good explosive performance indicate their potential applications as high-energy-density materials.

关键词： properties materials enthalpy

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Rapid assessment and explanation of tree species abundance along the elevation gradient in Gaoligong Mountains,Yunnan,China

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Chinese Science Bulletin 2007年第A2期52卷 225-231页

作者： sun ZhenHua PENG ShengJing OU XiaoKun Institute of Ecology and Geobotany Yunnan University Kunming 650091 China

这篇文章在西方云南在 Gaoligong 山沿着举起坡度与气候的变量介绍树种类丰富和它的协会的分析，中国。从在 Gaoligong 山区的科学报纸和书的数据被收集并且外推阐明由检验气候的变量的沿着坡度的在举起范围和树种类的举起中点之间的举... 详细信息

这篇文章在西方云南在 Gaoligong 山沿着举起坡度与气候的变量介绍树种类丰富和它的协会的分析，中国。从在 Gaoligong 山区的科学报纸和书的数据被收集并且外推阐明由检验气候的变量的沿着坡度的在举起范围和树种类的举起中点之间的举起模式和关系的机械学的理解。树种类丰富与一座山峰显示出一个单峰的模式在中间举起(大约 2000 m ) 并且有一个狭窄的举起范围的种类发生在更高或更低的举起，当一个更宽的举起范围在坡度的中间被发现时。树种类丰富是最高在温度和水可获得性是中等的的地方。在影响种类的气候的变量之间的关系看起来由于在不同坡度改变的这些效果的直接、间接的因素，和效果。

关键词：树种云南省高黎贡山生态系统

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Surface borehole synthesis tension deformation fracture time-space rule

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International Journal of Mining Science and Technology 2012年第4期22卷 465-470页

作者： Liu Jianzhong sun Haitao Hu Qianting China Coal Research Institute Beijing 100013China Post Doctor Mobile Station Chongqing Research Institute of China Coal Technology&Engineering Group Corp. Chongqing 400039China National Key Laboratory of Gas Disaster Detecting Preventing and Emergency ControllingChongqing 400037China

In order to release the tension and shear effect of the superjacent rock strata movement during excavation in coal mine,protect the surface borehole case from fracturing fast and make a good use of the surface borehole during goaf methane drawing,a common synthesis tension deformation fracture model was set up based on the synthesis tension effect of the rock strata,and the deformation rule of the surface borehole case with time and space was *** results suggest that,to reduce the deformation the surface borehole should be built between the boundary of the stope and the knee of subsidence *** the same time,a 3DEC simulation model and an engineering example were carried out to examine the rules of theoretical *** result suggests that the model and the rules accord to the test and have good building and protection engineering application values to the surface borehole.

关键词： Surface boreholeMethane drawingSynthesis tensionTime-space rules

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Perfect Transfer of Many-Particle Quantum State via High-Dimensional Systems with Spectrum-Matched Symmetry

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Communications in Theoretical Physics 2007年第3X期48卷 445-448页

作者： LI Ying SONG Zhi sun Chang-Pu Department of Physics The Key Lab of Weak Light Nonlinear Photonics Ministry of Education Nankai University Tianjin 300071 China Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080~ China

The quantum state transmission through the medium of high-dimensional many-particle system （boson or spinless fermion） is generally studied with a symmetry analysis. We discover that, if the spectrum of a Hamiltonian matches the symmetry of a fermion or boson system in a certain fashion, a perfect quantum state transfer can be implemented without any operation on the medium with pre-engineered nearest neighbor （NN）. We also study a simple but realistic near half-filled tight-bindlng fermion system wlth uniform NN hopping integral. We show that an arbitrary many-particle state near the fermi surface can be perfectly transferred to its translational counterpart.

关键词： high-dimensional many-particle system perfect quantum state transfer

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ANALYSIS OF THE DYNAMIC BEHAVIOR OF A GRIFFITH PERMEABLE CRACK IN PIEZOELECTRIC MATERIALS WITH THE NON-LOCAL THEORY

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Acta Mechanica Solida Sinica 2003年第1期16卷 52-60页

作者： Zhou Zhengong Wang Biao sun Yuguo Center for Composite Materials and Electrio-Optics Research Center Harbin Institute of TechnologyHarbin 150001China

The dynamic behavior of a Griffith permeable crack under harmonic anti-plane shear waves in the piezoelectric materials is investigated by use of the non-local theory. To overcome the mathematical difficulties, a one-dimensional non-local kernel is used instead of a two-dimensional one for the anti-plane dynamic problem to obtain the stress and the electric displacement near the crack tips. By means of Fourier transform, the problem can be solved with a pair of dual integral equations that the unknown variable is the jump of the displacement across the crack surfaces. These equations are solved with the Schmidt method and numerical examples are provided. Contrary to the previous results, it is found that no stress and electric displacement singularities are present at the crack tip. The finite hoop stress and the electric displacement depend on the crack length, the lattice parameter of the materials and the circle frequency of the incident waves. This enables us to employ the maximum stress hypothesis to deal with fracture problems in a natural way.

关键词： crack piezoelectric materials non-local theory Schmidt method

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Recent progress in solution-processed flexible organic photovoltaics

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npj Flexible Electronics 2022年第1期6卷 871-884页

作者： Lulu sun Kenjiro Fukuda Takao Someya Thin-Film Device Laboratory RIKEN2-1 HirosawaWakoSaitama 351-0198Japan Center for Emergent Matter Science(CEMS) RIKEN2-1 HirosawaWakoSaitama 351-0198Japan Department of Electrical Engineering and Information Systems School of EngineeringThe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan

The certified power conversion efficiency(PCE)of organic photovoltaics(OPV)fabricated in laboratories has improved dramatically to over 19%owing to the rapid development of narrow-bandgap small-molecule acceptors and wide bandgap polymer donor *** next pivotal question is how to translate small-area laboratory devices into large-scale commercial *** requires the OPV to be solution-processed and flexible to satisfy the requirements of high-throughput and large-scale production such as roll-to-roll *** review summarizes and analyzes recent progress in solution-processed flexible *** a detailed discussion from the perspective of the behavior of the narrow bandgap small-molecule acceptor and wide bandgap polymer donor active layer in solution-processed flexible devices,the existing challenges and future directions are discussed.

关键词： donor narrow translate

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An Arabidopsis ctpA homologue is involved in the repair of photosystem II under high light

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Chinese Science Bulletin 2008年第7期53卷 1021-1026页

作者： YIN ShuMing sun XuWu ZHANG LiXin School of Life Sciences Lanzhou University Lanzhou 730000 China Photosynthesis Research Center Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of Sciences Beijing 100093 China

A T-DNA insertion mutant AtctpA1 was identified to study the physiological roles of a carboxyl-terminal processing protease (CtpA) homologue in Arabidopsis. Under normal growth conditions, disruption of AtctpA1 did not result in any apparent alterations in growth rate and thylakoid membrane protein components. However the mutant plants exhibited increased sensitivity to high irradiance. Degradation of PSII reaction center protein D1 was accelerated in the mutant during photoinhibition. These results demostrated that AtctpA1 was required for efficient repair of PSII in Arabidopsis under high irradiance.

关键词： ctpA 同源染色体光合作用强光

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Constructal entransy dissipation rate minimization for heat conduction based on a tapered element

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Chinese Science Bulletin 2011年第22期56卷 2400-2410页

作者： XIAO QingHua CHEN LinGen sun FengRui College of Naval Architecture and Power Naval University of Engineering Wuhan 430033 China

Based on constructal theory,the structure of a tapered element and high-conductivity link is optimized by taking the minimization of the entransy dissipation rate as the optimization *** results show that the mean temperature difference of the heat transfer cannot always decrease when the internal complexity of the control-volume *** exists an optimal constructal order leading to the minimum mean temperature difference for heat *** thermal current density in high-conductivity links with variable shapes does not linearly depend on the ***,the optimized constructs based on the minimization of the entransy dissipation rate are different from those based on the minimization of the maximum temperature *** with the construct based on the minimization of the maximum temperature difference,the construct based on the minimization of the entransy dissipation rate can reduce the mean temperature difference,and improve the heat transfer performance *** entransy describes the heat transfer ability more suitably,various constructal problems in heat conduction may be addressed more effectively using this basis.

关键词：构形理论耗散率最小化热传导元素锥形优化目标平均温差

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Vegetation and environmental changes in western Chinese Loess Plateau since 13.0 ka BP

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Journal of Geographical Sciences 2010年第2期20卷 177-192页

作者： sun Aizhi FENG Zhaodong MA Yuzhen School of Geography Science Southwest University Chongqing 400715 China MOE Key Laboratory of Western China＇s Environmental Systems College of Earth ＆ Environment SciencesLanzhou University Lanzhou 730000 China Department of Geology Baylor University Waco TX76795 USA College of Resources Science and Technology Research Beijing Normal University Beijing 100875 China

Pollen records from the Chinese Loess Plateau revealed a detailed history of vegetation variation and associated climate changes during the last 13.0 ka BP. Before 12.1 ka BP, steppe or desert-steppe vegetation dominated landscape then was replaced by a coniferous forest under a generally wet climate （12.1-11.0 ka BP）. The vegetation was deteriorated into steppe landscape and further into a desert-steppe landscape between 11.0 and 9.8 ka BP. After a brief episode of a cool and wet climate （9.8-9.6 ka BP）, a relatively mild and dry condition prevailed during the early Holocene （9.6-7.6 ka BP）. The most favourable climate of warm and humid period occurred during mid-Holocene （7.6-4.0 ka BP） marked by forest-steppe landscape and vegetation alternatively changed between steppe and desert-steppe from -4.0 to -1.0 ka BP.

关键词： Chinese Loess Plateau arid and semi-arid region pollen assemblage climate change

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