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Search Results: 1 - 10 of 127069 matches for " Decheng Li "
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Predicting Base Saturation Percentage by pH—A Case Study of Red Soil Series in South China  [PDF]
Anqi Wang, Bing Ju, Decheng Li
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.104040
Abstract: pH and base saturation percentage (BSP) are two basic indexes in identifying soil types in Chinese Soil Taxonomy. Some studies proved that there is significant correlation between BSP and pH, thus it could save the cost of laboratory work if we can infer BSP directly from pH. In this study, the measured values of BSP and pH of 162 and 232 horizon samples from 48 and 55 red soil series surveyed from 2009 to 2011 in Fujian and Guangdong respectively were adopted from Soil Series Database to set up the optimal correlation model between BSP and pH. The results showed that: 1) BSP ranged from 2.30% to 94.02% with a mean of 25.07%, while pH from 3.42 to 6.91 with a mean of 4.98 for the total soil samples. 2) There were significant differences in pH between different soil types (R2 were 0.624 for Ferralosols, 0.507 for Ferrosols, 0.515 for Argosols, and 0.456 for Cambosols, p < 0.01), in BSP between different parent materials (R2 were 0.580 for Quaternary red clay, 0.434 for granite, 0.642 for sandstone, and 0.712 for basalt, p < 0.01), in pH and BSP between different land use types (R2 were 0.623 for dryland, and 0.404 for forest land, p < 0.01). pH and BSP generally were in moderate variation (10% - 100%), and in positive skew distribution (>0), their probability density curves were mainly in flat or normal curves (<0.67). 3) There is significant positive correlation between BSP and pH, and the optimal correlation models are in quadratic form in most circumstances, but the optimal model and the accuracy are different in different circumstances, changed with different regions, parent materials, soil types and land use types. The accuracy of models established in other studies when predicting our soil samples was lower compared with our models. pH < 5.33 or <5.93 could be used roughly to judge BSP < 35% or <50% based on the model of all red soil series (y = 6.84x2 45.86x + 81.52, R2 = 0.494, p < 0.01).
A Brief Study on Using pHH2O to Predict pHKCl for Acid Soils  [PDF]
Anqi Wang, Decheng Li, Biao Huang, Yin Lu
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.102012
Abstract: pHKCl and pHH2O are two basic necessary indexes to reflect the acidity of asoil. Predicting pHKCl?directly from pHH2O?could save the cost of laboratory work. In this study, the values of pHKCl and of 442 and 310 horizon samples from 126 and 98 soil profiles (0 - 120 cm in depth) surveyed from 2014 to 2015 in Guangxi and Yunnan were used to establish the optimal correlation model between pHKCl and pHH2O. The results showed that: 1) pHKCl is lower than pHH2O, pHKCl?was 0.07 - 1.99 units with a mean of 0.99 units lower than for Guangxi, while 0.03 - 1.90 units with a mean of 0.89 lower than pHH2O?for Yunan. 2) There is significant positive correlation between pHKCl?and pHH2O, the optimal correlation models between pHKCl?(y) and pHH2O?(x) for Guangxi and Yunnan are y = 0.1963x2 1.0512x + 4.338, R2 = 0.836, p < 0.01 and y = 1.5882e0.1859x, R2 = 0.769, p < 0.01, respectively, and the values of MAE and RSME of the models are 0.13 and 0.36 for Guangxi, 0.08 and 0.28 for Yunnan, respectively. There are significant negative correlations between pHKCl?with exchangeable H+ and Al3+ (R2 = 0.487, 0.716, p < 0.01), and pH
Luminescent properties of Eu and Tb in SrB6O10 matrix
Yong Gao,Chunshan Shi,Decheng Li
Chinese Science Bulletin , 1997, DOI: 10.1007/BF02884228
Luminescent properties of Eu and Tb in SrB_(6)O_(10) matrix

Yong Gao,Chunshan Shi,Decheng Li,

科学通报(英文版) , 1997,
Evolution and significance of soil magnetism of basalt-derived chronosequence soils in tropical southern China  [PDF]
Decheng Li, Yanfang Yang, Jinping Guo, Bruce Velde, Ganlin Zhang, Feng Hu, Mingsong Zhao
Agricultural Sciences (AS) , 2011, DOI: 10.4236/as.2011.24070
Abstract: Soil samples were collected from eight basalt- derived chronosequence soils with the ages of 0.01, 0.58, 0.92, 1.33, 2.04, 3.04, 3.76 and 6.12 Ma respectively from Leizhou Peninsula and northern Hainan Island of tropical southern China. Magnetic parameters of magnetic susceptibility (MS), percentage of frequency-dependent magnetic susceptibility (FDS%), anhysteretic remanent magnetization (ARM), saturation isothermal remanent magnetization (SIRM), soft and hard isothermal remanent magnetization (IRMs and IRMh) of the collected samples were measured to study the evolution and the significance of the magnetism with soil age. The results show that the magnetic parameters changed fast from Primosols to Ferrosols (0.01 ~ 0.92 Ma) but slowly at Ferralosols stage (1.33 Ma~), it suggests a stable phase occurred for soil magnetism at Ferralosols, the existence of this phase could be supported by the little changes in the contents of clay, Fet and Fed. Obvious differences existed in the values of magnetic parameters between Ferralosols and other soil types (Primosols and Ferrosols), FDS%: Ferralosols > 10%, Primosols and Ferrosols < 10%; ARM, Ferralosols < 7000 × 10–8· SIm3·kg–1, Primosols and Ferrosols > 8000 × 10–8 SIm3·kg–1, thus, it is possible to differentiate Ferralosols from other soil types in tropical region by using magnetic indices.
Content, Density, Illuviation Mode and Depth of CaCO3 in Soils of Semiarid-Arid Qilian Mountains—An Altitude Sequence Study of the Hulugou Watershed  [PDF]
Ka Lin, Decheng Li, Ganlin Zhang, Yuguo Zhao, Jinling Yang, Feng Liu, Xiaodong Song
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.86036
Abstract: The parental material of soils in the Qilian Mountains of northwest China is mainly aeolian loess containing CaCO3 which may remain in soils under the semiarid-arid climate. To disclose the CaCO3 characteristics change with the altitude and the terrain attributes, we surveyed 18 soil profiles in an altitude sequence from 3076 m to 4510 m in the Hulugou Watershed in the Qilian Mountains, measured CaCO3 contents of all genetic horizon samples, analyzed the densities, illuviation modes and depths of CaCO3 in the profiles, extracted values of the terrain attributes of the profiles including altitude slope, aspect, plane curvature, profile curvature and terrain wetness index (TWI) from the 90 m resolution SRTM3 DEM data on ArcGIS 9.3 platform. We found that CaCO3 weighted content of the profiles ranged from 1.30 g·kg-1 to 93.09 g·kg-1, CaCO3 density from 0.05 kg/m2 to 75.69 kg/m2, CaCO3 illuviation depth from 12 cm to 54 cm. CaCO3 illuviation modes could be divided into three types, i.e., no illuviation mode in which the profile has only A horizon or CaCO3 content < 5 g·kg-1, middle illuviation mode in which CaCO3 accumulated in a middle horizon, and down illuviation mode in which CaCO3 content increases with the depth. CaCO3 weighted content, density and illuviation depth had significant correlation with certain terrain attributes. In general, the altitude sequence is an effective way to study CaCO3 characteristics in the alpine region, and the data of terrain attributes which can influence the precipitation and its redistribution in soil are potential in predicting soil CaCO3 characteristics in the alpine region.
Effects of Fertilizer Placement and Nitrogen Forms on Soil Nitrogen Diffusion and Migration of Red-Yellow Soil in China  [PDF]
Chaoqiang Jiang, Huoyan Wang, Dianjun Lu, Jianmin Zhou, Decheng Li, Chaolong Zu
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.811088
Abstract: A better understanding of nitrogen (N) diffusion and transformation in soils could reveal the capacity of the biological inorganic N and improve the efficiency of N fertilizers. A field micro-plot experiment was carried out to study the effects of fertilization methods (mixed uniformly with 12 cm top soil, placed in holes at a 12-cm depth, or placed in furrows at a 12-cm depth) and forms of N fertilizers (urea and ammonium phosphate) on the dynamics of soil N’s vertical diffusion and horizontal migration in red-yellow soil. The soil inorganic N ( NH4+-N and NH3--N) content following point deep placement was greater than that from mixed or furrow applications. Under point placement, the migration of soil inorganic N in urea and ammonium phosphate treatments occurred in the 6 - 15 cm layer at a horizontal distance of 0 - 9 cm. However, the nutrient preservation capability of the soil receiving ammonium phosphate was greater than that receiving urea under point deep placement. Thus, point deep placement had a tendency to increase the inorganic N in the soil and reduce inorganic N loss, which probably occurred due to the reduced soil volume with which the N fertilizer was mixed. According to crop growth and fertilizer requirements, the optimized fertilizer placement and N species resulted in a continuously high nutrient supply to crops for 90 d. However, the effects of point deep placement on increasing the N-use efficiency and reducing N loss have to be evaluated under natural field conditions.
Intelligent Urban Public Transportation for Accessibility Dedicated to People with Disabilities
Haiying Zhou,Kun-Mean Hou,Decheng Zuo,Jian Li
Sensors , 2012, DOI: 10.3390/s120810678
Abstract: The traditional urban public transport system generally cannot provide an effective access service for people with disabilities, especially for disabled, wheelchair and blind (DWB) passengers. In this paper, based on advanced information & communication technologies (ICT) and green technologies (GT) concepts, a dedicated public urban transportation service access system named Mobi+ has been introduced, which facilitates the mobility of DWB passengers. The Mobi+ project consists of three subsystems: a wireless communication subsystem, which provides the data exchange and network connection services between buses and stations in the complex urban environments; the bus subsystem, which provides the DWB class detection & bus arrival notification services; and the station subsystem, which implements the urban environmental surveillance & bus auxiliary access services. The Mobi+ card that supports multi-microcontroller multi-transceiver adopts the fault-tolerant component-based hardware architecture, in which the dedicated embedded system software, i.e., operating system micro-kernel and wireless protocol, has been integrated. The dedicated Mobi+ embedded system provides the fault-tolerant resource awareness communication and scheduling mechanism to ensure the reliability in data exchange and service provision. At present, the Mobi+ system has been implemented on the buses and stations of line ‘2’ in the city of Clermont-Ferrand (France). The experiential results show that, on one hand the Mobi+ prototype system reaches the design expectations and provides an effective urban bus access service for people with disabilities; on the other hand the Mobi+ system is easily to deploy in the buses and at bus stations thanks to its low energy consumption and small form factor.
Preliminary study on the living environment of hominids at the Donggutuo site, Nihewan Basin
ShuWen Pei,XiaoLi Li,DeCheng Liu,Ning Ma,Fei Peng
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0646-9
Abstract: The Donggutuo site, situated in the east margin of Nihewan basin, is one of the most important Paleolithic sites in China, characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region. Based on well-constructed sporopollen, sediment grain size analysis, magnetic susceptibility, and iron oxide analysis of the 2000–2001 excavated section, four stages of environmental change in the Nihewan Beds are identified by the authors. The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest, which is suitable for hominid occupation. The changes correspond to the stages of lake transgression and regression. The environment after the lake died out away has been cold and dry boschveld. The hominid activities at the site took place in the Early Pleistocene (1.10 Ma), which corresponds to the early three environmental stages. Therefore, it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making, procuring of raw materials for tools, concentrating stone artifacts, and hunting and butchering. In conclusion, the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site.
Using XML Encoding Rule Technology to Realize the APDU Encoding in Protocol Z39.50

Li Decheng Tan Shuqin,

现代图书情报技术 , 2005,
Abstract: The combination of the information resources in library and in network enviroment has become the research hotspot in the information field. In order to adapt the development of the network information and make use of the library resource fully,this thesis provides a method of coding the ASN. 1 in the protocol Z39. 50 with XER technology.
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