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Journal of Environmental Sciences 2021年第7期33卷 90-99页

作者： Yanhong Shi Yu Zhang xiangyang wu Hong Zhang Min Yang Zhe Tian School of the Environment and Safety Engineering Jiangsu UniversityZhenjiang 212013China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

The tet C gene has been found to be one of the most widely distributed tetracycline resistance( tet) genes in various environmental niches, but the detailed dissemination mechanisms are still largely unknown. In the present study, 11 tet C-containing Aeromonas media strains were isolated from an aerobic biofilm reactor under oxytetracycline stresses, and the genome of one strain was sequenced using the Pac Bio RSII sequencing approach to reveal the genetic environment of tet C. The tet C gene was carried by an IS 26 composite transposon, named Tn 6434. The tet C-carrying Tn 6434 structure was detected in all of the A. media strains either in a novel plasmid p Aeme2( n = 9) or other DNA molecules( n = 2) by PCR screening. The NCBI database searching result shows that this structure was also present in the plasmids or chromosomes of other 13 genera, indicating the transferability of Tn 6434. Inverse PCR and sequencing confirmed that Tn 6434 can form a circular intermediate and is able to incorporate into a preexisting IS 26 element, suggesting that Tn 6434 might be responsible for the dissemination of tet C between different DNA molecules. This study will be helpful in uncovering the spread mechanism of tet genes in water environments.

关键词： Aeromonas media tetC IS 26 Circular intermediate Inverse PCR

TiO2/EDTA-rich carbon composites： Synthesis, characterization and visible-light-driven photocatalytic reduction of Cr(Ⅵ)

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Chinese Chemical Letters 2018年第3期29卷 547-550页

作者： Zhijun Luo Lingling Qu Jianzhong Ji Jing wang Suying Jiang Zhiren wu xiangyang wu jiangsu University Zhenjiang 212013 China Enginneering Technology Center for Heavy Metal Wostewater Treatment and Recovery Environmental Protection Department of Jiangsu Province Yixing 214200 China Jiangsu ATK Environment Engineering Design and Research Institute Co. Ltd. Yixing 214200 China

TiO2/EDTA-rich carbon composites （TiO2/EDTA-RC） have been successfully synthesized via a low temperature carbonization process. TiO2/EDTA-RC exhibits marked absorption of visible light and excellent photoreduction of Cr（Ⅵ） activity under visible light irradiation （λ 〉 420 nm）. Due to the high carboxyl group content and strong coordination ability of EDTA, TiO2-EDTA complex can be easily fabricated between EDTA incorporated in carbon sheet and titanol group on the surface of TiO2. TiO2- EDTA complexes on the surface of TiO2/EDTA-RC, the LMCT complex, are responsible for the prominent photoreduction of Cr（Ⅵ） properties of TiO2/EDTA-RC under visible light irradiation. In addition, the unique structure of TiO2/EDTA-RC is also propitious to the visible-light photocatalytic reduction of Cr（Ⅵ）. Carbon sheet of TiO2/EDTA-RC acts as a supporter. Tio2 nanoparticles and EDTA homogeneously disperse into the carbon sheet supporter and form the TiO2-EDTA complexes, which can avoid the aggregation of TiO2 nanoparticles in the aqueous solution and provide more photocatalytic reaction points for the reduction of Cr（Ⅵ）.

关键词： TiO2 Carbon-based materials Nanostructures Photocatalysis Reduction of Cr(Ⅵ)

A Stochastic Optimization Approach for Dynamic Adaptive Streaming over NDN

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Journal of Communications and Information Networks 2021年第3期6卷 267-279页

作者： Xiaobin Tan Shunyi Wang Quan Zheng Bei Liu Yi He xiangyang wu Laboratory for Future Networks the University of Science and Technology of ChinaHefei 230027China The 54th Research Institute of China Electronic Technology Corporation Shijiazhuang 050081China

Nowadays,video streaming counts for the major part of network traffic over the ***,on account of the host-to-host mechanism of the traditional IP network,video distribution over IP-based Internet encounters ***,a new proposed future Internet architecture,named data networking(NDN)can improve the performance of video distribution by its features such as in-network storage,multi-path forwarding,*** this paper,we design an adaptive bitrate algorithm based on Lyapunov optimization theory over NDN to optimize the long-term quality-of-experience(QoE)of video distribution while ensuring the stability of the whole *** the network condition is abundant and stable,the problem can be simplified by approximating to a fixed-slot queuing model,but the theoretical performance will degrade when the network status is poor and fluctuate ***,we divide the problem into two models of fixed time slot and non-fixed time slot and design two Lyapunov optimization algorithms to adapt different network *** proposed algorithms do not require prior knowledge of the network bandwidth and are capable of running online with the client’s available *** and realistic experiment results demonstrate that our algorithms perform better than others in NDN.

关键词： named data networking dynamic adaptive streaming scalable video coding Lyapunov optimization quality of experience

Visualizing large-scale high-dimensional data via hierarchical embedding of KNN graphs

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Visual Informatics 2021年第2期5卷 51-59页

作者： Haiyang Zhu Minfeng Zhu Yingchaojie Feng Deng Cai Yuanzhe Hu Shilong wu xiangyang wu Wei Chen State Key Lab of CAD&CG Zhejiang UniversityHangzhouZhejiangChina University of California Santa Cruz San FranciscoUSA Hangzhou Dianzi University HangzhouZhejiangChina

Visualizing intrinsic structures of high-dimensional data is an essential task in data *** the past decades,a large number of methods have been *** all solutions,one promising way for enabling effective visual exploration is to construct a k-nearest neighbor(KNN)graph and visualize the graph in a low-dimensional ***,state-of-the-art methods such as the LargeVis still suffer from two main problems when applied to large-scale data:(1)they may produce unappealing visualizations due to the non-convexity of the cost function;(2)visualizing the KNN graph is still *** this work,we propose a novel visualization algorithm that leverages a multilevel representation to achieve a high-quality graph layout and employs a cluster-based approximation scheme to accelerate the KNN graph *** on various large-scale datasets indicate that our approach achieves a speedup by a factor of five for KNN graph visualization compared to LargeVis and yields aesthetically pleasing visualization results.

关键词： High-dimensional data visualization KNN graph Graph visualization

Stability Investigation and Improvement for DC Cascade Systems with Simplified Impedance-based Stability Criterion

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1044-1052页

作者： Junbin Fang Zhikang Shuai Yang Li Zhibing Wang xiangyang wu Xia Shen Z.John Shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Renewable Energy Department of China Electric Power Research Institute Beijing 100192China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616USA IEEE

In DC distributed power systems(DPSs),the complex impedance interactions possibly lead to DC bus voltage oscillation or *** previous research,the stability analysis of DPSs is implemented based on mathematical analysis in control *** specific mechanisms of the instability of the cascade system have not been intuitively *** this paper,the stability analysis of DPSs based on the traditional Nyquist criterion is simplified to the resonance analysis of the seriesconnected port impedance(Z=R+jX)of source and load *** reveals that the essential reason for impedance instability of a DC cascade system is that the negative damping characteristic(R<0)of the port the overall impedance amplifies the internal resonance source at reactance zero-crossing *** simplified stability criterion for DC cascade systems can be concluded as:in the negative damping frequency ranges(R<0),there exists no zero-crossing point of the reactance component(i.e.,X=0).According to the proposed stability criterion,the oscillation modes of cascade systems are classified.A typical one is the internal impedance instability excited by the negative damping,and the other one is that the external disturbance amplified by negativity in a low stability ***,the impedance reshaping method for stability improvement of the system can be further *** validity of the simplified criterion is verified theoretically and experimentally by a positive damping reshaping method.

关键词： DC cascaded system,impedance model impedance reconstruction stability criterion

In-suit fabricating an efficient electronic transport channels via S-scheme polyaniline/Cd_(0.5)Zn_(0.5)S heterojunction for rapid removal of tetracycline hydrochloride and hydrogen production

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Journal of Materials Science & Technology 2023年第22期153卷 205-218页

作者： Yan Xiao Yinhua Jiang Ershuai Zhou Wenli Zhang Yan Liu Jianming Zhang xiangyang wu Qi Qi Zhanchao Liu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China Institute of Environmental Health and Ecological Security School of the Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013China School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Foshan(Southern China)Institute for New Materials Foshan 528200China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The development of highly efficient catalyst is the key for photocatalytic technology to deal with water pollution and energy *** this work,the S-scheme polyaniline/Cd_(0.5)Zn_(0.5)S(PANI/CZS)nanocomposites were elaborately prepared for the first time by in-situ oxidation *** to pure PANI and Cd_(0.5)Zn_(0.5)S,this PANI/CZS hybrid displayed outstanding photocatalytic performance in removing tetracycline hydrochloride(TCH)and hydrogen evolution under light *** them,15 PANI/CZS sample could achieve 84.9%TCH degradation efficiency within 25 min,and the degradation rate(0.06931 min−1)was 5.13 times than that of Cd_(0.5)Zn_(0.5)S(0.0135 min^(−1)).The optimal photocatalytic H_(2) evolution rate of 30 PANI/CZS sample was 15.57 mmol g^(-1) h^(-1),which was twice that of Cd_(0.5)Zn_(0.5)S(7.34 mmol g^(-1) h^(-1)).These results were mainly attributed to the efficient electronic transport channels provided by S-scheme heterojunction *** density functional theory(DFT)calculation proved that the difference of work function resulted in band bending and forming built-in electric field on the contact interface of PANI/CZS,which facilitated the migration and separation of interfacial photogener-ated charge carriers for the strengthened photocatalytic ***,the degradation interme-diate products and pathways of TCH were also put forwarded in depth based on MS *** last,the S-scheme electron transport model and the photocatalytic reaction mechanism in PANI/CZS hetero-junction structure were *** work provided an innovative vision in developing high-performance S-scheme heterojunction multifunctional photocatalysts.

关键词： S-scheme heterostructure Cd_(0.5)Zn_(0.5)S PANI H_(2)evolution TCH photodegradation

QoE-Driven Rate Adaptation Algorithm for Fair Dynamic Adaptive Video Streaming in Named Data Networking 36

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QoE-Driven Rate Adaptation Algorithm for Fair Dynamic Adapti...

A Stochastic Optimization Approach for Dynamic Adaptive Scalable Video Streaming over NDN 36

第36届中国控制会议

作者： Jiawei Ni Xiaobin Tan Yunfeng Shao xiangyang wu Jin Zhu Laboratory for Future Networks University of Science and Technology of China

ISBN: (纸本)9781538629185

Nowadays,video streaming causes traffic over the *** Adaptive video Streaming（DAS） has emerged as a promising ***,existing researches in DAS focus on single client instead of multi-client which is much closer to *** if some methods are proposed for multi-client scenarios,they need to add coordinate proxy to the network or add additional function to routers or ***,the caches in Named Data Networking（NDN） have a significant impact on ***,we proposed a QoE-driven fair-DAS algorithm,able to learn and dynamically adapt its behavior depending on network *** evaluating this novel approach through simulations in several multi-client scenarios and comparing with the Rate and Buffer Based Adaptation（RBBA） algorithm,we are able to show that our algorithm resulted in a better video quality,fairness,stability and effectiveness,so a great improvement in overall QoE.

关键词： Dynamic Adaptive video Streaming(DAS) Fairness Multi-client Quality of Experience(QoE)

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A Stochastic Optimization Approach for Dynamic Adaptive Scal...

Construction of a few-layer g-C_3N_4/α-MoO_3 nanoneedles all-solid-state Z-scheme photocatalytic system for photocatalytic degradation

第36届中国控制会议

作者： xiangyang wu Xiaobin Tan Yunfeng Shao Jiawei Ni Jin Zhu Laboratory for Future Networks University of Science and Technology of China

ISBN: (纸本)9781538629185

Named Data Networking（NDN） is a general proposed network layer protocol which offers a set of rich functionality:in-network storage, multi-path forwarding, and data-centric security. The cache and multi-path feature improves the efficiency of transmission but increases the difficulty of the bandwidth estimation. In this paper, a dynamic layer switching strategy using Lyapunov Optimization is proposed for dynamic adaptive scalable video streaming over NDN. It aims for optimizing long-term quality-of-experience（QoE） of users via maximizing video quality subject to a constraint on playback smoothness, interruption and fluctuation. The proposed algorithm does not require a priori knowledge of the network bandwidth dynamics, and is capable of operating online with the client’s currently available information. Experimental results indicate that our algorithm performs better than others in NDN.

关键词： Named Data Networking Scalable Video Streaming Stochastic Optimization

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Journal of Energy Chemistry 2019年第2期28卷 65-71页

作者： Xiaoni Zhang Jianjian Yi Hanxiang Chen Mao Mao Liang Liu Xiaojie She Haiyan Ji xiangyang wu Shouqi Yuan Hui Xu Huaming Li School of the Environment and Safety Engineering Institute for Energy ResearchJiangsu University

The suppression of the recombination of electrons and holes(e–h) and the enhancement of the light absorption of semiconductors are two key points toward efficient photocatalytic ***,we report a few-layer g-C_3N_4/α-MoO_3 nanoneedles(flg-C_3N_4/α-MoO_3 NNs) all-solid-state Z-scheme mechanism photocatalyst synthesized via a typical hydrothermal method in a controlled *** recombination of the photo-induced e–h pairs could be effectively restrained by the Z-scheme passageway between the flg-C_3N_4 and α-MoO_3 NNs in the composite,which could also promise a high redox ability to degrade *** it became possible for the prepared photocatalyst to absorb light in a wide range of *** detailed mechanism was studied by electron spin-resonance spectroscopy(ESR).The low-dimensional nanostructure of the two constituents(α-MoO_3 NNs with one-dimensional structure and flg-C_3N_4 with two-dimensional structure) endowed the composite with varieties of excellent physicochemical properties,which facilitated the transfer and diffusion of the photoelectrons and increased the specific surface area and the active *** 10 wt% flg-C_3N_4/α-MoO_3 NNs showed the best photocatalytic performance toward RhB degradation,the rate of which was 71.86%,～2.6 times higher than that ofα-MoO_3 NNs.

关键词： Flg-C3N4 α-MoO3 nanoneedles All-solid-state Z-scheme mechanism Low-dimensional nanostructure Photocatalytic degradation

QUANTUM CHEMICAL STUDY ON STRUCTURAL ACIDITY OF HZSM-5 ZEOLITE

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分子催化 1990年第S1期4卷 103-110页

作者： wu Suochuan wu xiangyang (Department of Chemistry, Nanj ing Normal University, Nanjing, China)

The basic units of the framework structure of HZSM-5 zeolite are the five-membered rings which are linked by bridging oxygen atoms and as a result form units of four-membered rings or six membered rings. Semiempirical CNDO/2 quantum chemical method is used to calculate the charge density distribution for all these basic units, i.e., 4-, 5- and 6-membered rings of HZSM-5 zeolite. Quantitative relations between the structural parameter α0 of the acidity of HZSM-5 zeolite and the number of aluminum atoms NAl per unit cell are obtained. Zeolite may be considered as solids acting more or less as protonic polyacids in solution. This protonic acidity is expressed as activity, aH+= [H+]fH+ ,were =nH+aNAl/Zcat and the activity coefficient fH+ is equal to a constant multiplied by the structural parameter, fH+= Kα0, K is taken to be 32. Upder different （SiO2/Al2O3） ratios, therefore, the protonic activities could be obtained theoretically, and the calculation results are

关键词： zeolite membered acidity rings bridging hexane solids terminated constants proton