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Limits to growth of forest biomass carbon sink under climate change.
Widely recognized as a significant carbon sink, North American forests have experienced a history of recovery and are facing an uncertain future. This growing carbon sink is dictated by recovery from land-use change, with growth trajectory modified by environmental change. To address both processes, we compiled a forest inventory dataset from North America to quantify aboveground biomass growth with stand age across forest types and climate gradients. Here we show, the biomass grows from 90 Mg ha-1 (2000-2016) to 105 Mg ha-1 (2020 s), 128 Mg ha-1 (2050 s), and 146 Mg ha-1 (2080 s) under climate change scenarios with no further disturbances. Climate change modifies the forest recovery trajectory to some extent, but the overall growth is limited, showing signs of biomass saturation. The future (2080s) biomass will only sequester at most 22% more carbon than the current level. Given such a strong sink has limited growth potential, our ground-based analysis suggests policy changes to sustain the carbon sink
An Experimental Study on Indoor Massive 3D-MIMO Channel at 30-40 GHz Band
Three-dimensional (3D) multiple-input multiple-output (MIMO) channel sounder measurements are producposed for a multi-user MIMO channel at the 30-40 GHz mm-wave band. A 3D-MIMO downlink transmissions links withto two users is considered. The measurement campaign employing a vector network analyzer (VNA) washas been performed in an indoor office scenario. Based on the measurement results, weThe characterizeations of mm-wave 3D-MIMO channels are performed in the wavenumber domain and the time domain, which are jointly analyzed via a 3D inverse fast Fourier transform (IFFT). Measurement shows that the massive 3D-MIMO has a significant improvement on resolution of multipathes beyond none-massive 3D-MIMO
Financial Literacy, Portfolio Choice, and Financial Well-Being
This study examined potential effects of financial literacy on household portfolio choice and investment return, an indicator of financial wellbeing. Using data from the 2014 Chinese Survey of Consumer Finance, financial literacy was measured and further categorized into basic financial literacy and advanced financial literacy. This study tested the hypothesis that financial literacy affects household choice between stock and mutual fund. The results indicated that households with higher financial literacy, especially those with higher level of advanced financial literacy tended to delegate at least part of their portfolio to experts and invest in mutual fund. However, households who were overconfident about their financial literacy tended to invest by themselves and were more likely to hold only stocks in their portfolios. The findings also indicated that households with higher financial literacy had a better chance of receiving a positive investment return, suggesting that higher financial literacy may result in a better financial outcome
Deformed "Commutative" Chern - Simons System
Noncommutative Chern - Simons' system is non-perturbatively investigated at a
full deformed level. A deformed "commutative" phase space is found by a
non-canonical change between two sets of deformed variables of noncommutative
space. It is explored that in the "commutative" phase space all calculations
are similar to the case in commutative space. Spectra of the energy and angular
momentum of the Chern - Simons' system are obtained at the full deformed level.
The noncommutative-commutative correspondence is clearly showed. Formalism for
the general dynamical system is briefly presented. Some subtle points are
clarified.Comment: 15 page
Coherent States of the Deformed Heisenberg-Weyl Algebra in Noncommutative Space
In two-dimensional space a subtle point that for the case of both space-space
and momentum-momentum noncommuting, different from the case of only space-space
noncommuting, the deformed Heisenberg-Weyl algebra in noncommutative space is
not completely equivalent to the undeformed Heisenberg-Weyl algebra in
commutative space is clarified. It follows that there is no well defined
procedure to construct the deformed position-position coherent state or the
deformed momentum-momentum coherent state from the undeformed position-momentum
coherent state. Identifications of the deformed position-position and deformed
momentum-momentum coherent states with the lowest energy states of a cold
Rydberg atom in special conditions and a free particle, respectively, are
demonstrated.Comment: 10 pages, no figur
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