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Belowground root systems under pasture intercropping exhibit complex interactions, and the root interactions of different intercropping combinations are still poorly understood. Therefore, in this work, two perennial and annual herbages were intercropped in pairs and evaluated at a ratio of 1:1. The root morphology and topological structure differed significantly with intercropping combinations. (1) Compared with other cropping patterns, the mean root diameter (RD) of intercropped alfalfa (Medicago sativa L.) and common vetch (Vicia sativa L.) increased notably. The root surface area (RSA), root volume (RV), and mean RD increased significantly when oat (Avena sativa L.) was intercropped with alfalfa. Similarly, the RSA and RV increased in intercropped oat, intercropping relative to monocropping. (2) The forage topological index of the intercropping system was close to one, which was close to that of the herringbone branching. Additionally, the intercropping system had a lower intensity of underground root competition. The root system of the different forage intercropping combinations tended to transition to dichotomous branching. (3) The correlations between root parameters differed according to forage species. Therefore, different intercropping combinations had different belowground root levels of competitiveness and interactions, thereby changing the resource competition environment. [ABSTRACT FROM AUTHOR]

In order to improve the drawbacks of over-fitting and easily get stuck into local extremes of BACK propagation Neural Network, a new method of combination of wavelet transform and PSO-SVM (Particle Swarm Optimization- Support Vector Machine) power load forecasting model is proposed. By employing wave-let transform, the authors decompose the time sequences of power load into high-frequency and low-frequency parts, namely the low-frequency part forecast with this model and the high-frequency part forecast with weighted average method. With PSO, which is a heuristic bionic optimization algorithm, the authors figure out the prefer-able parameters of SVM, and the model proposed in this paper is tested to be more accurately to forecast the 24h power load than BP model.

Microwave correlation imaging is developed on the basis of the traditional radar imaging. It gets rid of the dependence of the traditional radar imaging on Doppler frequency, providing a new solution for the stationary or quasi-stationary target imaging. In this paper, the coronal plane microwave correlation imaging based on azimuth one-dimensional (1D) array was proposed. The resolution of the two-dimensional (2D) coronal plane along azimuth and elevation directions can be achieved by distributing the array in only one dimension without the synthetic aperture scanning in another dimension. By simulating the detection signals in the coronal plane region, it is determined this imaging method has the imaging resolution capability that is not available in the traditional SAR imaging in the coronal plane. The effectiveness of this imaging method was verified by the image reconstruction with three imaging algorithms. Moreover, the imaging performance including the signal-to-noise ratio was compared and analyzed. [ABSTRACT FROM AUTHOR]

The pot seedling transplanting has the advantages of non-hurting root and no need of recovering period, so it can extend the crop growing period, increase and bring forward the effective tillering, which is very important to the food security. Since Japan invented the first transplanter for rice pot seedling in 1975, large agricultural machinery companies have producted their own models in succession, such as Yanmar, Iseki and so on. The materials and manufacture technologies have been improved through the forty years development, but the basic structure and working principle are still the same. All the transplanting machines use 3 sets of mechanism to complete 3 kinds of movements of picking, transporting and planting. The existing machines have the disadvantages of complex structure, high cost and low efficiency. In domestic, the rice pot seedling transplanting machine uses double cranks to complete the 3 kinds of movements, it has relatively simple mechanism, and is suitable for the rice pot seedlings transplanting, but the problems of severe vibration and low efficiency are still existent. According to the above problems, the paper adopted the cubic non-uniform rational B-spline curve theory to fit non-circular gear pitch curve with coincidence of first and last data points as a closed curve. The shape of non-circular gear pitch curve was controlled and expressed through selecting the 13 data points, a new rotary planet gear train mechanism with non-circular gear was developed for rice pot seedling transplants. Through the kinematic analysis of the mechanism, the attitude and sharp point trajectory objective functions of seedling clip were built and transformed into the optimization mathematics model based on optimization of target determined. A computer aided analysis and optimization software of the transplanting mechanism with non-circular planet gear train for rice pot seedling was developed on the MATLAB GUI platform. Through adjusting data points by the man-machine interaction, the attitude and sharp point trajectory of seedling clip were optimized, and a set of structural parameters were obtained to meet the requirements of the rice pot seedling transplants. A three dimensional model was built in software of UG 8.0, and input to software of Admas 2010. The simulation results show that, both track results of theoretical analysis and virtual prototype experiment are fundamentally consistent, so the correctness of the kinematics mathematical model was verified by the virtual experiment. The research can provide a theoretical basis for developing transplanting mechanisms for rice pot seedling. [ABSTRACT FROM AUTHOR]

A low sintering temperature microwave dielectric material ZnZrNb2 O8 was reported. It exhibits a monoclinic structure, belongs to the space group P2/ c ( C2 h4), and Z = 1. The dielectric constant increased with increasing relative density. The Qf value increased with increasing packing fraction. The τf increased with increasing dielectric constant. The typical values of ZnZrNb2 O8 were ε = 30, Qf = 61 000 GHz, τ f=−52 × 10−6 °C−1, sintered at 950°C. [ABSTRACT FROM AUTHOR]

A low sintering temperature microwave dielectric material ZnZrNb2 O8 was reported. It exhibits a monoclinic structure, belongs to the space group P2/ c ( C2 h4), and Z = 1. The dielectric constant increased with increasing relative density. The Qf value increased with increasing packing fraction. The τf increased with increasing dielectric constant. The typical values of ZnZrNb2 O8 were ε = 30, Qf = 61 000 GHz, τ f=−52 × 10−6 °C−1, sintered at 950°C. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy and safety of prophylactic nebulized antibiotics in preventing intensive care unit (ICU)-acquired pneumonia through a meta-analysis., Methods: Randomized controlled trials (RCTs) investigating the potential reduction in the incidence of ICU-acquired pneumonia through prophylactic nebulized antibiotics were collected by searching the PubMed, Embase, and Cochrane Library databases from their inception to January 23, 2024. The primary endpoint was the incidence of ICU-acquired pneumonia, while the secondary endpoints included mortality, length of ICU stay, mechanical ventilation days, and nebulization-related side effects. Statistical analyses were performed using RevMan 5.3 and STATA 14.0 software., Results: A total of six RCTs were included in the analysis, involving 1,287 patients (636 patients in the study group received prophylactic antibiotic therapy, including Polymyxin B, Tobramycin, Ceftazidime, Colistimethate sodium, and amikacin; 651 patients in the control group primarily received saline). The results indicated that prophylactic nebulized antibiotic therapy significantly reduced the incidence of ICU-acquired pneumonia compared to that in the control group (odds ratio (OR) = 0.57, 95% confidence interval (CI) [0.43-0.74], P < 0.0001). No significant difference was observed in the mortality rate between the treatment and control groups (OR = 0.86, 95% CI [0.68-1.10], P = 0.24). Prophylactic nebulized antibiotic therapy also did not significantly reduce the length of ICU stay (MD = 0.2 days; 95% CI [-0.81 to 1.20], P = 0.70) or the number of mechanical ventilation days (MD = 0.43 days; 95% CI [-0.47 to 1.33], P = 0.35). Additionally, there was no evidence that prophylactic nebulized antibiotic therapy contributed to the development of multiple drug-resistant (MDR) bacterial pneumonia or increased the incidence of associated side effects, such as airway spasms., Conclusions: This meta-analysis suggests that ICU-acquired pneumonia can be prevented by prophylactic nebulized antibiotic therapy in critically ill patients without increasing the risk of MDR bacterial infections or airway spasms. However, the reduction in the incidence of ICU-acquired pneumonia did not result in significant improvements in mortality or length of ICU stay., Competing Interests: The authors declare that they have no competing interests., (© 2024 Gao et al.)