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The tea industry, as one of the most globally important agricultural products, is characterized by pests and diseases that pose a serious threat to yield and quality. These diseases and pests often present different scales and morphologies, and some pest and disease target sizes can be tiny and difficult to detect. To solve these problems, we propose TeaViTNet, a multi-scale attention-based tea pest and disease detection model that combines CNNs and Transformers. First, MobileViT is used as the feature extraction backbone network. MobileViT captures and analyzes the tiny pest and disease features in the image via a self-attention mechanism and global feature extraction. Second, the EMA-PANet network is introduced to optimize the model's learning and attention to the Apolygus lucorum and leaf blight regions via an efficient multi-scale attention module with cross-space learning, which improves the model's ability to understand multi-scale information. In addition, RFBNet is embedded in the module to further expand the perceptual range and effectively capture the information of tiny features in tea leaf images. Finally, the ODCSPLayer convolutional block is introduced, aiming to focus on acquiring richer gradient flow information. The experimental results show that the TeaViTNet model proposed in this paper has an average accuracy of 89.1%, which is a significant improvement over the baseline network MobileViT and is capable of accurately detecting Apolygus lucorum and leaf blight of different scales and complexities. [ABSTRACT FROM AUTHOR]

Spin-dependent nonlinear harmonic generations from nanostructures may provide a new class of design for future applications such as nonlinear optical switching and modulation and nonlinear information processing. Most reported works are based on the utilization of metasurfaces with specific symmetry (such as C3 and C4) and the application of the Pancharatnam–Berry phase approach, making them sensitive to local defects. In this work, we investigated a controllable second harmonic generation (SHG) based on the topological spin-dependent edge state, which is robust to a broad class of perturbations. Simulation results demonstrated that spin-dependent edge states with strong field localization can be obtained through spin–orbit coupling, resulting in SHG with increased efficiency. In addition, the propagation direction of the enhanced SHG could be dynamically controlled using an excitation source with left/right circular polarizations, exhibiting negligible backscattering and topological protection against local defects. The proposed approach may open a new avenue for manipulating light–light interactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Portable HSI technology reliably assessed the maturity of Camellia oleifera fruits in-field. • Ten quality indexes were measured for three maturity stages of Camellia oleifera. • The comprehensive maturity index (CMI) was obtained through factor analysis. • The CMI prediction models for Camellia oleifera fruits were built based on DL and ML. • Develop the discrimination model of Camellia oleifera fruits maturity stages. To efficiently detect the maturity stages of Camellia oleifera fruits, this study proposed a non-invasive method based on hyperspectral imaging technology. First, a portable hyperspectral imager was used for the in-field image acquisition of Camellia oleifera fruits at three maturity stages, and ten quality indexes were measured as reference standards. Then, factor analysis was performed to obtain the comprehensive maturity index (CMI) by analyzing the change trends and correlations of different indexes. To reduce the high dimensionality of spectral data, the successive projection algorithm (SPA) was employed to select effective feature wavelengths. The prediction models for CMI, including partial least squares regression (PLSR), support vector regression (SVR), extreme learning machine (ELM), and convolutional neural network regression (CNNR), were constructed based on full spectra and feature wavelengths; for CNNR, only the raw spectra were used as input. The SPA-CNNR model exhibited more promising performance (R P = 0.839, RMSEP = 0.261, and RPD = 1.849). Furthermore, PLS-DA models for maturity discrimination of Camellia oleifera fruits were developed using full wavelength, characteristic wavelengths and their fusion CMI, respectively. The PLS-DA model using the fused dataset achieved the highest maturity classification accuracy, with the best simplified model achieving 88.6 % accuracy in prediction set. This study indicated that a portable hyperspectral imager can be used for in-field determination of the internal quality and maturity stages of Camellia oleifera fruits. It provides strong support for non-destructive quality inspection and timely harvesting of Camellia oleifera fruits in the field. [ABSTRACT FROM AUTHOR]

Currently, air-assisted spraying is the most widely used high-efficiency pesticide spraying method used for treating fruit trees. Airflow from fans transports droplets into the canopy through kinetic energy. However, it changes the shape of the canopy and affects the deposition of droplets in the canopy. In this paper, through wind tunnel experiments, the drag forces exerted on three fruit trees (pear, peach and camellia) with different morphological characteristics were tested under different windspeeds. Changes in frontal area, canopy edge displacement, and optical porosity were recorded to determine the response of the trees that had different reconfiguration capabilities to the airflow and investigate the influence of porosity on morphological changes. The relationship between the drag force and windspeed was fitted through a power function, and the mean Vogel exponent for the pear, peach and camellia trees were −0.43, −0.54, and −0.31, respectively. Experimental results showed that the Vogel number of the same species of tree decreased with increasing porosity, and the morphological response of the canopy to the airflow was affected by the Vogel exponent. Canopy porosity had a significant impact on the Vogel exponent and the morphological changes of the canopy decreasing Vogel exponent with increasing porosity. • Morphological reconfiguration of three fruit trees characterised by Vogel exponent. • Porosity and Vogel exponent have important effects on aerodynamic characteristics. • Results provides a basis for air spray decision and droplet deposition prediction. [ABSTRACT FROM AUTHOR]

Studying the effects of cutting parameters on the ultimate shear stress and specific cutting energy of sisal leaves can provide a basis for the design of high-efficiency and energy-saving harvesting machinery. In this study, hybrid (H.) 11648 sisal leaves (83% wet basis) were investigated experimentally using the single-factor method and the response surface method under quasi-static cutting conditions. The results showed that the cutting speed, blade oblique angle, blade entry angle, and leaf elevation angle significantly influence the ultimate shear stress and specific cutting energy of sisal leaves. The interaction term of the blade oblique angle and leaf elevation angle significantly affects the ultimate shear stress, while the interaction term of the cutting speed and blade oblique angle significantly affects the specific cutting energy. The values of the optimal cutting parameters, namely the cutting speed, blade oblique angle, blade entry angle, and leaf elevation angle, obtained by solving the multi-objective response equation were 500 mm min−1, 24.23°, −28.8°, and 20°, respectively. Under this setting, the ultimate shear stress and specific cutting energy for the sisal leaf could be reduced by 43.48% and 10.71%, respectively, compared with the case close to practical harvesting. Within acceptable ranges of the ultimate shear stress and specific cutting energy, increasing the cutting speed and utilising viable parameter values that are close to the optimised ones can also have a positive effect on peak cutting force reduction, energy savings, and miniaturisation of harvesting machinery. • Cutting parameters affect the cutting force and energy consumption of sisal leaves. • Horizontal cutting or oblique cutting is better than vertical cutting. • Increase the cutting speed can reduce the cutting force and energy consumption. • Provide new ideas for designing sisal leaves harvesting machinery. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of the parameters used in discrete element simulation study of coconut bran, physical and simulation experiments were combined to calibrate discrete element simulation parameters of the species. First, the intrinsic parameters and actual stacking angle of coconut bran were measured through physical tests. Next, the simulated stacking angle was used as the response value, Plackett-Burman test was designed with Design-Expert software, and the parameters that had a significant impact on the stacking angle were identified and selected. The results of the screening test show that the static friction coefficient of coconut bran-coconut bran, the rolling friction coefficient of coconut bran-coconut bran and the static friction coefficient of coconut bran-steel plate have significant effects on the stacking angle. The relative error of the stacking angle was taken as the evaluation index, the steepest climbing test was performed on the three significant parameters, the value range of the significance parameter was optimized, and Box-Behnken test was adopted to establish the quadratic regression model between the stacking angle and significance parameters based on response surface methodology (RSM). the stacking angle of 20.08° measured by the physical experiment was taken as the target value in the model, and the regression equation was optimized to obtain the optimal combination of parameters: 0.48 for the static friction coefficient of coconut bran-coconut bran, 0.28 for the rolling friction coefficient of coconut bran-coconut bran, and 0.39 for the static friction coefficient of coconut bran-steel plate. Finally, the verification tests on the stacking angle and fluidity of coconut bran were carried out, and the results show the average relative errors of the two tests are small, which verify the reliability of the calibration results and research methods of coconut bran simulation parameters. The research results show the calibrated parameters can provide references for the selection of coconut bran discrete element simulation parameters and the design and optimization of related equipment. [Display omitted] • DEM-RSM is used to calibrate the simulation parameters of coconut bran. • The significant parameters on the stacking angle of coconut bran are carried out. • The optimal combination of parameters is obtained by optimizing regression equation. • The accuracy of the simulation parameters of coconut bran is improved. • Providing references for the design and optimization of related equipment [ABSTRACT FROM AUTHOR]

In this paper, we have proposed an improved convolutional neural network model based on the ShuffleNet V2 network for recognizing the orbital angular momentum (OAM) modes for the OAM based free space optical communication systems in the environments of atmospheric turbulence (AT). The network is trained by inputting the intensity images of the Laguerre Gaussian beams, which can effectively finish the training process due to its special designs, and can recognize the OAM modes with high accuracy. Compared with previous works for the single and multiplexing OAM modes, the proposed network model has high-precision and high-efficiency characteristics. Especially for the multiplexing OAM modes, our proposed system can achieve the recognition accuracy of 99.5% under strong AT and long-distance transmission. In addition, in order to prove that our system has good generalization ability and strong robustness, we used the trained model to test several groups of data obtained under untrained AT intensities, and the results showed that our model could still maintain high accuracy under the untrained AT intensities, which is very important to the realization of high-capacity optical communication technologies based on OAM in the future [ABSTRACT FROM AUTHOR]

While immunotherapy has dramatically revolutionized the treatment of non‐small cell lung cancer (NSCLC), it still faces challenges such as low therapeutic efficacy and immune‐related adverse events, indicating that safe and effective approaches to enhance NSCLC immunotherapy are still highly demanded. Epidermal growth factor receptor (EGFR) is an established target for molecularly targeted therapy of NSCLC. Overexpression and activating mutations of EGFR can promote the resistance of NSCLC to immunotherapy via upregulating inhibitory immune checkpoints such as programmed death receptor ligand 1 (PD‐L1) and indoleamine‐2,3‐dioxygenase‐1 (IDO1). Thus, therapeutic inhibition of EGFR also holds promise in modulating the immune microenvironment to advance NSCLC immunotherapy. In this study, we employed a proteolysis targeting chimera (PROTAC) that degrades EGFRL858R to investigate its potential in dually inhibiting PD‐L1 and IDO1 to potentiate the anti‐tumor immunity in NSCLC. We demonstrated that PROTAC significantly downregulated the protein levels of both PD‐L1 and IDO1 in NSCLC H3255 cell and tumor. We also confirmed that PROTAC significantly suppressed the H3255 tumor growth and enhanced the anti‐tumor immune response in H3255 tumor. Overall, our study provides a novel strategy for future NSCLC therapy. [ABSTRACT FROM AUTHOR]

• We propose the strategy of "Separation + Recognition" for solving the problem of the number limit of compound types. • We separate the observed compound jamming signals from multiple receiving channels. • A fast recovery algorithm to recover and identify the separated signals. To deal with various jamming signals based on digital radio frequency memories, a compound jamming signal recognition method based on source signal separation is proposed. In order to overcome label limitation of the supervised learning method in the recognition process, this paper puts forward "Separation + Recognition" strategy. Firstly, the received signals of multiple channels are preprocessed, and the number of signal sources is analyzed through the single-source detection algorithm. Then the received compound jamming signals are processed by source separation, and the independent single jamming signals can be obtained. On this basis, a fast signal compensation algorithm is added to compensate different source signals at overlapping time-frequency points, which effectively increases the integrity of the separated signals. The separated jamming signals are then put into the convolutional neural network for recognition, and the specific jamming types in the compound jamming signals can be obtained. It has been proved that the recognition accuracy of five kinds of compound jamming exceeds 90% when the jamming-to-noise ratio is 0 dB. [ABSTRACT FROM AUTHOR]

The acoustic vortex wave has exhibited high-potential applications such as communication. In this work, the authors propose an efficient method for quantitatively measuring the topological charge of an acoustic vortex through two kinds of annular apertures: an annular triangle aperture and an annular ellipse aperture. It is found that the characteristics of the diffraction pattern in the far-field are well related with the shape of apertures and the topological charges of the acoustic vortex wave. Therefore, the topological charge of acoustic vortex beams can be determined from the diffraction patterns, which provide an effective method for measuring the topological charge of acoustic vortex beams. [ABSTRACT FROM AUTHOR]

Compared with conventional methods that require electric manipulation of the transducer, passive diffraction gratings provide a simpler and more compact solution to generate an acoustic vortex. This work theoretically and numerically investigates a novel method for generation and detection of an acoustic vortex in water by using a passive Fermat's spiral diffraction grating (FSDG). When the proposed structure is illuminated by a plane acoustic wave, the constructive and destructive interferences of the diffracted waves by the FSDG could produce acoustic vortex beams. By changing the structure of the FSDG properly, the output can be high-order acoustic vortex or multiplexing acoustic vortex beams, whose topological charge is determined by the number and spiral direction of the FSDG arms. Then, the acoustic vortex beams can be detected by the same equipment but a different rotation direction. Both the intensity and phase distributions after detection demonstrate the effectiveness of the designed FSDG for generating and detecting the acoustic vortex beams. Obtained results may have potential applications for particle trapping, imaging, underwater acoustic communication, and so on. [ABSTRACT FROM AUTHOR]

Bamboo is one of the green building materials that have been used for centuries. Combining with metal materials will endow bamboo with new functions, such as weather resistance, anti-corrosion, conductivity, and electromagnetic shielding. However, there is a natural barrier between bamboo and metal materials. This paper proposes fabrication of novel bamboo-based metal composites (BMC) which are composed of bamboo substrate and metal coating, without any adhesive, using an efficient and sustainable arc thermal spraying technique. In this method, the metal wire is melted and deposited on the bamboo substrate through a high-temperature heat source. In the feasibility experiment, arc spraying using aluminum as the wire electrode was selected. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used to observe and test the fabricated specimens. It was demonstrated that when the spraying voltage was 40 V, the deposition rate was as high as 5.8 g/min with the average thickness of the metal coating exceeding 400 μm. The surface of the BMC aluminum coating was flat, continuous, and compact with an average roughness of about Ra 3.0 μm. Based on experimental results, the integrity of bamboo substrate in thermal spraying was discussed. Results from SEM–EDS test showed that there are crack areas and adhesion areas between bamboo and metal coatings, and the highest bonding strength exhibited over 1.0 MPa. This work provides a new practice of fabricating novel BMC through a green manufacturing method with high efficiency. The findings of this study may be useful in understanding the preparation of BMC and can help find their suitability for a wide range of applications. [ABSTRACT FROM AUTHOR]

Abstract For estimating the states of moving targets in the nonlinear system with non-Gaussian noise, the combination of Gaussian Sum Filter (GSF) and other nonlinear filters has been chosen as the filtering algorithm conventionally. The Smooth Variable Structure Filter (SVSF) is a new predictor-corrector method used for state and parameter estimation, which has good stability and robustness. In this paper we propose a new strategy called the modified GS-EKF-SVSF, which inherits good robustness of Gaussian Sum and Smooth Variable Structure Filter (GS-SVSF) and high accuracy of Gaussian Sum and Extended Kalman Filter (GS-EKF). A nonlinear system with non-Gaussian noise for target tracking is used to test the proposed new strategy. The simulation results demonstrate that our proposed strategy has higher accuracy and better robustness when there are modelling uncertainties existing in the system. [ABSTRACT FROM AUTHOR]

The objective of this work was to investigate the effect of cutting parameters on the cutting performance of sisal leaves under the impact cutting and to obtain the optimal cutting parameters to reduce cutting force and cutting energy. A rotary cutting method for sisal leaves was proposed, and the experimental results showed that cutting parameters had a significant impact on the ultimate shear stress and the specific cutting energy of sisal leaves. Increasing the cutting speed helps to reduce the ultimate shear stress and the specific cutting energy, but the specific cutting energy will increase when the cutting speed is greater than 3 m/s. Meanwhile, under the leaf elevation angle of 45° and the blade oblique angle of 40°, the minimum average ultimate shear stress (7.03 × 10−2 MPa) and minimum specific cutting energy (2.49 × 10−3 J/mm2) were achieved at the cutting speeds of 5 m/s and 3 m/s, respectively. Besides, the lowest cutting cross-section splitting degree was achieved under the blade oblique angle of 40°. The experiment results show that the cutting method proposed in this paper is effective, which provides an important basis for improving the current sisal leaf-cutting device and developing economic sisal leaves harvesting equipment in the future. [Display omitted] • A rotary cutting method was proposed for cutting sisal leaves. • The influence of cutting parameters on the cutting performance was investigated. • The optimal cutting parameter settings were obtained. • Increasing the blade oblique angle can improve the quality of cutting cross-section. [ABSTRACT FROM AUTHOR]

The area wetted by 500-μm diameter droplets of pesticide and deionised water placed at different positions on Eucalyptus urophylla × E. grandis (E.u × E.g) and Eucalyptus tereticornis (E.t) leaves was determined at an air temperature of 30 °C and a relative humidity of 60%. Dimethyl dichlorovinyl phosphate (DDVP), and efficient cypermethrin (EC) were diluted 1000 times in deionised water. Solutions the pesticides were prepared with surfactant concentrations (SC) of 0.1%, 0.25%, 0.5%, and 1%. For comparison SC solutions with water and deionised water were also used. Droplet deposition positions were located in the interveinal area, midrib, and secondary vein on both adaxial and abaxial surfaces. Without surfactant, all droplets remained nearly spherical and did not spread on the leaf surfaces. With surfactant, the deionised water and pesticide droplets had distinct spreading properties. For deionised water, both the wetted area and spread effectiveness peaked at 0.1% SC, while for pesticide droplets the wetted area peaked at 1% SC. However, the optimum SC was 0.25%. Compared with droplets on E.u × E.g leaves, droplets spread more on E.t leaves. The adaxial surface had better wettability than the abaxial surface. For pesticide droplets, the wetted area was a minimum on the midrib and the wetted area on the secondary vein was slightly larger than that on the interveinal area. [ABSTRACT FROM AUTHOR]

Copper complexes have been frequently involved in many Cu-mediated carbon–hydrogen halogenation reactions. We fortunately obtained three different valence benzoxazolyl–copper complexes, along with aryl carbon–hydrogen bromination, in the self-assembly reaction of ligands with CuBr2. The complexes have been successfully characterized by X-ray single crystal diffraction analyses. The results indicate that 1 consists of di-brominated p-benzoxazolylphenylamine (L) and an unusual high valence copper(iii) complex with tetrahedral geometry, 2 is the first polymeric catenulate di-brominated benzoxazolyl-copper(i) complex and 3 is the mono-brominated benzoxazolyl–copper(ii) complex. We speculate proposed mechanisms for the formation of these complexes and the bromination of aryl carbon–hydrogen based on these crystal structures. [ABSTRACT FROM AUTHOR]

Features of a truck-mounted fogger powered with a steady combustor are high efficiency, low usage, and low cost in control of forestry pest insects and diseases. The structure parameters of its exhausted tube are the key factors to affect oil solvent insecticide to atomize thermodynamically. We studied 3 types of atomizers: ring atomizer, coniform atomizer and column atomizer; 6 location points for the ring atomizer placed inner of the exhausted tube from 250 to 500 mm away from the exit of the exhausted tube; 3 structure parameters of a ring atomizer as jet flow direction of the orifices, orifice number and diameter; 3 jet flow directions as parallel to airflow, to center of pesticide ring and at 45° to airflow direction; 3 different diameters of exhausted-tubes as Φ70, Φ90, and Φ110 mm, which the experiment for atomizing effect was done respectively. The results showed that the ring atomizer was most effective in thermal atomizing; there were the defect phenomena with a coniform atomizer or a column atomizer, such as dropping liquid at the exit of the exhaust tube and combusting flame in the fog. However, the atomizing effect with the coniform atomizer was better than that of the column atomizer. The thermal fogging concentrate can atomize completely to uniform, fine droplets whose size distribution was in a narrow range of 4-6 μm, when the ring atomizer was positioned inner a Φ70 mm exhaust tube and in the range of 250-350 mm away from the exit of the exhaust tube. With the Φ90 mm or Φ110 mm exhausted tube, there were two droplet distribution regions: 4-7 μm for the fine droplet group whose volume ratio to total droplet volume was less than 16%, and 7-226 μm for the coarse droplet group,. The vast majority of coarse droplets could not be completely atomized thermodynamically. The relative span of droplet was only 0.18μm for the Φ70 mm exhaust tube, but were much higher (2.48 and 2.65μm) for the Φ90 and Φ110 mm exhaust tubes respectively. The parameters for a ring atomizer, such as the diameter, number and jet flow direction of the orifices basically did not affect the thermal atomizing performance. Thus, in the process of thermal atomizing for hot fogging concentrate, atomizer type, the exhaust tube diameter, and the position of the atomizer were the main factors influencing the performance of a thermal atomizer. [ABSTRACT FROM AUTHOR]

Abstract: Two novel soluble chemosensors based on Schiff-base diaminomaleonitrile derivatives which were modified by an aza-crown ether moiety have been synthesized. These chemosensors were fully characterized by 1H NMR, 13C NMR spectroscopy, mass spectrometry, IR, DSC and single crystal X-ray diffraction. The recognition abilities of the sensors with a range of metal ions were evaluated and their photophysical properties have been systematically investigated. DFT theoretical calculations were employed to understand the behavior of the sensors toward the Cu(II). The sensing mechanism was derived through experimental and theoretical calculations. The results consistently indicated that the monoaza-10-crown-5 species was the ideal sensor, which can be utilized to monitor Cu(II) in solution over a wide pH range. [Copyright &y& Elsevier]

Abstract: A simple D-π-A type ligand (L: 4′-(4-[4-(1H-[1,2,4]-triazolyl)styryl]phenyl)-2,2′:6′,2″-terpyridine) was designed and synthesized, which reacted with HgX2 (X=Cl, Br, I, SCN) yielding a series of uncommon five-coordinated mercury (II) complexes (Dyes 1–4). The ligand and Dye 4 were characterized by single crystal X-ray diffraction determination. Linear and nonlinear optical properties of the ligand and dyes were exhibited. Experimental results revealed that the two-photon absorption (TPA) cross-sections of the four dyes are considerably larger than that of the ligand. Density function theory (DFT) calculations performed on Dyes 1–4 showed that the halogens affect the accepting capability of the complexed metal due to different electron inductive effects, which finally influence the TPA cross-section values. [Copyright &y& Elsevier]

Abstract: A series of new one, two and three-branched two-photon absorption triazine dyes containing triphenylamine with a π-bond and a σ-electron pair as a bridge, and different electron-donating groups, have been synthesized and their photophysical properties have been systematically investigated. These dyes showed obvious solvatochromic effects, i.e., significant bathochromic shifting of the emission spectra and larger Stokes shifts were observed in more polar solvents mainly due to intramolecular charge-transfer (ICT). The two-photon absorption (2PA) cross section values were determined by two-photon excited fluorescence (TPEF) measurements in DMF. This result further proved that a σ-electron pair as a bridge is an efficient way to transfer charge as well as a π bridge to provide a large 2PA cross section, and that their 2PA cross section values (δ) increase with increasing electron-donating strength of the end group and branch number. In addition, two-photon fluorescence cell imaging of dye 7a in HeLa and MCF-7 cancer cells was demonstrated. [Copyright &y& Elsevier]

Abstract: Four novel dyes are prepared by thiophene as π bridge between carbazole central core and other terminal groups by Suzuki and Heck coupling reactions. These dyes are fully characterized by IR, 1H NMR, 13C NMR, MS and elemental analysis. Linear absorption, single- and two-photon excited fluorescence in various solvents are experimentally investigated. The calculated two-photon absorption cross sections of 9-Hexyl-3,6-di((5-phenyl)-2-thienyl)carbazole (1), 9-Hexyl-3,6-di((5-thienyl)-2-thienyl)carbazole (2), 9-Hexyl-3,6-di((5-p-vinylpyridyl)-2-thienyl)-carbazole (3) and 9-Hexyl-3,6-di-((5-o-vinylpyridyl)-2-thienyl)carbazole (4) for the lowest excited state are 537.84, 550.76, 1292.95 and 1340.40 × 10−50 cm4 s photon−1, respectively. Calculated and experimental data have shown that thiophene as π electron bridge improves the two-photon absorption cross sections greatly. Two-photon optical data recording experiments have been carried out at 820 nm laser radiation. [Copyright &y& Elsevier]

Abstract: A new donor–bridge–acceptor (D–π–A) type ligand (L: 4′-(4-[4-(imidazole)styryl]phenyl)-2,2′:6′,2″-terpyridine) with two-photon absorption and coordination ability was designed and synthesized. Self-assembly of the ligand with HgX2 (X = Cl, Br, I) yielded a series of new coordination complexes (Dyes 1–3) with five-coordinated mercury (ΙΙ), which were characterized by single crystal X-ray diffraction determination. Solvent molecules and various weak interactions, including hydrogen bonds (C–H···N, C–H···X) and π–π interactions played significant roles in the final topological structures. Linear and nonlinear optical properties of the ligand and three dyes were described. Experimental results revealed that two-photon absorption cross sections of three dyes are extraordinary stronger than that of ligand. [Copyright &y& Elsevier]

The deterioration of global environment, decreasing of biological diversity, increasing of natural disasters, exhausting of biological resources and acceleration of desertification emphasize the need to provide the human-beings with the suitable environments. Nowadays, precision agriculture and precision forestry have been emphasized to obtain the maximum output with minimum input and the least impact on the environment, so agricultural and forestry engineering systems require multi-disciplinary design groups to deal with some common interests and the concept of biomechinfotronics is needed. The word "biomechinfotronic" is introduced to describe the multidisciplinary aspects of this complex system. In the paper, the prospects, mission analysis, education system, research areas of biomechinfotronics are studied. The particular characteristics of biomechinfotronics are the synergistic integration of biological engineering with mechatronics, bioinformatics, infotronics, bioelectronics and intelligent computer systems for conducting common research and development and for recruiting and training students with wide specialties. [ABSTRACT FROM AUTHOR]

Submerged plants play a significant role in the remediation and purification of polluted water bodies. Reconstruction of submerged plants has been considered as an important ecological method to restore aquatic ecosystems. However, large-scale and efficient plantation of submerged plants in water restoration is a huge challenge. This paper proposes a novel mechanized planting method for submerged plants utilizing nutrition pots as planting units. Firstly, the details of the mechanized planting method were introduced. The mechanized planting method involves pre-planting the reproductive bodies of submerged plants in degradable nutrition pots, and then implanting them into the underwater soil through a planting device. Secondly, the interaction force between the nutrition pot and the soil was measured. It was found that the implantation force of nutrition pots increases with planting velocity. The planting force shows a significant increase trend when the water content in the soil decreases. Thirdly, the deformation of the nutrition pot was studied through simulations. It was discovered that the deformation of the nutrition pot mainly occurs at the bottom and the side walls near the bottom, and the limited deformation ensures the integrity of the nutrition pot. Finally, a planting device with a linear motion mechanism was designed, and a typical submerged plant, Vallisneria natans was tested, using agricultural paper seedling containers as the nutrition pots. It was demonstrated that the mechanized device successfully planted submerged plant nutrition pots into the soil, and the submerged plants survived and showed a clear growth trend. The mechanized planting method of submerged plants proposed in this article is expected to provide a new and friendly technology for ecological restoration of water source. [Display omitted] • A mechanized planting method for submerged plants in water ecological restoration is reported. • The interaction force between the nutrition pot and the soil was measured using force sensors. • A planting device was designed for the high-efficiency planting of submerged plants. • The planting method is expected to offer a technology for large-scale water ecological restoration. [ABSTRACT FROM AUTHOR]

• A method for locating wildlife crossings on roads in China was explored. • The Linkage Mapper model was used to simulate potential migration corridors. • Three scenarios of road barrier sections were defined based on the gazelle home range. • Preliminary monitoring shows a 62.5% usage of crossing structures by gazelle. Despite limited research on the topic, understanding the barrier effect of roads on wildlife habitats in China is crucial for the placement of wildlife crossing structures. First, a habitat suitability evaluation model for goitered gazelle (Gazella subgutturosa) was established. Then, using the Linkage Mapper model, potential migration corridors were simulated along the expressway. The migration corridors were then overlaid with the crossing structures to evaluate the barrier effects of the expressway. A total of 12 barrier segments were identified by the results, eight of which were found to have crossing structures, and preliminary monitoring indicated that five of the bridges have been used by goitered gazelle (62.5%). Based on the results, recommendations for the mitigation of the barrier effect of expressways on goitered gazelle are provided. [ABSTRACT FROM AUTHOR]

The traditional design strategy for constructing highly bright solid‐state luminescent materials relies on incorporating aggregation‐induced emission (AIE) scaffolds, molecular rotors, or bulky substituents to prevent close cofacial packing, which limits the strategy diversity in developing new materials. Herein, a strategy of tuning molecular packing by twisting molecular structure of conventional aggregation‐caused quenching fluorophore is proposed to endow materials with AIE effect and enhance the solid‐state fluorescence. Accordingly, a series of 1,4‐bis(diphenylamino)‐2,5‐disubstituted benzene fluorophores exhibiting AIE characteristics, high solid‐state fluorescence efficiency (up to 0.99), wide emission color tunability, and good near‐infrared (NIR) two‐photon absorption is facilely developed. All these luminogens can specifically stain intracellular lipid droplets with a high signal‐to‐noise ratio, high biocompatibility, and good photostability. Besides, the luminogens exhibit effective reactive oxygen species (ROS) generation capability upon low‐power white light irradiation. Among them, the AIE luminogen, named BDBDC, integrating the NIR emission, good NIR two‐photon absorption and strongest ROS generation demonstrates superior performances in two‐photon fluorescence imaging of various tissues and photodynamic cancer therapy. This molecular design philosophy provides a new way of designing highly bright solid‐state fluorophores for practical applications. [ABSTRACT FROM AUTHOR]

Path tracking is critical for agricultural vehicles to achieve autonomous operation and to improve operational efficiency and accuracy. This study aims to address the high-precision path tracking requirements for the tracked vehicle GY-8. An improved pure pursuit path tracking control method is proposed to enhance the performance of path tracking. For the GY-8 vehicle's single-sided braking and steering approach, a dual-wheel differential kinematic model is established. A smooth steering method using PWM (Pulse Width Modulation) is designed to reduce the likelihood of deviation from the predetermined path due to PWM braking steering. A method based on the theory of circular arc similarity is introduced to determine the path curvature and segmentation. The NSGA-II optimisation algorithm is employed to optimise and obtain the optimal look-ahead distance for different curvature segments, thereby enhancing the accuracy of path tracking. The improved algorithm was experimentally validated for path tracking on paved surfaces. In the experiments, the improved algorithm demonstrated average error, maximum error, error standard deviation, and Fréchet distance of 0.0266 m, 0.0973 m, 0.0195 m, and 0.0891 m, respectively. This represents a 15.6%, 25.8%, 4.9%, and 27.6% improvement over the pure tracking algorithm. When applying the improved pure tracking algorithm to path tracking in agricultural orchard soil environments, the results indicated maximum error, average error, and error standard deviation of 0.1272 m, 0.0351 m, and 0.0215 m, respectively. The overall findings suggest that the improved method significantly enhances the accuracy of path tracking, providing theoretical support for advancing navigation technology in tracked vehicles. • An improved path tracking control approach proposed. • Circular arc similarity method determines curvature of each path segment. • NSGA-II optimizes look-ahead distance for varying curvatures. • Experimental results show that the algorithm performs satisfactorily. [ABSTRACT FROM AUTHOR]

Commercial photosensitizers (PSs) present great potential in the field of clinical photodynamic therapy (PDT) yet face a formidable challenge owing to the extremely short lifespan of singlet oxygen (1O2). Herein, the 1O2 slow‐release "platform" is proposed based on an anthracene‐groups functionalized D‐π‐A system (AIC), which can capture and slowly release 1O2 produced by commercial PSs. Meanwhile, the reversible chemical process between AIC and 1O2 is demonstrated by a series of optical experiments and high‐resolution mass spectrum. Remarkably, by virtue of 1O2 slow‐release "platform", the sustaining mitochondrial autophagy and cell apoptosis still take place when the laser is cut off with a short period of irradiation, reducing the side effect of sustained irradiation. In general, the construction of 1O2 slow‐release platform opens up exciting opportunities for improving the PDT effect of commercial PSs. [ABSTRACT FROM AUTHOR]

Single‐benzene fluorophores have attracted increasing interest owing to their simple molecular structure and unique photophysical properties. Developing novel single‐benzene fluorophores with facile synthesis, bright and tunable dual‐state emissions, and diversified functions is highly desirable. Herein, a strategy of controlling electron density on amino of 2,5‐diaminoterephthalates is proposed to modulate their dual‐state emission, acidichromism, Cu2+ detection, and lipid droplets (LDs) staining. A series of efficient dual‐state single‐benzene fluorophores based on 2,5‐diaminoterephthalate skeleton with tunable emissions in blue to red region and large Stokes shifts is facilely developed. The obtained fluorophores with various substituents on amino groups exhibit different acidichromism property. Two of fluorophores (ABB and ABM) with high electron density on amino groups exhibit high sensitivity and selectivity toward Cu2+ detection with a ratiometric and “turn‐off” fluorescence mechanism for ABM and ABB, respectively. The limit of detection for Cu2+ is determined to be 1.40 × 10−7 and 4.35 × 10−9 mol L−1 for ABB and ABM, respectively. Moreover, three of fluorophores (ABT, ABB, and ABM) with green to red emission display superior LDs‐targeting capability with high specificity, and brightness. This molecular design philosophy provides a new way of designing highly bright dual‐state fluorophores for practical applications. [ABSTRACT FROM AUTHOR]

A single-rotor UAV fitted with a pulse-jet thermal fogging machine was developed. Computational fluid dynamics (CFD) was employed to simulate the downwash airflow and fog distribution of a single-rotor UAV fitted with a pulse-jet thermal fogger. The developed CFD models were validated in three steps by comparing the calculated results with the measurement experiments. Predicted air velocities of the single-rotor UAV downwash airflow agreed well with measured velocities. The model was also able to predict the fog droplet deposition density of the pulse-jet thermal fogger alone, and fitted to the single-rotor UAV, with the relative errors within 20% and 30%, respectively. The validated CFD model was then employed to investigate the effects of the headwind, crosswind and UAV operating height on the downwash airflow and the fog distribution. Results indicated that when the pulse-jet thermal fogging machine was mounted on the UAV, crosswinds needed to be avoided. At the UAV flight speed of 2 m s−1 and natural wind speed of 1 m s−1, a modest headwind appearance could help improve thermal fogging efficiency at different operating heights. The results have important research value and practical significance for improving the pesticide efficiency of UAV sprayers. • A single-rotor UAV fitted with a pulse-jet fogging machine was developed. • Air velocities and fog deposition density were simulated accurately. • Crosswinds needed to be avoided during operations. • A modest headwind appearance help improve thermal fogging efficiency. [ABSTRACT FROM AUTHOR]

Engineering high‐order multiphoton excited fluorescent (H‐MPEF) materials is of significant importance for sensing, 3D optical data storage and bioimaging. However, it remains a challenging endeavor due to a lack of appropriate construction strategies. This study demonstrates that incorporating octupolar modules within metal‐organic framework (MOF) offers new possibilities for the design of highly attractive H‐MPEF materials. Constructed from a typical MOF (UiO(bpdc)), the in situ formation of multibranched octupolar cyclometallated iridium(III) modules via post‐ligand coordination modification endowed the framework with enlarged static hyperpolarizabilities, an extended conjugated system, and enhanced charge transfer, ultimately unlocking its second near‐infrared (NIR‐II, 1000–1700 nm) light activated H‐MPEF performance including three‐ and four‐photon activity. Moreover, these exciting features, combined with subsequent orotic acid‐capping, enabled its application in cancer cell‐specific targeting oncotherapy using tissue‐penetrating NIR‐II light. This finding highlights the vital role of octupoles in H‐MPEF performance and sets a benchmark for unlocking the multiphoton activity of MOFs at the molecular level for deep‐seated tumor fluorescence imaging and therapy. [ABSTRACT FROM AUTHOR]

Research into vinyl-linked covalent organic frameworks (COFs) has grown significantly in recent years due to various attractive properties. Herein, we design and synthesize two highly crystalline and stable 2,4,6-collidine-derived vinylene-linked 2D COFs. Both COFs can act as efficient photocatalysts to facilitate visible-light-driven aerobic oxidation. The TM-TBT-COF was observed to exhibit superior activity and recyclability owing to its excellent semiconducting properties. [ABSTRACT FROM AUTHOR]

The long non‐coding RNA (lncRNA)–microRNA (miRNA) interaction network plays a crucial part in the pathogenesis of nasopharyngeal carcinoma (NPC). Here, we discovered a relationship between LINC01376 and miR‐4757 in NPC tumor development. First, LINC01376 was abnormally overexpressed in NPC tissues and cells, and its elevated expression was associated with advanced clinical stage and shorter distant metastasis‐free survival time. Moreover, biological experiments showed that LINC01376 facilitated the proliferative, invasive, and migratory abilities of NPC cells in vitro and in vivo. Mechanistically, bioinformatics and RT‐qPCR assays revealed that LINC01376 knockdown upregulated the expression level of downstream miR‐4757, including miR‐4757 primary transcript (pri‐miR‐4757) and mature miR‐4757. Furthermore, LINC01376 competitively sponged the transcription factor SP1 and reduced its enrichment in the upstream promoter region of miR‐4757 to repress miR‐4757 expression. Finally, insulin‐like growth factor 1(IGF1) was identified as the target of miR‐4757. Rescue experiments indicated that LINC01376 accelerated NPC cell proliferation, migration, and invasion through the miR‐4757‐5p/IGF1 axis. In conclusion, the SP1/miR‐4757/IGF1 axis, which is regulated by LINC01376 in NPC deterioration and metastasis, is expected to provide new insights into the molecular mechanism of NPC carcinogenesis. [ABSTRACT FROM AUTHOR]

Background: Automatic and precise jujube yield prediction is important for the management of orchards and the allocation of resources. Traditional yield prediction techniques are based on object detection, which predicts a box to achieve target statistics, but are often used in sparse target settings. Those techniques, however, are challenging to use in real-world situations with particularly dense jujubes. The box labeling is labor- and time-intensive, and the robustness of the system is adversely impacted by severe occlusions. Therefore, there is an urgent need to develop a robust method for predicting jujube yield based on images. But in addition to the extreme occlusions, it is also challenging due to varying scales, complex backgrounds, and illumination variations. Results: In this work, we developed a simple and effective feature enhancement guided network for yield estimation of high-density jujube. It has two key designs: Firstly, we proposed a novel label representation method based on uniform distribution, which provides a better characterization of object appearance compared to the Gaussian-kernel-based method. This new method is simpler to implement and has shown greater success. Secondly, we introduced a feature enhancement guided network for jujube counting, comprising three main components: backbone, density regression module, and feature enhancement module. The feature enhancement module plays a crucial role in perceiving the target of interest effectively and guiding the density regression module to make accurate predictions. Notably, our method takes advantage of this module to improve the overall performance of our network. To validate the effectiveness of our method, we conducted experiments on a collected dataset consisting of 692 images containing a total of 40,344 jujubes. The results demonstrate the high accuracy of our method in estimating the number of jujubes, with a mean absolute error (MAE) of 9.62 and a mean squared error (MSE) of 22.47. Importantly, our method outperforms other state-of-the-art methods by a significant margin, highlighting its superiority in jujube yield estimation. Conclusions: The proposed method provides an efficient image-based technique for predicting the yield of jujubes. The study will advance the application of artificial intelligence for high-density target recognition in agriculture and forestry. By leveraging this technique, we aim to enhance the level of planting automation and optimize resource allocation. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) is becoming one of the world's most common chronic liver diseases in childhood, yet no therapy is available that has been approved by the food and drug administration (FDA). Previous studies have reported that telomere and telomerase are involved the development and progression of NAFLD. This study was designed to investigate the potential beneficial effects of ctivated arbon -acetylysteine (ACNAC) microcapsules on the development of NAFLD in young rats as well as the underlying mechanism(s) involved. Three-week old male Sprague Dawley rats were given high-fat diet (HFD) with/without ACNAC treatment for 7 consecutive weeks. Liver pathologies were determined by hematoxylin and eosin (H&E) and Oil Red O staining, as well as by changes in biochemical parameters of plasma alanine transaminase (ALT) and aspartate transaminase (AST) levels, respectively. Glucose homeostasis was evaluated by the glucose tolerance test and the liver telomere length and activity were measured by real time PCR and telomeric repeat amplification protocol (TRAP). Western blot analysis was performed to determine the expression level of Bcl-2, Bax and Caspase-3. Our results demonstrated that ACNAC supplementation improved liver pathologies of rats that received long-term HFD feeding. ACNAC supplementation prevented HFD-induced telomere shortening and improved telomerase activity. Moreover, in comparison to HFD-fed rats, ACNAC supplementation markedly increased the expression of Bcl-2, but significantly decreased the expression of Bax and Caspase-3 in juvenile rats. Together, these results indicate that ACNAC may be a promising choice for preventing and treating NAFLD among children. [ABSTRACT FROM AUTHOR]

Mechanical harvesting is the most effective method for the forest fruit harvesting. Under forced vibration, the removal of fruits is affected by not only the excitation amplitude, frequency, and duration, but also the morphology and inherent frequency spectrum characteristics of the fruit tree itself. In order to discover the relationship between the frequency spectrum characteristics and the vibration responses and attain the difference among the vibration responses in different directions, the frequency spectrum of a small Y-shaped Ginkgo biloba tree in different directions was tested under the impact excitation in the laboratory. Then the spatial acceleration response under the harmonic excitation was detected at the frequency of the peak and trough points in the frequency spectrum curves. Results of this study indicate that there was a corresponding relation between the frequency spectrum characteristics and vibration responses. Strong vibration response couldn’t be induced by the fundamental frequency and the frequency lower than 10.00 Hz. The maximal amplitudes could be tested at the resonant frequency but the values were small at low frequency and increased as the excitation frequency increased. When the excitation frequency was higher than 25.00 Hz, stronger acceleration response couldn’t be induced again. The optimal excitation frequency was 23.75 Hz for the small Y-shaped Ginkgo biloba tree. At the same testing position, vibration responses in three directions exhibited the similar characteristics but different amplitudes. The acceleration amplitude in the direction parallel to the growing orientation of trees increased significantly as the testing position was located away from the excitation point. At the same time, this direction was the dominant direction during the process of the vibration response transmission. This suggests that during the mechanical harvesting of forest fruits, the frequency spectrum of trees could be firstly tested to obtain the resonant frequency. Then trees could be excited under the certain resonant frequency to achieve strong vibration response. Higher excitation frequency didn’t necessarily induce stronger vibration response. There was difference among different directions at the same testing position and fruits on different positions could be removed by the inertial force in different directions. [ABSTRACT FROM AUTHOR]

The maturity of Camellia oleifera fruit is one of the most important indicators to optimize the harvest day, which, in turn, results in a high yield and good quality of the produced Camellia oil. A hyperspectral imaging (HSI) system in the range of visible and near-infrared (400–1000 nm) was employed to assess the maturity stages of Camellia oleifera fruit. Hyperspectral images of 1000 samples, which were collected at five different maturity stages, were acquired. The spectrum of each sample was extracted from the identified region of interest (ROI) in each hyperspectral image. Spectral principal component analysis (PCA) revealed that the first three PCs showed potential for discriminating samples at different maturity stages. Two classification models, including partial least-squares discriminant analysis (PLS-DA) and principal component analysis discriminant analysis (PCA-DA), based on the raw or pre-processed full spectra, were developed, and performances were compared. Using a PLS-DA model, based on second-order (2nd) derivative pre-processed spectra, achieved the highest results of correct classification rates (CCRs) of 99.2%, 98.4%, and 97.6% in the calibration, cross-validation, and prediction sets, respectively. Key wavelengths selected by PC loadings, two-dimensional correlation spectroscopy (2D-COS), and the uninformative variable elimination and successive projections algorithm (UVE+SPA) were applied as inputs of the PLS-DA model, while UVE-SPA-PLS-DA built the optimal model with the highest CCR of 81.2% in terms of the prediction set. In a confusion matrix of the optimal simplified model, satisfactory sensitivity, specificity, and precision were acquired. Misclassification was likely to occur between samples at maturity stages two, three, and four. Overall, an HSI with effective selected variables, coupled with PLS-DA, could provide an accurate method and a reference simple system by which to rapidly discriminate the maturity stages of Camellia oleifera fruit samples. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT), characterized by high treatment efficiency, absence of drug resistance, minimal trauma, and few side effects, has gradually emerged as a novel and alternative clinical approach compared to traditional surgical resection, chemotherapy and radiation. Whereas, considering the limited diffusion distance and short lifespan of reactive oxygen species (ROS), as well as the hypoxic tumor microenvironment, it is crucial to design photosensitizers (PSs) with suborganelle specific targeting ability and low-oxygen dependence for accurate and highly efficient photodynamic therapy. In this study, we have meticulously designed three PSs, namely CIH , CIBr , and CIPh , based on molecular engineering. Theoretical calculation demonstrate that the three compounds possess good molecular planarity with calculated S 1 -T 1 energy gaps (Δ E S1-T1) of 1.04 eV for CIH , 0.92 eV for CIBr , and 0.84 eV for CIPh respectively. Notably, CIPh showcases remarkable dual subcellular targeting capability towards lipid droplets (LDs) and mitochondria owing to the synergistic effect of lipophilicity derived from coumarin's inherent properties combined with electropositivity conferred by indole salt cations. Furthermore , CIPh demonstrates exclusive release of singlet oxygen (1O 2)and highly efficient superoxide anion free radicals(O 2 ⦁−) upon light irradiation supported by its smallest S1-T1 energy gap (Δ E S1-T1 = 0.84 eV). This leads to compromised integrity of LDs along with mitochondrial membrane potential, resulting in profound apoptosis induction in HepG2 cells. This successful example of molecular engineering guided by density functional theory (DFT) provides valuable experience for the development of more effective PSs with superior dual targeting specificity. It also provides a new idea for the development of advanced PSs with efficient and accurate ROS generation ability towards fluorescence imaging-guided hypoxic tumor therapy. [Display omitted] • CIPh realized elevated levels of O 2 ⦁− and 1O 2 "turn on". • CIPh can effectively kill cancer cells for synergetic damage on LDs and mitochondria. • Reveal the mechanism of cell death. [ABSTRACT FROM AUTHOR]

Oxygen concentration and penetration depth are the two key factors that influence the therapeutic effect of photodynamic therapy (PDT) in hypoxic tumors. Developing a simple strategy to construct advanced type I photosensitizers (PSs) with near-infrared region (NIR) absorption has a wide application prospect but remains a challenge. Herein, based on simple D-π-A conjugated CQ-SO 3 and CQ-S-SO 3 , bovine serum albumin (BSA) was elaborately selected to construct the supramolecular assemblies CQ-SO 3 @BSA and CQ-S-SO 3 @BSA. Encouragingly, the high-stability CQ-S-SO 3 @BSA exhibited superior superoxide anion (O 2 ‑• ) generation and activated three-photon fluorescence properties (1240 nm excitation). Confocal microscopy imaging indicated that CQ-S-SO 3 @BSA can specifically target cancer cell membranes and penetrate 120 µm tissue depth, triggering cancer cell apoptosis under NIR-II light irradiation even in a hypoxic environment. This discovery emphasizes the potential for "killing two birds with one stone" based on supramolecular assembly, thereby opening up new possibilities for phototherapy. • Protein co-assembled strategy. • Superior O 2 ‑• generation. • NIR-II imaging-guided antihypoxic phototherapy. [ABSTRACT FROM AUTHOR]

Tetradentate N2S2 coordination platforms are widespread in biological systems and have endowed metalloenzymes and metalloproteins with abundant reactivities and functions. However, there are only three types of N2S2 scaffolds respectively based on the bipyridine, aryl and alkyl amine derivatives, which are significantly underdeveloped for coordination chemistry. With the objective of developing a new N2S2 coordination platform to assemble a series of first-row transition metal complexes, we have designed a novel tetradentate N2S2 ligand containing a central dipyrrin donor functionalized with two thioether-substituted aryl units. Interestingly, complexation of the N2S2 ligand with the chloride salts of Ni(II), Cu(II) and Zn(II) yields various geometries with various coordination numbers. The reaction between the ligand and NiCl2 readily forms two chloride-bridged centrosymmetric dinickel complexes in which the nickel centers are hexacoordinated by an N2S2Cl2 coordination environment in distorted octahedron geometry. In contrast, metalation of the ligand with CuCl2 gives a mononuclear copper complex consisting of a pentacoordinated copper center in a trigonal bipyramidal geometry with an N2S2Cl coordination sphere. Unexpectedly, the complexation of the ligand with ZnCl2 forms a homoleptic zinc complex in which the zinc center is surrounded by an N4 coordination sphere from two dipyrrin units in a non-planar pseudo-tetrahedral geometry despite the steric hindrance of two bulk thioether-substituted aryl units. These various geometries illustrate the potential structural flexibility of this new ligand. In addition, the optical properties of these compounds were also examined. This work thus provides a new N2S2 coordination platform with geometric flexibility. [ABSTRACT FROM AUTHOR]

The degree of the motion response of the ginkgo seed-stem system during mechanical vibration harvesting determines the separation force obtained, thereby affecting harvesting efficiency. A response surface stochastic finite element analysis was carried out to obtain the modal shapes and the ranges of natural frequencies of the seed-stem systems. It was initially based on model updating and considering the inherent variability of the ginkgo seed-stem system, Then, the dynamic response of the ginkgo seed-stem system under different vibration parameters was investigated. The results showed that at low frequencies, only the first-order natural frequency could lead to resonance and cause the seed-stem system to swing violently. Under horizontal excitation, the main resonance of the system was at an excitation frequency close to the natural frequency. Under vertical excitation, the system had a sub-harmonic resonance at an excitation frequency close to twice the natural frequency. When the excitation acceleration was much larger than the gravitational acceleration, due to the increase in the excitation frequency, the seed-stem bounced violently, significantly increasing the inertial forces on the ginkgo seeds. Thus, vertical excitation is more likely to cause the intense motion response of the seed-stem system than horizontal excitation. This study not only proposes a correction method for the finite element model of the seed-stem system but it also clarifies the effective excitation conditions for the ginkgo seed-stem system. It provides theoretical guidance for the efficient mechanical vibration harvesting of ginkgo seeds. • Finite element model was corrected using the response surface methodology. • The modal variability of the ginkgo seed-stem system was investigated. • Sub-harmonic resonance of seed-stem systems can be triggered by vertical excitation. • The bounce of ginkgo seeds resulted in a significant increase in its inertia force. [ABSTRACT FROM AUTHOR]

Pests and plant diseases cause damage at different levels to China's grain production and economic crops every year. The annual area damaged by pests and diseases is about 470 000 000 hm2, resulting in significant yield losses—about 20% of the total grain yield. A small-size unmanned helicopter has the advantages of flexible operation, strong automatic control ability, and less droplet drift. In addition, pesticides it sprays can penetrate a crop canopy assisted by rotor airflow. Hence, the agricultural chemical control for pests and diseases in medium and small sized fields using a small-size unmanned helicopter is an important means to guarantee grain production. It is one of effective methods for Chinese pesticide-spraying mechanization. In order to realize the low-altitude, low-volume, and high-efficiency spraying demand of an unmanned aerial vehicle (UAV), its spray system, which is the key UAV part, must meet the requirements of lightweight, low-volume spraying and uniform spray. Based on the domestic and foreign UAV nebulization technology of agricultural chemical spray nozzles, we tested the performance of rotary hydraulic atomizers, which combined the advantages of both centrifuge atomization and liquid atomization, in this study. A comprehensive performance test system of nozzle atomization was applied to detect the effect of important factors including structure parameters (nozzle diameter), spray parameters (spray flow rate and pressure), and operating parameters (rotational speed) on nozzle atomization efficiency (droplet size), deposition distribution, and spray span. We analyzed the correlation between spray parameters and pump power consumption. Combined with the effect of motor voltage on motor power, the optimum nozzle working parameters were selected. The results showed that the voltage of a nozzle rotary motor had a more significant effect on droplet diameter than nozzle diameter and spray pressure parameters did. Along with the increase of motor voltage, droplets became smaller, giving a better atomization effect. Motor voltage also notably influenced spray span. The more the voltage was, the bigger the spray angle was, and the larger the span became. Droplet deposition presented normal distribution in the spray range. The best working parameters (10 V of motor voltage; 0.35 MPa of spray pressure; 0.7 mm of nozzle diameter) for UAV rotary hydraulic atomizers were determined by the comprehensive test results. When these parameters were applied, the pump power consumption rate was lowest, the average droplet size was 112.35 μm, the spray span was 3.88 m, and the motor power consumption was 8.6 W. The nozzle atomization performance test system adopted in the present study has been calibrated and analyzed for error in other literature. Its experimental system error displayed was less than 1%, so the test results obtained through this platform are reliable. The results shown here provide a theoretical basis and technical support for the mounting of this novel UAV spray device-the rotary hydraulic atomizing nozzle-onto an UAV to perform relative experiments to improve UAV operating quality and spraying efficiency in the future. [ABSTRACT FROM AUTHOR]

Most of the existing laser welding process monitoring technologies focus on the detection of post-engineering defects, but in the mass production of electronic equipment, such as laser welding metal plates, the real-time identification of defect detection has more important practical significance. The data set of laser welding process is often difficult to build and there is not enough experimental data, which hinder the applications of the data-driven laser welding defect detection method. In this paper, an intelligent welding defect diagnosis method based on auxiliary classifier generative adversarial networks (ACGAN) has been proposed. Firstly, a ten-class dataset consisting of 6467 samples, was constructed, which originate from the optical and thermal sensory parameters in the welding process. A new structured ACGAN network model is proposed to generate fake data similar to the true defect feature distributions. In addition, in order to make the difference between different defects categories more obvious after data expansion, a data filtering and data purification scheme was proposed based on ensemble learning and an SVM (support vector machine), which is used to filter the bad generated data. In the experiments, the classification accuracy can reach 96.83% and 85.13%, for the CNN (convolutional neural network) algorithm model and ACGAN model, respectively. However, the accuracy can further improve to 97.86% and 98.37% for the fusion models of ACGAN-CNN and ACGAN-SVM-CNN models, respectively. The results show that ACGAN can not only be used as an algorithm model for classification, but also be used to achieve superior real-time classification and recognition through data enhancement and multi-model fusion. [ABSTRACT FROM AUTHOR]

• Introduced segmentation method blends Vision Transformer and Convolutional Neural Networks. • Model employs CBAM, Dense ASPP, and SP pooling to refine forest fire segmentation. • High accuracy and speed achieved on both original and augmented datasets. • Research propels real-time wildland fire monitoring, with broader agricultural applications. Forest fires, influenced by climatic and ecological changes, pose significant risks to global ecosystems and human communities. To address this challenge, our research introduces a segmentation method that integrates vision transformers (ViT) with conventional convolutional neural networks (CNNs). Within this framework, MobileViT serves as the basic architecture, with CNNs enhancing spatial resolution. Our model also incorporates the CBAM attention mechanism, the Dense ASPP module, and SP pooling to enhance segmentation performance. The model, optimized for lightweight and efficiency, achieved an F1-score of 87.2 % and a mIoU of 81.44 % on our custom dataset that underwent data augmentation. In addition, ablation experiments validate the value of each module in the performance of the composite model. Collectively, this research aims to advance real-time wildland fire monitoring capabilities. In addition, its potential extends to a broader range of applications encompassing various agricultural and forestry challenges. [ABSTRACT FROM AUTHOR]

Abstract: Three novel organotin(IV) complexes with 2-(9H-carbazol-9-yl) acetic acid (HL), of the formulae {[nBu2SnOL]2O}2 (1), [nBuSn(O)OL]6 (2) and [nBu3SnOL]6 (3) were prepared. All compounds were characterized by X-ray crystallography, confirming that complex (1) is tetranuclear one with ladder framework, complex (2) is a hexanuclear organotin(IV) complex with drum structure and complex (3) is a macrocycle with 24-membered stannoxane ring. Furthermore, all complexes were tested in vitro for their cytotoxic activity, using human hepatocellular carcinoma cell line (BEL-7402) and human hepatocellular liver carcinoma cell line (HepG2). Complex (1) displayed the best cytotoxicity and can be pointed out as a promising substrate to be subject of further investigations. [ABSTRACT FROM AUTHOR]

Abstract: Two silver(I) complexes [Ag2(dppm)2(L1)2(CH2Cl2)2] (1) and [Ag4(dppm)2(L2)2(NO3)2] (2) have been prepared by the reactions of [Ag2(dppm)2(NO3)2] with HL1 and HL2 [dppm=bis(diphenylphosphino)methane, HL1 =2-(9H-carbazol-9-yl) acetic acid and HL2 =(E)-3-(4-(9H-carbazole-9-yl) phenyl) acrylic acid], respectively. Both complexes have been structurally characterized by X-ray crystallography, confirming that 1 is a binuclear complex whereas 2 is a tetranuclear one. Both complexes were assayed for antibacterial activity against two Gram-positive bacterial strains (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538) and two Gram-negative bacterial strains (Pseudomonas aeruginosa ATCC 13525 and Escherichia coli ATCC 35218) by MTT method. Complex 2 exhibited powerful antibacterial activities against B. subtilis ATCC 6633 with MIC of 0.78μg/mL, which was superior to the positive controls penicillin G. On the basis of the biological results, structure-activity relationships were discussed. [Copyright &y& Elsevier]

Abstract: Two novel 1D infinite chain coordination polymers, [CdL(NO3)2] n and [CoL(NO3)2] n (L=4,4′-bis[2-(2-pyridyl)ethenyl]biphenyl) have been prepared by reacting Cd(NO3)2 and Co(NO3)2 with the novel ligand L. Complexes 1 and 2 have been characterized by elemental analysis, IR and single crystal X-ray diffraction determination. The metal ions in the polymers have six coordinate pseudo octahedral structures with two pyridyl nitrogen atoms of L and four oxygen atoms of nitrate. The ligand coordinates to metal ions forming bridges in different geometries (cis and trans coordination modes). The results of TGA determination show that the coordination polymers are quite thermally stable. The complexes exhibit a strong emission band with the maximum intensity at 524 and 545nm in solid-state, respectively, upon excitation at 350−450nm. [Copyright &y& Elsevier]

Background: The outbreak of Coronavirus Disease 2019(COVID-19) caused psychological stress in Chinese adults population. But we are unaware of whether the pandemic causes psychological stress on children. Methods: We used the Children's Impact of Event Scale questionnaire (CRIES-13) to investigate the degree of Post-traumatic Stress (PTSD) symptoms caused by the pandemic in students selected from schools in Sichuan, Jiangsu, Henan, Yunnan, and Chongqing provinces of China. Results: A total of 7769 students(3692 male and 4077 female), aged 8–18 years, were enrolled in the study, comprising 1214 in primary schools, 2799 in junior high schools and 3756 in senior high schools. A total of 1639 students (21.1%) had severe psychological stress reactions. A large proportion of senior high school students (23.3%) experienced severe psychological stress, and they had the highest median total CRIES-13 score. Female students were more likely to experience severe psychological stress and had higher median CRIES-13 total scores than males. Conclusion: COVID-19 has placed psychological stresses on primary and secondary school students in China. These stresses are more likely to reach severe levels among female students and senior high school students. [ABSTRACT FROM AUTHOR]

Particleboards are widely used in the artificial board market, which can be constructed from a variety of raw materials and require small amounts of energy to be produced. In the particleboard production process, forming machines play an important role as the key equipment for achieving continuous production. In recent years, airflow forming machines have received increasing attention in particleboard production lines because of their strong separation ability and low price. However, the internal flow field is complex and difficult to control, which affects the surface quality and strength of the particleboard. The most pressing technical difficulty is controlling the flow field characteristics of the airflow paver. At present, the research on this subject is conducted primarily through repeated experiments, which entail long research periods and high processing costs. To reduce human and financial costs, in this study, Computational Fluid Dynamics (CFD) is employed to investigate the flow field and the gas-solid two-phase flow field coupled with particle movement of an airflow forming machine. The accuracy of the calculation model is verified by comparing characteristic point velocities obtained from experimental analysis and a simulation. The simulation results show that in practical production, the frequency of a negative pressure fan should be greater than 27 Hz. It is necessary to set the shoulder properly, and the slab smoothness can be improved by moving the shoulder back on the premise of meeting the strength requirements of the box. The distance between the shoulders of the box body should be less than 2570 mm, and particles with uniform diameter should be added to the paving box to reduce the turbulence effect, improve the quality of particle forming and provide actual particleboard production with a solid theoretical foundation. [ABSTRACT FROM AUTHOR]

Sweetness is one of the most important quality traits for fruit which directly affects consumers' acceptance. The aim of this study was to detect and grade sweetness levels of intact peaches and nectarines by combining short-wave and long-wave Fourier-transform near-infrared spectroscopy (FT-NIRS). FT-NIR spectra of 720 samples (360 peaches and 360 nectarines) were collected using a system operated in range from 15,700 to 4000 cm−1. Soluble solids contents (SSC) were measured as indicators and samples were individually grouped into three sweetness levels based on predetermined thresholds. Partial least squares regression (PLSR) and principal component regression (PCR) were compared, and results showed that PLSR models developed using raw full spectra performed best with correlation coefficient (Rp) of 0.7747 and 0.8473, and root mean square error (RMSEP) of 0.6915% and 0.7228% in prediction. Furthermore, effective wavelengths were individually selected using regression coefficients (RC) and competitive adaptive reweighted sampling (CARS) to simplify the PLSR models. Through comparison, RC-PLSR resulted in comparable performance with original models showing Rp = 0.7716 and 0.8157, and RMSEP = 0.6943% and 0.7945%. To grade different sweetness levels, two-dimensional correlation spectroscopy (2D-COS) was innovatively conducted, and autopeaks characterizing the differences among different groups were retained. Partial least square discriminant analysis (PLS-DA) classification models based on autopeaks achieved a total correct classification rate (CCR) of 66.7% and 86.6% for peaches and nectarines, respectively. The overall results indicated the combination of short-wave and long-wave FT-NIRS was potentially useful in detecting and grading sweetness for these fruit varieties. [ABSTRACT FROM AUTHOR]