Deuterium and oxygen‐18 are common environmental tracers in water used to investigate hydrological processes such as evaporation and groundwater recharge, and to trace moisture source. In this study, we collected event precipitation from 01 January 2010 to 28 February 2011 at a site in Changsha, Yangtze River Basin to estimate the influence of moisture source and atmospheric conditions on stable isotope compositions. The local meteoric water line, established as δD = (8.45 ± 0.13) δ18O + (17.7 ± 0.9) (r2 = 0.97, n = 189), had a higher slope and intercept than global meteoric water line. Temperature–δ18O exhibited complex correlations, with positive correlations during Nov.–Apr. superior to during Jun.–Sep., which was attributed to distinctive moisture sources, but vague the overall period; amount effect examined throughout the year. Linear regressions between δ18O and δD value in different precipitation event size classes revealed progressively decreasing slope and intercept values with decreasing precipitation amount and increasing vapour pressure deficit, indicating that small rainfall events (0–5 mm) were subject to secondary evaporation effects during rainwater descent. In contrast, snowfall and heavy precipitation events exhibited high slope and intercepts for the regression equation between δ18O and δD. High concentrations of heavy isotopes were associated with precipitation events sourced from remote westerly air masses, degenerated tropical marine air masses from the Bay of Bengal (BoB), and inland moisture in the pre‐monsoon period, as determined from backward trajectories assessed in the HYSPLIT model. Meanwhile, low concentrations of heavy isotopes were found to correspond with remote maritime moisture from BoB, the South China Sea, and the west Pacific at three different air pressures in summer monsoon and post‐monsoon using HYSPLIT and records of typhoon paths. These findings suggest that stable isotope compositions in precipitation events are closely associated with the meteorological conditions and respond sensitively to moisture source in subtropical monsoon climates. Copyright © 2013 John Wiley & Sons, Ltd.

Different tablet and stylus design features were evaluated for usability and biomechanical properties. On the basis of short-term tasks, emulating functional tablets, usability was improved with the smaller and medium-sized tablets, portrait (vs. landscape) orientation, a back ledge grip and rubberised texture. There were no differences in productivity between design features.

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The correlations of isotopic ratios in precipitation with temperature, air pressure and humidity at different altitudes, in southwest China, are analyzed. There appear marked negative correlations for the δ 18 O in precipitation with precipitation amount, vapor pressure and atmospheric precipitable water (PW) at Mengzi, Simao and Tengchong stations on synoptic timescale; the marked negative correlations between the δ 18 O in precipitation and the diurnal mean temperature at 400 hPa, 500 hPa, 700 hPa and 850 hPa are different from the temperature effect in middle-high-latitude inland. Moreover, the notable positive correlation between the δ 18 O in precipitation and the dew-point deficit ΔT d at different altitudes is found at the three stations. On annual timescale, the annual precipitation amount weighted mean δ 18 O display the negative correlations not only with annual precipitation but also with annual mean temperature at 500 hPa. It can be deduced that, in the years with abnormally strong summer monsoon, more warm and wet air from low-latitude oceans is transported northward along the vapor channel located in southwest China and generates abnormally strong rainfall on the way. Meanwhile, the abnormally strong condensation process will release more condensed latent heat into atmosphere, and lead to the rise of atmospheric temperature during rainfall, but decline of the δ 18 O in precipitation. On the contrary, in the years with abnormally weak summer monsoon, the abnormally weak condensation process will release less condensed latent heat into atmosphere, and lead to the decline of atmospheric temperature during rainfall, but increase of the δ 18 O in precipitation. southwest China, stable isotope, precipitation, temperature, humidity, correlation In the past few decades, stable isotopes of oxygen ( 18 O, as H 2 18 O) and hydrogen (D, as HD 16 O) in water bodies have been found increasing applications in the studies of cloud physics, climatology, hydrology and palaeo-climatology [1,2] . Although very small amount in nature water, the stable isotopes respond to environmental variation very sensitively. Precipitation is an important link in the water cycle. The abundance of the stable isotopes in precipitation is closely associated with the weather process of generating condensation, initial conditions in vapor origin places and large-scale circulation patterns [3,4] .The global survey for the stable isotopic compositions in precipitation shows that there appears a marked positive correlation between stable isotopic ratio in precipitation and temperature in middle-high-latitude inland, which is called temperature effect [1,5] . Temperature effect arises from the fact that the temperature during phase change controls the fractionation rate of stable