By using methyl methacrylate (MMA) as the harder monomer, butyl acrylate (BA) as the softer monomer, acrylic acid (AA) as the functional monomer, acetoacetoxyethyl methacrylate (AAEM) as the crosslinking monomer, tert⁃butyl peroxybenzoate as the initiator, propylene glycol butyl ether as the solvent for prepared self⁃crosslinking acrylate emulsion by free radical solution polymerization and phase inversion, and the emulsion could be self⁃crosslinked after baking at high temperature without additional crosslinking agent. This article mainly studied the influence of acrylic acid, acetoacetoxyethyl methacrylate and curing time on the performance of the polyacrylic resin dispersion and the film property. The results show that the optimized formula is as follows: The dosage of AA and AAEM are 3.5% and 5.0% of the total monomer mass, respectively, and the baking time is 1.0 h at a curing temperature of 180 ℃. FT⁃IR and GPC analysis showed that AAEM was successfully attached to the molecular chain of acrylic resin; SEM and particle size analyzer analysis showed that the TG of the film is latex particles were spherical and uniformly distributed; DSC analysis showed that after the synthesized resin dispersion is significantly increased after the synthesized resin dispersion is baked at high temperature for a period of time.
The Cu/Fe catalyst was prepared by displacement method and characterized by X⁃ray diffraction (XRD). The degradation effect of Orange II by persulfate (PS) catalyzed by Cu/Fe and its influence factors were investigated, and the mechanism of degradation was also investigated. The experimental results show that Cu/Fe can catalyze PS to degradate Orange II wastewater successfully, and its catalytic effect is better than that of zero⁃valent iron. When pH=3, the mass concentration of PS is 2.0 g/L, the quality of Cu/Fe catalyst at a concentration of 0.250 g/L, the degradation rate of Orange II is up to 99%. The t⁃butanol and methanol are used as radical scavengers to confirmed that the active radicals in the process of degradation are SO〖_4^-〗· and ·OH.
A mononuclear cobalt complex [Co(H2L)(phen)2(H2O)]·4H2O (H2L2-=4,5⁃dihydroxy⁃1,3⁃disulfonate ion, phen=1,10⁃phenanthroline) was synthesized by hydrothermal method. The composition and structure of the complex were characterized by X ray single crystal diffraction, elemental analysis and thermogravimetric analysis. Single crystal diffraction study shows that the cobalt ion is six⁃coordinated, which can coordinate with the four nitrogen atoms of two phen ligands and the oxygen atoms of water molecule and sulfonate group, forming the twisted octahedral configuration in the complex. Compared with the ligand, the fluorescence emission peak of the complex has a blue shift, and the maximum emission peak is at 380 nm.
As an excellent nucleophile, 1⁃hydroxytryptamine derivatives have been widely used in the synthesis in recent years. With the development of indole alkaloids, 1⁃hydroxytryptamine derivatives will play an important role in the future research. In this paper, 1⁃hydroxytryptamine derivatives were synthesized by tryptamine synthesis method with indole substituted by benzene ring as substrate, protection of nitrogen atom in side chain of tryptamine, reduction of indole ring and oxidation of nitrogen atom in indole ring. Finally, the synthesis of the 1⁃hydroxytryptamine derivative was completed in a medium or higher yield. By this method, we synthesized a series of 1⁃hydroxytryptamine derivatives, and confirmed the accuracy of the structure of the compounds by 1H⁃NMR and 13C⁃NMR.
A novel preparation method of smart responsive glass sphere based composite carriers was reported in this study. Firstly, random block copolymers were synthesized by free radical polymerization of N⁃isopropylacrylamide, hydroxypropyl methacrylate and 3⁃trimethoxysilypropyl methacrylate. Then, the copolymer solution was uniformly sprayed on the surfaces of glass spheres by means of a self⁃made bottom spray fluidized bed reactor, and the bonding between copolymers and glass spheres was fabricated by thermal annealing, so as to form the copolymer/glass sphere composite carriers. The coating effects of the smart copolymers on the surfaces of glass spheres were investigated, including characteristic functional groups, surface microstructure, biocompatibility and thermosensibility. The results show that the temperature⁃responsive copolymers can be linked to the surfaces of glass spheres by bottom⁃spray coating technology, and the copolymer layers with certain thickness can be formed on the sphere surfaces. The composite carriers have good biocompatibility, and can realize effective cell adhesion and spontaneous desorption by using its intelligent response characteristics.
The adsorption properties of carbonaceous adsorbents (such as, activated carbon, biochar, CNTs and carbon⁃silica composites) for VOCs were summarized in this paper. The influence of the structure of adsorbents, the characteristics of VOCs, the humidity and the adsorption temperature were analyzed respectively. The development prospect of carbonaceous adsorbents in the future VOCs adsorption process was proposed. While continuously increasing the adsorption capacity of carbonaceous adsorbented for VOCs, improving the performance of recycling, reducing the impact of high⁃temperature and humidity environments on the adsorption capacity in industrial production was a new trend in the research and development of carbonaceous adsorbents in the future.
During the shale gas drainage test stage, the wellhead pressure and temperature are very high, and the produced gas contains a large amount of saturated water, which affects the normal operation of process equipment and gas production pipeline in the test platform. Based on this, on⁃site sampling and test analysis of saturated water were conducted to explore the cause of the effusion in the test platform. Aiming at the reason of liquid accumulation, the scheme of installing partition wall heat exchanger in front of the corrugated plate separator is proposed to reduce the airflow temperature and saturated water content at the inlet of the corrugated plate separator, and Fluent software is used to change the airflow temperature inside the heat exchange tube The situation was simulated. The results show that the average temperature of the air flow in the heat exchange tube can be cooled from 60.34 ℃ at the inlet to 30.00 ℃ at the outlet. The saturated water content can be reduced to 0.731 g/m3 by formula calculation. At the same time, the proposal of installing a hydrophobic hook in the flow channel of the corrugated plate separator is also proposed, and the separation characteristics of the streamlined and hooked corrugated plate separator are analyzed by Fluent software. The results show that the hooked corrugated plate the separation efficiency of droplets can be increased from 28.90% to 76.50%. When the droplet size reaches above 35 μm, the separation efficiency can reach up to 90.00%. The research results have important guiding significance for solving the problem of shale gas test platform liquid accumulation.
Collapsible loess is prone to self weight collapse after soaking. The strength of loess will be greatly reduced, and it will threaten the safe operation of buried pipelines along the way. In order to study the stability of buried pipelines in collapsible loess regions, the displacements, stresses and strains of different pipe outer diameters and wall thicknesses during collapsing were analyzed based on the finite element method. The limit length that the buried pipeline could withstand in the loess disaster under certain conditions was obtained by the eigenvalue buckling theory. The results show that: increasing the outer diameter and wall thickness of the pipeline and reducing the buried depth of the pipeline in the loess can effectively reduce the displacement of the pipeline in the collapsible loess; and increasing the outer diameter and wall thickness of the pipeline can also effectively avoid the phenomenon that the local stress of the pipeline is too high; the maximum stress and strain of the pipeline occur at the center of the collapsing zone and the fixed ends on both sides; according to the buckling eigenvalue theory, the ultimate length of the collapsible area of the pipeline is about 65 m when the soil mass has self weight collapsible, and increasing the outer diameter and wall thickness of the pipeline can enhance the buckling resistance of buried pipelines when self weight collapse after soaking.
The settlement of thermal insulation materials for overhead heavy oil injection pipelines will have a significant impact on the assessment of pipeline heat loss and calculation of economic benefits. A heat transfer model of the heat⁃insulating material settlement steam injection pipeline was established, and the effects of environmental wind speed, pipeline diameter and soil radiation on pipeline heat loss were analyzed.The results show that increasing the outdoor environment wind speed leads to increased heat loss of the eccentric insulation pipe, and when the environmental wind speed increases by 120%, the heat loss outside the pipeline insulation increases by 5.9%. The larger the pipe diameter, the smaller the heat loss of the air interlayer. The average heat flux of the outer wall of the insulated eccentric insulation pipeline is reduced by 1 036 W/m2 compared with the soil radiation.
The spindle is the core part of the high speed milling machine, its dynamic characteristics directly affect the machining accuracy of the milling machine.Taking a German GMN high⁃speed milling machine electric spindle as an example, the finite element method was used to establish a finite element model of the spindle⁃bearing system, the natural vibration characteristics of the spindle were studied, and the influence of bearing stiffness on the natural vibration mode and critical speed of the spindle was analyzed.On this basis, the unbalanced response characteristics of the high⁃speed spindle were studied, and the influence of the unbalance amount and position on the vibration sensitivity of the spindle was analyzed. It was found that the unbalanced response at both ends of the spindle was sensitive, especially at the end where the tool was connected. The results could provide a certain reference for the dynamic design of the high⁃speed machine tool spindle system.
In addition to the light oil which is easy to be exploited, there are many heavy oil which can not be directly exploited in the underground oil reservoir. The heavy oil reservoir is usually exploited by means of steam injection and thermal recovery. Steam dryness is an important parameter to measure the quality of wet saturated steam in heavy oil thermal recovery process, which has an important impact on the efficiency of heavy oil thermal recovery. In this paper, a new method of measuring the dryness of wet saturated steam in steam injection pipeline matrix conductance method was proposed. Based on this method, combining the thermodynamic properties of water and steam, an algorithm model of matrix conductance method for measuring the dryness of wet saturated steam was established. The causes of measurement errors and the methods to reduce the errors were analyzed. The calculation of the edge area of the instantaneous cross⁃section water area under the matrix was interpolated. Finally, the absolute error of the algorithm model was less than ±3.0%. This study also provided a reliable method for real⁃time monitoring of steam dryness, which was of great significance for improving the efficiency of heavy oil thermal recovery.
In engineering design, special area of pressure vessels always needs opening nozzles in order to satisfy complexity of technologies. Only considering the single load condition of the pressure vessels, the calculation of opening⁃nozzles in GB 150—2011 does not involve additional external load on opening⁃nozzles in practical projects. The SolidWorks software was used to locally model the tangentially opened pressure vessel of the cylinder, and the finite element analysis method was used to apply two internal conditions of the internal pressure and the external load of the internal pressure to the three⁃dimensional solid model to obtain the structural stress. Distribution and strength evaluation were carried out, and the influence of the additional external load on the structure of the pressure vessel was studied.The results show that the stress value in nozzle⁃vessel junction area increases sharply and it changes symmetrical distribution of stress in the connection between the nozzle and the vessel because of the external load of the nozzles. The analyzing results can provide some reference in stress analysis of the opening⁃nozzles with the united static load.
For the multi⁃performance evaluation model in the complex coking production process, the evaluation index is single, and the evaluation index can only reflect the production one⁃sidedly.The process without considering the problem of global factors, use the Analytic Hierarchy Process (AHP) to comprehensively consider safety, stability and economic aspects, and establish a global performance evaluation model. In order to solve the problem that decision makers are more likely to assign uncertainties to multiple indicators, use the intuitionistic fuzzy set (IFS) to obtain the preference relationship including membership degree, non⁃membership degree and hesitation degree. Consider the irrationality of consistency threshold, introduce a new threshold, and use entropy and cross entropy to calculate the index weight, and finally obtain the performance state of the target system. Finally, two different operating states of the coking production process were evaluated to prove the effectiveness and feasibility of the IFAHP method.
In order to improve the realism of the simulated scene, weathering the objects of the image is an effective method. Using an image processing method to achieve the fine weathering effect of the objects surface in the image. First of all, use the radial basis function (RBF) method to calculate the weathering degree image. Even if the color of the surface of the object changed greatly, the algorithm could calculate the degree of weathering more accurately. Then, use the image segmentation algorithm to extract the most weathered region as the "weathering exemplar". Finally, the patchmatch image repair algorithm was used to complete the "weathering exemplar", so that the "weathering exemplar" could be propagated seamlessly in the weathering area of the image. The results show that the proposed method can generate various types of weathering effects. Using the method of exemplar propagation can better simulate the weathering image.
A new image encryption method based on rotation transformation and chaos theory was proposed, which used chaos function to generate random phase mask (chaotic random phase mask). In the proposed technique, the image was encrypted using gyrator transform and two chaotic random phase masks. In the proposed method, the image was encrypted by using rotation transform and two chaotic random phase masks, and the chaotic random phase mask was generated by using three chaotic functions: Logistic map, Tent map and Kaplan⁃Yorke map. The computer simulations were presented to verify the validity of the proposed technique. By calculating the mean square deviation, the robustness of the blind decryption algorithm based on the seed value of rotation angle and chaotic random phase was evaluated, and the optical implementation scheme of encryption and decryption technology was given.
Parabolic partial differential equations play an important role in the fields of engineering technology and natural science, especially in the fields of seepage, heat conduction and diffusion. This paper mainly studies the numerical solution of parabolic equations. On the basis of mesh segmentation. First, a differential format with parameters is given. The Taylor series expansion method and the undetermined coefficient method are used to make the truncation error of the difference format reach O(τ^3+h^5). The parameters are determined by the equations to obtain a two⁃layer high⁃precision difference format. Then the Fourier analysis method is used. Solve the condition that achieves stability under this precision, that is r≤(19+√(1 141))/60.The numerical solution is compared with the exact solution by numerical examples, which verifies that the new method is feasible and effective.
