El Ni?o–Southern Oscillation(ENSO) is an oscillation of the ocean–atmosphere system in the tropical Pacific, which is argued to be energized by high-frequency stochastic atmospheric disturbances. Among these disturb...El Ni?o–Southern Oscillation(ENSO) is an oscillation of the ocean–atmosphere system in the tropical Pacific, which is argued to be energized by high-frequency stochastic atmospheric disturbances. Among these disturbances, westerly wind bursts(WWBs) play a crucial role in the development of El Ni?o by generating eastward-propagating downwelling Kelvin waves and suppressing the thermocline in the central-eastern equatorial Pacific. The present work elucidates distinct seasonal evolutions of WWBs during cyclic and noncyclic El Ni?o events, and their association with the local sea surface temperature anomalies(SSTAs). For noncyclic El Ni?o events, WWBs prevail over the western-central equatorial Pacific during spring of the developing year, accompanied by local warming SSTAs. In contrast, active WWBs cannot be observed until the developing summer for cyclic El Ni?o events. Significant differences in high-frequency WWBs and associated local deep convection appear in the developing spring season of noncyclic and cyclic El Ni?o events. These differences are closely linked to local SSTAs in the western-central equatorial Pacific via the stimulation of atmospheric deep convection,preceding the full manifestation of ENSO-associated large-scale SSTAs in the central-eastern tropical Pacific. The observed difference in WWBs for noncyclic and cyclic El Ni?o events and its association with the western-central equatorial Pacific SSTAs is realistically reproduced in a coupled general circulation model. This study enhances our comprehension of El Ni?o development by illustrating the intricate connection between WWBs and El Ni?o evolution from the ENSO cycle perspective.展开更多
High-fidelity quantum gates are essential for large-scale quantum computation.However,any quantum manipulation will inevitably affected by noises,systematic errors and decoherence effects,which lead to infidelity of a...High-fidelity quantum gates are essential for large-scale quantum computation.However,any quantum manipulation will inevitably affected by noises,systematic errors and decoherence effects,which lead to infidelity of a target quantum task.Therefore,implementing high-fidelity,robust and fast quantum gates is highly desired.Here,we propose a fast and robust scheme to construct high-fidelity holonomic quantum gates for universal quantum computation based on resonant interaction of three-level quantum systems via shortcuts to adiabaticity.In our proposal,the target Hamiltonian to induce noncyclic non-Abelian geometric phases can be inversely engineered with less evolution time and demanding experimentally,leading to high-fidelity quantum gates in a simple setup.Besides,our scheme is readily realizable in physical system currently pursued for implementation of quantum computation.Therefore,our proposal represents a promising way towards fault-tolerant geometric quantum computation.展开更多
EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are invest...EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.展开更多
A series of novel heteropolynuclear complexes of Ln (II1)-Cu (I1) and Cu(11) complex with noncyclic polyether Schiff base, salicylidene diethylene glycol diarnine (SALDA), have been synthesized for the first time. The...A series of novel heteropolynuclear complexes of Ln (II1)-Cu (I1) and Cu(11) complex with noncyclic polyether Schiff base, salicylidene diethylene glycol diarnine (SALDA), have been synthesized for the first time. The isolated complexes are formulated as [LnCu2(SALDAI3(NO3)5](N03)2.4H20 (Ln = La, Pr, Nd, Sm, Gd, Tb, Er, Yb, Y) and [Cu(SALDA)(NO3)](NO3). H20. Synthesis methods are reported herein. The differences in their compositions, structures and coordination have been investigated by UV, IR, magnetic susceptibility, especially by1H and13c NMR spectra. It has been found that v (C=N) in the Ln(II1)-Cu(II) complexes are split up into two peaks with a far distance and it may be used as a probe for distinguishing them from others. In addition, it is suggested that the ethereal oxygen donors are not all coordinated. The good catalysis effect for the polymerization of methyl methacrylate (MMA) are reported for the first time. The results show that the catalytic activity of Nd-Cu-SALDA complex is better than that of the others and its syndiotactic sequence is ～ 72 % as well, the conversion íncreases to 88%.展开更多
The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR ...The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ’ of complexes were estimated. A series of interesting regularity and new results were obtained.展开更多
Electron donors are widely exploited in visible-light photocatalytic hydrogen production.As a typical electron donor pair and often the first choice for hydrogen production,the sodium sulfide-sodium sulfite pair has b...Electron donors are widely exploited in visible-light photocatalytic hydrogen production.As a typical electron donor pair and often the first choice for hydrogen production,the sodium sulfide-sodium sulfite pair has been extensively used.However,the resultant thiosulfate ions consume the photogenerated electrons to form an undesirable pseudocyclic electron transfer pathway during the photocatalytic process,strongly limiting the solar energy conversion efficiency.Here,we report novel and bioinspired electron donor pairs offering a noncyclic electron transfer pathway that provides more electrons without the consumption of the photogenerated electrons.Compared to the state-of-the-art electron donor pair Na_(2)S-Na_(2)SO_(3),these novel Na_(2)S-NaH_(2)PO_(2)and Na_(2)S-NaNO_(2)electron donor pairs enable an unprecedented enhancement of up to 370%and 140%for average photocatalytic H_(2)production over commercial CdS nanoparticles,and they are versatile for a large series of photocatalysts for visible-light water splitting.The discovery of these novel electron donor pairs can lead to a revolution in photocatalysis and is of great significance for industrial visible-light-driven H_(2)production.展开更多
A novel Schiff base (TAMET) was synthesized by the condensation of tetraglycol aldehyde with methionine and a mild oxidant CrO3. (C5H5N)2 was selected for the reaction. Seven new rare earth complexes with this Schiff ...A novel Schiff base (TAMET) was synthesized by the condensation of tetraglycol aldehyde with methionine and a mild oxidant CrO3. (C5H5N)2 was selected for the reaction. Seven new rare earth complexes with this Schiff base have been synthesized and characterized by elemental analysis, TG-DTA, molar Conductivity, magnetic susceptibility and IR, especially 1H NMR spectra. Information was obtained from reflectance spectra and the coordination of sulfur atom to rare earths was discussed. The experimental results show that these compounds have some biological activity and could dispose of O2?-.展开更多
In this paper the generation of four-wave mixing （FWM） signal using a noncycling transition of caesium atoms is investigated when the pumping laser is locked to the transition 6S1/2F= 4→6P3/2^F1 = 4, and meanwhile ...In this paper the generation of four-wave mixing （FWM） signal using a noncycling transition of caesium atoms is investigated when the pumping laser is locked to the transition 6S1/2F= 4→6P3/2^F1 = 4, and meanwhile the probe frequency is scanned across the 6S1/2F = 4→6P3/2 transition. The efficiency of the four-wave mixing signal as a function of the intensity of the pumping beams and the detuning of the pumping beams is also studied. In order to increase the detection efficiency, a repumping laser which is resonant with 6S1/2F = 3→6P3/2F′= 4 transition is used. A theoretical model is also introduced, and the theoretical results are in qualitative agreement with experimental ones.展开更多
基金supported by the National Nature Science Foundation of China (Grant No.42088101)。
文摘El Ni?o–Southern Oscillation(ENSO) is an oscillation of the ocean–atmosphere system in the tropical Pacific, which is argued to be energized by high-frequency stochastic atmospheric disturbances. Among these disturbances, westerly wind bursts(WWBs) play a crucial role in the development of El Ni?o by generating eastward-propagating downwelling Kelvin waves and suppressing the thermocline in the central-eastern equatorial Pacific. The present work elucidates distinct seasonal evolutions of WWBs during cyclic and noncyclic El Ni?o events, and their association with the local sea surface temperature anomalies(SSTAs). For noncyclic El Ni?o events, WWBs prevail over the western-central equatorial Pacific during spring of the developing year, accompanied by local warming SSTAs. In contrast, active WWBs cannot be observed until the developing summer for cyclic El Ni?o events. Significant differences in high-frequency WWBs and associated local deep convection appear in the developing spring season of noncyclic and cyclic El Ni?o events. These differences are closely linked to local SSTAs in the western-central equatorial Pacific via the stimulation of atmospheric deep convection,preceding the full manifestation of ENSO-associated large-scale SSTAs in the central-eastern tropical Pacific. The observed difference in WWBs for noncyclic and cyclic El Ni?o events and its association with the western-central equatorial Pacific SSTAs is realistically reproduced in a coupled general circulation model. This study enhances our comprehension of El Ni?o development by illustrating the intricate connection between WWBs and El Ni?o evolution from the ENSO cycle perspective.
基金This work was supported by the Key R&D Program of Guangdong Province(Grant No.2018B030326001)the National Natural Science Foundation of China(Grant No.11874156)Science and Technology Program of Guangzhou(Grant No.2019050001).
文摘High-fidelity quantum gates are essential for large-scale quantum computation.However,any quantum manipulation will inevitably affected by noises,systematic errors and decoherence effects,which lead to infidelity of a target quantum task.Therefore,implementing high-fidelity,robust and fast quantum gates is highly desired.Here,we propose a fast and robust scheme to construct high-fidelity holonomic quantum gates for universal quantum computation based on resonant interaction of three-level quantum systems via shortcuts to adiabaticity.In our proposal,the target Hamiltonian to induce noncyclic non-Abelian geometric phases can be inversely engineered with less evolution time and demanding experimentally,leading to high-fidelity quantum gates in a simple setup.Besides,our scheme is readily realizable in physical system currently pursued for implementation of quantum computation.Therefore,our proposal represents a promising way towards fault-tolerant geometric quantum computation.
基金Project supported by the National Natural Science Foundation of Chinathe Natural Science Foundation of Zhejiang Province
文摘EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.
文摘A series of novel heteropolynuclear complexes of Ln (II1)-Cu (I1) and Cu(11) complex with noncyclic polyether Schiff base, salicylidene diethylene glycol diarnine (SALDA), have been synthesized for the first time. The isolated complexes are formulated as [LnCu2(SALDAI3(NO3)5](N03)2.4H20 (Ln = La, Pr, Nd, Sm, Gd, Tb, Er, Yb, Y) and [Cu(SALDA)(NO3)](NO3). H20. Synthesis methods are reported herein. The differences in their compositions, structures and coordination have been investigated by UV, IR, magnetic susceptibility, especially by1H and13c NMR spectra. It has been found that v (C=N) in the Ln(II1)-Cu(II) complexes are split up into two peaks with a far distance and it may be used as a probe for distinguishing them from others. In addition, it is suggested that the ethereal oxygen donors are not all coordinated. The good catalysis effect for the polymerization of methyl methacrylate (MMA) are reported for the first time. The results show that the catalytic activity of Nd-Cu-SALDA complex is better than that of the others and its syndiotactic sequence is ～ 72 % as well, the conversion íncreases to 88%.
文摘The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ’ of complexes were estimated. A series of interesting regularity and new results were obtained.
基金This work is financially supported by the National Key R&D Program of China(grant nos.2016YFA0202602 and 2021YFE0115800)the National Natural Science Foundation of China(grant nos.U20A20122 and 52103285)+3 种基金the Program of Introducing Talents of Discipline to Universities-Plan 111 from the Ministry of Science and Technology and the Ministry of Education of China(grant no.B20002)the“Algae Factory”European Horizon 2020 Program financed by FEDER and Wallonia Region of Belgium(grant no.1610187)the“DepollutAir”of Interreg V France-Wallonie-Vlaanderen and the Natural Science Foundation of Hubei Province(grant nos.2018CFB242 and 2020CFB416)the Youth Innovation Research Fund Project of the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing.T.H.acknowledges support from the Royal Academy of Engineering through a Research Fellowship(Graphlex).We also thank Prof.Pierre Van Cutsem,Department of Biology,University of Namur for his advice.
文摘Electron donors are widely exploited in visible-light photocatalytic hydrogen production.As a typical electron donor pair and often the first choice for hydrogen production,the sodium sulfide-sodium sulfite pair has been extensively used.However,the resultant thiosulfate ions consume the photogenerated electrons to form an undesirable pseudocyclic electron transfer pathway during the photocatalytic process,strongly limiting the solar energy conversion efficiency.Here,we report novel and bioinspired electron donor pairs offering a noncyclic electron transfer pathway that provides more electrons without the consumption of the photogenerated electrons.Compared to the state-of-the-art electron donor pair Na_(2)S-Na_(2)SO_(3),these novel Na_(2)S-NaH_(2)PO_(2)and Na_(2)S-NaNO_(2)electron donor pairs enable an unprecedented enhancement of up to 370%and 140%for average photocatalytic H_(2)production over commercial CdS nanoparticles,and they are versatile for a large series of photocatalysts for visible-light water splitting.The discovery of these novel electron donor pairs can lead to a revolution in photocatalysis and is of great significance for industrial visible-light-driven H_(2)production.
基金Project supported by the National Natural Science Foundation of China (No. 29671026)the Natural Science Foundation of Zhejiang Province (No. 296062)the State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics (No. 971502)
文摘A novel Schiff base (TAMET) was synthesized by the condensation of tetraglycol aldehyde with methionine and a mild oxidant CrO3. (C5H5N)2 was selected for the reaction. Seven new rare earth complexes with this Schiff base have been synthesized and characterized by elemental analysis, TG-DTA, molar Conductivity, magnetic susceptibility and IR, especially 1H NMR spectra. Information was obtained from reflectance spectra and the coordination of sulfur atom to rare earths was discussed. The experimental results show that these compounds have some biological activity and could dispose of O2?-.
基金Project supported by the National Natural Science Foundation of China （Grant No 60378004） and the Youth Science Foundation of Shanxi Province,China （Grant Nos 20031004 and 20041013）.
文摘In this paper the generation of four-wave mixing （FWM） signal using a noncycling transition of caesium atoms is investigated when the pumping laser is locked to the transition 6S1/2F= 4→6P3/2^F1 = 4, and meanwhile the probe frequency is scanned across the 6S1/2F = 4→6P3/2 transition. The efficiency of the four-wave mixing signal as a function of the intensity of the pumping beams and the detuning of the pumping beams is also studied. In order to increase the detection efficiency, a repumping laser which is resonant with 6S1/2F = 3→6P3/2F′= 4 transition is used. A theoretical model is also introduced, and the theoretical results are in qualitative agreement with experimental ones.
