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1. Climate change impacts plant carbon balance, increasing mean future carbon use efficiency but decreasing total forest extent at dry range edges

   https://doi.org/10.1111/ele.13945  

   Mathias, Justin M. ; Trugman, Anna T. ; Liu, ed., Lingli ( December 2021 , Ecology Letters)

   Carbon use efficiency (CUE) represents how efficient a plant is at translating carbon gains through gross primary productivity (GPP) into net primary productivity (NPP) after respiratory costs (R_a). CUE varies across space with climate and species composition, but how CUE will respond to climate change is largely unknown due to uncertainty inR_aat novel high temperatures. We use a plant physiological model validated against global CUE observations and LIDAR vegetation canopy height data and find that model‐predicted decreases in CUE are diagnostic of transitions from forests to shrubland at dry range edges. Under future climate scenarios, we show mean growing season CUE increases in core forested areas, but forest extent decreases at dry range edges, with substantial uncertainty in absolute CUE due to uncertainty inR_a. Our results highlight that future forest resilience is nuanced and controlled by multiple competing mechanisms.

    

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2. Detailed-balance analysis of Yb 3+ :CsPb(Cl 1−x Br x ) 3 quantum-cutting layers for high-efficiency photovoltaics under real-world conditions

   https://doi.org/10.1039/c9ee01493d  

   Crane, Matthew J. ; Kroupa, Daniel M. ; Gamelin, Daniel R. ( January 2019 , Energy & Environmental Science)

   Yb 3+ -Doped lead-halide perovskites (Yb 3+ :CsPb(Cl 1−x Br x ) 3 ) have emerged as unique materials combining strong, tunable broadband absorption with near-infrared photoluminescence quantum yields (PLQYs) approaching 200% at ambient temperature. These remarkable properties make Yb 3+ :CsPb(Cl 1−x Br x ) 3 an extremely promising candidate for spectral shaping in high-efficiency photovoltaic devices. Previous theoretical assessments of such “downconversion” devices have predicted single-junction efficiencies up to 40%, but have been highly idealized. Real materials like Yb 3+ :CsPb(Cl 1−x Br x ) 3 have practical limitations such as constrained band-gap and PL energies, non-directional emission, and an excitation-power-dependent PLQY. Hence, it is unclear whether Yb 3+ :CsPb(Cl 1−x Br x ) 3 , or any other non-ideal quantum-cutting material, can indeed boost the efficiencies of real high-performance PV. Here, we examine the thermodynamic, detailed-balance efficiency limit of Yb 3+ :CsPb(Cl 1−x Br x ) 3 on different existing PV under real-world conditions. Among these, we identify silicon heterojunction technology as very promising for achieving significant performance gains when paired with Yb 3+ :CsPb(Cl 1−x Br x ) 3 , and we predict power-conversion efficiencies of up to 32% for this combination. Surprisingly, PL saturation does not negate the improved device performance. Calculations accounting for actual hourly incident solar photon fluxes show that Yb 3+ :CsPb(Cl 1−x Br x ) 3 boosts power-conversion efficiencies at all times of day and year in two representative geographic locations. Predicted annual energy yields are comparable to those of tandem perovskite-on-silicon technologies, but without the need for current matching, tracking, or additional electrodes and inverters. In addition, we show that band-gap optimization in real quantum cutters is inherently a function of their PLQY and the ability to capture that PL. These results provide key design rules needed for development of high-efficiency quantum-cutting photovoltaic devices based on Yb 3+ :CsPb(Cl 1−x Br x ) 3 . 

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3. Cover Feature: A Delicate Balance between Antiferromagnetism and Ferromagnetism: Theoretical and Experimental Studies of A 2 MRu 5 B 2 (A=Zr, Hf; M=Fe, Mn) Metal Borides (Chem. Eur. J. 9/2020)

   https://doi.org/10.1002/chem.201905860  

   Shankhari, Pritam ; Bakshi, Nika G. ; Zhang, Yuemei ; Stekovic, Dejan ; Itkis, Mikhail E. ; Fokwa, Boniface P. ( January 2020 , Chemistry – A European Journal)

   null (Ed.)
4. A Delicate Balance between Antiferromagnetism and Ferromagnetism: Theoretical and Experimental Studies of A 2 MRu 5 B 2 (A=Zr, Hf; M=Fe, Mn) Metal Borides

   https://doi.org/10.1002/chem.201904572  

   Shankhari, Pritam ; Bakshi, Nika G. ; Zhang, Yuemei ; Stekovic, Dejan ; Itkis, Mikhail E. ; Fokwa, Boniface P. T. ( January 2020 , Chemistry – A European Journal)
5. Water Diffusion Measurements of Single Charged Aerosol Using H 2 O/D 2 O Isotope Exchange and Raman Spectroscopy in an Electrodynamic Balance

   https://doi.org/10.1039/C8CP07052K  

   Nadler, Katherine A. ; Kim, Pyeongeun ; Huang, Dao-Ling ; Xiong, Wei ; Continetti, Robert ( January 2019 , Physical Chemistry Chemical Physics)

   Sea spray aerosols contain a large array of organic compounds that contribute to high viscosities at low relative humidity and temperature thereby slowing translational diffusion of water. The Stokes-Einstein equation describes how viscosity is inversely correlated with the translational diffusion coefficient of the diffusing species. However, recent studies indicate the Stokes-Einstein equation breaks down at high viscosities achieved in the particle phase (>10 12 Pa·s), underestimating the predicted water diffusion coefficient by orders of magnitude and revealing the need for directly studying the diffusion of water in single aerosol. A new method is reported for measuring the water diffusion coefficient in single suspended charged sucrose-water microdroplets in the 30-60 micron diameter range. The translational water diffusion coefficient is quantified using H 2 O/D 2 O isotope exchange technique between 26-54% relative humidity (RH) with a recently developed mobile electrodynamic balance apparatus. The results are in good agreement with literature, particularly the Vignes-type parameterization from experiments using isotope exchange and optical tweezers. This mobile electrodynamic balance will allow future studies of atmospherically relevant chemical systems, including field studies. 

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