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.

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.

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.

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

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.

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.

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.

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.

Three-dimensional cooperative guidance laws against stationary and maneuvering targets

This paper presents the cooperative strategies for salvo attack of multiple missiles based on the classical proportional navigation（PN） algorithm.The three-dimensional（3-D） guidance laws are developed in a quite simple formulation that consists of a PN component for target capture and a coordination component for simultaneous arrival.The centralized algorithms come into effect when the global information of time-to-go estimation is obtained, whereas the decentralized algorithms have better performance when each missile can only collect information from neighbors.Numerical simulations demonstrate that the proposed coordination algorithms are feasible to perform the cooperative engagement of multiple missiles against both stationary and maneuvering targets.The effectiveness of the 3-D guidance laws is also discussed.

A High-Order Numerical Method to Study Three-Dimensional Hydrodynamics in a Natural River

A high-order numerical method for three-dimensional hydrodynamics is p-resented.The present method applies high-order compact schemes in space and a Runge-Kutta scheme in time to solve the Reynolds-averaged Navier-Stokes equations with the k-ǫturbulence model in an orthogonal curvilinear coordinate system.In ad-dition,a two-dimensional equation is derived from the depth-averaged momentum equations to predict the water level.The proposed method isfirst validated by its application to simulateflow in a 180◦curved laboratoryflume.It is found that the simulated results agree with measurements and are better than those from SIMPLEC algorithm.Then the method is applied to study three-dimensional hydrodynamics in a natural river,and the simulated results are in accordance with measurements.

Synthesis, crystal structure and magnetic property of a three-dimensional cagelike polymer [Co(4,4'-bpy)(NCS)_2(py)_2]_n

A new organic-inorganic hetero-coordination polymer with three different kinds of ligands [Co(4,4'-bpy)(NCS)2(py)2]n is synthesized in the extremely mild condition. The X-ray diffraction reveals that the title polymer has a highly tactic three-dimensional cagelike supramolecular structure. Although the coordination bond makes it a one-dimension chain, the hydrogen bond plays an important role in the formation of 3-D supramolecular frameworks. The determination of magnetic properties has been carried out, and shows that it behaves weak antiferromagnetic property with J(4,4' -bpy) = -3.8 cm-1.

Fast registration of multisource three-dimensional city models in GeoGlobe

We address the registration problem of multisource three-dimensional(3D)human-made buildings with remote sensing images and the earth’s surface in the context of virtual globes.Challenges include fast transformation of 3D coordinates with different reference systems as well as the efficient use of original model information for rigorous and accurate model registration.This paper introduces a novel fast and scalable registration approach that can establish correspondences between heterogeneous external 3D city models and images/terrain surfaces of virtual globes in an efficient and accurate manner.The approach utilizes the projected 3D feature information of 3D city models to develop robust coordinate transformation and reliable model registration methods.The proposed approach builds a solid foundation for the fusion of multisource geospatial data in a united virtual globe reference framework.We report experimental results of online registration tasks for up to over 13K buildings in an integrated 3D virtual globe platform,namely,GeoGlobe.

A new three-dimensional terrain-following tidal model of free-surface flows

A three-dimensional hydrodynamic model is presented which combines a terrain-following vertical coordinate with a horizontally orthogonal curvilinear coordinate system to fit the complex bottom topography and coastlines near estuaries, continental shelves, and harbors. To solve the governing equations more efficiently, we improve the alternating direction implicit method, which is extensively used in the numerical modeling of horizontal two-dimensional shallow water equations, and extend it to a three-dimensional tidal model with relatively little computational effort. Through several test cases and realistic applications, as presented in the paper, it can be demonstrated that the model is capable of simulating the periodic to-and-fro currents, wind-driven flow, Ekman spirals, and tidal currents in the near-shore region.

Quadratic Programming-based Approach for Autonomous Vehicle Path Planning in Space

Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one,and also can not solve the inherent constraints arising from the robot body and the exterior environment.To address these difficulties,this research aims to provide a feasible trajectory based on quadratic programming（QP） for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles.First,the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target,as well as the angle between the velocity and the position in the relative velocity coordinates（RVCs）.The optimization is in quadratic polynomial form according to QP formulation.Then,the avoidance task is modeled with linear constraints in RVCs.Some other constraints,such as kinematics,dynamics,and sensor range,are included.Last,simulations with typical multiple obstacles are carried out,including in static and dynamic environments and one of human-in-the-loop.The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances.Therefore,the QP model proposed in this paper not only adapts to dynamic environment with uncertainty,but also can satisfy all kinds of constraints,and it provides an efficient approach to solve the problems of path planning in three-dimensional space.

Radial magnetic field in magnetic confinement device

The intrinsic radial magnetic field（B r） in a tokamak is explored by the solution of the Grad–Shafranov equation in axisymmetric configurations through an expansion of the four terms of the magnetic surfaces. It can be inferred from the simulation results that at the core of the device, the tokamak should possess a three-dimensional magnetic field configuration, which could be reduced to a two-dimensional one when the radial position is greater than 0.6a. The radial magnetic field and the amzimuthal magnetic field have the same order of magnitude at the core of the device. These results can offer a reference for the analysis of the plasma instability, the property of the core plasma, and the magnetic field measurement.

APPLICATION OF BODY－FITTED CURVILINEAR COORDINATE TRANSFORMATION IN 3－D SEEPAGE FLOW COMPUTATION

In this paper, a three-dimensional seepage flow problem was solved by use of boundary-fitted curvilinear coordinates transformation technique. The application of the presented method in a practical project was briefly described.