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A comprehensive understanding of meteorological, emission and chemical influences on severe haze is essential for air pollution mitigation. However, the nonlinearity of the atmospheric system greatly hinders this understanding. In this study, we developed the quantitative decoupling analysis (QDA) method by applying the Factor Separation (FS) method into the model processes to quantify the effects of emissions (E), meteorology (M), chemical reactions (C), and their nonlinear interactions and impact on fine particulate matter (PM2.5) pollution. Taking a heavy‐haze episode in Beijing as an example, we show that different from the integrated process rate (IPR) and the scenario analysis approach (SAA) in previous studies, the QDA method explicitly demonstrate the nonlinear effects by decomposing the variation of PM2.5 concentration into individual contributions of E, M and C terms as well as the contributions from interactions among these processes. Results showed that M dominated the hourly fluctuation of the PM2.5 concentration. The C terms increase with increasing the level of haze, reaching maximum (0.37 μg · $\mathit{\cdot }$ m−3· $\mathit{\cdot }$ h−1) at the maintenance stage. Moreover, our method reveals that there are non‐negligible non‐linear effects of meteorological, emission, and chemical processes during pollution stage, with the mean accounting for 50% of the increase in PM2.5 concentrations, which is often ignored in the current air pollution control strategies. This study highlights that the QDA approach can be used to gain insight into the formation of heavy pollution, and to identify uncertainty in numerical models. Plain Language Summary: In this study, we developed the quantitative decoupling analysis (QDA) method by applying the factor separation method into the model processes for the first time to quantify the effects of emissions (E), meteorology (M), chemical reactions (C), and their nonlinear interactions on fine particulate matter (PM2.5) pollution. Different from the IPR and the SAA that used in previous studies, the QDA method explicitly considers the nonlinear effects by decomposing the hourly changes in the PM2.5 concentration into three pure contributions of E, M and C and the four multi‐contributions from interactions among these processes (i.e., ME, MC, CE, and MCE). Not only does this technique provide new reference ideas for the treatment of air pollution, but it is also an important tool for further studying the formation processes of heavy pollution and the influence of different physicochemical mechanisms. Key Points: The quantitative decoupling analysis (QDA) method applies the factor separation method into the model processes for the first timeThe QDA method quantify the effects of emissions, meteorology, chemical reactions, and their nonlinear interactions on PM2.5 pollutionThe QDA method provide a new technique for studying the formation processes of heavy pollution [ABSTRACT FROM AUTHOR]

Sorption-enhanced chemical looping gasification (SECLG) has a favorable ability to produce H 2 -rich syngas without any extra separation process. To comprehensively investigate the performances, the temperature in the fuel reactor (FR) side T FR , molar ratio of steam or CaO to carbon (λ steam/C , λ CaO/C), circulation ratio of oxygen carrier to carbon (λ OC/C) are changed to test their effects on the products. Then the coupling effects on SECLG are deeply analyzed by changing two and three of the operating parameters. Results demonstrate that under fundamental conditions, the sorption enhancement becomes unavailable when the temperature is higher than 775 °C but decreasing λ steam/C and increasing λ OC/C can elevate this critical temperature. Increasing the λ OC/C or λ steam/C can enhance the H 2 concentration first, then weaken H 2 concentration. The maximum value of H 2 concentration is 62.47% when λ OC/C = 0.4 and λ steam/C = 1.9. When the FR temperature is lower than 775 °C, there is an optimal λ OC/C for maximizing the H 2 concentration at a specific temperature. When the temperature is 650 °C, λ OC/C = 0.5 and λ steam/C = 1.9, the maximum value of H 2 concentration can reach 95.73% in SECLG. • A thermodynamic process simulation model of biomass SECLG is established. • The gasification performance of SECLG system is simulated under different conditions. • Coupling effects of two and three parameters are investigated based on this model. • When T FR is 650 °C, λ OC/C = 0.5 and λ steam/C = 1.9, maximum H 2 concentration is 95.73%. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature 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.)

Inspired by the scales on the surface of crucian carp, the biomimetic fan-shaped textures were designed and prepared on the TC4 contact surface and filled with solid lubricant SnAgCu-Nb2C (SACN). The coupling effects of fan-shaped textures and solid lubricants on the tribological properties of TC4 under variable frequency conditions were investigated. The results indicated that the fan-shaped textures could promote the precipitation of lubricants and provide sufficient lubricants for the worn surface, forming a uniform lubricating film on the worn surface, thus improving the tribological properties. In addition, at the low-frequency stage, the coupling of lubricants and textures had strong adaptability to frequency changes. [ABSTRACT FROM AUTHOR]

During the operational phase, complex systems are subject to various shocks, both random and continuous degradation. This coupling effect poses significant challenges for reliability assessment. The proposed method aims to provide a clear and objective evaluation of the system's reliability. In this paper, we propose a competitive failure reliability analysis method that considers the coupling effect of multiple shock processes and degradation processes. The random shocks are subdivided into external and internal shocks. The degradation increment is mainly influenced by external shocks, whereas internal shocks affect the degradation rate. The combined effect of these two shock processes accelerates the failure processes. Additionally, two different shock models are combined to create an extreme‐cumulative shock model to assess the impact of various shock processes and the degradation process on system reliability. The analysis examines the coupling effect between the degradation process and shock processes to explore the influence law between hard failure and soft failure. Subsequently, the reliability modeling of competitive failure processes is completed. Finally, practical case studies demonstrate the effectiveness and practicality of the proposed method. [ABSTRACT FROM AUTHOR]

Telecoupling interregional resource interaction based on cultivated land grain production (CLGP) plays a crucial role in ensuring national food security and advancing sustainable socio-environmental and economic development. Based on the provincial panel data of 31 administrative regions in China from 1990 to 2020, we used the spatial and temporal evolution of CLGP and the global Moran index to detect the spatial correlation of CLGP among the provinces in China; we adopted the SDM to study the telecoupling effect of CLGP among the provinces in China and decompose the effect, enabling us to propose policy recommendations for enhancing the telecoupling effect among the provinces. The results are as follows: (1) China's inter-provincial CLGP has shown an increasingly strong telecoupling effect over time, further validating the scientific nature of China's grain production pattern. (2) Cultivated land, irrigation area, the number of agricultural employees, the power of agricultural machinery, the proportion of grain sown, and total grain production have positive "flow" effects on spatial teleconnections between provinces and regions. (3) In terms of the total telecoupling effect, the most significant factor affecting CLGP is the ratio of the area sown with grain to the total area sown with crops. Meanwhile, the area of cultivated land in each region, the irrigated area, the agricultural labor force, the agricultural machinery total power, and the percentage of grain sowing in each region have the most direct telecoupling effect on CLGP. The conduct of the study further fleshes out the empirical research on interregional resource telecoupling linkages arising from resource deployment and utilization. [ABSTRACT FROM AUTHOR]

A complete road-soft ground model is established in this paper to study the dynamic responses caused by vehicle loads and/or daily temperature variation. A dynamic thermo-elastic model is applied to capturing the behavior of the rigid pavement, the base course, and the subgrade, while the soft ground is characterized using a dynamic thermo-poroelastic model. Solutions to the road-soft ground system are derived in the Laplace-Hankel transform domain. The time domain solutions are obtained using an integration approach. The temperature, thermal stress, pore water pressure, and displacement responses caused by the vehicle load and the daily temperature variation are presented. Results show that obvious temperature change mainly exists within 0.3 m of the road when subjected to the daily temperature variation, whereas the stress responses can still be found in deeper places because of the thermal swelling/shrinkage deformation within the upper road structures. Moreover, it is important to consider the coupling effects of the vehicle load and the daily temperature variation when calculating the dynamic responses inside the road-soft ground system.

In this paper, a load-sharing performance analysis method of the planetary gear system is proposed considering the coupling effects of double-helical gear and journal bearing. Firstly, the coupling effects between the meshing characteristics of the double-helical gear pair and the dynamic characteristics of journal bearing under the actual operation state are studied, the dynamic model of the double-helical gear planetary transmission system is established, and the load sharing coefficient before and after considering the coupling effects are calculated; secondly, the load sharing characteristic test rig of planetary transmission system is built, and the load sharing coefficient of gear system under the test condition is measured to verify the accuracy of the proposed method; finally, the effects of operating parameters and structural parameters on the load sharing characteristic of gear system are discussed. [ABSTRACT FROM AUTHOR]

During long-duration dynamic loads, such as wind loads or seismic effects, the internal temperature and pressure of a damping cylinder escalate rapidly, which induce shifts in the mechanical attributes of viscous fluid dampers (VFDs). This study investigated the mechanical performance of VFD considering the coupling effects of temperature and pressure under long-duration loads. First, we analyzed the mechanical and energy-dissipation performances of the dampers based on the dynamic mechanical tests considering different loading frequencies, displacement amplitude, and loading cycles. The experimental results indicated that both temperature and pressure influenced the output of the dampers, and in the sealed environment of the damper pip, temperature and pressure exerted mutual influence. Furthermore, the relationship between the damping coefficient and temperature–pressure coupling effects was obtained. Subsequently, an improved mathematical model for the mechanical performance of a gap-type VFD was proposed by considering the macroscopic energy balance of the entire fluid within the damper. Finally, the accuracy of the mathematical model for VFD under long-duration dynamic loads was validated by comparing the computational results with the experimental data. [ABSTRACT FROM AUTHOR]

This study introduces a Finite Element (FE) hybrid methodology for analyzing deepwater offshore oil and gas floating production systems. In these systems, flexible risers convey the production and are connected to a balcony on one side of the platform. The proposed methodology couples, in a cost-effective manner, the hydrodynamic model of the platform with the FE model that represents the risers and the mooring lines, considering all nonlinear dynamic interactions. The results obtained and the associated computational performance are then compared with those from traditional uncoupled analyses, which may present inaccurate results for deepwater scenarios, and from fully coupled analyses that may demand high computational costs. Moreover, particular attention is dedicated to integrating global and local stress analyses to calculate the fatigue resistance of the flexible riser. The results demonstrate that the coupled global analyses adequately capture the asymmetric behavior due to all risers being connected to one of the sides of the platform, thus resulting in a more accurate distribution of fatigue damage when compared to the uncoupled methodology. Also, fatigue life is significantly affected by adequately considering the coupling effects. [ABSTRACT FROM AUTHOR]

The stability of earth-rock dams is a critical factor in hydraulic engineering, directly impacting the safety of reservoirs and downstream regions. Seepage and thermal conduction, key physical processes influencing dam stability, are typically studied independently. However, as environmental changes become increasingly significant, the interaction between these processes--the coupling effect--cannot be overlooked. This paper delves into the coupled effects of seepage and thermal conduction in earth-rock dams, initially establishing a coupled control equation for the seepage and temperature fields. Subsequently, a numerical model for the seepage process under thermal conduction coupling effects is developed. Through precise simulation, this study aims to enhance the predictive capability of dam behavior under various environmental conditions, thereby providing a scientific basis for dam design and maintenance. The research identifies that existing models often neglect the impact of temperature on seepage characteristics and exhibit biases in parameter selection and boundary condition settings, leading to inaccurate simulations of dam behavior in complex environments. Therefore, the numerical model in this study, considering key parameters such as convective heat transfer coefficients, offers a more comprehensive assessment of the stability and functionality of earth-rock dams in real-world conditions. [ABSTRACT FROM AUTHOR]

This paper systematically investigated the impact mechanisms of proton irradiation, atomic oxygen irradiation and space debris collision, both individually and in combination, on the laser damage threshold and damage evolution characteristics of HfO 2 /SiO 2 triple-band high-reflection films and fused silica substrates using a simulated near-Earth space radiation experimental system. For the high-reflection film samples, the damage thresholds decreased by 15.38%, 13.12% and 46.80% after proton, atomic oxygen and simulated space debris (penetration) irradiation, respectively. The coupling irradiation of the first two factors resulted in a decrease of 26.93%, while the combined effect of all the three factors led to a reduction of 63.19%. Similarly, the fused silica substrates exhibited the same pattern of laser damage performance degradation. Notably, the study employed high-precision fixed-point in situ measurement techniques to track in detail the microstructural changes, surface roughness and optical-thermal absorption intensity before and after proton and atomic oxygen irradiation at the same location, thus providing a more accurate and comprehensive analysis of the damage mechanisms. In addition, simulations were conducted to quantitatively analyze the transmission trajectories and concentration distribution lines of protons and atomic oxygen incident at specific angles into the target material. The research findings contribute to elucidating the laser damage performance degradation mechanism of transmissive elements in near-Earth space environments and provide technical support for the development of high-damage-threshold optical components resistant to space radiation. [ABSTRACT FROM AUTHOR]

Heart failure is a chronic and progressive condition characterized by the heart's inability to pump sufficient blood to meet the body's metabolic demands. It is a significant public health concern worldwide, associated with high morbidity, mortality, and healthcare costs. For advanced heart failure cases not responding to medical therapy, heart transplantation or mechanical circulatory support with ventricular assist devices (VADs) can be considered. In the specific case of bi-ventricular heart failure a replacement of both ventricles is required. In this context a Total Artificial Heart (TAH) may be proposed as a bridge to transplant solution. Additionally, bi-ventricular assist devices (BiVADs) are available to support both ventricles simultaneously. However Bi-ventricular heart failure management is difficult with poor outcomes. New surgical procedures appear to propose solutions after both ventricle failure. One of these intervention uses two continuous-flow VADs as a total artificial heart after cardiac explantation due to myocardial sarcoma. Unfortunately, this procedure makes patient management very difficult as pulmonary pressures and flow rate are no longer measurable after the surgical procedure. The setting of both pumps is hence a complex task for patient management. This article aims at helping clinicians on patient management undergoing double assistance after cardiac explantation by predicting the different outcomes on the vascular grid for all the possible rotational speed combination using a lumped model. Results provide a range of both pump operating conditions suitable for delivering a physiologically adapted flow to the vascular grid when combined with hypotensive treatments. [ABSTRACT FROM AUTHOR]

Telecoupling interregional resource interaction based on cultivated land grain production (CLGP) plays a crucial role in ensuring national food security and advancing sustainable socio-environmental and economic development. Based on the provincial panel data of 31 administrative regions in China from 1990 to 2020, we used the spatial and temporal evolution of CLGP and the global Moran index to detect the spatial correlation of CLGP among the provinces in China; we adopted the SDM to study the telecoupling effect of CLGP among the provinces in China and decompose the effect, enabling us to propose policy recommendations for enhancing the telecoupling effect among the provinces. The results are as follows: (1) China’s inter-provincial CLGP has shown an increasingly strong telecoupling effect over time, further validating the scientific nature of China’s grain production pattern. (2) Cultivated land, irrigation area, the number of agricultural employees, the power of agricultural machinery, the proportion of grain sown, and total grain production have positive “flow” effects on spatial teleconnections between provinces and regions. (3) In terms of the total telecoupling effect, the most significant factor affecting CLGP is the ratio of the area sown with grain to the total area sown with crops. Meanwhile, the area of cultivated land in each region, the irrigated area, the agricultural labor force, the agricultural machinery total power, and the percentage of grain sowing in each region have the most direct telecoupling effect on CLGP. The conduct of the study further fleshes out the empirical research on interregional resource telecoupling linkages arising from resource deployment and utilization.

The optical range of localized surface plasmon resonance (LSPR) is extended into the infrared region, thanks to the development of highly doped semiconductor nanocrystals. Particularly, the near‐infrared (NIR) range holds a significant interest in managing solar radiation. However, practical applications necessitate the arrangement of particles, which is known to possibly impact their optical properties through LSPR coupling effects. How such coupling modifies the LSPR response in semiconductor hosts remains largely unexplored. In this study, a protocol for producing composite coatings composed of cesium‐doped tungsten bronze nanocrystals embedded in a silica matrix is presented. Achieving individual dispersion of nanocrystals is made possible through careful selection of a surface polyglycerol ligand exchange. This allows to tune the interparticle distance by adjusting the nanocrystal volume fraction in the composite. The findings demonstrate that LSPR coupling effects significantly influence the LSPR intensity of nanocrystals in the composite when the nanocrystal‐to‐nanocrystal distance matches their size. Beyond elucidating the LSPR coupling effect, this study provides insights into the potential use of Cs‐HTB nanocrystals for solar control applications. Through the optimization of morphology and film structure, remarkable selectivity is obtained in terms of maintaining good transparency in the visible range while achieving high absorption in the NIR. [ABSTRACT FROM AUTHOR]

[Display omitted] • The multiscale core–shell structure Ni-MOF@N C with heterogeneous interfaces were constructed. • The optimal RL of Ni-MOF@N C 500 is −69.6 dB and the widest effective absorption bandwidth is 6.8 GHz. • The synergistic effect of N -doped carbon shell dielectric loss and Ni magnetic loss improves impedance matching. The design of metal–organic frameworks (MOF) derived composites with multiple loss mechanisms and multi-scale micro/nano structures is an important research direction of microwave absorbing materials. Herein, multi-scale bayberry-like Ni-MOF@ N -doped carbon composites (Ni-MOF@N C) are obtained by a MOF assisted strategy. By utilizing the special structure of MOF and regulating its composition, the effective improvement of Ni-MOF@N C's microwave absorption performance has been achieved. The nanostructure on the surface of core–shell Ni-MOF@N C can be regulated and N doping on carbon skeleton by adjusting the annealing temperature. The optimal reflection loss of Ni-MOF@N C is −69.6 dB at 3 mm, and the widest effective absorption bandwidth is 6.8 GHz. This excellent performance can be attributed to the strong interface polarization caused by multiple core–shell structures, the defect and dipole polarization caused by N doping, and the magnetic loss caused by Ni. Meanwhile, the coupling of magnetic and dielectric properties enhances the impedance matching of Ni-MOF@N C. The work proposes a particular idea of designing and synthesizing an applicable microwave absorption material that possesses excellent microwave absorption performance and promising application potential. [ABSTRACT FROM AUTHOR]

Calcareous sand is typically known as a problematic marine sediment because of its diverse morphology and complex inner pore structure. However, the coupling effects of morphology and inner pores on the mechanical properties of calcareous sand particles have rarely been investigated and understood. In this study, apparent contours and internal pore distributions of calcareous sand particles were obtained by three-dimensional (3D) scanning imaging and X-ray micro-computed tomography (X-μCT), respectively. It was revealed that calcareous sand particles with different outer morphologies have different porosities and inner pore distributions because of their original sources and particle transport processes. In addition, a total of 120 photo-related compression tests and 492 3D discrete element simulations of four specific shaped particles, i.e. bulky, angular, dendritic and flaky, with variations in the inner pore distribution were conducted. The macroscopic particle strength and Weibull modulus obtained from the physical tests are not positively correlated with the porosity or regularity in shape, indicating the existence of coupling effect of particle shape and pore distribution. The shape effect on the particle strength first increases with the porosity and then decreases. The particle crushing of relatively regular particles is governed by the porosity, but that of extremely irregular particles is governed by the particle shape. The particle strength increases with the uniformity of the pore distribution. Particle fragmentation is mainly dependant on tensile bond strength, and the degree of tensile failure is considerably impacted by the particle shape but limited by the pore distribution.

Aiming at the problem of chemical-mechanics-hydro (C-M-H) action encountered by rocks in underground engineering, chemical damage variables, water damage variables, and force damage variables are introduced to define the degree of degradation of rock materials. Stone is selected as the sample for acid corrosion treatment at pH 3, 4, and 7, and a chemical damage factor is defined that coupled the pH value and duration of exposure. Then based on the spatial mobilized plane (SMP) criterion and the Lemaitre strain equivalence hypothesis, this research develops a constitutive model considering rock chemical corrosion-water-confining pressure damage. The proposed damage constitutive model employs the extremum method to ascertain the two Weibull distribution parameters (m and F0) by theoretical derivation and exhibits satisfactory conformity between the theoretical and experimental curves. The damage constitutive model can be consistent in the stress–strain characteristics of the rock triaxial compression process, which verifies the rationality and reliability of the model parameters. The model effectively represents the mechanical properties and damage characteristics of rocks when subjected to the combined influence of water chemistry and confinement. The presented model contributes to a better understanding of tangible rock-engineered structures subjected to chemical corrosion in underwater environments. [ABSTRACT FROM AUTHOR]

Purpose: The Radiofrequency (RF)‐induced heating for an active implantable medical device (AIMD) with dual parallel leads is evaluated in this paper. The coupling effects between dual parallel leads are studied via simulations and experiments methods. The global transfer function technique is used to assess the RF‐induced heating for dual‐lead AIMDs inside four human body models. Methods: RF‐induced heating for spinal cord stimulator systems with 60 and 90 cm length leads are studied at three parallel dual‐lead configurations (closely spaced, 8 mm spaced, and 40 mm spaced) and a single‐lead configuration. The global transfer function method is used to develop the AIMD models of different configurations and is used for lead‐tip heating assessments inside human body models. Results: In simulation studies, the peak 1g specific absorption rate/temperatrue rises of dual parallel leads systems is lower than those from the single‐lead system. In experimental American Society for Testing and Materials phantom studies, the temperature rises for the single‐lead AIMD system can be 2.4 times higher than that from dual‐lead AIMD systems. For the spinal cord stimulator systems used in the study, the statistical analysis shows the RF‐induced heating of dual‐lead configurations are also lower than those from the single‐lead configuration inside all four human body models. Conclusion: For the AIMD system in this study, it shows that the coupling effects between the dual parallel leads of AIMD systems can reduce RF‐induced heating. The global transfer function for different spatial distance dual‐lead configurations can potentially provide a method for the RF‐induced heating evaluation for dual‐lead AIMD systems. [ABSTRACT FROM AUTHOR]

During long-duration dynamic loads, such as wind loads or seismic effects, the internal temperature and pressure of a damping cylinder escalate rapidly, which induce shifts in the mechanical attributes of viscous fluid dampers (VFDs). This study investigated the mechanical performance of VFD considering the coupling effects of temperature and pressure under long-duration loads. First, we analyzed the mechanical and energy-dissipation performances of the dampers based on the dynamic mechanical tests considering different loading frequencies, displacement amplitude, and loading cycles. The experimental results indicated that both temperature and pressure influenced the output of the dampers, and in the sealed environment of the damper pip, temperature and pressure exerted mutual influence. Furthermore, the relationship between the damping coefficient and temperature–pressure coupling effects was obtained. Subsequently, an improved mathematical model for the mechanical performance of a gap-type VFD was proposed by considering the macroscopic energy balance of the entire fluid within the damper. Finally, the accuracy of the mathematical model for VFD under long-duration dynamic loads was validated by comparing the computational results with the experimental data.

In the present study, we tried to understand the spatially distributed damage in sandstone samples under the coupled stress-freeze-thaw (SFT) conditions. Firstly, uniaxial compressive stresses (i.e. 0 MPa, 10 MPa, 20 MPa, and 25 MPa) were applied to the samples, and then freeze-thaw (FT) cycles (0, 8, 16, and 24) were performed on the uniaxially stressed samples to realize the SFT coupling. Next, real-time CT scanning was conducted to observe the induced damage. The total porosity was introduced to quantitatively evaluate the damage degree. The local porosity variation, with the distance from the center of the sandstone sample, was analyzed to understand the spatial distribution of damage. Finally, the coupling effects of SFT on the damage gradient were discussed. The results indicate that the porosity rises with FT cycles, and the applied stresses can accelerate the increase in porosity. The damage increases exponentially with the distance from the center of the sample. The damage presents a spatial gradient distribution, not the commonly used uniform distribution in various studies. The damage gradient increases with FT cycles, and the increasing rate in damage gradient decreases at uniaxial stress of 0 MPa and 10 MPa first, but the increasing rate in damage gradient increases with FT cycles then at stress increasing to 20 MPa.

In this paper, the tool-tip responses for ball end milling, due to the coupling effects of a flexible rotor-bearing system, are investigated numerically. The milling machine tool spindle is modelled as the flexible rotor-bearing system. The critical speeds, natural modes, and unbalance responses of the system are calculated by applying the generalized polynomial expansion method. This generalized polynomial expansion method expresses the displacement as a series formed by the product of generalized coordinates and axial coordinate polynomials. According to the dynamic cutting force obtained by some scholars in the past, combined with the characteristics of the flexible rotor, the dynamic response of the tool-tip for ball end milling is numerically analyzed. The responses, including time histories, orbits, and FFT diagrams, are plotted to analyze the dynamic behaviors of the tool-tip. The coupling effects of the flexible rotor-bearing system on the system for ball end milling are first studied using the generalized polynomial expansion method. Unlike previous studies, the natural frequency varies with spindle speed and which of the different modes are included in the tool-tip response depends mainly on the spindle speed. Thanks to the gyroscopic effect, the critical speeds and responses of tool-tips can be discussed with respect to various spindle speed and tool flutes. The natural modes are accurately determined, and will excite critical speeds for certain modes, including forward and backward modes, thereby significantly affecting tool-tip response. In addition, the cutting force component associated with the tool-tip response affects the rotor-bearing system parameters, complicating the issue. Milling at higher spindle speed (2160–19,950 rpm), an important new result is found that the tool-tip oscillates with the cutting-force frequency, accompanied by a longer period vibration of the first backward mode of the rotor-bearing system. It can also be seen from the frequency spectrum analysis that, as the spindle speed increases, the peak amplitude of the first backward mode becomes larger. Milling at lower spindle speed (960, 1320 rpm), the in-plane vibration trajectory of the tool-tip gradually expands outwards clockwise around the origin until a stable loop is reached. This is because only the first backward mode of the rotor-bearing system is excited. Considering the coupling effect of the rotor-bearing system to perform the vibration analysis of the milling machine system, the parameters of the system can be designed or the spindle speed can be selected to avoid severe vibration during machining. [ABSTRACT FROM AUTHOR]

Stability assessment is one of the important subjects in airworthiness certification. Many destabilizing factors can deteriorate the performance and stability margin of the compressor, and there are coupling effects between the external factors. This paper applies a computational method to investigate the coupling effects of total pressure distortion and low Reynolds number on an axial transonic compressor. The study was carried out on NASA stage 67, in which extensive open experimental data is available. Full annulus, steady, three-dimensional CFD has been used to study the coupling effects of 180-deg inlet distortion at low Reynolds number. The assessment of the stability margin loss under coupling effects by traditional methods results in a relative error of 27%. The local operating point of the rotor at different passages has been tracked, and the results reveal the reasons for the failure of model predictions. Combined with the analysis of the flow field under coupling effects, development solutions for the traditional model are proposed. The modifications to the model agree well with the calculation results. Finally, the improved model was validated. And according to the analysis of the rotor passage working points, the rationality of the model modification was verified. [ABSTRACT FROM AUTHOR]

The meta-surface is introduced into the design of band-notched monopole antennas with single/dual/triple notched bands around 3.6/5.5/7.2 GHz for ultra-wideband (UWB) communication. We show that strong coupling effects between the meta-surface and the antenna would be created through tuning the orientations of the meta-cells according to the field distributions on the antenna surface, and eventually, filter the unwanted radiations of the antenna. Especially, by simply attaching different meta-surfaces on the back of the antenna, the band-notched properties are shown to be changeable without hurting the original structure of the antenna. Both simulation and measurement results demonstrate the monopole with replaceable meta-surfaces has achieved an UWB operating band ranging from 3 to 9 GHz for voltage standing wave ratio (VSWR) ≤ 2 with single/dual/triple notched bands covering frequencies around 3.6/5.5/7.2 GHz. Such a design would obtain significant notched performances for the desired bands and maintain the good radiations in the operating frequency, which make it a suitable candidate for UWB applications. [ABSTRACT FROM AUTHOR]

• A microscale convective heat transfer coefficient experimental measurement platform is constructed, and an equation for the convective heat transfer coefficient of polymer melt at the microscale is established. • A coupled mathematical model is established, capturing the coupling effects among viscosity, viscous dissipation, and convective heat transfer in polymer melts at the microscale. • As the characteristic dimensions of the microchannel decrease, the influence of coupling effects on the melt's temperature, velocity, viscosity, and viscous dissipation becomes more significant. • The mathematical model, which accounts for coupling effects, exhibits a deviation of less than 0.5 °C between its calculated temperature rise along the flow direction of the melt and the experimental measurements. This coupled model is capable of precisely forecasting the influence of coupling effects on the melt's temperature, velocity, viscosity, and viscous dissipation. The coupling effects among viscosity, viscous dissipation, and convective heat transfer during the polymer melt micro-molding process, influenced by microscale effects, notably impacted the melt's flow characteristics. The scarcity of theoretical exploration into these coupling effects has hindered the evolution of micro-molding. This research initially established the heat transfer coefficient equation at the microscale via experimental approaches, and by integrating multiphysics coupling theories, established a coupled mathematical model encompassing viscosity, viscous dissipation and convective heat transfer at the microscale. Then we computed and analyzed the melt flow characteristics within microchannels of varying characteristic dimensions and validated the temperature variations of the melt along the flow direction through experiments. The results showed that considering coupling effects resulted in a temperature rise along the flow direction that closely matched experimental data, with discrepancies below 0.5 °C, whereas ignoring these effects led to a maximum deviation of up to 2.4 °C. Analysis of velocity, viscosity, and viscous dissipation across radial section revealed that the discrepancies between ignoring and considering coupling escalated with decreasing dimensions. The maximum deviations for velocity, viscosity, and viscous dissipation in PMMA(polymethyl methacrylate) were 19.47 %, 10.71 %, and 39.28 %, respectively. These results emphasized the necessity of considering coupling effects when polymer melt micro-molding. [ABSTRACT FROM AUTHOR]

• A new quasi-static blade rubbing model involving shaft deformation is developed. • A compound modeling method for the shaft-blade-disk system is developed. • The dynamic characteristics of mixed rubbing modes is analyzed. • Asymmetric form of rub-impact will induce more frequent rub-impact behavior. Dynamic behavior analysis of blades under high cycle fatigue with rubbing fault is vital for estimating the reliability of rotating machinery. This paper focuses on a novel rubbing model and the flexible dynamic characteristics of a shaft-blade-disk system (SBDS) model with considerations of various forms of rub-impacts. Firstly, the deformation relations and the motion equations of the SBDS model in steady state are derived using Lagrange's principle. Secondly, a new quasi-static blade rubbing model involving shaft deformation and blade coupling effect is established, and the influence of rub-impact correlation parameters on rubbing force is further explored. Then, both the effect of shaft-disk coupling on the blades at various states and the dynamic characteristics of numerous rubbing modes are also investigated. The results revealed that the asymmetric form of rub-impact will induce more complex vibrational behavior (such as frequency components and trajectory differences), while the symmetrical rubbing modes can keep the system relatively stable. [ABSTRACT FROM AUTHOR]

Structural characteristics of electrical equipment are influenced by connected flexible conductors. In order to study the seismic performance of the double electrical equipment system (DEES) with flexible conductors, a simplified modeling method of the DEES with flexible conductors was proposed in this paper. The refined finite element model of the DEES with flexible conductors was established using ANSYS software. Its seismic response level was analyzed and compared with that of the standalone equipment. Besides, the impact of ground motion input was also investigated. The results show that the first two modal frequencies of the DEES will be reduced by the flexible conductor. The flexible conductor can reduce the seismic responses of the low-frequency equipment in the DEES, while it increases seismic responses of the high-frequency equipment. When the slack of the flexible busbar is greater than a critical value, the additional pulling force on the top of the equipment caused by the busbar can be kept at a low level, which is also related to the ground motion input.

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

This work investigates the asymmetric behaviour of the roll motions and damping effects on a Floating Production Storage and Offloading vessel (FPSO) with riser balcony on portside in deep-water scenarios. The focus is on assessing the importance of employing a fully coupled analysis methodology to consider all nonlinear dynamic interactions between the hull, mooring lines and risers; and to stress the differences from the traditional uncoupled methodology, in terms of both the roll motions and the riser top tensions. For this purpose, a set of simulations are performed using uncoupled and coupled models, under regular and irregular beam seas, perpendicular to the vessel centreline. Results from the coupled analyses show significant reductions in roll motions and riser tensions, indicating that coupling effects are relevant and must be considered by using accurate coupled analysis tools. [ABSTRACT FROM AUTHOR]

The integration of population, industry, transportation, and land is the objective requirement of the coordinated development of industrialization and urbanization. However, previous research has not appreciated long-time series of city–industry integration from the multi-scale perspective, and there is an over-reliance on statistical data, which limits the spatial perspective in evaluation systems. The purposes of the research are (1) understanding the connotations and essence of the integrated development of city and industry from different spatial scales, (2) introducing a spatial perspective into the evaluation system, with multi-source geospatial data, and (3) evaluating it dynamically. Results showed that (1) at the city scale, the degree of city–industry integration in Shanghai has an upward trend over the 20 years, with volatile changes. (2) At the scale of the industrial park, functional, social, and spatial integration show an increase. The contributions of city development change were ranked high to low as follows: functional integration, spatial integration, and social integration. (3) Multi-source geospatial data improve data availability for the research in this field. The multi-source data fusion fixes the lack or abnormalities of the data in traditional research, which enriches the evaluation perspective. The contributions of this article include (1) this study established the city-population, industry, and transportation interaction system (C-PIT) to describe the integrated development of city and industry at city and industrial park scales; (2) this study introduced the spatial perspective to construct a new evaluation approach, which is based on the coupling coordination degree, the entropy method, and multi-source data; and (3) this study conducted a long-time series analysis of two cases, Shanghai and Kangqiao industrial park. [ABSTRACT FROM AUTHOR]

To investigate the coupling effects of wave–wind, wave–current, and wave–current–wind on a pile foundation of a marine structure, harbor basin tests on loads induced by single and combined action of wave, current, and wind were conducted. The time histories, power spectrums, and characteristic values of drag forces in the test conditions were compared. Then, the coupling coefficients were calculated based on the characteristic values to quantitively evaluate the coupling effects. The influence of natural vibration of the pile on the characteristic values and coupling effects were studied by comparing the test loads between rigid and elastic models. The results show that the shapes of power spectrums of drag forces and their peak frequencies in the wave-involved conditions are similar to the spectrum of incident wave, which means that the steady current and uniform wind cannot change the frequency distribution of incident random wave. Although the drag forces of rigid and elastic model under wave–wind, wave–current, and wave–current–wind are not the linear superposition of corresponding single field, the coupling effects among them are quite weak as the coupling coefficients are small. It is speculated that the weak wave–wind coupling effect may be because, firstly, the interaction of wave and wind is limited to the zone near the water surface, which is far less than the height of the model; secondly, the wave-induced load is dominant compared to wind and current. The loads in test conditions of elastic model are similar to the rigid model; for that, the model's natural frequency is far away from the peak spectral frequency of incident wave, having little influence on the drag force. [ABSTRACT FROM AUTHOR]

Polarization conversion of chiral ordered structures can achieve effective electromagnetic attenuation through flexible field rotation. However, the mechanism of near‐field coupling generation on which it depends remains unclear, hindering the development of chiral wave‐absorbing materials. In this work, a beetle‐inspired ordered structure, which is a kind of chiral metamaterials (CMMs) consisting of high entropy alloy (HEA) electromagnetic dissipative unit and media‐layer, is rationally designed. Such CMMs show that the coupling and decoupling effects can achieve dynamic conversion between linearly polarized waves and circularly polarized waves, and the mechanisms analyzed and verified by simulation models confirm that as a universal method. The fabricated biomimetic metamaterials show desirable absorption with effective absorption bandwidth of 4.48 GHz at 2 mm interlayer medium thickness (≥75% absorptivity, reflection loss ≤ −6 dB) and minimum reflection loss (RLmin) of −53.6 dB. Moreover, pasting the flexible CMMs conformally on conventional coating surfaces can boost microwave‐invisible capacity, whose absorption bandwidth with RL lower than −6 dB increases to 5.18 GHz over HEA coating. In short, this work elucidates the mechanism of chiral near‐field coupling and provides a novel solution principle and methodology for using CMMs in wave‐absorbing materials. [ABSTRACT FROM AUTHOR]

As one of the most important dynamic excitation sources of the gear system, time-varying mesh stiffness (TVMS) is a key parameter of the gear system dynamics model. To calculate the mesh stiffness of straight bevel gears, a semi-analytical model for calculating the single mesh stiffness (SMS) was proposed based on the infinitesimal method and energy equivalence theory, considering the real transition surface of the tooth root, elastic coupling effects between tooth segments, and nonlinear contact between tooth pairs. Based on the principle of deformation compatibility and force balance and considering the extended tooth contact, which is the phenomenon of the incoming tooth pair coming in contact ahead of the theoretical start of contact and the outgoing tooth pair coming out of contact later than the theoretical end of contact, a semi-analytical calculation model of TVMS was established. Based on the analytical model, the TVMS with different torques and gear parameters was compared with that obtained from the finite element method (FEM). The causes of errors were then analyzed to verify the validity of the semi-analytical method. The results show that the mesh stiffness calculated by the semi-analytical model is in good agreement with that calculated by the FEM, and the calculation efficiency is considerably higher than that of the FEM. Finally, the influence of the gear parameters on the mesh stiffness is analyzed. This study is expected to be helpful in further enriching and developing the calculation theory of gear stiffness and providing a theoretical tool for gear dynamics research. [ABSTRACT FROM AUTHOR]

• Dual-scale view of algal blooms: remote sensing image and sediment core sample. • Utilization of multiple analysis methods, including Copula, GAM, and SEM analysis. • The nonlinear water quality and quantity variation exhibited a turning point in water level changes at 543 m. • Through indirect coupling effects, water level changes dominate water quality shifts, algal blooms, and diatom community variations. Algal blooms and sediment diatoms are crucial indicators of lake water ecology, influenced by water quantity and quality. However, the coupled effects of water quality and quantity changes on algal blooms are still unclear, especially for lakes in cold and arid regions. This study assessed the long-term variations in algal blooms in Hulun Lake using a novel approach combining remote sensing and sediment core samples for diatom analysis. Two mutation points from the structural change test were identified in approximately 2000 and 2010 for algal bloom area (MBE) and sediment diatom richness, indicating asynchronous algal blooms. A structural equation model (SEM) demonstrated that water level (WL) changes were the dominant influencing factor, co-driving the variations in algal blooms and sediment diatoms in conjunction with total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD). The results revealed nonlinear relationships between the lake WL, TN, Chla, and COD. The water level of 543 m emerged as a critical threshold affecting the relationship between water quality and quantity. Distinct differences in this relationship were observed when water levels were above or below this threshold. These variations became particularly pronounced during periods of high and low water levels. The results provide novel insights into the dynamics of algal blooms and can further support lake ecosystem conservation and management. [ABSTRACT FROM AUTHOR]

• A fiber layout method for composite patches driven by service loads was proposed. • The thermosetting composite patches were prepared using 3D printing technology. • A coupling effect between fiber orientation and distribution density was discovered. The urgent need for lightweight and high-strength patches in the field of aircraft structural repair has propelled continuous fiber-reinforced thermoset composites into a research hotspot. However, constrained by manufacturing processes, the designs of composite repair structures primarily focus on external shape and ply layup. These approaches presently lack design methods for the internal fiber adaptability of patches driven by in-service loads. In this paper, we proposed a method for fiber distribution and orientation design based on maximum normal stress. The composite simulation model was established based on fracture toughness. The influence of tensile-shear coupling effects on the mechanical response of composites and the fiber orientation design were examined in the study. The orientation-density coupling effects on the enhancement of patch strength were also analyzed. Furthermore, additive manufacturing technology was employed to fabricate thermoset composite patches. The results show that the composite patches designed in this paper exhibit a 10.50 % improvement in strength compared to traditional unidirectional patches. [Display omitted] [ABSTRACT FROM AUTHOR]

Photocatalysis is one of the most promising green technologies to utilize solar energy for clean energy achievement and environmental governance, such as artificial photosynthesis, water splitting, pollutants degradation, etc. Despite decades of research, the performance of photocatalysis still falls far short of the requirement of 5% solar energy conversion efficiency. Combining photocatalysis with the other physical fields has been proven to be an efficient way around this barrier which can improve the performance of photocatalysis remarkably. This review will focus on the recent advances in photocatalysis coupling by external physical fields, including Thermal-coupled photocatalysis (TCP), Mechanical-coupled photocatalysis (MCP), and Electromagnetism-coupled photocatalysis (ECP). In this paper, coupling mechanisms, materials, and applications of external physical fields are reviewed. Specifically, the promotive effect on photocatalytic activity by the external fields is highlighted. This review will provide a detailed and specific reference for photocatalysis coupling by external physical fields in a deep-going way. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology 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.)

Surface wear, as a major failure mode of gear systems, is an unavoidable phenomenon during the whole life of gears. It also induces other gear damages, such as fatigue cracks, surface pitting and spalling. Ultimately, those defects may result in the sudden failure of a gearbox transmission system, which can lead to a serious accident and unexpected economic loss. Therefore, it can provide huge cost and safety benefits to industries to monitor gear wear and predict its propagation. Gear wear raises the error rate of gear transmission systems, typically leading to improvements in dynamic loads, vibration, and noise. In return, the increased load conversely aggravates wear, creating a feedback cycle between dynamic responses and surface wear. For this purpose, a wear prediction model was incorporated into a tribo-dynamic model for quantitatively investigating how surface wear and gear vibration are mutually affected by each other. To obtain more precise dynamic responses, the tribo-dynamic model integrates the time-varying mesh stiffness, load-sharing ratio and friction parameters. To improve the computational efficiency and guarantee the calculation precision, an improved and updated wear depth methodology is constructed in the wear prediction model. This paper demonstrates the capability of the proposed dynamic wear prediction model in the investigation of the interaction effects between gear dynamics and surface wear, allowing for the development of improved gear wear prediction tools. The obtained results indicate that the surface wear impacts the dynamic characteristics, even with slight wear. In the initial stage of wear, the friction coefficient decreases slightly, largely due to the reduction in surface roughness; but the friction force increases because of the improved dynamic meshing force. Although the initial wear depth distributions of a pinion under dynamic and static conditions are similar, the wear depth distributions under dynamic conditions becomes significantly different compared to the those under static conditions with the wear process. The maximum wear depth of a pinion under dynamic conditions is about 1.6 times as the corresponding static conditions, when the wear cycle comes to 4 × 104. Similarly, the maximum accumulative wear depth of a pinion under dynamic conditions reaches 1.2 times of that under static conditions. Therefore, the proposed dynamic wear prediction model is more appropriate to be applied to the surface wear of gears. [ABSTRACT FROM AUTHOR]

NaNbO 3 is explored as a potential candidate for catalysis due to its excellent piezoelectricity. However, its photocatalysis is significantly limited for the inherent characteristics of wide band gap. In this work, NaNbO 3 and Ag dots-modified NaNbO 3 micron-sized powders are prepared and applied in piezo-photocatalysis to explore the coupling effects. The results show that the piezocatalysis degradation efficiency of RhB solution (the initial concentration C 0 = 5 mg/L) reaches 92.3% within 30 min, and the rate constant k is 0.0889 min−1. The efficiency of piezo-photocatalysis degradation reaches 92.7% in 25 min, and the rate constant k is 0.11 min−1 for NaNbO 3. The rate constant k of Ag dots-modified NaNbO 3 for piezo-photocatalytic degradation of RhB (C 0 = 5 mg/L) is increased to 0.16314 min−1. The optical and electrochemical activities of NaNbO 3 -0.75hAg are studied to reveal the role of Ag nanoparticles. The band gap of NaNbO 3 is 3.59 eV, which is decreased to 3.36 eV after the modification with Ag dots. The lower band gap means that e− in the valence band is more easily excited to shift the conduction band, which is beneficial to the photocatalytic reaction process. In addition, NaNbO 3 -0.75hAg has a higher photogenerated carrier density, a faster electron-hole pair separation and transfer rate, which are beneficial to the catalytic oxidation process. The work provides a useful means to decease the band gap of NaNbO 3 and achieve outstanding piezo-photocatalysis for degradation of hazardous organic dyes in contaminated water. [ABSTRACT FROM AUTHOR]