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In this paper, we proposed a generalized mosquito-borne epidemic model with a general nonlinear incidence rate, which was studied from both deterministic and stochastic insights. In the deterministic model, we proved that the endemic equilibrium was globally asymptotically stable when the basic reproduction number R 0 was greater than unity and the disease free equilibrium was globally asymptotically stable when R 0 was lower than unity. In addition, considering the effect of environmental noise on the spread of infectious diseases, we developed a stochastic model in which the infection rates were assumed to satisfy the mean-reverting log-normal Ornstein-Uhlenbeck process. For this stochastic model, two critical values, known as R 0 s and R 0 E , were introduced to determine whether the disease will persist or die out. Additionally, the exact probability density function of the stationary distribution near the quasi-equilibrium point was obtained. Numerical simulations were conducted to validate the results obtained and to examine the impact of stochastic perturbations on the model. In this paper, we proposed a generalized mosquito-borne epidemic model with a general nonlinear incidence rate, which was studied from both deterministic and stochastic insights. In the deterministic model, we proved that the endemic equilibrium was globally asymptotically stable when the basic reproduction number was greater than unity and the disease free equilibrium was globally asymptotically stable when was lower than unity. In addition, considering the effect of environmental noise on the spread of infectious diseases, we developed a stochastic model in which the infection rates were assumed to satisfy the mean-reverting log-normal Ornstein-Uhlenbeck process. For this stochastic model, two critical values, known as and , were introduced to determine whether the disease will persist or die out. Additionally, the exact probability density function of the stationary distribution near the quasi-equilibrium point was obtained. Numerical simulations were conducted to validate the results obtained and to examine the impact of stochastic perturbations on the model. [ABSTRACT FROM AUTHOR]

Xiaolangdi Reservoir is a key control project to control the water and sediment in the lower Yellow River, and a timely and accurate grasp of the reservoir’s water storage status is essential for the function of the reservoir. This study used all available Landsat images (789 scenes) and adopted the modified normalized difference water index, enhanced vegetation index, and normalized difference vegetation index to map the surface water from 1999 to 2019 in Google Earth Engine (GEE) cloud platform. The spatiotemporal characteristics of the surface water body area changes in the Xiaolangdi Reservoir in the past 21 years are analyzed from the water body type division, area change, type conversion, and the driving force of the Xiaolangdi water body area changes was analyzed. The results showed that (1) the overall accuracy of the water body extraction method was 98.86%, and the kappa coefficient was 0.96; (2) the maximum water body area of the Xiaolangdi Reservoir varies greatly between inter-annual and intra-annual, and seasonal water body and permanent water body have uneven spatiotemporal distribution; (3) in the conversion of water body types, the increased seasonal water body area of the Xiaolangdi Reservoir from 1999 to 2019 was mainly formed by the conversion of permanent water body, and the reduced permanent water body area was mainly caused by non-water conversion; and (4) the change of the water body area of the Xiaolangdi Reservoir has a weak negative correlation with natural factors such as precipitation and temperature, and population. It is positively correlated with seven indicators such as runoff and regional gross domestic product (GDP). The findings of the research will provide necessary data support for the management and planning of soil and water resources in the Xiaolangdi Reservoir.

Helikale Nanographene (NG) mit hohen Quantenausbeuten und starken chiroptischen Antworten sind entscheidend für die Entwicklung von lumineszenten Materialien mit zirkularer Polarisation (engl. circular polarized luminescence, CPL). Hier berichten wir von der erfolgreichen Synthese neuartiger π‐erweiterter Doppel‐[7]Helicene (ED7Hs), bei denen sich zwei Helicen‐Einheiten meta bzw. para am zentralen Benzenring befinden. Sie sind damit strukturelle Isomere des bekannten ortho‐ED7H. Die strukturelle Integrität und Geometrie der ED7Hs wurde eindeutig durch Röntgen‐Einkristalldiffraktometrie aufgeklärt. Die ED7Hs besitzen eine ausgeprägte Fluoreszenz mit Quantenausbeuten über 40 %. Durch Variation der relativen Positionen der Doppel‐[7]Helicene am zentralen Benzenring (ortho, meta, para) kann eine außergewöhnliche Verstärkung der chiroptischen Eigenschaften registriert werden. Diese Verbesserung zeigt sich in einem etwa fünffachen Anstieg der Absorbanz und Lumineszenz‐Dissymmetriefaktoren (gabs und glum) sowie einer erhöhten CPL‐Helligkeit von bis zu 176 M−1 cm−1, was die Leistung der meisten helicenbasierten chiralen NGs übertrifft. Des weiteren zeigen DFT‐Simulationen, dass die relative geometrische Lage der [7]Helicene eine präzise Anpassung der elektrischen und magnetischen Übergangsdipolmomente zur Folge hat, welche die beobachteten Verstärkungen der chiroptischen Eigenschaften erklären. Diese Studie liefert eine effektive Strategie zur Verstärkung der CPL‐Eigenschaften chiraler Nanographene, welche ihre Anwendbarkeit als CPL‐Emitter verbessert. [ABSTRACT FROM AUTHOR]

Chip multi-processor (CMP) has become the most common processor in the current cluster and desktop computer, and it is also the current development direction. On CMP, programs usually co-running with each other. However, programs commonly interfere with each other. Some time the interference takes big effect, which cause serious drop down of performance. In order to avoid the serious performance interference, programs should be scheduled reasonably to different socket to improve the program’s performance and system’s utilization. In this paper we propose a new scheduling method to realize a more reasonable scheduling. We do not only consider the LLC miss rate, but also consider the LLC reference of the programs. By the information of LLC reference and LLC miss rate, we schedule programs to different sockets, which realize a reasonable scheduling. The experiment result show that making use of the scheduling method proposed by our paper, program’s performance can improve 4%, because the performance improve is realized by on-chip resource, which is a big contribution.

In order to improve the positioning and navigation performance of Global Navigation Satellite System (GNSS) receivers, a novel method to extract auxiliary information for GNSS receiver is proposed in this paper, which obtains the area GNSS auxiliary information (AGAI) with enough credibility and area attribute. Firstly, a mass of historical GNSS intermediate frequency data is divided into blocks to be acquired and tracked parallel getting massive pseudorange and navigation message (MPD). Then, the massive MPD are weighted and fused parallel by an appropriate weight matrix, which is determined by a priori weighting based on altitude angle and posterior weighting based on M-residuals variable components estimation. Lastly, the fused information is corresponded to the corresponding location coordinate, completing the parallel extraction of AGAI. The method implemented by parallel programming models MapReduce of Hadoop to guarantee a high efficiency. Experimental results show that the positioning and velocity error of GNSS receivers are reduced by 18.24% and 20.48% using AGAI instead of traditional auxiliary information, and the execution time of the method using MapReduce is reduced by 46.72%, so the proposed method is reliable and effective. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

As the land use issue, caused by urban shrinkage in China, is becoming more and more prominent, research on urban shrinkage and expansion has become particularly challenging and urgent. Based on the points of interest (POI) data, this paper redefines the scope, quantity, and area of natural cities by using threshold methods, which accurately identify the shrinkage and expansion of cities in the Yellow River affected area using night light data in 2013 and 2018. The results show that: (1) there are 3130 natural cities (48,118.75 km2) in the Yellow River affected area, including 604 shrinking cities (8407.50 km2) and 2165 expanding cities (32,972.75 km2). (2) The spatial distributions of shrinking and expanding cities are quite different. The shrinking cities are mainly located in the upper Yellow River affected area, except for the administrative cities of Lanzhou and Yinchuan; the expanding cities are mainly distributed in the middle and lower Yellow River affected area, and the administrative cities of Lanzhou and Yinchuan. (3) Shrinking and expanding cities are typically smaller cities. The research results provide a quick data supported approach for regional urban planning and land use management, for when regional and central governments formulate the outlines of urban development monitoring and regional planning. [ABSTRACT FROM AUTHOR]

Helical nanographenes with high quantum yields and strong chiroptical responses are pivotal for developing circularly polarized luminescence (CPL) materials. Here, we present the successful synthesis of novel π-extended double [7]helicenes (ED7Hs) where two helicene units are fused at the meta- or para-position of the middle benzene ring, respectively, as the structural isomers of the reported ortho-fused ED7H. The structural geometry of these ED7Hs is clearly characterized by single-crystal X-ray analysis. Notably, this class of ED7Hs exhibits bright luminescence with high quantum yields exceeding 40 %. Through geometric regulation of two embedded [7]helicene units from ortho-, meta- to para-position, these ED7Hs display exceptional amplification in chiroptical responses. This enhancement is evident in a remarkable approximate fivefold increase in the absorbance and luminescence dissymmetry factors (g abs and g lum ), respectively, along with a boosted CPL brightness up to 176 M -1  cm -1 , surpassing the performance of most helicene-based chiral NGs. Furthermore, DFT calculations elucidate that the geometric adjustment of two [7]helicene units allows the precise alignment of electric and magnetic transition dipole moments, leading to the observed enhancement of their chiroptical responses. This study offers an effective strategy for magnifying the CPL performance in chiral NGs, promoting their expanded application as CPL emitters., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The incorporation of nanopores into graphene nanostructures has been demonstrated as an efficient tool in tuning their band gaps and electronic structures. However, precisely embedding the uniform nanopores into graphene nanoribbons (GNRs) at the atomic level remains underdeveloped especially for in-solution synthesis due to the lack of efficient synthetic strategies. Herein we report the first case of solution-synthesized porous GNR (pGNR) with a fully conjugated backbone via the efficient Scholl reaction of tailor-made polyphenylene precursor (P1) bearing pre-installed hexagonal nanopores. The resultant pGNR features periodic subnanometer pores with a uniform diameter of 0.6 nm and an adjacent-pores-distance of 1.7 nm. To solidify our design strategy, two porous model compounds (1 a, 1 b) containing the same pore size as the shortcuts of pGNR, are successfully synthesized. The chemical structure and photophysical properties of pGNR are investigated by various spectroscopic analyses. Notably, the embedded periodic nanopores largely reduce the π-conjugation degree and alleviate the inter-ribbon π-π interactions, compared to the nonporous GNRs with similar widths, affording pGNR with a notably enlarged band gap and enhanced liquid-phase processability., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)