检索结果-南通市图书馆

Morphology Control and Optical Absorption Properties of Ag Nanoparticles by Ion Implantation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2009年第5期25卷 669-672页

作者： G.X. Cai f. ren X.H. Xiao L.X. fan X.D. Zhou C.Z. Jiang Key Laboratory of Acoustic and Photonie Materials and Devices of Ministry of Education Wuhan University Wuhan 430072 China

Ion implantation is a powerful method for fabricating nanoparticles in dielectric. for the actual application of nanoparticle composites, a careful control of nanoparticles has to be achieved. In this letter, the size, distribution and morphology of Ag nanoparticles are controlled by controlling the ion current density, ion implantation sequence and ion irradiation dose. Single layer Ag nanoparticles are formed by Ag^＋ ion implantation at current density of 2.5 μ^A/cm2. By Ag and Cu ions sequential implantation, the size of single layer Ag nanoparticles increases. While, by Cu and Ag ions sequential implantation, uniform Ag nanoparticles with wide distribution are formed. The morphology of Ag nanoparticles changes to hollow and sandwiched nanoparticles by Cu^＋ ion irradiation to doses of 3×10^16 and 5×10^16 ions/cm^2. The optical absorption properties of Ag nanoparticles are also tailored by these ways.

关键词： Nanoparticles Ion implantation Transmission electron microscopy

Osteocyte morphology and orientation in relation to strain in the jaw bone

在线全文

学校读者我要写书评

暂无评论

International Journal of Oral Science 2018年第1期10卷 36-43页

作者： Vivian Wu rené f. M. van Oers Engelbert A. J. M. Schulten Marco No Helder Rommel G. Bacabac Jenneke Klein-Nulend Department of Oral Cell Biology Academic Centre for Dentistry Amsterdam (ACTA) Amsterdam Movement Sciences University of Amsterdam and Vrije Universiteit Amsterdam Amsterdam The Netherlands Department of Dental Materials Science Academic Centre for Dentistry Amsterdam (ACTA) Amsterdam Movement Sciences University of Amsterdam and Vrije Universiteit Amsterdam Amsterdam The Netherlands Department of Oral and Maxillofacial Surgery VU University Medical Center/Academic Centre for Dentistry Amsterdam (ACTA) Amsterdam Movement Sciences Amsterdam The Netherlands Department of Physics Medical Biophysics Group University of San Carlos Cebu City Philippines

Bone mass is important for dental implant success and is regulated by mechanoresponsive osteocytes. We aimed to investigate the relationship between the levels and orientation of tensile strain and morphology and orientation of osteocytes at different dental implant positions in the maxillary bone. Bone biopsies were retrieved from eight patients who underwent maxillary sinus-floor elevation with β-tricalcium phosphate prior to implant placement. Gap versus free-ending locations were compared using 1) a three-dimensional finite-element model of the maxilla to predict the tensile strain magnitude and direction and 2) histology and histomorphometric analyses. The finite-element model predicted larger, differently directed tensile strains in the gap versus freeending locations. The mean percentage of mineralised residual native-tissue volume, osteocyte number(mean ± standard deviations:97 ± 40/region-of-interest), and osteocyte shape(90% elongated,10% round) were similar for both locations. However, the osteocyte surface area was 1.5-times larger in the gap than in the free-ending locations, and the elongated osteocytes in these locations were more cranially caudally oriented. In conclusion, significant differences in the osteocyte surface area and orientation seem to exist locally in the maxillary bone, which may be related to the tensile strain magnitude and orientation. This might reflect local differences in the osteocyte mechanosensitivity and bone quality, suggesting differences in dental implant success based on the location in the maxilla.

关键词： SINUS fLOOR ELEVATION MINERAL DENSITY MAXILLARY HISTOMORPHOMETRY TOMOGRAPHY IMPLANTS SPINE

Global vector-field reconstruction of nonlinear dynamical systems from a time series with SVD method and validation with Lyapunov exponents

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2003年第12期12卷 1366-1373页

作者：刘卫东 K.f.ren S.Meunier-Guttin-Cluzel G.Gouesbet DepartmentofAerospaceTechnology NatlonalUniversityofDefenseTechnologyChangsha410073China L.E.S.P. U.M.R.6614INSAdeRouen76801SaintEtienneduRouvrayFrance

A method for the global vector-field reconstruction of nonlinear dynamical systems from a time series is studied in this paper. It employs a complete set of polynomials and singular value decomposition (SVD) to estimate a standard function which is central to the algorithm. Lyapunov exponents and dimension, calculated from the differential equations of a standard system, are used for the validation of the reconstruction. The algorithm is proven to be practical by applying it to a Rossler system.

关键词： global vector-field reconstruction Lyapunov exponents model validation

An effective bimetallic oxide catalyst of RuO_(2)-Co_(3)O_(4) for alkaline overall water splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3785-3793页

作者： fangfang ren Jiayu Xu Ligang feng College of Chemical and Environmental Engineering Yancheng Teachers UniversityYancheng 224007China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

The rational design of effective bifunctional electrocatalysts is of paramount importance for overall water-splitting technology in sustainable energy ***,bimetallic oxide catalysts(RuO_(2)-Co_(3)O_(4))derived from Ru combined MOf-derivatives(MOf=metal-organic framework)were demonstrated effective for overall water splitting in an alkaline solution,owing to the combined merits such as the two-dimensional interconnected network structure,the synergetic coupling effects and increased chemical *** as-prepared RuO_(2)-Co_(3)O_(4) only requires an overpotential of 260 mV for oxygen evolution and 75 mV for hydrogen evolution at 10 mA/cm^(2) in 1 M KOH solution;a low cell voltage of 1.54 V was required to reach the kinetic current density of 10 mA/cm^(2) for the water electrolysis when supporting on glass carbon electrode,and very good stability for 40 h was *** and theoretical results demonstrated the electronic structure optimization of bimetallic RuO_(2)-Co_(3)O_(4) compared to the individual metal oxide,which promoted interface charges redistribution and the d-band center downshift,resulting in increased activity and stability for water-splitting *** work provides a feasible approach for developing bimetallic oxides for application in energy-relevant electrocatalysis reactions.

关键词： ruthenium dioxide cobalt oxide metal-organic frameworks heterostructures overall water splitting

Elucidating the structure-activity relationship of Cu-Ag bimetallic catalysts for electrochemical CO_(2) reduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 345-351,I0009页

作者： Qining Huang Lili Wan Qingxuan ren Jingshan Luo Institute of Photoelectronic Thin film Devices and Technology State Key Laboratory of Photovoltaic Materials and CellsKey Laboratory of Photoelectronic Thin Film Devices and Technology of TianjinMinistry of Education Engineering Research Center of Thin Film Photoelectronic TechnologyNankai UniversityTianjin 300350China frontiers Science Center for New Organic Matter Nankai UniversityTianjin 300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential for catalyst ***,we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu *** tested in a flow cell,the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54%for ethylene production,much higher than the catalyst with Ag nanoparticles on the *** catalysts were further studied in the H-cell and zero-gap MEA *** was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic *** work elucidates the structure-activity relationship of bimetallic catalysts for CO_(2) reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.

关键词： Electrochemical CO_(2)reduction Bimetallic catalyst Cu-Ag Structure-activity relationship

fault diagnosis of HVAC system with imbalanced data using multi-scale convolution composite neural network

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第3期17卷 371-386页

作者： Rouhui Wu Yizhu ren Mengying Tan Lei Nie School of Mechanical Engineering Hubei University of TechnologyWuhan430068China Industrial Research Institute of Xiangyang Hubei University of Technology Xiangyang441100China

Accurate fault diagnosis of heating,ventilation,and air conditioning(HVAC)systems is of significant importance for maintaining normal operation,reducing energy consumption,and minimizing maintenance ***,in practical applications,it is challenging to obtain sufficient fault data for HVAC systems,leading to imbalanced data,where the number of fault samples is much smaller than that of normal ***,most existing HVAC system fault diagnosis methods heavily rely on balanced training sets to achieve high fault diagnosis ***,to address this issue,a composite neural network fault diagnosis model is proposed,which combines SMOTETomek,multi-scale one-dimensional convolutional neural networks(M1DCNN),and support vector machine(SVM).This method first utilizes SMOTETomek to augment the minority class samples in the imbalanced dataset,achieving a balanced number of faulty and normal ***,it employs the M1DCNN model to extract feature information from the augmented ***,it replaces the original Softmax classifier with an SVM classifier for classification,thus enhancing the fault diagnosis *** the SMOTETomek-M1DCNN-SVM method,we conducted fault diagnosis validation on both the ASHRAE RP-1043 dataset and experimental dataset with an imbalance ratio of 1:*** results demonstrate the superiority of this approach,providing a novel and promising solution for intelligent building management,with accuracy and f1 scores of 98.45%and 100%for the RP-1043 dataset and experimental dataset,respectively.

关键词： fault diagnosis chiller imbalanced data SMOTETomek multi-scale neural networks

Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in China from 2000 to 2020

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2024年第3期16卷 396-414页

作者： LI Shaoting MU Na ren Yanjun Thomas GLAUBEN College of Economics and Management Northwest A&F UniversityYangling 712100China Sino-German Center for Agricultural and food Economics Northwest A&F UniversityYangling 712100China Leibniz Institute of Agricultural Development in Transition Economies(IAMO) Halle 06120Germany

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally *** study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit *** addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based *** results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the *** terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative *** should be noted that these two influencing factors had different impacts on MPAs and ***,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

关键词： cultivated land use eco-efficiency(CLUE) slacks-based measure(SBM)model barycentre model standard deviation ellipse(SDE) panel Tobit model carbon emissions nonpoint source pollution

A review:the mechanism of plant-derived polysaccharides on osteoblasts and osteoclasts

在线全文

学校读者我要写书评

暂无评论

未来食品学报(英文) 2024年第3期4卷 183-192页

作者： Mengjie ren Adel f.Ahmed Meng Li Menghan Li Zhiruo Yan Jinmei Wang National R&D Center for Edible fungus Processing Technology Henan UniversityKaifeng 475004China Joint International Research Laboratory of food&Medicine Resource function Henan ProvinceKaifeng 475004China Medicinal and Aromatic Plants Researches Department Horticulture Research InstituteAgricultural Research CenterGiza 12511Egypt

Bone loss and deterioration of bone microarchitecture would increase the bone fragility and fracture risk,leading to the *** and more evidences proved that plant-derived polysaccharides could have a remarkable influence on osteoblasts and osteoclasts,exerting anti-osteoporosis *** to the previous research,the extract of Cibotium barumoz,Achyranthes bidentata,Curculigo orchioides,Epimedium brevicornum,Angelica sinensis,Polygonatum sibiricum,Dendrobium officinale,Morinda officinalis,Nelumbo mucifera,Diospyros kaki,Hordeum vulgare,Cistanche deserticola,Commiphora Myrrha and other plant-derived polysaccharides could benefit to the osteoblasts and *** essential mechanisms are mainly related to the activation or inhibition of many factors,including runt-related transcription factor 2(Runx2),B-catenin,osterix(Osx),activator protein-1(AP-1),osteocalcin(OCN/BGP),alkaline phosphatase(ALP),osteopontin(OPN),bone morphogenetic protein(BMP),phosphatidylinositol 3-kinase(PI3K)/C-Jun N-terminal kinase(JNK)/extracellular regulated protein kinase(ERK),osteoprotegerin(OPG),receptor activator of nuclear factor-kB(RANK),monocyte/macrophage colony-stimulating factor(M-CSf),tumor necrosis factor receptor-associated factor 6(TRAf-6),receptor activator of nuclear factor(Nf)-KB ligand(RANKL),nuclear factor of activated T cells 1(NfATc1),c-fos,matrix metallopeptidase-9(MMP-9),glycogen synthase kinase 3β(GSK3B)/B-catenin,nuclear factor E2-related factor 2(Nf2),as well as these related pathways,such as Wnt/p-catenin,BMP-2/SMAD1/5/8,PI3K/AKT,OPG/RANKL/RANK,Nf-κB,MAPKs,*** plant-derived polysaccharides could improve the dynamic balance of bone formation and resorption through promoting the differentiation and maturation of osteoblast or inhibiting its *** reviewed plant-derived polysaccharides and their regulating mechanisms on the osteoclasts and osteoblasts provide the evidences for the development of osteoporosis therapeutics.

关键词： Osteoporosis Plant-derived polysaccharides Osteogenesis promotion Osteoclasts inhibition

Can soil organic carbon sequestration and the carbon management index be improved by changing the film mulching methods in the semiarid region?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第5期23卷 1541-1556页

作者： Jialin Yang Liangqi ren Nanhai Zhang Enke Liu Shikun Sun Xiaolong ren Zhikuan Jia Ting Wei Peng Zhang College of Agronomy Northwest A&F UniversityYangling 712100China Key Laboratory of Crop Physi-Ecology and Tillage Science in Northwestern Loess Plateau Ministry of Agriculture and Rural AfairsNorthwest A&FUniversityYangling 712100China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Plastic film mulching has been widely used to increase maize yield in the semiarid area of ***, whether long-term plastic film mulching is conducive to agricultural sustainability in this region remains controversial.A field experiment was initiated in 2013 with five different film mulching methods:(i) control method, flat planting without mulching (CK),(ii) flat planting with half film mulching (P),(iii) film mulching on ridges and planting in narrow furrows(S),(iv) full film mulching on double ridges (D), and (v) film mulching on ridges and planting in wide furrows (R).The effects on soil organic carbon (SOC) content, storage, and fractions, and on the carbon management index (CMI)were evaluated after nine consecutive years of plastic film *** results showed that long-term plastic film mulching generally maintained the initial SOC *** with no mulching, plastic film mulching increased the average crop yield, biomass yield, and root biomass by 48.38, 35.06, and 37.32%, respectively, which led to the improvement of SOC ***, plastic film mulching significantly improved CMI, and increased the SOC content by 13.59%, SOC storage by 7.47%and easily oxidizable organic carbon (EOC) by 13.78%on average,but it reduced the other labile *** sequestration and CMI were improved by refining the plastic film mulching *** S treatment had the best effect among the four mulching methods, so it can be used as a reasonable film mulching method for sustainable agricultural development in the semiarid area.

关键词： plastic film mulching soil organic carbon labile organic carbon fractions semiarid area