Interregional and intersectoral interaction of digital economy in China

With the continuous advancement of the integration of the world’s digital economy, the economic development of various regions has become increasingly interdependent. However, the interregional interactions of digital industries have yet to be further elucidated. Here, based on the Multi-Regional Input-Output model, we take China, for example, and analyze the impact of digital industries on the economy from the industrial and regional. At the industry level, we discuss the economic spillover relationship between the digital industry and the three traditional industries, and analyzes the spatial and temporal differentiation in the inter-industry spillover status of China’s 30 provinces; at the regional level, we discuss the digital industrial economic spillover links and spillover states. The results show that: 1) The self-generating ability within the digital industry sector is the most significant factor influencing the industrial growth of China’s digital economy, followed by the interrelated effect between industry sectors, while the inter-industry feedback effect has a weak impact on the economic system. 2) There is a clear gap in the economic spillover capacity of the digital industry in 30 provinces, and the overall performance is decreasing in the eastern, central and western regions. 3) The intra-regional multiplier effect of digital industry shows a slowly decreasing trend, and the intra-regional digital economic spillover-feedback effect shows a growing trend. At the same time, the inter-regional digital economy interaction tends to decay in distance, indicating that regional accessibility has a significant impact on the inter-regional spillover effect

Hot deformation behavior and processing map of Mg-2Zn-1Al-0.2RE alloy

In this study, uniaxial hot compression tests were carried out between 200 and 400 °C over strain rates of 0.001–1 s–1 to investigate the hot deformation behavior of Mg-2Zn-1Al-0.2RE alloy with coarse grains. The average activation energy was measured to be 174.51 KJ/mol. In addition, a constitutive relation based on the Arrhenius equation was established. Dynamic recrystallization (DRX) kinetics were studied by Avrami equation to characterize the evolution of DRX volume fraction. DRX was favored at high temperatures of 300–400 °C and low strain rates of 0.001–0.01 s–1. According to dynamic material model and Prasad's instability criterion, a maximum power dissipation of 38% and 32% occurred at 400 °C/0.001 s–1 and 400 °C/0.01 s–1, respectively. According to the processing map, 330–400 °C/0.001–0.01 s–1 was determined as the optimum deformation parameter range

Effects of estradiol on reduction of osteoarthritis in rabbits through effect on matrix metalloproteinase proteins

Objective(s): Osteoarthritis (OA), as a known degenerative joint disease, is the most common form of arthritis. In this study, we aimed to elucidate unclear pathogenesis of OA. Materials and Methods: Rabbit models of OA were established by the transection of the anterior cruciate ligament. Rabbits were randomly divided into three equal groups: the experimental group (OA modeling, treated with estradiol), the control group (OA modeling, treated with normal saline) and the normal group (without OA modeling). The glycosaminoglycan (GAG) and hyaluronan (HA) content of knee joint were collected and assayed. In addition, gene expression of matrix metalloproteinase (MMP)-1, MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 were evaluated by real-time PCR and Western blot analysis. Results: Animal models were developed successfully. GAG and HA concentrations were significantly increased in the experimental and the normal group compared with the control group (P

Secular trends of hypertension prevalence based on 2017 ACC/AHA and 2018 Chinese hypertension guidelines: Results from CHNS data (1991‐2015)

Abstract This study aimed to assess the impact of the 2017 American College of Cardiology and American Heart Association (ACC/AHA) guideline and the 2018 Chinese hypertension guidelines on the different secular trends for hypertension prevalence. A total of 82 665 eligible individuals aged ≥20 years were selected from nine cross‐sectional study periods (1991‐2015) from the China Health and Nutrition Survey (CHNS). Over the 24‐year period, the long‐term trend for the prevalence of the 2017 ACC/AHA‐defined age‐adjusted hypertension showed an increase from 32.2% (95% confidence interval (CI): 31.0%‐33.3%) in 1991 to 60.0% (95% CI: 58.6%‐61.3%) in 2015 (Ptrend < 0.001). According to the 2018 Chinese guideline for hypertension, the weighted hypertension prevalence increased from 10.0% (95% CI: 9.4%‐10.5%) in 1991 to 28.7% (95% CI: 27.9%‐29.6%) in 2015 (Ptrend < 0.001). However, slopes of increasing prevalence of hypertension were significantly greater according to the 2017 ACC/AHA guideline than that based on Joint National Committee (JNC 7) report (β = 1.00% vs β = 0.67% per year, respectively, P = 0.041). Based on the 2017 ACC/AHA definition, the prevalence of stage 1 hypertension and elevated blood pressure significantly increase from 22.3% and 6.9% in 1991 to 31.2% and 10.1% in 2015 (all P < 0.05), respectively. The secular trend for the prevalence of hypertension according to the 2017 ACC/AHA guideline showed a greater rate of increase compared with the prevalence based on the 2018 Chinese hypertension guidelines. Public health initiatives should focus on the current status of hypertension in China because of the possible high prevalence of hypertension and concomitant vascular risks

A constitutive relation of AZ80 magnesium alloy during hot deformation based on Arrhenius and Johnson-Cook model

In order to understand the constitutive behavior of as-cast AZ80 with large grain size, the uniaxial hot compression tests were carried out over a series of isothermal upsetting experiments. The maximum deformation degree was 65%. The experimental temperatures were 523 K, 573 K, 623 K and 673 K and the strain rate was 0.001 s(-1), 0.01 s(-1), 0.1 s(-1), and 1 s(-1). The stress-strain curves can be divided into three stages which are work hardening stage, softening stage, and steady-state stage at low strain rate and high temperature, while the steady-state stage cannot be observed at low forming temperature and high strain rate because of incomplete dynamic recrystallization. The Arrhenius type relation predicts the peak stress with high accuracy but cannot satisfy the strain relevant requirement. The Johnson-Cook model shows an inappropriate ability to describe the constitutive behavior in this case. Therefore, a new mathematic model (a segmented model) with high prediction accuracy based on the modified Arrhenius type relation (including strain rate) and Johnson-Cook model is proposed. The modified Arrhenius type relation is used to reflect the constitutive behavior before the peak strain and the modified Johnson-Cook model is aimed at showing the stages after peak strain

Efficient SO₂ Absorptions by Four Kinds of Deep Eutectic Solvents Based on Choline Chloride

Four kinds of deep eutectic solvents (DESs) based on choline chloride (ChCl) with ethylene glycol (EG), malonic acid (MA), urea, and thiourea as hydrogen bond donors were prepared and characterized. All these DESs show good thermal stability and can be stable at 363 K, which is beneficial for the application in flue gas desulfurization. Then, SO₂ absorption capacities of these DESs were determined at different temperatures and SO₂ partial pressures. The absorption results demonstrate that ChCl–EG (1:2) and ChCl–thiourea (1:1) DESs exhibit excellent absorption performances, and the absorption capacities are 2.88 and 2.96 mol SO₂ per mol DES at 293 K and 1 atm, respectively. In addition, the SO₂ absorption and regeneration experiments were conducted. All solvents can be regenerated at 343 K with N₂ bubbling, and the absorption capacities of DESs remain without a significant loss after six absorption and desorption cycles. What’s more, the absorption mechanism of SO₂ in these DESs were investigated by IR and ¹H NMR

Solubility of Dilute SO₂ in Mixtures of <i>N</i>,<i>N</i>‑Dimethylformamide + Polyethylene Glycol 400 and the Density and Viscosity of the Mixtures

In this work, the isothermal gas–liquid equilibrium (GLE) data were measured for the system of polyethylene glycol 400 (PEG 400) + <i>N</i>,<i>N</i>-dimethylformamide (DMF) + SO₂ + N₂ at 308.15 K and 123 kPa with SO₂ partial pressures in the range of (16.8 to 115) Pa. The Henry’s law constant (<i>H</i>′) and standard Gibbs free energy change (Δ<i>G</i>) were calculated from these GLE data. Furthermore, the densities and viscosities of binary mixtures of DMF + PEG 400 were also measured over the whole concentration range at <i>T</i> = (298.15 to 313.15) K. From the experimental data, including density and viscosity values, the excess molar volumes (<i>V</i>_m^E), and viscosity deviations (Δη), the calculated results are fitted to a Redlich–Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and the calculated quantities

Comparison study of hot deformation behavior and processing map of AZ80 magnesium alloy casted with and without ultrasonic vibration

In order to compare the workability of AZ80 magnesium alloy casted with and without variablefrequency ultrasonic field (VUF), uniaxial hot compression tests were carried out in the temperature range of 523-673 K and the strain rate range of 0.001-1 s(-1) on a Gleeble-3500D thermo-mechanical simulator. The flow stress, constitutive relation, DRX kinetic model and processing map were analyzed based on the experimental data. The results show that, the VUF samples have lower peak stress and peak strain than DC samples at low strain rates, while the opposite situation can be observed at high strain rate. The calculated activation energy Q and stress exponent n for DC samples are 192.38 kJ/mol and 7.30158, which are higher than the calculated values for VUF samples, showing the figures of 165.30 kJ/mol and 7.30158, respectively. The VUF casted samples start DRX earlier and easier, and can obtain complete DRX structure at high strain rate. The VUF samples have larger workability range but smaller instability region than DC samples. Dense and irregular bulges can be observed on side surfaces of DC samples after compression, while surfaces of VUF samples are smooth. (C) 2019 Elsevier B.V. All rights reserved

Effect of solvent extraction on the composition of coal tar residues and their pyrolysis characteristics

A large amount of coal tar residues (CTRs) produced in the coal coking or gasification industry has not been effectively utilized in China. In this study, CTRs are extracted by 12 organic solvents. Detailed investigations are carried out via ultimate analysis, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG) analyzer. The pyrolysis process of CTRs and their extraction residues (RCTRs) can be accurately fitted by Coast-Redfern integral model. The results indicate that the reaction order (n), apparent activation energy (Ea) and pre-exponential factor (A) were in the range of 2–7, 34.42–60.08 kJ mol−1 and 102-105 min−1, respectively. Correlations are observed between parameters (H, C, O, H/C, WT, Rmax, n, Ea, and lnA) and the yield of RCTRs, suggesting that the composition and pyrolysis behavior are controlled by the solvent extraction. Specifically, extraction with n-heptane, methanol and ethanol could reduce the Ea and promote CTRs decomposition by disrupting the noncovalent bonds. When extracted with CS2, DMF, benzene, toluene, acetone, etc. the recovery rate of tar and the yield of pyrolysis products are improved, however, the reactivity decrease due to the increase in activation energy.</p