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The maximum rate of Rubisco carboxylation (Vcmax) determines leaf photosynthetic capacity and is a key parameter for estimating the terrestrial carbon cycle, but its spatial information is lacking, hindering global ecological research. Here, we convert leaf chlorophyll content (LCC) retrieved from satellite data to Vcmax, based on plants' optimal distribution of nitrogen between light harvesting and carboxylation pathways. We also derive Vcmax from satellite (GOME-2) observations of sun-induced chlorophyll fluorescence (SIF) as a proxy of leaf photosynthesis using a data assimilation technique. These two independent global Vcmax products agree well (r2=0.79,RMSE=15.46µmol m−2 s−1, P<0.001) and compare well with 3672 ground-based measurements (r2=0.69,RMSE=13.8µmol m−2 s−1 and P<0.001 for SIF; r2=0.55,RMSE=18.28µmol m−2 s−1 and P<0.001 for LCC). The LCC-derived Vcmax product is also used to constrain the retrieval of Vcmax from TROPical Ozone Mission (TROPOMI) SIF data to produce an optimized Vcmax product using both SIF and LCC information. The global distributions of these products are compatible with Vcmax computed from an ecological optimality theory using meteorological variables, but importantly reveal additional information on the influence of land cover, irrigation, soil pH, and leaf nitrogen on leaf photosynthetic capacity. These satellite-based approaches and spatial Vcmax products are primed to play a major role in global ecosystem research. The three remote sensing Vcmax products based on SIF, LCC, and SIF+LCC are available at https://doi.org/10.5281/zenodo.6466968 (Chen et al., 2022), and the code for implementing the ecological optimality theory is available at https://github.com/SmithEcophysLab/optimal_vcmax_R and https://doi.org/10.5281/zenodo.5899564 (last access: 31 August 2022) (Smith et al., 2022).

Abstract A Zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate, which involves electroplating Zn from a non‐aqueous electrolyte, followed by passivation in an oleic acid (OA) solution. The electrodeposited Zn coatings were porous, which facilitated the formation of a chemical conversion layer of Zn oleate (ZO) during OA passivation. The Zn coating after passivation had a two‐layer structure, which included an outer layer of ZO with a thickness of ∼26 μm and an inner layer of Zn with a thickness of ∼6 μm. The outer layer ZO is a type of metal soap with a smooth surface and durable hydrophobicity, such that water droplets can easily slip off its surface. Corrosion testing and electrochemical measurements in 3.5 wt.% NaCl aqueous solution indicate that the Zn coating after OA passivation exhibits outstanding anti‐corrosion properties compared with those exhibited by pure Zn coating. The corrosion products and mechanism of the two‐layer coating were explored. This study shows that smooth metal oleate coatings can provide hydrophobicity and corrosion resistance simultaneously to mild steel substrates.

Abstract The impact of strong Programmed Death-ligand 1 (PD-L1) expression on the clinical outcomes of osimertinib in treatment naïve advanced Epidermal Growth Factor Receptor (EGFR)-mutant Non-small Cell Lung Cancer (NSCLC) patients remains uncertain. We enrolled advanced NSCLC patients who harbored sensitizing EGFR mutation and were treated first-line with osimertinib between 2017 and 2021. The PD-L1 expression level was also tested. A total of 85 patients were included. The objective response rate to osimertinib was 78.9%, with the disease control rate being 90.8%. Median Progression-free Survival (PFS) was 22.1 months, while median Overall Survival (OS) was not reached (NR). Patients with the exon 19 deletion experienced better PFS than those with the exon 21 L858R mutation (NR vs 12.4 months, aHR 0.24 (95% CI, 0.10 to 0.57); p = 0.001). Seventy-one of these 85 patients had reported on their PD-L1 expression. Patients with a PD-L1

Abstract Aphelenchoides besseyi could cause great yield losses of rice and many economically important crops. Acetylcholinesterase (AChE) inhibitors were commonly used to manage plant-parasitic nematodes. However, nematodes resistant to AChE inhibitors have been increasingly reported due to the extensive use of these chemicals. The current study was aimed to establish the correlation between fenamiphos (an AChE-inhibitor) sensitivities and acetylcholinesterase genes (ace) by analyzing two isolates of A. besseyi (designated Rl and HSF), which displayed differential sensitivities to fenamiphos. The concentrations of fenamiphos that led to the death of 50% (LD50) of Rl and HSF were 572.2 ppm and 129.4 ppm, respectively. Three ace genes were cloned from A. besseyi and sequenced. Sequence searching and phylogenic analyses revealed that AChEs of R1 and HSF shared strong similarities with those of various vertebrate and invertebrate species. Molecular docking analysis indicated that AChEs-HSF had much higher affinities to fenamiphos than AChEs-R1. Quantitative reverse transcriptase-PCR analyses revealed that expression of three ace genes were downregulated in HSF but were upregulated in Rl after exposure to 100 ppm fenamiphos for 12 h. The results indicated that the expression of the ace genes was modulated in response to fenamiphos in different nematode strains. An increased expression of the ace genes might contribute to fenamiphos-insensitivity as seen in the Rl isolate.

Abstract Disposal of long-lived fission products (LLFPs) produced in reactors has been paid a lot attention for sustainable and clean nuclear energy. Although a few transmutation means have been proposed to address this issue, there are still scientific and/or engineering challenges to achieve efficient transmutation of LLFPs. In this study, we propose a novel concept of advanced nuclear energy system (ANES) for transmuting LLFPs efficiently without isotopic separation. The ANES comprises intense photoneutron source (PNS) and subcritical reactor, which consist of lead–bismuth (Pb-Bi) layer, beryllium (Be) layer, and fuel, LLFPs and shield assemblies. The PNS is produced by bombarding radioactive cesium and iodine target with a laser-Compton scattering (LCS) γ-ray beam. We investigate the effect of the ANES system layout on transmutation efficiency by Monte Carlo simulations. It is found that a proper combination of the Pb-Bi layer and the Be layer can increase the utilization efficiency of the PNS by a factor of ~ 10, which helps to decrease by almost the same factor the LCS γ-beam intensity required for driving the ANES. Supposing that the ANES operates over 20 years at a normal thermal power of 500 MWt, five LLFPs including 99Tc, 129I, 107Pd, 137Cs and 79Se could be transmuted by more than 30%. Their effective half-lives thus decrease drastically from ~ 106 to less than 102 years. It is suggested that this successful implementation of the ANES paves the avenue towards practical transmutation of LLFPs without isotopic separation.

Abstract Background Mutations in certain genes are known to increase breast cancer risk. We study the relevance of rare protein-truncating variants (PTVs) that may result in loss-of-function in breast cancer susceptibility genes on tumor characteristics and survival in 8852 breast cancer patients of Asian descent. Methods Gene panel sequencing was performed for 34 known or suspected breast cancer predisposition genes, of which nine genes (ATM, BRCA1, BRCA2, CHEK2, PALB2, BARD1, RAD51C, RAD51D, and TP53) were associated with breast cancer risk. Associations between PTV carriership in one or more genes and tumor characteristics were examined using multinomial logistic regression. Ten-year overall survival was estimated using Cox regression models in 6477 breast cancer patients after excluding older patients (≥75years) and stage 0 and IV disease. Results PTV9genes carriership (n = 690) was significantly associated (p < 0.001) with more aggressive tumor characteristics including high grade (poorly vs well-differentiated, odds ratio [95% confidence interval] 3.48 [2.35–5.17], moderately vs well-differentiated 2.33 [1.56–3.49]), as well as luminal B [HER−] and triple-negative subtypes (vs luminal A 2.15 [1.58–2.92] and 2.85 [2.17–3.73], respectively), adjusted for age at diagnosis, study, and ethnicity. Associations with grade and luminal B [HER2−] subtype remained significant after excluding BRCA1/2 carriers. PTV25genes carriership (n = 289, excluding carriers of the nine genes associated with breast cancer) was not associated with tumor characteristics. However, PTV25genes carriership, but not PTV9genes carriership, was suggested to be associated with worse 10-year overall survival (hazard ratio [CI] 1.63 [1.16–2.28]). Conclusions PTV9genes carriership is associated with more aggressive tumors. Variants in other genes might be associated with the survival of breast cancer patients. The finding that PTV carriership is not just associated with higher breast cancer risk, but also more severe and fatal forms of the disease, suggests that genetic testing has the potential to provide additional health information and help healthy individuals make screening decisions.

Abstract The impact of different first-line epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI)s to the clinical efficacy of osimertinib in EGFR-mutant non-small-cell lung cancer (NSCLC) patients with acquired T790M was still unclear. We enrolled 733 advanced EGFR-mutant NSCLC patients with gefitinib, erlotinib or afatinib as first-line EGFR-TKIs treatment for analysis. 373 patients received re-biopsies after progressive disease to first-line EGFR-TKIs treatment, and the total positive rate of T790M was 51.7%. 151 patients who harbored T790M received osimertinib as subsequent treatment. Among them, the median progression-free survival (PFS) of first-line EGFR-TKI (PFS1) was 14.0 months, and the median PFS of osimertinib (PFS2) was 10.1 months. The median PFS1 + PFS2 was 27.5 months, and the median overall survival from first-line EGFR-TKI was 61.3 months. Concerning different first-line EGFR-TKIs, the median PFS2 was 10.9 months in the gefitinib group, 10.0 months in the erlotinib group, and 6.7 months in the afatinib group (p = 0.534). The median PFS1 + PFS2 was 27.7 months, 26.8 months and 24.0 months in the gefitinib, erlotinib, and afatinib group, respectively (p = 0.575). In conclusion, both first-generation and second-generation EGFR-TKIs sequential osimertinib treatment provided good clinical efficacy in advanced EGFR-mutant NSCLC patients with acquired T790M mutation.

Effective separation of signal from noise (including physiological processes and head motion) is one of the chief challenges for improving the sensitivity and specificity of resting-state fMRI (rs-fMRI) measurements and has a profound impact when these noise sources vary between populations. Independent component analysis (ICA) is an approach for addressing these challenges. Conventionally, due to the lower amount of temporal than spatial information in rs-fMRI data, spatial ICA (sICA) is the method of choice. However, with recent developments in accelerated fMRI acquisitions, the temporal information is becoming enriched to the point that the temporal ICA (tICA) has become more feasible. This is particularly relevant as physiological processes and motion exhibit very different spatial and temporal characteristics when it comes to rs-fMRI applications, leading us to conduct a comparison of the performance of sICA and tICA in addressing these types of noise. In this study, we embrace the novel practice of using theory (simulations) to guide our interpretation of empirical data. We find empirically that sICA can identify more noise-related signal components than tICA. However, on the merit of functional-connectivity results, we find that while sICA is more adept at reducing whole-brain motion effects, tICA performs better in dealing with physiological effects. These interpretations are corroborated by our simulation results. The overall message of this study is that if ICA denoising is to be used for rs-fMRI, there is merit in considering a hybrid approach in which physiological and motion-related noise are each corrected for using their respective best-suited ICA approach.

Satellite-based models have been widely used to simulate vegetation gross primary production (GPP) at the site, regional, or global scales in recent years. However, accurately reproducing the interannual variations in GPP remains a major challenge, and the long-term changes in GPP remain highly uncertain. In this study, we generated a long-term global GPP dataset at 0.05∘ latitude by 0.05∘ longitude and 8 d interval by revising a light use efficiency model (i.e., EC-LUE model). In the revised EC-LUE model, we integrated the regulations of several major environmental variables: atmospheric CO2 concentration, radiation components, and atmospheric vapor pressure deficit (VPD). These environmental variables showed substantial long-term changes, which could greatly impact the global vegetation productivity. Eddy covariance (EC) measurements at 95 towers from the FLUXNET2015 dataset, covering nine major ecosystem types around the globe, were used to calibrate and validate the model. In general, the revised EC-LUE model could effectively reproduce the spatial, seasonal, and annual variations in the tower-estimated GPP at most sites. The revised EC-LUE model could explain 71 % of the spatial variations in annual GPP over 95 sites. At more than 95 % of the sites, the correlation coefficients (R2) of seasonal changes between tower-estimated and model-simulated GPP are larger than 0.5. Particularly, the revised EC-LUE model improved the model performance in reproducing the interannual variations in GPP, and the averaged R2 between annual mean tower-estimated and model-simulated GPP is 0.44 over all 55 sites with observations longer than 5 years, which is significantly higher than those of the original EC-LUE model (R2=0.36) and other LUE models (R2 ranged from 0.06 to 0.30 with an average value of 0.16). At the global scale, GPP derived from light use efficiency models, machine learning models, and process-based biophysical models shows substantial differences in magnitude and interannual variations. The revised EC-LUE model quantified the mean global GPP from 1982 to 2017 as 106.2±2.9 Pg C yr−1 with the trend 0.15 Pg C yr−1. Sensitivity analysis indicated that GPP simulated by the revised EC-LUE model was sensitive to atmospheric CO2 concentration, VPD, and radiation. Over the period of 1982–2017, the CO2 fertilization effect on the global GPP (0.22±0.07 Pg C yr−1) could be partly offset by increased VPD (-0.17±0.06 Pg C yr−1). The long-term changes in the environmental variables could be well reflected in global GPP. Overall, the revised EC-LUE model is able to provide a reliable long-term estimate of global GPP. The GPP dataset is available at https://doi.org/10.6084/m9.figshare.8942336.v3 (Zheng et al., 2019).

The Taiwan Earth System Model (TaiESM) version 1 is developed based on Community Earth System Model version 1.2.2 of National Center for Atmospheric Research. Several innovative physical and chemical parameterizations, including trigger functions for deep convection, cloud macrophysics, aerosol, and three-dimensional radiation–topography interaction, as well as a one-dimensional mixed-layer model optional for the atmosphere component, are incorporated. The precipitation variability, such as diurnal cycle and propagation of convection systems, is improved in TaiESM. TaiESM demonstrates good model stability in the 500-year preindustrial simulation in terms of the net flux at the top of the model, surface temperatures, and sea ice concentration. In the historical simulation, although the warming before 1935 is weak, TaiESM captures the increasing trend of temperature after 1950 well. The current climatology of TaiESM during 1979–2005 is evaluated by observational and reanalysis datasets. Cloud amounts are too large in TaiESM, but their cloud forcing is only slightly weaker than observational data. The mean bias of the sea surface temperature is almost 0, whereas the surface air temperatures over land and sea ice regions exhibit cold biases. The overall performance of TaiESM is above average among models in Coupled Model Intercomparison Project phase 5, particularly in that the bias of precipitation is smallest. However, several common discrepancies shared by most models still exist, such as the double Intertropical Convergence Zone bias in precipitation and warm bias over the Southern Ocean.

To effectively describe the uncertainty of remote sensing image segmentation, a novel region-based algorithm using fuzzy clustering and Kullback-Leibler (KL) distance is proposed. By regular tessellation, the image domain is completely divided into several sub-blocks to overcome the complex noise existed in high-resolution remote sensing images. Taking the blocks as the basic processing units, KL divergence is used to model the distance between blocks and clusters, which enables the model to describe the uncertainty of the non-similarity relationship. Besides, based on the theory of Markov Random Field (MRF), the regionalized KL entropy regularization term is established and added to the objective function to further consider the spatial constraints. Finally, the optimal segmentation results are obtained by estimating the parameters. The experiments carried out on different kinds of remote sensing images by comparing algorithms fully demonstrate the performance of the proposed algorithm.

Abstract Using a sample of $$1.31\times 10^{9} ~J/\psi $$ 1.31×109J/ψ events collected with the BESIII detector, we perform a study of $$J/\psi \rightarrow \gamma K{\bar{K}}\eta '$$ J/ψ→γKK¯η′ . X(2370) is observed in the $$K{\bar{K}}\eta '$$ KK¯η′ invariant-mass distribution with a statistical significance of $$8.3\sigma $$ 8.3σ . Its resonance parameters are measured to be $$M=2341.6\pm 6.5 \, \text {(stat.)} \pm 5.7 \, \text {(syst.)}~ \hbox {MeV}/c^{2}$$ M=2341.6±6.5(stat.)±5.7(syst.)MeV/c2 and $$\Gamma = 117\pm 10 \, \text {(stat.)}\pm 8 \, \text {(syst.)}~\hbox {MeV}$$ Γ=117±10(stat.)±8(syst.)MeV . The product branching fractions for $$J/\psi \rightarrow \gamma X(2370),X(2370)\rightarrow K^{+}K^{-}\eta '$$ J/ψ→γX(2370),X(2370)→K+K-η′ and $$J/\psi \rightarrow \gamma X(2370),X(2370)\rightarrow K_{S}^{0}K_{S}^{0}\eta '$$ J/ψ→γX(2370),X(2370)→KS0KS0η′ are determined to be $$(1.79\pm 0.23\, \text {(stat.)}\pm 0.65\,\text {(syst.)})\times 10^{-5}$$ (1.79±0.23(stat.)±0.65(syst.))×10-5 and $$(1.18\pm 0.32\, \text {(stat.)}\pm 0.39\, \text {(syst.)})\times 10^{-5}$$ (1.18±0.32(stat.)±0.39(syst.))×10-5 , respectively. No evident signal for X(2120) is observed in the $$K{\bar{K}}\eta '$$ KK¯η′ invariant-mass distribution. The upper limits for the product branching fractions of $${\mathcal {B}}(J/\psi \rightarrow \gamma X(2120)\rightarrow \gamma K^{+} K^{-} \eta ')$$ B(J/ψ→γX(2120)→γK+K-η′) and $${\mathcal {B}}(J/\psi \rightarrow \gamma X(2120)\rightarrow \gamma K_{S}^{0} K_{S}^{0} \eta ')$$ B(J/ψ→γX(2120)→γKS0KS0η′) are determined to be $$1.49\times 10^{-5}$$ 1.49×10-5 and $$6.38\times 10^{-6}$$ 6.38×10-6 at the 90% confidence level, respectively.

Knowledge gained about the mangrove species mapping is essential to understand mangrove species development and to better estimate their ecological service value. Spectral bands and spatial resolution of remote sensing data are two important factors for accurate discrimination of mangrove species. In this study, mangrove species classification in Shenzhen Bay, China was performed by using Sentinel 2 (S2) Multi Spectral Instrument (MSI) data and Google Earth (GE) high resolution imagery as data sources and their suitability in mapping mangrove forest at a species level was examined. In the classification feature groups, the spectral bands were from the S2 MSI data and the textural features were based on GE imagery. The SVM classifier was used in mangrove species classification processing with eight groups of features, which were based on different S2 spectral bands and different GE spatial resolution textural features. The highest overall accuracy of our mapping results was 78.57% and the Kappa coefficient was 0.74, which indicated great potential of using the combination of S2 MSI and GE imagery for distinguishing and mapping mangrove species.

Abstract We report on the measurement of the Central Exclusive Production of charged particle pairs h + h − (h = π, K, p) with the STAR detector at RHIC in proton-proton collisions at s $$ \sqrt{s} $$ = 200 GeV. The charged particle pairs produced in the reaction pp → p′ + h + h − + p′ are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles’ transverse momenta and pseudorapidities as well as by the forward-scattered protons’ momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0.04 GeV2 < −t 1 , −t 2 < 0.2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range |η| < 0.7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of π + π − and K + K − pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to π + π − production. For π + π − production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f 0(980), f 2(1270) and f 0(1500), with a possible small contribution from the f 0(1370). Fits to the extrapolated differential cross section as a function of t 1 and t 2 enable extraction of the exponential slope parameters in several bins of the invariant mass of π + π − pairs. These parameters are sensitive to the size of the interaction region.

In this paper, a two dimensional underdetermined direction of arrival estimation (DOA) of quasi-stationary signals using a parallel nested array structure is investigated. The quasi-stationary signals have the statistical property that they remain locally static over one frame but exhibit differences from one time frame to others. The special time domain property enables us to perform underdetermined direction-of-arrival estimation in time domain. By exploiting the temporary diversity of the quasi-stationary signals and effective difference coarray virtual array aperture provided inherently in the parallel nested array, more degrees of freedom can be used to resolve DOA estimation. The Khatri-Rao operation for the cross covariance matrix of the subarrays received data is adopted to convert the 2-D DOA estimation problem into two separate one-dimensional DOA estimation problems. Then, a subspace-based estimation of signal parameters via rotational invariance technique and a sparsity-based sparse Bayesian learning are proposed to realize the according one-dimensional DOA estimation. And the estimated azimuth and elevation angles can be properly automatically paired. Simulation results are carried out to demonstrate the effectiveness of the proposed algorithms for the 2-D underdetermined DOA estimation.

The source region of the Yellow River is an important source of water conservation in the Qinghai-Tibet Plateau. It is also an animal husbandry base that has a major impact on China. Its ecological environment changes will have a major impact on the safe and sustainable development of water use in Asia. The alpine grassland is an important part of the ecosystem of the Yellow River source area, and the spatial differentiation characteristics of the plaque have important indication significance for the ecological environment succession. In this paper, the alpine grassland in the source region of the Yellow River is taken as the research object. Based on the aerial image of the unmanned aerial vehicle, the EGI threshold method is used to extract the vegetation patches and the bare plaques to obtain high-precision field monitoring data, and the landscape ecology principle is used to analyze the four types of alpine grassland. The morphological characteristics of plaques in different grassland types are studied, and the spatial indications of spatial sequences are used to study the ecological significance of plaque succession. The results show that the number of plaques in swamp meadows, alpine meadows, degraded meadows and alpine grassland increase significantly, the degree of fragmentation increase, and the area of vegetation patches decrease significantly. The area of bare plaque increase significantly as the main trend; the distribution and dominance of landscape plaques are analyzed; the swamp meadow have the highest spread, the best aggregation, and the largest proportion of vegetation plaque, the highest degree of dominance, alpine grassland Conversely; in terms of the complexity of landscape patch shape; the area-weighted shape index and the area-weighted fractal dimension increase with the order of swamp meadows, alpine meadows, degraded meadows and alpine grasslands, tending to be complex plaque space. The ecological risk intensity index of alpine grassland in the source region of the Yellow River varies greatly, and the ecological risk of alpine grassland is high. The results of this study provide data support for elucidating the mechanism of spatial differentiation of alpine grass plaques, provide scientific assistance for grassland monitoring and management in the source area, and it provides an important basis for further discussion on ecological system protection, animal husbandry economy and sustainable development of alpine grassland in China. At the same time, it provides important theoretical support and ecological indication significance for the understanding of the alpine grassland ecosystem succession in the source area of the Yellow River.

The source region of the Yellow River is an important ecological barrier in China. Since the 1990s, under the influence of various factors, its runoff has decreased and the ecological environment has deteriorated, which has attracted great attention of governments. Vegetation is the general term of plant communities covering the surface, which is the natural link between the atmosphere, water and soil. It plays an important role in air regulation, soil conservation and maintaining the stability of the whole ecosystem. Therefore, the study on the differential characteristics and topographic influencing factors of alpine grassland change in the source region of the Yellow River can provide reference for the ecological environment protection in -this region in the future. Based on the remote sensing data of MODIS NDVI, we studied the spatial distribution pattern and temporal variation characteristics of vegetation coverage in the source region of the Yellow River from 2000 to 2009 by means of maximum synthesis method, pixel dichotomy model method and trend analysis method. Furthermore, combined with DEM topographic elevation data, we discussed the influence of topographic factors such as elevation, slope and aspect on fractional vegetation cover (FVC) change. The results showed that: (1) From 2000 to 2009, the FVC in the source region of the Yellow River fluctuated upward, showing the spatial distribution characteristics of the southeast region > the central region > the northwest region; (2) During the ten years from 2000 to 2009, the almost constant of FVC accounted for the largest area, and the areas with increasing FVC mainly concentrated in the northeast and northwest of the studied region, the areas with reduced vegetation coverage were scattered in various places in the studied region, mainly in the form of minimal patches or spots; (3) Different terrain factors had different effects on FVC and the effect of altitude on FVC changes was significantly greater than that of slope and aspect. With the increase of altitude, the proportion of significant reduction in FVC increased firstly and then decreased, while the proportion of significant increase in FVC was decreasing and the proportion of almost unchanged in FVC was increasing; With the increase of slope, the proportion in the above three cases (significant reduction, significant increase and almost unchanged in FVC) was increased, decreased gradually and fluctuated respectively. Under different aspect, the proportion in the above three cases varied little, fluctuating only within 1%.

As one of the most popular surveillance technologies in the 21st century, Lidar is applied in commercial, military and civilian applications. paper mainly introduces the development process of Chinese and American marine lidar detection technology, compares the hardware technical parameters of marine airborne laser lidar between China and the United States, and summarizes China's current airborne lidar detection technology and developed countries. Find the gap between developed countries. It introduces the most important application of this technology, and its contribution to the development of science and technology. Finally, summarize the various problems encountered in the development of the technology, analyse the reasons, and look forward to the future development trend.

There are many intertidal zones and island reefs in the coastal area, the traditional shipborne acoustic measurement method is extremely inefficient, so the coastal area three-dimensional integrated measurement has always been a difficult point in the field of remote sensing. Because the sea blue-green light window has good transparency and the laser point cloud data can quickly and accurately distinguish the characteristics of shallow sea water topography. At present, the most effective detection method for coastal areas in the world is the airborne dual-frequency laser radar detection technology, which has high measurement rate and wide coverage. The laser outputs both 1064nm and 532nm dual-wavelength laser, 1064nm laser forms sea surface echo, and 532nm laser penetrates sea water to form shallow sea and deep sea echo. However, during the propagation of seawater, the number of photon scattering increases with the increase of water depth, which will cause the attenuation of the echo signal. As a result, the detection of weak light in the large dynamic range is not high, which has been a difficult point for near-shore airborne sounding. To solve this problem, we designed a split-field, three-channel optical receiving system. The ZEMAX simulation results show that the dual-channel laser radar three-channel receiving optical system effectively reduces the optical crosstalk between the optical components and the channels, and achieves energy harvesting in different water depth channels. The structure dynamically compresses the photoelectric signal and improves the signal to noise ratio.

Wuzhou reach of Xunjiang River is the most valuable waterway in Guangxi. The research on the evolution of Xunjiang River in Wuzhou is of great practical significance in the aspects of river regulation and water conservancy construction. Based on Landsat images of normal water level in 1997, 2001, 2005, 2009, 2014 and 2018, this paper firstly conducts a quantitative analysis of evolution of the watercourse and shoals in Wuzhou section of Xunjiang River through using RS and GIS. Then the relationships between the changes of river course and sandbars of the research area and the annual rainfall and vegetation coverage of the upstream region are analyzed to determine the causes of the changes of watercourse and shoals of Xunjiang River in Wuzhou. The results show that the riverway contracted with a contraction amount of about 9.93 km2 from 1997 to 2005, and the expansion volume of sandbars was about 12.21 km2. From 2005 to 2014, the watercourse approximately expanded 12.33 km2, and the shoals shrank about 12.49 km2. From 2014 to 2018, the river course was a contraction trend, reducing about 1.57 km2 in area; the sandbars showed an expanding trend, with an expanding amount of about 0.82 km2. The changes of river channel and shoals are mainly influenced by the incoming water and silt from the upper reaches and are related to the annual rainfall and vegetation coverage of the upstream area. The correlation coefficient between watercourse area and upstream annual rainfall is 0.26, and that between riverway area and upstream vegetation coverage is 0.78. However, the correlations between the area of shoals and the annual rainfall and vegetation coverage of the upstream region are contrary to that of the river channel. The correlation coefficients between the area of shoals and the annual rainfall and vegetation coverage of the upstream district are −0.28 and −0.83 respectively.

China's economy has experienced rapid development in the past few decades, and economic development has also brought serious pollution problems, which has attracted wide attention of scholars at home and abroad. Based on the data of global PM2.5 remote sensing products and China's economic development from 1998 to 2016, the temporal and spatial variations of PM2.5 concentration in China from 1998 to 2016 were analyzed, and the response of PM2.5 concentration in China to economic development was studied. The results showed that the average annual PM2.5 concentration in 1998–2016 showed the spatial distribution characteristics of high in the East and low in the west; during 1998–2016, PM2.5 increased significantly in most regions, but decreased significantly in Inner Mongolia, Shaanxi, Ningxia and Gansu, while PM2.5 did not change significantly in some parts of the central region; during 1998–2007, PM2.5 concentration in most regions of China experienced rapid economic development. The concentration of PM2.5 in a few areas such as Inner Mongolia decreased significantly, while that in Yunnan, Sichuan and Inner Mongolia did not change significantly. During the 10 years of economic slowdown in China (2008–2016), the downward trend of PM2.5 concentration in China was expanding. The concentration of PM2.5 in the central and southern regions decreased or did not change significantly, except in the northwest and a few northeast regions. The change of PM2.5 concentration responds obviously to economic development, but the response of different regional economic development to the change of PM2.5 concentration is different.

China has experienced rapid urbanization and rapid development of economy in the past decades, resulting in severe damage to the urban ecological environment, causing changes in the urban thermal environment and triggering the urban heat island effect. Moreover, the heat island effect has become a hot topic for scholars. The urban heat island effect refers to the phenomenon that the urban surface temperature is significantly higher than that of surrounding suburbs due to the interaction of man-made and natural. The city is considered to be the largest man-made ecosystem. Its heat island effect will not only change the growth habit of urban vegetation， but also affect the outer environment of urban buildings, it further influences human life and has a great negative impact on human health. Therefore, the study of the spatial-temporal variation characteristics of urban heat island effect and its influencing factors can provide data support for the environmental quality control and urban planning of local government departments. Based on the surface temperature remote sensing product data, we studied the spatial distribution characteristics of urban heat island effect in Wuhan from 2001 to 2013, by calculating the temperature difference between the highest and lowest temperatures and the average interval method for heat island classification. We conducted a trend analysis of vegetation cover from 2001 to 2013 initially explore the effects of vegetation cover n heat island effect. The results showed that: (1) From 2001 to 2013, the intensity of heat island in Wuhan was strong in the city center, weaker surrounding city center and the weakest in the suburbs; From 2001 to 2011, the intensity of heat island in Wuhan city was significantly weaken, among which Huangpi, Xinzhou, Jiangxia, Hannan and Caidian district were weaken, and the urban heat island effect of the city center was enhanced; From 2011 to 2013, the intensity of heat island in Wuhan city presented an increasing trend, among which Huangpi district, Xinzhou district and Caidian district were the most obvious, and the urban heat island effect was slightly weaken. (2) Between 2001 and 2013, the vegetation cover in Huangpi district and Xinzhou district increased significantly, and the vegetation cover in the downtown, Jiangxia district and Dongxihu district decreased significantly, corresponding to the urban heat island effect of Wuhan increased volatility. Our results showed that the spatial distribution of urban heat island effect in Wuhan city fluctuated with time during the study period, and the vegetation cover had a significant influence on it.

The wavelet threshold method is widely used in signal denoising. However, traditional hard threshold method or soft threshold method is deficient for depending on fixed threshold and instability. In order to achieve efficient denoising of echo signals, an adaptive wavelet threshold denoising method, absorbing the advantages of the hard threshold and the soft threshold, is proposed. Based on the advantages of traditional threshold method, new threshold function is continuous, steerable and flexibly changeable by adjusting two parameters. The threshold function is flexibly changed between the hard threshold and the soft threshold function by two parameter adjustments. According to the Stein unbiased risk estimate (SURE), this new method can determine thresholds adaptively. Adopting different thresholds adaptively at different scales, this method can automatically track noise, which can effectively remove the noise on each scale. Therefore, the problems of noise misjudgement and incomplete denoising can be solved, to some extent, in the process of signal processing. The simulation results of MATLAB show that compared with hard threshold method and soft threshold method, the signal-to-noise ratio (SNR) of the proposed de-noising method is increased by nearly 2dB, and 4dB respectively. It is safely to conclude that, when background noise eliminated, the new wavelet adaptive threshold method preserves signal details effectively and enhances the separability of signal characteristics.

Drought is an extremely complex natural disaster phenomenon. Sustained drought will lead to the aggravation of water shortage, food production reduction, land desertification and ecological crisis, which will have a great impact on social and economic development, industrial and agricultural production and ecological environment. In recent years, human activities have intensified, the global climate has been warming, and the frequency and intensity of extreme events such as drought have been continuously strengthened, which has been widely concerned by scholars at home and abroad. The Beijing-Tianjin-Hebei region, as the political and cultural center of China, is seriously affected by the drought, which has a certain impact on the social economy of the region. Therefore, it is of great practical significance to carry out remote sensing drought monitoring and understand the temporal and spatial characteristics of drought. Based on MOD13A2 and MOD11A2 in MODIS products, this paper constructed the NDVI-Ts feature space to obtain the Temperature Vegetation Dryness Index (TVDI) in Beijing-Tianjin-Hebei region, and analyzed the spatial and temporal variation characteristics of drought in Beijing-Tianjin-Hebei region from 2001 to 2014 with TVDI as the drought index. The results showed that: (1) the NDVI-Ts feature space in the Beijing-Tianjin-Hebei region showed that when the value of NDVI rose from 0 to 1, the maximum temperature of the surface gradually decreased, while the minimum temperature gradually rose. Both of them had a linear relationship with NDVI, and their spatial shape was similar to a triangle, indicating that the study of drought in Beijing-Tianjin-Hebei was effective by using this spatial feature; (2) the Beijing-Tianjin-Hebei region experienced drought every year in the period of 2001–2014, and the drought was more serious in 2001, 2004, 2008, 2009, 2011 and 2012; (3) The drought in the Beijing-Tianjin-Hebei region was widespread, and the severely arid regions were mainly concentrated in the southern and central regions. In terms of drought intensity, the most frequent occurrences in the period of 2001–2014 were Xingtai, Hengshui, Shijiazhuang, and Handan, and the annual drought in 14 years; the least number of occurrences was Chengde, a total of 4 times; the number of occurrences was second only to Chengde, Tangshan, Zhangjiakou, Qinhuangdao, a total of 7 times. Our results indicated that the Beijing-Tianjin-Hebei region was prone to drought and the drought degree was severe.

Using conical end blanks is an effective method to improve the concave defects of cross wedge rolling, while the common method to get conical end blanks is machining, still causing material loss. Aimed at this situation, this paper proposes a roll-cutting forming method of conical end blanks based on metal-plastic forming. In order to clarify the rollcutting forming mechanism of the conical end, the displacement field and strain field variation during the forming process of the conical end are analyzed based on finite element simulation analysis, and the metal flow during the roll-cutting process is obtained. Moreover, the conical end blank formed by roll-cutting is sent to cross wedge rolling, the results verify the feasibility of roll-cutting conical end blank used for cross wedge rolling without stub bar.

Reef-building corals play an important role in marine ecosystems. However, owing to climate change, ocean acidification, and predation by invasive crown-of-thorns starfish, these corals are declining. As marine animals comprise polyps, reproduction by asexual budding is pivotal in scleractinian coral growth. The fibroblast growth factor (FGF) signaling pathway is essential in coral budding morphogenesis. Here, we sequenced the full-length transcriptomes of four common and frequently dominant reef-building corals and screened out the budding-related FGF and FGFR genes. Thereafter, three-dimensional (3D) models of FGF and FGFR proteins as well as FGF-FGFR binding models were reconstructed. Based on our findings, the FGF8-FGFR3 binding models in Pocillopora damicornis, Montipora capricornis, and Acropora muricata are typical receptor tyrosine kinase-signaling pathways that are similar to the Kringelchen (FGFR) in hydra. However, in P. verrucosa, FGF8 is not the FGFR3 ligand, which is found in other hydrozoan animals, and its FGFR3 must be activated by other tyrosine kinase-type ligands. Overall, this study provides background on the potentially budding propagation signaling pathway activated by the applications of biological agents in reef-building coral culture that could aid in the future restoration of coral reefs.

Multi-frequency range imaging (RIM) has been operated in the Chung-Li very high-frequency (VHF) radar, located on the campus of National Central University, Taiwan, since 2008. RIM processes the echo signals with a group of closely spaced transmitting frequencies through appropriate inversion methods to obtain high-resolution distribution of echo power in the range direction. This is beneficial to the investigation of the small-scale structure embedded in dynamic atmosphere. Five transmitting frequencies were employed in the radar experiment for observation of the precipitating atmosphere during the period between 21 and 23 August 2013. Using the Capon and Fourier methods, the radar echoes were synthesized to retrieve the temporal signals at a smaller range step than the original range resolution defined by the pulse width, and such retrieved temporal signals were then processed in the Doppler frequency domain to identify the atmosphere and precipitation echoes. An analysis called conditional averaging was further executed for echo power, Doppler velocity, and spectral width to verify the potential capabilities of the retrieval processing in resolving small-scale precipitation and atmosphere structures. Point-by-point correction of range delay combined with compensation of range-weighting function effect has been performed during the retrieval of temporal signals to improve the continuity of power spectra at gate boundaries, making the small-scale structures in the power spectra more natural and reasonable. We examined stratiform and convective precipitation and demonstrated their different structured characteristics by means of the Capon-processed results. The new element in this study is the implementation of RIM on spectral analysis, especially for precipitation echoes.

The growing complexity of quantum computing devices makes presents challenges for benchmarking their performance as previous, exhaustive approaches become infeasible. Here the authors characterise the quality of their 11-qubit device by successfully computing two quantum algorithms.

In this study, both the Greenhouse Gases Observing Satellite (GOSAT) and the Orbiting Carbon Observatory 2 (OCO-2) XCO2 retrievals produced by the NASA Atmospheric CO2 Observations from Space (ACOS) project (version b7.3) are assimilated within the GEOS-Chem 4D-Var assimilation framework to constrain the terrestrial ecosystem carbon flux during 1 October 2014 to 31 December 2015. One inversion for the comparison, using in situ CO2 observations, and another inversion as a benchmark for the simulated atmospheric CO2 distributions of the real inversions, using global atmospheric CO2 trends and referred to as the poor-man inversion, are also conducted. The estimated global and regional carbon fluxes for 2015 are shown and discussed. CO2 observations from surface flask sites and XCO2 retrievals from Total Carbon Column Observing Network (TCCON) sites are used to evaluate the simulated concentrations with the posterior carbon fluxes. Globally, the terrestrial ecosystem carbon sink (excluding biomass burning emissions) estimated from GOSAT data is stronger than that inferred from OCO-2 data, weaker than the in situ inversion and matches the poor-man inversion the best. Regionally, in most regions, the land sinks inferred from GOSAT data are also stronger than those from OCO-2 data, and in North America, Asia and Europe, the carbon sinks inferred from GOSAT inversion are comparable to those from in situ inversion. For the latitudinal distribution of land sinks, the satellite-based inversions suggest a smaller boreal and tropical sink but larger temperate sinks in both the Northern and Southern Hemisphere than the in situ inversion. However, OCO-2 and GOSAT generally do not agree on which continent contains the smaller or larger sinks. Evaluations using flask and TCCON observations and the comparisons with in situ and poor-man inversions suggest that only GOSAT and the in situ inversions perform better than a poor-man solution. GOSAT data can effectively improve the carbon flux estimates in the Northern Hemisphere, while OCO-2 data, with the specific version used in this study, show only slight improvement. The differences of inferred land fluxes between GOSAT and OCO-2 inversions in different regions are mainly related to the spatial coverage, the data amount and the biases of these two satellite XCO2 retrievals.

The common optical path payload is a new type of imaging payload that can acquire LiDAR data and CCD images simultaneously. This new payload integrates the linear LiDAR and linear CCD images according to the common optical system, and achieves the registration of LiDAR point cloud and CCD images by the alignment of common aperture optical axis and time synchronization control in the front of hardware. Based on the fixed matching relationship between CCD probes and LiDAR probes offered by optical path of common, this paper proposes a joint calibration method, which reduces the ranging error and misalignment error. And the results verify that this method can effectively improve the quality of the three-dimensional images. The standard deviations of validation area and roof are improved from 0.54 m to 0.14 m and 1.83 m to 0.26 m respectively.

High-precision on-orbit geometric calibration of spaceborne laser altimetry data is essential to its effective applications. Firstly, the existing calibration methods for laser altimeter data are analyzed. Then, a geometric calibration method based on curve matching is proposed. Compared to the existing methods, the proposed method does not rely on ground calibration field. Thus, it is efficiency in expense and time. Notably, three factors, i.e. matching method, initial control point selection and the step size of matching step, which significantly affect the results of calibration are analyzed respectively. The analysis was validated based on the original laser altimetry data obtained by ZY3-02 satellite. According to the results, the following conclusions can be drawn preliminarily: (1) Both the correlation coefficient maximum (COR) criterion and the mean square error minimum (MSD) criterion in the curve matching can be used to correct the systematic error in altimetry data. (2) The initial control points of the selected track should have a significant change trend and the slope within the laser footprints should be less than 15°. (3) Current experimental data show that the best step size for matching search is 10 m. The relevant conclusions can provide reference for the research of geometrical calibration and data processing of the same type of laser altimetry satellite.

UAV LiDAR systems have unique advantage in acquiring 3D geo-information of the targets and the expenses are very reasonable; therefore, they are capable of security inspection of high-voltage power lines. There are already several methods for power line extraction from LiDAR point cloud data. However, the existing methods either introduce classification errors during point cloud filtering, or occasionally unable to detect multiple power lines in vertical arrangement. This paper proposes and implements an automatic power line extraction method based on 3D spatial features. Different from the existing power line extraction methods, the proposed method processes the LiDAR point cloud data vertically, therefore, the possible location of the power line in point cloud data can be predicted without filtering. Next, segmentation is conducted on candidates of power line using 3D region growing method. Then, linear point sets are extracted by linear discriminant method in this paper. Finally, power lines are extracted from the candidate linear point sets based on extension and direction features. The effectiveness and feasibility of the proposed method were verified by real data of UAV LiDAR point cloud data in Sichuan, China. The average correct extraction rate of power line points is 98.18%.

In this paper, a simultaneous improvement of radiating and scattering performance for a patch antenna is realized. For achieving the wideband low-scattering property, a broadband AMC structure with orthogonally slot-embedding is proposed and analyzed, which is arranged around the antenna with another square ring unit in a chessboard configuration for phase cancellation. Meanwhile, a gain increment is also achieved due to the coupling between the radiation patch and the broadband AMC structure. Measured results indicate that at least a 10 dB RCS reduction is obtained from 11 GHz to 17.8 GHz. Additionally, the gain of the antenna has also been increased for more than 2 dB between 12 GHz and 13 GHz.

In conventional atmospheric models, isotope exchange between liquid, gas, and solid phases is usually assumed to be in equilibrium, and the highly kinetic phase transformation processes inferred in clouds are yet to be fully investigated. In this study, a two-moment microphysical scheme in the National Center for Atmospheric Research (NCAR) Weather Research and Forecasting (WRF) model was modified to allow kinetic calculation of isotope fractionation due to various cloud microphysical phase-change processes. A case of a moving cold front is selected for quantifying the effect of different factors controlling isotopic composition, including water vapor sources, atmospheric transport, phase transition pathways of water in clouds, and kinetic-versus-equilibrium mass transfer. A base-run simulation was able to reproduce the ∼ 50 ‰ decrease in δD that was observed during the frontal passage. Sensitivity tests suggest that all the above factors contributed significantly to the variations in isotope composition. The thermal equilibrium assumption commonly used in earlier studies may cause an overestimate of mean vapor-phase δD by 11 ‰, and the maximum difference can be more than 20 ‰. Using initial vertical distribution and lower boundary conditions of water stable isotopes from satellite data is critical to obtain successful isotope simulations, without which the δD in water vapor can be off by about 34 ‰ and 28 ‰, respectively. Without microphysical fractionation, the δD in water vapor can be off by about 25 ‰.

Dysregulated epidermal growth factor receptor (EGFR) expression is frequently observed in non-small cell lung cancer (NSCLC) growth and metastasis. Despite recent successes in the development of tyrosine kinase inhibitors (TKIs), inevitable resistance to TKIs has led to urgent calls for novel EGFR inhibitors. Herein, we report a rational workflow used to identify novel EGFR-TKIs by combining hybrid ligand- and structure-based pharmacophore models. Three types of models were developed in this workflow, including 3D QSAR-, common feature-, and structure-based EGFR-TK domain-containing pharmacophores. A National Cancer Institute (NCI) compound dataset was adopted for multiple-stage pharmacophore-based virtual screening (PBVS) of various pharmacophore models. The six top-scoring compounds were identified through the PBVS pipeline coupled with molecular docking. Among these compounds, NSC609077 exerted a significant inhibitory effect on EGFR activity in gefitinib-resistant H1975 cells, as determined by an enzyme-linked immunosorbent assay (ELISA). Further investigations showed that NSC609077 inhibited the anchorage-dependent growth and migration of lung cancer cells. Furthermore, NSC609077 exerted a suppressive effect on the EGFR/PI3K/AKT pathway in H1975 cells. In conclusion, these findings suggest that hybrid virtual screening may accelerate the development of targeted drugs for lung cancer treatment.

The spin-structure functions g1 and g2, and the spin-dependent partial cross-section σTT have been extracted from the polarized cross-sections differences, Δσ∥(ν,Q2) and Δσ⊥(ν,Q2) measured for the He3→(e→,e′)X reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6∘ and 9∘ from a longitudinally or transversely polarized 3He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first moments Γ1‾(Q2), Γ2(Q2) and ITT(Q2) are evaluated with high precision for the neutron in the Q2 range from 0.035 to 0.24GeV2. The comparison of the data and the chiral effective field theory predictions reveals the importance of proper treatment of the Δ degree of freedom for spin observables.

Neutrophilic inflammation occurs during asthma exacerbation, and especially, in patients with steroid-refractory asthma, but the underlying mechanisms are poorly understood. Recently, a significant accumulation of neutrophil extracellular traps (NETs) in the airways of neutrophilic asthma has been documented, suggesting that NETs may play an important role in the pathogenesis. In this study, we firstly demonstrated that NETs could induce human airway epithelial cell damage in vitro. In a mouse asthmatic model of neutrophil-dominated airway inflammation, we found that NETs were markedly increased in bronchoalveolar lavage (BAL), and the formation of NETs exacerbated the airway inflammation. Additionally, a small-molecule drug necrostatin-1 (Nec-1) shown to inhibit NETs formation was found to alleviate the neutrophil-dominated airway inflammation. Nec-1 reduced total protein concentration, myeloperoxidase activity, and the levels of inflammatory cytokines in BAL. Finally, further experiments proved that the inhibition of Nec-1 on NETs formation might be related to its ability to inhibiting mixed lineage kinase domain-like (MLKL) phosphorylation and perforation. Together, these results document that NETs are closely associated with the pathogenesis of neutrophilic asthma and inhibition of the formation of NETs by Nec-1 may be a new therapeutic strategy to ameliorate neutrophil-dominated airway inflammation.

Abstract Background Melioidosis is endemic in Southeast Asia and northern Australia. Infection usually follows percutaneous inoculation or inhalation or ingestion of the causative bacterium, Burkholderia pseudomallei, which is present in soil and surface water in endemic regions. Japanese encephalitis (JE) is a vector-borne viral zoonosis caused by Japanese encephalitis virus (JEV), leading to epidemic encephalitis in Southeast Asia. Both B. pseudomallei and JEV have spread dominantly in the Hainan and Guangdong provinces in China. Here we reported the first case of co-infection of B. pseudomallei and JEV, which was discovered in Huizhou in the Guangdong province in June 2016. Case presentation A 52-year-old man was admitted to the hospital with acute febrile illness and headache, diagnosed as respiratory infection, central nervous system (CNS) infection, septicemia, and hepatic dysfunction. Based on B. pseudomallei-positive blood and cerebrospinal fluid (CSF) cultures, the patient was diagnosed with melioidosis and treated aggressively with antibiotics. However, the patient failed to make a full recovery. Further laboratory tests focused on CNS infection were conducted. The co-infection of B. pseudomallei and JEV was confirmed after the positive IgM antibodies of JEV were detected in both CSF and blood. After diagnosis of co-infection with B. pseudomallei and JEV, the patient was provided supportive care in hospital and recovered after approximately 3 weeks. Conclusion Given the possibility of co-infection of B. pseudomallei and JEV, as well as variable case presentations, it is critical to enhance the awareness, detection, and treatment of co-infection in regard to melioidosis.

High temperature perpendicular ferroelectricity in nano thin films is crucial for miniaturization of electronic devices. Here the authors show the presence of stable and switchable out-of-plane ferroelectricity in tetragonal BiFeO3 thin films at the two-dimensional limit and 370% tunneling electroresistance in ferroelectric tunnel junctions.

Chemical mechanism reduction is common practice in combustion research for accelerating numerical simulations; however, there have been limited applications of this practice in atmospheric chemistry. In this study, we employ a powerful reduction method in order to produce a skeletal mechanism of an atmospheric chemistry code that is commonly used in air quality and climate modelling. The skeletal mechanism is developed using input data from a model scenario. Its performance is then evaluated both a priori against the model scenario results and a posteriori by implementing the skeletal mechanism in a chemistry transport model, namely the Weather Research and Forecasting code with Chemistry. Preliminary results, indicate a substantial increase in computational speed-up for both cases, with a minimal loss of accuracy with regards to the simulated spatio-temporal mixing ratio of the target species, which was selected to be ozone.

In this paper, changes of sediment yield and sediment transport were assessed using the Revised Universal Soil Loss Equation (RUSLE) and Geographical Information Systems (GIS). This model was based on the integrated use of precipitation data, Landsat images in 2000, 2005 and 2010, terrain parameters (slope gradient and slope length) and soil composition in Zhifanggou watershed, Gansu Province, Northwestern China. The obtained results were basically consistent with the measured values. The results showed that the mean modulus of soil erosion is 1224, 1118 and 875 t km−2 yr−1 and annual soil loss is 23 130, 21 130 and 16 536 in 2000, 2005 and 2010 respectively. The measured mean erosion modulus were 1581 and 1377 t km−2 yr−1, and the measured annual soil loss were 29 872 and 26 022 t in 2000 and 2005. From 2000 to 2010, the amount of soil erosion was reduced yearly. Very low erosion and low erosion dominated the soil loss status in the three periods, and moderate erosion followed. The zones classified as very low erosion were increasing, whereas the zones with low or moderate erosion were decreasing. In 2010, no zones were classified as high or very high soil erosion.

The rodent disaster is one of the main biological disasters in grassland in northern Xinjiang. The eating and digging behaviors will cause the destruction of ground vegetation, which seriously affected the development of animal husbandry and grassland ecological security. UAV low altitude remote sensing, as an emerging technique with high spatial resolution, can effectively recognize the burrows. However, how to select the appropriate spatial resolution to monitor the calamity of the rodent disaster is the first problem we need to pay attention to. The purpose of this study is to explore the optimal spatial scale on identification of the burrows by evaluating the impact of different spatial resolution for the burrows identification accuracy. In this study, we shoot burrows from different flight heights to obtain visible images of different spatial resolution. Then an object-oriented method is used to identify the caves, and we also evaluate the accuracy of the classification. We found that the highest classification accuracy of holes, the average has reached more than 80 %. At the altitude of 24 m and the spatial resolution of 1cm, the accuracy of the classification is the highest We have created a unique and effective way to identify burrows by using UAVs visible images. We draw the following conclusion: the best spatial resolution of burrows recognition is 1 cm using DJI PHANTOM-3 UAV, and the improvement of spatial resolution does not necessarily lead to the improvement of classification accuracy. This study lays the foundation for future research and can be extended to similar studies elsewhere.

Cadmium (Cd) is among the most available and most toxic heavy metals taken up by plants from soil. Compared to the classic plant-animal food chains, the host-parasitic plant food chains have, thus far, been largely overlooked in the studies of Cd trophic transfer. To investigate the pattern of Cd transfer during the infection of parasitic plants on Cd-contaminated hosts, we conducted a controlled experiment that grew soybeans parasitized by Chinese dodders (Cuscuta chinensis) in soil with different levels of Cd treatment, and examined the concentration, accumulation, allocation and transfer coefficients of Cd within this parasitic system. Results showed that among all components, dodders accounted for more than 40% biomass of the whole system but had the lowest Cd concentration and accumulated the least amount of Cd. The transfer coefficient of Cd between soybean stems and dodders was much lower than 1, and was also significantly lower than that between soybean stems and soybean leaves. All these features were continuously strengthened with the increase of Cd treatment levels. The results suggested no evidence of Cd biomagnification in dodders parasitizing Cd-contaminated hosts, and implied that the Cd transfer from hosts to dodders may be a selective process.