A new drain spacing formula

Abstract

A drain spacing formula is derived considering the variation in radial flux and the area above the drain level in the radial flow zone. The extent of the radial flow zone is ascertained by applying a mass balance and differentiability criterion of the water surface profile at the interface of radial and Dupuit-Forchheimer flow zones. The radial flow zone extends from the centre of the tile drain a distance of 2/π times the depth to impervious layer below the drain. For a normal ratio of recharge rate to hydraulic conductivity (R/K ≤ 0.0025), the water surface profile in the radial flow zone computed using Hooghoudt's formula is very different from the profile obtained by the new drain spacing formula; however, Hooghoudt's formula computes the maximum water table height which marginally differs from that found by the present method. For a ratio of high recharge rate to hydraulic conductivity (R/K = 0.1) and close drain spacing (L/D = 2), the difference in the maximum heights is 21%. Hooghoudt's formula overestimates the maximum water table position for L/D < 40. Unlike Hooghoudt's equivalent depth, the equivalent depth obtained using the present method is a function of the ratio of recharge rate to hydraulic conductivity.     

关于测绘生产单位人才流失的思考

本文简述了测绘生产单位人才流失的现状 ,分析了其原因 ,提出了吸引人才留住人才所必须作好的几方面工作 ,供人才管理部门参考。     

Study on wall-type gravel drains as liquefaction countermeasure for underground structures

One of the most dramatic causes of damage to engineering structures during earthquakes has been the development of soil liquefaction beneath and around the structures. In order to dissipate the excess pore water pressures near structures, gravel drains are usually employed. In this study, the use of recycled concrete crushed stones as gravel drain materials is addressed. In order to investigate the performance of wall-type gravel drains, two series of shaking table tests were performed. The test results showed that gravel drains, when appropriate grain size distribution is considered, effectively dissipate the excess pore water pressure underneath the structure, and consequently reduce the magnitude of uplift. To supplement the laboratory tests, finite element analyses were also performed. For specified structure, ground and earthquake conditions, there is a critical width of gravel drain at which no uplift of structure will occur. The results of the model tests and the finite element analyses were then employed in developing design charts for determining the critical width of gravel drain to prevent buoyant rise of structure when the surrounding soil mass liquefies.     

脑靶向紫杉醇纳米胶束的体外实验研究

目的 研发一种新型的治疗乳腺癌脑转移的靶向递药系统。方法 采用薄膜水化法制备载药胶束,将胶束与脑靶向分子Angiopep-2连接,使胶束具有脑靶向功能。结果 体外细胞实验证实该胶束具有良好的靶向性。结论 连接有靶向分子Angiopep-2的纳米胶束具有良好的脑靶向功能。     

Rapid hydrocarbon accumulation mechanism in later period in Kelasu thrust belt in Kuqa depression

Based on the analyses of generation, migration and accumulation of oil and gas in the structures of Kela 1, Kela 2 and Kela 3 in Kasangtuokai anticlinal belt using a series of geological and geochemical evidence, this paper proposes that the rapid rate of hydrocarbon generation, main drain path for over-pressured fluid flow and converging conduit system are indispensable conditions for the rapid, late-stage gas accumulation in the Kelasu thrust belt in the Kuqa depression. Due to structural over-lapping and the resultant rapid burial, the maturity of the source rocks had been increased rapidly from 1.3 to 2.5% Ro within 2.3 Ma, with an average rate of Ro increase up to 0.539% Ro/Ma. The rapid matura-tion of the source rocks had provided sufficient gases for late-stage gas accumulation. The kelasu structural belt has a variety of faults, but only the fault that related with fault propagation fold and cut through the gypsiferous mudstone cap could act as the main path for overpressured fluid release and then for fast gas accumulation in low fluid potential area. All the evidence from surface structure map, seismic profile explanation, authigenic kaolinite and reservoir property demonstrates that the main drain path related with faults for overpressured fluid and the converging conduit system are the key point for the formation of the giant Kela 2 gas field. By contrast, the Kela 1 and Kela 3 structures lo-cated on both sides of Kela 2 structure, are not favourable for gas accumulation due to lacking con-verging conduit system.     

试论喀斯特水动力剖面模式

喀斯特水动力剖面模式反映种类水文地质结构中喀斯特水的埋藏，迳流条件和水动力特点，由于地下水排泄形式不同，处于不同地貌部位的各类水文地质结构发育了复杂多样的水动力剖面模式，以５种排泄形式为基础，重点研讨了中国境内一些典型水动力剖面模式。     

一种竖井地基竖墙化等效计算方法

考虑井阻作用,推导了等应变条件下竖墙地基水平向固结解析解,并与等应变条件下的竖井地基径向固结解析解进行比较,得到竖墙地基平面应变问题和竖井地基轴对称问题之间的等效方法。该方法转换公式简单,且能保证两种情形下同一深度处平均孔压在任一时刻相等,确保了转换为平面应变有限元分析的准确性。     

Advances of geo-spatial intelligence at LIESMARS

ABSTRACT

The enhancement of computing power, the maturity of learning algorithms, and the richness of application scenarios make Artificial Intelligence (AI) solution increasingly attractive when solving Geo-spatial Information Science (GSIS) problems. These include image matching, image target detection, change detection, image retrieval, and for generating data models of various types. This paper discusses the connection and synthesis between AI and GSIS in block adjustment, image search and discovery in big databases, automatic change detection, and detection of abnormalities, demonstrating that AI can integrate GSIS. Moreover, the concept of Earth Observation Brain and Smart Geo-spatial Service (SGSS) is introduced in the end, and it is expected to promote the development of GSIS into broadening applications.     

脑转移瘤MR特征及Gd—DTPA在诊断中的作用

本文的目的在于评价Ｇｄ－ＤＴＰＡ增强扫描在正确诊断不同表现的转移瘤中的作用。材料与方法;应用平扫及Ｇｄ－ＤＴＰＡ增强扫描,对５５例脑转移瘤进行回顾性分析,并根据其既往病史、临床表现、病变部位及ＭＲ特征进行分类。结果：第一、二组有或无既往肿瘤病史,ＭＲ见脑内多发占位,病变典型,易于诊断;第三组无既往肿瘤病史,ＭＲ见脑内单发病变,无典型特征,诊断较困难。结论：多数脑转移瘤具有典型特征,易于诊断：少数非     

“无症状”性脑瘤的CT诊断及临床分析

目的是报道１１例“无症状”性脑瘤临床诊治经验及体会,方法,总结,分析１１例病人临床病例资料。结果 １１例病人均经ＣＴ或ＭＲＩ检查得以诊断,其中１０例行肿瘤切除术,１例予以保守随访。结论：ＣＴ和ＭＲＩ等先进医疗诊断设备的应用,是临床“无症状”脑瘤得以诊断的主要手段;“无症状”只是特定时期内相对而言其原因与高岭,颅内代偿空间扩大,脑瘤位于功能“哑区”以及多有良性表现有关;