Use of high spectral resolution remote sensing to determine leaf palatability of eucalypt trees for folivorous marsupials

In this study we assess the feasibility of remotely measuring canopy biochemistry, and thus the potential for conducting large-scale mapping of habitat quality. A number of studies have found nutrient composition of eucalypt foliage to be a major determinant of the distribution of folivorous marsupials. More recently it has been demonstrated that a specific group of secondary plant chemicals, the diformylphloroglucinols (DFPs), are the most important feeding deterrents, and are thus vital determinants of habitat quality. We report on the use of laboratory spectroscopy to attempt to identify one such DFP, sideroxylonal-A, in the foliage of Eucalyptus melliodora, one of the few eucalypt species browsed by folivorous marsupials. Reflectance spectra were obtained for freeze-dried, ground leaves using near infrared spectroscopy (NIRS) and for both oven-dried and fresh whole leaves using a laboratory-based (FieldSpec) spectroradiometer. Modified partial least squares (MPLS) regression was used to develop calibration equations for sideroxylonal-A concentration based on the reflectance spectra transformed as both the first and second difference of absorbance (Log 1/R). The predictive ability of the calibration equations was assessed using the standard error of calibration statistic (SECV). Coefficients of determination (r²) were highest for the ground leaf spectra (0.98), followed by the fresh leaf and dry leaf spectra (0.94 and 0.87, respectively). When applied to independent validation sub-sets, sideroxylonal-A was most accurately predicted from the ground leaf spectra (r² = 0.94), followed by the dry leaf and fresh leaf spectra (0.72 and 0.53, respectively). Two spectral regions, centred on 674 nm and 1394 nm, were found to be highly correlated with sideroxylonal-A concentration for each of the three spectral data sets studied. Results from this study suggest that calibration equations derived from modified partial least squares regression may be used to predict sideroxylonal-A concentration, and hence leaf palatability, of Eucalyptus melliodora trees, thereby indicating that the remote estimation of habitat quality of eucalypt forests for marsupial folivores is feasible.     

海潮负荷对自由核章动参数拟合的影响

基于武汉基准台超导重力仪重力潮汐观测资料 ,利用根据不同海潮模型获得的负荷重力改正值对观测数据作海潮改正 ,拟合了地球自由核章动 ( FCN)共振参数。结果表明 FCN的本征周期为 435 .2恒星日 ,品质因子为 4730 ,复共振强度为 ( - 6.34× 1 0 - 4,- 0 .0 9× 1 0 - 4)°/h。不同的海潮模型对 FCN本征周期和共振强度实部计算结果的影响很小 ,差异分别不超过± 1 .6%和± 7.7% ,对品质因子 Q值和共振强度虚部拟合结果的影响非常显著。基于 Ori96全球海潮模型得到的重力改正值可以很好地解释武汉基准台周日重力潮汐观测残差。     

Long internal waves in shear flows: topographic resonance and wave-induced global instability

Issues pertaining to a mechanism whereby long internal waves in shallow seas may give rise to enhanced rates of resuspension of sedimentary material are addressed. The proposed mechanism is intimately related to the creation of conditions in the bottom boundary layer which are favorable for flow separation and spontaneous onset of global instability. It is shown that long waves generated by topographic resonance and propagating upstream against the oncoming current, especially a sheared current, have a strong tendency to release a coherent, pulsating dynamics in their footprint. The passage-through-resonance problem for a sheared, stratified flow is considered, conditions for topographic resonance in the flow model are defined, and preliminary results for the unsteady dynamics in the boundary layer under the footprint of a long wave packet are presented.     

二级结构地震反应的实验研究

本文针对结构顶部的附属结构在正弦激励和地震动作用下的反应，设计了多层结构模型并研究了附属结构的多种情况。实验结果表明，附属结构在地震作用下可对主体结构产生不同的影响，根据附属结构的参数的不同可能导致主体结构的反应增大或减小，因此得出结论：在结构设计时对主体结构和附属结构进行整体考虑，能使结构的地震反应控制在最佳的水平。     

1：2．5万沟系次生晕地球化学找矿方法探讨

从系统论的观点出发，将1：2．5万沟系次生晕地球化学找矿方法的室内布样，野外采样，室内异常圈定与评价和室外异常查证4个阶段看作一个有机的整体，在工作中，从布样阶段开始直至异常评价结束的每一个阶段都考虑后续的各个阶段可能会出现的问题，并采取相应应对措施，从布样到野外异常查证都注意地质信息和化探信息的相结合，从而总结出一套简便快捷，行之有效的野外工作方法，经过多年的实践和完善，该方法已在野外工作中发挥很好的效益。     

东营凹陷下第三系深部碎屑岩储层次生孔隙垂向分布及成因分析

东营凹陷下第三系埋深大于 30 0 0 m的深部碎屑岩储层普遍发育 2～ 4个次生孔隙带 ,Φ=10 %～ 30 % ,K=0 .1× 10 - 3μm2～ 30× 10 - 3μm2 ,为中孔低渗低孔低渗油气储层。综合有机质热演化过程、成岩作用和构造断裂等分析 ,认为东营凹陷埋深大于 30 0 0m碎屑岩地层中 ,第一、二个次生孔隙带埋深在 30 0 0 m～ 390 0 m之间 ,其形成主要与有机质成熟过程释放有机酸对长石等颗粒的溶解有密切关系 ,在深大断裂附近储层同时受到大气淡水的影响 ,而深陷带包裹于暗色泥岩中的浊积砂岩的次生孔隙发育情况还与泥质岩异常压力带有关 ;第三个次生孔隙带埋深一般为 390 0 m～ 430 0 m,主要成因于粘土矿物转化造成的还原环境 ,同时受到硫酸盐热化学氧化还原反应的影响。这三个次生孔隙发育带对储集油气有效。第四个孔隙发育带埋深在 470 0 m以下 ,主要是构造成因的微裂缝 ,较难成为有效的油气储层。     

pH值对长石溶解度及次生孔隙发育的影响

本文从长石溶解反应的机理及各离子形态在溶液中分布的热力学角度出发 ,论述了pH值对三个长石端员及高岭石在流体中溶解度的影响。在此基础上 ,进一步探讨了流体酸碱度对长石向高岭石转化和次生孔隙发育程度的制约 ,并提出了衡量次生孔隙发育程度的参数———转化系数D。     

柱层累托石材料对有机废水的处理及效果评价

就使用柱层累托石材料对有机废水处理的实验研究进行讨论。采用累托石材料，在用量为15kg/t时，加入用量为4kg/t的还原剂FE，废水中COD去除率达70%；如果再用累托石进行二次吸附，其COD去除率达92%；处理水COD值降为96mg/L，达到GB8978-1996一级排放标准，同时实验了累托石的再生利用效果。     

梅雨锋生次级环流对暴雨的作用

本文采用了MM4中尺度数值模式对1991年7月5日08时至6日20时发生在江淮流域的梅雨锋暴雨过程进行了模拟。在模拟较理想的基础上，利用模式输出的高分辨率的动力协调资料，就暴雨过程中锋生次级环流各强迫项对暴雨的作用进行了诊断研究。结果表明：锋生次级环流对暴雨形成具有重要的作用，但在暴雨过程不同时期各项的作用差异很大。