Wet and Dry Tribological Behaviors of Circular Islandic Protrusion Patterns on M2 Steel Discs under Spinning Condition

Under spinning conditions, lubricant on islandic spot patterned M2 steel disc experiences centrifugal and tangential force components. Depending upon the relative position of the spots and the flow of lubricant, accumulation of lubricant in front of patterned islandic spots creates thrusting to mating part and subsequently reduces contact between the mating couple. Whilst wear debris is likely to be spun off the plateau of the spots to their neighbouring valleys so as to reduce wear. Hence, it gives favorable tribological characteristics. Aiming at verifying such mechanisms, studies were performed on M2 steel disc specimens slid with ASSAB 17 tool steel pin. The M2 steel disc specimens were respectively （i） machined with non-patterned （NP）, （ii） etched to produce in-lined （INE） islandic patterns, and （iii） etched to produce staggered （STE） islandic spot patterns. Results indicated that the INE patterned discs gave most favorable wear characteristics, the NP of the worse characteristics whilst the STE ranged in the middle. However, the actual contact mechanism leads to the descending sequence of favorable friction behaviors nominally as： NP, INE and STE.

Genetic evaluations of island populations of Rhesus Macaque (Macaca mulatta) in China: Implications for conservation management

DEAR EDITOR,The macaques belongs to the genus Macaca,consisting of at least 23 species(Roos et al.,2019).Among all congeners,rhesus macaque(M.mulatta)is regarded as the widest distributed non-human primate species in the world.Its native range spans in East Asia,northern part of Southeast Asia and Indian subcontinent(Liu et al.,2018).Listed as“Least Concern”on the IUCN Red List,this species is locally threatened due to habitat loss and degradation in China and Thailand(Lu et al.,2018).Nevertheless,pet release resulting in hybridization with other congeners(e.g.,rhesus macaque×crab-eating macaque(M.fascicularis))was documented in Hong Kong SAR,China(Wong&Ni,2000),threatening genetic integrity of wild populations.

Drivers,Trends,and Patterns of Changing Vegetation-greenness in Nansha Islands,China from 2016 to 2022

Changes in vegetation status generally also represents changes in the ecological health of islands and reefs(IRs).However,studies are limited of drivers and trends of vegetation change of Nansha Islands,China and how they relate to climate change and human activities.To resolve this limitation,we studied changes to the Normalized Difference Vegetation Index(NDVI)vegetation-greenness index for 22 IRs of Nansha Islands during normal and extreme conditions.Trends of vegetation greenness were analyzed using Sen's slope and Mann-Kendall test at two spatial scales(pixel and island),and driving factor analyses were performed by time-lagged partial correlation analyses.These were related to impacts from human activities and climatic factors under normal(temperature,precipitation,radiation,and Normalized Difference Built-up Index(NDBI))and extreme conditions(wind speed and latitude of IRs)from 2016 to 2022.Results showed:1)among the 22 IRs,NDVI increased/decreased significantly in 15/4 IRs,respectively.Huayang Reef had the highest NDVI change-rate(0.48%/mon),and Zhongye Island had the lowest(–0.29%/mon).Local spatial patterns were in one of two forms:dotted-form,and degradation in banded-form.2)Under normal conditions,human activities(characterized by NDBI)had higher impacts on vegetation-greenness than other factors.3)Under extreme conditions,wind speed(R^(2)=0.2337,P<0.05)and latitude(R^(2)=0.2769,P<0.05)provided limited explanation for changes from typhoon events.Our results provide scientific support for the sustainable development of Nansha Islands and the United Nations‘Ocean Decade’initiative.

Morphology of crater and caldera lakes in the Far Eastern region of Russia and the features of their development

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric characteristics.It has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal activity.While lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric indicators.It was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their basins.The volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous processes.For the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were calculated.Repeated observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 years.This analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their study.The results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying other volcanic lakes.

Synergistic effects of Pleistocene geological and climatic events on complex phylogeographic history of widespread sympatric species of Megaloptera in East Asia

Unraveling the phylogeographic histories of species remains a key endeavor for comprehending the evolutionary processes contributing to the rich biodiversity and high endemism found in East Asia.In this study,we explored the phylogeographic patterns and demographic histories of three endemic fishfly and dobsonfly species(Neochauliodes formosanus,Protohermes costalis,and Neoneuromus orientalis)belonging to the holometabolan order Megaloptera.These species,which share a broad and largely overlapping distribution,were analyzed using comprehensive mitogenomic data.Our findings revealed a consistent influence of vicariance on the population isolation of Neoc.formosanus and P.costalis between Hainan,Taiwan,and the East Asian mainland during the early Pleistocene,potentially hindering subsequent colonization of the later diverged Neon.orientalis to these islands.Additionally,we unveiled the dual function of the major mountain ranges in East Asia,serving both as barriers and conduits,in shaping the population structure of all three species.Notably,we demonstrated that these co-distributed species originated from Southwest,Southern,and eastern Central China,respectively,then subsequently migrated along multi-directional routes,leading to their sympatric distribution on the East Asian mainland.Furthermore,our results highlighted the significance of Pleistocene land bridges along the eastern coast of East Asia in facilitating the dispersal of mountain-dwelling insects with low dispersal ability.Overall,this study provides novel insight into the synergistic impact of Pleistocene geological and climatic events in shaping the diversity and distribution of aquatic insects in East Asia.

Population size estimates based on GPS telemetry

DEAR EDITOR,Accurate estimation of population size is a crucial issue in wildlife population ecology and conservation.While Global Positioning System(GPS)collars are well recognized as an effective method for monitoring wildlife behavior,their application in direct wildlife population size estimation remains underutilized.In this study,GPS telemetry was employed to survey a rhesus macaque(Macaca mulatta)population on Neilingding Island in Guangdong,China.From May 2021 to April 2022,32 macaques across nine groups were fitted with GPS collars,producing a dataset of 109739 location fixes.Analyzing data from all tracked individuals revealed the annual home ranges of the nine groups.

Flexible ultrasound arrays with embossed polymer structures for medical imaging

In recent years,the application of flexible electronic technology[1−3]combined with ultrasonic imaging[4]has blossomed,resulting in a shift in the application place of ultrasonic imaging technology from medical institutions to households.The utilization of this application has expanded from the physician’s positioning and guidance to real-time patient monitoring[5],while the range of application scenarios continues to widen.The transformative changes have made possible through the development of flexible transducer arrays[6,7].Prof.Sheng Xu's team at the University of California San Diego has pioneered the development of various flexible transducer arrays based on island-bridge structures[8]and serpentine electrodes[9].These transducer arrays incorporate rigid 1−3 composite piezoelectric transducers on an island,featuring thin electrodes between the islands to provide mechanical flexibility,metallic electrodes of serpentine structure to provide stretchability of the device,and elastomer materials are used to encapsulate the overall structure,ensuring structural stability and impedance matching to the skin tissue[10].These flexible transducer arrays have found extensive applications in human blood pressure detection[11],cardiac imaging[12],blood flow doppler imaging[13],tissue modulus detection[14],and tissue deep hemoglobin detection[15].

Potential morphological responses of an artificial beach to a flood in extreme events: field observation and numerical modelling

Conch Island is a typical artificial island at the Tanghe Estuary in Bohai Sea,China.To improve natural environment and boost local tourism,beach nourishment will be applied to its north-western shore.The projected beach is landward and opposite to the Jinmeng Bay Beach.Nowadays,with climate changes,frequent heavy rainfalls in Hebei Province rise flood hazards at the Tanghe Estuary.Under this circumstance,potential influences on the projected beach of a flood are investigated for sustainable managements.A multi-coupled model is established and based on the data from field observations,where wave model,flow model and multifraction sediment transport model are included.In addition,the impacts on the projected beach of different components in extreme events are discussed,including the spring tides,storm winds,storm waves,and sediment inputs.The numerical results indicate the following result.(1)Artificial islands protect the coasts from erosion by obstructing landward waves,but rise the deposition risks along the target shore.(2)Flood brings massive sediment inputs and leads to scours at the estuary,but the currents with high sediment concentration contribute to the accretions along the target shore.(3)The projected beach mitigates flood actions and reduces the maximum mean sediment concentration along the target shore by 20%.(4)The storm winds restrict the flood and decrease the maximum mean sediment concentration by 21%.With the combined actions of storm winds and waves,the maximum value further declines by 38%.(5)A quadratic polynomial relationship between the deposition depths and the maximum sediment inputs with flood is established for estimations on the potential morphological changes after the flood process in extreme events.For the uncertainty of estuarine floods,continuous monitoring on local hydrodynamic variations and sediment characteristics at Tanghe Estuary is necessary.

Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.

Factors Influencing the Spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

DNA methylation in poultry:a review

As an important epigenetic modification,DNA methylation is involved in many biological processes such as animal cell differentiation,embryonic development,genomic imprinting and sex chromosome inactivation.As DNA methylation sequencing becomes more sophisticated,it becomes possible to use it to solve more zoological problems.This paper reviews the characteristics of DNA methylation,with emphasis on the research and application of DNA methylation in poultry.

Island biogeography theory and the habitat heterogeneity jointly explain global patterns of Rhododendron diversity

Mountain biodiversity is of great importance to biogeography and ecology.However,it is unclear what ecological and evolutionary processes best explain the generation and maintenance of its high levels of species diversity.In this study,we determined which of six common hypotheses(e.g.,climate hypotheses,habitat heterogeneity hypothesis and island biogeography theory)best explain global patterns of species diversity in Rhododendron.We found that Rhododendron diversity patterns were most strongly explained by proxies of island biogeography theory(i.e.,mountain area)and habitat heterogeneity(i.e.,elevation range).When we examined other relationships important to island biogeography theory,we found that the planimetric area and the volume of mountains were positively correlated with the Rhododendron diversity,whereas the‘mountains-to-mainland’distance was negatively correlated with Rhododendron diversity and shared species.Our findings demonstrate that Rhododendron diversity can be explained by island biogeography theory and habitat heterogeneity,and mountains can be regarded as islands which supported island biogeography theory.

U-Pb zircon geochronology of basaltic pyroclastic rocks from the basement beneath the Xisha Islands in the northwestern South China Sea and its geological significance

As one of the micro-blocks dispersed in the South China Sea(SCS), the basement of the Xisha Islands has rarely been drilled because of the thick overlying Cenozoic sediments, which has led to a confused understanding of the pre-Cenozoic basement of the Xisha Islands. Well CK-1, a kilometer-scale major scientific drill in the Xisha Islands in the northwestern SCS, penetrated thick reefal limestone(0–888.4 m) and the underlying basement rocks(888.4–901.4 m). In this study, we present the zircon U-Pb ages of basement basaltic pyroclastic rocks from Well CK-1 in the Xisha Islands of the northwestern SCS to investigate the basement nature of the Xisha microblock. The basement of Well CK-1 consists of basaltic pyroclastic rocks on the seamount. The zircon grains yielded apparent ages ranging from ca. 2 138.9 Ma to ca. 36 Ma. The old group of zircon grains from Well CK-1 was considered to be inherited zircons. Two Cenozoic zircons gave a weighted mean 206Pb/238U age of(36.3 ± 1.1) Ma,Mean Squared Weighted Deviations(MSWD) = 1.2, which may represent the maximum age of the volcano eruption. The Yanshanian inherited zircons(116.9–105.7 Ma and 146.1–130.2 Ma) from Well CK-1 are consistent with the zircons from Well XK-1, indicating that the basement of Chenhang Island may be similar to that of Well XK-1. We propose that the Xisha micro-block may have developed on a uniform Late Jurassic metamorphic crystalline basement, intruded by Cretaceous granitic magma.

Coulomb-assisted nonlocal electron transport between two pairs of Majorana bound states in a superconducting island

We investigate the nonlocal transport modulated by Coulomb interactions in devices comprising two interacting Majorana wires,where both nanowires are in proximity to a mesoscopic superconducting(SC)island.Each Majorana bound state(MBS)is coupled to one lead via a quantum dot with resonant levels.In this device,the nonlocal correlations can be induced in the absence of Majorana energy splitting.We find that the negative differential conductance and giant current noise cross correlation could be induced,due to the interplay between nonlocality of MBSs and dynamical Coulomb blockade effect.This feature may provide a signature for the existence of the MBSs.

Gyrokinetic simulation of magnetic-island-induced electric potential vortex mode

Ion temperature gradient(ITG)-driven turbulence with embedded static magnetic islands is simulated by utilizing a gyrokinetic theory-based global turbulence transport code(GKNET)in this work.Different from the traditional equilibrium circular magnetic-surface average(EMSA)method,an advanced algorithm that calculates the perturbed magnetic-surface average(PMSA)of the electric potential has been developed to precisely deal with the zonal flow component in a non-circular magnetic surface perturbed by magnetic islands.Simulations show that the electric potential vortex structure inside islands induced by the magnetic islands is usually of odd parity when using the EMSA method.It is found that the odd symmetry vortex can transfer into an even one after a steep zonal flow gradient,i.e.the flow shear has been built in the vicinity of the magnetic islands by adopting the PMSA algorithm.The phase of the potential vortex in the poloidal cross section is coupled with the zonal flow shear.Such an electric potential vortex mode may be of essential importance in wide topics,such as the turbulence spreading across magnetic islands,neoclassical tearing mode physics,and also the interaction dynamics between the micro-turbulence and MHD activities.

Different mechanisms underlie similar species-area relationships in two tropical archipelagoes

Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain elusive.Here,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China Sea.We found positive plant species-area relationships for both coral and continental archipelagoes.However,our results showed that different mechanisms contributed to similar plant species-area relationships between the two archipelagoes.For coral islands,soil nutrients and spatial distance among communities played major roles in shaping plant community structure and species diversity.By contrast,the direct effect of island area,and to a lesser extent,soil nutrients determined plant species richness on continental islands.Intriguingly,increasing soil nutrients availability(N,P,K)had opposite effects on plant diversity between the two archipelagoes.In summary,the habitat quality effect and dispersal limitation are important for regulating plant diversity on coral islands,whereas the passive sampling effect,and to a lesser extent,the habitat quality effect are important for regulating plant diversity on continental islands.More generally,our findings indicate that island plant species-area relationships are outcomes of the interplay of both niche and neutral processes,but the driving mechanisms behind these relationships depends on the type of islands.

Spatiotemporal Evolution of Urban Heat Islands and Optimization of Spatial Network Construction in the Central Urban Area of Fuzhou City, China

Although accelerated urbanization has led to economic prosperity,it has also resulted in urban heat island effects.Therefore,identifying methods of using limited urban spaces to alleviate heat islands has become an urgent issue.In this study,we assessed the spatiotemporal evolution of urban heat islands within the central urban area of Fuzhou City,China from 2010 to 2019.This assessment was based on a morphological spatial pattern analysis(MSPA)model and an urban thermal environment spatial network constructed us-ing the minimum cumulative resistance(MCR)model.Optimization measures for the spatial network were proposed to provide a theor-etical basis for alleviating urban heat islands.The results show that the heat island area within the study area gradually increased while that of urban cold island area gradually decreased.The core area was the largest of the urban heat island patch landscape elements with a significant impact on other landscape elements,and represented an important factor underlying urban heat island network stability.The thermal environment network revealed a total of 197 thermal environment corridors and 93 heat island sources.These locations were then optimized according to the current land use,which maximized the potential of 1599.83 ha.Optimization based on current land use led to an increase in climate resilience,with effective measures showing reduction in thermal environment spatial network structure and function,contributing to the mitigation of urban heat island.These findings support the use of current land use patterns during urban heat island mitigation measure planning,thus providing an important reference basis for alleviating urban heat island effects.

Measuring urban thermal environment from accessibility-based perspective:A case study in a populous city

Understanding the spatial interaction among residents,cooling service,and heat risk area in complex urban areas is conducive to developing targeted management.However,traditional urban thermal environment assessments typically relied on simple linear integration of associated indicators,often neglecting the spatial interaction effect.To explore the spatial interaction among the three elements,this study proposes an accessibility-based urban thermal environment assessment framework.Using Zhengzhou,a rapidly urbanizing city,as an example,remotely sensed images from three periods(2010,2015 and 2020)were applied to extract urban green space(UGS)and hot island area(HIA).An improved two-step floating catchment area(2SFCA)method and bivariate local Moran’s I were employed to explore whether residents’clustering locations are more likely to access cooling service or to be exposed to heat risk.The results demonstrate that the UGS in the city has been expanding,whereas the HIA shrank within the inner city in 2015 and then increased in 2020.Even though the urban thermal environment may have improved in the last decade,the spatial interaction among the residents,cooling service and heat risk area could be exacerbated.Spatial autocorrelation shows an increase in locations that are disadvantageous for resident congregation.Even when sufficient cooling services were provided,residents in these areas could still be exposed to high heat risk.The developed urban thermal environment framework provides a novel insight into the residents’heat risk exposure and cooling service accessibility,and the findings could assist urban planners in targeting the improvement of extra heat exposure risk locations.

Local Climate Change Induced by Urbanization on a South China Sea Island

The South China Sea is a hotspot for regional climate research.Over the past 40 years,considerable improvement has been made in the development and utilization of the islands in the South China Sea,leading to a substantial change in the land-use of the islands.However,research on the impact of human development on the local climate of these islands is lacking.This study analyzed the characteristics of local climate changes on the islands in the South China Sea based on data from the Yongxing Island Observation Station and ERA5 re-analysis.Furthermore,the influence of urbanization on the local climate of the South China Sea islands was explored in this study.The findings revealed that the 10-year average temperature in Yongxing Island increased by approximately 1.11℃from 1961 to 2020,and the contribution of island development and urbanization to the local warming rate over 60 years was approximately 36.2%.The linear increasing trend of the annual hot days from 1961–2020 was approximately 14.84 days per decade.The diurnal temperature range exhibited an increasing trend of 0.05℃per decade,whereas the number of cold days decreased by 1.06days per decade.The rapid increase in construction on Yongxing Island from 2005 to 2021 led to a decrease in observed surface wind speed by 0.32 m s^(-1)per decade.Consequently,the number of days with strong winds decreased,whereas the number of days with weak winds increased.Additionally,relative humidity exhibited a rapid decline from 2001 to 2016 and then rebounded.The study also found substantial differences between the ERA5 re-analysis and observation data,particularly in wind speed and relative humidity,indicating that the use of re-analysis data for climate resource assessment and climate change evaluation on island areas may not be feasible.

Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations

Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.