Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.

Synthesis and Crystal Structure of a Three-dimensional Mn(Ⅱ) Coordination Polymer with 3-(Pyrazin-2-yloxy)-pyridine and Azide Anion as Mixed Bridge Ligand

A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along

A Hybrid Model to Predict Cartesian Planimetric Coordinates

Coordinates are basic needs for both geospatial and non-geospatial professionals and as a result, geodesists have the responsibility to develop methods that are applicable and practicable for determining cartesian coordinates either through transformation, conversion or prediction for the geo-scientific community. It is therefore necessary to implement mechanisms and systems that can be employed to predict coordinates in either two dimensional （2D） or three dimensional （3D） spaces. Artificial Intelligence （AI） techniques and conventional methods within the last decade have been proposed as an effective tool for modeling and forecasting in various scientific disciplines for solving majority of problems. The primary objective of this work is to compare the efficiency of artificial intelligence technique （Feed Forward Back propagation Neural Network （FFBPNN）） and conventional methods （Ordinary Least Squares （OLS）, General Least Squares （GLS）, and Total Least Squares （TLS）） in cartesian planimetric coordinate＇s prediction. In addition, a hybrid approach of conventional and artificial intelligence method thus, TLS-FFBPNN has been proposed in this study for 2D cartesian coordinates prediction. It was observed from the results obtained that FFBPNN performed significantly better than the conventional methods. However, the TLS-FFBPNN when compared with FFBPNN, OLS, GLS and TLS gave stronger and better performance and superior predictions. To further confirm the superiority of the TLS-FFBPNN the Bayesian Information Criterion was introduced. The BIC selected the TLS-FFBPNN as the optimum model for prediction.

Three-dimensional tidal current numerical model of the Oujiang Estuary

The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well.

APPLICATIONS OF FRACTIONAL EXTERIOR DIFFERENTIAL IN THREE-DIMENSIONAL SPACE

A brief survey of fractional calculus and fractional differential forms was firstly given.The fractional exterior transition to curvilinear coordinate at the origin were discussed and the two coordinate transformations for the fractional differentials for three-dimensional Cartesian coordinates to spherical and cylindrical coordinates are obtained, respectively. In particular, for v=m=1 ,the usual exterior transformations, between the spherical coordinate and Cartesian coordinate, as well as the cylindrical coordinate and Cartesian coordinate, are found respectively, from fractional exterior transformation.

Expression of strain tensor in orthogonal curvilinear coordinates

Based on an analysis of connotation and extension of the concept of the orthogonal curvilinear coordinates, we have deduced a platform of strain tensor expression of Cartesian coordinates, which turns out to be a function of Lame coefficient and unit vector. By using transform matrix between Cartesian coordinates and orthogonal eurvilinear coordinates, we have deduced a mathematical expression for correcting displacement vector differential in orthogonal curvilinear coordinates, and given a general expression of strain tensor in orthogonal curvilinear coordinates.

Using three-dimensional discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition

This paper presents a new method for extract three-dimensional （3D） discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pollen information and noise disturbance, the geometric normalized curvature voxels with the principal curvedness are first extracted to represent the intrinsic pollen volumetric data. Then the curvature voxels are decomposed into radial and angular components with spherical harmonic transform in spherical coordinates. Finally the 3D discrete Fourier transform is applied to the decomposed curvature voxels to obtain the 3D spherical Fourier descriptors for pollen recognition. Experimental results show that the presented descriptors are invariant to different pollen particle geometric transformations, such as pose change and spatial rotation, and can obtain high recognition accuracy and speed simultaneously.

Three-Dimensional Analytical Modeling of Axial-Flux Permanent Magnet Drivers

In this paper, the axial-flux permanent magnet driver is modeledand analyzed in a simple and novel way under three-dimensional cylindricalcoordinates. The inherent three-dimensional characteristics of the deviceare comprehensively considered, and the governing equations are solved bysimplifying the boundary conditions. The axial magnetization of the sectorshapedpermanent magnets is accurately described in an algebraic form bythe parameters, which makes the physical meaning more explicit than thepurely mathematical expression in general series forms. The parameters of theBessel function are determined simply and the magnetic field distribution ofpermanent magnets and the air-gap is solved. Furthermore, the field solutionsare completely analytical, which provides convenience and satisfactoryaccuracy for modeling a series of electromagnetic performance parameters,such as the axial electromagnetic force density, axial electromagnetic force,and electromagnetic torque. The correctness and accuracy of the analyticalmodels are fully verified by three-dimensional finite element simulations and a15 kW prototype and the results of calculations, simulations, and experimentsunder three methods are highly consistent. The influence of several designparameters on magnetic field distribution and performance is studied and discussed.The results indicate that the modeling method proposed in this papercan calculate the magnetic field distribution and performance accurately andrapidly, which affords an important reference for the design and optimizationof axial-flux permanent magnet drivers.

A three-dimensional k-ε-k_p model in curvilinear coordinates for sediment movement and bed evolution

To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load trans- port in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying wa- ter-sediment movements and bed evolution in a 120° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kp model is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model.

A Novel 3-D Zn(Ⅱ) Coordination Polymer for Inhibiting the Human Osteosarcoma Cells Growth

A new three-dimensional Zn（II） coordination polymer, namely [Zn4（bpydb）3（tz）2（H2O）2]n（1）, has been synthesized by the self-assembly reactions of Zn（NO3）2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional framework structure and is the first example of Zn-containing coordination polymers based on two kinds of ligands bpydb H2 and Htz. It crystallizes in triclinic, space group P1 with a = 14.9953（12）, b = 17.5335（17）, c = 20.2381（11）A, α = 115.225（7）, β = 92.329（5）, γ = 105.606（8）o, V = 4561.9（7） A^3, Z = 2, F（000） = 1644, Dc = 1.177 Mg/m^3, Mr = 1616.76 and μ = 1.098 mm^-1. The antitumor activities of compound 1 and its corresponding organic ligands（bpydb H2 and Htz） were investigated for inhibiting human osteosarcoma cells（MG-63 and U-2 OS） growth by MTT assay. It was found that compared with the two ligands, compound 1 exerted rather potent activities against all of these cell lines.

Hydrothermal Synthesis, Crystal Structure and Fluorescence Property of a Novel Coordination Polymer [Eu_2(C_6H_8O_4)_3(H_2O)_2]_n·n(4,4′-bpy)

A novel coordination polymer [Eu2(C6H8O4)3(H2O)2]n?n(4,4?-bpy) (Mr = 928.51) was synthesized by the hydrothermal reaction of EuCl3?6H2O, adipic acid and 4,4?-bpy, and determined by elemental analysis, IR spectroscopy, thermal gravimetric analysis, single-crystal diffraction and fluorescence property. X-ray analysis reveals that a three-dimensional network has been formed between Eu3+ by carboxyl of adipic acid. The crystal is of orthorhombic, space group Pbcn with a = 21.870(7), b = 7.652(2), c = 19.624(6) ?, V = 3284.1(17) ?3, Z = 4, Dc = 1.878 g/cm3, μ = 3.854 mm-1, F(000) = 1824, R = 0.0345 and wR = 0.0565. The coordination polymer exhibits intensive red light under UV excitation at room temperature, which is attributed to the 5D0→7F2 transition of Eu(Ⅲ) ions.

Analysis on the Demand and Countermeasures of Air Ground Coordination in China’s Aviation Medical Rescue

Compared with ground first aid, aviation medical rescue has better advantages in mountain disaster relief, remote transfer and rapid medical rescue response, which is an effective supplement to ground medical first aid. China’s aviation medical rescue is in its infancy, compared with the level of developed countries there is a big gap. Based on the development and characteristics of aviation medical rescue in China, this paper combs the process of air-ground cooperative rescue, analyzes the demand and current situation of air-ground cooperative rescue in aviation medical rescue in China, and puts forward some countermeasures to improve the ability of aviation medical rescue in China.

ANALYTICAL SOLUTIONS FOR THE LAYERED GEO-MATERIALS SUBJECTED TO AN ARBITRARY POINT LOAD IN THE CARTESIAN COORDINATE

This paper presents analytical solutions for the stress and displacement field in elastic layered geo-materials induced by an arbitrary point load in the Cartesian coordinate system. The point load solutions can be obtained by referring to the integral transform and the transfer matrix technique. However, former solutions usually exist in the cylindrical coordinate system subjected, to axisymmetric loading. Based on the proposed solutions in the Cartesian coordinate, it is very easy to solve asymmetric problems and consider the condition with internal loads in multi-layered geo-materials. Moreover, point load solutions can be used to construct solutions for analytical examination of elastic problems and incorporated into numerical schemes such as boundary element methods. The results discussed in this paper indicate that there is no problem in the evaluation of the point load solutions with high accuracy and efficiency, and that the material non-homogeneity has a significant effect on the elastic field due to adjacent loading.

Intelligent Sensing and Control of Road Construction Robot Scenes Based on Road Construction

Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.

平面刚体系统的参数预调节保辛算法

保辛积分方法在约束哈密顿系统中有着重要的应用,是因为其在长时间仿真中表现出极好的稳定性。然而随着仿真时长增加,保辛格式通常具有较大的相位误差累积。本文提出了一种平面多刚体系统的参数预调节保辛积分方法。通过推导具有待定参数的改进的拉格朗日方程,并将其与已有保辛格式相结合并预先调节相关参数取值,可以大幅降低数值解的相位误差。理论分析与数值结果表明参数预调节保辛积分方法不仅保持了辛结构,而且具有很低的相位误差累积。因此,参数预调节保辛积分方法可应用于长时间仿真分析。

直角坐标机器人轨迹自适应NURBS曲线插补算法

为了提升直角坐标机器人轨迹的分段精度,提出了一种直角坐标机器人轨迹自适应分段NURBS曲线插补算法。基于NURBSS曲线自适应速度调整原理,通过加减速区域分析和分段预处理,找出曲线上的曲率极大值,分辨这些点是否为速度敏感点,并通过前瞻处理,逆向插补每个速度敏感点,规划敏感区的进给速度,使各个轴的加减速限制与弓高误差可同时得到满足,并确定减速点位置,实时插补处理根据进给速度与当前插补点的位置,计算下一插补点的位置,实现实时插补。实验表明:该算法具有较高的分段精度与分段效率;可满足分段加减速的要求;速度波动率最低且始终在给定的速度范围内,能够良好地控制进给速度;前瞻处理后插补速度减速效果较好;插补计算耗时仅为0.6/ms。

遗传神经网络下机器人双头夹具参数优化研究

由于直角坐标机器人双头夹具动力学较为复杂,难以找到双头夹具最优参数组合,因此以直角坐标机器人为基础,提出遗传神经网络下机器人双头夹具参数优化方法。分析不同工况下双头夹具关节在夹持工件时的接触力,结合偏移量约束搭建双头夹具动力学模型。以动力学模型为基础,设置参数优化约束条件,包括竖直与水平移动距离、末端节点运行速度、夹具质量、等效应力、丝杠变形量等。结合相关约束条件,构建双头夹具参数优化目标函数,利用遗传神经网络对目标函数进行求解,获取目标函数最优解,该解即为双头夹具参数结果。经实验数据分析证明,所提方法优化后的双头夹具参数更接近于理想值,夹具灵敏度更高,能够有效提升其工作质量。

基于平面解析几何的天线匹配网络分析与设计

本文提出一种从平面解析几何角度分析与设计天线匹配网络的新方法。该方法在直角坐标系上将共轭匹配的全过程可视化,使得复杂繁琐的网络匹配与电磁计算更加直观且易于理解,可广泛应用于网络匹配和电磁计算中。

平尺配测微表检测坐标定位系统运动直线度

对应用平尺配测微表检测运动直线度进行研究,提出了一种新方法——截段回归法,此方法突破了平尺自身长度的局限性,弥补了其他标准器在被测对象尺寸超过其适用范围,或是直线度误差超过其测量范围时无法测量的不足。可进行更长距离、误差范围更大的直线度检测,并对方法进行了验证和不确定度评定。