Selection of Greenhouse Zucchini Varieties and High-Quality,High-Yield and High-Efficiency Cultivation Techniques

[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.

High-Yield High-Efficiency Positron Generation in High-Z Metal Targets Irradiated by Laser Produced Electrons from Near-Critical Density Plasmas

An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are investigated numerically. It is found that the positron yield is mainly affected by the number of electrons of energies up to several hundreds of MeV. Using near-critical density targets for electron acceleration, the number of high energy electrons can be increased dramatically. Through start-to-end simulations, it is shown that up to 6.78×10106.78×1010 positrons can be generated with state-of-the-art Joule-class femtosecond laser systems.

INVESTIGATION OF SURFACE TEMPERATURE IN HIGH-EFFICIENCY DEEP GRINDING

A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum temperature on contact area is investigated in different grinding conditions with a J-type thermocouple. The maximum contact temperatures measured in different conditions are found to be between 1 000 ℃ and 1 500 ℃ in burn-out conditions. The experiment results show good agreement with the new thermal model.

High-efficiency tea shoot detection method via a compressed deep learning model

Achieving high-efficiency and accurate detection of tea shoots in fields are essential for tea robotic plucking. A real-time tea shoot detection method using the channel and layer pruned YOLOv3-SPP deep learning algorithm was proposed in this study. First, tea shoot images were collected and data augmentation was performed to increase sample diversity, and then a spatial pyramid pooling module was added to the YOLOv3 model to detect tea shoots. To simplify the tea shoot detection model and improve the detection speed, the channel pruning algorithm and layer pruning algorithm were used to compress the model. Finally, the model was fine-tuned to restore its accuracy, and achieve the fast and accurate detection of tea shoots. The test results demonstrated that the number of parameters, model size, and inference time of the tea shoot detection model after compression reduced by 96.82%, 96.81%, and 59.62%, respectively, whereas the mean average precision of the model was only 0.40% lower than that of the original model. In the field test, the compressed model was deployed on a Jetson Xavier NX to conduct the detection of tea shoots. The experimental results demonstrated that the detection speed of the compressed model was 15.9 fps, which was 3.18 times that of the original model. All the results indicate that the proposed method could be deployed on tea harvesting robots with low computing power to achieve high efficiency and accurate detection.

Analysis and Design of Surface Permanent Magnet Synchronous Motor and Generator

This paper presents an analytical method to design the high-efficiency surface permanent magnet synchronous motor(SPMSM)or generator(SPMSG).The air-gap and permanent magnet size can be approximately determined based on our mathematics model,which is the most important part of SPMSM design.From our method,we can know that motor’s power out torque is related to the torque angle that we selected in our design and it affects the air-gap and permanent magnet size.If we choose a low torque angle,the motor or generator’s overload power handing capability will increase.The embrace value has a vital place in designing a motor or generator due to its effects on air gap flux density,cogging torque,efficiency and so on.In order to avoid the knee effect,the working point of the permanent magnet we selected in the design should be bigger than 0.5.The developed 36 slots,4 poles,surface mound permanent generator is proposed.The corresponding finite element analysis(FEA)model is built based on our design method.Structure optimization includes stator and rotor structure size,permanent magnet size,magnetic bridge and air gap length which are analyzed and simulated by ANSYS Maxwell 2D FEA.Thermal analysis is conducted,and the housing of the alternator is designed.The alternator prototype is fabricated and tested based on our design.

Wedge template optimization and parallelization of depth map in intra-frame prediction algorithms

To reduce the computational complexity and storage cost caused by wedge segmentation algorithm,a scheme of simplifying wedge matching is proposed.It takes advantage of the correlation of the wedge separation line of depth map and the direction of intra-prediction for 3D high-efficiency video coding(3D-HEVC).According to the difference of wedge segmentation between adjacent edge and opposite edge,a set only including 104×4 wedgelet templates is given.By expanding of the wedge wave of a certain minimum unit,a simple separation line acquisition method for different size of depth block is put forward.Furthermore,based on the array processor(DPR-CODEC)developed by project team,an efficient parallel scheme of the improved wedge segmentation mode prediction is introduced.By the scheme,prediction unit(PU)size can be changed randomly from 4×4 to 8×8,16×16,and 32×32,which is more in line with the needs of the HEVC standard.Veri-fied with test sequence in HTM16.1 and the Xilinx virtex-6 field programmable gate array(FPGA)respectively,the experiment results show that the proposed methods save 99.2%of the storage space and 63.94%of the encoding time,the serial/parallel acceleration ratio of each template reaches 1.84 in average.The coding performance,storage and resource consumption are considered for both.

Ecosystem-management-based Management Models of Fast-growing and High-yield Plantation and Its Eco-economic Benefits Analysis

The paper expounded the basic concept and principles of ecosystem management,and analyzed the state and trend of industrial plantation ecosystem management in other countries.Based on the analysis of typical case studies,the eco-economic benefits were evaluated for the management models of fast-growing and high-yield plantations.

State and Trend Analysis of Industrial Plantation Development in Foreign Countries

The paper firstly reviewed industrial plantation development in the main forestry countries worldwide, and then summarized the state and trend of the R & D of industrial plantation in foreign countries in terms of genetic improvement, breeding techniques, site evaluation techniques, density control techniques, long-term productivity maintenance techniques and diseases and pests control techniques. In the meantime, the three management models employed in industrial plantations abroad was introduced, i.e. intensive management, oriented management, and enterprise-based management and integration of forest, industry and paper-making, based on which four suggestions were proposed through summarizing the successful experiences in industrial plantation development abroad to facilitate the development of fast-growing and high-yield plantation in China from the technical perspective.