Bioelectrical signals can reflect physiological state of organs or tissues in plants and have a significant potential value in research of plant stress tolerance.In order to study the relationship between environment ...Bioelectrical signals can reflect physiological state of organs or tissues in plants and have a significant potential value in research of plant stress tolerance.In order to study the relationship between environment factors and electrical signals in plant,a portable multichannel physiological signal acquisition system which relevant in plant physiology research was developed.Environment parameters and electrical signals can be measured in different channels by the acquisition system simultaneously and the measurement data will be displayed in an embedded integrated touch screen which is the system processing core.The system was validated to be stable and reliable after the calibration and repeated experiments of recording electrical signals in Helianthus annuus L.展开更多
Wireless sensor networks have been applied in farmland and greenhouse.However,poor connectivity always results in a lot of nodes isolation in the network in a scenario.For this reason,the network connectivity is worth...Wireless sensor networks have been applied in farmland and greenhouse.However,poor connectivity always results in a lot of nodes isolation in the network in a scenario.For this reason,the network connectivity is worth considering to improve its quality,especially when the collected data cannot be sent to the data center because of the obstacles such as the growth of crop plants and weeds.Therefore,how to reduce the effect of crop growth on network connectivity,and enable the reliable transmission of field information,are the key problems to be resolved.To solve these problems,the method which adds long distance routing nodes to the WSN to reduce the deterioration of WSN connectivity during the growth of plants was proposed.To verify this method,the network connectivity of the deployed WSN was represented by the rank of connection matrix based on the graph theory.Consequently,the rank with value of 1 indicates a fully connected network.Moreover,the smaller value of rank means the better connectedness.In addition,the network simulator NS2 simulation results showed that the addition of long-distance backup routing nodes can improve the network connectivity.Furthermore,in experiments,using ZigBee-based wireless sensor network,a remote monitoring system in greenhouse was established,which can obtain environmental information for crops,e.g.temperature,humidity,light intensity and other environmental parameters as well as the wireless link quality especially.Experimental results showed adding of long-distance backup routing nodes can guarantee network connectivity in the region where received signal strength indication(RSSI)was poor,i.e.RSSI value was less than−100 dBm,and the energy was low.In conclusion,this method was essential to improve the connectivity of WSN,and the optimized method still needs further research.展开更多
Moisture content of corn directly affects its quality and storage time,and the rapid on-line detection of the moisture content of corn ears not threshed or in vivo in the fields is required.Because of the special shap...Moisture content of corn directly affects its quality and storage time,and the rapid on-line detection of the moisture content of corn ears not threshed or in vivo in the fields is required.Because of the special shape of corn ear,the rapid,low cost and non-destructive bioelectrical impedance measurement is more suitable for its moisture content detection.Using the four-electrode method with the Agilent E4980A precision LCR meter,the electrical impedance spectroscopies of the sweet corn ears and waxy corn ears at different moisture contents were acquired.The frequency range of the detection was from 20 Hz to 2 MHz and to enhance the contact,the attached-type electrodes were wrapped in cotton soaked with 0.1%NaCl solution.The impedance data over the frequency range from 300 Hz to 5 kHz were used to obtain the parameters of the bio-impedance Cole-Cole model.The results showed a good linear correlation(coefficient of determination R2=0.960)between the equivalent parallel resistance R∞of sweet corn ear and the moisture content value determined by standard chemical method.The research proved that the bioelectrical impedance spectroscopy can be used for detecting the moisture content of corn ear.展开更多
SIET(Self-referencing Ion Electrode Technique)provides a novel electrophysiological tool which can non-invasively measure the dynamic influxes and effluxes of ions caused by the diffusion along the concentration gradi...SIET(Self-referencing Ion Electrode Technique)provides a novel electrophysiological tool which can non-invasively measure the dynamic influxes and effluxes of ions caused by the diffusion along the concentration gradients in vivo.However,in this technique ion fluxes are converted to voltage signals using an ion selective microelectrode at a small amplitude of lV,which is easy to be interfered by the ambient noise.Hence,effective solutions to the suppression of noise and calibration of ion flux measurement system are very important for this method.A K^+-selective microelectrode was constructed using liquid ion exchangers(LIX)to investigate ion transport over plant tissue.A standard concentration gradient which simulates plant living cells was produced by an electrode with a certain tip diameter,filled with a solution containing a known K+concentration in 100 mmol/L.An ion diffusion simulation model was established.This model evaluated the performance of ion flux measurement system in accuracy and reliability by comparing the consistency of the measured value and the predicted curve.K^+fluxes were measured within 25 min at each measuring point of distance 10,20,30,40,50,80,and 100 lm from the K+source,respectively.It can be seen that the K^+fluxes changes little,which indicates that ion flux measurement system has a reliable stability.The study provides a theoretical basis for a new non-invasive ion flux measurement method creation and a new sensors design.展开更多
基金This research was supported by the Specialized Research Fund for the Doctoral Program of Higher Education(20130008110035)the National Key Scientific Instrument and Equipment Development Projects(2011YQ080052)the National Natural Science Foundation of China(61072016)。
文摘Bioelectrical signals can reflect physiological state of organs or tissues in plants and have a significant potential value in research of plant stress tolerance.In order to study the relationship between environment factors and electrical signals in plant,a portable multichannel physiological signal acquisition system which relevant in plant physiology research was developed.Environment parameters and electrical signals can be measured in different channels by the acquisition system simultaneously and the measurement data will be displayed in an embedded integrated touch screen which is the system processing core.The system was validated to be stable and reliable after the calibration and repeated experiments of recording electrical signals in Helianthus annuus L.
文摘Wireless sensor networks have been applied in farmland and greenhouse.However,poor connectivity always results in a lot of nodes isolation in the network in a scenario.For this reason,the network connectivity is worth considering to improve its quality,especially when the collected data cannot be sent to the data center because of the obstacles such as the growth of crop plants and weeds.Therefore,how to reduce the effect of crop growth on network connectivity,and enable the reliable transmission of field information,are the key problems to be resolved.To solve these problems,the method which adds long distance routing nodes to the WSN to reduce the deterioration of WSN connectivity during the growth of plants was proposed.To verify this method,the network connectivity of the deployed WSN was represented by the rank of connection matrix based on the graph theory.Consequently,the rank with value of 1 indicates a fully connected network.Moreover,the smaller value of rank means the better connectedness.In addition,the network simulator NS2 simulation results showed that the addition of long-distance backup routing nodes can improve the network connectivity.Furthermore,in experiments,using ZigBee-based wireless sensor network,a remote monitoring system in greenhouse was established,which can obtain environmental information for crops,e.g.temperature,humidity,light intensity and other environmental parameters as well as the wireless link quality especially.Experimental results showed adding of long-distance backup routing nodes can guarantee network connectivity in the region where received signal strength indication(RSSI)was poor,i.e.RSSI value was less than−100 dBm,and the energy was low.In conclusion,this method was essential to improve the connectivity of WSN,and the optimized method still needs further research.
基金This research was supported by the Special Fund for Agro-scientific Research in the Public Interest(20120302)the Program of the Co-Construction with Beijing and the Specialized Research Fund for the Doctoral Program of Higher Education(20130008110035).
文摘Moisture content of corn directly affects its quality and storage time,and the rapid on-line detection of the moisture content of corn ears not threshed or in vivo in the fields is required.Because of the special shape of corn ear,the rapid,low cost and non-destructive bioelectrical impedance measurement is more suitable for its moisture content detection.Using the four-electrode method with the Agilent E4980A precision LCR meter,the electrical impedance spectroscopies of the sweet corn ears and waxy corn ears at different moisture contents were acquired.The frequency range of the detection was from 20 Hz to 2 MHz and to enhance the contact,the attached-type electrodes were wrapped in cotton soaked with 0.1%NaCl solution.The impedance data over the frequency range from 300 Hz to 5 kHz were used to obtain the parameters of the bio-impedance Cole-Cole model.The results showed a good linear correlation(coefficient of determination R2=0.960)between the equivalent parallel resistance R∞of sweet corn ear and the moisture content value determined by standard chemical method.The research proved that the bioelectrical impedance spectroscopy can be used for detecting the moisture content of corn ear.
基金This research was supported by the National Natural Science Foundation of China(61571443)the National Key Scientific Instrument and Equipment Development Projects(2011YQ080052)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(20130008110035)the Beijing Higher Education Young Elite Teacher Project(YETP1756)the Special Fund of Fundamental Research Funds for the Central Universities(2013YJ008).
文摘SIET(Self-referencing Ion Electrode Technique)provides a novel electrophysiological tool which can non-invasively measure the dynamic influxes and effluxes of ions caused by the diffusion along the concentration gradients in vivo.However,in this technique ion fluxes are converted to voltage signals using an ion selective microelectrode at a small amplitude of lV,which is easy to be interfered by the ambient noise.Hence,effective solutions to the suppression of noise and calibration of ion flux measurement system are very important for this method.A K^+-selective microelectrode was constructed using liquid ion exchangers(LIX)to investigate ion transport over plant tissue.A standard concentration gradient which simulates plant living cells was produced by an electrode with a certain tip diameter,filled with a solution containing a known K+concentration in 100 mmol/L.An ion diffusion simulation model was established.This model evaluated the performance of ion flux measurement system in accuracy and reliability by comparing the consistency of the measured value and the predicted curve.K^+fluxes were measured within 25 min at each measuring point of distance 10,20,30,40,50,80,and 100 lm from the K+source,respectively.It can be seen that the K^+fluxes changes little,which indicates that ion flux measurement system has a reliable stability.The study provides a theoretical basis for a new non-invasive ion flux measurement method creation and a new sensors design.
