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Objective: The study aimed to investigate the effects of Periplaneta americana glycoprotein (PAG) on the growth and metabolites of Lactobacillus plantarum and Bifidobacterium adolescentis. Methods: With inulin as a positive control, the probiotic bacteria were cultured in medium containing different concentrations of PAG (MRS medium with PAG concentrations of 0.5, 1.0, 2.0, and 4.0 mg/mL, respectively. TPY medium with PAG concentrations of 1.0, 2.0, 4.0, and 8.0 mg/mL, respectively) to determine the OD600 and pH, and the contents of lactic acid, short-chain fatty acid (SCFA, snamely acetic acid, propionic acid and butyric acid) in the bacterial solution. Results: The growth of Lactobacillus plantarum was greatest when the concentration of PAG reached 1.0 mg/mL, while Bifidobacterium adolescentis grew best with a PAG concentration of 2.0 mg/mL. The OD600 value, production of lactic acid and SCFAs of Lactobacillus plantarum solution at 1.0 mg/mL PAG were higher than those of inulin, while the pH value was significantly lower. In the bacterial solution of Bifidobacterium adolescentis with 2.0 mg/mL PAG, the values of OD600 and the production of propionic acid and butyric acid increased compared to the same concentration of inulin, the lactic acid production was better than that of inulin at 12 h, the acetic acid production was better than that of inulin at 24 h, and the pH value decreased, indicating that PAG and inulin had different effects on promoting Bifidobacterium adolescentis to produce lactic acid and SCFAs. Conclusion: The PAG could promote the proliferation and organic acid production of Lactobacillus plantarum and Bifidobacterium adolescentis, and the effect was better than that of inulin.

Accurately determining the casing breakage characteristics in mining wells and proposing corresponding preventive and control measures can provide an important guarantee for the long-term stability of the wellbore. Taking the No. 21 coal seam and overlying strata in the Pingdingshan mining area as the research object, theoretical calculations and numerical simulation were used to determine the stress and displacement distribution law of separation section in the overlying strata. The correlation between the height of the overlying strata, the horizontal distance from the working face and stress and displacement were analyzed, and the relationship between the height of the overlying strata, the horizontal distance from the working face and the stress and displacement were fitted. Based on the actual development experience of mining wells in the research area, the main types of casing breakage in the optimal well layout area were determined. Combined with the commonly used casing mechanical parameters, the casing breakage location and length under the “two field” evolution were characterized. The commonly used local protection technologies for mining wells was summarized and the corresponding preventive and control measures were proposed. The results shown that, in the process of working face advancement, the stress of the overlying strata shown a change pattern of from fluctuation to linear decrease, and the displacement shown a change pattern of from almost unchanged to hyperbolic type. The casing in the optimal well layout area was mainly characterized by tensile shrinkage and shear fracture, and the casing reinforcement was applied to reinforce the casing in mining well. When N80 casing was used in the third section of the ground mining well in the research area, it was necessary to install anti- tensile and shear casing reinforcement in the upper 46 m of the coal seam at the sub-critical layer and in the upper 54 m of the coal seam at the soft/hard interlayer. When P110 casing was used, it is necessary to install anti-tensile reinforcement in the upper 46 m of the coal seam at the sub-critical layer. It is recommended to use P110 casing for all three sections of the surface mining wells in the research area to increase the wellbore stability in mining well. The research achievement can provide theoretical guidance for preventing casing breakage in the Pingdingshan mine and mining wells under similar conditions.

Aiming at the problem of low degree of exploration and research of geothermal geological conditions in the Shifugou area, which seriously restricts the development and utilization of geothermal resources, on the basis of available data, the geothermal geological conditions and the characteristics of the thermal reservoir in the Lanzhou faulted basin are summarized. Combined with the exploration results of the controlled source audio frequency magnetotelluric (CSAMT) method, the potential of geothermal resources development in the Shifogou area in the southern part of the basin is inferred. The results show that (1) the geothermal geological conditions in the Lanzhou faulted basin are obviously different. Taking the buried faults of Shengouqiao (F5) and Leitai River (F8) as the boundary, respectively, the faulted basin can be divided into the western Xigu district, central Qilihe district and eastern Chengguan-Shifogou district. (2) The geothermal temperature increases from west to east, and increases vertically from the depth of 2000 to 2500 m, inferring that this is the basic depth of geothermal exploitation in the Lanzhou faulted basin. (3) In the southern section of the eastern part may exist layered-conductive geothermal resources and fault-zone geothermal resources, it is inferred that there may exist “combined type” of layered and banded geothermal water in the Shifogou district, which is located in the F2 fracture zone or the intersection of F2 fracture zone and F8 fault zone. It is suggested that the exploration and production well depth of geothermal water in the faulted-zone thermal reservoir should be considered as 800−1100 m, and that the exploration and production well depth of the “combined” layered thermal reservoir should be considered as 1500−2000 m. The wellhead geothermal water temperature in this area is expected to reach 50−60 °C, the single well yield can reach 500−1000 m3/d, and the quality of the geothermal water can reach the standard for medical bathing. The results can provide a basis for geothermal resources exploration in Lanzhou.

6061-T6 aluminum alloy plate (3 × 150 × 300 mm3) was welded by tungsten inert gas (TIG) welding. The welding process methods are single-pass welding process and full welding process respectively. The effects of different welding processes on the performance of TIG welding 6061-T6 aluminum alloy were compared and studied. The effects of microstructure and precipitation on the microhardness and tensile strength were analyzed by optical microscope, scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS) characterization, electron backscattering diffraction (EBSD) characterization, microhardness and tensile test. The microstructure of the weld zone is mainly composed of aluminum solid solution (α-Al) dendritic structure and Al–Si eutectic structure. Through EBSD characterization analysis, the average grain size of the weld zone of the full welding process and the single-pass welding process is about 45 μm and 55 μm, and the grain size of the heat-affected zone and the weld zone of the two welded joints does not change significantly. The hardness curves of the two welded joints have the same distribution trend, which is roughly 'W' type distribution. In the tensile test, the tensile strength of the single pass welding process is lower than that of the full welding process, and the fracture of the tensile parts is dimple structure, which is ductile fracture. Through analysis and comparative study, the full welding process is better than the single-pass welding process when welding 6061-T6 aluminum alloy sheet.

Biodegradation is one of the important ways for the clean and efficient utilization of coal. However, the effectiveness of degradation by the combination of fungi and bacteria has not been well understood. In the present study, the combined degradation of the Yima coal was tested. The coal samples were firstly oxidized with nitric acid, followed by cultured in the media of Cunninghamella elegans and Bacillus sp.. The absorbance of A450, pH and metallic element (Cr, As, Mn, Pb, Co, Ni, Cu, Zn, Mo) contents of the degradation solution were determined by UV-visible spectrophotometry, pH meter and inductively coupled plasma mass spectrometry, respectively. The humic acid was analyzed by element analyzer, Fourier transform infrared spectroscopy and gas chromatog-raphy-mass spectrometry. The results showed that the humic acid yields of C. elegans, Bacillus sp. and their mixture were 58.17%, 61.00% and 67.17%, respectively. The pH of the degradation solution of mixed strains was similar to that of the bacteria. The characteristic products of the bacteria degradation were detected in the humic acid samples derived from mixed strains, while the opposite was true for the fungi. It was suggested that the combination of the two strains enhanced the alkaline environment and improved the degradation rate of nitric acid-treated coal. The bacteria played a leading role in the degradation process. Metallic elements (Cr, As, Mn, Pb, Co, Ni, Cu, Zn, Mo) were transferred from coal to the degradation solution during the degradation process, and the contents of Cr, As, Pb, Ni, Cu and Mo were fitted with A450, the coefficient of determination (R2) were greater than 0.6. It indicated that the contents of these six metal elements in the degradation solution could represent the degradation rate. Chemically extracted humic acid and biologically extracted humic acid were rich in the active functional groups such as carboxyl, hydroxyl, carbonyl, long-chain fatty acids (C16, C18) and four pyrrole derivatives. The biologically extracted humic acid also contained fatty acids (C3, C4, C5, C13, C14, C15), of smaller molecular weight, as well as nitrogen-containing compounds such as two pyrrole derivatives and a furan. The contents of C and H elements in the biologically extracted humic acid were higher than that in the chemically extracted humic acid.

The occurrence and production of coalbed methane is related to the development degree of pore system in coal reservoirs. The pore structure characteristics of original structural coal seam will change significantly after damage and deformation, thus affecting the adsorption/desorption and diffusion process of coalbed methane. Through the low-temperature liquid N2 and low-pressure CO2 adsorption analysis and isothermal adsorption experiments on coal with different structures from the No. 3 coal seam in Zhaozhuang coalfield in Qinshui Basin, the variation laws of pore structure and adsorption of coals with various destructive strengths were analyzed. Applying experimental data and numerical fractal modeling, the pore fractal characteristics of coal with different structures and their effects on methane adsorption and diffusion in coal were revealed. The results shown that with the increase of the destructive intensity of coal structures, the specific surface area and pore volume of coal increased, the proportion of 50-300 nm pores gradually decreased, the micropores and mesopores of 2-50 nm and ultra-micropores of less than 2 nm increased. As the main adsorption pores in coal, the ultra-micropores size was mainly distributed in 0.45-0.65 nm and 0.80-1.0 nm. The adsorption amount of N2, CO2 and CH4 increased with the increasing destructive degree of coal structure. The order of adsorption capacity from large to small was: intact coal>mylonitic coal > granulated coal > cataclastic coal. The fractal dimensions of the micro-, meso- and macro-porous structures indicated that the pore structure of tectonically deformed coals will be simplified. Coal with a higher damage intensity had a rougher pore surface (corresponding to a higher D1) and a more homogeneous pore size distribution (corresponding to a lower D2). The fractal dimension of ultra-microporous (Dm) gradually increased with the increasing structural destruction intensity of coal, and was positively correlated with Langmuir constant (VL) and the corresponding specific surface area, indicating that the increase of coal surface roughness led to the increase of specific surface area, which provided more adsorption points with high adsorption potential for gas adsorption and enhanced the adsorption capacity of coal. The effective diffusion coefficient and pore volume were positively correlated with the fractal dimensions D1 and negatively correlated with D2, which indicated better pore connectivity, increased pore volume, improved gas inlet and outlet efficiency, and enhanced gas diffusion efficiency of destroyed intact coal.

At cold temperatures, the stress after welding a blast furnace shell is not completely released because of the fast cooling speed, which results in cracks. To solve this problem, an integrated method combining gray relational analysis, back propagation (BP) neural network, and genetic algorithm-BP (GA-BP) was proposed in this study. Its aim was to analyze the dominant mechanism of residual stress in multi-layer and multi-pass welding process under the heating of ceramic sheet and achieve super-objective collaborative optimization of residual stress. GRA indicated that through the correlation analysis of welding parameters, residual stress, maximum temperature of characteristic point, and deformation, welding speed was determined to be an all-important factor affecting welding quality. A BP prediction model of residual stress was established. The predicted value was in good agreement with the experimental value, and the maximum error was 8.75%. The influence of each factor on the quality of welding seam is not a single, but a complex mechanism of mutual influence. GA-BP determined the combination of low level welding speed 28 mm/min, medium level welding current 210A and medium and low level welding voltage 21V as the optimal solution of low residual stress. The maximum prediction error of residual stress was 13.76%. The experimental results show that the maximum prediction error of residual stress is 4.4%, and the optimized weld has better macro and micro structure, which proves the feasibility of the multi-objective optimization method. Most importantly, the proposed method can effectively identify the optimal welding parameters, which can provide a reliable theoretical basis for engineering practice.

Explosion-welded steel/Al composite plate has advantages of excellent conductivity, heat conductivity, light weight, and corrosion resistance. While the elongation of explosion-welded steel/Al composite plate can not been predicted by the traditional damage fracture theory. Establishing a new prediction model to analyze the deformation behavior of steel/Al composite plate are necessary. First, the deformation behavior and interface microscopic characteristics of explosion-welded steel/Al composite plate were analyzed using uniaxial tensile tests and SEM experiments, the result showed that wave structure, brittle phase, and microcrack existed at the interface layer of composite plate, the uniform elongation and elongation of steel/Al composite plates basically deviate linearly from the mixing law. Second, simulation models were established to analyze the effect of interface wave structure, brittle phase, and interface microcracks on the instability and fracture behavior of explosion-welded steel/Al composite plate. The interface wave structure could enhance the elongation of the composite plate, while the uniform elongation of the composite plate decreased with the increasing of brittle phase and microcrack. When f0 = 0.985, the predicted tensile strength through simulation is 258.94 MPa, which only has a difference of 1.9 MPa from the experimental value, when the length of the crack increases from 0.03 mm to 0.2 mm, the uniform elongation of the composite plate decreases by 92.52%. Finally, M−K theory considering the characteristics of interface defects was established to predict the tensile instability behavior of steel/Al composite plates. The instability behavior of the composite plate considering interface defects could be accurately described using the modified M−K theory when the height of the interface groove of the composite plate was Δta/Δts=ha/hs and Δta+Δts=0.5mm.

In this paper, a novel method was proposed to improve the production efficiency and formability of titanium alloy, which was named triple-layer sheet hot stamping with a cold die cooling (THF). The titanium alloy sheet was clamped by two steel sheets with no adhesive added, then heated, transferred and formed together. In order to verify the ability in enhancing formability of this process, spherical part forming tests were carried out to study the formability under the single-layer sheet hot stamping (SHF) and THF. Finally, a plug socket part was formed to verify the practicability of the novel forming process. The finite element (FE) model was established to analyze the forming process finding that the formability of the parts were significantly improved after using THF process. Comparing with SHF process, the stamping depth increases by 135.7% at 900 °C in the THF process. The forming limit strain increases from 0.18 of the single-layer sheet to 0.51 of the triple-layer sheet. The forming limit strain obtained by the THF process is close to that of isothermal forming. The friction state is one of the main reason for improving formability. Moreover, for plug socket parts, there is almost no thinning of the part in the THF process at 900 °C. In conclusion, it has great advantages in improving the formability of titanium alloy using the THF process.

An accurate material constitutive model is very important to apply numerical simulation technology to predict, establish and optimize the thermoplastic forming process parameters of powder titanium alloy. To achieve this goal, the microstructure evolution and densification of TC4 powder titanium alloy were investigated during compression at temperatures from 860 °C to 960 °C, strain rates from 0.05 s−1 to 20 s−1 and strains from 0.357 to 1.204. The results show that the microstructure undergoes dynamic recrystallization under different conditions. High temperature, large deformation degree and low strain rate are helpful to reduce porosity, pore size and pore colony. Plastic deformation and diffusion are two main mechanisms of densification. The microstructure evolution and densification model were established, combining the power constitutive law, a unified constitutive model was proposed to predict flow stress, microstructure and relative density of TC4 powder titanium alloy. The model constants were determined through a genetic algorithm. The predicted values of flow stress and relative density agreed well with the experimental values. The variations in relative density with temperature, strain rate and strain were analyzed based on the prediction results.

Background: The arrival of the big-data era provides us with a chance to elaborate the spectrum and epidemiological characteristics of infectious diseases in children and adolescents aged 0–18 years in the pre-COVID-19 pandemic era. Methods: We collected data on infectious diseases in 891,981 participants from the Cheeloo Lifespan Electronic Health Research Data-library. The incidence density of each infection was calculated and stratified by age and region. The annual percentage change (APC) in incidence was estimated by logarithmic linear regression. Results: A total of 18,183 cases of 78 infections were diagnosed, with an overall incidence density of 626.33 per 100,000 person-years (PY). Of these, 6825 cases of 50 non-notifiable infectious diseases were identified. Children aged 1–3 years had the highest incidence of infections. The overall incidence revealed a significant increasing trend from 2013 to 2017 (APC = 36.9%, p < 0.05). Hand, foot, and mouth disease, pneumonia, and influenza were the three most common diseases. The incidence of pneumonia, rubella, scarlet fever, zoster, molluscum contagiosum, and syphilis increased significantly during the study period (all p < 0.05). Taian, Binzhou, and Weihai had the highest incidence of all other cities. The incidence of gastrointestinal infections increased markedly in the eastern coastal regions. Conclusions: More stress should be placed on a number of non-notifiable infectious diseases with a high burden and a significant increasing trend. Age-based and regional targeting efforts are needed to prevent and contain infectious diseases among children and adolescents.

Climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components, while the motion control of climbing manipulation-oriented robots (CMo-Rs) is still challenging considering anti-slippage problems. In this study, a CMo-R with full-scenery climbing capability and redundant load-bearing mobility is designed based on magnetic adsorption. A four-wheel kinematic model considering the slipping phenomenon is established. An adaptive kinematic control algorithm based on slip estimation using Lyapunov theory is designed for uncertain inclined planes. For comparison, the traditional PID-based algorithm without slip consideration is implemented as well. Numeric simulations are conducted to tackle the trajectory tracking problems for both circular and linear trajectories on the horizontal plane (HP), 50° inclined plane (50° IP), 60° inclined plane (60° IP), and vertical plane (VP). The results prove that our approach achieves better tracking accuracy. It demonstrated applicability in various climbing scenarios with uncertain inclined planes. The results of experiments also validate the feasibility, applicability, and stability of the proposed approach.

Abstract The fabrication of high‐speed electronic and communication devices has rapidly grown the demand for high mobility semiconductors. However, their high cost and complex fabrication process make them less attractive for the consumer market and industrial applications. Indium nitride (InN) can be a potential candidate to fulfill industrial requirements due to simple and low‐cost fabrication process as well as unique electronic properties such as narrow direct bandgap and high electron mobility. In this work, 3 µm thick InN epilayer is grown on (0001) gallium nitride (GaN)/Sapphire template under In‐rich conditions with different In/N flux ratios by molecular beam epitaxy. The sharp InN/GaN interface monolayers with the In‐polar growth are observed, which assure the precise control of the growth parameters. The directly probed electron mobility of 3610 cm2 V‐1 s‐1 is measured with an unintentionally doped electron density of 2.24 × 1017 cm‐3. The screw dislocation and edge dislocation densities are calculated to be 2.56 × 108 and 0.92 × 1010 cm‐2, respectively. The step‐flow growth with the average surface roughness of 0.23 nm for 1 × 1 µm2 is confirmed. The high quality and high mobility InN film make it a potential candidate for high‐speed electronic/optoelectronic devices.

Controlling the grain size is an essential issue in the metal plastic working processes. Based on the consensus view that grain boundaries are impassable borders for dislocations and that the number of dislocations within a grain affects the stress builds up among the adjacent grains, altering grain size has a great influence on the post-forming mechanical properties of the deformed workpieces. In the present research, the deformation behaviors of 20CrMoH, a typical hardenability steel, are investigated and the microstructure evolution of grain growth experiencing heat load and grain refinement under deformation load is also uncovered. According to the experimental stress-strain curves and grain size variation data, a set of internal variable constitutive equations are established, in which the material constants are calibrated by a genetic optimization algorithm. Comparing the predicted curves with the experimental values, it can be concluded that the constitutive equations can accurately reproduce the thermal deformation behaviors and grain size variation of the steel. The correlation coefficient of the calculated and experimental values is 0.9861, and the average relative error approximates 4%. The unified constitutive equations are compiled into a commercial finite element software with the help of user-defined subroutine interfaces. The simulation results demonstrate that the maximum accuracy error of a hollow shaft size is about 10%, and the error in the average grain size is 12.1%. It is confirmed that the internal variable constitutive equations describing the evolution of grain size established in this paper are suitable for the numerical simulation of the bulk-forming process.

Conjunction gears, which are also known as helical gears with clutch gears, are used mainly in the transmission and shift design of automobile gearboxes. In this paper, focusing on the hot forging process and microstructure changes after forging, hot forging is proposed for manufacturing a conjunction gear according to the characteristics of a combination gear. Combined with finite element numerical simulation, by comparing changes in temperature, equivalent stress, equivalent strain, recrystallization fraction, and average grain size, the effect of the optimization of the forging process of a combined tooth billet is achieved using the response surface methodology. Finally, optimal forging process parameters are obtained through experimental research, and the quenched structure after hot forging is observed.

Based on the Gurson-Tvergaard-Needleman (GTN) damage model, the damage evolution and ductile fracture of 7075 aluminum alloy sheets during the tensile process were predicted. First, the true stress–strain curve and micro morphology of 7075 aluminum alloy at 310 °C∼460 °C were obtained using ultra-high temperature confocal microscope with tensile and compression functions, and the damage characteristics of the fracture position of the tensile specimen were observed by Scanning Electron Microscope (SEM). Then, using the finite element reverse calibration method, the identification method of GTN damage parameters under high temperature was systematically explained and the damage characteristic parameters of 7075 aluminum alloy under high temperature (310 °C∼460 °C) were obtained. The influence of fluctuations in damage parameters on the macroscopic mechanical behavior of materials and the influence of temperature on the value of material damage variables were analyzed. Finally, the void volume fraction of 7075 aluminum alloy at 360 °C was obtained by microscopic observation and compared with the void volume fraction obtained by the finite element reverse calibration method. The results show that the effect of temperature on void volume fraction is basically the same as that of plasticity. The change of void volume fraction has a greater impact on the mechanical properties of the material. There is a small gap between the void volume fraction obtained using the microscopic observation method and the void volume fraction obtained using the finite element reverse calibration method, which verifies the accuracy of the finite element reverse calibration method.

At present, the macro-parameters such as critical desorption pressure, comprehensive diffusion coefficient, and permeability are commonly used to characterize the properties of a reservoir, and the productivity of coalbed methane (CBM) wells can be predicted through numerical simulation or established mathematical models, and the types of low-producing CBM reservoirs can be classified. However, low production from CBM wells is often caused by the weakness of one (or more) of desorption, diffusion, and seepage in CBM reservoirs, and the evaluation of a single link and macro-parametric characterization of reservoir properties cannot really ascertain the cause of the low production from a given CBM well.In the present work, the influences of pores and fracture structure, fluid flow dynamics and resistance on the desorption, diffusion, and seepage of CBM were considered from the perspective of system theory, and the evaluative parameter index system of low-productivity reservoirs was established. This avoids the one-sidedness of the evaluative results arising when only considering macro-parameters. New methods of obtaining the evaluative parameters pertaining to desorption, diffusion, and seepage are proposed: the methods include isothermal adsorption experiments, the use of logging curves, drainage data, mercury injection, and a classical mathematical model. These methods combined the data from experiments with in-situ data, and ensure the accuracy and practicability of the resulting evaluative parameters. On this basis, types of low-production reservoirs were classified using an analytic hierarchy process with multi-parameter superposition.The evaluative results pertaining to Shizhuang North block in the Qinshui Basin, Shanxi Province, China show that there are six types of low-yield reservoirs among the evaluative wells tested. Among them, diffusion is the main factor governing the low yield of CBM wells, followed by desorption and seepage. Herein, the reservoir constraint on CBM production is comprehensively evaluated, identifying the main controlling link affecting the low productivity of CBM wells, and laying a theoretical foundation for targeted transformation measures.

For the purpose of manufacturing the automotive body structure parts with tailored properties, the hot stamping process with partial heating was experimentally and numerically investigated. In this study, the deformation behaviors of the steel 22MnB5 with the fully and incompletely austenitized microstructure were studied by hot tensile testing and modeled by the modified Zerilli–Armstrong constitutive equations taking the lattice structure into account. The classical Kirkaldy–Venugopalan transformation kinetics equations were modified to be suitable for the investigated steel, and the diffusional phase transformation equations were calibrated by using the continuous cooling transformation data. By the virtue of user subroutine VUHARD in finite element program ABAQUS, the metallurgical-field coupled finite element model was established for simulating the hot stamping process with partial heating. A special fixture was developed to realize the partial heating process of circular sheet blank. The finite element simulation and experimental research were carried out for a cup-shaped part. Finally, the phase distribution, hardness variation, shape error, and thickness variation of the cup-shaped part were analyzed and discussed. The validity and accuracy of the constitutive model and the transformation kinetics model were verified by comparing the simulation results with the experimental data. Besides, the present research results also demonstrate the hot stamping parts with variable mechanical properties can be manufactured by changing the austenitization degree of sheet blank during the heating stage.

Most of the previous studies exploring the changing patterns of wetland in the Yellow River Delta (YRD) were conducted based on sparse time-series images, which ignored its severe environmental gradient and rapid evolution process of the wetland. The changes in the dominant factors in the evolution of the wetland in the YRD are not clear. This study used the dense time-series Sentinel-2 images to establish a wetland database of the YRD, and then analyzed the spatial distribution characteristics of, and temporal changes in, the wetland during 2015–2022. Finally, the dominant factors of the spatio-temporal evolutions of the wetland were explored and revealed. The results showed the following. (1) During 2015–2022, the wetland in the YRD was dominated by artificial wetland, accounting for 54.02% of the total wetland area in the study area. In 2015–2022, the total wetland area increased by 309.90 km2, including an increase of 222.63 km2 in natural wetlands and 87.27 km2 in artificial wetlands. In the conversion between wetland types, 218.73 km2 of artificial wetlands were converted into natural wetlands, and 75.18 km2 of natural wetlands were converted into artificial wetlands. The patch density of rivers, swamps, and salt pans increased, showing a trend of fragmentation. However, the overall degree of landscape fragmentation in wetlands weakened. The trend of changes in the number of patches and landscape shape index was the same, while the trend of changes in Shannon’s diversity index and Contagion index was completely opposite. (2) Natural factors, such as precipitation (0.51, 2015; 0.65, 2016), DEM (0.57, 2017; 0.47, 2018; 0.49, 2020; 0.46, 2021), vegetation coverage (0.59, 2019), and temperature (0.48, 2022), were the dominant influencing factors of wetland changes in the YRD. The dominant single factor causing the changes in artificial wetlands was vegetation coverage, while socio-economic factors had lower explanatory power, with the average q value of 0.18. (3) During 2015–2022, the interactions between the natural and artificial factors of the wetland changes were mostly nonlinear and showed double-factor enhancement. The interactions between temperature and sunshine hours had the largest explanatory power for natural wetland change, while interactions between precipitation and vegetation coverage, and between temperature and vegetation coverage, had large contribution rates for artificial wetland change. The interactions among natural factors had the greatest impacts on wetland change, followed by interactions between natural factors and socio-economic factors, while interactions among socio-economic factors had more slight impacts on wetland change. The results can provide a scientific basis for regional wetland protection and management.

The wear resistance and hardness of stainless steel (SS) balls formed by cold skew rolling are effectively improved due to the change in internal microstructure. In this study, based on the deformation mechanism of 316L stainless steel, a physical mechanism-based constitutive model was established and implemented in a subroutine of Simufact to investigate the microstructure evolution of 316L SS balls during the cold skew rolling process. The evolution of equivalent strain, stress, dislocation density, grain size, and martensite content was studied via simulation during the steel balls’ cold skew rolling process. The corresponding skew rolling experiments of steel balls were carried out to verify the accuracy of the finite element (FE) model results. The results showed that the macro dimensional deviation of steel balls fluctuates less, and the microstructure evolution agrees well with the simulation results, which proves that the established FE model has high credibility. It shows that the FE model, coupled with multiple deformation mechanisms, provides a good prediction of the macro dimensions and internal microstructure evolution of small-diameter steel balls during cold skew rolling.

To investigate the biogas generation characteristics of the organic matter in lignite, methanol extraction was conducted to obtain the soluble fraction and the residual of lignite, which were subsequently taken as the sole carbon source for biogas production by a methanogenic consortium. Afterward, the composition of compounds before and after the fermentation was characterized by UV-Vis, GC-MS, and HPLC-MS analysis. The results indicated that the methanogenic microorganisms could produce H2 and CO2 without accumulating CH4 by utilizing the extract, and the methane production of the residue was 18% larger than that of raw lignite, reaching 1.03 mmol/g. Moreover, the organic compounds in the methanol extract were degraded and their molecular weight was reduced. Compounds such as 1, 6-dimethyl-4-(2-methylethyl) naphthalene, 7-butyl-1-hexylnaphthalene, simonellite, and retene were completely degraded by microorganisms. In addition, both aromatic and non-aromatic metabolites produced in the biodegradation were detected, some of which may have a negative effect on the methanogenesis process. These results revealed the complexity of the interaction between coal and organism from another point of view.

Over the past several decades, the increasing popularization of psychological counseling has underlined a strong need for an indigenous approach to counseling. The current study adopted a single-case study method to construct a narrative of the indigenization process of psychotherapy in mainland China based on a comprehensive description of one prominent counseling psychologist’s experience over the past half-century. Through interviews and records of fieldwork involving the psychologist (as the case) in 10 months between 2016 and 2017, the current study analyzed the indigenization process from the following three aspects: knowledge production, counseling practice, and student training. The findings showed that there was an underlying tension between the psychologist’s traditional wisdom and his professional training in scientific psychology during the indigenization process. However, the findings of this study further revealed something missing from previous studies. First, the client-centered counselor did not assume “power” during counseling sessions, which differs from critical viewpoints in medical anthropology. Second, the students being trained underwent fundamental changes in values rather than learning a technique or resolving problems. Third, the psychologist’s life history affected his thoughts and professional practice, which occurred in a sociocultural historical context. Finally, the implications for the future direction of the indigenization of counseling practice are discussed.

Background: Air pollution leads to many adverse diseases, especially respiratory diseases and cardiac symptoms. However, it has not been studied the association between air pollution and influenza cases in Jinan City, especially during the outbreak of COVID-19; Methods: The data were obtained from China’s Disease Information System, and influenza cases during 2020–2021 in Jinan City were collected from it. We used the generalized additive Poisson model to measure the association between air pollutants and the daily influenza cases after adjusting for possible influence variables; Results: There were 4767 influenza cases. PM2.5 and PM10 on lag 0, lag 3, and lag 4 were significantly associated with an increased risk of influenza; gaseous pollutants (NO2 and SO2) led to higher risk than particulate matter pollutants (PM2.5 and PM10). There were no significant differences for sex subgroup analyses. Except for O3, the incidence risk of males and females was highest on lag 3 and lag 4. For the study of different age groups, influenza cases aged over 59 years had a slightly larger relative risk when exposed to all air pollutants (except O3) than the younger group; Conclusions: The overall number of influenza cases decreased in 2020–2021. PM2.5, SO2, CO, and NO2 were significantly associated with the risk of influenza during 2020–2021. Countermeasures should be developed according to the characteristics of influenza risk to prevent and control it.

A metal-melting direct writing process, using semi-solid isothermal heat treatment to form high-quality semi-solid components, realized the integrated innovation of semi-solid formation and additive manufacturing. An experimental study was carried out on semi-solid isothermal heat treatment for metal-melting direct-writing technology, using 2A12 aluminum alloy as raw material. The semi-solid isothermal heat treatment was carried out over different temperature ranges, and four-stages evolution mechanism of the semi-solid microstructure in the semi-solid melting direct writing process was investigated. The effects of holding temperature and time on the microstructure of the semi-solid isothermal heat treatment of the alloy were put forward. According to the analysis of the results of the semi-solid-melting direct-writing test, the corresponding relationship between semi-solid microstructure and extrusion formability was found. The results show that when the holding temperature is 640–650 °C and the holding time is 20–25 min, the liquid phase rate can reach about 40%, and the direct-writing forming technology can be carried out stably.

Solution and aging heat treatment are effective means to improve the mechanical properties of Al-Li alloys. The solution treatment and aging treatment tests of 2060 Al-Li alloy were carried out. The yield strength, tensile strength, elongation, Vickers hardness, and microstructure of specimens after heat treatment were obtained by the tensile test at room temperature, Vickers hardness test, SEM analysis, TEM analysis, and EDS analysis. The effects of solution and aging heat treatment parameters on mechanical properties of 2060 Al-Li alloy were analyzed by response surface model and test results. The results show that sufficient solution can make the Cu-rich second phase of the alloy continuously dissolves into the aluminum matrix, and consequently obtain the supersaturated solid solution, the insoluble second phase is mainly θ’ (Al2Cu) phase, T(Al2Cu2Mg3) phase, and S’ (Al2CuMg) phase. The strength and hardness of the alloy are improved, but the ductility worsens with the degree of solution treatment enhances. With the increase of aging temperature and aging time, the strength and hardness of the alloy increase, but the elongation decreases. Taking tensile strength, elongation, and Vickers hardness of the alloy as the optimization objectives, the NSGA-II multi-objective optimization algorithm was used to optimize the process parameters of solution and aging heat treatment, and the heat treatment experiment was carried out. The optimization results show that the best mechanical properties of the alloy with matching strength and toughness can be obtained under the solution treatment at 466 °C/60 min and aging treatment at 185 °C/13 h.

Cross wedge rolling has the advantages of high production efficiency, good product quality, high material utilization, environmental protection, and low cost. It is one of the best processing methods for producing shaft blanks. In this paper, a cross wedge rolling die of TC4 titanium alloy is studied. Based on the Archard wear model, a modified model suitable for cross wedge rolling die wear analysis is derived through finite element simulation. Then, the modified Archard wear model is imported into Deform-3D software for finite element analysis. Orthogonal experimental design is used to combine and analyze different process parameters. Finally, the beetle antennae search (BAS)-genetic algorithm (GA)-back propagation neural network (BPNN) algorithm is used to predict the degree of die wear and to optimize the simulation parameters, which can acquire the process parameters that have the least impact on die wear. The results show that the wear distributions of cross wedge rolling tools is uneven. In general, the most serious areas are basically concentrated in the wedge-shaped inclined plane and rectangular edge lines. The reason is that the tangential force and radial force received by the die are relatively large, which leads to increased wear. Moreover, the temperature change is most severe on the wedge-shaped ridge line. When in contact with the workpiece, the temperature rises sharply, which makes the local temperature rise, the mold hardness decrease, and the wear accelerate. Through response surface method (RSM) analysis, it is concluded that the deformation temperature is the main factor affecting wear depth, followed by the forming angle, and that there is an interaction between the two factors. Finally, the feasibility of the BAS-GA-BP algorithm for optimizing the wear behavior of dies is verified, which provides a new process parameter optimization method for the problem of die wear in the cross wedge rolling process.

Gallium oxide (Ga2O3) is an attractive semiconductor that is very suitable for deep ultraviolet (DUV) inspection. However, due to the existence of many types of oxygen vacancies in the amorphous Ga2O3 (a-Ga2O3) film, it greatly limits the performance of the a-Ga2O3-based photodetector. Here, we perform oxygen plasma treatment on the a-Ga2O3/p-Si photodetector to reduce the concentration of oxygen vacancies in the a-Ga2O3 film, so that the dark current is reduced by an order of magnitude (from 1.01 × 10−3 A to 1.04 × 10−4 A), and the responsivity is increased from 3.7 mA/W to 9.97 mA/W. In addition, oxygen plasma processing makes the photodetector operate well at 0 V bias. The response speed is that the rise time is 2.45 ms and the decay time is 1.83 ms, while it does not respond to the DUV illumination without oxygen plasma treating at a zero bias. These results are attributed to the fact that oxygen plasma treatment can reduce the Schottky barrier between a-Ga2O3 and the electrode indium tin oxide (ITO), which promotes the separation and collection efficiency of photo-generated carriers. Therefore, this work proposes a low-cost method to improve the performance of Ga2O3 film-based DUV photodetectors.