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Drought stress during the reproductive stage is one of the most important constraints on growth and productivity of soybean. There is compelling evidence that physiological and molecular approaches can effectively improve drought resistance in soybean, but strategies derived from soil management are poorly documented, especially under field conditions. In this study, we combined data from field experiments and used multivariate regression analyses to investigate factors determining soybean yield variability over two growing seasons with drought stress during the reproductive stage. Phosphorus application and soil available phosphorus explained a significant proportion of the variation in soybean yield under drought stress. As a whole, soybean fields that received adequate P supply had greater yields than those that did not. However, excessive P application significantly decreased soybean yield. These results suggest that P control is critical to mitigate soybean yield losses resulting from drought at the reproductive stage. [ABSTRACT FROM AUTHOR]

Abstract. We report a novel two-channel experimental scheme to record femtosecond amplitude and phase dynamics for dephasing studies. The measurement of free-induction decay in one channel and pulse autocorrelation for the central wavelength of the exciting pulses at the other channel as the reference allows the recording of time-resolved amplitude and phase dynamics of the free-induction decay throughout the dephasing process. The technique is applied to the study of coherent dynamics of the photocarriers in semiconductor GaAs. The observed phase dynamics is well simulated with optical Bloch vector components analysis for the homogeneously broadened two-level model and the experimental and theoretical study is extended for the three-level system. The two-pulse-induced phase spectroscopy should be generally applicable to different kinds of materials by recording the population difference for the two-level system with pulse-induced fluorescence. PACS: 42.65 -k; 71.35+z [ABSTRACT FROM AUTHOR]

Investigates and compares three laser-based alternating current heating methods for measuring thermal diffusivity of free-standing thin-film structures. Use of a modulated laser beam as the heating source and a miniature thermocouple as the temperature sensor; Laser heating configurations tested.

The rare earth materials, KNdFe(CN)6.3H2O (KNFCN), NdFe(CN)6.4H2O (NFCN), and NdFeO3 (NFO) are characterized by absorption and fluorescence spectra. The dephasing times (T2) and the fluorescent lifetimes (T1) of the materials are determined. The critical bit rate (Wcrit) for ultra-high-speed population density control is discussed. The feasibility of using the materials for ultra-high-speed, all-optical switching devices is presented [ABSTRACT FROM PUBLISHER]

Investigates the temperature dependence of the thermophysical properties of gallium arsenide/aluminum arsenide periodic structure. Method used in measuring thermal diffusivity; Source of the structure's thermal conductivity; Assessment on the cause of reduction in thermal conductivity.