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asymmetry of upper ocean salinity response to the Indian Ocean dipole events as seen from ECCO simulation

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Acta Oceanologica Sinica 2016年第7期35卷 42-49页

作者： ZHANG Ying DU Yan ZHANG Yuhong GAO Shan State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

The interannual variability of salinity and associated ocean dynamics in the equatorial Indian Ocean is analyzed using observations and numerical simulations by the Estimating the Circulation and Climate of the Ocean （ECCO） model. The results show that salinity anomalies in the upper ocean are asymmetrically associated with the Indian Ocean dipole （IOD） events, with stronger response during their positive phases. Further investigations reveal that zonal currents along the equator, the Wyrtki jets, dominate the salinity transport. During the positive IOD events, the Wyrtld jets have stronger westward anomalies. The positive skewness of the IOD explains that the amplitude of the anomalous Wyrtld jets is stronger in the positive IOD events than that in the negative events.

关键词： Wyrtld jets salinity transport Indian Ocean dipole asymmetry

Study of the asymmetry of hot-spot self-emission imaging of inertial confinement fusion implosion driven by high-power laser facilities

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Plasma Science and Technology 2020年第8期22卷 20-26页

作者：董云松康洞国蒋炜刘志诚陈忠靖张兴李欣孙传奎尹传盛董建军杨志文蒲昱东晏骥余波黄天晅缪文勇戴振生葛峰峻杨冬王峰杨家敏江少恩 Research Center of Laser Fusion Chinese Academy of Engineering PhysicsMianyang 621900People's Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100088People's Republic of China Department of Engineering Physics Tsinghua UniversityBeijing 100086People's Republic of China

Implosion asymmetry is a crucial problem quenching ignition in the field of inertial confinement fusion.A forward-calculation method based on 1D and 2D hydrodynamic simulations has been developed to generate and study the x-ray images of hot-spot self-emission,indicating asymmetry integrated over the entire drive pulse.It is shown that the x-ray imaging photon energy should be higher to avoid the influence of the remaining shell.The contour level(percentage of the maximum emission intensity)and spatial resolution should be as low as possible,optimally less than 20%and 3μm,for characterization of higher-mode signatures such as Ps-P12 by x-ray self-emission images.On the contrary,signatures of lower-mode such as P2 remain clear at all contour levels and spatial resolutions.These key results can help determine the optimal diagnostics,laser,and target parameters for implosion experiments.Recent typical hot-spot asymmetry measurements and applications on the Shenguang 100 kJ class laser facility are also reported.

关键词： inertial confinement fusion implosion x-ray self-emission hot-spot asymmetry

Signature of the 27-day variation in hemispheric sunspot activity and asymmetry during 2010-2015

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Research in Astronomy and Astrophysics 2021年第4期21卷 331-340页

作者： Prithvi Raj Singh Ahmad Islam Saad Farid Tarun Kumar Pant Abhay Kumar Singh Department of Physics Banaras Hindu UniversityVaranasi-221005India Physics and Chemistry Department Faculty of EducationAlexandria UniversityAlexandria-21526Egypt Space Physics Laboratory VSSCThiruvananthapuram-695022India

In the present work,we study the time evolution,significance of the N-S asymmetry excesses presented as a function of the solar cycle and prominent rotational periods(~27 d)separately for the northern and southern hemispheres.We have investigated short-term variations of the hemispheric solar activity(sunspot numbers and sunspot areas)during the time period 2010-2015,which covers the ascending and the maximum phase of solar cycle 24.We have implemented the Lomb-Scargle periodogram and continuous wavelet transform power spectrum techniques to study the time evolution and dominant rotational periods separately for the northern and southern hemispheres,and whole solar disk.Our results showed that the northern hemisphere exhibited longer solar synodic periods than the southern hemisphere,indicating that the northern hemisphere has a lower rotation rate.Moreover,the northern hemisphere was found to be dominant before transferring to the southern hemisphere during mid-2013.Also,the sunspot areas clearly demonstrated a two-peak structure of solar activity in the northern and southern hemispheres respectively during 2012 and 2014.The statistical significance of the southern hemisphere affirmed enhanced excess during the maximum phase of solar cycle 24.

关键词： Sunspots Sunspot Area asymmetry Solar Cycle

asymmetry in the Arctic Oscillation Teleconnection with January Cold Extremes in Northeast China

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Atmospheric and Oceanic Science Letters 2015年第6期8卷 386-391页

作者： HE Sheng-Ping Climate Change Research Center Chinese Academy of Sciences Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences

The connection of the Arctic Oscillation(AO)with the frequency of temperature extremes over East Asia during boreal winter has been documented by many studies.This study describes an asymmetry in the relationship between the January AO and the simultaneous cold extremes in Northeast China(NEC),and further reveals a breakdown of this relationship.It is demonstrated that the frequency of January cold extremes in NEC shows significant(insignificant)negative correlation with the simultaneous negative(positive)phase of the AO.One possible explanation for such an asymmetry is that the Arctic center of negative AO extends more southwards to Siberia compared with that of positive AO,conducive to a closer connection with the frequency of an extreme Siberian high.As a result,the frequency of January cold extremes in NEC shows a more significant relationship with the negative AO.The other related explanation is that,concurrent with the negative phase of the AO,there is an evident meridional stationary planetary wave in the upper troposphere around(30°N,100–300 hP a),which disappears in the positive AO.Therefore,the negative AO could better reflect the fluctuation of the subtropical westerly wind and the synoptic-scale transient wave activity,which is closely related to the frequency of cold extremes in NEC.Along with a positive polarity of the AO trend since the mid-1980s,the connection between the cold extremes over NEC and the AO during January has been weakened.

关键词： Arctic Oscillation temperature extremes asymmetry

Model for asymmetry of Shock/Boundary Layer Interactions in Nozzle Flows

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第1期35卷 146-153页

作者： Wang Chengpeng Zhuo Changfei College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Department of Aerospace Engineering Nanjing University of Science and Technology

The reason for the asymmetry phenomenon of shock/boundary layer interactions(SBLI)in a completely symmetric nozzle with symmetric flow conditions is still an open question.A model for the asymmetry of nozzle flows was proposed based on the properties of fluid entrainment in the mixing layer and momentum conservation.The asymmetry model is deduced based on the nozzle flow with restricted shock separation,and is still applicable for free shock separation.Flow deflection angle at nozzle exit is deduced from this model.Steady numerical simulations are conducted to model the asymmetry of the SBLIs in a planar convergent-divergent nozzle tested by previous researchers.The obtained values of deflection angle based on the numerical results of forced symmetric nozzle flows can judge the asymmetry of flows in a nozzle at some operations.It shows that the entrainment of shear layer on the separation induced by SBLTs is one of the reasons for the asymmetry in the confined SBLIs.

关键词： asymmetry shock/boundary layer interactions nozzle flow entrainment

Ethambutol-induced optic neuropathy with rare bilateral asymmetry onset:A case report

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World Journal of Clinical Cases 2022年第2期10卷 663-670页

作者： Wen-Yan Sheng Shuang-Qing Wu Ling-Ya Su Li-Wei Zhu Department of Ophthalmology Affiliated Hangzhou Chest HospitalZhejiang University School of MedicineHangzhou 310003Zhejiang ProvinceChina

BACKGROUND Ethambutol-induced optic neuropathy(EON)most commonly manifests as bilateral symmetrical loss of vision and often cause serious and irreversible visual impairment because of the lack of early detection and effective treatment.We followed a case of EON with rare binocular asymmetric clinical manifestations and observed the changes of visual function and retinal structure after drug withdrawal,so as to further understand the clinical characteristics of this disease.CASE SUMMARY A 54-year-old man complained of gradual visual decline in the left eye.The patient presented with best-corrected visual acuity of 20/20 in the right eye and 20/50 in the left eye.Color vision examination revealed difficulty in reading green color plates in the left eye.The visual field manifested as concentric contraction in the left eye.After nearly a month of drug withdrawal,the right eye had a similar decline in visual function.At the last visit,19 mo after drug withdrawal,the visual function significantly recovered in both eyes.During follow-up optical coherence tomography(OCT)examination,both eyes manifested the thickness of the retinal nerve fiber layer from mild thickening to thinning and finally temporal atrophy,and the ganglion cell-inner plexiform layer showed significant thinning.The difference was that a reversible structural disorder in the outer retina of the nasal macula was detected in the left eye by macular high-definition OCT.CONCLUSION Nephropathy and high blood pressure,which damage the retinal microcirculation,may cause damage to the outer layer of the retina.Ethambutol may influence photoreceptor as well as retinal ganglion cells.

关键词： Ethambutol-induced optic neuropathy Retinal nerve fiber layer Ganglion cell-inner plexiform layer Optical coherence tomography asymmetry Case report

asymmetry of Atmospheric Responses to Two-Type El Nino and La Nina over Northwest Pacific

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Journal of Meteorological Research 2019年第5期33卷 826-836页

作者： Mingcheng CHEN Tim LI Xiaohui WANG Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China International Pacific Research Center and Department of Atmospheric Sciences School of Ocean and Earth Science and TechnologyUniversity of Hawaii at ManoaHonoluluHI96822USA

The mechanism for asymmetric atmospheric responses to the central Pacific(CP) El Ni?o and La Ni?a over the western North Pacific(WNP) is studied in this paper. The negative anomalies of rainfall over the key region of WNP are explained by diagnosing the column-integrated equations of moisture and moist static energy(MSE). It is revealed that the nonlinear advection of moist enthalpy is critical to introduce negative rainfall anomalies over the region. The anomalous easterly(westerly) in La Ni?a(CP El Ni?o) causes negative advection of anomalous moist enthalpy, inducing negative heating anomaly and an anticyclone anomaly in the WNP, which weakens(strengthens) the cyclone(anticyclone) in La Ni?a(CP El Ni?o). The MSE budget analysis shows a larger nonlinear term in CP El Ni?o than in eastern Pacific(EP) El Ni?o, inconsistent with the amplitudes of sea surface temperature anomalies. The reason is that the nonlinear term transforms to positive above 700 h Pa in EP El Ni?o, offsetting the negative advection below 700 h Pa and thus making the nonlinear term smaller. The nonlinear term is negative at low levels in CP El Ni?o, resulting in a larger nonlinear term. The stronger precipitation anomalies in the WNP during EP El Ni?o can be attributed to the linear moist enthalpy advection. The mean easterly wind at mid levels causes a larger(smaller) positive moist enthalpy advection in CP(EP) El Ni?o, due to a larger(smaller) moist enthalpy gradient, resulting in a positive(negative) linear moist enthalpy advection, which weakens(strengthens) the negative precipitation anomalies in the key region.

关键词： asymmetry La Nina eastern Pacific(EP) El Nino central Pacific(CP) El Nino moist enthalpy

The asymmetry of Subsurface Temperature Anomalies Associated with ENSO in the Equatorial Western Pacific

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Atmospheric and Oceanic Science Letters 2015年第1期8卷 23-28页

作者： HUA Li-Juan YU Yong-Qiang State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences

The phenomenon of ENSO asymmetry has been recognized for many years, but most studies have focused on the asymmetry of surface temperature anomalies in the equatorial eastern Pacific. Here, the authors investigate the temperature asymmetry associated with ENSO in the subsurface of the western Pacific through analysis of observations and numerical experiments with an ocean GCM. Both the observation and simulation exhibit significant ENSO asymmetry, characterized by negative temperature skewness in the equatorial western Pacific and positive skewness in the eastern Pacific. Heat budget analysis reveals that nonlinear dynamical heating results in the positive temperature asymmetry in the equatorial eastern Pacific, but tends to weaken the negative temperature asymmetry in the equatorial western Pacific. The climatological meridional current transports the temperature anomalies and corresponding negative asymmetry from the off-equator region to the equator in the subsurface of the western Pacific. Through a sensitivity experiment with reversed wind stress forcing, the authors suggest that the skewness of the wind stress anomalies does not contribute to the negative temperature asymmetry in the western Pacific in the first-order approximation, while the internal nonlinear dynamics does play a key role. The study suggests that, as a result of nonlinear processes, the oceanic responses to anomalous wind stress are nonlinear and asymmetric in the tropical Pacific.

关键词： ENSO asymmetry nonlinearity western Pacific

Enhancing single-molecule conductance of platinum (Ⅱ) complexes through synergistic aromaticity-assisted structural asymmetry

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Science China Chemistry 2020年第4期63卷 467-474页

作者： Ping Duan Junyang Liu Jin-Yun Wang Kai Qu Shuning Cai Fei Wang Lichuan Chen Xiaoyan Huang Ruihao Li Jia Shi Qian-Chong Zhang Wenjing Hong Zhong-Ning Chen State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)NELCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Seeking the strategies of designing highly conductive molecular structures is one of the core researches in molecular electronics.As asymmetric structure has manifested feasible properties in comprehensive fields, we introduce the structures of asymmetric platinum(Ⅱ) complexes into the charge transport study at single-molecule scale for the first time. The single-molecule conductance measurement results reveal that, in platinum(Ⅱ)-aryloligoynyl structures, the conductance of asymmetrically coordinated complexes is obviously higher than that of the symmetric isomers with the same molecular length, while the conductance is almost identical in symmetric and asymmetric platinum(Ⅱ)-oligoynyl complexes. Theoretical study uncovers that, upon connecting to the oligoynyl structure, the aromatic group effectively extends the π-system of the whole conductive backbone and gathers the HOMO population mainly on the longer oligoynyl ligand, which reduces the energy barrier in electron transport and enhances the conductance through HOMO energy lifting. This result provides feasible strategy for achieving high conductive molecular devices.

关键词： single-molecule conductance organometallic asymmetry conductance enhancement