Since 2002, the Soil and Water Conservation Bureau, which is responsible for the conservation and administrative management of hillside in Taiwan, has been cooperating with Feng Chia University. Together, they have su...Since 2002, the Soil and Water Conservation Bureau, which is responsible for the conservation and administrative management of hillside in Taiwan, has been cooperating with Feng Chia University. Together, they have successfully carried out the establishment and maintenance of 13 fixed debris flow monitoring stations over the island and 2 mobile debris flow monitoring stations. During July 2004, a powerful southwest air current brought by Mindulle Typhoon caused serious flood in central and southern Taiwan. This paper aims to describe the establishment of debris flow monitoring systems in Taiwan and the observation of the debris flow event during Mindulle Typhoon at Aiyuzi River in Shenmu Village, Nantou County by the monitoring station.展开更多
Liquid composite moulding (LCM) processes are used to manufacture high quality and complex-shaped composite parts in the automotive, marine, aerospace and civil industries. On-line sensing plays an important role in c...Liquid composite moulding (LCM) processes are used to manufacture high quality and complex-shaped composite parts in the automotive, marine, aerospace and civil industries. On-line sensing plays an important role in controlling the quality of the final product in the LCM manufacturing environment. The long-period fiber grating (LPG) technology, a new real-time fiber optic sensor system, was developed to monitor the flow front progression. The sensor operation and characterization under various process conditions were discussed in detail. The experimental results showed that LPG sensors were robust and reliable to detect the arrival of resin at pre-selected locations in structures with low-medium fiber volume fraction; however were limited at different depths in structures with high fiber volume fraction.展开更多
Convenient non-invasive flow monitoring would facilitate the operation and control in microfluidic chips,but is challenging due to the small space of microchannels and complex operation required in traditional optical...Convenient non-invasive flow monitoring would facilitate the operation and control in microfluidic chips,but is challenging due to the small space of microchannels and complex operation required in traditional optical methods.In this work,we propose a novel non-invasive strategy to probe microfluidic flows via streaming potential phenomenon.By sealing one side of the microchannel with a piece of hydrogel film,streaming potential inside the channel can be clearly detected by electrodes at outer surface of the hydrogel due to ion diffusion in the hydrogel.Flow is detected without sensors contacting with the internal liquid.Moreover,the electrodes shape like a tiny probe,which can move around mapping the flow distribution in a chip with the spatial resolution of 1 mm and flow rate detection limit of 3μL·min–1.Bubbles inside the channels can also be detected,due to the fluctuation of streaming voltage when gas-liquid interface flows through the electrode,showing an easy and potential way for multi-functional flow monitoring in microfluidic chips.展开更多
There was limited knowledge about the flow fluctuations and cycling processes of saline springs in the Nangqen Basin in the Sanjiang tectonic zone.In this work,the flow variations of the saline springs during the wet ...There was limited knowledge about the flow fluctuations and cycling processes of saline springs in the Nangqen Basin in the Sanjiang tectonic zone.In this work,the flow variations of the saline springs during the wet and dry seasons were monitored using volumetric and cross-sectional methods,and the cycling process of the saline springs was quantitatively identified using the integrated hydrochemical and isotopic methods.The results show that most saline springs in the Nangqen Basin had significantly different flow rates,ion concentrations,and TDS concentrations.The ions mainly come from carbonate and sulfate minerals.There is no internal hydraulic connection between these saline springs,and the impact of seasonal changes on the flow is relatively small,indicating that the saline springs originate mainly from deep circulation.The recharge elevation of the saline springs ranges 3661-4990 m a.s.l.,with an average of 4100 m a.s.l.The circulation depth of the saline springs ranges of 240-570 m,with an average of 431 m.The recycle time ranges of 1.15-30.86 years,with an average of 15.66 years.These results could provide a scientific basis for the development and utilization of saline spring resources in the Nangqen Basin.展开更多
Laser speckle imaging is a common technique to monitor blood flow.The fluctuations in speckle intensity can be related to the blood flow by calculating the speckle contrast,the ratio between the standard deviation of ...Laser speckle imaging is a common technique to monitor blood flow.The fluctuations in speckle intensity can be related to the blood flow by calculating the speckle contrast,the ratio between the standard deviation of speckle fluctuations and the average intensity.However,this simple statistic calculation is easily affected by motion artifacts.In this study,we applied sample entropy analysis instead of calculating standard deviations of the speckle fluctuations.Similar to the traditional method,sample entropy-based speckle contrast increases linearly with flow rate but was shown to be more immune to sudden movements during an upper arm occlusion test.展开更多
Blood flow is essential for maintaining normal physiological functions of the human body.Endoscopic laser speckle contrast imaging(LSCI)can achieve rapid,high-resolution,label-free,and long-term blood flow perfusion v...Blood flow is essential for maintaining normal physiological functions of the human body.Endoscopic laser speckle contrast imaging(LSCI)can achieve rapid,high-resolution,label-free,and long-term blood flow perfusion velocity monitoring in minimally invasive surgery.However,conventional endoscopic LSCI uses a lowcoherence laser illumination scheme,leading to restricted angles of illumination,compromised laser coherence,uneven laser illumination distribution,and low coupling efficiency,all of which degrade the quality of LSCI in the endoscope.In this paper,we propose that conical fiber(CF)-coupled high-coherence laser can be used to achieve large-angle,high-coherence,high-uniformity,and high coupling efficiency laser illumination in the endoscope.Additionally,we establish an effective model for calculating the divergence angle of CFs.Through phantom and animal experiments,we reveal that laser illumination based on CF markedly enhances endoscopic LSCI performance.This technology broadens the imaging field of view,enhances the signal-to-noise ratio,enables more sensitive detection of minute blood flow changes,expands the detectable flow range,and improves signal-to-background ratio of endoscopic LSCI.Our findings suggest that CF-based laser illumination stands as a highly promising advancement in endoscopic LSCI.展开更多
Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformatio...Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery,the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM,CBF returned to the baseline level within 4 hours,but in patients with giant AVM,CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.展开更多
This paper covers a micro sensor analog signal processing circuit system（MASPS） chip with low power and a digital signal processing circuit board implementation including hardware connection and software design. Att...This paper covers a micro sensor analog signal processing circuit system（MASPS） chip with low power and a digital signal processing circuit board implementation including hardware connection and software design. Attention has been paid to incorporate the MASPS chip into the digital circuit board.The ultimate aim is to form a hybrid circuit used for mixed-signal processing,which can be applied to a micro sensor flow monitoring system.展开更多
基金Taiwan Soil and Water Conservation Bureau (SWCB- 95-164)
文摘Since 2002, the Soil and Water Conservation Bureau, which is responsible for the conservation and administrative management of hillside in Taiwan, has been cooperating with Feng Chia University. Together, they have successfully carried out the establishment and maintenance of 13 fixed debris flow monitoring stations over the island and 2 mobile debris flow monitoring stations. During July 2004, a powerful southwest air current brought by Mindulle Typhoon caused serious flood in central and southern Taiwan. This paper aims to describe the establishment of debris flow monitoring systems in Taiwan and the observation of the debris flow event during Mindulle Typhoon at Aiyuzi River in Shenmu Village, Nantou County by the monitoring station.
基金This work was supported by the National High-Tech Foundation(863)under the gr ant 2001AA335020.
文摘Liquid composite moulding (LCM) processes are used to manufacture high quality and complex-shaped composite parts in the automotive, marine, aerospace and civil industries. On-line sensing plays an important role in controlling the quality of the final product in the LCM manufacturing environment. The long-period fiber grating (LPG) technology, a new real-time fiber optic sensor system, was developed to monitor the flow front progression. The sensor operation and characterization under various process conditions were discussed in detail. The experimental results showed that LPG sensors were robust and reliable to detect the arrival of resin at pre-selected locations in structures with low-medium fiber volume fraction; however were limited at different depths in structures with high fiber volume fraction.
基金supported by the National Natural Science Foundation of China(Grant Nos.51976141,52006123,62161160311).
文摘Convenient non-invasive flow monitoring would facilitate the operation and control in microfluidic chips,but is challenging due to the small space of microchannels and complex operation required in traditional optical methods.In this work,we propose a novel non-invasive strategy to probe microfluidic flows via streaming potential phenomenon.By sealing one side of the microchannel with a piece of hydrogel film,streaming potential inside the channel can be clearly detected by electrodes at outer surface of the hydrogel due to ion diffusion in the hydrogel.Flow is detected without sensors contacting with the internal liquid.Moreover,the electrodes shape like a tiny probe,which can move around mapping the flow distribution in a chip with the spatial resolution of 1 mm and flow rate detection limit of 3μL·min–1.Bubbles inside the channels can also be detected,due to the fluctuation of streaming voltage when gas-liquid interface flows through the electrode,showing an easy and potential way for multi-functional flow monitoring in microfluidic chips.
基金supported by the National Natural Science Foundation of China(Nos.42007169,U20A2088)the Natural Science Foundation of Qinghai Province(No.2020-ZJ-932Q)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2019QZKK0805-02)。
文摘There was limited knowledge about the flow fluctuations and cycling processes of saline springs in the Nangqen Basin in the Sanjiang tectonic zone.In this work,the flow variations of the saline springs during the wet and dry seasons were monitored using volumetric and cross-sectional methods,and the cycling process of the saline springs was quantitatively identified using the integrated hydrochemical and isotopic methods.The results show that most saline springs in the Nangqen Basin had significantly different flow rates,ion concentrations,and TDS concentrations.The ions mainly come from carbonate and sulfate minerals.There is no internal hydraulic connection between these saline springs,and the impact of seasonal changes on the flow is relatively small,indicating that the saline springs originate mainly from deep circulation.The recharge elevation of the saline springs ranges 3661-4990 m a.s.l.,with an average of 4100 m a.s.l.The circulation depth of the saline springs ranges of 240-570 m,with an average of 431 m.The recycle time ranges of 1.15-30.86 years,with an average of 15.66 years.These results could provide a scientific basis for the development and utilization of saline spring resources in the Nangqen Basin.
基金GIST Research Institute(GRI)funded by GIST in 2019 and 2020Brain Research Program(2016M3C7A1905475)+1 种基金Basic Research Program(2018R1A2B6006797)through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICTKBRI basic research program through Korea Brain Research Institute funded by Ministry of Science and ICT(21-BR-03-05)。
文摘Laser speckle imaging is a common technique to monitor blood flow.The fluctuations in speckle intensity can be related to the blood flow by calculating the speckle contrast,the ratio between the standard deviation of speckle fluctuations and the average intensity.However,this simple statistic calculation is easily affected by motion artifacts.In this study,we applied sample entropy analysis instead of calculating standard deviations of the speckle fluctuations.Similar to the traditional method,sample entropy-based speckle contrast increases linearly with flow rate but was shown to be more immune to sudden movements during an upper arm occlusion test.
基金National Key Research and Development Program of China(2021YFC2400102)National Natural Science Foundation of China(62275095,82261138559,62305125,61890951,61890950)+2 种基金Hainan University Research Startup Fund(KYQD(ZR)20072,KYQD(ZR)22074)Chinese Academy of Medical Sciences Initiative for Innovative Medicine(2019-I2M-5-014)Innovation Fund of WNLO。
文摘Blood flow is essential for maintaining normal physiological functions of the human body.Endoscopic laser speckle contrast imaging(LSCI)can achieve rapid,high-resolution,label-free,and long-term blood flow perfusion velocity monitoring in minimally invasive surgery.However,conventional endoscopic LSCI uses a lowcoherence laser illumination scheme,leading to restricted angles of illumination,compromised laser coherence,uneven laser illumination distribution,and low coupling efficiency,all of which degrade the quality of LSCI in the endoscope.In this paper,we propose that conical fiber(CF)-coupled high-coherence laser can be used to achieve large-angle,high-coherence,high-uniformity,and high coupling efficiency laser illumination in the endoscope.Additionally,we establish an effective model for calculating the divergence angle of CFs.Through phantom and animal experiments,we reveal that laser illumination based on CF markedly enhances endoscopic LSCI performance.This technology broadens the imaging field of view,enhances the signal-to-noise ratio,enables more sensitive detection of minute blood flow changes,expands the detectable flow range,and improves signal-to-background ratio of endoscopic LSCI.Our findings suggest that CF-based laser illumination stands as a highly promising advancement in endoscopic LSCI.
文摘Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery,the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM,CBF returned to the baseline level within 4 hours,but in patients with giant AVM,CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.
基金Project supported by National Natural Science Foundation of China(No60843005)the Basic Research Foundation of Beijing Institute of Technology,China(No20070142018)
文摘This paper covers a micro sensor analog signal processing circuit system（MASPS） chip with low power and a digital signal processing circuit board implementation including hardware connection and software design. Attention has been paid to incorporate the MASPS chip into the digital circuit board.The ultimate aim is to form a hybrid circuit used for mixed-signal processing,which can be applied to a micro sensor flow monitoring system.
