Design and test of the arc-shaped nail-tooth roller residual film recovery machine from the sowing layer

Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-shaped nail-tooth roller structure was designed.Meanwhile,the key device structures were designed and the main working parameters were analyzed.Then,taking the working depth,the forward speed of the machine and the rotation speed of the nail tooth roller as the test factors,and the film collection rate and film intertwining rate as the test indicators,the single factor tests and the Box-Behnken response surface tests were carried out to evaluate the performance of the sowing layer residual film recovery machine.Consequently,the results showed that the order of significant factors was the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller.Besides,the optimal working parameters were determined,which the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller were 100 mm,4.8 km/h,and 49.3 r/min,respectively.Moreover,the predicted value of the film collection rate was 69.20%.Finally,the verification test was taken with the optimal working parameter,and the results showed that the film collection rate was 66.84%,and the film intertwining rate was 1.39%.The relative error between the test value and the predicted value of the film collection rate was 3.40%.It indicated that the machine can perform the collection of sowing layer residual films.This study can provide a theoretical basis and reference for the design of new sowing layer residual film machines.

Novel method for the visual navigation path detection of jujube harvester autopilot based on image processing

To realize automatic harvesting of the jujube,the jujube harvester was designed and manufactured.For achieving the jujube harvester autopilot,a novel algorithm for visual navigation path detection was proposed.The centerline of tree row lines was taken as the navigation path.The method included four main parts:image preprocessing,image segmentation,tree row lines access,and navigation path access.The methods of threshold segmentation,noise removal,and border smoothing were utilized on the image in Lab color space for the image segmentation.The least square method was employed to fit the tree row lines,and the centerline was obtained as the navigation path.Experimental results indicated that the average false detection rate was 3.98%,and the average detection speed was 41 fps.The algorithm meets the requirements of the jujube harvester autopilot in terms of accuracy and speed.It also can lay the foundation for accomplishing the jujube harvester vision-based autopilot.

Plasmonic rhenium trioxide self-assembled microtubes for highly sensitive, stable and reproducible surface-enhanced Raman spectroscopy detection

Compared with noble metals, improving the sensitivity of semiconducting surface-enhanced Raman scattering(SERS) substrates is of great significance to their fundamental research and practical application of Raman spectroscopy. Herein, a simple chemical method is developed to synthesize a rhenium trioxide(ReO_(3)) microtubes assembled with highly crystalline nanoparticles. The ReO_(3) microtubes show a strong and well-defined surface plasmon resonance(SPR) behavior in visible region, which is rare for non-noble metals. As a low-cost SERS substrate, the plasmonic ReO_(3) microtubes exhibit a Raman enhancement factor of 8.9×10^(5) and a lowest detection limit of 1.0×10^(-9) mol/L for phenolic pollutants. Moreover, these ReO_(3) microtubule SERS substrates show excellent chemical stability and can resist the corrosion of strong acids and bases.

Image detection and verification of visual navigation route during cotton field management period

In order to meet the actual operation demand of visual navigation during cotton field management period,image detection algorithm of visual navigation route during this period was investigated in this research.Firstly,for the operation images under natural environment,the approach of color component difference,which is applicable for cotton field management,was adopted to extract the target characteristics of different regions inside and outside cotton field.Secondly,the median filtering method was employed to eliminate noise in the images and realize smoothing process of the images.Then,according to the regional vertical cumulative distribution graph of the images,the boundary characteristic of the cotton seedling region was obtained and the central position of the cotton seedling row was determined.Finally,the detection of the candidate points cluster was realized,and the navigation route was extracted by Hough transformation passing the known point.The testing results showed that the algorithms could rapidly and accurately detect the navigation route during cotton field management period.And the average processing time periods for each frame image at the emergence,strong seedling,budding and blooming stages were 41.43 ms,67.83 ms,68.80 ms and 74.05 ms,respectively.The detection has the advantage of high accuracy,strong robustness and fast speed,and is simultaneously less vulnerable to interference from external environment,which satisfies the practical operation requirements of cotton field management machinery.

Origin and Classification of Geothermal Water from Guanzhong Basin,NW China:Geochemical and Isotopic Approach

Combined with tectonic evolution, a multi-isotopic method （δD, δ^18O, ^87Sr/^86Sr and ^14C） and hydrochemistry data have been used to study the origin and classification of geothermal water in the Guanzhong Basin. The study shows that geothermal water of Xianli terrace primarily came from north- west direction when accepting recharge. A small amount supply source of geothermal water in Xi＇an City is from Qinling Mountain and the principal supply source comes from the west direction, but geothermal water of Chang＇an District mainly accepts supply from Qinling Mountain. Based on geothermal environ- ment is open or not, the degree of water-rock interaction, and the origin of geothermal water, geothermal water of the study area can be divided into four types： A, geothermal water of Gushi depression, perfect closed thermal environment and significant water-rock interaction, belonged to residual sedimentary wa- ter origin; B, geothermal water of Xianyang City, good closed environment and relatively significant water-rock interaction, belonged to residual sedimentary water origin mixed with fossil leaching water; C, geothermal water of Xi＇an City, half closed environment and some water-rock interaction, belonged to fossil leaching water origin; D, geothermal water of Chang＇an District, open environment and mixed with modern precipitation, belonged to fossil leaching water origin.

沙棘hrh-miRn458靶向转录因子WRI1调控油脂合成

转录因子WRI1(WRINKLED 1)在油脂合成过程中发挥重要调控作用,其转录和翻译水平调控机理以及下游的靶基因现已基本明确,但尚未见其转录后调控的报道。为探讨沙棘(Hippophae rhamnoides)hrh-miRn458与转录因子WRI1之间的靶向关系,并阐明其在果肉和种子发育过程中的表达模式,通过生物信息学方法预测hrh-miRn458成熟体序列及其与候选靶基因WRI1的结合位点,采用双荧光素酶报告基因检测和RNApulldown技术相结合的方法验证hrh-miRn458与WRI1基因之间的靶向关系,并应用qRT-PCR方法分析hrh-miRn458与WRI1在沙棘不同发育期果肉和种子油脂合成过程中的表达变化。结果表明,生物信息学预测WRI1基因的CDS区第309–327位与hrh-miRn458成熟体序列的15个碱基互补;荧光检测显示pmirGLO-WRI1-WT+hrh-miRn458 mimics显著抑制荧光素酶活性(P<0.001);RNA pull down实验证实hrh-miRn458与WRI1存在互作关系;不同发育期果肉和种子中hrh-miRn458的表达量总体呈先下降后上升趋势,其靶基因WRI1的表达量则呈先上升后降低趋势;同一时期,果肉中hrh-miRn458的表达量明显低于种子,而果肉中的WRI1表达量则明显高于种子。综上,沙棘hrh-miRn458靶向转录因子WRI1,且二者在果肉和种子油脂合成过程中存在负调控关系。研究结果为深入理解沙棘种子油脂合成机制及培育高油品种提供了参考依据。

Design and parameter optimization of spiral-dragon type straw chopping test rig

In order to address the problems of large chop length,high energy consumption and poor chopping effect that were associated with a horizontal total mixed rations(TMR)mixer,a straw chopping device was designed;further,its structure and working principle were analyzed.In this study,wheat straw was chosen as the test object.The number of processing times,number of fixed blades,cutting speed,number of tooth plates and the inclined angle of the box were considered as the test factors.The standard straw length rate and average power were used as evaluation indices for conducting the orthogonal rotation combination experiment with five factors and five levels of quadratic regression.The experimental results denoted that the order of influencing factors on the standard straw length rate can be given as follows:the number of processing times,number of fixed blades,cutting speed,number of tooth plates and inclined angle of the box.The order of the influence of each factor on the average power can be given as follows:the cutting speed,number of fixed blades and number of tooth plates.Further,the optimum structural and working parameters of the device can be determined as follows:linear cutting speed of 17-20 m/min,box inclined angle of 70°-80°,20-23 fixed blades,5-6 processing times and 4-7 tooth plates.Under such a circumstance,the standard straw length rate reached up to 70.5%-77.4%and the average power was low at 5.8-7 kW.The results can be used as reference for designing a chopping device for a TMR mixer.