用地磁脉动日食效应探讨甚低纬Pc3-4地磁脉动源

在3次日食期间,利用甚低纬区和从低纬到甚低纬过渡区地面站进行的地磁脉动观测资料,分析了Pc3-4地磁脉动的南北分量（H）和东西分量（D）在H-D平面内矢端图主轴方向的变化．结果表明,当观测点纬度低于日全食带纬度时,H-D矢端图主轴有90°相移现象;当观测点纬度高于日全食带纬度时,则无这种现象．由此我们推测,甚低纬区和从低纬到甚低纬过渡区Pc3-4地磁脉动可能主要是过滤机制产生的．     

Estimation of Oxygen Consumption Rate Using T-DO Diagram in the Benthic Layer of Ohmura Bay, Kyushu, Japan

We have observed the temporal variation of oxygen deficient water with short time scale (less than a few days) in the central area of Ohmura Bay, Kyushu, Japan, in summer, 1995 and 1996. The vertical profiles of temperature were similar to those of dissolved oxygen. We noticed a linear relation between temperature and dissolved oxygen in the bottom layer, and applied the T-DO relation to estimate the net oxygen consumption rate, rather than direct evaluation of the advection and diffusion. Oxygen consumption rate just above the bottom was estimated to be about 0.21 g O₂ m^–3day^–1 in July 1995, and about 0.28 g O₂ m^–3day^–1 in August 1996. The net oxygen consumption rate estimated for the bottom layer below the second thermocline was about 0.61 g O₂ m^–3day^–1 with variability from 0.55 to 0.66 g O₂ m^–3day^–1 during July 25 to 29, 1995. This is was about 0.64 g O₂ m^–3day^–1 with variability from 0.18 to 1.4 g O₂ m^–3day^–1 during August 22 to 30, 1996. The net oxygen consumption rates are about half of those measured with a closed system in the Seto Inland Sea.     

地球物理剖面揭示大兴安岭域壳幔结构及其地质意义

大兴安岭域,包括大兴安岭及其两侧盆地,穿过额尔古纳地块、兴安地块、松嫩地块和辽源地体.本文在东北地区已有的近东西向的全球地学断面（GGT）资料基础上,在大兴安岭两侧补充了2条近南北向的地球物理剖面,组构了综合地球物理栅状图;又结合区域内其他7条经综合解译的地球物理剖面,分析讨论了研究区壳幔结构特征及其地质意义.论文得到如下初步结果：（1）研究区莫霍界面以大兴安岭重力梯级带为分界,西部和东部深度有明显差异;以索伦山-西拉木伦河缝合带为界的南北岩石圈-软流圈界面（LAB）深度、软流圈有明显差异.呈现出地壳东西分带、岩石圈地幔南北分块的特征.（2）额尔古纳-兴安微板块具有较稳定的岩石圈地幔组构,与南部的中朝板块的岩石圈地幔具有较大差别;额尔古纳地块与西伯利亚板块的岩石圈特征更为接近.（3）获得古缝合带位置线索.林西以南的翁牛特下方存在明显的LAB南北向抬升,这是古亚洲洋闭合在岩石圈尺度上留下的遗迹;索伦山缝合带东延至西拉木伦河,是古亚洲洋闭合的场所.（4）大兴安岭域跨过两条板块缝合带,该区域北部与中部岩石圈组构特征相近,但它们的岩石圈地幔基底并不相同,这是在塔源-喜桂图缝合带于早古生代的拼合之后由数亿年的长期壳幔物质横向均衡作用所致.     

弯折断层系统上超剪切破裂传播的产生条件

断层的破裂速度是描述地震震源过程的重要物理量.如果震源破裂的传播速度超过剪切波速,将会对地震波场产生影响,造成更大的破坏性.超剪切破裂的产生受多种因素影响,断层的几何形状是因素之一.本文针对弯折断层的情况,采用三维空间非结构化网格的边界积分方法计算参数空间中的破裂相图,从中分析超剪切破裂的产生条件.以15°、25°和4...     

Ferrous iron in post-perovskite from first-principles calculations

We investigate by first-principles calculations the effect of ferrous iron, Fe²⁺, on the structure and the equation of state of MgSiO₃ post-perovskite. We find that ferrous iron is high-spin over the pressure range of the mantle assuming a ferromagnetic structure. The bulk modulus and the specific volume increase with the addition of ferrous iron to MgSiO₃. We find that Fe partitions preferentially to post-perovskite and broadens the two-phase pressure range.     

含锂、钾硼酸盐水溶液体系固液相平衡研究

采用等温溶解平衡法测定了含锂、硼硼酸盐水溶液体系在35℃时的溶解度、密度和折光率,根据实验数据,绘制了相应的溶解度图、密度图、折光率图和pH值图。该体系溶解度相图包含一个共饱点,两个单盐结晶区,分别为结晶相区较大的（L+ Mg2B6O11·15H2O）和结晶相区较小的（L + K2B4O7·4H2O）,溶液体系中没有固溶体和复盐产生。溶液的密度、折光率和pH值随着硼酸钾溶液的浓度增大而呈现与规律的变化,并采用半经验公式对溶液的密度和折光率进行计算,计算值和实验值吻合较好。     

Isothermal Evaporating Phase Equilibria in the Quaternary System (LiCl+NaCl+Li2SO4+Na2SO4+H2O)at 348.15 K and 0.1 MPa:An Experimental and Theoretical Study

The gradient solar pond technique is an economic separating process employed in the inorganic chemical industrial production of salt lake chemical engineering processes. In this paper,a novel isothermal evaporation experimental method was employed to simulate the evaporation phase equilibrium for the reciprocal quaternary system( LiCl + NaCl + Li_2 SO_4+ Na_2 SO_4+ H_2 O) at 348. 15 K to serve as a useful guide for lithium salt production via the depth solar ponds. The isothermal evaporation equilibrium solubilities and physicochemical properties,including the densities and pH values,were experimentally investigated. The dry-salt phase diagram,water-phase diagram,and the diagram of the physicochemical properties versus composition were plotted with respect to the experimental data. The drysalt phase diagram consists of three invariant points,seven univariant solubility curves,and five crystallization regions,specifically halite( NaCl,Ha),thenardite( Na_2 SO_4,Th),double salt( Li_2 SO_4·Na_2 SO_4,Db_2),lithium sulfate monohydrate( Li_2 SO_4·H_2 O,Ls),and lithium chloride monohydrate( LiCl·H_2 O,Lc). Based on Pitzer and its extended HMW model,the Pitzer single salt parameters,mixing ion interaction parameters,and thermodynamic stable equilibrium constants for the quaternary system at 348. 15 K were obtained. The calculated phase diagram and experimental isothermal phase diagram at 348. 15 K exhibited a great difference. Based on these results,the isothermal evaporation phase diagram can truly reflect the salt sedimentary in salt lakes and can be applied as a useful guide for the solar pond process.     

Solid-Liquid Phase Equilibria in the Aqueous System Containing Potassium, Magnesium, and Borate at 308.15 K

Experimental studies on the solubility,density,refractive index,and pH value in the aqueous system containing potassium,magnesium,and borate at 308. 15 K were determined with the method of isothermal dissolution equilibrium. Based on the experimental results,the diagrams of solubility,density,refractive index,and pH value in this system were plotted. We found that there were one eutectic point and two crystallization regions corresponding to the large area of inderite( L + Mg_2 B_6 O_(11)·15 H_2 O) and the relatively small area of potassium borate tetrahydrate( L + K_2 B_4 O_7·4 H_2 O),respectively. Neither double salt nor solid solution was found in this system. The physicochemical properties( density,refractive index,and pH value) in solution at 308. 15 K changed regularly with increasing potassium borate concentration. The calculated values of density and refractive index using empirical equations of the aqueous system were in good agreement with the experimental values.     

西台吉乃尔盐湖卤水自然蒸发试验研究

根据西台吉乃尔盐湖卤水组成进行相图分析,并进行自然蒸发,获得自然蒸发试验数据,对西台吉乃尔盐湖卤水综合利用提供依据。