Search

Instrumental Analysis”is an important foundational course offered for chemistry related majors such as chemistry, chemical engineering, medicine, environment, materials, and life sciences. It has a wide range of applications and strong interdisciplinary nature. Curriculum ideological and political education is an important measure to implement the fundamental task of cultivating morality and talents, inherit the red gene, and cultivate new talents of the times. “Instrumental Analysis” is an important carrier and medium of ideological and political education in the curriculum. Based on the teaching background of“Instrumental Analysis”and experimental courses, this article deepens the reform of course objectives, content, structure, and mode, and organically integrates ideological and political elements such as patriotism, cultural confidence, craftsmanship spirit, exploration and innovation, and ideal beliefs with the content of the Instrument Analysis course, strengthen the guiding role of teachers in ideological and political education in the curriculum, enhance the professional quality and moral cultivation of students, achieve the unity of knowledge transmission and value shaping, and provide reference and guidance for the implementation of ideological and political education in the curriculum. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A series of star-shaped multi-arm styrene-butadiene copolymers (S-g-SSB-6) were synthesized by living anionic polymerization, with n-butyllithium as initiator, styrene and butadiene as monomers, 2,2-di(tetra-hydrofuran-2-yl) propane as polar structure regulator and hexachlorodisilane as coupling agent. The molecular weight and its distribution, coupling arm number and coupling efficiency of S-g-SSB-6 were characterized by gel permeation chromatogram. The rheological properties of S-g-SSB-6, star-shaped multi-arm styrene-butadiene copolymer with SiCl4 as coupling agent, and linear styrene-butadiene copolymer (L-SSB) were characterized by rotational rheometer, and the effects of branched chain length and branched chain flexibility on the rheological properties of S-g-SSB-6 were also investigated. The results showed that the coupling arm numbers of S-g-SSB-6 reached 4.1, and the coupling efficiency was greater than 80%. S-g-SSB had lower melt viscosity and better fluid flow than those of L-SSB under the same weight-average molecular weight. When the branching degree was the same, the melt viscosity of S-g-SSB-6 increased with the increase of single arm molecular weight and molecular chain rigidity.

A homogeneous phosphate ester rare earth catalytic system was constructed with solubilized neodymium di(2-ethylhexyl) phosphate eater as the main catalyst, alkyl aluminum and aluminum chloride as co-catalyst and the third component, respectively. The copolymerization of butadiene and isoprene was catalyzed by this catalytic system. The effects of the composition and dosage of alkyl aluminum and aluminum chloride, catalyst dosage, and monomer feeding ratio on the properties of the copolymer were studied. The results showed that the catalytic system could efficiently catalyze the copolymerization of butadiene and isoprene, and the resulting polymer was a random butadiene-isoprene rubber with high cis-1,4-unit stereoregularity and narrow molecular weight distribution. When diisobutylaluminum hydride was chosen as the alkyl aluminum, the catalytic system exhibited reversible coordination chain transfer polymerization characteristics with 10.3 polymer molecular chains gene-rated per neodymium atom.

The microstructure and composition of styrene-conjugated diene block copolymer and its hydrogenation product hydrogenated styrene-conjugated diene block copolymer (HSBC) were determined by nuclear magnetic resonance spectroscopy, degree of benzene ring hydrogenation of HSBC was calculated and compared with the calculation result of ultraviolet spectrum. The results showed that compared with the ultraviolet spectrum, the nuclear magnetic resonance spectroscopy had the advantages of simple steps, fast and efficient, and calculated degree of benzene ring hydrogenation of HSBC was in good agreement with the calculation results of UV method.

Secondary structures of protein amide Ⅲ band and its thermal denaturation in natural rubber were studied by midinfrared (MIR) spectroscopy. The result of variable temperaturet deconvolution MIR spectroscopy showed that the infrared absorption peak intensity of irregular curled, β-folded, α-spiral and β-corner se-condary structures decreased when the temperature increased from 293 to 393 K. The result of two-dimensional MIR spectroscopy showed that there were significant differences in the sensitivity of amide Ⅲ band secondary structures to heat, with the irregular curled secondary structure being the first to change. Under thermal disturbance factor, the irregular curled secondary structure change was a key step in the overall secondary structure change of the amide Ⅲ band.

With ethylene-vinyl acetate-glycidyl methacrylate (EVM-GMA) rubber as matrix, γ-aminopropyltriethoxysilane (APTES) as grafting monomer and azodicarbonamide as foaming agent, double crosslinked foaming materials were prepared by combination of water crosslinking and peroxide crosslinking. The cell morphology, dynamic mecha-nical properties, and physical and mechanical properties of the foaming materials were investigated by scanning electron microscopy, dynamic mechanical property spectrometer and electronic universal tes-ting machine. The results showed that the double crosslinked foaming process could be realized, and the crosslinking network formed by water crosslin-king could effectively improve the uniformity and dispersion of cell size. When the amount of dicumyl peroxide was 0.25 phr (mass), the double crosslinked foam material had the narrowest cell size distribution, the best foaming effect, and better energy absorption effect, which was suitable for application of damping materials.

Nitrile rubber latex was prepared by conventional emulsion polymerization combined with low-temperature batch polymerization process, the latex was hydrogenated with self-made ruthenium catalyst, and the influence of catalyst amount and hydrogen pressure on the hydrogenation effect of nitrile rubber latex was systematically studied. The results showed that the average particle size of the prepared nitrile rubber latex was 69.13 nm, and the particle size of the latex remained basically unchanged and the latex remained stable before and after hydrogenation. The higher the hydrogen pressure was, the better the catalytic hydrogenation effect was. When the mass fraction of catalyst was 0.017 5%, degree of hydrogenation of the product was more than 99% and no gel was obtained.

Pre-post processing model of ABAQUS was developed secondarily based on Python language, and the simulation evaluation plug-in of typical O-ring seal structure was formed. The results showed that based on the plug-in, geometric mode-ling, material assignment, mesh division, boundary loading, and result post-processing could be quickly performed and automatically generate Word reports , which could helped identify key design parameters that affected the sealing performance, verified design rationality, saved simulation time and greatly improved simulation efficiency.

Non-isothermal transient flow simulations of conventional threaded screws and field sy-nergy torsion screws with different segmented edge helix angles, were performed using ANSYS Polyflow software. The simulations focused on the effects of these screw structures on rubber material mixing, heat transfer, and plasticizing uniformity during the extrusion process. The results indicated that the overall performance of the field synergy torsion screw was generally superior to that of the conventional threaded screw, with the screw having a segmented edge helix angle of 45° being the optimal configuration. The spiral flow induced by the field synergy torsion screw improved the synergy between the velocity field, velocity gradient field, and temperature gradient field of the rubber material, enhancing mixing and heat transfer, and thereby improving the plasticizing quality of the rubber material.

Room temperature vulcanized silicone rubber was selected as the repair material, and pee-ling samples were prepared with four types of substrates. The theoretical values of peel forces between materials were predicted by constructing a mathematical model for calculating the peel force on the material surface. At the same time, experimental va-lues of peel forces between different materials were obtained through peel force test. The results indica-ted that the relative size relationship between the theoretical and experimental values of peel force in all samples was consistent, and the absolute deviation between the theoretical and experimental values of peel force for a single sample was below 1 N. The calculation results of this mathematical model could reflect the relative strength of peel strength between different materials well.

"Ethylene-methyl acrylate copolymer (EMA)/chloroprene rubber (CR) thermoplastic vulcanizate (TPV) was prepared by dynamic vulcanization and tear strength with different m(EMA)/m(CR) was investigated. The Mullins effect of TPV under tear mode and reversible behavior under heat treatment were studied. The results showed that tear strength of EMA/CR TPV was the highest when m(EMA)/m(CR)was 40/60. There was obvious Mullins effect in EMA/CR TPV under uniaxial cyclic tearing mode, and when the strain rate increased, the maximum tear strength, internal friction and damping factor of EMA/CR TPV all increased. When the tear strain increased, the maximum tear strength, instantaneous residual deformation, internal friction and damping factor of EMA/CR TPV all increased, but the stress softening factor decreased. The reversible recovery ability of Mullins effect of EMA/CR TPV was enhanced after heat treatment, and the reversible recovery effect was the best at 80 ℃. "

"In order to improve the performance of crumb rubber modified asphalt, chloroprene rubber (CR) with a mass ratio of 11/100 to matrix asphalt and ethylene-vinyl acetate copolymer (EVA) with a mass ratio of 3/100 were used as modifiers to prepare modified asphalt. CR/EVA was activated by low-temperature plasma to further improve the performance of compound modified asphalt. The road performance of single modified, compound modified and low-temperature plasma activated compound modified asphalt (A-CR/EVA-MA) were studied. The microscopic mechanism of each modified asphalt was analyzed by scanning electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy. The results showed that the road performance of each modified asphalt was improved, and the overall performance of the activation modification system was better than those of compound modification and the single modification system. The penetration, softening point, ductility, Brookfield viscosity and anti-rutting factor of A-CR/EVA-MA increased by 46%, 47%, 94%, 253%, and 278% respectively compared to the matrix asphalt, and the storage stability was also further improved. The low-temperature plasma activation technology increased the specific surface area and surface functional group content of the modifier, improved the adsorption capacity of the modifier to the light components in the asphalt, promoted the close combination of CR, EVA and asphalt, and improved effectively the road performance of the modified asphalt. "

"Metal-organic framework materials(MOFs) were used as deodorizers for ethylene-propylene-diene rubber（EPDM） sealing strips, and the effects of MOFs on curing behavior and mechanical properties of EPDM were studied. The inhibition effect of MOFs on the odor of volatile organic compounds released by EPDM was also investigated. The results showed that addition of MOFs could promote vulcanization of EPDM and its mechanical properties remained basically unchanged. MOFs had a good adsorption effect on odor molecules, such as organic amines and carbon disulfide, and the odor level of EPDM had decreased from 4.5 to 2.0. "

Zinc sorbate (ZDS) reinforced hydrogenated nitrile rubber was prepared using sorbic acid and zinc oxide as raw materials by in situ generation method, and the in situ reaction mechanism of sorbic acid and effect of zinc sorbate on physical and mechanical properties of the hydrogenated nitrile rubber were investigated. The results showed that zinc sorbate could be generated in situ during the vulcanization stage. With increase of addition of sorbic acid and zinc oxide, the crosslinking degree of vulcanizate gradually increased, and tensile strength showed a trend of first increasing and then decreasing. When the addition amount of sorbic acid and zinc oxide were 23 g and 10 g, respectively, the tensile strength reached maximum of 24.5 MPa. Pretreatment of the rubber compound could significantly improve its mechanical properties, but the pretreatment time should not be too long, otherwise the mechanical properties would decrease.

The ablation mechanism of ablation-resistant silicone rubber was described and the research progress of ablation-resistant modification of silicone rubber by chemical modification such as block copolymerization, graft copolymerization and crosslinking or physical modification such as adding fillers and flame retardants at home and abroad was reviewed with 37 references. Finally, the future development direction of ablation-resistant silicone rubber was prospected.

Agricultural microgrids offer a promising solution for energy supply in remote rural areas in a low-cost manner. In this paper, under uncertain conditions of renewable energy output and electricity load demand, a robust optimal scheduling model combined with the isolated agricultural microgrid and irrigation system containing a pumped hydro storage (PHS) power station is proposed, considering the factors that the wind-landscape pumped storage integrated agricultural microgrid can satisfy the uncertain fluctuations of power load demand and water load demand. By utilizing the abundant water resources in rural areas and the advantages of landscape drainage and storage compensation, the total cost of the system is minimized while the absorption of renewable energy is increased. Considering distributed generation, power load demand and water load demand, turbine flow, and irrigation flow, the proposed model is characterized by diversity, multi-constraint, and discontinuity. A gravitational whale optimization algorithm (GWOA) is proposed to solve the model. The simulation results of an agricultural microgrid show that the GWOA can obtain a more competitive solution than the CPLEX solver and other newly developed algorithms do. In addition, the impact of the change of water load demand caused by precipitation uncertainty on the operating cost of the irrigation system and the necessity of using PHS power station are explored.

With the construction of a diversified electricity market, the factors affecting electricity prices are gradually increasing, and the market environment has undergone more drastic changes. In order to improve the accuracy of short-term electricity price prediction, an improved Transformer-particle swarm optimization (PSO) short-term electricity price prediction method considering multiple factors affecting electricity prices is proposed. First, based on the consideration of historical electricity prices and historical loads, the relevant factors of electricity price formation are further analyzed. The autocorrelation function is used to analyze the multi-cycle characteristics of electricity price and adjust input sequence, which overcomes the problem of limited prediction accuracy caused by using historical data only and adjusting the input sequence by experience. Then, by combining long short-term memory (LSTM), self-attention mechanism, multi-layer attention mechanism, and adopting a multi-input structure, an improved Transformer model is established to further enhance the ability of the LSTM model to capture long short-term dependencies between different time step information, to overcome the information utilization bottleneck of LSTM, and to adapt to complex multiple sequence inputs including historical electricity prices and various electricity price causes. In addition, the PSO intelligent algorithm is utilized to search for the optimal learning rate of the model at different learning stages, overcoming the limitations of manually adjusting the learning rate. Finally, the PJM market electricity price is used for example analysis. The results show that the proposed short-term electricity price prediction model can be applied to the market environment where electricity prices are affected by various factors and drastic changes, and effectively improve the accuracy of short-term electricity price prediction.

The complex and multiple uncertainties of offshore wind power pose great challenges to the safety and robustness of transmission grid structures. In order to improve the adaptability of grid structure to offshore wind power, a robust expansion planning method based on Vague soft set is proposed. First, Monte Carlo simulation is employed to construct the offshore wind Vague scenarios, which transform multiple comprehensive uncertainties of offshore wind power into uncertain parameter sets from true membership function, pseudo-membership function, and unknown information measure based on the Vague soft set theory. Then, a two-stage robust expansion planning model based on Vague scenario set is established for transmission network with offshore wind power penetration. The minimum total investment cost of offshore and onshore line and network loss is taken as the objective function in the first stage, while the minimum objectives of wind abandonment and cutting load for offshore wind power are proposed with the alternating current power flow constraint based on second-order cone relaxation in the second stage. Based on the expected values of wind abandonment and cutting load returned by the second stage model, the operation variables of the first stage model are modified to ultimately obtain the iterative transmission network robust planning scheme. Finally, the Gurobi mathematical optimization engine is used to analyze the Garver 6-node system and IEEE 39-node system to verify the effectiveness and feasibility of the proposed robust expansion planning method.

In order to give full play to the advantages of shared energy storage in improving economy and energy utilization, while considering the role of multi-energy complementation and coupling of integrated energy microgrids in active distribution networks, a multi-objective optimal allocation strategy of shared energy storage is proposed for the active distribution network connected with integrated energy microgrid. First, the optimization objectives of the economy and voltage stability of the distribution network and the configuration capacity of the shared energy storage are analyzed, the coordinated operation of the source-net-load side multi-flexible resources of the active distribution network is considered, and the active distribution network and the integrated energy microgrid are modeled. Then, the model is solved based on the Pareto optimal multi-objective particle swarm algorithm. Finally, the optimization algorithm of shared energy storage configuration is established in conjunction with the IEEE 33-node distribution system to verify the effectiveness of the proposed configuration strategy.

In view of the fact that the current integrated port energy system (IPES) considers neither the time scale difference of refrigerated containers in port scheduling nor the impact of renewable energy and load uncertainty, this paper proposes a day-ahead and intra-day two-stage rolling optimization scheduling method for a container IPES. In day-ahead scheduling, based on the temperature rise process of refrigerated containers, a port cold chain energy demand model is established, which is combined with the logistics process after the arrival of refrigerated containers. Then, the day-ahead output values of each unit in the system are obtained with the goal of the lowest operating cost. In intra-day scheduling, a two-layer rolling model is proposed to obtain the adjusted output of the port energy equipment, which considers the prediction error of shore power load and renewable energy as well as the different response speeds of cooling, heating and power. The calculation results show that the collaborative optimization scheduling of refrigerated containers and the container IPES can effectively reduce the port operation cost and carbon emissions. The two-stage day-ahead and intra-day rolling optimization scheduling can improve the economy and stability of the system.

The quantitative evaluation of the uncertainty in distributed photovoltaic power is significant for the safe and stable operation of distribution network. Considering the significant differences in power characteristics of different output fluctuation patterns, in order to obtain a prediction model suitable for different fluctuation patterns and to perform a refined assessment of power uncertainty, this paper proposes a method for pattern recognition and ultra-short-term probabilistic forecasting of power fluctuating in aggregated distributed photovoltaic clusters. First, the satellite cloud images and photovoltaic power data are integrated, and the pattern recognition model of fluctuation is constructed via the feature extraction of power fluctuation, realizing the mining of fluctuation rules. On this basis, the difference in predictability of different fluctuation patterns and the correlation between fluctuation patterns and prediction errors are considered via classification modeling, so that the width of prediction interval can better adapt to the characteristics of prediction error distribution. Thus, refined consideration of power uncertainty of different fluctuation patterns is realized to improve the precision of probabilistic prediction, provide more references for power grid dispatching, and weaken the influence of the strong volatility in distributed photovoltaic power on the power system.

With the continuous increase of electrification in seaports, the single energy supply mode of seaport microgrid is evolving towards multi-energy integration. Aimed to achieve the goals of peak carbon and carbon neutrality, an optimal carbon trading mechanism-based allocation scheme of hybrid electric and thermal storage system is proposed to further maximize the economic and environmental benefits. First, the integrated energy system model of a seaport is established, incorporating a scheme within the carbon trading market. Then, a bi-level optimization framework is proposed, in which the upper layer is utilized to optimize the allocation of the hybrid energy storage system and the lower layer is employed to optimize the operation. Afterwards, a combination algorithm of the mesh adaptive direct search and the adaptive chaotic particle swarm optimization is developed to solve the proposed problem. Finally, the real-world data of Tianjing port is utilized to verify the method. The numerical results demonstrate that with the help of the proposed method, both the cost and carbon emissions are dramatically reduced.

Aimed at the coupling problem of the combined wind-storage system participating in different call time scale scenarios in electricity markets, an optimal dispatching method of the combined wind-storage system oriented to the application of multi-time scale scenarios in electricity markets is proposed to guide the combined wind-storage system to suppress short-term wind power fluctuation, and participate in the electric energy market and the reserve ancillary service market, so as to realize the collaborative optimization among different call time scale scenarios application and maximize the economic benefits of the combined wind-storage system. First, considering the profit mechanism of different scenarios, the objective function is established with the objective of maximizing the economic benefits of multiple scenarios of the combined wind-storage system. Then, the constraints of the combined wind-storage system participating in various application scenarios and multi call time scale coupling constraints are established. Finally, the numerical simulation verifies that the proposed method can improve the comprehensive operation profit of the combined wind-storage system in the day-ahead electric energy market and the reserve ancillary service market while ensuring that the wind power fluctuation does not exceed the limit.

To improve the current automated guided vehicle (AGV) charging strategy at automated terminals, which is not fully coordinated with the distributed power supply, a joint optimization method of AGV logistics scheduling and orderly charging is proposed. First, the synergetic relationship between AGV logistics scheduling and charging scheduling is analyzed, and a joint optimization framework is built. Then, a method to calculate the distance traveled by AGVs while considering the segregation requirements of trucks inside and outside the terminal is proposed. Afterwards, for the AGV charging module, the judgment conditions of AGV charging status and the pile selection method are defined. Furthermore, to minimize the cost of purchasing electricity at the terminal, a joint optimization model of logistics scheduling and orderly charging is constructed by considering time-of-use tariff, distributed power feed-in tariff, power balance constraint, state of charge constraint at the termination moment, upper and lower bound constraints of decision variables, and logistics scheduling constraint. Finally, a fast solution method based on improved particle swarm optimization algorithm is proposed, of which the effectiveness and economic efficiency are verified by an actual case of a terminal.

Fault diagnosis in power distribution networks is crucial for fault location, enhancement of fault processing efficiency, and reduction of power outage losses. Currently, the impact of switch operations and other interferences is seldomly considered in fault diagnosis algorithm designing and testing, which may lead to frequent mal-function and poor performance in practical applications. In this paper, a detailed analysis and modeling of the transient process of switch operation in distribution networks is proposed with the combination of the Mayr and the Helmer models. The transient waveform of the on-site operation process is compared and analyzed with the simulation waveforms generated in PSCAD. Based on the accuracy verification of the model, typical fault scenarios in distribution networks, including switch operation processes, are constructed for fault diagnosis algorithm tests. Compared to the traditional model, the model proposed can simulate and generate disturbance data close to the on-site switch operation process for reliability testing of fault diagnosis algorithms. Finally, several suggestions for optimizing the fault diagnosis algorithm and testing process are proposed through result analysis.

The rapid development of electric vehicles (EVs) and unmanned aerial vehicles (UAVs) provides new ways for personnel search and material distribution during emergency periods. This paper proposes an EV-UAV joint rescue system, in which the UAVs use the EVs as charging and maintenance base stations to provide various services for the objects to be rescued, and the EVs can use distributed generations to obtain diversified electricity supply, which improves the adaptability and endurance level of the system in emergencies. The coordinated scheduling model of the EV-UAV system is established in the mixed-integer linear programming (MILP) formulation, which considers factors including electricity consumption, electricity replenishment, loading capacity, distribution route, and distribution time window of the EVs and the UAVs. Case studies verify the validity of the model proposed, compare the EV-UAV and ground vehicle (GV)-UAV rescue systems, and illustrate the technical characteristics and application potential of the EV-UAV system in emergency assistance.

The charging safety of electric vehicle (EV) is closely related to the state of health (SOH) in power battery pack. Therefore, the high-performance and real-time estimation of SOH is an important basis for safety detection in the charging process. Power battery is deeply effected by factors such as complex structure, types of battery cell, driving habits, temperature, and charging behavior. Compared to SOH estimation methods based on experimental data from one or few battery cells, research on real-time SOH estimation of the power battery meets with insufficient problems in battery model, data getting, real-time, accuracy, and so on. Aimed at these drawbacks, a high performance SOH estimation method in power battery pack is proposed by introducing the broad learning system(BLS) optimized by radial basis function (RBF) into the empirical battery degradation model based on the idea of multi-method integration and fusion. First, the empirical degradation model and offline historical charging data are used to obtain the initial SOH value. Then, a radial basis function neural network is applied to get the initial weight matrix of the BLS to optimize the BLS method, and establish the RBF-BLS neural network. The estimation error can be trained by the RBF-BLS neural network and real-time charging data, and compensate for the initial SOH to gain a higher precise SOH value. Finally, a computer simulation example based on actual charging data from a charging operation enterprises is used to verify the effectiveness and superiority of the proposed method.

Aiming at the uncertainty of the source and load in micro energy grid, a robust optimal scheduling model considering multi-interval uncertainty set of source-load and integrated demand response is proposed. First, considering the uncertainty of wind power, photovoltaic output and electric, and thermal and cooling loads in the micro energy grid, a multi-interval uncertainty set of source-load is established. Then, in order to fully tap the potential of load side dispatching, an integrated demand response model is established, which includes reducible electric load, transferable electric load, flexible cooling, heating load, and replaceable load, based on which, the uncertainty of integrated demand response is considered. Afterwards, with the lowest dispatching cost of micro energy grid as the objective function, a two-stage robust optimal scheduling model of micro energy network is constructed, which considers the multi-interval uncertainty set of source load and the integrated demand response. The model is solved by the column and constraint generation algorithm, the strong duality theory, and the large M method. Finally, the rationality and effectiveness of the proposed model are verified through the analysis of numerical examples.

In view of the fact that the conversion of various energy forms such as electricity, gas, and heat in the regional integrated energy system (RIES) seriously affects the economy of the system operation, a mathematical model and an optimization model of RIES energy flow are established to improve the economy of the system and the absorption of renewable energy. First, the mathematical models of all kinds of energy conversion equipment in the system are established to determine the constraints of three kinds of energy transmission networks, namely electricity, natural gas, and heat. Then, taking economic operation as the primary objective, and taking into account the objective function of low carbon emissions and increasing the uptake rate of renewable energy, the RIES multi-energy flow optimization model is constructed. Finally, based on the large-scale integrated energy system, the load side demand response is introduced and the simulation model is established. The simulation results show that the introduction of demand response improves the flexibility of system scheduling, reduces the dependence of the system on energy storage equipment, and effectively reduces the energy consumption cost of users.

In order to enhance the generation efficiency of wave energy converter (WEC) arrays, an optimization method for three-tether WEC array based on an improved honey badger algorithm is proposed. First, to overcome the shortcomings of the primal honey badger algorithm (HBA), such as slow convergence speed and low convergence accuracy, three improvement strategies are introduced, i.e., good point set initialization, chaos mechanism, and honey badger population mutation. Then, three wave farms including 2-buoy, 10-buoy, and 20-buoy are tested to verify the advancement and effectiveness of the improved honey badger algorithm (IHBA). The simulation results of the 2-buoy array demonstrate that there are multiple groups of optimal solutions in WEC array optimization. Furthermore, IHBA, HBA, genetic algorithm, and particle swarm optimization can find these optimal solutions at different speeds. Nevertheless, with increasing size of the WEC array, three comparative algorithms fall into local optima solutions. On the contrary, IHBA still exhibits a strong optimization ability and can seek global optima solutions. Finally, the q-factor values obtained by IHBA in 10-buoy and 20-buoy arrays reach 1.059 and 0.968, respectively, which are dramatically larger than those of other algorithms.

An accurate and timely monitoring for the inertia support capability of the point of interconnection of aggregated sources to the grid in a low-inertia new power system is crucial for the safety, stability, and economic operation of the system. In order to explain the basic idea of the online point-to-grid inertia monitoring method, the definition of inertia of power system based on the swing equation and existing online monitoring methods are analyzed. Then, in order to improve the accuracy of the existing online inertia monitoring method, an equivalent inertia constant identification method based on the regression method is developed. Combining the proposed inertia constant identification method with the online inertia monitoring method, a systematic method for online monitoring of the inertia support capacity of point-to-grid in new power system is developed based on synchronous phasor measurement units. Finally, the simulation analysis of a modified New England 10-machine 39-bus system proves the accuracy and the feasibility of the developed real-time inertia monitoring method for the new power system.

Purposes To explore the dynamic performance of circulating fluidized bed(CFB) combustion ash subgrade under the driving load, the dynamic resilient modulus characteristics of GF and DTH combustion ashes under different curing ages, compaction degrees, water contents, and stress levels were investigated on the basis of laboratory dynamic triaxial tests. Methods With the aid of mercury intrusion porosimetry(MIP), the pore distribution characteristics of CFB combustion ash were analyzed. Findings The measured results reveal that within a certain range, the dynamic resilient modulus of CFB combustion ash increases with the increase of f-CaO and SO3 content and curing age, and increases significantly in 0~7 d, and slowly in 7~28 d; the increase of compaction degree, water content, confining pressures, and deviator stress increase the dynamic resilient modulus of CFB combustion ash. With the increase of compaction degree and water content, the improvement of dynamic resilient modulus gradually decreases. Both deviator stress and confining pressure affect the dynamic resilient modulus of CFB combustion ash, and the effect of confining pressure is relatively more significant. The results of MIP show that the total porosity and large pore diameter (>2 000 nm) density of GF combustion ash sample are lower than those of DTH combustion ash sample under the same conditions. With the decrease of water content, the total porosity and the large pore size density become higher, the dynamic resilient modulus becomes lower. Fitting the results of dynamic resilient modulus of two kinds of CFB combustion ash with different water contents and compaction degrees after curing for 28 days shows that the prediction results of the three-parameter theoretical model with bulk stress and octahedral shear stress as variables have a high correlation with the test results (R2>0.96), suggesting that the model can effectively predict the dynamic resilient modulus of CFB combustion ash.

Purposes In order to effectively alleviate the urban flood caused by extreme rainstorm weather, the site selection and quantity optimization of rainwater storage tanks (SST) in urban rainwater drainage system were investigated. Methods Game theory (GT) was used to combine the subjective weights obtained by the analytic hierarchy process with the objective weights obtained by the improved entropy value method. Furthermore, the grey relevance analysis (GRA) and technique for order preference by similarity to ideal solution (TOPSIS) were combined to establish a quantitative assessment framework for urban waterlogging and non-point source pollution risks. The risk level was determined according to the relative proximity of each node, and SST was set for the node with higher risks. The number of SST was then optimized according to the reduction rates of stagnant water and total suspended solids. With Changzhi City, Shanxi province as an example, the control effect of this method on urban waterlogging and non-point source pollution under different rainfall return periods was discussed. Findings The results show that at 5 a and 10 a rainfall return periods, the comprehensive coefficients of variation of GRA-TOPSIS method are 0.355 and 0.361, respectively, and the extreme values are both 0.496, higher than that of GRA or TOPSIS alone. Conclusions Optimization method of GT weighting and coupling GRA-TOPSIS can better eliminate the risk of urban waterlogging and non-point source pollution with less economic investment, and provide a new thought for SST location and quantity optimization.

Purposes The internally porous and highly thermally stable glazed hollow beads (GHB) can reduce the high temperature damage and deterioration of concrete to a certain extent, and improve the fire resistance of concrete. In order to further clarify the mechanism of GHB in improving the fire resistance of concrete, starting from the meso-scale concrete, we proposed a modeling method for RATIC meso-scale model that can take into account the initial defects and the replacement rate of recycled coarse aggregate (RCA). Methods The effects of RCA replacement rates (0, 50%, 100%), GHB contents (0, 70%, 100%), and porosity (0, 2%, 4%) on the mechanical properties of RATIC after high temperature were explored by utilizing the plastic damage model commonly used at curent stage. Findings The results show that with the increase of fire temperature, the damage distributions of the RATIC specimens under load exhibit a gradually increasing trend, and the damage distribution of the specimens after 500 ℃ is more serious than that before 400 ℃. The addition of GHB alleviates the damage and deterioration inside the concrete to a certain extent, while the addition of RCA exacerbates this phenomenon. In addition, the strength of RATIC specimens gradually decreases with the increase of porosity.

Purposes The typical street canyon-building of the city is researched in this work. Methods On the basis of field measurement and numerical simulation CFD(Computational Fluid Dynamics), the airflow pattern and pollutant distribution in street canyon and indoor the building with windows opening were investigated. Findings The results show that the opening of windows on the outer wall of building disturbs the surrounding air flow, which leads to the enhancements of the vortex flow in the street canyon, and the variation of local wind direction and wind speed in different heights. The turbulence intensity of the street-facing buildings on the leeward side is more obviously affected by the opening of the windows than that of the buildings on the windward side,1~4 floors are 20.6% higher than the case of unopened windows. The change of indoor pollutant concentration on each floor is roughly consistent with the outdoor street canyon pollutant distribution. The indoor pollutant concentration of leeward buildings is much higher than that of windward buildings. Concentrations of indoor pollutants in leeward buildings decrease with the increase of floors, the pollutants on floors 1~4 account for 43.7% of the total pollution. The indoor pollutant concentration of buildings on the windward side first decreases along the building height, but does not show a monotonous trend of decreasing floor by floor. The pollutant concentration value is the smallest near the middle floor of building, then increases under the combined action of window disturbance and street canyon circulation vortex. The whole solution of street canyon-window building overcomes the inconsistency between the inflow level setting of simulated street buildings and the actual working conditions, better solves the problems of complex vortex boundary setting and different window opening positions from floor to floor.

Purposes To investigate the influence of different tamping methods on the reinforcement effect of sand dynamic compaction, this research has been done from the perspective of soil stress distribution characteristics. Methods The dynamic compaction model test was carried out in the outdoor field to monitor the vertical and radial soil pressures in the soil and falling weight acceleration during tamping process, and the displacements in the soil were analyzed by numerical simulation method. Findings It is concluded that in the construction of dynamic compaction method, the vertical soil pressure waveform is the shock wave waveform or the vibration attenuation wave shape, and the radial earth pressure waveform is the impact waveform; There are two reinforcement modes in the process of dynamic compaction, the soil under tamping point is mainly vertically compacted, while the soil side of tamping point also has significant radial compaction; At the same level of dynamic compaction, heavy falling weight is suitable for deep soil and radial soil reinforcement, while light falling weight is suitable for rapid reinforcement of shallow soil. Conclusions The research results have a certain guiding significance for the selection of tamping methods of the same energy level dynamic compaction.

Purposes To achieve the reuse of solid waste, the feasibility of using compacted tailings-bentonite material as an impermeable material for landfill cover system is explored in this study. The maximum dry density values of tailings-bentonite mixtures with varying bentonite contents are determined through compaction tests. Methods Saturated permeability coefficients of the tailings-bentonite mixtures were measured by using a consolidation permeameter. Additionally, the pore characteristics of the samples were analyzed through mercury intrusion porosimetry and scanning electron microscopy tests. Finally, the service performance of compacted tailings-bentonite mixture in cover systems was investigated by using numerical simulations. Findings The results reveal that the maximum dry density of the tailings-bentonite mixture first increases and then decreases with increasing bentonite content, reaching the maximum of 1.94 g/cm3 at 10% bentonite content. The permeability coefficient of the compacted tailings-bentonite mixture decreases with the increase of bentonite content. A bentonite content of 10% or higher satisfies the permeability requirement for the impermeable layer, i.e., ks=5.61×10-10 m/s, ≤10-9 m/s; in this case, an impermeable layer with a thickness of 10 cm meets the requirement that annual percolation ≤30 mm. Additionally, setting a certain slope to facilitate lateral drainage can effectively reduce the percolation through landfill cover system.

Purposes It is important to explore the law of capillary action on the corrosion of X70 steel in soil. Methods On the basis of the theory of unsaturated soil and electrochemical impedance spectroscopy, combined with polarization curve technology, electrochemical impedance technology, scanning electron microscopy, and other test methods, the electrochemical corrosion behavior of X70 steel caused by capillarity in silty clay was investigated through the simulation test of one-dimensional soil column instrument under indoor conditions. Findings The test results show that capillary action has a certain influence on the electrochemical corrosion behavior of X70 steel, that is, the corrosion rates of steel sheet at the height of 12 and 27 cm of soil column first increase and then decrease with embedding time, and the corrosion rate of steel sheet at the height of 42 and 57 cm of soil column first decrease and then increase with embedding time; The rising rate of capillary water in silty clay meets the law of being first fast and then slow. Conclusions The corrosion type of X70 steel sheet surface is mainly pitting corrosion, and the corrosion product surface is accompanied by deep and wide cracks. With the increase of soil sample height, the corrosion degree decreases, and the size and number of corrosion pits show a decreasing trend on the whole. In the rising process of capillary water, when X70 steel sheet is at the solid-liquid-gas three-phase boundary, its corrosion rate is the fastest and the corrosion degree is the most serious.

Purposes This work has been carried out to determine the optimal composite mix ratio of eggshell powder and metakaolin as cement replacement materials for simultaneously enhancing the compressive strength of cement mortar and the sulfate resistance of cement paste. Methods Eggshell powder and metakaolin were used to replace cement to make specimens, and the strength of cement mortar and sulfate resistance of cement paste were tested separatehy. Findings The strength test results show that 20% metakaolin content increases the cement strength most significantly, and the cement strength decreases significantly when the metakolin content increases to 30%. When the 20% metakaolin content is fixed and 5% eggshell powder is added, the cement mortar still maintains the strength close to that of cement mortar with 20% metakaolin. When the content of eggshell powder increases to 10%, the cement strength decreases obviously. The sulfate resistance test results show that the additions of 10% and 20% metakaolin lead to the volume expansion and fragmentation of cement-based materials in sulfate environment. After adding eggshell powder, this phenomenon is alleviated. The specimens with eggshell powder and pure cement show the same sulfate resistance. Conclusions When the eggshell powder and metakaolin are compounded in an appropriate proportion, the strength of cement-based matenals can be improved and their sulfate resistance can be maintained at the same time.

Purposes For improving the mechanical properties of GO incorporated cement paste, two types of nano-silica (crystalline and amorphous) and coal-bearing metakaolin (CMK) were used seprately to improve GO dispersion in cement paste. Methods UV-vis spectrophotometry was used to investigate the effects of ultrasound time and different dosages of amorphous nano-silica (ANS) and crystalline nano-silica (CNS) on the dispersion of GO in saturated calcium hydroxide solution. The effects of different particle materials on GO dispersion were characterized by using compressive strength results. The dehydration and decomposition processes of various phases of hydration products were observed by thermogravimetric (TG) analysis, and the effect of adding different particle materials and GO on the pore structure of cement paste was analyzed by mercury intrusion porosimetry (MIP). Findings According to UV-vis spectroscopic study, when the contents of ANS and CNS were 2% and 1.5% by weight of cement, respectively, GO dispersion in saturated Ca(OH)2 solution is improved greatly. Compared with two nano-silicas, CMK is more effective to improve the compressive strength of GO incorporated cement paste. At the age of 28 d, the flexural strength and compressive strength of the cement paste incorporated with 4% CMK and 0.03% GO are 26.93% and 30.41%, respectively, higher than those of a plain cement paste sample. The results of TG and MIP tests showed that the pozzolanic reaction of CMK can effectively refine the pore structure of cement paste, improve GO dispersion, and enhance the bonding between hydration products and GO, which is the main reason why CMK can effectively improve the mechanical properties of GO incorporated cement paste.

Purposes The construction of disaster prevention and refuge green spaces is crucial in urban safety engineering. Taiyuan City has made significant efforts in urban construction to enhance its capacity to respond to possible disasters. However, challenges persist, including insufficient quantity, unreasonable distribution, and lack of scientific quantification in site selection. Methods To address these issues, the current status and the selection planning of disaster prevention and refuge green spaces in Taiyuan City were investigated in this study. Factors influencing the selection of such spaces were identified, and their weights were calculated by using the Analytic Hierarchy Process. Spatial analysis was conducted by using GIS technology to derive scientifically grounded site selection results. Finally, by taking the Yingze District of Taiyuan City as the object, specific site selection recommendations were proposed. Findings The proposed method can offer a scientific theoretical foundation for the selection of disaster prevention and refuge green spaces in Taiyuan City, making professional contributions to enhancing urban disaster prevention and refuge capabilities and constructing ecologically livable cities.

Purposes Leakage detection in underground pipelines such as prestressed concrete cylinder pipes is a crucial aspect of urban infrastructure management and maintenance. In this study, an innovative magnetic anomaly multi-feature fusion network (MMF) is designed and introduced to identify weak magnetic distribution types in underground pipelines. Methods The network leverages standard orthogonal basis functions (OBF) and minimum entropy detection (MED) features were used to comprehensively and accurately capture the complex characteristics of magnetic leakage signals. First, magnetic anomaly detection was conducted by using OBF and MED at different radial distances to acquire measured target magnetic field features. Second, an MMF was devised to integrate magnetic field features, and a multi-head attention mechanism was incorporated to capture intricate relationships and features within the sequence of magnetic fields. Finally, a multi-feature entropy weighting method was employed to allocate network weights on the basis of input feature entropy. Findings Experimental results demonstrate that the MMF network achieves a precision of 98.86% in anomaly classification, with an AUC evaluation result of 99.25%. Additionally, the model is more streamlined, exhibiting higher computational efficiency, and is capable of delivering satisfactory performance within a relatively short training period.

Purposes The flexible bedding layer and pile cap have great influences on the pile-soil stress ratio, load sharing ratio, and settlement of CFG pile composite foundation, and further research is still needed about how the flexible bedding layer and pile cap jointly affect the characteristics of the composite foundation in field tests. Methods By using a section of CFG pile composite foundation with soft foundation treatment as the engineering background, field in-situ tests were conducted for the combinations of bedding thicknesses of 100, 200 and 300 mm and pile cap size of 0.8, 1.0, and 1.2 m under the control of constant number of geogrid layers to investigate the pile-soil stress ratio, load sharing ratio, and settlement characteristics of CFG pile composite foundation. Findings Field tests show that with the increase of cushion thickness from 100 to 300 mm, pile-soil load ratio decreases by 51.5%, pile-soil stress ratio decreases by 52.5%, and total settlement increases by 7.9%. As the diameter of pile cap increases from 0.8 to 1.2 m, the pile-soil load ratio increases by 29.0%, the pile-soil stress ratio decreases by 29.2%, and the total settlement is 10.4%. For the regional geological conditions in this work, it is advisable to choose the CFG pile composite foundation with cushion thickness of 100 mm and pile cap diameter of 1.2 m.

Purposes In this study, a functional resonance imaging adaptation (fMRIa) experiment was conducted to examine the multi-level adaptation mechanism in 16 ROIs of the human brain cortex. Methods Random dot stereograms were defined by horizontal binocular disparity as visual stimuli. And six different adaptation conditions were designed to separate different adaptation sources. Adaptation strengthes were measured as changes in the BOLD signal between adaptation and test periods. Findings ANOVA results show that both the dorsal and ventral pathways exhibit advanced adaptation effects to shape attributes. Additionally, adaptations to average disparity information in the V7 and IPS regions along the dorsal visual pathway exist, indicating that low-level disparity computations in these regions are used to precisely encode the depth structure of 3D shapes, while the ventral pathway is used for shape classification. Conclusions These evidences validate the multi-evel adaptation for stereo-curvature aftereffects. The findings can provide guidance for optimizing the construction of stereoscopic scenes in virtual reality.

Purposes Hydrogen energy, as an efficient and clean secondary energy in the 21st century with its high heat value and extremely environmentally friendly combustion products, has become the most promising alternative energy source to replace traditional fossil fuels. The necessity of hydrogen development, promotion, and utilization under the dual-carbon goal of “carbon peaking in 2030 and carbon neutralvty in 2060” as well as the current hydrogen energy development policies and strategic layout in China are analyzed. Methods By investigating the research progresses and achievements of green hydrogen production technologies, the technology of hydrogen production by water splitting and its main devices are summarized, and the development status and trend of hydrogen production by water splitting and the related devices are reviewed. The research status of electrolytic cell and its important components (such as membrane electrode assembly, hydrogen tension bolt assembly and end pressure plate) and the main problems existing in key equipment are analyzed, and the future development trend of alkaline electrolytic cell and proton etchange membrane electrolytic cell are prospected. Conclusion This review provides a reference for the future development of hydrogen production equipment.

Purposes This research has been carried out to investigate the wind load characteristics of dual-slope solar panels. Methods Wind tunnel tests with rigid models were conducted to investigate the effects of wind direction, inclination angle, and panel spacing on the surface wind pressure distributions and shape coefficients of dual-slope solar panels. The experimental results were compared with recommended values specified in three national standards including China, America, and Japan, and the shape coefficients were then suggested. Findings The results show that the extreme value of local shape coefficient occurs at the corner of windward edge of the solar panel at the wind direction of 15°. The most unfavorable wind direction for the overall shape coefficient of dual-slope solar panels is 0°, and the wind loads on the panel increase as the inclination angle increases. For solar panels with large inclination angles, the spacing has a significant influence on the wind loads acting on the structures, and the windward panel is more sensitive to spacing than the leeward panel. When the inclination angle is greater than 15°, the overall shape coefficient of the leeward panel is higher than the specification value for the structure with similar shape as the dual-slope solar panel, as given in the “Load code for the design of building structures” of China.

Purposes This study is conducted to explore the indirect measurement method of mechanical properties of solidified heavy metal contaminated soil. Methods The combined resistivity-unconfined compression test method was carried out to investigate the strength and electrical properties of solid waste solidified contaminated soil. Findings The results show that the red mud-carbide slag-phosphogypsum solidified contaminated soil has higher strength, in which, both peak stress and failure strain increase with the increase of curing age. The solidified soil also exhibits a stable change law between its strength and resistivity. There is a stable variation law between the strength and resistivity of the solidified soil, which shows a good linear relationship. A power function relationship between strain and dynamic resistivity is also observed through stress-strain-dynamic resistivity curve analysis. An electrical characterization model of mechanics is established by replacing the strain with dynamic resistivity in the strain softening model. Coincidence degree of the model is high according to comparison and verification, indicating that the dynamic resistivity change value has high reliability to represent the stress and deformation performances of the solidified soil.

Purposes Carbon dioxide capture and utilization is a choice to alleviate the greenhouse effect and address the energy crisis. In order to promote the reaction under more mild conditions, photothermal catalysis is used to reduce CO2 with the advantages of photocatalysis and thermal catalysis. Thermal energy is generated by photothermal materials (self-heating) or external heat sources. Methods This paper focuses on photothermal catalysis based on photothermal effect (self-heating). Findings At present, the main problems of photothermal catalytic reduction of CO2 to carbon-containing compounds lie in the difficult adsorption and activation of CO2, poor product selectivity and poor photothermal effect. This review summarizes the definition, principle and advantages of photothermal catalysis, focusing on the analysis and summary of strategies to improve the performance of photothermal catalytic reduction of CO2 from the aspects of reaction thermodynamics, reaction path, factors affecting photothermal effect and catalyst modification. The factors that affect the photothermal effect are summarized in detail, including the photoresponse range of the catalyst, the light intensity, the heat storage capacity of the catalyst and the plasmon resonance effect of the metal. Conclusions Future studies should focus on strategies to improve CO2 conversion and product selectivity by using the thermal effect of photoheating, and improve the photothermal conversion efficiency and product selectivity by regulating the morphology and reaction path of the catalyst, so as to realize the industrial application of photothermal catalysis.

In order to solve the problem of high- temperature in the common engineering desalted water during the summer production process of low-temperature styrene-butadiene rubber plant, four heat exchangers were added to the original equipment for improvement. Through the counter current heat transfer method of cold latex passing through the tube side and desalted water passing through the shell side, the low-temperature latex after the polymerization reaction was heat exchanged with desalted water, so as to achieve the purpose of reducing the desalted water temperature. The economic benefits of implementing the technical scheme were evaluated. The results showed that the cold energy utilization technology could effectively reduce the energy consumption of the refrigeration compressor, the amount of circulating water and the consumption of additives, and achieve the purpose of stable control of the reaction.