Biogenic silica in surface sediments of the northeastern and southern South China Sea

本研究测定了南海东北部和南部海域表层沉积物的生物硅含量(SIO2%),其含量范围分别为1.08%—3.01%和0.79%—9.06%,平均值分别为1.76%和4.22%。研究结果表明,南海表层沉积物中的生物硅含量与站位水深呈正相关关系;南海东北部的表层沉积物中的生物硅含量与其中的矿物含量、铁离子浓度、间隙水中的营养盐浓度不存在明显的相关性;南海南部海域表层沉积物中的生物硅含量与烧失量、有机碳含量、碳酸盐含量呈正相关关系,与粘土矿物含量相关性不明显。Biogenic silica(BSi) contents in surface sediments from the northeastern South China Sea(NSCS) and southern South China Sea(SSCS) were measured.The BSi contents(SiO2%)were in the range of 1.08%–3.01% and 0.79%–9.06%,with the means of 1.76% and 4.22% for the NSCS and SSCS,respectively.The results showed that the BSi contents in surface sediments have positive correlation with water depth of the sampling locations.The BSi contents in the NSCS had no evident correlation with minerals,ferrum ion concentrations in surface sediments or nutrients in the pore waters of sediments.The BSi contents in the SSCS had positive correlations with organic material and carbonate contents but not with clay material contents.国家基础研究发展计划项目(2005CB422305

纪念五四宪法颁布暨全国人民代表大会成立五十周年理论研讨会纪要

今年 9月是五四宪法颁布、全国人民代表大会成立五十周年。五四宪法是新中国的第一部宪法 ,为我国的社会主义民主法制奠定了基础 ,具有划时代的意义。坚持和完善人民代表大会制度 ,是新的历史条件下推进政治体制改革和社会主义政治文明建设的重要内容。基于“以学术表达纪念、以纪念促进学术”的目的 ,中国社会科学院法学研究所于 2 0 0 4年 9月 5日举办了“纪念五四宪法颁布暨全国人民代表大会成立五十周年理论研讨会”。来自全国各地的 70余位代表莅临会议 ,研讨了诸多热点和前沿问题

ST段抬高型急性心肌梗死院前溶栓治疗中国专家共识

急性心肌梗死仍然严重威胁我国人民健康,在我国广大城乡地区,形势更为严峻[1,2]。及时救治急性心肌梗死患者,降低死亡率和保护心脏功能刻不容缓。鉴于我国的实际情况,院前溶栓治疗在大城市以外的城乡地区具有重要意义。为此,中国医师协会胸痛专业委员会及中国医学救援协会心血管急救分会专门组织有关专家制订了本共识,旨在帮助院前医疗急救人员对急性心肌梗死患者选择最佳

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

The distributions of radionuclides in a sediment core and sedimentary rate in the intertidal zone of Xinghuawan Bay

利用2007年8月31日采集于福建兴化湾西岸的潮间带沉积物岩心样品,用γ谱方法测量了其放射性核素含量,对岩心中核素的分布及其成因进行了讨论,估算了研究区沉积物的沉积速率,探讨了沉积物的物源,结果表明:(1)238u2、28TH2、28rA2、26rA2、10Pb1、37CS和40k的含量分别为35.0--60.6、52.6--69.3、49.0--66.5、22.7--36.2、26.3--84.8、0.5--1.3和775--831 bQ/kg;(2)用238u2、26rA1、37CS和40k作为示踪剂进行物源分析发现,兴化湾潮间带沉积物主要源于邻近的福州和莆田地区的土壤,所占比率分别为54%和46%;(3)用210PbEX和137CS方法估算得兴化湾西岸潮间带沉积物的平均沉积速率分别为0.38 CM/A和0.36 CM/A。岩心中210PbEX分布表明,自20世纪末,研究区潮间带沉积速率加快。One sediment core was collected from intertidal zone located west coast of Xinghuawan Bay,Fujian,China.The radionuclide contents in the cores were measured by γ spectrometry and the vertical distributions of the nuclides were discussed.The sources of sediment were evaluated using 238U,226Ra,137Cs and 40K as tracers.The sedimentary rate was estimated by 210Pbex and 137Cs methods.The detectable nuclides in this core are 238U,228Th,228Ra,226Ra,210Pb,137Cs and 40K.The contents of these nuclides are 35.0--60.6,52.6--69.3,49.0--66.5,22.7--36.2,26.3--84.8,0.5--1.3 and 775--831 Bq/kg,and with the averages of 45.4,61.2,61.2,31.4,45.6,0.9 and 804 Bq/kg respectively.The 238U activities in the 0--40 cm zone were comparable within the measuring error and high 238U contents were found in the depth of 50～60 cm and below which 238U activities fluctuate with no trend.With the similar trend,from surface to 22 cm depth the activities of 228Th and 228Ra are lower and increase slowly with increasing depth,and they are consistent within the error.Throughout the entire core length the 228Ra and 228Th is decay equilibrium.226Ra activities increase with increasing depth from surface to 22 cm depth,and the contents comparable from 22 cm to 72 cm,occurring fluctuation deeper than 72 cm.The 210Pb activities decrease exponentially both from surface to 12 cm and in the zone of 16～40 cm,but below the depth of 40 cm 210Pb is decay equilibrium with 26Ra.The distribution has a maximum activity at the depth of 16 cm,above which the 137Cs contents are consistent within measuring error but below which decrease with depth.40K is uniform distribution through entire length of the core.The sedimentation sources of Xinghuawan Bay are mainly from the surface soil of Fuzhou and Putian Prefectures surrounding it.Using 238U,226Ra,137Cs and 40K as tracer,by the content data of these four nuclides in the sediments measured in this study and in the land soil reported by literature,we calculated the contributions of the soils of Fuzhou and Putian Prefecture are 54% and 46% respectively.That means that natural radionuclides can be used as tracers to analyse material source of sediment.Sedimentation rate based on 210Pbex and 137Cs was estimated,that was 0.38 cm/a and 0.36 cm/a.From the 210Pbex distribution,we can deduce the sedimentation rate had changed at about 2000.The sedimentation rate was 0.27cm/a before 2000 and 1.07cm/a after that time,which was considered as abundant terrigenous material supplied by human activities after 2000.国家自然科学基金资助项目(40306018

利用能源植物治理土壤重金属污染

随着工农业的发展,土壤重金属污染日益加剧,严重威胁着粮食生产和人类健康。植物修复因其成本低、环境友好以及可大规模原位修复等优点备受关注,成为近年来迅速发展的重金属污染土壤治理技术。在介绍国内外植物修复技术发展与应用现状的基础上,提倡大力发展能源植物修复重金属污染土地,并结合湖南重金属污染田间试验结果,重点对甜高粱(Sorghum bicolor(Linn.)Moench)用于重金属污染土壤修复的优势、可行性及提高修复效率的措施进行了深入分析与探讨。利用甜高粱治理土壤重金属污染,能将土壤修复与生物能源生产有机结合,使重金属从粮食链转入能源链,同时兼顾了生态和经济效益,具有广阔的应用前景

The determination of iodine in the sediment cores from the intertidal zone of the Xinhua Bay,the Jiulong Estuary and the Dongshan Bay

用碱熔法处理样品,水沥取,用分光光度法测量了采集自福建省兴化湾、九龙江河口和东山湾3个海湾潮间带沉积物岩心的碘分布。兴化湾、九龙江河口和东山湾3岩心中的碘含量分别为2.5~43.7,17.3~39.6和11.3~29.1Mg/kg。3个沉积物岩心中的碘含量稍高于福建省的土壤的碘含量,与我国海域的沉积物碘含量在同一水平,但明显低于文献报道的开阔海域沉积物的碘含量。兴化湾和东山湾沉积物中的碘与有机碳含量有较好的相关性;在九龙江河口采集的岩心中的碘与有机物碳含量的相关性较差。推测海洋源的沉积物碘与有机碳含量相关性较好,而陆源沉积物的碘与有机碳含量相关性较差。Three sediment cores are collected from the intertidal zone of the Xinhua Bay,the Jiulong Estuary and the Dongshan Bay of Fujian Province,southeastern China.The iodine contents in the sediment samples sliced by the three cores are measured by a spectrophotometric method after alkali fusion and leached with water.The results show that the iodine contents are between 2.5and 43.7mg/kg in the core from the Xinhua Bay,and 17.3and 39.6mg/kg in that from the Jiulong Estuary and 11.3and 29.1mg/kg in that from the Dongshan Bay respectively.The iodine contents in sediment samples of this study are higher than that of China's soils and at same level with those of China's Seas sediment.The iodine contents are well correlated with the organic carbon content in the sediments from the Xinhua Bay and the Dongshan Bay,respectively,where matter may mainly from the ocean.The correlation between iodine and organic carbon content is not well close in the sediments from the Jiulong Estuary,where the material is mainly terrigenous.It is shown that the correlation between iodine and organic carbon contents in the sediments from the ocean is well,but not close in that terrigenous fraction.国家自然科学基金资助项目“应用129I的海洋铁锰结壳年代学”(41073044