In this study,a compact 16-channel integrated charge-sensitive preamplifier named the smart preamplifier(SPA)was developed to support the large-scale detector array used in modern nuclear physics experiments.Two types...In this study,a compact 16-channel integrated charge-sensitive preamplifier named the smart preamplifier(SPA)was developed to support the large-scale detector array used in modern nuclear physics experiments.Two types of SPA,namely SPA02 and SPA03(with external field effect transistor),have been manufactured to match silicon detectors with small and large capacitances,respectively.The characteristics of the SPA include fast response of typically less than 6 ns for pulse rising time and low equivalent noise of 1.5 keV at zero input capacitance.The energy sensitivity and pulse decay time can be easily adjusted by changing the feedback capacitance Cfand resistance Rfin various applications.A good energy resolution of 24.4 keV for 5.803-MeV alpha particles from 244 Cm was achieved using a small-sized Si-PIN detector;for the silicon strip detectors in the test with the alpha source,a typical energy resolution of 0.6–0.8%was achieved.The integrated SPA has been employed in several experiments of silicon strip detectors with hundreds of channels,and a good performance has been realized.展开更多
Plasticity of cerebellar Purkinje cells(PC)is influenced by progeste rone via the classical progeste rone receptors PR-A and PR-B by stimulating dendritogenesis,spinogenesis,and synaptogenesis in these cells.Dissociat...Plasticity of cerebellar Purkinje cells(PC)is influenced by progeste rone via the classical progeste rone receptors PR-A and PR-B by stimulating dendritogenesis,spinogenesis,and synaptogenesis in these cells.Dissociated PC cultures were used to analyze progeste rone effects at a molecular level on the voltage-gated T-type-Ca^(2+)-channels Ca_(v)3.1,Ca_(v)3.2,and Ca_(v)3.3 as they helped determine neuronal plasticity by regulating Ca^(2+)-influx in neuronal cells.The results showed direct effects of progesterone on the mRNA expression of T-type-Ca^(2+)-channels,as well as on the protein kinases A and C being involved in downstream signaling pathways that play an important role in neuronal plasticity.For the mRNA expression studies of T-type-Ca^(2+)-channels and protein kinases of the signaling cascade,laser microdissection and purified PC cultures of diffe rent maturation stages were used.Immunohistochemical staining was also performed to characte rize the localization of T-type-Ca^(2+)-channels in PC.Expe rimental progesterone treatment was performed on the purified PC culture for 24 and 48 hours.Our results show that progesterone increases the expression of Ca_(v)3.1 and Ca_(v)3.3 and associated protein kinases A and Cin PC at the mRNA level within 48 hours after treatment at latest.These effects extend the current knowledge of the function of progesterone in the central nervous system and provide an explanatory approach for its influence on neuronal plasticity.展开更多
An experimental muon source(EMuS) will be built at the China Spallation Neutron Source(CSNS). In phase I of CSNS, it has been decided that EMuS will provide a proton beam of 5 kW and 1.6 GeV to generate muon beams. A ...An experimental muon source(EMuS) will be built at the China Spallation Neutron Source(CSNS). In phase I of CSNS, it has been decided that EMuS will provide a proton beam of 5 kW and 1.6 GeV to generate muon beams. A 128-channel muon spin rotation/relaxation/resonance(μSR) spectrometer is proposed as a prototype surface muon spectrometer in a sub-branch of EMuS. The prototype spectrometer includes a detection system, sample environment, and supporting mechanics. The current design has two rings located at the forward and backward directions of the muon spin with 64 detectors per ring. The simulation shows that the highest asymmetry of approximately 0.28 is achieved by utilizing two 10-mm-thick brass degraders. To obtain the optimal asymmetry, the two-ring structure is updated to a four-ring structure with 32 segments in each ring. An asymmetry of 0.42 is obtained through the simulation, which is higher than that of all the current μSR spectrometers in the world.展开更多
Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform samp...Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform sampling signal was deduced. First we obtained an expression for the S/N ratio of a 1-channel A/D uniform sampling signal when the sampling frequency was equal to or greater than 2 times the frequency of the sampled signal. Based on the S/N ratio of a 2-channel A/D,alternating,non-uniform sampling signal,we analyzed the distribution of quantitative error using the quantitative error probability density method and the distribution convolution formula. From this the S/N ratio expression of a 4-channel A/D sampling signal was deduced. The simulation result shows that the deduced expression is correct.展开更多
Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments...Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).展开更多
A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fl...A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fly line,screening box and shielded wire.The EN data were acquired from two Q235 carbon steel specimens placed in 0.5 mol/L H2SO4 solution and 0.1 mol/L NaCl solution.The experimental result shows that this system can achieve an accuracy of 10 pA and 10 μV,and it can be applied to on-site multi-channel EN test.展开更多
Purpose: Adenosine stress CMR is commonly used to assess myocardial ischaemia. Obtaining high quality images requires maximising signal to noise ratio (SNR) over a large double-oblique field of view (FOV) whilst minim...Purpose: Adenosine stress CMR is commonly used to assess myocardial ischaemia. Obtaining high quality images requires maximising signal to noise ratio (SNR) over a large double-oblique field of view (FOV) whilst minimising artefacts. A 32-channel surface coil may provide a higher SNR over a larger FOV compared to standard coils, possibly leading to improved image quality. Materials and Methods: 50 adenosine perfusion CMR scans were performed on a Philips Achieva CV 1.5T, with either a 5 or 32-channel coil (25 patients each) using standardised acquisition protocols. 3 short axis slices were acquired per cardiac cycle and the resulting cine images were scored by two blinded CMR specialists on a quality scale of 1 to 5. Phantom studies were performed using similar acquisition parameters and the SNR was calculated and compared across a range of acceleration factors. Results: The mean patient age was 62 ± 11 years and 50% of patients were male. The image quality scores were higher using the 32-channel coil (mean 3.8 ± 0.7 vs 3.2 ± 0.9 p = 0.002). The average phantom SNR was greater for the 32-element coil across the range of acceleration factors measured (103 vs 86 p = <0.001). Conclusions: The 32-channel coil produces significantly higher quality images and a higher SNR than the 5-channel coil in routine perfusion CMR.展开更多
Patch clamp techniques were applied to investigating the regulation of the inward K^+channels in Vicia stomatal guard cells by cytoskeletal microtubules. The intracellular addition of either microtubule-disassembling ...Patch clamp techniques were applied to investigating the regulation of the inward K^+channels in Vicia stomatal guard cells by cytoskeletal microtubules. The intracellular addition of either microtubule-disassembling reagent amprophos-methyl (APM) or microtubule-stabilizing reagent taxol resulted in significant inhibition of the inward K^+ -currents across the plasma membranes of Vicia stomatal guard cells. The results suggest that the activation of the inward K^+channels in stomatal guard cells requires proper dynamic organization of cytoskeletal microtubules. The regulation of the inward K^+-channels in guard cells by microtubules may mediate the regulation of stomatal movements by cytoskeleton.展开更多
AIM: To assess values of 24-h esophageal pH-monitoring parameters with dual-channel probe (distal and proximal channel) in children suspected of gastroesophageal reflux disease (GERD). METHODS: 264 children suspected ...AIM: To assess values of 24-h esophageal pH-monitoring parameters with dual-channel probe (distal and proximal channel) in children suspected of gastroesophageal reflux disease (GERD). METHODS: 264 children suspected of gastroesophageal reflux (GER) were enrolled in a study (mean age χ = 20.78 ± 17.23 mo). The outcomes of this study, immunoallerrgological tests and positive result of oral food challenge test with a potentially noxious nutrient, enabled to qualify children into particular study groups. RESULTS: 32 (12.1%) infants (group 1) had physiological GER diagnosed. Pathological acid GER was confirmed in 138 (52.3%) children. Primary GER was diagnosed in 76 (28.8%) children (group 2) and GER secondary to allergy to cow milk protein and/or other food (CMA/FA) in 62 (23.5%) children (group 3). 32 (12.1%) of them had CMA/FA (group 4-reference group), and in remaining 62 (23.5%) children neither GER nor CMA/FA was confirmed (group 5). Mean values of pH monitoring parameters measured in distal and proximal channel were analyzed in individual groups. This analysis showed statistically significant differentiation of mean values in the case of: number of episodes of acid GER, episodes of acid GER lasting > 5 min, duration of the longest episode of acid GER in both channels, acid GER index total and supine in proximal channel. Statistically significant differences of mean values among examined groups, especially between group 2 and 3 in the case of total acid GER index (only distal channel) were confirmed. CONCLUSION: 24-h esophageal pH monitoring confirmed pathological acid GER in 52.3% of children with typical and atypical symptoms of GERD. The similar pH-monitoring values obtained in group 2 and 3 confirm the necessity of implementation of differential diagnosis for primary vs secondary cause of GER.展开更多
Patch clamping whole-cell recording techniques were applied to study the inward K + -channels in ,Ara-bidopsis root cortex cells. The inward K+-channels in the plasma membranes of the root cortex cell protoplasts were...Patch clamping whole-cell recording techniques were applied to study the inward K + -channels in ,Ara-bidopsis root cortex cells. The inward K+-channels in the plasma membranes of the root cortex cell protoplasts were activated by hyperpolarized membrane potentials. The channels were miglv selective tor K + ions over Na + ions. The channel activity was significantly inhibited by the external TEA+, or Ba2+ The changes in eytoplasmic Ca2+ concentrations did not affect the whole-cell inward K + -currents. The possible asoeiation between the ehannel selectivity to K+ and Na+ ions and plant salt-toleranee was also discussed.展开更多
This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF...This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF） uses dynamic constraints in conjunction with projections of data onto parabolic cylinder functions to determine the amplitude of all equatorial waves.EWEIF allows us to decompose an instantaneous wave flow into individual equatorial waves with a presumed equivalent depth without using temporal or spatial filtering a priori.Three sets of EWEIF analyses are presented. The first set is to confirm that EWEIF is capable of recovering the individual waves constructed from theoretical equatorial wave solutions under various scenarios. The other two sets demonstrate the ability of the EWEIF method to derive time series of individual equatorial waves from instantaneous wave fields without knowing a priori exactly which waves exist in the data as well as their spatial and temporal scales using outputs of an equatorial β-channel shallow-water model and ERA-Interim data. The third set of demonstrations shows, for the first time, the continuous evolutions of individual equatorial waves in the stratosphere whose amplitude is synchronized with the background zonal wind as predicted by quasi-biennial oscillation theory.展开更多
One of the detrimental effects of high salmity on plant cells is considered to be the result of an ion imbalance, particularly a high ratio of Na^+ to K^+ ions, in the cytoplasm. Such an imbalance is probably due to a...One of the detrimental effects of high salmity on plant cells is considered to be the result of an ion imbalance, particularly a high ratio of Na^+ to K^+ ions, in the cytoplasm. Such an imbalance is probably due to a great increase of entry of Na^+ ions into cells and a decline in absorption of K^+ ions under high-salinity conditions. Thus, plant cells展开更多
Based on cross-gain modulation of Amplified Spontaneous Emission (ASE) in Semiconductor Optical Amplifier (SOA), single to 16-channel wavelength conversion at 10Gb/s is first demonstrated simultaneously without any ad...Based on cross-gain modulation of Amplified Spontaneous Emission (ASE) in Semiconductor Optical Amplifier (SOA), single to 16-channel wavelength conversion at 10Gb/s is first demonstrated simultaneously without any additional probe lights.展开更多
Previous data showed that a Na+-transmem-brane flux was accompanied with acrosome reaction of sperm. However, the electrophysiological recording and characterization of Na+ current in human sperm membrane have not bee...Previous data showed that a Na+-transmem-brane flux was accompanied with acrosome reaction of sperm. However, the electrophysiological recording and characterization of Na+ current in human sperm membrane have not been yet reported. In the present investigation, membrane proteins extracted from human sperms were reassembled into liposome bilayer, and then the liposomes were fused by dehydration-rehydration into giant liposomes with the diameter of more than 10μm. By patch clamping the giant liposomes two kinds of single channel currents were recorded in a NaCl solution system. Both of them were Na+-carried, TTX-sensitive and strongly rectifying, but with different unit conductance and open probability. Moreover, bursting activity and channel-substates as well as two open time constants were observed in the larger channel.展开更多
基金supported by the National Key R&D Program of China(No.2018YFA0404404)the National Natural Science Foundation of China(Nos.11635015,U1732145,11705285,11805280,U1867212,and 11961131012)the Continuous Basic Scientific Research Project(No.WDJC-2019-13).
文摘In this study,a compact 16-channel integrated charge-sensitive preamplifier named the smart preamplifier(SPA)was developed to support the large-scale detector array used in modern nuclear physics experiments.Two types of SPA,namely SPA02 and SPA03(with external field effect transistor),have been manufactured to match silicon detectors with small and large capacitances,respectively.The characteristics of the SPA include fast response of typically less than 6 ns for pulse rising time and low equivalent noise of 1.5 keV at zero input capacitance.The energy sensitivity and pulse decay time can be easily adjusted by changing the feedback capacitance Cfand resistance Rfin various applications.A good energy resolution of 24.4 keV for 5.803-MeV alpha particles from 244 Cm was achieved using a small-sized Si-PIN detector;for the silicon strip detectors in the test with the alpha source,a typical energy resolution of 0.6–0.8%was achieved.The integrated SPA has been employed in several experiments of silicon strip detectors with hundreds of channels,and a good performance has been realized.
文摘Plasticity of cerebellar Purkinje cells(PC)is influenced by progeste rone via the classical progeste rone receptors PR-A and PR-B by stimulating dendritogenesis,spinogenesis,and synaptogenesis in these cells.Dissociated PC cultures were used to analyze progeste rone effects at a molecular level on the voltage-gated T-type-Ca^(2+)-channels Ca_(v)3.1,Ca_(v)3.2,and Ca_(v)3.3 as they helped determine neuronal plasticity by regulating Ca^(2+)-influx in neuronal cells.The results showed direct effects of progesterone on the mRNA expression of T-type-Ca^(2+)-channels,as well as on the protein kinases A and C being involved in downstream signaling pathways that play an important role in neuronal plasticity.For the mRNA expression studies of T-type-Ca^(2+)-channels and protein kinases of the signaling cascade,laser microdissection and purified PC cultures of diffe rent maturation stages were used.Immunohistochemical staining was also performed to characte rize the localization of T-type-Ca^(2+)-channels in PC.Expe rimental progesterone treatment was performed on the purified PC culture for 24 and 48 hours.Our results show that progesterone increases the expression of Ca_(v)3.1 and Ca_(v)3.3 and associated protein kinases A and Cin PC at the mRNA level within 48 hours after treatment at latest.These effects extend the current knowledge of the function of progesterone in the central nervous system and provide an explanatory approach for its influence on neuronal plasticity.
基金supported by the National Natural Science Foundation of China(No.11527811)the Key Program of State Key Laboratory of Particle Detection and ElectronicsA part of the work performed in the UKRI ISIS Detector Group was sponsored by the China Scholarship Council
文摘An experimental muon source(EMuS) will be built at the China Spallation Neutron Source(CSNS). In phase I of CSNS, it has been decided that EMuS will provide a proton beam of 5 kW and 1.6 GeV to generate muon beams. A 128-channel muon spin rotation/relaxation/resonance(μSR) spectrometer is proposed as a prototype surface muon spectrometer in a sub-branch of EMuS. The prototype spectrometer includes a detection system, sample environment, and supporting mechanics. The current design has two rings located at the forward and backward directions of the muon spin with 64 detectors per ring. The simulation shows that the highest asymmetry of approximately 0.28 is achieved by utilizing two 10-mm-thick brass degraders. To obtain the optimal asymmetry, the two-ring structure is updated to a four-ring structure with 32 segments in each ring. An asymmetry of 0.42 is obtained through the simulation, which is higher than that of all the current μSR spectrometers in the world.
基金Projects 07KJZ11 supported by the President Fund of Xuzhou Medical School07KJB310117 by the Education Department of Jiangsu Province
文摘Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform sampling signal was deduced. First we obtained an expression for the S/N ratio of a 1-channel A/D uniform sampling signal when the sampling frequency was equal to or greater than 2 times the frequency of the sampled signal. Based on the S/N ratio of a 2-channel A/D,alternating,non-uniform sampling signal,we analyzed the distribution of quantitative error using the quantitative error probability density method and the distribution convolution formula. From this the S/N ratio expression of a 4-channel A/D sampling signal was deduced. The simulation result shows that the deduced expression is correct.
文摘Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).
基金Supported by the National Basic Research Program of China("973"Program,No.2011CB610505)National Natural Science Foundation of China(No.61240038)
文摘A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fly line,screening box and shielded wire.The EN data were acquired from two Q235 carbon steel specimens placed in 0.5 mol/L H2SO4 solution and 0.1 mol/L NaCl solution.The experimental result shows that this system can achieve an accuracy of 10 pA and 10 μV,and it can be applied to on-site multi-channel EN test.
文摘Purpose: Adenosine stress CMR is commonly used to assess myocardial ischaemia. Obtaining high quality images requires maximising signal to noise ratio (SNR) over a large double-oblique field of view (FOV) whilst minimising artefacts. A 32-channel surface coil may provide a higher SNR over a larger FOV compared to standard coils, possibly leading to improved image quality. Materials and Methods: 50 adenosine perfusion CMR scans were performed on a Philips Achieva CV 1.5T, with either a 5 or 32-channel coil (25 patients each) using standardised acquisition protocols. 3 short axis slices were acquired per cardiac cycle and the resulting cine images were scored by two blinded CMR specialists on a quality scale of 1 to 5. Phantom studies were performed using similar acquisition parameters and the SNR was calculated and compared across a range of acceleration factors. Results: The mean patient age was 62 ± 11 years and 50% of patients were male. The image quality scores were higher using the 32-channel coil (mean 3.8 ± 0.7 vs 3.2 ± 0.9 p = 0.002). The average phantom SNR was greater for the 32-element coil across the range of acceleration factors measured (103 vs 86 p = <0.001). Conclusions: The 32-channel coil produces significantly higher quality images and a higher SNR than the 5-channel coil in routine perfusion CMR.
文摘Patch clamp techniques were applied to investigating the regulation of the inward K^+channels in Vicia stomatal guard cells by cytoskeletal microtubules. The intracellular addition of either microtubule-disassembling reagent amprophos-methyl (APM) or microtubule-stabilizing reagent taxol resulted in significant inhibition of the inward K^+ -currents across the plasma membranes of Vicia stomatal guard cells. The results suggest that the activation of the inward K^+channels in stomatal guard cells requires proper dynamic organization of cytoskeletal microtubules. The regulation of the inward K^+-channels in guard cells by microtubules may mediate the regulation of stomatal movements by cytoskeleton.
基金Supported by Grant of State Committee for Scientific Research (KBN) No 4P05E 04719
文摘AIM: To assess values of 24-h esophageal pH-monitoring parameters with dual-channel probe (distal and proximal channel) in children suspected of gastroesophageal reflux disease (GERD). METHODS: 264 children suspected of gastroesophageal reflux (GER) were enrolled in a study (mean age χ = 20.78 ± 17.23 mo). The outcomes of this study, immunoallerrgological tests and positive result of oral food challenge test with a potentially noxious nutrient, enabled to qualify children into particular study groups. RESULTS: 32 (12.1%) infants (group 1) had physiological GER diagnosed. Pathological acid GER was confirmed in 138 (52.3%) children. Primary GER was diagnosed in 76 (28.8%) children (group 2) and GER secondary to allergy to cow milk protein and/or other food (CMA/FA) in 62 (23.5%) children (group 3). 32 (12.1%) of them had CMA/FA (group 4-reference group), and in remaining 62 (23.5%) children neither GER nor CMA/FA was confirmed (group 5). Mean values of pH monitoring parameters measured in distal and proximal channel were analyzed in individual groups. This analysis showed statistically significant differentiation of mean values in the case of: number of episodes of acid GER, episodes of acid GER lasting > 5 min, duration of the longest episode of acid GER in both channels, acid GER index total and supine in proximal channel. Statistically significant differences of mean values among examined groups, especially between group 2 and 3 in the case of total acid GER index (only distal channel) were confirmed. CONCLUSION: 24-h esophageal pH monitoring confirmed pathological acid GER in 52.3% of children with typical and atypical symptoms of GERD. The similar pH-monitoring values obtained in group 2 and 3 confirm the necessity of implementation of differential diagnosis for primary vs secondary cause of GER.
基金Project supported by the National Natural Science Foundation of China (Grant No. 39470359)
文摘Patch clamping whole-cell recording techniques were applied to study the inward K + -channels in ,Ara-bidopsis root cortex cells. The inward K+-channels in the plasma membranes of the root cortex cell protoplasts were activated by hyperpolarized membrane potentials. The channels were miglv selective tor K + ions over Na + ions. The channel activity was significantly inhibited by the external TEA+, or Ba2+ The changes in eytoplasmic Ca2+ concentrations did not affect the whole-cell inward K + -currents. The possible asoeiation between the ehannel selectivity to K+ and Na+ ions and plant salt-toleranee was also discussed.
基金supported by grants from the National Science Foundation(Grant No.AGS-1354834)the NASA Interdisciplinary Studies Program(Grant No.NNH12ZDA001NIDS)
文摘This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF） uses dynamic constraints in conjunction with projections of data onto parabolic cylinder functions to determine the amplitude of all equatorial waves.EWEIF allows us to decompose an instantaneous wave flow into individual equatorial waves with a presumed equivalent depth without using temporal or spatial filtering a priori.Three sets of EWEIF analyses are presented. The first set is to confirm that EWEIF is capable of recovering the individual waves constructed from theoretical equatorial wave solutions under various scenarios. The other two sets demonstrate the ability of the EWEIF method to derive time series of individual equatorial waves from instantaneous wave fields without knowing a priori exactly which waves exist in the data as well as their spatial and temporal scales using outputs of an equatorial β-channel shallow-water model and ERA-Interim data. The third set of demonstrations shows, for the first time, the continuous evolutions of individual equatorial waves in the stratosphere whose amplitude is synchronized with the background zonal wind as predicted by quasi-biennial oscillation theory.
基金Project supported by the National Natural Science Foundation of China.
文摘One of the detrimental effects of high salmity on plant cells is considered to be the result of an ion imbalance, particularly a high ratio of Na^+ to K^+ ions, in the cytoplasm. Such an imbalance is probably due to a great increase of entry of Na^+ ions into cells and a decline in absorption of K^+ ions under high-salinity conditions. Thus, plant cells
文摘Based on cross-gain modulation of Amplified Spontaneous Emission (ASE) in Semiconductor Optical Amplifier (SOA), single to 16-channel wavelength conversion at 10Gb/s is first demonstrated simultaneously without any additional probe lights.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 98700197).
文摘Previous data showed that a Na+-transmem-brane flux was accompanied with acrosome reaction of sperm. However, the electrophysiological recording and characterization of Na+ current in human sperm membrane have not been yet reported. In the present investigation, membrane proteins extracted from human sperms were reassembled into liposome bilayer, and then the liposomes were fused by dehydration-rehydration into giant liposomes with the diameter of more than 10μm. By patch clamping the giant liposomes two kinds of single channel currents were recorded in a NaCl solution system. Both of them were Na+-carried, TTX-sensitive and strongly rectifying, but with different unit conductance and open probability. Moreover, bursting activity and channel-substates as well as two open time constants were observed in the larger channel.
