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Alternating Relaxed Twin Bounded Support Vector Clustering

WIRELESS PERSONAL COMMUNICATIONS 2018年第2期102卷 1129-1147页

作者： Fang, Jiayan Liu, Qiao Qin, Zhiguang Univ Elect Sci & Technol China Sch Informat & Software Engn Chengdu Sichuan Peoples R China Sichuan Prov Key Lab Network & Data Secur Chengdu Sichuan Peoples R China

Maximum margin clustering (MMC) and its improved version are based on the spirit of support vector machine, which will inevitably lead to prohibitively computational complexity when these learning models are encountered with an enormous amount of patterns. To accelerate the clustering efficiency, we propose alternating twin bounded support vector clustering to decompose the original large problem in MMC and its variants into two smaller sized ones, in which solving expensive semi-definite programming is avoided by performing alternating optimization between cluster-specific model parameters and instance-specific labeling assignments. Also the structural risk minimization principle is implemented to obtain good generalization. Additionally, in order to avoid premature convergence, a relaxed version of our algorithm is proposed, in which the hinge loss in the original twin bounded support vector machine is replaced with the Laplacian loss. These two versions can be easily extended to the nonlinear context via kernel tricks. To investigate the efficacy of our clustering algorithm, several experiments are conducted on a number of synthetic and real-world datasets. Experimental results demonstrate that the proposed method has better performance than other existing clustering approaches in terms of clustering accuracy and time efficiency and also possesses the powerful ability to process larger-scaled datasets.

关键词： Maximum margin clustering Twin support vector machine Alternating optimization hinge loss Laplacian loss

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A novel AAO-SBSPR process based on phosphorus mass balance for nutrient removal and phosphorus recovery from municipal wastewater

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WATER research 2018年 144卷 763-773页

作者： Zhu, Zhengyu Chen, Wenling Tao, Tao Li, Yongmei Tongji Univ Coll Environm Sci & Engn State Key Lab Pollut Control & Resource Reuse Shanghai 200092 Peoples R China Shanghai Inst Pollut Control & Ecol Secur Shanghai 200092 Peoples R China

A novel MO-SBSPR (Anaerobic-Anoxic-Oxic/Sequencing Batch Sidestream Phosphorus Recovery) process was developed for phosphorus (P) recovery and nutrient removal from municipal wastewater. Meanwhile, an operational strategy based on the P mass balance for the process was proposed, where P recovery rate was coupled with sludge retention time (SRT) so as to reduce the impact of P recovery on P content in activated sludge and maintain a stable operation of the process. The results show that the proposed operational strategy is helpful for the stable operation of the AAO-SBSPR process and up to 65% of the influent P was recovered with the phosphate removal efficiency of 99.1%. Both P recovery and extended SRT had limited influence on the P release and uptake rates of polyphosphate accumulating organisms (PAOs). The results of high-throughput sequencing analysis indicated that the relative abundance of Accumulibacter increased while SRT was extended under high P recovery rate. Moreover, significant promotion of simultaneous nitrogen removal and P uptake was observed, where the ratio of anoxic P uptake to the total P uptake of the whole process increased from 41.7% in the AAO process to 77.5% in the AAO-SBSPR process, combined with the increase of total nitrogen (TN) removal efficiency from 71.9% to 80.4%. The P recovery process is also beneficial for the reduction of sludge production and nitrification process as SRT was extended for high P recovery rate. Overall, the AAO-SBSPR process together with the operational strategy proposed in this study provides a promising and practical alternative for P recovery from municipal wastewater. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Phosphorus recovery AAO-SBSPR process Operational strategy P mass balance Sludge retention time Nutrient removal

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Graphene oxide-facilitated transport of Pb²⁺and Cd²⁺ in saturated porous media

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SCIENCE OF THE TotAL ENVIRONMENT 2018年 631-632卷 369-376页

作者： Jiang, Yanji Zhang, Xiongxiong Yin, Xianqiang Sun, Huimin Wang, Nong Northwest A&F Univ Coll Nat Resources & Environm Yangling 712100 Shaanxi Peoples R China Minist Agr Key Lab Plant Nutr & Agri Environm Northwest Chin Yangling 712100 Shaanxi Peoples R China Minist Agr Peoples Republ China Agroenvironm Protect Inst Tianjin 300191 Peoples R China

This paper provides an overview of the effect of graphene oxide (GO) on sorption, transport, and remobilization of Pb2+ and Cd2+ ions in saturated porous media. The affinity of GO to Pb2+ and Cd2+ ions was investigated via kinetic and isothermal sorption experiments. Laboratory packed-column experiments were also conducted to investigate the cotransport of Pb2+ and Cd2+ ions with GO across a quartz sand matrix. In addition, thePb(2+)- and Cd2+-preequilibrated sand column was sequentially flushed with GO to test its remobilization effect on these ions. GO exhibited a high affinity toward both Pb2+ and Cd(2+)ions with maximum sorption capacities of 1428.57 and 911.43 mg g(-1) , respectively. On the other hand, while GO improved the transport ability of Pb2+ and Cd2+ , both ions reduced the mobility of GO in saturated porous media. Data from the elution experiment revealed that the high affinity of GO toward the metal ions led to the remobilization of the presorbed Pb2+- and Cd2+ ions onto the quartz sand surfaces and their concurrent migration across the sand column. XDLVO (Extended Deijaguin-Landau-Verwey-Overbeek) calculations were employed to interpret the GO transport behavior in the column wells. The cotransport of Pb2+ and Cd2+ ions with GO in the saturated quartz sand was successfully simulated by the advection-dispersion-reaction equation. Findings from this study provide an insight on the potential implications of remobilization and spread of pollutants by nanomaterials existing in vulnerable ecosystems. (C) 2018 Elsevier B.V. All lights reserved.

关键词： Graphene oxide Pb2+ Cd2+ Transport Sand column XDLVO theory

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Heterostructured Nanorings of Fe-Fe₃O₄@C Hybrid with Enhanced Microwave Absorption Performance

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ACS APPLIED MATERIALS & INTERFACES 2018年第11期10卷 9369-9378页

作者： Jian, Xian Xiao, Xiangyun Deng, Longjiang Tian, Wei Wang, Xin Mahmood, Nasir Dou, ShiXue Univ Elect Sci & Technol China Sch Mat & Energy Chengdu 611731 Sichuan Peoples R China Univ Elect Sci & Technol China Sch Elect Sci & Engn State Key Lab Elect Thin Films & Integrated Devic Natl Engn Res Ctr Electromagnet Radiat Control Ma Chengdu 610054 Sichuan Peoples R China RMIT Univ Sch Engn 124 La Trobe St Melbourne Vic 3001 Australia Univ Wollongong Australian Inst Innovat Mat Inst Superconducting & Elect Mat North Wollongong 2500 Australia

Microwave absorption is a critical challenge with progression in electronics, where fine structural designing of absorbent materials plays an effective role in optimizing their microwave absorption properties. Here, we have developed Fe3O4@C (FC) and Fe-Fe3O4@C (FFC) hybrid nanorings via a hydrothermal method coupled with a chemical catalytic vapor deposition technique. FC and FFC hybrid nanorings have fine carbon coating while their size can easily be tunable in a certain range from 80-130 to 90-140 nm. The optimized FC and FFC hybrid nanorings bear minimum reflection loss (RL) values of -39.1 dB at 15.9 GHz and -32.9 dB at 17.1 GHz, respectively, whereas FFC shows an effective absorption bandwidth (RL values < -10 dB) ranged from 5.2 to 18 GHz. Such an enhanced microwave absorption performance of hybrid nanorings is mainly due to the suitable impedance characteristics, multilevel interfaces, and polarization features in nanorings. This work provides an approach to design hybrid materials having a complex structure to enhance the microwave absorption properties.

关键词： hybrid nanorings catalytic chemical vapor deposition iron oxide carbon overcoat microwave absorption

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Collaborative scheduling for optimization of public ground transportation 17

Collaborative scheduling for optimization of public ground t...

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17th CotA International Conference of Transportation Professionals: Transportation Reform and Change - Equity, Inclusiveness, Sharing, and Innovation, CICTP 2017

作者： Chen, Erhui Liu, Jing Yu, Zhongdong Beijing NEWCOM Technology Co. Ltd. IT Industrial Park No. 10 Electronic City Chaoyang District Jiuxianqiao North Rd. Beijing100015 China

ISBN: (数字)9780784480915

ISBN: (纸本)9780784480915

Transit scheduling is the basis of the operation and organization plan of a public transportation enterprise;it is also the core of bus dispatching. In this paper, we will compile the collaborative departure schedule in the bus route of the region to maximize the convenience for passengers. This paper introduces formulation of a regional schedule as a special kind of 0-1 knapsack problem with a special coordination coefficient of no capacity constraint and with the minimum passenger transfer time as the objective. The synergy coefficient is defined, and the corresponding mathematical optimization model is established, which realizes the regional and coordinated development of the public transit timetable. The enterprise can effectively allocate vehicle resources and human resources, in order to lay the foundation to achieve a comprehensive system of regional bus operators. © ASCE.

关键词： Combinatorial optimization

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Understanding the Friction Reduction Mechanism Based on Molybdenum Disulfide Tribofilm Formation and Removal

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LANGMUIR 2018年第45期34卷 13523-13533页

作者： Xu, Dichu Wang, Chun Espejo, Cayetano Wang, Jiugen Neville, Anne Morina, Ardian Zhejiang Univ Sch Mech Engn Hangzhou 310027 Zhejiang Peoples R China Univ Leeds Inst Funct Surfaces Sch Mech Engn Leeds LS2 9JT W Yorkshire England

Among friction modifier lubricant additives, molybdenum dialkyldithiocarbamate (MoDTC) provides excellent friction behavior in boundary lubricated tribocontacts. It is well established that the low friction obtained with MoDTC is as a result of the formation of lattice structure MoS2 nanosheets. However, the relationship between the molybdenum species quantity, its distribution on the contact surface, and the friction behavior is not yet fully understood. In this work, Raman microscopy and atomic force microscopy (AFM) have been used with the aim of understanding the link between the friction behavior and the MoDTC/ZDDP tribofilm formation and removal. Tribotests were coupled with a collection of ex-situ Raman intensity maps to analyze the MoS2 tribofilm buildup. Post-test AFM analyses were implemented on the ball wear scar to acquire the average MoDTC/ZDDP tribofilm thickness. In-situ Raman spectra analyses were carried out to detect the MoS2 tribofilm removal. A good correlation was achieved between the friction coefficient measurements and Raman maps when using a linear relationship between the microscopic friction and the local amount of MoS2 tribofilm. After a rapid increase, the average MoDTC/ZDDP tribofilm thickness levels out to a steady state as the friction drop ceases. The removal rate of MoS2 from tribofilms, obtained at different temperatures, suggests that the MoS2 tribofilms are much easier to remove from tribocontacts compared to antiwear ZDDP tribofilms. This is the first study that sets out a framework to link MoS2 amount and coverage to the friction behavior, providing the basis for developing numerical models capable of predicting friction by taking into account tribochemistry processes.

关键词： Thickness Redox reactions Friction Raman spectroscopy Wear

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Toxicity and bio-distribution of carbon dots after single inhalation exposure in vivo

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Chinese Chemical Letters 2018年第6期29卷 895-898页

作者： Yue Yang Xiangling Ren Zhenning Sun Changhui Fu Tianlong Liu Xianwei Meng Zili Wang College of Animal Science and Technology Southwest University Chongqing 400716 China Laboratory of Controllable Preparation and Application of Nanomaterials CAS Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China College of Veterinary Medicine China Agricultural University Beijing 100193 China

Because of the advantages of excellent light stability, carbon dots（CDs） are considered to be a promising agent in the bio-marker application. Nevertheless, there are many unresolved issues with the toxicity of CDs in vitro and in vivo. In the study, CDs were synthesized by citric acid and ethylenediamine into deionized water, then the inhalation toxicity and bio-distribution of CDs in vivo were systematically assessed. The results showed that CDs caused animals death at higher dosages and induced injury in the lung and liver including inflammation and necrosis after single inhalation exposure at 5, 2 and 1 mg/kg dosages of the CDs. We also found that the injury increase with a dose-dependent and time-dependent manner. Fluorescent examination and TEM results showed that CDs mainly located at the lung and *** the fluorescent intensity increase with a time-dependent manner. This study provides a theoretical basis of the respiratory toxicity of CDs, and provides a basis for the use of CDs as a bio-marker.

关键词： Carbon dots Toxicity Bio-distribution Inhalation Fluorescent intensity

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Competition and Differentiation of a Pair of Morpheme-inverted Words in Mandarin Chinese: Douzheng and Zhengdou 18th

Competition and Differentiation of a Pair of Morpheme-invert...

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18th Chinese Lexical Semantics Workshop (CLSW)

作者： Li, Wensi Beijing Normal Univ Inst Chinese Informat Proc Beijing 100875 Peoples R China

ISBN: (纸本)9783319735733;9783319735726

A large number of morpheme-inverted words are unique elements in Chinese vocabulary, which is an important lexical phenomenon occurred in the history of the development and evolution of Chinese vocabulary. As a corpus driven study, this paper discusses a pair of morpheme-inverted words douzheng and zhengdou from microscopic perspective. Based on the statistics and analysis, this paper explores the origin, occurrence time, evolution process, service conditions and the reasons of semantic changes of douzheng and zhengdou. And this study aims at providing some reference for the study of morpheme-inverted words from microscopic perspective.

关键词： morpheme-inverted words douzheng zhengdou evolution

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Determination of Heterotic Groups and Heterosis Analysis of Yield Performance in indica Rice

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Rice science 2018年第5期25卷 261-269页

作者： WANG Yingheng CAI Qiuhua XIE Hongguang WU Fangxi LIAN Ling HE Wei CHEN Liping XIE Hua'an ZHANG Jianfu College of Crop Sciences Fujian Agriculture and Forestry University Fuzhou 350002 China Rice Research Institute Fujian Academy of Agricultural Sciences Fuzhou 350019 China Key Laboratory of Germplasm Innovation and Molecular Breeding of Hybrid Rice for South China Ministry of Agriculture / Fuzhou Branch National Rice Improvement Center / Fujian Engineering Laboratory of Crop Molecular Breeding / Fujian Key Laboratory of Rice Molecular Breeding Fuzhou 350003 China Incubator of National Key Laboratory of Fujian Germplasm Innovation and Molecular Breeding Between Fujian and Ministry of Sciences & Technology Fuzhou 350003 China National Rice Engineering Laboratory Fuzhou 350003 China

To compare the heterosis levels among various groups of parental lines used extensively in china, identify foundational heterotic groups in parental pools and understand the relationship between genetic distance and heterosis performance, 16 parental lines with extensive genetic variation were selected from various sub-groups, and 39 hybrid combinations were generated and evaluated in Fujian and Hainan Provinces of china. The main results were as follows：（1） The 16 parental lines can be grouped into 7 sub-groups consisting of 1 maintainer sub-group and 6 restorer sub-groups; （2） Mean grain yield of the restorer lines was higher than that of the maintainer lines, and mean yield of parental lines was higher than that of the hybrid combinations; （3） The two best heterotic patterns were II-32A × G5 and II-32A × G6, moreover, the order of restorer sub-groups according to grain yield, from the highest to lowest, was G7, G6, G5, G4, G3 and G2; high specific combining ability values were observed for combinations of II-32A × G5, II-32A × G6 and Tianfeng A × G7; （4） Hybrid combinations derived from II-32A crossed with 13 restorer lines had higher yield trait values （mid-parent heterosis, better-parent heterosis, standard heterosis over check and specific combining ability） than any other combinations; （5） Genetic distance was positively correlated with panicle number, grain length and length-to-width ratio （P 〈 0.05） and negatively correlated with grain width, grain yield, seed-setting rate, as well as mid-parent heterosis, standard heterosis over check, and specific combining ability for grain yield （P 〈 0.01）. These heterotic groups and patterns and their argonomic traits will provide useful information for future hybrid rice breeding programs.

关键词： rice heterosis heterosis group general combine ability specific combine ability genetic distance

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Vascular endothelial growth factor-B: Impact on physiology and pathology

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CELL ADHESION & MIGRATION 2018年第3期12卷 215-227页

作者： Zhu, Hongyu Gao, Mingming Gao, Xiangdong Tong, Yue China Pharmaceut Univ Sch Life Sci & Technol State Key Lab Nat Med Nanjing Jiangsu Peoples R China Univ Georgia Dept Pharmaceut & Biomed Sci Athens GA 30602 USA

Angiogenesis plays an important role in controlling tissue development and maintaining normal tissue function. Dysregulated angiogenesis is implicated in the pathogenesis of a variety of diseases, particularly diabetes, cancers, and neurodegenerative disorders. As the major regulator of angiogenesis, the vascular endothelial growth factor (VEGF) family is composed of a group of crucial members including VEGF-B. While the physiological roles of VEGF-B remain debatable, increasing evidence suggests that this protein is able to protect certain type of cells from apoptosis under pathological conditions. More importantly, recent studies reveal that VEGF-B is involved in lipid transport and energy metabolism, implicating this protein in obesity, diabetes and related metabolic complications. This article summarizes the current knowledge and understanding of VEGF-B in physiology and pathology, and shed light on the therapeutic potential of this crucial protein.

关键词： cancer cardiovascular diseases diabetes neurodegenerative diseases VEGF-B

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