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Journal of Hydrodynamics 2007年第3期19卷 303-308页

作者： li Xi CHU vincent H. Department of Ocean and Traffic Engineering Hohai University Nanjing 210098 China Deptartment of Civil Engineering and Applied Mechanics McGill University Montreal H3A 2K6 Canada

A laboratory study of the turbulence front initiated by the Rayleigh-Taylor instabilities was conducted by overturning a two-layer stratified flow in a tank. Dye was introduced to the upper layer and the concentration of the dye was determined using a video imaging method. The mass center of the heavier upper layer moved continuously to a lower elevation because of the intrusion of the heavier fluid into the lower layer and the lighter fluid into the upper layer. The downward movement of the mass center was accurately determined from the dye concentration profile. It is concluded that the initial advancement of the mass center follows a quadratic relation with time and the final advancement obeys a linear relation with time.

关键词： Rayleigh-Taylor instability stratified flow turbulent mixing video imaging technique overturning experiment

Evolution of the rare earth trade network:A perspective of dependency and competition

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Geoscience Frontiers 2024年第3期15卷 183-191页

作者： Jilan Xu Jiahao li vincent Charles Xin Zhao School of Urban and Regional Science Shanghai University of Finance and EconomicsShanghai 200433China School of Business East China University of Science and TechnologyShanghai 200237China School of Management University of BradfordBradford BD71DPUnited Kingdom School of Statistics and Applied Mathematics Anhui University of Finance and EconomicsBengbu 233030China

As a global strategic reserve resource,rare earth has been widely used in important industries,such as military equipment and ***,existing analyses based solely on the total volume of rare earth trade fail to uncover the underlying competition and dependency *** address this gap,this paper employs the principles of trade preference and import similarity to construct dependency and competition *** network analysis is then employed to study the evolution of the global rare earth trade network from 2002 to *** main conclusions are as *** global rare earth trade follows the Pareto principle,and the trade network shows a scale-free *** has emerged as the world’s largest importer and exporter of rare earth since *** the dependency network,China has become the most dependent country since *** result of community division shows that China has separated from the American community and formed new communities with the Association of Southeast Asian Nations(ASEAN)*** United States of America has formed a super-strong community with European and Asian *** the competition network,the distribution of competition intensity follows a scale-free *** countries face low-intensity competition,but there are numerous competing *** competition related to China has increased ***,the competition source for the United States of America has shifted from Mexico to China,resulting in China,the USA,and Japan becoming the core participants in the competition network.

关键词： Rare earth Trade network Dependency Competition Complex network analysis

Superfluid phases and excitations in a cold gas of d-wave interacting bosonic atoms and molecules

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Chinese Physics B 2021年第6期30卷 463-468页

作者： Zehan li Jian-Song Pan W vincent liu Department of Physics and Astronomy University of PittsburghPittsburghPA 15260USA Wilczek Quantum Center School of Physics and Astronomy and T.D.Lee InstituteShanghai Jiao Tong UniversityShanghai 200240China

Motivated by recent advances in orbitally tuned Feshbach resonance experiments, we analyze the ground-state phase diagram and related low-energy excitation spectra of a d-wave interacting Bose gas. A two-channel model with d-wave symmetric interactions and background s-wave interactions is adopted to characterize the gas. The ground state is found to have three interesting superfluid phases: atomic, molecular, and atomic–molecular. In great contrast to what was previously known about the p-wave case, the atomic superfluid is found to be momentum-independent for the d-wave case discussed here. The Bogoliubov spectra above each superfluid phase are obtained both analytically and numerically.

关键词： d-wave interaction quantum gas Bogoliubov spectrum superfluid

Flexible Job Shop Composite Dispatching Rule Mining Approach Based on an Improved Genetic Programming Algorithm

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Tsinghua Science and Technology 2024年第5期29卷 1390-1408页

作者： Xixing li Qingqing Zhao Hongtao Tang Xing Guo Mengzhen Zhuang Yibing li Xi vincent Wang Hubei Key Laboratory of Modern Manufacturing and Quality Engineering School of Mechanical EngineeringHubei University of TechnologyWuhan 430068China Hubei Digital Manufacturing Key Laboratory School of Mechanical and Electronic EngineeringWuhan University of TechnologyWuhan 430070China Department of Production Engineering KTH Royal Institute of Technology Stockholm SE-10044Sweden

To obtain a suitable scheduling scheme in an effective time range,the minimum completion time is taken as the objective of Flexible Job Shop scheduling Problems(FJSP)with different scales,and Composite Dispatching Rules(CDRs)are applied to generate feasible ***,the binary tree coding method is adopted,and the constructed function set is ***,a CDR mining approach based on an Improved Genetic Programming Algorithm(IGPA)is *** population initialization methods are introduced to enrich the initial population,and a superior and inferior population separation strategy is designed to improve the global search ability of the *** the same time,two individual mutation methods are introduced to improve the algorithm’s local search ability,to achieve the balance between global search and local *** addition,the effectiveness of the IGPA and the superiority of CDRs are verified through comparative ***,Deep Reinforcement Learning(DRL)is employed to solve the FJSP by incorporating the CDRs as the action set,the selection times are counted to further verify the superiority of CDRs.

关键词： flexible job shop scheduling composite dispatching rule improved genetic programming algorithm deep reinforcement learning

Impossible meet-in-the-middle fault analysis on the LED lightweight cipher in VANETs

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Science China(Information Sciences) 2018年第3期61卷 118-130页

作者： Wei li vincent RIJMEN Zhi TAO Qingju WANG Hua CHEN Yunwen liU Chaoyun li Ya liU School of Computer Science and Technology Donghua University imec-COSIC KU Leuven Shanghai Key Laboratory of Integrate Administration Technologies for Information Security Department of Computer Science and Engineering Shanghai Jiao Tong University Department of Applied Mathematics and Computer Science Technical University of Denmark Trusted Computing and Information Assurance Laboratory Institute of SoftwareChinese Academy of Sciences College of Science National University of Defense Technology Department of Computer Science and Engineering University of Shanghai for Science and Technology

With the expansion of wireless technology, vehicular ad-hoc networks(VANETs) are emerging as a promising approach for realizing smart cities and addressing many serious traffic problems, such as road safety, convenience, and efficiency. To avoid any possible rancorous attacks, employing lightweight ciphers is most effective for implementing encryption/decryption, message authentication, and digital signatures for the security of the VANETs. light encryption device(LED) is a lightweight block cipher with two basic keysize variants: LED-64 and LED-128. Since its inception, many fault analysis techniques have focused on provoking faults in the last four rounds to derive the 64-bit and 128-bit secret keys. It is vital to investigate whether injecting faults into a prior round enables breakage of the LED. This study presents a novel impossible meet-in-the-middle fault analysis on a prior round. A detailed analysis of the expected number of faults is used to uniquely determine the secret key. It is based on the propagation of truncated differentials and is surprisingly reminiscent of the computation of the complexity of a rectangle attack. It shows that the impossible meet-in-the-middle fault analysis could successfully break the LED by fault injections.

关键词： VANETs LED lightweight cipher impossible meet-in-the-middle fault analysis

Improving Water Use Efficiency of Wheat Crop Varieties in the North China Plain: Review and Analysis

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Journal of Integrative Agriculture 2013年第7期12卷 1243-1250页

作者： MEI Xu-rong ZHONG Xiu-li Vadez vincent liU Xiao-ying Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences/State Engineering Laboratory of Efficient Water Use and Disaster Mitigation for Crops/Key Laboratory for Dryland Agriculture Ministry of Agriculture International Crop Research Institute for the Semi-Arid Tropics (ICRISAT)

The North China Plain （NCP）, one of the most important agricultural regions in China, is facing a major water-resource crisis evoked by excessive exploitation of groundwater. To reduce water use while maintaining high crop production level, improving variety water use efficiency （WUE） is an urgent need, especially because other water-saving measures such as water delivery, irrigation, and agricultural practices have already achieved most possible progresses. Evaluation of variety WUE can be performed accurately at the individual plant level （WUEp）. Reviewing the studies on physiological factors affecting WUE p performed up to date, stomatal conductance was considered to be an important trait associating closely with WUE p . The trait showed a large degree of varietal variability under well-watered conditions. Crop varieties differ highly in sensitivity of stomata to soil and air drying, with some varieties strongly reducing their stomatal conductance in contrast with those lightly regulating their stomata. As a result, difference among varieties in WUE p was enlarged under water deficit conditions in contrast with those under well-watered conditions. The relationship between stomatal conductance and yield depends on water availability of whole growing period in local areas. Usually, large stomatal conductance results in a high yield under good irrigation system, whereas a low stomatal conductance can lead to yield benefit under limited stored soil moisture conditions. In the NCP, winter wheat is the largest consumer of irrigation water, improvement strategies for high WUE aiming at wheat crops are in urgent need. We suggest, for the well-irrigated areas with excessive exploitation of groundwater, the wheat breeding program need to combine medium stomatal conductance （0.35 mmol H2O m-2 s-1 or so）, high carboxylation efficiency, and high harvest index. Areas with partial/full access to irrigation, or infrequent drought, should target wheat varieties with high stomatal

关键词： water use efficiency yield stomatal conductance water deficit

Hybrid Dextran-gadolinium Nano-suitcases as High-relaxivity MRI Contrast Agents

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Chinese Journal of Polymer Science 2018年第3期36卷 391-398页

作者： Hao Wang Ting-Ting Dai Bo-Lun Lu Sheng-li li Qing Lu vincent Mukwaya Hong-Jing Dou The State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Plastic and Reconstructive Surgery Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai Key Laboratory of Tissue EngineeringShanghai 200011China Department of Radiology Renji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127 China

Dextran-poly（glycidyl methacrylate）（Dex-PGMA） nano-suitcases were synthesized efficiently via a graft copolymerization induced self-assembly （GISA） approach. On this basis, the Dex-PGMA nano-suitcases were modified with hydrazide, and the attachment of multiple chelated Gd（III） ions to the interior of the nano-suitcases affords nanoscale MRI contrast agents with high relaxivity values. The highly fenestrated dextran shell of the nano-suitcases assures water exchange which readily occurs between the surrounding environment and the Gd（III） ions encapsulated within the hybrid nano-suitcases. The complexation between the hydrophilic hydrazide interior of the nano-suitcases and Gd（III） ions results in an impressive Gd payload at 22.6 wt% in the hybrid nano-suitcases. The longitudinal relaxivity （rl） of the hybrid nano-suitcases is reported as 44.4 L/（mmol-s）, which is 9-14 folds of that of commercial Gd-DTPA agents. In vivo MRI studies demonstrate that the hybrid nano-suitcases accumulated in the lymph node of the rat due to their nanoscale dimensions and displayed strong signals in vivo. The results indicated that the hybrid nano-suitcases provide a promising platform for the diagnosis of lymph node related diseases.

关键词： Crosslinked polymer nanoparticles Gadolinium(lli) MRI contrast agents Lymph node imaging

Neurovascular ageing:transcriptomic readout and implications on therapeutic targeting in Alzheimer’s disease

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Neural Regeneration Research 2021年第12期16卷 2411-2412页

作者： Zhongqi li Bonaventure Ip vincent C.T.Mok Ho Ko Division of Neurology Department of Medicine and TherapeuticsThe Chinese University of Hong KongHong Kong Special Administrative RegionChina li Ka Shing Institute of Health Sciences The Chinese University of Hong KongHong Kong Special Administrative RegionChina(Li ZKo H)Margaret K.L.Cheung Research Centre for Management of ParkinsonismThe Chinese University of Hong KongHong Kong Special Administrative RegionChina Chow Yuk Ho Technology Centre for Innovative Medicine The Chinese University of Hong KongHong Kong Special Administrative RegionChina Gerald Choa Neuroscience Centre School of Biomedical SciencesDepartment of PsychiatryPeter Hung Pain Research InstituteFaculty of MedicineThe Chinese University of Hong KongHong Kong Special Administrative RegionChina

Ageing is one of the greatest risk factors for neurodegenerative *** the complex biological changes in ageing increase the brain’s susceptibility to neurodegeneration remains incompletely *** into neurodegenerative disorders has shifted from a neuron-centric approach,to the contributing roles of age-related neurovascular and glial cell dysfunction.

关键词： incomplete susceptibility ageing

Climate Change Impacts on Agroecosystems in China:Processes,Mechanisms and Prospects

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Chinese Geographical Science 2023年第4期33卷 583-600页

作者： BAO Lun YU lingxue li Ying YAN Fengqin LYNE vincent REN Chunying State Key Laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Acad emy of SciencesChangchun 130012China University of Chinese Academy of Sciences Beijing 100049China Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China IMAS-Hobart University of TasmaniaTasmania 7004Australia

Building a more resilient response system to climate change for sustainable development and reducing uncertainty in China’s food markets,requires access to historical research gaps and mapping future research progress for decision ***,the lack of quantitative and objective analyses to ensure the stability and development of agroecosystems increases the complexity of agro-climatic mechanisms,which leads to uncertainty and undesirable *** this paper,we review the characteristics of climate change in China(1951–2020),reveal the mechanisms of agroecosystem structure in response to climate,and identify challenges and opportunities for future efforts in the context of research *** aim is to improve the scientific validity and relevance of future research by clarifying agro-climatic response *** results show that surface temperature,precipitation,and frequency of extreme weather events have increased to varying degrees in major agricultural regions of China in 1951–*** they have strong geographic variation,which has resulted in droughts in the north and floods in the ***,climate change has complicated the mechanisms of soil moisture,Net Primary Productivity(NPP),soil carbon pool,and crop pest structure in *** lends to a reduction in soil water holding capacity,NPP,soil carbon content,and the number of natural enemies of diseases and insects,which in turn affects crop ***,human interventions can mitigate the deterioration of these *** have also realized that the methodology and theory of historical research poses a great challenge to future *** and projected climate trends identified current gaps in interdisciplinary integration and multidisciplinary research required to manage diverse spatio-temporal climate change impacts on *** efforts should highlight integrated management and decision making,multidisciplinary big data coupling,and numerica

关键词： climate change agroecosystem Net Primary Productivity(NPP) soil carbon pool risk management crop yield