Geothermal and other effects on amino acid racemization in selected Deep-Sea Drilling Project cores

Kinetic parameters for the epimerization of isoleucine in multispecific foraminiferal asemblages were used to establish the effects of burial depth and the geothermal gradient on the extent of reaction. It was observed that with a little as thirty meters of burial in a normal thermal regime there were differences between the extent of epimerization measured and that which would have been predicted for thermal equilibrium with bottom water temperatures. As would be expected, these differences are greatest when the heat flow (the geothermal gradient) and/or the sedimentation rates are highest. These effects were observed in most of the DSDP samples studied, and have been used to estimate the average heat flux since the time of sample deposition. Occasional anomalous effects were observed which could not be related to past or present heat flux. These were determined to be due to such geologic occurrences as slumping and reworking or to recent sample contamination. Other problems emerged related to bottom water temperatures including changes over geologic time which are unknown and could not be deduced. Thus, the presence of epimerization anomalies in DSDP cores as noted above limits the effectiveness of amino acid geochronology in such cores, unless these anomalies can be recognized as ab initio.     

GIS支持的澜沧江下游区泥石流爆发危险性评价

澜疮江下游区是我国泥石流灾害相对频发的地区之一，在分析泥石流形成发育影响因素的基础上，指出澜沧江下游区泥石流的爆发主要受沟道坡度，植被覆盖度／土地利用和降水等环境因素影响，据此，构建了泥石流爆发危险性评价数据库，知识库和危险性评价数字环境模型，在ARC／INFO，GIS的支持下，提取了坡度，植被盖度和降雨量等主要泥石流危险性评价指标。依据知识库对各类因子进行了分级和赋权，对澜沧江下游区泥石流爆发危险性进行了区划。     

新疆耕地资源卫星遥感调查数据分析研究

依据卫星遥感调查结果。分析新疆耕地资源类型（包括现耕地和后备宜耕地类型）的数量、质量、分布组合特点以及中低产田产生的原因及其后备宜耕荒地的限制因素，提出新疆耕地资源合理开发利用与中低产田治理的总体构思与设想。     

海洋微藻多糖提取纯化条件的研究

研究了提取介质、超声条件和洗脱条件对海洋微藻多糖提取纯化效果的影响。实验结果表明不同pH的提取介质可以提取得到不同种类的多糖，超声条件以300W、20min最佳，用葡聚糖凝胶Sephadex-G200柱(长50cm，直径2cm)纯化粗多糖，当加样量为4ml，用0．2mol／L NaCl溶液洗脱效果最好。     

Influence of food quality on egg production and viability of the marine planktonic copepod Acartia omorii

Egg production, egg viability and fecal pellet production were determined for individual Acartia omorii, which were fed diets of two species of diatoms (Skeletonema costatum and Phaeodactylum tricornutum) and three species of dinoflagellates (Scrippsiella trochoidea, Heterocapsa triquetra and Cochlodinium polykrikoides). Diets were analyzed for fatty acid content as an indicator of food quality. Depending on the diet, egg production of A. omorii varied over time, diminishing with some diets (S. trochoidea, C. polykrikoides, P. tricornutum). This rate of reduction was much more rapid for a diet of C. polykrikoides, which caused egg production to decrease to ca. 2.4 eggs f⁻¹ d⁻¹ in only four days. As for all diets, egg viability was high at the beginning but with the C. polykrikoides and P. tricornutum diets, it rapidly decreased with time. Fecal pellet production also varied with time, depending on the diet. Egg production rate was closely correlated with fecal pellet production. There was no direct relationship between egg viability and egg production rate, but both egg production and viability were affected by the nutritional quality of food. Egg viability was also highly dependent on the composition of fatty acids in the eggs. Egg viability showed positive correlation with the ratio of ω3:ω6 groups among egg fatty acids, and negative correlation with the ratio of 20:5 (n−3) : 22:6 (n−3). While comparing several diets, egg production rate was higher on diets (H. triquetra and S. trochoidea) containing ample amounts of essential fatty acids such as 18:4 (n−3) and 22:6 (n−3). The results suggest that fertility of A. omorii was dependent upon the quality of the food, and dinoflagellate diets, with the exception of C. polykrikoides, were preferable to diatom diets.     

Indicatrices of Scattering of Light and the Composition of Suspension in the Black Sea

We analyze the data of measurements of the indicatrices of scattering of light in the Black Sea in winter 1991 and summer 1998, present their principal characteristics, and discuss their correlations and spatial variability. The data on scattering of light are used to determine the number and weight concentrations of various fractions of particles suspended in water. The characteristics of scattering of light and the composition of suspension in the Black Sea are compared with the data obtained in 1973 and with the data accumulated in the Aegean and Ionian Seas and in the Indian Ocean.__________Translated from Morskoi Gidrofizicheskii Zhurnal, No. 1, pp. 63–76, January–February, 2005.     

广西北海湾COD与水文生物要素及不同形态氮磷的关系

本文探讨了北海深COD值的分布特征及其与水文，生物要素及不同形态氮，磷含量的关系，结果表明；河流输入对本湾COD值的影响突出表现在春、夏季、冬季最小，秋季则以沿岸排废，排污影响为主，水文要素对COD值的分布起主导控制作用，生物化学作用仅占次要地位；春、夏、冬三个季度月COD值与氮含量的相关性较为显著，秋季则与磷含量的相关性较为显著。     

郯庐活断层与1668年郯城8.5级地震灾害

郯庐断裂带的地震活动主要集中于中部的下辽河－莱州湾段和潍坊－嘉山段，各段在活断层和地震活动方面存在不同的表现。１６６８年地震发生于潍坊－嘉山段的中部，是全新世断层活动的结果。该地震产生了性重的人口损失和建筑物破坏，其地震灾害具有典型性。未来应注意渤海地区地震的群集型活动以及安丘地区和新沂－泗洪地区的强震活动。还应注意在新的经济条件下新的地震灾害内容和新的灾害类型。     

Two geomagnetic excursions during the Brunhes chron recorded in Chinese loess-palaeosol sediments

Detailed palaeomagnetic integrated with rock magnetic studies have been carried out on a loess-palaeosol sequence in Baoji, Shaanxi province, southern Chinese Loess Plateau. For most samples stepwise thermal demagnetization revealed two well-defined magnetization components. A low-temperature component (LTC), which was isolated between 100 and 200 °C, is consistent with the present geomagnetic field direction. A high-temperature component (HTC), which was isolated between 250 and 620–680 °C, shows normal, reversed or transitional polarities. Our new magnetostatigraphy revealed two distinct geomagnetic excursions recorded in loess unit of L5 and palaeosol unit of S7, respectively, and the Matuyama-Brunhes (M-B) polarity boundary in loess unit of L8. Rock magnetic experiments demonstrated that the specimens from the excursion zones have the same magnetic properties as those from the Brunhes normal or Matuyama reversed polarity zones. Measurements of anisotropy of magnetic susceptibility (AMS) showed that the sediments have primary sedimentary fabrics. Based on the palaeoclimatological and magnetostratigraphic age models, the middle Brunhes excursion in loess L5 is dated at 413–433 ka, and the early Brunhes excursion is estimated to occur 23–33 ka after the M-B reversal. Comparing with previously reported geomagnetic excursions in the Brunhes chron, the middle Brunhes excursion (L5) is likely global. For the early Brunhes excursion (S7), we need further studies to examine its global occurrence.     

大兴安岭富林-兴隆沟一带金及多金属成矿条件分析

研究区位于额尔古纳地块的额木尔山中间隆起带东部边缘塔河过渡带内，砂金资源极为丰富，成矿条件十分优越，具有良好的找矿远景.通过对区内地层、岩浆岩、构造、地球物理、地球化学、遥感等综合信息进行分析，初步总结了区内成矿规律，指出找矿的有利部位，并对区内找矿关键作了简单探讨，为区内下步找矿工作取得突破性进展提供了一定的思路.