桐庐杂岩体中共存的两种碱性长石研究

桐庐同熔型火山－侵入杂岩中出现两种碱性长石，一种为无色透明，另一种为微红色，本文利用X射线衍射仪，电子探针，透射电镜对其结构态，成分及出溶微结构进行了对比研究。结果表明，两者成分差别不大，而结构差别较大，无色透明的为透长石，出溶叶片发育；微红色的为正长石或低透长石，出溶结构不发育。而且随着冷却速率的变慢，无色透明碱性长石的Al/Si有序度增大，微红色碱性长石的有序度降低，分析后认为这种共存现象是岩浆混和造成的，从而为桐庐杂岩体的岩浆混合成因提供了有力的证据。     

数字化气氡观测干扰因素的分析研究

在进行地下流体数字化气氡观测及将观测资料应用于震情分析的过程中 ,发现某些干扰因素对数字化气氡观测和水氡的影响不同。在目前所用观测仪器和方法的条件下 ,气温对气氡值的影响系数为 - 0 4 % /℃ ;气压对气氡测值的影响系数为 0 1% /hPa ;不同类型的气水分离装置对气氡观测的影响很显著 ;同一含水层的井 (泉 )出水量的短期变化可引起观测水井流量的变化 ,但对气氡测值影响不显著 ;气氡测值对逸出气流量的变化反映不明显 ;逸出气含有杂质及气路泄漏等均会引起测值的下降。结合仪器的工作原理 ,对干扰产生的机制以及排除的方法进行了讨论     

相山铀矿田横涧矿床的成因归属

横涧矿床位于相山火山-侵入杂岩体（相山铀矿田）的北部，是相山众多与花岗斑岩有关的铀矿床的典型代表，矿体主要产于横涧花岗斑岩体中，其外接触带粉砂岩、变质岩中也有矿体分布。矿体形态为脉状，是岩浆热液作用的产物，成矿前热液呈碱性，第一期成矿热液呈弱碱性，第二期成矿热液呈弱酸性，该花岗斑岩以往认为是潜火山岩，但潜火山岩本身概念太复杂，实际上不便运用，相山铀矿田边部的浅成一超浅成侵人体，与其说是潜花岗斑岩（潜英安斑岩）石油如说是花岗斑岩（英安斑岩）。横涧矿床是斑岩铀矿床。     

A Computational Model for Velocity Separation in Shallow Sea

Based on the hydrodynamical feature and the theoretical velocity profiles of tidal flow and vvind-induced flow in shal-low sea, a computational model is established for the first time, which can separate observed velocity into tidal velocity and wind-induced velocity by use of the least square method. With the model, not only the surface velocities of tidal flow and vvind-induced flow are obtained, but also the bed roughness height is determined and the wind velocity above the wa-ter surface is estimated. For verification of the model, the observed velocity in the Yellow River Estuary and the laborato-ry test is separated, then it is applied to the Yangtze River Estuary. All the results are satisfactory. The research results show that the model is simple in method, feasible in process and reasonable in result. The model is a valid approach to analysis and computation of field dala, and can be applied to separate the observed velocity in shallow sea; at the same time, reasonable boundary conditions of th     

An Experimental Study of Several Special Issues Regarding the Ice Force on Conical Structures

The effect of the cone spacing of a conieal structure on the ice force is studied by model experiments. The ice force reduction coefficient presented in this paper expresses the relationship between the ice force and the arrangement of cones. The experiments prove that the mode of the ice failure before the boundary of upward-downward bending cone (UDBC) is crushing. A conclusion can also be drawn from the experiments that the ice force on the boundary of UDBC is by far less than that on a vertical pile with the same diameter. Moreover, the ice force frequencies on upright and inve-rted cones are obtained under the field condition of the platform JZ20-2, respectively. The results show that the alterna-tion of the ice force on UDBC can hardly induce resonance of platform JZ20-2.     

The Structure of A Turbulent Jet in A Crossflow-Effect of Jet-Crossflow Velocity

A comprehensive numerical study on the three-dimensional structure of a turbulent jet in crossflow is performed. The jet-to-crossflow velocity ratio (R) varies in the range of 2 - 16; both vertical jets and inclined jets without excess streamwise momentum are considered. The numerical results of the Standard two-equation k-ε model show that the turbulent structure can be broadly categorised according to the jet-to-crossflow velocity ratio. For strong to moderate jet discharges, i.e. R> 4, the jet is characterized by a longitudinal transition through a bent-over phase during which the jet becomes almost parallel with the main freestream, to a sectional vortex-pair flow with double concentration maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless distance of around 20-60. The similarity coefficients are only weakly dependent on R. The cross-section scalar field is kidney-shaped and bifurcated, vvith distinct double concentr     

Breaking Criteria for Regular Waves on Gentle Slopes

Nelson pointed out that the wave breaking criterion(H/d)_b for gentle slopes(i<1/100),inwhich H is the wave height and d is the water depth at the breaking point,is smaller than that for beachslopes of i>1/100),i.e.,the value of(H/d)_b for gentle slopes may be smaller than 0.6.Goda indicatedthat the wave breaking criterion given by himself is a result based on theoretical study,so it should be alsocorrect and can be used for gentle beaches,i.e.,the value of(H/d)_b for gentle slopes may be still largerthan 0.7.By use of high order nonlinear wave theory,this problem is analyzed in this study and the reasonwhy there is a large difference between different studies is explained.Moreover,the bottom energy loss dur-ing wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed.     

Normalization of Hydrodynamic Coefficients in Morison Equation

-The hydrodynamic coefficients C_d and C_m are not only dependent on the size of slender cylin-der,its location in water,KC number and Re number,but also vary with environmental conditions,i.e.,in regular waves or in irregular waves,in pure waves or in wave-current coexisting field.In this paper,thenormalization of hydrodynamic coefficients for various environmental conditions is discussed.When aproper definition of KC number and proper characteristic values of irregular waves are used,a unified re-lationship between C_d,C_m and KC number for regular waves,irregular waves,pure waves and wave-cur-rent coexisting field can be obtained.     

Application of Line Boundary Technique to 2D Tidal Current Simulation

To deal with the problems concerning the shore boundary,moving boundary and engineeringboundary which are encountered frequently in 2D tidal current simulation by the finite difference method,theconcept of line boundary is introduced and studied here,and then the line boundary technique in common useis proposed in this paper.Analysis of some calculation cases shows that this technique is practical,effective,and simple in 2D tidal current simulation involving different boundaries.     

Theory and Practice of Soft Clay Engineering

-The shear strength and deformation properties of soft clay are discussed first. Then some methods for predicting the performance of soft clay foundation are proposed. Finally, case histories are presented to illustrate some discussed aspects of soft clay.