HP?MOF?74(Mg x Ni1-x ) (x=0.25, 0.50, 0.75) was synthesized by solvothermal method with Mg and Ni as central metals and sodium dodecylbenzene sulfonate (SDBS) as template. Using flue gas CO2 and N2 as adsorbents, the performance of HP?MOF?74(Mg x Ni1-x ) in adsorption and separation of CO2/N2 at 273 K and 298 K was investigated, the isotherms of CO2 and N2 on three different HP?MOF?74(Mg x Ni1-x ) materials were measured at 273 K and 298 K by static volumetric method, and the experimental data sets were fitted by Dual Site Langmuir Freundlich (DSLF) and Single Site Langmuir Freundlich (SSLF) models. The adsorption selectivity of CO2/N2 binary mixture was estimated according to the Ideal Adsorption Solution Theory (IAST). In addition, the isosteric heat of adsorption (Qst) was calculated using the Clausius Clapeyron equation. The results show that the CO2 adsorption capacity of HP?MOF?74(Mg0.50Ni0.50) sample is 4.864 mmol/g at 273 K and 100 kPa; the adsorption isotherms of CO2 and N2 on HP?MOF?74(Mg x Ni1-x ) are in good agreement with Dual Site Langmuir Freundlich (DSLF) and Single Site Langmuir Freundlich (SSLF) models respectively, indicating that the adsorption behavior of CO2 is double sites adsorption, while the adsorption behavior of N2 is single site adsorption; at 273 K and 100 kPa, the IAST adsorption selectivity of HP?MOF?74(Mg0.25Ni0.75) for CO2 is 2 263, and the adsorption capacity and selectivity are better than those of traditional adsorbent MOF?74; the CO2 isosteric heat of adsorption on HP?MOF?74(Mg x Ni1-x ) is higher than that of N2, indicating that the surface free binding energy of CO2 on HP?MOF?74(Mg x Ni1-x ) is higher.
Chemical wax inhibitors are widely used in the field of waxy crude oil extraction and transportation, providing an important guarantee for the safe and efficient operation of the waxy crude oil extraction and transportation process. At present, many basic experimental studies and numerical simulation studies on chemical wax removal have been carried out to explore the types, mechanism of action and application scope of chemical wax inhibitors. Common chemical wax inhibitors mainly include fused?ring aromatic hydrocarbon type wax inhibitors, surfactant type wax inhibitors, high molecular polymer pour point depressant type wax inhibitors and new nano?particle wax inhibitors. They usually prevent the association and deposition of wax crystals by water film theory or wax crystal modification theory. Among them, fused?ring aromatic hydrocarbon wax inhibitors, surfactant wax inhibitors, and polymer pour point depressant wax inhibitors have disadvantages such as poor environmental friendliness, poor environmental adaptability or poor economy. The focus of future research should be to explore green, efficient and general?purpose chemical paraffin inhibitors, use nanoparticles to improve the performance of paraffin inhibitors, and continue to explore more environmentally friendly chemical paraffin inhibitors.
A strain ISB5 with the ability to degrade the non?ionic surfactant Triton X?100 was screened from the activated sludge in the aerobic aeration tank of a sewage treatment plant in a chemical plant. Through sequencing and comparison analysis of the 16S rDNA of the strain, the strain ISB5 was identified as Pseudomonas sp. The culture conditions of strain ISB5 to degrade Triton X?100 were further investigated, and the suitable degradation conditions of the strain were obtained: Culture temperature is 30 ℃, initial concentration of Triton X?100 is 4 g/L, culture time is 28 h, shaking rate is 150 r/min, filling volume is 100.00 mL, inoculation the amount is 1.00% (volume ratio of strain ISB5 to medium). The degradation rate of TritonX?100 by the strain under this condition can reach more than 93.0%.
Electrospinning is a fiber manufacturing process in which polymers are drawn and spun under the action of a high?voltage electrostatic field. This method has been widely used in material chemistry due to the simple preparation, low cost as well as easily available of micro?nano?scale fibers. In this paper, a polysulfur high?nucleus caged compound (Co48) constructed by thiacalixarene was used as the loading material, and polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA) blend (PAN/PMMA) was used as the spinning support, Co9S8 nanoparticles loaded carbon nanofibers (Co9S8@CNFs) were prepared by electrospinning technique. Composite nanofibers were prepared by spinning carriers with PAN and PMMA mass ratios of 10∶0, 7∶3 and 5∶5, respectively, and the carbon nanofiber composites obtained after heat treatment were used as electrode materials for the study of lithium?ion battery materials. The addition of PAN and PMMA has a positive effect on the electrochemistry of the final product compared to the calcined product of Co48 crystals. The composites fabricated from PAN and PMMA presented high specific capacity，good cycling stability and rate capability.
β?cyclodextrin polymers modified with Fe3O4 (β?CDP@Fe3O4) was synthesized in alkaline medium using β?cyclodextrin (β?CD) as monomer and epichlorohydrin as crosslinker. The adsorption performances of β?CDP@Fe3O4 on bisphenol A (BPA) under static and dynamic conditions were investigated. The results of static experiment show that the adsorption performance of 100 mg/L BPA (pH=5.6) is best at 0.10 g β?CDP@Fe3O4. At this point, the equilibrium adsorption capacity, adsorption rate and the maximum adsorption capacity are 45.600 mg/g, 91.3%, and 113.600 mg/g, respectively. The results of dynamic experiment show that the smaller the liquid hourly space velocity, the higher the adsorbent utilization rate, and with the increase of BPA concentration, the adsorption breakthrough time and saturation time are declined. At the same time, the synthesis and adsorption mechanism of β?CDP@Fe3O4 were discussed. A rapid adsorption rate for the removal of BPA onto β?CDP@Fe3O4 from water solution was achieved, and the adsorption process was mainly due to hydrogen bond and hydrophobic interaction. β?CDP@Fe3O4 has good regenerative performance, through 6 cycles of static adsorption?desorption, and 3 cycles of dynamic adsorption?desorption without significant changes in adsorption performance.
The evaluation of gas field development effect plays an important role in discovering the main contradictions existing in the current development, improving the level of gas field management and putting forward adjustment countermeasures. In this paper, a quantitative evaluation method for the development effect of condensate gas field is proposed from the three aspects of productivity, energy retention degree and well logistics property, and considering the recovery factor and pressure retention degree, et al. Firstly, the weight of each index is calculated based on the analytic hierarchy process, grey correlation method and RSR value comprehensive evaluation method, and then the membership matrix of each index is determined through the ridge distribution function and factor analysis method. Finally, the evaluation results are obtained through fuzzy change and optimal selection. The natural gas recovery rate of E+K gas reservoir in YH23 block is 82.95%, the condensate recovery rate is 58.57%, and the formation pressure maintenance degree is 87.8%. The development effect evaluation matrix Y =[0.623 7, 0.175 2, 0.201 1] can be obtained through calculation, which belongs to the class I development level. After verification, it is consistent with the actual evaluation results of the gas field, which proves that the proposed method is accurate and reliable, and points out the direction for the further development and adjustment of the gas field.
In view of the large displacement production of marine sandstone FOURD reservoir, it is found that the water drive pore volume multiples at different locations are different during the development process of bottom water reservoir, while the experiments measured in the conventional industry standard are insufficient to express the seepage characteristics of the reservoir after the high flooding multiple. The high?power water drive experiment shows that the half logarithm of core displacement multiples with different clay content has a linear relationship with oil displacement efficiency, and the water drive sweep volume of bottom water reservoir increased slowly. Based on the actual data of FOURD reservoir, the time?varying characteristics of the reservoir were characterized and studied by numerical simulation technology. According to the different north?south dynamics of FOURD reservoir, the water flooding degree in the south area is high and the sweep degree is difficult to improve. The oil displacement efficiency of the reservoir is improved by liquid extraction, and in the north area and where the impact degree is not high, the later potential tapping mode of well network encryption is adopted. After adopting the limit tapping potential strategy described in this paper, according to the results of numerical simulation and practical mine application, the swept volume increased by 11.1%, and the calibration recovery increased by 4.5%.
Due to the complex submarine environment, submarine pipeline steel often faces serious corrosion risk. Through potentiodynamic polarization technology and AC impedance technology, the effects of hydrostatic pressure, mass concentration of dissolved oxygen and growth days of sulfate reducing bacteria (SRB) on the electrochemical corrosion behavior of X70 pipeline steel in simulated solution in the South China Sea were investigated. Combined with electron microscope characterization technology, the corrosion morphology was analyzed, and the mechanism of the corrosion behavior of X70 steel under the coexistence of three environmental factors was clarified. The results show that the self corrosion current density of X70 pipeline steel in the experimental environment inoculated with SRB is twice that of sterile steel; under the pressure of 0~3.5 MPa, the corrosion degree first intensifies and then slows down; when SRB and dissolved oxygen coexist, the presence of oxygen inhibits the number of facultative anaerobic bacteria SRB, thus inhibiting corrosion.
In order to improve the fastening effect of the bolt flange of pressure vessel, the structure of the hydraulic wrench and the holding sleeve was improved, and the holding sleeve was optimized, and a new type of fixed wrench was designed. The paper introduced and compared the joint use of hydraulic wrench and holding sleeve in bolt flange fastening operation, improved the structure of the holding sleeve, and analyzed the static structure of the new type fixed wrench by ANSYS. The results show that the structure optimization can effectively improve the fastening effect of flange bolts of pressure vessel.
Titanium alloys are widely used in the aerospace field due to their high strength, low density, corrosion resistance and other excellent properties. Therefore, it is necessary to theoretically study the evolution of titanium alloys for the quantitative design of new titanium alloys. In this paper, using the valence electron structure parameters calculated by Yu's theory, combined with the rules of cellular automata, a simulation method of the Ti?2Nb alloy β?phase solid solution microstructure was established, and he microstructures of Ti?2Nb alloys at 1 000, 1 050, 1 100, 1 150 and 1 200 ℃ were simulated. The research results show that the model method can associate the phase structure unit with the nucleation and growth of the β microstructure; the quantitative relationship between the number of nucleation points in theβmicrostructure and the solid solution temperature can be characterized by the binding energy of the phase structure unit calculated by Yu's theory; the evolution of the grain size of the β?phase microstructure with the solution time can be correlated by the simulation step. These studies can provide a reference for the establishment of a quantitative relationship between alloy composition， preparation process， structure， performance.
Based on the differential lever principle, a multi?stage compliant magnifying hinge was designed, and a micro?positioning platform with three translational degrees of freedom was assembled in an orthogonal way, and the symmetrical closed?loop structure formed has the characteristics of shock resistance, no cumulative error and better isotropy. The material is 7075 aluminum, and the stacked piezoelectric ceramics were used as the driving device to provide input displacement. Combined with the path search method and the static matrix method, the static balance equation and geometric deformation equation of the mechanism were obtained; the sensitivity analysis of the structural parameters was carried out, and the parameters with higher sensitivity in the mechanism are optimized with the displacement amplification ratio as the goal; a finite element analysis was performed on the assembly. The results shows that the stroke can reach 391.42 μm and the magnification is 13.05, and the platform has a high displacement magnification ratio and good positioning accuracy.
Due to the complexity and variability of atmospheric and vacuum distillation process, the coupling between process variables is serious, and the direct modeling will increase the difficulty of problem analysis. In order to improve the performance of the model, KPCA algorithm was used to select the variables of the model, and then the processed data were used as the input of the Gaussian process regression (GPR) model, and KPCA?GPR was used to establish the estimation model of the gasoline dry point on the atmospheric tower roof. The method solves the strong nonlinear correlation between different variables, and has the advantages of flexible nonparametric generalization and super?parameter adaptive adjustment. By calculating the empirical confidence interval, not only can the dry point of gasoline be predicted and estimated, but also can do the probability interpretation. The simulation results show that the KPCA?GPR method achieves better estimation results.
For most defogging algorithms, the effect on synthetic foggy images is different with the effect on real foggy images. Focusing on this problem, we propose a domain?adaptive single?image defogging algorithm which is based on a bidirectional conversion network. The bidirectional conversion network is designed to convert the foggy im?ages between the two domains. Our algorithm can be divided into two steps. Firstly, we reduce the difference be?tween the synthetic domain and the real domain by using the bidirectional conversion network; secondly, we remove fog from the input foggy images by using a convolutional neural network. To improve the effect and generalization ability of our algorithm, we use the synthetic RESIDE dataset and real foggy images as training data. Compared with results of some existing algorithms, the results show that our algorithm has better effects on foggy images of both domains, and our algorithm also improves the peak signal?to?noise ratio (PSNR) and structural similarity (SSIM).
Aiming at the problem that the existing online life prediction of lithium?ion batteries based on the correlation vector machine has a single consideration factor, which results in unsatisfactory prediction accuracy, a method based on principal component analysis (PCA) for weighted construction of characteristic factor variables was proposed. In this method, a variety of characteristic factor variables are taken as the research object to find the matrix of the score vector after the linear transformation. The feature coverage degree of different score vectors to the original variable data matrix is analyzed, and the corresponding feature vectors are constructed by weighted fusion. Using the vector as input, a prediction model is established by the relevance vector machine and the online prediction of lithium?ion battery life is performed, and the prediction results are finally obtained. International public battery data was used as the research object, and MATLAB experiments were used to verify that the method has the feasibility of multivariate prediction of battery life, and the prediction effect is better.
Taking advantage of its high?speed and high?precision characteristics, cooperative robots can improve production efficiency by imitating human creative and complex actions. At present, the simulation of human action mainly comes from the long?term debugging of the deployment personnel, which is lack of general solutions and can′t be deployed quickly. Based on this, an anchor?free RepVGG network?based Siamese network collaborative robot target tracking algorithm was proposed. The algorithm consists of a siamese network module, a classification regression module and a robot execution module. The siamese network module used the improved RepVGG network instead of ResNet as the backbone network to extract image features, which can improve the running speed of the whole network without losing accuracy，reduce the hardware requirements and is more friendly to special deep learning chips; the classification and regression module introduced the centrality branch to improve the prediction accuracy of the center point of the tracking frame; the robot execution module uses scale penalty and aspect ratio penalty to smooth the tracking boxes and ensure the smooth operation of the collaborative robots. Experimental results show that the average rate is 14 FPS higher than that before replacing the backbone network, which realizes real?time object tracking.