Maintenance and development of the Ural high and its contribution to severe cold wave activities in winter 2020/21

Two successive severe cold waves invaded eastern China from the end of 2020 to early 2021,leading to an extensive,severe,and persistent drop in temperature.The paper investigates the features and formation mechanisms of the two cold waves.The main results are as follows:(1)An anticlockwise turning of the transverse trough was observed in both cold waves.However,a broad ridge was maintained over the Ural area from mid-December 2020 till mid-January 2021.No breakdown or discontinuous westward shift of the blocking high was observed,which is different from typical cold waves in eastern Asia.(2)The maintenance and strengthening of northerly winds in front of the Ural high led to an increase in baroclinicity in-situ.In the downstream region,the gradient of the geopotential height contour in the south of the transverse trough rapidly increased and the advection of cold temperature consistently enhanced and advanced southwards.This in turn caused the intensification and southward expansion of the Siberian high.(3)Energy propagation of the quasi-stationary wave was a reason for the development and persistence of the Ural blocking.Prior to the occurrence of the two cold waves,the energy of the low-frequency stationary wave originating from near 0°E(or even to the west)propagated eastwards,which helped the Ural ridge intensify and maintain.Meanwhile,it also contributed to the development of the trough downstream of the ridge and resulted in the anticlockwise turning of the transverse trough,providing a favorable condition for the southward outbreak of cold air.

A BIOSENSOR USING COUPLED PLASMON WAVEGUIDE RESONANCE COMBINED WITH HYPERSPECTRAL FLUORESCENCE ANALYSIS

We developed a biosensor that is capable for simultaneous surface plasmon resonance(SPR)sensing and hyperspectral fuores cence analysis in this paper.A symmetrical metal-dielectric slabscheme is employed for the excitation of coupled plasnon waveguide resonance(CPWR)in thepresent work.Resonance bet ween surface plasmon mode and the guided waveguide mode gen-erates narrower full width half-maximum of the refective curves which leads to increased pre.cision for the determination of refractive index over conventional SPR sensors.In addition,CPWR also fers longer surface propagation depths and higher surface electric field strengthsthat enable the excitation of fluorescence with hyperspectral technique to maintain an appreci-able signal-to-noise ratio.The refractive index information obtained from SPR sensing and thechemical properties obt ained through hyperspectral fluorescence analysis confirm each other toexclude false-positive or false-negative cases.The sensor provides a comprehensive understandingof the biological events on the sensor chips.

Oxygen-deficient metal oxides:Synthesis routes and applications in energy and environment

Oxyge n vaca ncies impla ntation is an efficie nt way to adjust the physical and chemical properties of metal oxide nano materials to meet the requirements for particular applications.Through reasonable defects design,oxyge-deficient metal oxides with excellent optical and electrical properties are widely applied for environmental protection and energy uses.This review discusses recent advances in synthetic approaches of oxygervdeficient metal oxides and their applications in photocatalysis,electrocatalysis,and energy storage devices.The perspectives of oxyge n?deficie nt metal oxides for increased en ergy dema nd and en vironme ntal sustai liability are also exami ned.

A novel lysosome‐localized fluorescent probe with aggregation‐induced emission without alkalinizing effect

Herein,a novel small molecule probe,tetraphenylethylene‐cystein(TPE‐Cys),was rationally designed and developed for the intracellular lysosome localization.The combination of tetraphenylethylene and cysteine serve as a novel strategy for lysosome‐targeting,with significant aggregation‐induced emission increases with the proportion of water by as high as 25‐folds.Biofluorescence imaging experiments show that the probe TPE‐Cys has a good colocalization effect with the commercially available lysotracker red,with a Pearson correlation coefficient of 0.91.In addition,we also demonstrate that TPE‐Cys has good light stability.TPE‐Cys,as a neutral compound,is free of alkalinizing effect when applied in lysosome localization.Moreover,molecular dynamics simulations and density function theories are employed to explore the detailed aggregation process and the mechanism of TPE‐Cys aggregation in water solution.The mechanism of lysosome localization of probe TPE‐Cys was explained by cellular endocytosis process and the formation of larger particle in the more acidic environment of lysosomes.This work not only demonstrates an efficient strategy for the construction of fluorescent probes for lysosome localization,but also indicates that they are promising as live cell imaging tools.