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Bis (8-hydroxyquinoline) copper (CuQ2) is an important organometallic complex based on a central metal cation coordinated to quinolate ligands. However, CuQ2 exhibits limitations such as low fluorescence intensity, short fluorescence lifetime, and low efficiency of visible light absorption. In this study, density functional theory (DFT) calculations were performed to investigate the frontier molecular orbitals of CuQ2, revealing its potential for excellent luminescence properties. Subsequently, CuQ2 was synthesized using physical vapor deposition (PVD), yielding micron-sized CuQ2 particles. CuQ2 micron particles were characterized using scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), ultraviolet visible spectroscopy (UV–Vis), photoluminescence and fluorescence lifetime. The results demonstrate that the deposition temperature significantly influences the morphology, thermal stability and fluorescence properties of CuQ2. At a deposition temperature of 200 °C, the CuQ2-C sample forms spherical micron particles with uniform morphology, enhanced thermal stability, optimal visible light absorption efficiency, and highest fluorescence intensity. The CuQ2-C sample exhibits a maximum emission wavelength of 660 nm, a maximum excitation wavelength of 333 nm, and a fluorescence lifetime of 10.646 μs. [ABSTRACT FROM AUTHOR]

Bis(8‐hydroxyquinolates) Zinc (Znq2) can be used as a light‐emitting layer material in OLED devices to achieve its efficient electroluminescence effect. In this paper, Znq2 powder has been successfully synthesized and modified by the physical vapor deposition (PVD) method. Precursors and nano‐materials are characterized by XRD, SEM, PL, and so on. The performance of the modified material has been significantly improved. The emission intensity and absorption intensity in the deposited products increased with the increase in PVD temperature. At 453 K, luminous properties such as luminous intensity reach the optimal value including its fluorescence lifetime. Fluorescence lifetime values vary from 13 to 17 ns with the increase in temperature. The luminescence mechanism is also discussed. The energy gap and absorption spectrum of HOM‐LUMO are calculated by the DFT/UB3LYP method. The experimental values agree well with the theoretical values. The nanomaterial crystals modified by PVD technology are more orderly, impurities are reduced, and the luminous stability of the material is improved, which may be one of the reasons for the relatively slow decline in product life. The research combined with theoretical simulation is expected to be helpful to the research and promotion of such materials. [ABSTRACT FROM AUTHOR]

With the development of smart agriculture, autopilot technology is being used more and more widely in agriculture. Because most of the current global path planning only considers the shortest path, it is difficult to meet the articulated steering tractor operation needs in the orchard environment and address other issues, so this paper proposes a hybrid algorithm of an improved bidirectional search A* algorithm and improved differential evolution genetic algorithm(AGADE). First, the integrated priority function and search method of the traditional A* algorithm are improved by adding weight influence to the integrated priority, and the search method is changed to a bidirectional search. Second, the genetic algorithm fitness function and search strategy are improved; the fitness function is set as the path tree row center offset factor; the smoothing factor and safety coefficient are set; and the search strategy adopts differential evolution for cross mutation. Finally, the shortest path obtained by the improved bidirectional search A* algorithm is used as the initial population of an improved differential evolution genetic algorithm, optimized iteratively, and the optimal path is obtained by adding kinematic constraints through a cubic B-spline curve smoothing path. The convergence of the AGADE hybrid algorithm and GA algorithm on four different maps, path length, and trajectory curve are compared and analyzed through simulation tests. The convergence speed of the AGADE hybrid algorithm on four different complexity maps is improved by 92.8%, 64.5%, 50.0%, and 71.2% respectively. The path length is slightly increased compared with the GA algorithm, but the path trajectory curve is located in the center of the tree row, with fewer turns, and it meets the articulated steering tractor operation needs in the orchard environment, proving that the improved hybrid algorithm is effective. [ABSTRACT FROM AUTHOR]

With the development of bridge engineering, U-shaped girder bridges have been applied in numerous bridge designs due to their structural characteristics. However, the U-shaped girder bridge is sensitive to solar radiation effects, leading to uneven temperature distributions that can affect the service performance of the structure. Thus, this study proposes an analysis method for the temperature distribution of U-shaped girder bridges and develops a prediction model to estimate temperature gradients. First, an improved ASHRAE clear sky model is proposed to calculate the structural shadow areas under sunlight, which provides a basis for the numerical simulation of U-shaped girder bridges under solar radiation effect. Then, a three-dimensional finite element model of the U-shaped girder bridge is established, and its correctness is verified by comparing with the actual temperature data. The temperature distribution of the U-shaped girder bridge under solar radiation is simulated using the verified model to obtain the maximum temperature difference and temperature variation characteristics. Finally, a prediction model for the temperature gradient is developed using nonlinear fitting approaches, and its accuracy is confirmed through comparison with actual data. The results indicate that the temperature distribution of the U-shaped girder bridge has minor changes along the longitudinal direction, while there are significant changes in the transverse distribution; the temperature distribution exhibits nonlinear changes in the height direction of the two side webs and the lateral direction of the bottom slab, with the maximum temperature difference reaching 17 °C; the fitting effect of the prediction model is very good, the correlation coefficients of the fitting curve and the actual data are all greater than 88%, providing a basis for the analysis of the temperature effects on U-shaped girder bridges and its application in design specifications. [ABSTRACT FROM AUTHOR]

Background: Pulsed radiofrequency (PRF) of the lumbar dorsal root ganglion (DRG) has been widely used as a method to relieve lumbar radicular pain (LRP). However, the value of PRF application in LRP patients remains uncertain. This systematic review aimed to compare the effects of PRF of lumbar DRG and LEI in patients with LRP. Methods: A literature search was performed using well‐known databases for articles published up to May 2023. We included randomized controlled trials (RCTs) that evaluated the effects of PRF compared to LEI with or without steroids. We screened articles, extracted data, and assessed risk of bias in duplicate. The pain scores and Oswestry Disability Index (ODI) scores at 1, 3, and 6 months after procedures were obtained. A random‐effects meta‐analysis model was applied for outcomes. We evaluated evidence certainty for each outcome using the GRADE scoring system. This review was registered in the PROSPERO (ID: CRD42021253628). Results: A total of 10 RCTs were included and data of 613 patients were retrieved. We assessed the overall quality of the evidence as very low to moderate. PRF showed no difference in pain scores at 1 (mean difference [MD] −0.80, 95% confidence interval [CI] –1.59 to 0.00, low certainty) and 6 months (MD –2.37, 95% CI –4.79 to 0.05, very low certainty), and significantly improved pain scores at 3 months (MD –1.31, 95% CI –2.29 to −0.33, low certainty). There was no significant difference in ODI score at any interval (very low to low certainty). In the subgroup who underwent a diagnostic block, did not use steroids, and PRF duration greater than 360 s, PRF significantly reduced pain scores at 3 months after procedures. Conclusions: We found low quality of the evidence supporting adjuvant PRF to the lumbar DRG has a greater analgesic effect at 3 months after procedures in patients with LRP than LEI. We identified no convincing evidence to show that this treatment improves function. High‐quality evidence is lacking, and data were largely derived from short‐term effects. Given these limitations, high‐quality trials with data on long‐term effects are needed. [ABSTRACT FROM AUTHOR]

Photocatalytic sterilization technology is a strategy that is environmentally friendly for killing drug-resistant bacteria using solar energy. The role of reactive oxygen species (ROS) required for sterilization depends on the charge separation properties of the photocatalyst. Therefore, we modified the photocatalytic performance of CuIn5S8 by fabricating S-vacancies based on the work function (Φ) theory. The spin state density calculations show that S-vacancies lead to spin polarization, and it is easier to separate electrons and holes when their spin directions change. Electron paramagnetic resonance (EPR) results show that Vs-CuIn5S8-3 can produce more ROS. Under visible light irradiation, Vs-CuIn5S8-3 killed 99% of E. coli and MRSA in natural water within 30 minutes. The work adopted S-vacancies to regulate spin polarization and improve photocatalytic activity, which has great potential in natural water disinfection. [ABSTRACT FROM AUTHOR]

Bridges situated on small-radius reverse curves play a pivotal role within some railway networks, exerting influence over project-wide design progress. Typically, assessing the safety of bridge design parameters necessitates laborious vehicle-bridge dynamic coupling vibration numerical analysis or model experiments. To streamline the design process and enhance efficiency during the preliminary design phase, we propose an efficient method to assess the dynamic performance of bridges on small-radius reverse curves. This approach enables direct prediction of bridge dynamic performance based on design parameters, eliminating the need for numerical simulations and model experiments. We first develop a vehicle-bridge coupling vibration program grounded in train-curve bridge coupling vibration theory, validated using on-site measured data. Subsequently, through numerical simulation experiments, we evaluate 80 simply supported beam bridges on small-radius reverse curves under various operating conditions, generating ample dynamic response data for bridge pier tops and girders. These data are then compared with regulatory thresholds to assign dynamic performance labels. After identifying essential design parameters as data features using Fisher scores, we proceed to input these features into a support vector machine (SVM). Through supervised training with dynamic performance labels, this process empowers the SVM model to predict the dynamic performance of the bridge. Our results demonstrate that this method circumvents the need for detailed vehicle-bridge interaction analysis, yielding an impressive 86.9% accuracy in predicting dynamic performance and significantly boosting computational efficiency. Besides, the top five design parameters that significantly influence the prediction of bridge dynamic performance are obtained. This novel approach has the potential to expedite design assessments and enhance safety in railway bridge construction. [ABSTRACT FROM AUTHOR]

In this paper, using Styphnolobium japonicum, Cryptomeria fortunei and Pinus yunnanensis as raw materials, cellulose (CE) was first extracted by chemical method (CM1) and biological enzymatic method 2 (BM2), and then further prepared into nanocellulose fiber (CNF) by biological enzymatic method 1(CPM (CPM stands for cellulase and pectinase)). The CE and CNF were characterized by FTIR, XRD, SEM, DSC and TG. The results showed that the CNF prepared by CM1-CPM was cellulose type II, CNF prepared by BM2-CPM was cellulose type I. The best crystallinity of the CNF prepared by CM1-CPM reached 74.1% (C. fortunei CNF), the best yield was 24.0% (S. japonicum CNF) and the minimum average diameter was 62.6 nm (C. fortunei CNF). However, the best crystallinity of CNF prepared by BM2-CPM reached 80.1% (C. fortunei CNF), the best yield was 27.4% (C. fortunei CNF), and the minimum average diameter was 31.6 nm (C. fortunei CNF). And also, the thermal degradation analysis of the CNF prepared from the three raw materials revealed that the CNF prepared by BM2-CPM had better thermal degradability. Finally, the thermal stability analysis of the C. fortunei CNF was carried out, and it was found that the residual mass of CNF prepared by BM2-CPM was 48%, while the residual mass of C. fortunei CNF prepared by BM1-CPM was 22%, which showed the C. fortunei CNF prepared by BM2-CPM had better thermal stability. Therefore, the properties of nanocellulose prepared by BM2-CPM are optimal. [ABSTRACT FROM AUTHOR]

The inspiration for the footed robot was originally derived from biology, and it was an imitation of biological form and movement. In this paper, a bionic-robot dog is designed to reveal the motion characteristics of a quadruped robot mechanism through modeling, model kinematic analysis, and other methods. First, the structural characteristics and movement characteristics of the developed bionic-dog model are studied. The first step is to study the physiological structure of the dog, analyze the function of the dog's limbs, and then use a high-speed camera to capture the motion of the marked bionic-robot dog and shoot motion video of the bionic-robot dog in different motion states. The effective data of the marked points in the video are extracted using PHOTRON 1.0 software, and the extracted data are analyzed and processed in the software MATLAB R2020a, and finally the structural characteristics and motion laws of the bionic-robot dog are obtained. Then, a bionic-robot-dog experimental platform is built to conduct experiments with three planned gaits (dynamic gait, static gait, and gait transition). The experiments showed that the three gaits were consistent with the planned movements and the bionic-robot dog could perform stable fast-gait walking, slow-gait walking, and quickly complete gait transitions. All three gaits were simulated in ADAMS 2019 software, and the simulation results showed that all three gaits caused the bionic dog robot to move smoothly. [ABSTRACT FROM AUTHOR]

With the progress and development of AI technology and industrial automation technology, AI robot dogs are widely used in engineering practice to replace human beings in high-precision and tedious industrial operations. Bionic robots easily produce control errors due to the influence of spatial disturbance factors in the process of pose determination. It is necessary to calibrate robots accurately to improve the positioning control accuracy of bionic robots. Therefore, a robust control algorithm for bionic robots based on binocular vision navigation is proposed. An optical CCD binocular vision dynamic tracking system is used to measure the end position and pose parameters of a bionic robot, and the kinematics model of the controlled object is established. Taking the degree of freedom parameter of the robot's rotating joint as the control constraint parameter, a hierarchical subdimensional space motion planning model of the robot is established. The binocular vision tracking method is used to realize the adaptive correction of the position and posture of the bionic robot and achieve robust control. The simulation results show that the fitting error of the robot's end position and pose parameters is low, and the dynamic tracking performance is good when the method is used for the position positioning of control of the bionic robot. [ABSTRACT FROM AUTHOR]

A geared five-bar transplanting mechanism can meet the agronomic requirements for the vertical planting of Salvia miltiorrhiza. In order to improve the planting quality, this paper analyzed the structural composition and working principle of a transplanting mechanism and established an interactive human–computer auxiliary interface through a kinematic model. With the aid of an auxiliary interface, by taking the parameters of the transplanting mechanism as the factors and the parameters of the absolute trajectory and posture for the planter as the index, an orthogonal experimental design with five factors and five levels was carried out, and the optimal combination of the parameters of the mechanism was obtained. According to the optimal combination of the parameters of the mechanism, the structure of the transplanting mechanism was designed, a geared five-bar transplanting mechanism for Salvia miltiorrhiza prototype was developed, and a test bench system was built. The actual trajectory of the endpoint for the transplanting mechanism's prototype was obtained using high-speed photographic technology. The bench test results showed that according to a comparison of the actual trajectory, the posture for the planter and the theoretical analysis results were basically consistent, which verified the correctness, rationality, and consistency of the optimal design for the mechanism. [ABSTRACT FROM AUTHOR]

A variable velocity parallel four-bar cavitating mechanism for well-cellar can form the well-cellar cavitation which suits for well-cellar transplanting under a continuous operation. In order to improve the cavitating quality, this paper analyzed the structural composition and working principle of the cavitating mechanism and established the bidirectional coupling model of multi-body dynamics and the discrete element between the cavitating mechanism and soil through Recurdyn and EDEM software. Based on the model, a three-factor, five-level quadratic orthogonal rotational combination design test was conducted with the parameters of the cavitating mechanism as the experimental factors and the parameters of the cavitation as the response index to obtain the optimal parameter combination, and a virtual simulation test was conducted for the optimal parameter combination in order to study the cavitating law of the cavitating mechanism and soil. The test results showed that the depth of the cavitation was 188.6 mm, the vertical angle of the cavitation was 90.4°, the maximum diameter of the cavitation was 76.1 mm, the minimum diameter of the cavitation was 68.5 mm, and the variance in the diameters for the cavitation was 5.42 mm2. The cavitating mechanism with optimal parameters based on the Recurdyn–EDEM bidirectional coupling mode could further improve the cavitating quality. [ABSTRACT FROM AUTHOR]

Traffic sign detection is an essential component of an intelligent transportation system, since it provides critical road traffic data for vehicle decision-making and control. To solve the challenges of small traffic signs, inconspicuous characteristics, and low detection accuracy, a traffic sign recognition method based on improved (You Only Look Once v3) YOLOv3 is proposed. The spatial pyramid pooling structure is fused into the YOLOv3 network structure to achieve the fusion of local features and global features, and the fourth feature prediction scale of 152 × 152 size is introduced to make full use of the shallow features in the network to predict small targets. Furthermore, the bounding box regression is more stable when the distance-IoU (DIoU) loss is used, which takes into account the distance between the target and anchor, the overlap rate, and the scale. The Tsinghua–Tencent 100K (TT100K) traffic sign dataset's 12 anchors are recalculated using the K-means clustering algorithm, while the dataset is balanced and expanded to address the problem of an uneven number of target classes in the TT100K dataset. The algorithm is compared to YOLOv3 and other commonly used target detection algorithms, and the results show that the improved YOLOv3 algorithm achieves a mean average precision (mAP) of 77.3%, which is 8.4% higher than YOLOv3, especially in small target detection, where the mAP is improved by 10.5%, greatly improving the accuracy of the detection network while keeping the real-time performance as high as possible. The detection network's accuracy is substantially enhanced while keeping the network's real-time performance as high as possible. [ABSTRACT FROM AUTHOR]

According to the characteristics of rail defects, a rail microcrack detection method based on magnetoacoustic coupling effect is proposed in this paper. Firstly, the basic principle of a rail microcrack detection method based on magnetoacoustic coupling effect is described, and then the model is analyzed theoretically. Through simulation calculation, the current density distribution and Lorentz force distribution generated by electromagnetic excitation, the motion characteristics of particles under Lorentz force and the sound field distribution characteristics of magnetoacoustic signals generated by Lorentz force are obtained. Finally, an experimental platform was set up and the steel ring model was preliminarily tested. The magnetic and acoustic signals of the two steel ring boundaries excited by an electromagnetic field were collected. These signals correspond to the position distribution of the steel ring. The state change of rail microstructure will cause a change in the conductivity characteristics of rail materials, and will affect the characteristics and distribution of sound pressure in the detection. Therefore, the detection method based on the magnetoacoustic coupling effect can detect the surface microcracks of high-speed rail. This method has great feasibility and development potential in the field of rail flaw detection. [ABSTRACT FROM AUTHOR]

Mining areas are suffering from serious environmental hazards, such as soil erosion, water pollution as well as land degradation. In this study, two types of mining areas in Anhui Province, China—one a copper mining area and the other a coal mining area—were selected to compare the soil properties under different vegetation restoration conditions, which can be generally classified into reclaimed and non-reclaimed areas. Soil catalase and urease activities and soil chemical properties were chosen to be the main indicators of soil quality. Principal component analysis was used to evaluate the overall soil fertility in the copper and coal mining areas. Results showed that in the copper mining area soil catalase activity was between 12.36 and 19.17 μg g−1 h−1 and urease activity was between 0.03 and 12.05 μg g−1 h−1. And in coal mining area, soil catalase activity was between 3.52 and 9.72 μg g−1 h−1 and urease activity was between 2.71 and 10.81 μg g−1 h−1. Moreover, soil catalase and urease activities in degraded areas were lower than those in reclaimed areas. Soil catalase activity and soil urease activity were significantly correlated with total potassium and total nitrogen, respectively. Soil quality in land types with vegetation restoration was higher than in non-reclaimed areas and old subsidence areas, while soil quality in the copper mining area was generally higher than in the coal mining area. Thus, the optimum measure in this region to ameliorate these degraded soils is vegetation restoration, which helps not only to improve the environment, but also to enhance soil quality in these degraded lands. [ABSTRACT FROM AUTHOR]

The geometrical structure, defect formation energies, electrical and optical properties of C and/or Cr doped anatase TiO2 are calculated by GGA + U method under the framework of density functional theory. The relationship between band structure and light absorption is revealed. The results show that the lattice is obviously distorted after doping, and the stability of C and Cr co‐doping is higher than just Cr doping, second only to Cr doped TiO2. The contribution of C is forming impurity energy levels, and the contribution of Cr is to reduce the band gap in the single doped system. In the co‐doped system, Cr atoms are used as donor impurities and C atoms act as acceptor impurities. The impurity energy is composed of C 2p and Cr 3d orbital hybridization, which reduces the band gap and promotes the separation of the impurity levels. C and Cr co‐doping expands the light absorption of TiO2 to the entire visible region, thereby increasing the absorption coefficient and effectively enhancing the photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Some environmental problems, especially soil salinity hinder the regional sustainable development of eastern China coastal region. Salinity mainly comes from tide weave, seawater flooding and seawater intrusion. Over exploitation of groundwater, which is the result of unfitful land use systems, leads to seawater intrusion and salt concentration increase. Agroforestry systems can enrich soil fertility and prevent soil salinization, furthermore help maintain biodiversity and enhance productivity. For the intergrated multiple ecosystems the most critical issue is to select optimum tree species and rationally arrange these plants. The basics of this multiple ecosystem is that different plants will occupy variable ecological niches within an area, both in space and in soil depth. Shelterbelts and trees intercropping with agricultural crops are major types of the multiple ecosystem. Shelterbelts can reduce wind speed and consequently lessen evaporation and erosion of the soil, increase pasture growth by up to 60% on exposed sites, increase crop yields by up to 25%. Besides intercropping with jujube, other agroforestry multiple ecosystem such as forestry plus agriculture, forestry plus agriculture plus fishery, and forestry plus animal husbandry are the most appropriate ways to utilise land resource in this region. [ABSTRACT FROM AUTHOR]

We studied the effect of isoproterenol on the Ca-activated K(BK) channel in smooth muscle cells isolated from the basilar artery of the guinea pig. Cells were studied in a whole-cell configuration to allow the clamping of intracellular Ca concentration, [Ca]. Macroscopic BK channel currents were recorded during depolarizing test pulses from a holding potential ( V) of 0 mV, which was used to inactivate the outward rectifier. The outward macroscopic current available from a V of 0 mV was highly sensitive to block by external tetraethylammonium·Cl (TEA) and charybdotoxin, and was greatly augmented by increasing [Ca] from 0.01 to 1.0 μM. With [Ca] between 0.1 and 1.0 μM, 0.4 μM isoproterenol increased this current by 58.6±17.1%, whereas with [Ca] at 0.01 μM a sixfold smaller increase was observed. With [Ca]≥0.1 μM, 100 μM dibutyryl-adenosine 3′:5: cyclic monophosphate (cAMP) and 1 μM forskolin increased this current by 58.5±24.1% and 59.7±10.3%, respectively. The increase with isoproterenol was blocked by 4.0 μM propranolol extracellularly, and by 10 U/ml protein kinase inhibitor intracellularly. Single-channel openings during depolarizing test pulses from a V of 0 mV recorded in the whole-cell configuration under the same conditions (outside-outwhole-cell recording) indicated a slope conductance of 260 pS. In conventional outside-out patches, this 260-pS channel was highly sensitive to block by external TEA, and in inside-out patches, its probability of opening was greatly augmented by increasing [Ca] from 0.01 to 1.0 μM. Outside-out-whole-cell recordings with [Ca]≥0.1 μM indicated that 100 μM dibutyryl-cAMP increased the probability of opening of the 260-pS channel by 152±115%. In inside-out patches, the catalytic subunit of protein kinase A increased the probability of opening, and this effect also depended on [Ca], with a 35-fold larger effect observed with 0.1-0.5 μM Ca compared to 0.01 μM Ca. We conclude that the BK channel in cerebrovascular smooth muscle cells can be activated by β-adrenoceptor stimulation, that the effect depends strongly on [Ca], and that the effect is mediated by cAMP-dependent protein kinase A with no important contribution from a direct G-protein or phosphorylation-independent mechanism. Our data indicate that the BK channel may participate in β-adrenoceptor-mediated relaxation of cerebral vessels, although the importance of this pathway in obtaining vasorelaxation remains to be determined. [ABSTRACT FROM AUTHOR]