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Search Results: 1 - 10 of 43980 matches for " Xiaoqiong Wu "
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A PTS Optimization Scheme with Superimposed Training for PAPR Reduction in OFDM System  [PDF]
Renze Luo, Rui Li, Xiaoqiong Wu, Shuainan Hu, Na Niu
Communications and Network (CN) , 2014, DOI: 10.4236/cn.2014.62012
Abstract:

Partial Transmit Sequences (PTS) is an efficient scheme for Peak-to-Average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, its remarkable drawback is the high computational complexity. In order to reduce the computational complexity, currently many PTS methods have been proposed but with the cost of the loss of PAPR performance of the system. In this paper, we introduce an improved PTS optimization method with superimposed training. Simulation results show that, compared with conventional PTS, improved PTS scheme can achieve better PAPR performance while be implemented with lower computation complexity of the system.

Effects of Inter-Particle Frictional Coefficients on Evolution of Contact Networks in Landslide Process  [PDF]
Lian Jiang, Enlong Liu, Jianqiu Tian, Xiaoqiong Jiang
Engineering (ENG) , 2017, DOI: 10.4236/eng.2017.911055
Abstract: During the process of landslide, its dynamic mechanism is important to understand and predict these kinds of natural hazard. In this paper, a new method, based on concepts of complex networks, has been proposed to investigate the evolution of contact networks in mesoscale during the sliding process of slope. A slope model was established using the discrete element method (DEM), and influences of inter-particle frictional coefficients with four different values on?dynamic landslides were studied. Both macroscopic analysis on slope?landslide?and mesoanalysis on structure evolution of contact networks, including the?average degree, clustering coefficientand N-cycle, were done during the process?of landslide. The analysis results demonstrate that: 1) with increasing inter-particle?frictional coefficients, the displacement of slope decreases and the stable angle of slope post-failure increases, which is smaller than the peak internal frictional angle; 2) the average degree decreases with the increase of inter-particle frictional coefficient. When the displacement at the toe of the slope is smaller,?the average degree there changes more greatly with increasing inter-particle?frictional coefficient; 3) during the initial stage of landslide, the clustering coefficientreduces sharply, which may leads to easily slide of slope. As the landslide?going?on, however, the clustering coefficientincreases denoting increasing stability?with?increasing inter-particle frictional coefficients. When the inter-particlefrictional coefficient is smaller than 0.3, its variation can affect the clustering coefficient?and stable inclination of slope post-failure greatly; and 4) the number of?3-cycle increases, but 4-cycle and 5-cycle decrease with increasing inter-particle frictional coefficients.
A Lightweight Data Aggregation Protocol in Wireless Sensor Networks for the Protection of Ancient Sites  [PDF]
Xiaojiang Chen, Dingyi Fang, Xueqing Huang, Baoying Liu, Xiaoqiong Gong, Wenbo Wang, Alessio Perrone
Journal of Sensor Technology (JST) , 2011, DOI: 10.4236/jst.2011.14013
Abstract: In the application of large-scale ancient site protection, it is necessary to continuously monitor the ambient light, temperature, humidity and so on. However, it is impractical to frequently replace the nodes’ battery in the protected areas. So, the key methods to prolong the network lifetime are to aggregate the collected data and reduce the number of transferring messages. In this paper a Lightweight Data Aggregation Protocol (LDAP) based on the characteristics of the environmental changes in ancient sites is proposed. It has been implemented in the Lab with a dozen of MICAz motes and deployed in the real ancient sites. The result shows that LDAP is effective in reducing the number of transferring packets and satisfies the real application requirements.
Comprehensive analysis of the impact of climatic changes on Chinese terrestrial net primary productivity
WenQuan Zhu,YaoZhong Pan,XiaoQiong Yang,GuoBao Song
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0521-5
Abstract: Recent climatic changes have affected terrestrial net primary productivity (NPP). This paper presents an investigation of the impact of climatic changes on Chinese terrestrial vegetation NPP by analyzing 18 years’ (1982 to 1999) climatic data and satellite observations of vegetation activity. Results indicate that climatic changes in China have eased some critical climatic constraint on plant growth. (1) From 1982 to 1999, modeled NPP increased by 1.42%·a 1 in water-limited regions of Northwest China, 1.46%·a 1 in temperature-limited regions of Northeast China and Tibet Plateau, and 0.99%·a 1 in radiation-limited regions of South China and East China. (2) NPP increased by 24.2%, i.e. 0.76 petagram of carbon (Pg C) over 18 years in China. Changes in climate (with constant vegetation) directly contributed nearly 11.5% (0.36 Pg C). Changes in vegetation (with constant climate) contributed 12.4% (0.40 Pg C), possibly as a result of climate-vegetation feedbacks, changes in land use, and growth stimulation from other mechanisms. (3) Globally, NPP declined during all three major El Ni o events (1982 to 1983, 1987 to 1988, and 1997 to 1998) between 1982 and 2000, but Chinese vegetation productivity responded differently to them because of the monsoon dynamics. In the first three events (1982 to 1983, 1987 to 1988, and 1992), Chinese vegetation NPP declined, while in the later two events (1993, 1997 to 1998) increasing obviously.
The Detoxification Effect of Nitrogen on Cadmium Stress in Populus yunnanensis
Tiantian Lin,Xiaoqiong Zhu,Fan Zhang,Xueqin Wan
Botany Research Journal , 2011, DOI: 10.3923/brj.2011.13.19
Abstract: In this study, researchers used Populus yunnanensis, a native precious poplar species which is only distributed in Southwestern China as a model species to study its morphological, physiological and biochemical responses to the interaction of different concentrations of nitrogen and Cd, discussing the detoxification effect of nitrogen to Cd stress in Populus yunnanensis. The treatments were consisted of three Cd levels (0, 2 and 4 mg kg-1) and three N levels (0, 20 and 40 mg kg-1). After 40 days treatment, the results indicated that at the same N level, Cd treatment had significant effect on all measured parameters, including plant growth, chlorophyll concentration, Malondialdehyde (MDA) concentration, antioxidant enzymes activities (SOD, POD, CAT and APX) and free proline. Meanwhile, study also showed there was significant difference among the three levels of N treatment. With the increasing concentration of N supplement, it showed more significant effect of alleviation to Cd induced damage in Populus yunnanensis.
Budesonide suppresses pulmonary antibacterial host defense by down-regulating cathelicidin-related antimicrobial peptide in allergic inflammation mice and in lung epithelial cells
Wang Peng,Wang Xiaoyun,Yang Xiaoqiong,Liu Zhigang
BMC Immunology , 2013, DOI: 10.1186/1471-2172-14-7
Abstract: Background Glucocorticoids are widely regarded as the most effective treatment for asthma. However, the direct impact of glucocorticoids on the innate immune system and antibacterial host defense during asthma remain unclear. Understanding the mechanisms underlying this process is critical to the clinical application of glucocorticoids for asthma therapy. After sensitization and challenge with ovalbumin (OVA), BALB/c mice were treated with inhaled budesonide and infected with Pseudomonas aeruginosa (P. aeruginosa). The number of viable bacteria in enflamed lungs was evaluated, and levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum were measured. A lung epithelial cell line was pretreated with budesonide. Levels of cathelicidin-related antimicrobial peptide (CRAMP) were measured by immunohistochemistry and western blot analysis. Intracellular bacteria were observed in lung epithelial cells. Results Inhaled budesonide enhanced lung infection in allergic mice exposed to P. aeruginosa and increased the number of viable bacteria in lung tissue. Higher levels of IL-4 and lower levels of IFN-γ were observed in the serum. Budesonide decreased the expression of CRAMP, increased the number of internalized P. aeruginosa in OVA-challenged mice and in lung epithelial cell lines. These data indicate that inhaled budesonide can suppress pulmonary antibacterial host defense by down-regulating CRAMP in allergic inflammation mice and in cells in vitro. Conclusions Inhaled budesonide suppressed pulmonary antibacterial host defense in an asthmatic mouse model and in lung epithelium cells in vitro. This effect was dependent on the down-regulation of CRAMP.
The Interaction Effect of Cadmium and Nitrogen on Populus yunnanensis
Tiantian Lin,Xiaoqiong Zhu,Fan Zhang,Xueqin Wan
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n2p125
Abstract: In this study, we used Populus yunnanensis, a native precious poplar species which is only distributed in southwestern China, as a model species to study its morphological, physiological and biochemical responses to the interaction of different concentrations of nitrogen and cadmium, discussing the interaction effect of cadmium and nitrogen on Populus yunnanensis. The treatments consisted of three cadmium levels (0 mg/kg, 2 mg/kg and 4 mg/kg) and three nitrogen levels (0 mg/kg, 20 mg/kg and 40 mg/kg). After 40 days treatment, the results indicated that at the same nitrogen level, cadmium treatment had significant effects on all measured indexes, including plants growth, chlorophyll concentration, malondialdehyde (MDA) concentration, antioxidant enzymes activities (SOD, POD, CAT and APX), free proline, soluble protein and non-protein thiol. In addition, Populus yunnanensis also showed a certain degree of resistance to cadmium stress. Meanwhile, study also showed there were significant difference among the three levels of nitrogen treatments and the higher nitrogen treatment showed more significant effect of alleviation on cadmium induced damage than that of lower nitrogen treatment in Populus yunnanensis.
Screening and Application of Phthalic Acid Degrading Bacteria  [PDF]
Wenhao Li, Xiaoqiong Yang, Gaodong Li, Cheng Li, Yuhan Xu, Jingguo Sun, Changjun Wang, Shunyi Li, Xin Ma, Qin Wang, Shouwen Chen, Jun Yu, Yong Yang
Open Journal of Applied Sciences (OJAppS) , 2018, DOI: 10.4236/ojapps.2018.812047
Abstract: O-phthalic acid is a kind of important pollutant, which accumulates in the environment with the extensive use of plastics and other products. Meanwhile, phthalic acid is one of the high content of allelopathic autotoxic substances secreted by tobacco. The accumulation of phthalic acid in soil is an important cause of tobacco continuous cropping effect. In order to degrade phthalic acid accumulated in environment, the barrier effect of tobacco continuous cropping caused by phthalic acid accumulation in soil can be removed. A strain capable of degrading phthalic acid was isolated from sludge of sewage treatment plant and compared with 16 s DNA. The homology between this strain and Enterobacter sp. is 99%. The optimum growth conditions are as follows: pH7 at 30°C, 500 mg/L of o-phthalic acid, inoculation concentration ≥ 1.2% and its highest degradation rate of o-phthalic acid is 74%. The results of pot experiment showed that the degradation efficiency of o-phthalic acid in soil was about 40%, which alleviated the inhibitory effect of o-phthalic acid accumulation on tobacco growth.
Characterization of the sesame (Sesamum indicum L.) global transcriptome using Illumina paired-end sequencing and development of EST-SSR markers
Wenliang Wei, Xiaoqiong Qi, Linhai Wang, Yanxin Zhang, Wei Hua, Donghua Li, Haixia Lv, Xiurong Zhang
BMC Genomics , 2011, DOI: 10.1186/1471-2164-12-451
Abstract: Sesame transcriptomes from five tissues were sequenced using Illumina paired-end sequencing technology. The cleaned raw reads were assembled into a total of 86,222 unigenes with an average length of 629 bp. Of the unigenes, 46,584 (54.03%) had significant similarity with proteins in the NCBI nonredundant protein database and Swiss-Prot database (E-value < 10-5). Of these annotated unigenes, 10,805 and 27,588 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. In total, 22,003 (25.52%) unigenes were mapped onto 119 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). Furthermore, 44,750 unigenes showed homology to 15,460 Arabidopsis genes based on BLASTx analysis against The Arabidopsis Information Resource (TAIR, Version 10) and revealed relatively high gene coverage. In total, 7,702 unigenes were converted into SSR markers (EST-SSR). Dinucleotide SSRs were the dominant repeat motif (67.07%, 5,166), followed by trinucleotide (24.89%, 1,917), tetranucleotide (4.31%, 332), hexanucleotide (2.62%, 202), and pentanucleotide (1.10%, 85) SSRs. AG/CT (46.29%) was the dominant repeat motif, followed by AC/GT (16.07%), AT/AT (10.53%), AAG/CTT (6.23%), and AGG/CCT (3.39%). Fifty EST-SSRs were randomly selected to validate amplification and to determine the degree of polymorphism in the genomic DNA pools. Forty primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism among 24 sesame accessions.This study demonstrates that Illumina paired-end sequencing is a fast and cost-effective approach to gene discovery and molecular marker development in non-model organisms. Our results provide a comprehensive sequence resource for sesame research.Sesame (Sesamum indicum L.), a member of the Pedaliaceae, is a diploid (2n = 26) dicotyledon and one of the oldest oil seed crops, growing widely in tropical and subtropical areas [1,2]. Sesame seeds are an important source of
Countermeasures on Adjustment of Regional Industry Structures Under Climatic Drying Change——A Case Study of Yulin City
干旱化背景下区域产业发展适应对策——以陕北榆林市为例

LIU Xiaoqiong,LIU Yansui,
刘晓琼
,刘彦随

地理科学进展 , 2006,
Abstract: 陕北榆林市既是我国重要的能源重化工基地,又是生态环境极端脆弱的危急区。如何在气候干旱化背景下围绕事关区域经济可持续发展的先导因素——水资源,实现能源矿产资源可持续开发,保障基地的稳定发展是关系能源重化工基地生死存亡并危及国家能源安全的大事。本文通过分析研究区气候变化及区域产业发展面临的各类问题,提出应在科学发展观指导下,以保护性利用水资源为核心,因地制宜地选用发展农业对策,促进能源矿产资源合理开发。
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