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• Seasonal patterns of SUHII worldwide are classified into five typical patterns. • Same seasonal patterns between DNC and daytime SUHII account for 80% globally. • Seasonal patterns of daytime SUHII indicate opposite seasonal variations to ∆EVI. • Daytime SUHII is corresponded to the opposite patterns to LHF but similar to NSR. Variations and controls of surface urban heat island (SUHI) drawn great attention since its close association with environmental issues and heat risk. However, three issues remained neglect, namely, the mismatch and insignificant variations, seasonal patterns for SUHII DNC (day-and-night contrast) and impacts from surface energy variations. Therefore, this paper classifies seasonal patterns of SUHII based on ATCS (annual temperature cycle with seasonal adjustment) into five typical patterns, and further investigates impacts from surface energy variations. There are three major findings. (1) Approximately 70% of global cities are identified as the spring-summer and summer-autumn patterns at daytime, while global cities identified as the winter-spring and insignificant patterns account for 36% and 24%. The seasonal patterns of DNC are significantly affected by that of daytime. (2) The seasonal patterns of SUHII indicate opposite seasonal variations to ∆ EVI (enhanced vegetation index) at daytime and ∆ WSA (white sky albedo) at nighttime. (3) The cities identified as the spring-summer and summer-autumn patterns of SUHII are corresponded to the opposite patterns of latent heat flux at daytime, but similar patterns of net shortwave radiation at both day and night. [ABSTRACT FROM AUTHOR]

We achieve low-temperature Cu-to-Cu direct bonding using highly (111)-orientated Cu films. The bonding temperature can be lowered to 200°C at a stress of 114psi for 30min at 10−3 torr. The temperature is lower than the reflow temperature of 250°C for Pb-free solders. Our breakthrough is based on the finding that the Cu (111) surface diffusivity is the fastest among all the planes of Cu and the bonding process can occur through surface diffusion creep on the (111) surfaces. [ABSTRACT FROM AUTHOR]