Characteristics of Energy Accumulation and Release of Seismogenic Tectonics and Seismic Risk Analysis in Some Areas in the Tianshan Mountains, Xinjiang

Comparative analysis between the quantitative data of active faults and seismicity reveals that a complete earthquake recurrence cycle includes the characteristic earthquake and the submaxima earthquakes in-between. The magnitude of the sub-maxima events is correlated with the elapsed time of the characteristic earthquake and the slip rate of the fault. The fault displacement includes the major stick-slip generated by the characteristic earthquakes and the minor stick-slip by the sub-maxima ones. The magnitude-frequency relationship still works in the complete recurrence cycle. The energy accumulation in the cycle is divided approximately into four phases, and the seismicity differs at each phase. The relation of the maximum displacement with the average displacement of the characteristic earthquake suggests the partitioning of deformation between the characteristic and the sub-maxima earthquakes. Based on the above analysis, relevant mathematical equations are put forward for the quantitative assessment of the potential magnitude and earthquake risk of seismogenic tectonics. Tentative study has been carried out in this aspect in some areas of Tianshan.     

Effect of enclosure and nutrient enrichment on Microcystis blooms in Donghu Lake

1 INTRODUCTION Surface blooms of nuisance cyanobacteria are often a signal of eutrophication (Jacoby et al., 2000). They are generally favored by conditions of low nitrogen to phosphorus ratios, high total phosphorus content, high water temperature, high …     

天然水体中生物膜对水环境中磷的生物地球化学过程影响

介绍了生物膜及其发育形成机理,生源要素磷与底泥、悬浮颗粒、藻类及细菌之间的相互作用,生物膜中微生物对生源要素磷循环的作用及其检测方法。通过对该领域近几年最新研究成果的总结,得出生物膜尤其是细菌对元素磷迁移转化的影响起着重要作用;对今后研究重点作出展望,在考虑生物膜存在的条件下,深入研究沉积物、悬浮颗粒、藻类及细菌与磷循环的相互作用机制,将有助于弄清楚水体富营养化发生的过程及机理。     

H2释放扰动电离层的数值模拟

由于电离层中分子性离子与电子的复合要比氧离子与电子的复合快得多,因此H₂在电离层高度释放可有效地引起电子的消耗。本文基于一个包括中性气体扩散方程和离子化学反应方程的二维动力学模型,对H₂在电离层高度释放过程进行了数值模拟研究,并分析了不同释放条件下的电子扰动特性。结果表明:1)500 mol H₂释放后,迅速向周围空间扩散,释放中心处的电子密度30 s内下降了近4%,F₂层临界频率下降了1%左右;2)在不同高度处释放H₂时,最大的电子密度相对变化率并不是在峰值高度附近处释放时出现的;3)释放化学物质的量越多,电子密度的扰动幅度也越大,但两者之间并不存在线性关系;4)相同量的H₂在电离层峰值高度处释放,白天的电子密度扰动幅度要大于夜间的扰动幅度。     

风浪作用下入湖河口内源释放特征

采用Y型沉积物再悬浮发生装置模拟3种风速条件下典型入湖河流河口沉积物再悬浮和沉降过程.结果表明,随着风速的增大,水柱中悬浮物总量增加;3种风速条件下氨氮(NH₄+-N)增量均为负;小风和中风过程,正磷酸盐(PO₄3--P)总量呈减小趋势,大风过程,正磷酸盐总量出现了明显上升,相对于初始值增加了46%,在5.1~8.7m/s的某一模拟风速条件下PO₄3--P的释放和吸附达到动态平衡,其表观值与初始值相等.总氮(TN)和总磷(TP)总量随着风速的增加而增大,TN最大增量是初始总量的2倍,而TP则是17倍;风浪过后TN、TP总量基本恢复到初始值.典型风速过程中,营养盐垂向分布无明显规律.     

四川南江坪河碱性岩体岩石学特征及成因

碱性岩在地表出露很少,主要分布于大陆内部稳定区和裂谷区以及大洋盆地以内,虽然分布较少,但它们与稀有、稀土及放射性元素关系密切,近来还发现了金、铂等贵金属矿产,越来越引起人们的重视。碱性岩的组成矿物常有斜长石、碱性长石、深色矿物特别是碱性深色矿物和似长石等,其按照SiO2的含量可以分为超基性碱性岩(霓霞岩     

厦门港湾潮间带沉积物中汞的赋存形态及其释放动力学

所研究的沉积物样品采自福建省厦门市的港湾潮问带地区,选择了10μg／dm’的汞标准使用液对采集回来的沉积物样品进行了预污染处理,利用预污染后的沉积物样品,在实验室中进行了一系列的汞释放动力学实验．实验结果表明,汞的释放量较低,达到释放平衡时的释放量小于5μg／kg,释放过程可分为2个阶段：前8h为快速释放阶段,之后为慢速释放阶段,大约在24h达释放平衡．采用了Tessier五步提取法对未污染过的沉积物原样及进行过预污染处理的沉积物样品进行了汞的形态分析,结果表明通过污染实验吸附到沉积物上的汞的各形态含量大小顺序为：HgS为主的惰性汞〉单质汞〉盐酸溶无机汞及甲基汞〉有机结合、螯合态汞〉水溶态、交换态等活性汞．     

不同条件下凡纳滨对虾(Litopenaeus vannamei)能量代谢研究

通过设置不同温度、盐度、pH值和摄食状态的方法,研究凡纳滨对虾在不同条件下的无机磷、亚硝酸氮、硝酸氮、氨氮的释放率.结果表明,温度、体重、盐度、pH值和摄食状态对其代谢存在影响.无机磷、亚硝酸氮、硝酸氮、氨氮的释放率与体重呈负相关;在20-30℃的温度范围内,随着温度的上升,凡纳滨对虾磷、亚硝酸氮、氨氮的释放率均上升,...     

Phosphorus budget of redeye mullet （Liza haematocheila T. ＆ S.） under graded feeding levels

Experiment on phosphorus budget of redeye mullet （Liza haematocheila T. ＆ S.） was conducted at water temperature 21℃ and salinity 33. The results showed that the growth phosphorus （phosphorus that allocated into growth, GP） increased from -30.84% to 15.83% by feeding on graded amount of diets （starvation, 1%, 2%, 3%, 4% body weight and satiation）. The GP linearly increased with feeding levels （FL） as GP （mg） = - 0.785 ＋ 0.604 FL, and at satiation the relationship between GP and body weight （BW） was GP （mg） = 1,5991 BW0.7685. In the budget, IP （intake phosphorus） = GP ＋ FP （faecal phosphorus） ＋ EP （excretion phosphorus）. FP showed an irregular tendency with different feeding levels, and EP decreased with increasing feeding levels but rebound at satiation. The P budget at satiation was 100IP = 15.84 GP ＋ 64.62 FP ＋ 19.55 EP.     

Effect of Nitrogen and Phosphorus on Tissue Nutrition and Biomass of Freshwater Wetland Plant in Sanjiang Plain, Northeast China

1 Introduction It has been reported that habitat nutrient availability frequently limited plant growth and determined species dominance and abundance in natural communities (Miao et al., 2000). Nutrient availability is also a main regulator of aquatic primary production. Human-induced nutrient enrichment results in die-back of native vegetation and alteration of species dominance in various aquatic eco- systems (Miao et al., 2000; Green and Galatowitsch, 2002). Particularly, nutrient enrichm…