Supply Ratio Research Articles

EDUCATIONAL PROGRAMS OF APPLIED BACHELOR'S DEGREE: MODERN LABOR MARKET REQUIREMENTS FOR PERSONNEL TRAINING

Currently, in the context of education modernization in the Republic of Kazakhstan, the problem of developing educational programs for applied bachelor's degree is becoming very urgent. Based on the analysis of statistical data, the article discusses the need for their implementation and successful functioning in the Republic of Kazakhstan. When analyzing the demand, it is necessary to take into account that the object of this analysis is the approximate ratio of supply and demand in the regional and republican labor markets for a particular specialty or profession, in which training is or will be conducted in a TVE organization. The analysis of sociological studies of international and domestic labor market shows which specialties and professions are most in demand. They are associated with the following areas of activity: nanotechnology, high-tech engineering, biotechnology, sales and marketing, IT technology, services, logistics and transport, medicine, chemical industry, “clean” energy and environment. Training in OPPB is carried out in the areas that combine groups of related professions, specialties and skill levels. The most in-demand areas are: business and management, metallurgy and metalworking, electrical engineering, construction, woodworking, textiles and clothing production, chemistry, physics and biology, printing, interior design, health and hygiene, food processing, agriculture, ecology and environmental protection environment, etc.

Spatial and temporal patterns of supply and demand risk for ecosystem services in the Weihe River Main Stream, NW China.

The rapid development of society and economy in the post-industrial era has exacerbated the spatial matching contradiction between the demand of humans and the supply of the natural environment, while ecosystem service (ES) as a bridge linking nature and society, identifying and assessing its supply-demand risk, was beneficial to ecosystem management and promoted regional high-quality development. Based on the data of multi-source remote sensing and statistics, the supply and demand levels of four ESs, which contain food supply, carbon storage, soil conservation, and water yield in the main stem of the Weihe River in 2000, 2010, and 2020, were quantitatively measured. The spatial and temporal analysis of the supply, demand, and supply-demand ratio of each service was carried out using spatial mapping. The spatio-temporal pattern of the supply-demand risk was recognized by the method of spatial overlay, which means overlaying the supply and demand for material quality, ratio, trend, and the degree of trade-off coordination together between each service. The results showed that (1) the demand for water yield decreased slightly while the demand for food and the supply of carbon storage remained stable. In addition, the supply and demand of other services showed an upward trend. (2) The spatial distribution of the supply-demand ratio of each service shows "high in the south and low in the north" and "high in the east and low in the west," among which the supply-demand ratio of carbon storage is decreasing. (3) The overall supply-demand risk of soil conservation in the study area is low with characteristics of small range and high degree, the risk distribution characteristics of the other services are high in the east and low in the west, and the risk is high in the city center and low around. Otherwise, the supply-demand risk of food supply showed a downward trend, the risk of carbon storage showed an upward trend, the risk of soil conservation remained stable, and the risk of water yield showed a significant downward trend. Based on static supply-demand risk identification, this study assesses supply-demand risk over two periods and analyzes the trend of supply-demand risk changes over time. It clarifies the extent and direction of supply-demand risk shifts, as well as provides improved theoretical support for ecosystem service management.

Nitrogen and Phosphorus Uptake Stoichiometry Tracks Supply Ratio During 2-year Whole-Ecosystem Nutrient Additions

Nitrogen and Phosphorus Uptake Stoichiometry Tracks Supply Ratio During 2-year Whole-Ecosystem Nutrient Additions

Study on optimum energy fuel mix for urban cities integrated with pumped hydro storage and green vehicles

This study proposes an optimum zero-carbon energy dominated fuel mix integrated with pumped hydro storage and green vehicles for a typical city to advance decarbonized operations by 2050 covering residential, commercial, industry and transport sectors. The flexible energy management strategy of the energy fuel and storage mix is proposed to integrate pumped hydro storage, battery vehicles and hydrogen vehicles to maintain power reliability and low-carbon transport. Multi-objective optimizations are conducted to determine optimum ratio composition of the energy fuel mix and sizing configurations of the pumped hydro storage, considering the trade-off between grid integration, energy cost and decarbonisation potentials. The research results show that the optimum energy fuel mix consists of 13% solar photovoltaics, 30% offshore wind power, 25% nuclear energy, 4% waste-to-energy and 28% natural gas. An additional 7% is sourced from natural gas to backup for the power mismatch, resulting in an energy capacity ratio of supply and demand at 1.07: 1. The hybrid pumped hydro and battery vehicle storage reduces the grid exchange energy of the mixed energy city by about 4041.36 GWh, lower by 40.89% than the case without storage. The levelized cost of energy of the optimum energy fuel mix for the decarbonized city is about 0.0846 US$/kWh. Obvious decarbonisation benefits can be achieved with the annual equivalent carbon emissions reduced by about 57.87% compared with the current local fuel mix. The flexible management and optimization model of developing the optimum zero-carbon energy dominated fuel mix integrated with pumped hydro storage and green vehicles provides a possible pathway towards carbon–neutral cities by 2050 covering the building, industry and transport sectors.

L-Theanine Mitigates the Harmful Effects of Excess High-Protein Diet in Rats by Regulating Protein Metabolism.

l-Theanine (LTA) is a non-protein amino acid that contributes to the flavor of tea and can regulate protein metabolism of healthy organisms. However, it is unknown whether it regulates protein metabolism in individuals on high-protein diets (HPDs). Here, Sprague-Dawley rats are fed HPDs with different protein supply ratios and administered a diverse dose of LTA for 40 days. Results show that HPDs with an energy supply ratio from protein >40% impair the liver and kidneys, elevate serum ammonia and urea nitrogen, induce amino acid (AA) catabolism, and promote fatty acid (FA) synthesis via FA-binding protein 5 (Fabp5) and acetyl-CoA carboxylase 1 (ACC1). LTA intervention alleviates HPD-induced hepatic and renal injury and improves serum biochemical indices. It increases hepatic free AA content and inhibits FA synthesis by downregulating Fabp5 and ACC1. It promotes protein synthesis by acting on the mammalian target of rapamycin (mTOR) pathway, thereby alleviating HPD-induced metabolic disorders. This study demonstrates that LTA mitigates kidney and liver damage induced by long-term excess HPDs by regulating protein metabolism.

The Status of Protein Supply to Patients in the Trauma and Surgical Intensive Care Units and the Effects of Feedback on Protein Supply: A Multicenter Study

Purpose: To investigate the status of protein supply by comparing the recommended amount with the delivered amount of protein in patients in the trauma and surgical intensive care units (ICU). Feedback on the protein supply status was presented to each hospital, and we evaluated whether the protein supply had increased to an appropriate level.Methods: In this retrospective observational multicenter study, nutritional information on patients in the trauma and surgical ICUs who had received nutritional support intervention was collected on the 1st Wednesday of each month at two-month intervals from August 2020 to June 2021, from nine domestic hospitals in Korea. Every two months, the nutritional status of each hospital was shared with all hospitals, and each nutritional support team received feedback on protein supply status.Results: There were 246 patients from nine hospitals included in this study, and data over the study period from six protein days, were analyzed. The mean ratios of delivered calories to calculated required calories were 74.0%, 80.8%, 85.4%, 77.9%, 71.3%, and 82.1% on Protein Days 1, 2, 3, 4, 5, and 6, respectively. The mean ratios of delivered protein to calculated required protein were 73.0%, 77.2%, 78.9%, 79.3%, 69.4%, and 89.6% on Protein Days 1, 2, 3, 4, 5, and 6, respectively.Conclusion: Protein supply increased to an appropriate level, feedback on protein supply status may have increased the protein supply ratio and promoted appropriate protein supply and nutritional support for patients in the trauma and surgical ICUs.

Peer-to-peer energy sharing with demand-side management for fair revenue distribution and stable grid interaction in the photovoltaic community

Peer-to-peer (P2P) energy sharing is considered a promising mode for developing the energy market, while the fairness of revenue distribution and utility grid stability is not widely concerned when implementing P2P energy sharing. Demand-side management (DSM) offers flexibility for community residents to participate in the P2P electricity market, which could help improve these issues. In this study, an innovative energy management method that integrates DSM into P2P energy sharing is proposed. It uses a uniform pricing and energy allocation mechanism based on the ratio of supply to demand, to ensure that every household can fairly participate in P2P sharing and enjoy low-cost PV electricity. Some evaluation indexes, i.e., power fluctuation factor and inequality index, are proposed to measure the grid stability and the fairness of revenue distribution. By considering these evaluation indexes and the total cost of the community, a multi-objective optimization approach is used to obtain the optimal scheduling scheme for flexible loads when community residents participate in the P2P sharing. The simulation results indicate that, compared to only P2P energy sharing, the proposed method could reduce the overall cost of the community, power fluctuation factor, and inequality index by 16.8%, 76%, and 62.6%, respectively.

Dynamic simulation and coupling coordination evaluation of water footprint sustainability system in Heilongjiang province, China: A combined system dynamics and coupled coordination degree model

With the development of the social economy, a reasonable evaluation of the sustainable utilization capacity of water resources (WR) is of great significance to alleviate the pressures of water shortages and pollution faced by cities. This study first proposed a water footprint sustainability (WFS) system using system dynamics to evaluate the influence of WR on the environment, economy, and society of Heilongjiang province. The WFS assessment used a comprehensive evaluation method, and the coupling coordination degree model was applied to analyze the coupling coordination of the WFS system. The results showed a fluctuating increase tendency in the total water footprint (WF), blue WF, green WF, agricultural WF, and ecological WF from 2000 to 2019. However, the gray WF, domestic WF, and industrial WF presented a fluctuating decrease. The prediction for the next 30 years indicated that the green WF, agricultural WF, and domestic WF would be stable while the other indicators would increase with time. The blue water shortage degree was greater than 1; however, the green water scarcity index and water pollution degree were less than 1. The economic sustainability of the total WF, blue WF, and gray WF increased year by year; however, the social sustainability of the total WF gradually weakened. In addition, the water supply and demand ratio was below 1. Overall, the regional WFS worsened, and the coupling degree and coupling coordination degree of the WFS system varied in the range of 0.85–0.91 and 0.28–0.31, respectively. This study was of great significance in realizing the sustainable management of regional WR.

Electric energy substitution technology suitable for Tibet

With the increase of population and the development of technology, energy use and pollution emissions continue to increase. While focusing on the development of new energy and renewable energy, electricity will continue to rise in future user energy supply ratios, and electrical alternative technology has become an important way for environmental protection and economic development. This paper takes the Tibetan region as an example to study the electrical alternative technology applicable to the Tibetan region. This paper selects the heat pump technology in the electric energy substitution technology, focuses on the analysis of the principle and unit structure of the heat pump technology, evaluates the performance of the heat pump with the performance coefficient and energy efficiency ratio, and analyses the performance of the heat pump through the T-S diagram and lgp-h diagram. It is concluded that with the improvement of the heating and cooling capacity of the single machine, its efficiency is higher and higher, and its energy-saving effect is also better.

Design of IoT-oriented demand side management model in microgrid via improved metaheuristic framework

The amplified use of power applications by customers is a rising concern in the energy field every day, which leads to an imbalanced ratio of supply and demand. The integration of renewable energy sources and increasing greenhouse gas emission leads to power demand and affects the climate. Shortage of power supply is the major issue in remote areas, to rectify this issue microgrids have become the best solution. Demand side management (DSM) is a very important means for avoiding major deficits from the supply side and improving energy efficiency (EE). The development in the management of energy mainly focuses on minimizing the entire cost of electricity with no limitation in the utilization part and instead, it chooses to lessen the power utilization at peak hours. This paper intends to introduce a sophisticated DSM and controlling scheme for an Efficient Energy Management system (EMS) in Smart Microgrids (SMG). Initially, an optimal cost-efficient EMS operation is established depending on Modified Cat Swarm Algorithm (M-CSA) model and is augmented via time-of-use pricing (ToU) theory. Subsequently, the SMG frequency and voltage are optimally controlled via an improved PID-based Mixed Sensitivity H-infinity (PID-MSH∞) model while functioning in islanded mode. Thus, the developed approach exploits the massive IoT (Internet of Things) aptitudes for ensuring a secure and economic operation of SMG. The energy cost value of the proposed method is 8138.9 which is 33.67%, 37.94%, 35.42%, and 32.27% superior than the traditional approaches such as CSA, IDE, GA and JA. Thus, several analyses are used to demonstrate the created approach's superiority.

Energy Management Systems Using Smart Grids: An Exhaustive Parametric Comprehensive Analysis of Existing Trends, Significance, Opportunities, and Challenges

The integration of widely fluctuating distributed generation (such as photovoltaic panels, wind power, electric vehicles, and energy storage systems) puts the stability of power technologies and distribution structures in jeopardy. However, the fundamental reason is that the electrical supply and demand ratio may not be balanced. An excess or scarcity of electricity in the production or consumption of energy can disrupt the system and cause serious difficulties such as voltage drops/rises and, in extreme cases, power outages. Energy management systems can efficiently increase the balance between supply and demand while reducing peak load during unscheduled periods. The energy management system can handle distributing or exchanging energy among the many energy resources available and economically supplying loads in a stable, safe, and effective manner under all power grid operating situations. This article examines the energy control system’s structure, goals, benefits, and challenges through an in-depth investigation of the various stakeholders and participants involved in this system. This review provides a detailed essential analysis of the operation of several programs used inside the power management system, such as demand response, demand management, and energy quality management. It also includes a summary of the smart grid’s functionalities, features, and related techniques and has discovered research gaps, challenges, and issues. Furthermore, in this article, the authors review the literature on the enabling technologies of smart grid and investigate the energy management system, which is among one of the major emerging technologies and quantifications of the various uncertainty techniques. In this paper, the authors also discussed the comprehensive review of researchers’ efforts and contributions to the smart energy management system in the smart grid. It also compares and evaluates the key optimization approaches utilized to achieve the remarkable aims of energy management structures while also fulfilling a variety of constraints. This comprehensive review will be very beneficial for the new researchers, and it would be a great contribution to the research community.

Green financing role on renewable energy dependence and energy transition in E7 economies

The study aims to inquire how green financing influence renewable energy dependence and renewable energy transition in E7 settings. For this, the DEA estimation approach is used. The findings shown that renewable energy dependence is vital to efficiently extending energy transition in E7 context. More specifically, for renewable energy transition, renewable energy demand and supply ratio, energy consumption to GDP ratio, energy production elasticity, energy consumption elasticity, energy conversion efficiency and R & D investment through green financing are very essential. The findings further explained that there is 5% variance in China, 17% variance persisting in India, 11% variance in Turkey, 7% variance in Russia, 18.6% variance in Mexico and 3.1% per cent variance in Indonesia on a per annum basis for investing green finances in the renewable energy sector for energy transition. Study findings also indicated the E7 economies generated a 24% shift in the study period towards renewable energy from traditional energy production and consumption sources. By this, a significant rise on renewable energy dependence is observed. And it is due to green finance utilization in numerous hydro energy plants residing in E7 countries. The study is novel in its framework and the context. Though past researchers inquired how green finances is linked with economic performance, energy innovation, environmental sustainability and renewable energy sources, the issue has not been investigated based on how the renewable energy dependence generates a shift due to green financing, and how it promotes renewable energy transition in E7 economies as addresed by this research. By this the study is novel and suggests the practical recommendations to initiate effective renewable energy management system in E7 settings.

METHODOLOGY OF FACTOR ANALYSIS OF INCOME OF CITY GAS NETWORK ENTERPRISES

The article considers the method of calculating the influence of a number of factors on the change in income of enterprises of city gas networks. In the process of factor analysis of this indicator, it is recommended to use a number of economic-mathematical models containing factors that characterize the peculiarities of the production and operation process of enterprises of city gas networks. It is proposed to calculate the quantitative influence on the general change of this indicator of such important production and economic factors as the volume of natural gas obtained by the analyzed enterprise, the volume of gas supplied to the network, the volume of gas sold to consumers, the ratio of gas supply to the network, the sales ratio of gas to consumers, the average tariff of a unit of gas sold to consumers, the level of profitability of a unit of gas received, gas supplied to the network and gas sold to consumers. The positive aspect of this approach is that in the process of analytical calculations, indexes of factor indicators are used, and not their absolute values for the case when such data are not available. At the same time, when using this method, it is suggested to follow the rule in which the basic value of the analyzed income indicator is multiplied by the indices of the previous factors of the calculation formula and by the relative growth of the factor whose influence is calculated. To determine the absolute impact of these factors on the overall change in income, it is recommended to carry out a step-by-step factor analysis of this indicator, which is based on the method of chain substitutions. This methodical approach allows, depending on the available initial information and the purpose of the analysis, to calculate the impact on the change in income of a different number of factors (two, three, etc.). The given method of modeling and factor analysis of income makes it possible to decompose this indicator into a number of constituent parts, to present it in the form of multiplicative economic and mathematical models, to determine the absolute and relative influence of the most important factors on the overall change of this indicator for any period of time of the enterprise’s operation, to investigate the regularities of such impact, use the obtained analytical information to substantiate organizational and management decisions regarding further improvement of the efficiency of use of available resources. Keywords: methodology, analysis, income, model, simulation.

Financial Deepening and Small and Medium Scale Enterprises (SMEs) Output in Nigeria

The study examined the relationship between financial deepening (FD) and entrepreneurial growth (EG) in Nigeria for the period of 1986-2021 (36years). This was done in respect to the measures of FD, namely; Ratio of Broad Money Supply to Gross Domestic Product (M2/GDP), Ratio of Private Sector Credit to Gross Domestic Product (PSC/GDP), Ratio of Market Capitalization to Gross Domestic Product (MCAP/GDP) and Ratio of Loans to Small and Medium Scale Enterprises to Gross Domestic Product (LSMSE/GDP) in relation to EG was proxied by Small and Medium Scale Enterprises Output (SMSEO) in Nigeria. The data for the study was sourced from Central Bank of Nigeria (CBN) Statistical Bulletin and World Bank Development Indicators. Then, the stationary and normality tests was carried out, followed by the descriptive statistics, correlation and multiple regression tool of analysis with the aid of E-VIEW 9.0 statistical package. The results showed that M2/GDP, PSC/GDP, MCAP/GDP and LSMSE/GDP have positive and negative significant effect on SMSEO in Nigeria. Hence, the study indicated that FD had a considerable impact on EG in Nigeria. The report proposed that the CBN compel deposit money Banks (DMBs) to extend greater loan facilities to entrepreneurs (private sector), including young graduates and new entrepreneurs, without collateral to enable them to participate in successful businesses. In addition, venture capital firms should be developed to aid in EG, resulting in the production of value and wealth.

Spatial-temporal pattern of ecosystem service supply-demand and coordination in the Ulansuhai Basin, China

• Ecosystem services supply, demand, match degree and coordination dynamics were assessed at basin scale and county scale. • Spatially correlations between influencing factors and coupling coordination degree were investigated by mixed effects model. • Different development policies at county scale according to local dynamic of coupling coordination degree and total ES supply-demand match degree were formulated. Accurately quantifying the spatiotemporal patterns in ecosystem service (ES) 1 1 ES-Ecosystem service. supply and demand and their coupling coordination dynamics, as well as identifying the spatial heterogeneity of the influencing factors for coupling coordination degree are necessary for regional sustainable development. This study used the Ulansuhai Basin in Inner Mongolia Province of China as a case to quantify the supply, demand, and supply-demand ratio of ES (meat production, grain production, carbon storage, water yield, nitrogen purification, and phosphorus purification) from 2000 to 2020. The synthesized coefficient of ES supply (ESCI) 2 2 ESCI-Synthesized coefficient of ES supply. and demand (ESDI), 3 3 ESDI-Synthesized coefficient of ES demand. the match degree of total supply and demand (MD), 4 4 MD-Match degree of total ES supply and demand. and the coupling coordination degree (CD) 5 5 CD-Coupling coordination degree between total ES supply and demand. were taken as indices to explore the relationship between the ESCI and ESDI and the coordination relationships. A mixed effects model was used to determine the spatial heterogeneity response of CD to different influencing factors. The results showed that the total ES supply in the Ulansuhai Basin always met the demand. The area with the highest ESCI was always observed in the Urad Front Banner, while Linhe district had the highest ESDI. Although incoordination improved from mild to superior from 2000 to 2020 at the basin scale, significant spatial variations were observed at the county scale. In addition, the variation in CD was significantly correlated with population, followed by precipitation, and cropland area. The findings comprehensively explore the match and coordination between ES supply and demand, and the spatial heterogeneity of the effects of the influencing factors on CD. Our study can contribute to the formulation of future policies for regional ecological restoration and sustainable development.

Low Nitrogen Fixation Related to Shallow Nitracline Across the Eastern Indian Ocean

AbstractThe eastern Indian Ocean (EIO) is characterized by oligotrophic surface water with abundant dust supply, and thus, this environment is considered to provide a favorable niche for cyanobacterial diazotrophs. However, direct measurements have reported low nitrogen fixation with the dominance of heterotrophic diazotrophs, suggesting that the EIO has unique geophysical features and nutrient supplies controlling diazotrophy, in contrast to those in the Atlantic and Pacific Oceans. In this study, we investigated the activity and community of diazotrophs across the EIO from the Bay of Bengal to the west of Australia. Low nitrogen fixation was observed broadly in the EIO (26.1–75.6 μmol N m−2 d−1), except in the west of Australia (82–286 μmol N m−2 d−1). Although the surface nitrate concentration was low in the EIO, the upward nitrate flux was higher because of the shallower nitracline than that in other oligotrophic oceans. This created widespread conditions with low aeFe:N (supply ratio of aerosol iron to nitrogen), resulting in low nitrogen fixation rates. NifH amplicon sequencing demonstrated the dominance of heterotrophic diazotrophs widely in the EIO, with spatial segregation from cyanobacterial diazotrophs (Trichodesmium, UCYN‐A1). In general, cyanobacterial diazotrophs were abundant in the surface waters of the Bay of Bengal and west of Australia with a high aeFe:N supply, whereas heterotrophic diazotrophs were dominant in other broad regions. This finding demonstrates that the shallow nitracline and associated high upward nitrate supply are key factors for the unique diazotrophy in the EIO.

Effects of supply ratio of chicken manure extract and yeast solution on reproductivity and culture conditions of euryhaline rotifers ( Brachionus plicatilis )

Effects of supply ratio of chicken manure extract and yeast solution on reproductivity and culture conditions of euryhaline rotifers ( <i>Brachionus plicatilis</i> )

Ride-pooling services with differentiated pooling sizes under endogenous congestion effect

This paper analytically examines the ride-pooling market equilibrium under a single or multiple ride-pooling service(s) considering different pooling sizes (number of riders sharing the same vehicle) and endogenous congestion effect of the ride-pooling fleet, and investigates the optimal operation decisions of the service operator(s) regarding the pricing, fleet size, and pooling size in different administrative and market regimes. We firstly examine the scenario with a single ride-pooling service platform given a specific vehicle type for either profit-maximization or social welfare-maximization (different administrative regimes), and then extend the model to the scenario with two differentiated ride-pooling services (given different vehicle types), where the platforms may either compete or cooperate (different market regimes). We have the following major findings. First, the pooling size should be optimized to accommodate the congestion effect and thus simultaneously increase operator’s profit and social welfare. The optimal pooling size balances the marginal pickup time, crowding cost and waiting time cost, and the optimal value is different in different market regimes. Second, the ride-pooling service operator will internalize the congestion effect of providing more vehicles to serve customers, which yields a larger ratio of waiting customers to vacant vehicles (larger demand–supply ratio). Under two differentiated ride-pooling services, in addition to the direct congestion effect of providing more vehicles, its effect on the other operator’s decision will also be internalized by the service operator in concern. Our results also suggest that the competition between platforms tends to reduce the waiting customers-vacant vehicles ratio (demand–supply ratio), while the cooperation between or integration of two operators might yield a large ratio. Third, when the endogenous congestion effect of fleet size is zero, the operator’s profit at social optimum will always be negative when the matching function exhibits increasing return to scale and the marginal operation cost is less than the average operation cost, which means that the social welfare seeking operator has to be subsidized. When the endogenous congestion effect of the fleet size is positive, the ride-pooling service operator may earn a positive profit at social optimum under certain conditions. This study enhances the understanding in relation to users’ reactions to differentiated ride-pooling services, how such services interact with congestion, and how such services can be optimized in different market regimes.

Magnesium stable isotopes as a potential geochemical tool in agronomy – Constraints and opportunities

A sustainable use of soil resources is urgently required to cope with the increasing demand for agricultural products during climate change. To inspire farmers on new soil cultivation methods like subsoil management requires not only yield measurements but also nutrient use efficiency measurements for which analytical tools are still missing. Stable isotopes of the macronutrient magnesium (Mg) are a potential novel subsoil management evaluation tool in agronomy and soil/plant sciences because its isotope ratios shift considerably during Mg uptake by crops. The feasibility of Mg stable isotopes was first demonstrated conceptually by simulating subsoil management on soils with low, middle, and high inventories of bioavailable Mg and crop plants typically cultivated in Germany. This simulation showed that the magnitude of Mg isotope shifts among crops and the exchangeable fraction of Mg in soil is resolvable from the long-term external precision of Mg isotope analyses only if three conditions are met. First, the crop uptake-related Mg isotope fractionation factor should be at the upper end of hitherto published fractionation factors. Second, a high Mg uptake flux of crop plants (e.g., sugar beets) is matched by a low Mg supply from the exchangeable fraction in soil (e.g., sandy soils). Third, subsoil management causes a considerable deepening of the rooting system (e.g., flipping the topsoil root cluster below 30 cm depth). If these conditions are met, Mg stable isotopes can be used in a qualitative manner to identify the main Mg uptake depth, and in a quantitative manner by calculating the Mg use efficiency, defined here as the ratio of Mg uptake versus Mg supply, solely from Mg isotope ratios. This concept was tested for Alfisols on field trials by conducting deep loosening with and without the incorporation of compost. Magnesium isotope shifts in crops and the exchangeable fraction of Mg in soil were mostly unresolvable from the long-term external precision of Mg isotope analyses, which positively tested the Mg isotope concept for well nurtured soils. However, systematic Mg isotope shifts among bulk crops cultivated on and beside a melioration strip were found and attributed to the uplift of isotopically distinct compost-derived Mg on the melioration strip and root restricting layers beside the melioration strip. Given that the Mg isotope composition of the exchangeable fraction barely varies with depth, field-based crop uptake-related ‘apparent’ Mg isotope fractionation factors of winter wheat and spring barley could be determined, which differed from one another (Δ26Mgwheat-rem. exch. = 0.63 ± 0.05‰, Δ26Mgbarley-rem. exch. = 0.37 ± 0.12‰). Nonetheless, the quantitative approach of Mg isotopes was violated when calcareous fertilizer was applied to the field as differences in the isotope-derived Mg use efficiency could be attributed to the uneven distribution of lime-derived Mg with depth. Using Mg stable isotopes as a new geochemical routine for agronomy and soil/plant sciences requires future work focussing on isotope fractionation factors related to crop uptake and intra-plant translocation of Mg – which may depend on species, environmental conditions, and nutrient status – to allow minimally invasive sampling of the soil-plant system and to reduce sample sets.

Impact of water-sediment diversion and afflux on erosion-deposition in the Luoshan-Hankou reach, middle Yangtze River, China

• New empirical formulae for estimating erosion-deposition in Luoshan-Hankou reach. • A functional chart differentiating erosion-deposition types of Luoshan-Hankou reach. • Diversion-afflux states for maximum and equilibrium erosion-deposition in the reach. It is not yet fully understood how water-sediment diversion and afflux along a mainstream reach of a river affect erosion-deposition in downstream reaches. This study focuses on the Luoshan-Hankou mainstream reach of the middle Yangtze River, China. The Luoshan-Hankou reach is vitally important for flood control, being located downstream of three diversion mouths and an afflux outlet along the Jingjiang reach. We establish empirical formulae for sediment transport rates at boundary cross-sections, and hence estimate the amount and proportion of erosion-deposition and its relative increase (termed erosion-deposition promotion) in the Luoshan-Hankou reach. We then propose critical net water supplies from Dongting Lake to Luoshan-Hankou reach based on maxima and equilibria of erosion-deposition and its promotion. It is found that net water supply partly drives erosion-deposition in the Luoshan-Hankou reach where maximal proportions of deposition and deposition-promotion may be approximated by 0.01 c -37.67 and 0.01 c -37.67 + c -1, in which c is a dimensionless parameter representing the erosion-deposition condition in Luoshan-Hankou reach for no water-sediment exchange. At Zhicheng hydrological station, the critical ratio of net water supply to overall water discharge is 0.418 c -33.33 -1, and critical net water supply ratios for equilibria of erosion-deposition and its promotion are −1 (or c -33.33 -1) and 0 (or (0.06 + 3.257 c 54.61 ) -1 -1). A chart based on net water supply and c is devised representing four types of erosion–deposition and its promotion for the Luoshan-Hankou reach. Historical data over the past 65 years demonstrate that erosion-deposition and its promotion in the reach are respectively governed by c and net water supply; there is a remarkable shift from alternate erosion-deposition to monotonic erosion whilst the erosion-deposition effect remains consistent. The foregoing are in agreement with observed data, and comparable with data for the Jingjiang reach (affected by the three water-sediment diversion mouths). Satisfactory flood-control conditions in the convergence zone between the Yangtze mainstream and Dongting Lake accompanied by increasing erosion in the Luoshan-Hankou reach are predicted for the future.