Abstract: The so-called groundwater quality simulation is to study the spatial and temporal variation law of the concentration of a certain soluble substance (element or other component) when it is dispersed and transported by simulation method, to predict the instantaneous dynamics and expansion range of polluted groundwater, and to provide scientific basis for formulating reasonable and effective prevention measures. In recent years, the environmental hydrogeology survey results of some provinces, cities and regions in China show that the groundwater in most cities in China has been polluted to varying degrees. This situation directly affects industrial and agricultural production and people's health. However, in the past, environmental hydrogeology work was mostly limited to surface investigation, lacking quantitative and predictive evaluation research. Monitoring groundwater quality dynamics and forecasting the development trend of groundwater pollution is one of the main tasks of groundwater pollution investigation and research. Relevant information shows that some countries in the world have already carried out this research and established a predictive groundwater quality model. Among them, the United States has established 22 material transport models and 5 heat transport models; France has established 5 models of material transport and 4 models of heat transport. The following countries have only established material transport models: 7 in Israel; 2 in the UK; 2 in Canada; 1 in West Germany and 1 in Japan. Therefore, we believe that the study of groundwater quality simulation experiment, which is still blank in China's scientific field, has become an important subject that needs to be carried out urgently to ensure the four modernizations and people's health. The hydrogeological conditions and dynamic characteristics of groundwater resources have been comprehensively analyzed and studied. It points out that the continuous exploitation of groundwater resources in 2018 … Read More

Abstract: Taking Anyang City, Henan Province, China, as an example, this paper mainly discusses the ecological role of artificial wetlands in water-scarce cities, elaborates the important ecological functions of artificial wetlands in urban ecosystems, and demonstrates the practical experience of artificial wetland renovation and sponge city construction through specific cases, such as the wetland redevelopment project of Magnuson Park in the United States. Read More

Abstract: As the society pays more and more attention to environmental protection and sustainable development of, green education has gradually become an important topic in the field of education. This study addresses the impact of green education on secondary school students' green thinking and behavior in depth. Using a questionnaire survey, this study finds that formal green education in schools helps to motivate secondary school students to pay extra for purchasing environmentally friendly products, and reinforces the green idea of "reuse, reuse many times". Informal green education helps secondary school students to establish the idea of "green living and eco-friendly shopping". In addition, there is no significant difference between the choices of green behaviors of secondary school students in public and private settings, and there is no significant difference between the choices of green behaviors of secondary school students in public and private settings. These findings are of great theoretical value in understanding the influence of green education on secondary school students' green thinking and behavior. Read More

Abstract: In order to study the influence of effective stress on the sensitivity of coal permeability stress, three groups of low permeability dense coal samples were selected in the range of confining pressure of 2 MPa ~ 4 MPa. Under the influence of single factor of effective stress, the cross-contrast seepage experiment of coal samples under different effective stress conditions was carried out by using steady seepage method, and the variation characteristics of effective stress sensitivity of coal samples were systematically analyzed by using permeability damage rate and permeability curvature. The results show that: (1) under various confining pressures, with the increase of effective stress, the damage rate of coal permeability decreases according to the law of negative exponential function, and the greater the effective stress, the greater the damage rate of coal permeability; (2) The effective stress is constant, the smaller the confining pressure is, the greater the curvature of permeability is, the greater the influence of effective stress on coal seam permeability is, and the stronger the sensitivity is. Read More

Abstract: Taking the molybdenum tailings produced after beneficiation of the Luanchuan molybdenum mine in Henan Province as the research object, the effects of alkali ore ratio, calcination time and calcination temperature on the activation effect of molybdenum tailings, and the effects of leaching time, leaching temperature and leaching liquid-solid ratio on the silicon leaching rate were investigated by using sodium hydroxide alkali melting-water leaching process. The results show that the optimal conditions for activation are as follows: alkali-ore ratio 1.2:1, calcination time 1 h, calcination temperature 700°C. Under these conditions, the concentration of alkali fusion leaching (Si+Al) of molybdenum tailings is 1.396 mg/L. The optimum conditions for leaching are as follows: leaching time 7 h, leaching temperature 45°C, leaching liquid-solid ratio 6: 1. Under these conditions, the leaching rate of silicon can reach 26.88%. During the calcination process, the crystal structure of quartz is destroyed, and sodium hydroxide reacts with quartz at high temperature to form soluble silicate, which improves the activity of molybdenum tailings and increases the dissolution of silicon Read More

Abstract: Luanchuan is surrounded by mountains, most of the area belongs to the mountain terrain, there are more metal mining areas, retained many large and small tailings ponds. The mining area is one of the seven major sources of groundwater pollution, that is, the tailings reservoir area has the risk of groundwater pollution. At present, the groundwater environment is investigated and evaluated, mainly the design and implementation of the groundwater environment monitoring well in the tailings reservoir area. Firstly, four monitoring Wells are built in the tailings pond. Monitoring well construction includes drilling core, reaming, pipe filling gravel, water sealing and well washing; Finally, a pumping test was carried out to determine the groundwater recharge and aquifer richness in the tailings reservoir area. The unit water inflow q of the aquifer in the area is 0.67L/s·m. After the completion of the monitoring well construction, it is determined whether the groundwater environment in the study area is polluted based on the experimental analysis. Once the water around the tailings pond is polluted, it is very likely to affect the drinking water source of the downstream villages, and the residents will seriously endanger their health after drinking. Read More

Abstract: The analysis shows that using regime classification for individual phases, it is possible to obtain a more reliable design scheme for two phase flows. In contrast to the flow structure, the concept of mode is more accessible for calculating an industrial pipeline. In this case, transient processes can be determined and calculated. The analysis shows that in field conditions it is very difficult to determine transition boundaries for flow structures. However, taking into account the structural approach, it is very difficult to determine the boundaries of the flow, and based on the laws of hydrodynamics of a homogeneous liquid and gas, it is possible to determine the transition of one regime to another using the Reynolds number. This technique is based on the theory of the great Russian scientist Academician A.P. Krylov. Let us note that this theory has not yet lost its specialty in the fishing industry. Based on numerous data, a method for calculating the gas-liquid mixture in horizontal pipes is proposed. Based on the laws of homogeneous liquid and gas, an equation for the distribution of speed, flow and pressure loss in a pipeline is obtained. The analysis shows that, based on the laws of homogeneous liquid and gas, it is possible to propose a method for calculating the hydrodynamic parameters of a two-phase flow, such as liquid and gas in a round pipe. This technique is based on the theory of Academician A.P. Krylov, which characterizes the reliability of this technique. Read More

Abstract: In order to study the influence of cavity on surrounding rock stability,a tunnel in Yunnan Province was taken as the research object,and the problem of voids in the tunnel was qualitatively analyzed and evaluated.FLAC3D was used to simulate and analyze the distribution location of voids,the number of voids,and the influence of voids in the excavation process.The influence of plastic zone,stress field and displacement field on the stability of surrounding rock was evaluated.The results showed that the onsite measured data were consistent with the simulation results.When the cavity existed at the top and side,bottom and side,the cavity at the side had a greater impact on the tunnel than the cavity at the bottom and top,and the cavity at the bottom had a greater impact than the cavity at the top.When the annular cavity was encountered in the excavation process,the displacement value of surrounding rock decreased under the support of primary lining and bolt,and the reduction range of arch bottom was greater than that of arch top.This study can provide a certain reference for the excavation stability of similar tunnel projects with cavities. Read More

Abstract: In view of the increasingly high degree of mechanization of coal mining and the increasing difficulty of mining, seismic exploration based on ground seismic method is not applicable in coal seams. Therefore, a trough wave seismic detection method of geophysical prospecting method is introduced into coal mine tunneling roadway, which provides a method and means for ascertaining the geological anomalies in front of the tunnel face. Combined with modern geological information, seismic data can be visualized and interpreted by geological personnel, which can identify geological anomalies such as faults, collapse columns, goafs and water inrush areas in the process of coal seam excavation and mining, and reduce the occurrence of disasters and accidents in the mining process. Read More

Abstract: Corrosion problems are widely found in various industries, and corrosion inhibitors also play an important role in various corrosion environments, especially in oil exploration. However, as China's oilfield exploitation enters a high water injection period, the mining environment is becoming more and more harsh, and the requirements for oilfield corrosion inhibitors are getting higher and higher. At the same time, various scaling phenomena have emerged one after another in the process of oilfield exploitation. The corrosion and scale inhibitor with good scale inhibition reflects its advantages, and the integration of corrosion and scale inhibition has become a major tendency in the development of corrosion inhibitors. This review introduces different corrosion inhibitors, and focuses on the research on corrosion inhibitors at home and abroad. At the end of the review, it puts forward views on the future development direction of corrosion inhibitors. Read More

Abstract: The thinning of the arable layer causes soil quality degradation, seriously affecting crop growth and even threatening national food security. This article focuses on the problems and needs of poor timeliness, high cost, and inability to dynamically warn about the thinning of the tillage layer in black soil farmland, and conducts research on corresponding warning methods. Based on daily rainfall data, the percentile method is used to calculate the threshold for erosive rainfall event driven warning. Based on erosive rainfall event driven coupling of external soil erosion stress meteorological elements and influencing processes, as well as the connotation of geographic events, the concept definition of geographic events for thinning warning of arable layer thickness is given. The semantic description and discovery method of geographic events are provided, and geographic event driven rules and the technical process of thinning warning of arable layer thickness are formulated. There is a significant correlation between rainfall and topsoil thickness, with a correlation coefficient of 0.83. A soil thickness thinning warning simulation was conducted based on the daily rainfall data of Hailun City, Heilongjiang Province in 2020. On June 14, 2020, when the daily rainfall exceeded the event threshold, an automatic warning for thinning of the plow layer was triggered, achieving a dynamic warning process for thinning of the plow layer. The research results indicate that this method is helpful in solving the problem of thinning warning of the cultivated layer thickness in black soil farmland, and can provide technical support for the quality construction, protection, and management of black soil farmland. Read More

Abstract: Skin is the body's first defense against external injuries, in daily production life, skin as an organ is easily injured, forming surface trauma. Wound dressings play a pivotal role in the process of skin wound repair. In order to meet the clinical demand for wound dressings, functional wound dressings with excellent biocompatibility, excellent antimicrobial activity, absorption of wound exudate and promotion of wound tissue repair have been developed. We categorize wound dressings into traditional medical dressings and novel medical wound dressings, and review the wound dressings included in the latter in terms of types, preparation methods, and effects. In future treatments for chronic wounds, researchers will integrate and utilize the antimicrobial activity, biocompatibility, and mechanical properties of wound dressings to investigate advanced wound dressings with multiple functions. Read More

Abstract: China is currently facing various water problems such as water scarcity, water pollution, floods, and loss of aquatic habitats. These water problem syndromes are systemic and comprehensive problems that urgently require a more comprehensive solution. The proposal of the "Sponge City" theory is based on this background. According to Jiaozuo "7.20 extremely heavy rainstorm Event", based on the sponge city theory, citing ecological principles, and following ecological principles, this paper discusses the ecological transformation of the Xin River to achieve the purpose of artificially rebuilding the river ecosystem. Read More

Abstract: At present, the sustainable utilization of fishery resources has become a hot topic in the study of fishery sustainable development, and it is also an important research content in the theory and practice of sustainable development. In the 21st century, in addition to climate change and other factors, a large number of artificial Marine economic activities have caused great damage to the ecological environment of the habitat of fishery resources. At present, the protection of fishery resources is imminent, and to protect fishery resources, we need to conduct a good survey of existing fish. Based on the survey technology of fish resources, this paper introduces the traditional survey technology and modern fish resources survey technology in detail, analyzes the existing problems and countermeasures, and provides reference for the study of fish resources survey. Read More

Abstract: Mastering the distribution of selenium in soils is vital for the development of selenium-enriched industries. This study focuses on Xintang Township in Enshi City, western Hubei Province, known for its selenium-rich soils, analyzing 2,469 soil samples to understand selenium distribution and its influencing factors. Key findings include: 1. Selenium content in surface soils ranges from 0.14 to 25.74 mg/kg, with an average of 0.81 mg/kg, and 86.23% of the area has selenium-rich soils. 2. Soil selenium content is significantly influenced by the parent material, especially soils from the Permian black rock series, showing higher selenium levels with an enrichment factor of 3.74. 3. Soil type impacts selenium distribution, with yellow lime soil and brown lime soil showing high enrichment factors of 3.94 and 2.62, respectively. Read More

Abstract: Since the 1990s, with the implementation of the reform and opening up policy, the rapid development of China's economy, the progress of urbanization is getting faster and faster, and as one of the urban wastes, the treatment of domestic waste has also attracted more and more attention. The municipal solid waste incineration treatment, and the heat generated after combustion is used to generate electricity, referred to as "garbage incineration power generation", because this way can make the waste to reduce, harmless, and can be converted into part of the electricity, because it is widely used in the treatment of municipal solid waste by local governments. Due to the shortage of government funds, most domestic waste incineration projects are implemented in BOT mode. Waste incineration power generation projects are often a large investment, for investors, the recovery period is long, the technical requirements are high, the investment agreement signed with the government is also very complex, coupled with the imperfect supporting laws and policies in China, so that the process of waste incineration power generation projects have many problems and risks, through the operation, construction, investment and other links. Based on the theoretical content of risk management in project management and combined with practical cases, this paper puts forward countermeasures and suggestions for important risks in the project, so as to analyze and discuss the risks of garbage incineration BOT project. Firstly, this paper investigates and collates the research situation of relevant projects at home and abroad, and systematically summarizes the project research results from three aspects, namely, BOT risk management of waste incineration power generation projects, BOT model of projects and BOT project risk research. Secondly, the multi-case study method was used to analyze the risks of 3 typical waste-to-power generation BOT projects, collect risk factors, construct risk … Read More

Abstract: Gas is a gaseous geological body and a product of geological genesis. The geological structure and the historical evolution of coal bearing strata control the generation conditions of coal-bed gas and the preservation conditions of coal-bed gas subjected to depression, uplift, compression and tension in previous tectonic movements. The geological conditions that control the occurrence of gas disasters determine the state of gas occurrence, gas content, gas pressure, gas emission and the risk of coal and gas outburst in coal seams. There are obvious characteristics of zoning and zoning. Gas occurrence and gas outburst are controlled by various geological factors, and geological structure plays a decisive role in coal and gas outburst. Studying the influence of geological structure on gas occurrence law and gas outburst and mastering gas geological law can achieve the purpose of gas prediction and gas control. This paper discusses the influence of fold, fault and sliding structure on gas occurrence, and discusses the influence of geological structure on gas outburst from three aspects of coal seam gas pressure, in-situ stress and coal body structure. It can provide a basis for the prediction of gas outburst and has important significance for the prevention and control of gas accidents in coal mines. Read More

Abstract: Addressing the challenge of suppressing voltage and frequency oscillations during mode transitions and achieving smooth transitions between grid-connected and islanded operation modes in peer-to-peer structured optical storage microgrids, is an urgent technical issue. This paper proposes a control strategy for smooth mode transitions based on numerical soft starters, focusing on the dynamic characteristics of voltage and frequency in optical storage microgrids during grid-connected and islanded operation modes. The numerical soft starter smoothens the input reference value of the current inner loop, reducing the impact of transient surge current on the current inner loop during transitions, thus ensuring the oscillations of bus voltage and frequency during microgrid mode transitions. In islanded operation mode, a VSG control strategy is introduced by constructing a small signal model to analyze the frequency response characteristics of the system under different inertia and damping characteristics, setting appropriate control parameters to provide strong frequency support for the system during islanded operation. Finally, an optical storage microgrid system is established using Matlab/Simulink to conduct simulation experiments under conditions such as grid-connected/islanded mode transitions, load fluctuations, and sudden changes in photovoltaic output power, validating the effectiveness of the proposed smoothing strategy. Read More

Abstract: The study of coalbed methane (CBM) seepage within dual-porosity medium constitutes a significant research endeavor in the field of geology and coalbed methane reservoir engineering. This research delves into the complex dynamics governing CBM flow through porous coal matrices within dual-porosity systems. Employing advanced methodologies including numerical simulation and experimental analysis, this investigation aims to elucidate the mechanisms underlying CBM migration, encompassing diffusion and adsorption phenomena within the coal matrix, as well as interactions with adjacent strata. The outcomes of this study carry substantial implications for optimizing CBM extraction techniques and promoting the sustainable utilization of this invaluable natural resource. Read More

Abstract: A farmland in the southern suburb of Jiaozuo City was selected As the research area, 36 surface soil samples were collected, and the contents of heavy metals (Cd, Cr, Zn, Ni, Cu, Pb and As) in soil were determined. The ecological risk of heavy metals in soil was assessed by single factor pollution index method, Nemerow comprehensive pollution index method and potential ecological risk index method. The results showed that the average contents of Cd, Cr, Zn, Ni, Cu, Pb and As in the soil were 1.25, 62.96, 79.00, 28.91, 22.60, 11.02 and 42.25mg/kg, respectively. Cd and As in soil exceeded the standard, and the exceedance rate was 92.75% and 83.5%. The single factor pollution index was Cd>As>Cr>Zn>Cu>Ni>Pb from large to small, and Cd reached the moderate pollution level. The results of Nemerow comprehensive pollution index showed that Cd reached the level of severe pollution, and As was the level of severe pollution. The evaluation results of potential ecological risk index showed that Cd was at the moderate risk level, As was at the slight risk level, and other heavy metals were at the slight risk level. The comprehensive potential ecological risk index RI value was 13.87-266.80, which was at the slight to moderate risk level. Cd and As were the main risk sources of soil heavy metals, and their contribution rates to the comprehensive potential ecological risk index were 79% and 18%, respectively. Read More

Abstract: The health implications associated with the consumption of food contaminated by heavy metals (HMs) and metalloids, specifically arsenic (As), remain a global concern. This study aimed to investigate the occurrence of HMs and As in various food categories, including cereals (rice, wheat, and corn), vegetables (leafy greens, edible mushrooms, kale, solanaceous fruits, and tubers), and legumes (peanuts, soybeans, and mung beans), commercially available in Jiaozuo city. Additionally, we sought to assess the potential health risks posed to human consumers by the ingestion of these three food categories. To evaluate the extent of contamination, both single-factor analysis and Nemerow's synthetical pollution index were employed. The assessment of health risks was conducted using the health risk model recommended by the United States Environmental Protection Agency. Specifically, cereals exhibited exceedance rates of 2.60% for Cr, 44.16% for Hg, 3.90% for Ni and 3.90% for Pb. Notably, vegetable samples exhibited exceedance rates of 0.90% for Hg and 17.12% for Zn. Among legume samples, exceedance rates were 16.98% for Cr, 75.47% for Ni and 13.21% for Pb, while other HMs and As remained within standard limits. The cumulative contamination level of HMs in each diet category ranked in the order of legumes > cereals > vegetables. Based on the daily intake of cereals, legumes and vegetables, the Total Target Hazard Quotient for HMs in both children and adults exceeded a value of 1, indicating the potential noncarcinogenic risks (non-CRs) associated with consumption of these three dietary categories. Conversely, the CR induced by HMs through the consumption of these foods remained within acceptable levels for both children (8.92×10-6) and adults (2.65×10-6). It is noteworthy that the health risk posed by HMs through food consumption was more pronounced in children than in adults. Read More

Abstract: The ecosystem water use efficiency (WUE), which is the ratio of carbon gain (gross primary productivity, GPP) to water consumption (evapotranspiration, ET), is widely regarded as a crucial link in coupling the carbon and water cycles of terrestrial ecosystems on a global scale. The estimation of cropland WUE is considerably important for improving agricultural management, simulating the carbon–water cycle processes of croplands, and enhancing crop yields. Currently, the estimate of WUE primary relies on the modeled GPP and ET data. However, differences in model structures and parameter uncertainties cause remarkable differences in the accuracy of the estimated WUE among different models. The eddy covariance technology enables the continuous observation and research of carbon and water fluxes at a site scale, ensuring simulation accuracy. However, the technology is constrained by its limited spatial coverage. In this study, we integrated data from 20 global cropland sites and built 7 machine learning models based on remote sensing to directly estimate cropland WUE, thereby expanding the spatial scope of WUE simulations, omitting the simulation process for obtaining GPP and ET, and ensuring a certain degree of precision. Results show that, compared with other machine learning algorithms, the ensemble learning model has the strongest ability to reproduce cropland WUE, with a determination coefficient of 0.90 and a root mean square error of 1.54–1.75 . These results indicate that a combination of machine learning methods and remote sensing can reasonably simulate the WUE of agricultural ecosystems. Read More

Abstract: Trace element manganese is an essential element for human body, but the high concentration of manganese will adversely affect human health and all aspects of daily production and life. Elevated levels of manganese directly affect the color of the water, making it more prone to discoloration when used to wash clothes or dishes. Prolonged exposure to this water may cause organ damage. The groundwater in the study area is sampled and tested, and the test data is analyzed. The main results are as follows: the groundwater manganese ions in the study area exceed the standard, and the concentration of manganese ions in the southwest mountainous area is higher than that in other areas. In southwest China, due to the planting of a large number of tea trees, the main source of manganese in groundwater is manganese-containing fertilizer, and sewage recovery and treatment should be considered in combination with slope rainwater recovery equipment. In other fields, the manganese in groundwater is mainly from domestic sewage. The combined treatment of manganese ions in groundwater by chemical method and contact oxidation method is considered. Read More

Abstract: The industrial transformation is an important path for China to continuously advance towards the goals of carbon neutrality and peak carbon emissions. It is also an essential route for China's industries to move towards higher stages of development. The industrial transformation in China carries multiple significances, yet it is also confronted with various challenges. These include significant energy demands, insufficient levels of manufacturing capabilities, and economic disparities among different regions, all of which hinder the development of a low-carbon economy in China. To promote the transformation of Chinese industrial enterprises under the guidance of the new development philosophy, several key measures should be taken. Firstly, it is essential to establish a diversified energy supply system and vigorously develop the green energy industry. Secondly, efforts should be made to develop a green and low-carbon new industrial system while gradually phasing out industries with excess capacity. Thirdly, policies conducive to low-carbon transformation should be implemented, alongside the improvement and development of carbon financial markets and the strengthening of the role of technological innovation in driving industrial transformation and upgrading. Read More

Abstract: Impervious surface is an important indicator for analyzing urban expansion, measuring the degree of urbanization, and characterizing the urban ecological environment. Accurately extracting impervious surface data is of great significance to regional economic development, disaster prediction, ecological restoration, and environmental assessment. In this paper, using multi-spectral, synthetic aperture radar (SAR) and surface temperature retrieval (LST) data, from the four perspectives of spectral features, time series features, SAR texture features, and coherence features, an index feature that highlights impervious surface information is constructed. The model generates a 10m impervious surface product in the urban area of Shaoguan, and verifies the accuracy of the real sample based on the 0.8m GF-2 data in the same period. The results indicate that the overall accuracy of extracting impermeable surfaces in the study area is 94%, with a Kappa coefficient of 0.92. The multi feature fusion random forest model combining optical data and SAR data has high extraction accuracy and applicability in the mountainous areas of southwestern China, which improves the misclassification of bare land and other land types as impermeable surfaces. Read More

Abstract: A total of 41 surface soil samples were collected from the farmlands along Guangliji River and Jianggou River in Jiaozuo area, and 7 heavy metals such As Cr, Cu, Zn, AS, Cd, Pb and Ni were determined by ICP-MS (Varian-820).The soil accumulation index method, single factor pollution index method, Nemerow comprehensive pollution index method and potential ecological risk index method were used to evaluate the pollution status and potential ecological risk of heavy metals in the study area. The results showed that compared with the risk screening value (pH>7.5) given in the "Soil Quality Standard for Soil Pollution Risk Control of Agricultural Land" (GB15618-2018), Cd in farmland soil along the two rivers exceeded the screening value by 5.7 times and 1.5 times, respectively, and was the main local pollutant. The Nemero comprehensive pollution index of the farmland along Guangliji River and Jianggou River was 9.71 and 1.88, respectively, which were in the level of heavy pollution and light pollution. The comprehensive potential ecological risk index of farmland along the two rivers is 417.65 and 85.79, with strong ecological risk and slight ecological risk respectively. The comprehensive evaluation shows that there is a certain degree of heavy metal pollution in the farmland soil along the river in Jiaozuo area, especially Cd pollution, and the ecological risk in some areas has exceeded the acceptable level, which should arouse the attention of the local government and relevant departments. Read More

Abstract: In recent years, China has carried out urban renewal in an orderly manner. Based on the new stage, to accelerate the construction of a low-carbon innovative society under the urban renewal, we should improve the low-carbon indicator system, deepen the transformation of existing urban communities, and enhance the urban low-carbon innovation capacity. Based on the review and reference of the evaluation system of low-carbon related pilot work, the practice of low-carbon community index system in foreign countries, and the existing research and practice of other Chinese scholars on the existing community low-carbon index system, this paper proposes the construction principles of low-carbon community evaluation index system. This paper summarizes the influencing factor framework of the construction of energy-saving buildings, low-carbon transportation and low-carbon living environment in the process of low-carbon existing communities, and selects the secondary and tertiary indicators according to the influencing factors. A set of low-carbon community index system is proposed to evaluate the existing community, and the operability of the evaluation index system is verified by questionnaire survey Read More

Abstract: Four major coal mine accidents, for example, one of coal mine safety production management problems and way to tackle, based on the analysis of the current trend of the development of coal industry in China, on the basis of the objective factors and subjective factors of lead to safety hazard analysis, and the problems existing in the safety management and safety management measures are summarized, do management concept, technology, equipment, creative corporate culture and so on. Read More

Abstract: Climate change and human activities are the main causes of discharge variation. Therefore, calculating the contribution of climate change and human activities to discharge variation in the Inner Mongolia Basin of the Yellow River can provide a reference basis for alleviating water resources stress in the Inner Mongolia Basin of the Yellow River. Firstly, based on the water balance theory and the Budyko hypothesis-based evapotranspiration formula, this study constructed a coupled water and heat balance equation and calibrated and validated the model using observed annual discharge depth data from the Toudao Guai hydrological station. The results show that the water-heat coupling model has good simulation accuracy at the annual scale, with NSE=0.76, RMSE=10.45, and RRMSE=19.5%, and overall, the simulated discharge results are close to the observed values. Secondly, this study also used the Mann-Kendall test method to determine the abrupt change points of discharge and analyzed the contribution rates of various meteorological factors. The results indicate that precipitation accounts for 88.79% of the discharge variation in the Inner Mongolia segment of the Yellow River basin, followed by land surface changes at 13.6%, while potential evaporation has the smallest contribution to discharge variation. Read More

Abstract: Titanium alloy has excellent characteristics that cannot be compared with other metals such as light specific gravity, high specific strength, wide applicable temperature range, corrosion resistance, and hydrogen storage. The traditional titanium alloy smelting process is mainly based on titanium sponge as raw material, which has a long process, high energy consumption, heavy pollution, and other problems, which seriously restricts the sustainable development of titanium alloy in the world. The common methods of preparing titanium alloy are alloy melting, metal thermal reduction, powder metallurgy, and the gradually emerging molten salt electrolysis. Among them, molten salt electrolysis is recognized as the most promising method to replace the traditional titanium alloy production process, and certain achievements have been made in recent years in terms of both process and basic theory research. In this paper, the common processes of titanium alloy preparation by molten salt electrolysis at home and abroad, such as molten salt electrolytic co-deposition method, cathodic alloying method and liquid cathode method, new FFC method, and its derived SOM method, etc., will be summarized systematically, and the future research will be put forward. Read More

Abstract: In order to deeply explore the permeability enhancement effect and permeability enhancement mechanism of the three chemical permeability enhancement technologies, the pore structure change and permeability enhancement mechanism of anthracite coal were studied from the perspective of coal pore structure. The following conclusions are drawn: the permeation effect of the four solutions from large to small is 99% CS2, 10% NaClO, 8% HF, 8% The total pore volume of HCl and HCl solution decreases after acidification, the pore volume of HF solution increases after acidification, the number of pores in the coal sample after oxidation of NaClO solution increases, and the micropores are transformed into mesopores, and the pore volume of CS2 solution increases after extraction, and the pore expansion effect is better than that of the other three solutions, and the pore volume with a pore diameter greater than 2 nm affects the flow of gas between pores, and the larger the pore volume, the higher the permeability. The pores with a pore diameter of less than 2 nm have little correlation with the permeability of coal and rock, and the micropores do not affect the gas flow Read More

Abstract: Geothermal energy, as a renewable and clean energy source, holds immense potential in meeting energy demands and reducing carbon emissions. Its unique sustainability and environmental friendliness make it an important complement to addressing today's energy challenges. Coaxial tubing in-situ heat exchange technology for geothermal wells, as a key extraction method for geothermal energy, is subject to control by multiple critical factors that directly relate to its efficiency and feasibility. This paper aims to delve into the technology of coaxial tubing in-situ heat exchange for geothermal wells through numerical simulation analysis, with a focus on studying the impacts of three key factors on its performance: heat transfer medium flow rate, inlet water temperature, and cement thermal conductivity. Through numerical analysis, this study aims to reveal the variations of these factors to provide more refined control methods and optimize the coaxial tubing in-situ heat exchange technology for geothermal wells. By conducting experimental simulations and numerical analysis on these key factors, this paper aims to provide strong support for optimizing the coaxial tubing in-situ heat exchange technology for geothermal wells, which will contribute to advancing geothermal energy technology and promoting the sustainable utilization of clean energy. Read More