检索结果-南通市图书馆

Biomedical Named Entity Recognition Based on Self-supervised Deep Belief Network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第3期29卷 455-462页

作者： zhang yajun LIU Zongtian ZHOU Wen Shanghai Institute of Precision Measurement and Test School of Computer Engineering and Science Shanghai University

Named entity recognition is a fundamental and crucial issue of biomedical data mining. For effectively solving this issue, we propose a novel approach based on Deep belief network(DBN). We select nine entity features, and construct feature vector mapping tables by the recognition contribution degree of different values of them. Using the mapping tables, we transform words in biomedical texts to feature vectors. The DBN will identify entities by reducing dimensions of vector *** extensive experimental results reveal that the novel approach has achieved excellent recognition performance,with 69.96% maximum value of F-measure on GENIA 3.02 testing corpus. We propose a self-supervised DBN, which can decide whether to add supervised fine-tuning or not according to the recognition performance of each layer,can overcome the errors propagation problem, while the complexity of model is limited. Test analysis shows that the new DBN improves recognition performance, the Fmeasure increases to 72.12%.

关键词： Biomedical named entity recognition Feature selection Feature vector mapping Threshold judgement Self-supervision

Mechanical characterization of soft silicone gels via spherical nanoindentation for applications in mechanobiology

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第4期37卷 554-561,I0001页

作者： yajun zhang Xiaoning Yang Chunyang Xiong Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Jiangsu Key Laboratory of Medical Optics Suzhou Institute of Biomedical Engineering and TechnologyChinese Academy of SciencesSuzhou 215163China

As a biocompatible material,soft silicone gels like CY52-276 have been applied to many engineering fields associated with interactions between mammalian cells and extracellular matrices/substrates,due to its nontoxicity,ease of preparation,optical transparency and tunable mechanical *** quantification of mechanical properties of silicone gels is crucial for quantitatively investigating mechanical responses of cells to *** the material with high surface energy,we design a new strategy for the nanoindentation technique to reduce or even eliminate the effect of interfacial adhesions with the aid of some specified ***,we dissect the dependence of its Young’s modulus on the ratios of monomers and crosslinkers and curing conditions,and therefore identify a dose-response relationship between its moduli and the corresponding prepolymer *** the non-linear large deformation nanoindentation tests,we further showed that the two-parameter Mooney-Rivlin model may well characterize the hyperelastic deformations of the materials with different composition *** pave the way for more precise exploration of the interaction between cells and extracellular matrix and the underlying mechanotransduction pathways in mechanobiology.

关键词： Silicone gel Young's modulus Nanoindentation Mechanobiology

Synthesis of hierarchical dendritic micro–nano structure ZnFe_2O_4 and photocatalytic activities for water splitting

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2016年第8期24卷 1112-1116页

作者： Zhongping Yao yajun zhang Yaqiong He Qixing Xia Zhaohua Jiang School of Chemical Engineering and Technology State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology

Hierarchical dendritic micro–nano structure Zn Fe_2O_4 have been prepared by electrochemical reduction and thermal oxidation method in this work. X-ray diffractometry, Raman spectra and field-emission scanning electron microscopy were used to characterize the crystal structure, size and morphology. The results show that the sample(S-2) is composed of pure ZnFe_2O_4 when the molar ratio of Zn^(2+)/Fe^(2+)in the electrolyte is 0.35. Decreasing the molar ratio of Zn^(2+)/Fe^(2+), the sample(S-1) is composed of ZnFe_2O_4 and α-Fe_2O_3, whereas increasing the molar ratio of Zn^(2+)/Fe^(2+), the sample(S-3) is composed of ZnFe_2O_4 and Zn O. The lattice parameters of ZnFe_2O_4 are influenced by the molar ratio of Zn^(2+)/Fe: Zn at excess decreases the cell volume whereas Fe at excess increases the cell volume of Zn Fe_2O_4. All the samples have the dendritic structure, of which S-2 has micron-sized lush branches with nano-sized leaves. UV–Vis diffuse reflectance spectra were acquired by a spectrophotometer. The absorption edges gradually blue shift with the increase of the molar ratio of Zn^(2+)/Fe^(2+). Photocatalytic activities for water splitting were investigated under Xe light irradiation in an aqueous olution containing 0.1 mol·L^(-1)Na_2S/0.02 mol·L^(-1)Na_2SO_3 in a glass reactor. The relatively highest photocatalytic activity with 1.41 μmol·h-1· 0.02 g^(-1)was achieved by pure ZnFe_2O_4sample(S-2). The photocatalytic activity of the mixture phase of Zn Fe_2O_4 and α-Fe_2O_3(S-1) is better than ZnF e_2O_4 and ZnO(S-3).

关键词： ZnFe2O4 Electrochemical reduction and thermal oxidation Dendritic micro–nano structure Hydrogen production

Electrocaloric effect in ferroelectric materials:From phase field to first-principles based effective Hamiltonian modeling

在线全文

学校读者我要写书评

暂无评论

Materials Reports(Energy) 2021年第3期1卷 34-63页

作者： Jingtong zhang Xu Hou yajun zhang Gang Tang Jie Wang Department of Engineering Mechanics School of Aeronautics and AstronauticsZhejiang UniversityHangzhou310027PR China Department of Mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhouGansu730000PR China Theoretical Materials Physics Q-MATCESAMUniversity of LiegeB-4000LiegeBelgium Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou310027PR China

Electrocaloric effect(ECE)of ferroelectrics has attracted considerable interest due to its potential application in environmentally friendly solid-state *** discovery of giant ECE in ferroelectric thin films has greatly renewed the research activities and significantly stimulated experimental and theoretical *** this review,the recent progress on the theoretical modeling of ECE in ferroelectric and antiferroelectric materials are introduced,which mainly focuses on the phase field modeling and first-principles based effective Hamiltonian *** firstly provide the theoretical foundation and technique details for each *** a comprehensive review on the progress in the application of two methods and the strategies to tune the ECE are ***,we outline the practical procedure on the development of multi-scale computational method without experiemtal parameters for the screening of optimized electrocaloric materials.

关键词： Electrocaloric effect Ferroelectric materials Phase field simulation Machine learning models First-principles based effective Hamiltonian modeling

Spintronic devices for neuromorphic computing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第7期63卷 124-126页

作者： yajun zhang Qi Zheng XiaoRui Zhu Zhe Yuan Ke Xia Center for Advanced Quantum Studies and Department of Physics Beijing Normal UniversityBejing 100875China Peng Cheng Laboratory Center for Quantum ComputingShenzhen 518005China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China

In the past decades,significant progress has been achieved in artificial intelligence,which is now widely applied in image recognition,big data analysis,unmanned vehicle control and other cognitive tasks[1].These applications nevertheless are highly energy consuming partly because of the mismatch between the neural-network-computing-based software im-plementation and the von Neumann architecture of present *** promising solution is developing neuro-morphic chips without the so-called von Neumann bottle-neck,which are suitable for performing the desired computation based on artificial neural networks(ANNs).

关键词： consuming desired computing

Synthesis and relaxivity of Gd(Ⅲ), Fe(Ⅲ) and Mn(Ⅱ) complexes with dihydropyridine derivative of diethvlenetriaminepentaacetic acid

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第z1期48卷 93-96页

作者： CHANG Jianhua ZHENG Shuzhan JIAN yajun BAI Yinjuan zhang Shiping Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China

A novel ligand of DTPA-dihydropyridine derivative was synthesized by reaction of DTPA-dianhydride with 4-aniline-1,4-dihydropyridine. Its complexes of gadolinium, manganese and iron were prepared. Their spin-lattice relaxivities (T1) were investigated. The results show that the NMR T1 relaxivitives (R1) for complexes of Fe(Ⅲ), Mn(Ⅱ) are less than that of Gd(Ⅲ) complex,which has a high relaxivity (R1) on the surrounding water protons, indicating that the Gd(Ⅲ) complex possesses the precondition to be contrast agents for magnetic resonance imaging.

关键词： diethylenetriaminepentaacetic acid, dihydropyridine, magnetic resonance imaging contrast agent, relaxivity.

Precious Fossil-Bearing Beds of the Lower Cretaceous Jiufotang Formation in Western Liaoning Province, China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2007年第3期81卷 357-364页

作者： zhang Lijun YANG yajun zhang Lidong GUO Shengzhe WANG Wuli ZHENG Shaolin Shenyang Institute of Geology and Mineral Resources Ministry of Land and Resources Shenyang Liaoning 110032

Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil birdand reptile-bearing beds of the formation in the Dachengzi, Chaoyang, *** and Fuxin-Yixian basins. Among them, the precious fossil-bearing beds in the Dachengzi Basin may be recognized as the Xidagou Bed of the second member and the Yangcaogoudonggou Bed of the third member; those in the Chaoyang Basin may be confirmed as the Shangheshou Bed of the second member and the Dongpochi Bed of the third member; those in the Dapingfang-Meileyingzi Basin are as the Lamagou Bed of the second member, the Huanghuagou Bed of the lower third member and the Yuanjiawa Bed of the upper third member; and those in the Fuxin-Yixian Basin are listed as the Tuanshanzi Bed of the second member and the Pijiagou Bed of the third member. Since these basins are distinctly separated and the bird and reptile fossils are mostly new genera and species, we have to use the associated fossil ostracod assemblages as index to correlate the Xidagou Bed with the Shangheshou Bed and the Lamagou Bed, and to correlate the Yuanjiawa Bed with the Yangcaogoudonggou Bed and the Pijiagou Bed. Primarily, we established the sequence of the precious fossil-bearing beds of the Jiufotang Formation in western Liaoning. They are represented by, in ascending order, the Xidagou Bed of the second member, the Huanghuagou Bed of the lower third member, and the Yuanjiawa Bed of the upper third member. Obviously, this work has significance for the study on the time-space distribution and radiation of birds and dinosaurs during the period of the middle Early Cretaceous.

关键词： division correlation precious fossil-bearing beds Lower Cretaceous JiufotangFormation western Liaoning

Associations between parental support for physical activity and moderate-to-vigorous physical activity among Chinese school children： A cross-sectional study

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2017年第4期6卷 410-415页

作者： Yang Liu yajun zhang Sitong Chen Jialin zhang Zongchen Guo Peijie Chen School of Physical Education and Sport Training Shanghai University of Sport Shanghai 200438 China Shanghai Research Center for Physical Fitness and Health of Children andAdoleseents Shanghai University of Sport Shanghai 200438 China rSchool of Physical Education Shaoxing University Shaoxing 312000 China Educational Management Information Center Ministry of Education Beijing 100816 China School of Kinesiology Shanghai University of Sport Shanghai 200458 China

Purpose: The objective of this study was to examine the associations between parental support for physical activity(PA) and levels of moderate-to-vigorous physical activity(MVPA) among Chinese school ***: Study participants were 81,857 school-aged children(aged 9–17 years; mean age = 13 years; 49.0% boys) and their parents or guardians who took part in the 2016 Physical Activity and Fitness in China—The Youth Study project. The independent variables included various forms of parental support for PA ascertained through a survey completed by parents or guardians. The dependent variable was the children's average MVPA in minutes per day by self-report. Structure equation modeling was used to examine the associations between parental support for PA and children's MVPA ***: The overall mean for MVPA participation time for the child participants was 48.82 ± 28.71 min/day. Significant associations between various forms of parental support and MVPA among children were found. Parental encouragement, accompanying, financial support, involvement,and role modeling for PA were positively associated with a high level of student MVPA participation. Parental PA knowledge-sharing was not associated with MVPA. The patterns of the associations were similar across sex, residence locale(i.e., urban and rural), and school grades(primary,junior middle, and junior high schools).Conclusion: Findings from this study suggest that, among Chinese school children, parental support for PA is important in promoting and facilitating children's participation in MVPA.

关键词： 2hildren and youth sports Chinese family Exercise Parenting

Supplementation of Lycium barbarum residue increases the growth rate of Tan sheep by enhancing their feed intake and regulating their rumen microbiome and metabolome

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第9期23卷 3129-3144页

作者： yajun zhang Xiao Chang Bing Wang Dawei Wei Rongzhen Zhong Yansheng Guo Min Du Guijie zhang College of Forestry and Prataculture Ningxia UniversityYinchuan 750021China Jilin Provincial Key Laboratory of Grassland Farming Northeast Institute of Geography and AgoecologyChinese Academy of SciencesChangchun 130102China State Key Laboratory of Animal Nutrition/College of Animal Science and Technology China Agricultural UniversityBeijing 100193China College of Animal Science and Technology Ningxia UniversityYinchuan 750021China Nutrigenomics and Growth Biology Laboratory Department of Animal SciencesWashington State UniversityPullmanWA 99164USA

Lycium barbarum residue(LBR),a by-product of *** processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal ***,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in *** explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment *** results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.

关键词： Lycium barbarum residue rumen microbiome metabolomics growth performance Tan sheep