TRANSPORT OF THE SUSPENDED SEDIMENT IN THE CHANGJIANG ESTUARY

The Changjiang River is characterized by the enormous volume of runoff and the great amount of sediment load with remarkable seasonal variation. The annual runoff sometimes is respondent to the amount of sediment load, and sometimes not. The amount of monthly sediment load after the month of the maximum runoff is larger than those before the month. The sediment concentration and net quantity of sediment transport in the vicinity of the river mouth varies greatly in time between the ebb and flood, spring and neap, and dry seasons and flood seasons. The three bifurcations also have differences in concentration and net quantity in space. Even in the same bifurcation they have differences in and out of the sand bar. At present, the North Channel is the main passage for water and sediment load emptying into the sea from the Changjiang River. More than 50 percent of the sediments from the river basin are deposited nearby the South Branch entrance and the main depositional area is situated in subaqueous delta off the South Channel. Between 122°30'E and 123°E is an important boundary for eastward sediment dispersion from which the suspended sediment are dispersed towards the east by south.     

Reliability of rayleigh wave dispersion curve obtained from f–k spectral analysis of microtremor array measurement

The paper utilizes previously developed microtremor simulation technique to evaluate the reliability of Rayleigh wave dispersion curve estimated by f–k spectral analysis of microtremor array measurement. The simulated microtremors are obtained for a fictitious (TEST) site. Attempt is also made to obtain the dispersion curve for two real sites (OHDATE and SKC) by inverse analysis of the microtremor array measurement using f–k spectra method. The estimated dispersion curve from simulated microtremors (TEST site) compares well with the theoretical dispersion curve, demonstrating the reliability of f–k spectra method and indicating that the estimated dispersion curve from microtremor measurements could be adequately used as the target for inverse analysis purposes. It is also demonstrated that the dispersion curve from microtremor measurements can be utilized to estimate the soil profile at OHDATE and SKC sites by inverse analysis. Results show that the theoretical dispersion curve of the fundamental mode of Rayleigh wave after the end of inverse analysis are in good agreement with the dispersion curve obtained by f–k spectral analysis of microtremor array measurement.     

北京城市规划区水源热泵系统应用适宜性分区

鉴于北京市水源热泵系统应用过程中存在地下水水资源因不能完全回灌造成浪费及运行效率未能充分发挥等问题,本文针对水源热泵系统运行过程中地下水的抽灌模式,根据北京规划市区的水文地质条件,对水源热泵系统应用的适宜性进行了分区,为水源热泵技术因地制宜、合理有序应用提供了科学的思路。     

洞庭湖泥沙淤积数值模拟模式

在确保沙量守恒的非恒定流、非均匀沙的二维水沙数学模型的基础上,通过洞庭湖水沙输运和河床变形计算实践,比较了两种冲泻质与床沙质的转化模式,提出了包括冲泻质在内的泥沙淤积模式和水沙动边界计算模式.从洞庭湖泥沙输运和河床变形计算的结果看,洞庭湖泥沙淤积数值模式具有较好的稳定性和较高的模拟精度,说明所建湖泊泥沙模型的良好性能和具有推广运用的前景.     

山东济阳坳陷二氧化碳气成藏模式分析

山东济阳坳陷CO2气藏类型众多,成藏模式存在多样性。根据CO2气藏组分含量和同位素的分析结果,发现济阳坳陷CO2气藏以幔源成因为主,岩浆气源体是最重要的CO2气源体,火山岩体、火山通道和岩浆气源体附近的断裂对CO2气的运移成藏起关键作用。通过卸压条件下CO2的运移、CO2在断裂(裂缝)中的运移、CO2在孔隙—裂缝双重介质中的运移、CO2在砂质沉积物中的运移等一系列实验模拟,研究岩浆释出CO2气的运移成藏过程。结合已知气藏的运移成藏地质过程,建立济阳坳陷CO2气藏的3种地质模式,即侵入体—断裂—储集层转折成藏模式、侵入体—储集层直接成藏模式和埋藏火山通道—储集层直接成藏模式,为济阳坳陷CO2气成藏研究及其综合勘探奠定基础。     

三江平原地下水资源合理开发利用模式探讨

本文按地下水系统及行政区划分析了三江平原各地区地下水资源的可开采资源量及地下水资源开采潜力,针对不同地区提出不同的地下水开采方案,做到科学有序、合理开采.     

实验室测绘教学仪器的管理

在分析了当前测绘仪器管理存在问题的基础上，从仪器在实验室的管理体制、模式方面做了有益探讨和分析，提出了测绘仪器实行动态管理和开放使用的模式。     

多次覆盖技术在探地雷达勘探中的应用

多次覆盖技术作为一种增强信号、压制干扰的方法,广泛用于地震勘探工作中,可以大大提高有用信号的信噪比。本文作者把多次覆盖技术引入探地雷达测量工作中,通过与剖面法作对比试验来论证多次覆盖技术在探地雷达勘探中应用的可行性及优缺点。作者根据试验资料总结探地雷达工作中雷达波传播规律、工作参数、资料处理方法,对丰富探地雷达勘探技术作了一次有益的尝试。     

Differences Between Mode I and Mode II Crack Propagation

Although mode I and mode II crack propagation show many similarities, in particular when analysed by linear elastic fracture mechanics, they differ significantly in the micro-structural behaviour. These differences, which are clearly noticeable in the fracture surface morphology, lead to fundamental differences in the macroscopic behaviour. Thus, mode II crack expansion under remote loading, appears to obey micro-structural scaling laws, implying that the dimensions of the process region stay essentially constant during crack expansion, rather than increasing with crack length. Therefore, expanding mode II cracks can almost reach the Rayleigh velocity, and actually also intersonic velocities. An expanding mode I crack, on the other hand, seems to obey continuum scaling laws, implying that the dimensions of the process region increase in proportion to crack length, leading to self-similar crack expansion at a velocity significantly below the Rayleigh speed and dependent on the remote load.