Decoupling Effect Research Articles

Analysis of Decoupling Effects and Influence Factors in Transportation: Evidence from Guangdong Province, China

In recent years, global environmental issues have become increasingly prominent. The transportation industry, as the fundamental sector of national economic development, is also characterized by high energy consumption and carbon emissions. Therefore, it is imperative to conduct research on the carbon emission problem within this industry. In light of the Tapio decoupling model, an analysis of the correlation between traffic carbon emissions and economic development in Guangdong province during 1999–2019 was carried out. With the aim of encouraging Guangdong province’s low-carbon transportation development, the factors affecting the transportation industry are analyzed utilizing the generalized Divisia index model (GDIM). We also introduced passenger and freight turnover as an influencing factor for analysis. The findings indicate that (1) Guangdong province’s traffic carbon emissions increased from 1999 to 2019; (2) the traffic carbon emissions’ decoupling effect is mainly “weakly decoupled”, and the overall decoupling effect is not strong in Guangdong province; (3) among the traffic carbon emissions’ factors, the effects of the production value of traffic and the turnover volume are at the forefront, and the effect of turnover volume has gradually exceeded the production value of traffic in recent years. The suppression of the intensity of carbon emissions is relatively large, while the suppression of the intensity of energy consumption and transport is relatively weak. Based on this, strategies were proposed to promote a cleaner energy mix, improve energy use efficiency, create energy savings, develop green technologies, and foster the restructuring of transportation.

Nonlinear evolution of weakly coupled double tearing modes with equilibrium sheared toroidal flow

Abstract The nonlinear evolution of weakly coupled DTMs with and without sheared toroidal flow is systematically investigated with the three-dimensional, toroidal-geometry, and nonlinear MHD code CLT. Due to the explosive growth of the weakly coupled DTMs, the pressure crashes are much more severe than those caused by the strongly coupled DTMs. The weakly coupled DTMs can easily be decoupled by sheared toroidal flow, and then the mutually driven term between the two tearing modes becomes periodically positive and negative, leading to periodic growth. The interaction slows the rotation between the two tearing modes when the phase difference is close to 180 degrees. When the islands are sufficiently large, the interaction can overcome the decoupling effect of the shear flow, and the two tearing modes then lock with each other. Due to the different coupling effects of the two tearing modes, the threshold island width or perturbed magnetic field for mode-locking increases with increasing separation. The coupling effect between the two tearing modes is also related to the resistivity. If the resistivity is high, the coupling effect between the two tearing modes can be huge. A stronger shear flow is needed to decouple them, and even a small island can lead to mode-locking in high-resistivity plasma.

Supernormal Temperature Sensing Performance Realized through the Blue Emitting Level of Er3+ along with Detection Ability in Deep Tissues.

Fluorescence intensity ratio (FIR)-type optical thermometers based on thermally coupled energy levels (TCLs) of rare earth ions are suitable candidates for noncontact temperature detection in living organisms, microelectronics apparatus, and so forth. Therefore, the improvement of the thermometric sensitivity of TCL-based thermometers has become a research hotspot in recent years. Herein, ultrahigh sensitivity and outstanding resolution for temperature sensing have been realized in YNbO4: Yb3+/Er3+. Unusually, the thermally coupled three-level system of Er3+: 4F7/2/2H11/2/4S3/2 is first employed for optical thermometry based on FIR technology. A supernormal thermometric sensitivity of 2.67% K-1 is obtained from the thermally coupled 4F7/2 and 4S3/2 states due to the large energy gap between them, significantly surpassing that of most temperature sensors in the same category. Furthermore, the existence of the intermediate level 2H11/2 can effectively prevent the decoupling effect between 4F7/2 and 4S3/2. Additionally, the temperature sensing behavior realized by the Stark sublevels of the Er3+: 4I13/2 → 4I15/2 transition, with a penetration depth of 8 mm, shows the potential of temperature measurement in deep biological tissues, benefiting from its excitation and emission wavelengths located in the biological window. All of the data reveal that YNbO4: Yb3+/Er3+ is an ultrasensitive optical thermometer and exhibits the capacity of temperature detection in deep tissues.

Catalyzing green transformation: mitigating oil price impact on CO2 emissions in Saudi Arabia via renewable energy transition

AbstractExploring the relationship between international oil prices, income, and carbon dioxide (CO2) emissions in Saudi Arabia, this study examines if renewable energy consumption plays a lowering tool in international oil prices' impact on CO2 emissions, employing conventional econometric methods and the functional coefficient approach. The study reveals that the interaction between renewable energy consumption and international oil prices has a negative and statistically significant impact on CO2 emissions. This emphasizes the potential for Saudi Arabia to reduce carbon emissions by prioritizing renewable energy projects. In addition, a positive and statistically significant relationship between income and CO2 emissions is found, emphasizing the need to decouple economic growth from emissions growth. Furthermore, an interesting decoupling effect between oil price elasticity of CO2 emissions and per capita GDP is noted from the early 2000s–2015. This indicates that economic growth driven by rising oil prices can be managed to mitigate environmental impact, showcasing Saudi Arabia's commitment to sustainable development. Policy recommendations involve intensifying efforts to promote renewable energy implementation, lowering fossil fuel dependence in power generation, and incentivizing emissions reduction for a more sustainable energy future.

Ultra‐Thin Metal Oxide Superstructure of Pd(001) as Passivation Interlayer at Organic/Metal Interface

AbstractAt organic molecule/metal interfaces for electronic applications, it is required of the metal surface to be passivated in view of preserving the molecular properties of the ordered organic layer. This can be achieved by screening the metal with a single atomic layer of O, namely, ultra‐thin metal oxide (UTMO) layers. Cobalt tetraphenylporphyrins (CoTPP) on oxygen passivated Fe(001), with 1 ML O coverage, have revealed a molecule/substrate decoupling effect due to the formation of an ultra‐thin Fe oxide layer at the interface. However, the threshold concentration of surface O required to observe the decoupling effect has not been assessed yet. In this work, the possibility of stabilizing different ultra‐thin Pd oxide superstructures, characterized by a different number of O atoms per unit cell, is exploited to investigate the O decoupling effect on CoTPP films. Two Pd oxide superstructures are considered: Pd(001)‐p(2 × 2)O and Pd(001)‐p(√5 × √5)R27°O, with 0.25 and 0.80 ML O coverages, respectively, which are characterized by low‐energy electron diffraction (LEED), X‐ray and ultra‐violet photoelectron spectroscopies (XPS/UPS) and inverse photoemission spectroscopy (IPES). The results suggest a lower limit of 0.80 ML O coverage as a passivation interlayer to obtain an ordered and decoupled CoTPP monolayer on Pd(001).

Theory and quantum dynamics simulations of exciton-polariton motional narrowing.

The motional narrowing effect has been extensively studied for cavity exciton-polariton systems in recent decades both experimentally and theoretically, which is featured by (1) the subaverage behavior and (2) the asymmetric linewidths for the upper polariton and the lower polariton. However, a minimal theoretical model that is clear and adequate to address all these effects as well as the linewidth scaling relations remains missing. In this work, based on the single mode 1D Holstein-Tavis-Cummings (HTC) model, we studied the motional narrowing effect of the polariton linear absorption spectra via both semi-analytic derivations and numerically exact quantum dynamics simulations using the hierarchical equations of motion approach. The results reveal that under collective light-matter coupling between a cavity mode and N molecules, the polariton linewidth scales as 1/N under the slow limit, while scales as 1/N under the fast limit, due to the polaron decoupling effect. Furthermore, by varying the detunings, the polariton linewidths exhibit significant motional narrowing, covering both characters mentioned above. Our analytic linewidth expressions [Eqs. (34) and (35)] agree well with the numerical exact simulations in all the parameter regimes we explored. These results indicate that the physics of motional narrowing is adequately accounted for by the single-mode 1D HTC model. We envision that both the numerical results and the analytic polariton linewidths expression presented in this work will offer great theoretical value for providing a better understanding of the exciton-polariton motional narrowing based on the HTC model.

Drivers of industrial carbon emissions in the Yangtze River Delta region, China: A combination of decoupling and LMDI models

ABSTRACT The expansion of the industrial economy has resulted in high carbon emissions (CE) from the Yangtze River Delta (YRD) region. Industrial CE reduction is a non-negligible way to achieve green and low-carbon development. In this paper, we aim to study the decoupling effect of industrial CE and its socio-economic influencing factors in the YRD region from 2005 to 2020. First, the decoupling relationship between industrial CE and industrial output in the YRD region is measured. Then, using the LMDI method, the variation of industrial CE is decomposed into six factors: energy structure ( Δ c s ), energy intensity ( Δ c i ), economic scale ( Δ c e ), labor structure ( Δ c l ), urbanization rate ( Δ c u ) and population size ( Δ c p ) effect. Subsequently, by combining with the decoupling and LMDI models, the contribution of each factor to the decoupling of industrial CE is studied, and the elasticity of each factor is expressed by η s , η i , η e , η l , η u , and η p . The main findings show that: (1) There are two states of weak and strong decoupling between industrial CE and the industrial economy in the YRD. (2) Δ c e is the most powerful factor in promoting industrial CE, while Δ c i and Δ c l are the factors that inhibit industrial CE in the YRD. (3) η i and η l have promoted the decoupling of industrial CE from economic advancement in the YRD and its three provinces and one city, while η e has consistently been the largest obstacle to the decoupling process. Finally, the policy recommendations proposed in this paper aim to help policy-makers and practitioners in the YRD region achieve a win-win balance between industrial CE and industrial output, and inspire further research on the decoupling and decomposition of industrial CE from an academic perspective.

Research on morphing aircraft maneuver control based on active disturbance rejection control

Aiming at the problems of model uncertainties caused by morphing aircraft during morphing process and disturbance encountered when maneuvering, a morphing aircraft maneuver control method based on active disturbance rejection control (ADRC) is proposed to eliminate the influences of model uncertainty and external disturbance and improve the rapidity and accuracy of maneuver control. Firstly, a nonlinear model for morphing aircraft is established and the impact mechanism of morphing process is analyzed. Then, the ADRC technique is used to design the angular rate robust control law and the control performance of ADRC law is analyzed under the influence of disturbance. Finally, the immelmann turn maneuver is selected to verify the performance of the designed control law with aerodynamic parameters perturbation combined with the morphing process. The simulation results show that the method possesses good decoupling effect and strong disturbance rejection ability. Moreover, the aircraft's maneuverability and the control margin of control surface can be effectively improved through morphing

Design optimization of two-dimensional wireless passive force sensor based on finite element analysis

Abstract A two-dimensional wireless and passive sensor based on finite element analysis (FEA) is designed, analyzed, optimized, and tested. The sensor is using the inverse magnetostrictive effect. The sensor included three pieces of sensitive elements that stick to the sensitive area of the elastomer. The FEA mothed is used to assist the design, analysis, and optimization process. The strain-sensitive area of the tension and torque are located in different areas, according to the finite element analysis. When the sensor was fabricated, the sensor’s output performance was tested. The experiment results show that the effective range of tension is 40 N, and the effective range of torque is 4 N·m. The optimized smart structure has a good decoupling effect, which can reduce coupling between dimensions. Finally, the two-dimensional force information can be detected passively and wirelessly.

Carbon decoupling effects of energy consumption permit trading schemes: Evidence from China

As a fundamental policy instrument for facilitating the profound transformation of China's energy sector, the carbon decoupling effect of the energy consumption permit trading scheme (ECPTS) is a crucial issue to be evaluated. This paper aimed to explore the carbon decoupling effect and mechanisms of China's ECPTS by utilizing the difference-in-differences (DID) estimator. The findings indicated that the ECPTS significantly enhanced the degree of carbon decoupling, and the dynamic effect tended to gradually expand this decoupling effect. This conclusion holds even after conducting several robustness tests. Moreover, heterogeneity is observed in the carbon decoupling effect of the ECPTS, with regions characterized by higher levels of economic development, lower carbon emissions, and higher resource endowments exhibiting more pronounced decoupling effects. Furthermore, the mechanism analysis revealed that the ECPTS primarily improves carbon decoupling through the optimization of the energy mix and the reduction of the energy use scale. Conversely, the role of industrial structure and technological innovation has yet to fully manifest. Consequently, it is imperative to continue promoting and refining the construction of the ECPTS market. Additionally, stimulating investment in optimizing industrial structures and fostering technological innovation, along with the formulation of regionally tailored policy measures, may propel the carbon decoupling effect of ECPTSs.

Optical Emission Spectra of Molecular Excitonic Polariton Computed at the First‐Principles Level QED‐TDDFT

In microcavity, strong coupling between light and molecules leads to the formation of hybrid excitations, i.e., the polaritons, or exciton‐polaritons. Such coupling may alter the energy landscape of the system and the optical properties of the material, making it an effective approach for controlling the light emission from molecular materials. However, due to the complexity of vibrational modes, spectroscopic calculations for organic exciton‐polaritons remain to be challenging. In this work, based on the linear‐response quantum‐electrodynamical time‐dependent density functional theory (QED‐TDDFT), we employ the thermal vibrational correlation function (TVCF) formalism to calculate the molecular optical spectrum of the lower polaritons (LP) at first‐principles level for three molecules, i.e., anthracene, distyrylbenzenes (DSB), and rubrene. The polaron decoupling effect is confirmed from our first‐principles computations. The theoretical emission spectra of LP provide fruitful insights for molecular and device design in microcavities that are otherwise hindered due to the lack of vibrational information.

Mapping rockfall hazard and detecting precursory damage in rock slopes with passive seismic: Lessons from the La Praz case-study

We conducted repeated successive passive seismic surveys on the La Praz unstable rock slope (∼13,000–15,000 m3, Savoie, France), spanning over more than ten years. The last survey was conducted two months before its complete collapse in August 2023. We used the amplitude of Horizontal to Vertical Spectral Ratio at peak (aHVSR(fp)) to discriminate stable from unstable areas and delineate the fractures with major mechanical decoupling effect. We also classified the compartments in terms of rockfall hazard: the most prone-to-fall areas showed the highest aHVSR(fp) (in the range [26–157]), compared to [7.5–19] on intermediate areas and 2.7 on adjacent stable rock mass.The frequency of HVSR main peak (fp) on three unstable rock compartments showed unambiguous −15%, −14% and −11% drops prior to the collapse. These drops significantly exceed the range of environmentally driven resonance frequency wandering observed on site and generally reported as a limitation in the literature. These drops were interpreted as progressive in-depth slope damage. Interestingly, fp losses were detected solely on the three most prone-to-fall rock compartments showing the highest aHVSR(fp). The unveiling of in-depth damage processes on such a complex, heterogenous and highly fractured rock slope using passive seismic is a first.

High resolution optimized high-order schemes for discretization of non-linear straight and mixed second derivative terms

In this paper, we propose a new set of midpoint-based high-order discretization schemes for computing straight and mixed nonlinear second derivative terms that appear in the compressible Navier-Stokes equations. Firstly, we detail a set of conventional fourth and sixth-order baseline schemes that utilize central midpoint derivatives for the calculation of second derivatives terms. To enhance the spectral properties of the baseline schemes, an optimization procedure is proposed that adjusts the order and truncation error of the midpoint derivative approximation while still constraining the same overall stencil width and scheme order. A new filter penalty term is introduced into the midpoint derivative calculation to help achieve high wavenumber accuracy and high-frequency damping in the mixed derivative discretization. Fourier analysis performed on the both straight and mixed second derivative terms show high spectral efficiency and minimal numerical viscosity with no odd-even decoupling effect. Numerical validation of the resulting optimized schemes is performed through various benchmark test cases assessing their theoretical order of accuracy and solution resolution. The results highlight that the present optimized schemes efficiently utilize the inherent viscosity of the governing equations to achieve improved simulation stability - a feature attributed to their superior spectral resolution in the high wavenumber range. The method is also tested and applied to non-uniform structured meshes in curvilinear coordinates, employing a supersonic impinging jet test case.

Research on the temporal and spatial pattern evolution characteristics and decoupling effect of electricity power consumption in China

Exploring the evolution of spatial and temporal patterns of electricity power consumption in China is of great significance and value for the promotion of Carbon Peaking and Carbon Neutrality Strategy and the scientific allocation of electricity resources. Therefore, this paper takes China as an example and innovatively applies nighttime light data from a combination of two remote sensing satellites. And using spatial analysis methods to analyze the evolution of spatial and temporal patterns of electricity power consumption over a longer study time series. Meanwhile, this paper also uses the Tapio decoupling model to study the decoupling effect of electricity power consumption and economic growth in China. The results of the study show that, during the period 2000–2019, China's electricity power consumption was in an unbalanced state, with the eastern coastal region dominating. It also formed a gradient distribution from the coastal area to the inland area. In terms of spatial connection, it shows an unbalanced distribution pattern of “low in the west and high in the east”. In addition, the spatial linkage of electricity power consumption among provinces is more than 93 % of weak linkage, and gradually increases to 97 %, indicating that the spatial linkage of electricity power consumption among regions is gradually weakening. The decoupling state of electricity power consumption in China is characterized by two types of decoupling: Weak decoupling and Expansive coupling. The decoupling status has experienced a significant change from 84 % of provinces being Expansive coupling to 100 % of provinces being Weak decoupling.

Decoupling effect stimulated independent dendrite growth of eutectic phases under microgravity and containerless states

Eutectic growth process is usually characterized by the simultaneous coupled growth of two different solids within one uniform liquid phase, while fluid dynamics normally predicts the equiaxed shrinkage for floating viscous droplets on freezing. Here a decoupling effect was induced by the microgravity and containerless states aboard space station, which led to the independent dendrite growth of two eutectic phases within extremely undercooled liquid Nb-Si refractory alloy. The confronting fluid flow pattern driven by polar heterogeneous nucleation was found to stimulate the elongated surface deformation of alloy droplet at a high dendrite growth velocity.

Simulation on dynamic passive control of structures using corrugated viscoelastic damping treatments

Passive damping treatments using viscoelastic materials (VEMs) are widely applied as addon solutions to control the dynamic response of light structures. These surface treatments are simple, reliable, and can be optimized by using proper design rules and simulation tools. In this work, a new treatment configuration is proposed, simulated, and assessed, being compared with the most effective configuration currently used. The novelty resides in the VEM layer’s geometry, which in the proposed configuration assumes a waved shape. This waved shape is imposed to the viscoelastic layer due to indentations created in the inner faces of the host structure and the constraining layer. The results demonstrate that the wavy configuration, designated as corrugated viscoelastic layer (CVL), outperforms the typical damping treatments for relatively thick host structures and when using thick VEM layers. In addition, this new configuration reduces the stiffness decoupling effect due to the soft VEM layer, restoring the flexural stiffness of the original undamped structure.

Driving forces of CO2 emissions from the transport, storage and postal sectors: A pathway to achieving carbon neutrality

In tandem with the urbanisation process, China's transport sector is currently experiencing rapid development and was ranked third out of all the industrial sectors in terms of generating CO2 emissions in 2020, which poses a huge challenge to achieving carbon neutrality. Primarily using the energy consumption data from China's transport, storage and postal sectors (TSPS) and input and output data between 2007 and 2020, this study first uses the Tapio decoupling model to evaluate the decoupling effect in the TSPS. Structural decomposition analysis is then applied to explore sectoral linkages and decompose the forces driving CO2 emissions. Additionally, we explore the main determinants of the energy structure effect and final demand in terms of energy consumption and industrial sector demand. Our results show that the target sector experienced a weak decoupling, which implies that the low-carbon transformation of this sector became increasingly apparent. Factor decomposition shows that improvements in energy intensity, energy structure and the production input and output structure have contributed significantly to reducing CO2 emissions, but these gains have been largely offset by final demand, resulting in a net reduction of 27.97 million tons from 2007 to 2020. The increased usage of low carbon forms of energy, such as natural gas, is the key driver behind the emissions reduction effect in terms of the energy structure. However, the higher final demand from the construction sector and the wholesale and retail trades are the main factors that have increased CO2 emissions. By adopting a sectoral and energy structure decomposition perspective, our study can be used to provide guidance to governments seeking to pursue carbon-reduction policies to achieve carbon peak and carbon neutrality, in the TSPS in particular.

Pathway for China's provincial carbon emission peak: A case study of the Jiangsu Province

This study establishes the LEAP-Jiangsu model and uses the improved multilevel logarithmic mean Divisia index, Tapio decoupling, and synergistic effect models to explore the carbon reduction paths. The improved multilevel logarithmic mean Divisia index model analyzed the influencing factors of the historical and future carbon emissions. A provincial LEAP model was established to predict the time and value of carbon emission peaks. The Tapio decoupling and synergistic effect models were used to clarify the relationship between carbon emissions and economic development, the synergistic effect of carbon and pollutant reduction, and the terminal sector's carbon reduction potential. The results show that Jiangsu Province will most likely achieve carbon peaking in 2025∼2030, and the peak carbon emission is about 792∼853.9 Mt. Terminal energy intensity, power production structure, and terminal energy consumption structure are the main influencing factors of carbon reduction, with a cumulative contribution rate of about 74.4 %–83.5 %. The power production structure is critical in promoting the decoupling of economic development and carbon emissions. The contribution rates of energy intensity reduction, industrial structure optimization, improving terminal electrification level, and energy structure adjustment are 30.3 %, 26.2 %, 20.9 %, and 17 %, respectively. Coordinating carbon reduction measures will have better synergistic carbon and pollutant reduction effects.

Research on decoupling control of single leg joints of hydraulic quadruped robot

PurposeThis study proposes a predictive neural network model reference decoupling control method for the coupling problem between the leg joints of hydraulic quadruped robots, and verifies its decoupling effect..Design/methodology/approachThe machine–hydraulic cross-linking coupling is studied as the coupling behavior of the hydraulically driven quadruped robot, and the mechanical dynamics coupling force of the robot system is controlled as the disturbance force of the hydraulic system through the Jacobian matrix transformation. According to the principle of multivariable decoupling, a prediction-based neural network model reference decoupling control method is proposed; each module of the control algorithm is designed one by one, and the stability of the system is analyzed by the Lyapunov stability theorem.FindingsThe simulation and experimental research on the robot joint decoupling control method is carried out, and the prediction-based neural network model reference decoupling control method is compared with the decoupling control method without any decoupling control method. The results show that taking the coupling effect experiment between the hip joint and knee joint as an example, after using the predictive neural network model reference decoupling control method, the phase lag of the hip joint response line was reduced from 20.3° to 14.8°, the amplitude attenuation was reduced from 1.82% to 0.21%, the maximum error of the knee joint coupling line was reduced from 0.67 mm to 0.16 mm and the coupling effect between the hip joint and knee joint was reduced from 1.9% to 0.48%, achieving good decoupling.Originality/valueThe prediction-based neural network model reference decoupling control method proposed in this paper can use the neural network model to predict the next output of the system according to the input and output. Finally, the weights of the neural network are corrected online according to the predicted output and the given reference output, so that the optimization index of the neural network decoupling controller is extremely small, and the purpose of decoupling control is achieved.

Modulating the ESIPT Mechanism and Luminescence Characteristics of Two Reversible Fluorescent Probes by Solvent Polarity: A Novel Perspective.

As reversible fluorescent probes, HTP-1 and HTP-2 have favourable applications for the detection of Zn2+ and H2S. Herein, the impact of solvent on the excited-state intramolecular proton transfer (ESIPT) of HTP-1 and HTP-2 was comprehensively investigated. The obtained geometric parameters and infrared (IR) vibrational analysis associated with the intramolecular hydrogen bond (IHB) indicated that the strength of IHB for HTP-1 was weakened in the excited state. Moreover, structural torsion and almost no ICT behaviour indicated that the ESIPT process did not occur in HTP-1. Nevertheless, when the 7-nitro-1,2,3-benzoxadiazole (NBD) group replaced the H atom, the IHB strength of HTP-2 was enhanced after photoexcitation, which inhibited the twisting of tetraphenylethylene, thereby opening the ESIPT channel. Notably, hole-electron analysis and frontier molecular orbitals revealed that the charge decoupling effect was the reason for the fluorescence quenching of HTP-2. Furthermore, the potential energy curves (PECs) revealed that HTP-2 was more inclined to the ESIPT process in polar solvents than in nonpolar solvents. With a decrease in solvent polarity, it was more conducive to the ESIPT process. Our study systematically presents the ESIPT process and different detection mechanisms of the two reversible probe molecules regulated by solvent polarity, providing new insights into the design and development of novel fluorescent probes.