高浑浊度河口沉积物的沉积机理评述   总被引：2，自引：0，他引：2  

王飞  张龙军 《海洋湖沼通报》2004,(2):21-29

该文主要介绍了潮流对沉积作用的影响，沉积物的再悬浮和最大浑浊带的形成机制以及影响沉积物絮凝沉降的因素。潮流是搬运河口泥沙的主要动力，沉积在河口拦门沙的泥沙会在潮流的作用下向河口外继续搬运。沉积物的再悬浮和最大浑浊带密不可分，正是由于沉积物在周期性潮流的作用下引起再悬浮，为最大浑浊带的形成提供了条件。影响沉积物絮凝沉降的因素很多，有内因，也有外因。内因是颗粒物自身的性质；外因如盐度、流速、pH值等。  相似文献   

南黄海夏季表层海水中pCO2分布的初步探讨     

王峰  张龙军  张经 《中国海洋大学学报(自然科学版)》2002,32(6):1007-1011

作者在 1 999年夏季的航次中 ,获得了南黄海表层海水 p CO2 的实测数据。本文结合水文、化学和生物等要素的同步观测资料 ,对影响 p CO2 分布和变化的某些重要现象进行了初步探讨。研究表明南黄海表层海水 p CO2 的分布存在较大的不均匀性 ,这是边缘海区海水中生物、物理和化学因素复合作用的结果。除长江口门外的 p CO2 高值区外 ,南黄海表层海水的 p CO2 值与叶绿素、水温大体呈负相关 ,而与海水的盐度基本上呈正相关。  相似文献   

Preparation of Mn₃O₄ from low-grade rhodochrosite ore by chemical bath deposition method     

Jing Zhao  Longjun Xu  Taiping Xie  Chao Xie 《中国地球化学学报》2015,(1):55-61

Mn3O4was prepared with the chemical bath deposition(CBD) method. A Mn SO4 solution was obtained by the leaching and purifying of low-grade rhodochrosite ore(LGRO), which was used as raw material. The prepa ration procedures were studied and promoted. The result showed that the Mn3O4 with the highest purity and highes specific surface area could be obtained under the following processes. An Mn SO4 solution of 1.0 mol/L was added into a beaker under a flow rate of 30 m L/h. The p H of the reaction solution was adjusted to 10 using NH3 H2 O a80 °C. Then the solids were washed and dried at 200 °C fo2.5 h. The total Mn content(TMC) of Mn3O4 was 72.0 %The ionic distributions was formulated as [Mn2?[Mn2??0.3024Mn30.2937Mn4?h0.37860.0254]2O4. The average crys tallite size of Mn3O4 with a tetragonal hausmannite struc ture was found to be about 35 nm by X-ray diffraction(XRD) analysis. The BET specific surface area of the Mn3O4 measured was 32 m2/g.  相似文献   

海上风电工程基础结构抗震性能研究   总被引：1，自引：0，他引：1  

徐龙军  何晓云  谢礼立 《地震工程与工程振动》2012,32(3):1-7

为了探讨海上风电工程基础与结构体系的抗震性能,采用ANSYS程序建立了三种基础型式的风电塔架结构数值模型,先采用振型分解反应谱法计算了结构的地震响应,进而分别将传统地震动和最不利地震动作为输入地震动,分析了三种基础结构体系的最大地震响应。结果显示:风电结构属典型的长周期结构,基础型式对结构的振动周期影响明显,单立柱桩式结构振动周期最长,八桩承台结构振动周期最短。地震作用下,单立柱桩结构的顶端位移响应也最大;振型反应谱法与传统地震动作用下结构的响应满足现行建筑抗震规范的要求,但最不利地震作用下结构的位移响应偏大,不满足规范对位移的相关规定;组合三桩结构底部基础与结构连接处是应力集中区。海上风电工程结构抗震设计的重要性应引起充分重视。  相似文献   

东海冬、夏两季表层海水的二氧化碳分压   总被引：7，自引：5，他引：2  

张龙军  王彬宇  张经 《中国海洋大学学报(自然科学版)》1999,(Z1)

１９９７ 年冬、１９９８ 年夏在东海进行了两个航次的调查,采用气相色谱一喷洒式平衡器系统,现场测定了表层海水和大气的ＣＯ２ 分压。东海表层海水ＣＯ２ 分压受东海环流、生物活动、季节等因素影响而变化。冬季受垂直混合作用的影响,陆架区是ＣＯ２ 的源;黑潮水是ＣＯ２ 的汇,夏季受生物活动的影响,陆架区水系是ＣＯ２ 的汇;黑潮及影响区域是ＣＯ２ 的源。  相似文献   

Spatiotemporal distribution of fish eggs and larvae in the Huanghe(Yellow) River estuary,China in 2005–2016     

SONG Yingfei  ZHANG Longjun  LUO Xianxiang 《海洋湖沼学报（英文）》2019,(5):1625-1637

Decreasing fish resources in estuaries is a subject of anthropogenic activities. Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in a fishery. As the fifth largest river estuary in the world, the Huanghe (Yellow) River estuary (HRE) is a typical estuary that has been seriously aff ected by human activities. Annual surveys on ichthyoplankton and environmental factors were conducted in the months of May of 2005 and 2009-2016 in the HRE to investigate the spatiotemporal distribution of fish eggs and larvae and the associated infl uencing factors. A total of 23 and 20 species of eggs and larvae, respectively, were collected. The dominant orders were Perciformes (51.2%) and Clupeiformes (25.6%). The average number of fish species eggs and larvae were 6.0 and 4.1 in average abundance of 0.91 and 0.13 ind./m^3 , respectively. The dominant species were mainly low-commercial-value small-sized fishes, such as Clupanodon punctatus , Harengula zunasi, and Acanthogobius, whereas certain traditional commercial fishes, such as Trichiurus lepturus , and Clupea pallasii, were not seen. Analysis of the fish egg and larval community revealed four temporal assemblages and two spatial assemblages. Salinity was the main factor on the spatial distribution of ichthyoplankton communities, the species number and Shannon-Weiner diversity index (H′) of the fish egg and larval community near the river mouth with lower salinity were signifi cantly lower than the community far away from the river mouth with higher salinity. In addition, increases of water temperature promoted the number and abundance of fish species eggs, and the areas of abundant prey tended to have a more diversified and abundant of ichthyoplankton species. In overall, overfishing, dam construction, and other human activities were the main drivers that led to the substantial decline in fishery resources in the HRE.  相似文献   

Effect of manganese tailings on capsicum growth     

Zhengguo Zhou  Longjun Xu  Jinlian Xie  Chenglun Liu 《中国地球化学学报》2009,28(4):427-431

The impact of Mn in manganese waste rocks and electrolytic manganese residues on the growth of capsicum was studied via pot experiments. The product yield and manganese nutrition were mainly evaluated in this study. The results showed that the ingredients of manganese tailings were beneficial to the increase of chlorophyll contents in the capsicum. The chlorophyll contents were raised by 12.6%–28.7%, 7.18%–12.1% and 9.70%–13.7%, respectively, corresponding to the idiophase of flower bud, the initial florescence and the fruit expansion stage. Moreover, the additive significantly improved capsicum’s economic features, such as its height, stem width, fruit length and weight and the yield of fresh fruit. These parameters were raised by 11.9%–25%, 18.6%–25.6%, 20.7%–35.4%, 10.4%–27.6% and 11.4%–65.7%, respectively. At the meantime, the manganese taken up by stems and leaves of the capsicum also increased by 11.7%–23.4% and 33.9%–62.8%, respectively. The manganese which remained in the soil was less than that in the original soil due to plant absorption and rainfall loss in pot experiments. It is concluded that both manganese residues and the mixture of manganese waste rock and manganese residue could indeed be made full use of as a fertilizer which can provide Mn nutrition.  相似文献   

基于强震记录的核电厂抗震标准反应谱研究          下载免费PDF全文

覃锋  徐龙军  谢礼立 《地震学报》2011,33(1):103-113

依据基岩场地上的汶川地震强震记录,分析了地震动地面峰值和核电站抗震标准反应谱的特性,证明了在推导和使用标准反应谱时所考虑的地面峰值加速度与地面峰值速度之比(PGA/PGV)受地面峰值加速度和震中距的影响,将对标准反应谱形状产生明显的影响.另外还发现了基岩场地的竖向峰值加速度可能要远比通常认为水平向峰值加速度的2/3大....  相似文献   

Carbon distribution and fluxes of 16 rivers discharging into the Bohai Sea in summer   总被引：2，自引：1，他引：1  

XIA Bin  ZHANG Longjun 《海洋学报(英文版)》2011,30(3):43-54

Riverine carbon input is closely related to the inshore aquatic environment,the marine carbon pool and climate change.Samples were synchronously obtained from 16 rivers discharging into the Bohai Sea (China) in 1-5 July 2005.The dissolved organic carbon (DOC) concentrations of the 16 rivers were mainly controlled by anthropogenic activities.The particulate organic carbon (POC) of the Haihe,Luanhe,Ziyaxinhe,Chaobaixinhe,Xiaoqinghe,Xiaolinghe,Duliujianhe,Jiyunhe,and Majiahe Rivers mainly originated from pollu...  相似文献   

Acid Volatile Sulfide and Simultaneously Extracted Metals in Tidal Flat Sediments of Jiaozhou Bay, China   总被引：1，自引：0，他引：1  

ZHANG Xiangshang ZHANG Longjun 《中国海洋大学学报(英文版)》2007,6(2):137-142

It is well known that acid-volatile sulfide （AVS） plays an important role in influencing the toxicity of divalent cationic metals within anoxic sediments. In studying sediment core samples collected from tidal flats within the Jiaozhou Bay, China, we found that the AVS concentration gradually increases with depth and decreases from high tidal flat to low tidal flat areas. We evaluated the chemical activity and bioavailability of heavy metals in the tidal flat based on the molar ratio of simultaneously extracted metals （SEM） and AVS. The value of SEM/AVS is generally less than 1 in this area except for the surface layer, which suggests that the heavy metals only have chemical activity in the surface layer. SEM is most highly concentrated at the boundary of the redox layer SEM have similar depth distributions throughout the tidal flat. The aeration of low tidal flat sediment indicates that SEM gradually move to deeper sites via interstitial water.  相似文献