Submarine hydrothermal vents occur over a wide depth range from a few meters to several thousands of meters. Most existing hydrothermal fluid samplers are focused on deep-sea environments and are not suited for collec...Submarine hydrothermal vents occur over a wide depth range from a few meters to several thousands of meters. Most existing hydrothermal fluid samplers are focused on deep-sea environments and are not suited for collecting shallow-water fluids. In this study, a new gas-tight sampler which can be easily deployed by both submersibles and scuba divers to collect fluid samples from both deep-sea and shallow-water hydrothermal vents is presented. The proposed sampler uses an electric control sampling valve for fluid collection and a system to measure and display the temperature of the hydrothermal fluid while sampling. It is capable of working in manual mode to be controlled via external signals, or in automatic mode to collect a fluid sample according to the temperature. The master-slave architecture of the electronic system makes the sampler flexible in meeting many different deployment requirements. The performance of the sampler has been demonstrated by preliminary field tests at a shallow-water hydrothermal vent site.展开更多
DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in China.We identified 17 call types across all age/sex cla...DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in China.We identified 17 call types across all age/sex classes based on human auditory perception,spectrogram assessment,and quantitative analysis of 25 acoustic parameters extracted from 409 high-quality calls.In total,11 types of calls produced by adults corresponded to the simple one-male multi-female social groups of white-headed langurs.展开更多
An increasing number of underwater gliders have been applied to lake monitoring. Lakes have a limited vertical space. Therefore, good space-saving capacity is required for underwater gliders to enlarge the spacing bet...An increasing number of underwater gliders have been applied to lake monitoring. Lakes have a limited vertical space. Therefore, good space-saving capacity is required for underwater gliders to enlarge the spacing between monitoring waypoints. This paper presents a space-saving steering method under a small pitch angle （SPA） for appearance-fixed underwater gliders. Steering under an SPA increases the steering angle in per unit vertical space. An amended hydrodynamic model for both small and large attack angles is presented to help analyze the steering process. Analysis is conducted to find the optimal parameters of net buoyancy and roll angle for steering under an SPA. A lake trial with a prototype tiny underwater glider （TUG） is conducted to inspect the applicability of the presented model. The trial results show that steering under an SPA saves vertical space, unlike that under a large pitch angle. Simulation results of steering are consistent with the trial results. In addition, multiple-waypoint trial shows that monitoring with steering under an SPA covers a larger horizontal displacement than that without steering.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 41106081）, and the Science Fund for Creative Research Groups of the National Natural Science Foundation of China （No. 51221004）
文摘Submarine hydrothermal vents occur over a wide depth range from a few meters to several thousands of meters. Most existing hydrothermal fluid samplers are focused on deep-sea environments and are not suited for collecting shallow-water fluids. In this study, a new gas-tight sampler which can be easily deployed by both submersibles and scuba divers to collect fluid samples from both deep-sea and shallow-water hydrothermal vents is presented. The proposed sampler uses an electric control sampling valve for fluid collection and a system to measure and display the temperature of the hydrothermal fluid while sampling. It is capable of working in manual mode to be controlled via external signals, or in automatic mode to collect a fluid sample according to the temperature. The master-slave architecture of the electronic system makes the sampler flexible in meeting many different deployment requirements. The performance of the sampler has been demonstrated by preliminary field tests at a shallow-water hydrothermal vent site.
基金supported by the National Natural Science Foundation of China (31900335, 31870514,32170492)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA23080000, XDA19050000)+2 种基金China Postdoctoral Science Foundation (2020M670453)Guangxi Science&Technology Project (2021AC19023)Guangxi Key Laboratory of Rare and Endangered Animal Ecology,Guangxi Normal University(20-A-01-05)。
文摘DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in China.We identified 17 call types across all age/sex classes based on human auditory perception,spectrogram assessment,and quantitative analysis of 25 acoustic parameters extracted from 409 high-quality calls.In total,11 types of calls produced by adults corresponded to the simple one-male multi-female social groups of white-headed langurs.
基金Project supported by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China （No. 51521064） and the National High-Tecb R＆D Program （863） of China （No. 2014AA09A513 ）
文摘An increasing number of underwater gliders have been applied to lake monitoring. Lakes have a limited vertical space. Therefore, good space-saving capacity is required for underwater gliders to enlarge the spacing between monitoring waypoints. This paper presents a space-saving steering method under a small pitch angle （SPA） for appearance-fixed underwater gliders. Steering under an SPA increases the steering angle in per unit vertical space. An amended hydrodynamic model for both small and large attack angles is presented to help analyze the steering process. Analysis is conducted to find the optimal parameters of net buoyancy and roll angle for steering under an SPA. A lake trial with a prototype tiny underwater glider （TUG） is conducted to inspect the applicability of the presented model. The trial results show that steering under an SPA saves vertical space, unlike that under a large pitch angle. Simulation results of steering are consistent with the trial results. In addition, multiple-waypoint trial shows that monitoring with steering under an SPA covers a larger horizontal displacement than that without steering.
