地球干冰事件始末──地球奥秘新探索

本文通过大量事实表明，地球早期由于二氧化碳大气发生临界点相变，引发了一场全球性干冰致冷事件，形成了数千米厚的干冰盖层。液态水、古老变质岩系、原始生物等都是在干冰盖层背景下形成的。干冰的最后解体消融约在最近的１—２亿年。海洋是干冰盖层与岩浆蒸气直接作用的产物。     

基于Quaternary编码的球面三角格网邻近搜索算法(英文)

The characteristic of Quaternary codes is analyzed. The rule of distinguishing triangle direction is given out. An algorithm of neighbor finding by decomposing the Quaternary code from back to front is presented in this paper. The contrastive analysis of time complexity between this algorithm and Bartholdi＇s algorithm is approached. The result illustrates that the average consumed time of this algorithm is about 23.66% of Bartholdi＇s algorithm.     

计算介质球极化场的一种简单方法

各向同性均匀介质球在均匀电场中被极化而具有电偶极矩,成为激发电场的二次源,在空间发生电场。本文利用一个简单变换,把问题变换为一个均匀带电球体电场问题。此种分析方法不需用特殊函数,而且物理概念清晰,易于理解。     

多层球体对电磁场散射响应的求解方法

为建立多层球体对电磁场散射响应的求解方法,将球外入射电磁场分为TM和TE极化波两部分,通过求解Debye位方程可得到多层球体各层中两种极化场的通解形式,利用边界条件建立了TM波（或TE波）球面波阻抗（或导纳）的递推关系,借助于阻抗（或寻纳）导出了球体对TM波（或TE波）所产生散射场的一般表达式．文中具体求解了球体对平面波径向和横向偶极子场的散射响应．     

物流场论及其在经济分析中的应用

本文提出存在于人类生产活动中的一种“场”现象——物流场及其运动规律的一种概念体系和分析方法。利用物流场与对应区域的生产和社会发展相互关系,来分析经济和社会发展特别是地理、交通经济方面的问题。并对我国和世界主要国家的物流场以及交通运输经济若干问题作了一个探讨性分析。     

Simulation of diffraction of ocean waves by a submerged sphere in finite depth

Based on the linear diffraction theory, an investigation is made on the interaction of water waves with a completely submerged sphere in water of finite depth in this paper. The method of multipole expansions is used to obtain the fluid velocity potential in the form of double series of the associated Legendre functions with the unknown coefficients of the infinite set of infinite matrix equations. The truncation property of the matrices and the convergence of the multipole series coefficients are investigated for various wavelengths and depths. The systematic numerical simulation, based on our analytical solution, is carried out and the fields of the hydrodynamic diffraction pressure and fluid velocity around the sphere, the three-dimensional free surface elevation, and total exciting forces acting on the sphere are graphically presented for a wide range of the body submergences, ocean depths and wavelengths.     

宾汉流体的触变性及球体绕流阻力

通过推导和实验,建立了宾汉触变流体的屈服应力及不沉降最大球体直径随浑水静止历时增长而变化的公式;建立了宾汉触变流体运动的Navier-Stokes方程,求解该方程时,导得了球体在宾汉触变流体中沉降时的绕流阻力及阻力系数公式。用各种来源的宾汉触变体浑水的流变试验资料及X射线屏幕上观测球体运动的试验资料验证上述公式,取得了良好的结果。     

Framing the frontier – Tracing issues related to soybean expansion in transnational public spheres

Rapid soybean expansion in South America has been linked to numerous socio-environmental problems, including deforestation in sensitive biomes. As a major importing region of soybeans, wider public awareness has also put pressure on the European Union. Different governance initiatives involving various groups of stakeholders have sought to address these issues. However, what is identified as a relevant problem, as a region of interest or which actors are mentioned in this context are all matters of claims-making processes between different groups and mediated through various channels of communication. This study uses a text-mining approach to trace the construction of socio-ecological problems related to soybean expansion and the actors and regions linked with these issues in public discourse. The focus lies on print media from the European Union, but several additional sources are included to investigate the similarities and differences between various communication channels and regions. These include newspaper articles from producing countries and international news agencies, scientific abstracts, corporate statements, and reports from advocacy groups gathered from the mid-1990s to 2020. The results show that European mass media have shifted their focus from consumer labeling, health, and concerns over genetically modified organisms towards more distant or abstract phenomena, such as deforestation and climate change. This has been accompanied with a broader view on different stakeholders, but also with a strong regional focus on the Amazon biome. There has also been much less attention on direct concerns for communities in producing regions, such as land conflicts or disputes over intellectual property rights. We conclude that while European public spheres appear to become more receptive to issues related to impacts in sourcing regions, there remains a narrow focus on specific problems and regions, which reflects a fundamental asymmetry in different stakeholders' ability to shape transnational deliberations and resulting governance processes.     

Batch Dissolution Kinetics: The Shrinking Sphere Model with Salts and Its Potential Application to Biogenic Silica

The full potential of batch dissolution experiments in geochemical and industrial applications has been hampered by the lack of an equation to describe the increase in dissolved solid concentration with time. This study provides new experimental results on the dissolution of salts and new equations, which describe dissolution according to the shrinking sphere model. Sieved salts were found to dissolve according to the shrinking sphere model while the dissolution of the parent material, raw (agglomerated) salt, fitted an exponential dissolution curve. The implications of this to the development of a systematic approach to batch dissolution, irrespective of the solid, is explored. Mathematical equations are derived for the dissolution of solids in under-saturated systems, which are much simpler than ones available, so far. In turn these provide easier comprehension of the workings of the shrinking sphere model. Finally, existing results for biogenic silica dissolution are reviewed in the light of the above-mentioned experimental and modelling advances. An earlier claim that shrinking sphere dissolution had been observed is refuted.     

Least-squares Minimization Approaches to Interpret Total Magnetic Anomalies Due to Spheres

We have developed three different least-squares approaches to determine successively: the depth, magnetic angle, and amplitude coefficient of a buried sphere from a total magnetic anomaly. By defining the anomaly value at the origin and the nearest zero-anomaly distance from the origin on the profile, the problem of depth determination is transformed into the problem of finding a solution of a nonlinear equation of the form f(z)=0. Knowing the depth and applying the least-squares method, the magnetic angle and amplitude coefficient are determined using two simple linear equations. In this way, the depth, magnetic angle, and amplitude coefficient are determined individually from all observed total magnetic data. The method is applied to synthetic examples with and without random errors and tested on a field example from Senegal, West Africa. In all cases, the depth solutions are in good agreement with the actual ones.