We perform ^(23)Na nuclear magnetic resonance(NMR) and magnetization measurements on an S=1,quasi-2D honeycomb lattice antiferromagnet Na_(3)Ni_(2)BiO_(6).A large positive Curie-Weiss constant of 22.9 K is observed.Th...We perform ^(23)Na nuclear magnetic resonance(NMR) and magnetization measurements on an S=1,quasi-2D honeycomb lattice antiferromagnet Na_(3)Ni_(2)BiO_(6).A large positive Curie-Weiss constant of 22.9 K is observed.The NMR spectra at low fields are consistent with a zigzag magnetic order,indicating a large easy-axis anisotropy.With the field applied along the c*axis,the NMR spectra confirm the existence of a 1/3-magnetization plateau phase between 5.1 T and 7.1 T.The transition from the zigzag order to the 1/3-magnetization plateau phase is also found to be a first-order type.A monotonic decrease of the spin gap is revealed in the 1/3-magnetization plateau phase,which reaches zero at a quantum critical field H_(C)≈8.35 T before entering the fully polarized phase.These data suggest the existence of exchange frustration in the system along with strong ferromagnetic interactions,hosting the possibility for Kitaev physics.Besides,well below the ordered phase,the 1/T_(1) at high fields shows either a level off or an enhancement upon cooling below 3 K,which suggests the existence of low-energy fluctuations.展开更多
An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of ...An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.展开更多
The complete fusion reaction of^(55)Mn+^(159)Tb was studied on the gafilled recoil separator SHANS2.Nineteen ER-α1-α2 decay chains from^(210)Th produced from the 4n evaporation channel were observed.The a-particle e...The complete fusion reaction of^(55)Mn+^(159)Tb was studied on the gafilled recoil separator SHANS2.Nineteen ER-α1-α2 decay chains from^(210)Th produced from the 4n evaporation channel were observed.The a-particle energy and half-life of 210Th were determined as 7922(14)keV and 14(4)ms,respectively.In addition,the decay properties of Eα=7788(14)keV and T_(1/2)=36+15-8 ms were obtained for 21Th.The measured a decay prop-erties of^(210)Th and^(211)Th were consistent with literature data.The cross sections were measured to be 0.59+035 nb and 0.19-012 nb for^(210)Th and^(211)Th,respectively.The equilibrium charge state of the recoiled nucleus^(210)Th was determined experimentally.The new data were helpful for estimating the equilibrium charge states of elements 119 and 120,which could be produced via the^(240)Pu(^(55)Mn,3n)^(292)119 and^(243)Am(^(55)Mn,3m)^(295)120 reactions,respect-ively.展开更多
类风湿关节炎(rheumatoid arthritis,RA)是一种临床常见的以滑膜炎为主的自身免疫性疾病。炎性细胞因子和破骨细胞刺激滑膜组织增生、炎症反应、骨质破坏及关节功能障碍等,在RA的致病因素中占据关键位置。本文对中药单体及其提取物、中...类风湿关节炎(rheumatoid arthritis,RA)是一种临床常见的以滑膜炎为主的自身免疫性疾病。炎性细胞因子和破骨细胞刺激滑膜组织增生、炎症反应、骨质破坏及关节功能障碍等,在RA的致病因素中占据关键位置。本文对中药单体及其提取物、中药复方及制剂、中药配伍,以及中医治疗通过调控骨保护蛋白(osteoprotegerin,OPG)/NF-κB受体激活因子(receptor activator of NF-κB,RANK)/NF-κB配体激活因子(receptor activator of NF-κB ligand,RANKL)信号通路干预RA的相关研究进行综述。结果表明,中药中的有效分子机制不同,但是可以起到调控信号通路的作用,刺激成骨细胞活性,抑制炎性细胞因子分泌,减少破骨细胞分化,从而防治RA,为中医药多靶点、多途径治疗RA提供理论依据。展开更多
Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With prote...Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With protection against charge noise, the valley degree of freedom is also conceived to encode a qubit to realize noise-resistant quantum computing.Here, based on the spin qubit composed of one or three electrons, we characterize the intrinsic properties of valley in an isotopically enriched silicon quantum dot(QD) device. For one-electron qubit, we measure two electric-dipole spin resonance(EDSR) signals which are attributed to partial occupation of two valley states. The resonance frequencies of two EDSR signals have opposite electric field dependences. Moreover, we characterize the electric field dependence of the upper valley state based on three-electron qubit experiments. The difference of electric field dependences of the two valleys is 52.02 MHz/V, which is beneficial for tuning qubit frequency to meet different experimental requirements. As an extension of electrical control spin qubits, the opposite electric field dependence is crucial for qubit addressability,individual single-qubit control and two-qubit gate approaches in scalable quantum computing.展开更多
The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout pr...The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout process are sensitive to the choice of the thresholds and limited by the experimental hardware. By demonstrating the linear dependence between the measured spin state probabilities and readout visibilities along with dark counts, we describe an alternative threshold-independent method for the single-shot readout of spin qubits in semiconductor quantum dots. We can obtain the extrapolated spin state probabilities of the prepared probabilities of the excited spin state through the threshold-independent method. We then analyze the corresponding errors of the method, finding that errors of the extrapolated probabilities cannot be neglected with no constraints on the readout time and threshold voltage. Therefore, by limiting the readout time and threshold voltage, we ensure the accuracy of the extrapolated probability. We then prove that the efficiency and robustness of this method are 60 times larger than those of the most commonly used method. Moreover, we discuss the influence of the electron temperature on the effective area with a fixed external magnetic field and provide a preliminary demonstration for a single-shot readout of up to 0.7K/1.5T in the future.展开更多
基金Project supported by the National Key R&D Program of China (Grant Nos. 2023YFA1406500, 2022YFA1402700, and 2021YFA1400400)the National Natural Science Foundation of China (Grant Nos. 12134020, 12374156, 12104503,12061131004, 12225407, and 12074174)。
文摘We perform ^(23)Na nuclear magnetic resonance(NMR) and magnetization measurements on an S=1,quasi-2D honeycomb lattice antiferromagnet Na_(3)Ni_(2)BiO_(6).A large positive Curie-Weiss constant of 22.9 K is observed.The NMR spectra at low fields are consistent with a zigzag magnetic order,indicating a large easy-axis anisotropy.With the field applied along the c*axis,the NMR spectra confirm the existence of a 1/3-magnetization plateau phase between 5.1 T and 7.1 T.The transition from the zigzag order to the 1/3-magnetization plateau phase is also found to be a first-order type.A monotonic decrease of the spin gap is revealed in the 1/3-magnetization plateau phase,which reaches zero at a quantum critical field H_(C)≈8.35 T before entering the fully polarized phase.These data suggest the existence of exchange frustration in the system along with strong ferromagnetic interactions,hosting the possibility for Kitaev physics.Besides,well below the ordered phase,the 1/T_(1) at high fields shows either a level off or an enhancement upon cooling below 3 K,which suggests the existence of low-energy fluctuations.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China(No.2018YFE0310200)National Natural Science Foundation of China(Nos.11705242,11805138 and 12175156)the Fundamental Research Funds for the Central Universities in China(Nos.YJ201820 and YJ201954)。
文摘An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB34010000)the Guangdong Major Project of Basic and Applied Basic Research (2021B0301030006)+5 种基金the National Key R&D Program of China (2018YFA0404402)the CAS Project for Young Scientists in Basic Research (YSBR-002)the Youth Innovation Promotion Association CAS (2020409)the National Natural Science Foundation of China (11975279,11965003,12105328)the Special Research Assistant Project of the Chinese Academy of Sciencesthe Central Government Guidance Funds for Local Scientific and Technological Development,China (Guike ZY22096024)
文摘The complete fusion reaction of^(55)Mn+^(159)Tb was studied on the gafilled recoil separator SHANS2.Nineteen ER-α1-α2 decay chains from^(210)Th produced from the 4n evaporation channel were observed.The a-particle energy and half-life of 210Th were determined as 7922(14)keV and 14(4)ms,respectively.In addition,the decay properties of Eα=7788(14)keV and T_(1/2)=36+15-8 ms were obtained for 21Th.The measured a decay prop-erties of^(210)Th and^(211)Th were consistent with literature data.The cross sections were measured to be 0.59+035 nb and 0.19-012 nb for^(210)Th and^(211)Th,respectively.The equilibrium charge state of the recoiled nucleus^(210)Th was determined experimentally.The new data were helpful for estimating the equilibrium charge states of elements 119 and 120,which could be produced via the^(240)Pu(^(55)Mn,3n)^(292)119 and^(243)Am(^(55)Mn,3m)^(295)120 reactions,respect-ively.
基金supported by Chongqing Talent Plan:Leading Talents in Innovation and Entrepreneurship,China(No.CQYC201903051)University Innovation Research Group of Chongqing,China(No.CXQT20023)+4 种基金Qingnian Project of Science and Technology Research Program of Chongqing Municipal Education Commission,China(No.KJQN202001106)China Postdoctoral Science Foundation(No.2021M700556)Natural Science Foundation of Chongqing,China(No.cstc2021jcyj-bsh X0114)Natural Science Foundation of China(Nos.U20A20234,51874062)Chongqing Foundation and Advanced Research Project,China(No.cstc2019jcyj-zdxm X0010)。
文摘类风湿关节炎(rheumatoid arthritis,RA)是一种临床常见的以滑膜炎为主的自身免疫性疾病。炎性细胞因子和破骨细胞刺激滑膜组织增生、炎症反应、骨质破坏及关节功能障碍等,在RA的致病因素中占据关键位置。本文对中药单体及其提取物、中药复方及制剂、中药配伍,以及中医治疗通过调控骨保护蛋白(osteoprotegerin,OPG)/NF-κB受体激活因子(receptor activator of NF-κB,RANK)/NF-κB配体激活因子(receptor activator of NF-κB ligand,RANKL)信号通路干预RA的相关研究进行综述。结果表明,中药中的有效分子机制不同,但是可以起到调控信号通路的作用,刺激成骨细胞活性,抑制炎性细胞因子分泌,减少破骨细胞分化,从而防治RA,为中医药多靶点、多途径治疗RA提供理论依据。
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12074368, 92165207, 12034018, and 92265113)the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0302300)+1 种基金the Anhui Province Natural Science Foundation (Grant No. 2108085J03)the USTC Tang Scholarship。
文摘Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With protection against charge noise, the valley degree of freedom is also conceived to encode a qubit to realize noise-resistant quantum computing.Here, based on the spin qubit composed of one or three electrons, we characterize the intrinsic properties of valley in an isotopically enriched silicon quantum dot(QD) device. For one-electron qubit, we measure two electric-dipole spin resonance(EDSR) signals which are attributed to partial occupation of two valley states. The resonance frequencies of two EDSR signals have opposite electric field dependences. Moreover, we characterize the electric field dependence of the upper valley state based on three-electron qubit experiments. The difference of electric field dependences of the two valleys is 52.02 MHz/V, which is beneficial for tuning qubit frequency to meet different experimental requirements. As an extension of electrical control spin qubits, the opposite electric field dependence is crucial for qubit addressability,individual single-qubit control and two-qubit gate approaches in scalable quantum computing.
基金supported by the Chongqing Talent Plan:Leading Talents in Innovation and Entrepreneurship,China (No.CQYC201903051)the University Innovation Research Group of Chongqing,China (No.CXQT20023)+2 种基金the Chongqing Natural Science Foundation,China (No.CSTB2022NSCQ-MSX0326)the National Natural Science Foundation of China (No.51871038)the Basic Research and Frontier Exploration Project of Chongqing Science and Technology Commission,China (No.cstc2021ycjh-bgzxm0173).
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12074368,92165207,12034018,and 62004185)the Anhui Province Natural Science Foundation (Grant No.2108085J03)the USTC Tang Scholarship。
文摘The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout process are sensitive to the choice of the thresholds and limited by the experimental hardware. By demonstrating the linear dependence between the measured spin state probabilities and readout visibilities along with dark counts, we describe an alternative threshold-independent method for the single-shot readout of spin qubits in semiconductor quantum dots. We can obtain the extrapolated spin state probabilities of the prepared probabilities of the excited spin state through the threshold-independent method. We then analyze the corresponding errors of the method, finding that errors of the extrapolated probabilities cannot be neglected with no constraints on the readout time and threshold voltage. Therefore, by limiting the readout time and threshold voltage, we ensure the accuracy of the extrapolated probability. We then prove that the efficiency and robustness of this method are 60 times larger than those of the most commonly used method. Moreover, we discuss the influence of the electron temperature on the effective area with a fixed external magnetic field and provide a preliminary demonstration for a single-shot readout of up to 0.7K/1.5T in the future.
