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Chizhou, China

Xiaoying S.,Nanjing University of Science and Technology | Huanyan Q.,Nanjing University of Science and Technology | Haisheng H.,Chizhou College
International Journal of Digital Content Technology and its Applications | Year: 2011

Wireless networked control system (WNCS) is given profound attention because of dynamic, flexibility and inexpensiveness. However, it is difficult to use a single simulator to simulate a WNCS which is a hybrid system. A co-simulation framework based on OPNET, Matlab and C++ is presented to capture both the system dynamics and communication events and depict the real WNCS accurately. MATLAB is good for simulating the mathematical modeling and feedback control, while OPNET is apt at simulating the WLAN communication behavior. The co-simulation framework can help WNCS designer understand and improve the performance of the WNCS. Source

Pan G.,Nanjing Agricultural University | Xu X.,Nanjing Agricultural University | Xu X.,Chizhou College | Smith P.,University of Aberdeen | And 2 more authors.
Agriculture, Ecosystems and Environment | Year: 2010

Soil C sequestration in cropland could play an important role in mitigating the rapidly increasing CO2 emissions in China. Many efforts had been dedicated to estimating the potential for C sequestration in croplands. Potential increases in SOC in China's croplands had been recently evaluated using inventory-up-scaling simulation and crop-soil C process-based modeling. In this study, data of SOC change at monitoring sites from croplands across mainland China were collected from publications available from 1985 to 2006 to perform a statistical analysis. The data set comprises 1081 observations (404 from rice paddies, RPs and 677 from dry croplands, DCs). Frequency analysis indicates that over 70% of observations show an increase in SOC, which is higher among RPs than DCs. To quantify SOC dynamics, a Relative Annual Change Index in g kg-1 year-1 (RAC, g kg-1 year-1) is defined and calculated using the initial and final SOC values for the duration of monitored observations. RAC values ranged from -0.806 to 0.963 g kg-1 year-1 for DCs and from -0.597 to 0.959 g kg-1 year-1 for RPs, respectively. From this data, the average is estimated to be 0.056 ± 0.200 g kg-1 year-1 for DCs, and 0.110 ± 0.244 g kg-1 year-1 for RPs, with an overall estimate for China's croplands, with RPs and DCs combined, of 0.076 ± 0.219 g kg-1 year-1. A mean increase in topsoil C (0-20 cm) stock of China's croplands was estimated to be 25.5 Tg C year-1 (8 Tg C year-1 in RPs and 17.5 Tg C year-1 in DCs) between 1985 and 2006, with a total topsoil C stock increase of 0.64 Pg C over the whole period. The annual stock increase may offset ∼20%, on average, of the total CO2 emissions of China for 1994. This study suggests an important role of China's croplands, especially rice paddies, for C sequestration to mitigate climate change. © 2009 Elsevier B.V. All rights reserved. Source

Hu C.,Chizhou College
Applied Mechanics and Materials | Year: 2012

Surface characteristics of the regular polygon contour parts and turning process,including tool movement characteristics,feed speed and feed acceleration, is analyzed with the harmonic analysis principle when cutting the parts. Using MATLAB to draw the displacement, velocity and acceleration variations chart of polygon workpiece turning. © (2012) Trans Tech Publications, Switzerland. Source

Chen J.B.,Chizhou College
Advanced Materials Research | Year: 2014

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C separately with four mass ratios of 70/30/0, 70/25/5, 65/30/5, 60/30/10. The solvent resistance were investigated by experiments, their results showed that the concentrated H2SO4 resistance of alloy plates had been improved by alloying in 6h, the acetone resistance of mass ratio of 70/25/5 is preferably, increasing the content of PES, the acetone resistance becomes relatively stable, in addition, the chloroform and N, N-dimethyl formamide resistance of mass ratio of 70/25/5 is also preferably, and the polarity of the reagent has a limit influence on solvent resistance of plastics alloy materials. © (2014) Trans Tech Publications, Switzerland. Source

Zhang L.,Chizhou College
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2014

The process of urbanization is closely related to land use. When the level of urbanization evolves from primary level to senior level, land-intensive use of small towns will be continuously upgraded along with the increase of adjustment and optimization of industrial structure, urban high-rise buildings, and strengthening of national protection policy cultivated land, which is when the demand of cultivated land exhibits a decreasing trend in the process of transition of urbanization from the primary stage to the advanced stage, similar to the law of diminishing marginal returns of economics. Therefore, there is the effect of minimum ultimate moment of urbanization on cultivated land in theory. Exploring the ultimate moment has an important guiding significance for the policies of cultivated land under the evolutionary background of compilation of land-use planning and formulation of urbanization development. Taking Anhui Province as an example, a total of 18 indices, such as the proportion of urban permanent population in total population, are selected to establish the evaluation system of urbanization comprehensive level from four dimensions of population, space, economy, and social life, of which the composite index is calculated by the entropy weighting method. The Logarithmic Mean Divisia Index (LMDI) decomposition model is used to calculate the reduced cropland share due to urbanization. Based on economic marginal theory, the least-squares regression analysis method is adopted to construct the measurement model of marginal cropland change rate due to urbanization. With the aid of EXCEL software through scatter diagrams with trend lines, the optimal goodness of fit is applied to obtain the curves and the derivative method of advanced mathematic extremum, so as to estimate the extreme moment of urbanization evolution with the least impact on cropland. The results show that: the urbanization composite index of Anhui Province rose from 0.0319 in 1996 to 0.9945 in 2012, of which the increase range is faster than that of population urbanization level. Urbanization leads to cropland reduction declining after 2002, in line with the diminishing law of marginal effect in economics. The marginal cropland change rate due to urbanization in Anhui Province was reduced from 1 292 517.63 in 2002- 2003 to 7 430.35 in 2011-2012, presenting an overall downward trend; the fitting curve of marginal cropland change rate is a U-shaped parabola with an upward opening. When the urbanization comprehensive index is 7.325, i.e. in 2022-2023, the urbanization will have the least effect on cropland, while before 2023, the contradiction between urbanization and cropland protection will be more prominent in Anhui Province. Based on the results of the study, it is reasonable to arrange scale, structure, layout, and timing from the scientific establishment of the urbanization development of land use planning of urban construction land. Optimization and upgrading of industrial structure are used to promote intensive use of urban land. Various policies, laws, and regulations are strictly implemented in the state protection of cultivated land. Policy suggestions are put forward in strictly maintaining land gate, strengthening land inspection, and other aspects. The research results not only provide references for Anhui Province to scientifically formulate land use planning and coordinate the urbanization evolution and cropland protection policy, but also for other similar research. ©, 2014, Chinese Society of Agricultural Engineering. All right reserved. Source

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