Physical and chemical environments of abnormal vitrinite reflectance evolution in the sedimentary basins

Based on the tested data of pressure and vitrinite reflectance of some wells in sedimentary basins, abnormal high pressure is regarded as not the only factor to retard the increase of vitrinite reflectance (R _o). Apart from the types of the organic matter, the physical environment (temperature and pressure) and chemical environment (fluid composition and inorganic elements) will result in the abnormal vitrinite reflectance values in the sedimentary basins. This paper tested trace elements and vitrinite reflectance data from the the abnormal high pressure and normal pressure strata profiles, respectively, and found that the acidic and lower salinity starta are favorable for the increase of R _o. By discussing the corresponding relationship between the contents of some trace elements in the mudstone and the vitrinite reflectance values, the typical trace elements were found to suppress and/or catalyze the vitrinite reflectance of organic matter, while the elements of Ca, Mn, Sr, B, Ba and P may result in the retardation of R _o. However, elements of Fe, Co, Zn, Ni and Rb may catalyze the organic matter maturation. This study is conductive to the organic maturation correction, oil and gas assessment and thermal history reconstruction by the paleothermometry. Translated from Acta Geologica Sinica, 2006, 80(11): 1760–1769 [译自: 地质学报]     

2001—2020年黄河流域植被覆盖变化及其影响因素

基于MODIS NDVI植被指数和气象数据集,以集合经验模态分解、趋势分析和随机森林回归分析等方法,分析了黄河流域2001—2020年植被覆盖时空变化特征,并对其气候驱动因素进行探讨。结果表明：（1）2001—2020年黄河流域植被覆盖整体呈显著增长趋势,增速为0.055/10a （P<0.05）,2010年之前增速（0.067/10a）大于2010年之后的增速（0.051/10a）。（2）空间上,植被覆盖增加区域主要分布在陕北黄土高原、甘肃省东南部、内蒙古自治区河套平原等退耕还林还草生态工程实施区域,而植被覆盖显著下降区域则集中在关中平原城市群、黄淮海平原以及青藏高原等区域。（3）气温、降水和CO₂浓度等对黄河流域植被生长起到正向促进作用,且绝对敏感性依次降低,而大气饱和水汽压差、太阳辐射等对植被生长起到抑制作用。本研究结果可为评估气候变化对黄河流域植被覆盖变化的综合影响提供参考依据。     

基于改进FCLS算法的南极海冰密集度估算及算法比较

海冰具有良好的热力隔绝效应,它通过影响海洋和大气的热交换进而影响全球的气候变化。海冰密集度是极区海冰研究的重要指标之一。为实现高空间分辨率多类型海冰密集度的估算,本文将亮温极化梯度率和光谱梯度率引入基于全约束最小二乘法(fully constrained least squares,FCLS)的海冰密集度估算方法,并利用南极海冰过程与气候计划(Antarctic Sea Ice Processes and Climate,ASPe Ct)对改进方法的精度进行验证,然后与NASA Team2(NT2)算法和ARTIST Sea Ice(ASI)算法获得的海冰密集度结果进行了对比分析。结果显示,3种算法中本研究的方法精度最高,全年均方差13.8%,偏差为-0.7%;改进的方法对多年冰的估算精度优于一年冰。     

基于SPI指数的甘肃省河东地区干旱时空特征分析

干旱是西北地区主要的自然灾害之一。本文以甘肃省河东地区作为研究区,基于该地区38个气象站1971-2010年逐月降水数据计算标准化降水指数（SPI指数）,分析了不同时间尺度SPI指数的时间序列特征,探讨了SPI₃和SPI₁₂的年代际距平和倾向率的时空变化,以及特旱、重旱和中旱的发生频次。结果表明：（1）随着时间尺度的增加,SPI指数随机性在减弱,持续性在加强。干旱出现较多的时期为1991-2005年,出现较少的时期为1974-1982年。（2）20世纪80年代以前河东地区偏湿,90年代以后河东地区有偏干的趋势。河东地区行政区划分为7个部分,70-80年代,除甘南地区外,其余地区的SPI₃倾向率均显著增加;80-90年代,河东地区SPI₃倾向率持续减少,减少最明显的为定西地区;90年代到21世纪初,河东地区SPI₃倾向率又有增加趋势。对于SPI₁₂来说,自20世纪70年代到2010年,除甘南、陇南和天水地区的SPI₁₂倾向率为先减少后增加以外,其余地区均呈现先增加,后减小,然后再增加的趋势。（3）3个月时间尺度干旱的分布范围广,发生频次高,主要发生于河东地区的北部。12个月时间尺度的特旱主要发生在河东地区的北部,重旱和中旱主要发生在河东地区的东部。     

白令海北部陆坡晚第四纪的古海洋与古气候学记录

白令海北部陆坡B2 9柱状样中放射虫Cycladophoradavisiana含量曲线和深海SPECMAP氧同位素记录的对比 ,为该柱状样建立了晚第四纪约 1 0万年以来的地层年代框架。该柱状样中微体化石、碳屑颗粒、筏冰碎屑 (石英和岩屑颗粒 )的定量分析结果表明 ,作为表层生产力指标的粗组份自氧同位素 5 .3期以来呈阶梯状增加 ,反映表层生产力阶段式的增长 ;碳屑颗粒丰度自氧同位素 5 .3期至末次冰消期的增加说明白令海末次冰消期以前气候较全新世干冷 ,天然火灾发生的概率较全新世大大增加 ;冰期和早、中全新世较高的筏冰碎屑反映了冰期和早、中全新世白令海陆架海冰的扩大以及气候转暖所导致的海冰消融的过程 ,揭示了白令海对过去全球气候变化的响应。     

Measurement of stress effects (scope for growth) and contaminant levels in mussels (Mytilus edulis) collected from the Irish Sea

The objective of this research was to quantify the impact of pollution along the coastlines of the Irish Sea. Pollution assessment was based on the combined measurement of scope for growth (SFG), and chemical contaminants in the tissues of mussels (Mytilus edulis) collected from 38 coastal sites around the Irish Sea during June-July in 1996 and 1997. On the UK mainland coast, the SFG showed a general trend with a significant decline in water quality in the Liverpool and Morecambe Bay region. High water quality was recorded along the west coast of Wales, as well as southwest England and northwest Scotland (clean reference sites outside the Irish Sea). Along the coast of Ireland there was a similar trend with reduced SFG within the Irish Sea region. SFG was generally low north of Duncannon and then improved north of Belfast. The poor water quality on both sides of the Irish Sea is consistent with the prevailing hydrodynamics and the spatial distribution of contaminants associated with urban/ industrial development. The decline in SFG of mussels on both sides of the Irish Sea was associated with a general increase in contaminant levels in the mussels. Certain contaminants, including PAHs, TBT, sigmaDDT, Dieldrin, gamma-HCH, PCBs, and a few of the metals (Cd, Se, Ag, Pb), showed elevated concentrations. Many of these contaminants were particularly elevated in the coastal margins of Liverpool Bay, Morecambe Bay and Dublin Bay. A quantitative toxicological interpretation (QTI) of the combined tissue residue chemistry and SFG measurements indicated that at the majority of coastal sites, c. 50 to > 80% of the observed decline in SFG was due to PAHs as a result of fossil fuel combustion and oil spills. TBT levels were highest at major ports and harbours, but these concentrations only made a minor contribution to the overall reduction in SFG. At no sites were individual metals accumulated to concentrations that could cause a significant effect on SFG. The study identified many sites where the observed reduction in SFG was far greater than predicted from the limited number of chemical contaminants analysed, thus indicating the presence of additional 'unknown toxicants'. Sewage (containing domestic, agricultural and industrial components) appears to be an important contributor to reduced SFG and linear alkylbenzenes (LABs) and As may provide suitable 'sewage markers'. There was a highly significant positive correlation between SFG and As (P < 0.001). This relationship may be due to reduced As uptake by algal food material and mussels at sites with elevated P04 concentrations (e.g. at sites with sewage inputs). Phosphate is a known competitive inhibitor of As accumulation, at least in algae. The results highlight that further research is required on 'sewage markers' in mussels. The SFG approach therefore provides a rapid, cost-effective and quantitative measure of pollution impact, as well as a means of identifying the causes through a QTI of tissue contaminants levels. It also serves to identify the presence of unidentified toxicants and areas that require further study.     

南海海洋地磁固定观测站建设初步研究

为填补我国海洋地磁固定观测的空白,支撑科学研究、防灾减灾、海洋资源开发,维护国家的海洋权益和履行我国在南海海域负有的国际责任,急需在南海建设岛礁和海底地磁固定观测站。通过初步分析国外海洋地磁观测站案例、南海岛礁基础设施现状以及海底观测网计划实施情况,认为南海海洋地磁固定观测站建设的条件已经成熟。文中给出了合理空间布局、分步实施、因地制宜及智能化观测的建议。     

北川羌族自治县国际旅游城镇建设研究

5.12汶川大地震后,北川县城易地重建,并将以建设国际旅游城镇为重要目标之一。分析了北川国际旅游城镇建设所面临的新的约束条件,从资源禀赋结构变化、地域文化重建、旅游产业先导、旅游环境安全等方面揭示其特殊性。从供需两个角度以大旅游产业的视角,构建并拓展了国际旅游城镇建设的一般要素模型。在此基础上,探讨了北川须重点发展的关键竞争力要素,提出四大精品国际旅游产品的开发思路,以及国际旅游城镇建设的必要支撑措施。     

中国对虾配合饵料中维生素C添加量的研究

于１９９１年７月２１日－８月１９日在河北省唐海县西林养殖场以养成期中国对虾为材料，在其配合饵料中添加维生素Ｃ进行中国对虾对维生素Ｃ需要量的试验。结果表明，当中国对虾体长为５．５－７．５ｃｍ时，若以本项研究采用的配合饵料的基本成分和配比为基础，配饵中维生素Ｃ的最佳变化添加量为０．０１８％－０．０３０％。研究发现，变动的维生素Ｃ适宜添加量对于中国对虾具有明显的促进生长，增强抗病力和抗低氧能力以及提高存     

庙岛群岛海域光棘球海胆生态的初步研究

庙岛群岛的光棘球海胆主要分布于北四岛（南、北隍城岛,大、小钦岛）,砣矶岛及大、小竹山岛等,而南五岛极少分布。砣矶岛的海胆多是２～３年生壳径４～６ｃｍ的个体,海胆性腺成熟期为７月中旬至８月中旬,性腺发育与水温、栖息场和饵料等有关。海胆体重随季节而变化,繁殖季节体重Ｗ（ｇ）与壳径Ｄ（ｃｍ）相关,Ｗ＝２．５８２Ｄ２．０３４（ｒ＝０．８７）,性腺重ＧＷ（ｇ）与壳径Ｄ（ｃｍ）关系为ＧＷ＝０．０４０３Ｄ３．０８２８（ｒ＝０．８２７３）,壳径Ｄ（ｃｍ）与壳高Ｈ（ｃｍ）呈线性关系Ｈ＝０．５２２５Ｄ＋０．０６６８（ｒ＝０．９０７８）。壳径生长随年龄而变慢,２．８ｃｍ的幼海胆年增长２．１ｃｍ;６．１ｃｍ的成海胆年增长０．４３ｃｍ。光棘球海胆嗜食海带和裙带菜,平均日摄食量６．０ｃｍ的海胆为２．６ｇ,４．０ｃｍ的为１．３４ｇ,３．１ｃｍ的为１．３ｇ,幼海胆摄食率较高的原因是因其生长发育快速,活动强度和代谢水平高。