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Chinese Journal of Polymer Science 2024年第8期42卷 1227-1242页

作者： Jia-Wei Gao li Chen Ye-Shun Zhong Chao-Wei Xing yi-guo li Zong-Bao Wang School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)***,high stretch and shear flow fields are necessary for the formation of shish *** this study,UHMWPE gel films with reserved shish crystals were prepared by gel molding,the structural evolution and properties of UHMWPE films stretched at temperatu res of 100,110,120and 130℃were investigated by in situ small-angle X-ray scattering(SAXS)/ultra-small-angle X-ray scattering(USAXS)/wide-angle X-ray diffraction(WAXD)measu rements as well as scanning electron microscopy(SEM)and differential scanning calorimetry(DSC)*** findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot ***,the reserved shish crystals promote the structu ral evolution of UHMWPE films to a greater extent when stretched at 120 and 130℃,compared to 100 and 110℃,resulting in higher crystallinity,orientation,thermal properties,breaking strength and Young's *** pared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding,UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching,resulting in increased breaking strength and Young's modulus.

关键词： UHMWPE low-entangled films Reserved shish crystals Structural evolution Hot stretching

IC Cloud: Enabling Compositional Cloud

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International Journal of Automation and computing 2011年第3期8卷 269-279页

作者： yi-Ke guo li guo Department of Computing Imperial College London London SW7 2BZ UK

Cloud computing has attracted great interest from both academic and industrial communities. Different paradigms, architectures and applications based on the concept of cloud have emerged. Although many of them have been quite successful, efforts are mainly focusing on the study and implementation of particular setups. However, a generic and more flexible solution for cloud construction is missing. In this paper, we present a composition-based approach for cloud computing （compositional cloud） using Imperial College Cloud （IC Cloud） as a demonstration example. Instead of studying a specific cloud computing system, our approach aims to enable a generic framework where wrious cloud computing architectures and implementation strategies can be systematically studied. With our approach, cloud computing providers/adopters are able to design and compose their own systems in a quick and flexible manner. Cloud computing systems will no longer be in fixed shapes but will be dynamic and adjustable according to the requirements of different application domains.

关键词： Cloud computing compositional cloud infrastructure as a service (IaaS) cloud service cloud elasticity.

ANALYSIS OF EDL EFFECTS ON THE FLOW AND FLOW STABIliTY IN MICROCHANNELS

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Journal of Hydrodynamics 2010年第5期22卷 725-731页

作者： YOU Xue-yi guo li-xiang School of Environmental Science and Engineering Tianjin University 300072 Tianjin China

The effects of the Electrical Double Layer （EDL） on the liquid mean flow and the flow stability in microchannels are investigated by solving the Poisson-Boltzmann equation. The models of the traditional streaming Electrical Current Balance （ECB） and the newly introduced streaming Electrical Current Density Balance （ECDB） are applied to determine the electrical streaming current. The numerical results show that the electrical streaming current backflow in the ECB model near the wall can be removed by using the ECDB model, which is suitable to study the effects of the EDL on the mean flow and the flow stability in microchannels. The flow is found more unstable if the ECDB model is applied.

关键词： electrical double layer Poisson-Boltzmann equation electrical streaming current balance flow stability microchan

Microbial and hydrodynamic properties of aerobic granules in a sequencing batch reactor treating landfill leachate

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 219-229页

作者： Yan-jie WEI Min JI guo-yi li Fei-fei QIN Key Laboratory of Environmental Protection in Water Transport Engineering Ministry of Communications Tianjin Research Institute of Water Transport Engineering Tian/in 300456 China School of Environmental Science and Engineering Tianjin University Tianjin 300072 China Tianjin Tanggu Sino French Water Supply Co. Ltd Tianjin 300450 China

A sequencing batch reactor （SBR） seeded with activated sludge was established for landfill leachate treatment. Small bio-aggregates began to appear after 40-d operation, and gradually changed to mature aerobic granules, with a mean size of 0.36-0.60 ram. Their sludge volume index at 5 min （SVI5 rain）, mixed liquor volatile suspended solids （MLVSS）, and wet density were around 35 ml/g, 3.4 g/L, and 1.062 g/cm3, respectively. The settling velocities of the granules in distilled water ranged from 0.3 to 1.3 cm/s, which were faster than those in landfill leachate with a salt content of 1.4% （w/v）, and also slightly faster than those predicted by Stokes＇ law for porous but impermeable particles. Microbial community evolution during the granulation process and stages under different nitrogen loading rates （NLRs） were monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）, cloning, and sequencing of 16S ribosomal RNA （rRNA） fragments. Results revealed that some primary and dominant communities in inoculating activated sludge died out gradually; while a few common bacteria, inhabiting soils, municipal wastewater, or activated sludge systems, dominated in the SBR system throughout. In addition, some other dominant species, associated with the aerobic granulation process, were thought to play a significant role in the formation and growth of aerobic granular sludge. During the stable operation time under low NLR, a few species were present in abundance, and may have been responsible for the high organic removal efficiency at this time.

关键词： Aerobic granules Microbial community Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE),Landfill leachate

Structural Evolution of PGA Nascent Fiber during Single Low-Temperature and Segmented High-Temperature Hot Stretching

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Chinese Journal of Polymer Science 2023年第7期41卷 1078-1092页

作者： Yu-Shuang Miao Hua-Shuai Cui Jin guo Jin-Tang Zhu yi-guo li Zong-Bao Wang School of Materials Science and Chemical Engineering Key Laboratory of Impact and Safety EngineeringMinistry of EducationNingbo UniversityNingbo315211China State Key Laboratory of Biobased Fiber Manufacturing Technology China Textile AcademyBeijing100025China

Polyglycolide (PGA) fibers applied as surgical sutures strongly depend on their microstructure. The structural evolution of PGA nascent fibers during single low-temperature stretching and segmented high-temperature stretching was analyzed based on a combination of in situ WAXD/SAXS and DSC measurements. The results indicated that the hot stretching was conducive to the crystal perfection and the local fragmentation and recrystallization of the lamellar crystals may occur under stress induction. The single low-temperature stretching of PGA nascent fibers could be divided into three stages: the stretching of amorphous regions, stretch-induced crystallization and the stretching of crystalline regions. The elongation at break of the fibers can be substantially increased by adopting a segmented stretching method, and the high-temperature stretching can also significantly increase the crystallinity and orientation. The amorphous orientation peak appearing in the low-temperature stretching was gradually converted to crystallization peak during the heating process, which greatly improved the crystallinity and orientation of the fibers. High-temperature stretching compared with low-temperature stretching was more favorable for crystal perfection and structural evolution, where lamellar crystals underwent stress-induced fragmentation recrystallization to transform to fibrous crystals as the strain increased.

关键词： PGA fiber Structural evolution Hot stretching

High throughput route selection in multi-rate wireless mesh networks

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 13-18页

作者： WEI yi-fei guo Xiang-li SONG Mei SONG Jun-de Personal Communication Networks Computer Aided Design Center School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Most existing Ad-hoc routing protocols use the shortest path algorithm with a hop count metric to select paths. It is appropriate in single-rate wireless networks, but has a tendency to select paths containing long-distance links that have low data rates and reduced reliability in multi-rate networks. This article introduces a high throughput routing algorithm utilizing the multi-rate capability and some mesh characteristics in wireless fidelity （WiFi） mesh networks. It uses the medium access control （MAC） transmission time as the routing metric, which is estimated by the information passed up from the physical layer. When the proposed algorithm is adopted, the Ad-hoc on-demand distance vector （AODV） routing can be improved as high throughput AODV （HT-AODV）. Simulation results show that HT-AODV is capable of establishing a route that has high data-rate, short end-to-end delay and great network throughput.

关键词： wireless mesh networks Ad-hoc AODV routing protocol multi-rate WiFi

A Synchrotron in situ X-ray Study on the Multiple Melting Behaviors of Isomorphous Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P(HB-co-HV))with Middle HV Content

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Chinese Journal of Polymer Science 2020年第9期38卷 1015-1024,I0008页

作者： Hao Zhu You Lv Dan Shi yi-guo li Wei-Jun Miao Zong-Bao Wang Ningbo Key Laboratory of Specialty Polymers State Key Laboratory Base of Novel Functional Materials and Preparation ScienceFaculty of Materials Science and Chemical EngineeringNingbo UniversityNingbo 315211China

The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed by differential scanning calorimetry(DSC),and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction(WAXD)and small angle X-ray scattering(SAXS)*** emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell *** on the in situ WAXD and SAXS measurements,we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon *** comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV)and P(HB-co-28.7%HV)result from the melting of different lamellae rather than the melting/*** thinner,unstable uniform lamellae with HV counits total inclusion melt first and the thicker,stable sandwich lamellae with HV counits partial inclusion melt *** addition,the large second melting peak in P(H B-co-19.4%HV),differing from that of samples with HV content of 28.7 mol%and 36.2 mol%,is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform *** present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.

关键词： P(HB-co-HV) Isomorphous Middle HV content Synchrotron radiation

The Influence of Ethyl Branch on Formation of Shish-Kebab Crystals in Bimodal Polyethylene under Shear at Low Temperature

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Chinese Journal of Polymer Science 2021年第8期39卷 1050-1058,I0008页

作者： Zong-Bao Wang yi-Min Mao Xu-Ke li yi-guo li Chatchai Jarumaneeroj Boonyakeat Thitisak Piyawan Tiyapiboonchaiya Wonchalerm Rungswangd Benjamin S.Hsiao Ningbo Key Laboratory of Specialty Polymers School of Materials Science and Chemical EngineeringNingbo UniversityNingbo 315211China Department of Materials Science and Engineering University of MarylandCollege ParkMaryland 20742USA NIST Center for Neutron Research National Institute of Standards and TechnologyGaithersburgMaryland 20899USA SCG Chemicals Co. Ltd.Siam Cement Group(SCG).1 Siam Cement Rd.BangsueBangkok 10800Thailand USA Department of Chemistry Stony Brook UniversityStony BrookNY 11794-3400USA

Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was *** situ small-angle X-ray scattering(SAXS)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low *** the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same *** degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below *** study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no *** partly oriented lamellar crystals were formed for the bimodal PE with ethyl *** the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.

关键词： Bimodal polyethylene Shish-kebab Ethyl branch Shear

Relationship between Carotid Atherosclerosis and Cerebral Infarction

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Chinese Medical Sciences Journal 2010年第1期25卷 32-37页

作者： Guang-wen li Guan-yi Zheng Jin-guo li Xu-dong Sun Department of Geriatrics Union Hospital Fujian Medical University Fuzhou 350001 China

Objective To study the relationship between carotid atherosclerosis and cerebral infarction (CI). Methods Between November 2008 and March 2009,147 CI patients (CI group) and 48 patients with non-cerebrovascular diseases (control group) were enrolled from inpatients of Neurology Department of our hospital. The diagnostic criterion of thickened carotid intima was set as 1.0 mm≤intima-media thickness (IMT) 0.05). Conclusions Carotid atherosclerosis is to some extent able to reveal the atherosclerotic condition of cerebral arteries and act as an important predictor for the risk of CI. T

关键词： carotid atherosclerosis cerebral infarction intima-media thickness color Doppler ultrasonography

Membrane fouling behavior and microbial community succession in a submerged membrane bioreactor treating harbor oily wastewater

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第9期17卷 745-757页

作者： Yan-jie WEI guo-yi li Key Laboratory of Environmental Protection in Water Transport Engineering Tianjin Research Institute for Water Transport Engineering Tianjin 300456 China

A membrane bioreactor （MBR） was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand （COD）, oil content, suspended solids （SS）, and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances （EPS） accumulated on the membrane surface, especially the proteins, were of great importance for the transmembrane pressure （TMP） increment and membrane fouling. The MBR was optimized via improving aeration rate and reducing the ratio of Ar/Ad （At and Ad are the cross-sectional areas of the riser and the downcomer of the MBR）. The increasing rate of TMP was slowed, indicating that the optimization strategy could effectively mitigate membrane fouling. Microbial community evolution was monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）, cloning, and sequencing of 16S ribosomal ribonucleic acid （rRNA） fragments. Results revealed that low community shift occurred during the whole operational period. Geobacter sp. and Rhodocyclales sp., which have also been identified by other studies in a petroleum refinery wastewater MBR or an infiltration basin receiving highway runoff, dominated in the MBR system throughout. Comamonas sp. was thought to accommodate the lower aeration rate in this study, while Rhodocyclales sp. preferred the higher aeration rate. In addition, during the operational time under high organic loading rate, a few species were present in abundance, and may have been responsible for the good removal performance at this time.

关键词： Membrane bioreactor (MBR) fouling Extracellular polymeric substances (EPS) Harbor oily wastewater Microbialcommunity