Covariance Patterns of Foraminiferal dgr18O: An Evaluation of Pliocene Ice Volume Changes Near 3.2 Million Years Ago

Oxygen isotope data for a Pliocene interval from 3.6 to 2.8 million years ago show a mean increase (0.5 per mil) of benthic delta(18)O at about 3.2 million years ago, whereas planktic delta(18)O does not increase. This lack of covariance indicates that the event at 3.2 million years did not result in a permanent increase in the ice budget of either the Northern or the Southern Hemisphere.     

The Origin of the Superstructure in Bi2Sr2CaCu2O8+dgr as Revealed by Scanning Tunneling Microscopy

Real-space images with atomic resolution of the BiO plane of Bi(2)Sr(2)CaCu(2)O(8+delta) were obtained with a scanning tunneling microscope. Single-crystal samples were cleaved and imaged under ultrahigh vacuum conditions at room temperature. The images clearly show the one-dimensional incommensurate superstructure along the b-axis that is common to this phase. High-resolution images show the position of the Bi atoms, revealing the structural nature of the superlattice. A missing row of Bi atoms occurs either every nine or ten atomic sites in both (110) directions, accounting for the measured incommensurate periodicity of the superstructure. A model is proposed that includes missing rows of atoms, as well as displacements of the atomic positions along both the a- and c-axis directions.     

The effect of algal symbionts on the accuracy of Sr/Ca paleotemperatures from coral

The strontium-to-calcium ratio (Sr/Ca) of reef coral skeleton is commonly used as a paleothermometer to estimate sea surface temperatures (SSTs) at crucial times in Earth's climate history. However, these estimates are disputed, because uptake of Sr into coral skeleton is thought to be affected by algal symbionts (zooxanthellae) living in the host tissue. Here, we show that significant distortion of the Sr/Ca temperature record in coral skeleton occurs in the presence of algal symbionts. Seasonally resolved Sr/Ca in coral without symbionts reflects local SSTs with a temperature sensitivity equivalent to that of laboratory aragonite precipitated at equilibrium and the nighttime skeletal deposits of symbiotic reef corals. However, up to 65% of the Sr/Ca variability in symbiotic skeleton is related to symbiont activity and does not reflect water temperature.     

The 18O/16O and 17O/16O ratios in atmospheric nitrous oxide: A mass-independent anomaly

Measurements of the oxygen isotope ratios (18O/16O and 17O/16O) in atmospheric nitrous oxide (N2O) from La Jolla, Pasadena, and the White Mountain Research Station (elevation, 3801 meters) in California and the White Sands Missile Range in New Mexico show that N2O has a mass-independent composition. These data suggest the presence of a previously undefined atmospheric process. The La Jolla samples can be explained by a mixing between an atmospherically derived source of mass-independent N2O and biologically derived mass-dependent N2O. Possible origins of the mass-independent anomaly in N2O are discussed.     

Water isotope ratios D/H, 18O/16O, 17O/16O in and out of clouds map dehydration pathways

Water isotope ratios have been measured by laser absorption spectroscopy in and out of cirrus clouds formed in situ and convectively generated in anvils over subtropical regions. Water vapor in the tropical and subtropical upper troposphere shows a wide range of isotopic depletion not observed previously. The range suggests that dehydration of upper tropospheric air occurs both by convective dehydration and by gradual dehydration mechanisms. Twenty-five percent of upper tropospheric water sampled is in ice particles whose isotopic signatures are used to identify those grown in situ from those lofted from below.     

Sr18菌代谢产物对线虫应激能力的影响

基于Sr18菌代谢产物在24 h内具有显著的杀线虫活性,为进一步探究其杀线虫机理和作用规律,测定其在16 h内对线虫应激能力的影响。结果表明,在4 h时处理组对外界条件刺激的敏感性明显提高,运动频率均高于对照组,表明4 h为Sr18菌代谢产物对线虫产生作用的转折点;8 h后处理组活跃程度明显减弱,对刺激的反应较对照组缓慢,随着刺激时间增加,处理组的活跃性有所增加但不显著,表明Sr18菌代谢产物已产生明显的药效作用,致使线虫对刺激反应迟钝。Sr18菌代谢产物对线虫应激能力的影响呈现"平稳-上升-下降"的规律,进一步探究Sr18菌代谢产物的作用机理为实践中的合理用药提供理论依据。     

基于计算机模拟对南海珊瑚礁养殖系统的研究

构建南海近海渔场混合养殖模型代替目前的单一养殖.利用层次结构模型、Agent模型和计算机MAR仿真技术,得出了南海珊瑚礁混合养殖系统中不同营养级的代表性物种最佳比例,在最优水质条件下种群的最佳数量.混合养殖系统中,绿藻、兔子鱼、蛤、虾、海胆、石斑鱼的最佳比例为的0.056,0.065,0.067,0.072,0.064,0.676.最优水质条件下,各种群的最佳数量为:石斑鱼种群密度为6.3×104个·hm-2,文蛤3.3×106个·hm-2,海胆3.75×106个·hm-2,虾2.25×107个·hm-2,兔子鱼9.0×106个·hm-2,海藻5.0×109个·m-3.     

On Pleistocene Surface Temperatures of the North Atlantic and Arctic Oceans

Two additional interpretations are given for the important data of D. B. Ericson on the correlation of coiling directions of Globigerina pachyderma in late Pleistocene North Atlantic sediments with ocean surface temperatures. One interpretation relates the distribution of this species to the distribution and circulation of ocean water masses. On the basis of our ice-age theory, our second interpretation uses the data and correlations of Ericson to establish temperature limits of a thermal node, a line on which glacial and interglacial temperatures were equal, for the North Atlantic Ocean. This line crosses the strait between Greenland and Scandinavia. Further, Ericson's interpretation of the 7.2 degrees C isotherm implies that the glacial-stage surface waters of the Arctic Ocean were between 0 degrees and 3.5 degrees C.     

The 18O/16O Ratio of 2-Billion-Year-Old Seawater Inferred from Ancient Oceanic Crust

An oxygen isotope profile of the 2-billion-year-old Purtuniq ophiolite overlaps with similar profiles of younger ophiolites and the modern oceanic crust. This overlap implies (i) that there was a similar style of seawater-ocean crust interaction during the past 2 billion years; (ii) that the oxygen isotope composition of early Proterozoic seawater was similar to the modern value; (iii) that early Proterozoic sea-floor spreading rates were similar to, or greater than, average modern rates; and (iv) that early Proterozoic carbonate rocks and cherts with low (18)O/(16)O ratios do not reflect global-scale (18)O depletion of early Proterozoic oceans.     

18O/16O, 30Si/28Si, D/H, and 13C/12C Studies of Lunar Rocks and Minerals

The delta (18)O of minerals from lunar gabbros and basalts are: plgioclases +6.06 to +6.33), pyroxenes (+5.70 to +5.95), and ilmenites (+3.85 to +4.12). The uniformity of these results indicates isotopic equilibrium in the mineral assemblages. Estimated plagioclase-ilmenite temperautres range from 1150 degrees C to 1340 degrees C. The bulk (18)/ (16)O and (30)Si/ (28)Si ratios of these lunar rocks are identical with ratios of terrestrial basalts, but the lunar glass, breccia, and dust are slightly enriched in the heavier isotopes. The lunar hydrogen (formed from solar wind) has a delta D/H of less than-873 per mil and the value may be even lower, as it is probably contaminated with terrestrial hydrogen. The delta (13)C of lunar dust and breccia is unusually high relative to reduced carbon in meteorites or on earth.     

杀线虫真菌Sr18发酵液对松材线虫超微结构的影响

Sr18真菌是一株自主分离获得的具有广谱杀线虫活性的生防菌。为探明该菌的杀线虫作用机理,以松材线虫为靶标,借助场发射高分辨扫描电镜及透射电镜,对1/2浓度的Sr18发酵液小分子活性组分处理后的线虫及未处理的正常线虫进行了超微观察。高分辨率扫描电镜观察结果表明,小分子物质对松材线虫头部、体壁和尾部均有损伤,并观察到内容物外溢的现象。透射电镜观察结果显示,线虫表皮和体腔分离,细胞核受损严重,形状不规则,粗面内质网核糖体聚集,线粒体空泡样变,肌纤维受损。这些现象从形态结构角度证实了该发酵液小分子活性成分对线虫的损伤是整体性的毒杀作用,排除了表面触杀的机制。这为进一步揭示Sr18的杀线虫机理以及线虫生防制剂的开发提供了重要理论依据。      

海浪效应对海面粗糙度的影响研究

基于日本气象厅22001号浮标站与美国国家浮标数据中心提供的41008号浮标站观测资料,利用Smith88、YT96、TY01和O02这4种海面粗糙度方案研究中高风速条件下真实海浪效应对海面粗糙度的影响;同时,利用浮标数据和COARE3.0算法,比较中高风速条件下缺乏真实海浪信息时,自主设计的有效波高、谱峰周期参数化方案与COARE3.0自带的Taylor01波浪特征量参数化方案计算海面粗糙度的效果。结果表明,无论哪种浮标资料,不考虑真实海浪效应的2种方案(Smith88和YT96)均比考虑真实海浪效应的2种方案(O02和TY01)计算出的粗糙度偏低,说明在中高风速条件下必须要考虑真实海浪效应对海面粗糙度的影响。此外,初步证实了自主设计的波浪特征量参数化方案在缺乏真实海浪信息时,计算效果优于COARE 3.0算法自带的Taylor01波浪特征量参数化方案。     

W-HE生物表面活化剂对玉米产量及产量性状的影响

为了明确W-HE生物表面活化剂的使用效果,经过3a试验,调查其对玉米产量及植株素质的影响。结果表明:使用W-HE生物表面活化剂能促进玉米前期的生长发育,促进根系的生长和干物质的积累,植株生长加快,果穗变大,百粒重提高,双穗率提高,增产幅度达10%以上。     

Sr18菌代谢产物对松材线虫蛋白质和酶活力的影响

基于Sr18菌(Syncephalastrum racemosum)代谢产物在8 h内具有显著的杀线虫活性,测定了其在8h内对松树线虫体内总蛋白质含量、SOD、CAT、TCh E和ATP酶活性的影响。结果表明,4 h时处理组总蛋白质的含量陡增至0.544 2 mg/m L,显著高于对照组0.429 1 mg/m L,Sr18菌代谢产物干扰了线虫体内蛋白质的代谢;在8 h内,处理组的SOD、CAT、TCh E和ATP酶这4种酶活性均低于对照组,Sr18菌代谢产物对线虫体内这4种酶都有不同程度的影响。这一结果为利用Sr18菌代谢产物研究和开发微生物源杀线剂奠定了理论基础。     

贡嘎山东北坡地表水地球化学特征及影响因素

【目的】阐明高山地区地表水水化学特征是理解高山地区元素地球化学循环及其对下游水安全影响的基础。【方法】在贡嘎山东北坡采集了27个地表水样和2个积雪样品,采用Gibbs、阴阳离子三角图、元素比值以及主成分分析法,以揭示该地区地表水地球化学特征及控制因素。【结果】研究发现,贡嘎山东北坡地表水水化学类型为Ca-HCO_(3-),总溶解固体(TDS)平均含量为50.2 mg/L,低于其下游的大渡河和长江,表明该地区风化程度较低。尽管该地区基岩以花岗岩为主,但硅酸盐岩风化对水体离子的贡献相对较少,水体主离子组成主要受碳酸盐岩风化的控制。此外,研究还发现高海拔地区降水对水化学特征也有一定的影响。【结论】在风化程度较低的高山地区,碳酸盐岩风化对当地水化学特征具有决定性的影响。     

太湖及洪泽湖太湖新银鱼耳石元素锶钙比的比较研究

利用元素电子显微探针分析技术,对南太湖(白雀乡水域)、北太湖(吴塘门至乌龟山水域)以及洪泽湖(老子山水域)的太湖新银鱼(Neosalanx taihuensis)的矢耳石进行了元素微化学分析,如锶及钙元素分布、积累、浓度比等特征的比较研究。元素定量线分析和面分布分析结果均直观而明显地表明,北太湖太湖新银鱼的个体可以分为两种类型,一类耳石具高锶钙比(21.41±0.50,N=4),另一类耳石具低锶钙比(1.64±0.12,N=5);南太湖个体耳石的锶钙比值居中(3.12±0.07,N=10);而洪泽湖个体耳石的锶钙比普遍偏高(5.42±0.32,N=9)。这些个体类别间锶钙比值的差异均显著(P<0.05)。此外,洪泽湖个体耳石标本有高锶环的存在,而太湖个体耳石中锶的分布水平较均一化。上述结果显示,一方面太湖和洪泽湖太湖新银鱼耳石锶钙比类型差异明显;另一方面太湖不同水域太湖新银鱼耳石的锶钙比类型亦不尽相同;反映出耳石锶钙比特征具有可以用来区别太湖新银鱼不同水域资源群体的潜力。     

阿拉伯海域围网渔场时空分布及其与海表环境因子的关系

为了解阿拉伯海海表环境因子对围网作业渔场的影响,采用2016-2017年中国印度洋拖围网生产数据和同期海表温度、叶绿素浓度、表层海流和海面高度数据,统计分析了围网作业重心变化,以及围网CPUE与海表环境因子关系,并利用频次分析和经验累积分布函数计算出最适宜的海洋环境区间。结果表明:阿拉伯海的海表环境、围网作业和渔场重心受印度洋季风影响明显,围网渔场渔汛主要在东北季风期间,渔场重心移动方向与表层季风相似。东北季风期间,围网作业渔场的海表温度呈现由高到低再到高的小幅波动趋势。CPUE随着叶绿素浓度高值区域南北收缩,呈现南北移动纬向特征;且CPUE呈径向分布在西边界流速较大的海域右侧,多出现在海流最大值和最低值中间区域。东北季风期间,围网渔场适宜海表温度在25.5～28℃,叶绿素浓度在0.2～0.5 mg/m~3,表层海流在0.05～0.25 m/s,海表高度0.20～0.35 m。     

土壤有机废渣的生物降解研究

[目的]探讨土壤微生物降解化工废渣的影响因素及有效措施。[方法]在试验区用四分法在地表20cm内取土壤样品,分别测出单位质量的燃烧失重,再向每块试验区施入不同的废渣,每隔5d取样后,测定其燃烧失重,获得各块土壤有机废渣随时间的降解数据。[结果]土壤有机废渣的生物降解受废渣性质、废渣表面积、土壤含氧量、土壤pH、含湿量和土壤温度的影响。有机物的好氧降解比厌氧降解快的多,完全的多。土壤pH影响生物的活动,应维持在7～9。土壤含湿量控制50%～60%是微生物活动的最佳条件。土壤温度在零度以下,生物降解基本停止。[结论]在实际应用于工业化处理有机废渣时,还需对某种土质和某种废渣作进一步研究,控制生物降解速率和程度及其管理措施。     

南海海洋渔业生物数字化标本馆的构建思路与应用

阐述了建立南海海洋渔业生物数字化标本馆生物标本信息化标准体系的原则,应用ASP.net技术,并以SQL Server作为服务端开发工具,建成了南海海洋渔业生物数字化标本馆管理系统和数据库,实现了网上生物标本资源信息发布.并对目前存在的问题进行了讨论.     

热带海表面温度与对流关系分析

通过研究热带海表温度（SST）与地气对外辐射（OLR）关系探讨了热带海表温度与对流强度之间的相关性。结果显示,在温度小于约28℃时,OLR随SST的升高而增大,当SST大于28℃时,OLR随SST升高而减小,28℃左右为SST与OLR的相关关系拐点。OLR的异常反映了对流活动的异常,当对流活动的强弱和分布发生变化,必然会引起热源出现变异,因而影响环流的异常。通过对厄尔尼诺与拉尼娜事件的合成分析得到,OLR与SST之间的关系与厄尔尼诺和拉尼娜期间大气异常环流型的形成是非常密切的。由于OLR和SST之间存在相关性的拐点,使得厄尔尼诺和拉尼娜期间对流的上升或下沉区域位置有所不同,也进一步证实SST是决定对流的一个关键因子。