A new species of rhacophorid of the genus Rhacophorus is described from the Shiwandashan National Nature Reserve, Guangxi, Southern China. Rhacophorus pinglongensis sp. nov. is compared with congeners from China and o...A new species of rhacophorid of the genus Rhacophorus is described from the Shiwandashan National Nature Reserve, Guangxi, Southern China. Rhacophorus pinglongensis sp. nov. is compared with congeners from China and other parts of Southeast Asia. The new species is distinguished from its congeners by combination of following characters：（1） small size（adult male, SVL 32.0-38.5 mm）;（2） smooth and green dorsum;（3） flanks, axilla, ventral surface of forearms, inguinal, anterior and posterior surfaces of thighs, ventral surface of shank, and dorsal surface of feet covered with black blotches with white spots or white spots with a faint orange tint;（4） ventral surface of feet and webbing tangerine;（5） supratympanic fold weak;（6） outer margin of forearms and feet with low dermal ridges;（7） calcars absent on heels;（8） iris silver, diffusing to ecru laterally with light khaki ring along margin. The new species is closely related to R. dorsoviridis, R. moltrechti, and R. nigropunctatus based on adult morphology. Currently, this species is known only from mid-elevation montane evergreen forest in the Shiwandashan National Nature Reserve, Guangxi, China.展开更多
Local melting and the eutectic film and liquation crack formation mechanisms during friction spot weld- ing （FSpW） of Al-Zn-Mg-Cu alloy were studied by both experiment and finite element simulation. Their effects on...Local melting and the eutectic film and liquation crack formation mechanisms during friction spot weld- ing （FSpW） of Al-Zn-Mg-Cu alloy were studied by both experiment and finite element simulation. Their effects on mechanical properties of the joint were examined. When the welding heat input was high, the peak temperature in the stir zone was higher than the incipient melting temperature of the Al-Zn-Mg-Cu alloy. This resulted in local melting along the grain boundaries in this zone. In the retreating stage of the welding process, the formed liquid phase was driven by the flowing plastic material and redistributed as a ＂U-shaped＂ line in the stir zone. In the following cooling stage, this liquid phase transformed into eutectic films and liquation cracks. As a result, a new characteristic of＂U＂ line that consisted of eutectic films and liquation cracks is formed in the FSpWjoin. This ＂U＂ line was located in the high stress region when the FSpW joint was loaded, thus it was adverse to the mechanical properties of the FSpW joint. During tensile shear tests, the ＂U＂ line became a preferred crack propagation path, resulting in the occurrence of brittle fracture.展开更多
基金supported by Natural Science Foundation of Guangxi Province,China (Grant No:2012GXNSFAA053057 and 2016GXNSFAA380007)
文摘A new species of rhacophorid of the genus Rhacophorus is described from the Shiwandashan National Nature Reserve, Guangxi, Southern China. Rhacophorus pinglongensis sp. nov. is compared with congeners from China and other parts of Southeast Asia. The new species is distinguished from its congeners by combination of following characters：（1） small size（adult male, SVL 32.0-38.5 mm）;（2） smooth and green dorsum;（3） flanks, axilla, ventral surface of forearms, inguinal, anterior and posterior surfaces of thighs, ventral surface of shank, and dorsal surface of feet covered with black blotches with white spots or white spots with a faint orange tint;（4） ventral surface of feet and webbing tangerine;（5） supratympanic fold weak;（6） outer margin of forearms and feet with low dermal ridges;（7） calcars absent on heels;（8） iris silver, diffusing to ecru laterally with light khaki ring along margin. The new species is closely related to R. dorsoviridis, R. moltrechti, and R. nigropunctatus based on adult morphology. Currently, this species is known only from mid-elevation montane evergreen forest in the Shiwandashan National Nature Reserve, Guangxi, China.
基金supports by the Project of Guangdong Provincial Science and Technology Program(2015B090922011)the 2017 GDAS’ Special Project of Science and Technology Development(2017GDASCX-0847)the Project of Guangdong Provincial Key Laboratory(2012A061400011)
文摘Local melting and the eutectic film and liquation crack formation mechanisms during friction spot weld- ing （FSpW） of Al-Zn-Mg-Cu alloy were studied by both experiment and finite element simulation. Their effects on mechanical properties of the joint were examined. When the welding heat input was high, the peak temperature in the stir zone was higher than the incipient melting temperature of the Al-Zn-Mg-Cu alloy. This resulted in local melting along the grain boundaries in this zone. In the retreating stage of the welding process, the formed liquid phase was driven by the flowing plastic material and redistributed as a ＂U-shaped＂ line in the stir zone. In the following cooling stage, this liquid phase transformed into eutectic films and liquation cracks. As a result, a new characteristic of＂U＂ line that consisted of eutectic films and liquation cracks is formed in the FSpWjoin. This ＂U＂ line was located in the high stress region when the FSpW joint was loaded, thus it was adverse to the mechanical properties of the FSpW joint. During tensile shear tests, the ＂U＂ line became a preferred crack propagation path, resulting in the occurrence of brittle fracture.
