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Search Results: 1 - 10 of 104443 matches for " Zhang Dongliang "
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Performance Analysis for Large-Scale Parallel Microscopic Traffic Simulation System
Yin Fei,Zhang Dongliang
International Journal of Distributed Sensor Networks , 2009, DOI: 10.1080/15501320802575112
Abstract: PMTS (Parallel Microscopic Traffic Simulation) is a large-scale microscopic traffic network simulation system using a real traffic network of Shanghai, China. It describes traffic events in object oriented mode, uses MPI (Message Passing Interface) as communicate middleware, partitions the simulation traffic network into subnetworks, and runs simulations of subnetworks concurrently on a cluster of processors connected by high-speed Ethernet. To optimize the performance of PMTS, a number of challenges need to be solved, including traffic network partition, subnetworks communication and synchronization, and workload balance.
Characteristics Analysis on Short-Time Heavy Rainfall during the Flood Season in Shanxi Province, China  [PDF]
Xiaoting Tian, Dongliang Li, Jinhong Zhou, Yaqing Zhou, Zexiu Zhang
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.73011
Abstract: In order to provide a reference for the correct forecasting of short-term heavy rainfall and better disaster prevention and mitigation services in Shanxi Province, China, it is very important to carry out systematic research on short-term heavy precipitation events in Shanxi Province. Based on hourly precipitation data during the flood season (May to September) from 109 meteorological stations in Shanxi, China in 1980-2015, the temporal and spatial variation characteristics of short-time heavy rainfall during the flood season are analyzed by using wavelet analysis and Mann-Kendall test. The results show that the short-time heavy rainfall in the flood season in Shanxi Province is mainly at the grade of 20 - 30 mm/h, with an average of 97 stations having short-time heavy rainfall each year, accounting for 89% of the total stations. The short-time heavy rainfall mainly concentrated in July and August, and the maximal rain intensity in history appeared at 23 - 24 on June 17, 1991 in Yongji, Shanxi is 91.7 mm/h. During the flood season, the short-time heavy rainfalls always occur at 16 - 18 pm, and have slightly different concentrated time in different months. The main peaks of June, July and August are at 16, 17 and 18 respectively, postponed for one hour. Short-time heavy rainfall overall has the distribution that the south is more than the north and the east less than the west in Shanxi area. In the last 36 years, short-time heavy rainfall has a slight increasing trend in Shanxi, but not significant. There is a clear 4-year period of oscillation and inter-decadal variation. It has a good correlation between the total precipitation and times of short-time heavy rainfall during the flood season.

by LIN Dongliang,HUANG Wei,ZHANG Yuanghu,

金属学报 , 1987,
Hydrogen Absorption and Electrochemical Properties of As-Quenched Nanocrystalline Mg20Ni10 – xCux (x = 0 – 4) Alloys  [PDF]
Jinliang Gao, Zhonghui Hou, Qilu Ge, Dongliang Zhao, Shihai Guo, Yanghuan Zhang
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.13027
Abstract: Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10 – xCux (x = 0, 1, 2, 3, 4) were synthesized by rapid quenching technique. The microstructures of the as-cast and quenched alloys were characterized by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics of the alloys were measured using an automatically controlled Sieverts apparatus. The electrochemical hydrogen storage performances were tested by an automatic galvanostatic system. The results show that all the as-quenched alloys hold a typical nanocrystalline structure, and the rapid quenching does not change the major phase Mg2Ni. The hydrogen absorption and desorption capacities of the alloys significantly increase with rising quenching rate. Additionally, the rapid quenching significantly improves the electrochemical hydrogen storage capacity of the alloys, but it slightly impairs the cycle stability of the alloys.
The Biomass Dosage Influences the Effects of Diethyl Aminoethyl Hexanoate on Micropropagation of Echinacea purpurea (L.) Moench  [PDF]
Xiaolu Chen, Dongliang Li, Junjie Zhang, Qingling Li, Yuesheng Yang, Hong Wu
Journal of Biosciences and Medicines (JBM) , 2016, DOI: 10.4236/jbm.2016.412014
The plant growth regulator diethyl aminoethyl hexanoate (DA-6) has proved highly effective on micropropagation of the medicinal plant purple coneflower (Echinacea purpurea (L.) Moench), however, sharp variation of the effects existed among explants in the same treatment, making the application of DA-6 in micropropagation difficult. In order to clarify factors that influencing the treating results of DA-6, explants with different biomass dosage were prepared and inoculated onto medium supplemented with different concentrations of DA-6. It was found that among the three kinds of biomass dosage explants, the lowest biomass explants required the lowest concentration of DA-6, and the highest biomass explants required the highest concentration of DA-6 for the best results on adventitious buds regeneration. Similar results were obtained when regenerated buds of three different biomass dosages were cultured. It could be concluded from the above experimental results that for achieving better DA-6 application results, the concentration of DA-6 should be determined not only by the types but also by the biomass dosage of the explants. The present finding might help to improve the micropropagation efficiency in E. purpurea, and might be applicable for other species
BN Nanoparticles/Si3N4 Wave-Transparent Composites with High Strength and Low Dielectric Constant
Dongliang Zhao,Yujun Zhang,Hongyu Gong,Baoxin Zhu,Xiaoyu Zhang
Journal of Nanomaterials , 2011, DOI: 10.1155/2011/246847
Abstract: Si3N4 wave-transparent composites with different volume content of BN nanoparticles (BNnp/Si3N4) were prepared by gas pressure sintering at 1800°C in N2 atmosphere. The effects of BN nanoparticles on the dielectric and mechanical properties of BNnp/Si3N4 composites were investigated. The results showed that the addition of the BN nanoparticles improved the dielectric properties of BNnp/Si3N4 composites effectively and decreased the mechanical properties. When the volume content of BN nanoparticles was 10%, the dielectric constant and dielectric loss tangent were 4.31 and 0.006, respectively, and the bending strength and fracture toughness still reached 198.9 MPa and 3.36 MPa·m1/2. The high mechanical properties of BNnp/Si3N4 composites with 10% BN nanoparticles were attributed to homogeneously dispersed BN nanoparticles which were embedded in the pores formed by the rod-like β-Si3N4.
Seasonal characters of regional vegetation activity in response to climate change in West China in recent 20 years

ZHANG Jie,ZHANG Qiang,YANG Lihua,LI Dongliang,

地理学报 , 2006,
Abstract: Using NDVI data of NOAA-AVHRR in recent 20 years and the temperature and precipitation data of West China, the vegetation activity is discussed by adopting the EOF and REOF decomposed functions. Results show that the overall increasing trend of vegetation activity in different seasons reflects an advanced and prolonged growth period of vegetation under the circumstance of climate warming, but the vegetation evolvement has much inconsistency between different regions and seasons. There are four notable regions, eight sub-areas for vegetation evolvement in spring and summer, and nine sub-areas in autumn. The vegetation activity in most sub-areas is increasing. The most notable region is represented by Lhaze station on the Tibetan Plateau. Two other marked stations are represented by Altay station in Xinjiang Uygur Autonomous Region and Pengshui station in Sichuan Province. But the time series analysis of NDVI makes clear that the trends of the other two sub-areas, Turpan station in Xinjiang and Huashan station in Shaanxi Province, are descending. It is an important reason for vegetation evolvement that temperature ascends in most of the regions and descends in the east region in some seasons. But another important reason for vegetation evolvement is that precipitation is ascending in the west and descending in the east of the region.
A Multiple-Dimensional Tree Routing Protocol for Multisink Wireless Sensor Networks Based on Ant Colony Optimization
Hui Zhou,Dongliang Qing,Xiaomei Zhang,Honglin Yuan,Chen Xu
International Journal of Distributed Sensor Networks , 2012, DOI: 10.1155/2012/397961
Abstract: Routing protocol is an important topic in the wireless sensor networks. For MultiSink wireless sensor networks, the routing protocol designs and implementations are more difficult due to the structure complexity. The paper deals with the problem of a multiple-dimensional tree routing protocol for multisink wireless sensor networks based on ant colony optimization. The proposed protocol is as follows: (1) listening mechanism is used to establish and maintain multidimensional tree routing topology; (2) taking into consideration hops, packet losses, retransmission, and delay account, a distributed ant colony algorithm is proposed. When nodes select routes in the data transmission, the algorithm is utilized to realize the real-time optimization by coordination between nodes. The simulation results show that the proposed protocol can realize the QoS optimization for multisink wireless sensor networks, and its performance is better than the routing protocol of minimum hop numbers. 1. Introduction Multisink wireless sensor architecture networks have received more and more attention due to their advantages such as improving network throughput, balancing energy consumption, and prolonging network lifetime. Moreover, the reliability and robustness of networks are improved because multisink nodes increase the transmission routines of the sensor node information [1, 2]. Due to multiple sink nodes in multisink wireless sensor networks (multisink WSNs), the network topology is complex, which brings many difficulties to design and implement the network protocols. Currently, research on multisink WSNs is still insufficient, especially for the cooperation and quality of service (QoS) of multisink WSNs. In this paper, the problem of a multiple dimensional tree routing protocol for multisink WSNs will be investigated based on listening and ant colony optimization (ACO), where multiple dimensional tree routing is defined in Section 3. Listening mechanism is first used to establish and maintain multidimensional tree routing topology in the proposed protocol. Then, a distributed ant colony algorithm is presented with the consideration of hops, packet losses, retransmission and delay. The rest of this paper is organized as follows. (i) Section 2 states the related works about the multisink WSNs routing researches and the applications of the ant colony optimization in WSNs. (ii) Section 3 describes the multisink WSNs model. (iii) Section 4 introduces the routing establishment of the listening-based routes for the multisink WSNs and the routing selection based on the
Preparation, characterization and photodegradation of methylene blue based on TiO2 microparticles modified with thiophene substituents
Pei Liu,Peng Zhang,DongLiang Cao,WenTing Xue
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5447-x
Abstract: The new microparticles, 2-formylthiophene (FT)/TiO2 and (E)-1,2-bis(5-formyl-2-thienyl) ethylene (EBFTE)/TiO2 were synthesized with a silane coupling agent. The prepared TiO2 composites were characterized using Ultraviolet-Vis absorption (UV-Vis), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analyzer (TGA). Methylene blue was used as a model material to examine the photocatalytic activities of the prepared catalysts under both Ultraviolet-Vis (UV) and visible (Vis) light. The enhanced photocatalytic activities were observed in the presence of (FT)/TiO2 and EBFTE/TiO2 under Vis light. It suggests that FT or EBFTE plays a block or active role in the photodegradation mechanisms under UV and Vis light irradiation, respectively.
Fabrication of the 19-filament Fe/Cu clad MgB2 wire via in situ powder-in-tube method
ZhengGuang Yu,YanWei Ma,DongLiang Wang,ZhaoShun Gao,XianPing Zhang
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0383-x
Abstract: Using commercial amorphous B powder (92% in purity) and Mg powder (99% in purity) as starting materials, 19-filament Fe/Cu clad MgB2 wires were fabricated by an in situ powder-in-tube method. Heat treatment was performed at 700°C for 1 h under an argon gas atmosphere. The influence of Mg/B ratio on the microstructure and superconducting properties of the wires was investigated. It was found that the major phases of MgB2 wires were MgB2 accompanied with relatively small amounts of MgO and Fe2B impurities. With 5% excess Mg addition, the onset T C slightly decreased. However, the transport J C at 4.2 K and 4 T reached 1.07×104 A·cm 2, increasing by a factor of 1.4 compared to the stoichiometric sample. Moreover, the Mg1.05B2 sample showed an improved field dependence of J C, suggesting that less voids and smaller grain size of the Mg1.05B2 core lead to better grain connectivity and stronger flux pinning.
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