Flexoelectric effects in materials can bring novel physical properties that are absent in their perfect crystal, and have a wide range of applications, such as mechanical sensors and wrinkled triboelectric nanogenerators. In this work, electronic structures and transport properties of bended alpha-In2Se3 monolayer are investigated through first-principles calculations and nonequilibrium Green's function (NEGF). We find that two different kinds of type-II band structures can be obtained in (P) over tilde up arrow and (P) over tilde down arrow flexed alpha-In2Se3, which show opposite band bending. Carriers in the center of (P) over tilde up arrow and (P) over tilde down arrow flexed alpha-In2Se3 are mainly holes and electrons, respectively, which dominate the current behavior of the alpha-In2Se3 p-i-n (PIN) field-effect transistor (FET). The (P) over tilde up arrow PIN-FET has enhanced forward current and the rectification ratio due to the larger density of holes. Our study achieves the homogeneous junction through bended alpha-In2Se3, which may simplify the device procession and be used as electromechanical sensors.

Summary Understanding how pressure propagates in a reservoir is fundamental to the interpretation of pressure and rate transient measurements at a well. Unconventional reservoirs provide unique technical challenges as the simple geometries and flow regimes [wellbore storage (WBS) and radial, linear, spherical, and boundary-dominated flow] applied in well test analysis are now replaced by nonideal flow patterns due to complex multistage fracture completions, nonplanar fractures, and the interaction of flow with the reservoir heterogeneity. In this paper, we introduce an asymptotic solution technique for the diffusivity equation applied to pressure transient analysis (PTA), in which the 3D depletion geometry is mapped to an equivalent 1D streamtube. This allows the potentially complex pressure depletion geometry within the reservoir to be treated as the primary unknown in an interpretation, compared with the usual method of interpretation in which the depletion geometry is assumed and parameters of the formation and well are the unknown properties. The construction is based upon the solution to the Eikonal equation, derived from the diffusivity equation in heterogeneous reservoirs. We develop a Green’s function that provides analytic solutions to the pressure transient equations for which the geometry of the flow pattern is abstracted from the transient solution. The analytic formulation provides an explicit solution for many well test pressure transient characteristics such as the well test semi-log pressure derivative (WTD), the depth of investigation (DOI), and the stabilized zone (SZ) (or dynamic drainage area), with new definitions for the limit of detectability (LOD), the transient drainage volume, and the pseudosteady-state (PSS) limit. Generalizations of the Green’s function approach to bounded reservoirs are possible (Wang et al. 2017) but are beyond the scope of the current study. We validate our approach against well-known PTA solutions solved using the Laplace transform, including pressure transients with WBS and skin. Our study concludes with a discussion of applications to unconventional reservoir performance analysis for which reference solutions do not otherwise exist.

Prediabetes and its pathophysiology remain important issues. We aimed to examine the cluster characteristics of prediabetes and explore their associations with developing diabetes and its complications based on 12 variables representing body fat, glycemic measures, pancreatic β cell function, insulin resistance, blood lipids, and liver enzymes. A total of 55,777 individuals with prediabetes from the China Cardiometabolic Disease and Cancer Cohort (4C) were classified at baseline into six clusters. During a median of 3.1 years of follow-up, significant differences in the risks of diabetes and its complications between clusters were observed. The odds ratios of diabetes stepwisely increase from cluster 1 to cluster 6. Clusters 1, 4, and 6 have increased chronic kidney diseases risks, while the prediabetes in cluster 4, characterized by obesity and insulin resistance, confers higher risks of cardiovascular diseases compared with others. This subcategorization has potential value in developing more precise strategies for targeted prediabetes prevention and treatment.

The Fast Marching Method (FMM) is an efficient tool for the solution of the Eikonal equation to characterize frontal propagation in heterogeneous and anisotropic media. Previous studies have applied the FMM in solving the Eikonal equation to obtain the “diffusive time of flight” (DTOF), which is used to characterize the pressure front propagation in subsurface porous media. In the DTOF (τ) based one-dimensional flow simulation, the accuracy of the pressure solution relies significantly upon the drainage volume characterization and the DTOF calculation, both of which are influenced by the reservoir heterogeneity. We study first order discretization schemes of the Eikonal equation in porous media with different levels of heterogeneity and determine the impact of the corresponding DTOF solutions upon the one-dimensional flow simulation. The local solution of the Eikonal equation is formulated based on a piecewise uniform approximation of the DTOF gradient that satisfies a causality requirement within each simplex that provides the available nodal DTOF values. A homogenization approach is developed for use within the local solution for corner point grid cells, in which effective properties are obtained across adjacent grid cells. Comparison of the computational cost and error from different discretizations of the Eikonal equation and the corresponding pressure solution with increasing heterogeneity, demonstrates the need for increased angular resolution compared to the most usual cell centered 5-point discretization. The study also demonstrates the need for more accurate solutions in the near well region, suggesting a multi-stencil approach with higher angular and linear resolution near the well, and a less accurate and less costly calculation in the bulk of the computational grid.

Abstract Background Whether smoking modifies the associations of diabetes and risk factor management with subsequent risk of cardiovascular disease (CVD), and whether the smoking related CVD risk differs among people with and without diabetes are unclear. This study aimed to examine the associations and interactions of smoking, diabetes, and risk factor management in relation to incident CVD. Methods This nationwide, population-based, prospective cohort study of 20 communities from various geographic regions recruited adults aged 40 years or older during 2011–2012. The follow-up survey was conducted between 2014 and 2016. This study included 126,181 participants who were free from CVD at baseline. Results Study participants included 19,397 current smokers (15.4%), 6,049 former smokers (4.8%), and 100,735 never smokers (79.8%). Mean (SD) age ranged from 55.8 (8.6) years to 60.7 (9.1) years. Compared with never smokers, heavy smokers exhibited a greater risk of CVD events among participants with diabetes (multivariable-adjusted hazard ratio [HR], 1.45; 95% CI, 1.17–1.78) than among participants without diabetes (HR, 1.20; 95% CI, 1.01–1.42; P for interaction = 0.006). Compared with participants without diabetes, participants with diabetes who were never smokers and had 5 or more controlled risk factors showed no significantly excess CVD risk (HR, 0.93; 95% CI, 0.71–1.22), but the cardiovascular benefits from risk factor management were counteracted among participants with diabetes who were current smokers (HR, 1.28; 95% CI, 0.77–2.14) or former smokers (HR, 1.22; 95% CI, 0.66–2.28). Conclusions Smoking and diabetes interacted with each other in relation to increased risk of CVD events, and the beneficial effect of risk factor management on CVD risk among participants with diabetes was attenuated by current or former smoking.

The coal-dominated energy structure in the Beijing–Tianjin–Hebei region has caused serious air pollution and contradicts the construction of a clean, low-carbon, safe and efficient energy system. Substituting geothermal energy for fossil energy such as coal can effectively alleviate this problem. Located in the hinterland of the Beijing-Tianjin-Hebei region, the Jizhong Depression is rich in geothermal resources and has great development potential, though the degree of current development and utilization is not high. Vigorously developing geothermal energy can not only effectively alleviate the air pollution problem in the Beijing–Tianjin–Hebei region, but also optimize the regional energy structure. Geothermal reservoir temperature determines the development and utilization value of geothermal resources, and accurate evaluation of the geothermal reservoir temperature of geothermal resources can provide a reliable basis for the subsequent development of geothermal resources in the Jizhong Depression. Aiming at the commonly used sandstone geothermal reservoir and carbonate geothermal reservoir in the Jizhong Depression, this paper collected 24 sandstone geothermal reservoir geothermal fluids and 14 carbonate geothermal reservoir geothermal fluids in the central-southern area of the Jizhong Depression and a water chemistry test was carried out. According to the test results of water chemistry, the temperature of the geothermal reservoir is estimated by using the cation geothermometer, the SiO2 geothermometer and the multi-mineral equilibrium method, and it is compared with the actual temperature measurement results of the boreholes. The results show that the direct use of a geothermal geothermometer for calculation will cause large errors. Through water–rock balance analysis, the use of a Na-K-Mg balance diagram, SiO2 and 1000/T relationship diagram and Na/K and 1000/T relationship diagram can determine whether the geothermal fluid is suitable for the geothermometer, which can effectively reduce the error. The chalcedony geothermometer in the central and southern part of the Jizhong Depression is the most suitable. The multi-mineral balance method, the Na-K geothermometer and the K-Mg geothermometer have also achieved good results, while the quartz and Na-K-Ca geothermometers are not suitable for the south-central Jizhong Depression area.

Negative pressure has emerged as a powerful tool to tailor the physical properties of functional materials. However, a negative pressure control of spin-phonon coupling for engineering magnetism and multiferroicity has not been explored to date. Here, using uniform three-dimensional strain-induced negative pressure in nanocomposite films of (EuTiO3)0.5:(MgO)0.5, we demonstrate an emergent multiferroicity with magnetodielectric coupling in EuTiO3, matching exactly with density functional theory calculations. Density functional theory calculations are further used to explore the underlying physics of antiferromagnetic-paraelectric to ferromagnetic-ferroelectric phase transitions, the spin-phonon coupling, and its correlation with negative pressures. The observation of magnetodielectric coupling in the EuTiO3 reveals that an enhanced spin-phonon coupling originates from a negative pressure induced by uniform three-dimensional strain. Our work provides a route to creating multiferroicity and magnetoelectric coupling in single-phase oxides using a negative pressure approach.

BACKGROUND:National investigations on age-specific modifiable risk factor profiles for cardiovascular disease (CVD) and mortality are scarce in China, the country that is experiencing a huge cardiometabolic burden exacerbated by population ageing. METHODS:This is a nationwide prospective cohort study of 193,846 adults in the China Cardiometabolic Disease and Cancer Cohort Study, 2011-2016. Among 139,925 participants free from CVD at baseline, we examined hazard ratios and population-attributable risk percentages (PAR%s) for CVD and all-cause mortality attributable to 12 modifiable socioeconomic, psychosocial, lifestyle, and metabolic risk factors by four age groups (40-<55 years, 55-<65 years, 65-<75 years, and ≥75 years). FINDINGS:Metabolic risk factors accounted for 52·4%, 47·2%, and 37·8% of the PAR% for CVD events in participants aged 40-<55 years, 55-<65 years, and 65-<75 years, respectively, with hypertension being the largest risk factor. While in participants aged ≥75 years, lifestyle risk factors contributed to 34·0% of the PAR% for CVD, with inappropriate sleep duration being the predominant risk factor. Most deaths were attributed to metabolic risk factors (PAR% 25·3%) and lifestyle risk factors (PAR% 24·6%) in participants aged 40-<55 years, with unhealthy diet and diabetes being the main risk factors. While in participants aged ≥55 years, most deaths were attributed to lifestyle risk factors (PAR% 26·6%-41·0%) and socioeconomic and psychosocial risk factors (PAR% 26·1%-27·7%). In participants aged ≥75 years, lifestyle risk factors accounted for 41·0% of the PAR% for mortality, with inappropriate sleep duration being the leading risk factor. INTERPRETATION:We identified age-specific modifiable risk profiles for CVD and all-cause mortality in Chinese adults, with remarkable differences between adults aged ≥75 years and their younger counterparts. FUNDING:National Natural Science Foundation of China.

Background National investigations of age-specific modifiable risk profiles for diabetes are crucial to promote personalised strategies for the prevention and control of diabetes, particularly in countries such as China, which is experiencing both a diabetes epidemic and a rapidly ageing population. We aimed to examine the associations of 12 potentially modifiable socioeconomic, lifestyle, and metabolic risk factors with diabetes in a nationwide prospective cohort of Chinese adults across four age groups. Methods We analysed data from the China Cardiometabolic Disease and Cancer Cohort Study, a nationwide, population-based, cohort study done between )an 1,2011, and Dec 31,2016. Among 93 781 participants without diabetes at baseline and with complete information available about risk factors and diabetes incidence, we examined the hazard ratios (HRs) and population-attributable risk percentages (PAR%s) of incident diabetes associated with 12 potentially modifiable risk factors: two socioeconomic risk factors (less education and intermediate or low grade occupation), five lifestyle risk factors (unhealthy diet, physical inactivity, current alcohol consumption, current smoking, and unhealthy sleep), and five metabolic risk factors (general or central obesity, insulin resistance, prediabetes, hypertension, and dyslipidaemia) across four age groups (40 to <55 years, 55 to <65 years, 65 to <75 years, and >= 75 years). Findings With 337932 person-years' follow-up, 6171 participants developed diabetes. Although diabetes risk attributable to metabolic risk factors decreased slightly with age, metabolic risk factors accounted for most incident diabetes cases across all age groups (from a PAR% of 73.8% in participants aged 40 to <55 years to 65.5% in those aged >= 75 years), with prediabetes (ranging from a PAR% of 56.6% to 47.4%, with increasing age) and hypertension (PAR% of 16.8% to 28.6% with increasing age) being the leading risk factors across all age groups. By contrast, diabetes risk attributable to lifestyle risk factors increased substantially with age (with a PAR% of 9.9% in adults aged 40 to <55 years increasing to 29.7% in adults aged >= 75 years), and was especially evident in participants aged 75 years or older, in whom unhealthy sleep was the largest lifestyle factor, accounting for a PAR% of 17.0%. The impact of socioeconomic risk factors on diabetes was mainly driven by less education, which contributed to a PAR% of 7.1% to 12.4% in participants younger than 75 years but conferred no excess risk in participants aged 75 years or older. The risk of diabetes associated with unhealthy sleep significantly increased with age group (HR 1.04 [95% CI 0.95-1-13] among participants aged 40 to <55 years vs 1.36 [1.01-1.85] among participants aged >= 75 years; p(interaction)=0-0054), but there was an age-related decrease in the risk of diabetes associated with obesity (1.35 [1.23-1.48] vs 0.99 [0-72-1.36]; p(interaction)=0.0003), prediabetes (3.00 [2.67-3.37] vs 2.18 [1.41-3-37]; p(interaction)=0.0014), and dyslipidaetnia (1.23 [1.13-1.34] vs 0.90 [0.66-1.21]; p(interaction)=0.016) Interpretation These findings provide novel insights into age-related modifiable risk factor profiles for diabetes in Chinese adults, highlighting the importance of prioritising risk factors according to age groups for effective prevention and management of diabetes. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.

AIMS/HYPOTHESIS:We aimed to evaluate the effect of NAFLD on the risk of incident cardiovascular disease (CVD) and estimated glomerular filtration rate (eGFR)-based chronic kidney disease (CKD), and further test the joint effects and interactions between NAFLD status and individual metabolic element, as well as the total 'ABCs' metabolic goal achievement, on the CVD and CKD risk among 101,296 patients with prediabetes or diabetes from a prospective cohort study. METHODS:We conducted the study based on the China Cardiometabolic Disease and Cancer Cohort (4C) study, a large-scale, population-based prospective cohort. After excluding alcohol abuse and other cause of hepatic diseases, we used fatty liver index (FLI) ≥ 60 as a proxy of NAFLD and stratified the probability of fibrosis by aspartate transaminase/alanine transaminase ratio (AAR) with cut-offs of 0.8 and 1.4. 'ABCs' metabolic goal was defined as subjects who had HbA1c < 6.5% (A), SBP/DBP < 130/80 mmHg (B), and LDL-C < 100 mg/dL (C). During 3.8 years follow-up, we validated 2340 CVD events based on medical records and identified 1943 participants developed CKD based on centrally tested eGFR. RESULTS:The multivariable adjusted hazard ratios (HRs) were 1.15 (95% confidence interval (CI), 1.05-1.27) for CVD events and 1.33 (95% CI, 1.20-1.48) for CKD among NAFLD patients, compared with participants without NAFLD. Of NAFLD patients, relative to individuals with low AAR (<0.8), those with high AAR (≥1.4) were more likely to experience CVD events [1.62 (1.21-2.18)] and CKD [1.63 (1.17-2.28)]. Participants with NAFLD and comorbid poorly controlled metabolic risk factors had higher risk of CVD events or CKD than having either alone, with a significant interaction between poor glycemic control and NAFLD on the risk of vascular complications. CONCLUSIONS:NAFLD was associated with incident CVD and CKD among patients with prediabetes or diabetes. Such associations were substantially modified by the comprehensive achievement of metabolic goal.

AIM:The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age. METHODS:This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models. RESULTS:Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age. CONCLUSION:Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Calibration of reservoir model properties by integration of well-test data remains an important research topic. Well-test data have been recognized as an effective tool to describe transient flow behavior in petroleum reservoirs. It is also closely related to the drainage volume of the well and the pressure-front propagation in the subsurface. Traditional analytic means of estimating reservoir permeability relies on an interpretation of the diagnostic plot of the well pressure and production data, which usually leads to a bulk average estimation of the reservoir permeability. When more detailed characterization is needed, a forward model that is sensitive to the reservoir heterogeneity needs to be established, and a numerical inversion technique is required. We use the concept of the diffusive time of flight (DTOF) to formulate an asymptotic solution of the diffusivity equation that describes transient flow behavior in heterogeneous petroleum reservoirs. The DTOF is obtained from the solution of the Eikonal equation using the fast marching method (FMM). It can be used as a spatial coordinate that reduces the 3D diffusivity equation to an equivalent 1D formulation. We investigate the drainage-volume evolution as a function of time in terms of the DTOF. The drainage volume might be directly related to the well-test derivative, which can be used in an inversion calculation to calibrate reservoir model parameters. The analytic sensitivity coefficients of the well-test derivative with respect to reservoir permeability are derived and incorporated into an objective function to perform model calibration. The key to formulating the sensitivity coefficients is to use the functional derivative of the Eikonal equation to derive the analytic sensitivity of the DTOF to reservoir permeability. Its solution is implemented by tracking the characteristic trajectory of the local Eikonal solver within the FMM. The major advantage of calculating the sensitivity coefficients using the FMM is its significant computational efficiency during the iterative inversion process. This inverse-modeling approach is tested on a 2D synthetic heterogeneous reservoir model and then applied to the 3D Brugge Field, where a single well with constant flow rate is simulated. The well-test derivative is shown to be inversely proportional to the drainage volume and is treated as the objective function for inversion. With an additional constraint to honor the prior model, our inverse-modeling approach will adjust the reservoir model to obtain permeability as a function of distance from the well within the drainage volume. It provides a modification of reservoir permeability both within and beyond the depth of investigation (DOI).

The desire for room-temperature multiferroicity has motivated the search for hidden phase transitions at higher temperatures. By means of the imposition of vertical strain in EuTiO3 (ETO)–MgO nanocomposite films, we unveil two hidden phase transitions in the strained ETO phase at around T′ = 80 K and T* = 230 K, and we are able to tune the behavior of the electrical conductivity at these temperatures. Compared with the phase transition temperatures in bulk ETO, T′ remains unchanged and T* is increased owing to stretching of the c-axis lattice. Interface-limited conduction appears at both transitions, in contrast to the bulk-limited mode shown at other temperatures. With regard to the underlying mechanism, it is found that controllable behavior of conduction at the transition temperatures can be achieved by the common effect of vertical strain and oxygen vacancies. Overall, the present work highlights the importance of the effect of vertical strain in revealing and enhancing the tunability of properties at hidden phase transitions.

Nano-multilayered TiAlN/CrAlN coatings combining advantages of Ti-Al-N and Cr-Al-N are considered to be promising candidates for advanced machining processes. Here, the structure and thermal properties of Ti1-xAlxN/CrAlN (x = 0.48, 0.58, and 0.66) multilayered coatings as well as referential Ti1-xAlxN and Cr0.32Al0.68N monolithic coatings were investigated. Ti1-xAlxN coatings show a structural transformation from cubic structure for x = 0.48 to mixed cubic and wurtzite structure for x = 0.58 and 0.66, and Cr0.32Al0.68N coating exhibits a single cubic structure. Through a multilayer arrangement with Cr0.32Al0.68N layers, the Ti0.52Al0.48N and Ti0.42Al0.58N layers can be stabilized in their metastable cubic structure, but the Ti0.34Al0.66N layer still tends to crystallize in the mixed cubic and wurtzite structure. The hardness of Ti0.52Al0.48N/CrAlN and Ti0.42Al0.58N/CrAlN coatings is higher than that of corresponding monolithic coatings regardless of as-deposited and annealed states. Especially, after annealing at 800°C, the Ti0.52Al0.48N/CrAlN and Ti0.42Al0.58N/CrAlN coatings reach their peak hardness of ~34.2 and 32.8 GPa due to the spinodal decomposition of Ti1-xAlxN layers. However, the oxidation resistance of Ti1-xAlxN/CrAlN coatings is mainly up to the Al content of Ti1-xAlxN layers, where only the Ti0.34Al0.66N/CrAlN coating can survive the 10 h exposure to air at 1000°C.

Since the superiority of tribological properties, V-containing coatings, with the potential to generate lubricious Magnéli oxides at elevated temperatures, are regarded as excellent candidates for machining applications. Here, a study was conducted to shed light on the intrinsic thermal stability, mechanical properties and oxidation resistance of V-alloyed CrAlN coatings deposited by cathode arc evaporation. The hardness of Cr0.48Al0.52N and Cr0.44Al0.50V0.06N coatings with a single-phase face-centered cubic structure is 30.8 ± 0.9 and 33.0 ± 1.3GPa, respectively. Upon annealing in Ar atmosphere, Cr0.44Al0.50V0.06N coating reveals a retarded precipitation of wurtzite AlN as well as a postponement in Cr–N disintegration as compared to V-free Cr0.48Al0.52N coating, owing to the solid solution of V with a stronger binding capacity with nitrogen. The improved structural stability of Cr0.44Al0.50V0.06N coating contributes to the mild decline in hardness and elastic modulus upon annealing. When exposed to air, the incorporation of V into CrAlN promotes the formation of (Al, Cr)2O3 mixed oxide as well as additional V2O5, leading to a significantly lower onset temperature for oxidation. The existence of V2O5 degrades the protective of (Al, Cr)2O3 oxide layer and causes a complete oxidation of Cr0.44Al0.50V0.06N coating at 950°C, where only a dense and thin oxide scale can be detected in Cr0.48Al0.52N coating.

With the goal of integrating superconducting iron chalcogenides with Si-based electronics, superconducting FeSe0.1Te0.9 thin films were directly deposited on Si and SiOx/Si substrates without any buffer layer by a pulsed laser deposition (PLD) method. Microstructural characterization showed excellent film quality with mostly c-axis growth on both types of substrates. Superconducting properties (such as superconducting transition temperature T-c and upper critical field H-c2) were measured to be comparable to that of the films on single crystal oxide substrates. The work demonstrates the feasibility of integrating superconducting iron chalcogenide (FeSe0.1Te0.9) thin films with Si-based microelectronics.