Spatiotemporal heterogeneity analysis of Yangtze River delta urban agglomeration: evidence from nighttime light data (2001-2019)

The long-term changes of the relationship between nighttime light and urbanization related built-up areas are explored using nighttime light data obtained from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS, data before 2013) and the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP/VIIRS, data after 2012) and information of the spatiotemporal heterogeneity of urban evolution. This study assimilates two datasets and diagnoses the spatial heterogeneity in administrative city scale based on built-up area tendencies, temporal heterogeneity in pixel scale based on nighttime light intensity tendencies, and GDP associated spatiotemporal variability over the Yangtze River Delta comparing the first two decades of this century (2001-2010 versus 2011-2019). The analysis reveals the following main results: (1) The built-up areas have generally increased in the second period with the center of fast expansion moving southward, including Suzhou-Wuxi-Changzhou, Hangzhou, Ningbo, Nanjing, and Hefei. (2) Urban development in the original city core has saturated and is spilling over to the suburbs and countryside, leading to nighttime light intensity tendency shift from a "rapid to moderate" and a "moderate to rapid" development (a "hot to cold" and a "cold to hot" spatial clustering distribution). (3) The tendency shifts of built-up area and nighttime light intensity occur most frequently in 2010, after which the urban development is transforming from light intensity growth to built-up area growth, particularly in the developed city cores. The urban agglomeration process with nighttime light intensity reaching saturation prior to the urban development spreading into the surrounding suburbs and countryside, appears to be a suitable model, which provides insights in addressing related environmental problems and contribute to regional sustainable urban planning and management

Laboratory experimental study of ocean waves propagating over a partially buried pipeline in a trench layer

YesSeabed instability around a pipeline is one of the primary concerns in offshore pipeline projects. To date, most studies focus on investigating the wave/current-induced response within a porous seabed around either a fully buried pipeline or a thoroughly exposed one. In this study, unlike previous investigations, a series of comprehensive laboratory experiments are carried out in a wave flume to investigate the wave-induced pore pressures around a partially embedded pipeline in a trench layer. Measurements show that the presence of the partially buried pipeline can significantly affect the excess pore pressure in a partially backfilled trench layer, which deviates considerably from that predicted by the theoretical approach. The morphology of the trench layer accompanied with the backfill sediments, especially the deeper trench and thicker backfill (i.e.,b≥1D,e≥0.5D), provides a certain degree of resistance to seabed instability. The amplitude of excess pore pressure around the trench layer roughly exhibits a left-right asymmetric distribution along the periphery of the pipeline, and decays sharply from the upper layer of the trench to the lower region. Deeper trench depth and thicker buried layer significantly weaken the pore-water pressures in the whole trench area, thus sheltering and protecting the submarine pipeline against the transient seabed liquefaction.The National Key research and development program of China (2017YFC1404200), the research grants of Jiangsu (BK20150804), the marine renewable energy research project of State Oceanic Administration (GHME2015GC01), Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University (Project No: 2016491011), the Royal Academy of Engineering the Distinguished Visiting Fellowship (DVF1718-8-7

The State Equation of the Yang-Mills field Dark Energy Models

In this paper, we study the possibility of building Yang-Mills(YM) field dark energy models with equation of state (EoS) crossing -1, and find that it can not be realized by the single YM field models, no matter what kind of lagrangian or initial condition. But the states of $-1<\omega<0$ and $\omega<-1$ all can be naturally got in this kind of models. The former is like a quintessence field, and the latter is like a phantom field. This makes that one can build a model with two YM fields, in which one with the initial state of $-1<\omega<0$, and the other with $\omega<-1$. We give an example model of this kind, and find that its EoS is larger than -1 in the past and less than -1 at the present time. We also find that this change must be from $\omega>-1$ to $<-1$, and it will go to the critical state of $\omega=-1$ with the expansion of the Universe, which character is same with the single YM field models, and the Big Rip is naturally avoided.Comment: 20 pages, 4 figures. minor typos correcte

Extended calculations of energy levels, radiative properties, AJA_{J}, BJB_{J} hyperfine interaction constants, and Land\'e gJg_{J}-factors for nitrogen-like \mbox{Ge XXVI}

Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, highly accurate calculations are performed for the lowest 272 fine-structure levels arising from the $2s^{2} 2p^{3}$, $2s 2p^{4}$, $2p^{5}$, $2s^{2} 2p^{2} 3l$~($l=s,p,d$), $2s 2p^{3}3l$ ($l=s,p,d$), and $2p^{4} 3l$ ($l=s,p,d$) configurations in nitrogen-like Ge XXVI. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Land\'e $g_{J}$-factors, and E1, E2, M1, M2 line strengths, oscillator strengths, and transition rates among these 272 levels are provided. Comparisons are made between the present two data sets, as well as with other available experimental and theoretical values. The present data are accurate enough for identification and deblending of emission lines involving the $n=3$ levels, and are also useful for modeling and diagnosing fusion plasmas

Full-field 3D shape measurement of discontinuous specular objects by direct phase measuring deflectometry

With the advent of intelligent manufacturing, phase measuring deflectometry (PMD) has been widely studied for the measurement of the three-dimensional (3D) shape of specular objects. However, existing PMDs cannot measure objects having discontinuous specular surfaces. This paper presents a new direct PMD (DPMD) method that measures the full-field 3D shape of complicated specular objects. A mathematical model is derived to directly relate an absolute phase map to depth data, instead of the gradient. Two relevant parameters are calibrated using a machine vision-based method. On the basis of the derived model, a full-field 3D measuring system was developed. The accuracy of the system was evaluated using a mirror with known positions along an accurate translating stage. The 3D shape of a monolithic multi-mirror array having multiple specular surfaces was measured. Experimental results show that the proposed DPMD method can obtain the full-field 3D shape of specular objects having isolated and/or discontinuous surfaces accurately and effectively

Learning Flow-based Feature Warping for Face Frontalization with Illumination Inconsistent Supervision

Despite recent advances in deep learning-based face frontalization methods, photo-realistic and illumination preserving frontal face synthesis is still challenging due to large pose and illumination discrepancy during training. We propose a novel Flow-based Feature Warping Model (FFWM) which can learn to synthesize photo-realistic and illumination preserving frontal images with illumination inconsistent supervision. Specifically, an Illumination Preserving Module (IPM) is proposed to learn illumination preserving image synthesis from illumination inconsistent image pairs. IPM includes two pathways which collaborate to ensure the synthesized frontal images are illumination preserving and with fine details. Moreover, a Warp Attention Module (WAM) is introduced to reduce the pose discrepancy in the feature level, and hence to synthesize frontal images more effectively and preserve more details of profile images. The attention mechanism in WAM helps reduce the artifacts caused by the displacements between the profile and the frontal images. Quantitative and qualitative experimental results show that our FFWM can synthesize photo-realistic and illumination preserving frontal images and performs favorably against the state-of-the-art results.Comment: ECCV 2020. Code is available at: https://github.com/csyxwei/FFW

Fixed point theorems for the sum of three classes of mixed monotone operators and applications

In this paper we develop various new fixed point theorems for a class of operator equations with three general mixed monotone operators, namely A(x,x)+B(x,x)+C(x,x)=x on ordered Banach spaces, where A, B, C are the mixed monotone operators. A is such that for any t∈(0,1), there exists φ(t)∈(t,1] such that for all x,y∈P, A(tx,t−1y)≥φ(t)A(x,y); B is hypo-homogeneous, i.e. B satisfies that for any t∈(0,1), x,y∈P, B(tx,t−1y)≥tB(x,y); C is concave-convex, i.e. C satisfies that for fixed y, C(⋅,y):P→P is concave; for fixed x, C(x,⋅): P→P is convex. Also we study the solution of the nonlinear eigenvalue equation A(x,x)+B(x,x)+C(x,x)=λx and discuss its dependency to the parameter. Our work extends many existing results in the field of study. As an application, we utilize the results obtained in this paper for the operator equation to study the existence and uniqueness of positive solutions for a class of nonlinear fractional differential equations with integral boundary conditions

Entanglement detection beyond the CCNR criterion for infinite-dimensions

In this paper, in terms of the relation between the state and the reduced states of it, we obtain two inequalities which are valid for all separable states in infinite-dimensional bipartite quantum systems. One of them provides an entanglement criterion which is strictly stronger than the computable cross-norm or realignment (CCNR) criterion.Comment: 11 page