Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
30,473
result(s) for
"Wu, Liang"
Sort by:
Building Extraction in Very High Resolution Remote Sensing Imagery Using Deep Learning and Guided Filters
Very high resolution (VHR) remote sensing imagery has been used for land cover classification, and it tends to a transition from land-use classification to pixel-level semantic segmentation. Inspired by the recent success of deep learning and the filter method in computer vision, this work provides a segmentation model, which designs an image segmentation neural network based on the deep residual networks and uses a guided filter to extract buildings in remote sensing imagery. Our method includes the following steps: first, the VHR remote sensing imagery is preprocessed and some hand-crafted features are calculated. Second, a designed deep network architecture is trained with the urban district remote sensing image to extract buildings at the pixel level. Third, a guided filter is employed to optimize the classification map produced by deep learning; at the same time, some salt-and-pepper noise is removed. Experimental results based on the Vaihingen and Potsdam datasets demonstrate that our method, which benefits from neural networks and guided filtering, achieves a higher overall accuracy when compared with other machine learning and deep learning methods. The method proposed shows outstanding performance in terms of the building extraction from diversified objects in the urban district.
Journal Article
Hyperunified field theory and gravitational gauge–geometry duality
A hyperunified field theory is built in detail based on the postulates of gauge invariance and coordinate independence along with the conformal scaling symmetry. All elementary particles are merged into a single hyper-spinor field and all basic forces are unified into a fundamental interaction governed by the hyper-spin gauge symmetry SP(1, Dh-1). The dimension Dh of hyper-spacetime is conjectured to have a physical origin in correlation with the hyper-spin charge of elementary particles. The hyper-gravifield fiber bundle structure of biframe hyper-spacetime appears naturally with the globally flat Minkowski hyper-spacetime as a base spacetime and the locally flat hyper-gravifield spacetime as a fiber that is viewed as a dynamically emerged hyper-spacetime characterized by a non-commutative geometry. The gravitational origin of gauge symmetry is revealed with the hyper-gravifield that plays an essential role as a Goldstone-like field. The gauge–gravity and gravity–geometry correspondences bring about the gravitational gauge–geometry duality. The basic properties of hyperunified field theory and the issue on the fundamental scale are analyzed within the framework of quantum field theory, which allows us to describe the laws of nature in deriving the gauge gravitational equation with the conserved current and the geometric gravitational equations of Einstein-like type and beyond.
Journal Article
Physiological and molecular advances in magnesium nutrition of plants
Background
Mg is a macronutrient for plant growth. Mg deficiency has become an important limiting factor in intensive agricultural production, resulting in reduced crop yield and quality. Given that Mg is also essential for human and animals’ diets, Mg nutrition in plants has become an important issue not only for food security but also for human health.
Scope
We review recent progress in physiological and molecular mechanisms underlying Mg biological functionality, as well as Mg transport and Mg deficiency symptoms in plants.
Conclusions
As both a structural component and a regulatory factor, Mg helps plants achieve higher photosynthetic efficiency, nitrogen use efficiency and stress resistance. Plants need a certain range of Mg concentration for their growth, and a number of key genes responsible for Mg uptake, translocation and detoxification have been identified. Despite its functional importance, basic researches on Mg nutrition are still scarce. A deeper investigation of the genetic and molecular mechanisms employed in Mg nutrition will help to improve crop yield and intensify Mg application in the field. Developing more approaches to enhance Mg concentration in crop edible parts is urgently required for human diet and health.
Journal Article
Upscaled production of an ultramicroporous anion-exchange membrane enables long-term operation in electrochemical energy devices
The lack of high-performance and substantial supply of anion-exchange membranes is a major obstacle to future deployment of relevant electrochemical energy devices. Here, we select two isomers (m-terphenyl and p-terphenyl) and balance their ratio to prepare anion-exchange membranes with well-connected and uniformly-distributed ultramicropores based on robust chemical structures. The anion-exchange membranes display high ion-conducting, excellent barrier properties, and stability exceeding 8000 h at 80 °C in alkali. The assembled anion-exchange membranes present a desirable combination of performance and durability in several electrochemical energy storage devices: neutral aqueous organic redox flow batteries (energy efficiency of 77.2% at 100 mA cm
−2
, with negligible permeation of redox-active molecules over 1100 h), water electrolysis (current density of 5.4 A cm
−2
at 1.8 V, 90 °C, with durability over 3000 h), and fuel cells (power density of 1.61 W cm
−2
under a catalyst loading of 0.2 mg cm
−2
, with open-circuit voltage durability test over 1000 h). As a demonstration of upscaled production, the anion-exchange membranes achieve roll-to-roll manufacturing with a width greater than 1000 mm.
The design of highly selective yet robust anion exchange membranes remains a challenge. Here, the authors prepare a stable polymer membrane composed of terphenyl isomers, demonstrate roll-to-roll manufacturing, and assess its properties in redox flow batteries, water electrolyzers and fuel cells.
Journal Article
Multiobjective Multidepot Capacitated Arc Routing Optimization Based on Hybrid Algorithm
The multidepot capacitated arc routing problem (CARP) is investigated with the hybrid optimization algorithm of the Dijkstra algorithm and genetic algorithm. The complex multidepot CARP is transformed into multiple single depot CARP by systematic clustering analysis. After completing the system clustering, the Dijkstra algorithm is used to adjust the boundary arc locally and merge it to a reasonable depot, while in the genetic algorithm, the structure of the chromosome is reset to use the path as the way of real coding, and the elite selection is used to decode to obtain the optimal path optimization scheme. Finally, Lanzhou road network data as experimental data, through Matlab to achieve the practicability of the algorithm in sprinkler applications. The results show that the improved genetic algorithm can successfully solve the multi-segment CARP with a certain road network scale, ensuring the correctness and feasibility of the algorithm. In addition, the efficiency of the algorithm in the later iteration is basically controlled at about 0.5 seconds, indicating that the efficiency of the algorithm is worth identifying.
Journal Article
Quadruple perovskite ruthenate as a highly efficient catalyst for acidic water oxidation
Development of highly active and durable oxygen-evolving catalysts in acid media is a major challenge to design proton exchange membrane water electrolysis for producing hydrogen. Here, we report a quadruple perovskite oxide CaCu
3
Ru
4
O
12
as a superior catalyst for acidic water oxidation. This complex oxide exhibits an ultrasmall overpotential of 171 mV at 10 mA cm
−2
geo
, which is much lower than that of the state-of-the-art RuO
2
. Moreover, compared to RuO
2
, CaCu
3
Ru
4
O
12
shows a significant increase in mass activity by more than two orders of magnitude and much better stability. Density functional theory calculations reveal that the quadruple perovskite catalyst has a lower Ru 4d-band center relative to RuO
2
, which effectively optimizes the binding energy of oxygen intermediates and thereby enhances the catalytic activity.
Electrocatalytic water splitting provides a renewable path to store energy in chemical bonds, but highly efficient oxygen-evolving catalysts in acid media remain limited. Here the authors report a quadruple perovskite ruthenate oxide as an effective and stable oxygen evolution electrocatalyst.
Journal Article