In this paper, based on the background of hydrogen photolysis of water, adapts the computational fluid dynamics software combined with secondary development to numerically analyze the heat transfer process inside the solar photocatalytic reactor. A high⁃quality structured hexahedral photocatalytic reactor grid was established to analyze the temperature distribution characteristics of the solar photocatalytic reactor model numerically, compile the Gaussian heat flow and validate the model combined with the solar photocatalytic water activity evaluation system for hydrogen production. This article will focus on the effect of solar radiation on the temperature distribution of the fluid inside the reactor and the reactor under full spectrum, and study the differences in temperature distribution and causes under different conditions.
In order to achieve the emulsification viscosity reduction of heavy oil in Huanxiling oil production plant of Liaohe oilfield, the emulsifier solution with the mass fraction of 30%, emulsifying temperature of 50 ℃, emulsifying time of 1 h, stirring speed of 200 r/min, stirring time of 5 min, under the shear rate of 16.9 s－1, the effect of single emulsifier and compounding emulsifier on the stability and viscosity⁃reducing rate of emulsion is investigated. The results show that the optimal compounding mode of the compounding emulsifier is as follow: 0.7% OP⁃12 and 0.8% sodium oleate; the best compound emulsifier and heavy oil could form a stable emulsion, and the viscosity can be reduced from 1 020.9 mPa•s to 72.0 mPa•s, and the viscosity reduction rate reachs 92.95%. The emulsion with the best compound emulsifier and heavy oil has better stability than the single agent OP⁃12 and heavy oil emulsion.
The separation and purification conditions of total flavonoids from Flos Lonicerae were studied by polyamide column chromatography. Based on the concentration of the total flavonoids, by the way of the adsorption and desorption abilities of polyamide resin, the optimum parameters of the separation and purification of the total flavonoids of Hibiscus manihot L are selected and evaluated. The main results are as follows: Purification conditions are as follows: the concentration of sample solution is 4.68 mg/mL,the pH is 4~5, adsorption rare is 1.5 mL/min, sample volume is 1.5 BV, water washing resin column with 3.0 BV, the elution rate is 1.5 mL/min with 5.0 BV 80% ethanol has a best effect with polyamides for five times. The result provided a basis for further development andapplication of Hibiscus manihot L.
Polyester has unique biodegradability, bioabsorbability and biocompatibility. The existing raw materials for the production of polyester products generally come from the petrochemical industry is not a biomass material. In this experiment, methylene succinic acid (IA) and its sulfonated product succinic acid⁃2⁃methyl sulfonate (ISNa) and 1,4⁃butanediol (BD) were used as raw materials, Polycondensation method to prepare a new type of water⁃based polyester (PBIINa). The effects of catalyst type, polycondensation time and system temperature on the properties of PBIINa were investigated. The product structure was characterized by Fourier transform infrared spectroscopy (FT⁃IR) and nuclear magnetic resonance (1H⁃NMR) and the water solubility of the polyester was tested. The study found that the optimum conditions for the synthesis of the polyester: the esterification stage 5.0 h system temperature 180 ℃, n(BD)/n(IA)/n(ISNa)=1.00∶0.88∶0.17, catalyzed by SnCl2, system pressure 0.1 MPa, polycondensation stage 2.5 h, system temperature 160 ℃.
N,N'⁃methylenebisacrylamide (MBA) is used as a crosslinking agent, octadecyl acrylate (SA) is a hydrophobic monomer, and dimethylaminoethyl methacrylate (DMAEMA) is a hydrophilic monomer. Vinyl porphyrin (MTPP) is a photothermal monomer, and PSDM⁃MTPP shape memory hydrogel with red light responsiveness was successfully prepared by free radical copolymerization. The experimental results show that a low light intensity (<528 mW/cm2) and a short irradiation time can motivate the PSDM⁃MTPP hydrogel recover to original shape. Moreover, maintaining multiple intermediate states and regioselective responses. This shape memory gel with fast response, high recovery rate, remote control and spatial selectivity has potential application value in biomedical field. The obtained shape memory hydrogel with fast response, high recovery rate, remote control and spatial selectivity provided potential application in biomedical field.
Complex [Cu(2,6⁃pidic)(H2O)2]2 was synthesized to obtain monocrystals using the hydrothermal method, whose space group P⁃1. The crystallographic data shows that a=0.469 92(2) nm, b=0.893 20(3) nm, c=1.030 36(6) nm. Each structure cell contains two molecules, one of which is isolated from the other. Coordination number of the center copper ions is five. Complex magnetic susceptibility measurement confirmed the antiferromagnetic interactions between the Cu2+ ions.
Composite oxides are of great interest to researchers due to their excellent physicochemical properties, while zirconium⁃containing composite oxides are used in catalytic hydrodesulfurization, dearomatization, gas phase Beckmann rearrangement reactions of cyclohexanone oximes, and removal of organic contaminants that have wide range of applications. This article reviews the three main preparation methods for zirconium⁃containing composite oxide catalysts (sol⁃gel method, hydrothermal synthesis method, co⁃precipitation method) as well as the defects and advantages of these three methods. Some other preparation methods are also briefly introduced.
Because of geological disasters, corrosion defects, third party damage and other factors, there are many hidden dangers in the safe transportation of oil and gas pipelines. Therefore, it is of great practical significance to study the law of leakage and diffusion of buried natural gas pipelines for the prediction and location of leakage points and the formulation of emergency plans.Numerical analysis of the leakage and diffusion process of buried natural gas pipeline is carried out, the influence of leakage velocity, wind speed and environmental temperature on CH4 the methane concentration are analyzed and summed up diffusion law.The research results can provide theoretical support for the accurate location and emergency plan of the buried gas pipeline leakage point.
It is difficult to accurately interpret reservoir fluid with complex oil⁃water relation, by the conventional two⁃dimensional or three⁃dimensional geochemical chart, because of the fuzzy oil⁃bearing or water⁃bearing representation reflected by single two or three geochemical parameters. On the basis of geochemical data validated by oil production test, the geochemical pyrolysis parameters that directly reflect the distribution relationship of oil, gas and water in the reservoir are constructed. Four geochemical parameters are constructed and three two⁃dimensional subgraphs are constructed, which realize the comprehensive and comparison analysis of oil⁃bearing and water⁃bearing characteristic of samples. The final reservoir interpretation is obtained through the analysis of comprehensive geochemical cross chart united pyrolysis gas chromatography and geological fluorescence. The application of geochemical cross chart has achieved good effects in Agadem block, Niger.
The characteristics of gas⁃liquid two⁃phase flow during the pigging process is helpful to the design and operation of the pipeline itself and the upstream and downstream equipment. In this paper, the multiphase flow simulation software OLGA is used to study the gas⁃liquid two⁃phase flow law during the process of natural gas pipeline pigging. The changes of key analysis pipeline such as flow pattern, pressure, liquid holdup, pigging velocity, fluid volume and other parameters. The results show that: the pigging process in the undulating terrain, the gas⁃liquid two⁃phase stratified flow, slug flow and annular flow pattern. The pressure at the entrance of the pipeline is the largest, and the pressure decreases gradually along with the pressure fluctuation; the overall speed of the pig is not fluctuating, the average speed is about 3.5~3.8 m/s. The maximum length of liquid slug in the process of pigging is 3 851.0 m. The liquid holdup is constantly changing, the maximum clear liquid is close to 300 m3. The research conclusion has certain practical significance to the pigging operation of the natural gas pipeline in the relief area.
For the study of variable diameter tube affects the quantity of sequential oil transportation of the refined oil, applying multiphase flow model, the 90# gasoline and 0# diesel oil as the object of alternate transportations, according to different variable diameter pipeline structure form and different tapered Angle on the oil transportation.The results show that the growth rate of the length of the mixing section decreases obviously and the length of the mixing section decreases for a short time when the mixing oil enters the sudden expansion pipe, then the length of the mixed oil section growth accelerated obviously, but inferior to the level before variable diameter and with the increase of taper Angle, the different length were mixed with different degrees of decreased; after the mixed oil section flows into reducing pipe, the length of the mixed oil section growth obviously larger, and appeared the trend of decrease, but still higher than before the variable diameter, and with the increase of tapered tube taper Angle, the length of the mixed oil section all have varying degrees of increase.
In order to study the vibration characteristics of the downhole gear transmission system,based on the 3D modeling software CREO, a three⁃dimensional geometric model of the main and driven gears of the downhole gear transmission system was established. And using the ANSYS software import function to establish the three⁃dimensional finite element model of transmission gear. By reading the dynamic mechanical modal analysis of the finite element model of gear, the natural frequencies of the gears and the corresponding main modes are obtained. This study can be used as a theoretical reference to avoid the frequency of external excitation response in the design process, so as to avoid the resonance of the transmission system and effectively improving the fatigue strength of the gear transmission system.
The dynamic response characteristics of the internal rotor⁃bearing system are directly related to the pros and cons performance of the turbine.In this paper, the finite element method is used to model the rotor⁃bearing system, considering the effect of bearing stiffness on the critical speed of the system, the unbalanced response characteristics at the same speed and different speeds,the unbalanced response characteristics are discussed in detail, the sensitive position of the system is determined, which provides the basis for the optimization design of the steam turbine.
The theoretical analysis of the stress concentration factor K of three types of tubes with three different types of unfused defects is very complicated. In this paper, the finite element numerical analysis software is used to be established the finite element model of the three⁃way pipe with defects under the action of internal pressure. After calculation, the stress concentration factor K and its variation law under the four influencing factors are obtained. The results show that the stress concentration factor K of the three⁃way tube with three different unfused defects is relatively large in the shoulder and collar region, and the stress concentration is serious. The stress concentration factor K increased slowly with the increase of the axial length and depth of the defect, and decreased rapidly with the increase of the circumferential length of the defect.
The main contribution is to present stability analysis criterion for a type of norm⁃bounded uncertain perturbed discrete systems(NUPDS) with its states is subjected to a novel ellipsoidal outer approximation,which is different from the traditional bound description of general state. Based on the Lyapunov method, a delay dependent criterion and the corresponding state feedback control law, which are expressed in terms of linear matrix inequalities(LMIs) technology, are proposed to guarantee the asymptotic stability for the perturb delay systems. The solution of the LMIs can be obtained easily using existing efficient convex optimization techniques. A numerical example is given to illustrate effectiveness of the proposed method.
Based on the inverse kinematics solution of 6⁃PTRT parallel robot, the constraints on the workspace are analyzed. The three⁃dimensional boundary search method is used to search the workspace in space, and then the simulation is carried out by MATLAB software programming. The shape and distribution characteristics of the workspace are visualized. The workspace volume is solved by polar coordinate search method. The correlation between the structure parameter and the workspace is analyzed by using the control variable method,and the specific effect of the structural parameter on the workspace distribution and volume is clarified. This has important guiding significance for the structural design and practical application of 6⁃PTRT parallel robot.
With the popularization of network cameras and the continuous development of image processing technology, visual⁃based fire monitoring systems have received more and more attention. The current method of visual⁃based fire monitoring system is to detect the flame generated after a fire. The disadvantage is that the fire has already occurred during the alarm. The proposed fire detection system firstly finds out the suspected smoke area through the motion detection and the motion characteristics when the smoke just appears, and on this basis, the smoke and flame detection are carried out in the suspected smoke area. The smoke detection combines the smoke color characteristics and texture features. Flame detection uses the combination of flame two color features to improve detection accuracy. The experimental results show that the system can provide an alarm before the fire spreads and accurately detect the location of the fire ignition point, so the effectiveness of the proposed method is verified.
A high efficiency and high precision testing method for tightness detection method of aluminum foil seal is proposed.First of all, the thermal images of aluminum foil seal are obtained by a thermal imager.Then we use MATLAB software for getting the information of thermal image in batches,and then the image preprocessing. Then BP neural network was optimized by genetic algorithm to extract and classify image features.The experimental results show that this sealing test method has high recognition rate and short training time, which provides a guarantee for automatic screening and elimination of bad sealing products in the subsequent aluminum foil sealing production line.
