Interaction Law Research Articles

Efficient visible-light-driven CH4 reforming by covalent organic frameworks: Enhancing the activity of cadmium-based catalyst

Dry reforming of methane to prepare synthesis gas is an innovative and practical solution to the current energy crisis as well as environmental issues such as the greenhouse effect. However, the traditional thermocatalytic methane reforming process has limitations, such as high energy consumption and harsh reaction conditions. Here, a novel strategy for the conversion of CO2 and CH4 is reported: the fast and efficient preparation of CO and H2 using solar energy at ambient temperature. In this work, the covalent organic framework (COF) composite is prepared with the hydrothermal method, and its physicochemical properties are studied using different characterization methods. Then, CdS@COF (CCF) is creatively used in the photocatalytic system of CO2-CH4, and the interaction law between the coupling of different mass fractions of COF and CdS and the performance of photocatalytic CH4 reforming is explored. Notably, the CdS@COF (5/5) catalyst shows the best performance in the photocatalytic conversion of CO2 and CH4, with CO and H2 yields of 640μ mol g−1 and 113.24μ mol g−1, respectively. Additionally, the structure–activity relationship between CdS@COF and the photocatalytic conversion of CO2 and CH4 is studied by density functional theory calculation (DFT), including the demonstration of Z-shaped heterojunctions, the adsorption and activation of CO2 and CH4, and the state density of the composites. Finally, based on isotopic tracer experiments, a possible mechanism for CdS@COF photocatalytic reforming of CH4 is proposed. This work provides new research ideas for designing organic semiconductor composites and achieving carbon neutrality.

Experimental investigation on the propagation of hydraulic fractures in massive hydrate-bearing sediments

Hydraulic fracturing is regarded as one of the potential technical means to realize efficient development of natural gas hydrate. Massive-distributed hydrates are widespread around the world, although the solid fluidization method has been proposed to develop this kind of reservoir, the process of this method is complex, and there are still a lot of key problems need to be solved. Meanwhile, when the hydrate decomposed during production, how to maintain formation stability is still an unsolved key problem. Therefore, we consider using hydraulic fracturing technology to exploit this kind of reservoir. On the one hand, the fractures formed by high viscosity fracturing fluid can improve the reservoir permeability. On the other hand, the proppant added during fracturing can play a good supporting role to the formation. In this work, a series of large-size (300 × 300 × 300 mm) hydraulic fracturing physical simulation experiments were conducted under true triaxial stress states to investigate hydraulic fracture propagation law in massive-distributed hydrate-bearing reservoir. The effects of massive hydrate size, approaching angle and fracturing fluid displacement on the fracture propagation were studied. The experimental results indicated that massive hydrate exerts an important influence on hydraulic fracture propagation. Two main massive hydrate-hydraulic fracture interaction modes were observed in our experiments: (a) When the massive hydrate size is small, the hydraulic fractures mainly propagated along the interface between the sediment matrix and the massive hydrate. (b) The hydraulic fractures penetrated the massive hydrate, which usually occurs when hydraulic fracture encountered large-size massive hydrate, and the penetrated position moves from both sides to the central position of the massive hydrate. The approaching angle has a significant effect on the massive hydrate-hydraulic fracture interaction law. Under the condition of high approaching angle, hydraulic fractures easily penetrated the massive hydrate. The influence of fracturing fluid displacement on massive hydrate-hydraulic fracture interaction is closely related to massive hydrate size. When hydraulic fractures encountered the small-size massive hydrate, increasing the displacement has a limited effect on massive hydrate-hydraulic fracture interaction, and the hydraulic fractures still mainly propagated along the interface. When large-size massive hydrates are distributed in the sample, increasing the displacement has a significant effect on the massive hydrate-hydraulic fracture interaction, and hydraulic fractures tend to branch, the complex fracture geometry would be formed. In this study, a new large-size massive hydrate sample preparation method was proposed, and the effects of various factors on the hydraulic fracture propagation law were investigated experimentally, which can provide guidance for the fracturing design of massive hydrate-bearing reservoir.

Optimization of Composite Grouting Material Proportioning Based on Regression Analysis Method

In order to improve the impermeability of ordinary “cement–water glass” double-liquid grouting material, this study prepares a composite grouting material with sodium bentonite, cement, and water glass as the main materials, water-reducing agent, and early strength agent as activators. In this study, orthogonal tests were conducted using an L16(45) orthogonal table and the test results were analyzed using regression analysis. Using bentonite instead of partial cement, the experimental factors of the bentonite ratio, glass slurry ratio, water-reducing agent admixture, and early strength agent admixture were used to study the laws of single-factor and two-factor interactions on the initial apparent viscosity, setting time, and compressive strength of composite grouting materials. After obtaining the optimal ratio of composite grouting materials, the mechanism of formation of material strength and seepage resistance properties was revealed. The results show that the mass ratio of bentonite to cement and the mass ratio of water glass to slurry have a large effect on the material properties, and there is an interactive effect of several factors at the same time. The optimal ratio of the material is 28.42% water, 36.58% cement, 6.20% bentonite, 0.04% water-reducing agent, 0.9% early strength agent, and 27.85% water glass. The microstructural analysis shows that the denseness of the stone body structure is enhanced, and thus the strength and impermeability of the material are improved. This composite grouting material improves injectability and seepage resistance and is more suitable for underpinning grouting of weakly cemented soft rocks, but the ratio optimization method and model used in this study can be applied to other materials.

Effects of Stage Spacing on Contra-Rotating Propeller Aerodynamic Interactions

To identify the law of aerodynamic interactions of contra-rotating propellers (CRPs) and improve their aerodynamics, this study investigates the aerodynamic interactions of 4 CRPs (six blades in front and six in back) with different stage spacings using the Reynolds-averaged Navier-Stokes (RANS) equations-based method. The results showed that the CRP whose stage spacing was 0.25 times the propeller diameter delivered the highest average efficiency and that the aerodynamic interactions between the front and rear propellers decreased as the spacing widened, and compared with the rear propeller, the front one was more sensitive to stage spacing due to the aerodynamic interaction-generated thrust fluctuations. It can be seen that stage spacing exerts a significant effect on CRP aerodynamic interactions. Therefore, choosing an appropriate stage spacing in CRP design is of great significance to enhance its aerodynamics.

Reactivity of high active aluminum powder with RDX and HMX mixtures

In order to reveal the interaction law of high active aluminum powder with RDX and HMX mixture, the thermal decomposition behavior of highly active Al powder and its interaction with typical nitramine explosive RDX and HMX were studied by differential scanning calorimetry (DSC), thermogravimetry (TG), thermo-mass spectrometry (TG-DTG-DSC-MS) and CO2 laser ignition technology. Results show that when the nanometer aluminum powder and RDX and HMX respectively, two typical nitramine explosive mixing action is of little influence on the mixing action to respond to the thermal decomposition of HMX, depress RDX points liberation degree of temperature, both the thermal decomposition process of mixed system for random nucleation and subsequent growth process, the ignition delay time decreases with the increase of laser ignition power density. The ignition delay time and ignition energy of the mixture of high active aluminum powder and RDX are greater than that of the mixture of high active aluminum powder and HMX and the high active aluminum powder.

A design of laser pyrotechnic device based on fiber laser detonation

In order to meet the application requirements of high performance, high safety and high reliability of laser explosives in future weapons and equipment, this paper tries to solve the problem of interaction reliability between laser and energetic materials, and studies the interaction law between fiber laser and energetic materials with high beam quality. The principle prototype of all-fiber laser ignition with high beam quality is developed. The interaction between high beam quality pulsed laser and energetic materials was studied. Fast and efficient ignition of pulsed fiber laser based on high beam quality is realized. Compared with semiconductor laser, the output brightness of fiber laser is high and the light energy is concentrated under the condition of the same output power, which is conducive to the instantaneous generation of high temperature hot spot when interacting with the agent, which can effectively improve the ignition efficiency. And the photoelectric conversion efficiency is high, can effectively reduce the energy supply. It is an ideal pyrotechnic device which can improve the safety of weapons and equipment in modern war.

Study on Value Symbiosis and Niche Evolution of the Corporate Venture Capital Ecological Community for Innovation and Knowledge

Within the context that global scientific and technological innovation continues to break through discipline constraints and achieve cross-domain group breakthrough development, large enterprises are constantly seeking new ways of opening and enabling. Corporate venture capital (CVC) has become an important way for large enterprises to seize knowledge, achieve symbiotic innovation, and explore external resources. By employing the bionics research method and focusing on the symbiosis mechanism between large enterprises and start-ups, this paper conducts an in-depth analysis on the symbiosis motivation, the composition of the symbiosis system, and the symbiosis environment, and explores the evolutionary simulation after the increase or decrease of resource capacity, the intrusion of the innovation population, or the equipotential integration into the innovation ecosystem when the external environmental factors change to verify the coordinated development within the enterprise population and between the enterprise population and the environment. The results show that: (1) The symbiosis, self-consistency, evolution, spillover, and other effects within the CVC ecological community fully realize the “positive sum game” process of both sides; (2) The large enterprise population and entrepreneurial enterprise population in the CVC ecological community form a two-dimensional symbiotic system; and (3) When the resource capacity of the innovation ecosystem changes, the innovation population invades the system with a strong jump in the queue, and the innovation population participates in the system with a weak allelic fusion. This paper points out the influence, interaction, and evolution development laws between enterprise species, enterprise groups, and the innovation system environment and enriches and expands the theory of the relationship between venture capital and enterprise innovation.

Optimal predictive guidance law based on guidance law identification using variable structure interactive multiple guidance law model

For a defender protecting a target from an incoming high-maneuvering homing missile, an Optimal Predictive Guidance Law (OPGL) is proposed based on a guidance law identification algorithm. First, a guidance law identification algorithm based on the Interactive Multiple Guidance law Model (IMGM) is designed. IMGM uses multiple sub-filters for parallel processing, and there is interaction between the inputs and outputs of the sub-filters. Second, the VSIMGM algorithm is further designed based on the IMGM algorithm. In this algorithm, a new guidance law model subset is constructed based on the original guidance law model set. By reducing the number of models, the model error is reduced, and the identification probability of the guidance law model is improved. Then, based on the identification result of the identification algorithm, the OPGL is given by using the variational method through the steps of linearizing the kinematic model and reducing the order of state equation. The OPGL reduces the overload requirement of the defender and improves interception accuracy without assuming the maneuver mode of a homing missile. Finally, the effectiveness of the proposed OPGL and guidance law identification algorithm based on VSIMGM is demonstrated using numerical simulation. Compared with the guidance law identification algorithm based on MMAE and IMGM, the guidance law identification algorithm based on VSIMGM can quickly, stably, and accurately identify the guidance law. In addition, based on the guidance law identification results of the homing missile, compared with proportional navigation, augmented proportional navigation, differential game guidance (DGG), and sliding mode guidance (SMG), OPGL can reduce the required overload of the missile and achieve accurate interception.

Synergistic Effects of Epoxidized Soybean Oil and Polyester Fiber on Crumb Rubber Modified Asphalt Using Response Surface Methodology.

The incorporation of crumb rubber (CR) into asphalt pavement materials can improve the performance of asphalt pavement and generate environmental benefits. However, the storage stability of the crumb rubber asphalt (CRA) remains an issue that needs to be resolved. This study explores the interaction laws among various modified materials based on the response surface methodology. Optimal preparation dosages of each material are determined, and performance predictions and validations are conducted. The storage stability of the CRA compounded with epoxidized soybean oil (ESO) and polyester fiber (PF) is investigated by combining traditional compatibility testing methods with refined characterization methods. The results indicate that the modification of CRA exhibits better rheological properties when the percentages of CR, PF, and ESO are 22%, 0.34%, and 3.21%, respectively. The addition of ESO effectively complements the light components of CRA to improve asphalt compatibility, and the addition of PF alleviates the adverse effects of ESO's softening effect on rheological properties through stabilization and three-dimensional strengthening. The scientifically compounded additions of ESO and PF can effectively enhance the storage stability and rheological properties of CRA, promoting the development of sustainable and durable roads.

Numerical modeling of a majestic masonry structure: A comparison of advanced techniques

The present study aims to provide a comparative analysis between discontinuous models (DM) and continuous models (CM) for the analysis of majestic masonry structures subjected to seismic events. Specifically, the study models the ‘Santa Maria Annnuziata’ church damaged after the Central Italy earthquake sequence in 2016 and 2017 years. The DM is evaluated using different types of interaction laws between blocks: the Discrete Element Method (DEM) and the Non-Smooth Contact Dynamic method (NSCD). The nonlinearity of the material in the CM, instead, is considered using the Concrete Damage Plasticity model (CDP). To assess the models' effectiveness in identifying vulnerable elements, non-linear dynamic analysis is performed through the main earthquake events recorded nearby the church during the Central Italy earthquake. Following this, the models are subjected to the 7.8- magnitude earthquake that occurred in February 2023 in Turkey to observe the damage evolution under higher magnitude events. The primary objective of this study is to improve the understanding of the strengths and weaknesses of both models and their potential applications in the analysis of historic masonry structures.

Spin Currents Induced in Open-Shell Molecules by Static and Uniform Magnetic and Electric Fields in the Presence of a Spin-Orbit Coupling Interaction and Conservation Law.

The derivation of the total induced current density vector field, in the presence of static and uniform magnetic and electric fields, is illustrated in a more clear and formally correct language together with a discussion on the charge-current conservation law not presented before for the spin-orbit coupling contribution. The theory here exposed turns out to be in fully agreement with the theory of Special Relativity and it is applicable to open-shell molecules in the presence of a nonvanishing spin orbit coupling. The discussion here exposed turns out to be accurately valid for a strictly central field due to the chosen approximation of the spin-orbit coupling Hamiltonian, but it is appropriate to deal correctly with molecular systems. The ab initio calculation of spin current densities has been implemented at both unrestricted Hartree-Fock and unrestricted DFT levels of theory. Some maps of spin currents on molecules of interest, i.e., the CH3 radical and the superoctazethrene molecule are also illustrated.

Indirect magnetic signals in Weyl semimetals mediated by a single Fermi arc

Recently, abundant transport phenomena characterizing the surface states of Weyl semimetals (WSMs) have been reported. To generate these phenomena, electrons have to complete a closed intersurface orbit. Due to the unavoidable impurities in real materials, this orbit could be destroyed by the impurity scattering, which limits the detection of the surface states in WSMs. Here, we investigate the RKKY interaction between magnetic impurities, solely mediated by a single surface band, in semi-infinite WSMs. It is found that peculiar oscillations and slowly decaying laws of the RKKY interaction can act as the signals to capture the dispersive nature of the surface states of WSMs. The underlying physics is attributed to two effects: the band-edge effect and the bending effect of the surface band, which can control the RKKY interaction individually or compete with each other to produce more complex magnetic behaviors. In addition, the band-edge effect together with the finite Fermi energy would result in another interesting oscillation with battering pattern. All the results are significantly different from that in previous literatures where surface states have to couple with bulk states (or other surface states of different spins) to generate nonzero magnetic interaction. Compared to the previous models of surface states, the model here is more practical and is helpful for the deeper understanding of the surface magnetic properties in WSMs.

Extruded 3D Printing Assisted Electrochemical Additive Manufacturing

This essay investigates an additive manufacturing technique of an extruded 3D printing-assisted electrochemical deposition. The effects of solutions with different additive (Cl− and brightener) concentrations on the surface micromorphology and deposition rate of the formed films were investigated by using characterization data from test tools such as an electrochemical workstation, X-ray diffractometer, and scanning electron microscope, as well as discussing the laws of interaction between these two additives during the electrodeposition process. The experimental results show that when the concentration of Cl− in the copper plating solution is 2×10−3 mol/L and the brightener concentration is 10 ml/L, the electrodeposition experiments yielded deposited copper films with a significantly preferred orientation on the (111) crystal plane, and the prepared copper film has thicker deposited film and better surface quality. To validate the additive manufacturing method for extruded 3D printing-assisted electrochemical deposition, deposition experiments of 25-layer copper samples were carried out utilizing the best process parameters.

An analytical self-consistent model for the adhesion of Gibson solid

A full self-consistent model (FSCM) for the adhesive contact between an axisymmetric rigid punch and a Gibson solid (an incompressible, linear graded elastic material) is established, which gives a self-consistent relation between the surface gap and interaction. Power-law shaped indenters and the Lennard–Jones interaction law are studied as representative cases, and the self-consistent equation is expressed in a dimensionless form with two independent parameters, namely the shape index and the Tabor number. The self-consistent equation for Gibson solid is a higher order polynomial equation with respect to the surface gap, which differs from the nonlinear integral equation for power-law graded elastic material. By taking the surface gap as the independent variable instead of the radius, the self-consistent equation is solved explicitly, which gives the first explicit form of the solution to an FSCM. When the Tabor number exceeds a critical value, jump-in instability and adhesion hysteresis occur, and the folding phenomenon that the Gibson solid surface is flipped and folded along the radial direction is observed. The critical Tabor number is determined in an explicit form and it is found to be independent of the surface index. The extended Maugis–Dugdale (M–D) model for Gibson solid is invalid when the Tabor number is large enough and the extended Johnson–Kendall–Roberts (JKR) model does not present the soft limit, due to their assumption of simple contact. An asymptotic solution is derived for the soft limit of the FSCM, which gives a power-law asymptotic relation between the dimensionless pull-off force and the Tabor number. This study provides a self-consistent toy model for the adhesive contact of Gibson solid and may deepen the understanding on the adhesion of graded materials.

Research on the Control Performance of Depth-Fixed Motion of Underwater Vehicle Based on Fuzzy-PID

The control performance of the fixed-depth motion is related to the performance of the underwater vehicle. Due to the complex and changing environment underwater and various potential risks, the variety of underwater operations, and the variability of the structural parameters and environmental parameters of the underwater vehicle, the control performance is compromised when performing constant depth motion. It is of much significance to study the control method of the fixed-depth motion to improve the performance of the underwater vehicle. The transfer function of underwater vehicle’s depth-setting motion was established, and the fuzzy-PID controller was established for simulating the control of depth-setting movements of underwater vehicles. The interaction law between PID initial parameters and controller performance was studied, and the interaction law between the change of underwater vehicle mass and the hydrodynamic coefficient and controller performance was also studied. The results show that the fuzzy-PID controller can realize the control of the underwater vehicle’s depth-setting motion, and the control effect was independent of the initial PID parameters, thus avoiding the dependence of the formulation of PID parameters on manual control experience. When the mass and hydrodynamic coefficient of the underwater vehicle change, the fuzzy-PID controller can still maintain good control performance and has strong adaptive ability.

Numerical study of the effect of heat-flow coupling on interface instability based on front tracking

The interfacial instability of two-phase immiscible fluids in inclined tubes at constant temperature boundary conditions is numerically investigated by the front-tracking method. By analyzing the effects of inclination angle φ, Marangoni number (Ma), and Rayleigh number (Ra) on the interfacial instability, the interaction law between unstable interface fluctuation and heat transfer is studied. The results show that the larger the inclination angle, the easier the interface is destabilized, and the heat transfer at the interface will also decrease. In the comparison of inclination angles of 0°, 30°, 45°, and 60°, the heat transfer is more stable at 45°. The heat flux between fluids decreases with the increase of Ma number, and Ma number has little effect on the interfacial fluctuation. It mainly affects the interfacial morphology by changing the surface tension gradient at the interface, which is mainly reflected in the end of the convolution interface. The larger the Ma number, the more inward the interface develops. Ra number has an obvious inhibitory effect on the interfacial instability. The effect of Ra number on heat-flow transfer at the interface shows alternating changes. In the initial stage, the heat transfer between fluids in the inclined tube is greater than that in the horizontal tube, but in the later stage, the heat transfer is less than that in the horizontal tube.

Behavioral pathway analysis of pedestrian injury severity in pedestrian-motor vehicle crashes

Despite the health and environmental benefits of walking as an active and sustainable mode of transport, the increasing number of road crashes involving pedestrians has become a public health concern. This study investigates the direct and indirect effects of various contributing factors on pedestrian injury severity in pedestrian-motor vehicle crashes. Data on pedestrian-vehicle crashes from North Carolina between 2015 and 2019, including the pedestrian pre-crash actions and injury severity, were used. Path analysis was applied to uncover the inter-relationship between contributing factors, pedestrian pre-crash behaviors, and injury severity using random parameter ordered logit and mixed logit models. The results indicate that pedestrian intoxication, lighting condition, number of lanes, speed limit, and vehicle type contribute directly and indirectly (through pre-crash behaviors) to increasing injury severity. It was also observed that pedestrian position and traffic control directly decreased injury severity but indirectly increased injury severity through pre-crash behaviors. This study provides valuable information about the relationship between various crash factors and pedestrian injury severity. For researchers and agencies interested in pedestrian safety improvements, this study gives valuable insight by uncovering the roles of pedestrians’ pre-crash action on injury severity outcomes. For countermeasures, the study recommends better street lighting and re-evaluation of posted speed limits on roads with high pedestrian traffic. A regular educational campaign should inform pedestrians of the importance of yielding to motorists at locations without crosswalks. Also, drivers’ compliance with existing pedestrian-vehicle interaction laws should be monitored, especially at intersections.

Novel solutions of (2+1) dimensional modified Bogoyavlenskii’s breaking soliton equation with variable coefficients

In this paper, by using the homogeneous equilibrium method, the exact solutions of a modified Bogoyavlenskii’s breaking soliton equation are derived and the soliton solutions with arbitrary functions are constructed. Then, the basic law of interaction between the different solitons are revealed and some new local structures are addressed and discussed. The periodic solitons, parabolic solitons and folded solitons of arbitrary shape propagating with variable speed are considered. It is helpful not only to verify the numerical solution and analyze the stability of the solution, but also to understand the dynamics of the high dimensional nonlinear wave field.

Thermal Modeling of Polyamide 12 Powder in the Selective Laser Sintering Process Using the Discrete Element Method.

Selective laser sintering (SLS) is one of the key additive manufacturing technologies that can build any complex three-dimensional structure without the use of any special tools. Thermal modeling of this process is required to anticipate the quality of the manufactured parts by assessing the microstructure, residual stresses, and structural deformations of the finished product. This paper proposes a framework for the thermal simulation of the SLS process based on the discrete element method (DEM) and numerically generated in Python. This framework simulates a polyamide 12 (PA12) particle domain to describe the temperature evolution in this domain using simple interaction laws between the DEM particles and considering the exchange of these particles with the boundary planes. The results obtained and the comparison with the literature show that the DEM frame accurately captures the temperature distribution in the domain scanned by the laser. The effect of laser power and projection time on the temperature of PA12 particles is investigated and validated with experimental settings to show the reliability of DEM in simulating powder-based additive manufacturing processes.

Research on cutter surface shapes and rock breaking efficiency under high well temperature

The cutter is the main cutting element for breaking rock, and the interaction laws between the cutter with different surface shapes (abbreviated as cutter shapes) and rocks are different. The rock breaking mechanism of PDC circular cutter, elliptical cutter and ridge cutter on different rocks is studied by experiment and simulation, which the results show that the ridge cutter has the strongest penetration ability, followed by elliptical cutter, and the PDC circular cutter have the weakest when scraping rocks with different temperatures. Compared with circular cutter scraping granite, the crushing specific work of elliptical cutter and ridge cutter is reduced by 9%–11% and 18%–28% respectively. When scraping sandstone, the crushing specific work decreases by 9%–18% and 14%–24% respectively, and the ridge cutter have the largest debris and particle size. The 3D cutters such as ridge cutter have the largest damage value to the rock, which is easier to reduce the rock strength, and the rock breaking efficiency is higher. Compared with the circular PDC cutter, the maximum cutter edge Cpress stress of Benz cutter, ridge cutter and elliptical cutter decreased by 52.9%, 52.4% and 16.8% respectively, the stress fluctuation in Benz and ridge cutter is smaller than that in circular cutter, which is conducive to prolonging the cutter working life. The 3D cutter, such as ridge and Benz cutter are conducive to prolonging the working life when drilling high hardness, strong abrasiveness and high temperature formations.