With the development of chemical industry, the discharge of industrial wastewater increase gradually, which has caused serious environmental pollution. Therefore, developing an efficient treatment technology to solve this problem is urgently needed. Photocatalysis is an efficient strategy to remove organic pollutants in aqueous condition. TiO2 is one of the most excellent photocatalytic material to be used in pollutant degradating, due to its higher chemical stability, photocatalytic activity and environmental friendliness. However, TiO2 particles are aggregated easily in aqueous media and difficult to be recycled, which hinders its practical applications. Dispersing TiO2 nanoparticles on the surface of mineral materials can reduce the aggregation of TiO2, increase the number of surface active sites, and improve its photocatalytic activity. This paper reviews new research progress of mineral supported TiO2 composites in photocatalytic degradation of organic pollutants.
Using Marie vacuum residue as raw material, the acetic acid⁃peroxyacetic acid oxidation system was used to pre⁃oxidize the vacuum residue, and N, N⁃dimethylformamide (DMF) was used to extract and remove sulfide in the residue. Under the conditions of m(residue)/m(solvent)=1∶1, Investigate the effects of oxidant dosage, reaction time and temperature on the removal of sulfur content in residue oil. X⁃ray photoelectron spectroscopy (XPS) and Fourier infrared spectrometer (FT⁃IR) The organic sulfur type distribution and functional groups of the residual oil before and after oxidation were detected. The results show that under the conditions of m(residue oil)/m(solvent)/m(acetic acid⁃peroxyacetic acid)=5∶5∶4, oxidation temperature 70 ℃, and oxidation time 50 minutes, the C-S stretching vibration absorption peak of the oxidized residue is obviously weakened. Thiophene type sulfur can be removed by extraction after being oxidized to sulfones. The sulfur content of the residue is reduced from 4.01% to 2.67%, the desulfurization rate reaches 33.37%, and the residue yield is 94.82%.
The composition of Fushun oil shale (OS) was analyzed by Fourier transform infrared spectroscopy (FTIR) and X⁃Ray Diffractomer(XRD).The effects of transition metal salt catalysts (shale ash as a carriers on NiCl2·6H2O, CuCl2·2H2O, ZnCl2) on the catalytic effect of pyrolysis of OS and precipitation of volatilization were investigated by TG⁃MS. Coats⁃Redfern model was used to analyze the effect of transition metal salt catalyst on the activation energy of OS pyrolysis. The results show that the minerals in OS are mainly composed of quartz, aluminosilicate and a small amount of carbonate, and the organic matter is mainly aliphatic compound. Three transition metal salt catalysts can all promote the pyrolysis of OS. The OS can be rapidly pyrolyzed at 390.1~581.8 ℃ when it is pyrolyzed alone, accounting for 76.19% of the total weight loss. According to the kinetic analysis, the activation energy required by OS pyrolysis can be reduced by the transition metal salt catalysts. NiCl2·6H2O has the highest capacity (18.7 kJ/mol) to reduce the activation energy of OS pyrolysis, which is 23.55% lower than that of OS pyrolysis alone. The catalytic activity of the transition metal salt catalysts are in a sequence of NiCl2·6H2O>CuCl2·2H2O>ZnCl2. In addition, the transition metal salt catalysts can also promote the cracking, aromatization and coking of volatiles in the pyrolysis of the OS, Thereby increasing the content of aliphatic hydrocarbons (represented by alkanes and alkenes) and aromatic hydrocarbons in volatiles.
Periconansons C⁃F is a natural product of cytochalasin. Its structure contains a six and six bicyclic skeleton. We think that we can complete the construction of this skeleton structure through one⁃step D⁃A reaction. We synthesized its key D⁃A reaction intermediate.KF is used as base and O2 is used as oxidant to oxidize the required hydroxyl group. After the intramolecular D⁃A reaction, it is possible to complete the total synthesis of four molecules, such as percoannosins C-F.
This paper described the emission situation of pollutants from coal combustion in China, and it was pointed out that the removal technology of fine particulate matter was an important goal to be solved urgently. The research progress of soot control technology for coal burning at home and abroad was reviewed, and the principle, characteristics and research progress of the smoke and dust control technology were introduced. The results show that low⁃low temperature electric dust removal technology, agglomeration technology and synergistic removal technology have become the hot spots of fine particulate emission control technology and have a good application prospect. In addition, the analysis points out the difficulties faced by each part and the development direction, and provides reference for the removal of fine particulate matter from smoke and dust to meet the requirement of ultra⁃low emission standard.
Carbon fibers (CFs) has been a hotspot in composites as a reinforcing phase. The types and dispersion methods of CFs and the methods for evaluating their dispersibility in cement⁃based composites, the preparation process of CFs surface coating modification and its advantages and disadvantages were reviewed. The coating modification treatment could prepare carbon fiber reinforced cement⁃based composite materials (CFRC) with good performance. At the same time, the influential factors of CFRC mechanical properties were systematically discussed and studied, including water⁃cement ratio, including water⁃cement ratio, curing age, molding process, silicon powder content, additives, CFs content and length, etc.It is concluded that the key to further improving the mechanical properties of CFRC is to improve the dispersion and compatibility of CFs in the cement matrix, and provide a reference for the future preparation of high⁃performance CFRC.
In this paper, a novel hydrophobic modified cationic polyacrylamide flocculant P(AM⁃DAC⁃APG) was successfully synthesized by copolymerization of acrylamide (AM) as the main monomer, acryloxyethyl trimethyl ammonium chloride (DAC) as the cationic monomer and alkyl glycoside (APG) as the hydrophobic monomer, initiated by low⁃pressure ultraviolet light. FTIR, SEM and 1H⁃NMR were used to observe and analyze its chemical structure and surface morphology. The effects of other factors such as total monomer concentration and initiator concentration on the polymerization were studied. Optimum polymerization conditions were confirmed as total monomer concentration of 35.0%, initiator concentration of 0.2%, illumination time of 90 min, m（AM）/m（DAC）of 3, hydrophobic monomer concentration of 2.0%, urea concentration of 3.0%. The novel hydrophobic modified polyacrylamide flocculant with intrinsic viscosity and cationic charge density of 1 384.8 mL/g and 5.091 mmol/g was obtained under these conditions.
Linbei area was located in the middle of the central uplift zone of Huimin depression. Aiming at the problems of unclear reservoir type, trap scale and reservoir validity of the Jishan sand body in this area, starting from hydrocarbon source conditions, reservoir physical properties, distribution of sedimentary facies and structural features, through the data of drilling and oil testing results, comprehensive application of geological, geochemical analysis and geophysical research means, in depth analysis of hydrocarbon accumulation conditions and main control factors. The results show that: the high⁃quality source rock in the third member of Shahejie formation is the main source of Linbeijishan sand body, and the good configuration of sand bodies in different periods in time and space is the basis for the formation of hydrocarbon accumulation; the relationships between the developed faults and the pathway system of framework sand body in the area provides a good migration channel for oil and gas, which results in the zonal distribution of oil and gas reservoirs along the North⁃South fault steps; The mudstone in the upper part of the third member of Shahejie formation and the thick mudstone at the top of the Jishan sand body are stable, The sand body of each stage are separated by mudstone and pinched out from the east to the west, the high salinity primary CaCl2 water type with good sealing property developed in the third member of Shahejie formation and the lateral sealing of some faults act together to provided good preservation conditions for oil and gas reservoirs.
Based on the study of the material dissolution mechanism,it was clear that uniform solubility and controllable solubility were the key properties of soluble materials.Dissolvable magnesium and aluminum metal material were designed. The test results of the sample show that the designed dissolution rate of a dissolvable materials is 0.184 g/h under the conditions of 1% Cl- mass fraction of the solution and a temperature of 90 ℃. The advantages and disadvantages of bridge plug structure design at home and abroad were compared, based on the concept of dissolution difference and the objective of optimizing pressure bearing, anchoring and dissolution performance, a new dissolvable bridge plug, which meet the fracturing demand of Liaohe Oilfield, was developed. The results of indoor evaluation tests show that, the fracturing ball can be dissolved in 30.0 hours under the conditions of 1% Cl- mass fraction of the solution and a temperature of 90 ℃;the maximum working pressure of the dissolvable bridge plug is 70.0 MPa, the effective sealing time is more than 12.0 hours, and the dissolution time is 16.0 days. The field test was carried out with the developed dissolvable bridge plug. During the field test, the setting and releasing operation was successful, and the soluble ball was obviously in place. The bridge plug has been dissolved after 18.0 days of spraying. The successful development of dissolvable bridge plug will provide important supports for the large⁃scale volume fracturing technology in Liaohe Oilfield.
Determining the total price of construction projects and effective control of investment are not only important components of construction project management, but also directly related to the economic benefits of investment institutions. Taking 4 different construction schemes of an oil depot as examples, the project cost evaluation index system is constructed. On this basis, technical and economic analysis was introduced through cloud model, classification standard was established, and entropy weight method was used to determine the weight of all grass⁃roots indicators. Finally, four construction schemes were evaluated based on cloud model generator. The results show that the order of membership of the schemes is M1＞M3＞M2≈M4. The peak point of M1 appears earliest, between 2.0 and 2.5, and the peak point of M4 appears later. The influential basic indexes are fire protection engineering, foundation engineering, heat insulation engineering and project measure cost, of which the measure cost accounts for more than 1/10 of the total project cost. Therefore, on the premise of ensuring the construction requirements, we should strengthen the control of the project cost in such aspects as fire engineering, foundation engineering, thermal insulation engineering and project measure cost, so as to achieve the purpose of the optimal design and the most economical investment in the construction of the best project.
Based on the analysis of the remanufacturing process of oil drilling and production equipment, a remanufacturing cost evaluation method is proposed by quantitatively evaluating the cost expenditure of each remanufacturing step. This method focuses on the influence of process cost, energy consumption cost and environmental cost on remanufacturing of equipment parts. And a strategy to evaluate remanufactureability directly from the cost consumption is obtained. As the application of this method, we take the reproductivity of waste oil drill pipe and the reproductivity evaluation of drilling pump crankshaft as an example. The test results indicate that our method can well evaluate the remanufactureability of the petroleum drilling and production equipment parts. As a whole，the proposed method is helpful to supplement the existing evaluation system. It is effective to guide the remanufacturability judgment of key parts of oil drilling and production equipment.
Modern automatic assembly puts forward higher requirements for the stability and accuracy of material conveying. In order to meet industrial needs, a piezoelectric vibration that uses a rectangular piezoelectric vibrator as an excitation source and works in a vertical drive mode was designed. Feeder. By simplifying the double⁃cantilever piezoelectric vibrating feeder and establishing its dynamic model, the expressions of natural frequency and device amplitude were derived, and some factors affecting natural frequency and amplitude were analyzed. Use ANSYS Workbench software to analyze the dynamics of the device. The natural frequency of the system was 118.85 Hz, and the harmonic response analysis of the device was performed. The results show that when the driving voltage is 200 V, the system driving frequency is between 116.00～122.00 Hz, and the double cantilever piezoelectric vibration gives The feeder has the ability to transport materials, the vibration amplitude is the largest at the point closest to the resonance point (118.00 Hz), and the transport efficiency is the highest, which can meet the requirements of industrial production.
The reachable set analysis for the semi⁃Markov jump linear system (S⁃MJLS) with mismatched control form was researched. Without considering the bounded transfer rate constraint,a controller was designed that allowed the controller mode to be mismatched with the system mode, sufficient conditions were gotten that the system state trajectory was bounded. Then, control strategies of mode independent and mode dependent were also considered, some generalizations of uncertain and partially known correlation matrices were further discussed.Finally, the effectiveness and superiority of modal mismatch control methodwere verified by examples and simulation results.
The location of high⁃speed railway stations has always been in a contradiction. The government should not only reduce the impact of high⁃speed railway stations on people's lives, but also consider the cost of demolition. How to make the location of high⁃speed railway stations more scientific has become a problem that needs careful consideration. Therefore, the model of economic contribution degree was established by using linear regression analysis and grey prediction method to obtain the economic contribution degree of high⁃speed railway station to the city;based on the relevant data of high⁃speed railway in Liaoning Province, considering the construction cost, construction time, transfer convenience and economic contribution, a high⁃speed railway station location evaluation model based on principal component analysis was proposed and the evaluation model was used to analyze the siting of three high⁃speed railway stations in Liaoning Province. The results show that the siting of Shenyang North Railway Station is the most successful,and the passenger flow and distance from the city center are the important factors affecting the development of high⁃speed railway.
