57 research outputs found
Completion of the Ablowitz-Kaup-Newell-Segur integrable coupling
Integrable couplings are associated with non-semisimple Lie algebras. In this
paper, we propose a new method to generate new integrable systems through
making perturbation in matrix spectral problems for integrable couplings, which
is called the `completion process of integrable couplings'. As an example, the
idea of construction is applied to the Ablowitz-Kaup-Newell-Segur integrable
coupling. Each equation in the resulting hierarchy has a bi-Hamiltonian
structure furnished by the component-trace identity
Robust Switching Control Strategy for a Transmission System with Unknown Backlash
This paper proposes a robust switching control strategy for a transmission system with unknown backlash. Firstly, the adverse effects of backlash nonlinearity in the transmission system are analyzed. Then the backlash model and different operating modes of the transmission system with backlash are investigated. For each operating mode, an individual controller is designed to make the system robust against the unknown backlash and various frequencies of the input signal. Moreover, a supervisory controller is proposed to estimate the current mode of the transmission system and coordinate the controller switching between different modes. Simulations are done to verify that our switching control strategy can efficiently reduce the oscillation caused by backlash and is quite robust against the variation of the frequency of the input signal
Revealing intra-urban spatial structure through an exploratory analysis by combining road network abstraction model and taxi trajectory data
The unprecedented urbanization in China has dramatically changed the urban
spatial structure of cities. With the proliferation of individual-level
geospatial big data, previous studies have widely used the network abstraction
model to reveal the underlying urban spatial structure. However, the
construction of network abstraction models primarily focuses on the topology of
the road network without considering individual travel flows along with the
road networks. Individual travel flows reflect the urban dynamics, which can
further help understand the underlying spatial structure. This study therefore
aims to reveal the intra-urban spatial structure by integrating the road
network abstraction model and individual travel flows. To achieve this goal, we
1) quantify the spatial interaction relatedness of road segments based on the
Word2Vec model using large volumes of taxi trip data, then 2) characterize the
road abstraction network model according to the identified spatial interaction
relatedness, and 3) implement a community detection algorithm to reveal
sub-regions of a city. Our results reveal three levels of hierarchical spatial
structures in the Wuhan metropolitan area. This study provides a data-driven
approach to the investigation of urban spatial structure via identifying
traffic interaction patterns on the road network, offering insights to urban
planning practice and transportation management
Nondestructive Characterization of Drying Processes of Colloidal Droplets and Latex Coats Using Optical Coherence Tomography
In this chapter, we review the applications of optical coherence tomography (OCT) on the nondestructive characterization of the drying processes of colloidal droplets and latex coatings. Employing time-lapse, high-speed imaging, OCT can be used to monitor the dynamic process of drying colloidal droplets. With the aid of high-scattering, micron-sized tracer particles, fluid flows have been captured; phase boundaries are also visible in liquid crystal droplets; and the speckle contrast analysis differentiates the dynamics of particles, showing the packing process and the coffee ring phenomenon. In a waterborne latex coat, time-lapse OCT imaging reveals spatial changes of microstructures, i.e., detachment of latex, cracks, and shear bands; with speckle contrast analysis, 1D and 2D particles’ packing process that is initiated from latex/air interface can also be monitored over time. OCT can serve as an experimental platform for fundamental studies of drying colloidal systems. In the future, OCT can also be employed as an in-line quality control tool of polymer coatings and paints for industrial applications
Divergent assembly of soil microbial necromass from microbial and organic fertilizers in Chimonobambusa hejiangensis forest
IntroductionVariability in microbial residues within soil aggregates are becoming progressively essential to the nutritive and sustainability of soils, and are therefore broadly regarded as an indispensable part of soil organic matter. It is unexplored how the widespread implementation of microbial fertilisers in agricultural production impacts soil organic nutrients, in particular the microbial residue fraction.MethodsWe performed a three-year field experiment to verify the distinct impacts of microbial and organic fertilizers on carbon accumulation in soil microbial leftovers among aggregate fractions.ResultsMicrobial residual carbon was shown to decrease insignificantly during the application of microbial fertilizer and to rise marginally afterwards with the utilization of organic fertilizer. However, the combined effects of the two fertilizers had substantial impacts on the accumulation of microbial residual carbon. Changes in the structure of the fungi and bacteria shown in this study have implications for the short-term potential of microbial fertilizer shortages to permanent soil carbon sequestration. Additionally, our findings revealed variations in microbial residue accumulation across the microbial fertilizers, with Azotobacter chroococcum fertilizer being preferable to Bacillus mucilaginosus fertilizer due to its higher efficiency. In this scenario of nutrient addition, fungal residues may serve as the primary binding component or focal point for the production of new microaggregates, since the quantity of SOC provided by fungal residues increased while that supplied by bacterial residues decreased.DiscussionOur findings collectively suggested that the mechanisms behind the observed bacterial and fungal MRC (microbial residue carbon) responses to microbial fertilizer or organic fertilizer in bamboo forest soils are likely to be distinct. The application of microbial fertilizers for a limited duration led to a decline soil stable carbon pool, potentially influencing the regulation of soil nutrients in such hilly bamboo forests
A comprehensive genome variation map of melon identifies multiple domestication events and loci influencing agronomic traits
Melon is an economically important fruit crop that has been cultivated for thousands of years; however, the genetic basis and history of its domestication still remain largely unknown. Here we report a comprehensive map of the genomic variation in melon derived from the resequencing of 1,175 accessions, which represent the global diversity of the species. Our results suggest that three independent domestication events occurred in melon, two in India and one in Africa. We detected two independent sets of domestication sweeps, resulting in diverse characteristics of the two subspecies melo and agrestis during melon breeding. Genome-wide association studies for 16 agronomic traits identified 208 loci significantly associated with fruit mass, quality and morphological characters. This study sheds light on the domestication history of melon and provides a valuable resource for genomics-assisted breeding of this important crop.This work was supported by funding from the Agricultural Science and Technology Innovation Program (to Yongyang Xu, S.H., Z.Z. and H.W.), the China Agriculture Research System (CARS-25 to Yongyang Xu and H.W.), the Leading Talents of Guangdong Province Program (00201515 to S.H.), the Shenzhen Municipal (The Peacock Plan KQTD2016113010482651 to S.H.), the Dapeng district government, National Natural Science Foundation of China (31772304 to Z.Z.), the Science and Technology Program of Guangdong (2018B020202007 to S.H.), the National Natural Science Foundation of China (31530066 to S.H.), the National Key R&D Program of China (2016YFD0101007 to S.H.), USDA National Institute of Food and Agriculture Specialty Crop Research Initiative (2015-51181-24285 to Z.F.), the European Research Council (ERC-SEXYPARTH to A.B.), the Spanish Ministry of Economy and Competitiveness (AGL2015–64625-C2-1-R to J.G.-M.), Severo Ochoa Programme for Centres of Excellence in R&D 2016–2010 (SEV-2015–0533 to J.G.-M.), the CERCA Programme/Generalitat de Catalunya to J.G.-M. and the German Science Foundation (SPP1991 Taxon-OMICS to H.S.)
A comprehensive genome variation map of melon identifies multiple domestication events and loci influencing agronomic traits
Melon is an economically important fruit crop that has been cultivated for thousands of years; however, the genetic basis and
history of its domestication still remain largely unknown. Here we report a comprehensive map of the genomic variation in
melon derived from the resequencing of 1,175 accessions, which represent the global diversity of the species. Our results suggest that three independent domestication events occurred in melon, two in India and one in Africa. We detected two independent sets of domestication sweeps, resulting in diverse characteristics of the two subspecies melo and agrestis during melon
breeding. Genome-wide association studies for 16 agronomic traits identified 208 loci significantly associated with fruit mass,
quality and morphological characters. This study sheds light on the domestication history of melon and provides a valuable
resource for genomics-assisted breeding of this important crop.info:eu-repo/semantics/acceptedVersio
18F-FDG PET/CT may be a suitable method for preoperative diagnosis and evaluation of Chinese older patients with hilar cholangiocarcinoma
Abstract Background As the most common cholangiocarcinoma, hilar cholangiocarcinoma (HCCA) is a challenge in hepatobiliary surgery and causes a very poor prognosis. This study was designed to explore whether 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) may be a suitable method for preoperative diagnosis and evaluation of Chinese older patients with hilar cholangiocarcinoma. Methods This study enrolled 53 patients (≥ 65 years) with HCCA. 18F-FDG PET/CT scan was performed in all patients within one week before operation. Results 18F-FDG PET/CT identified the tumors in all patients (100%). There were 48 patients (90.6%) with the same Bismuth-Corlette classifications determined by 18F-FDG PET/CT and operative pathology, whereas Bismuth-Corlette classifications of 5 patients (9.4%) were underestimated by 18F-FDG PET/CT compared with that determined by operative pathology. 18F-FDG PET/CT identified 19 patients (sensitivity: 67.9%) in 28 patients with lymph node metastases, and 22 patients (specificity: 88.0%) in 25 patients without lymph node metastases, with an accuracy of 77.4%. 18F-FDG PET/CT identified 8 patients (sensitivity: 47.1%) in 17 patients with liver, peritoneal or other distant metastases, and 35 patients (specificity: 97.2%) in 36 patients without liver, peritoneal or other distant metastases, with an accuracy of 81.1%. 18F-FDG PET/CT identified 17 patients (sensitivity: 73.9%) in 23 patients with unresectable tumors, and 24 patients (specificity: 80.0%) in 30 patients with resectable tumors, with an accuracy of 77.4%. Conclusions 18F-FDG PET/CT may be a suitable method for preoperative diagnosis and evaluation, and offer valuable information for effective operation in Chinese older patients with HCCA
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