Effects of flooding on the amino acid and carbohydrate patterns of Phragmites australis     

Heike Koppitz   《Limnologica》2004,34(1-2):37

Changes in the contents and composition of dissolved amino acids and carbohydrates were monitored in different Phragmites australis stands in Germany. Four different reed clones planted in 1997 in a degraded fen area in NE-Germany were compared with respect to the seasonal development in the total amount of amino acids and sugars in the basal culm internodes. The individual Phragmites clones showed significant differences in the absolute content of both parameters indicating an influence of the genotype. Flooding affected the ratio of amino acids to carbohydrates within the reed clones. Plants grown in flooded parts of the fen area revealed a significantly higher total amino acid content together with a lower total content of carbohydrates.Furthermore, the effects of extreme flooding on the content and composition of amino acids and carbohydrates in the basal culm internodes of Phragmites australis were studied in nine reed stands with different degrees of damage on Lake Constance. Shoots from extremely damaged reed stands were characterised by a significant decrease in the total content of carbohydrates, an increase in the total content of amino acids and an increase in the share of γ-aminobutyric acid. These changes in the content and composition of carbohydrates and amino acids were discussed with respect to their value as stress indicators, such as for oxygen deprivation which causes a hypoxic metabolic state in Phragmites australis stands.  相似文献   

Errors Due to the Common Ray Approximations of the Coupling Ray Theory     

Klimeš  L.  Bulant  P. 《Studia Geophysica et Geodaetica》2004,48(1):117-142

The common ray approximation considerably simplifies the numerical algorithm of the coupling ray theory for S waves, but may introduce errors in travel times due to the perturbation from the common reference ray. These travel-time errors can deteriorate the coupling-ray-theory solution at high frequencies. It is thus of principal importance for numerical applications to estimate the errors due to the common ray approximation.We derive the equations for estimating the travel-time errors due to the isotropic and anisotropic common ray approximations of the coupling ray theory. These equations represent the main result of the paper. The derivation is based on the general equations for the second-order perturbations of travel time. The accuracy of the anisotropic common ray approximation can be studied along the isotropic common rays, without tracing the anisotropic common rays.The derived equations are numerically tested in three 1-D models of differing degree of anisotropy. The first-order and second-order perturbation expansions of travel time from the isotropic common rays to anisotropic-ray-theory rays are compared with the anisotropic-ray-theory travel times. The errors due to the isotropic common ray approximation and due to the anisotropic common ray approximation are estimated. In the numerical example, the errors of the anisotropic common ray approximation are considerably smaller than the errors of the isotropic common ray approximation.The effect of the isotropic common ray approximation on the coupling-ray-theory synthetic seismograms is demonstrated graphically. For comparison, the effects of the quasi-isotropic projection of the Green tensor, of the quasi-isotropic approximation of the Christoffel matrix, and of the quasi-isotropic perturbation of travel times on the coupling-ray-theory synthetic seismograms are also shown. The projection of the travel-time errors on the relative errors of the time-harmonic Green tensor is briefly presented.  相似文献   

坐标转换参数的求解方法及其应用     

陈贻胜 《上海国土资源》2006,(2):53-56

根据坐标转换参数的解算模型,介绍几种常见的坐标转换参数的求解方法及其参数个数与精度;探讨选择坐标转换参数的条件及转换参数的应用,从而阐明转换参数对GPS技术的推广和全球资料的统一的重要作用。  相似文献   

应用数字近景摄影测量提取岩体裂隙迹长信息方法研究   总被引：5，自引：0，他引：5  

王凤艳  陈剑平  庞贺民 《世界地质》2006,25(1):39-42

针对传统以皮尺为主要工具的岩体裂隙迹长测量方法精度及效率较低、尤其是遇有危险场地不能遥测等缺点,研究应用数字近景摄影测量的方法获取岩体裂隙迹长信息,以普通非量测数码相机为主要工具,以JX-4A数字摄影测量工作站为依托进行信息处理,可以快速获取隧道施工掌子面裂隙迹线图。经实验比较分析,数字近景摄影测量方法获取岩体裂隙信息在精度和效率方面都优于传统方法。  相似文献   

二维地震勘探变观量板图及其应用   总被引：1，自引：0，他引：1  

WANG Li-bin ZHANG Hai-ying REN Ri-chun LIU Hai-tao GAO Yuan Geophysical Prospecting Company of Coal Geology in Jilin Province  Changchun  China 《吉林大学学报(地球科学版)》2006,(Z2)

在以炸药为震源的二维地震勘探野外资料采集施工中,需要避开各种不能钻井放炮的障碍物,根据勘查区设计任务书的施工参数,可以画出变观量板图。变观量板图具有快速变观的作用,野外所遇到的不同距离的障碍物可以通过变观避开,给施工提供方便,变观量板图具有实际应用价值。  相似文献   

2维DLT变换用于建筑物变形监测的试验研究     

赵卿  尹晖 《测绘与空间地理信息》2006,29(6):17-19

直接线性变换(D irect LinearTransformation)解法是建立观测点像方空间坐标和同名点物方空间坐标之间直接线性关系的算法。本次试验通过使用普通数码相机,并应用2维直接线性变换进行了建筑物变形监测的试验研究,试验结果表明,使用普通数码相机代替常规测量方法能够满足变形监测三等精度要求。  相似文献   

太原市东山矿区岩溶地下水排供结合研究   总被引：1，自引：0，他引：1  

李振栓  段展青 《中国煤田地质》1997,9(3):40-43

太原市为华北地区严重缺水城市之一，而与此紧紧相连的太原市东山煤矿，丰富的岩溶地下水造成750下山煤层无法开采。为了解决东山煤矿12873万t煤炭资源带压开采问题及缓解太原市供水紧张的局面。笔者从分析东山岩溶水系统水文地质条件入手，对井田内水文地质条件进行了定量研究，认为将东山煤矿的疏干降压与太原市的供水结合起来其利大于弊。  相似文献   

GPS测量控制网公共点兼容性分析   总被引：1，自引：0，他引：1  

黄声享 《测绘信息与工程》1996,(2)

介绍了几种基本的ＧＰＳ网公共点兼容性分析方法。结合实例，应用平差成果和数理统计理论，就各种方法作了较为详细的分析和探讨。  相似文献   

Linearized inversion of 3-D multi-offset data: background reconstruction and AVO inversion     

L. T. Ikelle 《Geophysical Journal International》1995,123(2):507-528

  相似文献   

数据库应用系统通用模块的研究     

Gao Wenpei 《吉林大学学报(地球科学版)》1989,(3)

通过对各种数据库管理应用系统的研究,寻求其通用的部分,把它们研制成通用的管理模块,反过来用到各种管理系统中去。 这样避免了轶件开发过程中低水平的重复性劳动;为了提高软件的质量,提高开发某一应用系统的速度,研制出一套适合于各种各样用途的工具模块,当需开发一个新的管理系统时,用这些工具模块很快就可以编制出一个较大的程序;通用模块的开发是站在软件工程的高度,遵循结构程序设计原理,按照自顶向下,逐步求精的原则和方法进行研制的,便于移植和维护,使各种管理系统走向标准化。  相似文献