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Ultralow dispersion gradient refractive index (GRIN) microlens arrays (MLAs) covering the visible to mid-infrared wavelength range are imprinted in GeS 2 -Ga 2 S 3 -CsI chalcohalide glass by an efficient and economical microthermal poling process. The effect of poling voltage on GRIN microstructure, structural rearrangement, optical properties of the poled glasses, and imaging of the imprinted MLAs have been investigated. Optical focal length of the GRIN MLAs decreases from 353 to 63 μm with increasing the poling voltage from 200 to 1000 V, which is in accordance with imprinting-induced phase difference increase from 0.57 λ to 1.19 λ. Optimal chromatic aberration (between 520 and 850 nm) as low as 5% is achieved in the GRIN MLAs. Formation mechanism of GRIN MLAs is mainly associated with an enhanced transverse migration of Cs+ ions within mesh square area, which is provided by an improved anode of microthermal poling setup. Thus, an efficient and inexpensive process developed can produce broadband and ultralow dispersion GRIN MLAs for imaging, display, and photovoltaic applications. [ABSTRACT FROM AUTHOR]

The potential of satellite soil moisture (SM) in improving hydrological modeling has been addressed in synthetic experiments, but it is less explored in real data cases. Here, we investigate the added value of Soil Moisture and Passive (SMAP) and Advanced Scatterometer (ASCAT) SM data to distributed hydrological modeling with the soil and water assessment tool (SWAT) in a highly human disturbed catchment (126, 486 km2) featuring a network of SM and streamflow observations. The investigation is based on the ensemble Kalman filter (EnKF) considering SM errors from satellite data using the triple collocation. The assimilation of SMAP and ASCAT SM improved the surface (0–10 cm) and rootzone (10–30 cm) SM at >70% and > 50% stations of the basin, respectively. However, the assimilation effects on distributed streamflow simulation of the basin are un-significant and not robust. SM assimilation improved the simulated streamflow at two upstream stations, while it deteriorated the streamflow at the remaining stations. This can be largely attributed to the poor vertical soil water coupling of SWAT, suboptimal model parameters, satellite SM data quality, humid climate, and human disturbance to rainfall-runoff processes. This study offers strong evidence of integrating satellite SM into hydrological modeling in improving SM estimation and provides implications for achieving the added value of remotely sensed SM in streamflow improvement. [ABSTRACT FROM AUTHOR]

This work presents the influence of glass matrix SiO 2 –B 2 O 3 –NaF on the formation of near-infrared (NIR)-shielding functional units in energy-saving glass windows. The structural analyses by XRD, XPS, and Raman confirmed that the NIR-shielding performance is insensitive to SiO 2 or B 2 O 3 glass network formers but is significantly impacted by the concentration of NaF. This is because the presence of a reasonable amount of NaF provides the much-needed sodium for the formation of NIR-shielding functional units Na 5 W 14 O 44 but too much NaF (>22 mol.%) can inhibit the formation of Na 5 W 14 O 44 by transforming the W– O –W chain in the interconnected [WO 6 ] and [WO 4 ] polyhedrons into W–O- bonds. By adjusting NaF to the optimal level (16 mol.%) and adding only a small amount of H 2 WO 4 (1.9 mol.%) as the tungsten source in the raw materials, excellent optical properties and thermal insulation performance have been achieved in the produced bulk glass, with a high transmission of 65.8% at 550 nm in the visible light region and a low transmission of 6.6% at 1550 nm in the NIR region. This performance is much better than soda lime glass and ITO glass and is comparable to cesium tungsten bronze-based membrane coated glass. This study paves a way for glass composition design to achieve high NIR-shielding performance with the minimum amount of tungsten source, leading to cost-effective glass fabrication and enhanced mechanical strength of energy-saving glass windows. [ABSTRACT FROM AUTHOR]

NIR-shielding window materials were fabricated by direct embedding of Ta 0.3 W 0.7 O 2.85 nanocrystals in bulk borosilicate glass-ceramics during a facile melt-quenching process. Optical and thermal performance of the prepared windows can be adjusted by varying the concentration of H 2 WO 4 and Ta 2 O 5 in the starting materials. The optimized window fabricated from raw materials containing 4.5 mol% H 2 WO 4 and 0.3 mol% Ta 2 O 5 exhibited high visible light transmittance 74.4% and strong NIR-shielding ability ΔT = 68.9%. Its thermal insulation performance is much better than soda lime glass or ITO glass, and its visible light transmission is higher than cesium-tungsten-bronze-based film coated glass. The distribution of Ta 0.3 W 0.7 O 2.85 functional nanocrystals in the glass matrix was confirmed by sample characterization using XRD, Raman, XPS, HRTEM and EDS. The NIR-shielding property has been attributed to local surface plasmon resonance due to oxygen vacancies in the Ta 0.3 W 0.7 O 2.85 nanocrystals. This study sheds a light on fabricating energy-saving windows with a tunable NIR-shielding performance. [ABSTRACT FROM AUTHOR]

Background: CPT-11 (irinotecan) is one of the most efficient agents used for colorectal cancer chemotherapy. However, as for many other chemotherapeutic drugs, how to minimize the side effects of CPT-11 still needs to be thoroughly described.Objectives: This study aimed to develop the CPT-11-loaded DSPE-PEG 2000 targeting EGFR liposomal delivery system and characterize its targeting specificity and therapeutic effect on colorectal cancer (CRC) cells in vitro and in vivo.Results: The synthesized liposome exhibited spherical shapes (84.6 ± 1.2 nm to 150.4 nm ± 0.8 nm of estimated average sizes), good stability, sustained release, and enough drug loading (55.19%). For in vitro experiments, SW620 cells treated with CPT-11-loaded DSPE-PEG2000 targeting EGFR liposome showed lower survival extended level of intracellular ROS production. In addition, it generated an enhanced apoptotic cell rate by upregulating the protein expression of both cleaved-caspase-3 and cleaved-caspase-9 compared with those of SW620 cells treated with free CPT-11. Importantly, the xenograft model showed that both the non-target and EGFR-targeted liposomes significantly inhibited tumor growth compared to free CPT-11.Conclusions: Compared with the non-target CPT-11-loaded DSPE-PEG2000 liposome, CPT-11-loaded DSPE-PEG2000 targeting EGFR liposome treatment showed much better antitumor activity in vitro in vivo. Thus, our findings provide new assets and expectations for CRC targeting therapy. [ABSTRACT FROM AUTHOR]

• A novel method (JSTB) was proposed to control flow-induced noise. • The control effect of JSTB on turbulent fluctuating pressure was studied. • The mechanism of JSTB in reducing flow-induced noise was revealed. • Noise reduction effects of JSTB were proved through simulation and experiment. At medium to high speeds, the flow-induced structural vibration noise generated by structural vibration under the excitation of the turbulent fluctuating pressure can seriously damage the acoustic performance of underwater vehicles. In this paper, we have proposed a new and noiseless method, called junction suction and trailing edge blowing (JSTB), to reduce the flow-induced structural vibration noise of the wing–plate model. We have investigated the effects of JSTB on the flow and sound fields through a combination of numerical simulations and experimental tests. The experiments are conducted in a low-noise gravity water tunnel. Numerical results show that JSTB significantly reduces the peak values of the internal self-noise at 70 Hz, 180 Hz, 225 Hz, and 265 Hz when the velocity is 6.87 m s − 1 . The model radiated noise reduction is more prominent in the 20–1000 Hz frequency range, with an optimal noise reduction level of 15.4 dB. The simulation results agree well with the experimental results. JSTB can effectively reduce the internal sound pressure level, turbulent fluctuating pressure, and radiated sound power of the model. This work provides a novel solution for the flow-induced structural vibration noise control of underwater vehicles. [ABSTRACT FROM AUTHOR]

Background: Osteoporosis (OP) is a systemic skeletal disease marked by bone mass reduction and bone tissue destruction. Hormone replacement therapy is an effective treatment for post-menopausal OP, but estrogen has poor tissue selectivity and severe side effects. Results: In this study, we constructed a poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs)-based drug delivery system to co-load 17β estradiol (E2) and iron oxide (Fe3O4) together, modified with alendronate (AL) to achieve bone targeting and realize a magnetically remote-controllable drug release. The NPs were fabricated through the emulsion solvent diffusion method. The particle size was approximately 200 nm while the encapsulation efficiency of E2 was 58.34 ± 9.21%. The NPs were found to be spherical with a homogenous distribution of particle size. The NPs showed good stability, good biocompatibility, high encapsulation ability of E2 and excellent magnetic properties. The NPs could be effectively taken up by Raw 264.7 cells and were effective in enriching drugs in bone tissue. The co-loaded NPs exposed to an external magnetic field ameliorated OVX-induced bone loss through increased BV/TV, decreased Tb.N and Tb.Sp, improved bone strength, increased PINP and OC, and downregulated CTX and TRAP-5b. The haematological index and histopathological analyses displayed the NPs had less side effects on non-skeletal tissues. Conclusions: This study presented a remote-controlled release system based on bone-targeted multifunctional NPs and a new potential approach to bone-targeted therapy of OP. [ABSTRACT FROM AUTHOR]

In the context of the evolving landscape of reduction in carbon emissions and integration of renewable energy, this study uses system dynamics (SD) modeling to explore the interconnected dynamics of carbon trading (CT), tradable green certificate (TGC) trading, and electricity markets. Using differential equations with time delays, the study provides a comprehensive analysis of structural relationships and feedback mechanisms within and between these markets. Key findings reveal the intricate interplay between carbon prices, green certificate prices, and electricity prices under various coupling mechanisms. For example, under the three-market coupling mechanism, carbon trading prices stabilize around 150 Yuan/ton, while green certificate prices reach a peak of 0.45 Yuan/KWH, impacting electricity prices, which fluctuate between 0.33 and 1.09 Yuan / KWH during the simulation period. These quantitative results shed light on nuanced fluctuations in market prices and the dynamics of anticipated purchases and sales volumes within each market. The insights gleaned from this study offer valuable implications for policy makers and market stakeholders in navigating the complexities of carbon emission reduction strategies, the integration of renewable energy and market equilibrium. By understanding the dynamics of multi-market coupling, stakeholders can better formulate policies and strategies to achieve sustainable energy transitions and mitigate impacts of climate change. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mathematical model of CFD-DEM calculation method was used. • The inhale and dust exposure characteristics of driver were analyzed. • Different area airflow patterns of bronchus were analyzed. • The deposition rate of different particle diameters were analyzed. To study the dust exposure law of the operator in the anchor digging working face, the CFD-DEM method was used to numerically simulate the dust deposition pattern in the bronchus of the anchor digging driver. The results show that the highest dust concentration in the vortex region of the anchor digging working face can reach 2364.76 mg/m3, seriously endangering the health of anchor digging driver. The average dust concentration in the respiratory hemisphere of the driver is 510.57 mg/m3, and the range of inhaled dust diameter is 0–60 μm in the breathing state of moderate labour. Over time, the deposition mass in the bronchial showed a pattern of rapid and then slow increase, which was consistent with the trend of the Boltzmann model. Increasing dust particle diameter was positively correlated with bronchial deposition rate and negatively correlated with alveolar deposition rate. Among them, 0–10 μm particles were deposited throughout the bronchus and a large number of particles were deep into the alveoli, with the alveolar deposition rate as high as 56.3 %, while the alveolar deposition rate for particles of 10–20 μm decreased to 20.4 %, and for particles larger than 30 μm, the effect on the alveoli was smaller. [ABSTRACT FROM AUTHOR]

• A multicomponent acid solution consisting of SDBS,BS-12, HF and C6H8O7 was used to acidifie coal samples. • Acidification treatment can promote the formation of oxygen-containing functional groups C O and C O. • Provide an effective method for realizing high-efficiency clean mining of coal. • The micro mechanism of wettability was explained using molecular dynamics software. In order to explore the influence mechanism of different surfactants on the wettability of coal samples acidified with multi-component acid solutions, the effects of multi-component acid solutions and surfactant composite acid solutions on the functional groups and microcrystalline structures of coal samples were studied. In this paper, a multicomponent acid solution consisting of sodium dodecyl benzene sulfonate (SDBS), dodecyl dimethyl betaine (BS-12), hydrofluoric acid (HF), and citric acid (C 6 H 8 O 7) was used to acidification and contact angle experiments on coal samples. Fourier transform infrared spectroscopy (FTIR) results show that acidification can promote the formation of C O and C O, and the synergistic effect of surfactant BS-12 on multi-component acid solution is more prominent. X-ray diffraction (XRD) results show that the variation trend of aromatic lamellar diameter L a of coal samples is consistent with the aromatic layer spacing d 002. Surfactants can slow down the damage of multi-component acid solution to the microcrystalline structure of coal samples. The change of contact angle shows that the instantaneous synergistic wetting effect of BS-12 is better than that of SDBS. At the same time, molecular dynamics simulation technology was used to verify the effect of surfactants on the wettability of multi-component acid solutions. Therefore, this study provides a feasible method and theoretical guidance for improving the efficiency of coal production and utilization through chemical means. [ABSTRACT FROM AUTHOR]

[Display omitted] • LVB experienced extensive conversion of forest and grass to agricultural land. • SWAT model presents good applicability in seasonal runoff modeling in LVB. • annual runoff generally increased with seasonal differences due to LULC changes. • hydrological drought aggravated over central western and eastern LVB with increased frequency and lengthened duration. Understanding the hydrological impacts of land use and land cover (LULC) changes is significant for sustainable water resources management and planning. The Lake Victoria basin (LVB) has experienced extensive forest and grass degradation and agricultural land expansion under rapid socio-economic development and population growth in recent decades. However, the hydrological impacts of LULC changes for the whole LVB is still poorly documented. This study first investigated the LULC changing effects of LVB, focusing on its impacts on the annual and seasonal runoff and the hydrological drought based on a distributed hydrological modeling of the Soil and Water Assessment Tool (SWAT). SWAT model showed comparatively good applicability in seasonal runoff simulation of LVB, with the percent bias (PBIAS) kept within ± 20 % and the coefficient of determination (R2) over 0.6 at ten hydrological stations available over the calibration and validation phases. Generally, the annual runoff obtained a monthly increase of 1.5 mm under collective LULC changes. Moreover, the LULC effects presented considerable seasonal dependence. A largest runoff increase of approximately 4 mm was detected in short rainy season attributed to the combined surface runoff and groundwater increase. Insignificant runoff increase was observed in long rainy and dry seasons under the complementary effects of surface runoff increase and groundwater decrease. Additionally, the hydrological drought was generally aggravated with increased drought frequency and lengthened duration, particularly for the central western and eastern regions with massive conversion of forest to agricultural land. The findings provide importance implication for rational water resources management and drought disaster response for the LVB. [ABSTRACT FROM AUTHOR]

Although superhydrophobic surfaces can change the flow regime of the boundary layer, most studies have focused on microscale channel flow. In this work, we use the slip boundary condition to simulate the superhydrophobic surface model on the macroscale. Flow regime changes and the hydrodynamic noise of the superhydrophobic surface model are investigated at different velocities. Results show that the superhydrophobic surface can reduce the hydrodynamic noise in the frequency range of 10–5000 Hz. When the velocity was 3.66 m/s, the noise reduction level of superhydrophobic surface model is 11.6 dB compared with that of the no-slip model. Furthermore, in the frequency range of 2000–5000 Hz, the superhydrophobic surface exhibit superior hydrodynamic noise reduction that could reach 23.4 dB. Consequently, experiments are conducted at different flow velocities to verify the noise reduction effect of the superhydrophobic surface. The experimental results show that the hydrodynamic noise is effectively reduced after the control of superhydrophobic surface. This work provides macroscale simulation results for hydrodynamic noise from a superhydrophobic surface, and indicates that hydrodynamic noise can be effectively reduced by a superhydrophobic surface. • Slip velocity boundary condition was used on superhydrophobic surfaces to study the flow and noise characteristics of superhydrophobic surfaces on macroscale models. • Hydrodynamic noise reduction mechanism of superhydrophobic surface was studied and superhydrophobic surfaces were innovatively used to control the hydrodynamic noise from underwater vehicles. • Noise control effect of superhydrophobic surface over the frequency range 10 Hz–5000 Hz was proved by simulation and experiment. [ABSTRACT FROM AUTHOR]

To effectively monitor the spatio–temporal dynamics of the surface water extent (SWE) in Lake Victoria, this study introduced a novel methodology for generating a seamless SWE time series with fine resolution by integrating daily a Moderate-resolution Imaging Spectroradiometer (MODIS) and Landsat imagery. In the proposed methodology, daily normalized difference vegetation index (NDVI) time series data with 30 m resolution were first generated based on the constructed pixel-by-pixel downscaling models between the simultaneously acquired MODIS-NDVI and Landsat-NDVI data. In the compositing process, a Minimum Value Composite (MinVC) algorithm was used to generate monthly minimum NDVI time series, which were then segmented into a seamless SWE time series of the years 2000–2020 with 30 m resolution from the cloud background. A comparison with the existing Landsat-derived JRC (European Joint Research Centre) monthly surface water products and altimetry-derived water level series revealed that the proposed methodology effectively provides reliable descriptions of spatio–temporal SWE dynamics. Over Lake Victoria, the average percentage of valid observations made using the JRC's products was only about 70% due to persistent cloud cover or linear strips, and the correlation with the water level series was poor (R2 = 0.13). In contrast, our derived results strongly correlated with the water level series (R2 = 0.54) and efficiently outperformed the JRC's surface water products in terms of both space and time. Using the derived SWE data, the long-term and seasonal characteristics of lake area dynamics were studied. During the past 20 years, a significant changing pattern of an initial decline followed by an increase was found for the annual mean SWE, with the lowest area of 66,386.57 km2 in 2006. A general seasonal variation in the monthly mean lake area was also observed, with the largest SWE obtained during June–August and the smallest SWE observed during September–November. Particularly in the spring of 2006 and the autumn of 2020, Lake Victoria experienced intense episodes of drought and flooding, respectively. These results demonstrate that our proposed methodology is more robust with respect to capturing spatially and temporally continuous SWE data in cloudy conditions, which could also be further extended to other regions for the optimal management of water resources. [ABSTRACT FROM AUTHOR]

Air connectivity is a crucial factor for economic development, especially for a free port city such as Hong Kong. This paper examines the role changes of Hong Kong in providing connectivity for the international market that originates from regional airports in Mainland China. The time-dependent earliest arrival time method is employed to assess its connectivity levels compared with other Chinese air gateways in 1998 and 2018, with measurement of three indicators: accessibility, dependency, and centrality. Empirical evidence demonstrates that extensive progress of accessibility and dependency has been presented in both Hong Kong and other Chinese gateways as for liberal arrangements after 2001, while foreign transfers are still an inescapable theme to strengthen air connections. In addition, Hong Kong retained its hub status even while deemed inferior to Beijing and Shanghai in the international market of Mainland China, especially for the Northeast and East Coastal region and air travel to Asia-Pacific, Europe, Middle East, and Africa. What is more, although Hong Kong benefited from its massive traffic generation, major air gateways would be dispersedly located across Mainland China with the rise of central China, geographical proximity effect, and differential market cultivation. [ABSTRACT FROM AUTHOR]

Gradient refractive index (GRIN) micro-optics present unique opportunities for control of the chromatic properties, new degrees of freedom for optical design as well as the potential for use in new optical system applications. GRIN microgratings were imprinted in GeS 2 -Ga 2 S 3 -MCl (M = Na, K, Cs) chalcohalide glasses by microthermal poling, and the effects of the type and concentration of alkali cations on their performance were investigated. Two effective imprinting formation regions of the GRIN microstructure based on the poling saturation voltage (U s) and glass composition are observed at fixed poling time and temperature. The U s increases from 140 to 750 and 2600 V in accordance with the activation energy (E a) of alkali ions (Na+ to K+ and Cs+) increasing from 45.15 to 58.62 and 92.58 kJ/mol for studied samples. The saturated numbers of diffraction order (N s) of the gratings in these samples are 7, 9 and 6, respectively, the highest number being provided by the K+-containing sample. This is in accordance with imprinting-induced phase differences (0.14λ, 0.19λ and 0.09λ) measured in the fabricated samples containing Na+, K+ and Cs+ ions. Furthermore, the U s of samples decreases from 1500 to 300 V with four concentrations of K+ from 10 to 30%, associated with their E a of K+ decreasing from 69.62 to 53.46 kJ/mol, while N s increases from 8 to 14, which is attributed to the increase of the phase difference in the GRIN structures. The controllable GRIN microstructures are realized by adjusting the type and concentration of alkali cations in chalcohalide glasses, which is expected to drive the design of broadband GRIN microgratings. [ABSTRACT FROM AUTHOR]

Remote sensing and land surface models promote the understanding of soil moisture dynamics by means of multiple products. These products differ in data sources, algorithms, model structures and forcing datasets, complicating the selection of optimal products, especially in regions with complex land covers. This study compared different products, algorithms and flagging strategies based on in situ observations in Anhui province, China, an intensive agricultural region with diverse landscapes. In general, models outperform remote sensing in terms of valid data coverage, metrics against observations or based on triple collocation analysis, and responsiveness to precipitation. Remote sensing performs poorly in hilly and densely vegetated areas and areas with developed water systems, where the low data volume and poor performance of satellite products (e.g., Soil Moisture Active Passive, SMAP) might constrain the accuracy of data assimilation (e.g., SMAP L4) and downstream products (e.g., Cyclone Global Navigation Satellite System, CYGNSS). Remote sensing has the potential to detect irrigation signals depending on algorithms and products. The single-channel algorithm (SCA) shows a better ability to detect irrigation signals than the Land Parameter Retrieval Model (LPRM). SMAP SCA-H and SCA-V products are the most sensitive to irrigation, whereas the LPRM-based Advanced Microwave Scanning Radiometer 2 (AMSR2) and European Space Agency (ESA) Climate Change Initiative (CCI) passive products cannot reflect irrigation signals. The results offer insight into optimal product selection and algorithm improvement. [ABSTRACT FROM AUTHOR]

By the analytical method, this paper investigates the mode-coupling friction-induced instability and the resulting stick-slip self-excited vibration of the marine stern water-lubricated rubber bearing-shaft system. The 2-DOF simplified theoretical model is reasonably developed to characterize stern water-lubricated rubber bearing-shaft system. The complex eigenvalue analysis is conducted to analyze the instability behaviors of the model. Results show the normal force and nonlinear stiffness often deteriorate the stability of the model. Subsequently, two types of analytical expressions for stick-slip vibration amplitude of the model are by the Krylov-Bogoliubbov-Mitropolsky method, which match well with the results from numerical integration. Then, parameter discussion about the influences of friction coefficient, damping, normal force and nonlinear contact stiffness on self-excited vibration amplitudes are performed. The results indicate that the bearing-shaft system can keep the steady-state static equilibrium or the oscillations with small amplitude if the proper parameter values of the variables are chosen, which will benefits controlling the friction-induced vibration of the water-lubricated rubber bearing-shaft system. The novelty of this work is to give analytical expressions for stick-slip self-excited vibration amplitude of the simplified model. [ABSTRACT FROM AUTHOR]

Cyanation has attracted considerable attention in organic synthesis because nitriles are key structural motifs in numerous important dyes, agrochemicals, natural products and drug molecules. As the fourth generation of cyanating reagents, isocyanides occupy a prominent place in the synthesis of nitriles due to their favorable stability, easy operability and high reactivity. In recent years, three types of cyanation with isocyanides have been established: the cleavage of the C–NC bond of tertiary alkyl isocyanides (Type I), the rearrangement of aryl isocyanides with azides (Type II), and the reductive cyanation of ketones with α-acidic isocyanides (Type III). This review focuses on advances in cyanation with isocyanides with an emphasis on reaction scope, limitations and mechanisms, which could reveal their remarkable value and superiority for accessing various nitriles. In addition, the future development prospects of this specific field are also introduced. We believe that this feature article will serve as a comprehensive tool to navigate cyanation with isocyanides across the vast area of synthetic chemistry. [ABSTRACT FROM AUTHOR]

The availability of streamflow records in Africa has been declining since the 1980s due to malfunctioning gauging stations and data collection failures. Africa also has insufficient hydrological information owing to the allocation of few resources to research efforts. Unreliable runoff datasets and large uncertainties in runoff trends due to climate change patterns and human activities are major challenges to water resource management in Africa. Therefore, this study aimed to improve runoff estimates and to assess runoff trend responses to climate change and human activities in Africa during 1981–2016. Using statistical methods, monthly gridded runoff datasets were generated for the period of 1981–2016 from a modified runoff curve number method calibrated with river discharge data from 535 gauging stations. According to the cross-validation results, the constructed runoff datasets comprised the Nash and Sutcliffe coefficients ranging from 0.5 to 1, coefficients of determination ranging from 0.5 to 1, and percent biases between ±25% for a large number of stations up to 73%, 80%, and 91% of the 535 gauged catchments used as references. Analysis of runoff trend responses to climate change and human activities revealed that land cover change contributed more (72%) to the observed net runoff change (0.30% a−1) than continental climate changes (28%). These contributions were results of cropland expansion rate of 0.46% a−1 and a precipitation increase of 0.07% a−1. The performance and simplicity of the statistical methods used in this study could be useful for improving runoff estimations in other regions with limited streamflow data. The results of the current study could be important to natural resource managers and decision-makers in terms of raising awareness of climate change adaptation strategies and agricultural land-use policies in Africa. [ABSTRACT FROM AUTHOR]

A facile protocol for the preparation of indole–isoindole derivatives was developed and proceeds via a palladium-catalyzed [3+2] cyclization of isocyanides with alkynyl imines. In this transformation, the palladium catalyst has a triple role, serving simultaneously as a π acid, a transition-metal catalyst and a hydride ion donor, thus enabling the dual function of isocyanide both as a C1 synthon for cyanation and a C1N1 synthon for imidoylation. Significantly, the reaction is the sole successful example for accessing indole–isoindole derivatives, and will open up new avenues to assemble unique N-heterocycle frameworks. Furthermore, the synthetic value of this protocol is demonstrated in the late-stage modification of physiologically active molecules and in the construction of aggregation-induced emission compounds. [ABSTRACT FROM AUTHOR]

Salt stress is one of the important environmental factors that inhibit the normal growth and development of plants. Plants have evolved various mechanisms, including signal transduction regulation, physiological regulation, and gene transcription regulation, to adapt to environmental stress. MicroRNAs (miRNAs) play a role in regulating mRNA expression. Nevertheless, miRNAs related to salt stress are rarely reported in bread wheat (Triticum aestivum L.). In this study, using high−throughput sequencing, we analyzed the miRNA expression profile of wheat under salt stress. We identified 360 conserved and 859 novel miRNAs, of which 49 showed considerable changes in transcription levels after salt treatment. Among them, 25 were dramatically upregulated and 24 were downregulated. Using real−time quantitative PCR, we detected significant changes in the relative expression of miRNAs, and the results showed the same trend as the sequencing data. In the salt−treated group, miR109 had a higher expression level, while miR60 and miR202 had lower expression levels. Furthermore, 21 miRNAs with significant changes were selected from the differentially expressed miRNAs, and 1023 candidate target genes were obtained through the prediction of the website psRNATarget. Gene ontology (GO) analysis of the candidate target genes showed that the expressed miRNA may be involved in the response to biological processes, molecular functions, and cellular components. In addition, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis confirmed their important functions in RNA degradation, metabolic pathways, synthesis pathways, peroxisome, environmental adaptation, global and overview maps, and stress adaptation and the MAPK signal pathway. These findings provide a basis for further exploring the function of miRNA in wheat salt tolerance. [ABSTRACT FROM AUTHOR]

SUMMARY: Leaf senescence involves massive multidimensional alterations, such as nutrient redistribution, and is closely related to crop yield and quality. No apical meristem, Arabidopsis transcription activation factor, and Cup‐shaped cotyledon (NAC)‐type transcription factors integrate various signals and modulate an enormous number of target genes to ensure the appropriate progression of leaf senescence. However, few leaf senescence‐related NACs have been functionally characterized in wheat. Based on our previous RNA‐sequencing (RNA‐seq) data, we focused on a NAC family member, TaNAC69‐B, which is increasingly expressed during leaf senescence in wheat. Overexpression of TaNAC69‐B led to precocious leaf senescence in wheat and Arabidopsis, and affected several agricultural traits in transgenic wheat. Moreover, impaired expression of TaNAC69‐B by virus‐induced gene silencing retarded the leaf senescence in wheat. By RNA‐seq and quantitative real‐time polymerase chain reaction analysis, we confirmed that some abscisic acid (ABA) biosynthesis genes, including AAO3 and its ortholog in wheat, TraesCS2B02G270600 (TaAO3‐B), were elevated by the overexpression of TaNAC69‐B. Consistently, we observed more severe ABA‐induced leaf senescence in TaNAC69‐B‐OE wheat and Arabidopsis plants. Furthermore, we determined that TaNAC69‐B bound to the NAC binding site core (CGT) on the promoter regions of AAO3 and TaAO3‐B. Moreover, we confirmed elevated ABA levels in TaNAC69‐B‐OE wheat lines. Although TaNAC69‐B shares 39.83% identity (amino acid) with AtNAP, TaNAC69‐B did not completely restore the delayed leaf senescence in the atnap mutant. Collectively, our results revealed a positive feedback loop, consisting of TaNAC69‐B, ABA biosynthesis and leaf senescence, that is essential for the regulation of leaf senescence in wheat. Significance Statement: Leaf senescence is vital for crop yield and quality; however, the mechanisms underlying the regulation of leaf senescence in wheat remain unknown. This study revealed a tripartite positive feedback loop comprising TaNAC69‐B expression, abscisic acid biosynthesis and leaf senescence that is crucial for the regulation of leaf senescence in plants and potentially impacts their yield. This loop can be targeted to optimize the progression of leaf senescence in wheat via molecular breeding. [ABSTRACT FROM AUTHOR]

Based on the gas–solid two-phase flow theory, numerical simulation of the dust dispersion law of fully mechanized mining work under different inclination angles and comparative analysis of field-measured data show that with the increase of working face inclination, the inclination of airflow into the unmined zone increases from 25° to 50° and the maximum wind speed increases from 2.16 to 2.25 m/s after the mixing of cutting turbulent wind and system ventilation. Meanwhile, the range of high-concentration dust clusters, suspension time, lateral migration intensity, and deposition zone increase to varying degrees; dust clusters increases from 62.02 to 202.46 m3. When X < 53.96 m, the dust concentration in the sidewalk-breathing zone shows a sine function with the length of the working face, and when X ≥ 53.96 m, it satisfies the exponential decay function. Based on this, the tracking closed dust control technology is proposed. Combining the offset angle of the airflow and t the gathering position of dust mass, the wind curtain angle and air velocity are automatically controlled to ensure that the dust is restricted to one side of the cable trough. [ABSTRACT FROM AUTHOR]

A series of MoVTeNbO x -mixed metal oxides were synthesized by high-pressure hydrothermal method. The effects of temperature and time during the preparation process on the structure and catalytic performance of MoVTeNbO x were investigated. It was demonstrated that high content of M1 phase (94.5%) MoVTeNbO x with typical needle-shape morphology and high surface abundance of V5+ (68.9%) could be fabricated by high-pressure hydrothermal method in a short time (30–60 min) without hydrogen peroxide post-treatment. The catalytic results of propane selective oxidation showed that the MoVTeNbO x sample synthesized at 200 °C for 30 min possessed the highest surface V5+ abundance and largest proportion of terminating (001) plane, displaying the highest selectivity (74.1%) for acrylic acid. Moreover, the prepared MoVTeNbO x showed excellent stability in high temperature continuous reaction. [Display omitted] • MoVTeNbO x was fabricated facilely by high-pressure hydrothermal technology. • This developed method could shorten preparation time dramatically. • High content M1 phase MoVTeNbO x could be obtained without H 2 O 2 post-treatment. • Synthesized MoVTeNbO x had high surface V5+ abundance of 68.9%. • As prepared MoVTeNbO x exhibited excellent catalytic performance. [ABSTRACT FROM AUTHOR]

The factors affecting tourist behavior are complex and diverse, but research on its effect from a purely spatial perspective is still limited. The aim of this paper is to explore the dichotomous interaction between tourists and islands: the behavioral patterns of tourists in island destinations and the mechanisms by which island spaces constrain tourist behavior. This study uses fine-grained global positioning system (GPS) tracking data actively authorized and released by tourists. We empirically studied tourist behavior from a spatial constraint perspective and discovered the following: island space has a strong influence and constraining effect on tourist behavior; different spatial attributes have different constraining effects on tourist behavior; and people with different identities interact with different attributes of space to produce different spatial properties, resulting in a 'harmony-contradiction' model of spatial interaction. These findings are of great value in expanding the perspective of spatial constraints and exploring the interactions between people and land. They are also of great practical significance in promoting spatial planning synergy, facilitating the construction of high-quality island-based tourism destinations, and building a harmonious relationship between people and land. [ABSTRACT FROM AUTHOR]

• The climatological spatial scales (CSS s) of meteorological droughts are investigated. • The CSS s of multi-timescale droughts in China are determined and attributed. • The CSS s generally show a significant decrease with increasing timescale. • The five climate anomalies have significant impacts on the multi-scale CSS s. • The climate anomalies and the CSS s show complex spatiotemporal interaction effects. This study investigates the climatological spatial scales (CSS s) of meteorological droughts in China and the linkages to climate variability. The Global Precipitation Climatology Centre monthly gridded precipitation with a spatial resolution of 25 km × 25 km for 1961–2010 is used. The standardized precipitation index at different timescales (1-, 3-, 6-, 9-, 12-, 24-, 36-, and 48-month) is applied to characterize meteorological droughts. The CSS s of meteorological droughts are calculated using a method considering spatial correlation and anisotropy. The relationships between the CSS s and main monsoons and climate teleconnections in five selected regions are quantified using dynamic spatial panel models. The five regions are South China (SC), the Yangtze River Valley (YRV), North China (NC), Northeast China (NE), and the Tibetan Plateau (TIB). The following results are obtained: (1) The CSS s of multi-timescale meteorological droughts in China are determined. The means of the CSS s at various timescales in China are 68.9, 73.8, 71.8, 69.7, 68.8, 65.9, 62.9, and 60.8 × 104 km2, respectively. The CSS s in eastern China generally show a significant decrease with increasing timescale. (2) Significant quantification relationships (R2 greater than 0.85) suggest that there is not a simple linear relationship between climate anomalies and the CSS s, but rather a complex spatiotemporal interaction including exogenous and endogenous interaction effects. The CSS s not only strongly depend on their neighbors on the same timescale but also significantly depend on the CSS s of neighbors on adjacent timescales. Three monsoon indices (Indian monsoon, East Asian monsoon, and western North Pacific monsoon) have significant impacts on the multi-timescale CSS variations in the five regions, especially for NE, YRV, SC, and TIB, while the El Niño–Southern Oscillation and Pacific Decadal Oscillation affect mainly SC and YRV. These findings could broaden our understanding of the spatiotemporal relationships of droughts and be useful for drought risk management. [ABSTRACT FROM AUTHOR]

• SMAP soil moisture (SM) biases are investigated based on core validation sites data. • The p.m. retrievals outperform a.m. retrievals due to better accuracy in clear days. • Dual channel algorithm has the potential to improve SM retrieval in bad weathers. • SM bias correlates negatively with soil temperature and positively with its bias. • Soil wetness, temperature and vegetation parameters jointly contribute to SM biases. The Soil Moisture Active Passive (SMAP) mission provides state-of-the-art global soil moisture (SM) datasets. However, seasonal SM biases and their contributing factors have not be systematically reviewed. This study evaluated the biases of SMAP V6 dual channel algorithm (DCA), single channel algorithm H-pol (SCA-H) and V-pol (SCA-V) SM products based on core validation sites data. All algorithms perform better under clear- than cloudy-sky, and in cloudless daytime than nighttime. Consecutive clear-sky benefits SM retrieval, progressively lowering the uncertainty of SM retrievals while at the cost of dry biases. Cloudy-sky deteriorates the quality of SM retrievals, and wet biases increase with the duration time of cloudy-sky. The modified V7 DCA has a major improvement, owning the potential to provide accurate retrievals under cloudy-sky. SMAP SM biases are co-determined by vegetation index, soil temperature and their biases, and a single factor only explains at most 54% variance in SM biases. Generally, SMAP SM bias is negatively correlated with soil temperature and positively correlated with its bias. SM bias correlates positively with vegetation index and its bias for single channel algorithms, and the underestimation of SM increases with vegetation density for DCA. To get a complete picture of SMAP SM biases, a total differential of radiative transfer equation is recommended for decomposing SMAP SM biases. To this end, more validation sites are required covering diverse land cover types and providing continuous data records. [ABSTRACT FROM AUTHOR]

[Display omitted] • The decadal runoff changes in two contrasting watersheds in the Tienshan Mountains were analyzed. • Water balance closure was achieved by considering remotely sensed snow/ice melt and actual evapotranspiration (ET). • Rainfall and snow/ice melt dominated the increasing of decadal runoff in the humid Kashi watershed. • Rainfall and human activity jointly dominated the increasing of decadal runoff in the arid Boertala watershed. • Most of the changes in snow/ice melt and ET were contributed from the high and low elevation regions, respectively. Water processes in the Tienshan Mountains have undergone great changes under the impacts of climate warming and human activities. Here, based on the Budyko framework, we investigated the respective contributions of climate change and human activities to decadal runoff changes (1982–2014) in two contrary watersheds, i.e., the humid Kashi watershed in the Yili River valley and the arid Boertala watershed in the Ebinur Lake basin, in the Tienshan Mountains, where closing the water balance is difficult due to the scarcity of precipitation gauges. To achieve closure of the decadal water balance of the study watersheds, we estimated evapotranspiration from a complementary relationship model and snow/ice melt using the degree-day method with the remote sensing snow cover product. We found that the increase of rainfall (+61.6 mm) and snow/ice melt (+57.3 mm) dominated the increase of runoff (+87.2 mm, from 398.2 mm in 1982–1992 to 485.4 mm in 1993–2014) in the Kashi watershed, contributing 47.1 mm (54.8%) and 43.8 mm (51.0%), respectively, to the increase of runoff. Unlike the Kashi watershed, human activities contributed −13.8 mm (−103.7%) to the runoff (+13.9 mm, from 61.4 mm in 1982–1997 to 75.3 mm in 1998–2014) in the Boertala watershed. Most of the increase in rainfall (+62.5 mm) and snow/ice melt (+13.6 mm) was consumed by the increase of ET (+64.0 mm) instead of runoff. Further analysis showed that most of the increases in snow/ice melt and ET were contributed from the high (>2500 m) and low (<1500 m) elevation regions, respectively. Snowmelt showed a decreasing trend in low elevation regions. Our study highlighted the importance of snow/ice melt and ET in understanding decadal changes in runoff in the Tienshan Mountains. [ABSTRACT FROM AUTHOR]