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Increasing exploration interest in oil and gas hosted by early Cambrian strata has focused research efforts on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon, and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite with calcareous cement. The content of the sandstone samples is quartz (39.8%–73.9%), with illite (7.9%–27.6%) and calcite (4.5%–29%). The mineral particles of sandstone samples are mainly well sorted with a fine particle size, suggesting strong paleohydrodynamic force. The value of SiO2 is 37.69%–78.19%, followed by Al2O3 (6.11%–13.67%). Compared with upper continental crust, the boron in the sandstone samples is relatively enriched, whereas Sc, Sr, and Ba are relatively depleted. The ΣREE content is 124.46–323.99 ppm. Phosphorus is of biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite, and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone was deposited under oxic conditions and a warm and humid paleoclimate with saline to brackish features on a passive continental margin. Phosphorus occurring in sandstones is sensitive to paleoclimate and can be used as an indicator to judge paleoclimate, as it is more enriched in warm and humid weather. [ABSTRACT FROM AUTHOR]

β-NaYF 4 :Yb 3+ , Tm 3+ @ TiO 2 core-shell upconversion nanoparticles (UCNPs) were synthesized and incorporated into the TiO 2 mesoporous layer of perovskite solar cells (PSCs). Changes of the upconversion spectra of the UCNPs suggest the existence of the electron injection from NaYF 4 :Yb 3+ , Tm 3+ to the conduction band (CB) of TiO 2 through the NaYF 4 :Yb 3+ , Tm 3+ /TiO 2 nano-heterojunctions. The core-shell UCNPs that incorporated into the TiO 2 mesoporous layer not only act as the upconversion centers to use the NIR light but also serve as the light scatter centers to enhance the light harvesting. When using mesoporous layer containing the core-shell UCNPs in PSCs, the efficiency of the best devices is 16.27%, which is about 16.38% higher than that of the devices without core-shell UCNPs (13.98%). The significant enhancement in the performance of the PSCs is attributed to light scattering, NIR light upconversion and electron injection from the UCNPs to the CB of TiO 2 . [ABSTRACT FROM AUTHOR]

Wide‐bandgap (WBG) perovskite solar cells (PSCs) have garnered significant attention for their potential applications in tandem solar cells. However, their large open‐circuit voltage (VOC) deficit and serious photo‐induced halide segregation remain the main challenges that impede their applications. Herein, a post‐treatment strategy without thermal annealing is presented to form a 2D top layer of 2‐thiopheneethylammonium lead halide (n = 1) on WBG perovskites. This thermal annealing‐free post‐treatment method can more effectively passivate the defects of WBG methylamine (MA)‐free formamidinium/cesium lead iodide/bromide perovskite films and suppress photo‐induced perovskite phase segregation, as compared with the thermal annealing method that yields multi‐2D phases. The resulting opaque and semi‐transparent 1.66 eV‐bandgap perovskite solar cells deliver maximum power conversion efficiencies of 21.47% (a small VOC deficit of 0.43 V) and 19.11%, respectively, both of which are among the highest reports for inverted MA‐free WBG PSCs. Consequently, four‐terminal all‐perovskite tandem cells realize a remarkable efficiency of 26.64%, showing great promise for their applications in efficient multi‐junction tandem solar cells. [ABSTRACT FROM AUTHOR]

Gold-bearing quartz veins of the Taihua Group consisting of Archean metavolcanic rocks are a main gold deposit type in the Xiao Qinling area, one of the three biggest gold production areas in China. The quartz veins experienced strong alteration characterized by a typical mesothermal hydrothermal altered mineral assemblage. The grade of gold is affected by the contents of sulphides, e.g. galena, pyrite and chalcopyrite. Results of minor elements analysis for the of gold-bearing quartz veins indicate higher contents of Au and high contents of Ag, Pb, Cu, Cd, W, and Mo. Abundant fluid inclusions were found in the gold-bearing quartz veins. Three types of fluid inclusions were identified: (1) aqueous inclusions; (2) CO-bearing inclusions; and (3) daughter crystal-bearing fluid inclusions. Homogenization temperatures ranged from 110 to 670°C with low and high peaks appearing at 160-180°C and 280-300°C, respectively. The salinity of aqueous inclusions varies between 1.8 wt% and 38.2 wt% NaCl. The homogenization temperature and salinity show a positive correlation. The H and O isotopes of fluid inclusions in the gold-bearing quartz veins indicate that magmatic solution and metamorphic hydrothermal solution, together with meteoric water, were involved in the formation of gold-bearing fluid. Mesozoic magma activities related to granite intrusions should be the main source of CO fluid with higher temperature and salinity. [ABSTRACT FROM AUTHOR]

Water splitting is a vital reaction for the storage of renewable energy, which requires highly active and steady catalysts to produce hydrogen and oxygen. While the development of efficiently stable bifunctional electrocatalysts for the simultaneous production of hydrogen and oxygen remains challenge. Herein, we show a simple multi-step process to prepare porous CuCo 2 S 4 /NiCo 2 S 4 core-shell materials directly as bifunctional electrocatalyst electrodes for water splitting. The porous NiCo 2 S 4 -sheets combined with CuCo 2 S 4 -rods on nickel foam not only can provide for more active sites and higher specific surface area, but also maintain their structural integrity. At a current density of 10 mA cm−2, the CuCo 2 S 4 /NiCo 2 S 4 core-shell electrodes deliver lower overpotentials of 271 mV and 206 mV for the oxygen and hydrogen evolution reaction, respectively. The CuCo 2 S 4 /NiCo 2 S 4 core-shell electrodes are successfully used as bifunctional electrocatalyst towards overall water splitting and showed overpotential of 1.66 V at the current density of 10 mA cm−2. A ≈97% current density retention for 50 h is represented which illustrates the superior stability of this electrode material and water splitting device. Subsequently, a water splitting process is demonstrated using electrochemical cell based on CuCo 2 S 4 /NiCo 2 S 4 core-shell electrodes driven by a perovskite solar cell module. H 2 and O 2 are generated. Our work here demonstrates the possibility of wide application of catalytic material to produce clean energy driven by perovskite solar cell. The work also illustrates the potential applications of CuCo 2 S 4 /NiCo 2 S 4 core-shell nanometer materials for clean energy generation. [ABSTRACT FROM AUTHOR]

• Molecular weight has a significant effect on the mobility and electrical conductivity of the PTPD. • The interfacial charge transferring and transport between the perovskite and PTPD varies with the PTPD' molecular weight. • We fabricate the inverted PSCs based on MAPbI 3 with a champion PCE of 19.24% with negligible hysteresis. Inverted planar perovskite solar cells (PSCs) with poly(N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine) (PTPD) layer as hole-transporting layer (HTL) exhibit high power conversion efficiencies (PCEs) over 20%. However, the influence of PTPD's molecular weight (Mw) on the performance of PSCs has not been reported yet. Herein, we employ PTPD with various molecular weights as HTL to fabricate highly efficient inverted planar PSCs. Our results show that PTPD with 75 kDa possesses superior conductivity, which can quicken the charge carrier extraction from perovskite to HTL. In addition, the MAPbI 3 perovskite film atop the 75-kDa PTPD is smoother with higher crystallinity and lower defect density. As a result, inverted planar PSCs with 75-kDa PTPD as HTL deliver a highest PCE of 19.24%. Our work provides a beneficial reference for future preparation of stable and highly efficient inverted PSCs with polymer HTL. [ABSTRACT FROM AUTHOR]

Effective coupling between upconversion nanoparticles (UCNPs) and localized surface plasmon resonance (LSPR) nanostructures have been successfully used to improve the upconversion luminescence (UCL) of lanthanide ions. Here, to explore a more effective coupling method between Cu 1.8 S and UCNPs, Cu 1.8 S@NaYF 4 : X%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles were synthesized. In comparison to NaYF 4 @NaYF 4 : Yb3+, Er3+ nanoparticles, the UCL intensity of the green and red emissions of Cu 1.8 S@NaYF 4 : 30%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles were conspicuously increased by ~28-fold and ~101-fold, respectively. The significant enhancement of UCL in Cu 1.8 S@NaYF 4 : 30%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles comes from the synergistic contribution of two aspects: LSPR light scattering of the Cu 1.8 S core and the increased near-infrared absorption from the appropriate amount of Yb3+ ions in the intermediate layer. The present work is important for possible applications of such core-shell nanoparticles to photocatalysis, bioluminescent labeling, and perovskite solar cells. [ABSTRACT FROM AUTHOR]

Keywords: Isolation; quarantine; SARS-CoV-2; Beta variant; Alpha variant; COVID-19; transmission; international travel EN Isolation quarantine SARS-CoV-2 Beta variant Alpha variant COVID-19 transmission international travel 1 2 2 01/05/22 20211201 NES 211201 Quarantine of international travelers at arrival, often in specialized quarantine centers or hotels, is a measure frequently used by many countries to reduce the risk of importation.[1-2, 3] Evidence of the risk for transmission by contaminated environment or fomites via infected travellers from such quarantine facilities is lacking. Isolation, quarantine, SARS-CoV-2, Beta variant, Alpha variant, COVID-19, transmission, international travel Environmental surfaces from their quarantine rooms were sampled and tested for SARS-CoV-2, using the same methods as reported in a previous study.4 In total, 22 environmental samples collected from 11 sampling sites of each quarantine room were taken. [Extracted from the article]

Quasi‐two‐dimensional (quasi‐2D) perovskite light‐emitting diodes (PeLEDs) are considered as one of the most potential candidates in electroluminescence territory owing to their unique quantum confinement effect and excellent thermal stability of the light. Nevertheless, heterogeneous energy domain distribution leads to severe non‐radiative recombination in the process of energy transfer, which enormously hinders the performance and application of PeLEDs. Herein, an ambipolar amino acid, 5‐aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. The coordinated ambipolar molecule not only reconstitutes energy domains of perovskites but also minimizes the interfacial defects of PeLEDs. Accordingly, the presence of 5AVA in perovskite precursors leads to dramatic suppression of the n = 1 and n = 2 phases and accelerates energy transfer from wide bandgap domains to narrow bandgap ones. As a result, maximum external quantum efficiency (EQE) of 19.3% (18.20% ± 1.10%) is achieved in quasi‐2D green PeLEDs with current efficiency of 61.7 cd A−1. [ABSTRACT FROM AUTHOR]

External encapsulation technique as a straightforward craft process has been adopted to prevent the infiltration of moisture and oxygen, thereby improving environmental stabilities of lead halide perovskite solar cells (PSCs). However, irreversible light‐induced degradation originating from various vacancies and ion diffusion or migration inside the device cannot be efficiently solved by external encapsulation. Herein, an internal encapsulation strategy by introducing NbCl5 at the buried tin oxide/perovskite interface and spin‐casting n‐butylammonium bromide on top of perovskite is developed to comprehensively passivate the vacancies and hence block the channels for ion diffusion or migration. The internal encapsulation strategy results in better homogeneous electron transport layer and effective vacancy passivation at the buried interface and simultaneously generates a more homogeneous, better crystallized perovskite in the vertical direction with significantly reduced residual PbI2. Furthermore, fewer oxygen vacancies and formation of ultrathin Nb2O5 lead to a better interfacial energy level alignment for electron transfer. As a result, power conversion efficiency (PCE) of the resulting PSCs is as high as 24.01%. More importantly, the device demonstrates an excellent stability, retaining 88% of its initial PCE at its maximum power point tracking measurement (under 100 mW cm–2 white light illumination at ≈55 °C temperature, in N2 atmosphere) after 1000 h. [ABSTRACT FROM AUTHOR]

P‐type semiconductor cuprous oxide (Cu2O) offers promising optoelectronic applications such as solar cells and photodetectors owing to its considerable absorption coefficients and high carrier mobility. However, polycrystalline Cu2O films with low carrier mobility resulting from excessive grain boundaries and structure disorder fail to meet the demands for these optoelectronic applications. Here a stress‐assisted thermal oxidation method to fabricate p‐type <110>‐textured quasi‐single crystalline Cu2O (c‐Cu2O) wafers with centimeter‐scale grains is developed. It is found that strain energy induced by thermal contact stress plays a critical role in crystal growth. The resultant <110>‐textured quasi‐single c‐Cu2O wafers exhibit excellent crystallinity with rocking curve having a low full width at half maximum of 0.022°, a low defect density of 2 × 1011 cm−3, a high mobility exceeding 100 cm2 V−1 s−1, and a long minority lifetime of 98.5 µs. Such quasi‐single c‐Cu2O wafers lead to efficient solar cells with an open‐circuit voltage of 0.95 V and highly responsive photodetectors with superior cycling stability. These results indicate not only the advancement of fabricating high‐quality Cu2O wafers upon controllable methodology but also the promising optoelectronic applications using p‐type metal oxide semiconductors. [ABSTRACT FROM AUTHOR]

The association between floods and the risk of dysentery remain controversial. Therefore, we performed a meta-analysis to clarify this relationship. A literature search was performed in PubMed, Web of science, and Embase for relevant articles published up to November 2019. Random-effects model was used to pool relative risks with 95% confidence intervals. The sensitivity analysis was carried out to evaluate the stability of the results. Publication bias was estimated using Egger's test. Eleven studies from 10 articles evaluated the association between floods and the risk of dysentery in China. The pooled RR (95% CI) of dysentery for the flooded time versus non-flooded period was 1.48 (95% CI: 1.14–1.91). Significant association was found in subgroup analysis stratified by dysentery styles [dysentery: 1.61 (95% CI: 1.34–1.93) and bacillary dysentery: 1.46 (95% CI: 1.06–2.01)]. The pooled RR (95%CI) of sensitivity analysis for dysentery was 1.26 (95% CI: 1.05–1.52). No significant publication bias was found in our meta-analysis. This meta-analysis confirms that floods have significantly increased the risk of dysentery in China. Our findings will provide more evidence to reduce negative health outcomes of floods in China. [ABSTRACT FROM AUTHOR]

Metal halide perovskite nanocrystals (NCs) serve as a kind of ideal semiconductor for luminescence and display applications. However, the optoelectronic performance and stability of perovskite NCs are mainly subjected to current ligand strategies since these ligands exhibit a highly dynamic binding state, which complicates NC purification and storage. Herein, a method named diffusion‐induced extraction is developed for crystallization (DEC) at room temperature, in which silicone oil serves as a medium to separate the solvent from perovskite precursors and diethyl ether promotes the nucleation, leading to highly emissive perovskite NCs. The formation mechanism of NCs using this approach is elucidated, and their optoelectronic properties are fully characterized. The resultant NCs ink exhibits a high photoluminescence quantum yield (PLQY) over 90% with a narrow full width at half maximum of 17 nm. The DEC method strengthens the interaction between ligand and NCs via the hydrophobic silicone oil. Therefore, the NCs maintain almost 95% of their initial PLQYs after aging more than seven months in air. The findings will be of great significance for the continued advancement of high PLQY perovskite NCs through a better understanding of formation dynamics. The DEC strategy presents a major step forward for advancing the field of perovskite semiconductor nanomaterials. [ABSTRACT FROM AUTHOR]

Tracing and isolation of close contacts is used to control outbreaks of coronavirus disease 2019 (COVID‐19) in China. However, risk factors associated with the occurrence of COVID‐19 among close contacts have not been well described. A total of 106 household contacts were included in this study, of whom 19 developed into COVID‐19 cases, and the secondary attack rate was 17.9%. Multivariable analysis showed that increasing risk of occurrence of COVID‐19 among household contacts was associated with female index patients (adjusted hazard ratio [aHR] = 3.84, 95% CI = 1.07–13.78), critical disease index patients (aHR = 7.58, 95% CI = 1.66–34.66), effective contact duration with index patients > 2 days (aHR = 4.21, 95% CI = 1.29–13.73), and effective contact duration > 11 days (aHR = 17.88, 95% CI = 3.26–98.01). The sex and disease severity of index patients with COVID‐19 and longer effective contact duration with patients with confirmed COVID‐19 could help epidemiologists to identify potential COVID‐19 cases among household contacts at an early stage. [ABSTRACT FROM AUTHOR]

Antireflection (AR) film is a widely used technology to enhance the performance of photovoltaic devices that require transparent electrodes in the photovoltaic industry. At present, several AR films including monolayer MgF2 or multilayered composite films, textured polydimethylsiloxane (PDMS) and porous SiO2 have been successfully applied due to their excellent properties. Nevertheless, all of the above-mentioned AR films have some minor drawbacks to overcome, for instance, the cost or thermal durability. Herein, we report a cost-effective and low-temperature method to fabricate a mesoporous aluminum oxide (meso-Al2O3) layer as the AR coating with high thermal durability, which will meet the fabrication condition of various photovoltaic devices. Briefly, the process begins at magnetron sputtering a compact Al2O3 film, which shows no AR effect, followed by a hot water treatment at 80 °C to turn the compact film into a mesoporous film with graded-index and AR effect. The application of meso-Al2O3 AR film enhances the maximum transmittance of our laboratory-used fluorine-doped tin oxide (FTO) from 84% to 89%, which is in good agreement with our theoretical simulation named graded-index approximation. Taking perovskite solar cells (PSCs) as an example, planar PSCs with meso-Al2O3 AR film deliver excellent photon conversion efficiency of 21.5%, which is higher than that of cells without meso-Al2O3 AR film (20.9%). [ABSTRACT FROM AUTHOR]

Aiming to solve the problem of instance-intensive workflow scheduling in private cloud environment, this paper first formulates a scheduling optimization model considering the communication time between tasks. The objective of this model is to minimize the execution time of all workflow instances. Then, a hybrid scheduling method based on the batch strategy and an improved genetic algorithm termed fragmentation based genetic algorithm is proposed according to the characters of instance-intensive cloud workflow, where task priority dispatching rules are also taken into account. Simulations are conducted to compare the proposed method with the canonical genetic algorithm and two heuristic algorithms. Our simulation results demonstrate that the proposed method can considerably enhance the search efficiency of the genetic algorithm and is able to considerably outperform the compared algorithms, in particular when the number of workflow instances is high and the computational resource available for optimization is limited. [ABSTRACT FROM AUTHOR]

The article focuses on the stratigraphic analysis of the Ordovician period where the level of the greenhouse gases was at it's highest level.

In this manuscript, Ni ions-doped NaYF:Yb/Er nanoparticles have been synthesized via a modified hydrothermal method. The upconversion luminescence intensities of the green (G) and red (R) emission of NaYF:Yb/Er co-doped with 20 mol% Ni ions are the strongest which increase 32.84 and 20.99 times than that without doping Ni, respectively. In addition, the R/G ratio decreases with the concentration of Ni increasing from 0 to 40 mol%. The underlying reason for luminescence enhanced and the R/G ratio decreased by Ni doping is explored by a series of controlled experiments, and the mechanism based on the crystal field asymmetry, different substitution by Ni, the energy transition of Er is studied in detail. The study indicates that the misshapen crystal field plays an important role in enhancement fluorescence emission, and several factors affect the R/G ratio including the crystal field, the substitution site and the energy transition. Our result may play a certain function for study and design of high-performance upconversion materials. [ABSTRACT FROM AUTHOR]

Background and Objectives: Fruit, vegetable, seafood, and dairy intake may reduce the risk of type 2 diabetes, but this relationship is unclear. We aimed to examine the associations between fruit, vegetable, seafood, and dairy intake and type 2 diabetes prevalence in a Chinese population.Methods and Study Design: A total of 4,343 individuals aged 35-74 years participated in a population-based cross-sectional study in Qingdao, China. The frequency and quantity of fruit, vegetable, seafood, and dairy intake were determined using a standard food frequency questionnaire. Diabetes was classified according to the WHO/IDF 2006 criteria. Logistic regression analysis was employed to estimate odds ratio (OR) for type 2 diabetes in relation to fruit, vegetable, seafood, and dairy intake in a multivariable model.Results: The multivariate-adjusted ORs (95% confidence interval) for the presence of type 2 diabetes were 0.68 (0.46-0.98), 0.50 (0.37-0.68), and 0.91 (0.66-1.25), respectively, for the highest versus the lowest groups regarding total fruit and vegetable, fruit or vegetable intake in women. The ORs for type 2 diabetes prevalence regarding the quantity of fruit and vegetable, fruit, and yogurt intake were 0.88 (0.78-0.99), 0.71 (0.61-0.82), and 0.56 (0.32-0.98) in women, but not in men. Seafood consumption was inversely associated with diabetes risk in men, but not in women; the corresponding figures were 0.58 (0.35-0.96) and 0.92 (0.63-1.36), respectively.Conclusions: Fruit, vegetable, and yogurt intake in women and seafood intake in men were inversely associated with type 2 diabetes prevalence in this Chinese population. These findings require confirmation in a prospective study. [ABSTRACT FROM AUTHOR]

We evaluated the genetic and environmental contributions to metabolic cardiovascular risk factors and their mutual associations. Eight metabolic factors (body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, total serum cholesterol, serum triglycerides, and serum uric acid) were measured in 508 twin pairs aged 8–17 years from the Qingdao Twin Registry, China. Linear structural equation models were used to estimate the heritability of these traits, as well as the genetic and environmental correlations between them. Among boys, body mass index and uric acid showed consistently high heritability (0.49–0.81), whereas other traits showed moderate to high common environmental variance (0.37–0.73) in children (8–12 years) and adolescents (13–17 years) except total cholesterol. For girls, moderate to high heritability (0.39–0.75) were obtained for six metabolic traits in children, while only two traits showed high heritability and others mostly medium to large common environmental variance in adolescents. Genetic correlations between the traits were strong in both boys and girls in children (rg = 0.64–0.99 between body mass index and diastolic blood pressure; rg = 0.71–1.00 between body mass index and waist circumference), but decreased for adolescent girls (rg = 0.51 between body mass index and waist-to-hip ratio; rg = 0.55 between body mass index and uric acid; rg = 0.61 between body mass index and systolic blood pressure). The effect of genetic factors on most metabolic traits decreased from childhood to adolescence. Both common genetic and specific environmental factors influence the mutual associations among most of the metabolic traits. [ABSTRACT FROM PUBLISHER]

• 1. Bilayer ETL ZnO/Mg x Zn 1-x O and HTL dopant-free PM6 are introduced. • 2. ZnO/Mg x Zn 1-x O provides a cascaded energy level alignment with CsPbI 2 Br. • 3. ZnO/Mg x Zn 1-x O improves CsPbI 2 Br film quality. • 4. PM6 energetically aligns better with CsPbI 2 Br than spiro-OMeTAD. • 5. CsPbI 2 Br-based PSCs delivers a champion PCE over 16% with V OC deficit of 0.58 V. All-inorganic perovskite CsPbI 2 Br is a promising wide bandgap light absorber for tandem solar cells owing to its appropriate bandgap and great thermal stability. However, high open-circuit voltage (V OC) deficit has been a major obstacle for obtaining high efficiency in CsPbI 2 Br-based solar cells and thus limiting their application. Herein, we employ a strategy of interface engineering that deploys a bilayer electron transporting layer (ETL) and dopant-free hole transporting layer (HTL) to significantly mitigate the energy loss. A bilayer ETL ZnO/Mg x Zn 1-x O and Poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione)] (PM6) are energetically more compatible with the energy band of CsPbI 2 Br than ZnO and 2,2′,7,7′-tetrakis (N, N-di-p-methoxy-phenylamine)-9,9′-spirobifluorene (spiro-OMeTAD), which facilitate the photogenerated electron and hole transfer at perovskite/charge transporting layer interfaces. Moreover, the quality of the CsPbI 2 Br perovskite film deposited atop bilayer ETL ZnO/Mg x Zn 1-x O is substantially enhanced compared to that on top of ZnO. Both the more favorable energy level alignment and reduced defect density alleviate energy loss in the resultant solar cells. Perovskite solar cells with the structure of ITO/ZnO/Mg x Zn 1-x O/CsPbI 2 Br/PM6/MoO 3 /Ag give rise to an open-circuit voltage (V OC) of 1.34 V, which is one of the highest V OC among all-inorganic CsPbI 2 Br solar cells. The resultant V OC deficit drops to be lower than 0.6 V. As a result, the optimized all-inorganic CsPbI 2 Br-based solar cells yield a champion power conversion efficiency of 16.04%. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO 2) as an electron transport layer (ETL) has made impressive achievements in planar-structure heterojunction perovskite solar cells (PSCs). However, the improvement of the SnO 2 quality, connected with its trap density, electrical conductivity and band energy alignment, is still worth concerning. The quality of the SnO 2 film especially from wet coating techniques is quite sensitive to the environment conditions in the preparation process thus leading to poor repeatability. High repeatability of every functional layer fabrications is one of the basic requirements toward commercialization for PSCs. Herein, we add hydrogen peroxide (H 2 O 2) into the SnO 2 precursor solution (denoted as H 2 O 2 –SnO 2) to enable the quality improvement of ETL. The resultant H 2 O 2 –SnO 2 film exhibits less trap density, improved electrical conductivity, outstanding film fabrication repeatability and better energy level alignment, leading to significantly higher charge carrier extraction and reduced device hysteresis effect. By employing H 2 O 2 –SnO 2 ETL, PSCs with excellent repeatability and performance uniformity deliver a champion power conversion efficiency (PCE) of 22.15% with negligible hysteresis, and show impressive long-term stability. This research paves a new way for the further performance enhancement of planar PSCs and the higher quality modified SnO 2 may find applications in other opto-electronic devices. • Hydrogen peroxide was introduced to passivate defects of SnO 2 as ETL in PSCs. • The PSCs using hydrogen peroxide-modified SnO 2 ETL exhibited better repeatability. • The PSCs of hydrogen peroxide-modified SnO 2 ETL delivered a PCE of 22.15%. • The stability of PSCs with hydrogen peroxide-modified SnO 2 ETL was prolonged. [ABSTRACT FROM AUTHOR]

Factors associated with negative conversion of SARS-CoV-2 RNA in hospitalized patients have not yet been systematically determined. We conducted a retrospective cohort study of COVID-19 patients in Qingdao, China. Both univariate and multivariate analysis were performed to identify independent factors for time to viral RNA negative conversion. Data on patients with re-detectable viral RNA after showing negative on RT-PCR test (intermittent negative status) were also analyzed. A total of 59 patients confirmed with COVID-19 were included in this study, with a median duration of 1 (interquartile range, IQR: 0–2) day from symptom onset to hospital admission. Median communicable period (from first day of positive nucleic acid test to first day of consecutive negative results) was 14 (IQR: 10–18) days, and 7 (IQR: 6–10) days for 10 patients with intermittent negative results. Age older than 45 years (hazard ratio, HR: 0.378; 95% confidence interval, CI: 0.205–0.698) and chest tightness (HR: 0.290; 95%CI: 0.091–0.919) were factors independently affecting negative conversion of SARS-CoV-2 RNA. Headache (odds ratio: 7.553; 95%CI: 1.011–28.253) was significantly associated with intermittent negative status, with a predicted probability of 60%. Older age and chest tightness were independently associated with delayed clearance of SARS-CoV-2 RNA in hospitalized patients. These predictors would provide a new perspective on early identification of patients with prolonged viral shedding and facilitate optimal isolation protocols and treatment strategies. Unlabelled Image • Older age were independently associated with delayed clearance of SARS-CoV-2 RNA. • Chest tightness were independently associated with delayed clearance of SARS-CoV-2 RNA. • Intermittent negative status was predicted a probability of 60% if occurring headache. [ABSTRACT FROM AUTHOR]