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• A variational level set model based on additive image decomposition is proposed. • A novel indirect regularization scheme is introduced in the model. • The proposed model can effectively segment intensity inhomogeneous images with noise. The variational level set model is widely used in image segmentation. However, it suffers from the limited performance when the images are contaminated by noise and intensity inhomogeneity. To solve this problem, a variational level set model based on additive decomposition is proposed in this paper. First, we decompose the image into three components: structure, intensity inhomogeneity and noise, which are regularized by different metrics. Specially, the structure component is regularized as a piecewise constant function in bounded variation (BV) space; the intensity inhomogeneity is modeled as a smooth function that is regularized by H 1 space, and the residual containing noise is measured by L 2 norm. Furthermore, a new indirect regularization term for level set function is designed to enhance the accuracy of the segmentation outcomes. And then, alternate direction iteration algorithm combining with gradient descent and ADMM to solve the proposed model. Experiments on both synthetic and real images validate the proposed model. Compared with five state-of-the-art models, the experimental results demonstrate that the proposed model exhibits the significant improvement in both accuracy and efficiency, outperforming all other methods. Quantitative evaluations show the average segmentation coefficients for Jaccard, Dice and Accuracy against ground truth are 0.93, 0.95 and 0.96, respectively, and the average running time is 0.80 seconds, further confirming its superior performance. [ABSTRACT FROM AUTHOR]

Total variation (TV) regularization model has the excellent performance in noise-removing and edge-preserving. However, it often yields staircase artifacts in the smooth region of the restorations. To attack this problem, we propose a generalized hybrid nonconvex variational regularization model in this paper, which utilizes two nonconvex regularizers to impose the priors to the two different components of the images, respectively. One is nonconvex TV regularizer that measures the piecewise constant component of the input image, and the other is nonconvex Laplacian regularizer that models the piecewise smooth component. New model inherits the advantages of the nonconvex regularization and the first- and second-order hybrid variational regularization, which can well remove the noises while preserving edges and reducing staircase artifacts. To solve this nonconvex minimization problem efficiently, we propose a first-order algorithm based on alternating direction method of multipliers (ADMM) combining with majorization–minimization (MM) scheme. In addition, a sufficient condition for the convergence of the proposed algorithm is provided. In the experiments, we compare the proposed model with several state-of-the-art image denoising models, numerical results illustrate the effectiveness of the proposed model and algorithm for both synthetic and real images in terms of peak signal to noise ratio (PSNR) and structural similarity (SSIM) indexes. [ABSTRACT FROM AUTHOR]

With increasing family income, the prevalence of overweight has risen and become a serious threat to individual health and a major public health challenge in China. This study attempts to shed light on the mechanism of income impact on the adult health outcomes of BMI and overweight through five potential channels: nutritional intakes, dietary diversity, dietary knowledge, food preference, and dining out. Using the panel data from the China Health and Nutrition Survey (CHNS), we investigate the causal relationship between income and health by considering the changes in the minimum wage as a valid instrument to address the endogeneity problem of income in health estimation. The results indicate that rising income increases the adults' BMI and the propensity to be overweight; approximately 15.58% and 16.20% of income impact on BMI and overweight could be explained by the five channels considered, respectively. Among the five channels, dietary diversity plays the most significant role in explaining the income impact. We observe significant heterogeneity in income-BMI gradients across various income quantiles and subsamples. Specifically, income-BMI gradients tend to increase along with income percentiles, and income has a significantly positive impact on BMI and overweight for the male sample but it shows no significant impact for the female sample. • Five important mechanisms of income impact on BMI and overweight are highlighted. • The endogeneity of income is addressed by using minimum wage as an instrument. • Rising income increases the adults' BMI and the propensity to be overweight. • Dietary diversity plays the most significant role in explaining the income impact. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract This work aims to investigate the changes in the shear and oscillation responses of an ethoxylated alkylamine emulsion with the addition of acetic acid and establishes their relationships with the emulsion phase inversion. The initial emulsion behaves as a non-Newtonian fluid exhibiting shear thinning with a viscoelastic gel structure (at rest). Upon the addition of acetic acid, the emulsion first transforms to a structureless (at rest) non-Newtonian fluid with lower viscosity and worse shear thinning compared with the initial state and then converts back to a non-Newtonian fluid with a higher gel strength, higher elasticity (at rest) and better shear thinning than the initial state as the phase inversion proceeds from an oil-continuous stage to a bicontinuous stage. This regained non-Newtonian character can be maintained throughout the whole bicontinuous stage and can even extend to the beginning of the water-continuous stage which is obtained from the bicontinuous stage by increasing the acetic acid content; however, it is ultimately replaced by a structureless (at rest) non-Newtonian fluid that exhibits lower viscosity and worse shear thinning compared with the initial state as the acetic acid content increases. The establishment of relationships among the interfacial moduli and deformation, geometrical factors (i.e., interfacial curvature, droplet shape and size and positional structure) and the liquid crystal phase behaviors help to elucidate the mechanisms that control the rheological transitions of emulsions. Based on these results, a novel water-washable viscoelastic emulsion drilling fluid is proposed. [ABSTRACT FROM AUTHOR]

Reversible invert emulsion muds (RIEMs) offer unique advantages over other oil-based muds for the completion of a well due to the pH-responsiveness of reversible emulsifiers. This paper presents new insights into the effects of pH-responsiveness on the completion performance of RIEMs and the mechanisms involved. At pH 4 and 6, RIEMs are easy to remove, but the formation damage is relatively severe. At pH 10, the removal of RIEMs is relatively difficult but can be facilitated by intense and repeated flushes. Once the mud has been removed, there is little formation damage. At pH 8, the mud is very difficult to remove, and the greatest amount of formation damage is observed. The spontaneous curvature of the surfactant layer changes at pH 4 and 6, resulting in the emulsion inversion and thereby enabling the removal of RIEMs by the solvent effect. These changes do not occur at pH 8 and 10. More emulsifiers adsorb to the rock surface at pH 4, 6, and 8, resulting in a strongly oil-wet condition and high formation damage. The desorption of emulsifiers occurs at pH 10, causing a water-wet condition and low formation damage. The variety in chemical states accounts for the changes in the adsorption behavior of the emulsifiers. [ABSTRACT FROM AUTHOR]

• NH 2 - and HO- functionalized ionic liquids (ILs) inhibit shale hydration excellently. • NH 2 - functionality was more favorable to shale inhibition than HO- functionality. • ILs in WBDs inhibit viscosity build-up at high temperatures. • ILs cause the filtration and inhibition failure of WBD without colloidal protection. • ILs inhibit shale hydration by minimizing crystalline and osmotic hydration of clay. Shale hydration is the main cause of wellbore instability during drilling using water-based drilling fluids (WBD). In this work, NH 2 - and HO-functionalized ionic liquids (ILs) were investigated for their performances on inhibiting the shale hydration, as well as their influences on the properties of WBD, using immersion and sedimentation tests, linear swelling test, hot-rolling dispersion test, rheological and filtration experiments. The mechanisms were identified by X-ray diffraction (XRD), zeta-potential and particle size distribution analyses, scanning electron microscopy (SEM) and related theoretical analysis. Evaluation experiment results showed that the NH 2 -functionalized IL had the best inhibition performance, followed by poly(propylene glycol)bis(2-aminopropyl ether), HO-functionalized IL and KCl. NH 2 -functionality was more favorable to shale inhibition than HO-functionality. When used in WBD, ILs could prevent viscosity building-up at high temperature, but cause filtration and inhibition failure, which could be mitigated when polyanionic cellulose (PAC) was added in WBD prior to inhibitors. Three critical observations helped elucidate the inhibitive mechanisms: the intercalation of cationic groups of ILs into the clay interlayers, the decrease of both interlayer spacing and double layer thickness. The NH 2 -functionalized IL allowed the smallest interlayer spacing and double layer thickness and therefore performed best in inhibition. The inhibition failure in WBD with ILs depended on two aspects: the consumption of ILs untimely and the filtration failure of WBD. PAC could decrease both of ILs' loss within WBD and water loss toward shale, mitigating the WBD's inhibition failure. Our work will facilitate the rational design of efficient and environmentally acceptable inhibitors and their rational applications in WBD for drilling shale formation. [ABSTRACT FROM AUTHOR]

Clay is closely associated with the drilling of oil and gas by influencing the shale wellbore stability and the rheology of drilling fluids. In this work, four imidazolium-based ionic liquids (ILs) were used to modify the typical clay (i.e., sodium bentonite (Na-Bent)), and their effects on the Na-Bent rheological and swelling properties were evaluated by shear rheological measurements, immersion experiment, linear swelling measurements. The mechanisms involved were identified by using fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Zeta-potential and environmental scanning electron microscopy (ESEM) analysis. Evaluation experiment results showed that the adsorption of each IL could both significantly affect the Na-Bent rheological property and inhibit the Na-Bent swelling, which strongly depended on ILs' structures and concentrations. The mechanism study revealed that the cationic groups of ILs could adsorb on Na-Bent prior to water molecules, followed by expelling water and compressing the double electrode layers, and therefore inhibit the Na-Bent swelling. The adsorption of ILs could also change aggregation behaviors of the Na-Bent particles, by which the "house of cards" structures in Na-Bent dispersions were improved or destroyed, resulting in changes in rheological properties of Na-Bent dispersions. Unlabelled Image • An ionic liquid (IL) can affect the clay rheological and swelling behaviors • Effects of IL on clay depend on IL's structure and concentration • Preferential adsorption of IL expels water and compresses double electrode layers • IL inhibits clay swelling by minimizing crystalline and osmotic hydration of clay • Changes of "house of card" structure account for the clay rheological transitions [ABSTRACT FROM AUTHOR]

Increasing consumer demand has increased environmental pressure. Altering consumer behavior may be one strategy to achieve emission reduction targets. China's carbon labeling system is still in its infancy, and consumers' response to carbon labeling products is still uncertain. This study investigates consumers' willingness to pay (WTP) for carbon-labeled agricultural products (CAP) in different regions, the factors influencing them, and the strategies to implement carbon labeling. The results suggest that 77.60% of respondents are willing to pay more for CAP. The premium WTP for carbon-labeled milk, corn, bananas, tomatoes, and eggs is 25.66%, 31.96%, 24.08%, 23.62%, and 20.64%. Low-carbon awareness and the peer effect greatly and favorably impact people's reception of carbon labeling. Respondents' WTP for carbon labeling is considerably and favorably influenced by their acceptance of carbon labeling. We also put forward some suggestions on the promotion strategy of CAP from the perspective of government, enterprises, and consumers. • This study investigates consumers' WTP for carbon-labeled agricultural products (CAP). • 77.60% of respondents are willing to pay more for CAP. • People's reception of CLP is impacted by low-carbon awareness and peer effect. • Respondents' WTP for carbon labels is influenced by their acceptance of CAP. • We offer some advice on promoting CAP from multiple perspectives. [ABSTRACT FROM AUTHOR]

In this paper, the inhibition of chitosan quaternary ammonium salt (HTCC) in the drilling fluid was studied. The inhibition was evaluated by linear swelling test, mud making test and rolling recovery. The results indicated that the inhibition of HTCC was better than polyether amino, which be used widely in the oil flied as the excellent shale inhibitor. Especially HTCC is an environmental friendly and biodegradable. The inhibition mechanism of HTCC was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, Scanning electron microscopy, Zeta potential, Gel strength measurement analysis. The negative charge in the surface of montmorillonite (MMT) was neutralized by the positive charge. HTCC was absorbed and coated in the surface and intercalated in the interlayer of MMT, which reduced the hydration repulsion of diffuse electric double layer and leaded to the inhibiting hydration of clay. Hydrogen bonding between hydroxyl, amino groups in the HTCC and the surface of clay can be formed in the process. The coordination of electrostatic interaction and hydrogen bonding prevented the water molecules from the gallery of clay, which resulted from the absorption and intercalation of HTCC in the surface and interlayer of MMT. The high molecular weight of HTCC was coated in the surface of MMT, which further expelled the hydration swelling of clay. It kept the high inhibition even if the ether bond hydrolysis partly in high temperature, comparing to polyether amino which the inhibition be reduced. [ABSTRACT FROM AUTHOR]

An emission inventory, involving both air pollutants (APs) and greenhouse gases (GHGs), is needed so that the questions of air pollution and climate change can be co-addressed, coordinated, and collaborated upon. In this study, an emission inventory, including both APs and CO 2 (representing GHGs), was developed for China 2019 using two special measures. First, the framework of air pollution source classification was used for the integrative inventory and then the CO 2 emissions for each sector/subsector/source in the GHG inventory were precisely arranged into the framework of APs by every possible means such as drawing on the constraints from the International Industrial Classification of All Economic Activities (ISIC), which enabled the sharing of common or intrinsically connected activity data for both APs and CO 2. Second, an attempt was made to deduce the activity data of various industrial processes through proper interpretation of the information carried in Pollutant Permits. The calculated emissions of APs and CO 2 were found to be comparable to the results of other studies. Additionally, the average per capita CO 2 and pollution equivalents (PEs) were 10.29 ± 6.75 tons and 11.72 ± 7.35 tons, respectively, over the provincial regions with per capita gross domestic product (GDP) lower than ￥70000 (about $10000). Whereas the average per capita CO 2 and PEs dropped to 6.10 ± 1.83 tons and 6.70 ± 2.09 tons, respectively, over the provincial regions with per capita GDP higher than ￥70000. This somewhat supports the philosophy of the Environmental Kuznets Curve (EKC) regarding the close connection between emission and development. Moreover, the two emission intensities (for APs and CO 2) were found to vary synchronously among the provinces, reflecting the inter-linked fates of the two emissions under the control measures oriented toward either APs or GHGs. [Display omitted] • An emission inventory integrating air pollutants and CO 2 are compiled. • GHG classification framework are used for the integrative inventory with additional constraints from ISIC. • Pollutant-Permit information is employed to derive activity data of industrial processes and links. • The EKC philosophy on emission/development relation is partly supported. [ABSTRACT FROM AUTHOR]

Background The thyroid cancer (TC) incidence in China has increased dramatically during the last three decades. Typical in this respect is the case of Hangzhou city (China), where 7147 new TC cases were diagnosed during the period 2008–2012. Hence, the assessment of the TC incidence risk increase due to environmental exposure is an important public health matter. Methods Correlation analysis, Analysis of Variance (ANOVA) and Poisson regression were first used to evaluate the statistical association between TC and key risk factors (industrial density and socioeconomic status). Then, the Bayesian maximum entropy (BME) theory and the integrative disease predictability (IDP) criterion were combined to quantitatively assess both the overall and the spatially distributed strength of the “exposure-disease” association. Results Overall, higher socioeconomic status was positively correlated with higher TC risk (Pearson correlation coefficient = 0.687, P < 0.01). Compared to people of low socioeconomic status, people of median and high socioeconomic status showed higher TC risk: the Relative Risk (RR) and associated 95% confidence interval (CI) were found to be, respectively, RR = 2.29 with 95% CI = 1.99 to 2.63, and RR = 3.67 with 95% CI = 3.22 to 4.19. The “industrial density-TC incidence” correlation, however, was non-significant. Spatially, the “socioeconomic status-TC” association measured by the corresponding IDP coefficient was significant throughout the study area: the mean IDP value was − 0.12 and the spatial IDP values were consistently negative at the township level. It was found that stronger associations were distributed among residents mainly on a stripe of land from northeast to southwest (consisting mainly of sub-district areas). The “industrial density-TC” association measured by its IDP coefficient was spatially non-consistent. Conclusions Socioeconomic status is an important indicator of TC risk factor in Hangzhou (China) whose effect varies across space. Hence, socioeconomic status shows the highest TC risk effect in sub-district areas. [ABSTRACT FROM AUTHOR]

High chemical inertness of porous graphitic carbon particles (PGC) makes their surface modification rather difficult. Here a facile way is proposed to prepare a PGC stationary phase with quaternary ammonium-polyvinyl alcohol mixed functional groups for hydrophilic interaction liquid chromatography (HILIC) by generating a thin layer of polyvinyl alcohol (PVA) and poly(diallyldimethylammonium chloride) (DDAC) copolymer onto PGC particles. The phase shows obvious positively electrostatic character and typical HILIC character, exhibiting different selectivity relative to several HILIC phases and bare PGC. To the best of our knowledge, this is the first fully pH-stable, quaternary ammonium functionalized HILIC phase. It is much superior to silica-based HILIC phases in terms of wide pH tolerance (2.1–12.7) and low bleeding. [ABSTRACT FROM AUTHOR]

In this paper, the nano terpolymer of acrylamide (AM), 2-acrylamido-2-methyl -1-propane sulfonic acid (AMPS), N-vinyl-pyrrolidone (NVP) was synthesized by free radical polymerization in water solution. The addition of ethanol was used to control molecular weight of terpolymer. The plugging properties and mechanism of terpolymer were studied. The characterization and properties of nano terpolymer were studied by Fourier transform infrared spectroscopy, particle size analyzer, transmission electron microscopy. The results indicated that the structure of terpolymer was consistent with design. It was nano material in water and kept on nanoscale stable in drilling fluid. The filtration property of terpolymer was studied by drilling fluid filter press and the results indicated that the filtration property of terpolymer was equal to fluid loss agent. Nevertheless, the addition of inorganic nanoparticles resulted in high amount of filtration volume in the same conditions because of extensive agglomeration of inorganic nanoparticles. The stability of nano materials in solution was requirement to plug nanopores. The resistance properties to salinity, calcium and high temperature were studied, and the results showed that the properties were better than PAC which is widely used in oil flied as fluid loss agent. The plugging properties of terpolymer were studied by specific surface and porosity physical adsorption instrument (BET) and the membrane efficiency tester. BET results showed that the surface area of natural rock reduced after treated with terpolymer, indicating terpolymer entered into nanopores of shale because of the adsorption in the surface of shale. In study of the membrane efficiency test, the addition of terpolymer resulted in significantly reducing of shale permeability. It was further presented that nanopores of shale were plugged by terpolymer. [ABSTRACT FROM AUTHOR]

Catering oil fumes are a major hazard to human health. In particular, the typical Chinese cooking style is characterised by a high temperature frying process that produces high levels of cooking oil fumes. However, limited data relating to this sector mean that national emission inventory data specific to the catering service industry do not exist. To address above deficiency and thus to establish the inventory of a city, or a province, or even a country, a door-to-door survey campaign was launched in the Chinese cities of Heze and Linfen to determine the structure of local catering industries. Data revealed that the number of catering businesses per 104 people was 17 ± 4. Of these, 3.0 ± 1.4, 15.0 ± 1.4, and 82.0 ± 0.0% were classified as large, medium, and small enterprises, respectively. Furthermore, the installation rates of fume purifiers were 74 ± 13, 66 ± 9, and 51 ± 14% for large, medium, and small enterprises, respectively, with net removal efficiencies of 63 ± 11, 50 ± 7, and 31 ± 8%, respectively. This information was extrapolated across all provincial regions of China to construct a provincial and national emission inventory. In 2017, China's national catering industry released approximately 34 kt of volatile organic compounds (VOCs), 38 kt of particulate matter with a diameter less than 2.5 μm (PM 2.5), 48 kt of particulate matter with a diameter less than 10 μm (PM 10), 1 kt of black carbon (BC), and 27 kt of organic carbon (OC). A significant correlation was observed between vegetable oil consumption and emissions (e.g., for VOCs, y = 14.94 x + 76.50, R2 = 0.87, where y is VOCs emissions and x is vegetable oil consumption), indirectly corroborating the rationality of the inventory. Moreover, this correlation provides the potential for a dynamic inventory based on vegetable oil consumption. Future studies are proposed to address more influential factors to improve the reliability of the national inventory and refer to big data, rather than door-to-door investigation, to identify the amount of catering service businesses in a region. Unlabelled Image • Intensive surveys on catering industry information performed in two Chinese cities • Survey data help establish a national emission inventory of catering industry. • A significant correlation observed between vegetable oil consumption and emissions. • This correlation indirectly verifies by the rationality of the inventory. • This relation useful for dynamically updating emission inventory of catering sector [ABSTRACT FROM AUTHOR]