We use measurements from NASA's Van Allen Probes to calculate the decay time constants for electrons over a wide range of energies (30 keV to 4 MeV) and values ( = 1.3-6.0) in the Earth's radiation belts. Using an automated routine to identify flux decay events, we construct a large database of lifetimes for near-equatorially mirroring electrons over a 5-year interval. We provide the first accurate estimates of the long decay timescales in the inner zone ( 100 days), which are highly resolved in energy and free from proton contamination. In the slot region and outer zone, we compare our lifetime calculations with prior empirical estimates and find good quantitative agreement (lifetimes 1-20 days). The comparisons suggest that some prior estimates may overestimate electron lifetimes between 2.5-4.5 due to instrumental effects and/or background contamination. Previously reported two-stage decays are explicitly demonstrated to be a consequence of using integral fluxes.
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http://dx.doi.org/10.1029/2019GL086053 | DOI Listing |
ACS Cent Sci
January 2025
Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States.
In quantum information science and sensing, electron spins are often purified into a specific polarization through an optical-spin interface, a process known as optically detected magnetic resonance (ODMR). Diamond-NV centers and transition metals are both excellent platforms for these so-called color centers, while metal-free molecular analogues are also gaining popularity for their extended polarization lifetimes, milder environmental impacts, and reduced costs. In our earlier attempt at designing such organic high-spin π-diradicals, we proposed to spin-polarize by shelving triplet = ±1 populations as singlets.
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January 2025
Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, P. R. China.
Near-infrared light response catalysts have received great attention in renewable solar energy conversion, energy production, and environmental purification. Here, near-infrared photodegradation is successfully achieved in rare earth single atom anchored NaYF@g-CN heterojunctions by the synergistic effect of Z-scheme heterojunction and antenna of rare earth single atoms. The UV-vis light emitted by Tm can not only be directly absorbed by g-CN to generate electron-hole pairs, realizing efficient energy transfer, but also be absorbed by NaYF substrate, and generating photo-generated electrons at its impurity level, transferring the active charge to the valence band of g-CN, forming a Z-scheme heterojunction and further improving the photocatalytic efficiency.
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January 2025
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Zeolitic nanosheets possess great potential in catalysis due to their enhanced transport property and accessibility toward bulky molecules compared to conventional micron- meter scale crystals. However, the generation of Beta zeolite nanosheets, which are crucial for industrial catalysis, is still challenging for its intergrowth nature. In this work, aluminosilicate Beta nanosheets of ca.
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January 2025
Key Lab of Marin Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, P. R. China.
Altering the generation route of reactive species is a potent means to augment the photocatalytic activity. In this study, MoS/MIL-101(Fe) S-scheme heterojunction (MF2) is prepared using a water/solvent thermal method for photocatalytic degradation of chlorsulfuron. Driven by the internal electric field, the local electron density of MF2 is redistributed, thus enhancing the adsorption of O.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
Under conditions that are close to the real cellular environment, the human telomeric single-stranded overhang (∼200 nt) consisting of tens of TTAGGG repeats tends to form higher order structures of multiple G-quadruplex (G4) blocks. On account of the higher biological relevance of higher order G4 structures, ligand compounds binding to higher order G4 are significant for the drug design toward inhibiting telomerase activity. Here, we study the interaction between a cationic porphyrin derivative, 5,10,15,20-tetra{4-[2-(1-methyl-1-piperidinyl)propoxy]phenyl}porphyrin (T4), and a human telomeric G4-dimer (AG(TAG)) in the mimic intracellular molecularly crowded environment (PEG as a crowding agent) and K or Na solution (i.
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