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In the aerobic rice system, adapted rice cultivars are grown in non-flooded moist soil. Aerobic rice may be suitable for double cropping with winter wheat in the Huai River Basin, northern China plain. Field experiments in 2005 and 2006 were conducted to study the response of aerobic rice and winter wheat to sequential rates of nitrogen (N), phosphorus (P) and potassium (K) in aerobic rice--winter wheat (AR-WW) and winter wheat--aerobic rice (WW-AR) cropping sequences. Fertilizer treatments consisted of a complete NPK dose, a PK dose (N omission), a NK dose (P omission), a NP dose (K omission), and a control with no fertilizer input. Grain yields of crops with a complete NPK dose ranged from 3.7 to 3.8 t ha-1 and from 6.6 to 7.1 for aerobic rice' and 'winter wheat', respectively. N omissions caused yield reductions ranging from 0.5 to 0.8 t ha-1 and from 1.6 to 4.3 t ha-1 for rice and wheat, respectively. A single omission of P or K did not reduce rice and wheat yields, but a cumulative omission of P or K in a double cropping system significantly reduced wheat yields by 1.2-1.6 t ha-1. N, P and K uptake of both crops were significantly influenced by fertilizer applications and indigenous soil nutrient supply. Nutrient omissions in a preceding crop reduced plant N and K contents and uptake additionally to direct effects of the fertilizer treatments in wheat, but not in rice. Apparent nutrient recoveries (ANR) differed strongly between 'aerobic rice' and 'winter wheat'; in rice: for N it ranged from 0.30 to 0.32, for P from 0.01 to 0.06, and for K from 0.03 to 0.19 and in wheat: for N from 0.49 to 0.71, for P from 0.09 to 0.15, and for K from 0.26 to 0.31. Further improvements of crop productivity as well as nutrient-use efficiencies, should be brought about by developing cropping systems, by an appropriate choice of adapted cultivars, by a site- and time-specific fertilizer management and by eliminating other yield-limiting factors. It is concluded that nutrient recommendations should not be based on the yield response of single crops only, but also on the after-effects on nutrient availability for succeeding crops. A whole cropping system approach is needed. [ABSTRACT FROM AUTHOR]

Based on the principle of virtual work, an updated Lagrangian finite element formulation for the geometrical large deformation analysis of galloping of the iced conductor in an overhead transmission line is developed. In numerical simulation, a threenode isoparametric cable element with three translational and one torsional degrees-offreedom at each node is used to discretize the transmission line. The nonlinear dynamic system equation is solved with the Newmark time integration method and the Newton-Raphson nonlinear iteration. Numerical examples demonstrate the efficiency of the presented method and the developed finite element program. A new possible galloping mode, which may reflect the saturation phenomenon of a nonlinear dynamic system, is discovered under the condition that the lowest order of vertical natural frequency of the transmission line is approximately two times of the horizontal one. [ABSTRACT FROM AUTHOR]

A theoretical analysis of the lateral resonances in 1–3 piezocomposites with poling initial stress is conducted using the Bloch wave theory. Based on the linear piezoelectricity theory, theoretical formulations that include initial stress for the propagation of acoustic plane waves are made. Numerical calculations are performed to study the effects of the initial stress on the lateral mode frequencies and the stop band. It is found that lateral mode frequencies increase with the piezoelectricity of the piezocomposites, but decrease with the poling initial stress. The influence of the initial shear stress on the lateral mode frequencies is minimal, and can thus be neglected. [ABSTRACT FROM AUTHOR]