Force Mechanism Research Articles

A multi-verse Optimizer Approach Based on a Salp Swarm for Image Feature Selection to Observe Changes in Urban Lands

Many changes have occurred in most urban areas, and it is usually governed by many geographical and social factors, the result will be either the expansion or contraction of these cities. In this paper, an optimizer method called salp swarm optimization (SSO) is used to build a driving force model for urban lands according to the changes in the driving force mechanism. The principle of (SSO) is extracting the driving force classification rules corresponding to different types of land use change samples by imitating the behavior of salp. The classification rules are constructed in the form of "IF ... THEN", and three different fitness functions are selected for simulation verification. The data set used in this search represents images from Global Positioning System (GPS) satellites and remote sensing data. The experimental results show that the overall accuracy evaluation of the salp swarm optimization model is superior to other algorithms, indicating that the SSA is feasible for land use change modeling.

Exploring mechanisms of asymmetric droplet impact dynamics on roughness gradient surface

Droplet impact on surfaces with varying roughness and wettability is a common phenomenon in both natural and industrial environments. While previous studies have primarily examined asymmetric droplet rebound driven by impact velocity or Weber number, the influence of surface structure and associated impact mode transitions has received less attention. In this study, molecular dynamics simulations and detailed analyses are employed to investigate the mechanisms governing droplet rebound on nanopillar arrays with gradient distributions. Results reveal that nanopillar height significantly influences rebound direction, with two distinct directional transitions occurring as the height increases. Additionally, the effects of surface structure and Weber number on impact patterns, rebound velocity, and contact time are systematically evaluated, with contact angle calculations shedding light on the underlying force mechanisms. A phase diagram is developed to illustrate the relationship between rebound direction, Weber number, and nanopillar height. The study further extends the analysis to substrates with bidirectional gradient distributions, demonstrating consistency with single-directional gradient results and validating the broader applicability of the findings. This research provides critical insights into droplet dynamics on roughness gradient surfaces, emphasizing the role of nanopillar height and impact mode in controlling droplet behavior and highlighting potential applications in the design of structured array surfaces.

The complementary and substitutional effects of forced and emergent mechanisms in multisourcing

This paper examines the effect of forced and emergent competition- and cooperation-enhancing mechanisms on joint multisourcing performance. We draw on research on coopetition in IS multisourcing and the literature on the crowding-out effect to theorise the interplay between these mechanisms. We argue that the key to understanding whether these mechanisms complement or substitute each other lies in the distinction between forced and emergent mechanisms, as these respectively invoke either an economic or a social logic among vendors.We test these ideas through a survey study of 108 multisourcing arrangements. Our results show that while a forced competition and an emergent cooperation mechanism can individually improve joint performance inmultisourcing, the co-existence of economic and social logics results in a substitutional effect.A complementaryeffect is achieved when competition andcooperation mechanisms are of the same logic. Our study extends the existing IS outsourcingliterature by shedding light on the role of forced andemergent mechanisms, either as competition or cooperation-enhancing, in enhancingmultisourcingperformance.

Coal‐wall spalling prevention mechanism using advance‐grooving pressure relief in the large‐mining‐height working face of a shallow coal seam

AbstractIn mining, the roof structure of a working face with a large mining height in a shallow‐buried coal seam is prone to cutting instability in front of the support, which causes support crushing and coal‐wall spalling. This study analyzes 2201 working faces with large mining heights in the Haiwan No. 3 Mine by investigating the mechanical response law of coal walls under the transient excitation of roof structure instability. A mechanical model of coal walls under dynamic and static load coupling is established, revealing the formation mechanism of coal wall spalling and its main influencing factors. Prevention and control technologies of advanced grooving and pressure relief are proposed, and grooving parameters are determined. The results show that: During the mining process of large mining height working face in shallow buried coal seam, the step change of static response of coal wall is induced by the transient instability of roof structure, and the high abutment pressure is formed on the coal wall. At the same time, the strain energy and gravitational potential energy of roof cutting instability are released to form a dynamic load. Under the action of dynamic and static load, the plastic failure dissipation power of the coal wall is greater than the critical power, and the coal wall spalling occurs. The main influencing factors are mining load, mining height, and internal friction angle of the coal wall. The method of advanced grooving pressure relief can change the roof structure and coal force mechanism, by cutting off the connection between the coal wall and immediate roof, reducing the height of the coal wall force, effectively controlling the position of the roof cut off break line, reducing the static load effect of the roof on the coal, and transferring the position of the dynamic load response to the depth of the coal wall. When the grooving height‐depth ratio k is 0.75, the peak value of the abutment pressure moves 5.57 m to the front of the working face, and the pressure relief effect is the best. The above research results provide an effective active protection method for controlling coal wall spalling in fully mechanised working face with large mining height.

Force mechanism analysis of composite microbial dust suppressants based on extracellular polymeric substances (EPS) mode components

As an important potential dust suppression method, the slow onset time is one of the key factors that restrict the effect of microbial dust suppressant. In the early stage, we have confirmed that extracellular polymeric substances (EPS) can improve the dust suppression effect by wetting coal dust and increasing Ca2+ nucleation sites. Therefore, in this study, chitosan (CTS) and bovine serum albumin (BSA) in different ratios (CTS: BSA = 1:1, 1:2, 2:1) as model molecules of EPS were combined with Bacillus subtilis to prepare efficient and fast microbial dust suppressants. Furthermore, the interaction forces were analyzed through molecular dynamics simulation. Results showed that adding CTS and BSA would improve the dust suppression effect, and the dust suppression effect was the best when the ratio of CTS: BSA was 1:2. In addition, the contact angle decreased as the BSA content increased. The Fourier transform infrared spectroscopy (FTIR) results showed that when the ratio of CTS to BSA was 1:2, the dust suppressants were easier to interact with coal dust by the key functional groups and form calcite type CaCO3. The molecular dynamics simulation results showed that the main interaction was Van der Waals force. In addition, the interaction force was strongest when CTS: BSA was 1:2, increasing by 137% compared with the microbial dust suppressants without CTS or BSA. This study provides theoretical support for the development of efficient and rapid microbial dust suppressants.

Study on the Promotional Effect and Mechanism of New Quality Productive Forces on Green Development

The new quality productive forces have the potential to spur both the green transformation of the industrial structure and innovative advances in green technology, which will further strengthen the foundation for sustainable growth. This study analyzes panel data from 30 provinces between 2012 and 2022 to build an evaluation system for new quality productive forces and green development at the provincial level. The entropy weight TOPSIS approach is used to assign weights to each indicator. Methods including fixed effects, mediation effects, and spatial econometrics are used to examine the contribution of new quality productive forces to green development and its mediation mechanism. The study finds that: (1) New quality productive forces significantly promote green development, and the conclusion still holds after a robustness test using the instrumental variables method and excluding municipalities. (2) The new quality productive forces contribute significantly to green development by improving technology and optimizing industrial structure. (3) The new quality productive forces not only directly enhance the green development level of the region, but also positively influence the green development level of the neighboring regions through the spatial spillover effect. (4) The eastern and central regions are more affected by new productivity in terms of green development. Based on these, efforts should be made to develop new quality productive forces, increase technological research and investment, and promote the development of industrial structure to be more environmentally friendly and efficient to promote green development.

The shear performance of DSCW-RC joints with lap-spliced steel bars

The double steel plate concrete composite shear wall (DSCW) structure combines the advantages of steel and concrete, offering high strength, stiffness, and durability. The joint formed by the DSCW and reinforced concrete foundation (RC foundation) was often unavoidable in engineering practice. Research related to the mechanical behavior of the DSCW-RC foundation is limited. This paper investigated the shear performance of DSCW-RC joints with lap-spliced steel bars. A total of seven specimens were designed and tested. The influences of steel plate thickness, steel bar arrangement, and stud spacing on the shear behavior of the joints are elucidated. The test results indicate that the predominant failure mode of the specimens occurred in the upper part of the local steel plate, with reinforcement yielding. While steel bar diameter and stud spacing minimally affected the shear strength, they significantly influenced the failure displacement at the joint interface. The failure deformation increased with increasing steel bar diameter and decreased with increasing stud spacing. Moreover, the thickness of the steel plate profoundly impacted structural shear strength and deformation, with both deformation and bearing capacity increasing with plate thickness. In addition, this study explores the force-transferring mechanism of such joints under shear load, offering a crucial reference for subsequent analyses of the composite force mechanism of DSCW - RC foundation joints.

Force-mediated recruitment and reprogramming of healthy endothelial cells drive vascular lesion growth

Force-driven cellular interactions are crucial for cancer cell invasion but remain underexplored in vascular abnormalities. Cerebral cavernous malformations (CCM), a vascular abnormality characterized by leaky vessels, involves CCM mutant cells recruiting wild-type endothelial cells to form and expand mosaic lesions. The mechanisms behind this recruitment remain poorly understood. Here, we use an in-vitro model of angiogenic invasion with traction force microscopy to reveal that hyper-angiogenic Ccm2-silenced endothelial cells enhance angiogenic invasion of neighboring wild-type cells through force and extracellular matrix-guided mechanisms. We demonstrate that mechanically hyperactive CCM2-silenced tips guide wild-type cells by transmitting pulling forces and by creating paths in the matrix, in a ROCKs-dependent manner. This is associated with reinforcement of β1 integrin and actin cytoskeleton in wild-type cells. Further, wild-type cells are reprogrammed into stalk cells and activate matrisome and DNA replication programs, thereby initiating proliferation. Our findings reveal how CCM2 mutants hijack wild-type cell functions to fuel lesion growth, providing insight into the etiology of vascular malformations. By integrating biophysical and molecular techniques, we offer tools for studying cell mechanics in tissue heterogeneity and disease progression.

Numerical investigation and seismic performance evaluation of an innovative prefabricated structural system

This paper focuses on an innovative structural system with separated gravity and lateral resisting systems (SGLR system), which is suitable for multi-story prefabricated buildings and demonstrates different seismic performance from the traditional rigid frame system (RF system). Elaborate three-dimensional (3D) finite element models for RF and SGLR systems are established and verified by test results. Based on the numerical models, the load-displacement relationship, force mechanism, energy dissipation capacity, local buckling, and stress and strain distribution of SGLR system are investigated in detail in comparison with RF system. In order to conduct the seismic performance evaluation, four groups of RF and SGLR substructures are designed with different lateral stiffness. Pushover analysis and response spectrum analysis are carried out, and safety factors are calculated on the basis of the incremental N2 method. It is indicated that SGLR system has lower loading capacity, smaller safety margin but larger deformation capability than RF system with the same lateral stiffness. Considering that the inter-story drift ratio is a common design index, more stringent design requirements should be proposed for SGLR system to obtain seismic performance equivalent to that of RF system.

On the use of fractal geometry to boost galloping-based wind energy harvesting

In this study, we introduce fractal bluff bodies to galloping energy harvesters (GEH) to improve the performance of wind energy harvesting. Three basic sectional shapes are proposed for GEH, from which four fractal bluff bodies are developed. An aero-electro-mechanical model with distributed parameters is established to elucidate the underlying mechanism. Then numerical simulations and wind tunnel tests are conducted based on a fabricated prototype. Compared with the conventional galloping energy harvester with a cuboid bluff body (GEH-CB), the GEH with a fractal bluff body (GEH-FB) owns a lower cut-in wind speed and can generate higher voltages. The galloping critical wind speed for GEH-FB is reduced by 0.4 m/s. Furthermore, the output voltage can increase by 51.97% at the wind speed of 5 m/s. Especially, compared to the GEH-CB, the GEH-FB demonstrates a great advantage in terms of power density, being approximately 164.1% higher. Three-dimensional computational fluid dynamics (3D-CFD) shows that the wake vortex area and the space between the adjacent vortices both increase, which explains the aerodynamic mechanism of a large aerodynamic force and a performance enhancement in wind galloping energy harvesting. Finally, some practical application tests exhibit the effectiveness of the proposed fractal galloping harvesters.

Experimental analysis of quasi‐static indentation in composite sandwich multilayers with corrugated core

AbstractThis study examines the effects of multilayering in sandwich panel composite structures with different corrugated core configurations under quasi‐static indentation loading. The panels were fabricated using woven glass fibers and epoxy resin via the Vacuum Infusion Process. Experiments were conducted using two hemispherical cylindrical indenters with a diameter of 20 mm (ID = 20 mm) and 10 mm (ID = 10 mm) and the behavior of the composite structure in terms of contact force and fracture mechanisms for different core corrugations (square and butterfly) were investigated in two ways with foam and without foam. The experimental results demonstrate that, among corrugated core geometries without foam, butterfly cores outperform square cores in terms of structural strength, maximum force, moment force, energy absorption, specific energy absorption, and displacement until full indentation. Moreover, the butterfly core shows a higher peak load and different failure mechanisms compared to the square core. Under loading with a 10 mm indenter, the butterfly core without foam only experienced perforation in the loading area, without fracture completely. Also, adding foam did not change failure mechanisms and mechanical behavior in the butterfly geometry. However, in the square geometry, foam filled gaps between the core, preventing fracture completely and leading to only perforation in the loading area, unlike the specimen without foam. The visual analysis during the quasi‐static indentation process revealed several significant damage mechanisms, including matrix cracking, fiber breakage, delamination, buckling and crushing of cell walls, damage to top sheets, core separation, and complete indentation of the samples.Highlights Delamination and indentation failure mechanisms were seen on the butterfly core. Skin indentation and rib fracture failure mechanisms were seen on the square core. Butterfly corrugated cores revealed the best performance without/with foam. The core shape was more effective on the strength than the foam addition.

The Impact of New Quality Productive Forces on Carbon Emissions in Manufacturing Enterprises

The article innovatively explores new quality productive forces, focusing on their core role in driving carbon emissions. It investigates new quality productive forces' mechanisms and development pathways within the new economic environment. The paper delves deeper into the intrinsic connections between new quality productive forces and carbon emissions than existing research. Firstly, the paper investigates the impact and transmission mechanisms of China's new quality productive forces on green development. It calculates the carbon emissions of 2,364 manufacturing companies listed on the Shanghai and Shenzhen stock exchanges from 2011 to 2021. The study's empirical findings indicate that new quality productive forces promote carbon emissions reduction for publicly listed companies in the manufacturing sector. Lastly, the regression formula includes the number of patents listed companies hold. It is to consider the relationship between new quality productive forces and carbon emissions.

Optical force and torque in near-field excitation of C3H6: A first-principles study using RT-TDDFT.

Optical trapping is an effective tool for manipulating micrometer-sized particles, although its application to nanometer-sized particles remains difficult. The field of optical trapping has advanced significantly, incorporating more advanced techniques such as plasmonic structures. However, single-molecule trapping remains a challenge. To achieve a deeper understanding of optical forces acting on molecular systems, a first-principles approach to analyze the optical force on molecules interacting with a plasmonic field is crucial. In our study, the optical force and torque induced by the near-field excitation of C3H6 were investigated using real-time time-dependent density functional theory calculations on real-space grids. The near field from the scanning tunneling probe was adopted as the excitation source for the molecule. The optical force was calculated using the polarization charges induced in the molecule based on Lorentz force. While the optical force and torque calculated as functions of the light energy were in moderate agreement with the oscillator strengths obtained from the far-field excitation of C3H6, a closer correspondence was achieved with the power spectrum of the induced dipole moment using near-field excitation. Time-domain analysis of the optical force suggests that the simultaneous excitation of multiple excited states generally weakens the force because of mismatches between the directions of the induced polarization and the electric field. This study revealed a subtle damping mechanism for the optical force arising from intrinsic electronic states and the influence of beating.

Research on the driving factors and impact mechanisms of green new quality productive forces in high-tech retail enterprises under China's Dual Carbon Goals

In recent years, the issue of global climate change has become increasingly severe, prompting countries worldwide to intensify their control over carbon emissions to achieve sustainable development goals. As a crucial component of the modern economy, high-tech retail enterprises significantly influence the entire industry's sustainable development through technological innovations and business models. This study focuses on Chinese high-tech retail enterprises, employing a theoretical framework grounded in Resource Dependency Theory and the dialectics of productive forces and relations from a Marxist political economy perspective, supported by Structural Equation Modeling (PLS-SEM). The study identifies the degree of green technology application, corporate environmental policy response strategies, and consumer environmental awareness and demand as mediating variables. The aim is to deeply explore the impact mechanisms driving green and new-quality productivity in Chinese high-tech retail enterprises and to provide an in-depth understanding of the sustainable development of their green and new-quality productivity. The findings indicate that external resources such as policy support, technological innovation, and market demand significantly impact the green productivity of high-tech retail enterprises. Government environmental policies and subsidy measures provide institutional safeguards and resource support for enterprises; technological innovation drives the application and efficiency improvement of green technologies; and market demand for environmentally friendly products promotes the green transformation of enterprises. The study explores how enterprises can integrate different external resources to maximize the benefits of green productivity, including formulating policy response strategies, strengthening technological innovation and R&D investment, seizing market opportunities, and establishing cooperative relationships. These findings offer necessary theoretical support and practical insights into the resource dependency strategies and the mechanisms impacting the development of green productivity in high-tech retail enterprises. This study provides valuable theoretical and practical references for high-tech retail enterprises in promoting the development of green and new-quality productivity. It offers valuable suggestions and guidance for enterprise decision-making and policy formulation. By revealing the dialectical interaction between external resources and internal production relations, this study provides a systematic path analysis and strategic recommendations for achieving the Dual Carbon goals.

Research on column overdesign factor of reinforced concrete frame structures in the 2022 Ms 6.8 Luding earthquake

The strong column-weak beam failure mode of reinforced concrete (RC) frame structures is one of the most important targets of structural seismic design and is primarily realized by a reasonable column overdesign factor (COF). However, most RC frame structures in previous earthquakes were often subjected to strong beam-weak column failure modes. To address this issue, the RC frame with a strong column-weak beam failure mode and a typical strong beam-weak column RC frame in the 2022 Ms 6.8 Luding earthquake were intensively studied in this study. The differences between the two failure modes of the RC frame structure were comparatively analyzed at both the overall structure and member levels. A numerical simulation was conducted to obtain the structural response under actual ground motion. Finally, a probabilistic analysis method was adopted to process the COF data of the RC frame joints. The results indicate that the structural safety redundancy of the RC frame with the undesired failure mode cannot be fully utilized, whereas the RC frame with the strong column-weak beam failure mode allows more structural members to participate in the energy dissipation through a complex redistribution mechanism of internal forces. Damage to the infill wall further mitigates the degree of damage to the main structure and reduces the risk of soft-story failure. The COF of the actual RC frame structure shows a non-uniform distribution, and it is recommended that the COF be higher than 1.5 for the seismic design of the structure following the Chinese code.

The Generation Mechanism of the Side Force and Yawing Moment of a Rotating Missile with Wrap-Around Fins

The rotation of a missile generates a side force perpendicular to the plane containing the attack angle and produces a yawing moment that tilts the body out of the plane, significantly affecting the flight stability of rotating missiles. The non-planar asymmetry of the wrap-around-fin rotating missile determines its more complex rotational effects. This study utilizes the dual time-step method to solve the unsteady Navier–Stokes equations, investigating the characteristics of the side force and yawing moment of the wrap-around-fin rotating missile under supersonic conditions and uncovering the mechanism behind the generation of the side force and yawing moment. The results reveal that the side force and yawing moment of the wrap-around-fin missile are composed of static values and induced values from rotation. The static side force and yawing moment of the wrap-around-fin missile are not zero, while those of the flat-plate-fin missile are zero. This difference is primarily caused by the non-axisymmetric nature of the wrap-around fin, resulting in the static side force and yawing moment of the wrap-around-fin missile being 40% greater than those of the flat-plate-fin missile. The rotation of the missile increases the effective angle of attack on the convex surface of the fin and decreases it on the concave surface, leading to an imbalance in the pressure changes on the windward and leeward sides. This is the main reason for the generation of the induced side force and yawing moment due to rotation. The induced values from rotation vary linearly with the rotation rate, and their magnitudes can be several times those of the static values.

A Critical Review of the Crucial Role of the Yellow River's Sediment in the Interfacial Migration and Fate of Pollutants and Prospects for the Application of Environmental Sediment Restoration.

Considering the increasing sediment content and increasing sediment flux of the Yellow River over the years, it is of significance to investigate the potential interfacial force mechanism between pollutants and Yellow River sediment. This article has reviewed the current research on the Yellow River sediments' mineral structures while investigating the potential interaction force between sediment and pollutants in the water environment. This article has conducted a comprehensive analysis of the influence of sediment on the migration of pollutants in the water environment. What is more, the authors have provided an outlook on the future applications of sediment in ecological environmental systems. Yellow River sediment mainly included minerals and some clay phases, while its irregular surface provided sites for the interface adsorption of pollutants. The interface force between the sediment and pollutants is mainly attributed to promoting bacterial growth on the surface of sediments, physisorption, and chemisorption forces. The sediments carry and transport pollutants during the long-distance water flow migration process. The sediment should be effectively utilized and better integrated into ecological or environmental restoration systems. This article provides a reference for studying the behavior of Yellow River sediment and the direction of future efficient utilization.

Bubble adhesion dynamics on solid surfaces: Interfacial behavior, force, and energy perspectives using a self-developed dynamic force testing system

Bubble-solid surface adhesion is crucial for industrial processes such as wastewater treatment, and the separation of minerals, plastics, and biomass. In this paper, a novel dynamic force testing system was developed to provide a detailed understanding of bubble-solid adhesion dynamics by simultaneously collecting “time-displacement-force” signals and capturing real-time images. The interfacial behavior and force mechanisms of bubble adhesion to solid surfaces with varying hydrophobicity were investigated. Higher hydrophobicity results in more pronounced “snap-in” adhesion and greater adhesion strength. Instead of fully detaching, bubble breaks at the capillary neck and leaves a microbubble on the solid surface, whose size increases with hydrophobicity, indicating different interfacial behaviors in subsequent reaction. The evolution of Laplace force and surface tension force was further analyzed and the toroidal approximation shows over 60 μN error in Laplace force calculation for large bubble deformations. Thus, for the first time, the “gorge” method was employed to calculate the bubble adhesion force in the presence of a capillary neck. Error analysis indicates that this method, while maintaining simplicity, achieved higher accuracy (lower error) by calculating the Laplace force based on the neck area and accounting for the surface tension force along the tangent at the neck. Energy analysis show that the detachment energies in the stretching and sliding phases correspond to the energy barrier to be overcome for detachment and the “effective work” of interfacial change, respectively. This provides new insights into detachment mechanisms and industrial process modelling, such as flotation.

Design of a seed implantation robot with puncture force and image feedback mechanism for prostate cancer brachytherapy

Design of a seed implantation robot with puncture force and image feedback mechanism for prostate cancer brachytherapy

Conjugate heat transfer analysis on the action mechanism of centrifugal force and centrifugal buoyancy in staggered labyrinth seals

The heat transfer characteristics of smooth and honeycomb staggered labyrinth seals were investigated using the conjugate heat transfer method. Three pressure ratios (π = 1.2, 1.6, and 2.0), three rotational speeds (RPM = 0, 10,000, and 20,000), and two wall-to-fluid temperature ratios (TR = 0.4 and −0.67) are considered to explore the influence of centrifugal force and centrifugal buoyancy. The results indicate that the heat transfer coefficient of staggered labyrinth seals increases with pressure ratio due to the increased flow velocity and the thinner boundary layer. As a result of the interaction of inertia force and centrifugal force, some enhancement positions of heat transfer coefficient shift slightly. Notably, centrifugal buoyancy has a negative impact on heat transfer at TR = −0.67, but a positive impact at TR = 0.4. When TR = −0.67, there is a peak of the heat transfer coefficient with increased rotational speed due to centrifugal buoyancy. In addition, the heat transfer coefficient at TR = −0.67 is lower than that at TR = 0.4, especially at high rotational speeds. It is proposed that heat transfer correlations be developed by incorporating the Taylor number and rotating Grachev number.