We discuss problems of minimum degree-constrained trees T k , where each vertex of a complete graph K n with a metric satifying triangle inequality is restricted to at most k neighbors. We show that for any k and m, the ratio w(Tk) w(Tk+m) can be arbitrarily close to k;m = 1 + m m+k?2 and give an O(n log(k + m))) algorithm that converts a T k+m into a T k such that w(T k) < k;m T k+m. For the s...

Abstract. Near-surface air temperature (Ta) is an important physical parameter that reflects climate change. Many methods are used to obtain the daily maximum (Tmax?), minimum (Tmin?), and average (Tavg) temperature, but affected by multiple factors. To Ta data (Tmax?, Tmin?, Tavg) with high spatio-temporal resolution in China, we fully analyzed advantages disadvantages of various existing data...

Reference evapotranspiration (ET0) is of great significance in studies hydrological cycle, agricultural water resources, and hydrometeorology. The present study collected daily meteorological data at 536 stations China from 1984 to 2019, calculated ET0 using the FAO Penman–Monteith equation, analyzed spatial distribution temporal variation characteristics variables four different scales (contin...

The proposed revisions to the ANSI Z136, ICNIRP, and IEC 60825-1 laser exposure limits for multiple pulse ocular exposure for wavelengths from 400 to 1400 nm are examined for pulse durations tp tmin (Ti). The three rules that are defined to be applied for multiple pulse exposures (or for classification for IEC 60825-1) are compared to identify criteria for which one of the rules is the critical...

Understanding future changes in water supply and requirement under climate change is of great significance for long-term resource management agricultural planning. In this study, daily minimum temperature (Tmin), maximum (Tmax), solar radiation (Rad), precipitation 26 meteorological stations RCP4.5 RCP8.5 MIRCO5 the period 2021–2080 were downscaled by LARS-WG model, average relative humidity (R...

Understanding the effects of climate change on phenological structure plant communities will require measuring variation in sensitivity among thousands co‐occurring species across regions. Herbarium collections provide vast resources with which to do this, but may also exhibit biases as sources data. Despite general recognition these caveats, validation herbarium‐based estimates against obtaine...

Precise estimation of reference evapotranspiration (ET0) is significant importance in hydrologic processes. In this study, a genetic algorithm (GA) optimized back propagation (BP) neural network model was developed to estimate ET0 using different combinations meteorological data across various climatic zones and seasons China. Fourteen locations were selected represent five major climates. Mete...

Plant phenology depends largely on temperature, but temperature alone cannot explain the Northern Hemisphere shifts in start of growing season (SOS). The spatio–temporal distribution SOS sensitivity to climate variability has also changed recent years. We applied partial least squares regression (PLSR) method construct a standardized evaluation index and analyzed combined effects air (Tem), wat...