Column leaching process of rare earth and aluminum from weathered crust elution-deposited rare earth ore with ammonium salts

In order to better understand the leaching process of rare earth （RE） and aluminum （Al） from the weathered crust elutiondepositedRE ore, the mass transfer of RE and Al in column leaching was investigated using the chromatographic plate theory. Theresults show that a higher initial ammonium concentration in a certain range can enhance the mass transfer process. pH of leachingagent in the range of 2 to 8 almost has no effect on the mass transfer efficiency of RE, but plays a positive role in the mass transferefficiency of Al under strong acidic condition （pH〈4）. There is an optimum flow rate that makes the highest mass transfer efficiency.The optimum leaching condition of RE is the leaching agent pH of 4？8, ammonium concentration of 0.4 mol/L and flow rate of0.5 mL/min. The mass transfer efficiencies of RE and Al both follow the order： （NH4）2SO4〈NH4Cl〈NH4NO3, implying thecomplexing ability of anion.

Detrital Mode and Geochemistry of the Shurijeh Formation (Late Jurassic-Early Cretaceous) in the Central and Western Parts of the Intracontinental Kopet-Dagh Basin, NE Iran: Implications for Provenance, Tectonic Setting and Weathering Processes

Petrographical and geochemical methods were combined to investigate the provenance, geodynamic and weathering history of the Shurijeh sandstones, Kopet-Dagh Basin. The point-counting method and XRF technique are used for modal and geochemical analyses. Based on petrographical examinations, it seems that the Shurijeh sandstones are mainly deposited in the craton interior and recycled orogen belts. In addition to petrographical investigation, geochemical analyses （major oxides and trace elements） of Late Jurassic-Early Cretaceous rocks reveal that the sedimentation processes are performed in a passive continental margin. Such interpretation is supported with geodynamic and paleogeographical studies of the Kopeh-Dagh basin during this time. The geochemical investigations suggested that the composition of probable source rocks mostly was acidic-intermediate with minor mafic igneous rocks. Based on the above, Paleo-Tethys remnants and their collision-related granitoids, in the south and west of Mashhad, may have been the source area for these rocks. CIA values, which range from 63.8 to 94.9 in samples, are suggesting a moderate to relatively high degree of alteration （weathering） in the source area. Therefore, petrographical and paleogeographical studies of siliciclastic rocks can be used for the provenance, tectonic setting and paleoweathering studies in the source area.

Analysis on the Heavy Snow Weather Process in Benxi Area

[Objective] The aim was to study the formation and development of a heavy snow in Benxi area. [Method] Based on conventional meteorological data, the formation and development of a heavy snow in Benxi area from December 4th to 5th in 2009 were analyzed from the aspects of weather situation evolution and physical quantity field feature. [Result] The heavy snow was caused by upper trough and North China cyclone. In this process, there was upper level divergence and lower level convergence over Benxi area, and it was warm at low attitude and cold at high attitude; southwest jet at low attitude transported water vapor from Bohai Sea to eastern Liaoning, which provided good water vapor condition for snow, but it didn’t reach heavy snow due to inadequate ascending force. The development of Ural Mountains high ridge played an important role in the snow process and the strengthened high ridge moving northward was beneficial to the southward movement of cold air and deepening of upper trough. Analysis on physical quantity field could provide reference for predicting beginning and ending time and strength of heavy snow. [Conclusion] The study could provide basis for the forecast of heavy snow.

Weathering Processes on Martian Craters: Implications on Recurring Slope Lineae and the Location of Liquid Water

Recent attention has been put into recurring slope lineae (RSL), after the discovery that water is present in them. It is assumed that RSL are due to flowing water. However, even though that might be the case, the general characteristics of RSL as well as their seasonal and spatial distribution in Mars, and their occurrence within craters, suggest that RSL correspond to the weathering of frozen aquifers, which coincides with slope stability processes occurring in impact craters and scree slopes from Earth. In this study, we associated RSL with similar weathering processes occurring on impact craters and hydrogeological processes occurring on Earth (including ice, water, and wind erosion and natural aquifer recharge processes). We were able to create a conceptual model on how RSL develop, why are they found mostly in mid latitudes around craters, why are they present in more frequency in one side of crates in high latitudes, and why are there more RSL in the Martian southern hemisphere. Considering the whole hydrogeological processes occurring in craters that experience RSL, we were able to predict where large quantities of liquid water are most likely to be present in the red planet.

Analysis of Rainfall Weather Process in Most of China from 3-6 October, 2021

Heavy rain is a common abnormal weather in China, which is prone to major natural disasters such as floods. By using China National Climate Center’s DERF2.0 (the second-generation product of monthly dynamic extended ensemble prediction) models and NCEP (National Centers for Environmental Prediction) data, and using synoptic and dynamic methods and other research methods, the rainfall weather process in most of China from October 3-6, 2021 is analyzed. The results show that: 1) this process had a long duration, large cumulative rainfall and strong extreme. 2) The warm and wet flow and the cold air intersected in the central and western regions of China and Northeast China, which resulted in a regional rainstorm process within ten days. 3) There was a low-level jet moving from Guizhou and Hunan to the south of Northeast China, bringing a lot of water vapor. To sum up, the rainfall process of this round has a certain relationship with the adjustment of atmospheric circulation.

A Numerical Research on the Influences of the Diurnal Variation of Solar Radiation on the Medium-Range Weather Processes

In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two typical winter and summer cases, we find that the influences of the diurnal variation of solar radiation on summer weather are really important, especially on its rainfall, surface heat transport and 500 hPa height field. On winter weather, however, the influences are very weak.

Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground

Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)hammer.Seven transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time series.The mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time series.These processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and rod-untightening.The drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six drillholes.Each curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering grades.The effect from fluctuation of the applied pressures is evaluated quantitatively.Detailed analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time.

Application and reliability analysis of DPM system in site investigation of HK weathered granite

A drilling process monitor （DPM） for ground characterization of weathered granite is presented. The monitor is portable and can be mounted on a hydraulic rotary drilling rig to record various drilling parameters in real time during normal subsurface investigation. The identification method for dominative and subsidiary interfaces has been established. The study reveals that the monitored drilling parameters are dependent on geotechnical materials and can be further applied to characterize ground interfaces. The t-test between manual logging and DPM logging has been carried out. The results show that the DPM has high accuracy in interfaces detection and well agreement with the manual logging. The findings show that the device and data analysis method are of potential application in subsurface drilling exploration in weathered granites. It also seems to have prospective uses in the determination of orebody boundary as well as in the detection of geohazards.

Groundwater Quality and Identification of Hydrogeochemical Processes within University of Lagos, Nigeria

Water samples from twenty one boreholes were collected within University of Lagos and analyzed for physical properties, trace elements and cations using inductively coupled plasma optical emission spectrometry (ICP-OES). Physical analysis of the samples shows slight acidity and alkalinity with 78% of the samples exceeded recommended standards. They can be classified as fresh water based on TDS and EC. Chloride concentrations fall within water standards in most samples while Al, Na, Pb and Br exceeded recommended standards in most samples. Gibbs plot, relationship between total cations, Na + K, Ca + Mg and Cl showed that all the groundwater samples fall in the water-rock interaction field which suggests that the weathering of rocks and influence of sea water primarily controls the major chemistry of groundwater in the area. Sodium Absorption Ratio (SAR) for all the water samples was less than 10 and excellent for irrigation purpose. Only 33% of water samples were suitable for irrigation based on Soluble Sodium Percentage (SSP) and Magnesium Adsorption Ratio (MAR), whereas based on Kellys Ratios (KR) all the water samples were not good for irrigation purpose having KR greater than 1. Fifty percent of the water samples showed pollution index (PI) above 1 with highest contribution (37.8%) from lead (Pb). Mn, Al, Ni, Fe and As contributed 29.3%, 19.13%, 8.66%, 4.25% and 0.82% respectively.

Instrumented borehole drilling for interface identification in intricate weathered granite ground engineering

The successful application in drilling for HK simple weathered granite foundation has revealed its further use in instru- mented drilling system as a ground investigation tool in the detection of other lithology formations, geohazards, underground water, and boundary of orebody. To expand the further use and test the accuracy in identification of formation, an R-20 rotary-hydraulic drill rig was instrumented with a digital drilling process monitoring system （DPM） for drilling in an intricate decomposed granite site. In this test ground, the boreholes revealed that the weathered granite alternately changes between moderate and strong. The qualitative and quantitative analysis of the penetrating parameters, indicates the effective thrust force, rotary speed, flushing pressure, penetrating rate, and displacement of the bit fluctuate at ground interfaces. It shows that the parameters get a good response with the change of rock strength at the interfaces, which can reveal the change of the intricate granite formation. Besides, a variable-slope method has been established, for identification of dominative and subsidiary interfaces in the granite site. The result from a t-test shows that the confi- dence of the instrumented drilling system in identification of the geotechnical interfaces is up to 99%.

Machine Learning of Weather Forecasting Rules from Large Meteorological Data Bases

Discovery of useful forecasting rules from observational weather data is an outstanding interesting topic.The traditional methods of acquiring forecasting knowledge are manual analysis and investigation performed by human scientists.This paper presents the experimental results of an automatic machine learning system which derives forecasting rules from real observational data.We tested the system on the two large real data sets from the areas of centra! China and Victoria of Australia.The experimental results show that the forecasting rules discovered by the system are very competitive to human experts.The forecasting accuracy rates are 86.4% and 78% of the two data sets respectively

Diagnostic Analysis on a Regional Rainstorm Weather in North-central Henan Province

[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.

Analysis of a Rare Continuous Rainy Process in Midsummer

[Objective] The research aimed to analyze a rare low temperature and rainy weather process which happened in Anhui Province from July 22 to August 14,2009.[Method] Based on the data of conventional observation,NCEP analysis field and automatic station,a rare low temperature and rainy weather process which occurred in Anhui Province from July 22 to August 14,2009 was analyzed.The formation reason of continuous rainy process in midsummer was discussed.The circulation characteristics and influence systems of continuous rainy process were revealed.On the base,the influences of configuration of circulation fields and difference of physical quantity fields at high and low layers on range and intensity of precipitation were analyzed.[Result] According to the circulation situation and influence system,the continuous rainy process could be divided into four stages:July 22-24,from July 27 to August 1,August 4-8 and August 9-14.Moreover,it was respectively affected by northeast low vortex,cold and warm air,high-level low trough,typhoon and periphery of subtropical high at four stages.The maintenance of big specific humidity zone provided sufficient water vapor condition for the continuous rainy weather.The rainstorm appeared in dense zone of specific humidity line,where the specific humidity >13 g/kg in the humidity front zone.A temperature trough maintained at 850 hPa.The cold air which continued to diffuse and go south was main reason of the abnormally low temperature during the continuous rainy period.Moreover,it provided ascending motion condition for precipitation maintenance.[Conclusion] The research provided references for actual forecast of continuous rainy weather.

Analysis of a Cold Wave Process in Jiujiang and Its Numerical Model Forecast

The cold wave weather process in Jiujiang in the early spring of February 2020 was analyzed.The results show that the establishment of blocking high near Lake Baikal and the rapid southward of cold air after accumulation resulted in the cold wave weather accompanied by strong cooling,hale and rain(snow)weather in Jiujiang.Before the cold wave broke out,the ground warmed up significantly,which was also one of thermal conditions for this cold wave weather.Water vapor conditions were abundant at middle and low levels;at 850 hPa,temperature dropped by 12-14℃during February 14-15,and-4℃isotherm appeared in the southern part of central Jiangxi,which is a favorable condition for rain(snow)in most areas of Jiujiang.

Rainfall Estimation using Image Processing and Regression Model on DWR Rainfall Product for Delhi-NCR Region

Observed rainfall is a very essential parameter for the analysis of rainfall,day to day weather forecast and its validation.The observed rainfall data is only available from five observatories of IMD;while no rainfall data is available at various important locations in and around Delhi-NCR.However,the 24-hour rainfall data observed by Doppler Weather Radar(DWR)for entire Delhi and surrounding region(up to 150 km)is readily available in a pictorial form.In this paper,efforts have been made to derive/estimate the rainfall at desired locations using DWR hydrological products.Firstly,the rainfall at desired locations has been estimated from the precipitation accumulation product(PAC)of the DWR using image processing in Python language.After this,a linear regression model using the least square method has been developed in R language.Estimated and observed rainfall data of year 2018(July,August and September)was used to train the model.After this,the model was tested on rainfall data of year 2019(July,August and September)and validated.With the use of linear regression model,the error in mean rainfall estimation reduced by 46.58% and the error in max rainfall estimation reduced by 84.53% for the year 2019.The error in mean rainfall estimation reduced by 81.36% and the error in max rainfall estimation reduced by 33.81%for the year 2018.Thus,the rainfall can be estimated with a fair degree of accuracy at desired locations within the range of the Doppler Weather Radar using the radar rainfall products and the developed linear regression model.

Chen-Chao Koo and the Early Numerical Weather Prediction Experiments in China

Although the first successful numerical weather prediction(NWP)project led by Charney and von Neumann is widely known,little is known by the international community about the development of NWP during the 1950s in China.Here,a detailed historical perspective on the early NWP experiments in China is provided.The leadership in NWP of the late Professor Chen-Chao Koo,a protége of C.G.Rossby at the University of Stockholm during the late 1940s and a key leader of modern meteorology(particularly of atmospheric dynamics and physics)in China during the 1950s−70s,is highlighted.The unique contributions to NWP by Koo and his students,such as the ideas of formulating NWP as an“evolution”problem,in which the past data over multiple time steps are utilized,rather than an initial-value problem,and on the cybernetic aspects of atmospheric processes,i.e.,regarding the motion of the atmosphere at various time scales as an optimal control system,are also emphasized.

Evaluation of diagnostic ratios of medium and serious weathered oils from five different oil sources

Laboratory experiments were conducted to simulate oil weathering process, a medium to long term weathering process for 210-d, using samples collected from five different oil resources. Based on relative deviation and repeatability limit analysis about indexes of these samples, the results show there had been significant changes in diagnostic ratios among the initial and weathered samples of different oils during this process. Changes of selected n-alkane diagnostic ratios of all oil samples displayed more obviously than diagnostic ratios of terpanes,steranes and PAHs in this process. Almost all selected diagnostic ratios of terpanes, steranes and PAHs can be efficiently used in tracking sources of hydrocarbon pollution, differentiating from the n-alkane diagnostic ratios.In these efficient diagnostic ratios, only four ratios maintained good stability in the weathering processes and are more suitable because their relative deviation（RSD） are lower than 5%.

中国极端天气气候研究——“地球系统与全球变化”重点专项项目简介及最新进展

全球变暖背景下,极端天气气候事件频发,并表现出群发性、持续性、复合性等特点,不可预测性增加;持续性强降水、极端低温、复合型极端高温干旱、群发性热浪和台风等极端天气气候事件对我国经济社会和可持续发展影响巨大。然而,上述极端天气气候事件的新特征、关键过程和机理尚不完全清楚,重大极端事件的预报预测水平亟待提升。文章首先简要介绍“地球系统与全球变化”重点专项项目“中国极端天气气候事件的形成机理及其预测和归因”的基本情况。项目拟在分析全球变化背景下对我国造成重大影响的极端天气气候事件新特征的基础上,深入研究多尺度海-陆-气耦合过程影响极端天气气候事件的机理,挖掘极端天气气候事件次季节-季节预测的前兆信号;发展动力与物理统计相结合的极端事件预测新方法,研制针对中国极端事件的新一代高分辨率数值预报与检测归因系统。文章重点总结了自2022年12月项目立项至今取得的最新研究成果和进展。

数值预报中气象卫星资料同化前处理技术进展

在数值天气预报变分同化中,利用同化前处理将卫星资料完成有效信息优选、资料拼接和稀疏化、初级通道选择、下边界参数耦合等处理,实现卫星资料同化对数值天气预报业务的正贡献,是决定海量卫星资料同化效率、质量和效果的重要环节。针对多种格式的卫星资料,中国气象局研发标准格式的高时效卫星资料拼接等技术,有效减小整轨卫星资料时间滞后对数值天气预报业务的负面影响。对于风云气象卫星资料,将云和降水检测、资料质量分析等处理置于同化前处理中,实现多光谱资料融合的同化预质量控制,保证了风云卫星微波温度探测资料和红外高光谱资料的同化正贡献。利用统一资料格式对预处理卫星资料进行再处理,拓展针对卫星成像和主动探测资料的处理,将卫星资料同化的部分质量控制功能置于卫星资料同化前处理中,是风云卫星资料同化前处理技术发展的重要趋势。

Effect of Aging on Solar Reflectance of White Cool Roof Coatings:Natural Weathering and the Influence on Building Energy Needs for Different Climate Conditions in Brazil

The use of cool materials on the building envelope is one of the most cost-effective ways to increase indoor thermal comfort conditions in hot climates and decrease the cooling energy needs.Despite the benefit of reducing cooling loads,researches have demonstrated that aging of roof coatings changes the initial solar reflectance(SR),which influences the long term building thermal and energy performance.Thus,this work presents preliminary natural weathering tests performed on samples of nine white coatings exposed to natural weathering for one year in the city of Sao Carlos,Brazil.Solar reflectances were measured with a spectrophotometer before and after exposure,every 3 months,for identifying the effect of aging along the time.The findings showed changes of 13%to 23%on SR after one year of natural weathering,with higher decrease on SR for rougher surfaces.The cleaning process restored from 90%to 100%of the original SR,which means maintenance can be an effective solution to restore the initial SR.Simulations indicated that roofs with higher solar reflectance increase indoor thermal comfort conditions and decrease the cooling energy need for buildings in hot climates,but the aging of white coatings increased the cooling energy needs along the time.