At present, the biggest problem in lignin research is how to achieve efficient depolymerization of lignin, which is mainly due to the structural instability of lignin. In view of this problem, the natural structure of lignin, the structural changes of lignin in the process of separation and depolymerization were summarized and the specific effects of structural changes of lignin on the depolymerization process were also discussed. Literature survey shows that maintaining the structural integrity of lignin plays a key role in promoting the depolymerization of lignin, and put forward the prospect of the development trend of lignin depolymerization.

In order to study the rapid start⁃up of biofilters in seawater recirculating aquaculture systems, this study investigated the removal effects of seawater biological fluidized bed on pollutants under different hydraulic retention time (HRT) and temperature conditions, and explored the impact on initiation of seawater biological fluidized bed. The results show that: HRT=1 h experimental group can achieve material conversion and return to equilibrium more quickly, which is suitable for membrane loading; the high temperature conditions (28 ℃) are suitable for fluidized bed initiation, and the biofilm attachment growth can be observed more quickly.

The detection of explosive nitro compounds is a key research topic in the field of environmental pollution control and public safety. The luminescent platinum complexes [Pt(ppy)(CH3CN)2]ClO4 with high fluorescence quantum efficiency was applied as fluorescent probe to detect nitrocompound 4⁃nitrotoluene (4⁃NT). The fluorescence emission intensity of [Pt(ppy)(CH3CN)2]ClO4 decreased gradually until quenching with the addition of 4⁃NT. The detection efficiency KSV of 40.2 L/mmol was obtained by fitting experimental data with Stern⁃Volmer equation, and the minimum limit of detection was 1.83×10-6 mol/L. It is confirmed by spectrum experiment and DFT calculation that the detection mechanism of 4⁃NT by [Pt(ppy)(CH3CN)2]ClO4 was investigated to be synergistic effect of energy transfer and electron transfer.

TG was used to study the thermogravimetric behavior of Fushun oil shale at different heating rates in argon atmosphere. Four thermal kinetic models, DAEM model, Coats⁃Redfern method, FWO method and Doyle method, were compared and analyzed. The results show that the results of different dynamic model analysis are different: Coats⁃Redfern method, activation energy (E) has little change, and E belongs to the average value in a certain temperature range, which increases with the increase of heating rates as a whole. E is 109.40 kJ/mol when the heating rate is 20 ℃/min. The E of the DAEM model, the Doyle method, and the FWO method all increase with the increase of conversion rate. In addition, the E obtained by the DAEM model and the FWO method are relatively close, the DAEM model has the highest coefficient of determination. Therefore, the DAEM model is the most suitable for the kinetic analysis of Fushun oil shale pyrolysis among four thermodynamic analysis methods.

Surface enhanced Raman spectroscopy (SERS) is a technique widely used in detecting analytes at low concentrations and could provide structural information at the sametime. It is necessary to find the optimal particle size, shape and spatial distribution to optimize the SERS substrate. Current research efforts are focused on fabricating new kind of nanocomposite using as SERS substrates. Porous materials have long been employed as SERS substrate because of their unique features, the porosity that enable them as efficient adsorbents for target molecule. The porous α⁃Fe2O3 was used as solid support. In this paper, porous nano α⁃Fe2O3 was synthesized by hydrothermal method using porous α⁃Fe2O3 as solid carrier, and then calcined into Fe, so that there were porous channels on the surface of Fe. PATP aqueous solution and melamine aqueous solution were used as probe molecules. By adjusting the size of Au nanoparticles and investigating its influence on SERS performance, the optimum performance of 50 nm Au was obtained.The structures and compositions of the nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X⁃ray diffraction (XRD), and N2 adsorption. Our research illustrates a new kind of porous Fe2O3⁃Ag nanocomposite, that could be used as effective SERS substrate to adsorb and detect trace level of target analyte.

A strategy for the formation of amide bonds with one side protection of diamine was reported. A method was found to obtain a large number of mono⁃side protective diamines. When the reaction temperature was 0 ℃, adding the protective group to diamine solution slowly did not need catalyst to synthesize tert⁃butyl N⁃(6⁃aminohexyl)carbamate. The reaction had strong selectivity and good universality. The reaction had strong selectivity and good universality. This process can selectively and efficiently obtain the single amino protection product. The excessive diamine can be recycled and utilized, which improves the utilization rate of raw materials. It is a green and environment⁃friendly reaction.

The minimum miscible pressure is one of the important parameters of CO2 injection in oil field. In order to determine the minimum miscible pressure between crude oil and CO2 in the tight reservoir of lucaogou formation, jimusar sag, Xinjiang, the laboratory slim tube test and interfacial tension test were carried out. The results show that the MMP measured by slim tube test in Xinjiang tight oil reservoir is 18.70 MPa, slightly higher than the MMP measured by the interfacial tension experiment, which is 18.44 MPa. The difference between the two is 1.4%, and both lower than the reservoir pressure of 43.00 MPa. Therefore, CO2 and crude oil can be miscible under the reservoir conditions. When the equilibrium pressure increases, the IFT decreased more as more CO2 dissolved in crude oil. When the system equilibrium pressure increased from 0.73 MPa to 28.46 MPa, the IFT value between crude oil and CO2 decreased from 22.62 mJ/m2 to 1.83 mJ/m2. When the equilibrium pressure was between 0.73 MPa to 13.33 MPa, the dissolution of CO2 in crude oil took the leading role. However, when the equilibrium pressure was between 15.84 MPa to 28.46 MPa, the extraction of light components in crude oil took the leading role, and the interaction mechanism between crude oil and CO2 changes from CO2 solubility to CO2 extraction of light components at the pressure of 13.67 MPa. Through the experimental study, the understanding of the MMP of the target reservoir and the microscopic interaction mechanism between crude oil and CO2 is deepened, which provided theoretical support for the formulation of CO2 injection development of the target reservoir.

Based on the research results in gas field developmment, this paper summarized the development of optimization at domestic and foreign from two aspects: Infilled well deployment, piped network design, pointed out the difficulties and development directions of each part, and provided reference for gas field mining. The analysis points out that there are some difficulties in algorithmic improvement and well pattern density identification in the deployment of infill wells. Further research is needed in the deployment direction of shale gas field infill wells. Model establishment and algorithm improvement are the difficulties in pipe network research, further study of three⁃dimensional terrain relief layout analysis is required.

With the rapid advancement of ecological civilization construction in China, energy utilization methods such as recycling industrial waste heat and developing clean energy have gradually received widespread attention in the market. In this paper, a dual⁃loop cycle⁃kalina (DORC⁃KC) cogeneration system based on LNG cold energy utilization was designed. In addition, a new method for reducing acid gas emissions from industrial waste heat was proposed. Through the construction of the system thermodynamic model, the key thermodynamic parameters affecting the system carbon capture were analyzed in detail. The results show that the top cycle in the double cycle uses cyclopentane as the working fluid. By increasing the evaporation temperature and evaporation pressure, the maximum net output of the system is 367.9 kW,and the thermal efficiency is 33.29%. In the Kalina cycle, factors such as flux and concentration have a positive impact on system efficiency. The optimal thermal efficiency is 15.42% and the cold energy recovery efficiency is 20.65%. The reduction in compression pressure reduces the amount of circulating water but increase the quantity of the liquefaction of CO2. When the compression pressure is 472 kPa, the system has the highest exergy efficiency of 34.30%, carbon capture rate of 47.00%, and the amount of recycled water recovered is 167 616 t.

In order to explore the flow characteristics of vertical pipe in the deep⁃sea horizontal pipe⁃catenary system, in this paper, aiming at an oil and gas field in the south China sea, the influence of diameters, total flow rate, water cut and outlet pressure were simulated. The results show that the position of the flow state in the pipe is the boundary, and the influence of each influencing factor on the flow state parameters in the pipe shows different changes, but the temperature distribution along the pipe is not affected by the relevant factors; From the perspective of the research scope of the above four parameters, the influence process of each parameter is divided into different stages. The influence of pipe diameter is divided into two stages: D=0.06~0.12 m and D=0.12~0.50 m, the total flow of Q=0.001~0.030 m3/s and Q=0.100~0.300 m3/s, the water content of w=10%~25% and w=25%~30%, and the outlet pressure is divided into three stages, including 0~5.0, 5.0~7.0, 7.0~10.0 MPa.

The corrosion behavior of auxiliary anode under the combined action of alternating current density and cathodic protection were studied. Firstly, the corrosion rate and corrosion image were analyzed by immersion experiment, and the corrosion process was determined. Secondly, the electrochemical behaviors of the auxiliary anode under different conditions were analyzed by electrochemical test, and the corrosion behaviors of the auxiliary anode under different conditions were characterized according to the change of its corrosion kinetic parameters. The results show that the corrosion product layer formed under lower alternating current density overlays on the surface to slow down the corrosion, while the higher alternating current density can break down the corrosion product layer to activate the corrosion reaction. The cathodic protection current causes the corrosion product layer to be in the constant destruction and the generation process, further promotes the corrosion reaction. The results of immersion experiment are in good agreement with those of electrochemical test.

The wormlike sealing ring is located in the sealed groove of Dn1160 type pressure sintering furnace, which is prone to tear and damage.This article uses the finite element analysis method to nonlinear contact analysis of wormlike ring. The Von Mises stress and contact stress of worm⁃shaped rings are numerically simulated by Ansys software, and the results are compared.The cracking failure characteristics and easy tearing positions of worm⁃shaped rings under different parameters and working conditions are obtained. At the same time, the research results of predecessors are consulted to further optimize ring sealing ability.Finally, the research results provide a new idea for the design and optimization of the same kind of seal ring.

The Stress concentration is the main reason of damage to ferromagnetic metal pipelines. Through effective detection,the use status of metal pipelines can be predicted and the safety of equipment can be effectively guaranteed. The ferromagnetic effect of the material under stress is analyzed by the energy balance theory of ferromagnetic materials. The 3D simulation model of ferromagnetic materials is built by simulation software based on the metal band theory, and the magnetic effect characteristics of the system under tension stress are calculated. The weak magnetic field detecting sensor based on differential symmetrical structure is designed and manufactured. The stress concentration system of different types of pipelines is detected by the stress detection system based on the weak magnetic sensor. The stress concentration is verified by other stress detection methods. The results show that the weak magnetic sensor can effectively detect the weak magnetic field signal on the pipeline surface, and the weak magnetic field signal shows violent fluctuation characteristics in the stress concentration region. Various detection methods verify the effectiveness of the weak magnetic stress detection. Weak magnetic stress detection technology can effectively detect pipeline stress concentration caused by defects or deformation.

In order to further improve the corrosion resistance of S32750 super duplex stainless steel, the passivation treatment was carried out by nitric acid passivation. The corrosion resistance of S32750 super duplex stainless steel was investigated by electrochemical polarization curve, electrochemical impedance spectroscopy, Mott⁃Schottky curve and immersion method,and the corrosion surface morphology of the sample surface before and after corrosion was observed. The results show that the nitric acid passivation time has a significant effect on the corrosion resistance of S32750 super duplex stainless steel passivation film. When the passivation time is less than 120 minutes, the longer the passivation time, the smaller the corrosion rate is, and the better the passivation film corrosion resistance is.

This paper studies the stability of complex network systems with nonlinear coupled nodes. For the network coupying matries,the switching points of sub⁃systems discrete points in complex networks by using method that the Nimensinal complex network system transformed into the form of kronecker product.Then based on the Lyapunov function method, sufficient conditions for the stability of complex network systems are obtained. Based on the Lyapunov stability determination method, sufficient conditions for satisfying the stability of complex network systems are obtained. Finally, numerical examples are given to verify the effectiveness of the design method.

Voice forgery is detected by digital audio watermarking and pattern recovery techniques. The three methods used by digital watermarking mode for speech signal forgery detection are replacement, insertion and deletion. If some changes are made to the speech signal, the watermark mode will also change, and the mode recovery can be used to measure or detect whether the speech signal has been modified or forged. The proposed method uses the cyclic pattern embedding to overcome synchronizing problems of previous detection techniques. In addition, pattern recovery enhances the robustness to compression. This method has been tested and verified using six recording devices, which was used for collecting verbal data. The speech signals were sampled at the rate of 8 kHz and digitized at 16 bits resolution. Randomly chosen regions were substituted, removed, and compressed in MP3 at the rate of 16 kbps as well as in CELP at the rate of 11.5 kbps. The experiment shows the perfect detection for three kinds of forgeries and it proved the validity of the proposed method.

Hydrogen as a new energy plays a vital role in the future energy development.Hydrogen production from electrolyzed water includes two reactions of hydrogen evolution and oxygen evolution, which has the advantages of low price, no pollution, abundant reserves, and the oxygen evolution reaction is a rapid step in hydrogen production from electrolyzed water. A simple co⁃precipitation method was proposed to recombine carbon materials onto Co9S8 catalytic materials, and the oxygen evolution properties were characterized. Compared with Co9S8 without composite carbon material, a small amount of carbon material could significantly improve the oxygen production performance of Co9S8.The structure, morphology and electrochemical properties of the materials were tested by X⁃ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarization curves, chronoamperometry and AC impedance. The results show that the prepared Co9S8/C material has no impurity phase. When the current intensity is 10 mA/cm2, the overpotential is 350 mV, and the Tafel slope is 102 mV/dec, it has high electrocatalytic oxygen production performance.

The oxidation⁃extraction process was used to desulfurize of the visbreaking diesel oil, O3 was used as oxidant, formic acid was used as catalyst, and polar oxides such as sulfoxide and sulfone were extracted and separated from diesel oil by polar organic solvent. The effects of oxidation time, oxidation temperature, ratio of extractant to oil and amount of formic acid on the desulfurization rate of diesel oil in the reaction system were investigated, and the optimum reaction conditions were determined. The results showed that the sulfur content of visbreaking diesel oil decreased from 4 980 μg/g to 490 μg/g and the desulfurization rate was 90%. By comparing the properties of visbreaking diesel oil before and after oxidation, it can be concluded that the oxidation⁃extraction method can also improve the chromaticity and acidity of visbreaking diesel oil.

In the process of foam flooding in heavy oil fields, the performance of single foaming agent is unstable. In view of this difficult problem, a new foaming agent system for foam flooding is designed in this paper. The foam synthesis index and temperature and salt resistance are taken as the evaluation indexes by Waring⁃Blender agitation method four kinds of foaming agents such as betaine, CTAB, SDBS and SDS were selected. The best foaming agents were betaine and CTAB. Through the experimental selection of different proportion of foaming single agent, the oil washing ability test and sand filling tube simulation experiment of CTAB and betaine system with 2∶1 ratio were carried out. The results show that the foaming agent system have good temperature and salt resistance and strong oil washing ability. In the sand⁃filled pipe simulation experiment, the two displacement modes of steam flooding plus foam flooding and steam foam alternating injection flooding are compared. The results show that the oil recovery can reach 60.7% by alternately injecting steam and foam fluid into the reservoir, which has certain reference value.

In order to explore the effect of different types of anionic⁃nonionic surfactants on the emulsification effect of heavy oil and obtain a reliable structure⁃activity relationship. In this paper, six monomeric anionic⁃nonionic surfactants C14E3C, C14E5C, C14E7C, C14E9C, C16E3C, C18E3C and two Gemini anionic⁃ nonionic surfactants OP4, OP15 were selected for a heavy oil block in Shengli Oilfield. By using a spinning drop interfacial tensiometer, stability analyzer, we investigated the effects of surfactant mass fraction, oil⁃water mass ratio, and polymer addition on oil⁃water interfacial tension, particle size and stability of crude oil emulsion. The results show that: the type of monomer has little effect on the stability of the emulsion with the increase of the oxyethylene (EO) group, and the growth of the alkyl chain can increase the stability of the emulsion to a small extent. For Gemini⁃type anionic⁃nonionic surfactants, the increase of the number of oxyethylene (EO) groups can increase the stability of the emulsion slightly. The monomer type has a smaller molecular size than the Gemini type, and the interfacial tension steady state value is generally low. At the same time, the addition of the polymer can increase the stability of the emulsion.

The heat transfer effect of nanofluid in electric heater was studied. Fe3O4⁃water nanofluid was prepared by two⁃step method. The effect of Fe3O4⁃water nanofluid with various nanoparticle concentrations (mass fraction of 0.1%~2.0%) on heating efficiency of the electric heater with or without magnetic field was studied. Mechanism of enhanced heat transfer by Fe3O4⁃water nanofluids under a magnetic field was also discussed. Results show that the Fe3O4⁃water nanofluid with a mass fraction of 1.0% obtains 18.2% enhancement of heat transfer on environment temperature compares to without a magnetic field. The Fe3O4⁃water nanofluid with a mass fraction of 1.0% obtains 35.1% enhancement of heat transfer on environment temperature with an external magnetic field. This research provides an important reference for enhancements of natural convective heat transfer in nanofluid applications.

Photoelectrocatalytic technology can provide an energy conservation and environmental protection way for environmental governance and chemical production. High efficient photoanodes materials are one of the challenges in the practical application of photoelectrocatalytic technique, therefore, high performance photoanode materials have been designed and developed for enhancing the application efficiency of photoelectrocatalytic technique. Fe2O3 has become a hot spot in the field of photocatalysis because of its narrow band gap, high stability and low price. In order to develop the high performance Fe2O3 photoanodes materials, many studies focused on the energy band position, conductivity and photogenerated the hole diffusion length. This review summarized the preparation techniques (hydrothermal method, spray pyrolysis, chemical vapor deposition, atomic layer deposition, etc), modification methods (“junction” construction, doping, morphological control, ect) and modified hydrogen production of the Fe2O3 photoanodes materials, the challenges and opportunities in this promising research area were proposed.

In solvent⁃free condition, a new 1D chain holmium phosphite Ho(H2PO3)4(C6N2H16)0.5 (compound 1) decorated by phosphite groups has been synthesized using N,N'⁃Dimethylpiperazine (Me2ppz) as structure directing agent, and further been characterized by powder XRD, infrared spectroscopy, thermogravimetric, inductively coupled plasma and CHN elemental analyses. Single crystal X⁃ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic crystal system with the P21/c space group. The structure of compound 1 is constructed by HoO6 octahedra and [H2PO3]- pseudo⁃pyramids units via vertex oxygen atoms. It is worth noting that compound 1 is the first rare earth phosphite compound which is synthesized in solvent⁃free condition. Moreover, a pair of left⁃ and righ⁃handed helical chains are present in the structure. In addition, coordination mode and geometry of lanthanide phosphonate, phosphate and phosphite are listed in this paper.

With the developments of deep sea and marginal oil fields, FPSO has been widely used in offshore oil and gas field development.FPSO, as an oil and gas production device with both energy production and consumption, takes an economic energy distribution scheme on the premise of meeting its energy demand, which not only helps to reduce construction costs, but also helps to improve the energy efficiency of the entire system and promote energy conservation. Taking the annual total cost of energy system as the objective function, the MILP model of FPSO distributed energy system is established and solved under the conditions of energy balance and technical constraints to determine the equipment selection and capacity, and the corresponding operation plan to achieve the purpose of energy conservation and consumption reduction. The model is validated by an example of FPSO in the Bohai sea. The results show that the cost of distributed energy system can be reduced by 14.6% compared to traditional operating schemes. In addition, considering the impact of different energy prices on the economy of the system, it is found that the increase in natural gas prices has a great impact on the design and operation of DES.

Methane hydrate can be used as a carrier to store and transport natural gas. However, they generate slowly under natural conditions,so it is necessary to improve the rate of methane hydrate formation.To this end, the effect of the amphoteric surfactant LAD⁃40 on the methane hydrate formation rate in various mass fractions (10~500 μg/g) was examined. The results show that when the pressure is constant, compared with the nucleation temperature of methane hydrate formation under pure water conditions, adding any mass fractions of LAD⁃40, the nucleation temperature of methane hydrate changes little, which fails to improve the thermodynamic conditions of methane hydrate formation; because of the existence of LAD⁃40, the gas⁃liquid contact area was increased, the nucleation time was shortened, and the hydrate form in the reactor phase. As the LAD⁃40 mass fraction increases, the methane hydrate formation rate increases linearly, and the gas consumption does not change much, however, compared with methane hydrate formation under pure water conditions, it is significantly improved.

In order to explore the influence of deep sea T⁃tube flow difference and pipe diameter abrupt change on the flow characteristic parameters of the vertical pipe, a certain oil and gas field in the South China Sea was taken as the research object, and the numerical simulation method was used. The results show that the influence of flow rate difference is related to the sum of the total flow rate instead of the each flow; the effect of changing diameters of riser pipe on relevant parameters can be divided into three stages: DC=0.03 m, DC=0.06~0.12 m and DC=0.24 m. And when the vertical riser has a sudden change, the flow parameters are mainly related to its minimal pipe diameter.

Taking geothermal heat as the heat source, KCS⁃11, KCS⁃34 and KSG⁃1 as the bottom cycles respectively, the thermodynamic and thermoeconomic performance of three systems combining flash⁃Kalina cycle and absorption refrigeration cycle (F⁃KCS11⁃ARC, F⁃KCS34⁃ARC, F⁃KSG1⁃ARC) were compared and analyzed. The results show that the total exergy loss of the F⁃KCS11⁃ARC system is 5.3% and 2.7% lower than that of the F⁃KCS34⁃ARC system and the F⁃KSG1⁃ARC system,respectively,and the component with the largest exergy loss is the heat exchanger 1. The F⁃KCS34⁃ARC system has the highest thermal efficiency, but the F⁃KCS11⁃ARC system has the highest heat recovery efficiency when the geothermal source temperature is in the range of 155～220 °C, and the smaller geothermal source temperature and flash pressure can make the system obtain higher heat recovery efficiency.Thermal economic analysis shows that pump 1 is the most expensive component in all three systems, the next is steam turbine 2. The F⁃KCS11⁃ARC system has the lowest cost, the highest annual net income, and the smallest investment recovery period, with values of 2.09×106 $, 6.61×105 $ and 3.72 years, respectively.

As a new type of high⁃efficiency mixing equipment, static mixers are widely used in industrial production due to their good mixing effect and simple operation. In this paper, the SK type static mixer was introduced into the crude oil storage tank to solve the problem of uneven distribution of crude oil density. The three⁃dimensional incompressible flow field was numerically simulated by FLUENT. The Eulerian multiphase flow model was used to simulate the velocity field, concentration field, temperature field and pressure field of the fluid in the static mixer. The results show that: under the action of the spiral blades of the static mixer, the crude oil moves cyclically along the opposite direction of the blade and changes periodically. Through the cutting, shearing and rotating action of the crude oil, the oil is almost completely mixed at the exit,which shows that SK static mixer has better mixing effect and less pressure loss and can reduce the energy consumption cost.

The problems of deformation failure of vertical storage tank under wind load were studied. The floating roof tank was established by using the Workbench software. The eigenvalues were used for buckling analysis and the buckling deformation diagrams of the tank were plotted. The modal maps of different orders were read by software to analyze the locations and causes of deformation of the tank. And by changing the wind speeds, the changes of the stress on the windward and leeward sides of the tank were studied. The results show that the displacement of the shell is mainly radial displacement. As the height increases, the stress caused by wind load is mainly changed from axial stress to circumferential stress. The equivalent stress is generally rising at the circumferential angle of 0°. The equivalent stress of the tank wall at the circumferential angle of 180° decreases first and then increases. The research results can provide reference for the wind resistant design of storage tanks.

The problem of mixed H∞ and passive model reference tracking control for a class of discrete switched systems with Discrete time⁃delay based on asynchronous switching was studied. By using the piecewise Lyapunov functional theory and average dwell time method, sufficient conditions for the Discrete time⁃delay switched systems to be exponentially stable with asynchronous mixed H∞ and passive model reference tracking performance were given in the form of linear matrix inequalities. Finally, a simulation example was provided to illustrate the effectiveness of the proposed method.

In this paper, an improved RBF prediction model was proposed to solve the problems of cumbersome calculation and many influencing factors in the process of coking energy consumption. In the energy consumption prediction model, target flue temperature, flue suction, moisture, volatile matter and coking time were taken as input variables, and coking energy consumption as output variables. Because RBF network had many shortcomings such as poor learning ability and slow convergence speed, an energy consumption prediction model based on improved differential evolution algorithm was proposed. By using the differential evolution algorithm with strong global search ability, the optimal values of the center value, width and output weight of the basis function in RBF network were selected as the center value, width and output weight of RBF neural network. The results show that the improved RBF prediction has high accuracy, stability and training speed, which is of great significance for reducing coking energy consumption, increasing coke output and improving economic benefits of enterprises.

In this paper, layered titanic acid H1.07Ti1.73O4•H2O (HTO) was treated with hydrogen peroxide solution to achieve the hydrogen peroxide intercalation and modification of HTO. The hydrogen peroxide molecules entered into the interlayer of TiO6 octahedral layer, forming a peroxytitanium coordination bond with Ti4+ in the layer, which increased the negative charge density of the TiO6 layers. XRD, SEM, TEM, XRF, FT⁃IR and other methods were used to characterize the samples before and after ion exchange. The ion exchange experiments show that compared with HTO, the ion exchange efficiency and ion exchange capacity of H2O2⁃modified HTO are greatly enhanced. And the main reason is that the introduction of H2O2 leads to the increase of negative charge of TiO6 octahedral layers.

X⁃ray fluorescence spectroscopy was used to explore the spatial distribution characteristics and potential ecological risks of heavy metals (Cu, Pb, V, Zn, Cr, Mn) in street dust in different functional areas of the city.The heavy metal content in the dust samples of the cultural and educational districts, commercial districts, residential areas, industrial areas, traffic areas and mixed areas in Benxi City was analyzed,and the results show that the average contents of heavy metals in street dust samples are 3.4, 3.1, 0.9, 5.5, 2.0 and 1.0 times of the Benxi Soil Element Background Values, respectively. The spatial distribution of heavy metal elements was that Cu, V and Cr were highest in the cultural and educational districts, Pb, Zn and Mn were highest in the industrial districts, Cu, Pb and Zn were lowest in the mixed districts, Cr and Mn were lowest in the commercial districts, and V was lowest in the residential districts. The environment risk of heavy metal pollution in street dust of Benxi city was assessed by Potential Ecologically Risk Index .The assessment results show that V, Cr and Mn are low potential ecological hazards, Zn is a medium potential ecological hazard, Cu and Pb have reached heavy potential ecological hazards.

The desulfurization law of high sulfur petroleum coke was studied by chemical oxidation method. In this paper, hydrogen peroxide was used as oxidant, formic acid, acetic acid and propionic acid were used as catalysts. The influences of petroleum coke particle size, the ratio of oxidant volume and petroleum coke mass (liquid⁃solid ratio), reaction time and reaction temperature on the desulfurization effect were investigated. The experimental results show that the desulfurization effect of hydrogen peroxide⁃formic acid oxidation system is the best, which is better than the other two oxidation systems. The petroleum coke particle size is 100 mesh, the liquid⁃solid ratio is 20 mL/g, the oxidation reaction time is 18 hours, and the reaction temperature is 60 ℃ for oxidation. Under the optimum conditions of the desulfurization experiment, the sulfur content of petroleum coke decreased from 3.32% to 2.65%, and the desulfurization rate reached 20.2%.

The direct meta⁃C-H functionalization has proved to be more challenging due to the high energy transition state of marcrocyclic metallacycles which makes its formation extremely difficult. In this paper, the reaction of allyl acetic acid alkenylation based on pyrimidine template under palladium catalysis was studied. The reaction conditions were optimized, the influences of solvent effect, catalyst and oxidant type on the reaction were investigated, and the optimal reaction conditions were obtained. The experimental results show that the designed pyrimidine⁃directed aryl acetic acid C-H bond activation reaction can realize the meta⁃selective functionalization reaction of aryl acetic acid derivatives. A meta⁃alkenylation ibuprofen derivatives with potential drug activity can be constructedby using this strategy.

In this paper, methyl bromoacetate and triphenylphosphine were used as starting materials. First, bromophosphorus salt was prepared, and then alkali was added to prepare Wittig reagent. Preparation of α,β⁃unsaturated carboxylic acid ester (methyl cinnamate) by Wittig reaction using benzaldehyde and Wittig reagent The results show that the optimal conditions for the reaction are: Wittig reagent and benzaldehyde are used as raw materials, benzene is used as a solvent, and potassium carbonate is added as an additive. The reaction is stirred at room temperature for 24 hours, and the final product methyl cinnamate is obtained in a higher yield (86%). At the same time, the configuration of the product is a trans olefin product, indicating that the method has good stereoselectivity.

In order to study the phenomenon that the particles contained in the two⁃phase flow in the nuclear power plant are deposited in the pipeline under high temperature and high pressure, the mechanism of particle erosion on the pipeline is deeply explored. The similar principle and approximate modeling method are used to design and build a nuclear power pipeline. The experimental platform for the key parameters of the actual operation of the system.The results of the 30 h elbow deposition experiment show that the outer wall and inner wall of the 90° horizontal elbow are the sedimentary hot area, the outer wall axial angle of 30～45 degrees is the maximum sedimentary area, the maximum deposition of Co elements is 1.98×10－10 g on 8 mm×8 mm×3 mm sample. The results of this paper can provide data basis for radiation dose prediction and radiation protection of nuclear power plants.