PRECIPITATION OF CALCIUM CARBONATE FROM SEAWATER

Slight perturbations of the oceanic DOC by addition of oxalic acid, tryptophan, and sodium humate did not affect the magnesium content of spontaneously precipitated Mg-calcites. However, the copresence of spontaneously precipitated aragonite and of Mg-calcite as a function of the initial degree of supersaturation was changed by the dissolved organic matter. Times of nucleation for carbonates was affected by organic matter at low organic concentrations because of coating and at high concentrations due to complexation.     

RESOLUTION OF MULTICOMPONENT FLUORESCENT MIXTURES BY ANALYSIS OF THE EXCITATION-EMISSION-FREQUENCY ARRAY

Fluorescence lifetime provides a third independent dimension of information for the resolution of totalluminescence spectra of multicomponent mixtures.The incorporation of this parameter into theexcitation-emission matrix(EEM)by the phase modulation technique results in a three-dimensionalexcitation-emission-frequency array (EEFA).Multicomponent analysis based on the three-dimensionalEEFA brings a qualitative change for the resolved spectra,i.e.individual spectra can be uniquely resolved,which is impossible with any two-dimensional analysis.In this paper we present a method for analyzingthe EEFA.We show mathematically that with the three-dimensional analysis of the EEFA individualspectra and lifetimes can be obtained.Our algorithm is developed in mathematical detail and isdemonstrated by its application to a two-component mixture.     

利用单一的和集合的方法预告区域预报技巧

本文利用平均海平面气压的模式预报误差(MFE)的3个预告因子研究了预告澳大利亚有限区域模式36小时预报技巧的可能。两个预告因子使用单一预报:其中1个以对于初始分析和预报的MFE的统计回归为基础;另1个因子利用了预报的持续性程度。第3个因子应用了与其它NWP中心的预报集合偏差。根据5个月的逐日36小时预报,发现了上述预告因子与MFE的相关系数分别是0.58、0.18和0.40。用最佳线性方法把上述3个因子组合后与MFE的相关系数增加到0.71。用两个月的独立资料集进一步对组合因子进行试验,得出的相关系数是0.67。因此,把这种方法应用于独立的和非独立的资料中,可以解释MFE方差的近50％。这证明了这种方法对于在总体上鉴别模式预报好坏有业务应用价值。澳大利亚东南部的实例研究,进一步证明了这些预告因子在整个预报区域中可以相当好地鉴别预报技巧。     

Logs and snags in a shola forest of Kerala, India

Introduction Dead wood is an important structural and functional component of a forest ecosystem(Fridman and Welheim 2000). Recent studies also indicate that dead wood is important for maintaining both plant and animal diversity in different forest ecosystems (Grove 2001) as it serve as an energy source (Bray and Gorham 1964) and habitat for an array of organisms. Dead wood can also help reduce erosion, increase soil organic matters (McFee and Stone 1966), and suitable conditions for seedli…     

Geological Relationships Between the Intrusions,Country Rocks,and Ni-Cu-PGE Sulfides of the Kharaelakh Intrusion,Noril′sk Region:Implications for the Roles of Sulfide Differentiation and Metasomatism in Their Genesis

The Ni-Cu-platinum group element sulfide ore deposits of the Kharaelakh Intrusion,Noril′sk Region,Siberia,represent a large concentration of sulfides associated with a small differentiated intrusion formed at the edge of the Siberian Craton in the roots of the Siberian Trap flood basalt.The deposit is associated with an intrusion that occupies a flanking periclinal structure adjacent to the Noril′sk-Kharaelakh Fault.The intrusion is strongly differentiated and comprises taxitic gabbrodolerites,picritic gabbrodolerites,and gabbrodolerites within the main body which in turn forms a chonolith within a sheet-like intrusion that extends laterally to form extensive undifferentiated sills of gabbrodolerite.The intrusion substantially replaces the stratigraphy of the country rocks,and although it appears to have exploited the axis of structures developed in response to transtension,the intrusion has created space by both mechanical dilation of stratigraphy and magmatic replacement of pre-existing sedimentary rocks.The frontal lobes of the main intrusion have complex apophyses of gabrodolerite on a range of scales that demonstrate replacement of the sedimentary rocks and link to the development of an extensive metamorphic halo in the country rocks.This halo is much narrower over the main body of the intrusion,and these observations have implications for the thermal history of the intrusion.Mg-skarns and breccias are developed in the roof of the main body of the intrusion.Within the intrusion,the taxitic rocks contain vesicles and the blebby sulfides developed in the picritic and taxitic gabbrodolerites appear to have a linkage to volatile phases.Cuprous sulfide mineralization developed at the roof of the Kharaelakh Intrusion is associated with metamorphosed and skarn-bearing country rocks,and appears to have been generated by a combination of sulfide fractionation and associated metasomatism.The geological relationships appear consistent with a chonolith model for the development of the differentiated intrusion and mineralization,but the extent of metasmorphism of the country rocks appears to be related to the unusual thickness of gabbrodolerite apophyses at the flanks of the intrusion rather than metamorphism produced by the passage of mafic magma through the intrusion.Variations in disseminated sulfide compositions and metasomatic textures in the skarns are described,and a model is proposed which balances traditional views on the evolution of the magma conduits with the impact of magmatic fluids transported through the magma column(i.e.transmagmatic fluids).The importance of structures in controlling the nature of the conduit,and the resultant small intrusions with excess sulfide is a feature of many other Ni-Cu sulfide deposits including Voisey′s Bay,and it is suggested that the sulfides are more likely to have beentransported from depth into their final resting place rather than developed by in-situ equilibration of sulfide with fresh magma in the chonolith.     

Numerical modeling of shallow water table behavior with Lisse effect

Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table rises in soils, which are significantly faster and higher than those in soils without air entrapment. Two numerical models, Integrated Hydrologic Model (IHM) and HYDRUS-1D (a single-phase, one-dimensional Richards′ equation model) were tested at an area of west central Florida to help further understanding the shallow water table behavior during a long term air entrapment. This investigation employed field data with two modeling approaches to quantify the variation of air pressurization values. It was found that the air pressurization effect was responsible at time up to 40 cm of water table rise being recorded by the observation well for these two models. The values of air pressurization calculated from IHM and HYDRUS-1D match the previously published values. Results also indicated that the two numerical models did not consider air entrapment effect (as the predictive parameters remain uncertain) and thus results of depth to water table from these models did not compare to the observations for these selected periods. Incorporating air entrapment in prediction models is critical to reproduce shallow water table observations.     

A model test system with a dynamic load device for geotechnical engineering in cold regions

A model test system with a dynamic load device for geotechnical engineering in cold regions is presented. This system consists of a model test tank, a refrigeration device and temperature controller, a dynamic load device, together with sensors and data loggers for detecting stress, deformation, and temperature changes. The system can accommodate soil blocks up to 3 m in length, 2.5 m in width, and 1 m in height. The lowest temperature provided by the refrigeration device is -20 °C. The maximum load provided by the dynamic load device is 100 kN and the vibration frequency of the dynamic load can range from 0.1 to 10 Hz. A number of waveforms, such as sine waves, rectangular waves, triangle waves, and other user-defined waves can be generated by the dynamic load device controller.     

The mean value concept in mono-linear regression of multi-variables and its application to trace studies in geosciences

The "mean value concept" in a mono-linear regression of multi-variables is clarified.Its applications to reconstruction of the past 90-year salinity of the sea surface water in Xisha Islands and to tracing the past 80 ka paleo-geomagnetic events from the Luochuan loess 10Be record are introduced in detail,which show the significance and the potential of the "mean value concept" in geoscience research.     

中生代燕山褶皱冲断带的构造演化—以河北省和辽宁省为重点的研究

从渤海湾和辽宁省开始 ,燕山山脉沿北纬 40°左右一直向西延伸到河北和内蒙古的边界。继续向西 ,以太古宙为基底的燕山山脉被上第三系所覆盖 ;因此 ,虽然内蒙古的阴山很可能就是燕山向西的延伸 ,但还缺乏有力的证据。中生代燕山褶皱冲断带以陆源沉积、岩浆作用和构造变形 (包括多期的褶皱作用 ,挤压、伸展及走滑断层作用 )为特征。对北京、冀北与辽西地区侵入岩及火山岩的野外工作及测年 (U Pb,40 Ar 39Ar方法 )研究揭示出该区中生代复杂的构造变形特征 ;而这种构造变形特征被归因于 :(1)中生代以前 (二叠纪到中生代早期 )复杂的早期变形序列 ,以及 (2 )中生代时期交替发生的主要构造形迹向南和向北的构造汇聚作用。燕山在中侏罗世之前 (早于 180 Ma)向南运动的低角度的逆冲断层发育在一条二叠纪三叠纪岩浆弧的南部 ,太古宙基底及元古宙和显生宙盖层均卷入其中。该次推覆作用可能是 (1)古生代时期蒙古弧与安第斯型的大陆弧沿华北板块的北部边缘发生碰撞的后果 ,或 (2 ) (北部陆块 )向南俯冲于华北太古宙“克拉通”之下时形成的 ,类似于美国科迪勒拉型的弧后、前陆褶皱冲断带。此次褶皱冲断发生之后 ,该推覆断层的上盘经历了广泛的剥蚀 ,随后中侏罗世火山沉积地层同时沉积在上、下盘之上。我们的研究表明