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China's commitment to attaining carbon neutrality by 2060 has galvanized research into carbon sequestration, a critical approach for mitigating climate change. Despite the rapid urbanization observed since the turn of the millennium, a comprehensive analysis of how urbanization influences urban carbon storage throughout China remains elusive. Our investigation delves into the nuanced effects of urbanization on carbon storage, dissecting both the direct and indirect influences by considering urban-suburban gradients and varying degrees of urban intensity. We particularly scrutinize the roles of climatic and anthropogenic factors in mediating the indirect effects of urbanization on carbon storage. Our findings reveal that urbanization in China has precipitated a direct reduction in carbon storage by approximately 13.89 Tg of carbon (Tg C). Remarkably, urban sprawl has led to a diminution of vegetation carbon storage by 8.65 Tg C and a decrease in soil carbon storage by 5.24 Tg C, the latter resulting from the sequestration of impervious surfaces and the elimination of organic matter inputs following vegetation removal. Meanwhile, carbon storage in urban greenspaces has exhibited an increase of 6.90 Tg C and offsetting 49.70% of the carbon loss induced by direct urbanization effects. However, the indirect effects of urbanization predominantly diminish carbon storage in urban greenspaces by an average of 5.40%. The degree of urban vegetation management emerges as a pivotal factor influencing the indirect effects of urbanization on carbon storage. To bolster urban carbon storage, curbing urban sprawl and augmenting urban green spaces are imperative strategies. Insights from this study are instrumental in steering sustainable urban planning and advancing towards the goal of carbon neutrality. [Display omitted] • - Analyzed 30 m resolution urban carbon storage changes from 2000 to 2020. • - Evaluated direct and indirect urbanization impacts on carbon storage. • - Identified a direct urban expansion carbon loss of 13.89 Tg. • - Noted a 6.90 Tg C increase in urban greenspaces, mitigating 49.70% of the loss. • - −5.40% indirect effect on greenspaces, aggravating decline in carbon storage. [ABSTRACT FROM AUTHOR]

A high-order accurate quadrature rule for the discretization of boundary integral equations (BIEs) on closed smooth contours in the plane is introduced. This quadrature can be viewed as a hybrid of the spectral quadrature of Kress (Math. Comput. Model. 15(3-5), 229–243 1991) and the locally corrected trapezoidal quadrature of Kapur and Rokhlin (SIAM J. Numer. Anal. 34(4), 1331–1356, 1997). The new technique combines the strengths of both methods, and attains high-order convergence, numerical stability, ease of implementation, and compatibility with the “fast” algorithms (such as the Fast Multipole Method or Fast Direct Solvers). Important connections between the punctured trapezoidal rule and the Riemann zeta function are introduced, which enable a complete convergence analysis and lead to remarkably simple procedures for constructing the quadrature corrections. The paper reports a detailed comparison between the new method and the methods of Kress, of Kapur and Rokhlin, and of Alpert (SIAM J. Sci. Comput. 20(5), 1551–1584, 1999). [ABSTRACT FROM AUTHOR]

Frequency-domain wave scattering problems that arise in acoustics and electromagnetism can be often described by the Helmholtz equation. This work presents a boundary integral equation method for the Helmholtz equation in 3-D multilayered media with many doubly periodic smooth layers. Compared with conventional quasi-periodic Green's function method, the new method is robust at all scattering parameters. A periodizing scheme is used to decompose the solution into near- and far-field contributions. The near-field contribution uses the free-space Green's function in an integral equation on the interface in the unit cell and its immediate eight neighbors; the far-field contribution uses proxy point sources that enclose the unit cell. A specialized high-order quadrature is developed to discretize the underlying surface integral operators to keep the number of unknowns per layer small. We achieve overall linear computational complexity in the number of layers by reducing the linear system into block tridiagonal form and then solving the system directly via block LU decomposition. The new solver is capable of handling a 100-interface structure with 961.3k unknowns to 10 − 5 accuracy in less than 2 hours on a desktop workstation. • Boundary integral equation method and periodizing scheme for the Helmholtz equation in 3-D multilayered media. • High-order surface quadrature rule based on an error-corrected Trapezoidal quadrature method. • Linear growth of computational cost and memory usage against the number of layers. • A numerical example with 101 layers. [ABSTRACT FROM AUTHOR]

This paper discusses the planar closed orbits of the three-dimensional autonomous system where P, Q and R are polynomials with { P, Q, R} = 2. We demonstrate that this system would not have any planar closed orbit for some coefficients. [ABSTRACT FROM AUTHOR]

The transfer of land plays a crucial role in revitalizing land resources, acting as a catalyst for promoting the high-quality development of agriculture. The land transfer ratio is a crucial metric for assessing the progress of rural land transfer and the effective allocation of rural land resources. Thus, this study examines the rural land transfer ratio across 30 provinces in China from 2005 to 2020. The study explores the distribution characteristics of the ratio using the rank-size rule and trend surface analysis. The LISA space-time transition method is employed to analyze the spatial and temporal dynamics of the rural land transfer ratio and examine its convergence. The study aims to comprehensively analyze the spatial distribution characteristics and evolutionary patterns of rural land transfer in China, illustrating the convergence and influencing factors during the development process. The results indicate that: (1) The rural land transfer ratio in China is generally increasing, with a spatial pattern showing an upward trend from west to east and from north to south. The main spatial contrast is between the eastern and western regions, with a relatively minor distinction between the southern and northern regions. (2) The LISA space-time transition highlights a significant spatial locking effect in China's rural land transfer ratio, suggesting strong spatial integration in its evolution. (3) Clear indications of σ convergence, absolute β convergence, and club convergence are evident in China's rural land transfer ratio. This suggests a gradual reduction in internal disparities among provinces and regions, where areas with higher land transfer ratios influence spatial spillover effects on adjacent lower areas. (4) Factors such as transportation infrastructure, irrigation, water conservancy construction, and farmers' per capita income collectively influence the spatial and temporal evolution of China's rural land transfer ratio, with dominant driving factors varying across different periods. [ABSTRACT FROM AUTHOR]

A graphical abstract is mandatory for this journal. It should summarize the contents of the article in a concise, pictorial form designed to capture the attention of a wide readership online. Authors must provide images that clearly represent the work described in the article. Graphical abstracts should be submitted as a separate file in the online submission system. Image size: please provide an image with a minimum of 531 × 1328 pixels (h × w) or proportionally more. The image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96 dpi. Preferred file types: TIFF, EPS, PDF or MS Office files. You can view Example Graphical Abstracts on our information site. Authors can make use of Elsevier's Illustration Services to ensure the best presentation of their images also in accordance with all technical requirements. • Assign rotational spectra of the carbon-13 isotopologues of pyrrole-water. • Obtain a two-dimensional potential energy surface scan on water-center motions. • Establish the average ground state structure, water tunneling path, and barrier. • Identify a barrierless, water large amplitude motion. The rotational spectrum of pyrrole-water was investigated before (Tubergen et al., 1993) In this work, we have applied a recently developed semiempirical tight-binding quantum chemistry program and DFT calculations to identify possible low energy conformers of the pyrrole-water complex which feature σ- and π-type hydrogen-bonding interactions. Using a cavity-based and two chirped pulse Fourier transform microwave spectrometers, we have measured and assigned all monosubstituted 13C isotopologues of pyrrole-water in their natural abundances. The 14N nuclear quadrupole hyperfine splittings and water tunneling doublets of these rarer isotopologues have also been observed and analyzed. Furthermore, we have carried out potential energy surface scans along possible paths of water large amplitude motions and identified all four previously proposed pyrrole-water geometries and correlated them to one global minimum and three transition states. The theoretical investigation together with the additional 13C experimental data allow one to confidently identify the ground state geometry and also estimate the water tunneling barrier. [ABSTRACT FROM AUTHOR]

• A spectrally-accurate close evaluation scheme for Stokes boundary integral operators. • Adaptive panel refinement for arbitrarily shaped boundaries. • Graded meshes to treat corners. • Example problems from microfluidic chip design and vascular network flows. We present a fast, high-order accurate and adaptive boundary integral scheme for solving the Stokes equations in complex—possibly nonsmooth—geometries in two dimensions. We apply the panel-based quadratures of Helsing and coworkers to evaluate to high accuracy the weakly-singular, hyper-singular, and super-singular integrals arising in the Nyström discretization, and also the near-singular integrals needed for flow and traction evaluation close to boundaries. The resulting linear system is solved iteratively via calls to a Stokes fast multipole method. We include an automatic algorithm to "panelize" a given geometry, and choose a panel order, which will efficiently approximate the density (and hence solution) to a user-prescribed tolerance. We show that this adaptive panel refinement procedure works well in practice even in the case of complex geometries with large number of corners, or close-to-touching smooth curves. In one example, for instance, a model 2D vascular network with 378 corners required less than 200K discretization points to obtain a 9-digit solution accuracy. [ABSTRACT FROM AUTHOR]

Effect of Mn (14.94,18.21, and 23.6 wt%) and Al (0.002,0.75, and 1.47 wt%) contents on hot ductility of five high alloy Fe-xMn-C-yAl austenitic Twinning induced plasticity (TWIP) steels were investigated by Gleeble-3500 thermo-mechanical simulator in the temperature range 700–1200 ℃ under a constant strain rate of 3 × 10 −3 s −1 . The results indicated that the hot ductility of different Mn-containing TWIP steels are not appreciable with all the reduction of area (RAs) values lower than 30%, and RAs would be further decreased as the Mn content increased. The matrix of TWIP steel is inhomogeneous with severe Mn microsegregation in the interdendritic zone. Moreover, the C microsegregation ratio increases from 0.85 to 1.16, 0.76–1.22, to 0.74–1.32 when Mn concentration increases from 14.94 wt%, 18.21 wt%, to 23.6 wt%, respectively. Additionally, the microstructure and the true stress-true strain curves suggested that dynamic recrystallization (DRX) took place in 14.94 wt% Mn bearing TWIP steel, while the fraction of DRX grains decreased dramatically with increasing Mn content. Therefore, it is inferred that the high Mn addition inhibited DRX, together with the acceleration effect of C microsegregation by Mn addition should be the most predominant factor of the hot ductility loss with Mn content increases in TWIP steels. On the other hand, Al addition to TWIP steels resulted in a dramatic increase of AlN particles content. The AlN particle accounted for nearly 64% of the total precipitate content for the 1.59 wt% Al containing TWIP steel. Compared with Al-free TWIP steel, the excessive number of fine AlN particles in the 1.59 wt% Al containing steel effectively pinned the austenite grain boundaries, which inhibited the occurrence of DRX and simultaneously promote grain boundary sliding, resulting in the deterioration of hot ductility. [ABSTRACT FROM AUTHOR]

Cardiac ischemia, hypoxia, arrhythmias, and heart failure share the common electrophysiological changes featured by the elevation of intracellular Ca2+ (Ca2+ overload) and inhibition of the inward rectifier potassium (IK1) channel. IK1 channel agonists have been considered a new type of anti‐arrhythmia and cardioprotective agents. We predicted using a drug repurposing strategy that tetramisole (Tet), a known anthelminthic agent, was a new IK1 channel agonist. The present study aimed to experimentally identify the above prediction and further demonstrate that Tet has cardioprotective effects. Results of the whole‐cell patch clamp technique showed that Tet at 1–100 μmol/L enhanced IK1 current, hyperpolarized resting potential (RP), and shortened action potential duration (APD) in isolated rat cardiomyocytes, while without effects on other ion channels or transporters. In adult Sprague–Dawley (SD) rats in vivo, Tet showed anti‐arrhythmia and anticardiac remodeling effects, respectively, in the coronary ligation‐induced myocardial infarction model and isoproterenol (Iso, i.p., 3 mg/kg/day, 10 days) infusion‐induced cardiac remodeling model. Tet also showed anticardiomyocyte remodeling effect in Iso (1 μmol/L) infused adult rat ventricular myocytes or cultured H9c2 (2‐1) cardiomyocytes. Tet at 0.54 mg/kg in vivo or 30 μmol/L in vitro showed promising protections on acute ischemic arrhythmias, myocardial hypertrophy, and fibrosis. Molecular docking was performed and identified the selective binding of Tet with Kir2.1. The cardioprotection of Tet was associated with the facilitation of IK1 channel forward trafficking, deactivation of PKA signaling, and inhibition of intracellular calcium overload. Enhancing IK1 may play dual roles in anti‐arrhythmia and antiventricular remodeling mediated by restoration of Ca2+ homeostasis. [ABSTRACT FROM AUTHOR]

• An analytical framework for soft modes of rotation-cross vector metamaterial chains is proposed. • An anomalous nonlinear phenomenon is found: the polarization index of all nodes are equal. • Through adjusting the polarization index, the morphology of the vector boundary mode can be tuned. • Existence conditions of static-topological-soliton vector boundary modes are clarified. • Different collision responses of boundary modes are revealed for even- and odd-nodes chains. The boundary modes of highly distorted mechanical metamaterials exhibit obvious nonlinear effects. However the characteristics of vector boundary modes (boundary modes with two coupled components—translation and rotation) of nonlinear mechanical metamaterials have not been revealed, which severely limits their applications in vector deformation controls of robots and intelligent structures. In this work, by building the continuous and discrete models of nonlinear mechanical metamaterials with vector couplings, an analytical framework for soft modes of rotation-cross vector metamaterial chains is proposed. An anomalous nonlinear phenomenon is found, namely, the polarization indices (the ratio of displacement to the increment of rotation angle) of all nodes are equal, which is further verified by the experiment. Specially, the results show that the morphology of the vector boundary mode can be tuned through adjusting the polarization index. Based on this, existence conditions of static-topological-soliton boundary modes under couplings of translation and rotation are revealed explicitly, and the results further show that the vector boundary modes based on static-topological-solitons are robust and immune to structural imperfections, which is crucial to achieve precise vector deformation controls. These novel rules and phenomena presented in this work can provide new ideas and important bases for vector deformation controls of nonlinear mechanical metamaterials and their applications in lightweight robots and intelligent structures. [Display omitted] [ABSTRACT FROM AUTHOR]

The COVID-19 outbreak has injured the global industrial supply chain, especially China as the world's largest manufacturing base. Since 2020, China has implemented a rigorous lockdown policy, which has sternly damaged sectoral trade in export-oriented coastal areas. Fujian Province, which mainly processes imported materials, has a more profound influence. Although the COVID-19 lockdown has had some detrimental consequences on the world economy, it also had some favorable benefits on the global ecology. Previous studies have shown that the lockdown has altered the physical water quantity and quality, but the lack of total, virtual, and physical water research that combines water quantity and water quality simultaneously to pinpoint the subject and responsibility of water resources consumption and pollution. This research quantified the physical, virtual, and total water consumption and water pollution among 30 sectors in Fujian Province based on the theory of water footprint and the Economic Input-Output Life Cycle Assessment model. SDA model was then used to investigate the socioeconomic elements that underpin variations in the water footprint. The results show that after the lockdown, the physical water quantity and the physical grey WF in Fujian Province decreased by 2.6 Gm3 (−6.7%) and 0.4 Gm3 (−1.3%) respectively. The virtual water quantity decreased by 2.3 Gm3 (−4.5%), whereas the virtual grey WF rose by 1.5 Gm3 (4.3%). The total water quantity dropped by 3.3 Gm3 (−4.9%), while the grey WF increased by 1.2 Gm3 (2.5%), i.e. the COVID-19 lockdown decreases physical water quantity and improves local water quality. More than 50% of the water comes from virtual water trade outside the province (virtual water is highly dependent on external), and around 60% of the grey WF comes from physical sewage in the province. The COVID-19 lockdown reduced water outsourcing across the province (paid nonlocally decrease) but increased pollution outsourcing (paid nonlocally increase). And gross capital formation's contribution to the growth in water footprint will continue to rise. As a result, this study suggested that Fujian should take advantage of sectoral trade network to enhance the transaction of green water-intensive intermediate products, reduce the physical water consumption of blue water-intensive sectors, and reduce the external dependence on water consumption. Achieving the shared responsibility of upstream and downstream water consumption and reducing the external dependence on water in water-rich regions is crucial to solving the world's water problems. This research provides empirical evidence for the long-term effects of COVID-19 lockdown on the physical and virtual water environment. [Display omitted] • The impact of the COVID-19 lockdown on Fujian's water footprints (WFs) is explored. • The lockdown measures reduce physical water consumption with water quality improved. • Over 50% of water consumption is external and 60% of grey WF is local-based. • Fujian should leverage sectoral trade network to enhance its water sustainability. [ABSTRACT FROM AUTHOR]

A characterization of non-metallic inclusions in Fe-Mn-Si-Al twinning-induced plasticity (TWIP) steels during argon oxygen decarburization-electroslag remelting-forging (AOD-ESR-forging) process has been performed. The two main kinds of inclusions found in TWIP-AOD ingots are single Al(O)N and MnS(Se)-Al(O)N aggregates. After the ESR process, Al(O)N and MnS(Se) inclusions in all size ranges significantly decrease while other kinds of inclusions show only minor changes. In the present study, the precipitation, growth, and dissolution of AlN and MnS inclusions have been analyzed by thermodynamics and kinetics. It is found that AlN inclusions in TWIP steels can already precipitate in the liquid. Furthermore, AlN inclusions precipitated in the liquid TWIP steels can act as the heterogeneous nuclei of MnS inclusions, and thus forming Al(O)N and MnS(Se) · Al(O)N clusters. After ESR refining, the precipitation temperature of AlN and MnS inclusions will be significantly decreased, and AlN inclusions cannot be formed in the liquid TWIP steels in particular. The kinetic analysis show that the growth of AlN inclusions will be difficult during the ESR process, because their growth rate decreases significantly, while the dissolution rate increases. [ABSTRACT FROM AUTHOR]

Objectives The incidence of arrhythmia is associated with autoantibodies against the second extracellular loop of β 1 -adrenergic receptor (β 1 -AAbs). The current study was designed to determine the mechanisms by which arrhythmia experimentally might be induced by β 1 -AAbs. Methods Blood samples were collected from patients with varied arrhythmias or coronary heart disease (CHD) and healthy subjects. The titer of β 1 -AAbs was assessed. Passive immunization rat models with β 1 -AAbs were established to determine whether β 1 -AAbs induced arrhythmia. Conventional intracellular microelectrode technique and whole cell patch clamp were employed to record action potential duration (APD), resting potential (RP), L-type calcium current ( I Ca-L ), sodium–calcium exchange current (INCX), transient outward potassium current ( I to ), inward rectifier potassium current ( I k1 ) and delayed rectifier potassium current ( I k ). Results High levels of β 1 -AAbs were found in the sera of heart disease patients, especially in ventricular arrhythmia (VA). Transfusion with β 1 -AAbs could induce arrhythmias in normal rats in vivo. β 1 -AAbs purified from the sera of active immunized rats induced triggered activity (TA), delayed after depolarization (DAD), and prolonged APD in the papillary muscles of rats. β 1 -AAbs prolonged QT interval, increased I Ca-L and decreased I K1 , I to and I Na–Ca in rat ventricular myocytes in vitro. All these effects can be inhibited by β 1 -AR blocker metoprolol. Conclusions These results demonstrate for the first time that β 1 -AAbs could directly induce ventricular arrhythmia by prolonging QT interval. [ABSTRACT FROM AUTHOR]

• A multi-scale gully erosion monitoring method was developed. • Long-term gully morphology changes from 1959 to 2018 were monitored. • Impact of land use and topographic factors on gully-head retreat was evaluated. • Topographic thresholds of gully initiation were determined. Gully erosion has been widely regarded as an extreme process of land degradation around the world. Gully development rate and topographic thresholds obtained by measuring the morphological parameters of multiple gullies and their influencing factors are important indicators used to characterize gully activity and potential locations of gully initiation. However, existing gully measurement and observation methods are time-consuming and labor-intensive, and usually only a single or several gullies can be measured at a time. The objectives of this study are to develop a multi-scale gully erosion monitoring method by combining unmanned aerial vehicle (UAV) technology with historical aerial photogrammetry and a field survey, achieve the measurement of gully morphological parameters (length, width, depth, area, width-depth ratio, cross-sectional area and volume) and environmental factors (land use, slope gradient and drainage basin area) for numerous gullies in larger regions, and finally, solve the issue of the accurate calculation of regional topographic thresholds and gully development rates. We applied a multi-scale gully erosion monitoring method in the marginal zone of the Chinese Loess Plateau to investigate the gully changes from 1959 to 2018 and further identified long-term gully development patterns and their main control factors. We identified 46 permanent gullies via a field survey. Long-term developments in 30 permanent gullies were obtained using historical aerial photographs and UAV images. The topographic threshold relationship between the upslope drainage basin area (A) and local slope gradient (S) was determined using the remaining 16 incipient gullies derived from UAV images. The results indicated that the gully dimensions experienced significant expansion; the linear gully-head retreat was considerably stronger than the gully widening and deepening. The contribution of the eroded volume from the gully-head retreat to the total eroded volume was 6.1 times that of the gully sidewall retreat, indicating that gully-head retreat was the primary mechanism for gully development during the study period. The area of the gully-head drainage basin played a more significant role than the slope gradient and land use to explain the gully-head retreat. The S-A topographic threshold relationship was S = 0.0478 A −0.4915, implying that overland flow erosion was the dominant gully erosion process in the study area. Our results provide the gully development rate and topographic threshold relationship in the marginal zone of the Loess Plateau and clarify the potential location of gully development, while proposing that effective reduction of the drainage basin area can aid in curbing gully erosion. This study suggests a multi-scale gully erosion monitoring method for rapidly and precisely obtaining long-term gully development characteristics in various regions. [ABSTRACT FROM AUTHOR]

Arrhythmogenesis of chronic myocardial infarction (MI) is associated with the prolongation of action potential, reduction of inward rectifier potassium (I K1 , Kir) channels and hyper-activity of Calcium/calmodulin-dependent kinase II (CaMKII) in cardiomyocytes. Zacopride, a selective I K1 agonist, was applied to clarify the cardioprotection of I K1 agonism via a CaMKII signaling on arrhythmias post-MI. Male SD rats were implanted wireless transmitter in the abdominal cavity and subjected to left main coronary artery ligation or sham operation. The telemetric ECGs were monitored per day throughout 4 weeks. At the endpoint, isoproterenol (1.28 mg/kg, i.v.) was administered for provocation test. The expressions of Kir2.1 (dominant subunit of I K1 in ventricle) and CaMKII were detected by Western-blotting. In the telemetric rats post-MI, zacopride significantly reduced the episodes of atrioventricular conduction block (AVB), premature ventricular contraction (PVC), ventricular tachycardia (VT) and ventricular fibrillation (VF), without significant effect on superventricular premature contraction (SPVC). In provocation test, zacopride suppressed the onset of ventricular arrhythmias in conscious PMI or sham rats. The expression of Kir2.1 was significantly downregulated and p -CaMKII was upregulated post-MI, whereas both were restored by zacopride treatment. I K1 /Kir2.1 might be an attractive target for pharmacological controlling of lethal arrhythmias post MI. [ABSTRACT FROM AUTHOR]