Evolution Of Coupling Research Articles

Coupled evolution between plant hydrologic cycle and organic reef from Late Devonian to Mississippian

古生代陆地植物的起源和繁盛，导致地表水文循环发生了显著变化，对地球表层系统产生了深远的影响。陆地植物一方面通过蒸腾作用增加地表降雨量，加剧了大陆硅酸盐风化作用和有机碳埋藏量；另一方面通过地表径流将陆源营养元素带入海洋，导致海洋初级生产力提高、海水缺氧程度和有机碳埋藏量增加。在晚泥盆世-密西西比亚纪期间，陆地植物和海洋生物礁系统均发生了显著变化，可识别出三个耦合演化阶段：（1）晚泥盆世弗拉期–法门期（Frasnian–Famennian/F–F）转折期植物多样性和覆盖面积明显增加并向高纬度扩张，伴随Kellwasser生物灭绝事件和显生宙最大的层孔海绵–珊瑚礁系统崩溃；（2）泥盆纪–石炭纪（Devonian–Carboniferous/D–C）转折期种子植物多样性显著增加，伴随Hangenberg生物灭绝事件、层孔海绵–珊瑚礁消失、以及密西西比亚纪早期后生动物礁缺失；（3）密西西比亚纪中–晚期（Middle–Late Mississippian/M–LM）种子植物科达类树木的丰度显著增加，伴随M–LM生物灭绝事件和珊瑚礁系统崩溃。种子植物不仅具有较深的根系，还可以克服对水分的依赖，从近岸湿润低地向内陆干旱高地扩张，进而加强陆地水文循环过程。泥盆纪–石炭纪陆地植物（尤其是种子植物）繁盛引发水文循环和硅酸盐风化作用增强，进而导致气候变冷、海水温度降低和缺氧程度加剧可能是控制海洋后生动物礁系统崩溃或消失的主要因素之一；另外，构造运动伴随的陆壳抬升和火山作用可以促进硅酸盐风化，进一步导致海洋环境恶化和生态系统崩溃。

Dynamic Multistage Coupling of FeS2/S Enables Ultrahigh Reversible Na–S Batteries

AbstractThe fundamental challenges that coexisted around sulfur cathode energy storage systems, are the severe polysulfide dissolution and low reactivity resulting in poor reversibility and short cycle life, specifically, in inexpensive sodium ion batteries. Herein, the solution‐processed synthesis of ultra‐high intimate contacted FeS2/S architecture is reported and evolution of the dynamic multistage coupling between the FeS2 and S in sodium–sulfur batteries is revealed. Atomic visualization and in situ spectroscopy conclude that: NaxFeS2 (0 <x ≤1) effectively captures sodium polysulfides and promotes the conversion of S8 to Na2S4 to Na2S2/Na2S; simultaneously, the presence of Na2S2/Na2S traps the continuous growth of iron grains during continuously discharging to 0.4 V, thereby boosting the reversibility and high capacity. Moreover, the density functional theory further analyses the unique coupling effect of Na2Sx with different intermediate states of FeS2. The electrode with unique structure and dynamic coupling exhibits outstanding cycle reversibility and extremely long life, which delivers a reversible capacity of 860 mAh g−1 after 1000 cycles with no capacity decay at 0.5 A g−1. Even under a practical areal capacity of 4 mAh cm−2, it still shows pretty‐well cycling stability.

Pivotal role of reversible NiO6 geometric conversion in oxygen evolution.

Realizing an efficient electron transfer process in the oxygen evolution reaction by modifying the electronic states around the Fermi level is crucial in developing high-performing and robust electrocatalysts1-3. Typically, electron transfer proceeds solely through either a metal redox chemistry (an adsorbate evolution mechanism (AEM), with metal bands around the Fermi level) or an oxygen redox chemistry (a lattice oxygen oxidation mechanism (LOM), with oxygen bands around the Fermi level), without the concurrent occurrence of both metal and oxygen redox chemistries in the same electron transfer pathway1-15. Here we report an electron transfer mechanism that involves a switchable metal and oxygen redox chemistry in nickel-oxyhydroxide-based materials with light as the trigger. In contrast to the traditional AEM and LOM, the proposed light-triggered coupled oxygen evolution mechanism requires the unit cell to undergo reversible geometric conversion between octahedron (NiO6) and square planar (NiO4) to achieve electronic states (around the Fermi level) with alternative metal and oxygen characters throughout the oxygen evolution process. Utilizing this electron transfer pathway can bypass the potential limiting steps, that is, oxygen-oxygen bonding in AEM and deprotonation in LOM1-5,8. As a result, the electrocatalysts that operate through this route show superior activity compared with previously reported electrocatalysts. Thus, it is expected that the proposed light-triggered coupled oxygen evolution mechanism adds a layer of understanding to the oxygen evolution research scene.

Region-dependent meteorological conditions for the winter cold hazards with and without precipitation in China

Cold hazard is one of the major meteorological disasters in winter. However, the meteorological conditions for the cold hazard events vary significantly with both the feature of the event and the region of occurrence. This study divides winter cold hazard events in China into three categories based on the daily gridded dataset of cold hazards from November 1980 to March 2020: events without wintry precipitation (hazardous low temperature, abrupt temperature drop, and/or freezing), with wintry precipitation only (hazardous sleet and/or snowstorm), and with both. The region-dependent multivariate meteorological conditions for each category of cold hazards are investigated using ERA5 reanalysis data. Results show that the surface air temperature (T2m) and its anomaly (T2m_anom) are lower than climatology during cold hazards. But the difference in T2m among provinces exceeds 30 °C, and even for the same province, the difference among different categories of cold hazards exceeds 10 °C. The region- and category-dependent differences of T2m_anom and daily temperature drop (∆T24) are also large, about 5 °C and 2 °C d−1, respectively. The Multivariate Empirical Orthogonal Function analysis has further been applied to not only the abovementioned temperature-related variables but also the precipitation-related variables (i.e., daily accumulated total precipitation, daily accumulated snowfall, and daily mean snow depth) in the middle and lower Yangtze River region, which reveals the event-mean state and spatial–temporal coupling evolution during the progression of the event for the selected key meteorological variables. The meteorological conditions for cold hazards put forward by this study could provide region-dependent and category-dependent reference for the prediction and warning of cold hazards.

Organic selenium compounds determination in the complex matrix by the 1H-77Se HMBC method

The development of the organic Selenium (Se) speciation assay to evaluate Se-enriched yeasts (SeYs) with high selectivity and good sensitivity is highly desired. We investigated contents of three organic Se compounds with a proton-detected 1H-77Se multiple-bond correlation (1H-77Se HMBC) method in a complex yeast matrix. The method showed quantitative correlation peaks resulting by the long-range coupling (nJ(77Se,1H), n = 2, 3) between 1H and 77Se atoms. Broadband excitation and homonuclear coupling evolution suppression can be achieved by utilizing the shaped pulse in the 77Se dimension and the constant time period, respectively. Several NMR methods were compared to improve performances of the 1H-77Se HMBC method in sensitivity. The limit of quantifications (LOQs) were 0.10, 0.11, and 0.15 mmol/L for SeMet, MeSeCys and SeCys2, respectively. Furthermore, the method can greatly raise the resolution without any separation technique compared to other one- and two-dimensional NMR and chromatographic method. The validation of the methodology showed satisfactory specificity, accuracy, precision, and linearity. The method was suitable for routine analysis, quality control and market supervision of Se species in the enriched-Se yeast.

Radiative plateau inflation with conformal invariance: Dynamical generation of electroweak and seesaw scales

We investigate a scale-invariant $B-L$ scenario where the Standard Model (SM) is supplemented with a dark scalar $\phi$ which has gauge \& Yukawa interactions, with the couplings $g_{BL}$ and $y$, respectively, leading to radiative plateau inflation at scale $\phi=M$ in the ultraviolet (UV), while dynamically generating the Electroweak and Seesaw scales \textit{\'a l\'a} Coleman-Weinberg in the infrared (IR). This is particularly achieved by implementing threshold corrections at an energy scale $\mu_T$ arising due to the presence of vector-like fermions. We show that implementing the inflationary observables makes the couplings solely dependent on the plateau scale $M$, leaving us with only two independent parameters $M$ and $\mu_T$. Within the theoretically consistent parameter space defined by $m_{Z_{BL}} > 850~\rm GeV$, from the assumption of independent evolution of the dark sector couplings from the SM couplings and $M < 5.67~M_P$ required for the realisation of inflationary \textit{plateau-like} behaviour of the potential around $\phi=M$, where $M_P=2.4\times10^{18}$ GeV is the reduced Planck mass, we identify the parameter space that is excluded by the current LHC results from the search for the heavy $Z_{BL}$ boson. For typical benchmark points in the viable parameter regions, we estimate the reheating temperature to be $\mathcal{O}(TeV)$ thus consistent with the standard Big Bang Nucleosynthesis (BBN) constraints. For typical benchmark points ($M=5.67,~1,~0.1~M_P$) we predict the scales of inflation to be $\mathcal{H}_{inf}=2.79\times10^{12}$ GeV, $1.53\times10^{10}$ GeV and $1.53\times10^7$ GeV, respectively.

Phase field modeling of coupling evolution of fracture and dielectric breakdown in ferroelectric materials

Ferroelectric materials have attracted increasing attention due to their distinguished electromechanical coupling properties. Fracture and dielectric breakdown are two main failure behaviours of ferroelectric materials, which may occur simultaneously under large mechanical and electrical loads. Understanding the coupling evolution of fracture and dielectric breakdown is crucial for the application of ferroelectric materials under complex electromechanical environments. In the present study, a phase field model with multiple order parameters is developed to investigate the coupling evolution behaviours of fracture and dielectric breakdown of ferroelectric materials subjected to the mechanical and electrical loadings. In the phase field model, coupled electromechanical degradation functions are proposed to model the interface boundary conditions of fracture and dielectric breakdown. Generalized configurational forces of fracture and dielectric breakdown are obtained from the phase field model to analyse the driving forces for the evolution of fracture and dielectric breakdown. The interaction between fracture and dielectric breakdown is predicted by using the phase field model with a set of interface boundary conditions. The simulation results show that dielectric breakdown occurs at impermeable crack tips due to the concentrated electric field, while the stress distribution around the crack tip and the driving force of crack propagation are influenced by dielectric breakdown. The attraction of crack to electrical treeing path and the deflection of electrical treeing to crack path are predicted during the coupling evolution of fracture and dielectric breakdown. The results of this work provide an in-depth insight into the electromechanical coupling failure of fracture and breakdown of ferroelectric materials. The developed model framework can be employed to investigate more complex electromechanical coupling failures of dielectric, piezoelectric and ferroelectric materials and structures.

Design, evolution, formation and effect mechanism of coupling distributed soft and hard micro-regions in Al–Zn–Mg–Cu–Fe alloys with high formability

Here, we report the design, evolution, formation and effect mechanism of coupling distributed soft and hard micro-regions, and propose the mechanism of evading the strength-formability trade-off dilemma for Al–Zn–Mg–Cu alloys. The results show that the coupling distributed soft and hard micro-regions, i.e., spherical shell distribution of soft and hard micro-regions, can be formed based on the precise theoretical calculation and thermomechanical processing control. Simultaneously, a heterogeneous grain distribution of fine and coarse grains can be induced in the alloys, which results in the greatly improved average plasticity-strain ratio r to the value of 0.761. This value is much higher than those of the other 7xxx series Al alloys with a similar ultimate tensile strength. Based on the microstructure evolution, the forming mechanism of heterogeneous grain distribution was proposed. These findings shed light on new strategies for designing and developing high-strength and high-formability Al–Zn–Mg–Cu alloys and other Al alloys.

Coupled evolution of piston asperity and cylinder bore contour of piston/cylinder pair in axial piston pump

The wear condition of the piston/cylinder pair is crucial to the performance and reliability of the axial piston pump. The hard piston surface, the soft cylinder bore surface, and the interface oil film affects each other during the wear process. Specifically, in the mixed lubrication region, the geometry of the hard piston surface asperity directly affects the wear of soft cylinder bore surface, while the asperities may deform or even degrade when penetrating and sliding against the cylinder bore. So far, there is no suitable method to simulate their coupled evolution. This paper proposed a wear process simulation model considering the real-time interaction between the elasto-plastic deformation of the piston surface asperity, the wear contour of the cylinder bore, and the lubrication condition of the interface. An offline library of the elasto-plastic constitutive behavior of the asperity based on the finite element method (FEM) is established as a part of the simulation model to precisely analyze the deformation and degradation of the asperity and quickly invoke them in the numerical wear process simulation. The simulation and experimental results show that the piston asperity and the cylinder bore contour converge to a steady state after running-in for about 0.5 h. The distribution of the simulated asperity degradation and wear depth is also verified by the experiment.

Temperature-driven spin-zero effect in TaAs2

The electrical and thermo-electrical transport properties of the semimetal TaAs2 have been measured in a magnetic field applied along the [−2 0 1] direction. The resulting field dependences of the resistivity as well as the Hall, Seebeck, and Nernst coefficients below T ≈ 100 K can be satisfactorily described within the two-band model consisting of electron and hole pockets. At low temperature, all of the measured coefficients exhibit significant contributions from quantum oscillations. The fast Fourier-transform (FFT) of the oscillatory Nernst signal shows two fundamental frequencies, Fα = 105 T and Fβ = 221 T, and the second harmonic of the latter (F2β = 442 T). The ratio between the FFT amplitudes of Fβ and F2β changes with temperature in an unusual way, indicating the observation of a spin-zero effect caused by temperature change. This is likely related to the substantial temperature dependence of the Landé g-factor, which in turn may stem from the non-parabolic energy dispersion or temperature evolution of the spin-orbit coupling.

Structure construction, evolution analysis and sustainability evaluation of Water-Ecological-Economic system

Under the influence of human activities, the unary water cycle has been transformed into a “natural–social” dualistic water cycle, and the analysis of driving mechanism of the water system under the dualistic water cycle has become an important proposition for sustainable human-water development. This study explored the connotation, framework, and structure of the Water-Ecological-Economic (WEE) system. The WEE system encompasses water resources, society and economy, water use efficiency, water environment, and water ecology subsystems which interact functionally. And system dynamics is used to drive the evolution of system coupling. For each subsystem's characteristics, its sustainability evaluation index is proposed. MDM-TOPSIS combination evaluation model is applied to calculate the weights of indices and the sustainability comprehensive indicator of WEE system. Taking Nanyang in China as a case study, the results show that the sustainability of the WEE system has a downward trend in the early stage, but in the middle and late stages, ecological and environmental protection is considered, the sustainability level shows an upward trend with the support of several safeguard policies. The WEE system and its sustainability assessment theory proposed in this study will provide scientific support to water resources management and sustainable development planning.

How many 1-loop neutrino mass models are there?

It is well-known that at tree-level the d = 5 Weinberg operator can be generated in exactly three different ways, the famous seesaw models. In this paper we study the related question of how many phenomenologically consistent 1-loop models one can construct at d=5. First, we discuss that there are two possible classes of 1-loop neutrino mass models, that allow avoiding stable charged relics: (i) models with dark matter candidates and (ii) models with “exits”. Here, we define “exits” as particles that can decay into standard model fields. Considering 1-loop models with new scalars and fermions, we find in the dark matter class a total of (115+203) models, while in the exit class we find (38+368) models. Here, 115 is the number of DM models, which require a stabilizing symmetry, while 203 is the number of models which contain a dark matter candidate, which maybe accidentally stable. In the exit class the 38 refers to models, for which one (or two) of the internal particles in the loop is a SM field, while the 368 models contain only fields beyond the SM (BSM) in the neutrino mass diagram. We then study the RGE evolution of the gauge couplings in all our 1-loop models. Many of the models in our list lead to Landau poles in some gauge coupling at rather low energies and there is exactly one model which unifies the gauge couplings at energies above 1015 GeV in a numerically acceptable way.

Biogeodynamics: Coupled evolution of the biosphere, atmosphere, and lithosphere

Biogeodynamics: Coupled evolution of the biosphere, atmosphere, and lithosphere

Quantitative simulation and verification of urbanization and eco-environment coupling coil in Beijing-Tianjin-Hebei urban agglomeration, China

• A new framework to verified quantitatively the UECCs theory. • UECCs types of BTHUA and 13 cities were simulated and judged. • Evolution states of UECCs were summarized as nine types based on ratio of geometric area. • Urban scale and function, industry transformation, technology progress can affect UECCs. • Implications can be proposed to mitigate the conflicts of UE for different types of cities. The coupling evolution characteristics of urbanization and eco-environment (UE) can be summarized as five types in theory: linear, index curve, logarithmic curve, double index curve, S-shaped curve. According to the ratio of geometric area, the evolution states of the urbanization and eco-environment coupling coil (UECC) can be summarized as nine types: zero, primary, low-level, lower-medium-level, medium-level, upper-medium-level, high-level, highest-level, excessive urbanization. They reflect different evolution laws corresponding to different types of urban development stages, characteristics, patterns. The study quantitatively simulated and verified the coupling coil theory of UECCs, constructed comprehensive identification index systems and models for coupling coils. Results are as follows: from 2000 to 2019, the coupling relationships of UE in Beijing-Tianjin-Hebei urban agglomeration and metropolis, Beijing, Tianjin, Shijiazhuang, accord with S-shaped curve UECC; eco-cities, Zhangjiakou, Chengde, Qinhuangdao, accord with index curve UECC; Baoding, Langfang accord with logarithmic curve UECC; Handan, Xingtai, Cangzhou, Hengshui, Tangshan accord with double index curve UECC; linear UECC never exist in real life. Changes in urban scale and function, transformation of industrial structure, technological progress can be the key driving factors to boost the coupling state of UECCs from a low level to a medium level, and gradually to a high level. Some implications can be proposed to mitigate the conflicts between urbanization and eco-environment for different types of cities.

Research on the Temporal and Spatial Evolution of the Dynamic Coupling and Coordinated Development of Two-Way FDI in Jinan City

Under the background of "dual circulation", to implement the international investment concept of "bringing in" and "going global", it is urgent to realize the coupling and coordinated development of IFDI and OFDI. On the basis of trying to explore the coupling and coordination mechanism of two-way FDI in Jinan City, this paper uses the system coupling evaluation model to measure the coupling degree and coupling coordination degree. The results show that from 2003 to 2020, the coupling degree of two-way FDI in Jinan was at a high level of coupling, but the coupling coordination degree was low.

Evolution of hormone-phenotype couplings and hormone-genome interactions

When selection favors a new relationship between a cue and a hormonally mediated response, adaptation can proceed by altering the hormonal signal that is produced or by altering the phenotypic response to the hormonal signal. The field of evolutionary endocrinology has made considerable progress toward understanding the evolution of hormonal signals, but we know much less about the evolution of hormone-phenotype couplings, particularly at the hormone-genome interface. We briefly review and classify the mechanisms through which these hormone-phenotype couplings likely evolve, using androgens and their receptors and genomic response elements to illustrate our view. We then present two empirical studies of hormone-phenotype couplings, one rooted in evolutionary quantitative genetics and another in comparative transcriptomics, each focused on the regulation of sexually dimorphic phenotypes by testosterone (T) in the brown anole lizard (Anolis sagrei). First, we illustrate the potential for hormone-phenotype couplings to evolve by showing that coloration of the dewlap (an ornament used in behavioral displays) exhibits significant heritability in its responsiveness to T, implying that anoles harbor genetic variance in the architecture of hormonal pleiotropy. Second, we combine T manipulations with analyses of the liver transcriptome to ask whether and how statistical methods for characterizing modules of co-expressed genes and in silico techniques for identifying androgen response elements (AREs) can improve our understanding of hormone-genome interactions. We conclude by emphasizing important avenues for future work at the hormone-genome interface, particularly those conducted in a comparative evolutionary framework.

Engineering FeP4/CoFe2O4 heterostructure with balanced proton adsorption ability for efficient hydrogen evolution reaction

Developing cost-efficient electrocatalysts for hydrogen evolution reaction (HER) with low overpotential, fast kinetics and good stability is one of the challenges to promote the industrial application of water electrolysis technology. Herein, we construct a novel heterostructure electrocatalyst with abundant FeP4 nanoparticles grown on the surface of CoFe2O4 nanosheets for efficient HER catalysis. FeP4, as the crucial co-catalyst, not only promotes the proton adsorption process due to its large electronegativity but also improves the electron structure around the Co sites for optimizing H* coupling and H2 evolution process. Consequently, the FeP4/CoFe2O4 heterostructure electrocatalyst shows a much improved HER performance (η100 = 168 mV) and a faster reaction kinetics by comparing with the pristine FeP4 and CoFe2O4. Further electrochemical characterization demonstrates that the heterostructure is also beneficial to increase active sites and enhance intrinsic activity. This work provides a feasible perspective for constructing heterostructure to acquire excellent HER catalysts.

SORDOR pulses: expansion of the Böhlen-Bodenhausen scheme for low-power broadband magnetic resonance.

A novel type of efficient broadband pulse, called second-order phase dispersion by optimised rotation (SORDOR), has recently been introduced. In contrast to adiabatic excitation, SORDOR-90 pulses provide effective transverse 90 rotations throughout their bandwidth, with a quadratic offset dependence of the phase in the plane. Together with phase-matched SORDOR-180 pulses, this enables the Böhlen-Bodenhausen broadband refocusing approach for linearly frequency-swept pulses to be extended to any type of 90/180 pulse-delay sequence. Example pulse shapes are characterised in theory and experiment, and an example application is given with a -PROJECT experiment for measuring relaxation times with reduced distortions due to -coupling evolution.

Radiative coupling of two quantum emitters in arbitrary metallic nanostructures

We propose a general formalism beyond Weisskopf–Wigner approximation to efficiently calculate the coupling matrix element, evolution spectrum and population evolution of two quantum emitters in arbitrary metallic nanostructures. We demonstrate this formalism to investigate the radiative coupling and decay dynamics of two quantum emitters embedded in the two hot spots of three silver nano-spheroids. The vacuum Rabi oscillation in population evolution and the anti-crossing behavior in evolution spectrum show strong radiative coupling is realized in this metallic nanostructure despite its strong plasmon damping. Our formalism can serve as a flexible and efficient calculation tool to investigate the distant coherent interaction in a large variety of metallic nanostructures, and may be further developed to handle the cases for multiple quantum emitters and arbitrary dielectric–metallic hybrid nanostructures.

Coupled simultaneous evolution of disease and information on multiplex networks

We analyzed the interaction processes between disease and disease-based information on multiplex networks. Unlike previous models, an epidemic can spread in parallel with the information diffusion during a time step. We used the probability theory to derive a novel individual-based transmission model, which is different from the reported methods, and developed a pairwise formulation of this model. Interestingly, when the infection rate is enough large, the infection curve firstly achieves a large peak, then rapidly decreases to a steady state. In addition, we considered the other two coexistence mechanisms of disease and information during a time step, and found that all mechanisms have the same condition of epidemic outbreak. The theoretical results strongly agree with discrete-time stochastic simulations, and may provide insights for a wide application range for multi-dynamic spreading processes.