分层液中的“浮冰”（初二）

题 如图1所示，装有水的容器中漂浮着一块冰，在水的表面上又覆盖着一层油，那么当冰块全部熔化之后，油面的高度如何变化?(P水>P冰>P油)

Anodic process on Cu-Al alloy in KF-AlF3-Al2O3 melts and suspensions

Anodic processes on Cu-10 Al electrode in molten KF-AlF3-Al2O3(saturated) and suspensions were characterized using chronopotentiometric and cyclic voltammetric techniques. Effects of cryolite ratio(CR= x(KF)/x(AlF3)), temperature and particle volume fraction(φ) on the electrochemical behaviour of the anode were demonstrated. Initially, the anode was polarised in the galvanostatic mode in melt and suspensions(φ=0.12, 0.15) at 750 ℃ with 0.4 A/cm^2 current density. The anode potential in melt varied between 2.5 and 3.2 V and in suspensions(φ= 0.12) between 3.3 and 3.4 V. XRD analysis was conducted to study the oxide phases on the anode surface. Anode limiting current densities and mass transfer coefficients drastically decreased with the increase of φ in the suspension. The results suggest that the Cu-10 Al electrode works better in suspensions with CR of 1.4 and particle volume fraction of 0.09 at 800 ℃.

Interaction of Ships within Navigable Ice Channel

At intensive winter navigation, the ships should separate under movement on opposite courses or make overtaking of slowly moving cargo vessels in the water areas covered with ice. Under navigation within ice channel, possibilities for maneuvering are reduced; therefore, danger of collision of ships exists. The ice floes between vessels hulls and outside are the major factors defining values and direction of side force and yawing moment that arise on their hulls during divergence. Ice loads on the ship hull exceed considerably the loads caused by water flow around hull. Performed previously experiments in the ice basin have detected that besides increase of side force and yawing moment modules the change of side force directions occurs during the divergence of vessels in comparison with same maneuvering on water area without ice cover. Article contains the detailed problem definition and mathematical model of ships interaction during opposite passing by or overtaking and technical approach to computation of loads on vessels hulls. As example of strategy application, the simulation of loads on overtaking ship was performed, and main results of computations are presented. Outcomes of investigation are character of variation of side force and yawing moment during passage along overtaken ship and dependence of the peak values of additional ice resistance, side force and yawing moment on beam distance between vessels and thickness that are contained in the article.

Influences of sea ice on eastern Bering Sea phytoplankton

The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton community. The dominant species were Grammonema islandica （Grunow in Van Heurck） Hasle, Fragilariopsis cylindrus （Grunow） Krieger, F. oceanica （Cleve） Hasle, Navicula vanhoeffenii Gran, Thalassiosira antarctica Comber, T. gravida Cleve, T. nordenskioeldii Cleve, and T. rotula Meunier. Phytoplankton cell densities varied from 0.08× 10^4 to 428.8× 10^4 cells/L, with an average of 30.3× 10^4 cells/L. Using cluster analysis, phytoplankton were grouped into three assemblages defined by ice-forming conditions： open wate.r, ice edge, and sea ice assemblages. In spring, when the sea ice melts, the phytoplankton dispersed from the sea ice to the ice edge and even into open waters. Thus, these phytoplankton in the sea ice may serve as a “seed bank” for phytoplankton population succession in the subarctic ecosystem. Moreover, historical studies combined with these results suggest that the sizes of diatom species have become smaller, shifting from microplankton to nannoplankton-dominated communities.

Optimization of ice cuttings transportation by cable-suspended core auger drills

Ice cores contain an abundance of information about the Earth＇s climate in the past, and recovered from shallow drilling down to 300-350 m give sufficient information for reconstructing of the last climatic changes and for monitoring of pollution from human being. Cable-suspended core auger drills use an armored cable with a winch to provide power to the down-hole motor system and to retrieve the down-hole unit. Because of their lightweight, convenient transportation and installation, high penetration rates and low power consumption, core auger drills are widely used for shallow drilling in ice. Nowadays at least 14 types of auger electromechani- cal drills were designed and tested in different foreign and national glaciological laboratories. However, auger options were usually determined by experience, and the main parameters （ helix angle of the fights and rotational speed） are varied in a wide range from drill to drill. If parameters of auger are not chosen properly, poorly en- gineered drills had troubles with low efficiency of cuttings transportation, jam of ice cuttings, repeated fragmen- tation, cutters icing and stop penetration, abnormal power consumption, high rotation torques, and so on. Thus, this paper presents the method of optimization of iee cuttings transportation of cable-suspended core auger drill on the base of the theory of rotary auger. As the result, the optimal helix angle was determined correspond- ing to the rotational speed from the transportation efficiency point of view.

Dynamic Characteristics of Irregular Ice Floes Based on Polyhedral Discrete Element Method

In polar regions, floating ice exhibits distinct characteristics across a range of spatial scales. It is well recognized that the irregular geometry of these ice formations markedly influences their dynamic behavior. This study introduces a polyhedral Discrete Element Method (DEM) tailored for polar ice, incorporating the Gilbert-Johnson-Keerthi (GJK) and Expanding Polytope Algorithm (EPA) for contact detection. This approach facilitates the simulation of the drift and collision processes of floating ice, effectively capturing its freezing and fragmentation. Subsequently, the stability and reli ability of this model are validated by uniaxial compression on level ice fields, focusing specifically on the influence of compression strength on deformation resistance. Additionally, clusters of ice floes nav igating through narrow channels are simulated. These studies have qualitatively assessed the effects of Floe Size Distribution (FSD), initial concentration, and circularity on their flow dynamics. The higher power-law exponent values in the FSD, increased circularity, and decreased concentration are each as sociated with accelerated flow in ice floe fields. The simulation results distinctly demonstrate the con siderable impact of sea ice geometry on the movement of clusters, offering valuable insights into the complexities of polar ice dynamics.

Automatic extraction of floating ice at Antarctic continental margin from remotely sensed imagery using object-based segmentation

Information of Antarctic iceberg and sea ice are valuable to Antarctic ice melting patterns studies which are helpful to understand climate conditions and general trends of our planet.This paper presents an automatic floating ice extraction method based on image segmentation technology using region growing.It effectively solves the over-segmentation and under-segmentation problems by merging the gray,contour,location and other information of each ice-object.A pixel-based extraction method is proposed to extract the small ices within 5 pixels.LANDSAT TM data,Chinese environment disaster satellite HJ1B data,and MODIS 1B data used to detect Floating ice at Antarctic continental margin respectively.The results showed that the extraction accuracies of the three kinds of data were all higher than 81 percent,while the accuracies of both TM data and HJ1B data were higher than 90%.Object-based information extraction methods can not only obtain the total area and number of floating ice objects in the whole region,but also provide precise details of single objects,including area,perimeter,contour,average brightness.