Promoting grain production through high-standard farmland construction:Evidence in China

Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.

Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other fields.In this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall.The designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding technique.Quasi-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled structure.The experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

Analysis and Modeling of Time Output Characteristics for Distributed Photovoltaic and Energy Storage

Due to the unpredictable output characteristics of distributed photovoltaics,their integration into the grid can lead to voltage fluctuations within the regional power grid.Therefore,the development of spatial-temporal coordination and optimization control methods for distributed photovoltaics and energy storage systems is of utmost importance in various scenarios.This paper approaches the issue from the perspective of spatiotemporal forecasting of distributed photovoltaic(PV)generation and proposes a Temporal Convolutional-Long Short-Term Memory prediction model that combines Temporal Convolutional Networks(TCN)and Long Short-Term Memory(LSTM).To begin with,an analysis of the spatiotemporal distribution patterns of PV generation is conducted,and outlier data is handled using the 3σ rule.Subsequently,a novel approach that combines temporal convolution and LSTM networks is introduced,with TCN extracting spatial features and LSTM capturing temporal features.Finally,a real spatiotemporal dataset from Gansu,China,is established to compare the performance of the proposed network against other models.The results demonstrate that the model presented in this paper exhibits the highest predictive accuracy,with a single-step Mean Absolute Error(MAE)of 1.782 and an average Root Mean Square Error(RMSE)of 3.72 for multi-step predictions.

Endogenous Endothelin-1 Regulates Hypoxia-Induced Atrial Natriuretic Peptide Secretion by Activating the MAPK/ERK and PI3K/Akt Signaling Pathways in Isolated Beating Rabbit Atria

The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significantly enhanced the release of ET-1 and the expression of the ET receptor (ETR) type A and B (ETRA and ETRB) in atrial tissues, with a concomitant increase in ANP secretion. The ETRA or ETRB antagonist, BQ123 (0.3 μmol/L) or BQ788 (0.3 μmol/L), respectively attenuated hypoxia-induced ANP secretion. Both antagonists significantly attenuated the levels of hypoxiainduced atrial phosphorylated (p)-extracellular signal-regulated kinase (ERK) and p-protein kinase B (Akt). The ERK and Akt inhibitors, PD098059 (30 μmol/L) and LY294002 (30 μmol/L), respectively mimicked the effect of the ETR antagonists. These results demonstrated that acute hypoxia- mediated atrial ET-1 regulated ANP secretion through ETR and the subsequent mitogenactivated protein kinase (MAPK)/ERK and ETR-phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. These pathways may mediate atrial endocrine functions under hypoxic conditions.

基于二维最大熵和教与学优化算法的图像分割

作为一种全局阈值方法,二维最大熵综合考虑了图像灰度信息和空间信息,在图像信噪比低的情况下,也能得到理想的图像分割结果。为了提高图像分割的运算速度和效率,在基本的二维最大熵理论的基础上,提出使用非线性惯性权重的教与学优化方法对二维最大熵进行优化,将二维最大熵作为教与学优化算法的适应度函数,利用优化后的最优阈值对图像进行分割。由于非线性惯性权重的教与学优化方法参数较少,收敛速度快,通过连续优化,能较快确定最佳分割阈值。实验结果证明,所提图像分割方法不仅速度快、准确,而且具有较强的适应性。

Recent Progress in Dual-Polarization Radar Research and Applications in China

Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have been successfully utilized to investigate precipitation microphysics and improve radar quantitative precipitation estimation(QPE).The recent progress in dual-pol radar research and applications in China is summarized in four aspects.Firstly,the characteristics of several representative dual-pol radars are reviewed.Various approaches have been developed for radar data quality control,including calibration,attenuation correction,calculation of specific differential phase shift,and identification and removal of non-meteorological echoes.Using dual-pol radar measurements,the microphysical characteristics derived from raindrop size distribution retrieval,hydrometeor classification,and QPE is better understood in China.The limited number of studies in China that have sought to use dual-pol radar data to validate the microphysical parameterization and initialization of numerical models and assimilate dual-pol data into numerical models are summarized.The challenges of applying dual-pol data in numerical models and emerging technologies that may make significant impacts on the field of radar meteorology are discussed.

Statistical Characteristics of Raindrop Size Distribution in the Tibetan Plateau and Southern China

The characteristics of raindrop size distribution （DSD） over the Tibetan Plateau and southern China are studied in this paper, using the DSD data from April to August 2014 collected by HSC-PS32 disdrometers in Nagqu and Yangjiang, com- prising a total of 9430 and 63661-rain raindrop spectra, respectively. The raindrop spectra, characteristics of parameter variations with rainfall rate, and the relationships between reflectivity factor （Z） and rainfall rate （R） are analyzed, as well as their DSD changes with precipitation type and rainfall rate. The results show that the average raindrop spectra appear to be one-peak curves, the number concentration for larger drops increase significantly with rainfall rate, and its value over southern China is much higher, especially in convective rain larger drops, especially for convective rain in southern China. Standardized Gamma distributions better describe DSD for All three Gamma parameters for stratiform precipitation over the Tibetan Plateau are much higher, while its shape parameter （,u） and mass-weighted mean diameter （Dm）, for convective precipitation, are less. In terms of parameter variation with rainfall rate, the normalized intercept parameter （Nw） over the Tibetan Plateau for stratiform rain increases with rainfall rate, which is opposite to the situation in convective rain. The/1 over the Tibetan Plateau for stratiform and convective precipitation types decreases with an increase in rainfall rate, which is opposite to the case for Dm variation. In Z-R relationships, like ＂Z = ARb＇＇, the coefficient A over the Tibetan Plateau is smaller, while its b is higher, when the rain type transfers from stratiform to convective ones. Furthermore, with an increase in rainfall rate, parameters A and b over southern China increase gradually, while A over the Tibetan Plateau decreases sub- stantially, which differs from the findings of previous studies. In terms of geographic location and climate over the Tibetan Plateau and southern China, the precipitation in the pre-flood seasons is dominated by strong convective rain, while weak convective rain occurs frequently in northern Tibet with lower humidity and higher altitude.

Statistics-based Optimization of the Polarimetric Radar Hydrometeor Classification Algorithm and Its Application for a Squall Line in South China

A modified hydrometeor classification algorithm （HCA） is developed in this study for Chinese polarimetric radars. This algorithm is based on the U.S. operational HCA. Meanwhile, the methodology of statistics-based optimization is proposed including calibration checking, datasets selection, membership functions modification, computation thresholds modification, and effect verification. Zhuhai radar, the first operational polarimetric radar in South China, applies these procedures. The systematic bias of calibration is corrected, the reliability of radar measurements deteriorates when the signal-to-noise ratio is low, and correlation coefficient within the melting layer is usually lower than that of the U.S. WSR-88D radar. Through modification based on statistical analysis of polarimetric variables, the localized HCA especially for Zhuhai is obtained, and it performs well over a one-month test through comparison with sounding and surface observations. The algorithm is then utilized for analysis of a squall line process on 11 May 2014 and is found to provide reasonable details with respect to horizontal and vertical structures, and the HCA results---especially in the mixed rain-hail region--can reflect the life cycle of the squall line. In addition, the kinematic and microphysical processes of cloud evolution and the differences between radar- detected hail and surface observations are also analyzed. The results of this study provide evidence for the improvement of this HCA developed specifically for China.

Chemical probing reveals insights into the signaling mechanism of inflammasome activation

Caspase-1-mediated IL-1β production is generally controlled by two pathways. Toll-like receptors （TLRs） recognize pathogen-derived products and induce NF-KB-dependent pro-IL-1β transcription; NOD-like receptors （NLRs） assemble caspase-l-activating inflammasome complexes that sense bacterial products/danger signals. Through a targeted chemical screen, we identify bromoxone, a marine natural product, as a specifc and potent inhibitor of the caspase-1 pathway. Bromoxone is effective over diverse inflammatory stimuli including TLR ligands plus ATP/nigeri- cin, cytosolic DNA, flagellin and Bacillus anthracis lethal toxin. Bromoxone also efficiently suppresses easpase-1 acti- vation triggered by several types of bacterial infection. Bromoxone acts upstream or at the level of the inflammasome in a transcription-independent manner. Bromoxone also inhibits pro-IL-1β expression by targeting components up- stream of IKK in the TLR-NF-kB pathway. The unique dual activities of bromoxone are shared by the known TAK1 inhibitor that specifically blocks Nalp3 inflammasome activation. Hinted from the mechanistic and pharmacological properties of bromoxone, we further discover that several known NF-KB inhibitors that act upstream of IKK, but not those targeting IKK or IKK downstream, are potent blockers of different NLRs-mediated caspase-1 activation. Our study uncovers a possible non-transcriptional molecular link between the NLR （Nalp3）-mediated inflammasome pathway and TLR-NF-kB signaling, and suggests a potential strategy to develop new anti-inflammatory drugs.

Comparative Analysis of the Characteristics of Rainy Season Raindrop Size Distributions in Two Typical Regions of the Tibetan Plateau

Mêdog and Nagqu are two typical regions of the Tibetan Plateau with different geographical locations and climate regimes.These differences may lead to discrepancies in the raindrop size distributions(DSDs)and precipitation microphysical processes between the two regions.This paper investigates discrepancies in the DSDs using disdrometer data obtained during the rainy season in Mêdog and Nagqu.The DSD characteristics are studied under five different rainfall rate categories and two precipitation types(stratiform and convective).For the total datasets,the number concentrations of drops with diameters D>0.6(D<0.6)mm are higher(lower)in Nagqu than in Mêdog.The fitted normalized gamma distributions of the averaged DSDs for the five rainfall rate categories show that Nagqu has a larger(lower)mass-weighted mean diameter D_(m)(normalized intercept parameter,lgNw)than Mêdog does.The difference in D_(m)between Nagqu and Mêdog increases with the rainfall rate.Convective clusters in Nagqu could be identified as continental-like,while convective precipitation in Mêdog could be classified as maritime-like.The relationships between the shape factorμand slope parameterΛof the gamma distribution model,the radar reflectivity Z,and the rainfall rate R are also derived.Furthermore,the possible causative mechanism for the notable DSD variation between the two regions during the rainy season is illustrated using reanalysis data and automated weather station observations.Cold rain processes are mainly responsible for the lower concentrations of larger drops observed in Nagqu,whereas warm rain prevails in Mêdog,producing abundant small drops.

Pyrolysis behaviour and combustion kinetics of waste printed circuit boards

The effective recycling of waste printed circuit boards(WPCBs)can conserve resources and reduce environmental pollution.This study explores the pyrolysis and combustion characteristics of WPCBs in various atmospheres through thermogravimetric and Gaussian fitting analyses.Furthermore,this study analyses the pyrolysis products and combustion processes of WPCBs through thermogravimetric and Fourier transform infrared analyses(TG-FTIR)and thermogravimetry-mass spectrometry(TG-MS).Results show that the pyrolysis and combustion processes of WPCBs do not constitute a single reaction,but rather an overlap of multiple reactions.The pyrolysis and combustion process of WPCBs is divided into multiple reactions by Gaussian peak fitting.The kinetic parameters of each reaction are obtained by the Coats-Redfern method.In an argon atmosphere,pyrolysis consists of the overlap of the preliminary pyrolysis of epoxy resin,pyrolysis of small organic molecules,and pyrolysis of brominated flame retardants.The thermal decomposition process in the O_(2) atmosphere is mainly divided into two reactions:brominated flame retardant combustion and epoxy combustion.This study provided the theoretical basis for pollution control,process optimization,and reactor design of WPCBs pyrolysis.

求解变分不等式和不动点问题的公共元的修正次梯度外梯度算法

该文在实Hilbert空间中引入了一类新的求解变分不等式问题的惯性次梯度外梯度算法.在适当的参数假设下,证明了由该算法所产生的序列强收敛于伪单调变分不等式问题的解集与拟非扩张映射不动点集合的公共元素.最后,给出了数值实验来说明所提算法的有效性.该文所得的结果推广和改进了文献中的一些已有结果.

A Ka-band Solid-state Transmitter Cloud Radar and Data Merging Algorithm for Its Measurements

This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar（i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3） is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month＇s continuous measurements during summertime at Naqu on the Tibetan Plateau,we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes＇ data to the merged data were estimated.The performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of -35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However,large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational modes.The percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.

FvWRKY50 is an important gene that regulates both vegetative growth and reproductive growth in strawberry

The WRKY transcription factors play important roles in plant growth and resistance,but only a few members have been identified in strawberry.Here we identified a WRKY transcription factor,FvWRKY50,in diploid strawberry which played essential roles in strawberry vegetative growth,and reproductive growth.Knocking out FvWRKY50 by genome editing accelerated flowering time and leaf senescence but delayed anthocyanin accumulation in fruit.Further analysis showed that FvWRKY50 acted as a transcriptional repressor to negatively regulate the expression of flowering-and leaf senescence-related genes,including FvFT2,FvCO,FvFT3,and FvSAUR36.Notably,FvWRKY50 directly upregulated the expression of FvCHI and FvDFR by binding their promoter under normal conditions,but at low temperature FvWRKY50 was phosphorylated by FvMAPK3 and then induced protein degradation by ubiquitination,delaying anthocyanin accumulation.In addition,the homozygous mutant of FvWRKY50 was smaller while the biallelic mutant showed normal size.These new findings provide important clues for us to further reveal the regulatory mechanisms of strawberry growth and fruit ripening.

Differentiation of gestational diabetes mellitus by nuclear magnetic resonance-based metabolic plasma analysis

This study aimed to investigate the metabolic profile of gestational diabetes mellitus(GDM)at both antepartum and postpartum periods.Seventy pregnant women were divided into three groups:the normal glucose-tolerant group(NGT,n=35),the abnormal glucose-tolerant groups without insulin therapy(A1GDM,n=24)or with insulin therapy(A2GDM,n=11).Metabolic profiles of the plasma were acquired by proton nuclear magnetic resonance(1H-NMR)spectroscopy and analyzed by multivariate statistical data analysis.The relationship between demographic parameters and the potential metabolite biomarkers was further explored.Group antepartum or postpartum showed similar metabolic trends.Compare with those of the NGT group,the levels of 2-hydroxybutyrate,lysine,acetate,glutamine,succinate,tyrosine,formate,and all three BCAAs(leucine,valine,isoleucine)in the A2GDM group were increased dramatically,and the levels of lysine,acetate,and formate in the A1GDM group were elevated significantly.The dramatically decreased levels of 3-methyl-2-oxovalerate and methanol were observed both in the A1GDM group and A2GDM group.Compare to the A1GDM group,the branched-chain amino acids(BCAAs)of leucine,valine,and isoleucine were increased dramatically in the A2GDM group.The levels of aromatic amino acids(AAAs),tyrosine and phenylalanine,were significantly increased in GDM women,consistent with the severity of GDM.Interference of amino acid metabolism and disturbance in energy metabolism occurred in women with different grades of GDM.Metabolic profiles could reflect the severity of GDM.Plasma BCAA concentrations showing strong positive correlations with weight and pre-delivery BMI.This study provides a new perspective to understand the pathogenesis and etiology of GDM,which may help the clinical management and treatment of GDM.

Fatigue test setups and analysis methods for asphalt mixture: A state-of-the-art review

Fatigue performance evaluation on asphalt mixture provides an essential reference for asphalt mixture design and pavement structure design.Laboratory fatigue test has been widely used by researchers and engineers to assess the fatigue performance of asphalt mixture,due to its low cost,high efficiency,and strong operability.To ensure performance assessment reliability,fatigue test operated in the laboratory needs to simulate the loading and environmental conditions occurring in the field asphalt layer.As a result,loading setups in laboratory fatigue tests,including loading mode,loading frequency,loading waveform,temperature,and the controlled mode,have been carefully devised by researchers.This paper reviews the above common setups in fatigue tests,which aims to illustrate the classical and latest considerations as well as ideas proposed by researchers for improving fatigue test procedures.As fatigue response data of asphalt mixture is measured from fatigue test,an analysis method is required to process the data and identify fatigue behaviors of the material.Presently,the frequently-used fatigue data analysis methods include the fatigue life model,stiffness-modulus-based method,energy-based method,and viscoelastic continuum damage(VECD)method.This paper also provides a review survey on the main concepts,indicators,and models included in those methods to facilitate their applications.Meanwhile,the latest research progress and outputs related to the four methods are also introduced and discussed to reveal the state-of-the-art developments in this research area.

基于分级的危险化学品运输风险评价研究

随着我国经济持续快速的发展,对危险化学品需求快速增加。由于危险化学品其特殊的性质,一旦发生事故将比一般的运输事故有更大的破坏性,因此在运输中需要给予特别的关注。基于这样的背景,本文通过风险评价模型对危险化学品运输中的风险进行了分析。首先本文考虑了危险化学品运输中会发生的各种成本,然后将运输风险分级处理,并通过一定的函数形式转化为成本,从而将危险化学品的运输成本与风险成本在同一目标函数中表示,该模型可为政府制定政策减少风险以及企业选择合理的路径降低成本提供依据。本文将更多的因素考虑到风险评价模型中,从而增加了其准确性和实际意义。

Spin and spin-orbit coupling effects in nickel-based superalloys:A first-principles study on Ni_(3)Al doped with Ta/W/Re

Heavy elements(X=Ta/W/Re)play an important role in the performance of superalloys,which enhance the strength,anti-oxidation,creep resistance,and anti-corrosiveness of alloy materials in a high-temperature environment.In the present research,the heavy element doping effects in FCC-Ni(γ)and Ni_(3)Al(γ')systems are investigated in terms of their thermodynamic and mechanical properties,as well as electronic structures.The lattice constant,bulk modulus,elastic constant,and dopant formation energy in non-spin,spin polarized,and spin-orbit coupling(SOC)calculations are compared.The results show that the SOC effects are important in accurate electronic structure calculations for alloys with heavy elements.We find that including spin for bothγandγ'phases is necessary and sufficient for most cases,but the dopant formation energy is sensitive to different spin effects,for instance,in the absence of SOC,even spin-polarized calculations give 1%to 9%variance in the dopant formation energy in our model.Electronic structures calculations indicate that spin polarization causes a split in the metal d states,and SOC introduces a variance in the spin-up and spin-down states of the d states of heavy metals and reduces the magnetic moment of the system.

Calcyclin-binding protein contributes to cholangiocarcinoma progression by inhibiting ubiquitination of MCM2

Background:Cholangiocarcinoma(CCA)represents the epithelial cell cancer with high aggressiveness whose five-year survival rate is poor with standard treatment.Calcyclin-binding protein(CACYBP)shows aberrant expression within several malignant tumors,but the role of CACYBP in CCA remains unknown.Methods:Immunohistochemical(IHC)analysis was used to identify CACYBP overexpression in clinical samples of CCA patients.Moreover,its correlation with clinical outcome was revealed.Furthermore,CACYBP’s effect on CCA cell growth and invasion was investigated in vitro and in vivo using loss-of-function experiments.Results:CACYBP showed up-regulation in CCA,which predicts the dismal prognostic outcome.CACYBP had an important effect on in-vitro and in-vivo cancer cell proliferation and migration.Additionally,knockdown of CACYBP weakened protein stability by promoting ubiquitination of MCM2.Accordingly,MCM2 up-regulation partly reversed CACYBP deficiency’s inhibition against cancer cell viability and invasion.Thus,MCM2 might drive CCA development by Wnt/β-catenin pathway.Conclusions:CACYBP exerted a tumor-promoting role in CCA by suppressing ubiquitination of MCM2 and activating Wnt/β-catenin pathway,hence revealing that it may be the possible therapeutic target for CCA treatment.

A discussion on improving typhoon observation through radar by scanning the negative elevation angle

Certain feasibilities and features were discussed in typhoon detection by radar with a negative elevation angle according to the relationship between the remote detecting range and the elevation angle of the new generation weather radar, in order to rectify the disadvantages of detecting capability for remote low-level echo with a lowest elevation angle of 0.5° in the common detecting mode. The data obtained from detecting the typhoon of Haitang and Changmi with radar for their negative elevation angles and the observed data for the common lowest elevation angle of 0.5° were compared to each other. The results showed that the detection of remote low level cloud system with radar could be improved by using the negative elevation angle, and the structure and the evolution trend of a typhoon could be better judged. The increasing degree of detection for negative elevation angles in the current volume scanning mode should be helpful for predicting the intensity and developing trend of windstorms, to further improve the capability of warning and nowcasting. The detection of negative elevation angle could also help reveal the development and change of typhoon＇s low level cloud system. As far as the typhoons of Haitang and Changmi were concerned, the detecting area of Changmi was increased by 1.09 times with the negative elevation angle of 0.31°, compared with the elevation angle of 0.48° if the threshold value for the sea echo within 100 km was eliminated. Several volume scans of Haitang were increased by 2.1%-7.9% for the negative elevation angle of 0.36° compared with the elevation angle of 0.49° . Therefore, the radar detecting capability of typhoons could be improved by the detection of negative elevation angles to some extent. This could make up for the disadvantages of a low detecting capability for remote low-level echo in the common detecting mode. At the same time, a negative elevation angle could be easily influenced by the ground clutter and the close sea wave clutter which interfered with the assessment of the typhoon structure at times. Assessing these advantages and disadvantages, some advantages for using negative elevation angle were discovered from the observation of the typhoons Haitang and Changmi, if the negative elevation angle with radar was selected reasonably in some conditions. As a result, a certain value arose for improving and monitoring the early warning system for typhoons, paying close attention to the detection of negative elevation angles.