NiO is a p-type wide bandgap semiconductor of use in various electronic devices ranging from solar cells to transparent transistors. Understanding and improving its optical and transport properties ...have been of considerable interest. In this work, we have investigated the effect of Li doping on the electronic, optical and transport properties of NiO epitaxial thin films grown by pulsed laser deposition. We show that Li doping significantly increases the p-type conductivity of NiO, but all the films have relatively low room-temperature mobilities (<0.05 cm
2
V
−1
s
−1
). The conduction mechanism is better described by small-polaron hoping model in the temperature range of 200 K <
T
< 330 K, and variable range hopping at
T
< 200 K. A combination of X-ray photoemission and O K-edge X-ray absorption spectroscopic investigations reveal that the Fermi level gradually shifts toward the valence band maximum (VBM) and a new hole state develops with Li doping. Both the VBM and hole states are composed of primarily Zhang-Rice bound states, which accounts for the small polaron character (low mobility) of hole conduction. Our work provides guidelines for the search for p-type oxide materials and device optimization.
NiO is a p-type wide bandgap semiconductor of use in various electronic devices ranging from solar cells to transparent transistors. This work reports the controlling of conductivity and increase of work functions by Li doping.
We investigate a particular type of classical nonsingular bouncing cosmology, which results from general relativity if we allow for degenerate metrics. The simplest model has a matter content with a ...constant equation-of-state parameter and we get the modified Hubble diagrams for both the luminosity distance and the angular diameter distance. Based on these results, we present a Gedankenexperiment to determine the length scale of the spacetime defect which has replaced the big bang singularity. A possibly more realistic model has an equation-of-state parameter which is different before and after the bounce. This last model also provides an upper bound on the defect length scale.
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Methylammonium lead halide (MAPbX3) perovskites exhibit exceptional carrier transport properties. But their commercial deployment as solar absorbers is currently limited by their intrinsic ...instability in the presence of humidity and their lead content. Guided by our theoretical predictions, we explored the potential of methylammonium bismuth iodide (MBI) as a solar absorber through detailed materials characterization. We synthesized phase‐pure MBI by solution and vapor processing. In contrast to MAPbX3, MBI is air stable, forming a surface layer that does not increase the recombination rate. We found that MBI luminesces at room temperature, with the vapor‐processed films exhibiting superior photoluminescence (PL) decay times that are promising for photovoltaic applications. The thermodynamic, electronic, and structural features of MBI that are amenable to these properties are also present in other hybrid ternary bismuth halide compounds. Through MBI, we demonstrate a lead‐free and stable alternative to MAPbX3 that has a similar electronic structure and nanosecond lifetimes.
Call me MA‐Bi‐I! A lead‐free alternative to hybrid lead perovskites is explored for solar cells: methylammonium bismuth iodide (see figure). This material exhibits higher air stability than hybrid lead perovskites, while demonstrating optoelectronic properties promising for solar absorbers.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Although the sun is really far away from us, some solar activities could still influence the performance and reliability of space-borne and ground-based technological systems on Earth. Those ...time-varying conditions in space caused by the sun are also called solar storm or space weather. It is known that aviation activities can be affected during solar storms, but the exact effects of space weather on aviation are still unclear. Especially how the flight delays, the top topic concerned by most people, will be affected by space weather has never been thoroughly researched. By analyzing huge amount of flight data (~ 4 × 10
records), for the first time, we quantitatively investigate the flight delays during space weather events. It is found that compared to the quiet periods, the average arrival delay time and 30-min delay rate during space weather events are significantly increased by 81.34% and 21.45% respectively. The evident negative correlation between the yearly flight regularity rate and the yearly mean total sunspot number during 22 years also confirms such correlation. Further studies show that the flight delay time and delay rate will monotonically increase with the geomagnetic field fluctuations and ionospheric disturbances. These results indicate that the interferences in communication and navigation during space weather events may be the most probable reason accounting for the increased flight delays. The above analyses expand the traditional field of space weather research and could also provide us with brand new views for improving the flight delay predications.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Solar flares are one of the severest solar activities that have important effects on near-Earth space. Previous studies have shown that flight arrival delays increase as a result of solar flares, but ...the intrinsic mechanism behind this relationship is still unknown. In this study, we conducted a comprehensive analysis of flight departure delays during 57 solar X-ray events by using a huge amount of flight data (~ 5 × 10
records) gathered over a 5-year period. It is found that the average flight departure delay time during solar X-ray events increased by 20.68% (7.67 min) compared to quiet periods. Our analysis also revealed apparent time and latitude dependencies, with flight delays being more serious on the dayside than on the nightside and longer (shorter) delays tending to occur in lower (higher) latitude airports during solar X-ray events. Furthermore, our results suggest that the intensity of solar flares (soft X-ray flux) and the Solar Zenith Angle directly modulate flight departure delay time and delay rate. These results indicate that communication interferences caused by solar flares directly affect flight departure delays. This work expands our conventional understanding of the impacts of solar flares on human society and provides new insights for preventing or coping with flight delays.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Using a low background data sample of 9.7×10^{5} J/ψ→γη^{'}, η^{'}→γπ^{+}π^{-} events, which are 2 orders of magnitude larger than those from the previous experiments, recorded with the BESIII ...detector at BEPCII, the decay dynamics of η^{'}→γπ^{+}π^{-} are studied with both model-dependent and model-independent approaches. The contributions of ω and the ρ(770)-ω interference are observed for the first time in the decays η^{'}→γπ^{+}π^{-} in both approaches. Additionally, a contribution from the box anomaly or the ρ(1450) resonance is required in the model-dependent approach, while the process specific part of the decay amplitude is determined in the model-independent approach.
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The Paleotethyan tectonic history of northeast Tibet remains hotly debated, particularly regarding the nature of the Jinsha suture. Different interpretations of the Jinsha suture lead to different ...tectonic reconstructions of northeast Tibet, southern Eurasian continent. We identified three tectonic units along the western segment of the Jinsha suture in the Yushu–Zhiduo region: the Bayan Har–Songpan–Garzê fold belt (BSB), the Yushu mélange, and the eastern portion of the Qiangtang block (EQ). New geochemical and geochronological studies help to identify a Triassic continental magmatic arc (the Yushu arc) that developed upon the EQ and that is geochemically similar to magmatism in the Yidun arc. Structural studies, combined with 40Ar/39Ar analyses, reveal a complex deformational history of the Yushu–Zhiduo region: earlier‐stage top‐to‐the‐north asymmetrical fabrics are preserved exclusively in the Yushu mélange, which yields a phengite 40Ar/39Ar age of 230.5 ± 0.8 Ma; later‐stage orthogonal fabrics developed in the BSB and EQ (superposed upon the earlier fabrics in the Yushu mélange), likely resulted from a collision between the BSB and the Yushu arc that continued until ∼195 Ma. The structural patterns and deformation history of Yushu arc region are comparable with those recorded in the Yidun arc region. Thus, the previously defined Jinsha suture should be subdivided into western and southern segments. The western Jinsha suture is continuous with the Garzê‐Litang suture, while the southern Jinsha‐Ailaoshan suture marks the site of the closure of several intracontinental rift basins that have likely been overprinted by intra or back‐arc extension.
Key Points
The Yidun and Yushu arcs, northeast Tibet, have identical tectonothermal history
The southern Jinsha‐Ailaoshan suture doesn't represent a mature ocean
The western Jinsha suture extends eastward and connects to Garze‐Litang suture
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Mutations in the PLA2G6 gene at the PARK14 locus have been reported in complicated parkinsonism. To assess the prevalence of and phenotypes associated with PLA2G6 gene mutations, we screened PLA2G6 ...mutations in a cohort of patients with autosomal recessive early-onset parkinsonism (AREP).
We selected 12 families with AREP in which the Parkin, PINK1, DJ-1, ATP13A2, and FBXO7 gene mutations had been previously excluded. All patients came from the mainland of China. The entire PLA2G6 coding region and exon-intron boundaries were sequenced from genomic DNA templates. We then performed PET studies on individuals in the pedigree with a homozygous PLA2G6 mutation, and investigated the enzyme activity level of the mutation.
A homozygous missense mutation, c.G991T (p.D331Y), was identified in an autosomal recessive case. A younger sister of the p.D331Y-carrying patient was also homozygous for the mutation, but with no extrapyramidal symptoms. A PET study showed a substantial reduction in dopamine transporter (DAT) binding in the p.D331Y patient, and a slight reduction in DAT binding in his sister. In vitro, we experimentally demonstrate that the D331Y mutation caused an approximately 70%reduction in enzyme activity.
We have confirmed that the PLA2G6 gene allocated PARK14 locus and is associated with AREP.
Abstract Background and aims Epidemiologic studies are inconsistent regarding the association between folate and coronary heart disease (CHD) risk. The aim was to perform a meta-analysis to determine ...whether an association exists between folate and total CHD endpoints in prospective studies. Methods and results We searched the PUBMED and EMBASE databases for studies conducted from 1966 through August 2010. Data were independently abstracted by 2 investigators using a standardized protocol. Study-specific risk estimates were combined by using a random effects model. A total of 14 studies were included in the meta-analysis: 7 studies on dietary folate intake and 8 studies on blood folate levels. For dietary intake, the summary relative risk (RR) indicated a significant association between the highest folate intake and reduced risk of CHD (summary RR: 0.69; 95% CI: 0.60, 0.80). Furthermore, an increase in folate intake of 200 ug/day was associated with a 12% decrease in the risk of developing CHD (summary RR: 0.88; 95% CI: 0.82, 0.94). For blood folate levels, we also found a borderline inverse association of highest blood folate levels on CHD risk (summary RR: 0.74; 95% CI: 0.53, 1.02); our dose-response analysis indicated that an increment in blood folate levels of 5 mmol/l was associated with an 8% decrease in the risk of developing CHD (summary RR: 0.92; 95% CI: 0.84, 1.00). Conclusion This meta-analysis suggests that dietary folate intake and blood folate level are inversely associated with CHD risk.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•P-milling solves the kinetic and synthetic problems of Mg(In) simultaneously.•Mg(In) solid solution catalyzed with in situ formed MgF2 is prepared.•Mg(In) solid solution shows improved desorption ...kinetics (Ea=127.7kJ/mol).•Dual tuning of the thermodynamic and kinetic properties of MgH2 is realized.
The reversible formation of Mg(In) solid solution provides a new way to tune the dehydriding thermodynamics of MgH2. However, the preparation of this solid solution is quite difficult and its dehydriding kinetics is rather sluggish. This work offers a novel technique, plasma milling (P-milling), to solve the two problems simultaneously. The efficiency of the synthesis of Mg(In) solid solution, with a hydrogen capacity of up to 5.16wt.%, is improved significantly. Meanwhile, the kinetics is also modified by the catalyzing effect of in situ synthesized MgF2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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