In the face of the challenge of balancing urban economic development and environmental protection, the concept of a healthy city has emerged as a promising model for sustainable urban development. ...This study empirically investigates the impact of healthy city construction on green growth by utilizing a difference-in-difference model estimation on a panel dataset of 279 Chinese prefecture-level cities from 2007 to 2019. The findings reveal that healthy city construction significantly contributes to green growth, particularly in pilot cities, and this effect is observed across cities of different sizes and economic bases. Additionally, we identify two channels through which healthy city construction promotes green growth: enhancing innovation capacity and enriching human resources. These findings have implications not only for Chinese cities navigating the path towards green growth but also for other developing nations striving for economic transformation and environmentally sustainable development.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The total free energy of a molecule includes the classical molecular mechanical energy (which is understood as the free energy in vacuum) and the solvation energy, which is caused by the change of ...the environment of the molecule (solute) from vacuum to solvent. The solvation energy is important to the study of the intermolecular interactions. In this paper we develop a fast surface-based generalized Born method to compute the electrostatic solvation energy along with the energy derivatives for the solvation forces. The most time-consuming computation is the evaluation of the surface integrals over an algebraic spline molecular surface (ASMS), and the fast computation is achieved by the use of the nonequispaced fast Fourier transform (NFFT) algorithm. The main results of this paper involve (a) an efficient sampling of quadrature points over the molecular surface by using nonlinear patches, (b) fast linear time estimation of energy and intermolecular forces, (c) error analysis, and (d) efficient implementation combining fast pairwise summation and the continuum integration using nonlinear patches.
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CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Many oil wells in closed reservoirs continue to produce in the pseudo-steady-state flow regime for a long time. The principal objective of this work is to investigate the characteristics of two key ...pseudo-steady-state parameters—pseudo-steady-state constant (bDpss) and pseudo-skin factor (S)—for a well penetrated by a fracture with an azimuth angle (θ) in an anisotropic reservoir. Firstly, a general analytical pressure solution for a finite-conductivity fracture with or without an azimuth angle in an anisotropic rectangular reservoir was developed by using the point-source function and spatial integral method, and two typical cases were employed to verify this solution. Secondly, with the asymptotic analysis method, the expressions of pseudo-steady-state constant and pseudo-skin factor were obtained on the basis of their definitions, and the effects of permeability anisotropy, fracture azimuth angle, fracture conductivity and reservoir shape on them were discussed in detail. Results show that all the bDpss-θ and S-θ curves are symmetric around the vertical line, θ = 90° and form a hump or groove shape. The optimized fracture direction in an anisotropic reservoir is perpendicular to the principal permeability axis. Furthermore, a new formula to calculate pseudo-skin factor was successfully proposed based on these two parameters’ relationship. Finally, as an application of pseudo-steady-state constant, a set of Blasingame format rate decline curves for the proposed model were established.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Glucose oxidase (GOD) was covalently immobilized onto Fe₃O₄/SiO₂ magnetic nanoparticles (FSMNs) using glutaraldehyde (GA). Optimal immobilization was at pH 6 with 3-aminopropyltriethoxysilane at 2% ...(v/v), GA at 3% (v/v) and 0.143 g GOD per g carrier. The activity of immobilized GOD was 4,570 U/g at pH 7 and 50°C. The immobilized GOD retained 80% of its initial activity after 6 h at 45°C while free enzyme retained only 20% activity. The immobilized GOD maintained 60% of its initial activity after 6 cycles of repeated use and retained 75% of its initial activity after 1 month at 4°C whereas free enzymes retained 62% of its activity.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Based on a large amount of core analysis data in eastern Pre-Caspian Basin, the relationship between permeability and porosity and its influencing factors are studied. The sedimentary environments of ...the Carboniferous System in eastern Pre-Caspian Basin include open platform, restricted platform and evaporate platform. For dolomite reservoirs there are three main combination patterns of pores, namely, inter-crystalline and solution pores, inter-crystalline micro-pores, inter-crystalline and intra-crystalline pores, among which the first combination are highest in porosity and permeability. For limestone reservoirs, the main combination patterns of pores are inter-particle pores, inter-particle and intra-particle pores and moldic pores. Lacking connecting pore throats, moldic pores are poor in permeability. In the dolomite reservoirs, fractures and vugs are well-developed and increase the permeability significantly. Under similar porosity, the permeability is obviously determined by the size of pore throat and the percentage of middle to large size throats in different types of reservoirs. In limestone reservoirs, fractures are principally micro-fractures, the percentage of connecting pores to total pores is positively correlated with permeability; while in dolomite reservoirs, there is not such an obvious relationship between the percentage of connected pores to total pores and permeability. Sedimentary environment, controlling the distribution features of reservoir types, is the cause of the complex relationship between permeability and porosity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rockburst is a complex dynamic disaster in coal mining and affected by many factors. To accurately predict the rockburst hazard among complex influencing factors, a prediction model of rockburst ...hazard based on the Gaussian process for binary classification (GPC) was proposed after the identification of the intrinsic relationship between multiple factors of coal mines and rockburst. Through computerized machine learning and integrated intelligent analysis, the non-linear mapping of rockburst hazard and its influencing factors was established. The multi-factor pattern recognition model was constructed using artificial intelligence. The prediction criteria of the rockburst hazard probability and the hazard probability value of the prediction area unit were determined by applying neural network and fuzzy inference methods. In addition, the rockburst hazardous zone was classified, and the corresponding technical scheme for the prevention was put forward. The validity and feasibility of the regional prediction of rockburst hazard based on GPC were verified in the engineering practice. This method is highly targeted and can improve the accuracy and precision of rockburst prediction, thus contributing to the safe and efficient production of coal mines.
Based on the perspective of urban agglomerations, this paper explores the impact mechanism of environmental regulation on haze, and tries to find the most suitable environmental regulation intensity ...for haze control in urban agglomerations. This paper uses the fixed-effect model and panel threshold model to verify the effect of environmental regulations on haze concentration in 206 cities in China. A grouping test is also conducted to verify whether a regional heterogeneity arises due to different regional development levels for five urban agglomerations and non-five urban agglomerations, respectively. The results show that: (1) In the linear model, strengthening environmental regulation can reduce the haze concentration, but this effect is not significant. The effect of environmental regulation on haze control in the five major urban agglomerations is better than that in the non-five major urban agglomerations; (2) In the nonlinear model, the impact of environmental regulation on haze shows a “U” trend in the five major urban agglomerations and an inverted “U” trend in the non-five major urban agglomerations. Although the results are not significant, we can still conclude that the impact of environmental regulation on haze varies depending on the level of regional economic development. Therefore, the environmental regulation should be formulated according to local conditions; (3) In the threshold model, the impact of environmental regulation on the haze concentration in five major urban agglomerations has a threshold effect. In the five major urban agglomerations, although environmental regulation can effectively reduce haze concentration, the governance effect will weaken as the environmental regulation increases. This study plays a positive role in guiding local governments to adjust environmental regulation intensity according to local conditions and helping local environmental improvement.
A fracture-pore carbonate reservoir in eastern Pre-Caspian basin was taken as an example to analyze the oil phase behavior change and seepage physical characteristics change of weakly volatile oil ...reservoirs with the decrease of formation pressure. Based on the analysis, the water-flooding development technique policy of the reservoir under different formation pressure was presented. Experiments show that the weakly volatile crude oil degasifies as the formation pressure decreases, with methane and intermediate hydrocarbons separated out successively, and the crude oil gradually transforms into ordinary black oil. With the separation of light hydrocarbons, the saturation of in-place oil drops rapidly, the viscosity increases, and the oil permeability reduces, leading to lower well productivity. Retention of formation pressure is a vital factor controlling the reservoir development effect. The lower the formation pressure, the lower the ultimate recovery. Given low formation pressure, water-flooding is required to recover the formation pressure. In water-flooding, the lower level the formation pressure is retained at, the lower the reasonable pressure to be recovered is, and the lower the ultimate recovery is. Compared with zones without fractures, the zone with fractures provides lower injection-production ratio when water-flooding is conducted under the same formation pressure, and its water-flooding time has more impact on oilfield recovery. Therefore, it is recommended to develop weakly volatile oil reservoir by early water-flooding in a moderate way.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Fracture aperture of a fractured reservoir can be affected by both matrix elasticity and fracture compressibility when the reservoir pressure decreases, namely stress sensitivity. An elasticity ...parameter coupling Young’s modulus and Poisson’s ratio was introduced to reflect this geomechanical behavior, and a new model incorporating geomechanics was developed to analyze the flow behavior of a horizontal well in a naturally fractured reservoir. Pressure solutions for two cases—uniform-flux and infinite-conductivity—were derived, respectively. For the uniform-flux case, the effect of dimensionless elasticity parameter on the pressure-drop profile becomes stronger with continuing production, and the profile may be like a bow. Nine flow regimes can be observed on the transient response of the infinite-conductivity case. Stress sensitivity mainly affects the late-flow period and a larger dimensionless elasticity parameter causes a greater pressure drop. Due to stress sensitivity, the pressure derivative curve exhibits an upward tendency in the pseudo-radial flow regime, and the slope is greater than “1” in the pseudo-steady flow regime. For KT-I formation in the North Truva field, its elasticity parameter decreases with the increase of Young’s modulus or Poisson’s ratio and ranges from 8 × 10−8 Pa−1 to 1.1 × 10−7 Pa−1. Meanwhile, the transient response of H519 has a slight negative correlation with Young’s modulus and Poisson’s ratio in the pseudo-steady flow regime.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper explores how the relationship between FDI and SO2 emissions has been affected by the energy transition. We applied a semi-parametric method to a STIRPAT model using Chinese provincial ...panel data from 2002 to 2016 to conduct an empirical analysis of FDI and SO2 emissions and analyze the effects of FDI on the energy transition. We found that FDI and SO2 emissions are characterized by an inverted U-shaped relationship; FDI and coal consumption have an inverted U-shaped relationship, and FDI and natural gas consumption have a U-shaped relationship. Moreover, the use of coal significantly increases SO2 emissions while the use of natural gas significantly reduces them. Our research shows that technological advances have increased coal consumption and that there has been no reduction of SO2 emissions in China. Overall, our analysis provides mixed support for the pollution haven and pollution halo hypotheses.
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•The negative influence of FDI on SO2 is not the technological progress brought by “pollution halo”.•Energy transition is the cause of the inverted U-shaped relationship between FDI and SO2 emissions.•Natural gas consumption exhibited a large potential in SO2 mitigation.•The semi-parametric method is used to test the impact of FDI on SO2 emissions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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