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Mo2 FeB2 is a good boron based cermet material with high temperature resistance, wear resistance and high strength. It has broad application in the field of mould. The structural stability, elastic properties, hardness and electronic structure of Mo2 FeB2 with Nb alloying were investigated by using first-principles calculations. The calculated cohesive energy and formation enthalpy showed that Nb prefers to occupy the Fe site of Mo2 FeB2, and the Nb at Fe site of Mo2 FeB2 possesses better mechanical properties compared with that at Mo site. Moreover, the calculated results showed that Nb doping could increase the shear modulus, Young’s modulus, bulk modulus and hardness, but slightly decrease the ductility. The suitable doping concentration should be 2.5 at. %. The calculated electronic structure indicated that the increase of mechanical properties is attributed to the formation of Nb-B covalent bonds. [ABSTRACT FROM AUTHOR]

As a new type of intelligent mine, homing mine plays an important role in modern maritime warfare. In order to improve the interception probability of the passing target by the mine barrage composed of homing mine. Firstly, in order to obtain the detection area of homing mine in the battlefield environment, the target detection system of homing mine was modelled in this dissertation. Then, based on the genetic algorithm, the deployment position of the homing mine is optimized. By simulating the situation when multiple targets pass through mine barrage before and after optimization, obtain the average probability of the target triggering the homing mine before and after the optimization. The superiority of homing mine placement after optimization is verified. It has guiding significance for the laying of mine positions of homing mine. [ABSTRACT FROM AUTHOR]

The misuse of metronidazole（MNZ） has caused serious pollution of the water environment. In this paper, the adsorption effects of MNZ on single-walled carbon nanotube（CNT） and Fe doped carbon nanotube（Fe-CNT） were studied by first-principles calculation. The adsorption structure, adsorption energy, electron orbital, charge transfer and state density of single-walled CNT and Fe-CNT and MNZ were calculated respectively. The results show that the original CNT has a weak adsorption effect on MNZ, while the interaction between Fe-CNT and MNZ is significantly enhanced. Therefore, Fe-CNT is expected to be candidates for adsorbing the water contaminant MNZ. [ABSTRACT FROM AUTHOR]

Mercury is a toxic heavy metal, and mercury emitted in various forms in production and life poses a certain degree of threat to ecology and human health. Therefore, it is of great importance to find highly effective mercury adsorbents. Based on the first-principles calculation method of density functional theory, the adsorption and oxidation mechanism of mercury on Ti2NO2（MXene） and Ti2NO2 with an oxygen vacancy(Ov-Ti2NO2) defect was studied. The calculation results show that the adsorption of Hg0 on the surface of Ti2NO2 is physical adsorption and the adsorption on the surface of Ov-Ti2NO2 is chemical adsorption. The presence of oxygen vacancies on the surface of Ti2NO2 can improve the interaction between HgO and Ov-Ti2NO2, thereby increasing the adsorption energy by 116 kJ/mol. The reaction barrier of Hg0 oxidation to HgO on the surface of Ov-Ti2NO2 is 92.55 kJ/mol, which is smaller than the energy barrier of its oxidation reaction on the surface of Ti2NO2（101.42 kJ/mol), which is more conducive to the oxidation of Hg0. In addition, the energy required for the desorption of HgO on Ov-Ti2NO2 surface is 226.18 kJ/mol, which is much higher than that of 110.49 kJ/mol on Ti2NO2 surface, indicating that the Ov-Ti2NO2 has better control ability of product HgO than Ti2NO2, which can inhibit secondary pollution caused by HgO desorption. [ABSTRACT FROM AUTHOR]

An experimental device for testing droplet evaporation under the action of ionic wind was designed. The dynamic evaporation behaviors of evaporation rate, oscillation amplitude and oscillation frequency of deionized water droplet under different electric fields and ambient gases were investigated, and the velocity distribution of ion wind field was also measured. The results show that when the voltage is lower than the corona voltage, the electric field force can reduce the droplet evaporation rate. When the voltage is higher than the corona voltage, the formation of ion wind can strengthen the droplet evaporation. Both of the increases in voltage and gas ions mobility can augment the ionic wind speed, which intensifies the droplet oscillation and increases the droplet evaporation rate. Compared with the natural evaporation of droplet, the maximum enhancement ratio of droplet evaporation rate under the action of ion wind can reach 9.89. With the increasing of voltage, the ion wind changes from the unstable status to the stable status. [ABSTRACT FROM AUTHOR]

The electrical contact materials are widely used in various low-volt age switching devices such as electrical switches, relays, contactors and circuit breakers, and their characteristics are of great importance to the switching capacity, reliability, stability and service life of the overall electrical system. The conventional Ag- based contact materials have good performance, but still suffer from defects such as high contact resistance, low interfacial bonding strength, and poor plasticity, and their applications are limited to some extent. Tn recent years, domestic and foreign researchers have reported new group element contact materials such as Ag-Sn()2- Me(), Ag-GNPs, Ag-MAX and Ag-RE on the basis of the traditional Ag-based contact materials. This paper will review the current research status of new Ag-based contact materials in terms of their organization and properties as well as arc erosion performance, and finally summarize the key scientific issues and challenges facing new Ag-based contact materials and look forward to their future development trends. [ABSTRACT FROM AUTHOR]

In this paper, N-doped fluorescent carbon quantum dots (CDs) were prepared by solvothermal synthesis using citric acid as carbon source, urea as nitrogen source, and N, n-dimethylformamide as reaction solvent. The products were characterized by infrared spectrometer, X-ray photoelectron spectrometer, UV-visible spectrophotometer, fluorescence spectrometer, fluorescence microscope and transmission electron microscope. The effects of reaction temperature and reaction time on fluorescent carbon quantum dots were investigated. The results show that spherical CDs particles with uniform distribution, uniform size and particle size of about 7 nm can be obtained at the reaction temperature of 140℃ for 10h, and the surface of CDs contains carboxyl, amino and hydroxyl groups. The obtained CDs has strong fluorescence intensity and concentration quenching effect. Under ultraviolet light, blue light and green light, it emits blue fluorescence, blue green fluorescence and red fluorescence respectively. [ABSTRACT FROM AUTHOR]

The heating free direct rolling technology for bar and wire rod can transport the billet directly from the continuous casting machine to the rolling mill for rolling, completely eliminating the traditional heating furnace and achieving the goal of energy conservation and emission reduction. Compared with traditional bar and wire rolling processes, the lower direct rolling rate is one of the factors that affects the promotion of non heating direct rolling technology. A new steel feeding control model was proposed, and based on the actual production process parameters on site, the operational effects of the first in first out ( FIFO) model and the proposed control model were studied and compared. The results show that under the connection of four machines and four streams on a rolling line, the direct rolling rate using FIFO control model is 88. 7%, which is in good agreement with the measured direct rolling rate. However, using the proposed control model can increase the direct rolling rate to 94. 3% . At the same time, simulation studies were conducted on the direct rolling rates of two models under the connection of five machines and five streams on a rolling line. The results show that the direct rolling rates using the FIFO control model and the proposed control model are 74. 3% and 81. 7%, respectively. Through comparison of results, it was found that the control factors of steel feeding directly affect the direct rolling rate. In addition, the matching degree between the flow rate of the continuous casting machine and the capacity of the rolling mill is also an important factor affecting the direct rolling rate. [ABSTRACT FROM AUTHOR]

Laser additive manufacturing is regarded as a new green creation method. It is a technology that is grounded in the principles of laser deposition technology, such as laser cladding and laser cladding welding, and is utilized for achieving the restoration of geometry or comprehensive performance in damaged parts of various components. The current status of additive manufacturing technology both domestically and internationally was specified. Additionally, a detailed introduction was provided regarding the process types of laser additive manufacturing and its applications across various industries. Finally, an outlook on the development trend of laser additive manufacturing technology was presented. [ABSTRACT FROM AUTHOR]

Pneumatic impact test technology provide an economical and controllable method for the impact safety research of large mass specimens. In order to meet the requirements of precise velocity control, the basic working principles and the correlations among the functional components of a pneumatic impact test facility were studied, and the internal ballistic mathematical models of the impact test device were established. The models were verified the with the test data. Furthermore, the influences of temperature, valve opening time, flow loss and damping on internal ballistic performance were analyzed. The results show that the internal ballistic models have good universality in the range of 30 ~100 m/ s, and the prediction accuracy is less than 5% . Within a certain range, the influence of valve opening time and flow loss on speed is more than 11% . The influence of temperature is little, which is about 3% . The influence of air damping and friction damping can be ignored. The methods and results can provide reference for relevant test techniques and gas launch devices. [ABSTRACT FROM AUTHOR]

As the most important component of greenhouse gases, the change of carbon dioxide content will directly affect global climate change. Selective capture of CO2 in post combustion gases is of great significance to mitigate environmental problems caused by excessive CO2 concentration. In this paper, the first principle calculation method was used to study the selective adsorption performance of V2CO2 MXene material for CO2. Firstly, the structures and properties of V2CO2 MXene materials with different functional groups were studied. It was found that V2CO2 had good stability. Later, the adsorption behavior of V2CO2 on CO2 was studied. The results showed that when CO2 was horizontally adsorbed, V2CO2 had a strong adsorption capacity for CO2 gas molecules, which met the ideal value(-0.42 eV-0.82 eV) of CO2 adsorption on the surface of high-performance adsorbent, and could be suitable for detecting/capturing CO2 gas molecules. In addition, the adsorption behavior of N2 on V2CO2 under the same conditions was further studied. The results showed that the adsorption of V2CO2 on N2 was very weak. Therefore, V2CO2 can selectively adsorb CO2 from CO2/N2 mixture, which is expected to be a candidate material for selective adsorption of CO2 in post combustion gases. [ABSTRACT FROM AUTHOR]

In order to explore the data information of wool textile quality traits between F1 hybrid generation of Tan Sheep × Hu Sheep at 2-month-age and Tan Sheep at 2-month-age, the differences of wool textile quality between F1 hybrid generation of Tan Sheep, Hu Sheep and Tan Sheep were compared.The results showed that there was the textile quality differences of heterotypical wool and non-medullated wool between F1 hybrid generation of Tan Sheep × Hu Sheep at 2-month-age and Tan Sheep at 2-month-age.The average fiber diameter of the heterotypical wool between two breeds had significant differences, the average natural length of the the heterotypical wool and non-medullated wool had significant differences.The correlation coefficients of the textile quality traits between F1 hybrid generation of Tan Sheep x Hu Sheep at 2-month-age and Tan Sheep at 2-month-age had little differences.The study results showed that the genetic characteristics of Tan Sheep（fur sheep） and Hu Sheep（lambskin sheep） showed certain heterosis [ABSTRACT FROM AUTHOR]

In the context of climate change, economic globalization and rapid urbanization, the multi-hazard risk has become a major threat to human society. Risk assessment is the foundation of risk prevention. Based on an in-depth examination of literature, this paper summarizes the theories and methodologies for assessing multi-hazard risk in the past two decades. The compre‐ hensive risk assessment has two significant theory foundations: the conceptual models which in‐ dicate the combination way of multi-hazards and the risk frameworks which describe the risk ele‐ ments and their relationships as well as developing the assessment models. The key to multi-haz‐ ard risk assessment is the integration of single hazard risk, and the method for integration can be classified to two categories: integration of risk values and integration of hazard processes. It de‐ serves closer attention to investigate both the complex relationship between various disasters and risk elements as well as the complex impact of environmental changes on disaster risk. The sce‐ nario-based modeling and risk assessing method may be a better choice for meeting the demands of the current era. It is feasible to take the single hazard risk analysis as a starting point, the in‐ terrelationships between various hazards as traction, and the scenario analysis method as a pro‐ pellant to implement multi-hazards risk assessment. [ABSTRACT FROM AUTHOR]

The allocation and regulation of water resources in the Yellow River Basin is crucial for the economic development and people's lives of various regions. In order to improve the prediction accuracy of the Yellow River water level, a water resources planning and prediction model of the Yellow River was proposed, which combined the sparse search algorithm (SSA) and the long short-term memory (LSTM) network. In other words, after optimizing the hyper-parameters of LSTM model by SSA algorithm, the Yellow River water level was predicted. The results show that the EMAP(Mean Absolute Percentage Error), ERMS (Root Mean Square Error), EMA (Mean Absolute Error) and R² of SSA-LSTM model are 0.006 3, 0.030 4, 0.024 7 and 0.994 5 respectively. Compared to Multi-Layer Perception (MLP) and LSTM control models, the EMAP, ERMS and EMA of the SSA-LSTM model are significantly reduced, while R² improved. The difficult issue of manual parameter selection in LSTM model is solved by using SSA automatic parameter selection. This method can not only greatly reduce the training time of the model, but also find the optimal network parameters, so as to exercise the best performance of the model. The SSA-LSTM model has good accuracy and robustness in predicting the water level of the Yellow River, which can provide a basis for the regulation of water resources in the Yellow River. [ABSTRACT FROM AUTHOR]

With the wide application of micro-electromechanical systems and the increasing shortage of energy, it is an urgent problem to continuously and stably supply energy for micro-electromechanical systems. A novel chamfer cylinder vortex-induced vibration piezoelectric energy harvester was proposed, for broadening the working bandwidth and improving the output performance. The models of vortexinduced vibration piezoelectric energy harvester with diagonal tangent cylinder of 30°, 45° and 60° and smooth cylinder were established, and were verified by wind tunnel experiments. The output voltage and output power of vortex-induced vibration piezoelectric energy harvester with chamfer cylinder of 30°, 45° and 60° and smooth cylinder at optimal load resistance and various airflow velocities were investigated. Results show that when the optimal load is 0. 5 MΩ and wind speed ranges from 1. 413 m/ s to 3. 164 m/ s, output voltage and output power of piezoelectric energy harvester with diagonal tangent cylinder first increase and then decrease with the increase of the airflow velocity. A maximum output voltage of 4. 274 V and output power of 0. 037 mW can be obtained at the chamfer angle of 30° and airflow velocity of 3. 057 m/ s. The working bandwidth and the harvesting performance of the chamfer cylinder vortex-induced vibration piezoelectric energy harvester is improved over smooth cylinder. The output power of the piezoelectric energy harvester with the chamfer angle of 30° is 106% higher than that of smooth cylinder. This work provides a new method for designing more efficient piezoelectric energy harvester. [ABSTRACT FROM AUTHOR]

Methanol is a promising source that can replace non - renewable petroleum energy. Therefore, it is of great significance to oxidize the methane into methanol because methane is not easy to transport although its huge reserves. The stability between Sc atoms and C24 N24 is firstly studied through density function al theory ( DIT ) calculations. The results show that the binding energy between Sc and C24 N24 ( - 9. 064 e V) is more negative than the cohesive energy of Sc a toms ( -4. 518 eV), indicating that S c@ C24 N24 possesses good stability. On this basis, the oxidation process of methane to methanol is further studied on the Sc@ C24 N24 single - atom catalysis using N2O as the oxidant. The results show that N2O is firstly adsorbed on Sc@C24 N24 and then directly decomposed into N2 and O .&· N2 is rel eased and only Oads is adsorb ed on C24 N24 as act iv e oxygen for the following catalytic oxidation process of methane to methanol. The process includes two steps: I ) CH4 + Oads~ CH 3 * + OH *, the reaction barrier in this process is 0. 43 e V; 2) CH3 * + OH * ~ CH3 OH, the reaction barrier is 0. 63 eV in this step. Finally, the obtained CH3OH molecule will leave the surface of Sc@C24 N24 single a tom catalyst and the energy required for this step is 1. 29 eV. These findings provide theoretical guidance for the catalytic oxidation of methanol, and Sc@C24 N24 is expected to be a highly efficient monatomic catalyst for catalytic methane to methanol. [ABSTRACT FROM AUTHOR]

To provide accurate and reliable data for underground mine water inrush accidents and achieve realtime continuous monitoring of rock stress, seepage water temperature, and water pressure in submarine mines, a multifunctional monitoring instrument for rock stress, water pressure, and water temperature was developed. The technical goals and working principles of the instrument are described, and the data storage and transmission mechanisms are analyzed. The practical application in the submarine mining field of Sanshandao gold mine shows that the maximum water pressure error of the instrument is O. I MP a, and the temperature error is O. 3 "C, which meets the engineering requirements and enables real-time continuous monitoring of underground mining areas, rock stress, water pressure, and water temperature with reliable data. [ABSTRACT FROM AUTHOR]

In order to solve the problem of working mechanism of anti-floating anchor-rotary grouting body in the process of groundwater buoyancy and foundation pit earthwork unloading, a self-balanced anti-floating anchor-rotary grouting body anti-floating model test device was developed to carry out the anti-floating model test. The research results reveal the working mechanism of load transfer between anchor bolt and jet grouting body, anchor bolt external anchoring section and jet grouting body under the combined action of groundwater buoyancy and foundation pit earthwork unloading. The relationship between the ultimate bearing capacity of anchor bolt and jet grouting body and the thickness of jet grouting body and the spacing of anchor bolt is analyzed. It is suggested that the thickness of anchor bolt and jet grouting body is the best for the pullout resistance of single anchor bolt and group anchor, which provides theoretical basis and engineering application selection suggestions for the bottom water stop structure of new non-dewatering and environmentally friendly deep foundation pit. [ABSTRACT FROM AUTHOR]

Most pastoral areas in China are subjected to arid and semi-arid zones, particularly with annual precipitation of less than 400 mm. Since irrigation is indispensable for the cultivated grass industry, the protection of natural grassland can focus on the water, land, forage, and livestock balance with the development of the irrigation cultivated grasslands, rather than the forage-livestock balance only. Taking the specific pastoral management units as the entry point, this study aims to propose a new evaluation for the tradeoff between the water and land for the family pasture from the perspective of the water cycle. A water-land-forage-livestock balance was constructed to consider the quality differences between forage species in the calculation of the forage-livestock balance. An example was taken as the typical family pasture in the Otog Front Banner of the Inner Mongolia Autonomous Region in China. The assessment showed that the current water, land, forage, and livestock status of the family pasture were in a mild overload state, with a water resource overload rate of 6.05%. In the condition of water, land, forage, and livestock balance, the livestock overload rates with/without considering forage quality were 5.38% and 12.98%, respectively. By contrast, the livestock overload rates with/without considering forage quality were 1.29%, and 9.05%, respectively, under current planting conditions (without considering water resource overload). An optimal combination of water-use schemes was proposed to feature the different planting structures and irrigation adjustments, according to the status quo in this family pasture. A systematic analysis was made to determine the available water supply, and the carrying capacity for the irrigation of cultivated grasslands, and livestock under multiple optimizations. It was found that the carrying capacity was determined for the irrigation of cultivated grasslands by the available water supply. More water-efficient irrigation was adopted to select the forage crops with the decreased water consumption, in order to significantly improve the support capacity of water resources in the irrigation-cultivated grasslands. Livestock carrying capacity significantly increased after considering the forage quality, indicating more consistency with the actual condition of this family pasture. Consequently, the family pasture was maintained the current areas of cultivated grassland without increasing, while adjusting the irrigation of alfalfa to underground drip irrigation. Once the irrigation form was adjusted to drip irrigation under the condition of oat planting, the number of livestock was reduced to 464 sheep units, in order to maintain the balance of water, land, forage, and livestock in the family pasture. Furthermore, the oats were adjusted to grow the corn or alfalfa in the median condition of oats. Although the number of livestock was more than the current number of livestock, some suggestions can keep the current number of livestock raised in family pastures, in order to make more room for the rest and recuperation of water resources and natural grassland. The finding can provide a new approach to calculating and managing the water, land, forage, and livestock balance in pastoral areas. [ABSTRACT FROM AUTHOR]

Based on the hydrogeological characteristics deep in Shuiyindong Gold Mine, references to relevant domestic mine water control experience and scientific achievements, and a comparison of water control schemes, the research designed to use the water control scheme of underground near ore bodies curtain grouting. The test of underground near ore body curtain grouting shows that underground grouting can effectively fill karst caves and karst fissure water paths and effectively connect and form a stable artificial water-isolation curtain body with a certain thickness. The research can provide water control experience for similar mines. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Exercise intervention is one of the main treatments for fibromyalgia, but there is no consistent conclusion on the choice of different exercise modalities. In this article, a network Meta-analysis was used to comprehensively and quantitatively evaluate the effects of different exercise modalities on fibromyalgia syndrome. METHODS: PubMed, EMbase, Scoups, The Cochrane Library, Web of Science, CNKI, WanFang Database, and China Biomedical Literature Database were searched for relevant literature, with a search timeframe from the establishment of each database to June 2023. The outcome indicators included five continuous variables, including fibromyalgia impact questionnaire-revised (FIQ) scores, visual analogue scale (VAS) scores, quality of life, quality of sleep, and depression. The Cochrane Risk of Bias Assessment Tool was used to evaluate the quality of the included literature. RevMan 5.4 software was used to perform effect sizes, subgroup analyses, and sensitivity analyses of the data. Stata 17 software was used to perform reticulation and network Meta-analysis of the data. RESULTS: A total of 13 articles with 14 randomized controlled trials were finally included. The overall methodological quality of the literature was high. The results of traditional Meta-analysis showed that, compared with the control group, exercise therapy significantly improved the FIQ score [standardized mean difference (SMD)=-0.67, 95% confidence interval (CI): -0.83 to -0.50, P < 0.01], VAS score (SMD=-0.72, 95% CI:-0.90 to -0.54, P < 0.01), quality of life (SMD=1.03, 95% CI: 0.45 to 1.61, P=0.000 5), sleep quality (SMD=-0.62, 95% CI: -0.98 to -0.25, P=0.001), and depression (SMD=-0.63, 95% CI: -1.09 to -0.18, P=0.007). Network Meta-analysis showed that the probability of optimal intervention effect of exercise modalities on FIQ scores was ranked as: mind-body exercise (86.5) > resistance exercise (70.5) > aerobic exercise (41.7); the probability of optimal intervention effect of exercise modalities on VAS scores was ranked as: resistance exercise (85.3) > mind-body exercise (74.3) > aerobic exercise (34.5). CONCLUSION: Exercise therapy significantly improves FIQ scores, VAS scores, quality of life, sleep quality, and depression in patients with fibromyalgia syndrome. Mind-body exercise and resistance exercise are the most effective exercise modalities to reduce FIQ scores and VAS scores in patients with fibromyalgia syndrome. [ABSTRACT FROM AUTHOR]

Environmental endocrine disrupting chemicals (EDC) are widespread in people’s production and living environment. Due to a wide variety of endocrine disruptors, they not only interfere with human reproductive system, nervous system and immune system, but also exert a non⁃negligible influence on the thyroid, which is the largest endocrine organ in the body. The previous studies mostly focused on thyroid hormone and histopathology, and few reports were available on the associations between autoimmune thyroid diseases (AITD) or thyroid cancer (TC) and EDC. Therefore, the current review elucidates the potential adverse effects of EDC on thyroid, especially in autoimmune thyroid diseases and thyroid cancer, including induction of thyroid autoantibodies and the effect on T cell differentiation, etc., which may provide a basis for the study of the potential environmental exposure risk factors of autoimmune thyroid diseases and thyroid cancer, and has positive significance on prevention and treatment of these diseases. [ABSTRACT FROM AUTHOR]

To optimize the thermal resistance of thermoelectric generator for improving performance, the output performance variation of thermoelectric generator with different thermal resistance at both sides was investigated. The external ceramic substrates with different thermal conductivity and thickness were used to simulate the thermal resistance at both sides of thermoelectric generator. The variation of temperature difference, open-circuit voltage, output power and maximum output power of thermoelectric generator at different hot source temperatures and load resistances was analyzed. The results show that when the thermal resistance at both sides of the thermoelectric generator is the same, the temperature difference and the open-circuit voltage are increased with the increasing of hot source temperature. When the thermal resistance at both sides of thermoelectric generator is different, the open-circuit voltage and the maximum output power are increased with the increasing of hot source temperature. The effective temperature difference is increased with the increasing of load resistance, and the power is increased first with latter decreasing when the load resistance is increased. Compared to the performance of thermoelectric generator with the same thermal resistance at both sides, the ceramic substrate with smaller thermal resistance at the hot side is more beneficial to improve the output performance of thermoelectric generator, and the improvement effect is more obvious near the maximum power point. The open-circuit voltage, the maximum output power and the maximum effective temperature difference can be increased by 0.64 V, 0.87 W and 24.5 ℃, respectively. [ABSTRACT FROM AUTHOR]

Objective To explore the relationship between coagulation parameters, disease progression and short-term prognoses in children with acute traumatic brain injury. Methods From March 2020 to March 2021, clinical data were retrospectively reviewed for 389 children with acute traumatic brain injury. Coagulation parameters, severity of brain injury and Glasgow Outcome Scale ( GOS) of all children were collected at admission. And the relationship between changes of coagulation parameters, severity of brain injury and GOS was analyzed by Logistic regression. Results Age, computed tomography ( CT) manifestations and treatments methods among children with different degrees of traumatic brain injury were significantly different (P < 0. 05 ) . The differences of prothrombin time ( PT), international normalized ratio ( INR), fibrinogen ( FIB), thrombin time ( AVIT), D-dimer ( D-D),platelet ( PLT) and fibrin degradation product ( FDP) in mild, moderate and severe traumatic brain injury were statistically significant (P < 0. 05). During a follow-up period of 6 months, a significant negative correlation existed between injury severity and GOS ( r = 0. 666, P < O. 05 ) . The values of INR, PLT,PT, FIB, thromboplastin time (TT), D-d and FDP were prolonged in children with acute traumatic brain injury with different prognoses. Conclusion Coagulation dysfunctions exist in children after traumatic brain injury. The more serious the injury the more obvious abnormal blood coagulation and the worse the prognosis. Blood coagulation parameters provide rationales for evaluating prognoses and offering clinical interventions as soon as possible. [ABSTRACT FROM AUTHOR]

To improve the removal efficiency of flue gas fine particles in the desulfurization tower by wet desulfurization technology, a new set of purging electrically charged atomization nozzle device was designed and applied to the visual desulfurization tower model test bed. The effects of operating parameters on the particle removal efficiency were systematically investigated. The results show that the charge effect of spray droplets is greatly affected by spray flow rate and spray angle, and there is an optimal charge effect working condition value. With the increasing of particle size, the overall particle classification removal efficiency is increased. The particle removal efficiency is increased with the increasing of fluid flow rate and decreased with the increasing of flue gas flow rate, which is increased firstly with latter decreasing by increasing the dust concentration. The removal efficiency of particulate matter can be further improved after the droplet is charged, and the purpose of efficient removal of fine particulate matter can be realized. [ABSTRACT FROM AUTHOR]

In view of the issue that the runoff change was affected by many factors, characterized by randomness and nonlinearity and was difficult to predict accurately, based on the data of daily average runoff, daily precipitation and daily average sediment concentration of Huayuankou Hydrometrical Station on the Yellow River from 2008 to 2012, a multivariable input TCN Attention model combined with time convolution neural network (TCN) and attention mechanism was proposed to predict the daily runoff of the station, LSTM model and TCN model were selected for prediction and comparison experiments. The results show that the prediction performance of TCN model and TCN Attention model is better than that of LSTM model; The Attention mechanism can improve the prediction performance of TCN model by adjusting the feature vector weight. Compared with TCN model, the MAE, RMSE and MAPE values of TCN Attention model have been decreased by 20.25%, 24.90% and 24.39% respectively; TCN Attention model has better generalization performance, which can improve the prediction level of daily runoff. [ABSTRACT FROM AUTHOR]

In the traditional schedule-cost construction optimization system, two objectives, safety level, and environmental impact were introduced to construct the construction schedule-cost-safety-environment multi-objective optimization model, and the knee point driven evolutionary algorithm (KnEA) was used for multi-objective optimization. Firstly, the duration-cost-safety-environment objective function was constructed, in which the safety objective function was constructed using network system theory to construct the durationsafety and cost-safety functions, and the environmental objective function considers the direct and indirect impacts of the project on the environment. Secondly, the number of construction days and direct costs were used as inputs to set the parameters of the KnEA model, and the construction process combinations of typical engineering projects were selected to construct the construction. The multi-objective optimization model was constructed by selecting the construction process combinations of typical projects. Finally, the Pareto optimal solution set of process execution mode combination was obtained by using KnEA, which makes the duration cost safety environment optimal. Compared with the typical optimization algorithm, the effectiveness of KnEA in the multi-objective optimization of engineering construction was verified, which proves that the algorithm can effectively guide the optimization management of the construction process. [ABSTRACT FROM AUTHOR]

In this paper, the stabilities of carbon nanocones (CNC), B and N-doped carbon nanocones (B-CNC and N-CNC) are studied by first principle calculation combined with ab initio molecular dynamics. The results show that CNC, B-CNC and N-CNC can exist stably. On this basis, the adsorption behaviors of Na atoms on CNC, B-CNC and N-CNC are studied respectively. The results show that: 1) the adsorption of Na atom at the center of CNC five membered carbon ring is the strongest, and the adsorption energy is-2.52 eV. The energy gap (Eg) of CNC is 1.96 eV. 2) After B and N doping CNC, the conductivities of B-CNC and N-CNC are significantly enhanced. 3) Compared with CNC, the adsorption of Na atoms on B-CNC is enhanced, while the adsorption on N-CNC is significantly weakened. This shows that B-CNC is expected to be used as the anode material of Na ion battery. The research results of this paper provide theoretical guidance for the research of Na ion battery with CNC as anode material. [ABSTRACT FROM AUTHOR]

In the context of the high-quality development of preschool education, kindergarten heads put forward higher requirements for their own support: equal and appropriate training opportunities, useful and applicable training content, diverse, interactive and direct experience training methods, professional and intelligent trainers, and timely schedule without work-study conflict. However, the current kindergarten head training fails to meet their needs in the context of the new development, and there are problems such as the lack of fairness and suitability of training opportunities, and the lack of pertinence and effectiveness of training implementation. In this regard, the feasible paths to reform the future kindergarten head training are as follows: establishing and improving the modern kindergarten head training system that benefits all the staff, strengthening the research on the kindergarten head training and promoting the construction of the discipline of the kindergarten head training, giving full play to the kindergarten heads爷 subjectivity and implementing the training mode based on problem solving. [ABSTRACT FROM AUTHOR]

The high-voltage AC electric field was used to promote the separation of soybean oil-methanol transesterification product biodiesel and glycerin. The effects of electric field strength, alcohol-to-oil molar ratio and catalyst on the sedimentation rate of glycerin droplets were explored, and the physical prope11ies of biodiesel and by-product glycerin prepared under different transesterification conditions were measured. The results show that the high-voltage AC electric field can effectively improve the separation efficiency of biodiesel and glycerin. GC-MS test results show that high-strength electric fields has no effect on the quality of biodiesel. In the electric field formed by spiral electrode, the coalescence efficiency of glycerin reaches the maximum when the electric field strength of E' is 175 V · mm -1. Different molar ratios of alcohol and oil can cause differences in the physical properties of the by-product glycerin and have little effect on the sedimentation rate of glycerin droplets. The increase of alkaline catalyst content can promote the sedimentation of glycerin, and the sedimentation efficiency of glycerin under the action of potassium hydroxide is increased. [ABSTRACT FROM AUTHOR]

The corrosion performance of AZ series magnesium alloys (AZ31, AZ61 and AZ91) with different Al content in 3.5% NaCl solution is compared in order to find suitable corrosion-resistant materials. The microstructure is characterized by scanning electron microscope (SEM) and X-ray diffractometer (XRD). In 3.5% NaCl solution, its corrosion resistance is tested by polarization curve, electrochemical impedance spectroscopy (EIS) and immersion experiment. The results show that the corrosion behavior of AZ series magnesium alloys is pitting corrosion first and then surface corrosion. The polarization resistance (RP) of AZ61 is as high as 288.88 fl • cm2, the corrosion current density is as low as 0.0026 mA/cm2, and the average corrosion rate is 2.86X 10-4 g/(h • cm2). AZ61 has better corrosion resistance. As the Al content increases, the corrosion resistance of magnesium alloys first increases and then decreases. The increase in corrosion resistance is attributed to the coarsening and continuity of the |3-Mgi7Ali2phase. [ABSTRACT FROM AUTHOR]

The plasticizing process of single-base gun propellant is lack of reliable gradual fault detection ability and alarm evaluation under abnormal working conditions. Meanwhile, traditional data-driven method is difficult to deal with the mixed characteristics of linear and nonlinear relations contained in the process, and it is unable to highlight the difference of coupling correlation between variables. A multiway principal component analysis method based on normalized mutual information was proposed. In this method, the complex coupling relationship between multidimensional variables is characterized by normalized mutual information, and the correlation between variables of different dimensions is modified by weight. Then the data sets that reflects the coupling relationship between each variable and other dimension variables are obtained, and the corresponding monitoring models are established respectively. Finally, according to the Bayesian inference, the monitoring results of different models are fused into a set of global monitoring statistics to realize process monitoring. The experimental results show that the proposed method is effective, which can realize the rapid detection of multiple faults and the monitoring and warning of abnormal conditions in plasticizing process. [ABSTRACT FROM AUTHOR]

In this paper, first-principles calculations combined with ab initio molecular dynamics methods were used to study the stability of carbon nanocones (CNC), B- and N-doped carbon nanocones (B-CNC and N-CNC). Both B-CNC and N-CNC can exist stably. On this basis, the adsorption behaviors of Na atoms on CNC, B-CNC and N-CNC are studied respectively. The results show that: 1) Na atoms in the center of CNC five-membered carbon ring The adsorption at the top position is the strongest with an adsorption energy of -2.52 eV. The energy gap (Eg) of CNC is 1.96 eV. 2) After B and N doping CNC, the conductivity of both B-CNC and N-CNC is significantly enhanced. 3 ) Compared with CNC, the adsorption of Na atoms on B-CNC is enhanced, while the adsorption on N-CNC is significantly weakened. This indicates that B-CNC is promising as an anode material for Na-ion batteries. It provides theoretical guidance for the research of Na-ion batteries with anode materials. [ABSTRACT FROM AUTHOR]

目的 探讨入院时轻度(GCS=15分)颅脑损伤患儿头颅CT异常的危险因素，为临床医师制定诊疗决策提 供参考价值.方法 回顾性分析 2019年 9月—2021年 11月山西省儿童医院神经外科收治的 528例轻度颅脑损伤 患儿的临床资料，根据初次头颅CT结果将所有研究对象分为CT异常组和CT阴性组，对两组性别, 年龄, 受伤原因, 受伤后首次CT检查时间, 临床症状和体征进行单因素分析和多因素Logistic回归分析.结果 单因素分析结果显 示，跌倒, 高处坠落, 短暂昏迷, 头皮血肿, 面部软组织挫伤在两组间差异有统计学意义(P 均<0. 05).多因素 Lo‐gistic 回归分析结果显示，高处坠落(OR=52. 416，95%CI：1. 010～2720. 913，P=0. 049), 头皮血肿(OR=8. 436， 95%CI：1. 275～54. 650，P=0. 027)是头颅CT异常的独立危险因素.结论 对于GCS=15分的轻度颅脑损伤患儿，高 处坠落和头皮血肿是其头颅CT异常的独立危险因素. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is the most common type of liver cancer in China, and high molecular heterogeneity of HCC has caused the limitations in clinical efficacy; therefore, it is of great importance to explore its heterogeneity based on molecular classification and develop individualized diagnosis and treatment strategies. Various high-throughput sequencing techniques and multi-omics techniques in recent years have helped to establish multiple molecular classification systems, which gives us a deeper understanding of the molecular heterogeneity of HCC. This article summarizes the molecular classifications of HCC and discusses their association with clinicopathological features. This article also analyzes the new targets for molecular targeted therapy and immunotherapy and proposes new ideas for precise diagnosis and individualized treatment of HCC. [ABSTRACT FROM AUTHOR]

According to the crystal structure characteristics and charge compensation mechanism of NZP-type materials, Fe3+-modified NZP ceramic solid electrolytes, Na1+xZr2-xFex(PO4)3 (x=0, 0.1, 0.2, 0.3, 0.4), were designed and prepared by microwave sintering process at 950 ℃ for 1.5 h. The influences of Fe3+ on the phase composition, microscopic morphology, relative density, and ionic conductivity of the ceramic electrolyte were systematically studied. The results showed that the single-phase and compact Na1+xZr2-xFex(PO4)3 electrolytes were successfully prepared by microwave sintering at 950 ℃ for holding 1.5 h, which greatly reduced the sintering temperature and shorten the preparation period. With the increase of Fe3+ doping amount, the relative density of the sample increased, whose maximum is 93.8%. Moreover, the impedance test results revealed that the addition of Fe3+ could improve the ion conductivity of the samples. When the Fe3+ doping content was 0.3~0.4, the room-temperature ion conductivity reached 6.5×10-6 S/cm, and the ion conductivity at high temperature (573 K) was up to 1.56×10-3 S/cm. [ABSTRACT FROM AUTHOR]

Gadolinium contrast enhancement has been considered a safer enhancement method all long, but in recent years it has gradually been found that gadolinium contrast agent can be distributed and deposited in vivo as free gadolinium ions, which may cause certain hazards, such as deposition in the kidney may cause nephrogenic systemic fibrosis. With the increasing rate of magnetic resonance imaging enhanced examination, the application of gadolinium contrast agent will become more widespread, so that the phenomenon of nephrogenic systemic fibrosis, intracranial deposition, intraosseous deposition, deposition in skin, heart, lung tissue, liver and lymph nodes and other organs will increase, but there is no solution for the above phenomenon yet. Traditional Chinese medicine has unique insights into metal ion overload diseases and has been proven to reduce a variety of metal ion overload phenomena, which may provide powerful help to reduce excess gadolinium ions in vivo through further research in the future. [ABSTRACT FROM AUTHOR]

In order to improve the quality of ecological environment protection, wireless sensor network (WSN) is widely used in the ecol cal environment intelligent monitoring in the Yellow River Basin. The energy consumption and lifespan of sensor nodes are the key iss faced in wireless sensor network routing. In order to reduce the energy consumption of nodes in the routing process and prevent nodes from ing prematurely, the evolutionary algorithm was applied to WSN routing optimization. This paper improved the traditional optimization alg rithm and applied the improved adaptive evolution algorithm to routing optimization, and randomly selected 100-node WSN topology model verify the effectiveness of the algorithm. The results show that compared with the traditional evolutionary algorithm and ant colony algorithm the algorithm in this paper effectively reduces the energy consumption of sensors in the routing optimization of wireless sensor networks, in proves the algorithm convergence speed, prolongs the life of WSN, enhances the connection reliability and realizes real-time monitoring an protection of ecological environment in the Yellow River Basin. [ABSTRACT FROM AUTHOR]

Water quality prediction is the basic and prerequisite work for the management of water resources and prevention and control of water pollution, hut the research on water quality prediction in the Yellow River basin is relatively lagged behind. In order to improve the performance of the LSTM water quality prediction model mid increase its generalization ability, according to the periodic and non-linear characteristics of water quality changes, taking the dissolved oxygen concentration of the Xiaolangdi Reservoir on the Yellow River as the research object, a combination of convolutional neural network CNN and length was constructed. The CNN-LSTM prediction model of the time memory network LSTM had been verified by experiments. The model can efficiently extract water quality feature information and perform time series prediction. The prediction error is lower than that of the LSTM model. The average absolute error of the predicted value and the root mean square error arc 19.72% and 10.44% lower than that of the LSTM model respectively. The prediction of larger mid smaller values is more accurate mid it has better generalization performance. [ABSTRACT FROM AUTHOR]

Objective: To study the quality and application value of head and neck CT angiography (CTA) with single energy imaging and adaptive statistical iterative reconstruction (ASiR) technique. Methods: The imaging and clinical data of 120 patients who received head and neck CTA in our hospital from January 2019 to December 2019 were collected. The patients were randomly divided into three groups: group A (n=40), group B (n=40) and group C n=40 . The patients in group A underwent energy spectrum CT (60keV) +ASiR (40%), in group B (n>40%), underwent CT (60keV) + filtered back projection (FBP), and in group C (n>40), underwent conventional CT scan + FBP. The CT value, image noise value, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and subjective score of image quality were compared among the three groups. Results: There were statistically significant differences in CT value, background noise (SD), signal-to-noise ratio (SNR), contrast noise ratio (CNR) and subjective score of right internal carotid artery among the three groups (P<0.05); further pairwise comparison showed that CT value of C7 segment of right internal carotid artery in group A > group B > group C, and there was no significant difference between group A and group B (P>0.05), but there was statistical difference between group A and group C and between group B and group C There were significant differences between group A and group B, between group A and group C (P<0.05), but there was no significant difference between group B and group C (P>0.05); SNR and CNR were group A > group B > group C, and there were significant differences between group A and group B, group A and group C, group B and group C (P<0.05); subjective scores of group A > group B > group C, and group A and group C, group B and group C had significant differences (P<0.05) There were significant differences between group A and group C, group B and group C(P<0.05). The difference of ctdlvol, DLP and ED among the three groups was statistically significant (P<0.05); further pairwise comparison showed that ctdlvol, DLP and ed in group A < group B < group C. There was no significant difference in ctdlvol, DLP and ED between group A and group B (P>0.05), but there were differences between group A and group C, between group B and group C The difference was statistically significant (P<0.05). Conclusion: Energy spectrum CT combined with ASiR can improve the image quality of head and neck angiography and reduce the radiation dose. 60keV combined with 40% ASiR is recommended for clinical application. [ABSTRACT FROM AUTHOR]

Garment fit evaluation is one of the main bottlenecks in current fashion design and manufacturing. In the process of remote customization and online shopping the size of the clothes that does not fit has become the primary reason for users to return or exchange them which has seriously affected the intelligent upgrade of the clothing industry. Therefore how to judge the fit degree of a garment without actually trying it on is one of the main problems that needs to be solved urgently in the clothing industry. In previous studies garment fit was usually evaluated by some characteristic indexes such as ease allowance clothing wrinkle the spatial relationship between clothing and the human body and clothing pressure. However most of them have some problems such as the need to try on clothes and the complicated evaluation process which are not suitable for remote customization of clothing and online shopping. With the development of computer vision and machine learning technology a small number of scholars use 2D images to judge garment fit based on clothing wrinkle but only for specific garments and the generalization ability is weak. To solve the problem that garment fit cannot be discriminated in advance in the process of remote customization and online shopping this study took women' s suits as an example and put forward a method to discriminate the fitness of women's suits based on 2D human images. Firstly 2D images and 3D human body size of 462 young women aged 18 - 25 in northeast China were collected and a human body data set was established. Twenty-two samples were selected from this data set and virtual models were established for virtual try-on by using CLO3D software. According to the national clothing size standard of China 10 virtual women's suits with the same style and different sizes were made to establish the garment data set. Based on the principle of Kansei engineering the fitting evaluation labels of women' s suits namely tight fit and loose types were given by expert evaluation method combined with virtual fitting. Then a method to discriminate the fit of women' s suits by using garment features and 2D human image features was proposed. As for the garment features GFs the bust girth and length characteristics of women's suits the features of 2D human body image including the key point distance features DFs and overall features OFs were extracted. The specific extraction method is as follows. Firstly the 2D human body image was preprocessed and normalized and the human body contour was extracted by Canny edge detector and the five DFs in the 2D human body image were obtained namely the distance of chest thickness key points distance waist thickness key points distance hip thickness key points distance waist width key points distance and hip breadth key points distance. Then three OFs of the 2D human body image were extracted namely the body height pixel value feature H the feature of the projected unit area ρ and the feature of the projected area ratio of the front and side of the human body C. Finally the Bayesian classifier was used to establish the garment fit prediction model and the Fisher linear discriminant function was used to establish the women' s suit fit discriminant equation. In this paper computer vision technology was used to extract the feature indexes of garment fit evaluation and a machine learning algorithm was combined to realize the women's suit fit discrimination based on 2D human body images. Experimental results indicate that the garment features proposed in this paper and the 2D human body image features based on computer vision technology can be used to predict the fit of women' s suits and the discriminant model of women' s suits based on the Bayesian algorithm has achieved good discriminant accuracy and the cross-validation discriminant accuracy rate can reach 84. 8% so the model is valid. The women' s suit fit discrimination model based on 2D human image feature learning provides an effective and feasible method for garment fit in fashion design production manufacturing and online shopping. This method provides a theoretical basis for the quantitative evaluation of garment fit and is beneficial to the recommendation of clothing size and the improvement of patterns in clothing customization enterprises and online shopping. [ABSTRACT FROM AUTHOR]

With the development of internet, new-generation information technology represented by big data, AI and IOT, is accelerating the industrial integration among agriculture, manufacturing and service industries and driving high quality development of China’ s economy. In order to promote the application of new generation information technology in the process of ecological protection and high quality development in the Yellow River basin, this paper analyzed the current situation of natural resources, social and economic development and industrial composition of the Yellow River basin. Then on the basis of discussing the problems faced by ecological protection and high quality development of the basin, this paper put forward the general framework by using new-generation information technology to promote ecological protection and high quality development of the basin, that is to establish the air-space-ground integrated management of ecological environment, improve the comprehensive flood prevention and early warning system, maintain the management and control system of water resources in the Yellow River water supply area, strengthen the optimization and adjustment of industrial structure in the basin and establish a harmonized industrial chain in the basin. On the basis of the framework, it was suggested to establish an air-space-ground integrated big data platform, which could accelerate the ecological restoration along the Yellow River basin and ensure high quality development of the basin. [ABSTRACT FROM AUTHOR]

Objective To observe the changes of serum kallikrein binding protein（Kal）and vascular endothelial cadherin（VE-Cad）levels and to evaluate their predictive value for the prognosis of septic shock（SS). Methods Totally 201 patients with SS（observation group）were divided into the death group and survival group according to the 28-day prog⁃ nosis；another 200 healthy people who took physical examination in the same period were selected as the control group. The levels of serum VE-Cad and Kal, sepsis-related organ failure assessment（SOFA）score，and acute physiology and chronic health evaluation（APACHE）Ⅱ score in each group were compared between the observation group and the control group. On the 1st, 3rd and 5th days, the serum Kal and VE-Cad levels were compared between the death group and survival group. The correlation between the above indexes was analyzed by Pearson correlation. The risk factors for death of SS patients were analyzed by Logistic Regression analysis. The predictive value of serum VE-Cad and Kal levels for prognosis of patients with SS were analyzed by ROC. Results The levels of serum VE-Cad，SOFA，and APACHE Ⅱ scores in the observation group were higher than those in the control group, while the level of Kal in the observation group was lower than in the control group（all P<0. 05). On the 1st, 3rd and 5th days, the serum VE-Cad levels of the death group were higher than those of the survival group，and the serum Kal level was lower than that of the survival group（all P<0. 05)， and SOFA and APACHE Ⅱ scores of the death group were higher than those of the survival group（both P<0. 05）. Serum VE-Cad level was positively correlated with SOFA and APACHE Ⅱ scores in the death group on the 1st day after admission（both P<0. 05)，while serum Kal level was negatively correlated with SOFA and Apache Ⅱ scores（both P<0. 05）. Multivariate stepwise logistic regression analysis showed that VE-Cad（OR=1. 382，95%CI=1. 045-1. 786）was a risk fac⁃ tor for death of SS patients，and Kal（OR=0. 429，95%CI=0. 187-0. 968）was a protective factor for SS patients（P< 0. 05）. On the 1st day after admission，the AUC of serum VE-Cad combined with Kal in judging the prognosis of SS patients was significantly higher than that of VE-Cad or Kal alone（all P<0. 05), as well as the accuracy，sensitivity，and specificity（all P<0. 05). Conclusions The decrease of serum Kal level and the increase of VE-Cad level are the independent influencing factors for death of SS patients. The combined detection of serum Kal and VE-Cad can predict the prognosis of SS patients better than the single detection of each index. [ABSTRACT FROM AUTHOR]

Aiming at the problem of nonlinear static aeroelasticity of composite wings with high-aspect-ratio, the CFD / CSD bidirectional loose fluid-solid coupling calculation method was used to research the nonlinear static aeroelastic properties of composite wings and aluminum alloy wings with the same thickness. The aerodynamic load was solved by Navier-Stokes ( N-S) governing equation, and the nonlinear structural motion equation was solved. The structure characteristics, longitudinal aerodynamic characteristics and stability of the composite wing at different angles of attack were compared with the same thickness aluminum alloy wing. The results indicate that the composite wing is significantly lighter than the aluminum alloy wing, reaching 25. 95% . The elastic deformation of the composite wing in the lift direction is greater than that of the aluminum alloy wing, which has an increase of about 29. 6%. Comparing with the aluminum alloy wing, the stiffness of the composite wing is reduced. [ABSTRACT FROM AUTHOR]

Aiming at the problem of rotor structure characteristics in the working process of twin-screw compressor, a coupling simulation method of stress and deformation of screw rotor was designed, and the influence of different exhaust pressure and different rotating speed on rotor stress and deformation was studied. Based on finite volume method, the pressure field generated during the compressor operation was solved. Through the numerical interpolation technique, the aerodynamic load was applied to the structure grid of the rotor as the external load, and the real force model of rotor was established. The static equilibrium equation of the rotor structure was solved in the real stress model, and the displacement field and stress distribution of the rotor were obtained, and the research method in this paper was verified by " L-shaped large diameter buried pipeline" . The results indicate that the pressure field generated during the compressor operation has a great influence on the maximum deformation and maximum stress of the screw rotor, and when the speed/ exhaust pressure is constant, the selection of appropriate exhaust pressure/ rotational speed can effectively reduce the maximum deformation and maximum stress of the rotor. The research can provide some theoretical reference for the structure design and optimization of compressor. [ABSTRACT FROM AUTHOR]

Aiming at the problems of insufficient working height and low rescue efficiency of external rescue equipment in high-rise building fire, the fire distribution characteristics and rescue difficulties of high-rise building were analyzed, a new type of external rescue system in high-rise building fire was put forward. The cause and effect axis analysis diagram of the throwing device used in the rescue system were established by using TRIZ theory, and the shortcomings of the throwing device were determined. The technical contradictions involved in the system were analyzed and solved by the "principle of contradiction solution", the design of the rope retractor was optimized with the aid of the "object field model", which improved the safety of the throwing device. Finally, the stress and deformation of the hook in the throwing device were analyzed and verified with the help of ANSYS/workbench finite element analysis software, and the further optimization scheme was put forward. The results show that the optimized system has the characteristics of rapid rescue, strong environmental adaptability, simple operation and so on. The structure rigidity of the throwing device is high and the design is more reasonable, which provides a reference for the follow-up research of the rescue system. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the traditional active contour model cannot accurately segment images with intensity inhomogeneity and is sensitive to scale parameters an adaptive scale active contour model based on region information is proposed. The adaptive scale operator is constructed based on the local entropy of the image，and the energy function is constructed by using the local intensity clustering property of the image. A linear combination of a set of smooth basis functions is used to represent the bias field to increases the stability of the model. By minimizing this energy，the proposed model is able to simultaneously segment the image and estimate the bias field，and the estimated bias field can be used for intensity inhomogeneity correction. Experimental results show that compared with the other four models the proposal has higher segmentation accuracy and the segmentation result is robust to the initial level set function and noise in the image. [ABSTRACT FROM AUTHOR]

以氢化钛(TiH2)粉代替钛粉,与氮化铝(AlN)粉体混合,合成高纯的三元氮化物Ti2AlN 陶瓷粉体。 氢化钛与氮化铝按照摩尔比2∶1的配比,在混料机中混合12h,然后放入流动氩气气氛保护的管式炉中高温处 理。通过对在不同温度以及不同时间下进行热处理得到的产物进行物相分析,探究Ti2AlN 的形成机理,发现在 1400℃下保温2h得到的Ti2AlN 粉体纯度最高,约为96.2%(质量分数)。在同样条件下,以钛粉为钛源合成 Ti2AlN 粉体的纯度只有80.2%(质量分数)。因为氢化钛粉体价格低于钛粉,并且合成的样品纯度显著提高。所 以,以氢化钛粉代替钛粉为钛源,合成Ti2AlN 具有显著优势。同时研究了所合成Ti2AlN 粉体在不同酸溶液 (KF-HCl、NaF-HCl和NH4F-HCl)腐蚀行为。结果发现:将Ti2AlN(~ 2g)浸入由2gKF溶解在40mL6M HCl的KF-HCl混合液中,在50℃下搅拌48h得到碎片团簇型TiN。但是二维碳化物Ti2N MXene不能通过选 择性刻蚀Ti2AlN 的方法得到 [ABSTRACT FROM AUTHOR]

The black soil region of Northeast China is one of the most important grain production bases in China. It is also one of the four major water erosion areas in China, in which the erosion gully is the main form of water erosion. In order to analyze the causes of gully erosion and evaluate the basic situation of gully erosion in the northeast black soil area, it is necessary to analyze its morphology and distribution characteristic of gully erosion. In this paper, Nenjiang County was taken as the study area, which is located in the northwest of Heilong province, China. The aerial remote sensing images with ground resolution of 0.2 m and 1:50 000 Digital Elevation Model (DEM) were used to carry out census and statistics on the erosion gully, and the morphological characteristics such as the gully width, gully length and longitudinal slope of the erosion gully were analyzed, as well as the influence of terrain factors such as elevation, slope and aspects. The results of the second land use survey in China were used to obtain the land use situation around the erosion ditch. The results showed that: 1) The number of erosion gullies in Nenjiang County was 38 426, and the whole area of the erosion gullies were 16 277 095 m2. The erosion gully mainly occurred on hilly area, and was dominated by gully erosion, accounting for 74.50% and 51.05% of the total number and area, respectively. The next type was modern incised valley. Erosion gullies were mostly less than 500 m. 2) The width and length of the erosion gullies were positively correlated, and the slope was negatively correlated with the width and length. 3) Compared with slope, aspects generally had a little effect on the distribution of erosion gullies. Rills and ephemeral gullies mainly distributed on slopes of 2~6° and 6~15°, and gullies and modern incised valleys mainly distributed on slopes of 0~2° and 2~6°. More than 90% of rills and ephemeral gullies, and 80% of gullies and modern incised valleys were occurred on cultivated land. 4) Although the topographic threshold model of gulley in Nenjiang County was not fitted well, it could still be used to analyze the process of gully erosion. The model showed that the critical slope of the modern incised valley was small, the parameter which expressed the gully erosion process reflected the occurrence and development of the gullies might be influenced by the underground process. [ABSTRACT FROM AUTHOR]

The Oddi sphincter has a delicate structure, and the integrity of its function has an irreplaceable role in preventing retrograde infection due to the reflux of duodenal contents and bacteria and maintaining the balance of physiological environment inside and outside the liver, the pancreas, and the gallbladder. Endoscopic sphincterotomy impairs the integrity of the Oddi sphincter, and such negative effects have received more and more attention. This article reviews the research advances in the impairment of Oddi sphincter function caused by endoscopic sphincterotomy and points out that clinicians should understand and attach importance to such impairment, perform a comprehensive analysis from various aspects, and develop reasonable diagnosis and treatment regimens based on patient’s own conditions. [ABSTRACT FROM AUTHOR]