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Remote Raman spectroscopy is a technique that can detect and identify different target molecules through Raman vibrational modes from a remote distance. However, the current remote Raman technique is restricted by poor detection sensitivity, and it is still extremely challenging for trace explosive detection. Here, in order to achieve trace explosive detection from a remote distance, we innovatively propose two enhanced Raman spectroscopy methods by using a plasmonic spray and a laser beam focusing/Raman signal collecting instrument. In brief, a facile convex lens can converge the laser beam and collect Raman scattering signals, and a plasmonic spray can be used for surface-enhanced Raman scattering. Under the combination of the above enhancement methods, we achieve remote Raman detection of a variety of trace explosives with a concentration of ∼1 μg/cm

BACKGROUND: Conventional ultrasound and contrast-enhanced ultrasound (CEUS) are commonly used in the diagnosis of benign and malignant thyroid nodules. However, the value of the two methods in the diagnosis of benign and malignant thyroid nodules remains controversial. METHODS: PubMed, Medline, EBSCO, Science Direct, Cochrane Library, China National Knowledge Infrastructure (CNKI) database and manual journal retrieval were searched from January 2000 to January 2022, to include research on conventional ultrasound or CEUS in the diagnosis of benign and malignant thyroid nodule related clinical studies. Meta-analysis was conducted using RevMan5.3 and Stata Corp to analyze the sensitivity and specificity of conventional ultrasound and CEUS in the diagnosis of benign and malignant thyroid nodules with 95% confidence interval (CI) as indicators. Heterogeneity of the results was evaluated by Q test and I(2) in RevMan5.3. Deek’s method was used to evaluate publication bias. RESULTS: A total of 1,378 nodules were included in 11 literatures, including 535 malignant thyroid nodules and 843 benign thyroid nodules. Heterogeneity tests conducted for CEUS diagnostic sensitivity of the 6 included literatures indicated that there was no heterogeneity among the study groups [Q=2.05, degree of freedom (df) =5.00, I(2)=0.00%, P=0.84]. The combined sensitivity was 0.87, with 95% confidence interval (CI): 0.82 to 0.90. Heterogeneity tests on the diagnostic specificity of CEUS of the six included literatures suggested that there was heterogeneity among the different study groups (Q=14.27, df =5.00, I(2)=64.96%, P=0.01). The combined specificity was 0.84 (95% CI: 0.78 to 0.89). Heterogeneity tests performed on the sensitivity of five conventional ultrasound diagnosis articles revealed that there was heterogeneity among different study groups (Q=13.62, df =4.00, I(2)=70.64%, P=0.01). The combined sensitivity was 0.86 (95% CI: 0.78 to 0.92). Heterogeneity tests on the specificity of conventional ultrasound diagnosis in five included literatures indicated that there was heterogeneity among different study groups (Q=16.94, df =4.00, I(2)=76.39%, P=0.00). The combined specificity was 0.84 (95% CI: 0.75 to 0.90). There was no bias in the included literature. DISCUSSION: The sensitivity of CEUS in the diagnosis of benign and malignant thyroid nodules was slightly higher than that of conventional ultrasound, which provides a reference for the clinical diagnosis of benign and malignant thyroid nodules.

Ultrastable CsPbBr

Conspectus Over the past decade, the impressive development of metal halide perovskites (MHPs) has made them leading candidates for applications in photovoltaics (PVs), X-ray scintillators, and light-emitting diodes (LEDs). Constructing MHP nanocrystals (NCs) with promising optoelectronic properties using a low-cost approach is critical to realizing their commercial potential. Self-assembly and regrowth techniques provide a simple and powerful “bottom-up” platform for controlling the structure, shape, and dimensionality of MHP NCs. The soft ionic nature of MHP NCs, in conjunction with their low formation energy, rapid anion exchange, and ease of ion migration, enables the rearrangement of their overall appearance via self-assembly or regrowth. Because of their low formation energy and highly dynamic surface ligands, MHP NCs have a higher propensity to regrow than conventional hard-lattice NCs. Moreover, their self-assembly and regrowth can be achieved simultaneously. The self-assembly of NCs into close-packed, long-range-ordered mesostructures provides a platform for modulating their electronic properties (e.g., conductivity and carrier mobility). Moreover, assembled MHP NCs exhibit collective properties (e.g., superfluorescence, renormalized emission, longer phase coherence times, and long exciton diffusion lengths) that can translate into dramatic improvements in device performance. Further regrowth into fused MHP nanostructures with the removal of ligand barriers between NCs could facilitate charge carrier transport, eliminate surface point defects, and enhance stability against moisture, light, and electron-beam irradiation. However, the synthesis strategies, diversity and complexity of structures, and optoelectronic applications that emanate from the self-assembly and regrowth of MHPs have not yet received much attention. Consequently, a comprehensive understanding of the design principles of self-assembled and fused MHP nanostructures will fuel further advances in their optoelectronic applications. In this Account, we review the latest developments in the self-assembly and regrowth of MHP NCs. We begin with a survey of the mechanisms, driving forces, and techniques for controlling MHP NC self-assembly. We then explore the phase transition of fused MHP nanostructures at the atomic level, delving into the mechanisms of facet-directed connections and the kinetics of their shape-modulation behavior, which have been elucidated with the aid of high-resolution transmission electron microscopy (HRTEM) and first-principles density functional theory calculations of surface energies. We further outline the applications of assembled and fused nanostructures. Finally, we conclude with a perspective on current challenges and future directions in the field of MHP NCs.

Despite tidal action, which is influenced by sea level rise, having a substantial impact on plant communities, salt marsh plant communities in coastal wetlands also act as a coastal zone barrier. Phragmites australis and Spartina alterniflora were selected for the experiment in the Yellow River Delta wetland. The mechanical characteristics of the plants in the Yellow River Delta were investigated by field sampling, and the mechanical experimental data were used to simulate plant stresses under natural conditions using the ANSYS model based on finite element theory. The results are as follows: Assuming that the 2 plants have the same stem diameter, the deformation of S. alterniflora is greater than that of P. australis under both static tension and pressure conditions, confirming the phenomenon that the P. australis material has stronger strength resistance properties. When this model was applied to the force analysis in the natural state, it was discovered that the material strength attribute of P. australis is higher than that of S. alterniflora . From the perspective of morphology and structure, the stout stem of S. alterniflora can greatly alleviate the stress of itself under external force and greatly reduce the invasion effect of external force because field conditions are limited and do not reflect immediate mechanical feedback. The model simulation provides a way to accurately and efficiently obtain the mechanical action of plant body when discussing the mechanical action similar to wave action on plant stem and to explain some ecological phenomena from the perspective of mechanics.

Lead halide perovskites (LHPs) have attracted a tremendous amount of attention because of their applications in solar cells, lighting, and optoelectronics. However, the atomistic principles underlying their decomposition processes remain in large part obscure, likely due to the lack of precise information about their local structures and composition along regions with dimensions on the angstrom scale, such as crystal interfaces. Aberration-corrected scanning transmission electron microscopy combined with X-ray energy dispersive spectroscopy (EDS) is an ideal tool, in principle, for probing such information. However, atomic-resolution EDS has not been achieved for LHPs because of their instability under electron-beam irradiation. We report the fabrication of CsPbBr

Globalization of social and economic activities has led to the large-scale redistribution of plant species. The issue of whether alien species are invasive and thus pose a threat to local ecosystems has attracted attention in recent years. The characteristics of invasive alien species and the mechanism of successful invasion are still unclear. Here, we downloaded plant trait data on TRY-Plant Trait Database and classified alien species into four groups: high, medium, noteworthy, and harmless according to their distribution and degree of harm to local plant communities. We clarified the relationship between plant functional traits and invasion level, and established a prediction model based on plant functional traits and taxonomy. Our study found that species with smaller seeds, smaller individuals, lower special leaf area and longer seed bank longevity are more likely to be an invasive species after introduction to foreign ecosystems. In addition, seed longevity and seed mass are important for plants’ invasion. In summary, exotic species with longer seedbank longevity and lower seed dry mass are more likely to be invasive in China. We also trained two predictive models based on the recursive split tree method to check if we can predict a species’ invasion. Combining the two model together, statistically, we could predict if a species is invasive from its traits and taxonomy with a 91.84% accuracy. This model could help local governments, managers and stakeholders to evaluate shall we introduce some plant species in China.

Staphylococcus aureus is a common pathogen that causes various infections. Therefore, it is crucial to develop a fast and easy detection method for diagnosing and preventing S. aureus infections. In this study, MIRA assay was developed and validated (specificity; 100%) for the detection of S. aureus with nuc as the target gene. The reaction temperature and reaction time were then optimized, and the best reaction was at 40°C, 20 min. The assay could detect S. aureus in only 25 min. Additionally, the limit of detection of MIRA was 5 × 102 CFU/ml, 10-fold lower than that of the traditional PCR. Furthermore, this assay efficiently detected 219 S. aureus of 335 strains obtained from different bacterial samples (detection accuracy; 99.40%). In conclusion, this study provides a rapid and easy-to-operate method for the detection of S. aureus, and thus can be used for the timely diagnosis and prevention of S. aureus infection.

Grain boundaries (GBs) have a profound impact on mechanical, chemical, and physical properties of polycrystalline materials. Comprehension of atomic and electronic structures of different GBs in materials can help to understand their impact on materials' properties. Here, with aberration-corrected scanning transmission electron microscopy (STEM), the atomic structure of a 90° twist GB s in CsPbBr

The all-inorganic nature of CsPbI3 perovskites allows to enhance stability in perovskite devices. Research efforts have led to improved stability of the black phase in CsPbI3 films; however, these strategies-including strain and doping-are based on organic-ligand-capped perovskites, which prevent perovskites from forming the close-packed quantum dot (QD) solids necessary to achieve high charge and thermal transport. We developed an inorganic ligand exchange that leads to CsPbI3 QD films with superior phase stability and increased thermal transport. The atomic-ligand-exchanged QD films, once mechanically coupled, exhibit improved phase stability, and we link this to distributing strain across the film. Operando measurements of the temperature of the LEDs indicate that KI-exchanged QD films exhibit increased thermal transport compared to controls that rely on organic ligands. The LEDs exhibit a maximum EQE of 23 % with an electroluminescence emission centered at 640 nm (FWHM: ≈31 nm). These red LEDs provide an operating half-lifetime of 10 h (luminance of 200 cd m-2 ) and an operating stability that is 6× higher than that of control devices.

Tidal marsh wetlands in the Yellow River Delta provide valuable eco-services to the local population and global ecology. However, this area is suffering from serious degradation under the stresses of social development and climate change. Hydrological connectivity, a new framework in hydrology and ecology, has been proposed as the main factor affecting the ecological processes in coastal wetlands; however, its role in hydrology–soil–vegetation interactions remains unclear. In this study, the researchers parametrically quantified the hydrological connectivity in the tidal marsh wetlands and analyzed its relationship with Phragmites australis, one of the dominant species in this area. Our results showed threshold-like effects on the interaction between hydrological connectivity and P. australis on the plot scale. When biomass is lower than 2.2 kg/m2, the population density and structure size were found to increase with hydrological connectivity. When the biomass is higher than the threshold, the plots disconnected hydrologically because of high water consumption. Compared with soil chemistry, salinity, and water soil content, hydrological connectivity in the surface soil layer is more strongly linked to the plant traits and spatial structure in the tidal marsh wetlands due to the narrow ranges of other variables. Based on the authors’ analysis, the researchers do not recommend dense plantation of P. australis, especially near the freshwater sources in the tidal marsh, because of its high reproduction ability and competitive nature, which may cut the freshwater connectivity off, lowering the richness of plant species and habitat diversity.

Lead halide compounds, including lead halide perovskite nanocrystals (NCs), have attracted the interest of researchers in optoelectronics and photonics because of their high photoluminescence quant...

Considering the safety of ammunition, safety and arming (S&A) devices are usually designed in pyrotechnics to control energy transfer through a movable barrier mechanism. To achieve both intelligence and miniaturization, electrothermal actuators are used in MEMS S&A devices, which can drive the barrier to an arming position actively. However, only when the actuators’ energy input is continuous can the barrier be stably kept in the arming position to wait for ignition. Here, we propose the design and characterization of a double-layer electrothermal MEMS S&A Device with a bistable mechanism. The S&A device has a double-layer structure and four groups of bistable mechanisms. Each bistable mechanism consists of two V-shape electrothermal actuators to drive a semi-circular barrier and a pawl, respectively, and control their engagement according to a specific operation sequence. Then, the barrier can be kept in the safety or the arming position without energy input. To improve the device’s reliability, the four groups of bistable mechanisms are axisymmetrically placed in two layers to constitute a double-layer barrier structure. The test results show that the S&A device can use constant-voltage driving or the capacitor–discharge driving to drive the double-layer barrier to the safety or the arming position and keep it on the position passively by the bistable mechanism.

Molecular doping has recently been shown to improve the operating characteristics of organic photovoltaics (OPVs). Here, we prepare neutral Diquat (DQ) and use it as n-dopant to improve the perform...

Summary Solution-processed colloidal quantum dots (CQDs) are promising optoelectronic materials; however, CQD solids have, to date, exhibited either excellent transport properties but fusion among CQDs or limited transport when QDs are strongly passivated. Here, we report the growth of monolayer perovskite bridges among quantum dots and show that this enables the union of surface passivation with improved charge transport. We grow the perovskite layer after forming the CQD solid rather than introducing perovskite precursors into the quantum dot solution: the monolayer of perovskite increases interdot coupling and decreases the distance over which carriers must tunnel. As a result, we double the diffusion length relative to reference CQD solids and report solar cells that achieve a stabilized power conversion efficiency (PCE) of 13.8%, a record among Pb chalcogenide CQD solar cells.

Summary Luminescent solar concentrators (LSCs) enable large-area collection of sunlight relevant to building-integrated photovoltaics. Reduced-dimensional metal halide perovskite nanoplatelets (PNPLs) have recently emerged as candidates for low-loss large-area LSCs due to the optoelectronic properties of perovskites combined with the large Stokes shift attainable using the multiple quantum well (MQW) structure. LSCs using bromine-based PNPLs have been demonstrated; however, the band gaps of bromine-based perovskites limit the absorption range. Iodine-based PNPLs allow broader absorption, but emission can be achieved only if the chemistry of PbIx2−x precursor complexes is engineered to provide the appropriate MQW distribution. Here, by controlling the polarity and Lewis basicity of the precursor solution, we modify the solvent-Pb2+ coordination and synthesize PNPLs having a uniform MQW distribution. This improves energy funneling, enabling a film PLQY (photoluminescence quantum yield) of 56% and 10 × 10 cm LSCs with an optical conversion efficiency of 2.0%, a 1.3-fold enhancement compared to the best previously reported room-temperature-fabricated perovskite LSCs.

Blue-emitting perovskites can be easily attained by precisely tuning the halide ratio of mixed halide (Br/Cl) perovskites (MHPs). However, the adjustable halide ratio hinders the passivation of Cl ...

We acknowledge the use of KAUST Core Lab and KAUST Solar Center facilities. This work was supported by KAUST and the Office of Sponsored Research (OSR) under award no. OSR-2017-CRG-3380. F.G. is a Wallenberg Academy Fellow.

The leaf surfaces of plants are important organs for retaining particulate matter (PM). They can be renewed via washout processes (e.g., rainfall), thereby restoring the ability to retain new PM. Most of the current studies have focused on the mechanisms of rainfall characteristics on the renewal of PM on plant leaf surfaces and interspecific differences, while the effects of different leaf heights on PM renewal within the same plant canopy have been less studied. In addition, the dynamics of PM during rainfall, especially the water-soluble ions (WSII) component, are often neglected. This research used Salix matsudana, a tree species with a significant natural height difference between the upper and lower leaves of its canopy, as its study object. Using artificially simulated rainfall, the rainfall intensity was quantified as low, medium, and high (i.e., 30 mm/h, 45 mm/h, and 60 mm/h), and the rainfall process was divided into three sub-stages: pre (0-20 min), mid (20-40 min), and post (40-60 min). The experimental setup was divided into upper (2 m) and lower leaves (1 m) according to the height of the canopy. The concentration and distribution of water-insoluble PM (WIPM) were obtained using the elution weighing method, whereas WSII were obtained using ion chromatography. The dynamics of WIPM and WSII during the removal of PM from the leaf surface by rainfall were studied at different canopy heights, and the results showed that the composition and proportions of WIPM and WSII varied at different stages of the rainfall process and that the concentrations of WIPM and WSII removed from the upper leaves differed slightly from those of the lower leaves. In particular, the concentrations of WIPM and WSII removed from the lower leaves were greater than those from the upper leaves at high rainfall intensity (60 mm/h), showing consistency between rainfall removal of PM from the leaf surface at different heights within the plant canopy and deposition of PM, while at low (30 mm/h) and medium (45 mm/h) rainfall intensities the performance was slightly different.

Topological defects such as dislocations in crystalline materials usually have major impacts on materials' mechanical, chemical and physical properties. Detailed knowledge of dislocation core structures is essential to understand their impacts on materials' properties. However, compared with imaging of core structures of edge dislocations, direct imaging of a screw dislocation core is challenging from the traditional edge-on direction because the atomic displacements are parallel to the screw dislocation line. Here, a screw dislocation with a Burgers vector 1/2[110] in orthorhombic CsPbBr

The invasion of Spartina alterniflora (S. alterniflora) has caused serious damage to coastal wetland ecosystems in China, especially the mangrove wetlands in South China. This study aimed to validate the effect of imazapyr on S. alterniflora and soil. The controlled experiment was conducted in May 2021 at the Zhangjiangkou Mangrove Wetland Reserve. In the experiment, 25% (W) imazapyr was used, and six treatments were set up: 3035, 6070, and 9105 mL/acre 25% imazapyr and 1299, 2604, and 5202 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr. The results showed no side effects on mangrove plants in the spraying area. The highest control efficiency (95.9%) was given by 2604 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr. The residues of imazapyr in different soils were reduced to 0.10–0.59 mg/kg. The sequencing results showed no significant difference in the overall bacterial communities under different treatments (p &gt, 0.05). The soil bacterial diversity in the samples with adjuvant was higher than that in the samples without adjuvant, while the abundance values were the opposite. There were 10 main communities (&gt, 0.3%) at phylum level in all soil samples, among which Proteobacteria, Bacteroidetes, Acidobacteria, Chloflexi, and Actinobacteria were the dominant communities, and the latter four’s abundance changed significantly (p &lt, 0.05). There were significant abundance differences between the groups of oligotrophic and eutrophic bacteria. The redundancy analysis and Monte Carlo tests showed that the total organic carbon (TOC), total phosphorus (TP), available phosphorus (AP), ammonia nitrogen, and total nitrogen were the main factors affecting soil bacterial diversity. At the same time, TOC, AP, and TP were the most critical factors affecting the overall characteristics of soil bacterial communities in different treatments, while soil residues had no significant effect on bacteria. This might be due to the addition and degradation of imazapyr and the coverage of S. alterniflora. The best recommendation is 2604 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr to be applied in China’s mangrove wetland reserves and coastal wetlands.

Background: Desmoplastic small round cell tumor (DSRCT) mostly arose in the abdominopelvic cavity is an aggressive sarcoma with poor prognosis. The purpose of this study is to analyze ultrasonographic performance in prediction of prognosis of DSRCT.Method: Between March 1999 and October 2019, a total of 27 patients with pathologically confirmed DSRCT in our hospital were conducted. Clinical and ultrasonographic characterizations, including age, sex, symptoms, tumor size, number, location, shape, margin, echogenicity, homogeneity, vascularity, and metastases were recorded and analyzed with overall survival (OS) by using univariate analysis.Result: Ultrasonographic performance of DSRCT were irregular (74%), posterior echo enhancement (63%), calcification (51.9%), and liquefaction (55.6%) in tumors companied with ascites (63%), hydronephrosis (59%) and metastases (63%). The median OS was 22 months (range 7–36 months) and 5-year OS rate was 19.6%. Using univariate analysis, a higher hazard ratio (HR) of mortality was associated with liquefaction (HR: 3.09, 95% CI:1.23-7.76, p=0.016) and bone metastasis (HR: 2.95, 95%CI: 1.16-7.49, p=0.023). According to a risk staging system developed by selected predictors (low = neither liquefaction nor bone involvement; moderate = either liquefaction or bone involvement; high = both liquefaction and bone involvement), 40%, 10%, and 0 of 3-year survival were found in the low, moderate, and high risk patients, respectively.Conclusion: Ultrasound imaging is effective to evaluate prognosis of DSRCT. Findings of liquefaction and bone involvement in the ultrasonography may predict a poor prognosis of DSRCT patients.

Most studies to date on SnSe thermal transport are focused on single crystals and polycrystalline pellets that are obtained using high-temperature processing conditions and sophisticated instruments. The effects of using sub-10 nm-size SnSe nanocrystals on the thermal transport and thermoelectric properties have not been studied to the best of our knowledge. Here, we report the synthesis of sub-10 nm colloidal surfactant-free SnSe NCs at a relatively low temperature (80 °C) and investigate their thermoelectric properties. Pristine SnSe NCs exhibit p-type transport but have a modest power factor of 12.5 μW m−1 K−2 and ultralow thermal conductivity of 0.1 W m−1 K−1 at 473 K. Interestingly, the one-step post-synthesis treatment of NC film with methylammonium iodide can switch the p-type transport of the pristine film to n-type. The power factor improved significantly to 20.3 μW m−1 K−2, and the n-type NCs show record ultralow thermal conductivity of 0.14 W m−1 K−1 at 473 K. These surfactant-free SnSe NCs were then used to fabricate flexible devices that show superior performance to rigid devices. After 20 bending cycles, the flexible device shows a 34% loss in the power factor at room temperature (295 K). Overall, this work demonstrates p- and n-type transport in SnSe NCs via the use of simple one-step post-synthesis treatment, while retaining ultralow thermal conductivity.

Wind erosion from agricultural fields contributes substantial amounts of particulate matter (PM) in the form of dust to the atmosphere, with significant impacts on air quality and human health. Vegetation barriers affect particle transport via altering air flow, yet the impact of windbreaks on PM concentrations from agricultural soil erosion is still unknown. This study describes brief campaigns to explore the effects of windbreaks on PM concentrations in Zhangbei County, Heibei Province, China. Measurements were made in arable lands with windbreaks, of which the dominant tree species was Populus, following dust events from April to May, when the trees were without leaves. We selected windbreaks with different structures and measured PM concentrations at the windward and the leeward sides of the windbreaks, using high time-resolution measurements. The effects of windbreaks were quantified by calculating the PM concentration ratios in front of and behind the windbreaks. During dust events, the average value of maximum PM10 emissions was 109.87 μg/m3, which was above the threshold established by the World Health Organization (WHO) for air quality. The PM10 emissions increased with air temperature and wind speed. The highest PM10 emission was observed at a relative air humidity of 20%. PM1 and PM2.5 concentrations were not lower behind the windbreak than in front of the windbreak in most of the events, while PM10 concentrations could be reduced by an average of 27%. A significant increase in PM2.5/PM10 by 56.86% behind the windbreak indicates the high efficiency of the windbreak to reduce PM10 levels. Simply planting trees can, in some cases, increase downwind PM concentrations. Vegetation configuration and avoiding locating residential areas in the immediate lee of windbreaks should be considered when planning windbreaks.

Summary Defect passivation and surface modification of hybrid perovskite films are essential to achieving high power conversion efficiency (PCE) and stable perovskite photovoltaics. Here, we demonstrate a facile strategy that combines high PCE with high stability in CH3NH3PbI3 (MAPbI3) solar cells. The strategy utilizes inorganic perovskite quantum dots (QDs) to distribute elemental dopants uniformly across the MAPbI3 film and attach ligands to the film’s surface. Compared with pristine MAPbI3 films, MAPbI3 films processed with QDs show a reduction in tail states, smaller trap-state density, and an increase in carrier recombination lifetime. This strategy results in reduced voltage losses and an improvement in PCE from 18.3% to 21.5%, which is among the highest efficiencies for MAPbI3 devices. Ligands introduced with the aid of the QDs render the perovskite film’s surface hydrophobic—inhibiting moisture penetration. The devices maintain 80% of their initial PCE under 1-sun continuous illumination for 500 h and show improved thermal stability.

To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change, this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla, Quercus palustris, Platycladus orientalis, plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios (SRES). The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7 °C, and annual precipitation by 4.7–8.5 mm, depending on the emissions scenario used. These changes result in shifts in the range of each of the species. New suitable areas for distributions of B. platyphylla and Q. palustris will decrease in the future. The model points to significant shifts in the distributions of these species, withdrawing from their current ranges and pushing southward towards central Beijing. Most of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year period. The mixed broadleaf forests expand their ranges significantly. The P. orientalis forests, on the other hand, expand their range marginally. The results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 years. Water stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature reserves. There is a potential for the extinction of some species. Therefore, long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.

Many studies have qualitatively analyzed the response of hydrological characteristics to climate change in Haihe river basin, but quantitative research has been rare, which is essential for water resource management. To evaluate and quantitatively analyze the relationship between catchment runoff capacity and environmental factors, principal component analysis, step regression analysis, and sensitivity analysis were conducted. The results show that the runoff capacity of Haihe river basin was mainly controlled by vegetation types and soil texture; catchments with lower runoff capacity were mainly distributed in the upstream/northwest regions. In the catchments with middle runoff capacity, a 10% increase in precipitation (PRE), potential evapotranspiration (PE), and plant-available water coefficient (PAWC) would result in a 23.6% increase, 12.9% decrease, and 5.1% decrease in annual runoff, respectively, whereas in low runoff capacity catchments, a 10% increase in slope and leaf area index (LAI) would result in a 17.8% increase and 10.5% decrease in annual runoff, and in high runoff capacity catchments, a 10% increase in normalized differential vegetation index (NDVI) would result in a 12.6% increase in annual runoff. Soil conditions and vegetation configuration improvement in the upstream of Haihe river basin may contribute to the improvement of available water resources.

The rapid development of halide perovskite synthesis offers the opportunity to fabricate high-quality perovskite nanocrystals (NCs), whose structural uniformity can lead to assembled supra-structur...

The all-inorganic nature of CsPbI

The main factors controlling plant litter decomposition rates are litter quality and environmental factors. We investigated how different salinity and inundation conditions influence the decomposition rate and how litter quality affects dynamic change during the decomposition process in the Yellow River Delta wetland in northeastern China. To do this, we designed a field experiment using the litter bag method to study two selected dominant halophyte species (Phragmites australis and Suaeda salsa). We found litter decomposed faster when inundated across a range of salinities. Both the water chemical oxygen demand and NH3-N concentration were inversely correlated with salinity. The ratio of nitrogen to phosphorous showed an upward trend during the process of decomposition. The decomposition rate increased during the later stage of the process. Under inundation conditions, the decomposition rate of only S. salsa showed a positive correlation with salinity. The study results suggest that moderately higher salinity would increase anaerobic decomposition owing to the combined effect of salinity and inundation. The implications of our findings may be used to further assess the impact of environmental parameters and litter quality on the decomposition rate in estuarine wetland and can help determine a strategy for wetland reparation and remediation.

Dry deposition of particulate matter (PM) indicates the capacity of atmosphere self-depuration. To investigate seasonal dry deposition of PM in an urban forest, the concentration and ionic composition of PM2.5 (particulate matter with aerodynamic equivalent diameters less than 2.5 μm) and the deposition of PM and ions in PM at different layer were measured at three canopy heights in the Beijing Olympic Forest Park. Results showed that diurnal trends in PM concentration varied with height and that concentrations tended to be highest in the understory. During winter, when the absorption ability of plants, which withered, was reduced, and anthropogenic emissions, primarily from coal combustion, ion concentrations tended to be highest in the forest canopy. The anions SO42−, NO3−, and Cl− were the dominant ionic species, accounting for 82% of the total mass of water-soluble ions in PM2.5. Results showed a lower mass ratio of NO3−/SO42− (mean = 0.29, SD = 0.24), relative to previous studies, implying that vehicle emissions may have reduced in Beijing. The chemical forms of sulfate and nitrate were likely NH4NO3 and (NH4)2SO4; however, Ca(NO3)2 was the only chemical form detected based on the correlation coefficient between Ca2+ and NO3−. Concentrations of PM were negatively related to temperature and wind speed, and positively related to relative humidity. Within the forest canopy, the deposition velocity was low (high) during summer (winter). Furthermore, ion deposition fluxes were higher in the forest understory (1.5–6 m) during summer and in the canopy (6–10 m) during winter. This was attributed to seasonal trends in PM concentration.

Forests and wetlands, as two important ecosystems, play a crucial role in reducing the concentration of particulate matters. The main purpose of this study is to reveal the contribution of forest and wetland ecosystems to the reduction of particulate matter. We collected the concentration and meteorological data during the daytime in a forest and a wetland in the Olympic Park in Beijing. The main results are as follows: daily variation in the PM

In recent decades, China has experienced both rapid urbanization and heavy air pollution and the rapid urbanization trend would be continue in the next decade. Wetlands have been shown to be efficient in particle removal, primarily through dry deposition and leaf accumulation. Thus, a more comprehensive understanding of PM2.5 removal by wetlands during urbanization processes could inform urban planning. In the current study, three wetland plots, Cuihu Lake Park (CL), Summer Palace (SP), and Olympic Park (OP), were selected as low, medium, and highly degrees of urbanization site respectively based on the proportions of building and traffic district areas to compare the removal efficiencies. Results show the average dry deposition velocity in OP was significantly higher than CL and SP. Dry deposition is mainly influenced by meteorological conditions. Buildings and other infrastructure make the meteorological conditions conducive to deposition, resulting in higher wind velocity, higher temperature, and more intense turbulence between buildings. Variation in leaf accumulation was not statistically significant between the three plots, and plant species was the major factor affecting the amount of accumulation. The dry deposition contribution to particle removal increases with degree of urbanization. The average dry deposition accounted for 39.74%, 52.55%, and 62.75% at low, middle and high level respectively. Therefore, Wetlands with greater degree of urbanization improve PM2.5 removal efficiency primarily by accelerating the dry deposition process. The result emphasizes the importance of wetlands in particle removal in highly urbanized areas and thus more wetlands should be preserved and/or created during urban expansion.

Forests and vegetation are known to play an important role in capturing air pollutants, whereas the role of wetland plants in this context has been poorly understood. This study focused on particle accumulation in six common wetland plant species in a wetland in Beijing, China. The aim of the study was to show the capacity of the six plants species to accumulate particulates of two different size fractions (fine particles: diameter