4 research outputs found
A two-year field study and evaluation of water quality and trophic state of a large shallow drinking water reservoir in Shanghai, China
<p>Reservoirs have been widely constructed all over the world in recent years to alleviate the shortage of water resources. Nevertheless, the assessment method of water quality and its trophic status needs to be developed. In this study, water quality parameters of a newly constructed shallow reservoir were regularly monitored for a period of two years, which is used as a major drinking water source of Shanghai, China. Furthermore, the trophic state indices of the reservoir were investigated based on literature and evaluated with the two-year field data. The results indicated that the studied reservoir is reaching the mesotrophic–eutrophic boundary, where further nutrient enrichment could cause water quality degradation; total phosphorus is the limiting nutrient for algal growth in the studied reservoir. Results of the study can help operators understand change and status of water quality of the reservoir and provide valuable data demonstrating variation of water quality indicators and trophic characteristics in shallow reservoirs or lakes.</p
Additional file 1 of Double-pivot proper digital artery perforator flap for fingertip reconstruction
Additional file 1: Figure S1 Case 9. A dorsal oblique defect (A) on the distal phalanx was reconstructed using a double-pivot proper digital artery flap (blue line, B). Donor-site was covered by a skin graft under compression (C). Postoperatively, the flap survived well without skin pigmentation (D)
Ring-Fusion of Perylene Diimide Acceptor Enabling Efficient Nonfullerene Organic Solar Cells with a Small Voltage Loss
We
report a novel small molecule acceptor (SMA) named FTTB-PDI4
obtained via ring-fusion between the thiophene and perylene diimide
(PDI) units of a PDI-tetramer with a tetrathienylbezene (TTB) core.
A small voltage loss of 0.53 V and a high power conversion efficiency
of 10.58% were achieved, which is the highest value reported for PDI-based
devices to date. By comparing the fused and nonfused SMAs, we show
that the ring-fusion introduces several beneficial effects on the
properties and performances of the acceptor material, including more
favorable energy levels, enhanced light absorption and stronger intermolecular
packing. Interestingly, morphology data reveal that the fused molecule
yields higher domain purity and thus can better maintain its molecular
packing and electron mobility in the blend. Theoretical calculations
also demonstrate that FTTB-PDI4 exhibits a “double-decker”
geometry with two pairs of mostly parallel PDI units, which is distinctively
different from reported PDI-tetramers with highly twisted geometries
and can explain the better performance of the material. This work
highlights the promising design of PDI-based acceptors by the ring-fusion
strategy
Bandgap Engineering of InSe Single Crystals through S Substitution
Bandgap
engineering offers opportunities for tailoring the properties
of semiconductor materials for desired applications in microelectronics
and optoelectronics. Alloys of different semiconductor materials can
lead to the continuously tuning of the bandgap. Here, we report the
bandgap engineering in layered InSe single crystals by substituting
the Se atoms with S atoms. The formation of InS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> single crystal alloy
with <i>x</i> ≤ 0.3 is evidenced by the X-ray diffraction
and resonant Raman spectra. The photoluminescence (PL) spectra peak
position blue shifts from ∼1.27 to ∼1.42 eV as S composition
increases from 0 to 0.3 in the alloys, which is consistent with the
bandgap shifts calculated by density functional theory. Temperature
dependence of the PL spectra indicate that the presence of S atoms
decreases the strength of the electron–phonon interaction but
increases the average phonon energy in InS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> alloys. Our findings will
open an intriguing avenue in understanding the fundamental physics
in the III–VI layered semiconductor materials and their potential
applications in optoelectronic devices