scispace - formally typeset
Search or ask a question
Institution

Nanjing University of Information Science and Technology

EducationNanjing, China
About: Nanjing University of Information Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Precipitation & Aerosol. The organization has 14129 authors who have published 17985 publications receiving 267578 citations. The organization is also known as: Nan Xin Da.


Papers
More filters
Journal ArticleDOI
TL;DR: The PVO embedding is extended into a 2D form by integrating the pairwise prediction- error expansion, and a reversible 2D mapping adapted to the special distribution of prediction-error pairs is proposed.

86 citations

Journal ArticleDOI
TL;DR: China has been suffering high levels of fine particulate matter (PM2.5), and residential and industrial emissions are the top two sources, with a combined contribution of 40-50% in most provinces, with higher contributions in southern provinces such as Yunnan, Hainan and Taiwan.

86 citations

Journal ArticleDOI
TL;DR: The results show that the multi-frequency BDS observations will greatly improve the PPP performances and theoretical comparison of the models, positioning performances, precise time and frequency transfer, ZTD, inter-frequency bias (IFB), and differential code bias (DCB) are presented and evaluated.
Abstract: Nowadays, China BeiDou Navigation Satellite System (BDS) has been developed well and provided global services with highly precise positioning, navigation and timing (PNT) as well as unique short-message communication, particularly global system (BDS-3) with higher precision multi-frequency signals. The precise point positioning (PPP) can provide the precise position, receiver clock, and zenith tropospheric delay (ZTD) with a stand-alone receiver compared to the traditional double differenced relative positioning mode, which has been widely used in PNT, geodesy, meteorology and so on. However, it has a lot of challenges for multi-frequency BDS PPP with different strategies and more unknown parameters. In this paper, the detailed PPP models using the single-, dual-, triple-, and quad-frequency BDS observations are presented and evaluated. Firstly, BDS system and PPP method are introduced. Secondly, the stochastic models of time delay bias in BDS-2/BDS-3 PPP including the neglection, random constant, random walk and white noise are presented. Then, three single-frequency, four dual-frequency, four triple-frequency and four quad-frequency BDS PPP models are provided. Finally, the BDS PPP models progress and performances including theoretical comparison of the models, positioning performances, precise time and frequency transfer, ZTD, inter-frequency bias (IFB) and differential code bias (DCB) are presented and evaluated as well as future challenges. The results show that the multi-frequency BDS observations will greatly improve the PPP performances.

86 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provided source attribution and characterization of black carbon (BC) in Beijing's urban environment during the joint UK-China APHH (Air Pollution and Humanhealth) project, in both winter (November-December 2016) and summer (May-June 2017).
Abstract: . Black carbon (BC) is known to have major impacts on both human health and climate. The populated megacity represents the most complex anthropogenic BC emissions where the sources and related impacts are very uncertain. This study provides source attribution and characterization of BC in the Beijing urban environment during the joint UK–China APHH (Air Pollution and Human Health) project, in both winter (November–December 2016) and summer (May–June 2017). The size-resolved mixing state of BC-containing particles was characterized by a single-particle soot photometer (SP2) and their mass spectra was measured by a soot particle aerosol mass spectrometer (SP-AMS). The refractory BC (rBC) mass loading was around a factor of 2 higher in winter relative to summer, and more variable coatings were present, likely as a result of additional surface emissions from the residential sector and favourable condensation in the cold season. The characteristics of the BC were relatively independent of air mass direction in summer, whereas in winter air masses from the Northern Plateau were considerably cleaner and contained less-coated and smaller BC, but the BC from the Southern Plateau had the largest core size and coatings. We compare two online source apportionment methods using simultaneous measurements made by the SP2, which measures physical properties of BC, and the chemical approach using the positive matrix factorization (PMF) of mass spectra from the SP-AMS for the first time. A method is proposed to isolate the BC from the transportation sector using a mode of small BC particles (core diameter Dc µ m and coating thickness ct 50 nm). This mode of BC highly correlated with NOx concentration in both seasons ( ∼14 ng m −3 BC ppb −1 NOx ) and corresponded with the morning traffic rush hour, contributing about 30 % and 40 % of the total rBC mass (35 % and 55 % in number) in winter and summer respectively. The BC from coal burning or biomass burning was characterized by moderate coatings (ct = 50–200 nm) contributing ∼20 %–25 % of rBC mass. Large uncoated BC particles ( Dc>0.18 µ m and ct 50 nm) were more likely to be contributed by coal combustion, as these particles were not present in urban London. This mode was present in Beijing in both winter ( ∼30 %–40 % rBC mass) and summer ( ∼40 % rBC mass) but may be dominated by the residential and industrial sector respectively. The contribution of BC thickly coated with secondary species (ct > 200 nm) to the total rBC mass increased with pollution level in winter but was minor in summer. These large BC particles importantly enhanced the absorption efficiency at high pollution levels – in winter when PM 1 > 100 µ g m −3 or BC > 2 µ g m −3 , the absorption efficiency of BC increased by 25 %–70 %. The reduction of emissions of these large BC particles and the precursors of the associated secondary coating will be an effective way of mitigating the heating effect of BC in urban environments.

86 citations

Journal ArticleDOI
TL;DR: A balanced VM scheduling method is proposed accordingly to determine which VMs and where should be migrated, aiming at both reducing energy consumption and mitigating performance degradation, and results demonstrate the effectiveness and efficiency of the method.

86 citations


Authors

Showing all 14448 results

NameH-indexPapersCitations
Ashok Kumar1515654164086
Lei Zhang135224099365
Bin Wang126222674364
Shuicheng Yan12381066192
Zeshui Xu11375248543
Xiaoming Li113193272445
Qiang Yang112111771540
Yan Zhang107241057758
Fei Wang107182453587
Yongfa Zhu10535533765
James C. McWilliams10453547577
Zhi-Hua Zhou10262652850
Tao Li102248360947
Lei Liu98204151163
Jian Feng Ma9730532310
Network Information
Related Institutions (5)
Chinese Academy of Sciences
634.8K papers, 14.8M citations

90% related

University of Science and Technology of China
101K papers, 2.4M citations

88% related

City University of Hong Kong
60.1K papers, 1.7M citations

88% related

Harbin Institute of Technology
109.2K papers, 1.6M citations

88% related

Nanjing University
105.5K papers, 2.2M citations

87% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023173
2022552
20213,000
20202,492
20192,221
20181,822