Analysis of Precipitation Anomaly and a Failed Prediction During the Dragon-boat Rain Period in 2022

This study investigates the possible causes for the precipitation of Guangdong during dragon-boat rain period(DBRP) in 2022 that is remarkably more than the climate state and reviews the successes and failures of the prediction in2022. Features of atmospheric circulation and sea surface temperature(SST) are analyzed based on several observational datasets for nearly 60 years from meteorological stations and the NCEP/NCAR Global Reanalysis Data. Results show that fluctuation of the 200-h Pa westerly wind as well as the westerly jet is strengthened due to the propagation of wave energy, leading to strong updraft over southern China. Activities of a subtropical high and a shear line provide favorable conditions for the transport of moisture to Guangdong. With the support of powerful southwest winds, extreme precipitation is induced. ENSO is a good indicator of atmospheric circulation at mid-and high-levels during the DBRP in2022 but it performs badly at low levels. During recent years, the influence of ENSO on precipitation during the DBRP has decreased obviously. The SSTA of tropical southeast Atlantic(SEA) in spring may become the key indicator. During the years with warm SEA, wave trains propagate from northwest to southeast over Eurasia with energy enhancing the westerly jet, conducive to updraft over southern China and the occurrence of heavy precipitation. Meanwhile, the Rossby wave is triggered over Maritime Continent by heat sources of southern Atlantic-western Indian Ocean through the Gill response. Thus, strong transport of moisture and heavy rainfall occur.

RAIN-128算法的中间相遇攻击

RAIN是一族SPN结构的轻量级分组密码算法,该算法具有软硬件实现效率高、安_全性强等特点。中间相遇攻击被广泛应用于分组密码算法的安全性分析中。该文通过分析RAIN-128的结构特性和截断差分特征,利用差分枚举技术分别构造了4轮和6轮中间相遇区分器,给出了8轮及10轮的中间相遇攻击。当攻击轮数为8轮时,预计算阶段的时间复杂度为2^(68)次8轮RAIN-128加密,存储复杂度为2^(75)bit,在线攻击阶段的时间复杂度为2^(109)次8轮加密,数据复杂度是2^(72)个选择明文;当攻击轮数为10轮时,预计算阶段的时间复杂度为2^(214)次10轮加密,存储复杂度为2^(219)bit,在线攻击阶段的时间复杂度为2^(109)次10轮加密,数据复杂度是2^(72)个选择明文,分析结果显示,RAIN-128可以抵抗中间相遇攻击,并具有较高的安全冗余。

Plant life form determines spatiotemporal variability and climate response of plant seed rain in subtropical forests

Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients.In this study,we collected seeds from four sites in the Dalaoling Nature Reserve,Hubei Province,China,between 2011 and 2014,measured seed output and seed mass as seed rain traits,and compared their interannual and elevational variation.Then,we ran phylogenetic generalized mixed linear models(PGLMMs) to explore the effects of temperature and precipitation as well as interspecific differences on seed rain,and fitted the best regression models for seed rain vs.weather of canopy and understory species.The results showed no correlation between values of seed output and seed mass.However,the variation of the two traits showed significantly positive correlation.Seed output of canopy species generally decreased with increasing elevation,and showed significant interannual difference;however,seed output of understory species and seed mass for both canopy and understory species did not show consistency tends along elevational or in interannual variation.Seed output was significantly affected by temperature and precipitation,while seed mass mainly varied due to interspecific differences.Weather explained more the variation of the seed output of canopy species than that of understory species,with R^(2) values of 43.0%and 29.9%,respectively.These results suggested that canopy plants contributed more to the reproductive dynamics of the whole communities,and the canopy's buffer effect on the underground weakened the response of understory plants to weather variation in terms of their reproductive strategy.

A New Algorithm of Rain Type Classification for GPM Dual-Frequency Precipitation Radar in Summer Tibetan Plateau

In this study, a new rain type classification algorithm for the Dual-Frequency Precipitation Radar(DPR) suitable over the Tibetan Plateau(TP) was proposed by analyzing Global Precipitation Measurement(GPM) DPR Level-2 data in summer from 2014 to 2020. It was found that the DPR rain type classification algorithm(simply called DPR algorithm) has mis-identification problems in two aspects in summer TP. In the new algorithm of rain type classification in summer TP,four rain types are classified by using new thresholds, such as the maximum reflectivity factor, the difference between the maximum reflectivity factor and the background maximum reflectivity factor, and the echo top height. In the threshold of the maximum reflectivity factors, 30 d BZ and 18 d BZ are both thresholds to separate strong convective precipitation, weak convective precipitation and weak precipitation. The results illustrate obvious differences of radar reflectivity factor and vertical velocity among the three rain types in summer TP, such as the reflectivity factor of most strong convective precipitation distributes from 15 d BZ to near 35 d BZ from 4 km to 13 km, and increases almost linearly with the decrease in height. For most weak convective precipitation, the reflectivity factor distributes from 15 d BZ to 28 d BZ with the height from 4 km to 9 km. For weak precipitation, the reflectivity factor mainly distributes in range of 15–25 d BZ with height within 4–10 km. It is also shows that weak precipitation is the dominant rain type in summer TP, accounting for 40%–80%,followed by weak convective precipitation(25%–40%), and strong convective precipitation has the least proportion(less than 30%).

Spatiotemporal characteristics of seed rain and soil seed bank of artificial Caragana korshinskii Kom. forest in the Tengger Desert, China

Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles.

Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China

An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR.

Effect Evaluation of CBL Combined with Rain Classroom Teaching Method in Medical Statistics

Objective: To explore the application effect of CBL combined with rain classroom teaching method in medical statistics courses. Methods: The undergraduate students of medical imaging technology in 2019 and 2020 in a university were selected as the research objects. A cluster sampling method was used to select 79 undergraduate students from 2019 in the control group and 75 undergraduate students from 2020 in the experimental group. Traditional teaching method and CBL combined with rain classroom teaching method was used in the control group and experimental group respectively. The final examination scores of the two groups were compared. In experimental group, the correlation between the average score in the rain classroom and the final examination score was tested, and the teaching effect was evaluated. Results: The average score of final examination in experimental group and control group was 79.13 ± 10.32 points and 71.54 ± 14.752 points, respectively, which had a statistically significant difference (Z = 2.586, P = 0.012);the final examination scores of the students in the experimental group were positively correlated with the average scores of the rain classroom (r = 0.372, P = 0.001), and the proportion of satisfaction in the experimental group was 94.7%. Conclusion: The CBL combined with rain classroom teaching method can improve the teaching effectiveness of medical statistics courses.

Mesoscale and Microphysical Characteristics of a Double Rain Belt Event in South China on May 10–13,2022

A second rain belt sometimes occurs ahead of a frontal rain belt in the warm sector over coastal South China,leading to heavy precipitation.We examined the differences in the mesoscale characteristics and microphysics of the frontal and warm sector rain belts that occurred in South China on May 10–13,2022.The southern rain belt occurred in an environment with favorable mesoscale conditions but weak large-scale forcing.In contrast,the northern rain belt was related to low-level horizontal shear and the surface-level front.The interaction between the enhanced southeasterly winds and the rainfall-induced cold pool promoted the persistent growth of convection along the southern rain belt.The convective cell propagated east over the coastal area,where there was a large temperature gradient.The bow-shaped echo in this region may be closely related to the rear-inflow jet.By contrast,the initial convection of the northern rain belt was triggered along the front and the region of low-level horizontal shear,with mesoscale interactions between the enhanced warm-moist southeasterly airflow and the cold dome associated with the earlier rain.The terrain blocked the movement of the cold pool,resulting in the stagnation of the frontal convective cell at an early stage.Subsequently,a meso-γ-scale vortex formed during the rapid movement of the convective cell,corresponding to an enhancement of precipitation.The representative raindrop spectra for the southern rain belt were characterized by a greater number and higher density of raindrops than the northern rain belt,even though both resulted in comparable hourly rainfalls.These results help us better understand the characteristics of double rain belts over South China.

On Adaptation Measures to Solve Tel-Aviv’s Environmental Problems with “Sunny Rain”

Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s main river”will no longer be a dirty ditch;the fog from Ben-Gurion Airport was cleaned;neighborhoods,parks,around Tel Aviv were greened and all green spaces were irrigated with“Sunny Rain”.

Dynamic Response of Tensile Membrane Structure under Coupling Effect of Wind and Rain

Because of the small stiffness and high flexibility, the tension membrane structure is easy to relax and damage or even destroy under the action of external load, which leads to the occurrence of engineering accidents. In this paper, the damped nonlinear vibration of tensioned membrane structure under the coupling action of wind and rain is approximately solved, considering the geometric nonlinearity of membrane surface deformation and the influence of air damping. Applying von Karman’s large deflection theory and D’Alembert’s principle, the governing equations are established for an analytical solution, and the experimental results are compared with the analytical results. The feasibility of this method is verified, which provides some theoretical reference for practical membrane structure engineering design and maintenance.

The Relationship between Extreme Precipitation Events in East Africa during the Short Rainy Season and Indian Ocean Sea Surface Temperature

The East African short rainy season (October-November-December) is one of the major flood seasons in the East African region. The amount of rainfall during the short rainy season is closely related to the lives of the people and the socio-economic development of the area. By using precipitation data and sea surface temperature data, this study reveals the spatial and temporal variation patterns of extreme precipitation during the East African short rainy season. Key findings include significant rainfall variability, with Tanzania experiencing the highest amounts in December due to the southward shift of the Intertropical Convergence Zone (ITCZ), while other regions receive less than 100 mm. Extreme rainfall events (90th percentiles) are evenly distributed, averaging 2 to 10 days annually. Historical data shows maximum seasonal rainfall often peaks at 15 mm, with frequent occurrences of daily rainfall exceeding 10 mm during OND. Additionally, a positive correlation (0.48) between OND precipitation extremes and Indian Ocean Dipole (IOD) anomalies is statistically significant. These findings highlight the climatic variability and potential trends in extreme rainfall events in East Africa, providing valuable insights for regional climate adaptation strategies.

建筑群立面风驱雨捕集特性

风驱雨作为建筑围护结构中最重要的湿源,对建筑围护结构的热湿性能、力学性能、耐久性、建筑能耗和碳排放等均有重要影响。很多学者对建筑立面风驱雨展开深入的研究,但研究对象多为独栋建筑。实际上,中国建筑多以建筑群落的形式存在,建筑自身对风场有干扰,建筑群内各建筑立面的风向和风速均可能会发生较大变化,从而影响入侵到建筑立面的风驱雨。为了揭示建筑群内各建筑立面的风驱雨捕集特性,基于风相和雨相质量和动量守恒原理,采用欧拉多相流方法建立并验证建筑风驱雨模型,并应用该模型对建筑群立面的风驱雨捕集特性进行分析。以广州地区为例,由结果可知:建筑群立面风驱雨捕集比与独栋建筑立面风驱雨捕集比相比有较大差异,其中最大差异高达26.3%,最小差异亦可达5.2%。另外,由于受风阻效应的影响,建筑群内各建筑立面的捕集比也存在差异。

2024年2月华东和华中大范围低温雨雪冰冻灾害的成因和可预报性分析

利用全国2374个站点的逐日气温和降水资料、NCEP/NCAR大气环流再分析资料和Hadley中心的海温资料,研究了2024年2月华东和华中大范围低温雨雪冰冻灾害成因和可预报性。结果表明:2024年2月上旬和下旬这两次大范围低温雨雪冰冻天气过程,发生地区重叠度高,冰雪灾害严重;影响两次过程的副热带和中高纬环流系统配置较为一致,西北太平洋副热带高压(以下简称副高)稳定偏强和偏西,西伯利亚高压、南支槽和西北太平洋反气旋阶段性同步偏强,形成较强的协同作用,西伯利亚高压增强导致冷空气南下,副高、南支槽和西北太平洋反气旋同步增强则为华东和华中提供了充沛的水汽条件;2023年5月至2024年4月赤道中东太平洋地区发生了一次中等强度的El Nino事件,冬季热带印度洋和热带北大西洋海温异常偏暖,三大洋海温异常共同导致了副高持续偏强,也有利于西北太平洋反气旋的阶段性发展和增强,为2月的两次过程提供了充沛的水汽条件;次季节模式对两次过程的预报时效在1~2周左右,起报时间在2周以上时,目前模式无法准确预测欧亚中高纬环流系统的异常特征,导致对两次过程的预测能力较低。

用于雨线和雨滴去除的像素级核预测网络

针对现有的图像去雨算法通常需要设计先验知识和多阶段优化框架导致算法适应场景单一的问题,提出一种基于图像过滤统一去除雨线和雨滴的去雨核预测网络(RKPN)。有雨图像通过RKPN估计像素级去雨内核。采用空洞卷积提取多尺度特征,提出一个多分支特征聚合模块。通过数据增强构建一个雨线和雨滴混合数据集(RDRS),提升现实世界复杂场景中图像去雨算法的效果。对4个公开数据集和RDRS数据集的广泛实验结果表明,所提模型取得均高于MPRNet等主流网络的峰值信噪比和结构相似度。

双高背景下的人才培养模式创新--德技并修“雨耕”特色职业素质教育体系构建

通过对国内外职业教育理论及人才培养实践经验的学习研究,明确“德技并修”技能人才内涵与构成要素。搭建德技并修育人平台,健全德技并修育人体系;建设机电工匠培养体系,打造技术技能人才培养高地;建设机电工匠培养特区,培养卓越技术技能人才;构建全方位育人的同心圆,推进全过程育人的大格局。创新双高背景下人才培养模式,构建德技并修“雨耕”特色职业素质教育体系,借助学校教学平台结合企业的实践平台,将职业道德和工匠精神融入学生的整个培育过程中,坚持技能和德育并重,教会学生如何做人、如何做事,树立正确的人生观、价值观,培养高素质高技能人才。

酸雨-干湿循环-荷载综合作用下水泥稳定碎石强度特性分析

为研究酸雨环境中水泥稳定碎石基层的力学性能,通过室内试验模拟水泥稳定碎石受酸雨、干湿循环和荷载循环等多因素的综合作用,并对试件进行中性化测试和微观检测,揭示不同酸度、干湿循环周期和荷载循环次数下水泥稳定碎石基层的强度劣化规律。试验结果表明:在7个周期的干湿循环作用下,水泥稳定碎石试件的强度会随着溶液酸性的增强而增加,并且在短期的酸雨侵蚀试验中,试件内部的中性化程度很低;在pH=3的酸雨环境中,随着干湿循环作用次数的增加,试件由外而内不断劣化,其强度随之降低;在同样的酸雨环境中,干湿循环和荷载循环综合作用对试件强度的削弱更为明显,而且两者作用的顺序不同亦会对试件强度产生不同的影响。在此基础上建立了多因素作用下水泥稳定碎石的强度演化模型,通过与实测值进行对比验证,该模型预测精度较高,可用于旧路改造中水泥稳定碎石基层残余强度的预估。

Analysis of the Temporal-spatial Distribution and Seasonal Variation of the Acid Rain in Guangxi Province

The temporal-spatial distribution and seasonal variation of the precipitation acidity in Guangxi Province were statistically analyzed by means of the data from 2003 to 2008 in 10 Stations of Acid Rain Observation in the province and the data from 1996 to 2008 in two Monitoring Spots in Nanning and Baise,respectively.The results showed that annual average pH value of precipitation was <5.6 based on the analysis of the data from 10 Stations of Acid Rain Observation in the province,among which,the data from 5 stations indicated that annual average pH value of precipitation was <4.5.Thus,it can be thought that the serious acid rain had appeared in the province.There was an obvious seasonal variation in the extent of the acidity in precipitation and the acidity of precipitation in spring and winter was heavier than that in summer and autumn.

Analysis on Current Situation,Formation Causes and Control Countermeasures of Acid Rain Pollution in China

Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.

The Effects of Simulated Acid Rain on Photosynthetic Characteristics of Spring Wheat Leaves at the Jointing Stage

In order to investigate the effect of acid rain on photosynthetic characteristics of spring wheat,spring wheat at the jointing stage was sprayed with simulated acid rain at different pH levels of 1.5,2.5,3.5,4.5 and 5.6,and then,the photosynthetic parameters of spring wheat leaf was monitored.The results indicated that the pH value of simulated acid rain was positively and very significantly correlated with the net photosynthetic rate,stomata conductance,transpiration rate,water use efficiency and the chlorophyll relative content,whereas very significantly and negatively correlated with intercellular CO2 concentration.Due to acid rain,the net photosynthetic rate,stomata conductance,transpiration rate and the chlorophyll relative content decreased by 4.08%-67.04%,17.44%-58.44%,12.08%-48.08% and 12.16%-37.23% respectively,while intercellular CO2 concentration increased by 9.01%-14.29%.After simulated treatment with acid rain,the net photosynthetic rate had high significant positive correlation with stomata conductance,transpiration rate,water use efficiency,and the chlorophyll relative content,but high significant negative correlation with intercellular CO2 concentration.At the same time,transpiration rate was observed to be very significantly and positively correlated to stomata conductance and chlorophyll relative content,being significantly and positively correlated with water use efficiency,and very significantly and negatively correlated with intercellular CO2 concentration.In a word,the influence of simulated acid rain on photosynthetic characteristics of spring wheat leaf became more and more obvious with the increase of hydrogen ion concentration.

Analysis of Acid Rain Characteristics and Related Meteorological Conditions in Dalian

The variation characteristics of acid rain and the relationship between the formation of acid rain and meteorological conditions were analyzed based on the observation data and meteorological records collected from acid rain observation station in Dalian over 2006-2009.The results showed that Dalian was one of the regions with strong acid rain in northern China,with the frequency of 66% and pH value of 3.49.The acidity was the strongest in fall and weakest in spring;and the maximum and minimum frequencies were in summer and in winter respectively.Frequency of acid rain was inversely proportional to wind speed and concentration of inhalable particles in Dalian;acid rain occurred easily in foggy weather due to the steady stratification and abundant moisture;continuous precipitation did not mean the reduction of acidic material in the air,and the rainfall with increased acidity in the second day accounted for 42% in continuous precipitation cases.