Multi-decadal Changes of the Impact of El Niño Events on Tibetan Plateau Summer Precipitation

Precipitation on the Tibetan Plateau(TP)has an important effect on the water supply and demand of the downstream population.Involving recent climate change,the multi-decadal variations of the impact of El Niño-Southern Oscillation(ENSO)events on regional climate were observed.In this work,the authors investigated the changes in summer precipitation over TP during 1950-2019.At the multi-decadal scale,the authors found that the inhabiting impact of El Niño events on the TP summer precipitation has strengthened since the late 1970s.The main factor contributing to this phenomenon is the significant amplification in the decadal amplitude of El Niño during 1978-2019 accompanied by a discernible escalation in the frequency of El Niño events.This phenomenon induces anomalous perturbations in sea surface temperatures(SST)within the tropical Indo-Pacific region,consequently weakening the atmospheric vapor transport from the western Pacific to the TP.Additionally,conspicuous anomalies in subsidence motion are observed longitudinally and latitudinally across the TP which significantly contributes to a curtailed supply of atmospheric moisture.These results bear profound implications for the multi-decadal prediction of the TP climate.

Clinical significance of serum miR-21 in breast cancer compared with CA153 and CEA

Objective:MicroRNA-21(miR-21)has been shown to be a key regulator of carcinogenesis.There were few reports about the comparison of serum miR-21 with conventional tumor markers.This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer(BC)and compare it with CA153 and carcinoembryonic antigen(CEA).Methods:Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls.The levels of CA153 and CEA were measured through electrochemiluminescence assays.Then the sensitivity in diagnosis of BC was compared among miR-21,CA153 and CEA.Results:The level of serum miR-21 was significantly higher in BC patients than controls(P<0.001).The sensitivity and specificity of miR-21 were 87.6%and 87.3%,respectively,whereas the sensitivities of CEA and CA153 were only 22.47%and 15.73%.Conclusions:Compared with CEA and CA153,serum miR-21 has a higher sensitivity in diagnosis of BC.Although not correlated with the status of ER,PR and clinical stages,serum miR-21 may be a potential diagnostic indicator for BC,especially for the early stage.

Interannual and Interdecadal Variability of Winter Precipitation over China in Relation to Global Sea Level Pressure Anomalies

Based on the method of rotated principal component (RPC) analysis and wavelet transforms, the win-ter precipitation from 36 stations over China for the period 1881-1993 is examined. The results show thatthe three leading space-time modes correspond, in sequence, to winter rainfall anomalies over the reaches ofthe Yangtze River, the bend of the Yellow River, and the northeastern region of China. The three modes ex-hibit interannual oscillations with quasi-biennial and 8-year periods as well as interdecadal oscillationswith 16- and 32-year periods. The interannual oscillation (＜ 10 years) occurs in phase over the differentareas, and its maximum amplitude migrates northward considerably with prominent interdecadal variations.However, the interdecadal oscillations (10-32 years) are out of phase over the different regions, and theamplitude variations have the characteristics of stationary waves.The rainfall anomalies appear to be closely re lated to the anti-phase changes of mean sea-level pres-sure (SLP) over the Asian mainland and the North Pacific. When the SLP rises over the North Pacific anddecreases over the Asian mainland, the precipitation over East China increases noticeably. The linkage be-tween the rainfall over China and the SLP anomalies apparently results from the strength of the East Asianwinter monsoon and its associated temperature and moisture advection.

Sandwich ELISA for detecting urinary Survivin in bladder cancer

Objective: Survivin as a tumor marker in the diagnosis of bladder cancer has not been completely confirmed yet and there are few reports about using Survivin enzyme-linked immunosorbent assay (ELISA) kit to detect the urine of bladder cancer patients. This study aimed to develop a Survivin ELISA and validate its value in the detection of bladder cancer. Methods: Through square matrix titration, different combinations of coating antibody and detecting antibody, a Survivin ELISA was constructed. This assay was evaluated according to intra-assay precision, inter-assay precision and minimum detectable dose (MDD). Survivin levels were detected and analyzed in 102 bladder cancer patients and 102 healthy people by established ELISA. Then cutoff value was defined according to the analysis of receiver operating characteristic (ROC) curve. The sensitivity and specificity of detection were calculated on the basis of cutoff value to diagnose bladder cancer patients. Furthermore, the value of Survivin expression detected by ELISA among different clinicopathological characteristics of patients was also compared. Results: Through optimization of different conditions, intra-assay precision was 8.39%, inter-assay precision 8.57% and MDD 0.0625 ng/mL in this assay. When the optical density at 450 nm (OD 450 ) was 0.09, it could get the optimized diagnostic cutoff value. According to this value, the sensitivity and specificity of diagnosis in bladder cancer patients were 70.6% and 89.2%, respectively. The associations between patients' clinical variables and OD 450 were not significant except tumor numbers in patients. Conclusions: This experiment has preliminarily developed a Survivin ELISA and confirmed Survivin as a biomarker which owned a practical and significant value in the diagnosis of bladder cancer.

Double cores of the Ozone Low in the vertical direction over the Asian continent in satellite data sets

Using four satellite data sets(TOMS/SBUV, OMI, MLS, and HALOE), we analyze the seasonal variations of the total column ozone(TCO) and its zonal deviation(TCO*), and reveal the vertical structure of the Ozone Low(OV) over the Asian continent. Our principal findings are:(1) The TCO over the Asian continent reaches its maximum in the spring and its minimum in the autumn. The Ozone Low exists from May to September.(2) The Ozone Low has two negative cores, located in the lower and the upper stratosphere. The lower core is near 30 hPa in the winter and 70 hPa in the other seasons. The upper core varies from 10 hPa to 1 hPa among the four seasons.(3)The position of the Ozone Low in the lower and the upper stratosphere over the Asian continent shows seasonal variability.

Two mechanisms responsible for marine ecosystem regime shifts from fish landings data off the West Coast of California (WCC)

This investigation focuses on two mechanisms over the North Pacific connecting decadal regime shifts to regional ecosystem impacts. The physical conditions show the impacts of the atmospheric surface wind stress and the sea surface temperature (SST) physical conditions on the fish landings along the west coast of California (WCC) from 1928-2008. The two mechanisms are identified by the two types of wind stress (e.g. westerly-easterly;or cyclonic-anticyclonic) anomaly over the central North Pacific which results in SST anomalies in the WCC. In both mechanism cases, the local warm (cold) SST anomaly leads to the number of fish species rising (falling) in the WCC region. In addition, the wind stress and SST anomaly pattern over the North Pacific is closely related to the intensity of the regime shifts as identified in the fish landings off the WCC.

Discrete Symmetry in Relativistic Quantum Mechanics

EPR experiment on system in 1998 [1] strongly hints that one should use operators and for the wavefunction (WF) of antiparticle. Further analysis on Klein-Gordon (KG) equation reveals that there is a discrete symmetry hiding in relativistic quantum mechanics (RQM) that PT=C. Here PT means the (newly defined) combined space-time inversion (with x→-x,t→-t), while C the transformation of WF Ψ between particle and its antiparticle whose definition is just residing in the above symmetry. After combining with Feshbach-Villars (FV) dissociation of KG equation (Ψ=φ+x) [2], this discrete symmetry can be rigorously reformulated by the invariance of coupling equation of φ and x under either the combined space-time inversion PT or the mass inversion (m→-m), which makes the KG equation a self-consistent theory. Dirac equation is also discussed accordingly. Various applications of this discrete symmetry are discussed, including the prediction of antigravity between matter and antimatter as well as the reason why we believe neutrinos are likely the tachyons.

Abrupt Climate Regime Shifts, Their Potential Forcing and Fisheries Impacts

The purpose of this paper is to investigate whether a logical chain of events can be established to explain the abrupt climatic regime shift changes in the Pacific that link the atmosphere to the ocean to fisheries impacts. The investigation endeavors to identify synchronous abrupt changes in a series of data sets to establish the feasibility of abrupt of climate change often referred to as regime shifts. The study begins by using biological (fish catch/stock) markers to mathematically identify the dates of abrupt change. The dates are confirmed by a literature search of parameters that also show abrupt changes on the same dates. Using the biological date markers of abrupt change, analyses are performed to demonstrate that the interactions between the atmosphere, ocean, ecosystems and fisheries are a plausible approach to explaining abrupt climate change and its impacts.

Combinatorial Optimization of Physics Parameterization Schemes for Typhoon Simulation Based on a Simple Genetic Algorithm(SGA)

Each physical process in a numerical weather prediction(NWP)system may have many different parameterization schemes.Early studies have shown that the performance of different physical parameterization schemes varies with the weather situation to be simulated.Thus,it is necessary to select a suitable combination of physical parameterization schemes according to the variation of weather systems.However,it is rather difficult to identify an optimal combination among millions of possible parameterization scheme combinations.This study applied a simple genetic algorithm(SGA)to optimizing the combination of parameterization schemes in NWP models for typhoon forecasting.The feasibility of SGA was verified with the simulation of Typhoon Mujigae(2015)by using the Weather Research and Forecasting(WRF)model and Typhoon Higos(2020)by using the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST)modeling system.The results show that SGA can efficiently obtain the optimal combination of schemes.For Typhoon Mujigae(2015),the optimal combination can be found from the 1,304,576 possible combinations by running only 488 trials.Similar results can be obtained for Typhoon Higos(2020).Compared to the default combination proposed by the COAWST model system,the optimal combination scheme significantly improves the simulation of typhoon track and intensity.This study provides a feasible way to search for the optimal combinations of physical parameterization schemes in WRF and COAWST for more accurate typhoon simulation.This can help provide references for future development of NWP models,and for analyzing the coordination and adaptability of different physical process parameterization schemes under specific weather backgrounds.

微型仿生爬虫机器人类脑环境感知方法

微型仿生机器人是一种仿照生物外形和运动形态制作设计的机器人,凭借其体型小、机动性高、环境适应性强等优点,在复杂环境探索、敌情侦察等特殊场景中具有较高的应用前景,近年来备受研究人员的关注.但是微型机器人运动稳定性弱、单目相机环境感知精度低等问题的存在一直制约着其实际应用.本文仿照昆虫“独角仙”设计了一种新的微型仿生爬虫机器人,开发了基于生物运动调控机制的六足机器人控制系统,改进了基于啮齿类动物空间导航原理的同时定位与建图系统.使用自研的微型仿生爬虫机器人在人造沙盘和真实室内走廊两个场景中进行了实验验证.在人造沙盘场景,由于微型仿生爬虫机器人提供的环境图像质量模糊,ORB-SLAM3算法无法完成回环检测,不能正确识别曾经见过的场景.类脑同步定位与地图构建(simultaneous localization and mapping,SLAM)系统回环准确率高达100%,比原RatSLAM算法提高了4.36%.在真实室内走廊场景,ORB-SLAM3算法和RatSLAM算法建图效果都比较差,而类脑SLAM不仅有着较好的建图结果,而且在准确率100%的同时召回率也高达97.87%.与ORB-SLAM3和RatSLAM算法相比,类脑SLAM系统取得了较好的建图结果.因此,自研的微型仿生爬虫机器人具有灵活的运动能力、鲁棒的导航定位能力,促使微型仿生机器人离实际应用更近了一步.

Effect of hot isostatic pressure on the microstructure and tensile properties of γ'-strengthened superalloy fabricated through induction-assisted directed energy deposition

The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.

一种惩罚最大似然方法估计混合回归模型

本文考虑具有正态误差假设下混合回归模型的参数估计问题.由于似然函数的无界性,混合回归模型普通的最大似然估计不存在.本文提出一种惩罚最大似然方法来估计混合回归模型的参数,证明惩罚最大似然估计量(penalized maximum likelihood estimation, PMLE)具有强相合和渐近正态性.通过深入模拟研究,从估计精确性角度看,惩罚最大似然估计量有很好的表现.本文还给出一个音调感知的例子来说明理论结果的应用.

Evaluation of the Trend Uncertainty in Summer Ozone Valley over the Tibetan Plateau in Three Reanalysis Datasets

Trend uncertainty in the ozone valley over the Tibetan Plateau(OVTP)and the South Asian high(SAH)during1979–2009 in ERA-Interim(interim reanalysis data from the ECMWF),JRA-55(55-yr reanalysis data from the Japan Meteorological Agency),and NCEP-CFSR(Climate Forecast System Reanalysis)datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS(Total Ozone Mapping Spectrometer)and OMI(Ozone Monitoring Instrument)agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP(non-Tibetan Plateau)areas(27°–37°N,<75°E and>105°E).Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.

Interdecadal variability in the tropical Indian Ocean and its dynamic explanation

Interdecadal variability in the tropical Indian Ocean has been analyzed based on the long-term climatic observational data. Case study showed that strong interannual signals formed at the surface can penetrate the depth of seasonal thermocline, where the anomalies last a couple of years. Artificial time series based on damping with exponential decay of selected strong events agree well with the detected interdecadal variability in the tropical Indian Ocean.

Relationship between the Tibetan Plateau-tropical Indian Ocean thermal contrast and the South Asian summer monsoon

The impact of land-sea thermal contrast on the South Asian summer monsoon(SASM)was investigated by calculating the atmospheric heat sources(AHS)and baroclinic component with ERA5 data for the period 1979-2019.Using diagnostic and statistical methods,it was found that the thermal contrast between the Tibetan Plateau(TP)and the tropical Indian Ocean(TIO)affects the South Asian monsoon circulation through the meridional temperature gradient in the upper troposphere.The seasonal changes of the AHS of the TP and TIO are reversed.In summer,the TP is the strongest at the same latitude whereas the TIO is the weakest,and the thermal contrast is the most obvious.The heat sources of the TP and TIO are located on the north and south side of the strong baroclinic area of the SASM region,respectively,and both of which are dominated by deep convective heating in the upper troposphere.The TP-TIO regional meridional thermal contrast index(QI)based on the AHS,and the SASM index(MI)based on baroclinicity were found to be strongly positively correlated.In years of abnormally high QI,the thermal contrast between the TP and TIO is strong in summer,which warms the upper troposphere over Eurasia and cools it over the TIO.The stronger temperature gradient enhances the baroclinicity in the troposphere,which results in a strengthening of the low-level westerly airflow and the upper-level easterly airflow.The anomalous winds strengthen the South Asian high(SAH),with the warmer center in the upper troposphere,and the enhanced Walker circulation over the equatorial Indian Ocean.Finally,the anomalous circulation leads to much more precipitation over the SASM region.The influence of abnormally low QI is almost the opposite.

Sensitivity of Typhoon Lingling(2019)simulations to horizontal mixing length and planetary boundary layer parameterizations

Forecasting the intensity of typhoons is a difficult problem in numerical weather prediction.It is subject to many factors,among which the selection of physical parameterization schemes for the model is a hot topic of research.In this study,the effects of horizontal mixing length(represented by h_diff)and planetary boundary layer(PBL)schemes were investigated.Six idealized and four operational sensitivity experiments were designed based on simulation of the typhoon Lingling,which occurred over the western Pacific in 2019,using the Hurricane Weather Research and Forecasting model.The results of the idealized experiments showed that,as h_diff was increased,the slope of the typhoon eye area also increased,and its intensity became stronger.On the other hand,the results of the sensitivity experiments indicated that the intensity of the simulated typhoon was sensitive to the choice of PBL scheme,with the forecast bias of the QNSE(Quasi-Normal Scale Elimination)scheme being smaller than that of the GFDL(Geophysical Fluid Dynamics Laboratory)scheme.Angular momentum budget analyses indicated that,when increasing the h_diff,the convergence of angular momentum was larger in the boundary layer,which led to a faster spin-up of the vortex,further increasing the intensity of the typhoon.From the calculated horizontal and vertical vortex spread it was found that,when the h_diff was increased,the corresponding horizontal and vertical diffusion eddies also showed an increasing trend,which was also the reason for the strengthening of the typhoon.Meanwhile,the forecast bias decreased significantly with increasing horizontal mixing length when using the same PBL scheme.

Large-scale characteristics of landfalling tropical cyclones with abrupt intensity change

Data from the China Meteorological Administration and ERA-Interim are used to examine the environmental characteristics of landfalling tropical cyclones(TCs)with abrupt intensity change.The results show that,of all 657 landfalling TCs during 1979-2017,71%,70%and 65%of all landfalling TDs,TSs and TYs,respectively,intensify.Of all the 16595 samples,4.0%and 0.2%of typhoons and tropical storms,respectively,experience over-water rapid intensification(RI)process during their life cycle.Meanwhile,4.5%and 0.6%of typhoons and tropial storms,respectively,undergo overwater rapid decay(RD).These two kinds of cases,i.e.,RI and RD,are used to analyze their associated large-scale conditions.Comparisons show that the RI cases are generally on the south side of the strong western Pacific subtropical high(WPSH);warm sea surface temperatures(SSTs)and sufficient water vapor fluxes existing in RI samples is a dominant feature that is conducive to the development of TCs.Also,the moderate low-level relative vorticity is favorable for TC intensification.On the contrary,the RD TCs are located on the west side of the WPSH;significant decreasing SSTs and low-level water vapor transport may synergistically contribute to RD.Simultaneously,low-level relative vorticity seems to be unfavorable for the development of TCs.

An Adaptive Semi-Lagrangian Level-Set Method for Convection-Diffusion Equations on Evolving Interfaces

A new Semi-Lagrangian scheme is proposed to discretize the surface convection-diffusion equation.The other involved equations including the the levelset convection equation,the re-initialization equation and the extension equation are also solved by S-L schemes.The S-L method removes both the CFL condition and the stiffness caused by the surface Laplacian,allowing larger time step than the Eulerian method.The method is extended to the block-structured adaptive mesh.Numerical examples are given to demonstrate the efficiency of the S-L method.