广西钦州湾围垦工程对茅尾海潮汐动力参数的影响

北部湾茅尾海是中国南方重要的经济开发区,兴建有滨海新城和多个港口码头,近年来围垦开发严重。本研究通过建立二维水动力数值模型系统,分析重要潮汐动力参数,对比研究1985年与2020年间钦州湾围垦和港口建设对当地水动力环境的影响。结果表明：经过围填海和港口工程之后,茅尾海的潮差变化较小,略微增加了0.05 m左右;全日分潮K1、O1及半日分潮M2、S2是影响钦州湾潮汐动力较大的驱动力,围垦后在茅尾海内海地区都略微增加了0.02~0.03 m,其中K1、O1是影响茅尾海的关键潮汐动力参数,敏感性测试分析表明三墩公路建设、钦州港海岸围垦和核电厂导堤建设对茅尾海潮差增加贡献率大致占60%、20%和10%;同时,围垦对束窄钦州湾航道具有一定的优化效应,围垦后钦州湾外湾三条水道峰值通量都明显增加,形成航道束水攻沙效果,对通航和维护主航道稳定性具有一定优势。因此,仅从潮汐动力参数变化角度分析,目前的围垦和港口工程迎合了当地河势特征,对潮汐动力场扰动较小,具有优化局部水动力场环境和提升通航安全性作用。     

Influence of N,P, Fe Nutrients Availability on Nitrogen Metabolism-Relevant Genes Expression in Skeletonema marinoi

Nitrogen(N), Phosphorus(P), and Iron(Fe) are essential elements for cellular structure and metabolism. In addition to dissolved inorganic nitrogen(DIN), phytoplankton is able to utilize dissolved organic nitrogen(DON). There is general consensus that both bacteria and higher plants nitrogen metabolism is affected by phosphate availability; this was also found to be true in coccolithophorid. Iron affects the structure and function of ecosystems through its effects on nitrogen metabolism. However, it is unclear how these nutrients affect Skeletonema marinoi's nitrogen metabolism. Here, using RT-qPCR, we investigate effects of N, P, and Fe on S. marinoi's nitrogen metabolism and nitrate reductase activity. These results illuminate that in S. marinoi, various nutrients have direct regulation on these genes expression at the molecular level. The varying degree of responses for these genes expression with differing N sources may act to increase the efficiency of nutrient capture when nitrate is limited. Suitable gene expression occurs at a N/P ratio of 16, which represents the atomic N/P ratio of phytoplankton cells and N/P concentrations in ocean; thus, nitrogen metabolism gene expression should be regulated by the existing N/P ratios in the phytoplankton's internal and external environment. Fe concentration has a direct and significant effect on nitrogen metabolism by regulating gene expression and nitrate reductase activity. Gene expression profiles identified in S. marinoi provide a foundation for understanding molecular mechanisms behind diatom nitrogen metabolism with changing N, P, and Fe nutrients allowing a basic understanding of how diatom growth is affected by nutrient utilization.     

秦岭造山带中酸性岩浆作用中Zr、Hf地球化学行为探究

秦岭造山带属于中央造山带的重要组成部分,由不同时期,不同类型造山作用所形成的各种构造带复合组成,具复杂时空组合关系,成为一个特色鲜明的大陆造山带,故对其研究一直热度不减。本文从秦岭造山带中各种中酸性岩的Zr、Hf地球化学行为入手,通过对比不同时代、不同岩性中Zr、Hf的含量及Zr/Hf比值,分析Zr、Hf,在不同时代、不同SiO2含量的岩浆中的特性及演化规律,以此探讨秦岭造山带中岩浆在不同时代和不同构造背景下的演化规律。     

东海原甲藻线粒体细胞色素b(Cytb)基因的定量检测

建立了检测东海原甲藻线粒体细胞色素b(Cytb)基因mRNA含量的实时荧光定量PCR方法.以甲藻Cytb基因的简并引物扩增得到984 bp长的东海原甲藻Cytb基因片段,经克隆、测序,制备并纯化质粒.以光度法测定质粒浓度并作为标准品.对上述基因片段,利用PRIMER EXPRESS 3.0 设计引物,以梯度稀释的质粒标准品进行定量PCR反应,以SYBR Green I为荧光染料,制作标准曲线,得到基因拷贝数X与Ct值的关系为:Ct=-3.50 lg X+39.35(相关系数r为0.999).通过对不同生长时期的东海原甲藻样品的Cytb基因mRNA含量检测,发现该基因的表达量较稳定,平均值为(45.4±4.7)拷贝/细胞,受生长状态影响不大,可作为实时荧光定量PCR的内参基因.     

用化学平衡常数判断台湾岛东北部龟山岛附近海域海底热液活动形成自然硫的化学反应

由龟山岛热液气体推断几个可能化学反应方程式的存在,根据相关的假设条件,尽量接近于真实的龟山岛热液环境情况,通过计算、比较这些可能存在的化学反应在标况和龟山岛热液条件下的平衡常数,得出龟山岛热液活动区自然硫的形成可能反应式2H2S(g) O2(g)=2S(s) 2H2O(l)和CH4(g) SO2(g)=3S(s) 2H2O(l) CO2(g)起到了较大的作用。这与龟山岛热液活动所具有的水深浅,周围氧气含量高的事实以及采集的热液气体中含有大量CO2气体等情况十分一致。     

The role of Pacific water in the dramatic retreat of arctic sea ice during summer 2007

A model study is conducted to examine the role of Pacific water in the dramatic retreat of arctic sea ice during summer 2007. The model generally agrees with the observations in showing considerable seasonal and interannual variability of the Pacific water inflow at Bering Strait in response to changes in atmospheric circulation. During summer 2007 anomalously strong southerly winds over the PaCific sector of the Arctic Ocean strengthen the ocean circulation and bring more Pacific water into the Arctic than the recent （2000-2006） average. The simulated summer （3 months ） 2007 mean Pacific water inflow at Bering Strait is 1.2 Sv, which is the highest in the past three decades of the simulation and is 20% higher than the recent average. Particularly, the Pacific water inflow in September 2007 is about 0.5 Sv or 50% above the 2000-2006 average. The strengthened warm Pacific water inflow carries an additional 1.0 x 1020 Joules of heat into the Arctic, enough to melt an additional 0.5 m of ice over the whole Chukchi Sea. In the model the extra summer oceanic heat brought in by the Pacific water mainly stays in the Chukchi and Beaufort region, contributing to the warming of surface waters in that region. The heat is in constant contact with the ice cover in the region in July through September. Thus the Pacific water plays a role in ice melting in the Chukchi and Beaufort region all summer long in 2007, likely contributing to up to O. 5 m per month additional ice melting in some area of that region.     

确山县大金山含钾岩石矿床地质特征及工业利用

确山县大金山含钾岩石矿床位于华北地台南缘东端 ,属沉积—变质型非金属矿床 ,含钾岩层赋存于中元古界汝阳群中 ,初步探明矿石储量 389 6万t。本文阐述了矿床地质特征、生产钾镁肥的工艺试验及开发利用前景 ,为相关厂家生 (转 )产钾镁肥提供了生产依据     

Species-specific detection and quantification of scyphomedusae in Jiaozhou Bay,China, using a quantitative real-time PCR assay

Over the past decades, jellyfish occurred increasingly and abundantly in coastal areas worldwide. Usually, biomass of jellyfish, especially when they bloom, can...     

南海北部深水区中新世生物礁发育特征

基于近些年南海北部深水区采集的地震资料,对南海北部深水区中新世生物礁发育特点进行分析、对比和研究,认为西沙隆起地区发育典型的生物礁,具有丘状反射、强振幅、中频、中连和杂乱地震相,发现琼东南盆地北礁地区在中新世梅山组也有似礁相发育.通过对琼东南盆地深水区中新世生物礁层序地层学分析,认为生物礁在中新世梅山组海侵体系域和高位体系域发育.从对北礁地区典型生物礁剖面进行的波阻抗反演来看,其与LH11-1生物礁油田的波阻非常相似,波阻抗值为8×106-9×106kg/(m2·s).古地理分析认为,中新世西沙隆起区与北礁地区处于滨、浅海沉积环境,梅山组时期的陆缘碎屑供给量比较少,适于生物礁发育.