[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived f...[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.展开更多
An experimental measurement of the lifetime of 3d^(9) ^(2)D_(3/2) metastable level in Mo^(15+)is reported in this work.The Mo^(15+)ions are produced and trapped in an electron beam ion trap with a magnetic field of 0....An experimental measurement of the lifetime of 3d^(9) ^(2)D_(3/2) metastable level in Mo^(15+)is reported in this work.The Mo^(15+)ions are produced and trapped in an electron beam ion trap with a magnetic field of 0.65 T.The decay photons emitted from 3d^(9) ^(2)D_(3/2) level are subsequently recorded via a cooled photomultiplier tube.Through meticulous scrutiny of potential systematic uncertainties affecting the measurement outcomes,we have determined the lifetime of Mo^(15+)3d^(9)2D_(3/2)metastable level to be 2.83(22)ms.The experimental result provides a clear distinguishment from existing calculations based on various theoretical approaches.展开更多
A liquid-nitrogen cryogenic40Ca^(+)optical clock is presented that is designed to greatly reduce the blackbody radiation(BBR) shift. The ion trap, the electrodes and the in-vacuum BBR shield are installed under the li...A liquid-nitrogen cryogenic40Ca^(+)optical clock is presented that is designed to greatly reduce the blackbody radiation(BBR) shift. The ion trap, the electrodes and the in-vacuum BBR shield are installed under the liquid-nitrogen container,keeping the ions in a cryogenic environment at liquid-nitrogen temperature. Compared with the first design in our previous work, many improvements have been made to increase the performance. The liquid-nitrogen maintenance time has been increased by about three times by increasing the volume of the liquid-nitrogen container;the trap position recovery time after refilling the liquid-nitrogen container has been decreased more than three times by using a better fixation scheme in the liquid-nitrogen container;and the magnetic field noise felt by the ions has been decreased more than three times by a better design of the magnetic shielding system. These optimizations make the scheme for reducing the BBR shift uncertainty of liquid-nitrogen-cooled optical clocks more mature and stable, and develop a stable lock with a narrower linewidth spectrum,which would be very beneficial for further reducing the overall systematic uncertainty of optical clocks.展开更多
With the expansion of herbal medicine (HM) market, the issue on how to apply up-to- date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention...With the expansion of herbal medicine (HM) market, the issue on how to apply up-to- date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOF-MS) and ion trap mass spectrometry (IT-MS) is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis (2006-2011). The advantages and future developments of LC coupled with IT and TOF-MS are highlighted.展开更多
The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built i...The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.展开更多
We propose an effective scheme for the entanglement concentration of a four-particle state via entanglement swapping in an ion trap. Taking the maximally entangled state after concentration as a quantum channel, we ca...We propose an effective scheme for the entanglement concentration of a four-particle state via entanglement swapping in an ion trap. Taking the maximally entangled state after concentration as a quantum channel, we can faithfully and determinatively teleport quantum entangled states from Alice to Bob without the joint Bell-state measurement. In the process of constructing the quantum channel, we adopt entanglement swapping to avoid the decrease of entanglement during the distribution of particles. Thus our scheme provides a new prospect for quantum teleportation over a longer distance. Furthermore, the success probability of our scheme is 1.0.展开更多
This paper reports that a quantum dense coding can be implemented with ions confined in a linear trap and interacting with laser beams. The scheme is insensitive to the interaction between the quantum channel and the ...This paper reports that a quantum dense coding can be implemented with ions confined in a linear trap and interacting with laser beams. The scheme is insensitive to the interaction between the quantum channel and the environment. The Bell-state measurement is not involved and the probability of success in our scheme is 1.0.展开更多
Two schemes for the implementation of the two-qubit Grover search algorithm in the ion trap system are proposed. These schemes might be experimentally realizable with presently available techniques. The experimental i...Two schemes for the implementation of the two-qubit Grover search algorithm in the ion trap system are proposed. These schemes might be experimentally realizable with presently available techniques. The experimental implementation of the schemes would be an important step toward more complex quantum computation in the ion trap system.展开更多
We propose a practical scheme to generate cluster states by simultaneously accomplishing two-qubit conditional gating on an array of equidistant ions by using transverse modes. Our operation is robust to heating and i...We propose a practical scheme to generate cluster states by simultaneously accomplishing two-qubit conditional gating on an array of equidistant ions by using transverse modes. Our operation is robust to heating and insensitive to Lamb-Dicke parameter. Meanwhile, as it is carried out in a geometric quantum computing fashion, our scheme enables the fast and high-fidelity generation of cluster states. The experimental feasibility is discussed with sophisticated ion trap techniques.展开更多
In this scheme, two quantum oscillators in a planar radio frequency ion trap are coupled by the trap electrodes. The ions motional states encode the quantum bits (qubits), and a swap gate could be achieved. Under di...In this scheme, two quantum oscillators in a planar radio frequency ion trap are coupled by the trap electrodes. The ions motional states encode the quantum bits (qubits), and a swap gate could be achieved. Under different conditions of the experiments, the intensity of the coupling between'two quantum oscillators and the dissipation of the system are calculated. We compute fidelities for a quantum swap gate and discuss experimental issues.展开更多
We describe a new electrode design for a grooved surface-electrode ion trap,which is fabricated in printed-circuitboard technology with segmented electrodes.This design allows a laser beam to get through the central g...We describe a new electrode design for a grooved surface-electrode ion trap,which is fabricated in printed-circuitboard technology with segmented electrodes.This design allows a laser beam to get through the central groove to avoid optical access blocking and laser scattering from the ion trap surface.The confining potentials are modeled both analytically and numerically.We optimize the radio frequency(rf) electrodes and dc electrodes to achieve the maximum trap depth for a given ion height above the trap electrodes.We also compare our design with the reality ion chip MI I for practical considerations.Comparison results show that our design is superior to MI I.This ion trap design may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers.展开更多
We report measurement of heating rates of 40 Ca+ ions confined in our home-made microscopic surface-electrode trap by a Doppler recooling method. The ions are trapped with approximately 800 μm above the surface, and...We report measurement of heating rates of 40 Ca+ ions confined in our home-made microscopic surface-electrode trap by a Doppler recooling method. The ions are trapped with approximately 800 μm above the surface, and are subjected to heating due to various noises in the trap. There are 3-5 ions involved to measure the heating rates precisely and efficiently. We show the heating rates in variance with the number and the position of the ions as well as the radio-frequency power, which are helpful for understanding the trap imperfection.展开更多
In this study,we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin(TTX) in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrup...In this study,we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin(TTX) in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry(LC-QqLIT-MS).TTX was extracted by 1% acetic acid-methanol,and most of the lipids were then removed by freezing lipid precipitation,followed by purification and concentration using irnmunoaffinity columns(IACs).Matrix effects were substantially reduced due to the high specificity of the IACs,and thus,background interference was avoided.Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase.The method was evaluated by fortifying samples at 1,10,and 100 ng/g,respectively,and the recoveries ranged from 75.8%-107%,with a relative standard deviation of less than 15%.The TTX calibration curves were linear over the range of 1-1 000 ng/L,with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g.Using this method,samples can be further analyzed using an informationdependent acquisition(IDA) experiment,in the positive mode,from a single liquid chromatography-tandem mass spectrometry injection,which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion(EPI) library.The scheduled multiple reaction monitoring method enabled TTX to be screened for,and TTX was positively identified using the IDA and EPI spectra.This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products.The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility,and is suitable for the analysis of complex matrix pufferfish samples.展开更多
This paper proposes an experimentally feasible scheme for implementing quantum dense coding of trapped-ion system in decoherence-free states. As the phase changes due to time evolution of components with different eig...This paper proposes an experimentally feasible scheme for implementing quantum dense coding of trapped-ion system in decoherence-free states. As the phase changes due to time evolution of components with different eigenenergies of quantum superposition are completely frozen, quantum dense coding based on this model would be perfect. The scheme is insensitive to heating of vibrational mode and Bell states can be exactly distinguished via detecting the ionic state.展开更多
A brief introduction to the historical background and current status of electron beam ion traps (EBITs)is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally,EBI...A brief introduction to the historical background and current status of electron beam ion traps (EBITs)is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally,EBITs as a potential tool in hot-plasma diagnostics and in studying frontier problems of highly charged ion physicsare discussed.展开更多
Quantum computing requires ultracold ions in a ground vibrational state, which is achieved by sideband cooling. We report our recent efforts towards the Lamb Dicke regime which is a prerequisite of sideband cooling. W...Quantum computing requires ultracold ions in a ground vibrational state, which is achieved by sideband cooling. We report our recent efforts towards the Lamb Dicke regime which is a prerequisite of sideband cooling. We first analyse the possible imperfection in our linear ion trap setup and then demonstrate how to suppress the imperfection by compensating the excess micromotion of the ions. The ions, after the micromotion compensation, are estimated to be very close to the Doppler-cooling limit.展开更多
This paper reports that a cloud of laser-cooled ^40Ca^+ is successfully trapped and manipulated in the home-built linear ion trap constructed for quantum information processing (QIP). The frequency of the secular m...This paper reports that a cloud of laser-cooled ^40Ca^+ is successfully trapped and manipulated in the home-built linear ion trap constructed for quantum information processing (QIP). The frequency of the secular motion and the space charge density of the ion cloud are measured, which help knowing the characteristic of the trapping potential and are the prerequisite of QIP with the trapped ions.展开更多
Based on squeezed operators this paper has implemented an ideal unconventional geometric quantum gate (GQG) in ion trap-optical cavity system by radiating the trapped ions with the cavity field of frequency ωc and ...Based on squeezed operators this paper has implemented an ideal unconventional geometric quantum gate (GQG) in ion trap-optical cavity system by radiating the trapped ions with the cavity field of frequency ωc and an external laser field of frequency ωL. It can ensure that the gate time is shorter than the coherence time for qubits and the decay time of the optical cavity by appropriately tuning the ionic transition frequency ω0, the frequencies of the cavity mode ωc and the vibrational mode v. It has also realized the unconventional GQG under the influence of the cavity decay based on the squeezed-like operators and found that the present scheme works well for the smaller cavity decay by investigating the corresponding fidelity and success probability.展开更多
We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational...We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational frequency and thus the time required to complete the operation is greatly shortened, which is of importance in view of decoherence.展开更多
基金Supported by Scientific Research Project of Dalian Customs(2022DK09).
文摘[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1602500)the National Natural Science Foundation of China(Grant No.12274352)。
文摘An experimental measurement of the lifetime of 3d^(9) ^(2)D_(3/2) metastable level in Mo^(15+)is reported in this work.The Mo^(15+)ions are produced and trapped in an electron beam ion trap with a magnetic field of 0.65 T.The decay photons emitted from 3d^(9) ^(2)D_(3/2) level are subsequently recorded via a cooled photomultiplier tube.Through meticulous scrutiny of potential systematic uncertainties affecting the measurement outcomes,we have determined the lifetime of Mo^(15+)3d^(9)2D_(3/2)metastable level to be 2.83(22)ms.The experimental result provides a clear distinguishment from existing calculations based on various theoretical approaches.
基金supported by the National Key R&D Program of China (Grant Nos. 2022YFB3904001 and 2018YFA0307500)the National Natural Science Foundation of China (Grant Nos. 12121004 and 12022414)+4 种基金Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB21030100)CAS Project for Young Scientists in Basic Research (Grant No. YSBR055)CAS Youth Innovation Promotion Association (Grant Nos. Y201963 and Y2022099)the Natural Science Foundation of Hubei Province (Grant No. 2022CFA013)the Interdisciplinary Cultivation Project of the Innovation Academy for Precision Measurement of Science and Technology (Grant No. S21S2201)。
文摘A liquid-nitrogen cryogenic40Ca^(+)optical clock is presented that is designed to greatly reduce the blackbody radiation(BBR) shift. The ion trap, the electrodes and the in-vacuum BBR shield are installed under the liquid-nitrogen container,keeping the ions in a cryogenic environment at liquid-nitrogen temperature. Compared with the first design in our previous work, many improvements have been made to increase the performance. The liquid-nitrogen maintenance time has been increased by about three times by increasing the volume of the liquid-nitrogen container;the trap position recovery time after refilling the liquid-nitrogen container has been decreased more than three times by using a better fixation scheme in the liquid-nitrogen container;and the magnetic field noise felt by the ions has been decreased more than three times by a better design of the magnetic shielding system. These optimizations make the scheme for reducing the BBR shift uncertainty of liquid-nitrogen-cooled optical clocks more mature and stable, and develop a stable lock with a narrower linewidth spectrum,which would be very beneficial for further reducing the overall systematic uncertainty of optical clocks.
文摘With the expansion of herbal medicine (HM) market, the issue on how to apply up-to- date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOF-MS) and ion trap mass spectrometry (IT-MS) is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis (2006-2011). The advantages and future developments of LC coupled with IT and TOF-MS are highlighted.
基金financially supported by the National Key R&D Program of China(2018YFF0212503,2019YFF0216303,and 2016YFF0200502)the National Natural Science Foundation of China(21927812)the Research Project of the National Institute of Metrology(AKY1934)。
文摘The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.
基金Project supported by the National Natural Science Foundation of China (Grant No 10374025).
文摘We propose an effective scheme for the entanglement concentration of a four-particle state via entanglement swapping in an ion trap. Taking the maximally entangled state after concentration as a quantum channel, we can faithfully and determinatively teleport quantum entangled states from Alice to Bob without the joint Bell-state measurement. In the process of constructing the quantum channel, we adopt entanglement swapping to avoid the decrease of entanglement during the distribution of particles. Thus our scheme provides a new prospect for quantum teleportation over a longer distance. Furthermore, the success probability of our scheme is 1.0.
基金Project supported by the Key Education Foundation of Hunan Province, China (Grant No 06A038)
文摘This paper reports that a quantum dense coding can be implemented with ions confined in a linear trap and interacting with laser beams. The scheme is insensitive to the interaction between the quantum channel and the environment. The Bell-state measurement is not involved and the probability of success in our scheme is 1.0.
基金Project supported by Fok Ying Tung Education Foundation (Grant No 81008), the National Natural Science Foundation of China (Grant Nos 60008003 and 10225421), and Funds from Fuzhou University, China.
文摘Two schemes for the implementation of the two-qubit Grover search algorithm in the ion trap system are proposed. These schemes might be experimentally realizable with presently available techniques. The experimental implementation of the schemes would be an important step toward more complex quantum computation in the ion trap system.
基金supported by the National Natural Science Foundation of China (Grant Nos.10774163 and 10804132)
文摘We propose a practical scheme to generate cluster states by simultaneously accomplishing two-qubit conditional gating on an array of equidistant ions by using transverse modes. Our operation is robust to heating and insensitive to Lamb-Dicke parameter. Meanwhile, as it is carried out in a geometric quantum computing fashion, our scheme enables the fast and high-fidelity generation of cluster states. The experimental feasibility is discussed with sophisticated ion trap techniques.
基金Project supported by the Ministry of Science and Technology of China (Grant No. 2005CB724500)the National Natural Science Foundation of China (Grant Nos. 60490280 and 10874205)
文摘In this scheme, two quantum oscillators in a planar radio frequency ion trap are coupled by the trap electrodes. The ions motional states encode the quantum bits (qubits), and a swap gate could be achieved. Under different conditions of the experiments, the intensity of the coupling between'two quantum oscillators and the dissipation of the system are calculated. We compute fidelities for a quantum swap gate and discuss experimental issues.
基金Project supported by the National Natural Science Foundation of China (Grant No. 1097421)
文摘We describe a new electrode design for a grooved surface-electrode ion trap,which is fabricated in printed-circuitboard technology with segmented electrodes.This design allows a laser beam to get through the central groove to avoid optical access blocking and laser scattering from the ion trap surface.The confining potentials are modeled both analytically and numerically.We optimize the radio frequency(rf) electrodes and dc electrodes to achieve the maximum trap depth for a given ion height above the trap electrodes.We also compare our design with the reality ion chip MI I for practical considerations.Comparison results show that our design is superior to MI I.This ion trap design may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers.
基金Supported by the National Natural Science Foundation of China under Grant Nos Y5Z2111001,91421111 and 11674360
文摘We report measurement of heating rates of 40 Ca+ ions confined in our home-made microscopic surface-electrode trap by a Doppler recooling method. The ions are trapped with approximately 800 μm above the surface, and are subjected to heating due to various noises in the trap. There are 3-5 ions involved to measure the heating rates precisely and efficiently. We show the heating rates in variance with the number and the position of the ions as well as the radio-frequency power, which are helpful for understanding the trap imperfection.
基金Supported by the National Natural Science Foundation of China(No.41106109)the China National Food Safety Standards Development Project(No.ZHENGHE-2015-356)
文摘In this study,we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin(TTX) in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry(LC-QqLIT-MS).TTX was extracted by 1% acetic acid-methanol,and most of the lipids were then removed by freezing lipid precipitation,followed by purification and concentration using irnmunoaffinity columns(IACs).Matrix effects were substantially reduced due to the high specificity of the IACs,and thus,background interference was avoided.Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase.The method was evaluated by fortifying samples at 1,10,and 100 ng/g,respectively,and the recoveries ranged from 75.8%-107%,with a relative standard deviation of less than 15%.The TTX calibration curves were linear over the range of 1-1 000 ng/L,with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g.Using this method,samples can be further analyzed using an informationdependent acquisition(IDA) experiment,in the positive mode,from a single liquid chromatography-tandem mass spectrometry injection,which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion(EPI) library.The scheduled multiple reaction monitoring method enabled TTX to be screened for,and TTX was positively identified using the IDA and EPI spectra.This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products.The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility,and is suitable for the analysis of complex matrix pufferfish samples.
基金Project supported by the Important Program of Hunan Provincial Education Department (Grant No 06A038)Department of Education of Hunan Province (Grant No 06C080)Hunan Provincial Natural Science Foundation,China (Grant No 06JJ4003)
文摘This paper proposes an experimentally feasible scheme for implementing quantum dense coding of trapped-ion system in decoherence-free states. As the phase changes due to time evolution of components with different eigenenergies of quantum superposition are completely frozen, quantum dense coding based on this model would be perfect. The scheme is insensitive to heating of vibrational mode and Bell states can be exactly distinguished via detecting the ionic state.
基金the Outstanding Young Scientist Program of the Natural Science Foundation of China(No.10125520)by the Outstanding Young Professor Project of the Ministry of Education of China
文摘A brief introduction to the historical background and current status of electron beam ion traps (EBITs)is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally,EBITs as a potential tool in hot-plasma diagnostics and in studying frontier problems of highly charged ion physicsare discussed.
基金Project supported by the National Natural Science Foundation of China (Grants Nos. 10974225 and 11104325)the NCETPC(Grant No. NCET-10-0850)+1 种基金the Fundamental Research Funds for Central Universities of Chinathe National Fundamental Research Program of China (Grant No. 2012CB922102)
文摘Quantum computing requires ultracold ions in a ground vibrational state, which is achieved by sideband cooling. We report our recent efforts towards the Lamb Dicke regime which is a prerequisite of sideband cooling. We first analyse the possible imperfection in our linear ion trap setup and then demonstrate how to suppress the imperfection by compensating the excess micromotion of the ions. The ions, after the micromotion compensation, are estimated to be very close to the Doppler-cooling limit.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10774161,10774163 and 10974225)by National Fundamental Research Program of China (Grant No. 2006CB921203)
文摘This paper reports that a cloud of laser-cooled ^40Ca^+ is successfully trapped and manipulated in the home-built linear ion trap constructed for quantum information processing (QIP). The frequency of the secular motion and the space charge density of the ion cloud are measured, which help knowing the characteristic of the trapping potential and are the prerequisite of QIP with the trapped ions.
基金Project supported by the National Natural Science Foundation of China (Grant No 60667001)the Science Foundation of Yanbian University in China (Grant No 2007-31)
文摘Based on squeezed operators this paper has implemented an ideal unconventional geometric quantum gate (GQG) in ion trap-optical cavity system by radiating the trapped ions with the cavity field of frequency ωc and an external laser field of frequency ωL. It can ensure that the gate time is shorter than the coherence time for qubits and the decay time of the optical cavity by appropriately tuning the ionic transition frequency ω0, the frequencies of the cavity mode ωc and the vibrational mode v. It has also realized the unconventional GQG under the influence of the cavity decay based on the squeezed-like operators and found that the present scheme works well for the smaller cavity decay by investigating the corresponding fidelity and success probability.
基金The project supported by Fok Ying Tung Education Foundation under Grant No.81008+4 种基金
National Natural Science Foundation of China under Grant No.60008003
Natural Science Foundation of Fujian Province of China under Grant Nos.K20004 and F0110027
the Funds from Fuzhou University
文摘We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational frequency and thus the time required to complete the operation is greatly shortened, which is of importance in view of decoherence.
基金The project supported by Fok Ying Tung Education Foundation under Grant No. 81008, National Natural Science Foundation of China under Grant Nos. 60008003 and 10225421