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Impacts of Multi-Scale Solar Activity on *** Ⅱ:Dominant Timescales in Decadal-Centennial Climate Variability

Advances in Atmospheric Sciences 2012年第4期29卷 887-908页

作者： Hengyi weng State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029

Part II of this study detects the dominant decadal-centennial timescales in four SST indices up to the 2010/2011 winter and tries to relate them to the observed 11-yr and 88-yr solar activity with the sunspot number up to Solar Cycle 24. To explore plausible solar origins of the observed decadal-centennial timescales in the SSTs and climate variability in general, we design a simple one-dimensional dynamical system forced by an annual cycle modulated by a small-amplitude single- or multi-scale ＂solar activity.＂ Results suggest that nonlinear harmonic and subharmonic resonance of the system to the forcing and period-doubling bifurcations are responsible for the dominant timescales in the system, including the 60-yr timescale that dominates the Atlantic Multidecadal Oscillation. The dominant timescales in the forced system depend on the system＇s parameter setting. Scale enhancement among the dominant response timescales may result in dramatic amplifications over a few decades and extreme values of the time series on various timescales. Three possible energy sources for such amplifications and extremes are proposed. Dynamical model results suggest that solar activity may play an important yet not well recognized role in the observed decadal-centennial climate variability. The atmospheric dynamical amplifying mechanism shown in Part I and the nonlinear resonant and bifurcation mechanisms shown in Part II help us to understand the solar source of the multi-scale climate change in the 20th century and the fact that different solar influenced dominant timescales for recurrent climate extremes for a given region or a parameter setting. Part II also indicates that solar influences on climate cannot be linearly compared with non-cyclic or sporadic thermal forcings because they cannot exert their influences on climate in the same way as the sun does.

关键词： sun-climate relationship decadal-centennial climate timescales nonlinear forcing-response res- onant mechanism bifurcation mechanism scale enhancement for extremes

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Synchronous Parallel Block Coordinate Descent Method for Nonsmooth Convex Function Minimization

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journal of Systems Science & Complexity 2020年第2期33卷 345-365页

作者： DAI yutong weng yang College of Mathematics Sichuan UniversityChengdu 610064China

This paper proposes a synchronous parallel block coordinate descent algorithm for minimizing a composite function,which consists of a smooth convex function plus a non-smooth but separable convex *** to the generalization of the proposed method,some existing synchronous parallel algorithms can be considered as special *** tackle high dimensional problems,the authors further develop a randomized variant,which randomly update some blocks of coordinates at each round of *** proposed parallel algorithms are proven to have sub-linear convergence rate under rather mild *** numerical experiments on solving the large scale regularized logistic regression with 1 norm penalty show that the implementation is quite *** authors conclude with explanation on the observed experimental results and discussion on the potential improvements.

关键词： Block coordinate descent convergence rate convex functions parallel algorithms

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Single crystal growth, structural and transport properties of bad metal RhSb2

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Chinese Physics B 2020年第3期29卷 1-6页

作者： D S Wu y T Qian Z y Liu W Wu y j Li S H Na y T Shao P Zheng G Li j G Cheng H M weng j L Luo Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

We have successfully grown an arsenopyrite marcasite type RhSb2 single crystal, and systematically investigated its crystal structure, electrical transport, magnetic susceptibility, heat capacity, and thermodynamic properties. We found that the temperature-dependent resistivity exhibits a bad metal behavior with a board peak around 200 K. The magnetic susceptibility of RhSb2 shows diamagnetism from 300 K to 2 K. The low-temperature specific heat shows a metallic behavior with a quite small electronic specific-heat coefficient. No phase transition is observed in both specific heat and magnetic susceptibility data. The Hall resistivity measurements show that the conduction carriers are dominated by electrons with ne = 8.62 × 10^(18) cm^(-3) at 2 K, and the electron carrier density increases rapidly above 200 K without change sign. Combining with ab-initio band structure calculations, we showed that the unusual peak around 200 K in resistivity is related to the distinct electronic structure of RhSb_2. In addition, a large thermopower S(T) about -140 μV/K is observed around 200 K, which might be useful for future thermoelectric applications.

关键词： single crystal growth ab-initio band calculations susceptibility heat capacity thermodynamic transport properties

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III-Nitride-Based Quantum Dots and Their Optoelectronic Applications

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Nano-Micro Letters 2011年第3期3卷 200-207页

作者： G.E.weng A.K.Ling X.Q.Lv j.y.Zhang B.P.Zhang Department of Physics Laboratory of Micro-Nano Optoelectronics Xiamen University MEMS Research Center Xiamen University

During the last two decades, III-nitride-based quantum dots(QDs) have attracted great attentions for optoelectronic applications due to their unique electronic properties. In this paper, we first present an overview on the techniques of fabrication for III-nitride-based QDs. Then various optoelectronic devices such as QD lasers, QD light-emitting diodes(LEDs), QD infrared photodetectors(QDIPs) and QD intermediate band(QDIB) solar cells(SCs) are discussed. Finally, we focus on the future research directions and how the challenges can be overcome.

关键词： III-nitride-based quantum dots Lasers Light-emitting diods Infrared photodetectors Solar cells

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Impacts of Multi-Scale Solar Activity on *** Ⅰ:Atmospheric Circulation Patterns and Climate Extremes

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Advances in Atmospheric Sciences 2012年第4期29卷 867-886页

作者： Hengyi weng State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029

The impacts of solar activity on climate are explored in this two-part study. Based on the principles of atmospheric dynamics, Part I propose an amplifying mechanism of solar impacts on winter climate extremes through changing the atmospheric circulation patterns. This mechanism is supported by data analysis of the sunspot number up to the predicted Solar Cycle 24, the historical surface temperature data, and atmospheric variables of NCEP/NCAR Reanalysis up to the February 2011 for the Northern Hemisphere winters. For low solar activity, the thermal contrast between the low- and high-latitudes is enhanced, so as the mid-latitude baroclinic ultra-long wave activity. The land-ocean thermal contrast is also enhanced, which amplifies the topographic waves. The enhanced mid-latitude waves in turn enhance the meridional heat transport from the low to high latitudes, making the atmospheric ＂heat engine＂ more efficient than normal. The jets shift southward and the polar vortex is weakened. The Northern Annular Mode （NAM） index tends to be negative. The mid-latitude surface exhibits large-scale convergence and updrafts, which favor extreme weather/climate events to occur. The thermally driven Siberian high is enhanced, which enhances the East Asian winter monsoon （EAWM）. For high solar activity, the mid-latitude circulation patterns are less wavy with less meridional transport. The NAM tends to be positive, and the Siberian high and the EAWM tend to be weaker than normal. Thus the extreme weather/climate events for high solar activity occur in different regions with different severity from those for low solar activity. The solar influence on the mid- to high-latitude surface temperature and circulations can stand out after removing the influence from the E1 Nifio-Southern Oscillation. The atmospheric amplifying mechanism indicates that the solar impacts on climate should not be simply estimated by the magnitude of the change in the solar radiation over solar cycles when it i

关键词： solar impacts on climate surface thermal contrasts dynamical amplifying mechanism atmo- spheric circulations climate extremes

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Women in visual neural regeneration research

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Neural Regeneration Research 2025年第2期20卷 489-490页

作者： Tonia S.Rex David j.Calkins Vanderbilt Eye Institute Vanderbilt University Medical CenterNashvilleTNUSA

The year 2024 marks the 60^(th)anniversary of Title IX and 25 years since the New york Times revealed bias against female faculty members at the Massachusetts Institute of *** take an opportunity here to examine the state of gender bias in a relatively new yet already prominent field,neural regeneration in the visual system,for which there is a well-defined context useful for this *** National Eye Institute(NEI)provided the first round of research funding for its Audacious Goals Initiative(AGI)on visual neural regeneration in 2013 and the last round in ***,we focus on this *** sources included PubMed,the National Science Foundation(NSF),the NEI,the Blue Ridge Institute for Medical Research and data from the major professional organization for eye and vision research,the Association for Research in Vision and Ophthalmology(ARVO).

关键词： neural visual Times

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Generation of brain vascular heterogeneity:recent advances from the perspective of angiogenesis

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Neural Regeneration Research 2025年第7期20卷 2013-2014页

作者： Nathanael j.Lee Ryota L.Matsuoka Department of Neurosciences Lerner Research InstituteCleveland ClinicClevelandOHUSA Department of Molecular Medicine Cleveland Clinic Lerner College of MedicineCase Western Reserve UniversityClevelandOHUSA

Heterogeneous proper t i es of vascular endothelial cells in the brain:The brain displays large energy dynamics and consumption,and this high level of metabolic demands is fulfilled by a continuous supply of glucose and oxygen through its vascular *** vasculature consists of highly divergent blood vessel branches,giving rise to a dense network of capillaries that supply blood to all cells across the *** elaborated vascular network is thought to develop via angiogenesis,a process in which new blood vessels grow from pre-existing *** capillaries exhibit organotypic features distinct from other tissues and are formed primarily by two major endothelial cell(EC)types:those that form the semi-permeable blood-brain barrier(BBB)and those that develop highly permeable pores known as fenestrae(Matsuoka et al.,2022).The structural and functional differences between BBB and fenestrated vascular ECs represent a fundamental feature of brain vasculature and form the foundation for both brain function and homeostasis.

关键词： angiogenesis homeostasis network

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On Crystallization in Polypropylene-Polyethylene Blends

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应用化学 2001年第5期18卷 267-274页

作者： weng，j OLLEy，RH 等 j.j.ThomsonPhysicalLaboratory WhitekinghtsReadingRG66AFUK

Blends of polypropylene(PP) and low density polyethylene(LDPE) have been crystallized to form open structures(“cluster spherulites”) where the droplets of the minority PP are bridged by PP lamellae which have grown in the LDPE rich matrix. These are studied by permanganic etching followed by electron and optical microscopies. Two similar PP types are compared, one synthesized with Ziegler Natta catalyst and one with metallocene catalyst. The metallocene catalysed material crystallized much more slowly due to the presence of regio defects in the chains, even though the overall concentration of tacticity defects in the Ziegler Natta material is much higher. A mechanism involving reversal of helical direction at the regio defect interfering with the regular chain packing in the crystal is suggested. Growth of “cluster spherulites” is faster in regions where low molecular weight material is concentrated. It is slower where droplets are larger, and this is attributed to competition between PP lamellar growth in the matrix and diffusion of PP to already crystallized droplets.

关键词：聚丙烯聚乙烯共混物结晶

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Glass-forming Ability and Corrosion Resistance of Zr—Cu—Al—Co Bulk Metallic Glass

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journal of Materials Science & Technology 2016年第4期32卷 349-354页

作者： W.Zhou W.P.weng j.X.Hou Shagang School of Iron and Steel Soochow University

Investigations were carried out to examine the effects of Co addition on the glass-forming ability （GFA） and corrosion resistance of Zr46Cu46AI8 bulk metallic glass in chloride-containing solution. It is found that the GFA of （Zr46Cu46Al8）100-xCox （x = 0, 1, 2, and 4 at.%） alloys reduces with the increase in Co content and correlates well with the parameters, such as the supercooled liquid region width ATx, the reduced glass transition temperature Trg and γ. The corrosion resistance is however found to be enhanced with the in- crease in Co concentration. The addition of Co causes the enrichment of Zr and Al, but depletes Cu in the surface films, which effectively enhances the corrosion potential and lowers the corrosion current density.

关键词： Bulk metallic glassCo-additionGlass-forming abilityCorrosion resistance

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An FEGSTEM Study of Grain Boundary Segregation of Phosphorus during Quenching in a 2.25Cr-1Mo Steel

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journal of Materials Science & Technology 2005年第4期21卷 445-450页

作者： Shenhua SONG Luqian weng Department of Materials Science and Engineering Shenzhen Graduate School Harbin Institute of TechnologyShenzhen 518055 China

Quenching-induced phosphorus segregation to prior austenite grain boundaries in a 0.077 wt pct P-doped 2.25Cr-2Mo steel is examined using field emission gun scanning transmission electron microscopy （FEGSTEM）. A phosphorus level of around 1.56 at. pct is observed for the water-quenched sample. In recognition of insufficiently high spatial resolution of the technique for grain boundary composition analysis, the measured results are corrected by an analytical convolution method. The corrected phosphorus segregation level may be up to about 4.7 at. pct. The quenchinginduced phosphorus segregation is nonequilibrium segregation and the migration of vacancy-phosphorus complexes plays an important role in the kinetic process. For such a reason, the mechanism for migration of the complexes is discussed in some detail.

关键词： Grain boundary Segregation Low alloy steel Microanalysis

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