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Introduction: To improve the utilization rate of fertilizers, realize the precise spreading of fertilizers in controllable strips, and ensure the uniformity of fertilizer spreading in both longitudinal and transversal directions, a bifurcated swing tube fertilizer spreading device driven by a spatial hammer pendulum crank mechanism was designed. Methods: First, the drive mechanism was designed based on the cylindrical pair of the mechanism. A mathematical model pendulum equation was used to design the swing tube, and the equation of motion of fertilizer particles was established by analyzing the motion and force of fertilizer particles in fertilizer spreading. The dynamic parameters of the fertilizer spreading device (nozzle height, forward velocity, and swing frequency) were identified as the test factors affecting the uniformity of fertilizer spreading. Second, the coupling model based on MBD-DEM was established, and the coupling simulation analysis of the fertilizer spreading process was carried out using EDEM-RecurDyn software. Taking the nozzle height, forward velocity, and swing frequency as test factors and the uniformity coefficient of longitudinal and transversal fertilizer spreading as evaluation indexes of the fertilizer discharging effect, we analyzed the influence of a single factor on the indexes. Moreover, the ternary quadratic generalized rotating combination response surface test established the regression equations of three factors and two evaluation indexes. Finally, the simulation and bench test were verified under the optimal combination of parameters and compared with the single swing tube bench test with the same parameter conditions. Results: The results of the single-factor test showed that the fertilizer discharge effect was better when the nozzle height was 350.0–450.0 mm, the forward velocity was 0.5–1.5 m/s, and the swing frequency was 1.40–2.00 Hz. The results of the response surface test proved that the nozzle height, forward velocity, and swing frequency all had a highly significant effect on the uniformity coefficient of fertilizer spreading in the longitudinal and transversal directions (P <0.01). Moreover, the optimization concluded that when the nozzle height is 450.0 mm, the forward velocity is 0.5–0.8 m/s, and when the swing frequency is within the range of 1.40–2.00 Hz, the uniformity coefficient of longitudinal fertilizer spreading is ≤25% and the uniformity coefficient of transversal fertilizer spreading is ≤45%. The results of bench validation showed that the errors of longitudinal and transversal fertilizer spreading uniformity coefficients in the bench test were 3.46% and 1.44%, respectively, and the simulation agreed with the bench test. The results of comparative tests showed that the uniformity coefficient of the longitudinal and transversal of the fertilizer spreading device was reduced by 50.33% and 14.95%, respectively, for the bifurcated swing tube compared with that of the single swing tube. It is proved that the bifurcated swing tube strip fertilizer spreading device can achieve the purpose of uniform fertilizer spreading and performs better than the single swing tube in fertilizer spreading. Conclusion: The results and methods of this study can provide a reference for the design of swing tube strip fertilizer spreading devices and related fertilizer spreading performance tests. [ABSTRACT FROM AUTHOR]

In order to solve the problems of existing spiral fertilizer apparatuses, such as the variation in cavity filling rate with rotational speed, fluctuation of fertilizer discharge flow, and inability to discharge fertilizer precisely, a triple-head gradually reducing spiral fertilizer apparatus is designed, which gradually compresses fertilizer particles through the triple-head reducing fertilizer spiral structure to achieve complete cavity filling and uniform fertilizer discharge. The main factors that affect the particle motion state and the structural size of the spiral fertilizer through theoretical analysis are determined, and its theoretical fertilizer discharge amount and rotational speed are calculated. Using EDEM (Discrete Element Method Software 2022) to establish a simulation model of a single-head gradually reducing fertilizer apparatus, the spiral lead reduction percentage x1, spiral diameter reduction percentage x2, and rotational speed x3 are determined as experimental factors, and the filling rate μ and spiral torque Yaverage are used as experimental indicators to conduct a simulation study on the secondary universal rotation combination design experiment. The results show that when the rotational speed is 95 r/min, the spiral lead reduction percentage is 60.00~73.21%, the spiral diameter reduction percentage is 86.55~97.05%, the filling rate μ is greater than 95%, and the spiral torque Yaverage is less than 16 N·m. In order to further improve the uniformity of fertilizer discharge and ensure the controllable accuracy of fertilizer discharge, comparative verification experiments are conducted on single-, double-, and triple-head gradually reducing spiral fertilizer discharge devices and ordinary spiral fertilizer discharge devices. The results show that the precision of the gradually reducing spiral fertilizer apparatus is better than that of the ordinary spiral fertilizer apparatus. Moreover, it is determined that the three-head style performed best. The triple-head gradually reducing spiral fertilizer apparatus is also validated by randomly adjusting six rotational speeds. The experiment results show that the average deviation of the fertilizer discharge flow rate of the fertilizer apparatus from the preset value is 3.16%. The two have a minor deviation, and the fertilizer precision is high. Precise control of the amount of fertilizer discharged can be achieved by adjusting the rotational speed, and the research can provide a specific reference for the improved design and precise control of the spiral fertilizer apparatus. [ABSTRACT FROM AUTHOR]

In order to solve the traditional single-spiral fertilizer discharger issue of the fluctuation of fertilizer-discharge flow and the problem of precise fertilizer discharge, the innovative design of a cantilevered oblique placement of a fertilizer-discharging spiral structure in the form of an inclined spiral fertilizer discharger was realized, in which, through the fertilizer spiral's full end-filled extrusion, uniform delivery of the discharge was achieved. Discrete element simulation was used to compare the fertilizer-discharge characteristics of inclined and traditional single-spiral fertilizer dischargers, and the results proved that the inclined spiral fertilizer discharger effectively reduced the fluctuation of the fertilizer-discharge flow rate. Through a theoretical analysis preformed to determine the theoretical fertilizer discharge and the main parameters affecting the uniformity of fertilizer discharge, we identified the tilting angle of the fertilizer discharger (θ) and the distance from the termination spiral blade to the fertilizer outlet (l). A two-factor, five-level quadratic generalized rotary combination experiment was conducted with two parameters (θ and l) as the experiment factors and the variation coefficient of fertilizer-discharge uniformity (σ) as the experiment indicator. The experimental results showed that for σ, θ was a highly significant effect, l was a significant effect, and σ was less than 8.5%; when θ was 35.02° and l was 16.87 mm, the fertilizer-discharge performance was better. A bench experiment was used to compare the traditional and inclined spiral fertilizer dischargers, and the results showed that the relative error of the variation coefficient between the bench and the simulation experiment under this combination was 2.28%. And compared with the traditional spiral fertilizer discharger's σ average increase of 80.79%, the effect of fertilizer discharge was better than the traditional spiral fertilizer discharger. A fertilizer application controller was developed, and the bench performance was tested based on the measured fertilizer-discharge flow rate fitting equation of this combined inclined spiral fertilizer discharger. The results show that the electronically controlled inclined spiral fertilizer discharger has an average deviation of 3.12% from the preset value, which can be used to regulate the flow of fertilizer discharged through the fertilizer controller to realize precise fertilizer application, and this study can provide a reference for the optimal design of the spiral fertilizer discharger. [ABSTRACT FROM AUTHOR]

Image watermarking technology plays a key role in the protection of intellectual property rights. In addition to digital watermarking, optical watermarking has also been widely considered. A watermarking scheme based on Gerchberg–Saxton (GS) algorithm and integer wavelet transform (IWT) is proposed for image encryption. The scheme uses the unique phase reconstruction characteristics of GS algorithm, which makes it able to deal with a variety of complex local attacks in the process of protection and effectively restore the original image information. The obfuscation of position and numerical value information is realized by means of variable step Joseph space scrambling and pixel value bit processing. The carrier image is decomposed into subbands with different frequencies using IWT, all the information of the secret image is embedded bit by bit, which realizes the hiding of the image information. In addition, the SHA-256 function, the RSA algorithm, and the hyperchaotic system are combined to generate the cipher stream. The experimental results show that the algorithm has good imperceptibility and security, as well as strong robustness to cutting and salt and pepper noise attacks, and can restore the image quality well. [ABSTRACT FROM AUTHOR]

SUMMARY This paper further investigates some novel methods for generating complex grid multi-wing hyperchaotic attractors from four-dimensional (4D) quadratic hyperchaotic systems, based on our previous works. First, a modified double-wing hyperchaotic Lü system by using non-uniform variable scaling transformation is obtained, and n-wing hyperchaotic system equipped with a duality-symmetric multi-segment quadratic function is also constructed. Then, by switching control in the z direction, mirror symmetry conversion and rotation transformation, three classes of n × m-wing hyperchaotic systems are respectively realized. Finally, two types of improved module-based circuits are designed for generating various grid multi-wing hyperchaotic attractors. One characteristic of the proposed approaches lies in their generality, which is also suitable for constructing 4D grid multi-wing hyperchaotic Lorenz and Chen systems. Both numerical simulation and circuit implementation have demonstrated the feasibility and effectiveness of the proposed approaches. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Visfatin is an adipocytokine that has been demonstrated to be involved in cardiovascular diseases. This study aims at determining the role of visfatin in sepsis-induced cardiac injury and identify its possible mechanisms., Methods: Dynamic changes in visfatin expression in mice with lipopolysaccharide- (LPS-) induced septicemia were measured. Additionally, mice were pretreated with visfatin and further administered LPS to observe the effects of visfatin on cardiac injury. Finally, septic mice were also pretreated with JSH-23 to investigate whether visfatin regulates cardiac injury via the NF- κ B p65 pathway., Results: Visfatin expression levels in both the heart and serum were increased in LPS-treated mice and peaked at 6 hours, and visfatin was derived from cardiac macrophages. In septic mice, pretreatment with visfatin reduced the survival rate, worsened cardiac dysfunction, and increased the expression of cardiac injury markers, including creatine kinase myocardial bound (CK-MB) and lactate dehydrogenase (LDH). Treatment with visfatin also increased the infiltration of CD3+ cells and F4/80+ cells, amplified the cardiac inflammatory response, and elevated myocardial cell apoptosis. Treatment with JSH-23 reversed the effects of visfatin in septic mice., Conclusions: This study showed that visfatin amplifies the cardiac inflammatory response and aggravates cardiac injury through the p65 signaling pathway. Visfatin may be a clinical target for preventing cardiac injury in sepsis., Competing Interests: The authors declare no potential conflict of interest., (Copyright © 2022 Yewen Hu et al.)