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This paper takes the huff and puff development of multi-component thermal fluid as the main research object, based on the reservoir characteristics of multi-component thermal fluid in the development of heavy oil, through searching relevant literature and carrying out formation simulation experiments of multi-component thermal fluid core displacement, cavitation water jet rock breaking and other experiments, it is found that the dissolution of high-temperature components of multi-component thermal fluid, cavitation, viscosity reduction, and composition changes of multi-component thermal fluid will lead to reservoir sand production. Furthermore, through the sand production simulation experiment of multi-component thermal fluid huff and puff, it is found that the soaking time is the main factor affecting sand production. In view of the multi-round characteristics of huff and puff development, multi-round sand production simulation experiments are also carried out in this paper. In view of the multi-round characteristics of huff and puff development, multiple rounds of sand production simulation experiments were carried out. As the huff and puff rounds change, the influence of various factors on sand production becomes more and more obvious, that is, temperature has the strongest influence, and injection speed is the second. In short, the pressure is the weakest. This study is helpful to guide fine sand control, set up a reasonable production and mining system, and play a very important role in prolonging the life of oil and gas wells and improving economic benefits. [ABSTRACT FROM AUTHOR]

Focusing on the drilling fluid loss in fractured carbonate reservoirs during drilling operation, lattice Boltzmann mathematical model was proposed to characterize the drilling fluid loss in representative elementary volume (REV) scale based on simplified matrix-fracture dual-medium physical model. Velocity distribution in matrix-fracture system with drilling fluid loss was analyzed by numerical simulation, and drilling fluid loss behavior in matrix-fracture dual-medium system was discussed under the different geological conditions. The simulation results showed that microfractures dominated the loss channels for fractured tight carbonate rocks. The loss rate of drilling fluid in matrix exponentially increased with increasing porosity at lower range. The increase in fracture width led to the increase in flow average velocity, making the velocity in the fractures more uniform. Additionally, un- der the condition of the same total fractures width, the lost circulation rate in matrix-fracture system consisting of only one single fracture was higher than that in multiple fractures-combined system, In this paper, the lattice Boltzmann method was introduced to characterize the drilling fluid loss, and the results indicated that drilling fluid loss in fractured reservoir and filtration process from fracture to tight matrix could be well characterized by this method. This work could provide the theoretical foundation for drilling fluid loss and formation damage prevention in fractured tight reservoirs. [ABSTRACT FROM AUTHOR]

Due to the large number of blind individuals and the shortage of donor corneas available for transplantation, artificial corneas have gradually become a research hotspot, However, artificial corneas often experience implant tearing due to insufficient mechanical properties. In order to solve this problem, researchers at home and abroad have tried to improve the mechanical properties of corneal repair materials by a series of research work. This paper summarizes the progress relating to the mechanical properties of four common natural polymer-based corneal repair materials, namely collagen, gelatin, silk fibroin, and chitosan. The results show that physical methods such as photo-crosslinking and thermal crosslinking, chemical methods such as 1(3-dimethylaminopropyl) -3-ethylcarbodiimide (EDC)/N-hydroxysuccinimide (NHS) crosslinking, genipine or glutaraldehyde crosslinking and other composite methods can significantly improve the mechanical properties of corneal materials, but these methods still have some shortcomings. Therefore, further development of high-quality artificial corneas is crucial. It is hoped that the article can provide some reference and ideas for the study of improving the mechanical properties of corneal repair materials through summarization. [ABSTRACT FROM AUTHOR]

The flow process of heavy crude oil has a strong historical memory and global correlation. and the classical Newton constitutive model cannot effectively describe its rheological characteristics. In this paper, a spatial fractional constitutive model was established to well describe the rheological properties of heavy crude oil, Meanwhile, the flow and heat transfer processes were numerically simulated based on the finite element method (FEM). The influence of the fractional model order on the flow and heat transfer of crude oil was mainly studied, and the variations of the average Nusselt number and the friction resistance coefficient with the spatial fractional order were analyzed. In addition, the changes of local Nusselt number and convective heat transfer coefficient during the heat transfer process of crude oil were compared under two thermal boundary conditions, namely, the constant wall temperature and the heat flux, The result showed that the rheological property of crude oil was known as shear thinning; meanwhile, the flow speed of crude oil was obviously improved and the heat transfer performance was effectively enhanced with the increase of order α(a>1). Therefore, the rheological characteristics and flow as well as heat transfer laws of crude oil were deeply studied, which can provide theoretical guidance for further improving crude oil transport efficiency and economic operation in a pipe. [ABSTRACT FROM AUTHOR]

In this paper, the hydrogen-induced micromechanical property evolution of ferritic-austenitic duplex stainless steel was studied by nanoindentation and in situ hydrogen-charging method. The 2205 duplex stainless steel was selected as the research object in experiments, during which the nanohardness variation of ferrite and austenite was mainly analyzed, based on the obtained nanoindentation loaddisplacement curves under different hydrogen-charging time. The results show that the nanohardness of ferrite and austenite increases with hydrogen-charging time, presenting the hydrogen-induced hardening performance. After 3 hours hydrogen charging, the hydrogen-induced hardening effect of the two phases reaches saturation state, and the degree of increased nanohardness of austenite is higher than that of ferrite. The results show the hydrogen-induced hardening difference of ferrite and austenite, and demonstrate the research advantages of nanoindentation method in terms of characterizing hydrogen damage in the micro-scale, [ABSTRACT FROM AUTHOR]

This paper took the Shengjibao landslide in Fengjie county, Chongqing as an example. A static machine learning algorithm called the support vector regression (SVR) and a dynamic machine learning algorithm called the long short-term memory neural network (LSTM) were proposed to predict the landslide displacement. Then, the random forest (RF) algorithm was introduced to classify and predict the optimal solution between the SVR model and the LSTM model. Finally, the RF-optimized SVR-LSTM landslide displacement prediction model was obtained by assigning weights to the static-dynamic coupling model (SVR-LSTM) based on the probability values of the output from the RF model. The results show that LSTM model has better performance than the SVR model. RF optimized SVR-LSTM landslide displacement prediction model integrates the advantages of static and dynamic prediction models, and its prediction performance is better than that of the SVR model and the LSTM model, respectively. This study provides an idea of integrating landslide displacement prediction model, which can provide reference for geological disaster prediction in the Three Gorges Reservoir area [ABSTRACT FROM AUTHOR]

Stimuli-responsive drug controlled delivery systems are generally constructed by using natural polysaccharides biomacromolecules or their derivatives as the carriers, and the drug molecules are loaded into these biomacromolecules through chemical binding or physical adsorption. Stimuli-responsive natural polysaccharides biomacromolecules can sense the changes of their surroundings and respond to the changes in their physical or chemical properties, and thus the loaded drugs can be released from the carriers through the breakage of chemical bonding between drug and carrier or the degradation of the carrier itself and controlled delivery of the loaded drugs can be achieved. In this paper, we reviewed the commonly used stimuli modes, including exogenous stimuli and endogenous stimuli, single stimulus and multiple stimuli, and some of these stimuli modes have been reported by our own group. We believe that this review is of great importance for development of stimuli-responsive drug controlled delivery systems. [ABSTRACT FROM AUTHOR]

As most anomaly detection methods generally ignore the impact of video quality fluctuations in actual scenarios on their performance. Firstly, public datasets from the field of video anomaly detection were selected, and a distortion dataset for anomaly detection by artificially introducing common distortions found in surveillance videos through simulation methods was constructed. This paper systematically analyzes the impact of video quality fluctuations on the performance of four classic video anomaly detection algorithms. And the experimental results show that the degradation of surveillance data quality have a negative effect on the effectiveness of the video anomaly detection algorithm. Moreover, the impact of different distortion types and different degrees of distortion on the algorithm is different, as well as, Gaussian noise distortion and over brightness distortion have a greater impact on the algorithm. [ABSTRACT FROM AUTHOR]

Lost circulation is a significant challenge in oil and gas drilling, which can lead to various costly and time-consuming problems. It is of great significance to use artificial intelligence technology to accurately predict the risk of lost circulation. The lost circulation prediction problem was converted into an imbalanced classification problem, which pose challenges to traditional deep learning models due to the imbalance between categories and the lack of high correlation between drilling features. Accuracy is not an appropriate measurement for imbalanced classification algorithms. A deep AUC maximization (DAM) algorithm, which is called FAUC-S, is introduced in this paper. It trains a combination deep learning model by focusing on the AUC loss of hard samples (FAUC-S). Several traditional deep learning methods are also applied to classify lost circulation risk during oil exploration in the experiments. The result shows that the FAUC-S method achieved the highest accuracy, recall, and F1 score among the other three models. This confirms that the FAUC-S model has superior classification performance. Therefore, the successful implementation of this deep model can help drilling teams effectively solve drilling problems. [ABSTRACT FROM AUTHOR]

The development of highly efficient catalysts for oxygen reduction reaction (ORR) is the key to improve the performance of fuel cells and metal-air batteries. However, ORR is a kinetic slow reaction with high overpotential, which limits the energy conversion efficiency of fuel cells and metal- air batteries. High-entropy alloy is a new kind of alloy, which is consisted of five or more metal ele- ments with (nearly) equimolar ratios. With unique composition and structural advantages, high entro py alloy can effectively accelerate ORR kinetics and lower overpotential, showing remarkable catalytic performance toward ORR. In this paper, the structures, properties, preparation methods and applications of high entropy alloys in catalytic ORR were reviewed, and the challenges and development perspec- tives were proposed. [ABSTRACT FROM AUTHOR]

Molten metal die forging (MMDF) processes is an advanced process for high-performance forming of aluminum alloy parts, MMDF technology is applied to the forming of closed subframes, fo- cusing on the performance uniformity of MMDF process scheme and MMDF subframe in this paper. Simulation studies show that single-runner MMDF has fewer confluence positions, higher surface quality and higher process yield than MMDF solutions with auxiliary runners. Trial production proves that the single runner liquid forging of A356. 2 aluminum alloy subframe can be obtained by using the HVSC2500T horizontal MMDF machine designed and manufactured by Guangzhou Hede, and the sampling tensile strength of the body can reach 320 MPa while the elongation is 11. 12%. However, slag inclusion defects are prevalent in locations away from the sprue and where there is a confluence, and the strength and plasticity are low. [ABSTRACT FROM AUTHOR]

Software defined networking (SDN) is a network architecture technology with the functions of network programming and separation of data plane and control plane. The security issues in SDN have attracted much attention in the industry along with the emerging of SDN networks. Due to the characteristics of SDN network architecture, saturation attack is particularly prominent among many security problems. To solve these problems (1) saturation attack detection under traditional networks is difficult to adapt to in the SDN environment, and the detection rate is low; (2) The use of machine learning-based saturation attack detection method requires a large amount of historical data, which has certain requirements for the system’s computing and hardware resources, this paper proposes a saturation attack detection method based on subnet temperature in SDN network environment. Firstly, the network was divided by the concept of subnet, which reduces the detection granularity, improves the detection efficiency and reduces the resources required for detection. After that, the subnet temperature was used as the judgment standard to measure the occurrence of saturation attack, and the detection method of junction and subnet temperature gives a defense scheme for saturation attack. Finally, the simulation comparison was made on the experimental platform of Mininet, Ryu and sFlow. The experimental results showed that compared with other traditional detection technologies, the saturation attack detection algorithm proposed in this paper can ensure higher detection accuracy, higher reliability, complete detection data, high detection rate and low false alarm rate while using fewer system resources. [ABSTRACT FROM AUTHOR]

Steam assisted gravity drainage（SAGD） heavy oil development technology is influenced by development factors and geological factors, among which reservoir thickness is an important factor affecting the development of steam chamber and the state of steam, water and oil interface inside the steam chamber. The two main steam-assisted gravity drainage models are the double horizontal well model and the vertical-horizontal well combination model. In this paper, combined with the actual production data of Guantao block in Liaohe oilfield, the conceptual model under multiple well groups was established by using CMG-STARS software, and the control variable method was used only to change the single factor of reservoir thickness. The influence of reservoir thickness on the development effect of steam assisted gravity drainage was analyzed comparatively. In the case of the well group in this conceptual model,a thickness of around 50mis a threshold for variation in the effectiveness of SAGD development.In the early stage of SAGD development,the thickness of the double horizontal well is about 55m.In the later stage of development,the greater the thickness,the better the effect.The higher the reservoir thickness is,the better the effect is.When the reservoir thickness is more than 50m,the improvement trend of injection and production effect becomes relatively slow. [ABSTRACT FROM AUTHOR]

In this paper, the curing process of Elium resin of various thicknesses was simulated and experimentally verified using Abaqus simulation software. This was done in order to accurately predict the exothermic behavior of Elium resin. A finite element model of Elium resin curing was developed based on the transient non-linear heat transfer equation of the resin curing model. The findings demonstrate that the simulation results for the curing temperature agree with the experimental findings, and the peak curing temperature exhibits a non-linear increasing trend as resin thickness increases. When the peak curing temperature approaches 100 ℃, resin bubbles are produced, providing a theoretical foundation for optimising the Elium composite curing process. [ABSTRACT FROM AUTHOR]

Polarization modulation ranging method obtains the ranging results by finding the frequency corresponding to the minimum point on the light intensity frequency curve, so frequency extraction accuracy is the key factor of measurement accuracy. In this paper, the principle of polarization modulation ranging and the influence of frequency extraction accuracy on the ranging results were analysed. Then a gradient descent-based frequency search method for minima was proposed. A ranging system was set up and a section of optical fibre of approximately 3.9 m in length was measured. The standard deviation of the frequency difference was calculated to be 4.404 8×104 Hz and the variance of the distance measurement reached 3.666 7×10-7 m², which verified the feasibility of the method. [ABSTRACT FROM AUTHOR]

Aerial image has the characteristics of large amount of data, small target scale and dense distribution, and its angle of view is downcast, which is different from the head up view of ordinary image. Therefore, the traditional target detection algorithm for ordinary image cannot adapt to the target detection task of aerial image. For small target detection in aerial images, an improved algorithm based on YOLO-v5, Small-Tiny-YOLO-v5, was proposed. Firstly, GhostNet network was used as the backbone network of the improved algorithm; secondly, the attention mechanism module was added in the backbone network; thirdly, an aerial image data set for small targets was constructed. In addition, the idea of transfer learning was integrated in the training of the improved algorithm. Experimental results show that the model parameters of the proposed improved algorithm are lower than the original YOLO algorithm,and the accuracy and speed are also better than the original algorithm.In the public dataset and the dataset constructed in this paper,the accuracy has increased by 0.009and0.024respectively,and the speed has increased by 73.735% and 58.641%respectively. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-scale structure that integrates deep neural networks and Transformer features, aiming to address the issue of performance degradation in salient object detection networks when objects of different sizes appear in the same scene. When dealing with objects of different scales, the performance of existing methods often fluctuates due to the contradiction between sampling depth and receptive field size. To tackle this challenge, three different sampling rates were adopted to sample the feature maps,and the Transformer module was used to learn global context information.This method enables the effective fusion of the characteristics of Convolutional Neural Networks (CNNs) and Transformer networks,thereby innovatively proposing a salient object detection strategy for multi-scale objects.Experimental results on three public datasets,UHRSD-TE,DUT-OMRON,and DUTS-TE,demonstrate that this method performs excellently in the task of salient object detection for objects of different sizes in the same scene. [ABSTRACT FROM AUTHOR]

Machining distortion has always been a serious problem perplexing the aviation manufacturing industry. Taking the long beam parts as the research object, this paper analysed the evolution of bending energy caused by the initial residual stress in the material, defined the indexes of machining distortion stability and bending potential energy, and put forward a method to control the distortion stability by optimizing the release of bending potential energy. The results of theoretical analysis. simulation and machining test show that the stability of machining distortion in finishing stage can be significantly improved by optimizing the material removal sequence. [ABSTRACT FROM AUTHOR]

Travel time reliability is a key index to evaluate the intersection operational efficiency, and traffic incidents are one of the main factors causing intersection congestion. The study of an optimization method for intersection travel time reliability influenced by traffic incidents can help to improve the operation reliability of intersections and prevent the spread of congestion caused by traffic incidents. In this paper, the influence of the location of traffic incidents on the intersection operation was considered. assuming that the headway of the vehicle obeys the M3 distribution, and the calculation formula of the queue length was derived according to the gap acceptance theory and the vehicle arrival cumulative curve. The proposed optimization model takes the vehicle queue length as a constraint. which can optimize the reliability of intersection travel time. The simulated annealing algorithm was used to solve the model. The numerical results showed that the impact on travel time reliability was more serious when traffic incidents occured at the intersection approach. This method can effectively improve the reliability of intersection travel time under the influence of traffic incidents and alleviate the intersection congestion. [ABSTRACT FROM AUTHOR]

In this paper. using coal tar pitch and carboxymethyl cellulose (CMC) as precursors. activated carbons (AC) with high specific surface area were prepared through carbonization and KОН асtivation process. The results showed that prepared AC presented as amorphous carbon with low degree of graphitization. As the content of CMC increased, the structure of prepared AC got looser and rough, and the oxygen content increased. The specific surface area of AC firstly increased and then decreased with increasing CMC content. When the weight ratio of coal tar pitch to CMC was 2:1, the AC2:1 exhibited the best electrochemical performance with a specific capacity of 200 F/g at 5 A/g. The sample AC also showed excellent cycling stability as the specific capacity retention rate maintained 98. 6% after 10 000 cycles. [ABSTRACT FROM AUTHOR]

The Bozhong 13-2 block is located on the Bozhong 13 structural ridge and is controlled by NE and NE trending faults. Due to the complexity of geological structure, leakage mechanism, pressure system and engineering factors, the weak layer in this block is difficult to “avoid”, “identify”, “block”, “control” and “seal”. In this paper, weak layer is identified by “three three” method. Then,the bottom hole pressure difference during drilling in weak layer is carefully controlled by pressure analysis model and mudstone borehole instability model of plugging transition zone. Finally, the high strength plugging technology are used to improve the layer bearing capacity after drilling. After the application of this technology in three wells in Bozhong 13-2 block, no complex accidents, such as well collapse, well surge and well loss occurred in the drilling process, which saved the construction period of more than 45 days and the cost of about 90 million yuan. This technology provided technical support for the overall development of Bozhong 13-2 block. [ABSTRACT FROM AUTHOR]

To improve the combustion randomness and enhance the launch stability of traditional fireworks, the compressed air was introduced to drive the firework projectile instead of the traditional gunpowder combustion process in this paper. A simulation model and C++ program of the compressed air launching the spherical firework projectile were established to simulate both the acceleration process of the spherical projectile in the barrel and its free flight process in the air. Results showed that the simulation model can effectively reflect the motion characteristics and laws of the spherical projectile driven by the compressed air. For a spherical firework projectile with a diameter of 50 mm and a mass of 105 g, a barrel with an initial volume of 50 mL and a projectile trip of 1 m can be employed. This spherical firework projectile can reach the desired altitude of 150 m and 200 m, when the launching angle was set at 65° and the initial gas pressure is 2.65 MPa and 3.85 MPa respectively. The research results can provide effective theoretical support for the research and development of the spherical firework projectile launching system driven by compressed air. [ABSTRACT FROM AUTHOR]

In order to further improve the prediction accuracy of dissolved oxygen in aquaculture, this paper proposes a dissolved oxygen prediction model based on cross-validation grid optimization GBDTLSTM. First, the Gradient Boosting Decision Tree ( GBDT) is used to select characteristic factors that have a high degree of influence on dissolved oxygen. Then the Long Short-Term Memory Network (LSTM) is built based on the Keras deep learning framework, and the cross-validation grid optimization algorithm is used to optimize the LSTM parameters. Finally, the model in this paper is applied to a standard pond in the fishery base of Jintan City, Jiangsu Province to pr edict dissolved oxygen. The experimental results show that the mean square root error (RMSE), mean absolute error (M AE ) and mean relative error mean (MAPE) of the model are 0.208,0.158 and 2.635, respectively. The evaluation indexes are better than other comparison prediction models. It shows that the model has good predictive ability and generalization ability, which can meet the actual needs of modern aquaculture. [ABSTRACT FROM AUTHOR]

A new type of 3-DOF parallel mechanism with analytical position forward solution is proposed by the author, and its reverse dynamic equation is solved. Different from t he traditional dynamic paper using inverse kinematics, the displacement, velocity and acceleration equations of the mechanism are established and solved by forward kinematic analysis. T he inverse dynamic equation of t he mechanism is constructed and solved by analyzing the force on each member and based on Newton-Euifler method. Through Matlab example and ADAMS simulation, the inverse dynamics is verified by an example. The maximum driving force error of each moving pair is 1.32%, 5.8% and 5.2% respectively. This paper provides a theoretical basis for the design, manufacture and application of the mechamsm. [ABSTRACT FROM AUTHOR]

This paper investigates separate pyrolysis of corn stalk(CS)and polypropylene(PP)and co-pyrolysis of CS and PP over Zn-Al co-modified MCM-41 to produce aromatics, and the product distribution of catalytic co-pyrolysis of CS and PP was studied based on a rotating bed reactor. The results showed that the product contents and composition were significantly influenced in the presence of catalysts. Zn and Al showed a certain synergistic effect, under the catalysis of MCM-41 co-modified by Zn with mass fraction of 1% and Al with mass fraction of 3%, and the maximum proportions of aromatics(24.31%)and the minimum production of oxygenated compounds(12.37%)were obtained. In the experiment of catalytic co-pyrolysis of CS and PP in rotating bed, with the increase of pyrolysis temperature(500—800 ℃), the yield of bio-oil decreased gradually. The decrease of olefins and oxygenates in bio-oil significantly increased the content of aromatic hydrocarbons. With the increase of catalyst dosage(1:0—1:10), the yield of bio-oil reduced gradually. The contents of aromatic hydrocarbons in bio-oil increased obviously, while the contents of olefins and oxygenates decreased. With the increase of rotating speed(0—20 r/min), the yield of bio-oil first decreased and then increased. The extreme values of aromatics, olefins, and oxygenates in bio-oil were all obtained at 15 r/min. [ABSTRACT FROM AUTHOR]

Due to the fact that graphene possesses high conductivity, large specific surface area and ex- cellent mechanical properties, it has excellent application prospects in the field of supercapacitors. However, when it's directly used as the active electrode materials of supercapacitors, pure graphene face the problem of relatively low specific capacitance. In this paper, 3D porous nanocomposites com- posed of 2D graphene nanosheets, which was modified by OD molybdenum dioxide (MoO2) nanodots, were synthesized by one-step hydrothermal method. And the electrochemical properties of this kind of 0D-2D-3D multi-scale composites were studied as the active electrode materials of supercapacitors. The results showed that the specific capacitance was as high as 499 F/g at 2 mV/s, displaying excellent ca- pacity performance. [ABSTRACT FROM AUTHOR]

With the promotion of government affairs data transformation in Zhejiang Province, Zhejiang government affairs Ding Talk（referred to as “Ding Talk”）, as the office platform of government affairs system, is widely used in the province. The early warning information service application of the emergency early warning information release system（referred to as the “emergency system”） is carried out based on Ding Talk. The government realizes the early warning information service that can directly reach the government personnel, further expands the coverage of the early warning information of the emergency system, and improves the service efficiency of meteorological disaster prevention and reduction.This paper analyzed the existing functional framework of the emergency system in Zhejiang Province,and focused on the application research of various information service channels of Ding Talk,which is connected to the emergency system.In addition,we developed an online early warning service applet on the Ding Talk to realize real-time viewing of current effective early warnings.Ding Talk has highlighted its good business application ability and development prospects in developing early warning information services. [ABSTRACT FROM AUTHOR]

Aiming at the problems of similar appearance and occlusion of people in the video person re-identification, a video-based person re-identification model based on pyramid segmentation and attention mechanism was studied and designed. First, in order to enhance the recognition ability of the graph model for the local features of pedestrians, a multi-scale horizontal pyramid segmentation method was proposed. In addition, given that the simple spatiotemporal attention module was prone to damage person features due to occlusion, the spatiotemporal attention module was improved using the spatiotemporal correlation attention method, which gradually learns and aggregates spatially local information while interacting in time sequence to suppress person interference features and enhance discriminative features. This paper evaluates the model on Mars and DukeMTMC-VideoReID datasets, and the experimental results confirm the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In the process of landfill and operation, the shear strength of municipal landfill will change with the increase of age, and the stability of landfill itself will also change. In this paper, the analysis of shear strength parameters of garbage soil by domestic and foreign scholars was made, and the variation of cohesion and internal friction angle with age increasing was summarized. If the material of the landfill is similar, the cohesive force tends to decay with quadratic function while the internal friction angle increases with logarithmic function;moreover,after 10—15 years of landfill,the cohesion approached zero and the internal friction angle increases by 15°—25°．Then a layered landfill model was established,and the shear strength parameters related to age were given to each landfill layer.Finally,PLAXIS finite element software was used to analyze the slope stability of landfill at different ages.The stability safety factor decreases first and then increases with the age increase.The displacement is mainly concentrated in the middle of the slope while the settlement is mainly concentrated in the top of the slope.During the operation of landfill,attention should mainly be paid to the change of slope displacement and the safety of landfill around 10 years after sealing.The research results have obvious engineering significance for landfill design and site safely. [ABSTRACT FROM AUTHOR]

The paper studied the effect and mechanism of combined use of bezafibrate (Beza) and retinoic acid (RA) to induce the differentiation of APPswe M17 cells into neuron like cells by Western blot and cell morphology detection. The results showed that vector M17 cells hardly expressed APP, while APPswe M17 cell line expressed high levels of APP. 10 μmol/L RA could induce vector M17 to differentiate into neuron like cells, 250 μmol/L Beza and 10 μmol/L RA could induce the differentiation of APPswe M17 cells into neuron like cells. Its mechanism is to restore the differentiation potential of APPswe M17 cells by up-regulating the expression of DLP1 in APPswe M17 cells. [ABSTRACT FROM AUTHOR]

In order to solve the problem of construction stratum disturbance caused by shallow overburden layer of shield tunnel crossing river, and the problem of stratum settlement caused by synchronous grouting volume and Tunneling pressure- this paper is based on the actual situation of Changzhou Metro Line 2 Phase I project, combined with the method of anti-floating stability, this paper solves the minimum soil thickness required for the shield tunnel to pass through the river. At the same time. ABAQIJS is used to establish a three-dimensional finite element analysis model to verify the correctness of the calculation results. Calculation based on minimum soil thickness, an effective control method is proposed by comparing the settlement conditions under different grouting volumes and different tunneling pressures. The results show that the minimum required soil thickness of this interval is 9.13 m, and the larger the synchronous grouting amount, the larger the ground settlement, the larger the tunneling pressure and the smaller the ground settlement. The conclusions obtained can give a certain reference for the construction of shield tunnels crossing rivers. [ABSTRACT FROM AUTHOR]

A system-level model of the wind sensor system including the sensor chip and the conditioning circuit was proposed in this paper. The wind sensor was composed of a center temperature sensor,four heaters and four temperature sensors. The presented model was based on the theory of lumped parameters. An analogy was drawn between the heat flow and the electric current. Herein,the voltage is an analogy for the temperature,and the thermal resistance is the resistance in the thermal transfer like the resistance in the circuit. Further,the thermal analysis of the sensor chip and the electrical analysis of the conditioning circuit were developed in one system-level circuit by using the model. The test was performed in the wind tunnel. Experiment results presented here showed an agreement with the system-level model. The results presented here provided a valuable reference for the practical application of the wind sensor. [ABSTRACT FROM AUTHOR]

In this paper, four impellers with different blade inlet angles were designed by using ANSYS Bladegen software. The steady numerical calculation of whole flow field of single-blade centrifugal pump with different impellers was carried out, and the numerical calculation scheme adopted was verified. The results show that the pressure distribution on the middle section of the impeller is more uniform, but the range of low-velocity zone at the impeller inlet and in volute is larger, and the fluctuation of absolute velocity at the impeller outlet is less affected by the blade inlet angle with the increase of flow rate at the rated rotating speed.Under the same working condition, properly increasing the blade inlet angle can increase the range of high pressure area on the middle section of the impeller and improve the energy conversion capacity of the impeller, while reducing the pressure at the inlet of the blade suction surface. Under all flow conditions,the blade inlet angle is too small or too large, which is not conducive to reducing the collision loss caused by the collision between the liquid flow from the impeller and the liquid flow in volute,reducing the fluctuation of the blade load. [ABSTRACT FROM AUTHOR]

The research and application of the molten metal die forging (MMDF for short) of cast aluminum alloy are very active,but the research of MMDF of wrought aluminum alloy is rarely reported. MMDF is a process technology for forming parts by using the rheological properties of metal materials near the liquidus. Wrought aluminum alloy can also be used for MMDF. Firstly, the research and app lication status of MMDF wrought aluminum alloy was summarized in this paper, and then the key technology and strengthening and toughening mechanism of MMDF wrought aluminum alloy was comprehensively analyzed. Finally, it was pointed out that MMDF wrought aluminum alloy would form a series of new materials with high-strength and light density, and there would be three main research topics of MMDF wrought aluminum alloy in the future: (1) prevention and control of cracking, segregation and incomplete forming defects in indirect MMDF of complex workpiece; (2) optimization of heat treatment process of MMDF wrought aluminum alloy; (3) integrated control of the pretreatment of wrought aluminum alloy materials,design and manufacture of the dies,selection of the equipment and MMDF process to realize the high-performance forming. [ABSTRACT FROM AUTHOR]

The mist entrainment even flooding would unavoidably occur in traditional towers .Therefore,swirl bubble-cap is proposed,which would be expected to reduce the mist entrainment based on the principle of swirl coalescence and centrifugal sedimentation .In this paper,CFD numerical simulation is used to explore the hydrodynamic performance of swirl bubble-cap,including pressure drop and phase separation performance .The coalescence effect of the ratio of the average particle size at the outlet to the inlet is used to evaluate the phase separation performance .Firstly,the reliability of the simulation was verified with the pressure drop data tested .The RNGk-εmodel was used to deal with turbulence,the Euler-Euler model to deal with gas-liquid two-phase flow,the PBM model to consider the coalescence and breakage of droplets .Results showed that the pressure drop increased with the increase in feed flowrate,the coalescence effect increased with the increase in feed flowrate and then leveled off with further increase in feed flowrate,increased with the increase in droplet concentration and decreased with the increase in droplet size . [ABSTRACT FROM AUTHOR]

A non-Pt electrocatalyst for porous carbon molybdenum carbide with ruthenium nanoparticles was prepared in this paper. The carrier was synthesized by using two dimensional conjugated carbonit and ammonium molybdate as precursors, and the active metal ruthenium was uniformly dispersed with the support of hydrothermal method. Their structure consists of N-doped atoms and nanopores. These holes create highly accessible catalytic sites and good charge transfer ability in the material, thus providing good reaction kinetics for hydrogen evolution reaction（HER) . N-doped atoms regulate the electronic properties of the catalytic active sites in the material, which reduces the free energy of adsorption and desorption of hydrogen components participating in the reaction, providing good catalytic activity for HER. [ABSTRACT FROM AUTHOR]

So as to investigate the influence of intercritical annealing time on microstructure and mechanical properties of medium Mn steels based on the results of SEM, XRD and tensile properties, a Fe-0.21C-0.20Si-6.1Mn-0.97Al alloy was treated at different annealing times（10min,1hand 12h）in this papers. The results showed that the increase in annealing times from 10min to 1hled to the increase in mechanical properties of warm rolled medium Mn steels,as the annealing time further increased to 12h, the mechanical properties of the experimental steel decreased; the increase in annealing time led to the increase in average grain size and the equiaxed microstructure ratio; with the increase of annealing time from 10min to 12h, the retained austenite fraction and stability increased firstly, and then decreased. Based on the above results, it can be inferred that the microstructure and mechanical properties of medium Mn steel could be controlled by controlling the annealing time. [ABSTRACT FROM AUTHOR]

In the light of odor pollution in municipal solid waste(MSW)landfills, this paper reviews the research progress of analytical methods and control technologies of odorous gas. It was pointed out that the open operation areas were the major source of odorous gas in landfills. Besides, the olfactory method and instrumental method in the analysis of odor pollution were compared in terms of their principles, advantages and disadvantages. In addition, the principles and applications of several odor pollution control technologies, including the covering method, the spraying of anti-odor liquid and the combustion method, were also presented. Above all, recommendations were suggested in according to the limitations of current situation in the odor pollution control in China. [ABSTRACT FROM AUTHOR]

In this paper, we researched the typical configuration characteristics of wheel loader and its movable arm was analyzed on the statics and simulated based on finite element. A bionic movable arm was designed which was inspired by the internal structure of bamboo. Moreover, the bionic movable arm was compared with the original movable arm through finite element analysis under four ultimate working conditions: positive load insertion, positive load digging up, offset load insertion and offset load digging up. Finally, the results show that the bionic movable arm meets the structural strength and its weight is 17.03% lighter than the original one, which indicates the lightweight design of the movable arm of the loader is realized. [ABSTRACT FROM AUTHOR]

Taking the pavement environment as the research object, this paper provides a complete set of pavement environment monitoring and early warning system solution combined with software and hardware, which collects, transmits, processes and analyzes the monitoring data in real time. The artificial intelligence image recognition technology based on machine vision is added on the basis of traditional sensing equipment as well. A variety of road information fusion is carried out. It also provides hierarchical early warning according to the established early warning model. And relevant data and early warning information can be checked on browser in real time through the intelligent early warning platform. Through planning and design, the system is endowed with good expansibility and reusability, high efficiency and practicability. [ABSTRACT FROM AUTHOR]

The production of acrylic acid from lactic acid(lactic esters)is one of the research hotspots in the field of energy and chemical industry. This paper reviews the research on the production of acrylic acid by dehydration of lactic acid(lactic esters)and mainly focuses on the influence of catalyst type(sulfate, phosphate, hydroxyapatite, zeolites)on the dehydration reaction. The reaction mechanism and kinetic behavior were also analyzed and summarized. Finally, the development for the catalytic conversion of lactic acid(lactic ester)to acrylic acid in the future was predicted. [ABSTRACT FROM AUTHOR]

The preparation methods of M-SiO2 and the research development of M-SiO2 materials in flame-retarded polymers were reviewed in this paper. The preparation methods mainly included sol-gel method, hydrothermal synthesis, room temperature synthesis and microwave irradiation synthesis. The characterizations of four methods were described in this paper. According to the application types of M-SiO2 , its flame retardant applications in polymers mainly included the direct use of Mi-SiO2 as flame retardant synergist, functionalized M-SiO2 , preparation of M-SiO2 composites and hollow meso¬porous silica (HM-SiO2) materials. Based on the current applications, the development of M-SiO2 materials in flame-retarded polymers is proposed. [ABSTRACT FROM AUTHOR]

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The durability of rock is not only related to its own properties, but also to the service environment in which it is located. This paper briefly introduces MDE method. Through a specific project, the residual mass percentage of rock in a certain design life is calculated, the service life of rock in the current service environment is quantified, and the properties of such rock are judged by taking into full consideration the nature of rock itself and the service environment. It is concluded that the residual mass percentage of such rocks calculated based on MDE method meets the use requirements after the designed service life, which can provide reference for the evaluation of rock durability in other projects. [ABSTRACT FROM AUTHOR]

Automobile manufacturing industry is one of the basic industries in the national emerging economy. An automobile manufacturing plant includes four workshops: stamping, welding, painting and final assembly workshops. Automobile coating workshop is a workshop with a high degree of automation in the process of automobile manufacturing. Nowadays, the production mode of automobile industry has changed from batch production to customer order production, thus traditional automobile production lines can no longer meet the individual needs of automobile production. Therefore we designed a flexible automobile coating production control system based on RFID and fieldbus technology. This paper introduces the related functions of the automobile coating control system in detail, which mainly includes video monitoring system, body identification system, safety lamp system, production control system and production management system. The automobile coating control system has been put into operation in Tianjin for 3 years, and the control effect is good. [ABSTRACT FROM AUTHOR]

A “hard-connection” plug of drilling tool fractured on an offshore operation platform, which involved the fracture of beryllium bronze hexagonal nut and superalloy shell. This paper focuses on finding out the first broken piece, the failure mode and failure mechanism. Through the macro analysis of fracture, observation of micro morphology and EDS, microstructure and microhardness measurement, it is determined that the fracture of beryllium bronze hexagonal nut is caused by stress corrosion fracture and it causes one-time ductile fracture of the shell. The abnormal structure of beryllium bronze hexagonal nut, which caused by over aging heat treatment, leads to grain boundary reaction and reduces the mechanical properties of the material. It is the main reason for the stress corrosion fracture of hexagonal nut. The corrosion pit on the inner surface of hexagonal nut and stress concentration formed by machining knife mark are the inducing factors of stress corrosion fracture. [ABSTRACT FROM AUTHOR]

The 17-4PH eccentering ailll is fastened with the inner countersunk head hexagonal hole screw(17-4PH), which mainly bears shear force. During logging operation, the screw broke. In this paper, the failure analysis of the broken focuses on aspects of micro and macro morphology, hardness, metallography, inclusions, micro energy spectrum, chemical composition and artificial fracture morphology. According to the test results, the chemical composition of the screw material is qualified, while its hardness value is lower than the lower limit of the standard requirements, and there exist inclusions in the matrix. The metallographic structure is martensite and high-temperature ferrite, and the existence of ferrite destroys the continuity of the matrix. As a result, the hardness and mechanical properties decline. The fatigue fracture characteristics in the micrograph shows that the failure mechanism of the screw is fatigue fracture caused by shear stress. [ABSTRACT FROM AUTHOR]

The main strata of Shunnan district of middle Tarim is carbonate layers, and the pore pressure based on the present monitoring and predicting method is not correct. Based on the principle of Sigma logging, the Sigma index is corrected on the basis of the drilling rate and the high loss of pressure. Then the pore pressure monitoring method of Shunnan district is obtained by the correcting of the parameters of drilling rate equations. Meanwhile, the method in this paper is used in the typical well in Shunnan district. The results shows that, the calculation method presented in this paper is more applicable in this district. Compared with the real drilling situation, there are smaller errors, and the results of the method is 10% more accurate than Dc method, which indicates that the method can be promoted. [ABSTRACT FROM AUTHOR]

The main strata of Shunnan district of middle Tarim is carbonate layers, and the pore pressure based on the present monitoring and predicting method is not correct. Based on the principle of Sigma logging, the Sigma index is corrected on the basis of the drilling rate and the high loss of pressure. Then the pore pressure monitoring method of Shunnan district is obtained by the correcting of the parameters of drilling rate equations. Meanwhile, the method in this paper is used in the typical well in Shunnan district. The results shows that, the calculation method presented in this paper is more applicable in this district. Compared with the real drilling situation, there are smaller errors, and the results of the method is 10% more accurate than Dc method, which indicates that the method can be promoted. [ABSTRACT FROM AUTHOR]

Literature on disc centrifuge for oil-water separation has neglected the coalescence and breakup behavior of droplets, as well as its influence on the internal flow field and separation performance. As a result, the theory of disc centrifuge is difficult to deepen, which restricts the development and application of disc centrifuge. Therefore, the coalescence and breakup behavior of oil droplets in the disc centrifuge were investigated with the CFD-PBM coupling model in this paper, as well as the law of influence on the separation performance. The results show that the particle size of the inlet oil droplets is mainly 8—40 μm, while the particle size of the oil droplets in the pre-separation zone and the light phase outlet is above 80 μm, indicating that the oil droplets mainly coalesce at these two positions. In the disc gap and bottom runner, the particle size of the oil droplets was reduced from 80 μm in the pre-separation zone to about 70 μm, indicating that the oil droplets mainly break up at these two locations. In addition, comparing the separation efficiency obtained by simulation with the experimental results, it is found that the maximum error is only 5%, which shows that the coalescence and breakup behavior of oil droplets in disc centrifuge can be accurately revealed by PBM model. In summary, oil droplets do have obvious coalescence and breakup behavior in the disc centrifuge, and coalescence behavior is the main one. This article not only lays the foundation for the in-depth study of the separation performance of the disc centrifuge, but also provides a theoretical guidance for the structural design of the disc centrifuge. [ABSTRACT FROM AUTHOR]