The electrocatalysis reactions involving oxygen,such as oxygen evolution reaction(OER)and oxygen reduction reaction(ORR),play a critical role in energy storage/conversion applications,e.g.,fuel cells,metal-air batteri...The electrocatalysis reactions involving oxygen,such as oxygen evolution reaction(OER)and oxygen reduction reaction(ORR),play a critical role in energy storage/conversion applications,e.g.,fuel cells,metal-air batteries,and electrochemical water splitting.The high kinetic energy barrier of the OER/ORR is highly associated with the spin state interconversion between singlet OH^(−)/H_(2)O and triplet O_(2),which is influenced by the spin state and magnetism of catalysts.This Review summarizes recent progress and advances in understanding spin/magnetism-related effects in oxygen electrocatalysis to develop spin theory.It is demonstrated that the spin states(low,intermediate,and high spin)of magnetic transition metal catalysts(TMCs)can directly affect the reaction barriers of OER/ORR by tailoring the bonding of oxygen intermediates with TMCs.Besides,the spin states of TMCs can build a spin-selective channel to filter the electron spins required for the single/triplet interconversion of O species during OER/ORR.In this Review,we introduced many approaches to modulating spin state,for instance,altering the crystal field,oxidation state of active-site ions,and the morphology of TMCs.What’s more,a magnetic field can drive the spin flip of magnetic ions to achieve the spin alignment(↑↑)(i.e.,facilitating spin polarization),which will strengthen the spin selectivity for accelerating the filtration and transfer of the spins with the same direction for the generation and conversion of triplet ↑O=O↑.Importantly,the origin of magnetic field enhancement on OER/ORR are deeply discussed,which provides a great vision for the magnetism-assisted catalysis.Finally,the challenges and perspectives for future development of spin/magnetism catalysis are presented.This Review is expected to highlight the significance of spin/magnetism theory in breaking the bottleneck of electrocatalysis field and promote the development of high-efficientcy electrocatalysts for practical applications.展开更多
We explore the spin–orbit coupling(SOC) mechanism for structured light in coherent atomic media with low-light-level cross-Kerr nonlinearity. Using the five-level M-type electromagnetic induced transparency(EIT) syst...We explore the spin–orbit coupling(SOC) mechanism for structured light in coherent atomic media with low-light-level cross-Kerr nonlinearity. Using the five-level M-type electromagnetic induced transparency(EIT) system as a prototype, we show that spin–orbit splitting for a weak spinor image can be generated by a weak trigger field carrying orbital angular momentum(OAM) at low-light intensity. By quantum-optical analogy, the paraxial focusing and defocusing of the two pseudo-spin states in the spinor image can be governed by a Pauli-like equation. More importantly, by changing the EIT parameters, especially the topological charge of the weak trigger field, the SOC-induced radial quantization of the spinor image can be rather significant,giving rise to positive or negative OAM-OAM mode separation in free space. This suggests that the separation can be flexibly controlled due to strong image-vortex interaction based on fewphoton cross-Kerr modulation. Our findings may have the potential for all-optical OAM multiplexing and demultiplexing of structured light fields toward few-photon quantum control and multimode communication.展开更多
The behavior of lattice distortion in spin 1/2 antiferromagnetic XY models with random magnetic modulation is investigated with the consideration of spin-phonon coupling in the adiabatic limit. It is found that lattic...The behavior of lattice distortion in spin 1/2 antiferromagnetic XY models with random magnetic modulation is investigated with the consideration of spin-phonon coupling in the adiabatic limit. It is found that lattice distortion relies on the strength of the random modulation. For strong or weak enough spin phonon couplings, the average lattice distortion may decrease or increase as the random modulation is strengthened. This may be the result of competition between the random magnetic modulation and the spin phonon coupling.展开更多
In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magne...In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magnetometer studied can reduce the frequency noise of system and improve the magnetic sensitivity by microwave frequency modulation.Firstly,ESR spectra by sweeping the microwave frequency was obtained.Further,the microwave frequency modulated was gained through the mixed high-frequency sinusoidal modulation signal generated by signal generator.In addition,the frequency through the lock-in amplifier was locked,and the signal which was proportional to the first derivative of the spectrum was obtained.The experimental results show that the sensitivity of magnetic field detection can reach 17.628 nT/Hz based on microwave frequency modulation technology.The method realizes high resolution and sensitivity for magnetic field detection.展开更多
Room-temperature switchable materials showing multiple responses toward external stimuli are highly desired.Herein,we report bidirectional spin-state switch and fluorescence modulation of an Fe(II)complex(1)based on a...Room-temperature switchable materials showing multiple responses toward external stimuli are highly desired.Herein,we report bidirectional spin-state switch and fluorescence modulation of an Fe(II)complex(1)based on a rhodamine B 2-pyridinecarbaldehyde hydrazone ligand in both the solid state and solution.The complex is predominantly stabilized in the low-spin(LS)state at room temperature due to the strong ligand-field strength imposed by acylhydrazone pyridine.展开更多
A transverse relaxation determination of spin-exchange relaxation free （SERF） magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency （RF） excitation and light intens...A transverse relaxation determination of spin-exchange relaxation free （SERF） magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency （RF） excitation and light intensity excitation meth- ods used in SERF magnetometer, the light polarization modulation method has a high stability in low-frequency range, which indicates a more accurate transverse relaxation measurement.展开更多
电子自旋共振(ESR)是一种利用矿物在地质环境中的累计辐射能进行测年的技术方法,它采用的测年矿物石英广泛分布,并具有记录断层作用良好的计时零点,是同位素测年的重要补充。ESR信号强度是决定ESR年龄精确度的关键因素,但是各种参数条...电子自旋共振(ESR)是一种利用矿物在地质环境中的累计辐射能进行测年的技术方法,它采用的测年矿物石英广泛分布,并具有记录断层作用良好的计时零点,是同位素测年的重要补充。ESR信号强度是决定ESR年龄精确度的关键因素,但是各种参数条件对测量结果的影响方式及其程度缺乏系统研究。本文以取自断层带石英的一种顺磁中心——E’心为研究对象,运用单因素重复性实验方法,分析石英ESR定年中5种影响因素与ESR信号强度的相关关系。结果表明,微波功率、调制幅度、扫描宽度是影响ESR信号强度的主控因素,样品管方位及直径对测量结果影响不大。微波功率0.02~0.1 m W、调制幅度0.25~0.4 Gs可作为精确测量断层泥石英E’心普适性的参数区间,过大或过小的扫描宽度均不利于ESR测量,可利用在大扫描宽度条件下先预扫描再精细扫描的方法确定合适的扫描宽度,重复测量后求取平均值可有效降低测量误差。利用本文提出的参数区间及其确定的方法测量断层泥石英的E’心信号强度,能显著提高ESR测量精度。展开更多
基金financially supported by the National Natural Science Foundation of China(Grants No.52027801,52111530236)the National Postdoctoral Program for Innovative Talents(BX20220002)China Postdoctoral Science Foundation(2022M720204).
文摘The electrocatalysis reactions involving oxygen,such as oxygen evolution reaction(OER)and oxygen reduction reaction(ORR),play a critical role in energy storage/conversion applications,e.g.,fuel cells,metal-air batteries,and electrochemical water splitting.The high kinetic energy barrier of the OER/ORR is highly associated with the spin state interconversion between singlet OH^(−)/H_(2)O and triplet O_(2),which is influenced by the spin state and magnetism of catalysts.This Review summarizes recent progress and advances in understanding spin/magnetism-related effects in oxygen electrocatalysis to develop spin theory.It is demonstrated that the spin states(low,intermediate,and high spin)of magnetic transition metal catalysts(TMCs)can directly affect the reaction barriers of OER/ORR by tailoring the bonding of oxygen intermediates with TMCs.Besides,the spin states of TMCs can build a spin-selective channel to filter the electron spins required for the single/triplet interconversion of O species during OER/ORR.In this Review,we introduced many approaches to modulating spin state,for instance,altering the crystal field,oxidation state of active-site ions,and the morphology of TMCs.What’s more,a magnetic field can drive the spin flip of magnetic ions to achieve the spin alignment(↑↑)(i.e.,facilitating spin polarization),which will strengthen the spin selectivity for accelerating the filtration and transfer of the spins with the same direction for the generation and conversion of triplet ↑O=O↑.Importantly,the origin of magnetic field enhancement on OER/ORR are deeply discussed,which provides a great vision for the magnetism-assisted catalysis.Finally,the challenges and perspectives for future development of spin/magnetism catalysis are presented.This Review is expected to highlight the significance of spin/magnetism theory in breaking the bottleneck of electrocatalysis field and promote the development of high-efficientcy electrocatalysts for practical applications.
基金supported by the National Natural Science Foundation of China (Grant Nos.11574016 and 11204154)。
文摘We explore the spin–orbit coupling(SOC) mechanism for structured light in coherent atomic media with low-light-level cross-Kerr nonlinearity. Using the five-level M-type electromagnetic induced transparency(EIT) system as a prototype, we show that spin–orbit splitting for a weak spinor image can be generated by a weak trigger field carrying orbital angular momentum(OAM) at low-light intensity. By quantum-optical analogy, the paraxial focusing and defocusing of the two pseudo-spin states in the spinor image can be governed by a Pauli-like equation. More importantly, by changing the EIT parameters, especially the topological charge of the weak trigger field, the SOC-induced radial quantization of the spinor image can be rather significant,giving rise to positive or negative OAM-OAM mode separation in free space. This suggests that the separation can be flexibly controlled due to strong image-vortex interaction based on fewphoton cross-Kerr modulation. Our findings may have the potential for all-optical OAM multiplexing and demultiplexing of structured light fields toward few-photon quantum control and multimode communication.
文摘The behavior of lattice distortion in spin 1/2 antiferromagnetic XY models with random magnetic modulation is investigated with the consideration of spin-phonon coupling in the adiabatic limit. It is found that lattice distortion relies on the strength of the random modulation. For strong or weak enough spin phonon couplings, the average lattice distortion may decrease or increase as the random modulation is strengthened. This may be the result of competition between the random magnetic modulation and the spin phonon coupling.
基金National Natural Science Foundation of China(Nos.51635011,61503346,51727808)National Science Foundation of Shanxi Province(No.201701D121080)
文摘In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magnetometer studied can reduce the frequency noise of system and improve the magnetic sensitivity by microwave frequency modulation.Firstly,ESR spectra by sweeping the microwave frequency was obtained.Further,the microwave frequency modulated was gained through the mixed high-frequency sinusoidal modulation signal generated by signal generator.In addition,the frequency through the lock-in amplifier was locked,and the signal which was proportional to the first derivative of the spectrum was obtained.The experimental results show that the sensitivity of magnetic field detection can reach 17.628 nT/Hz based on microwave frequency modulation technology.The method realizes high resolution and sensitivity for magnetic field detection.
基金supported by the National Natural Science Foundation of China(nos.21871140 and 21401104).
文摘Room-temperature switchable materials showing multiple responses toward external stimuli are highly desired.Herein,we report bidirectional spin-state switch and fluorescence modulation of an Fe(II)complex(1)based on a rhodamine B 2-pyridinecarbaldehyde hydrazone ligand in both the solid state and solution.The complex is predominantly stabilized in the low-spin(LS)state at room temperature due to the strong ligand-field strength imposed by acylhydrazone pyridine.
基金Project supported by the National Natural Science Foundation of China(Grant No.61227902)the National Key R&D Program of China(Grant No.2017YFB0503100)the Natural Science Foundation of Beijing Municipality,China(Grant No.4162038)
文摘A transverse relaxation determination of spin-exchange relaxation free （SERF） magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency （RF） excitation and light intensity excitation meth- ods used in SERF magnetometer, the light polarization modulation method has a high stability in low-frequency range, which indicates a more accurate transverse relaxation measurement.
文摘电子自旋共振(ESR)是一种利用矿物在地质环境中的累计辐射能进行测年的技术方法,它采用的测年矿物石英广泛分布,并具有记录断层作用良好的计时零点,是同位素测年的重要补充。ESR信号强度是决定ESR年龄精确度的关键因素,但是各种参数条件对测量结果的影响方式及其程度缺乏系统研究。本文以取自断层带石英的一种顺磁中心——E’心为研究对象,运用单因素重复性实验方法,分析石英ESR定年中5种影响因素与ESR信号强度的相关关系。结果表明,微波功率、调制幅度、扫描宽度是影响ESR信号强度的主控因素,样品管方位及直径对测量结果影响不大。微波功率0.02~0.1 m W、调制幅度0.25~0.4 Gs可作为精确测量断层泥石英E’心普适性的参数区间,过大或过小的扫描宽度均不利于ESR测量,可利用在大扫描宽度条件下先预扫描再精细扫描的方法确定合适的扫描宽度,重复测量后求取平均值可有效降低测量误差。利用本文提出的参数区间及其确定的方法测量断层泥石英的E’心信号强度,能显著提高ESR测量精度。
