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Institution

University of Science and Technology Beijing

EducationBeijing, China
About: University of Science and Technology Beijing is a education organization based out in Beijing, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 41558 authors who have published 44473 publications receiving 623229 citations. The organization is also known as: Beijing Steel and Iron Institute.


Papers
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Journal ArticleDOI
TL;DR: In this article, continuous measurements of atmospheric ammonia (NH 3 ) were conducted using Ogawa passive samplers from February 2008 to July 2010 at an urban site and from January 2007-July 2010 at a rural site in Beijing, China.
Abstract: . Continuous measurements of atmospheric ammonia (NH 3 ) were conducted using Ogawa passive samplers from February 2008 to July 2010 at an urban site and from January 2007 to July 2010 at a rural site in Beijing, China. NH 4 + in fine particles was also collected at the rural site during 2008–2009. The field comparison between the Ogawa passive samplers and an active analyzer for NH 3 conducted at the urban site assures the quality and accuracy of the measurements. The concentrations of NH 3 at the urban site ranged from 0.7 to 85.1 ppb, with the annual average of 18.5 ± 13.8 and 23.5 ± 18.0 ppb in 2008 and 2009, respectively. The NH 3 concentrations at the rural site were lower than those at urban site, and varied from 0.8 to 42.9 ppb, with the annual average of 4.5 ± 4.6, 6.6 ± 7.0 and 7.1 ± 3.5 ppb in 2007, 2008 and 2009, respectively. The data showed marked seasonal variations at both sites. The results emphasized traffic to be a significant source of NH 3 concentrations in winter in urban areas of Beijing. This was illustrated by the strong correlations of NH 3 with the traffic related pollutants (NO x and CO) and also by the bimodal diurnal cycle of NH 3 concentrations that was synchronized with traffic. Similar patterns were not observed during the summer, suggesting other non-traffic sources became more important. At the rural site, the daily NH 4 + concentrations ranged from 0.10 to 36.53 μg m −3 , with an average of 7.03 μg m −3 from June 2008 to December 2009. Monthly NH 3 were significantly correlated with NH 4 + concentrations. Average monthly NH 3 /NH 4 + ratios varied from 0.13 to 2.28, with an average of 0.73. NH 4 + in PM 2.5 was primarily associated with SO 4 −2 at the rural site.

179 citations

Journal ArticleDOI
TL;DR: This paper addresses the vibration control and the input constraint for an Euler–Bernoulli beam system under a periodic distributed disturbance and aperiodic boundary disturbance and proposes a restrained adaptive boundary iterative learning control law based on a time-weighted Lyapunov–Krasovskii-like composite energy function.
Abstract: This paper addresses the vibration control and the input constraint for an Euler–Bernoulli beam system under aperiodic distributed disturbance and aperiodic boundary disturbance. Hyperbolic tangent functions and saturation functions are adopted to tackle the input constraint. A restrained adaptive boundary iterative learning control (ABILC) law is proposed based on a time-weighted Lyapunov–Krasovskii-like composite energy function. In order to deal with the uncertainty of a system parameter and reject the external disturbances, three adaptive laws are designed and learned in the iteration domain. All the system states of the closed-loop system are proved to be bounded in each iteration. Along the iteration axis, the displacements asymptotically converge toward zero. Simulation results are provided to illustrate the effectiveness of the proposed ABILC scheme.

178 citations

Journal ArticleDOI
TL;DR: In this paper, two wide bandgap A-D-A structured p-type organic semiconductor (p-OS) small molecules with weak electron-withdrawing ester end groups: SM1 with cyano group on the ester group and SM2 without the CN group.
Abstract: We synthesized two wide bandgap A–D–A structured p-type organic semiconductor (p-OS) small molecules with weak electron-withdrawing ester end groups: SM1 with cyano group (CN) on the ester group and SM2 without the CN group. SM1 showed stronger absorption, lower-lying HOMO energy level, and higher hole mobility in comparison with that of SM2 without the CN groups. The all-small-molecule organic solar cell (SM-OSC) with SM1 as donor and a narrow bandgap n-OS IDIC as acceptor demonstrated a high power conversion efficiency (PCE) of 10.11% and a high fill factor (FF) of 73.55%, while the PCE of the device based on SM2:IDIC is only 5.32% under the same device fabrication condition. The PCE of 10.11% and FF of 73.55% for the SM1-based device are the highest values for the nonfullerene SM-OSCs reported in the literature so far. The results indicate that the cyano substitution in SM1 plays an important role in improving the photovoltaic performance of the p-OS donors in the nonfullerene SM-OSC. In addition, the ...

178 citations

Journal ArticleDOI
TL;DR: A highly transparent triboelectric nanogenerator was designed to harvest the electrostatic energy from flowing water and can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in the authors' living environment and on smart home system and smart car system.
Abstract: Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

178 citations

Proceedings ArticleDOI
12 Dec 2009
TL;DR: A hierarchy of P2P reputation systems is suggested to protect clouds and datacenters at the site level and to safeguard the data objects at the file-access level to protect cloud service models, currently implemented by Amazon, IBM, and Google.
Abstract: Internet clouds work as service factories built around web-scale datacenters. The elastic cloud resources and huge datasets processed are subject to security breaches, privacy abuses, and copyright violations. Provisioned cloud resources on-demand are especially vulnerable to cyber attacks. The cloud platforms built by Google, IBM, and Amazon all reveal this weaknesses. We propose a new approach to integrating virtual clusters, security-reinforced datacenters, and trusted data accesses guided by reputation systems. A hierarchy of P2P reputation systems is suggested to protect clouds and datacenters at the site level and to safeguard the data objects at the file-access level. Different security countermeasures are suggested to protect cloud service models: IaaS, PaaS, and SaaS, currently implemented by Amazon, IBM, and Google, respectively.

178 citations


Authors

Showing all 41904 results

NameH-indexPapersCitations
Zhong Lin Wang2452529259003
Yang Yang1712644153049
Jun Chen136185677368
Jun Lu135152699767
Jie Liu131153168891
Shuai Liu129109580823
Jian Zhou128300791402
Chao Zhang127311984711
Shaobin Wang12687252463
Tao Zhang123277283866
Jian Liu117209073156
Xin Li114277871389
Jianhui Hou11042953265
Hong Wang110163351811
Baoshan Xing10982348944
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023161
2022807
20214,662
20204,369
20194,164
20183,586