Decoupling Effect Research Articles

6-DoF Magnetically Levitated Rotary Table With Dynamic Numerical Force and Torque Regulator

Multiaxis motion control over a large travel range is still difficult for magnetic levitation positioning systems because the accuracy of the magnetic force model deteriorates when both translation and rotation of the moving part take place. To overcome this issue, this paper studies a dynamic force and torque regulating method based on the numerical wrench model and validates it with a 6-degree-of-freedom (DoF) magnetically levitated (maglev) rotary table. In each sampling cycle, the current-wrench transformation matrix (CWTM) is determined by the numerical wrench model, and then it is employed to decide the exciting currents for each coil phase by solving the overdetermined equation. A field programmable gate array (FPGA) is used as the processor to meet the real-time requirement of the control system by taking advantage of the fine-grained parallelism in the numerical wrench model. A high level synthesis (HLS) tool, general intellectual property core, a very-high-speed integrated circuit hardware description language (VHDL) component, and a MicroBlaze processor are employed simultaneously to develop the controller. By utilizing the numerical regulator, the maglev rotary table realizes stable multiaxis motions. Comparative experiments with the existing analytical method illustrate that the numerical wrench model improves the static decoupling effect, decreases the positioning fluctuations, and enlarges the travel range.

Assessing and prospecting decoupling effect of carbon emissions from economic growth: Empirical studies from Chinese provinces

China has proposed ambitious goals of carbon peak and carbon neutrality, and will pay more attention to the relationship between economic development and carbon emissions. It's significant to assess the current environmental decoupling and prospect the future conditions in China. This article studies the decoupling status and influencing factors in Chinese provinces from 1996 to 2018 through Tapio decoupling index and decomposition model. The results show that most provinces are currently in a weak decoupling state. The growth of per capita GDP and population will affect the process of strong decoupling, while the optimization of energy intensity, energy structure and industrial structure will promote the realization of strong decoupling. Moreover, this paper prospects the decoupling scenarios of Chinese provinces from 2019 to 2035 and finds that all provinces will achieve strong decoupling before 2040, 2035 and 2030 under different carbon emissions scenarios respectively. To achieve the strong decoupling of economic output and carbon emissions as soon as possible, the government must improve energy efficiency, use renewable energy in large quantities, and promote the industrial transformation and upgrading.

A single solvating benzene molecule decouples the mixed-valence complex through intermolecular orbital interactions

SummaryCharacterization of covalency of intermolecular interactions in the van der Waals distance limit remains challenging because the interactions between molecules are weak, dynamic, and not measurable. Herein, we approach this issue in a series of supramolecular mixed-valence (MV) donor(D)-bridge(B)-acceptor(A) systems consisting of two bridged Mo2 units with a C6H6 molecule encapsulated, as characterized by the X-ray crystal structures. Comparative analysis of the intervalence charge transfer spectra in benzene and dichloromethane substantiates the strong electronic decoupling effect of the solvating C6H6 molecule that breaks down the dielectric solvation theory. Ab initio and DFT calculations unravel that the intermolecular orbital overlaps between the complex bridge and the C6H6 molecule alter the electronic states of the D-B-A molecule through intermolecular nuclear dynamics. This work exemplifies that site-specific intermolecular interaction can be exploited to control the chemical property of supramolecular systems and to elucidate the functionalities of side-chains in biological systems.

Intercomparison of Dynamically and Statistically Downscaled Climate Change Projections over the Midwest and Great Lakes Region

AbstractDownscaling of global climate model (GCMs) simulations is a key element of regional-to-local-scale climate change projections that can inform impact assessments, long-term planning, and resource management in different sectors. We conduct an intercomparison between statistically and dynamically downscaled GCMs simulations using the hybrid delta (HD) and the Weather Research and Forecast (WRF) Model, respectively, over the Midwest and Great Lakes region to 1) validate their performance in reproducing extreme daily precipitation (P) and daily maximum temperature (Tmax) for summer and winter and 2) evaluate projections of extremes in the future. Our results show the HD statistical downscaling approach, which includes large-scale bias correction of GCM inputs, can reproduce observed extremePandTmaxreasonably well for both summer and winter. However, raw historical WRF simulations show significant bias in both extremePandTmaxfor both seasons. Interestingly, the convection-permitting WRF simulation at 4-km grid spacing does not produce better results for seasonal extremes than the WRF simulation at 12 km using a parameterized convection scheme. Despite a broad similarity for winter extremePprojections, the projected changes in the future summer storms are quite different between downscaling methods; WRF simulations show substantial increases in summer extreme precipitation, while the changes projected by the HD approach exhibit moderate decreases overall. The WRF simulations at 4 km also show a pronounced decoupling effect between seasonal totals and extreme dailyPfor summer, which suggests that there could be more intense summer extremes at two different time scales, with more severe individual convective storms combined with longer summer droughts at the end of the twenty-first century.

Hydrogen sensing by plasmon decoupling effect in nanostructured Pd/Au films

Plasmon coupling effect occurs in plasmonic nanostructures when interparticle distances are in the order of particle size leading to spectral shifts in the plasmonic band. This effect has been recently highlighted for measurement of fluctuations in the interparticle distance at nanoscale level. In this study, nanostructured thin Au films were deposited on quartz substrates by pulsed laser deposition (PLD) for sensing of hydrogen gas. A blue shift from 730 to 560 nm in LSPR of Au films was observed when substrate temperatures rises from 25 to 600 °C due to variation in morphology of films from a continuous surface composed of tiny agglomerates to granular surface composed of bigger particles with increased interparticle spacing. For plasmon coupling sensing of hydrogen, a thin Pd film was deposited on top of nanostructured Au films. Upon hydrogen exposure, up to12 nm blue shift within few seconds was observed depending on hydrogen concentration. Based on field emission scanning electron microscope (FESEM) images and finite-difference time-domain (FDTD) simulations, this plasmon sensing is explained by hydrogen-induced decoupling due to the formation of surface stresses in Pd, which can affect the LSPR via an increase in interparticle spacing of Au nanoislands. • Nanostructured Au/quartz films were deposited prepared by pulsed laser deposition at different substrate temperatures. • The interparticle distance of Au films increases with temperature, leading to blue shift in the gold plasmonic absorption. • A thin Pd layer as hydrogen catalyst was deposited on Au/quartz samples by DC magnetron sputtering. • Hydrogen interaction led to a further blue shift, which was greater for films with smaller interparticle distance. • Using finite difference time domain (FDTD) simulation, this effect was attributed to a plasmon decoupling effect.

Decoupling Effect of County Carbon Emissions and Economic Growth in China: Empirical Evidence from Jiangsu Province.

Under the pressure of low-carbon development at county level in China, this paper takes Jiangsu province as an example to analyze the relationship between economic growth and carbon emissions, aiming to provide a reference for the low-carbon development in Jiangsu and other regions in China. Based on the county-level panel data from 2000 to 2017, this paper uses the Tapio elasticity model and environmental Kuznets curve model, and focuses on the differences in regional economic development and the impacts of the 2008 global economic crisis. The results show that, in general, the decoupling effect of carbon emissions in Jiangsu counties has gradually increased during the study period. Since 2011, all counties achieved the speed decoupling, with more than half of them showing strong decoupling. The environmental Kuznets curves of carbon emissions in different income groups are established, and changed before and after the 2008 global economic crisis. In 2017, only 10 of the 53 counties were on the right side of the curve, realizing the quantity decoupling between the two. Therefore, to achieve a win–win situation between carbon emission reduction and economic growth, efforts should be made from the aspects of industrial structure and energy efficiency, and measures should be taken according to local conditions.

Spatial Distribution of Colored Dissolved Organic Matter in the Western Arctic Ocean

Optical properties of colored dissolved organic matter (CDOM) were investigated along a latitudinal transect (67°–77° N) in upper water (<80 m depth) of the western Arctic Ocean. The absorption coefficient at 280 nm was 0.48–1.25 m−1, with the average for the oligotrophic basin area (1.04 ± 0.08 m−1) being slightly higher than that of the productive shelf area (0.95 ± 0.16 m−1), implying a decoupling effect between CDOM concentration and biological productivity in the western Arctic Ocean. The spectral slope coefficient S270–350 was negatively correlated with salinity, indicating that DOM molecular weight increases with salinity, and may be affected by melt-water input. Four fluorescent components were identified by excitation emission matrices elaborated by parallel factor analysis, including three humic-like (C1, C3, and C4) components and one protein-like (C2) component. Significant increases in concentrations of terrestrially derived humic-like C3 and C4 components with salinity were observed in the basin, mainly controlled by the physical mixing of surface fresh water and subsurface inflowing Pacific Ocean water. Terrestrial material carried by Pacific inflow is thus an important factor affecting the distribution of CDOM fluorescence components. The C3 and C4 fluorescence components may be useful as tracers of Pacific water in the western Arctic Ocean.

Factor decomposition and the decoupling effect of carbon emissions in China's manufacturing high-emission subsectors

The manufacturing industry makes the greatest contribution to China's carbon emissions, so reducing emissions among its high-emission subsectors is important to achieve China's overall reduction goals. Innovation is crucial to the green transformation and development of high-emission subsectors. Previous studies have hardly considered the effect of innovation factors on carbon emissions and decoupling of high-emission subsectors. This study incorporated innovation factors into the GDIM (generalized dividing index method) and DEI (decoupling effort index) models and decomposed them into three variables, the innovation input scale, innovation input carbon intensity, and innovation input efficiency, in order to compare the impact of different factors on carbon emissions and decoupling of high-emission subsectors. This approach expands the application scope of the GDIM method and helps to formulate the green transformation policies of the high-emissions manufacturing sector. The results were as follows. (1) The innovation input scale is the primary factor leading to the increase in carbon emissions. The cumulative increase of carbon emissions in the high-emission sectors from 1995 to 2019 was 3.45 billion tons. Innovation input carbon intensity is the primary factor that inhibits the carbon emissions growth. (2) There were significant differences in the degree of decoupling between the high-emission sectors in manufacturing in different periods. The decoupling effect of the manufacture of non-metallic mineral sector was the best; it achieved strong decoupling in 2015–2019, with the DEI reaching 2.17. (3) Decoupling efforts with regard to the carbon intensity of outputs and innovation inputs are the key factors that determine the decoupling of economic growth and carbon emissions in the high-emission subsectors of the manufacturing industry.

Improved subsurface soil moisture prediction from surface soil moisture through the integration of the (de)coupling effect

Soil moisture is a crucial component of the forest ecosystem because it primarily controls vegetation growth. However, the potential for predicting the subsurface from the surface soil moisture through (de)coupling in boreal larch forest (Larix gmenilii) in China has rarely been investigated. In the present study, the regression and residual as well as cross-correlation analyses were used to evaluate the relationship between the surface (5 cm) and subsurface (10, 20, and 40 cm as well as the profile soil moisture) soil moisture in the Larix gmenilii forest. The applicability of the exponential filter (ExpF) and cumulative distribution function matching (CDF) methods for estimating the subsurface using the surface soil moisture in the study area and the impacts of (de)coupling on the simulation accuracy were assessed. Our results shown that the coupling between surface and subsurface soil moisture decreased with soil depth increasing and decoupling is dominant in the range varying between 0.11 and 0.22 cm3cm−3. The CDF method exhibits superiority for estimating the subsurface soil moisture relative to the ExpF method in the study area. Furthermore, the surface soil moisture values in the coupling range capture the dynamics of the subsurface soil moisture, while decoupling significantly reduces the accuracy of simulating the subsurface soil moisture. Thus, we propose an approach involving the reconstruction of the coupling time series associated with the (de)coupling, which improves the accuracy of the subsurface soil moisture simulation, particularly at depth, where the coupling is weak. Thus, the (de)coupling effect should henceforth be incorporated in the future subsurface soil moisture simulation studies and is helpful to understand the hydrological process of soil, improve regional models and the associated parameters.

Research on China Cities' Total Factor Productivity of Carbon Emission: Based on Decoupling Effect.

Economic development depends on energy consumption, which is a major source of carbon emission. How to achieve economic decarbonization has become one of the key questions urgently needing to be solved on the road of carbon peak and carbon neutral development in China. Advancing total factor productivity (TFP) of carbon emission is an important way to promote economic decarbonization. For the carbon emission TFP, current research is mainly conducted from province level or an industry perspective, and studies its deference with various geographical locations, economic development levels, urbanization levels, etc., lacking the research that combines the decoupling effect to carbon emission TFP. The carbon emission TFP of Chinese cities and how to improve it remain unclear. Therefore, based on Tapio decoupling theory, this paper firstly analyzed the decoupling effect of China’s 284 cities from 2005 to 2019, and aggregated the cities into four groups according to the decoupling effect. Then, using the DEA–Malmquist index, this paper researched the carbon emission TFP and its driving factors based on the aggregation. The result shows that weak decoupling is the main decoupling status in China. As a whole, carbon emission TFP of Chinese cities does not perform well, but it shows a growth trend over time. Strong decoupling cities outperform expansive negative decoupling cities on carbon emission TFP. Technical change and pure technical efficiency change have inhibiting effect and promoting effect on carbon emission TFP, respectively, which are the main factors for the difference of carbon emission TFP between strong decoupling cities and expansive negative decoupling cities. Based on these findings, some common but differentiated recommendations are provided for improving Chinese cities’ carbon emission TFP.

Analysis of Correlation between Waste Accumulation and Countries Welfare Level

The article considers the results of countries analysis by progressiveness degree of waste management based on the correlation between changes in the volume of waste accumulation and indicators of wealth. The author’s novelty is systematization of quantitative and qualitative criteria for analysis and grouping of countries by the effectiveness of waste handling system. As a result of the comparative analysis, three groups of countries are presented: “Green” - European countries with a small population and high level of welfare, with an effective waste management system and a positive decoupling effect, but there is a problem of increasing the volume of waste per capita (Denmark, Sweden and Belgium). “Yellow” group consist of large European countries and Japan, where there is less waste per capita, a responsible approach to recycling and limiting plastic, but there is a problem of proportional growth in welfare and waste. “Red” group includes countries with a large population and problem of increasing the total waste volume, inefficient waste management and low level of recycling (China, USA and Russia). The study showed that the introduction of effective waste management (collection, recycling, waste culture) can be reduced the change index of personal waste and at the same time increase the change index of gross domestic product (per capita).

Haphazard Intentional Sampling in Survey and Allocation Studies on COVID-19 Prevalence and Vaccine Efficacy.

Haphazard intentional sampling is a method developed by our research group for two main purposes: (i) sampling design, where the interest is to select small samples that accurately represent the general population regarding a set of covariates of interest; or (ii) experimental design, where the interest is to assemble treatment groups that are similar to each other regarding a set of covariates of interest. Rerandomization is a similar method proposed by K. Morgan and D. Rubin. Both methods intentionally select good samples but, in slightly different ways, also introduce some noise in the selection procedure aiming to obtain a decoupling effect that avoids systematic bias or other confounding effects. This paper compares the performance of the aforementioned methods and the standard randomization method in two benchmark problems concerning SARS-CoV-2 prevalence and vaccine efficacy. Numerical simulation studies show that haphazard intentional sampling can either reduce operating costs in up to to achieve the same estimation errors yielded by the standard randomization method or, the other way around, reduce estimation errors in up to using the same sample sizes.

Макроэкономическая оценка экологического качества экономического роста на уровне региона

The research featured a macroeconomic assessment of the quality of economic growth. The analysis was based on various environmental factors, obtained in the process of strategic environmental assessment of the developmental priorities of the Kemerovo region in 2002–2020. The research objective was to determine the effect of environmental factors on eco-intensity and economic growth in this resource-based region in the context of global and national environmental challenges. The paper presents an overview of the methods of ecological and economic analysis suitable for strategic environmental assessment. The study featured mathematical methods of calculating the economic eco-intensity and the decoupling effect, as well as the model of economic growth developed by P. Victor. The decoupling effect was rather weak for the main types of negative impact, i.e. pollution, waste generation, disturbed lands, etc. The only green decoupling effect was revealed by the volume of contaminated wastewater. P. Victor's extended model showed the predominance of "brown" economic growth, while the increase in the carbon intensity of the gross domestic product for methane coincided with the significant decrease in the economic development of the region. The article also introduces a forecast of the economic development of the Kemerovo region, based on global and national trends of decarbonization. Transition to the use of the best available technologies should reduce the level of eco-intensity and increase the rate of decarbonization, both in the main industries and in methane processing.

Under the “Double Carbon” Target Study on the Decoupling Effect and Spatial and Temporal Characteristics of Carbon Emissions in China<br/>—Based on Decoupling Theory and EKC Curve Theory

Firstly, the decoupling effect of national per capita GDP and carbon emissions was analyzed based on Tapio decoupling model. Secondly, based on the provincial panel data, the spatial Dubin model was established to conduct empirical research on the impact of regional economic development on carbon emissions, aiming to clarify the influencing factors and temporal and spatial characteristics of Carbon emissions in China, and provide theoretical basis and reference for the realization of “double carbon” target. Finally, the following conclusions were drawn: 1) The decoupling state of national per capita GDP and carbon emissions is mainly weak decoupling, and the decoupling is ideal, at the same time, the emergence of strong decoupling shows that economic development and carbon emission reduction can coexist. 2) The carbon emissions of provinces (cities, autonomous regions) have spatial autocorrelation; Per capita GDP has a significant impact on carbon emissions, and its direct and indirect effects show inverted N-shaped and N-shaped curves respectively. 3) Both FDI and R&D drive carbon emissions negatively, while urbanization and electricity consumption drive carbon emissions positively, with the spatial spillover effects of FDI and urbanization being statistically insignificant. In addition, the direct and indirect effects of industrial structure and population density are opposite. Based on the above conclusions, it is recommended that all regions should strengthen joint prevention and control in the process of carbon emission reduction, promote close cooperation in regional energy conservation and emission reduction, develop a low-carbon economy, and take multiple measures to help achieve the “double carbon” target successfully.

Driving factors of China’s industrial carbon emissions and their decoupling effect: Decomposition and calculation of C-D production function based on time-varying parameters

Driving factors of China’s industrial carbon emissions and their decoupling effect: Decomposition and calculation of C-D production function based on time-varying parameters

Broadband high-efficiency near-infrared graphene phase modulators enabled by metal–nanoribbon integrated hybrid plasmonic waveguides

Abstract The phase modulator is a key component in optical communications for its phase modulation functions. In this paper, we numerically demonstrate a variety of ultra-compact high-efficiency graphene phase modulators (GPMs) based on metal–nanoribbon integrated hybrid plasmonic waveguides in the near-infrared region. Benefiting from the good in-plane mode polarization matching and strong hybrid surface plasmon polariton and graphene interaction, the 20 μm-length GPM can achieve excellent phase modulation performance with a good phase and amplitude decoupling effect, a low insertion loss around 0.3 dB/μm, a high modulation efficiency with V π L π of 118.67 V μm at 1.55 μm, which is 1–3 orders improvement compared to the state-of-the-art graphene modulators. Furthermore, it has a wide modulation bandwidth of 67.96 GHz, a low energy consumption of 157.49 fJ/bit, and a wide operating wavelength ranging from 1.3 to 1.8 μm. By reducing the overlap width of the graphene–Al2O3–graphene capacitor, the modulation bandwidth and energy consumption of the modulator can be further improved to 370.36 GHz and 30.22 fJ/bit, respectively. These compact and energy-efficient GPMs may hold a key to various high-speed telecommunications, interconnects, and other graphene-based integrated photonics applications.

Large Ericksen number limit for the 2D general Ericksen–Leslie system

In this paper, we address the issue of the so-called large Ericksen number limit for the general Ericksen–Leslie system of liquid crystals. By the standard nondimensionalization, we first prove that there exists a unique local smooth solution to the limiting system. Then we provide a qualitative estimate for the difference between the solutions of the general Ericksen–Leslie system and the limiting system, which corresponds to the partial decoupling effect in the limit of large Ericksen number.

Composite Decoupling Control of PMSM Based on Extended State Observer

In order to solve the problem that the dynamic decoupling performance of the traditional decoupling method is reduced due to the parameter disturbance of permanent magnet synchronous motor (PMSM), a composite decoupling control method based on extended state observer (ESO) is proposed in this paper. In this method, voltage drop across stator resistance, cross coupling terms, internal uncertains and external load torque are taken as disturbances. The disturbance is observed in real time by using the extended state observer and compensated to the output end of the current controller, so as to realize the current decoupling control of the system and achieve the purpose of precise control of the current loop. The results of theoretical analysis show and simulation show that the composite decoupling control strategy based on extended state observer has better dynamic decoupling effect.

Decoupling Control of a Multiaxis Hydraulic Servo Shaking Table Based on Dynamic Model

Hydraulic servo shaking table is an essential testing facility to simulate the actual vibration situation in real time. As a parallel mechanism, multiaxis hydraulic servo shaking table shows strong coupling characteristic among different degrees of freedom. When the multiaxis hydraulic shaking table moves to one direction, some unnecessary related motions will appear in other directions, which seriously affect the control performance. An effective approach to decouple motions in command direction and in unnecessary related directions is an urgent need for a higher precision control performance. In this work, the coupling phenomena and reasons of the multiaxis hydraulic servo table are analyzed based on dynamic model of a multiaxis hydraulic servo shaking table. In this regard, multiaxis hydraulic servo shaking table with strong coupling within the physical space is transformed into a set of single-input single-output systems that are independent of each other in the modal space. A decoupling control strategy is proposed in modal space to restrain the coupling motions. Simulation and experimental results show that the proposed control strategy can effectively improve the control performance and the decoupling effect.

Evaluation on the relevance of regional urbanization and ecological security in the nine provinces along the Yellow River, China

In-depth analysis and discussion of the interactive relationship between urbanization and ecological security are basis and prerequisite for ensuring the coordinated development of urbanization and ecological protection. This paper constructed the evaluation index system of urbanization level from four dimensions (i.e., population, economy, society, space) and ecological safety from three aspects (i.e., pressure, governance, environment). Then, the Urbanization Development Index (UDI) and Ecological Security Index (ESI) of the nine provinces along the Yellow River were calculated, and grey relationship and decoupling model were employed to study the interaction between urbanization and ecological security from 2008 to 2018. The main conclusions are as follows: a) The urbanization level and ecological security level of the nine provinces along the Yellow River show an overall upward trend while the increase rate gradually slows down, in which UDI and ESI increases from 0.24 to 0.58 and 0.30 to 0.41 respectively. b) The correlation degree between the urbanization level and the ecological security system is higher than 0.6, which is between the medium correlation and the extremely strong correlation. Population urbanization has the greatest impact on ecological security, with a correlation value of 0.74. Ecological governance has the strongest restraint on urbanization development and the correlation value is 0.72. c) There is a strong decoupling effect between urbanization and ecological security in the nine provinces along the Yellow River, and the future ecological security will gradually become more restrictive on the development of urbanization.