A doubled increasing trend of evapotranspiration on the Tibetan Plateau.

Estimation of evapotranspiration (ETa) change on the Tibetan Plateau (TP) is essential to address the water requirement of billions of people surrounding the TP. Existing studies have shown that ETa estimations on the TP have a very large uncertainty. In this article, we discuss how to more accurately quantify ETa amount and explain its change on the TP. ETa change on the TP can be quantified and explained based on an ensemble mean product from climate model simulations, reanalysis, as well as ground-based and satellite observations. ETa on the TP experienced a significant increasing trend of around (8.4 ± 2.2) mm (10 a)-1 (mean ± one standard deviation) during 1982-2018, approximately twice the rate of the global land ETa (4.3 ± 2.1 mm (10 a)-1). Numerical attribution analysis revealed that a 53.8% TP area with the increased ETa was caused by increased temperature and 23.1% part was due to soil moisture rising, because of the warming, melting cryosphere, and increased precipitation. The projected future increase in ETa is expected to cause a continued acceleration of the water cycle until 2100.

Comparative Study on the H-Abstraction Reactions of Isopropyl Acetate and Propyl Acetate by HO2 and OH Radicals.

Isopropyl acetate (IPA) and propyl acetate (PA) are recognized as promising biofuels suitable for applications as fuel additives and biodiesel models. The H-abstraction reactions with radicals stand out as the fundamental initiating reactions in the combustion kinetic models for IPA and PA. In the present work, the kinetic calculations of IPA and PA plus HO2 and OH radicals were investigated at M06-2X/cc-pVTZ//G4, M08-HX/maug-cc-pVTZ, and CCSD(T)/jul-cc-pVTZ levels. The thermodynamic calculations were obtained based on the G4 and CBS-APNO methods. Rate coefficients were calculated using both transition state theory and canonical variational transition state theory with tunneling correction at the temperature range of 250-2000 K. The total rate constants for the IPA + OH system were fitted as follows: k = 0.4674 × T3.927 exp(2128/T) (cm3 mol-1 s-1), and for the PA + OH system, the total rate constants were determined using the following equation: k = 0.0161 × T4.373 exp(2220/T) (cm3 mol-1 s-1). The rate coefficients of IPA + OH reactions determined based on the M08-HX/maug-cc-pVTZ level effectively replicate the experimental data, while H-abstraction rate coefficients of PA + OH by the CCSD(T)/jul-cc-pVTZ method accurately reproduce the experimental data. Refining the H-abstraction rate coefficients in the kinetic mechanism of PA, as proposed by Dayma et al. [Proc. Combust. Inst. 37 (2019) 429-436], has been achieved through incorporating the present calculated data, leading to the development of a revised mechanism. The validation of the updated mechanism against jet-stirred reactor data is presented, showcasing its effective performance in predicting JSR data.

Importance of soil moisture conservation in mitigating climate change.

A troubling feedback loop, where drier soil contributes to hotter climates, has been widely recognized. This study, drawing on climate model simulations, reveals that maintaining current global soil moisture levels could significantly alleviate 32.9% of land warming under low-emission scenarios. This action could also postpone reaching critical warming thresholds of 1.5 °C and 2.0 °C by at least a decade. Crucially, preserving soil moisture at current levels could prevent noticeable climate change impacts across 42% of the Earth's land, a stark deviation from projections suggesting widespread impacts before the 2060s. To combat soil drying, afforestation in mid-to-low latitude regions within the next three decades is proposed as an effective strategy to increase surface water availability. This underscores the substantial potential of nature-based solutions for managing soil moisture, benefiting both climate change mitigation and ecological enhancement.

Enhanced risk of record-breaking regional temperatures during the 2023-24 El Niño.

In 2023, the development of El Niño is poised to drive a global upsurge in surface air temperatures (SAT), potentially resulting in unprecedented warming worldwide. Nevertheless, the regional patterns of SAT anomalies remain diverse, obscuring where historical warming records may be surpassed in the forthcoming year. Our study underscores the significant influence of El Niño and the persistence of climate signals on the inter-annual variability of regional SAT, both in amplitude and spatial distribution. The likelihood of global mean SAT exceeding historical records, calculated from July 2023 to June 2024, is estimated at 90%, contingent upon annual-mean sea surface temperature anomalies in the eastern equatorial Pacific exceeding 0.6 °C. Regions particularly susceptible to recording record-high SAT include coastal and adjacent areas in Asia such as the Bay of Bengal and the South China Sea, as well as Alaska, the Caribbean Sea, and the Amazon. This impending warmth heightens the risk of year-round marine heatwaves and escalates the threat of wildfires and other negative consequences in Alaska and the Amazon basin, necessitating strategic mitigation measures to minimize potential worst-case impacts.

Green and highly effective extraction of bioactive flavonoids from Fructus aurantii employing deep eutectic solvents-based ultrasonic-assisted extraction protocol.

In China, Jiang Fructus aurantii (JFA) has attracted increasing interest as a famous traditional herbal medicine and valuable economic food for its valuable medicinal and industrial properties. In the current work, contrasted with conventional extraction techniques, natural flavonoids from JFA (naringin and neohesperidin) were extracted with remarkable effectiveness utilizing a sustainable deep eutectic solvents combined ultrasonic-assisted extraction (DESs-UAE) protocol. The optimal extraction capacity can be achieved by mixing 30 % water with a molar ratio of 1:3 for choline chloride and ethylene glycol, as opposed to the classical extraction solvents of 95 % ethanol, methanol, and water. Moreover, the DESs-UAE extraction programs were also systematically optimized employing Box-Behnken design (BBD) trials, and the eventual findings suggested that the best parameters were a 27 % water content in DES, a 16 mL/g liquid-solid ratio, a 72 min extraction time, and a 62 °C extraction temperature, along with the corresponding greatest contents of NAR (48.18 mg/g) and NEO (34.50 mg/g), respectively. Notably, by comparison with the pre-optimization data, the optimized DES extraction efficiency of flavonoids is markedly higher. Thereafter, the characterization of the solvents before and after extraction, as well as the differences between the four extraction solvent extracts, were compared using the FT-IR analyses. Furthermore, SEM results suggested that the penetration and erosion abilities of the plant cell wall of DES-1 were stronger than those of the other three traditional solvents, thus allowing more release of flavonoid compounds. In conclusion, the present research develops a straightforward, sustainable, and exceedingly efficient approach for the extraction of bioactive flavonoids from JFA, which has the potential to facilitate the efficient acquisition of active ingredients from TCM.

PB12+ and P2B12+/0/-: The Novel B12 Cage Doped by Nonmetallic P Atoms.

A new kind of nonmetallic atom-doped boron cluster is described herein theoretically. When a phosphorus atom is added to the B12 motif and loses an electron, a novel B12 cage is obtained, composed of two B3 rings at both ends and one B6 ring in the middle, forming a triangular bifrustum. Interestingly, this B12 cage is formed by three B7 units joined together from three directions at an angle of 120°. When two P atoms are added to the B12 motif, this novel B12 cage is also obtained, and two P atoms are attached to the B3 rings at both ends of the triangular bifrustum, forming a triangular bipyramid (Johnson solid). Amazingly, the global minimums of neutral, monocationic, and monoanionic P2B12+/0/- have the same cage structure with a D3h symmetry; this is the smallest boron cage with the same structure. The P atom has five valence electrons, according to adaptive natural density partitioning bonding analyses of cage PB12+ and P2B12, in addition to one lone pair, the other three electrons of the P atom combine with an electron of each B atom on the B3 ring to form three 2c-2e σ bonds and form three electron sharing bonds with B atoms through covalent interactions, stabilizing the B12 cage. The calculated photoelectron spectra can be compared with future experimental values and provide a theoretical basis for the identification and confirmation of PnB12- (n = 1-2).

High Coordination Numbers of Actinides (An) in AnC13+ Rings (An = Th and U).

An intriguingly high abundance of both ThC13+ and UC13+ cluster cations was observed in a previous mass spectrometry experiment; however, the structural identification of these cations has not yet been completed. In this study, we determined the lowest lying structures of ThC13+ and UC13+ clusters using an unbiased structural search method. The 13-coordinate planar ring configuration was the most stable for both ThC13+ and UC13+ cluster cations. The C-An bonds in ThC13+ and UC13+ show a small degree of covalency, originating from the overlap of the s, d, and f orbitals of the An atoms with C 2p orbitals of both π and σ characteristics. The infrared and electronic absorption spectra of the most favorable planar ring configurations were theoretically simulated to facilitate the identification of the molecular structures in future experiments. This study provides an in-depth understanding of the experimental mass spectra.

Reversed asymmetric warming of sub-diurnal temperature over land during recent decades.

In the latter half of the twentieth century, a significant climate phenomenon "diurnal asymmetric warming" emerged, wherein global land surface temperatures increased more rapidly during the night than during the day. However, recent episodes of global brightening and regional droughts and heatwaves have brought notable alterations to this asymmetric warming trend. Here, we re-evaluate sub-diurnal temperature patterns, revealing a substantial increase in the warming rates of daily maximum temperatures (Tmax), while daily minimum temperatures have remained relatively stable. This shift has resulted in a reversal of the diurnal warming trend, expanding the diurnal temperature range over recent decades. The intensified Tmax warming is attributed to a widespread reduction in cloud cover, which has led to increased solar irradiance at the surface. Our findings underscore the urgent need for enhanced scrutiny of recent temperature trends and their implications for the wider earth system.

Engineering a Cl- -Modulated Light-Driven Na+ Pump.

Microbial Na+ -pumping rhodopsin (NaR) is a promising optogenetic tool due to its unique ability to transport Na+ . Like most rhodopsin-based tools, NaR is limited to light-based control. In this study, our objective was to develop a novel mode of modulation for NaR beyond light control. By introducing a potential Cl- binding site near the putative Na+ release cavity, we engineered Nonlabens dokdonensis rhodopsin 2 (NdR2) to be modulated by Cl- , an essential chemical in organisms. The engineered NdR2 demonstrated an approximately two-fold increase in Na+ pump activity in the presence of 100 mM Cl- compared to Cl- -free solution. Increasing Cl- concentration decreased the lifetimes of the M and O intermediates accordingly. The analysis of competitive ion uptake suggested the bound Cl- may increase the Na+ affinity and selectivity. This chemical modulation allows for more diverse and precise control over cellular processes, advancing the development of next-generation optogenetic tools. Notably, our Cl- -modulated NdR2 establishes an innovative mechanism for linking Cl- to Na+ -related processes, with potential applications in optogenetic therapies for related diseases.

K+-Dependent Photocycle and Photocurrent Reveal the Uptake of K+ in Light-Driven Sodium Pump.

Engineering light-controlled K+ pumps from Na+-pumping rhodopsins (NaR) greatly expands the scope of optogenetic applications. However, the limited knowledge regarding the kinetic and selective mechanism of K+ uptake has significantly impeded the modification and design of light-controlled K+ pumps, as well as their practical applications in various fields, including neuroscience. In this study, we presented K+-dependent photocycle kinetics and photocurrent of a light-driven Na+ pump called Nonlabens dokdonensis rhodopsin 2 (NdR2). As the concentration of K+ increased, we observed the accelerated decay of M intermediate in the wild type (WT) through flash photolysis. In 100 mM KCl, the lifetime of the M decay was approximately 1.0 s, which shortened to around 0.6 s in 1 M KCl. Additionally, the K+-dependent M decay kinetics were also observed in the G263W/N61P mutant, which transports K+. In 100 mM KCl, the lifetime of the M decay was approximately 2.5 s, which shortened to around 0.2 s in 1 M KCl. According to the competitive model, in high KCl, K+ may be taken up from the cytoplasmic surface, competing with Na+ or H+ during M decay. This was further confirmed by the K+-dependent photocurrent of WT liposome. As the concentration of K+ increased to 500 mM, the amplitude of peak current significantly dropped to approximately ~60%. Titration experiments revealed that the ratio of the rate constant of H+ uptake (kH) to that of K+ uptake (kK) is >108. Compared to the WT, the G263W/N61P mutant exhibited a decrease of approximately 40-fold in kH/kK. Previous studies focused on transforming NaR into K+ pumps have primarily targeted the intracellular ion uptake region of Krokinobacter eikastus rhodopsin 2 (KR2) to enhance K+ uptake. However, our results demonstrate that the naturally occurring WT NdR2 is capable of intracellular K+ uptake without requiring structural modifications on the intracellular region. This discovery provides diverse options for future K+ pump designs. Furthermore, we propose a novel photocurrent-based approach to evaluate K+ uptake, which can serve as a reference for similar studies on other ion pumps. In conclusion, our research not only provides new insights into the mechanism of K+ uptake but also offers a valuable point of reference for the development of optogenetic tools and other applications in this field.

Na+ Binding and Transport: Insights from Light-Driven Na+-Pumping Rhodopsin.

Na+ plays a vital role in numerous physiological processes across humans and animals, necessitating a comprehensive understanding of Na+ transmembrane transport. Among the various Na+ pumps and channels, light-driven Na+-pumping rhodopsin (NaR) has emerged as a noteworthy model in this field. This review offers a concise overview of the structural and functional studies conducted on NaR, encompassing ground/intermediate-state structures and photocycle kinetics. The primary focus lies in addressing key inquiries: (1) unraveling the translocation pathway of Na+; (2) examining the role of structural changes within the photocycle, particularly in the O state, in facilitating Na+ transport; and (3) investigating the timing of Na+ uptake/release. By delving into these unresolved issues and existing debates, this review aims to shed light on the future direction of Na+ pump research.

Dynamic modulation of electric and magnetic toroidal dipole resonance and light trapping in Si-GSST hybrid metasurfaces.

The weak coupling of a toroidal dipole (TD) to an electromagnetic field offers great potential for the advanced design of photonic devices. However, simultaneous excitation of electric toroidal dipoles (ETDs) and magnetic toroidal dipoles (MTDs) is currently difficult to achieve. In this work, we propose a hybrid metasurface based on Si and phase transition material G e 2 S b 2 S e 4 T e 1 (GSST), which is formed by four Si columns surrounding a GSST column and can simultaneously excite two different TD (ETD and MTD) resonances. We also calculated the electric field distribution, magnetic field distribution, and multipole decomposition of the two resonances, and the results show that the two modes are ETD resonance and MTD resonance, respectively. The polarization characteristics of these two modes are also investigated, and the average field enhancement factor (EF) of the two modes is calculated. The dynamic modulation of the relative transmission and EF is also achieved based on the tunable properties of the phase change material GSST. Our work provides a way to realize actively tunable TD optical nanodevices.

Structural Evolution and Electronic Properties of Two Sulfur Atom-Doped Boron Clusters.

We present a theoretical study of structural evolution, electronic properties, and photoelectron spectra of two sulfur atom-doped boron clusters S2Bn0/- (n = 2-13), which reveal that the global minima of the S2Bn0/- (n = 2-13) clusters show an evolution from a linear-chain structure to a planar or quasi-planar structure. Some S-doped boron clusters have the skeleton of corresponding pure boron clusters; however, the addition of two sulfur atoms modified and improved some of the pure boron cluster structures. Boron is electron-deficient and boron clusters do not form linear chains. Here, two sulfur atom doping can adjust the pure boron clusters to a linear-chain structure (S2B20/-, S2B30/-, and S2B4-), a quasi-linear-chain structure (S2B6-), single- and double-chain structures (S2B6 and S2B9-), and double-chain structures (S2B5, and S2B9). In particular, the smallest linear-chain boron clusters S2B20/- are shown with an S atom attached to each end of B2. The S2B2 cluster possesses the largest highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap of 5.57 eV and the S2B2- cluster possesses the largest average binding energy Eb of 5.63 eV, which shows the superior chemical stability and relative stability, respectively. Interestingly, two S-atom doping can adjust the quasi-planar pure boron clusters (B7-, B10-, and B120/-) to a perfect planar structure. AdNDP bonding analyses reveal that linear S2B3 and planar SeB11- have π aromaticity and σ antiaromaticity; however, S2B2, planar S2B6, and planar S2B7- clusters have π antiaromaticity and σ aromaticity. Furthermore, AdNDP bonding analyses reveal that planar S2B4, S2B10, and S2B12 clusters are doubly (π and σ) aromatic, whereas S2B5-, S2B8, S2B9-, and S2B13- clusters are doubly (π and σ) antiaromatic. The electron localization function (ELF) analysis shows that S2Bn0/- (n = 2-13) clusters have different electron delocalization characteristics, and the spin density analysis shows that the open-shell clusters have different characteristics of electron spin distribution. The calculated photoelectron spectra indicate that S2Bn- (n = 2-13) have different characteristic peaks that can be compared with future experimental values and provide a theoretical basis for the identification and confirmation of these doped boron clusters. Our work enriches the new database of geometrical structures of doped boron clusters, provides new examples of aromaticity for doped boron clusters, and is promising to offer new ideas for nanomaterials and nanodevices.

Disentangling the effects of vapor pressure deficit on northern terrestrial vegetation productivity.

The impact of atmospheric vapor pressure deficit (VPD) on plant photosynthesis has long been acknowledged, but large interactions with air temperature (T) and soil moisture (SM) still hinder a complete understanding of the influence of VPD on vegetation production across various climate zones. Here, we found a diverging response of productivity to VPD in the Northern Hemisphere by excluding interactive effects of VPD with T and SM. The interactions between VPD and T/SM not only offset the potential positive impact of warming on vegetation productivity but also amplifies the negative effect of soil drying. Notably, for high-latitude ecosystems, there occurs a pronounced shift in vegetation productivity's response to VPD during the growing season when VPD surpasses a threshold of 3.5 to 4.0 hectopascals. These results yield previously unknown insights into the role of VPD in terrestrial ecosystems and enhance our comprehension of the terrestrial carbon cycle's response to global warming.

Novel trifunctional electrocatalyst of nickel foam supported Co2P/NiMoO4 heterostructures for overall water splitting and urea oxidation.

The process of electrocatalytic water splitting for hydrogen generation is significantly limited by sluggish kinetics of the anodic oxygen evolution reaction (OER). The efficiency of H2 electrocatalytic generation can be improved by reducing the anode potential or substituting urea oxidation reaction (UOR) for oxygen evolution process. Here, we report a robust catalyst based on Co2P/NiMoO4 heterojunction arrays supported on nickel foam (NF) for water splitting and urea oxidation. In the hydrogen evolution reaction in alkaline media, the optimized catalyst Co2P/NiMoO4/NF displayed a lower overpotential (169 mV) at a large current density (150 mA cm-2) compared to 20 wt% Pt/C/NF (295 mV@150 mA cm-2). In the OER and UOR, the potentials were as low as 1.45 and 1.34 V. These values surpass (for OER), or compare favorably to (for UOR), the most advanced commercial catalyst RuO2/NF (at 10 mA cm-2). This outstanding performance was attributed to the addition of Co2P, which has a significant effect on the chemical environment and electron structure of NiMoO4, while increasing the number of active sites and promoting charge transfer across the Co2P/NiMoO4 interface. This work proposes a high-performance and cost-effective electrocatalyst for water splitting and urea oxidation.

Toroidal dipole bound states in the continuum based on hybridization of surface lattice resonances.

Obtaining a high quality factor (Q factor) in applications based on metasurfaces is crucial for improving device performance. Therefore, bound states in the continuum (BICs) with ultra-high Q factors are expected to have many exciting applications in photonics. Breaking the structure symmetry has been viewed as an effective way of exciting quasi-bound states in the continuum (QBICs) and generating high-Q resonances. Among these, one exciting strategy is based on the hybridization of surface lattice resonances (SLRs). In this study, we investigated for the first time the Toroidal dipole bound states in the continuum (TD-BICs) based on the hybridization of Mie surface lattice resonances (SLRs) in an array. The unit cell of metasurface is made of a silicon nanorods dimer. The Q factor of QBICs can be precisely adjusted by changing the position of two nanorods, while the resonance wavelength remains quite stable against the change of position. Simultaneously, the far-field radiation and near-field distribution of the resonance are discussed. The results indicate that the toroidal dipole dominates this type of QBIC. Our results indicate that this quasi-BIC can be tuned by adjusting the size of the nanorods or the lattice period. Meanwhile, through the study of the shape variation, we found that this quasi-BIC exhibits excellent robustness, whether in the case of two symmetric or asymmetric nanoscale structures. This will also provide large fabrication tolerance for the fabrication of devices. Our research results will improve the mode analysis of surface lattice resonance hybridization, and may find promising applications in enhancing light-matter interaction, such as lasing, sensing, strong-coupling, and nonlinear harmonic generation.

Active quasi-BIC metasurfaces assisted by epsilon-near-zero materials.

Active devices play a critical role in modern electromagnetic and photonics systems. To date, the epsilon (ε)-near-zero (ENZ) is usually integrated with the low Q-factor resonant metasurface to achieve active devices, and enhance the light-matter interaction significantly at the nanoscale. However, the low Q-factor resonance may limit the optical modulation. Less work has been focused on the optical modulation in the low-loss and high Q-factor metasurfaces. Recently, the emerging optical bound states in the continuum (BICs) provides an effective way for achieving high Q-factor resonators. In this work, we numerically demonstrate a tunable quasi-BICs (QBICs) by integrating a silicon metasurface with ENZ ITO thin film. Such a metasurface is composed of five square holes in a unit cell, and hosts multiple BICs by engineering the position of centre hole. We also reveal the nature of these QBICs by performing multipole decomposition and calculating near field distribution. Thanks to the large tunability of ITO's permittivity by external bias and high-Q factor enabled by QBICs, we demonstrate an active control on the resonant peak position and intensity of transmission spectrum by integrating ENZ ITO thin films with QBICs supported by silicon metasurfaces. We find that all QBICs show excellent performance on modulating the optical response of such a hybrid structure. The modulation depth can be up to 14.8 dB. We also investigate how the carrier density of ITO film influence the near-field trapping and far-field scattering, which in turn influence the performance of optical modulation based on this structure. Our results may find promising applications in developing active high-performance optical devices.

Greenhouse gas emissions from extractive industries in a globalized era.

The extractive industry consumes vast amounts of energy and is a major contributor to greenhouse gas (GHG) emissions. However, its climatic impacts have not yet been fully accounted for. In this study, we estimated the GHG emissions from extractive activities globally with a focus on China, and assessed the main emission drivers. In addition, we predicted the Chinese extractive industry emissions in the context of global mineral demand and cycling. As of 2020, GHG emissions from the global extractive industry had reached 7.7 billion tons of CO2 equivalents (CO2e), accounting for approximately 15.0% of the global anthropogenic GHG emissions (excluding GHG emissions from land use, land-use change, and forestry activities (LULUCF), with China being the largest emitter, accounting for 3.5% of global emissions. Extractive industry GHG emissions are projected to peak by 2030 or even earlier to achieve low-carbon peak targets. The most critical pathway for reducing GHG emissions in the extractive industry is to control emissions from coal mining. Therefore, reducing methane emissions from mining and washing coal (MWC) should be prioritized.