厦门同安湾红树林及临近光滩沉积物孔隙水中溶解活性磷和亚铁分布特征的对比分析

为了解红树林与光滩磷、铁地球化学行为的差异,借助薄膜扩散梯度技术(ZrO-Chelex DGT),对厦门同安湾红树林及临近光滩孔隙水中溶解活性磷(DRP)、Fe~(2+)浓度进行了原位测量,并采集了相应沉积物柱状样进行测定分析。结果表明:(1)Fe~(2+)与DRP呈现较好的线性正相关,说明磷的吸附/解吸与铁氧化还原循环有关;(2)在不同深度,光滩孔隙水中DRP浓度均高于对应深度红树林。在浅层,由于溪水的补给造成光滩的磷富集;在深层,红树植物根部吸收导致磷浓度下降,光滩有机质含量较多,矿化释放DRP使其浓度较高;(3)孔隙水中的Fe~(2+)浓度分布表明,红树林区域随着深度的增加,逐渐由好氧环境进入厌氧环境;而光滩沉积物氧化还原环境可能受到红树林的影响,孔隙水Fe~(2+)在垂向上波动分布。     

Effects of salinity on embryonic and larval development of Chinese mitten crab Eriocheir sinensis(Decapoda: Brachyura) and salinity-induced physiological changes

To investigate the effects of salinity on early development of Chinese mitten crab(Eriocheir sinensis),and the salinity tolerance mechanism of embryos,different developmental stages of embryos(gastrula,eyespot and pre-hatching stage),and hatched stage I zoea and megalopa,were exposed to a range of salinities(1,5,10,15(control),20,25,30,35 and 40).Hatching,survival and molting were monitored.Effects of 24-hour hypersaline(35)and hyposaline(1)stress on egg diameter,water content,Na~+/K~+-ATPase(NKA)activity,and crustacean hyperglycemic hormone(CHH)gene mRNA expression in embryos and megalopa,are reported.Embryos are more tolerant of low(≤5)than high(≥25)salinities,with optimum ranges for gastrula and pre-hatching stage embryos being 5-20,and for eyespot embryo and stage I zoea,10-20.Most megalopa can molt to the first juvenile instar by day 5 at salinities between 1 and 40,whereas molting of megalopa stages was delayed at 40.Hypersaline conditions resulted in a loss of moisture,reduction of egg volume,and a significant increase in NKA activity and CHH mRNA expression at some developmental stages.Hyposaline conditions did not affect moisture content or egg volume,but resulted in decreased NKA activity and CHH mRNA expression in embryos.For megalopa stages,NKA activity was significantly upregulated following both hypo-and hypersaline stress.Our results suggest high salinity will inhibit development and hatching of E.sinensis embryos,and low salinity will affect the survival of their stage I zoea.Increased NKA activity in embryos and megalopa stages might indicate a hyporegulation response under hypersaline conditions.These findings provide useful information for spawning ground protection of indigenous E.sinensis and enrich the knowledge of embryonic tolerance mechanisms of hyperregulating crustaceans following osmotic stress.     

四元体系KCl-K2SO4-KBO2-H2O在298.15 K的Pitzer模型研究

在Pitzer电解质溶液理论的基础上采用两种模型计算了KCl-K₂SO₄-KBO₂-H₂O体系及其子体系的溶解度。模型I假设溶液中只有一种硼物种B(OH)₄^-,模型II假设溶液中有4种硼物种,分别对应于B(OH)₃、B(OH)₄^-、B₃O₃(OH)₄^-和B₄O₅(OH)₄^2-。模型I与模型II的溶解度计算结果接近,且与实验值吻合较好。采用模型II计算了上述体系溶液中的硼物种和OH^-的浓度。各硼物种的浓度主要受溶液中总硼浓度的影响,而很少受KCl和K₂SO₄的影响。计算结果说明在计算偏硼酸钾溶液体系溶解度时,可近似认为溶液中硼物种只有B(OH)_4...     

虾蟹壳提取物氨基葡萄糖美拉德反应及其产物的抗氧化性能研究

首次使用虾蟹壳提取物氨基葡萄糖单一物质制备美拉德反应产物(MRPs)。结果表明,MRPs清除DPPH·能力随反应物浓度、温度和时间的增加而增强;还原能力、清除·OH能力随反应物浓度增加而增强,还原能力随温度、时间增加先增后降,清除·OH能力随温度升高先增后降,随反应时间下降。115℃、0.5mg/ml、90min条件下制备的MRPs清除DPPH·的能力最强为88.73%;65℃、0.6mg/ml、40min的MRPs还原能力最强为A700nm=1.684;65℃、0.6mg/ml、10min的MRPs清除·OH的能力最强为98.72%。MRPs具有很强的抗氧化活性,比Vc和TBHQ抗氧化效果更好,但其抗氧化能力并不完全依赖于产物的褐变程度。氨基葡萄糖MRPs是优良的新型保鲜剂材料。     

Extraction and Dynamic Spatial-Temporal Changes of Grassland Deterioration Research Hot Regions in China

The authors use a web crawler to retrieve all periodical articles from CNKI between the 1950s and 2016 and then parse the abstracts of 293368 articles about grassland deterioration by word segmentation, location matching and other methods. The authors also construct a research hot regions extraction model of grassland deterioration in China based on a comprehensive research hot regions index of toponyms and then analyze the spatial pattern and dynamic change in research hot regions of grassland deterioration in China. The research shows the following: (1) The spatial heterogeneity of grassland deterioration in China can be effectively described by a model of grassland deterioration based on the comprehensive research hot regions index. (2) The research hot regions of grassland deterioration are mainly distributed in most regions of Inner Mongolia, Xinjiang, Qinghai, Tibet, Gansu and other provinces. The northeastern region of Inner Mongolia (such as Hulunbeier) and the eastern region of Inner Mongolia (such as Xilin Gol, Chifeng and Wulanchabu) are significant hot regions in the study of grassland deterioration. (3) The number of high research hot regions increases from 81 in the 1950s to 99 in the 2000s; the area increases from 1.038 million km² to 1.146 million km². The degree of hot for grassland deterioration research in 197 counties showed an upward trend. This paper also discusses the relationship between the region of research hot regions and the region of grassland deterioration and then indicates the differences between them in time matching, space matching and concept matching.     

西藏纳如松多铅锌矿床石英闪长岩成因:地球化学及Sr-Nd-Pb同位素证据

纳如松多矿区石英闪长岩具有低SiO_2、富MgO、CaO的特征,含10%～15%的角闪石,为准铝质、分异程度较低的高钾钙碱性-钾玄岩系列I型花岗岩。岩体发育较弱的Eu负异常,富集强不相容元素Rb、Th、U,而亏损Nb、Ta、Ti等高场强元素。同位素测试结果显示,纳如松多石英闪长岩具有相对较高的~(87)Sr/~(86)Sr初始比值(0.709 13～0.709 68)与负的ε_(Nd)(t)值(-5.8～-5.2),Pb同位素的~(206)Pb/~(204)Pb为18.6091～18.6438,~(207)Pb/~(204)Pb为15.6900～15.6986,~(208)Pb/~(204)Pb为39.2116～39.2225,指示岩浆可能为特提斯洋俯冲消减阶段产生的岛弧地幔楔部分熔融的产物。一种可能的成因模式为:晚白垩世,随着雅鲁藏布江板块向拉萨地块之下俯冲,俯冲板片流体交代上覆地幔楔,形成幔源基性岩浆,上侵到地壳后,诱发了岛弧基底物质的部分熔融,形成了中基性的纳如松多石英闪长岩,其形成可能是晚白垩世北向俯冲的新特提斯洋板块在回转初期的岩浆活动响应。     

埕岛地区曲流河砂体边界识别技术

正近几年,随着油气勘探程度不断提高,勘探难度逐年加大,寻找经济规模储量成为勘探技术工作中的重中之重。而埕岛地区新近系周边储量空白区,紧邻开发管网,能够实现整体开发,达到储量到产量的快速转化。埕岛地区新近系作为一个主要含油层系,在勘探开发中,单一河道砂体边界的识别是关键,由于河道砂体存在尺度小、散度大、地震资料分辨率有限等局限性,砂体边界识别存在不确定性。     

柴北缘构造带欧龙布鲁克地块西北缘辉长岩脉地球化学、年代学及Hf同位素特征

侵位于柴北缘构造带欧龙布鲁克地块西北缘达肯大坂岩群中的辉长岩脉岩石Al_2O_3、CaO含量较高,P_2O_5、TiO_2含量较低,属于钙碱性系列。稀土元素总量低(43.17×10-6～57.53×10~(-6)),LREE/HREE值为1.82～2.77,稀土元素配分曲线整体表现为右倾型。岩石Ti亏损,具高ThN/NbN值(3.75～8.03)和低Nb/La值(0.44～0.84)特征。辉长岩锆石的~(176Hf/~(177)Hf值介于0.282813～0.282979之间,ε_(Hf)(t)值为9.25～15.11,Hf模式年龄(T_(DM))分布在378～610Ma之间,平均494Ma。综合研究认为,辉长岩岩浆源区为软流圈地幔且后期可能受到壳源富集组分的混染。LA-ICP-MS锆石U-Pb定年结果表明,辉长岩脉形成于357±4Ma,即早石炭世。结合区域地质背景,认为早石炭世柴北缘仍处于后造山伸展的构造演化阶段,而辉长岩脉是后造山伸展阶段柴北缘造山带去根、软流圈地幔上涌作用形成的。     

微倾斜场地中地铁地下结构周围地基液化与变形特性振动台模型试验研究

强震中场地砂土液化产生的土层侧移对地面建筑结构和地下生命线工程造成了严重的破坏。可以预见,微倾斜液化场地的土层侧移也将对地铁地下结构的地震安全造成严重的威胁。鉴于此,开展了微倾斜（倾角为6o）可液化场地中两层三跨地铁地下车站结构与区间隧道连接部位地震反应的大型振动台模型试验研究。结果表明：微倾斜可液化场地中地铁车站结构两侧地基出现了明显的非对称液化分布特征,坡体下方水平土层比上方水平土层更易液化;因坡体内土体液化沿坡向下流滑引起了下方水平土层发生了明显的地面抬升,总体上坡体段内的地面侧移量最大,下方水平土层地面侧移量次之,坡体上方水平土层地面侧移量最小。同时,在试验过程中也发现,隧道和车站结构之间发生了明显的差异上浮,可能会造成连接部位附近结构的应力集中或加重该部位的地震破坏。