To evaluate the irrigation distribution uniformity and optimize the suitable combination of irrigation technical parameters for alternate furrow irrigation (AFI) and conventional furrow irrigation (CFI), field experiments on maize were conducted during 2010 and 2012 at the Shiyanghe Experimental Station in the arid area of north‐west China. A surface irrigation simulation model (SIRMOD) was used to optimize the combination of irrigation technical parameters such as field slope, furrow length and inflow rate. From the distribution uniformity (DU) results calculated from measured data in field experiments, under the same kind of soil texture, using the AFI method in the field could improve irrigation distribution uniformity for 9.67, 3.16 and 3.44% under a slope 1.5, 2.0 and 3.0‰ respectively; the relative error of DU between the simulation value from SIRMOD and the calculated value from field experiment was 4.25%, which was in an acceptable range. On the other hand, combinations of irrigation technical parameters of the CFI and AFI methods were simulated using SIRMOD with the distribution uniformity being the evaluation index. For the irrigation technical parameters, field slope ranging from 0 to 3.0‰, inflow rate from 1.0 to 8.0 l s−1 and furrow length from 25 to 300 m were chosen in this paper. Copyright © 2017 John Wiley & Sons, Ltd.

Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation (Rs) and vapor pressure deficit of the air (VPDair). Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in Rs and preceded the changes in VPDair both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize's sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and Rs in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPDair in comparison with wet soil and also increase the speed by which sap flow adjusts to Rs. However, sap flow lags that were associated with Rs before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements.

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A novel double-layer suspended stripline (DSSL) resonator with high unloaded quality factor is proposed. The DSSL resonator consists of a thin substrate with metal strips on both sides connected by a metallic via hole suspended in the centre of an air-filled cavity, which leads to a much higher unloaded quality factor than the conventional single-layer suspended stripline resonator with an identical resonant frequency. The resonance characteristics of the DSSL resonator are parametric analysed. For demonstration, a compact diplexer for basestation application with channel centre frequencies at 1.95 and 2.14 GHz and absolute bandwidths of 60 MHz is designed, fabricated and measured. The synthesised, simulated and measured results show a good agreement.