Small Amount Of Precipitation Research Articles

Forest cover and watering of the Pripyat River basin

The paper deals with the issues of the influence of forest cover on the average annual runoff of rivers in the Pripyat River basin. In the study area, under the influence of solar radiation, the temperature of the air and the soil surface increases, evaporation from the water surface also increases, and the moisture content of the upper layers of the soil decreases. In general, with an increase in forest cover, the annual layer of the runoff of the studied rivers increases, as well as with an increase in the amount of precipitation (in contrast to the runoff of short-term floods). However, with a forest cover of more than 20%–30% and a relatively small amount of precipitation, the runoff decreases, which is associated with the retention of part of the precipitation by the forest cover. With a large amount of precipitation and low forest cover, the runoff also decreases, which is probably due to the loss of precipitation water for evaporation, etc. The conducted studies show that, just as the forest affects water resources, the flow of moisture to watersheds also affects the state of forest systems. Moreover, this interaction is expressed by evaporation from forests. Under influence of change of a climate growth of evaporation is observed.

Time-Dependent Retention of a Mixture of Cs(I), Sm(III), Eu(III) and U(VI) as Waste Cocktail by Calcium Silicate Hydrate (C-S-H) Phases

In the context of the safe storage of high-level radioactive waste, the time-dependent retention of a waste cocktail (WC) consisting of Zr(IV), Mo(VI), Ru(III), Pd(II), Cs(I), Sm(III), Eu(III) and U(VI) was studied on the commercially available C-S-H phase Circosil®. The herein presented results focus on Cs(I), Sm(III), Eu(III) and U(VI). Precipitation and wall adsorption studies in the absence of the solid phase show only a small amount of precipitation for Sm(III) and Eu(III) (34 ± 18%) in the high-saline diluted Gipshut solution (DGS, pH 10.6, I = 2.6 M). For Cs(I) and U(VI), no precipitation was observed. In 0.1 M NaCl (pH 10.9), the measured retention could completely be attributed to wall adsorption for all four elements. The obtained Rd values for the time-dependent retention of Sm(III), Eu(III) and U(VI) on Circosil® of 105 to 106 L·kg−1 are in good agreement with the literature. For Cs(I) in the strongly saline background electrolytes, slightly higher Rd values of up to 8·102 L·kg−1 were determined for the crystalline Circosil® compared to the wet chemical C-S-H phases. Overall, the commercial product Circosil® is suitable as an alternative to synthesised C-S-H phases to observe trends in the retention behaviour of these elements. Comparison between both background electrolytes shows an increase in the amount and velocity of retention for all four elements with decreasing salinity. This confirms adsorption processes as the fastest and initial retention mechanism. Precipitation or incorporation of Eu(III), Sm(III) and U(VI) cannot be ruled out in the long term. Comparing the kinetic of this WC study to single-element studies in the literature, a longer uptake time to reach a steady state of 7 d in 0.1 M NaCl and 28 d in DGS instead of <1 d was observed for Eu(III) and Sm(III). The situation for Cs(I) is similar. This indicates competing effects between the different WC elements for adsorption sites on the C-S-H phases.

Analysis of the Permeability Change Resulting from Active Mineral Precipitation in Pores of Rocks by 3D-DEM

Carbon dioxide capture and storage (CCS) is a promising technique for reducing the concentration of CO2 in the atmosphere, and several million tons of CO2 are sequestered every year. The most important problem in CCS is ensuring aquifer safety. However, there is still room for improvement in the flow characteristics of aquifers to prevent CO2 leakage. To decrease the permeability of porous rocks, in this study, a method called ‘active mineral deposition’ was developed. In this method, some minerals are actively precipitated in aquifers, and the pores in the rock mass are closed by precipitated minerals. Because the pores are closed and stacked by minerals, the permeability of the rock mass is expected to decrease. For the precipitated minerals, CaCO3 is a promising mineral, and CaCO3 is precipitated in the pores of rocks. From microscopic observation, the approximate size of the precipitated mineral was estimated to be 10 μm in the rock pores. To verify the effect of the method, the permeability of the porous rocks was simulated using the three-dimensional discrete-element method (3D-DEM). Here, the rock minerals and pores were simulated using DEM elements, and the initial permeability of the models was estimated. Then, the small minerals, which represent precipitated minerals, were generated in the pore space, and changes in the intrinsic permeability, flow path, and pressure distributions in the rocks were estimated. The value of intrinsic permeability decreased to one tenth of the initial condition when 1% of the pore spaces were occupied by the precipitated minerals. A small amount of precipitation could change the permeability of the porous materials.

Mineral precipitation and hydrochemical evolution through evaporitic processes in soda brines (East African Rift Valley)

Soda lakes of the East African Rift Valley are hyperalkaline, hypersaline lakes extremely enriched in Na+, K+, Cl−, CO32−, HCO3−, and SiO2. In this paper, we investigate the chemical evolution in these lakes and the production of chemical sediments by salt precipitation via evaporation. Water samples from tributary springs and three lakes (Magadi, Nasikie Engida and Natron) have been experimentally studied by in-situ X-ray diffraction during evaporation experiments to characterize the sequence of mineral precipitation. These data are complemented by ex-situ diffraction studies, chemical analyses and thermodynamic hydrochemical calculations producing detailed information on the activity of all solution species and the saturation state of all minerals potentially generated by the given composition. Major minerals precipitating from these samples are sodium carbonates/bicarbonates as well as halite. The CO3/HCO3 ratio, controlled by pH, is the main factor defining the Na‑carbonates precipitation sequence: in lake brines where CO3/HCO3 > 1, trona precipitates first whereas in hot springs, where CO3/HCO3 ≪ 1, nahcolite precipitates instead of trona, which forms later via partial dissolution of nahcolite. Precipitation of nahcolite is possible only at lower pH values (pCO2 higher than −2.7) explaining the distribution of trona and nahcolite in current lakes and the stratigraphic sequences. Later, during evaporation, thermonatrite precipitates, normally at the same time as halite, at a very high pH (>11.2) after significant depletion of HCO3− due to trona precipitation. The precipitation of these soluble minerals increases the pH of the brine and is the main factor contributing to the hyperalkaline and hypersaline character of the lakes. Villiaumite, sylvite, alkaline earth carbonates, fluorapatite and silica are also predicted to precipitate, but most of them have not been observed in evaporation experiments, either because of the small amount of precipitates produced, kinetic effects delaying the nucleation of some phases, or by biologically induced effects in the lake chemistry that are not considered in our calculations. Even in these cases, the chemical composition in the corresponding ions allows for discussion on their accumulation and the eventual precipitation of these phases. The coupling of in-situ and ex-situ experiments and geochemical modelling is key to understanding the hydrogeochemical and hydroclimatic conditions of soda lakes, evaporite settings, and potentially soda oceans of early Earth and other extraterrestrial bodies.

Stable isotope composition in precipitation and groundwater of Shwan Sub-Basin, Kirkuk governorate, northeast of Iraq

Abstract Stable isotope composition of δ2H and δ18O was investigated in the water resources of the Shwan sub-Basin northeast of Iraq. The study objects conceived the possible factors that affect the stable isotopes’ composition in precipitation additionally to achieve information concerning recharge processes and estimate the groundwater recharge sources. In this study, four precipitation samples were collected at the study area for the 2020–2021 hydrological year. Thirty-two groundwater samples and one surface water sample from Lesser Zab River (LZR) were collected during the same period for two sampling seasons. The results of observed meteorological data show a very small amount of precipitation for the sampling year. This year is considered a dry hydrological year with total annual precipitation of 100.62 mm compared with the previous 40 hydrological years with total annual precipitation of 325.43 mm. The isotopic composition in precipitation was highly varied as it primarily depends on environmental conditions. The depleted values are recognized with the increasing precipitation amount, whereas the enriched values were the most affected by evaporation. Back trajectory analysis revealed that stable isotopes in precipitation are primarily influenced by air masses and moisture sources. The sources of the trajectory that came from the Mediterranean Sea, Arabian Gulf and the Red Sea would lead to variations in the values of precipitation stable isotope. Stable isotope values in groundwater showed that the samples for both periods are located between the East Mediterranean water line (EMWL) and global meteoric water line (GMWL) close to the local meteoric water line (LMWL) indicating that the groundwater recharge is mainly through precipitation. Groundwater recharges by an indirect recharge mechanism from the LZR, based on stable isotope similarity between depleted stable isotopes in groundwater and river water. The estimated groundwater recharge based on weighted oxygen isotopes is about 9.2% of annual rainfall infers that the recharge during the sampling year was very low. The low recharge value experiences dry weather conditions from low precipitation amounts besides increasing evaporation during the current study.

Study on the effect of CH4 dissolution on the microstructure of wax crystal in waxy crude oil

In this work, the influence of the dissolution of methane (CH4) gas on the wax crystal of waxy crude oil and the effect on the rheology of crude oil by dissolved CH4 were studied comprehensively. A self-deign high-pressure micro visualization device was developed to analyze wax crystals before and after gas dissolution. The crude oil from Shengli and Nanyang was tested by the device under various gas pressures. Results showed that the viscosity, maximum shear stress and equilibrium shear stress of Shengli crude oil decreased with the increasing pressure of the dissolved CH4. Due to the supersaturation of dissolved gas, the viscosity, maximum shear stress and equilibrium shear stress of Nanyang crude oil decreased initially and increased with the increasing pressure of dissolved CH4. The change in rheology of the dissolved gas crude oil can be a combined influence of gas pressure and dissolution mechanisms caused by CH4. Additionally, the wax precipitation point of Shengli crude oil decreased at the saturated dissolution of CH4, while Nanyang crude oil showed an increasing wax precipitation temperature. Notably, the wax precipitation area, number of wax particles, and average diameter of wax crystal in both crude oils gradually decreased with dissolution. However, a saturation of CH4 caused a small amount of precipitation of wax crystals in Nanyang crude oil, and the small wax crystals were aggregated to form the large wax crystals. The dissolution of CH4 gas can affect the wax crystallization process, crystallization ability, and morphology of wax crystals that resulted in significant variation in the rheology of crude oil.

Early validation study of the photochemical reflectance index (PRI) and the normalized difference vegetation index (NDVI) derived from the GCOM-C satellite in Mongolian grasslands

ABSTRACT The Global Change Observation Mission-Climate (GCOM-C), launched in 2017, has suitable bands matching the photochemical reflectance index (PRI) definition. It also has the bands for the normalized difference vegetation index (NDVI). The PRI has a unique capability to detect plant stress caused by excessive light and drought. However, no moderate-resolution satellites had suitable bands for the PRI, requiring two narrow bands in green light in the definition. In this study, we conducted the early validation study of PRI and NDVI derived from the GCOM-C satellite and demonstrated those accuracies and characteristics in Mongolian grassland. The Mongolian Steppes (dry grasslands) are widely distributed on the plateau and therefore suitable for satellite validation. It is particularly suitable for the PRI validation because Mongolian grasslands have water stress due to the small amount of precipitation in summer. Therefore, we carried out field campaigns at three study sites in Mongolia. In this study, we found the seasonal pattern of PRI suggesting the potential to detect the water stress of vegetation, which is essential information for informed management of the grasslands. However, the correlation between the satellite-derived PRI and the in-situ PRI was negative because of the dependence of GCOM-C PRI on the soil moisture at sparse vegetation. For the accuracy assessment of PRI, which depends on rapidly changing light and soil moisture in a day, more exact synchronization of in-situ and satellite observation is required. On the other hand, we found that the NDVI derived from GCOM-C was highly accurate: The correlation coefficient (R) between the satellite-derived NDVI and the in-situ NDVI was 0.988 (RMSE=0.052). GCOM-C NDVI has enough similarities with MODIS NDVI in terms of accuracy, spatial resolution, and frequency. For example, we demonstrated that GCOM-C NDVI could detect the phenology with the same or better accuracy than MODIS NDVI. We also demonstrated their difference: the soil moisture dependence in sparse vegetation. The less dependency of GCOM-C NDVI on the soil moisture leads to a better classification of vegetation and non-vegetation in the sparse grassland than MODIS NDVI.

北京山区干旱胁迫下侧柏叶片水分吸收策略

PDF HTML阅读 XML下载 导出引用 引用提醒 北京山区干旱胁迫下侧柏叶片水分吸收策略 DOI: 10.5846/stxb202010072553 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41877152）；林果业生态环境功能提升协同创新中心（市级）项目（CEFF-PXM2019_014207_000099） Leaf water absorption of Platycladus orientalis under drought stress in Beijing Author: Affiliation: Fund Project: National Natural Science( 41877152)；Project of Collaborative Innovation Center (municipal level) for forest and Fruit Industry ecological Environment Function Improvement( CEFF-PXM2019_014207_000099) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:干旱与半干旱地区，水分是限制树木生长的重要影响因子。由于降水稀缺且分配不均，叶片吸收水分是此地区树木吸收和利用小量级降水和凝结水的主要方式。北京山区处于易旱少雨的生态脆弱地带，森林植被经常遭受干旱胁迫，所以对该地区的森林系统而言，叶片直接吸收利用截留的降雨是干旱时期树木获得水分的重要途径。基于野外对比控制试验和室内盆栽模拟试验，选取北京山区的主要造林树种侧柏为研究对象，进行利用天然降雨与模拟降雨试验，研究降雨前后侧柏叶片吸水特征，探究侧柏在干旱环境下如何通过叶片吸水缓解干旱胁迫。结果表明：当侧柏长期处于干旱胁迫状态时，叶片可以利用降雨，从中获益用来缓解树木的干旱胁迫状态；叶片的吸水能力与降雨强度呈正相关关系，与土壤含水率呈负相关关系；重度干旱下侧柏植株在降雨强度为15 mm/h时叶片吸水现象最明显，叶水势变化最大为（1.18±0.17） MPa，叶片含水率变化最大为（8.47±1.00） mg/cm2；当土壤水率高于20.8%时，基本不发生叶片吸水现象。试验结果说明在干旱地区叶片吸水是树木除根系吸水外的重要水分来源方式，并且对干旱地区有效利用短缺水资源，减轻植物水分亏缺具有重要意义。 Abstract:In arid and semi-arid areas, water is an important factor that restricts the growth of trees. Due to the scarcity and uneven distribution of precipitation, the leaf absorption of water is the main way for trees in this area to absorb and use small amounts of precipitation and condensate. The mountainous area of Beijing is located in an ecologically fragile zone prone to drought and less rain. Forest vegetation often suffers from drought stress. Therefore, for the forest system in this area, the direct absorption and use of intercepted rainfall by leaves is an important way for trees to obtain water during dry periods. Based on field comparative control experiments and indoor pot plant simulation experiments, Platycladus orientalis, the main afforestation tree species in Beijing mountainous areas, was selected as the research object. Natural rainfall and simulated rainfall experiments were carried out to study the water absorption characteristics of Platycladus orientalis leaf before and after rainfall, and explore how Platycladus orientalis under arid environment alleviate drought stress by absorbing water by leaves. The results show that when Platycladus orientalis is under drought stress for a long time, the leaves can use rainfall to alleviate the drought stress of trees; the water absorption capacity of leaves is positively correlated with rainfall intensity and negatively correlated with soil moisture content; Under severe drought, Platycladus orientalis plants have the most obvious water absorption phenomenon when the rainfall intensity is 15 mm/h. The maximum change in leaf water potential is (1.18±0.17) MPa, and the maximum change in leaf water content is (8.47±1.00) mg/cm2; When the soil moisture content is higher than 20.8%, there is basically no water absorption by the blades. The test results show that leaf water absorption in arid areas is an important source of water for trees in addition to root water absorption, and it is of great significance for effective use of scarce water resources in arid areas and alleviating plant water deficit. 参考文献 相似文献 引证文献

Nanomaterial Antibacterial Technology in the Design of Antibacterial Fabrics for Sports Clothing

In recent years, nanomaterials have been widely used in sports equipment, and their application in sportswear has also attracted wide attention. This research mainly discusses the application of nanomaterial antibacterial technology in the design of antibacterial fabrics for sports apparel. The method of adding nano-TiO2 to the antibacterial textiles varies with the type of fiber or fabric, and the finishing method also changes accordingly. For chemical fibers, the method of blending spinning is mainly used. By adding nano-antibacterial particles in the spinning solution, the polymer is ejected from the spinneret to make antibacterial fibers. This processing method is characterized by good antibacterial durability. The preparation of antimite finishing agent is mainly the dispersion of nanopowder. The selection of the best dispersant is mainly determined by measuring the change of the volume sedimentation rate of TiO2 after 5 days under different dosage and pH value of each dispersant. Then, the particle size of nano-TiO2 and Ag in different dispersing conditions was tested by TEM, and finally, the best dispersing agent and dispersing process were determined. The optimum of nano-antimite and antibacterial finishing agent is as follows: the dispersing agent is TW-80, the amount of anhydrous ethanol in dispersing medium is 5 times that of powder, the amount of dispersing agent is 1.5 times that of powder, the pH value is 7, and the stirring time is not less than 30 min. In the preparation of nano-antimite and antibacterial finishing agent, nanomaterials were used. The weight of nano-TiO2 powder was 20 grams and that of Ag was 20 grams. The dispersion medium (absolute ethanol) was 100 mL of dispersant. The amount of TW-80 was 30 g, the amount of citric acid was 60 g, the emulsion was very stable, and there was only a small amount of precipitation after being static for 5 days. Considering the characteristics of silk knitted fabric, this experiment uses the exhaustion method in the finishing process to finish the silk knitted fabric. After 50 times of washing, the antibacterial rate of Staphylococcus aureus and Escherichia coli reached 95.13% and 87.44%, respectively. This study provides guidance for the application of nanomaterials in the antibacterial field of sports clothing.

Effect of rolling deformation on microstructure and properties of Cu–Ni–Mo alloy prepared by aluminothermic reaction

The metallic element Mo has almost no solid solubility in copper and can be used as a nucleation particle to refine the grain size and increase the recrystallization temperature of the alloy during solidification. It is expected to obtain copper alloys with good comprehensive properties by reasonably controlling the addition amount of Mo. However, it is difficult to prepare Cu–Mo alloys with uniform structure and there are few related literatures. In this paper, the aluminothermic reaction method, which has the advantages of simple process, low cost, and large size of the prepared alloy, was adopted, and a cluster model with the atomic ratio of Mo and Ni of 1:12 was introduced to design the alloy composition. Here, five alloys with different copper contents were prepared and followed by room temperature rolling with 40%, 60%, and 80% deformation. The results show that the as-cast Cu–Ni–Mo alloys exhibit good formability, have no macroscopic defects and present a small amount of precipitates. With the increase of alloy elements Ni and Mo, the hardness and strength of the alloys increase obviously, while the electrical conductivity decreases gradually. For the rolled alloys, a large number of lamellar deformed structures are formed, the grains are obviously refined, the precipitated phases are broken and the distribution is more uniform, thus the strength and hardness of the alloy increase significantly, the plasticity decrease significantly, while the conductivity changed little. In this study, high-strength samples were obtained, which may be a valuable exploration for the preparation of Cu–Ni–Mo alloy sheets with excellent microstructure and mechanical properties.

Two years study of Aspergillus metabolites prevalence in maize from the Republic of Serbia

Aspergillus species produce numerous metabolites, including mycotoxins, which prevalence in maize is a significant health and economic issue worldwide. The aim of this study was to investigate the prevalence of Aspergillus metabolites in 458 maize samples collected during 2016 and 2017 in the Republic of Serbia. Samples were analyzed by the liquid chromatography-tandem mass spectrometry method. Among the 32 investigated Aspergillus metabolites 9 and 20 were detected in maize samples collected from 2016 and 2017, respectively. The metabolites with the greatest prevalence in 2016 were kojic acid (12%) and 3-nitropropionic acid (10%), while the most commonly detected metabolites in maize from 2017 were kojic acid (54%), 3-nitropropionic acid (44%), aflatoxin B1 (31%), and averufin (29%). Maize growing season in 2017 was characterized by higher deviations of air temperature and a smaller amount of precipitation, which resulted in a greater prevalence of Aspergillus metabolites in maize from 2017 (65%) in comparison to 2016 (23%). Novelty impact statement The main novelty of this study is achieved through the creation of unique database, based on the analysis of 32 Aspergillus metabolites in the great number of maize samples, collected in two different years in the Republic of Serbia. The created extensive database of Aspergillus metabolites is one of the few from this part of Europe, and it will contribute to significant improvement and upgrading of currently existing knowledge and information in this field.

Evidence of foliar water uptake in a conifer species

Foliar water uptake (FWU) is the main mechanism used by herbaceous plants in arid areas to absorb small amounts of precipitation. It has an important ecological and hydrological effect for alleviating plant drought stress. However, it is unknown whether woody plants can absorb water through the leaves when water absorption via roots is insufficient. This study explored whether FWU exists and the FWU conditions in semi-humid rock mountainous areas. Isotopes were labeled to detect FWU under different soil water content (SWC) gradients (3.9–6.5%, 6.5–9.1%, 9.1–15.6%, 15.6–20.8%, and 20.8–26.0%) and different precipitation gradients (1 mm/h, 5 mm/h, 10 mm/h, and 15 mm/h) in simulated precipitation experiments with indoor potted plants. The results showed that FWU occurred in each treatment if the SWC ≤ 21.9% no matter the precipitation amount. Water absorption via FWU increased with the increase of precipitation intensity but decreased with the increase of SWC. The greatest ratios of FWU were 2.77% and 9.52% of precipitation intensity of 1 mm/h and 15 mm/h, respectively, in the 3.9–6.5% treatment. The precipitation absorbed by the leaves can be transported to the xylem or root system along the water potential gradient of leaves–branches–roots. The precipitation with reverse migration in branches and roots increased with the increase of the water potential gradient of leaves–branches–roots. These findings suggest that Platycladus orientalis can uptake water through roots and leaves, effectively alleviating drought stress. This study provides new insights into water use patterns and water migration in trees.

Identification of Extreme Weather Events Using Meteorological and Hydrological Indicators in the Laborec River Catchment, Slovakia

This study used the standardized precipitation index (SPI) and the standardized runoff index (SRI) to analyze dry and humid conditions in the hill-country catchment area of the Laborec River (Slovakia) over a period of 50 years (1970–2019). Analysis of the SPI and SRI over various time scales showed the occurrence of wet periods (index > 1.0) that were associated with precipitation exceeding the long-term norm, and dry periods (index below −1.0), which were the result of small amounts of precipitation. Analysis of the correlation between the SPI and SRI on different time scales revealed that the catchment showed a weaker response to precipitation over short time scales (1 and 3 months) and a stronger response over longer accumulation periods (6, 9, and 12 months). The highest annual correlation coefficient (r = 0.72) was recorded between SRI-6 at the Humenne hydrometric station and SPI-9 at the Medzilaborce meteorological station in the upper part of the catchment area. The strongest annual correlation (r = 0.69) was obtained between the Izkovce and Kamenica stations in the lower part of the catchment area. As shown by the cross-relationships examined over different periods of accumulation of flows and precipitation, hydrological droughts appeared as a result of the occurrence of meteorological droughts with a three-month delay. The conducted analysis showed that in the case of the Laborec river catchment area, there was a strong correlation between the occurrence of meteorological drought and hydrological drought.

The influence of sharply continental climate on immunophysiological parameters of cattle blood

The aim of the study was to research the influence of Central Yakutia's climate (Russia) on immunophysiological status of Kholmogor cattle (n=25). Cold winters, high summer temperatures and small amount of precipitation of the sharply continental climate require breeding of animals with high resistance and productivity. The objects of the study were blood samples. Complete blood count of samples determined that in the stall period leukocyte activity reaches the upper limit of the norm, or exceeds it. The highest values were observed in autumn. According to this, phagocytic activity was 84,11±2,56% and exceeded the norm by 7,3% (P<0,001). The neutrophil index was 8,5±0,2. The white cell count is appear to be increased by 16,8% in spring, as compared with other seasons. Meanwhile, phagocytic activity and phagocytic index in leukocytes are decreased by 24,1% and 16,6%, respectively. There was a significant increase in hematological parameters by 5.7%, 6.6% and 10.4% in January in comparison with autumn (P<0,05; P<,01). Significant decrease of erythrocyte number and hemoglobin level by 14,3% and 8,1%, respectively, were found in autumn compared with such levels in January (P<0,05; P<0,001). A decrease in these indicators occurs with an increase of the leukocytes number to 7,79±0,12х109 /L, which is 14,5% and 26,5% higher than those in the autumn and winter periods. The distinction is significant only for the winter period (P<0,01). Thus, it can be concluded that continuous stall period in conditions of Yakutia's sharply continental climate has a considerable influence on functioning of body systems and leukocyte activity in cattle blood.

Trends in Different Grades of Precipitation over the Yangtze River Basin from 1960 to 2017

Under the background of global warming, the trends and variabilities of different grades of precipitation have significant effects on the management of regional ecosystems and water resources. Based on a daily precipitation dataset collected from 148 meteorological stations in the Yangtze River Basin from 1960 to 2017, precipitation events were divided into four grades (small, moderate, large, and heavy precipitation events) according to the precipitation intensity to analyze the temporal and spatial change trends of different grades of precipitation amounts and frequencies, and the influence of different grades of precipitation on total precipitation was also discussed in this study. The results revealed that small precipitation amounts over the Yangtze River Basin decreased significantly, with a rate of −1.22%/10a, while heavy precipitation amounts showed a significant increasing trend (4.27%/10a) during the study period. The precipitation frequency of small and total events decreased significantly, with rates of −3.86%/10a and −2.97%/10a, respectively. Regionally, from the upper reaches to the lower reaches of the Yangtze River Basin, the contribution rate of small precipitation amounts and frequencies to the total precipitation gradually decreased, while heavy precipitation amounts and frequencies increased. The different grades of precipitation in region II showed a decreasing trend due to its unique geographical features. Furthermore, a Pearson correlation analysis was used to analyze the response of precipitation to long-term air temperature, demonstrating that small and moderate precipitation amounts and frequencies were mainly negatively correlated with long-term air temperature and that heavy precipitation amounts showed a stronger positive correlation with long-term air temperature (13.35%/K). Based on this, the rate of change in heavy precipitation in the Yangtze River Basin may be higher under the background of climate warming, which will lead to greater risks of extreme floods in the future. Evaluating and predicting the trends of different grades can provide a theoretical reference for agricultural production, flood control, and drought mitigation.

Long-term monitoring of the vegetation cover of mountain territories in the GIS for soil and landscape study of territories

Rational use of natural resources and preservation of the environment in good conditions is the basis of the stable state of the ecosystem. Mountain soil erosion is the most common process of degradation. Soil protection from erosion is becoming a global problem in the world, and in Uzbekistan, in particular. Natural conditions of the region create a potential danger of soil erosion. The reason for its manifestation is the misuse of land, non-compliance with necessary requirements for soil protection. In most cases, it is due to the location of homesteads and crops on erosion-prone soils that poorly protect soil from erosion, improper cultivation of soils on arable land, unregulated grazing of pastures, and damage to soil protective plantations. The climate, topography and soils can in some way create a potential danger of erosion, while the vegetation cover reduces the possibility of erosion or completely prevents it. V.V.Dokuchaev [6] has given great importance to vegetation in the problems of soil protection from erosion and a decrease in the flow of atmospheric precipitation. He wrote: “… in the early spring, and after heavy rains in the virgin steppe there are no large streams, while on old-growth fields they run in all directions, storm and foam.” A good vegetation cover sharply reduces the danger of erosion when a great amount of precipitation falls out. With high intensity of rains on slopes with a good vegetation cover, the danger of erosion may be much less than in the case of rainfalls with a small amount of precipitation and with less intensity on slopes with poor plantation or without any.

РАЗВИТИЕ ОСНОВНЫХ МИКОЗОВ НА РАСТЕНИЯХ РАЗЛИЧНЫХ СОРТОВ ВИНОГРАДА В УСЛОВИЯХ ДОНСКОЙ АМПЕЛОГРАФИЧЕСКОЙ КОЛЛЕКЦИИ

Information on the degree of resistance of grapevine plants of various varieties to the main phytopathogens (mildew, oidium) in the conditions of the Don ampelographic collec-tion is given. It was found that the meteoro-logical conditions of 2019 contributed to the depressive development of mildew and the epiphytotic development of oidium. The limit-ing factor for the development of mildew was the increased temperature in June, with maxi-mum values of 37.20C with low air humidity and a small amount of precipitation. Under the conditions of the ampelographic collec-tion, mildew sypmtoms were detected only on plants of unstable varieties: Dimackun, Neizvestnyj donskoj, Puhlyakovskij chernyj, Tavrosi, Cimladar, Cimlyanskij Sergienko, Cimlyanskij chernyj, Shampanchik – 2, Sham-panchik cimlyanskij. The meteorological con-ditions in July - moderate air temperature and high humidity in July, as well as the presence of foci of infection in the ampelocollections were favorable for oidium and contributed to the epiphytotic development of the pathogen, the first signs of which were detected in the phase of the beginning of berry growth. Dur-ing the growing season, despite the protective treatments against powdery mildew, the de-gree of pathogen infestation reached the max-imum values in 88% of the studied varieties. The smallest degree of oidium damage (3.3–3.6 points) was noted in the varieties Tavrosi, Kumshatsky beliy, Kumshatsky chernyj.

Устойчивый к засухе сорт сои Волгоградка 1

The constant intensification of global soybean production is closely related to the breeding and seed production of this crop. Therefore, the research focused on the development of new varieties is quite relevant. The long-term screening at various agricultural backgrounds in dry and relatively favorable years helped identify a high drought resistance of soybean line 214, named Volgogradka 1, which is included in the State Register of varieties approved for use in the Lower Volga region (Russia) and Ural region (Kazakhstan). The variety is of medium-early 33 ripening, tall with a semi-determinant type of growth and a semi-compressed bush shape. It is characterized by high resistance to the main soybean diseases, such as Septoria blight, bacteriosis, mosaic compared to the standard varieties. It develops a high yield of biomass - from 3.29 to 10 t/ha in dry matter, which is higher than the standards (3.58-6.39 t/ha), so it is ideal for use on monofodder, it is a good predecessor that enriches the soil with nitrogen. Due to the high linear growth and, consequently, to the root system deeply developed in the soil, the semi-determinant type of development, the agrocenosis of the variety Volgogradka 1 can effectively use a small amount of precipitation during the growth season and at a low hydrothermal coefficient of the territory. The variety Volgogradka 1 is able to develop from 2.51 to 3.85 t/ha of grain in crops with irrigation due to its increased branching, tallness, resistance to lodging of the stem and a highly branched root system, which significantly exceeds the standard varieties in this indicator. The expansion of Volgogradka 1 sowings under irrigation conditions will increase the yield of soybean and to accelerate its import substitution.

Suppressing precipitation during the reverse transformation from martensite to austenite in a cold-rolled austenite stainless steel

The precipitation behavior and its influence on the tensile properties of cold-rolled austenitic stainless steel, isothermally aged at 750 °C with and without a pulsed electric field, was investigated. During reverse transformation annealing, a large amount of coarse precipitate forms on the grain boundary and grain interior. However, when a pulsed electric field is applied in reverse transformation annealing, only a small amount of precipitate forms in the stainless steel; moreover, the suppressed precipitation effect did not significantly change with an increased annealing time. Simultaneously, the heat treatment comparison test at the almost same temperature clarifies that the pulsed electric field plays a critical role in inhibiting precipitate formation, rather than temperature. The corresponding mechanism reveals that the pulsed electric field disrupts the diffusion of solute Cr and Mo to the precipitate interface, which restricts precipitation growth. Furthermore, the growing precipitate is dissolved to reduce the difference in electrical resistance between the matrix and precipitate. Therefore, the precipitation behavior is strangled in the early stages with the pulsed electric field treatment, and the ductility of the cold-rolled stainless steel is further improved. The pulsed electric field was explored as a novel pathway to suppress precipitation behavior, and the results confirmed that the pulsed electric field was not only effective in impeding the precipitate growth of austenitic stainless steel, but could also be a useful technique to inhibit deleterious precipitation in other metallic materials.

Hydrochemical and operational parameters driving carbonate scale kinetics at geothermal facilities in the Bavarian Molasse Basin

The majority of scales observed at geothermal facilities exploring the Malm Aquifer in the Bavarian Molasse Basin are carbonates. They form due to a disruption of the lime–carbonic acid equilibrium during production caused by a reduction of the partial pressure of carbon dioxide due to pressure change and degassing. These scales are found at the pumps, production pipes, filters, heat exchangers, and occasionally in the injection pipes. In this study, scales of all sections of geothermal facilities were taken. The database consists of scale samples from 13 geothermal pumps, 6,000 m production pipe (sample interval 10 - 12 m), 11 heat exchanger revisions, 2 injection pipes, and numerous filter elements. The samples were analyzed by SEM-EDX, XRD, Raman spectroscopy, and acid digestion to assess their chemical and mineralogical composition. From direct gauge measurements at six facilities during pump changes, scale rates were determined along the production pipes. From indirect measurements (multifinger caliper measurements) scale rates are derived for the region below the pump. Hydrochemical analyses from the wellhead were taken from 13 sites to feed the hydrogeochemical models. The calcite scale rates in the production pipes increase from the pump to the wellhead, where they reach 1.5 - 4.1 mumol/(hbox {m}^2,cdot s). Scale rates below the pump reach up to 1.5 mumol/(hbox {m}^2,cdot s). Given the slight change of hydrochemistry on the rise through the production pipe, where < 4 % of dissolved calcium ions precipitate as scale, scale rates cannot be derived from water samples at the wellhead, but require direct gauge measurements. The small amount of precipitation, together with fully turbulent conditions suggests that all measured rates are controlled by the surface-reaction of calcite crystallization following the nomenclature of Appelo and Postma (2004). Two approaches are used for the modeling of the scale rates. The first approach is based on hydrogeochemical modeling with PHREEQC. Scale rates calculated by this method are one order of magnitude higher than the measured ones. The second approach is based on correlations between the measured scale rates at the wellhead at six facilities and identified thermodynamic scale drivers (Delta log (phbox {CO}_2), Delta total pressure, Delta pH, and hbox {SI}_{{calcite}}). The correlations allow linear regressions which are used for the prediction of the scale rate at the wellhead, along the whole production pipe, and below. The modeling results show that scale prediction based on the new regressions that rely on thermodynamic scale drivers works better than existing hydrogeochemical models, already without implementation of kinetic parameters (hbox {CO}_2-stripping and magnesium inhibition).