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911.
912.
The Shenhu area is one of the most favorable places for the occurrence of gas hydrates in the northern continental slope of the South China Sea. Pore water samples were collected in two piston cores (SH-A and SH-B) from this area, and the concentrations of sulfate and dissolved inorganic carbon (DIC) and its carbon isotopic composition were measured. The data revealed large DIC variations and very negative δ 13C-DIC values. Two reaction zones, 0–3 mbsf and below 3 mbsf, are identified in the sediment system. At site SH-A, the upper zone (0–3 mbsf) shows relatively constant sulfate and DIC concentrations and δ 13C-DIC values, possibly due to bioturbation and fluid advection. The lower zone (below 3 mbsf) displays good linear gradients for sulfate and DIC concentrations, and δ 13C-DIC values. At site SH-B, both zones show linear gradients, but the decreasing gradients for δ 13C-DIC and SO4 2− in the lower zone below 3 mbsf are greater than those from the upper zone, 0–3 mbsf. The calculated sulfate-methane interface (SMI) depths of the two cores are 10.0 m and 11.1 m, respectively. The depth profiles of both DIC and δ 13C-DIC showed similar characteristics as those in other gas hydrate locations in the world oceans, such as the Blake Ridge. Overall, our results indicate an anaerobic methane oxidation (AMO) process in the sediments with large methane flux from depth in the studied area, which might be linked to the formation of gas hydrates in this area.  相似文献   
913.
This paper reports all available geochemical data on sediments and pore waters from the Xisha Trough on the northern continental margin of the South China Sea. The methane concentrations in marine sediments display a downhole increasing trend and their carbon isotopic compositions (δ 13C = −25 to −51‰) indicate a thermogenic origin. Pore water Cl concentrations show a range from 537 to 730 mM, and the high Cl samples also have higher concentrations of Br, Na+, K+, and Mg2+, implying mixing between normal seawater and brine in the basin. The SO4 2− concentrations of pore waters vary from 19.9 to 36.8 mM, and show a downhole decreasing trend. Calculated SMI (sulfate-methane interfaces) depths and sulfate gradients are between 21 and 47 mbsf, and between −0.7 and −1.7 mM/m, respectively, which are similar to values in gas hydrate locations worldwide and suggest a high methane flux in the basin. Overall, the geochemical data, together with geological and geophysical evidence, such as the high sedimentation rates, high organic carbon contents, thick sediment piles, salt and mud diapirs, active faulting, abundant thermogenic gases, and occurrence of huge bottom simulating reflector (BSR), are suggestive of a favorable condition for occurrence of gas hydrates in this region.  相似文献   
914.
微量元素在水产动物的生命过程中是必不可少的,但是仅靠从水体中吸收是不能满足机体的正常需要的,还必须从饲料中摄取。至今,微量元素添加剂的发展经历了三代:第一代为无机盐类,常用的为硫酸盐等。无机盐类的微量元素添加剂易潮易结块,易与维生素发生拮抗,在植酸等抗营养因子存  相似文献   
915.
双水相萃取法富集分离螺旋藻藻蓝蛋白的研究   总被引:4,自引:0,他引:4  
以PEG/硫酸钠双水相体系,经一次萃取从钝顶螺旋藻(Spirulina platensis)细胞破碎液中富集分离藻蓝蛋白。结果表明,萃取最适宜的条件为12%PEG4000,15%Na2SO4,1%KCl,藻蓝蛋白收率为91.2%,分配系数达到8.01,分离因数达到6.33。对于螺旋藻藻蓝蛋白的富集分离,双水相萃取法与传统的盐析沉淀法相比,具有节省操作时间、简化操作过程、降低能耗和成本以及易于工艺放大等优点。  相似文献   
916.
青岛奥帆基地海域漂浮浒苔光合生理特点研究   总被引:7,自引:1,他引:6  
研究了青岛奥帆基地海域漂浮浒苔Enteromorpha prolifera (Muell)J.Ag.色素组成及含量、光合放氧及呼吸耗氧速率、P/R(净光合放氧速率/净呼吸耗氧速率)、抗氰呼吸等各项生理指标。结果表明,该海域漂浮浒苔的各项生理指标都在正常范围内,且有抗氰呼吸的存在,生长状况良好。  相似文献   
917.
The evaluation of sustainable land use is the key issue in the field of studying the sustainable land utilization. In general analysis, the sustainable land use is evaluated respectively from its ecological sustainability, economic sustainability and social sustainability in China and other countries in recent years. Although this evaluation is an important work, it seems insufficient and hard to comprehensively reflect the whole degree of land use sustainability. Thus, to make up this deficiency, this paper brings forward the evaluation indexes, which make it possible to quantitatively reflect the whole degree of land use sustainability, namely, the concept of "degrees of overall land use sustainability" (Dos), and research and measurement development of the method of and calculation in Dos. Taking the evaluation of the degree of land use sustainability in county regions of Yunnan Province as the actual example for analysis, results are basically as follows:
1) The degree of land use sustainability (Dos) is the ration index to organically and systematically integrate the degree of ecological friendliness (DeF), the degree of economic viability (Dev) and the degree of social acceptability (Dsa), able to comprehensively reflect the whole sustainability degree of regional land use
2) Based on the value of Dos, the grading system and standard for the sustainability of land use may be established and totally divided into five grades, namely, the high-degree sustainability, middle-degree sustainability, low-degree sustainability, conditional sustainability and non-sustainability. Meanwhile, the standard for distinguishing sustainability grades has also been confirmed so as to determine the nature of sustainability degrees in different grades. This makes the possibility for the combination of nature determination with ration in research result and provides with the scientific guideline and decision-making gist for better implementation of sustainable land use strategy.
3) The pract  相似文献   
918.
招远市黄金资源蕴藏丰富,开采历史悠久,素有“金城天府”之称,建国以来,累计向国家交售黄金近200t,是全国第一产金大市(县)。其矿山地质环境问题不同于一般的县市,通过对其矿山地质环境特点的分析,认为招远市金矿区矿山地质环境影响评价的重点为采空塌陷,地裂缝,渣石流等地质灾害及水环境等。  相似文献   
919.
济南北部地热田地热地质特征浅析   总被引:1,自引:0,他引:1       下载免费PDF全文
济南北部地热田地热资源类型属于层状裂隙岩溶型,热源是北部齐河-广饶断裂的沟通导热,盖层是第四系、新近系、石炭-二叠系、侏罗系.可利用的、具有开发价值的热储层为奥陶系灰岩热储,该热储层顶板埋深在700~2500m左右,热储层厚度由南向北逐渐增大,单井涌水量2000m3/d左右,孔口水温一般在38~57℃,地热田东部地热水矿化度1.4~3.5g/L左右,西部5.1~7.2g/L左右,地热水中富含氟、锶、偏硅酸等微量元素,具腐蚀性,结垢性弱,具较好的开发利用价值.经计算奥陶系热储层单井可采资源量为7.3×105m3/a,合理井间距为5000m.  相似文献   
920.
枣庄市山亭区位于枣庄市东北部,泰沂山区西南部,属低山丘陵区,全区大小山头1000多座,地形条件复杂,土地总面积1018.64km^2,山地丘陵占全区总面积的80%以上。山亭区的土地利用现状更新调查工作始于2004年,经过1年多的艰苦调查,查清了全区各类土地利用的现状,绘制了山亭区土地利用现状图,建成了山亭区土地利用数据库。2007年7月,山东省国土资源厅对山亭区的土地利用调查更新工作进行了验收。经验收,山亭区土地利用更新调查技术路线正确、方法先进,各项成果符合土地更新调查技术要求。  相似文献   
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