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A PRINCIPAL MODE OF CIRCULATION COVARIATION BETWEEN THE NORTHERN AND SOUTHERN HEMISPHERES AND ITS ASSOCIATION WITH ENSO DURING BOREAL WINTER 认领 引用
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作者 唐卫亚 管兆勇 钱代丽 《Journal of Tropical Meteorology》 SCIE 2017年第4期450-461,共12页
By employing the singular value decomposition(SVD) analysis, we have investigated in the present paper the covariations between circulation changes in the Northern(NH) and Southern Hemispheres(SH) and their associatio... By employing the singular value decomposition(SVD) analysis, we have investigated in the present paper the covariations between circulation changes in the Northern(NH) and Southern Hemispheres(SH) and their associations with ENSO by using the NCEP/NCAR reanalysis, the reconstructed monthly NOAA SST, and CMAP precipitation along with NOAA Climate Prediction Center(CPC) ENSO indices. A bi-hemispheric covariation mode(hereafter BHCM) is explored, which is well represented by the first mode of the SVD analysis of sea surface pressure anomaly(SLPA-SVD1). This SVD mode can explain 57.36% of the total covariance of SLPA. BHCM varies in time with a long-term trend and periodicities of 3—5 years. The long term trend revealed by SVD1 shows that the SLP increases in the equatorial central and eastern Pacific but decreases in the western Pacific and tropical Indian Ocean, which facilitates easterlies in the lower troposphere to be intensified and El Ni觡o events to occur with lower frequency. The spatial pattern of the BHCM looks roughly symmetric about the equator in the tropics, whereas it is characterized by zonal disturbances in the mid-latitude of NH and is highly associated with AAO in the mid-latitude of SH. On inter-annual time scales, the BHCM is highly correlated with ENSO. The atmosphere in both the NH and SH responds to sea surface temperature anomalies in the equatorial region, while the contemporaneous circulation changes in the NH and SH in turn affect the occurrence of El Ni觡o/La Ni觡a. In boreal winter, significant temperature and precipitation anomalies associated with the BHCM are found worldwide. Specifically, in the positive phase of the BHCM,temperature and precipitation are anomalously low in eastern China and some other regions of East Asia. These results are helpful for us to better understand interactions between circulations in the NH and SH and the dynamical mechanisms behind these interactions. 展开更多
关键词 Northern and Southern Hemispheres circulation variations covariation mode climate anomaly ENSO
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Single‑Layer ZnO Hollow Hemispheres Enable High‑Performance Self‑Powered Perovskite Photodetector for Optical Communication 认领 引用 被引量：8
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作者 Xiyan Pan Jianqiang Zhang +7 位作者 Hai Zhou Ronghuan Liu Dingjun Wu Rui Wang Liangping Shen Li Tao Jun Zhang Hao Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第4期259-270,共12页
The carrier transport layer with reflection reduction morphology has attracted extensive attention for improving the utilization of light.Herein,we introduced single-layer hollow ZnO hemisphere arrays(ZHAs)behaving li... The carrier transport layer with reflection reduction morphology has attracted extensive attention for improving the utilization of light.Herein,we introduced single-layer hollow ZnO hemisphere arrays(ZHAs)behaving light trapping effect as the electron transport layer in perovskite photodetectors(PDs).The singlelayer hollow ZHAs can not only reduce the reflection,but also widen the angle of the effective incident light and especially transfer the distribution of the optical field from the ZnO/FTO interface to the perovskite active layer confirmed by the 3D finitedifference time-domain simulation.These merits benefit for the generation,transport and separation of carriers,improving the light utilization efficiency.Finally,our optimized FTO/ZHA/CsPbBr3/carbon structure PDs showed high self-powered performance with a linear dynamic range of 120.3 dB,a detectivity of 4.2×1012 Jones,rise/fall time of 13/28μs and the f−3 dB of up to 28 kHz.Benefiting from the high device performance,the PD was demonstrated to the application in the directional transmission of encrypted files as the signal receiving port with super high accuracy.This work uniquely utilizes the features of high-performance self-powered perovskite PDs in optical communication,paving the path to wide applications of all-inorganic perovskite PDs. 展开更多
关键词 Hemisphere array Perovskite Photodetector Reflection reduction Optical communication
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Ultimate Strength Assessment of Steel-Welded Hemispheres under External Hydrostatic Pressure 认领 引用
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作者 Sang-Rai Cho Teguh Muttaqie +2 位作者 Seung Hyun Lee Jaewoo Paek Jung Min Sohn 《Journal of Marine Science and Application》 CSCD 2020年第4期615-633,共19页
This paper focusses on steel-welded hemispherical shells subjected to external hydrostatic pressure.The experimental and numerical investigations were performed to study their failure behaviour.The model was fabricate... This paper focusses on steel-welded hemispherical shells subjected to external hydrostatic pressure.The experimental and numerical investigations were performed to study their failure behaviour.The model was fabricated from mild steel and made through press forming and welding.We therefore considered the effect of initial shape imperfection,variation of thickness and residual stress obtained from the actual structures.Four hemisphere models designed with R from 50 to 130 were tested until failure.Prior to the test,the actual geometric imperfection and shell thickness were carefully measured.The comparisons of available design codes(PD 5500,ABS,DNV-GL)in calculating the collapse pressure were also highlighted against the available published test data on steel-welded hemispheres.Furthermore,the nonlinear FE simulations were also conducted to substantiate the ultimate load capacity and plastic deformation of the models that were tested.Parametric dependence of the level of sphericity,varying thickness and residual welding stresses were also numerically considered in the benchmark studies.The structure behaviour from the experiments was used to verify the numerical analysis.In this work,both collapse pressure and failure mode in the numerical model were consistent with the experimental model. 展开更多
关键词 Steel-welded hemisphere Collapse pressure Experiment Nonlinear FEA Ultimate strength formulation
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Metabolite changes in the ipsilateral and contralateral cerebral hemispheres in rats with middle cerebral artery occlusion 认领 引用 被引量：10
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作者 Lei Ruan Yan Wang +11 位作者 Shu-chao Chen Tian Zhao Qun Huang Zi-long Hu Neng-zhi Xia Jin-jin Liu Wei-jian Chen Yong Zhang Jing-liang Cheng Hong-chang Gao Yun-jun Yang Hou-zhang Sun 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第6期931-937,共7页
Cerebral ischemia not only causes pathological changes in the ischemic areas but also induces a series of secondary changes in more distal brain regions（such as the contralateral cerebral hemisphere）. The impact of ... Cerebral ischemia not only causes pathological changes in the ischemic areas but also induces a series of secondary changes in more distal brain regions（such as the contralateral cerebral hemisphere）. The impact of supratentorial lesions, which are the most common type of lesion, on the contralateral cerebellum has been studied in patients by positron emission tomography, single photon emission computed tomography, magnetic resonance imaging and diffusion tensor imaging. In the present study, we investigated metabolite changes in the contralateral cerebral hemisphere after supratentorial unilateral ischemia using nuclear magnetic resonance spectroscopy-based metabonomics. The permanent middle cerebral artery occlusion model of ischemic stroke was established in rats. Rats were randomly divided into the middle cerebral artery occlusion 1-, 3-, 9-and 24-hour groups and the sham group. ~1H nuclear magnetic resonance spectroscopy was used to detect metabolites in the left and right cerebral hemispheres. Compared with the sham group, the concentrations of lactate, alanine, γ-aminobutyric acid, choline and glycine in the ischemic cerebral hemisphere were increased in the acute stage, while the concentrations of N-acetyl aspartate, creatinine, glutamate and aspartate were decreased. This demonstrates that there is an upregulation of anaerobic glycolysis（shown by the increase in lactate）, a perturbation of choline metabolism（suggested by the increase in choline）, neuronal cell damage（shown by the decrease in N-acetyl aspartate） and neurotransmitter imbalance（evidenced by the increase in γ-aminobutyric acid and glycine and by the decrease in glutamate and aspartate） in the acute stage of cerebral ischemia. In the contralateral hemisphere, the concentrations of lactate, alanine, glycine, choline and aspartate were increased, while the concentrations of γ-aminobutyric acid, glutamate and creatinine were decreased. This suggests that there is a difference in the metabolite changes induced by ischemic injury in the contralateral and ipsilateral cerebral hemispheres. Our findings demonstrate the presence of characteristic changes in metabolites in the contralateral hemisphere and suggest that they are most likely caused by metabolic changes in the ischemic hemisphere. 展开更多
关键词 occlusion hemisphere glutamate aspartate metabolite creatinine lactate neuronal glycine carotid
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Differential Spontaneous Photon Emissions from Cerebral Hemispheres of Fixed Human Brains: Asymmetric Coupling to Geomagnetic Activity and Potentials for Examining Post-Mortem Intrinsic Photon Information 认领 引用 被引量：3
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作者 Justin N. Costa Nicolas Rouleau Michael A. Persinger 《Neuroscience & Medicine》 2016年第2期49-59,共11页
The emissions of biophotons have been considered a ubiquitous property of living systems and their components. We measured the “spontaneous” photon emissions from fixed whole and sectioned human brains within hyper-... The emissions of biophotons have been considered a ubiquitous property of living systems and their components. We measured the “spontaneous” photon emissions from fixed whole and sectioned human brains within hyper-dark settings. Significant differences in photon counts were measured from different spatial planes. The flux densities were in the order of 2 × 10-12 W per m2. The right hemispheres but not the left hemispheres displayed more photon emissions whose spectral power density profiles exhibited a conspicuous amplitude peak between 7.9 and 8 Hz. Brains measured in the hyperdark (~10-12 W·m2) after removal from the typical lighting of the laboratory emitted more photons than those that had been maintained in the hyperdark for one week. The significant correlation between the numbers of photons emitted from the left hemisphere (but not the right) and global geomagnetic activity also exhibited energy equivalence between the photon flux densities and the geomagnetic shift within the cerebral volumes. These results indicate that what has been assumed to be fixed unresponsive human brain tissue still emits small numbers of photons that may be residuals from ambient light and can potentially interact with global geomagnetic activity. The medical implications for post-mortem intrinsic photonic information based upon the anisotropic microstructures within the hemispheres of the human cerebrum are discussed. 展开更多
关键词 Photons Fixed Human Brain Geomagnetic Activity Hemispheric Differences Ambient Light
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Restoration of Ultimate Strength of Dented Hemispheres Under External Hydrostatic Pressure 认领 引用
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作者 HUANG Chen ZHANG Jian +1 位作者 WANG Fang DI Chen-yang 《China Ocean Engineering》 SCIE EI CSCD 2022年第3期500-507,共8页
This study aimed to restore the ultimate strength of dented stainless-steel hemispheres with a radius of 90 mm and a thickness of 0.86 mm.All of the hemispheres were subjected to external hydrostatic pressure.Small st... This study aimed to restore the ultimate strength of dented stainless-steel hemispheres with a radius of 90 mm and a thickness of 0.86 mm.All of the hemispheres were subjected to external hydrostatic pressure.Small stainless-steel stiffened caps were used to eliminate the effect of indention on the ultimate strength.These caps had a radius of 36 mm,a thickness of 0.76 mm,and a height of 10.44 mm.Six hemispherical samples,including two intact hemispheres,two dented hemispheres without stiffening,and two dented hemispheres with stiffening,were prepared.Each hemi-sphere was geometrically measured for shape and thickness,hydrostatically tested for destruction,and numerically evaluated for comparison.The experimental and numerical data agreed well with each other.As a result,a spherical cap can effectively restore the ultimate strength of dented hemispheres under external hydrostatic pressure.The proposed restoration approach can be used to strengthen underwater pressure hulls with large local geometric imperfections. 展开更多
关键词 hemisphere restoration ultimate strength hydrostatic pressure buckling
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Unsteady Natural Convection between Two Eccentric Hemispheres 认领 引用 被引量：1
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作者 Mariama Néné Koita Mamadou Lamine Sow +3 位作者 Omar Ngor Thiam Vieux Boukhaly Traoré Cheikh Mbow Joseph Sarr 《Open Journal of Applied Sciences》 2021年第2期177-189,共13页
Natural convection heat transfer in open or closed cavities takes place in different engineering areas. The hemispherical cavity is a part of basic geometries although it is not widely studied. The present paper repor... Natural convection heat transfer in open or closed cavities takes place in different engineering areas. The hemispherical cavity is a part of basic geometries although it is not widely studied. The present paper reports the numerical study of natural convection in a closed hemispherical annulus delimited by two vertically eccentric hemispheres filled with Newtonian fluid (air in this case with Pr = 0.7) is conducted. The inner hemisphere is heated by a heat flux of constant density and the outer one is maintained isothermal. Based on the Boussinesq assumptions, the governing equations are numerically studied using unsteady natural convection formulated with vorticity and stream-function variables. These equations are written by using bispherical coordinates system and solved by using a finite difference method. The effect of the control parameters such as the Rayleigh number (103 ≤ Ra ≤ 106) or the eccentricity (e = ±0.2, ±0.5, 0) in the dynamic and thermal behaviours of the fluid is investigated. 展开更多
关键词 Natural Convection Hemispherical Cavity Rayleigh Correlations Eccentricity Nusselt Number
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Depth perception differences between hemispheres,genders,and eye dominance A study on evoked potential 认领 引用
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作者 Ahmet Akay Gürbüz elebi 《Neural Regeneration Research》 SCIE CAS 2009年第11期947-950,共4页
BACKGROUND： Certain neural functions, such as peripheral reflexes, differ between genders, while higher brain functions, such as language, are asymmetrically distributed between the two hemispheres. The question rema... BACKGROUND： Certain neural functions, such as peripheral reflexes, differ between genders, while higher brain functions, such as language, are asymmetrically distributed between the two hemispheres. The question remains as to whether depth perception differs between hemispheric laterality and genders, and whether it is affected by eye dominance. OBJECTIVE： To determine whether depth perception is influenced by factors such as gender, eye dominance, and hemispheric lateralization by recording evoked potential associated with depth perception. DESIGN, TIME AND SETTING： A contrast observation based on neuroelectrophysiology was performed at the Department of Biophysics of Ege University Medical School between June 2006 and April 2007. PARTICIPANTS： A total of 34 subjects, 19 females and 15 males, were included in the study with a mean age of （31.0 ± 6.9） years. All subjects were free of neurological or psychological disorders, or problems such as strabismus or vision correction. METHODS： Random-dot stereograms were used to elicit brain activity. A specially designed signal acquisition system employing two computers was used to record evoked potentials from both hemispheres via two pairs of scalp electrodes placed over the occipitotemporal areas of both hemispheres at symmetrical locations. MAIN OUTCOME MEASURES： Negative potential with a mean latency of （211.21 ±25.55） ms and a mean amplitude of （6.05 ± 1.53） pV was recorded from both occipitotemporal areas in 30 out of 34 participants. This was termed ＂Nd＂ and represented the evoked potential associated with depth perception. RESULTS： There were no significant differences in Nd amplitude or latency between the two hemispheres, the two eyes, or genders （P 〉 0.05）. CONCLUSION： The evoked potential associated with depth perception was not influenced by gender, hemisphere, or eye dominance. 展开更多
关键词 random-dot stereogram depth perception, stereovision eye dominance hemisphere lateralization： sex difference
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Numerical Simulation of Natural Air Convection in Inclined Eccentric Hemispheres Enclosure 认领 引用
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作者 Mariama Néné Koita Mamadou Lamine Sow +3 位作者 Oumar Dramé Babacar Mbow Cheikh Mbow Joseph Sarr 《Open Journal of Applied Sciences》 2021年第6期722-735,共14页
The subject of natural convection heat transfer is motivated by a wide range of applications in engineering technology. The hemispherical cavity is a part of basic geometries although it is not widely studied. The eff... The subject of natural convection heat transfer is motivated by a wide range of applications in engineering technology. The hemispherical cavity is a part of basic geometries although it is not widely studied. The effect of inclinaison on natural convection fluid motions in the gap between two eccentric hemispheres is numerically studied. The inner hemisphere is subjected to a heat flux of a constant density and the outer one is maintened isothermal. The walls separating the two hemispheres are thermally adiabatic. Equations are formulated with vorticity and stream-functions variables. It is also assumed the fluid incompressible and obeys the approximation of Boussinesq. These equations are written by using bispherical coordinates system and solved by using a finite difference method. The results show the topology of flow is strongly dependent on the inclinaison because the flow can change from a unicellular regime to a multicellular regime by varying the inclination from 0 to π. By increasing the Rayleigh number (103Ra7), the flow intensifies. The results are shown in terms of streamlines and isotherms during their transient evolution. 展开更多
关键词 Bispherical Coordinates Hemispherical Cavities Rayleigh Number Nusselt Number Eccentricity Streamlines Isotherms
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Modelling and experimental investigation of frequency splitting of hemispherical resonator with machining errors 认领 引用
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作者 Chuanzhen MA Henan LIU +1 位作者 Jian CHENG Mingjun CHEN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期609-625,共17页
Hemispherical Resonator(HSR)is a typical high-performance component due to the complex coupling relationship between the machining errors and performance parameters.To understand the impact of machining errors on freq... Hemispherical Resonator(HSR)is a typical high-performance component due to the complex coupling relationship between the machining errors and performance parameters.To understand the impact of machining errors on frequency splitting,the frequency splitting model that couples the multiple machining errors was developed to elucidate the mechanism of frequency splitting and reveal the effect of geometric error parameters on frequency splitting innovatively.In addition,a method for characterizing machining errors is established to describe the circumferential mass uniformity of the hemispherical shell.Furthermore,measurement experiments of HSRs were performed to verify the accuracy of the model,and the results showed that the predicted errors of the model were within 15%.Both theoretical and experimental results demonstrated that the direct cause of frequency splitting is the uneven circumferential mass of HSR.In particular,the radial concentricity has the most significant influence on frequency splitting,followed by the coaxiality and roundness.Within the error range of 0–0.5μm,frequency splitting values change by 0.945 Hz,0.098 Hz,and 0.039 Hz,respectively.Furthermore,the coupling effect of machining errors and surface quality on frequency splitting was discussed,which showed machining errors is the predominant factor contributing to frequency splitting.This work not only enhance the understanding of the mechanism of frequency splitting,but also provide theoretical guidance for the parameter optimization involved in high-performance manufacturing of HSR. 展开更多
关键词 Frequency splitting Hemispherical resonator Machining errors Mass nonuniformity Surface quality
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Global thermospheric density response to the May 2024 extreme storm:TianMu-1 constellation observations 认领 引用
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作者 JiangZhao Ai XianGuo Zhang +8 位作者 YongPing Li YueQiang Sun WenLu Bai XiaoYu Guo JiaoJiao Zhang XiaoLiang Zheng Jia Li YuJie Wang XinChun Tang 《Earth and Planetary Physics》 EI CSCD 2026年第1期105-116,共12页
In this study,we analyze the impact of the May 2024 geomagnetic storm on the thermospheric mass density by using TianMu-1 constellation satellite(TM02,TM06,TM07,TM11,TM15)observations.These observations reveal intense... In this study,we analyze the impact of the May 2024 geomagnetic storm on the thermospheric mass density by using TianMu-1 constellation satellite(TM02,TM06,TM07,TM11,TM15)observations.These observations reveal intense large-scale traveling atmospheric disturbances(TADs)originating at high latitudes and propagating equatorward.Observations by TM02 captured the evolution of a TAD structure:An initial amplitude of~3.89×10-12kg/m3at hundred-kilometer scale subsequently intensified to 4.78×10-12kg/m3,with the spatial extent expanding to the thousand-kilometer level.Significant hemispheric asymmetry was observed:the absolute density was higher predominantly in the northern hemisphere(TM02,TM06,TM07,TM11),whereas the difference in the relative density consistently showed greater enhancements in the southern hemisphere across all satellites,with the maximum north-south density differences exceeding 195%-640%above 60°latitude.In conjunction with SuperDARN(Super Dual Auroral Radar Network)observations,this striking hemispheric asymmetry can likely be attributed to disparities in plasma convection patterns between the two hemispheres.Furthermore,density perturbation characteristics exhibited strong local time(LT)dependence:Near noon(~10.7 LT,TM02 descending),the northern hemisphere onset preceded the southern onset.Conversely,near dusk(~17.6 LT,TM15 descending),the southern onset led the northern onset by approximately 3 hours.Ascending orbits(TM02,TM06,TM07,TM15)typically yielded larger global density enhancements compared with smaller southern-confined enhancements during descending orbits.Satellite TM11 showed comparable perturbations in both ascending and descending orbits.By leveraging its unique orbital architecture,the TianMu-1 constellation enables global near-simultaneous multi-LT sampling,providing a robust data foundation for both scientific research and engineering applications. 展开更多
关键词 TianMu-1 constellation thermosphere density magnetic storm hemispheric asymmetry traveling atmospheric disturbances
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Wall Thickness Homogenization Control and Performance of Superplastically Formed Hemispherical Shell of TC4 Titanium Alloy 认领 引用
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作者 Ji Wei Zhang Zhaohuang +3 位作者 Lu Zichuan Wei Shi Qiu Xuyangfan Zhang Xuhu 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2026年第7期1683-1691,共9页
Spherical and capsule-shaped surface tension tanks are widely used in satellite,spacecraft,and other fields due to their advantages of lightweight structure,high efficiency,and high reliability.With the advancement of... Spherical and capsule-shaped surface tension tanks are widely used in satellite,spacecraft,and other fields due to their advantages of lightweight structure,high efficiency,and high reliability.With the advancement of space exploration,the demands for thinner walls,more complex structures,and uniform overall performance in the hemispherical shells of these tanks present significant challenges for hemispherical shell forming technique.A hemispherical shell with uniform wall thickness was prepared using the rapid direct-and-reverse superplastic forming method.Results reveal that the properties and microstructure of each section of the formed hemisphere shell are consistent with those of the initial plate,and the overall shell thickness is highly uniform. 展开更多
关键词 hemispherical shell of storage tank control of wall thickness direct-and-reverse superplastic forming mold design
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ENSO-Independent Contemporaneous Variations of Anomalous Circulations in the Northern and Southern Hemispheres:The Polar-Tropical Seesaw Mode 认领 引用 被引量：1
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作者 唐卫亚 管兆勇 《Journal of Meteorological Research》 SCIE CSCD 2015年第6期917-934,共18页
Using the NCEP/NCAR reanalysis and the ENSO indices from the Climate Prediction Center over the period 1978-2014,we have investigated the contemporaneous circulation variations in the Northern and Southern Hemispheres... Using the NCEP/NCAR reanalysis and the ENSO indices from the Climate Prediction Center over the period 1978-2014,we have investigated the contemporaneous circulation variations in the Northern and Southern Hemispheres by performing the singular value decomposition analysis of sea level pressure anomalies（SLPA） after the ENSO signal is regressed out.It is found that there exists a polar-tropical seesaw mode（PTSM） that characterizes with the out of phase fluctuations of SLPA between the polar and tropical regions in the Northern and Southern Hemispheres in boreal winter.This PTSM explains 47.74%of the total covariance of SLPA and is almost independent of ENSO.It demonstrates a long-term trend and oscillation cycles of 2-3 and 4-6 yr.The long-term trend in PTSM indicates that the sea level pressure gradually decreases in the tropics and increases in the polar region with time.This PTSM looks roughly symmetric about the equator besides the seesaw pattern of SLPA between the tropics and polar region in each hemisphere.The disturbances in the geopotential height field in association with the PTSM shows baroclinic features in the tropics whereas equivalent barotropic features in the mid and high latitudes in the troposphere.The anomalous thermal forcing in the tropical region is possibly one of the factors facilitating the formation of this PTSM.Significant global precipitation and temperature anomalies related to the PTSM are observed.In the positive PTSM phase,precipitation and temperature are higher than normal in southern Europe and the Mediterranean and surrounding areas,but lower than normal in northern Europe and Siberia.Precipitation is higher than normal while temperature is lower than normal in Northeast Asia.Significant temperature and precipitation anomalies possibly occur in the regions of western China,northern India,parts of North America,parts of subtropical Africa,Maritime Continent,and Antarctic.These results are helpful for better understanding of the circulation variations and the mechanisms behind the interactions between the Northern and Southern Hemispheres and the related winter climate anomalies over globe. 展开更多
关键词 Northern and Southern Hemispheres polar-tropical seesaw mode climate anomaly boreal winter
LOW-FREQUENCY SUMMER MONSOON IN INDONESIA-NORTHERN AUSTRALIA AND ITS RELATION TO CIRCULATIONS IN BOTH HEMISPHERES 认领 引用 被引量：3
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作者 朱乾根 智协飞 雷兆崇 《Acta meteorologica Sinica》 1990年第5期545-553,共9页
In terms of the expansion by extended empirical orthogonal function (EEOF) with data of ECMWF WMO and of outgoing longwave radiation(OLR) furnished by the NOAA polar-orbiting satellite,a study is made of November 1981... In terms of the expansion by extended empirical orthogonal function (EEOF) with data of ECMWF WMO and of outgoing longwave radiation(OLR) furnished by the NOAA polar-orbiting satellite,a study is made of November 1981 to March 1982 low-frequency (30--60 day)summer monsoon activity in the Indone- sian-North Australian zone (INAZ) together with its relation to atmospheric circulations in the Northern and Southern Hemispheres. Results show that at 850 hPa the southward blowing low-frequency NE(SW)wind from the eastern Asian coast changes, after crossing the euqator, to summer NW (SE) monsoon in the INAZ, which, when converging with (diverging from) the western-Australian enforced low-frequency SW (NE) wind, brings about strengthened (weakened) convection in the summer monsoon area and its eastward advance, with corresponding low- frequency variation shown in 850 hPa geopotential height. These outcomes are similar to those from the study of non-filtered actual observations, leading to the conclusion that the component of low-frequency variation illustrates major features characteristic of the variation in the tropical circulation. 展开更多
关键词 LOW-FREQUENCY SUMMER MONSOON IN INDONESIA-NORTHERN AUSTRALIA AND ITS RELATION TO CIRCULATIONS IN BOTH HEMISPHERES ITS
Hemispheric Asymmetry of Land–Ocean Distribution Causes Asynchronous Global Atmospheric Energy Response to Solar Forcing 认领 引用
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作者 Yuhui HAN Ming CAI +2 位作者 Zhenning LI Song YANG Xiaoming HU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2026年第6期1173-1181,共9页
The variation between Earth's perihelion and aphelion causes seasonal fluctuations in the total solar radiation(SR)received by the planet.Our analysis of observational data and Community Earth System Model(CESM)si... The variation between Earth's perihelion and aphelion causes seasonal fluctuations in the total solar radiation(SR)received by the planet.Our analysis of observational data and Community Earth System Model(CESM)simulations indicates that the temporal phase of atmospheric total energy in each hemisphere tends to follow the annual cycle of SR in each hemisphere with a delay of less than a month.However,the amplitude of the annual cycle of atmospheric energy in the Southern Hemisphere(SH)is weaker than that in the Northern Hemisphere(NH),despite the annual cycle of SR in the SH being 7%stronger than that in the NH.The stronger annual cycle response of atmospheric energy in the NH,despite its weaker annual cycle of SR,results in a six-month delay in the annual cycle of the global mean total atmospheric energy relative to the annual cycle of total SR received by Earth,as shown in both observations and CESM simulations.An aqua planet climate simulation reveals that the global and hemispheric mean atmospheric total energy in each hemisphere follows the SR annual cycles in both timing and amplitude.The contrast between the CESM and aqua planet simulations indicates that the difference in land–ocean distribution between the two hemispheres causes the asynchronous global atmospheric energy response to SR forcing.Using a dry radiative–convective coupled atmosphere–surface climate model,we confirm that this asynchronous global atmospheric energy response to SR forcing is driven by the hemispheric asymmetry in land–ocean distribution. 展开更多
关键词 hemispheric asymmetry land-ocean distribution total atmospheric energy solar radiation phase lag
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Correction to"The first record of fossil Vitaceae wood from the Southern Hemisphere,a new combination for Vitaceoxylon ramunculiformis,and reappraisal of the fossil record of the grape family(Vitaceae)from the Cenozoic of Australia" 认领 引用
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《Journal of Systematics and Evolution》 SCIE CSCD 2026年第4期832-832,共1页
Rozefelds AC,Pace MR.2018.The first record of fossil Vitaceae wood from the Southern Hemisphere,a new combination for Vitaceoxylon ramunculiformis,and reappraisal of the fossil record of the grape family(Vitaceae)from... Rozefelds AC,Pace MR.2018.The first record of fossil Vitaceae wood from the Southern Hemisphere,a new combination for Vitaceoxylon ramunculiformis,and reappraisal of the fossil record of the grape family(Vitaceae)from the Cenozoic of Australia.Journal of Systematics and Evolution 56:283-296.http://gffzzd3cc09b8251d45dfskuqnfv5bfpvf6p9b.ffgz.tsg.suse.edu.cn/10.1111/jse.12300.In the published article,the description of the new species on page 285 did not include a validating illustration,as the registration numbers cited in the captions of Figs.2,3 on Pages 286 and 287 were incorrect. 展开更多
关键词 reappraisal vitaceoxylon ramunculiformisand description new species fossil vitaceae wood grape family southern hemisphere vitaceoxylon ramunculiformis reappraisal fossil record
Donald Trump's Neo-Monroe Doctrine: Characteristics and Implications 认领 引用
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作者 Wu Hongying 《Foreign Affairs Journal》 2026年第1期50-67,97-105,共18页
After returning to the White House,President Donald J.Trump put forward the"Neo-Monroe Doctrine"(also known as the"Trump Corollary to the Monroe Doctrine").This,in essence,is a result when the 19th... After returning to the White House,President Donald J.Trump put forward the"Neo-Monroe Doctrine"(also known as the"Trump Corollary to the Monroe Doctrine").This,in essence,is a result when the 19th-century Monroe Doctrine was reactivated and radically upgraded in the early 21st century.The core of the Neo-Monroe Doctrine is to establish the Western Hemisphere as a"core interest zone"of the U.S.and to enforce absolute supremacy in the region through military,economic and political means. 展开更多
关键词 Economic Means Political Means Neo Monroe Doctrine Core Interest Zone Trump Corollary Western Hemisphere monroe doctrine Military Means
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Spatiotemporal distribution of seasonal snow density in the Northern Hemisphere based on in situ observation 认领 引用 被引量：1
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作者 Tao Che LiYun Dai Xin Li 《Research in Cold and Arid Regions》 CAS CSCD 2025年第3期137-144,共8页
The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow de... The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow depth to snow water equivalent(SWE)for the snow water resources research.Therefore,it is important to understand the spatiotemporal distribution of snow density for the appropriate estimation of SWE.In this study,in situ snow densities from more than 6,000 stations in the Northern Hemisphere were used to analyze the spatial and temporal variations in snow density.The results displayed that snow density varied spatially and temporally in the Northern Hemisphere,with range of below 0.1 to over 0.4 g/cm3.The average snow densities in the mountainous regions of western North America,southeastern Canada,and Europe range from approximately 0.24 to 0.26 g/cm3,which is significantly greater than the values of 0.16–0.17 g/cm3observed in Siberia,central Canada,the Great Plains of the United States,and China.The seasonal growth rates also present large spatial heterogeneity.The rates are over 0.024 g/cm3per month in Southeastern Canada,the west mountain of North America and Europe,approximately 0.017 g/cm3per month in Siberia,much larger than approximately 0.004 g/cm3per month in other regions.Snow cover duration is a critical factor to determine the snow density.This study endorses the small snow density in China based on meteorological station observations,which results from that the meteorological stations are dominantly distributed in plain areas with relative short snow cover duration and shallow snow. 展开更多
关键词 Snow density Snow depth Snow cover duration Northern Hemisphere
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A statistical survey of polar cap cold and hot patches in the Southern Hemisphere using a DMSP Satellite 认领 引用
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作者 Duan Zhang QingHe Zhang +11 位作者 Kjellmar Oksavik ZanYang Xing LRLyons HuiGen Yang Tong Xu Marc Hairston XiangYu Wang YuZhang Ma GuoJun Li Yong Wang Sheng Lu Jin Wang 《Earth and Planetary Physics》 EI CSCD 2025年第4期955-965,共11页
This paper is a statistical survey of Southern Hemisphere cold and hot polar cap patches,in relation to the interplanetary magnetic field(IMF)and ionospheric convection geometry.A total of 11,946 patch events were ide... This paper is a statistical survey of Southern Hemisphere cold and hot polar cap patches,in relation to the interplanetary magnetic field(IMF)and ionospheric convection geometry.A total of 11,946 patch events were identified by Defense Meteorological Satellite Program(DMSP)F16 during the years 2011 to 2022.A temperature ratio of ion/electron temperature(Ti/Te)<0.68 is recommended to define a hot patch in the Southern Hemisphere,otherwise it is defined as a cold patch.The cold and hot patches have different dependencies on IMF clock angle,while their dependencies on IMF cone angle are similar.Both cold and hot patches appear most often on the duskside,and the distribution of cold patches gradually decreases from the dayside to the nightside,while hot patches have a higher occurrence rate near 14 and 21 magnetic local time(MLT).Moreover,we compared the key plasma characteristics of polar cap cold and hot patches in the Southern and Northern Hemispheres.The intensity of the duskside upward field-aligned current of patches in the Southern Hemisphere(SH)is stronger than that in the Northern Hemisphere(SH),which may be due to the discrepancy in conductivities between the two hemispheres,caused by the tilted dipole.In both hemispheres,the downward soft-electron energy flux of the dawnside patches is significantly greater than that of the duskside patches. 展开更多
关键词 polar ionosphere polar cap patch irregularities statistical survey southern hemisphere.
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Hemispheric asymmetries and network dysfunctions in adolescent depression:A neuroimaging study using resting-state functional magnetic resonance imaging 认领 引用 被引量：4
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作者 Ying Xiong Ren-Qiang Yu +4 位作者 Xing-Yu Wang Shun-Si Liang Jie Ran Xiao Li Yi-Zhi Xu 《World Journal of Psychiatry》 SCIE 2025年第2期100-108,共9页
BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological s... BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies. 展开更多
关键词 Adolescent depression Brain network connectivity Neuroimaging biomarkers Functional magnetic resonance imaging Default mode network Salience network Hemispheric asymmetry
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