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Covalent modification of multiwalled carbon nanotubes with a low molecular weight chitosan

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Chinese Chemical Letters 2007年第3期18卷 361-364页

作者： Gang Ke Wen Chao Guan Chang Yu Tang Zhen Hu Wen Jie Guan dan lin Zeng Feng Deng Department of Chemistry Huazhong University of Science and Technology Wuhan 430074 China Key Laboratory of Cellulose and Lignocellulosics Chemistry Guangzhou Institute of Chemistry Chinese Academy of Sciences Guangzhou 510650 China Department of Physics Wuhan University Wuhan 430072 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China

Covalent modification of shortened multiwalled carbon nanombes （MWNTs） with a natural low molecular weight chitosan （LMCS） was accomplished by the nucleophilic substitution reaction. The LMCS modified MWNTs （MWNT-LMCS） were characterized by FTIR, solid-state ^13C NMR, and XPS spectroscopies, thermogravimetric analysis, and transmission electron microscopy. The results revealed that amino and primary hydroxyl groups of the LMCS participated mainly in the formation of the MWNT-LMCS conjugates. The MWNT-LMCS consists of 58 wt.% LMCS, and about four molecular chains of the LMCS were attached to 1000 carbon atoms of the nanotube sidewalls. As a novel derivative of the MWNTs, the MWNT-LMCS not only solved in DMF, DMAc and DMSO, but also in aqueous acetic acid solution.

关键词： Carbon nanotubes Chitosan Renewable resources Modification

Size distribution,directional source contributions and pollution status of PM from Chengdu,China during a long-term sampling campaign

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Journal of Environmental Sciences 2017年第6期29卷 1-11页

作者： Guo-Liang Shi Ying-Ze Tian Tong Ma dan-lin Song Lai-Dong Zhou Bo Han Yin-Chang Feng Armistead G.Russell State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300071China Chengdu Research Academy of Environmental Protection Sciences Chengdu 610000China Tianjin Key Laboratory for Air Traffize Operation Planning and Safety Technology Civil Aviation University of ChinaTianjin 300300China School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaC-A 30332-0512USA

Long-term and synchronous monitoring of PMIo and PM2.s was conducted in Chengdu in China from 2007 to 2013. The levels, variations, compositions and size distributions were investigated. The sources were quantified by two-way and three-way receptor models （PMF2, ME2-2way and ME2-3way）, Consistent results were found： the primary source categories contributed 63.4% （PMF2）, 64.8% （ME2-2way） and 66.8% （ME2-Bway） to PMIo, and contributed 60.9% （PMF2）, 65.5% （ME2-2way） and 61.0% （ME2-3way） to PM2.s. Secondary sources contributed 31.8% （PMF2）, 32.9% （ME2-2way） and 31.7% （ME2-3way） to PMIo, and 35.0% （PMF2）, 33.8% （ME2-2way） and 36.0% （ME2-3way） to PM2.s. The size distribution of source categories was estimated better by the ME2-3way method. The three-way model can simultaneously consider chemical species, temporal variability and PM sizes, while a two-way model independently computes datasets of different sizes. A method called source directional apportionment （SDA） was employed to quantify the contributions from various directions for each source category. Crustal dust from east-north-east （ENE） contributed the highest to both PM^o （12.7%） and PMzs （9.7%） in Chengdu, followed by the crustal dust from south-east （SE） for PMao （9.8%） and secondary nitrate ＆ secondary organic carbon from ENE for PMzs （9.6%）. Source contributions from different directions are associated with meteorological conditions, source locations and emission patterns during the sampling period. These findings and methods provide useful tools to better understand PM pollution status and tn dovolon offoctive nolhltion control gtrateMeg.

关键词： PM10 PM2.5 PMF2 ME2-3way Size distribution Source directional apportionment

Sensory innervation around immediately vs. delayed loaded implants: a pilot study

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International Journal of Oral Science 2015年第1期7卷 49-55页

作者： Yan Huang Jeroen van Dessel Wendy Martens Ivo Lambrichts Wei-Jian Zhong Guo-Wu Ma dan lin Xin Liang Reinhilde Jacobs Department of Imaging & Pathology Faculty of Medicine University of Leuven and Oral & Maxillo-facial Surgery University Hospitals Leuven State Key Laboratory of Oral Diseases West China Hospital of Stomatology Sichuan University Biomedical Research Institute Hasselt University School of Stomatology Dalian Medical University Center for Statistics Hasselt University

Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in ***^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in ***^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-i

关键词： animal experiments dental implants histomorphometry immediate loading mechanoreceptor myelinated nerve fibres osseoperception

A comparative study of differences in writing strategies among Chinese EFL learners, overseas Chinese ESL learners, and Northern American ENL learners

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Sino-US English Teaching 2010年第6期7卷 18-27页

作者： WU Li-lin ZHANG dan School of Foreign Languages Changsha University of Science ＆ Technology Hunan 410005 China

This paper concerns study of learning strategies from language learners. In the light of the types and models of strategies found in the study of ESL （English as a Second Language） learners＇ strategies abroad, the authors have summed up and induced 3 group learners＇ writing strategies stated in their reports, with which they have designed the surveying tool by using factor analysis. And then, the authors use descriptive and 1-way ANOVA （Analysis of Variance） analysis of SPSS16.0 （Statistical Program for Social Science） to examine the differences of strategies used by EFL （English as a Foreign Language） learners in China, overseas Chinese ESL learners in Northern Americas and Northern American ENL （English as a Native Language） learners. It is concluded by he results of the study that ENL and ESL learners are good at using various writing strategies. And there are significant differences in using writing strategies between ENL/ESL learners and EFL learners. The authors also conclude that the differences between ESL group and ENL group are not significant, much less than the ones between ESL group and EFL group. The authors make comparative analysis on the causes to the findings on the aspects of class teaching approaches and language learning surroundings, which bring out implications for teaching of English writing in China.

关键词： English writing strategies effective writing teaching approaches to writing Chinese EFLlearners Northern American ESL/ENL learners

Growth Rate in Spatial Ability Predicts Early Mathematics Competence

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Growth Rate in Spatial Ability Predicts Early Mathematics Co...

Impact of continuous low water stage on the breeding environment of Oncomelania hupensis: a case study of Poyang Lake area in China

第二十届全国心理学学术会议--心理学与国民心理健康

作者： Xiao Zhang dan lin Faculty of Education The University of Hong Kong Department of Psychological Studies The Education University of Hong Kong

There is a well-established relation between overall level of spatial ability and mathematics competence: people who are stronger in the former perform better on tests of the latter. However, does the rate of growth in spatial ability also matter? A total of 106 Chinese children(57 girls;age at first time point: M = 45.1 ± 3.4 months) in two preschools in Hong Kong participated in this study. Children were tested individually a total of five times across their first to third years of preschool as follows: in the spring(May, Time 1 [T1];N = 106) of the first year, the fall(November, Time 2 [T2];N = 88) and spring(May, Time 3 [T3];N = 80) of the second year, and the fall(November, Time 4 [T4];N = 75) and spring(May, Time 5 [T5];N = 71) of the third(final) year. Spatial perception and language ability were tested at each point from T1 to T4. Spatial analogic reasoning and spatial visualization were tested at T4. Mental rotation and mathematics and reading competencies were tested at T5. To examine the level and rate of growth in spatial perception and the effect of each of these on later mathematics competence(in contrast to reading), we performed growth-curve analyses. Moreover, we conducted control variable analyses to investigate whether the observed effects remained significant after accounting for the influences of spatial analogic reasoning, spatial visualization, mental rotation, and the level and growth rate in language ability. The results showed that growth rate in spatial perception during the preschool years significantly predicted mathematics competence at the end of preschool. This effect was over and above the overall levels of spatial perception and spatial reasoning and the level and rate of growth in language ability. The findings highlight the need to provide spatial learning opportunities for preschoolers whose rate of growth in this skill is slower than that of their peers.

关键词： spatial ability mathematics competence growth rate longitudinal research

来源： cnki会议评论

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Infectious Diseases of Poverty 2020年第4期9卷 156-157页

作者： Fei Hu Qi-Yue Li Xiao-Feng Dai Zhao-Jun Li Shang-Biao Lv Chun-Fang Lu Yi-Feng Li Min Yuan Yue-Ming Liu Ying Liu dan-dan lin Jiangxi Provincial Institute of Parasitic Diseases No.239First Gaoxin Rd.Gaoxin District330096NanchangJiangxi ProvincePeople’s Republic of China Jiangxi Province Key Laboratory of Schistosomiasis Prevention and Control Nanchang330096People’s Republic of China Jiangxi Normal University No.99Ziyang AvenueNanchang330022Jiangxi provincePeople’s Republic of China

Background Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its *** variation of water level greatly affects the reproduction and growth of ***,in this paper,we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding *** By employing remote sensing data from 1993 to 2016(April–June and September–November),the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and ***,the average daily water level data from the four hydrological stations(Hukou station,Xingzi station,Tangyin station and Kangshan station)which represent the typical state of Poyang Lake were collected from 1993 to *** variance of the monthly mean water level,inundation time and the average area were analyzed by variance to find a significance level ofα=*** According to hydrological data before and after 2003,the average water level after 2003 is significantly lower than that before 2003 in Poyang *** 2003,the time of inundateing the snail breeding period was later in April to June than that before 2003,while the time of wate-falling stage in September to November moved forward after 2003 than before *** them,the lowest water level affecting the breeding and growing period of *** in the northern part of Poyang Lake decreased from 11 m to 9 *** 2003,the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9–11 m,and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang *** By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003,it is found that the water level changes mainly affect the snail breeding are

关键词： Oncomelania hupensis Water level Lake meadow Snail control Poyang Lake China

Research on the Positioning of Government Functions in China under the Background of Smart City Construction

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International Journal of Technology Management 2013年第10期 116-118页

作者： ZHENG lin-feng NI dan College of Literature and Law Sichuan Agricultural University Ya'an P.R. China 625014

In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government＇ s leading role cannot give a better play due to the constraints of the traditional government functions. Therefore, it is necessary to carry out a reasonable position for the government functions in the construction of smart city. This paper issues that the government should reflect functions in the construction of smart city, such as the planning function of top-level design and unified planning; the organizational function of providing funds and talent protection; the coordinating function of promoting multiple-subject cooperation; the controlling function of establishing technical standards and legal norms.

关键词： Smart city Smart China Smart earth The position of govemment function The transformation of government functions

Changes in the Non-targeted Metabolomic Profile of Three-year-old Toddlers with Elevated Exposure to Polycyclic Aromatic Hydrocarbons

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Biomedical and Environmental Sciences 2024年第5期37卷 479-493页

作者： LI Yang lin dan ZHANG Xiu Qin JU Guang Xiu SU Ya ZHANG Qian DUAN Hai Ping YU Wei Sen WANG Bing ling PANG Shu Tao Department of Epidemiology and Health Statistics School of Public HealthQingdao UniversityQingdao 266021ShandongChina Department of Environmental Health Qingdao Municipal Center for Disease Control and PreventionQingdao Institute of Preventive MedicineQingdao 266033ShandongChina Physicochemical Laboratory Qingdao Municipal Center for Disease Control and PreventionQingdao Institute of Preventive MedicineQingdao 266033ShandongChina Section of Child Health Care Huangdao Maternity and Child Health Care Hospital of QingdaoQingdao 266499ShandongChina Qingdao Blood Center Qingdao 266071ShandongChina

Objective To investigate changes in the urinary metabolite profiles of children exposed to polycyclic aromatic hydrocarbons(PAHs)during critical brain development and explore their potential link with the intestinal *** Liquid chromatography-tandem mass spectrometry was used to determine ten hydroxyl metabolites of PAHs(OH-PAHs)in 36-month-old ***,37 children were categorized into low-and high-exposure groups based on the sum of the ten ***-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to identify non-targeted metabolites in the urine ***,fecal flora abundance was assessed by 16S rRNA gene sequencing using Illumina *** The concentrations of 21 metabolites were significantly higher in the high exposure group than in the low exposure group(variable importance for projection>1,Pdances(r=0.34–0.55),which were mainly involved in *** Higher PAH exposure in young children affected metabolic homeostasis,particularly that of certain gut microbiota-derived *** investigation is needed to explore the potential influence of PAHs on the gut microbiota and their possible association with neurodevelopmental outcomes.

关键词： Child Gut microbiota Non-targeted metabolomics Polycyclic aromatic hydrocarbons Urinary metabolite profile

Reducing relapse and accelerating osteogenesis in rapid maxillary expansion using an injectable mesoporous bioactive glass/fibrin glue composite hydrogel

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Bioactive Materials 2022年第12期7卷 507-525页

作者： Hanjiang Zhao Xiangyu Wang Anting Jin Minjiao Wang Zeying Wang Xingtai Huang Jiewen Dai Xudong Wang dan lin Steve GF.Shen Department of Oral&Cranio-Maxillofacial Surgery Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of Stomatology&Shanghai Research Institute of StomatologyShanghai200011PR China Shanghai University of Medicine and Health Sciences Shanghai201318China

Rapid maxillary expansion(RME),as a common treatment for craniomaxillofacial deformity,faces the challenge of high relapse rates and unsatisfactory therapeutic *** this study,a standardized Sprague-Dawley(SD)rat RME model was first established with a modified expander as well as retainer design and optimized anterior maxillary expanding force of 100 g which exerted the most synchronized mobility of mid-palatal suture and *** the standardized model,the high relapse rate was proven to be attributed to insufficient osteogenesis in expanded suture,requiring long-term retainer wearing in clinical *** reduce the relapse rate,mesoporous bioactive glass/fibrin glue(MBG/FG)composite hydrogels were developed for an in situ minimal invasive injection that enhance osteogenesis in the expanded *** component of 1 wt%MBG was adopted for enhanced mechanical strength,matched degradation rate and ion dissolution,excellent in vitro biocompatibility and *** of 1%MBG/FG composite hydrogel on osteogenesis in expanded mid-palatal sutures with/without retention were evaluated in the standardized *** results demonstrated that injection of 1%MBG/FG composite hydrogel significantly promoted bone formation within the expanded mid-palatal suture,inhibited osteoclastogenesis and benefited the balance of bone remodeling towards *** of retainer and injectable biomaterial was demonstrated as a promising treatment to reduce relapse rate and enhance osteogenesis after *** model establishment and the composite hydrogel development in this article might provide new insight to other craniomaxillofacial deformity treatment and design of bone-repairing biomaterials with higher regenerative efficiency.

关键词： Rapid maxillary expansion Sutural distraction osteogenesis Injectable hydrogel Mesoporous bioactive glass Bone regeneration