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Transmission capacity Analysis for Linear VANET under Physical Model

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china communications 2017年第3期14卷 97-107页

作者： Xinxin He Hang Zhang Weisen Shi Tao Luo norman c.Beaulieu Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing 100876 China

In this study, the transmission capacity of VANETs in a highway scenario is analysed on the basis of a 1D line model and the carrier sense multiple access with collision avoidance(cSMA/cA) protocol. We describe the cSMA/cA protocol used in IEEE802.11 p from the perspective of the geometric relationship amongst simultaneous transmitters. The desired channel and interfering channels are assumed to experience the same amount of path-loss and Rayleigh fading. On the basis of the proposed model, we analyse the attempted transmission probability of each road segment and the maximum intensity of active transmitters, including their theoretical values. Then, we employ the physical model to obtain the outage probability and derive the upper bound of the transmission capacity of a VANET, which is defined as the average spatial density of successful transmissions in the network. Simulation results indicate that the theoretical value offers a good bound on network capacity.

关键词： VANET transmission capacity line model cSMA/cA

Operational Wave Now- and Forecast in the German Bight as a Basis for the Assessment of Wave-Induced Hydrodynamic Loads on coastal Dikes

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Journal of Ocean University of china 2017年第6期16卷 991-997页

作者： DREIER norman FROHLE Peter Institute of River and coastal Engineering Hamburg University of Technology Hamburg Germany

The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.

关键词： German Bight North Sea wave forecast cosmo-Model SWAN hydrodynamic loads wave run-up EurOtop

Organic Gases in Fluid Inclusions of Ore Minerals and Their constraints on Ore Genesis:A case Study of the changkeng Au-Ag Deposit,Guangdong,china

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Acta Geologica Sinica(English Edition) 2003年第1期77卷 86-94页

作者： DavidI.norman Department of Earth & Environmental Sciences New Mexico Institute of Mining and Technology (NMT) Socorro NM87801 USA

The newly discovered changkeng Au-Ag deposit is a new type of sediment-hostedprecious metal deposit. Most of the previous researchers believed that the deposit was formed bymeteoric water convection. By using a high vacuum quadrupole gas mass spectrometric system, ninelight hydrocarbons have been recognized in the fluid inclusions in ore minerals collected from thechangkeng deposit. The hydrocarbons are composed mainly of saturated alkanes c_(1-4) and unsaturatedalkenes c_(2-4) and aromatic hydrocarbons, in which the alkanes are predominant, while the contentsof alkenes and aromatic hydrocarbons are very low. The sum alka/sum alke ratio of most samples ishigher than 100, suggesting that those hydrocarbons are mainly generated by pyrolysis of kerogens insedimentary rocks caused by water-rock interactions at medium-low temperatures, and themetallogenic processes might have not been affected by magmatic activity. A thermodynamiccalculation shows that the light hydrocarbons have reached chemical equilibrium at temperatureshigher than 200 deg c, and they may have been generated in the deep part of sedimentary basins(e.g., the Sanzhou basin) and then be transported by ore-forming fluids to a shallow position of thebasin via a long distance. Most of the organic gases are generated by pyrolysis of the type IIkerogens (kukersite) in sedimentary host rocks, only a few by microorganism activity. Thecompositions and various parameters of light hydrocarbons in gold ores are quite similar to those insilver ores, suggesting that the gold and silver ores may have similar metallogenic *** on the compositions of organic gases in fluid inclusions, the authors infer that the changkengdeposit may be of a tectonic setting of continental rift. The results of this study support fromone aspect the authors' opinion that the changkeng deposit is not formed by meteoric waterconvection, and that its genesis has a close relationship with the evolution of the Sanzhou basin,so it belon

关键词： ore mineral fluid inclusion organic gas changkeng Au-Ag deposit

Speciation with gene flow via cycles of isolation and migration:insights from multiple mangrove taxa

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National Science Review 2019年第2期6卷 275-288页

作者： Ziwen He Xinnian Li Ming Yang Xinfeng Wang cairong Zhong norman c.Duke chung-I Wu Suhua Shi State Key Laboratory of Biocontrol Guangdong Key Lab of Plant Resources Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education InstitutesSchool of Life Sciences Sun Yat-Sen University Department of Ecology and Evolution University of Chicago cAS Key Laboratory of Genome Sciences and Information Beijing Institute of GenomicsChinese Academy of Sciences Hainan Dongzhai Harbor National Nature Reserve Administration centre for Tropical Water and Aquatic Ecosystem Research James Cook University

Allopatric speciation requiring an unbroken period of geographical isolation has been the standard model of neo-Darwinism. While doubts have been repeatedly raised, strict allopatry without any gene flow remains a plausible mechanism in most cases. To rigorously reject strict allopatry, genomic sequences superimposed on the geological records of a well-delineated geographical barrier are necessary. The Strait of Malacca,narrowly connecting the Pacific and Indian Ocean coasts, serves at different times either as a geographical barrier or a conduit of gene flow for coastal/marine species. We surveyed 1700 plants from 29 populations of 5 common mangrove species by large-scale DNA sequencing and added several whole-genome assemblies. Speciation between the two oceans is driven by cycles of isolation and gene flow due to the fluctuations in sea level leading to the opening/closing of the Strait to ocean currents. Because the time required for speciation in mangroves is longer than the isolation phases, speciation in these mangroves has proceeded through many cycles of mixing-isolation-mixing, or MIM, cycles. The MIM mechanism, by relaxing the condition of no gene flow, can promote speciation in many more geographical features than strict allopatry can. Finally, the MIM mechanism of speciation is also efficient, potentially yielding mn(m > 1) species after n cycles.

关键词： speciation gene flow allopatry geographical isolation mangrove

Bending,compression and Bonding Performance of cross-Laminated Timber(cLT)Made from Malaysian Fast-Growing Timbers

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Journal of Renewable Materials 2022年第11期10卷 2851-2869页

作者： Norshariza Mohamad Bhkari Lum Wei chen Anis Azmi Muhammad Shaiful Nordin norman Wong Shew Yam Zakiah Ahmad lee Seng Hua Institute for Infrastructure Engineering and SustainableManagement(IIESM) Universiti TeknologiMARAShah Alam40450Malaysia School of civil Engineering College of EngineeringUniversiti Teknologi MARAShah Alam40450Malaysia Sapulut Forest Development Sdn.Bhd. Kota Kinabalu88400Malaysia Institute of Tropical Forestry and Forest Products(INTROP) Universiti Putra Malaysia UPMSerdang43400Malaysia

This study investigated the bending,compression as well as the bonding performance of cLT panels made from fast-growing timber species,i.e.,Laran(Neolamarckia cadamba)and Batai(Paraserianthes falcataria).The variables studied were timber species(Laran and Batai),layers of lamination(3-layer and 5-layer),loading direction in bending(in-plane and out-of-plane),loading direction in compression(x-,y-,and z-axis)and different treatment conditions for bonding performance *** desired outputs of this study were bending and compression properties(strength and stiffness)as well as bonding performance(block shear strength,wood failure percentage and delamination value).The bending and compression test were conducted according to EN16351:2015 and EN408:2012,*** the other hand,the bonding performance test was determined by block shear and delamination test based on EN16351:2015 and EN14374:2004,*** to block shear test,the samples were subjected to three different treatment *** results showed that cLT made from 3-layer Laran timber,loaded at out-of-plane direction exhibited the highest bending ***,cLT made from 5-layered Batai timber,loaded at in-plane direction showed the lowest bending *** samples for compression loaded at x-axis exhibited the best compressive ***,Laran cLT showed greater bonding performance determined by shear test compared to Batai cLT for both 3-and 5-layer *** the contrary,delamination results showed that Batai cLT demonstrated better bonding performance compared to Laran *** terms of bonding performance measured by wood failure percentage(WFP),most samples under various treatment conditions showed WFP≥80%except for samples under wet condition with WFP≤60%.

关键词： cross-laminated timber plantation timber flexural performance bonding performance

characterizing and Mitigating chemomechanical Degradation in High-Energy Lithium-Ion Battery cathode Materials

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Accounts of Materials Research 2022年第5期3卷 511-524页

作者： norman S.Luu Kyu-Young Park Mark c.Hersam Department of Materials Science and Engineering Northwestern UniversityEvanstonIllinois 60208United States Graduate Institute of Ferrous and Energy Materials Technology Pohang University of Science and TechnologyPohangKyungbuk 37673Republic of Korea Department of chemistry and Department of Electrical and computer Engineering Northwestern UniversityEvanstonIllinois 60208United

Lithium-ion batteries(LIBs)are nearly ubiquitous energy storage solutions,powering devices ranging from consumer electronics to electric *** advance these applications,current LIB research efforts are directed toward improving energy and power densities,cyclic lifetimes,charging speeds,and *** parameters are intrinsically tied to properties of the active electrode materials,such as the redox mechanism,chemical composition,and crystal *** particularly challenging issue is that the active electrode materials that possess higher theoretical energy densities are generally more susceptible to degradation during cycling.A notable example is the family of layered multicomponent transition metal oxides,which is the incumbent class of active LIB cathode materials for electric *** increase their theoretical capacities,the transition metal fraction in these materials is trending toward higher Ni ***,Ni-rich chemistries suffer from electrochemical,crystallographic,and mechanical degradation that increase in severity with increasing Ni ***,alternative high-energy cathode materials,including overlithiated layered oxides and disordered rock salt materials,present additional stability challenges that must be overcome before they can be realistically incorporated into LIB *** chemomechanical degradation in high-energy LIB cathode materials occurs at multiple length *** defects,such as antisite defects or vacancies,are commonly generated during electrochemical cycling and can contribute to the loss of cyclable active *** both the primary and secondary particle level,electrochemical cycling also induces significant volumetric changes and state-of-charge heterogeneity,generating regions of high stress and strain that are precursors to mechanical ***,at the electrode level,nonuniform charge transfer reactions throughout the electrode can lead to locally overcharged regions that become

关键词： Battery electrode cycling

Extensive gene flow in secondary sympatry after allopatric speciation

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National Science Review 2022年第12期9卷 24-36页

作者： Xinfeng Wang Ziwen He Zixiao Guo Ming Yang Shaohua Xu Qipian chen Shao Shao Sen Li cairong Zhong norman c.Duke Suhua Shi State Key Laboratory of Biocontrol Guangdong Key Laboratory of Plant Resources School of Life SciencesSouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Sun Yat-sen University Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering School of Life Sciences Fudan University Department of Laboratory Medicine& Pathology University of Washington Hainan Academy of Forestry (Hainan Academy of Mangrove) centre for Tropical Water and Aquatic Ecosystem Research James Cook University

In the conventional view,species are separate gene pools delineated by reproductive isolation(RI).In an alternative view,species may also be delineated by a small set of ’speciation genes’ without full RI,a view that has gained broad acceptance.A recent survey,however,suggested that the extensive literature on’speciation with gene flow’ is mostly(if not all) about exchanges in the early stages of *** is no definitive evidence that the observed gene flow actually happened after speciation is ***,we wish to know whether ’good species’(defined by the ’secondary sympatry’ test) do continue to exchange genes and,importantly,under what conditions such exchanges can be *** novo whole-genome assembly and re-sequencing of individuals across the range of two closely related mangrove species(Rhizophora mucronata and R. stylosa) reveal the genomes to be well delineated in *** became sympatric in northeastern Australia but remain distinct ***,their genomes harbor～4000-10 000 introgression blocks averaging only about 3-4 *** fine-grained introgressions indicate continual gene flow long after speciation as non-introgressable ’genomic islets,’～1.4 Kb in size,often harbor diverging genes of flower or gamete *** fine-grained introgression in secondary sympatry may help settle the debate about sympatric ***-allopatric *** conclusion,true’good species’ may often continue to exchange genes but the opportunity for detection is highly constrained.

关键词： mangroves population genomics speciation introgression species hybridization

convergent adaptation of the genomes of woody plants at the land–sea interface

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National Science Review 2020年第6期7卷 978-993页

作者： Ziwen He Shaohua Xu Zhang Zhang Wuxia Guo Haomin Lyu cairong Zhong David E.Boufford norman c.Duke The International Mangrove consortium Suhua Shi State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant Resources Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes School of Life Sciences Sun Yat-Sen University Hainan Dongzhai Harbor National Nature Reserve Administration Harvard University Herbaria centre for Tropical Water and Aquatic Ecosystem Research James Cook University the consortium of 26 Institutions

Sequencing multiple species that share the same ecological niche may be a new frontier for genomic *** such studies should shed light on molecular convergence, genomic-level analyses have been unsuccessful, due mainly to the absence of empirical controls. Woody plant species that colonized the global tropical coasts, collectively referred to as mangroves, are ideal for convergence studies. Here, we sequenced the genomes/transcriptomes of 16 species belonging in three major mangrove clades. To detect convergence in a large phylogeny, a ccS+ model is implemented, extending the more limited ccS method(convergence at conservative sites). Using the empirical control for reference, the ccS+ model reduces the noises drastically, thus permitting the identification of 73 convergent genes with Ptrue(probability of true convergence) > 0.9. Products of the convergent genes tend to be on the plasma membrane associated with salinity tolerance. Importantly, convergence is more often manifested at a higher level than at amino-acid(AA) sites. Relative to >50 plant species, mangroves strongly prefer 4 AAs and avoid 5 others across the genome. AA substitutions between mangrove species strongly reflect these tendencies. In conclusion, the selection of taxa, the number of species and, in particular, the empirical control are all crucial for detecting genome-wide convergence. We believe this large study of mangroves is the first successful attempt at detecting genome-wide site convergence.

关键词： convergent evolution genome mangrove adaptive evolution woody plants