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• The increasing trend of vapor pressure deficit (VPD) change in 1997–2020 is ten times higher than in 1981–1996. • Increasing VPD promoted cropland and grassland growth in Arid, while inhibited the growth of shrubland. • Significant positive or negative difference in the sensitivity to VPD for the same vegetation under different climatic zones. • The vast majority of vegetation showed a significant increase in the inter-annual trend of the sensitivity to VPD. • The relationship of higher sensitivity with lower VPD is not stable under different vegetation and climatic zones. Vapor pressure deficit (VPD) shows significant spatial and temporal variability in the context of global climate change, which is important for studying the implications of climate change on the structure and function of ecosystems to analyze the effects of VPD on vegetation dynamics. Spatial patterns of vegetation sensitivity to VPD have been recently investigated, however, the feedback of different vegetation types to VPD may vary depending on physiological characteristics, it is unclear how different types influence the sensitivity to VPD. In this study, the ERA5-Land reanalysis time-series dataset was used to analyze the spatial and temporal trends of VPD under different vegetation types. It was found that VPD showed an increasing trend in vegetated areas over the past 20 years with large spatial heterogeneity, generally increasing with drying conditions. On this basis, the spatial patterns of vegetation sensitivity to VPD and temporal trends in sensitivity were evaluated over the past 20 years in China using the enhanced vegetation index (EVI) and near-infrared reflectance of vegetation (NIRv) which can describe vegetation dynamics. The results show that the sensitivities under the two indices have high spatial consistency, with northeastern and central China showing positive sensitivities and southern China showing negative sensitivities, respectively. The positive sensitivities are relatively high for Deciduous Broadleaf Forests (DBF), Deciduous Needleleaf Forests (DNF), Grasslands (GL), and Croplands (CL) types, while the negative sensitivities are larger for Shrublands (SL) and Savannas (SA) types. Under different climatic zones, the sensitivity of CL and GL are independent of climatic zones (both showing positive), while the sensitivity of SL is negative in the Humid zone and positive in the Semi-Arid zone. Temporally, the sensitivity showed a slow increasing trend over the last 20 years. In terms of vegetation types, sensitivities of Evergreen Broadleaf Forests (EBF), DBF, GL and CL types showed a significant increasing trend (p < 0.05), except for the SL type, which showed a significant decreasing trend (p < 0.05). The trends of sensitivity are not affected by the differences in vegetation types (all of them show an increasing trend) under arid and semi-arid conditions, while dry sub-humid and humid have a greater impact on sensitivity trends. The finding of an overall increase in sensitivity suggests a mechanism of erratic change in vegetation growth under climate change. Notably, the increased sensitivity of certain vegetation types (especially GL and CL) suggests that these may become progressively vulnerable to increased VPD as global climate change persists, with the risk of moving from facilitation to inhibition of photosynthesis. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of MnO 2 nanowires decorated with transition metal-doped carbon quantum dots (MCQDs) is described for use as binder-free flexible solid-state supercapacitors. In particular, the water-soluble Fe and N co-doped MCQDs prepared by amidation reaction with ferric ammonium citrate and urea had ultrafine particle morphologies and showed super-hydrophilicity in aqueous solution, which greatly improved the contact probability between the electrode and the electrolyte. In addition, the co-doped MCQDs increased both the electrical conductivity and specific capacitance of the MnO 2 /carbon-based nanocomposites and limited the collapse and exfoliation of the MnO 2 structure during extended cycling. Compared with pristine MnO 2 electrode, the MCQDs/MnO 2 composite electrode exhibited faster charge-discharge rate and improved cycle stability with increased specific capacitance. The flexible symmetric supercapacitor constructed from the MCQDs/MnO 2 composite had a capacitance retention of 85.6 % after 10,000 charge/discharge cycles at a current density of 2 mA cm−2. In addition, the device showed a maximum power density of 4.8 W cm−2 at an energy density of 2.3 mW h cm−2, and a maximum energy density of 11.16 mW h cm−2 at a power density of 311.6 mW cm−2. The data that support the findings of this study are available from the corresponding author upon reasonable request. • A metal carbon quantum dots (MCQDs)/MnO 2 nanowire composite is described. • The MCQDs/MnO 2 composite was used to construct flexible solid-state supercapacitors. • Super-hydrophilic MCQDs improved the contact probability of the interface. • MCQDs improved the conductivity, specific capacitance and cycling stability of MnO 2. • The flexible symmetric supercapacitor exhibited good electrochemical performance. [ABSTRACT FROM AUTHOR]

MnO 2 /biomass-derived porous carbon (BPC) composites have been prepared by a hydrothermal method, in which the BPC 3D porous carbon structure was based on a banana peel. The banana peel, after freeze drying, can maintain its hierarchical natural porous structure, which provides enough growth space for MnO 2 and reduces the agglomeration of MnO 2 particles. The MnO 2 /BPC composites were characterized by XRD, FT-IR, XPS, TGA, SEM, TEM, BET. The electrochemical performance of the composites was tested in three-electrode supercapacitors using 1 M Na 2 SO 4 aqueous solution as an electrolyte. Due to the large amounts of hierarchical pores and large pore volume, the as-prepared composites exhibited good electrochemical performance. Electrochemical measurements indicated that the MnO 2 /BPC composites applied in supercapacitors had a specific capacitance of 139.6 F g −1 at 300 mA g −1 , and exhibited a good cycling stability with a capacitance retention ratio of 92.3% after 1000 cycles (at 1 A g −1 ). The MnO 2 /BPC composites with 3D porous structure are promising materials in the application of supercapacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design strategies for 2D/2D NH 2 -TiO 2 /ReS 2 heterojunction photocatalyst. • The transition of NH 2 -TiO 2 /ReS 2 from type-Ⅰ to S-scheme heterojunction by amination modification. • An innovative construction engineering for 2D/2D heterojunction The 2D/2D heterojunction photocatalyst demonstrates a broad range of applications owing to its large interface contact area. At present, most of the current 2D/2D structures are constructed by self-assembly, which mainly forms a relatively weak van der Waals force at the interface. This poses a challenge to achieving effective carrier separation. Here, we proposed an innovative strategy of molecular-connected heterojunctions to address this challenge. The strategy uses (3-aminopropyl) trimethoxysilane (APTMS) to modify the surface of TiO 2 and construct NH 2 -TiO 2 /ReS 2 heterojunction, which not only alters the material's Zeta potential but also uses molecular chains connecting TiO 2 and ReS 2. Simultaneously, the design of molecular-connected heterojunction changes the work function of TiO 2 , leading to the transformation of the TiO 2 /ReS 2 heterojunction from type-Ⅰ to S-scheme, thereby achieving a selective carrier separation. The constructed NH 2 -TiO 2 /ReS 2 photocatalytic heterojunction composite has a hydrogen production rate of 451.3 μmol g-1 h−1, which is over 11 and 3 times than TiO 2 and TiO 2 /ReS 2 , respectively, and exhibits excellent long-term photocatalytic stability. This study presents a novel approach for achieving strong interface bonding and introduces an innovative approach for constructing 2D/2D photocatalytic heterojunctions. [ABSTRACT FROM AUTHOR]

Nanoflower-like NiCo 2 O 4 is grown directly on a three-dimensional gelatin-based carbon–nickel foam (GCNF), which is prepared by a facile hydrothermal strategy with annealing treatment. The as-synthesized binder-free NiCo 2 O 4 /GCNF composites are used for high-performance supercapacitors. The binder-free design can avoid the "dead surface" caused by binders and additives in traditional electrodes, thus achieving more efficient charge and mass exchange, leading to improved conductivity of electrodes. Furthermore, the proposed design provides a wider interface area and abundant active sites, which significantly improve the electrochemical capacitance performance. The electrode has a high specific capacitance of 1416 F g−1 at a current density of 1 A g−1, and excellent cycling performance. An asymmetric supercapacitor (ASC) was assembled with the structure NiCo 2 O 4 /GCNF//activated carbon and a maximum voltage of 1.5 V delivers a high energy density of 48.6 W h kg−1 at a power density of 749.3 W kg−1. Moreover, the ASC shows good cycling performance with 88.5% capacitance retention after 10,000 cycles at a high rate of 5 A g−1. Image 1 • Nanoflower-like NiCo 2 O 4 was grown on a 3D gelatin-based carbon–nickel foam. • Edible gelatin as a carbon source and contributes to the capacitance of electrode. • The NiCo 2 O 4 /GCNF composites were used as binder-free electrodes for supercapacitors. • The assembled asymmetric supercapacitor exhibits good electrochemical performance. [ABSTRACT FROM AUTHOR]

Abstract: Leaf area index (LAI) is a major indicator for crop growth monitoring and yield estimation. Data assimilation as an effective tool for crop LAI estimation fully considers the properties of actual observations and physical model simulations. In this work, we present a new data assimilation scheme, introducing a very fast simulated annealing (VFSA) optimization algorithm into the process of crop LAI assimilation with a four dimensional variational data assimilation (4DVAR) algorithm. Firstly, calibrating the input parameters of a crop growth simulation model based on history observations. Secondly, quantitatively describing the relationship between fields observed data and model simulated data by the cost function of 4DVAR algorithm. Finally, the optimization process of the cost function is accomplished by the VFSA optimization algorithm, and further the optimal solution is taken as the best combination of input parameters of physical model for LAI estimation. Winter wheat in Beijing is taken as an experimental object. The numerical results show not only the improved time efficiency of this proposed assimilation scheme, but also enhanced assimilation accuracy of all LAI assimilations, especially for LAI 3.00. Theoretical analysis and practical experiments confirm the application prospect of VFSA optimization algorithm in LAI variational assimilation. [Copyright &y& Elsevier]

Lodging is a common phenomenon in maize production, which seriously affects its yield, quality, and mechanical harvesting capacity. With good penetrating power, satellite radar can monitor crop growth even under cloudy weather conditions. In this study, a method based on the change in plant height before and after lodging in maize is proposed to calculate the lodging angle and monitor the lodging degree by using dual-polarization Sentinel-1A data. The results show that the optimal sensitive polarization combinations of maize plant height before and after lodging are VH/VV and VV, respectively. The lodging angle is calculated using the plant height inversion results before and after lodging. The overall accuracy of classifying lodging grade of maize is 67%. The proposed model based on lodging angle could effectively mapped the maize lodging range on a regional scale and classify the lodging grades. [ABSTRACT FROM AUTHOR]

• The invariant shape spectral preprocessing method is effective for WYMV detection. • Machine learning has great potential for narrow to wide band migration applications. • The 3SV-SIW-SVM mode is most effective for WYMV detection. Wheat yellow mosaic disease (WYMD) is a low-temperature soil-borne disease that causes serious yield and economic losses. Reflectance spectroscopy has great potential for detecting crop diseases, but it has not been applied for detection of WYMD. Herein, we collected 2 years of wheat physiological and reflectance spectroscopy data at green-up and jointing stages, and conducted disease detection studies. We evaluated standard normal variate (SNV), multiplicative scatter correction (MSC), and spectral separation of soil and vegetation (3SV) as preprocessing methods for invariant spectral shapes, and 96 spectral indices. The spectral index wavelength (SIW), threshold method, and variance inflation factor (TVIF) were used as feature selection methods combined with machine learning to construct a systematic disease detection scheme. The results showed that the visible region centred at 750 nm was the most sensitive wavelength. Additionally, 900–––1000 nm was the sensitive wavelength in the middle and latter stages, during disease aggravation and fertility development. The preprocessing method was best with 3SV, which was highly consistent with the characteristic regions of the original spectra, followed by SNV and MSC. spectral indices OR-BG1 I, SNV-RPMI, MSC-RPMI and 3SV-CTRI 1 could be applied to detect WYMD, and the best index was 3SV-CTRI 1, with OA and Kappa values of 75.88% and 0.516, respectively. The effectiveness of the SIW feature selection method and coupling with machine learning was superior to TVIF. The best results among different machine learning models were obtained with SVM, followed by RF and KNN. The optimal 3SV-SIW-SVM disease detection mode achieved OA and Kappa values of 94.71% and 0.893, respectively, for field data validation, and 68.06% and 0.381, respectively, for simulated satellite data validation. The findings will facilitate migration of ground-based research to satellite platforms, and provide new ideas for quantitative identification of crop diseases. [ABSTRACT FROM AUTHOR]

Lithium titanate (Li 4 Ti 5 O 12 , LTO) has several disadvantages as active material for Li-ion batteries (LIBs) such as low conductivity and poor capacity. To overcome these drawbacks and specifically to improve electrical performance of LTO, we used solvothermal method to synthesis LTO and to dope it simultaneously with Al and Mn. Doped LTO was then incorporated into composites containing graphene (G), carbon nanotube (CNT) or carbon quantum dots (CQDs) to enhance specific capacity and conductivity of LIB anodes containing these composites as active materials. To have a further study of different carbon materials composite with doped LTO, these materials we obtained were thoroughly characterized. LTO doping and incorporation into composites not only increased its specific capacity and also decreased its impedance. Al3+ and Mn4+ substituted Ti4+ located at 16 d sites. First cycle specific capacity values and impedance values of anodes consisting of composites containing doped LTO and G, CNT or CQDs were 261.7, 286.2 and 296.5 mA h/g (at C/10 rate) and 13.99, 8.28, 18.79 Ω, respectively. Capacity retention after 100 cycles for these anodes was 84.6, 90.67 and 83.4%. LTO doping by Al3+ and Mn4+ and combining it with G, CNT or CQDs effectively improved its electrochemical performance. The best performance was obtained for anodes containing composites consisting of a combination of doped LTO and CNT. • Used carbon quantum dots to form a composite with Al3+ and Mn4+ co-doped LTO as anode material for the first time. • Compared the influence of composites with different nano-structure carbon materials. • The specific capacity of LTO-Al/Mn-CQDs increased to 296.5 mA⋅h⋅g−1 at 0.1 C. [ABSTRACT FROM AUTHOR]