用光谱技术精神病划的制图综合

本文中，采用滤波技术和有条件的最佳拟合调整来介绍线划制图综合的过程，首先将原始线划的一系列坐标变换成它们的斜率值，再通过会立叶变换计算出斜率的光谱，使用数字指数滤波和逆付立叶变换得到滤波后的斜率。然后再将滤波后的斜率变换成派生的光滑线划，该线划就是对原始线划进行最佳拟合。这个最佳拟合处理确保原始线划与派生线划之间的相似 ；采用滤波是根据原始地图和派生地图的比例尺自动选择的。     

ILWIS软件核心的最新发展

文章阐述了导致ILWIS当前版本发展方法论上的一些重要的考虑。主要设计变动在于处理多种地理参照领域的方式和系统的属性数据库，该数据库用了本机构研制的软件。文章还提出了如何使将来的ILWIS版本具备全面综合的地学数据库环境的新设计思想的见解。     

多层次模糊模型综合评判城市环境质量

城市环境质量综合评价中,影响环境的因素很多。这众多的因素在不同的层次中对城市环境起综合的影响作用,它们往往带有“模糊性”。采用一般数学方法难于揭示其客观的结论,更难于在不同城市或区域之间进行有效的比较。本文采用模糊数学对其诸因素进行多层次综合评判,用其各个等段上的隶属度反映城市环境质量的综合定性结论,并与等级模糊映射值的转置矩阵进行运算,得出各个城市或城区环境质量综合评价值,用综合评价值相比较有效地反映出各城市环境质量优劣水平。     

模糊集合论用于制图综合中地图物体选取结构模型的研究

地图物体选取的定额模型和结构模型对机助制图综合和地图数据库专家系统中是缺一不可的。结构模型是在选取定额数量的控制下,解决具体选取那些物体,而研究某物体的选取须考虑的因素甚多,並且其间关系是隐会的,普遍存在模糊性。因而采用传统的二值逻辑来处理会既麻烦又损失较多的制图信息。本文以河流选取为例,用模糊集合理论对其建立结构模型进行初步探讨,并用简单样图说明方法和步骤。     

Compound-specific isotopic analyses: a novel tool for reconstruction of ancient biogeochemical processes

Patterns of isotopic fractionation in biogeochemical processes are reviewed and it is suggested that isotopic fractionations will be small when substrates are large. If so, isotopic compositions of biomarkers will reflect those of their biosynthetic precursors. This prediction is tested by consideration of results of analyses of geoporphyrins and geolipids from the Greenhorn Formation (Cretaceous, Western Interior Seaway of North America) and the Messel Shale (Eocene, lacustrine, southern Germany). It is shown (i) that isotopic compositions of porphyrins that are related to a common source, but which have been altered structurally, cluster tightly and (ii) that isotopic differences between geolipids and porphyrins related to a common source are equal to those observed in modern biosynthetic products. Both of these observations are consistent with preservation of biologically controlled isotopic compositions during diagenesis. Isotopic compositions of individual compounds can thus be interpreted in terms of biogeochemical processes in ancient depositional environments. In the Cretaceous samples, isotopic compositions of n-alkanes are covariant with those of total organic carbon, while delta values for pristane and phytane are covariant with those of porphyrins. In this unit representing an open marine environment, the preserved acyclic polyisoprenoids apparently derive mainly from primary material, while the extractable, n-alkanes derive mainly from lower levels of the food chain. In the Messel Shale, isotopic compositions of individual biomarkers range from -20.9 to -73.4% vs PDB. Isotopic compositions of specific compounds can be interpreted in terms of origin from methylotrophic, chemautotrophic, and chemolithotrophic microorganisms as well as from primary producers that lived in the water column and sediments of this ancient lake.     

Return of the coral reef hypothesis: basin to shelf partitioning of CaCO3 and its effect on atmospheric CO2

Differences in the rate of coral reef carbonate deposition from the Pleistocene to the Holocene may account for the Quaternary variation of atmospheric CO2. Volumes of carbonate associated with Holocene reefs require an average deposition rate of 2.0 x 10(13) mol/yr for the past 5 ka. In light of combined riverine, midocean ridge, and ground-water fluxes of calcium to the oceans of 2.3 x 10(13) mol/yr, the current flux of calcium carbonate to pelagic sediments must be far below the Pleistocene average of 1.2 x 10(13) mol/yr. We suggest that sea-level change shifts the locus of carbonate deposition from the deep sea to the shelves as the normal glacial-interglacial pattern of deposition for Quaternary global carbonates. To assess the impact of these changes on atmospheric CO2, a simple numerical simulation of the global carbon cycle was developed. Atmospheric CO2 as well as calcite saturation depth and sediment responses to these carbonate deposition changes are examined. Atmospheric CO2 changes close to those observed in the Vostok ice core, approximately 80 ppm CO2, for the Quaternary are observed as well as the approximate depth changes in percent carbonate of sediments measured in the Pacific Ocean over the same time interval.     

Porphyrin and chlorin distributions in a Late Pliocene lacustrine sediment

The tetrapyrroles in a highly immature Late Pliocene lacustrine sediment (Willershausen, Germany) show a simple distribution of both chlorin and porphyrin components as the free bases. The major components are C32 desoxophylloerythroaetioporphyrin (DPEP), a C33 bicycloalkano porphyrin, the chlorin analogue of the latter, and desoxophylloerythrin and its chlorin counterpart. The structure of the novel bicycloalkano chlorin was determined using a combination of two-dimensional phase-sensitive COSY NMR and nOe studies. Measurements of delta 13C and other data indicate that DPEP and the bicycloalkano porphyrin were derived from the chlorophyll(s) of photosynthetic organisms utilising a common source of CO2, probably diatoms. The occurrence of DPEP and other minor alkyl porphyrins indicates that the chlorophyll defunctionalisation pathway leading to these components can occur at low temperature and was probably biologically mediated, as was the condensation leading to the fused ring components.     

木兰湖度假区环境规划与管理研究

木兰湖度假区环境规划与管理研究徐肇忠，陈亮，邹榕（武汉测绘科技大学城市建设学院）木兰湖位于武汉市黄破县东北，原系一处天然山拗。５０年代后筑坝蓄水，逐渐形成湖泊，现在它已成为武汉市最大的水源地，蓄水量占了整个黄破县水库总蓄水量的５０％。木兰湖水域开阔，...