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As an important trace molecular detection technique, surface-enhanced Raman scattering (SERS) has been extensively investigated, while the realization of simple, low-cost, and controllable fabrication of wafer-scale, flexible SERS-active substrates remains challenging. Here, we report a facile, low-cost strategy for fabricating wafer-scale SERS substrates based on Ag-TiO2 nanoparticle–film hybrids by combining dip-coating and UV light array photo-deposition. The results show that a centimeter-scale Ag nanoparticle (AgNP) film (~20 cm × 20 cm) could be uniformly photo-deposited on both non-flexible and flexible TiO2 substrates, with a relative standard deviation in particle size of only 5.63%. The large-scale AgNP/TiO2 hybrids working as SERS substrates show high sensitivity and good uniformity at both the micron and wafer levels, as evidenced by scanning electron microscopy and Raman measurements. In situ bending and tensile experiments demonstrate that the as-prepared flexible AgNP/TiO2 SERS substrate is mechanically robust, exhibiting stable SERS activity even in a large bending state as well as after more than 200 tensile cycles. Moreover, the flexible AgNP/TiO2 SERS substrates show excellent performance in detecting sub-micrometer-sized plastics (≤1 μm) and low-concentration organic pollutants on complex surfaces. Overall, this study provides a simple path toward wafer-scale, flexible SERS substrate fabrication, which is a big step for practical applications of the SERS technique. [ABSTRACT FROM AUTHOR]

The watershed system has a complex game relationship between the benign operation and coordinated development of various elements of flood-sediment transportation, eco-environment, and socio-economy (FES). With the increasing breadth, depth, and intensity of human activities in watersheds, it is urgent to coordinate the FES. The relationship of water–sediment in the Yellow River Basin (YRB) is complex, with a prominent contradiction in water supply and a fragile ecosystem. This research tries to build a comprehensive evaluation model for FES and explore the complex interaction between FES in the YRB from 2000 to 2020. The results demonstrated that (1) the comprehensive flood-sediment transportation index (CFTI) and comprehensive eco-environment index (CEI) presented fluctuating growth. In contrast, the comprehensive socio-economy index (CSI) revealed a linear growth trend. The CFTI of Sanmenxia, CEI of Toudaokuan, and CSI of Ningxia had the highest growth rates, with 36.03%, 6.48%, and 107.5%, respectively. (2) FES's positive and negative effects were alternating, with heterogeneity in both time and space. (3) The coupling coordination degree (CCD) in the YRB indicated an increasing trend, ranging from 0.53 to 0.87, from reluctantly coordinated development to good coordinated development. The lagging subsystem was CFTI (2000–2001 and 2008–2020) and CSI (2002–2007), and the CEI was not lagging. (4) Exploratory Spatial Data Analysis (ESDA) demonstrated significant differences in the CCD of the YRB, and areas with similar CCD within the basin tend to be centrally distributed in space. At the same time, there was negative spatial autocorrelation in coordination. The results provide a scientific theoretical and methodological framework for strategic research on the YRB system's governance, protection, and management. [ABSTRACT FROM AUTHOR]

Nickel-rich cathode LiNi0.83Co0.11Mn0.06O2 (NCM) has a high specific discharge capacity and low cost, and is a very promising cathode material. However, NCM exhibits poor structural and chemical stability, resulting in poor cycle stability. Surface coating can maintain structural stability, isolate cathode materials and electrolytes, and effectively improve the cycle stability of NCM. The mixed ion–electron conductor Li7.3La3Zr1.7Co0.3O12 (LZC) was coated on the surface of NCM using an anhydrous co-precipitation method, with a coating thickness of 2% (molar ratio), which promotes the conduction of electrons and ions. The coated positive electrode material was prepared into a liquid electrolyte half battery. After 200 cycles at 1 C between 2.8 and 4.5 V, the capacity retention of NCM is only 62.2%, while the capacity retention of the most excellent coating sample increased to 79.2%. [ABSTRACT FROM AUTHOR]

As a cathode material for sodium-ion batteries (SIBs), P2-Na0.67Fe0.5Mn0.5O2 has the advantages of high capacity and high working voltage. However, the irreversible phase transition of P2-O2 causes the electrochemical performances to rapidly decline with cycling. The phase stability and therefore cycle stability could be effectively improved by cation doping. The precursor Fe0.5Mn0.5CO3 is prepared by coprecipitation method. The initial discharge-specific capacity of P2-Na0.67Fe0.5Mn0.5O2 in the voltage range of 2–4.3 V is 164 mAh·g−1, and its capacity retention rate after 100 cycles is 48.6%. Mg doping can improve the cycling stability and rate capability, while slightly reducing the initial capacity. The capacity retention is improved from 48.6 to 75.3% with Mg doping. [ABSTRACT FROM AUTHOR]

A direct coupling of antiferroelectric (AFE) and resistive switching (RS) is realized for the first time in an oxide heterostructures (non‐tunneling mechanisms). This allows the resistance of the heterostructure to switch between volatile and non‐volatile RS behavior, which indicates a threshold RS and broadly increases its practical applicability. The stacks of Pt/PbZrO3 (PZO)/LaNiO3/SrTiO3 (STO) is fabricated by laser pulse deposition. It exhibits a tunable RS behavior from volatile to nonvolatile through adjusting voltage amplitude. Moreover, a high ON/OFF ratio, good retention, and endurance characteristics are achieved. Furthermore, synaptic behaviors related to neural learning functions in PZO film is explored, that is, long‐term potential/depression, spike timing dependent plasticity, and paired pulse facilitation. This work provides a way to engineer AFE and RS pertinent functionality for the low‐energy‐consumption, non‐volatile neural computing. [ABSTRACT FROM AUTHOR]

NASICON solid electrolyte Na3Zr2Si2PO12 (NZSP) exhibits high chemical stability and can be utilized as cladding materials of cathodes to improve battery cycle stability. However, the electronic conductivity of NZSP is extremely low (∼10−9 S cm−1), which will hinder the electron conduction of cathode materials. To address this issue, the electronic conductivity of NZSP is improved by doping with transition metal elements (Co, Fe, Ni). Co‐doped NZSP has an electronic conductivity of 5.03 × 10−6 S cm−1. On the other hand, the ionic conductivity of doped samples remains stable, even slightly increased. The mechanical properties of pristine and doped samples are characterized with a micro indenter, which is also a key parameter for coating materials. [ABSTRACT FROM AUTHOR]

The ternary cathode material LiNi0.83Co0.12Mn0.05O2 (NCM) has excellent properties, such as superior energy density, low cost, and high voltage platform. Recently, it becomes one of the research hotspots of lithium-ion batteries (LIBs). However, NCM has insufficient cycle stability and cannot meet the demand for the high-rate capability, which limits its application in energy storage equipment. The precursor of NCM was modified with (Ni0.4Co0.2Mn0.4)1−xZrx(OH)2 by the co-precipitation. After high-temperature sintering, the diffusion of Zr4+ has significant impacts on the stability and capability for NCM. The doped sample exhibits a capacity retention rate of 79.5% at 1 C after 200 cycles and also delivers excellent rate performance, and the average specific discharge capacity is 189.4 mAh g−1 (2 C) and 180.6 mAh g−1 (5 C), respectively. [ABSTRACT FROM AUTHOR]

Water conservation (WC) is a critical ecological service function in the Yellow River Basin (YRB). There is currently a lack of detailed exploration of WC development processes and the impact mechanisms of driving factors at spatiotemporal scales in the YRB. By collecting data on DEM, land use, soil, meteorology, reservoirs, and observed discharge, this study established a large-scale WC model using the soil and water assessment tool (SWAT). The abrupt change test, empirical orthogonal function (EOF), wavelet analysis, hierarchical partitioning analysis (HPA), geodetectors, and aridity index were employed to analyze the multi-spatiotemporal characteristics and driving forces of WC calculated using the water balance method. The results are as follows: (1) The average WC among the YRB was 9.11 mm (74.68 × 10 8 m 3 ) from 1960 to 2020. Pasture and forests contributed to 48.65% and 22.05% of the average annual WC, respectively. (2) WC exhibited four forms: less/more in the YRB, more in the southeast (northwest), and less in the northwest (southeast). (3) Forests and pastures in land use had higher average WC capacity, while Gansu, Shaanxi, and Qinghai ranked in the top three for average WC among the nine provinces. (4) Precipitation was the major driving force affecting WC variations, with the interaction between precipitation and actual evapotranspiration being the most significant. (5) Drought was a significant cause of negative WC. Protecting and managing crucial WC areas was essential for improving the ecological environment. This research elucidates the driving forces of WC in the YRB, providing scientific support for improving regional WC and promoting sustainable development., (© 2024. The Author(s).)

Bi 2 (TeSe) 3 is a dominant n-type thermoelectric material used in commercial applications. However, its toxicity and rarity hamper further large-scale industrial applications. Herein, we develop a Ag 8 SiSe 6 -based composite as a promising n-type semiconductor with the advantages of nontoxicity and elemental abundance. Ag 8 SiSe 6 composites with Ag 2 Se and Si nanoprecipitation are fabricated by a unique precipitation reaction sensitive to the hot pressing process. The energy-filtering effect between these phases optimizes electrical resistivity (∼14.59 μΩ·m) and the Seebeck coefficient (above -150 μV·K -1 ) of the composites, resulting in a maximum power factor of ∼1772 μW·m -1 ·K -2 (@125 °C), which is the highest value in an argyrodite system near room temperature. Nanoprecipitation of Ag 2 Se and Si can also scatter more phonons and further reduce the lattice thermal conductivity to 0.20 W·m -1 ·K -1 . As a result, a maximum ZT value of ∼0.9 (@125 °C) and an average ZT value of ∼0.7 (25-200 °C) are obtained in the composite with 12 vol % Ag 2 Se and 0.23 vol % Si, which is sintered at 525 °C. These thermoelectric properties are comparable to those of a commercial n-type Bi 2 Te 3 compound. In addition, the Ag 8 SiSe 6 composite has robust mechanical properties (Vickers hardness of >110 HV and bending strength of 70.6 MPa), much better than those of other thermoelectric compounds, because of which Ag 8 SiSe 6 has great commercial application as an alternative to Bi 2 Te 3 -based compounds.