Abstract:

Abstract: CFD technology and PIV measurement were used to study the flow field and concentration distribution of the double-layer impeller in the agitator at different positions. Based on the Navier-Stokes equation and the standard κ-ε turbulence model, the turbulent flow field of the agitator was solved, and the flow pattern changes and mixing concentrations of the agitator at different rotational speeds and different blade heights were investigated. The results show that the flow pattern of the flow field basically does not change when the position of the double-layer impeller is changed, and the upper and lower "double circulation" flow is formed with the blade as the center. With the change of feeding position and blade height, there is basically no effect on the stirring power, but the concentration of different monitoring points changes greatly, and the impact on the mixing time is also greater. The use of paddle part feeding can make full use of the turbulence characteristics of the fluid, accelerate the mixing speed, shorten the mixing time, save costs and improve economic benefits.、

Abstract: In view of the problem of unstable gardenia in use, the method of adding compound food additives was adopted. Improve its stability. Using the medicinal gardenia fruit as raw material, the effects of 12 food additives such as sodium alginate and 7 different compound additives on their stability were investigated, and the best food additives and compound food additives were determined. It was found that sodium alginate and sodium formate alone could stabilize the molecular structure of gardenia yellow pigment more than EDTA-Na2 reported in literature. The combination of sodium alginate + sodium formate of the compound food additive has a better stabilization effect on the pigment. The pigment solution with the addition of the complex food additive sodium alginate + sodium tartrate + sodium formate was the most stable among all samples.

Abstract: A novel catalyst, PW-SBA-15, was prepared by post-synthesis method, and PW-SBA-15 was characterized to obtain its nitrogen adsorption isotherm. w(H2O2)=30% was used as oxidant, cyclohexene was oxidized by a pot boiling method to obtain the target product adipic acid, and its IR spectra were determined by Fourier infrared spectrometer, and the standard molar combustion enthalpy of adipic acid was determined by XRY-1C microcomputer oxygen bomb calorimeter as -2801.0 kJ·mol-1, and the standard molar enthalpy of adipic acid was calculated to be -989.32 kJ·mol-1. At the same time, the melting point and melting enthalpy of adipic acid were determined by DTG-60 differential thermal-thermogravimetric analyzer, which provided basic data for industrial production and design.

Abstract: The L zeolite synthesized on kaolin microspheres was modified to reduce its potassium oxide content and improve its silicon-aluminum ratio. The amount, temperature and time of ammonium sulfate during ion exchange were optimized, the effects of roasting on silicon-aluminum ratio and crystallinity were investigated, and ion exchange, citric acid treatment and water vapor roasting were combined to improve the silicon-aluminum ratio of zeolite. The results showed that the optimal reaction conditions during ion exchange were zeolite:water:ammonium sulfate ratio of 1g:10mL:1g, reaction temperature 80 °C, reaction time 2h. Ion exchange, citric acid treatment combined with hydrothermal roasting can significantly improve the silicon-aluminum ratio of zeolite while maintaining the integrity of the crystal structure, and when the citric acid concentration is 0.10 mol/L, the crystallinity of the three-cross lemon three-baked (E) sample is 82%, and the silicon-aluminum ratio reaches 13.60.

Abstract: A copper hydroxyphosphate catalyst was prepared by hydrothermal method, and the catalytic degradation of p-nitrophenol with copper hydroxyphosphate as a catalyst was studied in the presence of hydrogen peroxide. The effects of catalyst dosage, hydrogen peroxide dosage, pH value, temperature, initial concentration and other conditions on the degradation process were tested. The results show that copper hydroxyphosphate has excellent catalytic degradation of p-nitrophenol, and the degradation rate of p-nitrophenol can be greatly accelerated by adding a small amount of copper hydroxyphosphate catalyst. The larger the amount of catalyst, the larger the amount of hydrogen peroxide, and the faster the degradation rate; If the pH value is increased, the degradation rate will be slower, and the optimized pH is 2~3; Increasing temperature can speed up the rate of degradation.

Abstract: Through the determination of the solubility of thiourea and S-hydrocarbon isothiourea salts in solvent 95% ethanol, their content in the final reaction solution was determined, the amount of solvent was reduced, the post-treatment operation step of distillation and ethanol recovery was eliminated, and the recycling rate of solvent could reach more than 90%. According to the difference in solubility of Na2SO4 and NaBr in water, Na2SO4 and NaBr were separated from the aqueous phase of the reaction liquid by rotary evaporation, and the recovery rate of Na2SO4 could reach more than 95%. The composition of the oil phase was determined by gas chromatography-mass spectrometry, and the product with a purity of more than 99% was obtained by vacuum distillation, and the final yield could reach more than 70%. The kettle liquid was reduced by zinc powder to obtain a by-product dimercaptodiethyl sulfide.

Abstract: The flame characteristics in the double preheated regenerative annular furnace were simulated by using the RNGκ-ε turbulence model, the non-premixed (PDF) combustion model and the anisotropically scattered P-1 radiation heat transfer model, and the effects of different air injection angles and different preheating temperatures on the flame characteristics were compared. The results show that the volume of flame is larger when the air injection angle is 5°, but the loss of incomplete combustion is more. When the injection angle is 30° and 40°, the flame volume is relatively small, and the maximum combustion temperature is high. When the injection angle is 10°~20°, the comprehensive characteristics are better. The increase of preheating temperature improves the combustion stability, so that the maximum combustion temperature and the average combustion chamber temperature increase significantly.

Abstract: Anisotropic conductive adhesive film bonding structure is a widely used connection form in microelectronic packaging. Under the action of external load, the bonding interface is prone to damage and failure, which makes the structure fail. The cohesive zone model was used to simulate the damage and failure of the bonding interface of anisotropic conductive adhesive film bonding structures in peel test by finite element method. By comparing with the corresponding experimental data, the feasibility of the cohesion model for the numerical simulation of damage damage and failure of the bonding interface of conductive adhesive film is verified. The simulation analysis analyzes the relationship between the damage failure of the bonding interface and the opening displacement of the interface, and the calculation results show that the damage of the bonded interface will soon reach failure under the action of peeling force, which will cause the failure of the bonding interface.

Abstract: The emulsified oil wastewater was treated under microwave conditions with granular activated carbon (GAC) with different iron ion loads, and the influencing factors of microwave catalytic oxidation treatment of emulsified oil wastewater were discussed through orthogonal tests, and the catalytic oxidation dynamic behavior of emulsified oil wastewater was discussed according to the oil removal rate. The results show that the microwave action time is the main influencing factor of the treatment effect of emulsified oil wastewater, and the optimal process conditions are: Fe ion loading on GAC is 33.32 mg/g, microwave treatment power is 720 W, microwave treatment time is 45 min, and the COD value and oil content of effluent meet the discharge standard. In the microwave catalytic oxidation treatment of emulsified oil wastewater, the relationship between oil removal rate and treatment time satisfies the first-order kinetic equation.

Abstract: On the basis of the physical and mechanical properties test of raw materials, the mixing ratio of asphalt mixture AC-13 I was obtained by using the graphical method and adjusting and optimizing the mixing ratio. Through the Marshall test of asphalt mixture under different fiber types and different fiber content, the optimal asphalt dosage OAC of fiber asphalt mixture is obtained, and then the influence of fiber type and content on the dynamic stability of asphalt mixture is studied through high temperature rutting test, and the optimal amount of different types of fiber is obtained. The results show that the fiber can significantly improve the high temperature performance of asphalt mixture. Different kinds of fibers correspond to different optimal amounts in asphalt mixtures. Finally, a calculation model of the dynamic stability of the matrix asphalt mixture is established, considering the dynamic stability of the matrix asphalt mixture, the influence of fiber content and fiber type.

Abstract: The indirect tensile test (IDT) strength of asphalt mixture under different temperatures, different loading rates, different asphalt content and different grades was studied by indirect tensile test, and the results showed that temperature and loading rate were two important conditions affecting the test results. By comparing and analyzing the indirect tensile test results with the rutting test results, it is found that when the test temperature is 40°C and the loading rate is 50mm/min, the correlation between the IDT strength of the mixture and the rutting results is the best, which can be used as a mechanical index to evaluate the high temperature performance of asphalt mixture, and it is recommended to use it in the design process of asphalt mixture.

Abstract: The quantitative analysis method of volcanic ash activity was used to compare and analyze the activity effects between fine strontium slag, fine grinding slag and fly ash by comparing and analyzing the strength of rubber sand, the specific strength coefficient of active effect and the activity index. The analysis shows that the strength of the rubber sand can evaluate the mortar strength of the rubber sand specimen, but cannot quantify the strength contribution of the admixture. The specific strength index can quantitatively evaluate the active effect of admixtures in cement sand specimens of various ages and the strength percentage in the total strength of cement sand specimens, which makes up for the shortcomings of sand strength analysis. Among the admixtures studied, the active effect of grinding fine slag and calcined fine strontium slag was the best, and the former had better later activity, while the latter was more conducive to early activity development.

Abstract: Taking a 5m concrete pump truck with 45 sections of arm as the research object, the method of combining solid unit and contact unit is used to simulate the connection between each boom, and the plate and shell unit and beam unit are used to simulate the rest of the structure of the pump truck, and the finite element calculation model of the whole vehicle is established. Through mechanical analysis, it is concluded that when the boom is horizontal and perpendicular to the diagonal of the support point, it is a dangerous working condition of the pump truck. The overall structure of the pump truck was analyzed by finite element strength under dangerous working conditions. The calculation results show that large stresses are prone to occur at the connecting pin and the boom cylinder support. Field tests were carried out according to the calculation results, and the test results showed that the calculation analysis was in good agreement with the measured values.

Abstract: The membrane structure with flying rod supported by the tensile string three-dimensional truss integrates a variety of force characteristics such as membrane structure, flying rod and tensile string three-dimensional truss. The implementation process and key processing of the form-finding analysis of membrane structures with flying rods on ANSYS are given, and the hall roof of the water center in Xining, Qinghai Province is used as a case to find forming. The results show that the shape-finding shape is close to the requirements of the preliminary design modeling of the building, and the stress distribution on the membrane is relatively uniform. By comparing the vertical coordinate values of the top node of the final shape-finding flyrod after lifting, it is confirmed that the membrane structure with flying rod must be jointly form-finding with the elastic member when looking for form. The morphogenic analysis of the membrane structure with flying rod supported by the tensile string three-dimensional truss can not consider the self-weight of the structure, but the synergistic effect of the tensile string three-dimensional truss support needs to be considered.

Abstract: In order to provide experimental data and theoretical basis for BFRP reinforced beams, the bending performance of eight basalt fiber reinforced composite (BFRP) reinforced beams and three contrast beams was tested, and the effects of the number of BFRP paste layers, concrete strength grade, shear span, etc. on the flexural performance of the reinforced beams were analyzed. The test results show that . The bending bearing capacity and bending stiffness of the beam increase with the number of BFRP paste layers, the increase of concrete strength grade and the decrease of shear span, but it is not linear proportional. With the increase of the number of adhesive layers, the widening or increase of the U-hoop can effectively prevent the early destruction of the end. According to the test analysis, the calculation formula of the bending bearing capacity of the beam is proposed, and the calculation results are in good agreement with the test data, and are better than the calculation value of the formula of the < regulation > (CECS8:3).

Abstract: The overall structure and principle, main functional modules and implementation methods of remote monitoring and management system of engineering equipment based on GPS/GPRS technology, CAN bus and signal acquisition technology are analyzed, and the process of developing system functions using Delphi’s excellent network programming, multi-threading and data technology using object-oriented programming is emphasized, and the combination of dynamic array and pointer array is used to solve the problem of real-time communication and large data volume of real-time database system. The application of remote monitoring and management system shortens the maintenance cycle of engineering equipment, makes maintenance and management more active and convenient, so that the excavator works in the best operating condition and improves product competitiveness.

Abstract: In order to obtain the continuous value of the force acted on key hinged joints in a working excavator，this paper uses Pro／E4．0 and ADAMS 2005 to build up the virtual prototype of the hydraulic backhoe excavator SWE90U．In the virtual environment，the simulation of three typical working(bucket digging，arnldigging and smooth operation)and the study of the force acted on four key hinged joints of this excavator are accomplished，then，a series of corresponding curves of the force acted on the hinged joints is got．The results show that the change of the force acted on the joint between boom and arlrn is the most violent，but the change of the force acted on the joint between rocker and arnl is the flattest．

Abstract: An adaptive robust watermarking algorithm based on scale invariant feature transformation (SIFT) and wavelet transform is proposed to resist geometric attacks. Firstly, the SIFT algorithm is used to extract stable feature points from the carrier image. Then, the size and direction of each local feature area are determined according to the feature scale and direction adaptation. Finally, the feature regions with large feature scales that do not overlap with each other are selected, and the watermark is embedded in each local feature region by quantifying the wavelet coefficient. Simulation results show that the algorithm not only has good transparency, but also has strong ability to resist conventional signal processing and geometric attacks.

Abstract: Parallel programming is closely related to the architecture of parallel computers, so its complexity is much greater than serial programming. The concepts of data decomposition and cyclic body dependence are introduced, and an approximate relationship model of cache utilization and effective speed of parallel computer is proposed. Through this model and an example, the method process of reducing and disassembling the data dependence in the computing target in parallel programming design is described, so as to achieve the purpose of exploring as much instruction-level parallelism as possible, improving cache utilization, and improving the effective speed of parallel system.

Abstract: A dynamic program slice is a subset of a program consisting of all statements and control predicates that affect the value of a variable at a certain point of interest in the program. The author proposes a dynamic program slicing algorithm that simplifies dependencies, the main purpose of which is to solve the problem that H. Agrawal’s dynamic slicing algorithm is not accurate in calculating slices, which calculates variable slicing by determining the dependent nodes, controlling dependent nodes and node reachable statements through the program execution trajectory. Examples show that the algorithm improves the accuracy of dynamic slicing and reduces the complexity of calculating dynamic program slicing.

Abstract: Component object model COM based components have the advantages of reusability, language independence, self-description, etc., the Fortran computing program/mathematical model is built into COM components and integrated into the component software system is an inevitable development requirements.COM what are the basic characteristics of the components, how to plan and design Fortran COM components, the Fortran COM Server Wizard plug-in in the CVF computing development environment is to create Fortran What aspects of support are provided by COM components, and whether Fortran data types can be used directly in COM components, are some of the basic issues that Fortran programmers are concerned about.

Abstract: The stability of the network control system with random transmission delay and multi-packet transmission with more than one sampling period at the same time was studied. In the system, the sensor adopts time driven, and the controller and actuator adopt an event-driven way to model the multi-packet transmission control system as a switching control system. Then, based on the switching system analysis method and stability theory, and using the linear matrix inequality method, the sufficient conditions for the stability of the network control system are obtained. Finally, numerical examples are used to verify the effectiveness of the proposed method.

Abstract: The chemical corrosion behavior of bulk metallic glass (Fe1-x, Cox) 76Mo4 (P0.45C0.2B0.2Si0.15)20 (76x=0, 10 and 20) was studied. The polarization potential and polarization current of the Fe-based junction metal glass in HCl solution at different concentrations were investigated by electrochemical corrosion experiment, and the electrochemical corrosion characteristics were analyzed from the measured electrochemical polarization curve. The corrosion rate of the metal glass in HCl solution at different concentrations was determined by weight loss method, and the corrosion rate was lower than 0.08 g·m-2·h-1. The results showed that the studied Fe-based bulk metal-glass alloy system had excellent corrosion resistance in HCl solution. And with the increase of Co content, the corrosion resistance of the corresponding metal glass is further improved.

Abstract: On the basis of literature [7], the unreliable buffer zone is introduced into the unreliable dual-equipment production line system, and the system state probability change is analyzed on the basis of the discrete model. Using the literature [7] research method, the form of the internal state probability of the system is guessed, and the internal state equation is substituted to obtain the solution satisfying the internal state equation. If the conjecture is correct, then one must find a linear combination of this set of solutions satisfying the boundary conditions. By processing the probability of the relevant states of the system equipment and buffer, the solving order of the problem is reduced, and an approximate analytical method for evaluating the performance of the system is discussed and developed, and the research algorithm is given. Simulation results show the effectiveness of the proposed method.

Abstract: In order to seek a new method for calculating the stress state coefficient, based on a large number of measured data of 4200 rolling mill, using the Matlab neural network toolbox, taking the thickness of steel plates before and after rolling as input neurons, and taking the Qp obtained by measuring the rolling pressure and relying on the pressure formula for inverse operation as the output neurons, the BP neural network model and GRNN neural network model of the correspondence between the stress state coefficient of the rolling deformation zone and the thickness of the steel plate before and after rolling were established. The results show that it is feasible to predict the stress state coefficient by artificial neural network algorithm. The comparison between the GRNN neural network model and the BP model shows that the GRNN network has higher accuracy and stronger generalization ability.

Abstract: Aiming at the problem of nonlinear error in the movement of the tool tip due to the swing of the tool in five-axis numerical control (CNC) machining, a mathematical model of the error is established, and two methods to effectively reduce the error are proposed: the first method imputes the ideal linear tool tip trajectory instead of the data given by the NC program segment, and performs coordinate transformation on the interpolation point to calculate the motion control command output by the interpolator; The second method directly imputes the NC program segment, but projects the tool tip point corresponding to the point onto the ideal tool tip trajectory, transforms the projection point into coordinates, and coordinates the motion coordinates of each axis of the computer bed. Example calculations show that the proposed method can reduce the nonlinear swing error to less than 1μm, and the calculation time (35.6μs) can meet the real-time requirements of the numerical control system.

Abstract: The mechanism principle and characteristics of the new cycloidal single-cylinder diesel engine S195HC developed on the basis of S195 diesel engine were introduced, the piston motion law and its influence of S195HC new diesel engine were analyzed, and the gas distribution characteristics of S195HC new diesel engine were studied. The results show that compared with the traditional crank connecting rod mechanism, the piston of S195HC diesel engine stays near top dead center for a long time, and the piston is closer to top dead center, which is conducive to full combustion of fuel and improves the economy of internal combustion engine. The S195HC diesel engine does not have second-order and higher-order reciprocating inertial forces, which improves the mechanical vibration and noise of the internal combustion engine; The piston movement characteristics of the S195HC diesel engine facilitate the entry of fresh charge and improve the combustion process.

Abstract: Starting from the analysis of the network development and management needs of academic journals, a network information management platform for academic journals based on information network technology is constructed, the functions of each system are analyzed, and the system structure, module division and technical methods are expounded. The designed management platform includes five systems, including journal collection and editing system, journal publishing system, and journal subscription system. The journal collection and editing system includes six subsystems, including author submission subsystem, expert review subsystem, and editorial management subsystem. Based on the three-layer architecture of browser/web server/database server (B/S/S), the platform adopts standard Web technology and powerful multimedia database SQL server, which provides reference for the true realization of content informatization, management system, process networking, publication efficiency and first-class quality of journals.

Abstract: According to the three-dimensional incompressible Navier-Stokes equation and the standard κ-ε turbulence equation, the finite volume method was used to simulate the operation process of the train in the interval tunnel, the pressure change mechanism and pressure spatiotemporal variation characteristics of the screen door were studied, and the influence relationship between the train running speed, blocking ratio, piston wind shaft area, damper state and interval tunnel ventilation scheme and the screen door pressure was analyzed. The results show that the pressure change of the screen door is mainly determined by the two factors of the pressurized Cort turbulence of the train and the pressure wave in the interval tunnel, among which the pressurized Cort turbulence is the main influencing factor. The screen door pressure is proportional to the blocking ratio and the square of the train speed; Increasing the area of the piston air well and opening the piston damper is conducive to reducing the pressure of the screen door. The influence of the exhaust mode of the interval tunnel on the pressure of the screen door should be considered during the structural check.

Abstract: In order to solve the problem of path-based dynamic traffic distribution, the problem of reasonable set of paths between each start and end point is generated. Firstly, the commonly used path set generation methods, such as Dial algorithm, road section deletion algorithm, road section penalty algorithm and simulation method, are introduced, and then a reasonable path set generation and route rationality judgment index that can be used for dynamic traffic allocation problems are proposed. In a medium-sized road network, the effectiveness and correctness of the proposed algorithm are determined by simulation method, and the results show that the results given by the algorithm based on Dial algorithm, road segment deletion algorithm and road section penalty algorithm are more effective, while the path set bias given by the simulation algorithm is large.

Abstract: In order to improve the numerical calculation accuracy during mesh deformation, based on the concept of asymmetric finite elements, a US-FE-LSPIM QUADRILATERAL ELEMENT is proposed. This unit is composed of two different sets of shape functions, namely, the traditional set of four-node isoparameter functions and the set of FE-LSPIM quadrilateral element shape functions as test functions and test functions, respectively. It can easily apply displacement boundary conditions over the entire length. By studying the performance of the quadrilateral element in the two-dimensional free vibration of the cantilever beam, it is shown that the unit has high calculation accuracy. And under the deformed mesh, the result of this element is better than that of the QUAD4 element, which is insensitive to mesh deformation.

Abstract: As an important subsystem of the mine disaster system, some characteristics of the evolution of gas explosion accident show that it has a close relationship with chaotic phenomenon, so on the basis of the analysis of the time series observation and data analysis of the mine face gas outflow, the autocorrelation function, phase space reconstruction, Poincare section and return image in the chaos theory are applied to study and discriminate the chaotic characteristics of the working face gas outflow, which preliminarily proves that the working face gas gushing has chaotic characteristics. A comprehensive analysis of the evolution system of gas explosion shows that there is an obvious butterfly effect in the evolution process of gas explosion.

Abstract: In oder to improve precision of numerical calculation for distorted meshes。the US—FE—LSPIM QUAD4 element is developed based on the concept of unsymmetric finite element formulation．This element U—ses two different sets of shape funetions for the trial and test functions．viz．sets of FE—LSPIM QUAD4 element shape functions and sets of classical isoparametric shape functions．The US—FE—LSPIM QUAD4 element could easily fulfil exact essential boundary condition along the entire length of the edge．The element is used in the free vibration analysis of cantilever beam and shear wall．The results show that this element posses—ses good precision．Furthermore，this element is superior to QUAD4 element for distorted meshes and less sensitive to mesh distortion．

Abstract: Shanghai Hongqiao Comprehensive Housing Alternative Hub is the first large-scale comprehensive transportation hub integrating airport, railway station and maglev in China. Starting from the analysis of the characteristics of Hongqiao Hub, such as comprehensiveness and integration, ultra-large-scale, accumulation and compounding, this paper clarifies the view that Hongqiao Hub reflects the new trend of large-scale transportation building development in modern cities, and then summarizes these trends into urban complex trends, comprehensive hubization trends, and system characteristics trends.