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Abstract To improve the heat extraction efficiency from the wellbore fluids to the stratum in the geothermal well, thermal insulation cement, which contains of waste glass powder as a heat-insulating material, is proposed to apply in geothermal well’s middle and upper sections in the paper. Effect of such glass powers on mechanic and thermal property of thermal insulation cement was then investigated. Various tests were carried out to measure compressive strength, thermal conductivity, microstructure porosity etc. parameters of the thermal insulation cement. Results showed that the waste glass powder would enhance its the compressive strength and improve its the thermal insulation performance. Correlation study between contents of the added waste glass powder in geothermal cements and its mechanic and thermal property was conducted. It was found that thermal insulation cement exhibited its optimum performance when the added content of glass powers was 20% in weight. Analysis of the microstructure porosity with SEM found that the pores in thermal insulation cement with added waste glass powders were mostly closed, tiny and even, and therefore contributed to the compressive strength of the thermal insulation cement; such pores would be also beneficial to improving its thermal insulation performance.

Spatiotemporal changes in lake water resources critically affect the livelihoods and the sustainable development of the local social economy. Understanding the evolution of lake water resource and its influence on economic development is important for achieving sustainable development goals. Taking Africa’s largest lake, Lake Victoria, as the study area, a framework was developed to investigate long-term (2000–2019) water volume variations and their influence on local economic sustainable development. First, an estimation model of water volume variations was constructed based on an optimized joint process of multi-mission altimetry data and water surface area calculations of multispectral images. Furthermore, based on nighttime light remote sensing data, three factors (namely economic level, growth, and inequality) were calculated and applied to quantify the sustainability of local economic development. Finally, the influence mechanism was explored using the Pearson correlation coefficient and grey-value relationship analysis. The results reveal significant interannual and seasonal variations in water volume of the Lake Victoria. Spatially, the western part of Lake Victoria experienced more frequent changes than the east. From the three economic perspectives, the spatiotemporal evolution of water volume variations strongly affected the economic level, whereas economic growth is influenced the least. Additionally, different effects were observed in the surrounding countries. The water volume variations had the greatest impact on Uganda’s sustainable economic development from all three perspectives, with a significant lagged impact of three years on agricultural production. This study provides valuable insights into the dynamic influence of water resources on sustainable economic development, offering a viable alternative to mass field surveys, especially relevant for developing and underdeveloped regions.

The N6-methyladenosine (M6A) modification is the most common internal chemical modification of RNA molecules in eukaryotes. This modification can affect mRNA metabolism, regulate RNA transcription, nuclear export, splicing, degradation, and translation, and significantly impact various aspects of physiology and pathobiology. Radiotherapy is the most common method of tumor treatment. Different intrinsic cellular mechanisms affect the response of cells to ionizing radiation (IR) and the effectiveness of cancer radiotherapy. In this review, we summarize and discuss recent advances in understanding the roles and mechanisms of RNA M6A methylation in cellular responses to radiation-induced DNA damage and in determining the outcomes of cancer radiotherapy. Insights into RNA M6A methylation in radiation biology may facilitate the improvement of therapeutic strategies for cancer radiotherapy and radioprotection of normal tissues.

Aligning with UN Sustainable Development Goals (SDGs) 1 and 10, the ‘growth-poverty-inequality’ (GPI) nexus has become widely discussed in economic development research. It remains an important discourse regarding sustainable development. To monitor spatiotemporal economic development and analyse the GPI trilemma, especially in developing and undeveloped regions, a novel framework based on long-term, consistent night-time light (NTL) remote sensing (RS) data (2000–2020) was proposed and applied to the Nile River Basin. An optimized, multitemporal estimation strategy was developed for gross domestic product (GDP) estimation and spatialization. Then, the poverty map and inequality indices for the entire basin and each country were prepared. Combining GDP growth, the poverty map, inequality index, and other relevant economic statistics, the GPI nexus for the Nile River Basin was modelled. Findings suggest that the proposed framework can not only effectively map GPI dynamics but also accurately model the GPI nexus. We found that the economic development of countries in the Nile River Basin is characterised by widespread poverty and inequality and restricted spatial distribution. The spatiotemporal evolution patterns of GPI vary with upstream and downstream geographic locations. Regarding their interaction, study findings revealed that economic growth relieves poverty, whereas high inequality levels aggravate poverty. Moreover, high inequality dampens the positive effect of economic growth on poverty reduction. This study offers new insight into GPI trilemma modeling and analyses using NTL data, an economically viable alternative to mass field surveys that is especially relevant for developing and underdeveloped regions.

The traditional altimetry satellites based on pulse-limited radar altimeter only calculate along-track deflection of the vertical (DOV), which results in poorer precision of the prime vertical component than that of the meridian component and limits the precision of the marine gravity field inversion. We expect an improvement in the higher precision prime vertical component using the Ice, Cloud and land Elevation Satellite 2 (ICESat-2) sea surface height (SSH) data. In this paper, the 2′ × 2′ gridded DOVs derived from along-beam DOVs, cross-beam DOVs, and joint along-cross beam DOVs in the South China Sea (SCS; 0°–23°N, 103°–120°E) are calculated with the weighted least squares method, respectively. The inverse Vening–Meinesz (IVM) formula is applied to derive 2′ × 2′ gravity anomalies over the SCS from ICESat-2-derived gridded DOVs. In addition, the XGM2019e_2159-DOV and SIO V31.1-DOV models are used to assess the precision of the gridded DOVs. The XGM2019e_2159-GRA, SIO V31.1-GRA models, and ship-borne gravity anomalies are also adopted to evaluate the quality of gravity anomalies. The results show that the gridded DOVs calculated by the joint along-cross beam DOVs have the highest precision among the three gridded DOVs determined by ICESat-2. The precision of difference between gravity anomalies derived from the joint along-cross beam DOV and the above verification data are higher than those derived from the along-beam and cross-beam DOVs. We conclude that the joint along-cross beam DOV can effectively improve the precision of the gridded DOV, which is conducive to the inversion of a high-precision marine gravity field.

Human settlements are guided by the proximity or availability of a natural resource such as river or lake basins containing set of streams. The harmonious development of human activity and natural conditions along watershed areas needs close attention and in-depth study. In this paper, the urban agglomerations and ecological spaces in the Yangtze River Delta, China, the Chao Lake Basin and its surrounding watershed ecosystem is taken as research subject for its serious environmental degradation problems during social and economic development. This paper adopted an effective machine learning algorithm (kernel-ELM) to extract land use and land /cover information, and to analyze the land use/cover pattern evolution rules of the Chao Lake Basin with long term Landsat imagery. Subsequent studies were then carried out to demonstrate the flood-affected area and its ecological impact in the basin in 2020, to reveal the occupation on land cover types. The results indicate Conclusions are drawn from the experiment results: (1) There has been significant change in cultivated land, forest land and construction land out of six key land cover types with dynamic degree of −10.17%, 4.61, 67.04% respectively. (2) Algae bloom pollution was extracted from pattern classification results and it was up to 15% of the total water area by the year 2018. (3) The occupation on land use/cover types of the flood was revealed. The results prove effective application of remote sensing technology in environmental analysis and planning for data-driven evaluation of governing policy. This work serves as a scientific basis for environmental management and regional planning in the Chao Lake Basin and can be served as a basis and a reference for evaluating an ecological policy and its impact for other economic developing watershed human settlements with ecological issues.

Non-point source (NPS) pollution has greatly threatened socio-economic development and human health due to water environment degradation. It is very important to quantitatively analyze spatio-temporal variation rules of NPS pollution sources surrounding drinking water source area (DWSA) and their impact on the water environment with time-series satellite images. In this paper, we study a systematic remote sensing monitoring method on DWSA of upper Huangpu River, Shanghai. Firstly, an optimized Extreme Learning Machine (ELM) classification algorithm, namely Mixed Kernel ELM with Particle Swarm Optimization (PSO-MK-ELM) was constructed. Based on the PSO-MK-ELM, four NPS pollution sources- farmland, building land, woodland, and water were identified accurately and efficiently. Then their corresponding spatiotemporal analysis was performed with 30 years (1989–2019) Landsat images. On the basis of NPS pollution source area and census data from 1989 to 2017, the principal pollutants discharged into DWSA were also calculated with the common Export Coefficient Model (ECM). Finally, the contributions of the spatial and temporal changes of NPS pollution sources on pollutant emissions were analyzed. The result indicates the PSO-MK-ELM has an advantage of efficiency and accuracy in NPS pollution source extraction and our results are expected to provide a scientific basis and data support for NPS pollution control and DWSA protection for better practices for environmental management in megacities worldwide.

Rib spalling disaster at the coal mining faces severely restricted the safe and efficient output of coal resources. In order to solve this problem, based on the analysis of the current status of rib spalling in the three-soft coal seam 1508 Working Face of Heyang Coal Mine, a mechanical model of sliding-type rib spalling was established and the main influencing factors that affect rib spalling are given. The mechanism of grouting technology to prevent and control rib spalling has been theoretically analyzed. A similarity simulation experiment is used to analyze the change law of roof stress under the condition of three-soft coal seam mining. The optimal grouting pressure is determined by a numerical simulation experiment. And, silicate-modified polymer grouting reinforcement materials (SMPGMs) are used in field experiments. After twice grouting operations in the 1508 Working Face, the coal wall was changed from the original soft and extremely easy rib spalling to a straight coal wall and the amount of rib spalling has been reduced by 57.45% and 48.43, respectively. And, the mining height has increased by 0.16 m and 0.23 m, respectively. The experimental results show that the rib spalling disaster of the three-soft coal seam has been effectively controlled.

In the inclination direction, the fracture law of a longwall face roof is very important for roadway control. Based on the W1123 working face mining of Kuangou coal mine, the roof structure, stress and energy characteristics of W1123 were studied by using mechanical analysis, model testing and engineering practice. The results show that when the width of W1123 is less than 162 m, the roof forms a rock beam structure in the inclined direction, the floor pressure is lower, the energy and frequency of microseismic (MS) events are at a low level, and the stability of the section coal pillar is better. When the width of W1123 increases to 172 m, the roof breaks along the inclined direction, forming a double-hinged structure, the floor pressure is increased, and the frequency and energy of MS events also increases. The roof gathers elastic energy release, and combined with the MS energy release speed it can be considered that the stability of the section coal pillar is better. As the width of W1123 increases to 184 m, the roof in the inclined direction breaks again, forming a multi-hinged stress arch structure, and the floor pressure increases again. MS high-energy events occur frequently, and are not conducive to the stability of the section coal pillar. Finally, through engineering practice we verified the stability of the section coal pillar when the width of W1123 was 172 m, which provides a basis for determining the width of the working face and section coal pillar under similar conditions.

The spatiotemporal changes of lake water resources objectively reflect not only the process of the water resources balance, but also the ecological environment changes in the lake area. In recent decades, climate changes and human activities have caused great impacts on the spatial distribution of the earth’s water resources and the spatiotemporal process of the surface water cycle, which has caused a series of ecological crises and environmental problems, such as the drying-up of inland lakes, the disappearance of the oasis, water shortage or flooding and water pollution. Therefore, monitoring and fully understanding the dynamic changes of lakes is of great scientific significance for grasping regional water balance, water resources management, and sustainable development of the ecological environment. In this study, we focus on using multi-source satellite data on the estimation of water volume and multi-timescale variations analysis for large scale lakes. This study combines the problems in the practical application of “African Water Action”, taking the largest lake in Africa, Lake Victoria, as the study area, and utilizes long-term serial multi-source satellite data of the past 15 years (2003–2017), including Moderate-resolution Imaging Spectroradiometer (MODIS), Jason-1/-2/-3 and Gravity Recovery and Climate Experiment (GRACE) to perform the comprehensive analysis on the water volume change estimation. Firstly, the satellite altimetry data of Jason-1/-2/-3 and MODIS imagery was used to calculate series of water level, and to extract series of water surface area, respectively. On this basis, a more accurate regression model between the area and water level variation (ΔH) was constructed. Then, the model between water volume variation (ΔV) and ΔH, derived from area-ΔH model, was applied to calculate the relative water volume of Lake Victoria. Meanwhile, terrestrial water storage (TWS) changes between 2003 and 2016, derived from GRACE data, were also used for a comparative verification of the ΔV results. The results show the long-term series change trends of ΔV and the TWS are the same. Finally, the multi-timescale analysis of water volume changes was carried out on different time scales, such as the inter-annual, inter-monthly, and variation period.

Segregation occurs for most of dopants employed in crystal growth, leading to variation of dopant concentration and properties along the crystal. This article presented a review of recent research on melt flow and dopant distribution during the growth of Si and Ge crystal. The effects of melt flow and segregation on the dopant distribution in systems including Czochralski indium doped germanium crystals, Czochralski B-Ge codoped silicon crystals, and Ga doped germanium crystals grown by the VB method. The convection, solute distribution, and their effect on resistivity distribution during CZ antimony doped germanium single crystal still need further investigation.

To investigate the effects of 4-methyl-2-{[4-(toluene-4-sulfonyl)-thiomorpholine-3-carbonyl]-amino}-pentanoic acid isopropyl ester (HD5-6) against cerebral ischemia in rodents, the models with global and focal ischemia were induced by bilateral common carotid artery occlusion plus hypotension (BCAOH) and permanent cerebral artery occlusion (p-MCAO) in mice (n = 10 - 12 per group in BCAOH; n = 8 per group in p-MCAO) and rats (n = 10 - 11 in each group). HD5-6 prolonged lifetime and improved neurological function. Neurological deficits score in HD5-6 (30 mg/kg) decreased significantly. Malonaldehyde (MDA) in HD5-6-treated mice with ischemia considerably dropped. The infarction volume of the HD5-6-treated rats with MCAO-induced ischemia decreased significantly in the high dose group (P < 0.05, i.g. and P < 0.01, i.v.). Immunohistochemistry showed that Brain derived neurotrophic factor (BDNF) in the ipsilateral hemisphere increased and Vascular endothelial growth factor (VEGF) decreased with HD5-6 treatment. HD5-6 has protective effects against experimental cerebral ischemia in rodents and the action mechanism may involve anti-oxidation and neurogenesis. [ABSTRACT FROM AUTHOR]

A groundhook controlled semi-active suspension system equipped with magneto-rheological damper (MRD) is considered. Both the hysteresis of MRD and control discontinuity, the nonlinearity will greatly affect system stability of the vehicle. In this paper, the performance and nonlinear dynamic of semi-active suspension adopting modified groundhook is evaluated. The influence of frequency of harmonic excitation and parameter of modified groundhook controller on the nonlinear dynamics of the semi-active suspension system is investigated. More importantly, nonlinear dynamic analysis is carried out to study the semi-active suspension system, with the methods of bifurcation diagram, the Lyapunov exponent spectrum, time history, phase plane and power spectrum in detail for the first time. Furtherly, electromagnetic interference (EMI) problems induced by chaotic motion are analyzed and discussed according to EN 55022 for another first time. It is indicated that both of periodic, quasi-periodic and chaotic motions exist. The system undergoes a complex nonlinear dynamical evolution with the excitation change. The coupling influence between chaos and EMI problems cannot be ignored in the further design of the semi-active controller. This work laid a theoretical foundation for EMI reduction and nonlinear control of the intelligent MR semi-active suspension. [ABSTRACT FROM AUTHOR]