断弯褶皱正演模拟

断弯褶皱是挤压盆地中一种重要的构造模型。其形成原理是：在断层开始滑动时，形成一个膝折带，随着断层的继续滑动，膝折带不断增宽，形成单处台阶断弯褶皱。在平行条件的假设下，可以推导出单步台阶断弯褶皱各要素间的数学关系式，由此写出流程图，编写断弯褶皱的正演模拟的计算机程序，进而对挤压盆地的单步台阶断弯褶皱进行计算机模拟，并给出其模拟结果图。     

下辽河盆地外围深部构造特征及中生代构造演化模式

深部地质、地球物理综合研究表明，辽西地区与松辽南部地区在莫霍面起伏、岩石厚度、壳内高导层深度和分布形式及岩石圈的有效弹性厚度方面的均存在着重大差异，这种差异是造成辽西盆岭区与松辽盆地中生代构造发展差异的主要原因。软流圈顶面积深度和岩石圈有效弹性厚度决定了盆地类型，壳内高导分布控制着盆地构造样式。辽西盆地岭区和松辽盆地南部构造的差异可以解释二者之间构造演化的不同。     

Experimental transplanting of Posidonia australis seagrass in Port Hacking, Australia, to assess the feasibility of restoration

Over the last 50 years, about one-third of the original area of the seagrass Posidonia australis has been lost from Port Hacking (Australia) due to anthropogenic impacts. To assess the feasibility of restoring these seagrass meadows, healthy Posidonia rhizomes were transplanted to four impact sites and one control site. Survival rates of transplanted shoots were monitored in situ bi-monthly for 16 months and, at the end of the experiment, rhizome growth, shoot growth, shoot production and growth architecture were assessed by harvesting tagged rhizomes. A total of 575 shoots were transplanted and after 16 months 650 shoots were present. Four of the five sites exhibited high survival rates in the short term (less than six months) but only two impact sites, Burraneer Bay (BB) and Red Jacks Point (RJP), and the control site (CS) survived to the end of the experiment. Total number of shoots increased by 61% at CS, tripled at BB, but decreased by 22% at RJP. Rhizome growth varied significantly between site, from 22.3 +/- 1.4 cm yr(-1) at BB to 9.1 +/- 1.0 cm yr(-1) at RJP. Shoot growth did not vary significantly between sites and was approximately 2-3 cm yr(-1). At BB and CS there was substantial colonisation of the surrounding substrate, with new rhizomes, orthotropic shoots and transitional shoots produced. Survival of transplants appeared to depend on whether the factors that had caused the original loss of Posidonia were still operating in the study area.     

Using high hydraulic conductivity nodes to simulate seepage lakes

In a typical ground water flow model, lakes are represented by specified head nodes requiring that lake levels be known a priori. To remove this limitation, previous researchers assigned high hydraulic conductivity (K) values to nodes that represent a lake, under the assumption that the simulated head at the nodes in the high-K zone accurately reflects lake level. The solution should also produce a constant water level across the lake. We developed a model of a simple hypothetical ground water/lake system to test whether solutions using high-K lake nodes are sensitive to the value of K selected to represent the lake. Results show that the larger the contrast between the K of the aquifer and the K of the lake nodes, the smaller the error tolerance required for the solution to converge. For our test problem, a contrast of three orders of magnitude produced a head difference across the lake of 0.005 m under a regional gradient of the order of 10(-3) m/m, while a contrast of four orders of magnitude produced a head difference of 0.001 m. The high-K method was then used to simulate lake levels in Pretty Lake, Wisconsin. Results for both the hypothetical system and the application to Pretty Lake compared favorably with results using a lake package developed for MODFLOW (Merritt and Konikow 2000). While our results demonstrate that the high-K method accurately simulates lake levels, this method has more cumbersome postprocessing and longer run times than the same problem simulated using the lake package.     

Prediction of diffusion coefficients in porous media using tortuosity factors based on interfacial areas

Determination of aqueous phase diffusion coefficients of solutes through porous media is essential for understanding and modeling contaminant transport. Prediction of diffusion coefficients in both saturated and unsaturated zones requires knowledge of tortuosity and constrictivity factors. No methods are available for the direct measurement of these factors, which are empirical in their definition. In this paper, a new definition for the tortuosity factor is proposed, as the real to ideal interfacial area ratio. We define the tortuosity factor for saturated porous media (tau5) as the ratio S/S(o) (specific surface of real porous medium to that of an idealized capillary bundle). For unsaturated media, tortuosity factor (tau(a)) is defined as a(aw)/a(aw),o (ratio of the specific air-water interfacial area of real and the corresponding idealized porous medium). This tortuosity factor is suitably measured using sorptive tracers (e.g., nitrogen adsorption method) for saturated media and interfacial tracers for unsaturated media. A model based on this new definition of tortuosity factors, termed the interfacial area ratio (IAR) model, is presented for the prediction of diffusion coefficients as a function of the degree of water saturation. Diffusion coefficients and diffusive resistances measured in a number of saturated and unsaturated granular porous media, for solutes in dilute aqueous solutions, agree well with the predictions of the IAR model. A comparison of permeability of saturated sands estimated based on tau(s) and the same based on the Kozeny-Carman equation confirm the usefulness of the tau(s) parameter as a measure of tortuosity.     

基于录井标记语言的录井资料管理信息系统

针对常规数据库系统无法层级式存储录井资料、异构数据源间无法共享录井资料的问题,基于XML标准提出了录井标记语言-LogML(Logging Markup Language),并应用LogML作为录井资料的存储载体,自主开发出具有层级式存储、管理、共享、分析和可视化功能的录井资料管理信息系统一XMISL(XML Management Information System for Logging Data),为录井资料的网络化管理提供了切实可行的方案.     

Incorporation of inorganic carbon by Antarctic cryptoendolithic fungi

Fungi isolated from the cryptoendolithic community of the Ross Desert are capable of fixing inorganic carbon. Results suggest that lichen mycobionts and parasymbionts are adapted to different water regimes in the cryptoendolithic environment.