检索结果-南通市图书馆

Degenerate topological line surface phonons in quasi-1D double helix crystal SnIP

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1792-1799页

作者： Bo Peng Shuichi Murakami Bartomeu Monserrat Tiantian Zhang TCM Group Cavendish LaboratoryUniversity of CambridgeJ.J.Thomson AvenueCambridge CB30HEUnited Kingdom Department of Physics Tokyo Institute of TechnologyOokayamaMeguro-kuTokyo 152-8551Japan tokodai institute for element strategy Tokyo Institute of TechnologyNagatsutaMidori-kuYokohamaKanagawa 226-8503Japan Department of Materials Science and Metallurgy University of Cambridge27 Charles Babbage RoadCambridge CB30FSUnited Kingdom

Degenerate points/lines in the band structures of crystals have become a staple of the growing number of topological *** bulk-boundary correspondence provides a relation between bulk topology and surface *** line degeneracies of bulk excitations have been extensively characterised,line degeneracies of surface states are not well *** show that SnIP,a quasi-one-dimensional van der Waals material with a double helix crystal structure,exhibits topological nodal rings/lines in both the bulk phonon modes and their corresponding surface *** a combination of first-principles calculations,symmetrybased indicator theories and Zak phase analysis,we find that two neighbouring bulk nodal rings form doubly degenerate lines in their drumhead-like surface states,which are protected by the combination of time-reversal symmetry T and glide mirror symmetry *** results indicate that surface degeneracies can be generically protected by symmetries such as T My,and phonons provide an ideal platform to explore such degeneracies.

关键词： topological symmetry quasi

Insight into rare-earth-incorporated catalysts:The chance for a more efficient ammonia synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2022年第10期11卷 1499-1529页

作者： Yutong GONG Hongchen LI Can LI Xiaobing BAO Hideo HOSONO Junjie WANG State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China Materials Research Center for element strategy Tokyo Institute of TechnologyYokohama 226-8503Japan

Recent studies have suggested that rare earth(RE)elements in catalysts significantly influence the performance of the ammonia *** REs appear in various forms in the ammonia synthesis catalysts including supports(oxides,hydrides,and nitrides),promotors,and *** the conventional RE oxide-supporting catalysts(mainly Ru/REO),some new RE-containing catalyst systems,such as electrode and nitride systems,could drive the ammonia synthesis via a benign Mars-van Krevelen mechanism or multi-active-site mode,affording high ammonia synthesis performance under mild *** works demonstrate the great potential of RE-containing catalysts for more efficient ammonia *** review summarizes the contributions of different kinds of RE-based catalysts and highlights the function mechanism of incorporated ***,an overview of this area and the challenges for further investigation are provided.

关键词： ammonia synthesis rare earth(RE) heterogeneous catalysis mild conditions mechanism

Robust two-gap strong coupling superconductivity associated with low-lying phonon modes in pressurized Nb5Ir3O superconductors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第10期28卷 215-221页

作者： Bosen Wang Yaoqing Zhang Shuxiang Xu Jin-Guang Cheng Beijing National Laboratory for Condensed Matter Physics and institute of Physics Chinese Academy of SciencesBeijing 100190China institute for Solid State Physics University of TokyoKashiwanoha 5-1-5KashiwaChiba 277-8581Japan Materials Research Center for element strategy Tokyo Institute of TechnologyYokohama 226-8503Japan Songshan Lake Materials Laboratory Dongguan 523808China

We report robust superconducting state and gap symmetry of Nb5Ir3O via electrical transport and specific heat measurements. The analysis of specific heat manifests that Nb5Ir3O is a strongly coupled superconductor with ΔC/γnTc ~ 1.91 and double s-wave superconducting gaps of 2ΔL(0)/kBTc ~ 6.56 and 2ΔS(0)/kBTc ~ 2.36 accounting for 90% and 10%,respectively. The(Cp-γnT)/T^3 vs. T plot shows a broad peak at ~ 23 K, indicating phonon softening and the appearance of low-lying phonon mode associated with the interstitial oxygen. This behavior explains the monotonic increase of Tc in Nb5Ir3O(1-δ)by strengthening the electron-phonon coupling and enlarging the density of states at Fermi level. The Hall coefficient is temperature independent below 200 K, and changes its sign from positive to negative above 250 K, suggesting that carrier is across the hole-to electron-dominant regions and the multi-band electronic structures. On warming, the resistivity shows a gradual crossover from T^2-to T^3-dependence at a critical temperature T^*, and a broad peak at a temperature Tp. The reduced Tc under pressure is linearly correlated with lattice parameters c/a ratio and Tp, suggesting the important phonon contributions in Nb5Ir3O as a phonon-medicated superconductor. Possible physical mechanisms are proposed.

关键词： new superconductor high-pressure effect strongly coupled superconductor

Holistic Integrative Medicine Declaration

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2024年第5期18卷 938-940页

作者：无 Daiming Fan China institute for Development strategy of Holistic Integrative Medicine Xi’an 710032China 不详

“Integration is a hallmark of our era’s development and a magic key to solve epochal problems.”“Medicine originated from humanity’s initial expression of suffering and the primary desire to alleviate that suffering.”From this origin,human medicine has continually advanced through repeated challenges,displaying two major characteristics in its development.(1)“Dimensionality reduction and differentiation are the driving forces of medical development.”Since the introduction of natural science paradigms and methods into medicine,the process has evolved from complexity to simplicity,and from difficulty to ease.

关键词： Medicine simplicity originated

Problems of Rural Migrant Workers and Policies in the New Period of Urbanization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2008年第3期6卷 14-20页

作者： Gu Shengzu Zheng Lingyun Yi Shance institute of Development strategy Wuhan University Wuhan Hubei 430072 China

The huge migration of rural workers has new characteristics such as the bad order, high degree of concentration, low level of collective action, marginality in social status, unfair treatment, difficult integration of the new generation, and the new return trend of rural migrants, which causes ‘urban diseases’ in China. Countermeasures should be taken to develop medium-sized and small cities, integrate the labor market of the city and countryside, provide necessary public services, social security and vocational training, guide the rural migrant workers to return rationally, and help the new generation live in harmony with urban residents.

关键词： urbanization rural migrant workers strategy countermeasures

China-Russia Energy Cooperation:Its Present Situation and Prospect

在线全文

学校读者我要写书评

暂无评论

和平与发展 2007年第3期 59-64页

作者： Xia Yishan (The author is a Senior Researcher at China institute of International Studies Director,China institute for Energy strategy Studies and Guest Researcher of CPDS.) China institute for Energy strategy Studies and Guest Researcher of CPDS

Energy cooperation between China and Russia appears dissimilar to that between China and Kazakhstan and between China and the *** cooperation between China and Kazakhstan and between China and the Sudan takes the form that the Chinese corporations participate in the exploration and exploitation of local oil and gas resources,and gets back their shares the in oil and gas *** main form of energy cooperation between China and Russia,however,is that Russia exports oil and gas to China by way of *** order to

关键词： China-Russia Energy Cooperation

The strategy and Technology Selection for Non-CO_2 Greenhouse Gas Emission Control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2014年第1期5卷 28-33页

作者： ZHOU Ya-Min FENG Yong-Sheng National institute of International strategy Chinese Academy of Social Sciences National Academy of Economic strategy Chinese Academy of Social Sciences

The emission control of non-CO2greenhouse gases is conducive to slowing down global *** is also helpful in controlling environmental pollution,and beneficial in improving the local health *** paper aims at six kinds of non-CO2greenhouse gases under United Nations Framework Convention on Climate Change,namely methane(CH4),nitrous oxide(N2O),hydrofluorocarbons(HFCs),perfluorocarbons(PFCs),sulfur hexafluoride(SF6),and nitrogen trifluoride(NF3).This paper analyzes the emission status and trend of China’s non-CO2greenhouse gases,and provides some technology selections for non-CO2emission *** strategic policy arrangements and appropriate technology choices,China can gain environmental protection and greenhouse gas control.

关键词： non-CO2emission status trend technology selection

Synthesis of stable iodoplumbate and perovskite for efficient annealing-free device and long-term storage

在线全文

学校读者我要写书评

暂无评论

SusMat 2023年第6期3卷 821-833页

作者： Jihyun Kim Sang-Won Park Younghyun Lee Hideo Hosono Byungwoo Park Jinhyun Kim Department of Chemical and Materials Engineering University of SuwonHwaseongSouth Korea MDX Research Center for element strategy International Research Frontiers InitiativeTokyo Institute of TechnologyYokohamaJapan Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeonSouth Korea Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoulSouth Korea

As a next-generation photovoltaic device,perovskite solar cells are rapidly ***,both solution and device stability pose challenges for commercialization due to chemical degradation caused by internal and external ***,the decomposition of iodoplumbate in a perovskite solution hinders the long-term use of perovskite ***,the synthesis of stable perovskites at low temperature is important for stable devices and wide applications(flexible devices and high reproducibility).Herein,the critical composition of perovskite is found to obtain high stabilities of both iodoplumbate and perovskite crystals by utilizing CsPbBr_(3) and FAPbI_(3),exhibiting high device performance and long-term solution *** novel composition of CsPbBr_(3)-alloyed FAPbI_(3) not only crystallizes under annealing-free conditions but also demonstrates excellent iodoplumbate stability for 100 days(∼3000 h)without any ***,high device stabilities are achieved over 2000 and 3000 h under extreme conditions of A.M.1.5 and 85℃/85%relative humidity,***,the device exhibited a high power conversion efficiency of 23.4%,and furthermore,CsPbBr_(3)-alloyed FAPbI_(3) was devoted to widen the applications in both flexible and carbon-electrode devices,thereby addressing both scientific depths and potential commercial materials.

关键词： annealing free DFT calculation iodoplumbate long-term stability perovskite solar cells

Water resource governance in China's regional cooperation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2018年第3期16卷 267-276页

作者： Zhifei Li National institute of International strategy Chinese Academy of Social Sciences

A series of water disputes and conflicts have gradually emerged between China and some neighboring countries after 2000, influencing China's neighborhood relations. China increasingly realizes the importance and urgency of the water resource governance in the regional cooperation, but under complicated geopolitical context, China's water resource governance must serve several important main functions in its regional cooperation. Overall, water resource governance is the demands of crisis management and conflict prevention, and also is a kind of positive factor that promotes sub-regional cooperation. From the perspective of the current situation, China should take more proactive attitude toward the water resource governance, expand the areas and stakeholders of the water resource governance, and thus promote the formulation of water resource governance strategy.

关键词： Water security neighborhood relations China’s diplomacy regional cooperation