Evaluation on Cultivated Land Resource Ecological Service Value in Wuhan Metropolitan Area

The land ecosystem service function value contains the gas regulating function value, air purification function value, water conservation value, land conser-vation value, soil nutrient conservation value and maintain biodiversity value. Based on the method of market value and the data of Hubei Statistical yearbook, cultivat-ed land resources of ecosystem service function value is 730 038.69Mil ion in 2007-2009, and 714 774.99 Mil ion in 2010-2012 in Wuhan Metropolitan Area. After three years of development, Wuhan Metropolitan Area of ecological value of cultivated land has increased by about 3.97%. From the point of each composition, the im-portance of gas regulating function of cultivated land resources and water conserva-tion function is the forefront. From the point of spatial distribution, the highest of annual average value of the cultivated land ecological was Huanggang （1.725 bil ion yuan）, the lowest was Ezhou （217.868 6 mil ion yuan） in 2010-2012. From the point of space changes, the land ecological value increased only in Qianjiang city, while farmland ecological value in other cities was fal ing The conclusion is of direc-tive significance to the regional land protection policy and the farmland reasonable distribution, for Wuhan Metropolitan Area and other areas.

Primary resonance of fractional-order Duffing–van der Pol oscillator by harmonic balance method

The dynamical properties of fractional-order Duffing–van der Pol oscillator are studied, and the amplitude–frequency response equation of primary resonance is obtained by the harmonic balance method. The stability condition for steady-state solution is obtained based on Lyapunov theory. The comparison of the approximate analytical results with the numerical results is fulfilled, and the approximations obtained are in good agreement with the numerical solutions. The bifurcations of primary resonance for system parameters are analyzed. The results show that the harmonic balance method is effective and convenient for solving this problem, and it provides a reference for the dynamical analysis of similar nonlinear systems.

Characterization and molecular cloning of a serine hydroxymethyltransferase 1(OsSHM_1) in rice

Serine hydroxymethyltransferase (SHMT) is important for one carbon metabolism and photorespiration in higher plants for its participation in plant growth and development, and resistance to biotic and abiotic stresses. A rice serine hydroxymethyltransferase gene, OsSHM1, an ortholog of Arabidopsis SHM1, was isolated using map-based cloning. The osshm1 mutant had chlorotic lesions and a considerably smaller, lethal phenotype under natural ambient CO2 concentrations, but could be restored to wild type with normal growth under elevated CO2 levels (0.5% CO2), showing a typical photorespiratory phenotype. The data from antioxidant enzymes activity measurement suggested that osshm1 was subjected to significant oxidative stress. Also, OsSHM1 was expressed in all organs tested (root, culm, leaf, and young panicle) but predominantly in leaves. OsSHM1 protein is localized to the mitochondria. Our study suggested that molecular function of the OsSHM1 gene is conserved in rice and Arabidopsis.