Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 1 )

2019 ( 255 )

2018 ( 2222 )

2017 ( 2110 )

Custom range...

Search Results: 1 - 10 of 127035 matches for " Youwen Li "
All listed articles are free for downloading (OA Articles)
Page 1 /127035
Display every page Item
Analysis on Main Indexes for Evaluating 10 Medical Journals in Guangxi

LI YouWen,

中国科技期刊研究 , 2006,
Abstract: 目的:通过对广西10种医学期刊主要评价指标的分析,初步评价期刊的学术水平和质量。方法:利用《中国医院知识仓库》(简称CHKD)2000—2004年数据及《中国学术期刊综合引证报告》(2005版,简称CAJCCR)中的数据,对广西10种医学期刊的基金论文比、总被引频次、影响因子等主要评价指标进行统计和对比分析。结果:2004年CHKD和CAJCCR统计结果显示,广西10种医学期刊基金论文比均值、总被引频次均值、他引总引比均值分别为0.03和0.06、282和318、0.94和0.92;影响因子均值为0.134(CAJCGR)。CHKD的统计结果和CAJCCR数据有所差异,但总的倾向一致。结论:广西10种主要医学期刊大多为综合性期刊,刊载的论文侧重不同,学术水平和质量存在差异,主要评价指标均低于全国医学科学类期刊的平均水平,和我国优秀期刊相比仍存在较大的差距。
An Improved KNN Text Classification Algorithm Based on Clustering
Yong Zhou,Youwen Li,Shixiong Xia
Journal of Computers , 2009, DOI: 10.4304/jcp.4.3.230-237
Abstract: The traditional KNN text classification algorithm used all training samples for classification, so it had a huge number of training samples and a high degree of calculation complexity, and it also didn’t reflect the different importance of different samples. In allusion to the problems mentioned above, an improved KNN text classification algorithm based on clustering center is proposed in this paper. Firstly, the given training sets are compressed and the samples near by the border are deleted, so the multipeak effect of the training sample sets is eliminated. Secondly, the training sample sets of each category are clustered by k-means clustering algorithm, and all cluster centers are taken as the new training samples. Thirdly, a weight value is introduced, which indicates the importance of each training sample according to the number of samples in the cluster that contains this cluster center. Finally, the modified samples are used to accomplish KNN text classification. The simulation results show that the algorithm proposed in this paper can not only effectively reduce the actual number of training samples and lower the calculation complexity, but also improve the accuracy of KNN text classification algorithm.
Defect solitons in defective PT potentials with real part of dual-frequency lattices
Yunji Meng,Youwen Liu,Peining Li
Physics , 2011,
Abstract: We address the properties of defect solitons (DSs) in defective parity-time potentials with real part of dual-frequency lattices. The impact of defect on stability regions of DSs was considered. For positive defects, DSs whose real/imaginary parts are symmetric/antisymmetric (SA) functions of position are always stable in the semi-infinite gap and nonexistent in the first gap. While for negative defects, in semi-infinite gap, the SADSs are stable in most of their existence region besides low power region, but in the first gap, all the SADSs are stable. The ASDSs are unstable in the whole semi-infinite gap regardless of defects, but can be stable in the low power region for positive defects.
Effects of Different Fertilization Treatments on Soil, Leaf Nutrient and Fruit Quality of Citrus grandis var. longanyou  [PDF]
Rongfei Li, Yaodong Chang, Tao Hu, Xueyou Jiang, Guolu Liang, Zhiming Lu, Youwen Yi, Qigao Guo
World Journal of Engineering and Technology (WJET) , 2017, DOI: 10.4236/wjet.2017.52B001
The five-year-old “Longanyou” trees were used as the experimental material to study the effects of different fertilization treatments. The nutrient contents in soil and leaves, fruit yield and quality were determined, and then the correlations were analyzed. The results showed that: 1) The soil nutrient contents of 0 - 20 cm depth were more than the 20 - 40 cm, and the trends of nutrient contents of the 0 - 20 cm soil layers were as follows: treatment 2 (T2) > treatment 3 (T3) > treatment 4 (T4) > treatment 1(T1) > control (CK). However, the 20 - 40 cm depth had not significant difference between different treatments, but T2, T4 and T3 were higher than T1 and CK. It indicated that the soil effective nutrient content increased in T2 and T3. 2) Compared with the control, the content of K and B elements was improved obviously in leaves with the increase of organic manure application. The contents of P (1.60 g·kg-1), B (26.00 mg·kg-1) and Mg (1.18 g·kg-1) were the highest, and other nutrients contents were also higher, indicating that T2 could effectively improve the leaves’ nutrient contents. 3) The fruit yield per plant was the highest in T2 (95.40 kg plant-1), and the single fruit weight, total sugar, sugar and acid ratio, vitamin C were also the highest, but titratable acid was lower. It indicated that T2 effectively improved fruit yield and quality. 4) There were positive correlations between multiple factors of soil nutrients and the quality index, such as fruit peel thickness, total sugar, solid acid ratio, sugar and acid ratio, Vc content and single yield etc. There was significant correlation between K, B, Zn, Fe contents and fruit yield and quality index, and the contents of B, Zn and Fe in leaves were significantly correlated with soil nutrient, indicating that the contents of K, B, Zn, Fe in soil and leaf were closely related to fruit yield and quality. In sum, the T2 was the best fertilization scheme for orchard management practice of “Longanyou”.
The Dynamics of the Pulse Birth in an SIR Epidemic Model with Standard Incidence
Juping Zhang,Zhen Jin,Yakui Xue,Youwen Li
Discrete Dynamics in Nature and Society , 2009, DOI: 10.1155/2009/490437
Abstract: An SIR epidemic model with pulse birth and standard incidence is presented. The dynamics of the epidemic model is analyzed. The basic reproductive number ??? is defined. It is proved that the infection-free periodic solution is global asymptotically stable if ???<1. The infection-free periodic solution is unstable and the disease is uniform persistent if ???>1. Our theoretical results are confirmed by numerical simulations. 1. Introduction Every year billions of population suffer or die of various infectious disease. Mathematical models have become important tools in analyzing the spread and control of infectious diseases. Differential equation models have been used to study the dynamics of many diseases in wild animal population. Birth is one of the very important dynamic factors. Many models have invariably assumed that the host animals are born throughout the year, whereas it is often the case that births are seasonal or occur in regular pulse, such as the blue whale, polar bear, Orinoco crocodile, Yangtse alligator, and Giant panda. The dynamic factors of the population usually impact the spread of epidemic. Therefore, it is more reasonable to describe the natural phenomenon by means of the impulsive differential equation [1, 2]. Roberts and Kao established an SI epidemic model with pulse birth, and they found the periodic solutions and determined the criteria for their stability [3]. In view of animal life histories which exhibit enormous diversity, some authors studied the model with stage structure and pulse birth for the dynamics in some species [4–6]. Vaccination is an effective way to control the transmission of a disease. Mathematical modeling can contribute to the design and assessment of the vaccination strategies. Many infectious diseases always take on strongly infectivity during a period of the year; therefore, seasonal preventing is an effective and practicable way to control infectious disease [7]. Nokes and Swinton studied the control of childhood viral infections by pulse vaccination [8]. Jin studied the global stability of the disease-free periodic solution for SIR and SIRS models with pulse vaccination [9]. Stone et al. presented a theoretical examination of the pulse vaccination policy in the SIR epidemic model [10]. They found a disease-free periodic solution and studied the local stability of this solution. Fuhrman et al. studied asymptotic behavior of an SI epidemic model with pulse removal [11]. d'Onofrio studied the use of pulse vaccination strategy to eradicate infectious disease for SIR and SEIR epidemic models [12–15]. Shi
Alcohol ADME in Primates Studied with Positron Emission Tomography
Zizhong Li, Youwen Xu, Don Warner, Nora D. Volkow
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046676
Abstract: Background and Purpose The sensitivity to the intoxicating effects of alcohol as well as its adverse medical consequences differ markedly among individuals, which reflects in part differences in alcohol's absorption, distribution, metabolism, and elimination (ADME) properties. The ADME of alcohol in the body and its relationship with alcohol's brain bioavailability, however, is not well understood. Experimental Approach The ADME of C-11 labeled alcohol, CH311CH2OH, 1 and C-11 and deuterium dual labeled alcohol, CH311CD2OH, 2 in baboons was compared based on the principle that C–D bond is stronger than C–H bond, thus the reaction is slower if C–D bond breaking occurs in a rate-determining metabolic step. The following ADME parameters in peripheral organs and brain were derived from time activity curve (TAC) of positron emission tomography (PET) scans: peak uptake (Cmax); peak uptake time (Tmax), half-life of peak uptake (T1/2), the area under the curve (AUC60min), and the residue uptake (C60min). Key Results For 1 the highest uptake occurred in the kidney whereas for 2 it occurred in the liver. A deuterium isotope effect was observed in the kidneys in both animals studied and in the liver of one animal but not the other. The highest uptake for 1 and 2 in the brain was in striatum and cerebellum but 2 had higher uptake than 1 in all brain regions most evidently in thalamus and cingulate. Alcohol's brain uptake was significantly higher when given intravenously than when given orally and also when the animal was pretreated with a pharmacological dose of alcohol. Conclusion and Implications The study shows that alcohol metabolism in peripheral organs had a large effect on alcohol's brain bioavailability. This study sets the stage for clinical investigation on how genetics, gender and alcohol abuse affect alcohol's ADME and its relationship to intoxication and medical consequences.
A preliminary study on simplified simulation model of spring wheat growth
Wang Futang,Wang Shili,Li Youwen,Guo Yousan,
Wang Futang
,Wang Shili,Li Youwen,Guo Yousan

环境科学学报(英文版) , 1990,
Abstract: In the model developed in this paper, taking the characters and requirements of meteorological services into account, some conventional meteorological observations which are easy to be obtained have been ch.osen, and mathematical equations describing micro-growth processes of crops have been established on the basis of the field experiments, laboratorial analysis and computer's modelling tests with time interval of ten-days for several years (1987-1989), in accordance with the known biological and physical rules and corresponding reference literatures. It is a preliminary simplified simulation model of spring wheat growth in optimal water and nutrient conditions. The field experiments show that simulation results of this simplified model are satisfactory. The potential operational application and theoretical sense are significant in the meteorological forecast of yield and in the assessment of influences of climatic change on agriculture.
A Cognitive Interpretation of Discourse Deixis
Youwen Yang
Theory and Practice in Language Studies , 2011, DOI: 10.4304/tpls.1.2.128-135
Abstract: This paper aims at proposing a cognitive structure for discourse deixis, in terms of which deixis is understood and used to structure reality, so that reality is internally experienced and hence reproduced or changed. The paper also tries to argue that discourse deixis is metaphorically derived from place deixis. This analysis is consistent with and confirms the spatialization-of-form hypothesis, which requires a metaphorical mapping from physical space onto a conceptual space. To be specific, discourse deixis is based on the metaphorical understanding of discourse as time and time as space.
Computer-assisted Foreign Language Teaching: Theory and Practice
Youwen Yang
Journal of Language Teaching and Research , 2010, DOI: 10.4304/jltr.1.6.909-912
Abstract: One of the important components of applied linguistics is to study how computers are used in language teaching. This paper tries to scan the three stages of computer-assisted language learning (CALL) development, the relationship between CALL and linguistic theories and research methods. The paper also discusses some practical issues on CALL in China.
Interactive Cultural Cultivating in FLT
Youwen Yang
English Language Teaching , 2010, DOI: 10.5539/elt.v3n1p28
Abstract: Culture cultivating in foreign language teaching (FLT) is usually conducted through factual introductions in the form of articles, books, seminars, lectures or workshops. This approach regards L2 learners as passive receivers of cultural knowledge without their interaction involved. This paper aims at raising an interactive approach to develop L2 learner's cultural awareness through contrastive analysis on data collected in an FLT classroom on the basis of observation and introspection.
Page 1 /127035
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.