Daily Temperature Difference Research Articles

Effects of Temperature and Nitrogen Application on Carbon and Nitrogen Accumulation and Bacterial Community Composition in Apple Rhizosphere Soil.

Malus sieversii grows on the slopes of the Tianshan Mountains in Xinjiang where the difference in daily temperature is significant. In recent years, the rhizosphere soil health of Malus sieversii has been severely impacted by anthropogenic disturbance and pathogenic infestation. The soil nutrient content and soil microorganism diversity are the main components of soil health. Low temperature has negative effects on soil bacterial community structure by inhibiting the accumulation of carbon and nitrogen. However, the effects of temperature and nitrogen application on soil carbon and nitrogen accumulation and the bacterial community composition in the rhizosphere soil of Malus sieversii are unclear. We set two temperature levels, i.e., low temperature (L) and room temperature (R), combined with no nitrogen (N0) and nitrogen application (N1) to explore the response of plant carbon and nitrogen uptake, rhizosphere soil carbon and nitrogen accumulation and bacterial community composition to temperature and nitrogen fertilization. At the same temperature level, plant 13C abundance (P-Atom13C), plant 15N absolute abundance (P-Con15N), soil 15N abundance (S-Atom15N) and soil urease, protease and glutaminase activities were significantly higher under nitrogen application compared with the no-nitrogen application treatment. The bacterial community diversity and richness indices of the apple rhizosphere soil in the N1 treatment were higher than those in the N0 treatment. The relative abundances of Actinobacteria, Rhodopseudomonas, and Bradyrhizobium were higher in the LN1 treatment than in the LN0 treatment. Redundancy analysis (RDA) showed that plant 13C absolute abundance (P-Con13C) and plant 15N absolute abundance (P-Con15N) were the main factors affecting the soil bacterial community composition. In summary, Nitrogen application can alleviate the effects of low temperature stress on the soil bacterial community and is of benefit for the uptakes of carbon and nitrogen in Malus sieversii plants.

Evaluation of the Victorian Healthy Homes Program: protocol for a randomised controlled trial

IntroductionThe evaluation of the Victorian Healthy Homes Program (VHHP) will generate evidence about the efficacy and cost-effectiveness of home upgrades to improve thermal comfort, reduce energy use and produce health...

Frost heaving strain monitoring for lining structure in extreme cold and high-altitude area with FBG strain sensors

Due to the extreme temperature with significant variation in the alpine region, the tunnels in this area are subjected to intense freeze–thaw cycles and frost heaves, which leads to the cracking of the second lining structure. We propose an approach to monitor the frost heaving strain of the second lining and simultaneously measure the thermal strain and applied stress strain of the structure. The Fiber Bragg Grating (FBG) strain sensors are installed on the structure surface to measure the strains caused by the thermal strain and loaded stress. Meanwhile, one FBG temperature sensor is installed on the structure surface to measure the local temperature. Then, the structure thermal strain and applied stress strain are simultaneously measured based on the sensitivity difference for temperature and strain response of the above two measurement methods. The proposed approach is implemented in an alpine region tunnel. The results show that the local temperature is inversely proportional to the total strain and the thermal apparent strain of the second lining. The applied stress–strain of the lining fluctuates in a small range, and the thermal strain from the daily temperature difference incremental demodulation is very close to the daily strain difference. Therefore, the main cause of lining frost damage is the thermal strain due to the local temperature variation, and there is no frost heave occurred in the surrounding rock. Thus, the method is offered to monitor the freeze–thaw cycles and freeze-swelling effects in the extreme cold and high-altitude tunnels.

APPLICATION OF A DAY-NIGHT TEMPERATURE DIFFERENCE ENERGY CONVERTER FOR POWER SUPPLY OF REMOTE AGRICULTURAL FACILITIES

Due to the development of information technologies, microelectronics and control systems, all electronic devices are being minimized. In some cases there is a need for electricity supply to remote agricultural facilities, for example, nomadic apiaries, remote pastures, hunting camps, reindeer herder camps. To solve this problem, the article proposes to use power supply devices based on the day-night temperature difference developed by the authors. (Research purpose) The research purpose is increasing the environmental safety and the reliability of energy supply of autonomous hybrid energy complexes based on renewable energy sources using the device of the daily temperature difference in their construction. (Materials and methods) The article proposes a method for producing energy using the day-night temperature difference. The advantages of the method are the absence of harmful environmental influences, safety for humans and nature, the inexhaustibility of the source, the possibility of using the device anywhere and the simplicity of technical implementation at the modern level. The authors have developed a methodology for calculating the device, its structural elements for electrical strength for autonomous power supply of remote agricultural production facilities. Classical methods for calculating charged containers with a dynamic change in their values at ambient temperature drop have been used in the research. (Results and discussion) Equation presented allows the calculation of a converter for a given capacity of autonomous power supply to remote agricultural production facilities. The advantages of the energy converter device, that is free of radioactive materials, there are the absence of combustion processes, gases, odors or volatile fractions. (Conclusions) The service life of the device can be long, up to hundreds of years. This technology can also be successfully used in the power supply on planets and space objects, for example, on the Moon, Mars, and other planets, where the temperature difference can reach up to hundreds of degrees.

DEVELOPMENT OF AN AUTONOMOUS HYBRID ELECTRICAL COMPLEX WITH A TEMPERATURE CHANGE SYSTEM

Recently, due to the progress in the development of wind generators and solar panels, autonomous hybrid energy systems based on renewable energy sources, which include solar panels, wind generators and power units, have been used for reliable power supply to remote settlements. The vulnerability of a hybrid power plant is its dependence on external climatic conditions and power units require fuel. To solve this problem, it is proposed to supplement hybrid systems with the use of power systems based on the day-night temperature difference. Today, there are no developed circuit solutions for the structure of a hybrid electrical complex based on renewable energy sources with a system of daily temperature difference in its composition according to a scheme with a common AC bus. (Research purpose) The research purpose is developing electric circuits of an autonomous hybrid power plant based on renewable energy sources with a temperature change system taking into account the load and determining the turn-on time of the gasoline generator. (Materials and methods) Considered an electrical complex of hybrid type with four sources of electrical energy, which includes a system of daily temperature difference. (Results and discussion) We have developed schemes for an autonomous hybrid electrical complex based on renewable energy sources with a temperature change system and an alternating current bus for power supply to remote agricultural facilities. The problems of the complex when using several inverters operating on one AC bus in the circuit and ways to solve them were shown. We calculated the loads for each power system and deduced the condition for switching on the gasoline power unit in adverse weather conditions. (Conclusions) It was determined that the developed electrical circuits with a load control unit and a common master generator of a hybrid energy system based on renewable energy sources with a temperature difference power system allow creating an optimal mode of its operation and managing the entire hybrid system more efficiently.

大气气溶胶对北京杨树人工林生态系统生产力的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 大气气溶胶对北京杨树人工林生态系统生产力的影响 DOI: 10.5846/stxb202005281383 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（31872711） Effects of atmospheric aerosols on the ecosystem productivity of a poplar plantation in Beijing Author: Affiliation: Fund Project: Impact Mechanisms of Atmospheric Aerosols on Forest Ecosystem Carbon and Water Coupling 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:大气气溶胶可以影响到达地面的太阳辐射，进而影响植物光合作用和生态系统生产力，乃至区域上的碳收支。为探究北京地区气溶胶对杨树人工林生态系统生产力的影响，利用2006-2009年北京大气气溶胶数据结合北京大兴杨树人工林涡度相关系统监测的辐射、碳通量等数据，分析了气溶胶对散射辐射、光能利用效率（LUE）、生态系统初级生产力（GPP）的影响，并利用通径分析方法探究了气溶胶和生态环境因子对GPP的直接和间接影响。结果表明，北京市气溶胶光学厚度（AOD）具有明显的季节变化特征：春、夏两季大于秋、冬季，夏季气溶胶光化学厚度最大。大气气溶胶显著影响了地表辐射组分以及温度、湿度环境因子，随着AOD从0增大到3，总辐射减小了43.63%，散射辐射增加132.26%，散射辐射比例增大了2.55倍，而相对湿度增大48.52%，日温差增大3℃左右。当生态系统受水分胁迫时，气溶胶对生态系统生产力无显著影响，当生态系统处于非水分胁迫时，杨树人工林生态系统光能利用效率和生产力随着气溶胶浓度增大先增大后减小，当AOD为1.0-1.6时，GPP维持在较高的水平，当AOD>2.5时，GPP显著减小且小于背景气溶胶（AOD<0.4）的GPP。通径分析表明，水分胁迫条件下，气溶胶对杨树人工林生态系统生产力的间接影响很小；非水分条件下，散射辐射对生态系统生产力影响最大，气溶胶可以通过增大散射光施肥效应来增大生态系统生产力。不同的水分条件下气溶胶对杨树人工林生态系统的影响不同，非水分胁迫条件下适宜的气溶胶增大杨树人工林生态系统的生产力，严重的气溶胶污染（AOD>1.5）则导致杨树生态系统生产力下降。 Abstract:Atmospheric aerosols can affect the solar radiation reaching the ground, which in turn affects plant photosynthesis and ecosystem productivity, and even regional carbon balance. With the further development of global change, atmospheric aerosols pollution and drought stress coexist in some regions, and the high frequency and long duration of drought stress may lead to the conversion of ecosystems from carbon sinks to carbon sources. However, little is known about whether atmospheric aerosols can increase ecosystem productivity when the ecosystem are under water stress. Therefore, in this study we investigated the effects of atmospheric aerosols on diffuse radiation, light utilization efficiency (LUE) and the gross primary productivity (GPP) of poplar plantation under different water conditions in Beijing. The direct and indirect effects of atmospheric aerosols and ecological factors on GPP were explored by the path analysis method, which used the atmospheric aerosols data from 2006 to 2009 and combined with the radiation and carbon flux data monitored by Eddy covariance system in Daxing poplar in Beijing. The results showed that Beijing's atmospheric optical depth (AOD) had obviously seasonal change characteristics. The AOD was higher in spring and summer than that in autumn and winter, and the AOD was the largest in summer. The atmospheric aerosols had significant effects on radiation and micrometeorological factors. With the increase of AOD from 0 to 3, photosynthetically active radiation (PAR) decreased by 43.63%, diffuse radiation increased by 170%, and the fraction of diffuse radiation increased by 2.55 times, while the relative humidity increased by 48.52% and daily temperature difference increased about 3℃. When the ecosystem was under moisture stress, the atmospheric aerosols had no effect on the GPP. When the ecosystem was under non-moisture stress, the LUE and GPP of poplar plantation ecosystem increased first and then decreased with the increase of aerosol concentration. When the AOD was 1.0-1.6, the GPP was maintained at a high level. When the AOD>2.5, the GPP significantly decreased and less than the GPP of the background atmospheric aerosol (AOD<0.4). The path analysis showed that the indirect effect of atmospheric aerosols on ecosystem productivity of poplar plantation was not significant under water stress, the diffuse radiation had the greatest influence on the GPP, and the atmospheric aerosols could increase the ecosystem productivity by increasing diffuse fertilization effect under non-moisture stress. Overall, the atmospheric aerosols had different effects on poplar plantation ecosystem under different water conditions. The suitable atmospheric aerosols could increase the productivity of poplar plantation ecosystems, while severe atmospheric aerosols pollution (AOD>1.5) led to a decrease in poplar ecosystem productivity under non-water stress conditions. 参考文献 相似文献 引证文献

Continuous Parameterization of Leaf Area Index and Phenological Phases Within Deciduous Forests Based on Temperature Measurements

The Leaf-Area-Index (LAI) is commonly used to characterize the plant canopy and is a fundamental indication of plant vitality and photosynthetic activity. The forest health status is not only vital for economical reasons, but also has a significant impact on global carbon sequestration. The LAI has a highly dynamic character among deciduous forests and is prone to significant seasonal fluctuations. Accurate continuous LAI measurements do provide valuable information on growth characteristics, but they require considerable measurement effort. In this study, we tested a novel method that would allow for continuous low-effort LAI parameterizations. For our study we used temperature measurements from 2011 to 2019 obtained at two meteorological stations: Station one is an open land station, station two is located inside a forest stand characterized by European beech (measurements were undertaken as part of the ICP Forests program), both are located in Klausen Leopoldsdorf (Austria). We chose the difference in daily maximum temperature between the two sites for our LAI parametrization (LAIpar) since the forest canopy has a significant impact on local radiation conditions. We were able to identify phenological events such as leaf unfolding, the end of leaf growth, and the beginning and end of defoliation by examining at the average course of the year for LAIpar. The resultant LAIpar values were compared to annual values derived from hemispheric photographs taken near the stand temperature sensor. For the years 2011–2017, we found a strong correlation of 0.93 between LAI measures and LAIpar, which dropped to 0.69 after adding the year 2018 and 0.32 after adding 2019. We further compared the phenological events obtained from LAIpar to phenological observations. The impact of forests on their site climate, according to our findings, can be utilized to identify phenological and growth characteristics. The proposed method, however, is not a replacement for conventional LAI measurements.

Проблеми використання мікробіологічних систем у процесі ремісії вуглекислого газу із атмосферного повітря

The initiatives of the Kyoto Protocol, the Paris Convention on Climate Change 2015, the X Prize Prize Fund for Revolutionary Innovation and the announcement by Grand Elon Musk of the invention of the best carbon capture technology with a total budget of $ 100 million suggest that air absorption from carbon. In our opinion, the use of biological photosynthetic crops and technological solutions based on them, which will ensure the absorption of carbon dioxide, is a great prospect, as this process has already changed the Earth's atmosphere in the distant past. In addition, the use of plants will not only absorb carbon dioxide from the atmosphere, but also obtain additional raw materials rich in hydrocarbons and lipids, as well as generate oxygen. This technological solution to the problem of the presence of greenhouse gases establishes the feasibility of using the process of growing unicellular microalgae in photoreactor systems. Energy and technical and economic indicators of functioning of carbon dioxide utilization systems on the basis of standard approaches are determined. The need to create a system of automatic analysis of the state of culture based on the use of artificial intelligence and systems of automatic pattern recognition has been identified. The necessity of integration of the heat accumulator into the structure of the photoreactor for smoothing of daily temperature differences (which in turn minimized energy consumption) and systems of additional lighting and mixing is proved. A number of own designs of photoreactors and further ways of their modernization on use of polymeric films for isolation of working space of photoreactors for the purpose of avoidance of infection of culture are offered.

ОЦЕНКА ВЕРОЯТНОЙ ВЗАИМОСВЯЗИ ОБОСТРЕНИЙ БОЛЕЗНЕЙ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ С МЕТЕОРОЛОГИЧЕСКОЙ ОБСТАНОВКОЙ

Relevance. The analysis of these scientific publications has shown the relevance of studying the problem of the influence of sudden changes in meteorological factors on the functioning of the cardiovascular system, exacerbation of its leading diseases – arterial hypertension, brain vascular lesions, cerebrovascular diseases, angina. Aim: to identify the probable relationship of exacerbations of diseases of the cardiovascular system with the meteorological situation. Material and methods. A sample of data on the daily number of cases of patients 'requests for medical care to the registry of the Voronezh City Polyclinic No. 18 for 2018 was conducted. Results. At a temperature below-200C, which was registered on 27.02.2018, the number of requests for medical care due to hypertension without heart failure is 88 cases, with a diagnosis of brain vascular damage (specified) – 15, with a diagnosis of cerebrovascular disease-16, hypertension with heart failure-2, angina-0. The difference in the average daily temperature of more than 8 0C was recorded in 204 of 365 days. Out of 365 days, the atmospheric pressure drop of more than 6 mm Hg per day was recorded 52 times. Conclusions. The most informative characteristic of the six meteorological indicators taken into account in the study is a sharp drop in atmospheric pressure during the day, with which the number of cases of patients with cardiovascular diseases seeking medical care is statistically significantly correlated.

Performance and Thermal Perceptions of Runners Competing in the London Marathon: Impact of Environmental Conditions.

The 2018 Virgin Money London Marathon (2018 VMLM) was the hottest in the race’s 37-year history. The aims of this research were to (1) survey novice mass participation marathoners to examine the perceptual thermal demands of this extreme weather event and (2) investigate the effect of the air temperature on finish times. A mixed-methods design involving the collection of survey data (n = 364; male = 63, female = 294) and secondary analysis of environmental and marathon performance (676,456 finishers) between 2001 and 2019 was used. The 2018 VMLM mean finishing time was slower than the mean of all other London marathons; there were positive correlations between maximum race day temperature and finish time for mass-start participants, and the difference in maximum race day temperature and mean maximum daily temperature for the 60 days before the London Marathon (p < 0.05). Of the surveyed participants, 23% classified their thermal sensation as ‘warm’, ‘hot’ or ‘very hot’ and 68% ‘thermally comfortable’ during training, compared with a peak of 95% feeling ‘warm’, ‘hot’ or ‘very hot’ and 77% ‘uncomfortable’ or ‘very uncomfortable’ during the 2018VMLM. Organisers should use temperature forecasting and plan countermeasures such as adjusting the start time of the event to avoid high temperatures, help runners predict finish time and adjust pacing strategies accordingly and provide safety recommendations for participants at high-risk time points as well as cooling strategies.

Experimental Investigation and Theoretical Analysis on the Performance of Tube-Sheet Photovoltaic Thermal (PV/T) Collectors

The PV/T collectors realize the simultaneous output of electricity and thermal energy, which are more efficient than the separated photovoltaic (PV) or solar thermal collectors. In this paper, the electricity generation and thermal collection performances of tube-sheet PV/T collector are studied. The main research contents are as follows: an experimental test system of PV/T collector was built to test the electricity generation and thermal collection performances of tube-sheet PV/T at an inlet water temperature of 30°C. Moreover, the flow resistance test was carried out. In addition, the theoretical heat transfer model was established, and the thermal performance was calculated by theoretical analysis. The experimental data showed that the daily average temperature difference between the PV panel and the inlet water temperature was about 22.5°C. The daily average electrical efficiency was about 9.25%, and the daily average thermal efficiency was about 28.67%. The theoretical analysis of the tube-sheet PV/T model was carried out, and the calculated results were close to the experimental results. The main reason for the large temperature difference between the PV panel and water temperature was that the combined thermal resistance between the PV panel and the absorber plate was large, and reducing the combined thermal resistance could reduce the temperature of the PV panel. The effects of solar irradiance, ambient temperature and spacing of row tubes on the performance of thermal collection were analyzed to optimize the PV/T performance.

Environmental Exposure and Childhood Atopic Dermatitis in Shanghai: A Season-Stratified Time-Series Analysis

Background: Childhood atopic dermatitis (AD) is an inflammatory skin disease which sometimes predisposes to allergies. Environmental factors (low humidity, irritants, etc.) are prominent causative triggers of AD. Objectives: This study aims to explore the effects of both meteorological factors and air pollutants on childhood AD, and the modification effects by season in Shanghai, China. Methods: Quasi-Poisson generalized linear regression model, combined with a distributed lag nonlinear model was used to examine the nonlinear and lagged effects of environmental factors on childhood AD from 2009 to 2017 in Shanghai. We also performed a season-stratified analysis to determine the modification effects of environmental exposure by season on childhood AD. Results: There were 1,043,240 outpatient visits for childhood AD in total, at 3 major pediatric hospitals. Low temperature and relative humidity (RH), and high daily temperature difference (DTD) and air pollutants (i.e., NO₂) increased the relative risks (RRs) of outpatient visits for childhood AD in the whole year. In the cold season, an increased risk of outpatient visits for childhood AD was associated with low RH (RR 2.26, 95% CI 1.69–3.02) and high NO₂ (1.11, 95% CI 1.06–1.17). In the warm season, outpatient visits for childhood AD were associated with low temperature (3.49, 95% CI 3.22–3.77), low RH (1.89, 95% CI 1.74–2.06), high DTD (1.41, 95% CI 1.31–1.53), and high NO₂ (1.05, 95% CI 1.03–1.06). Conclusions: This study suggests that environmental exposure may be a key trigger for outpatient visits for childhood AD with apparent seasonal effects. Tailored preventive strategies to avoid environmental triggers of childhood AD should be developed.

Thermal Behavior and Stress Response of Steel-concrete Structures under Solar Radiation

Steel-concrete structures are widely used because of their large space and strong plasticity, but the long construction period, complex splicing process and other factors will make the main body of the structure directly exposed to solar radiation, resulting in temperature changes on the surface of steel structure and concrete structure. In order to obtain the stress changes of steel-concrete structures under solar radiation, two kinds of steel-concrete structures with different support forms were simulated. Under three temperature gradients, the thermal behavior and mechanical properties of two kinds of steel-concrete structures composed of upper steel roof and lower concrete support were analyzed. The results show that there is a linear relationship between the thermal behavior and stress response of steel-concrete structure and the daily temperature difference caused by solar radiation. Under the action of thermal effect, the stress difference between the lower steel frame of the full support structure and the lower steel frame of the support structure on both sides is about 10.7%.

Investigation of temperature gradients in composite girders in the southern region of the black sea

Based on an experimental composite concrete slab-steel beam girder and using a verified finite element thermal model, a case study analysis was performed to evaluate the temperature gradients in composite girders in the Black Sea’s Turkish city Samsun. The case study was conducted based on extreme data records of approximately 50 years. The extreme daily solar radiation and air temperature difference were utilized in finite element thermal analysis for six months that represent the different seasons of the year. The investigated months were the hot months (April, June, and July) and cold months (October, November, and December). The study focused on the vertical temperature gradients (along the vertical centerline of the girder) and the lateral temperature gradients (along the horizontal centerline of the topping concrete slab). The finite element results showed that the maximum vertical temperature gradient occurred in June and was 13.55 °C, while the maximum lateral temperature gradient occurred in December and was 10.11 °C. The results also showed that different behaviors of the positive vertical gradient were recorded for the cold months than those for the hot months. Similarly, the distributions of the positive lateral gradients were different for the two groups of months. These differences were attributed to the different sun movements and solar radiation striking angles in summer and winter.

The association between ambient temperature variability and myocardial infarction in a New York-State-based case-crossover study: An examination of different variability metrics

BackgroundShort-term temperature variability has been consistently associated with mortality, with limited evidence for cardiovascular outcomes. Previous studies have used multiple metrics to measure temperature variability; however, those metrics do not capture hour-to-hour changes in temperature. ObjectivesWe assessed the correlation between sub-daily temperature-change-over-time metrics and previously-used metrics, and estimated associations with myocardial infarction (MI) hospitalizations. MethodsHour-to-hour change-over-time was measured via three metrics: 24-hr mean absolute hourly first difference, 24-hr maximum absolute hourly first difference, and 24-hr mean hourly first difference. We first assessed the Spearman correlations between these metrics and four previously-used metrics (24-hr standard deviation of hourly temperature, 24-hr diurnal temperature range, 48-hr standard deviation of daily minimal and maximal temperatures, and 48-hr difference of daily mean temperature), using hourly data from the North America Land Data Assimilation System-2 Model. Subsequently, we estimated the association between these metrics and primary MI hospitalization in adult residents of New York State for 2000–2015 using a time-stratified case-crossover design. ResultsThe hour-to-hour change-over-time metrics were correlated, but not synonymous, with previously-used metrics. We observed 809,259 MI, 45% of which were among females and the mean (standard deviation) age was 70 (15). An increase from mean to 90th percentile in mean absolute first difference of temperature was associated with a 2.04% (95% Confidence Interval [CI]: 1.30–2.78%) increase in MI rate. An increase from mean to 90th percentile in mean first difference also yielded a positive association (1.86%; 95%CI: 1.09–2.64%). We observed smaller- or similar-in-magnitude positive associations for previously-used metrics. DiscussionFirst, short-term hour-to-hour temperature change was positively associated with MI risk. Second, all other variability metrics yielded positive associations with MI, with varying magnitude. In future research on temperature variability, researchers should define their research question, including which aspects of variability they intend to measure, and apply the appropriate metric. AlternativeAll metrics of temperature variability, including short-term hour-to-hour temperature changes, were positively associated with MI risk, though the magnitude of effect estimates varied by metric.

Estimation of Apple Flowering Frost Loss for Fruit Yield Based on Gridded Meteorological and Remote Sensing Data in Luochuan, Shaanxi Province, China

With the increase in the frequency of extreme weather events in recent years, apple growing areas in the Loess Plateau frequently encounter frost during flowering. Accurately assessing the frost loss in orchards during the flowering period is of great significance for optimizing disaster prevention measures, market apple price regulation, agricultural insurance, and government subsidy programs. The previous research on orchard frost disasters is mainly focused on early risk warning. Therefore, to effectively quantify orchard frost loss, this paper proposes a frost loss assessment model constructed using meteorological and remote sensing information and applies this model to the regional-scale assessment of orchard fruit loss after frost. As an example, this article examines a frost event that occurred during the apple flowering period in Luochuan County, Northwestern China, on 17 April 2020. A multivariable linear regression (MLR) model was constructed based on the orchard planting years, the number of flowering days, and the chill accumulation before frost, as well as the minimum temperature and daily temperature difference on the day of frost. Then, the model simulation accuracy was verified using the leave-one-out cross-validation (LOOCV) method, and the coefficient of determination (R2), the root mean square error (RMSE), and the normalized root mean square error (NRMSE) were 0.69, 18.76%, and 18.76%, respectively. Additionally, the extended Fourier amplitude sensitivity test (EFAST) method was used for the sensitivity analysis of the model parameters. The results show that the simulated apple orchard fruit number reduction ratio is highly sensitive to the minimum temperature on the day of frost, and the chill accumulation and planting years before the frost, with sensitivity values of ≥0.74, ≥0.25, and ≥0.15, respectively. This research can not only assist governments in optimizing traditional orchard frost prevention measures and market price regulation but can also provide a reference for agricultural insurance companies to formulate plans for compensation after frost.

Cooling adsorption type desert air water extractor based on STM32

With dry climate and scarce rainfall, the annual precipitation of desert areas is below 250 mm. The daily temperature difference of desert climate is very significant, the near surface temperature can reach 60 °C to 80 °C in summer and autumn noon, but it can be reduced to below 10 °C at night. If the climate characteristics of the desert can be reasonably used for low-cost water intake, it will provide great convenience to the aborigines and migrants in the desert. Some existing air water intake devices cannot produce good water intake effect due to the low air humidity in the desert. The device uses semiconductor refrigeration to improve the relative humidity of air, so that the adsorption efficiency is significantly improved. Using the low specific heat characteristics of sand to optimize the convection and condensation device, greatly reducing the energy consumption and mechanical failure rate. By using the P, N type semiconductor’s Palp effect, STM32 controls the switching circuit and then controls the voltage direction of the two ends of the semiconductor to realize the switching of refrigeration and heating modes. In this way, low-cost and high-efficiency water intake can be realized in the desert.

Biocrusts enhance non-rainfall water deposition and alter its distribution in dryland soils

Non-rainfall water deposition is an important water resource, critical for the survival of dryland vegetation and soil biota and maintaining dryland water balance. As a “living skin”, biocrusts are attracting increasing attention due to their potentially positive impacts on non-rainfall water deposition. However, the magnitude and underlying mechanisms of biocrust regulation of non-rainfall water are still unclear. In this study, we investigated the non-rainfall water deposition and distribution through continuous weighing micro-lysimeters (0–3, 3–6, and 6–10 cm depths) with bare soil and three types of biocrusts (cyanobacterial crusts, cyanobacterial-moss mixed crusts, and moss crusts) in a semiarid region of the Chinese Loess Plateau. Our results showed that the biocrusts were associated with significantly greater non-rainfall water deposition capacity (~13%–22%) in contrast to the bare soil, and biocrust type strongly influenced the daily non-rainfall water amount in the order: moss crusts > mixed crusts > cyanobacterial crusts > bare soil. Biocrusts were also associated with faster rates of non-rainfall water formation (42%; F ≥ 2.87, P ≤ 0.04), which may be linked to faster nighttime cooling in comparison to the bare soil. Atmospheric vapor condensation was the primary water source for non-rainfall water deposition at the 0–10 cm depth, as opposed to soil vapor condensation. Biocrusts had higher condensation from both sources, and had relatively more deposition from the atmosphere: atmospheric vapor condensation was greater by 114%-143% and soil vapor condensation was greater by 20%–30%. Moreover, >69% of the total non-rainfall water amount occurred in the top 3 cm of soil. The strong biocrust influence in the uppermost centimeters (F = 45.34, P < 0.001) appears to primarily drive the contrasts in non-rainfall water deposition in soils. Furthermore, all of the apparent effects of biocrusts on non-rainfall water deposition and distribution were reasonably attributed to the biocrust influences on soil physicochemical properties, especially the contents of fine particles, organic matter, high soil roughness, daily temperature difference, and moss morphology. In conclusion, biocrusts are associated with much greater non-rainfall water deposition capacity, and change non-rainfall water distribution along with soil depth, implying that they play a critical role in surface soil water balance of dryland ecosystems.

Moss-dominated biocrusts enhance water vapor sorption capacity of surface soil and increase non-rainfall water deposition in drylands

Surface soil vapor sorption and non-rainfall water (NRW) deposition are important sources, and can be highly influential in soil water dynamics and biochemical processes in drylands. As an important living skin, biocrusts have great impacts on soil water balance and play a vital role in water transport at near surface soil, while it remains unclear how biocrusts affect soil water vapor sorption and NRW deposition. In this study, we analyzed and modeled the water vapor sorption isotherms (WSIs) of moss-dominated biocrusts and uncrusted surfaces on loess soil and aeolian sand in the Chinese Loess Plateau. Furthermore, the actual NRW deposition amount of the biocrusts and uncrused soil in field was continuously measured across ~4 months in summer. Our results showed that the vapor sorption amount of the biocrusts was increased by up to 130.5% on the loess and 157.1% on the aeolian sand, and soil vapor sorption capacity of the biocrusts was mostly attributed to their higher contents of fine particles (clay and silt) and organic matter, and the moss morphology in comparison to the uncrusted soil. The Guggenheim-Anderson-de Boer (GAB) model performed well (R2 > 0.97, RMSE < 0.0005 g g−1, E < 13.2%) in simulating WSIs of each treatment. Moreover, the biocrusts enlarged the hysteresis effects by > 23.1%-200.0% as compared with the uncrusted soil at 0–10 cm depth. Additionally, the daily NRW amount of the biocrusts was increased by 19.2% on loess soil and 22.0% on aeolian sand, respectively, which means that the biocrusts significantly increased the NRW deposition capacity at 0–10 cm depth (F ≥ 11.12, P < 0.001). Lastly, the surface soil temperature of the biocrust layer was averagely 1.0–2.3 °C higher than that of the uncrusted soil during daytime, indicating that the biocrust layer enlarged the daily soil temperature differences between the crusted and uncrusted soils, and consequently increased the hourly NRW amount. In conclusion, this study demonstrates the important effects of biocrusts in improving vapor sorption capacity and NRW deposition of surface soil, and these properties in return would further generate feedback impacts on surface soil water and heat balances, enhancing microbial activity within the soil profile and nutrient adsorption from NRW in drylands.

Response of black currant plants to abnormalities in water and temperature regime 2020

The water-temperature regime features in the Central Chernozem region in 2020 were reviewed. The main deviations from the mean perennial values of air temperature and humidity, as well as the precipitation distribution in spring and summer were determined. It was revealed that the distinctive feature of the entire 2020 growing season was significant instability of weather conditions - dry periods with high air temperatures were followed by wet and cool periods. In addition, a high amplitude of the daily air temperature difference was noted, which was significantly exceeding the average perennial values. The phenotypic, biological and physiological responses of black currant plants to anomalies of the water-temperature regime were studied; in particular, monitoring of photosynthetic activity dynamics of black currant plants revealed differences in response depth to damaging effects of adverse weather, depending on the variety and age of the plants. It was found that in black currant plants older than 5 years, the reaction to temperature anomalies is weaker than in three-year-old’s. The reaction depth of phenological, biological and economic characteristics to the effect of water-temperature abnormalities firstly depends on the variety’s genotypic features.