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Ethephon (ETH) is a plant growth regulator extensively utilized in agriculture, but its overuse is associated with several health issues. However, detecting ETH sensitively and easily in the field is challenging due to the complexity and time-consuming operation of current approaches. In this study, we synthesized aluminum-based metal-organic frameworks (CAU-1) as fluorescent probes for the detection of ETH in fruit. ETH exposure enhanced and shifted the light green fluorescence of CAU-1 to blue through high absorption of phosphate by electrostatic attraction. We observed a linear correlation between fluorescent intensity and ETH concentration ranging from 2 mg/L to 400 mg/L, with the lowest detection limit at 1 mg/L. This fluorescent analysis exhibited good selectivity towards ETH. To facilitate easy identification of samples in the field, we designed a fluorescent paper-based platform with a logic gate operation, allowing visual distinction of samples containing ETH. We applied this platform to monitor ETH in various fruits, including apples, pears, and tomatoes, through fluorescent spectrum, and visual detection. The platform offered simplicity, speed, ease of use and sensitivity, providing a promising future for ETH detection in agriculture.

Abstract Lithium metal batteries with inorganic solid‐state electrolytes have emerged as strong and attractive candidates for electrochemical energy storage devices because of their high‐energy content and safety. Nonetheless, inherent challenges of deleterious lithium dendrite growth and poor interfacial stability hinder their commercial application. Herein, we report a liquid metal‐coated lithium metal (LM@Li) anode strategy to improve the contact between lithium metal and a Li6PS5Cl inorganic electrolyte. The LM@Li symmetric cell shows over 1000 h of stable lithium plating/stripping cycles at 2 mA cm−2 and a significantly higher critical current density of 9.8 mA cm−2 at 25°C. In addition, a full battery assembled with a high‐capacity composite LiNbO3@LiNi0.7Co0.2Mn0.1O2 (LNO@NCM721) cathode shows stable cycling performance. Experimental and computational results have demonstrated that dendrite growth tolerance and physical contact in solid‐state batteries can be reinforced by using LM interlayers for interfacial modification.

Prochloraz and its metabolites in strawberries have not been determined until now. Meanwhile, few reports in the literature have concerned the dissipation behavior and risk assessment of prochloraz and its metabolites in strawberries under greenhouse conditions in Beijing. A method for the determination of prochloraz and its metabolites in strawberries was developed using QuEChERS in combination with ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Prochloraz and its metabolites recovered from strawberries were present in concentrations of 73.06% to 116.01%, their RSDs ranged from 1.12% to 9.17%, and their limits of detection ranged from 0.1 to 1 μg kg−1. Then, a study was conducted on the dissipation of prochloraz in strawberries under greenhouse conditions. The dissipation of prochloraz in strawberries followed the first-order kinetic equation, and its half-life was 8.06 days. The health risk associated with prochloraz in strawberries was evaluated using the target hazard quotient (THQ) method and EFSA PRIMo model. The results showed that the THQ values, %ARfD values, and %ADI values were less than 1. These results indicate that no health concerns of prochloraz are associated with the consumption of the studied strawberries. The government can use the results of this study to support the establishment of a maximum residue level for prochloraz in strawberries.

Abstract Over the past few decades, the design and development of carbon materials have occurred at a rapid pace. In particular, these porous graphene‐like carbon nitride materials have received considerable attention due to their superior structures and performances in the energy transformation field. In this review, nitrogenated holey two‐dimensional graphene and polymeric carbon nitride will be discussed in depth. The structural properties, synthetic methods, and applications including electrocatalytic reactions, such as hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, and nitrogen reduction reaction, will be presented in detail. Finally, we will present the outlooks on the current obstacles to the development of carbon nitride materials. This comprehensive understanding will help guide and motivate researchers to develop and modify carbon nitride materials with better properties in the future.

In this work, the highly dispersed and large loading amount (>1 wt%) of copper single-atoms were achieved on TiO2, resulting into an apparent quantum efficiency of 56% at 365 nm, in addition to an excellent thermal stability as proved after storing 380 days.

Due to its wide use in agriculture, a convenient and sensitive detection method for triazophos is urgent need. In this study, a terbium-based metal-organic framework (Tb-MOF) is mildly prepared as a fluorescent probe for triazophos detection. The fluorescence of Tb-MOF can be quenched by triazophos through the inner filter effect (IFE) and static quenching effect (SQE). The fluorescence analysis exhibits high sensitivity and limit of detection of 0.12 ng·mL−1 with a linear range of 3–800 ng·mL−1 to triazophos. The fluorescence analysis displays good selectivity towards triazophos. In addition, this method has been successfully applied to the detection of triazophos in tap water and strawberry with good recovery rates. More importantly, a fluorescent paper-based sensor and a logic gate operation for the detection of triazophos based on the Tb-MOF are designed. This strategy was simple, free of modification and complicated operation, and easy to operate, which has good prospects for future applications of triazophos detection.

Extensive research has been conducted on plant protection unmanned aerial vehicle (UAV) chemical application technology in recent years owing to its importance as a means of pest and disease control. UAV spraying in orchards faces the drawback of drift risk and can be hazardous to non-targeted crops, humans, and the environment. A detailed and systematic analysis must be performed to determine the uniformity and drift risk of plant UAV sprays. In this study, a peach orchard is sprayed with a plant-protection UAV at three different flight velocities and we evaluate the combined pesticide deposition performance of the canopy, ground loss, downwind ground drift, and airborne drift. Additionally, the droplet size and coverage rate in the canopy are calculated by using water-sensitive paper. The results demonstrate that there is significant difference in the droplet size at flight velocities of 1–3 m/s. The droplet size in the lower canopy is slightly smaller than those in the middle and upper parts. Increasing the flight velocity helps the pesticide droplets to spread and penetrate the canopy. However, it also causes a non-uniform pesticide deposition, reduced effective coverage ratio and effective density ratio. Among the three pesticides used in the experiment, imidacloprid exhibits the best deposition efficiency. The deposition amount and normalized deposition amount in the canopy were the highest at a flight velocity of 2 m/s, accompanied by a lower ground loss under the canopy. The highest near-field ground drift is observed at a velocity of 1 m/s, and the far-field airborne drift is highest at 3 m/s. Lastly, this study provides a reference for the commercial application of plant-protection UAVs.

L-Histidine (L-His) is an essential amino acid, which is used to synthesize proteins and enzymes. The concentration of L-His in the body is controlled to regulate tissue growth and repair of tissues. In this study, a rapid and sensitive method was developed for colorimetric L-his detection using Cu2+ ions to inhibit the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB)–H2O2 system. H2O2 can oxidize TMB to oxTMB in the presence of copper, and the change in color from colorless (TMB) to blue (oxTMB) is similar to that observed in the presence of peroxidase. However, because the imidazole ring and carboxyl group of L-His can coordinate with Cu2+ ions to form stable L-His–Cu2+ complexes, the color of the TMB–H2O2 solution remains unchanged after the addition of L-His. Therefore, because L-His effectively hinders the colorimetric reaction of TMB with H2O2, this assay can be used to quantitatively determine the concentration of L-His in samples. Under optimized conditions, our colorimetric sensor exhibited two linear ranges of 60 nM to 1 μM and 1 μM to 1 mM for L-His detection and a detection limit of 50 nM (S/N = 3); furthermore, the assay can be performed within 20 min. Moreover, the proposed assay was used to determine the concentration of L-His in urine samples, suggesting that this convenient and label-free colorimetric method presents promising applications in bioanalytical chemistry and clinical diagnosis.

Human activities in the Arctic regions have been increasing in recent years due to the impacts of climate change, such as Arctic Sea ice decline. For example, there has been an increase in Arctic shipping routes. A robust navigation system with a high positioning accuracy is required when traversing the extremely challenging Arctic environment to ensure the safety of human activities. However, the high–precision GNSS navigation and the positioning method, e.g., real–time kinematic (RTK), is not available in the polar regions due to the accessibility issues of the required infrastructures. On the other hand, the International GNSS Service (IGS) enables real–time applications; additionally, quick and convenient satellite communication systems are also available. This offers the possibility of real–time precise point positioning (RT–PPP) with multi–GNSS for high-precision navigation in the Arctic. In our paper, we analyzed the performance of multi–GNSS RT–PPP in the Arctic Northeast Passage (NEP), highlighting the following contributions: First, a GNSS device is installed on the M/V TIANHUI, which passed through the NEP from 10 September to 20 September 2019; Second, we quantitatively evaluated the collected GNSS signals in terms of the maximum satellite elevations, number of visible satellites (NSAT), position dilution of precision (PDOP) values, signal–to–noise ratio (SNR), and multipath errors. Third, we evaluated the accuracy of the CLK93 real–time products compared with the Deutsches GeoForschungsZentrum (GFZ) final products GBM. Finally, we carried out experiments for both single– (SF) and dual–frequency (DF) RT–PPP in the NEP during the 11–day testing period. Our experimental results show that meter–level positioning accuracy can be achieved with SF RT–PPP, while the DF RT–PPP model reaches sub–decimeter values and even centimeter–level accuracy. In addition, using the multi–GNSS method, we showed that the average RMS values of DF RT–PPP in the horizontal and vertical directions are 0.080 m and 0.057 m, respectively, demonstrating an improvement of approximately 70% over single–GPS solutions.