BeAl_2O_4:Cr^(3+)的能谱及R_1和R_2线压力移位的理论计算

采用强场方案和三角基,通过对角化三角畸变立方场的d^3电子组态完全能量矩阵,拟合得到BeAl_2O_4:Cr^(3+)的能谱和波函数.利用获得的波函数,计算出了基态g因子和R_1、R_2线能谱压致移位值,计算值和实验结果相符合.各参数对能级压力移位率的影响也被定量计算,揭示了R_1和R_2线压力移位的物理起源.

红宝石R＇、B线及U、Y带压力移位的理论计算

基于电子径向波函数在加压下扩展的概念，把Ｂ、Ｃ、Ｄｑ、ξ等参量表示成线性压缩ｋ＼的函数，并进一步考虑三角场作用，理论计算了红宝石Ｒ＇、Ｂ线及Ｕ、Ｙ带的光谱压力移位，结果与实验数据符合很好。

MgO：V^（2＋）R线的压力移位值的拟合计算

在已有工作基础上，计入自旋—轨道相互作用，定量拟合计算了ＭｇＯ：Ｖ￣（２＋）的压力移位，得到了一套较为可靠的高压参数，理论计算结果与实验符合很好。

三角场对红宝石光谱压力移位的影响

本文从电子径向波函数在加压下扩展的概念出发，进下考虑三角场效应，将Ｂ、Ｃ、Ｄｑ、ζ、δ等参量表示为线性压缩比ｘ的函数，我们对红宝石的光谱移位进行了理论计算。所得结果与实验符合很好。本文研究表明：三角场效应在谱线的压力移位中起着重要的作用。

CALCULATION METHOD FOR EARTH PRESSURE CONSIDERING DISPLACEMENT

The calculation of earth pressure is a difficult problem in the pit foundation design. Aiming at the problem, the earth pressure calculation formulas considering the displacement are proposed. A method for determining the limit displacement is given and it is convenient for use. The result indicates that the earth pressure calculated by the formulas is between the earth pressure at rest and the Rankine earth pressure, the formulas can reflect the change rules of active and passive earth pressures along with the displacement. Moreover, the calculation result using the formulas is approximate to the monitoring result. It confirms the validity of the formula deduction and the rationality of the calculation results. As for the passive earth pressure, the calculation method is theoretically feasible.

A general method to calculate passive earth pressure on rigid retaining wall for all displacement modes

A general analytical method to calculate the passive rigid retaining wall pressure was deduced considering all displacement modes. First, the general displacement mode function was setup, then the hypotheses were made that the lateral passive pressure is linear to the corresponding horizontal displacement and the soil behind retaining wall is composed of a set of springs and ideal rigid plasticity body, the general analytical method was proposed to calculate the passive rigid retaining wall pressure based on Coulomb theory. The analytical results show that the resultant forces of the passive earth pressure are equal to those of Coulomb＇s theory, but the distribution of the passive pressure and the position of the resultant force depend on the passive displacement mode parameter, and the former is a parabolic function of the soil depth. The analytical results are also in good agreement with the experimental ones.

激光工作物质

TN244 96042275红宝石R’B线及U、Y带压力移位的理论计算=Theoretical calculations of pressure-inducedshifts of the R’ and B lines and the U and Y broad bands of the spectral for ruby[刊,中]/黄小益(郴州师范高等专科学校物理系.湖南,郴州(423000))∥发光学报.—1995,16(3).—228—231基于电子径向波函数在加压下扩展的概念。

CO2 Pressure Shift and Broadening of Water Lines Near 790 nm

Carbon dioxide pressure-broadened ro-vibrational transitions belonging to thev^2＋3v^3 band of H2160 have been measured with a sensitive cavity ring-down spectrometer. Water vapor of relatively low pressures （〈0.5 Torr） was used to limit the self-collisions among water molecules. After the calibration using the precise atomic transitions of Rb and a thermo- stabilized Fabry-Perot interferometer, 10^-5 cm^-1 frequency accuracy has been achieved. Line parameters are derived from least-squares fitting of the spectra using the ＂soft＂ collision model. The retrieved line parameters can be applied in the study of water absorption in the CO2-rich atmospheres of planets like Venus and Mars.

Numerical Simulation of Coal Floor Fault Activation Influenced by Mining

By means of the numerical simulation software ANSYS, the activation regularity of coal floor faults caused by mining is simulated. The results indicate that the variation in horizontal, vertical and shear stresses, as well as the horizontal and vertical displacements in the upper and the lower fault blocks at the workface are almost identical. Influ- enced by mining of the floor rock, there are stress releasing and stress rising areas at the upper part and at the footwall of the fault. The distribution of stress is influenced by the fault so that the stress isolines are staggered by the fault face and the stress is focused on the rock seam around the two ends of the fault. But the influence in fault activation on the upper or the lower fault blocks of the workface is markedly different. When the workface is on the footwall of the fault, there is a horizontal tension stress area on the upper part of the fault; when the workface is on the upper part of the fault, it has a horizontal compressive stress area on the lower fault block. When the workface is at the lower fault block, the maximum vertical displacement is 5 times larger then when the workface is on the upper fault block, which greatly in- creases the chance of a fatal inrush of water from the coal floor.

Response models of weakly consolidated soft rock roadway under different interior pressures considering dilatancy effect

Surrounding rocks of weakly consolidated soft rock roadway show obvious strain softening and dilatancy effects after excavation. A damage coefficient concerning modulus attenuation was defined. Response models of stress and displacement of surrounding rock of soft rock roadway and analytical expressions to calculate plastic zones under different interior pressures and non-uniform original rock stresses were derived based on damage theories and a triple linear elastic-plastic strain softening model. Influence laws of dilatancy gradient on damage development, distributions of stresses and displacement in plastic region were analyzed. Interior pressure conditions to develop plastic region under different origin rock stresses were established and their influences on plastic region distribution were also discussed. The results show that the order of maximum principle stress is exchanged between ~0 and trr with the increase of interior pressure P0, which causes distributions of plastic zone and stress shift. Dilatancy effect which has great influences on the damage propagation and displacements in plastic region has little effect on the size of plastic region and stress responses. The conclusions provide a theoretical basis for a reasonable evaluation of stability and effective supporting of weakly consolidated soft rock roadway.

Study on increasing calculation precision and convergence speed of streamline strip element method

The calculation precision and convergence speed of streamline strip element method are increased by (using) the method whose initial value of the exit lateral displacement is determined with strip element variation method, and the accurate tension lateral distribution model is adopted based on the original third power spline function streamline strip element method. The basic theory of the strip element method is developed. The calculated results by the improved streamline strip element method and the original streamline strip element method are compared with the measured results, showing that the calculated results of the improved method are in good agreement with the measured results.

Characterization of Hydraulic Fracture with Inflated Dislocation Moving Within a Semi-infinite Medium

Hydraulic fracturing is accompanied by a change in pore fluid pressure. As a result,this may be conveniently represented as inflated dislocation moving within a semi-infinite medium. Theory is developed to describe the pore pressures that build up around an inflated volumetric dislocation migrating within a saturated porous-elastic semi-infinite medium as analog to hydraulic fracturing emplacement. The solution is capable of evaluating the system behavior of both constant fluid pressure and zero flux surface conditions through application of a superposition. Characterization of horizontal moving dislocation processes is conducted as an application of these techniques. Where the mechanical and hydraulic parameters are defined,a priori,type curve matching of responses may be used to evaluate emplacement location uniquely. Pore pressure response elicited at a dilation,subject to pressure control is of interest in representing hydraulic fracturing where leak-off is an important component. The effect of hydraulic fracturing on fracture fluid pressure is evaluated in a poroelastic hydraulic fracture model utilizing dislocation theory. A minimum set of dimensionless parameters are defined that describe the system. Pore fluid pressures recorded during hydraulic fracturing of a well in the San Joaquin Valley of Central California is examined using the proposed model. The estimated geometry of the hydraulic fracture is matched with reasonable fidelity with the measured data.

Characteristics of deformation and stress distribution of small coa pillars under leading abutment pressure

Based on the engineering project on a small coal pillar of 12,521 working face roadway in Xieqiao Coalmine, data regarding surface displacements of the coal pillar, deep displacements and mining stress have been collected and analyzed. The results show that macroscopic transverse fractures of the inner coal pillar are developed within 2–4 m of the roadway surface, which is located outside the coal pillar anchorage zone. There is a displacement of 530 mm at the monitoring point in the 6 m deep zone of the pillar. Transfer of the fracture zone is found in a small coal pillar and the fractures within 3–4 m of the coal-rock zone from the roadway surface undergo propagation and closure of cracks which means this fracture zone is transferred from 3–4 m outside the roadway to only 2–3 m from the roadway surface. In the monitoring zone, vertical and horizontal stresses increase with a feature that shows that acceleration in the deep zone of the pillar is greater than that in the shallow zone. Furthermore, the acceleration of vertical stress is also greater than that of horizontal stress with a peak value in the 4 m zone.The research findings provide a reference for the regulation of a reasonable width of coal pillar in coalmines and optimal control design of surrounding rock.

Beam-track interaction of high-speed railway bridge with ballast track

Based on the construction bridge of Xiamen-Shenzhen high-speed railway(9-32 m simply-supported beam + 6×32 m continuous beam),the pier-beam-track finite element model,where the continuous beam of the ballast track and simply-supported beam are combined with each other,was established.The laws of the track stress,the pier longitudinal stress and the beam-track relative displacement were analyzed.The results show that reducing the longitudinal resistance can effectively reduce the track stress and the pier stress of the continuous beam,and increase the beam-track relative displacement.Increasing the rigid pier stiffness of continuous beam can reduce the track braking stress,increase the pier longitudinal stress and reduce the beam-track relative displacement,Increasing the rigid pier stiffness of simply-supported beam can reduce the track braking stress,the rigid pier longitudinal stress and the beam-track relative displacement.

Macro mechanical parameters’ size effect of surrounding rock of Shuibuya project’s underground power station

Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, classification of engineering rock mass, nu- merical simulation test and back analysis based on surrounding rock’s displacement monitoring results of Shuibuya Project’s underground power station, rock mass deforma- tion module’s size effect of surrounding rock of Shuibuya Project’s undegroud power sta- tion was studied. It’s shown that rock mass deformation module’s scale effect of sur- rounding rock of Shuibuya Project’s undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock’s. Finally the relation between rock mass deformation modules and the scale of research was established.

Distribution characteristics and impact on pump＇s efficiency of hydro-mechanical losses of axial piston pump over wide operating ranges

A novel performance model of losses of pump was presented,which allows an explicit insight into the losses of various friction pairs of pump.The aim is to clarify that to what extent the hydro-mechanical losses affect efficiency,and to further gain an insight into the variation and distribution characteristics of hydro-mechanical losses over wide operating ranges.A good agreement is found in the comparisons between simulation and experimental results.At rated speed,the hydro-mechanical losses take a proportion ranging from 87% to 89% and from 68% to 97%,respectively,of the total power losses of pump working under 5 MPa pressure conditions,and 13% of full displacement conditions.Furthermore,within the variation of speed ranging from 48% to 100% of rated speed,and pressure ranging from 14% to 100% of rated pressure,the main sources of hydro-mechanical losses change to slipper swash plate pair and valve plate cylinder pair at low displacement conditions,from the piston cylinder pair and slipper swash plate pair at full displacement conditions.Besides,the hydro-mechanical losses in ball guide retainer pair are found to be almost independent of pressure.The derived conclusions clarify the main orientations of efforts to improve the efficiency performance of pump,and the proposed model can service for the design of pump with higher efficiency performance.

3D-FSM·DDM IBEM numerical system of multi-medium

Based on the idea of the developed 3D-FSM.DDM boundary element method, the field with muti-medium was formulized firstly, then connected at the interface of two fields according to the continuous conditions of stress and displacement, after that, a boundary value problem with unified model was formed and solved. Ultimately, an applied numerical simulation system was developed. It was compared with the model having analytical solution for verifying the applicability and the calculating precision.

Xinhe Mine water inrush risk assessment based on quantification theoretical models

Taking the Xinhe mine's structure, mine pressure, structural fissure, fault andfault displacement, the distance between fault and water inrush point, thickness of block,water pressure those geological factors which influenced the water inrush as the independentvariable, based on these data of water inrush point and water uninrush point, usingthe method of quantification theory(Ⅰ,Ⅱ), it would quantitatively disposes the qualitativevariable, applied to calculation to evaluate the risk of Xinhe's water inrush.

DEM simulation of confining pressure effects on crack opening displacement in hydraulic fracturing

Hydraulic fracture is one of the key methods in well stimulation to increase production of oil and gas.Crack Opening Displacement(COD) is of great importance in this method since it is in direct relation with permeability and production rate.In this paper COD is measured by a distinct element model which has been validated by an exact solution.A comprehensive study has been performed on confining pressure effect on COD which is neglected in the analytical solution.Numerical results showed that confining pressure considerably affects COD.A multi-parameter regression(considering effect of confining pressure,rock mass properties and fluid pressure) was performed on numerical results which resulted in an equation.The proposed equation considers the effect of confining pressure and its results are in good agreement with numerical results.

Axial compression physical testing of traditional and bird beak SHS T-joints

The static tests of nine traditional and bird beak square hollow structure(SHS) T-joints with different β values and connection types under axial compression at brace end were carried out. Experimental test schemes, failure modes of specimens, jack load-vertical displacement curves, jack load-deformation of chord and strain intensity distribution curves of joints were presented. The effects of β and connection types on axial compression property of joints were studied. The results show that the ultimate axial compression capacity of common bird beak SHS T-joints and diamond bird beak SHS T-joints is larger than that of traditional SHS T-joint specimens with big values of β. The ultimate axial compression capacity of diamond bird beak SHS T-joints is larger than that of common bird beak SHS T-joints. As β increases, the increase of the ultimate axial compression capacity of diamond bird beak SHS T-joints over that of common bird beak joints grows. The ultimate axial compression capacity and the initial axial stiffness of all kinds of joints increase as β increases, and the initial axial stiffness of the diamond bird beak SHS T-joints is the largest. The ductilities of common bird beak and diamond bird beak SHS T-joints increase as β increases, but the ductility of the traditional SHS T-joints decreases as β increases.