Progress in low-frequency radio astronomy and I.S. Shklovskii’s contribution to its development

Radio astronomy at decameter wavelengths is currently undergoing very active development. Large-scale, new generation low-frequency radio telescopes are being constructed and already used in many countries around the world. As before, the largest, most sensitive, and most versatile telescope at decameter wavelengths is the Ukrainian UTR-2 radio telescope operating at 8–32 MHz, which has an effective area of more than 10⁵ m² and an angular resolution of about 0.5?, as well as the URAN interferometric system based on the UTF-2. Many studies that have been carried out on these facilities have been based on important results and far-sighted predictions of Shklovskii. These include, in particular, studies of dynamical spectra and the brightness distributions of the sporadic and quiescent decameter radio emission of the hot solar corona, complex, broadband radio spectroscopy of the interstellar medium, and multi-frequency monitoring of secular decreases in the flux densities of supernova remnants. The coordinated use of highly effective existing and newly constructed radio telescopes joined into ground networks, as well as specialized space missions, are opening new prospects for low-frequency radio astronomy.     

Evolution of silica accumulation in the earth’s history and its relation to biota development

Two branches of silica rockevolution related to oceans and continental blocks have been outlined. The boundaries of changes in types of silica rocks, their formation, and development of the organic world were established: (i) the beginning of the Phanerozoic was related to transformation from microbial to biogenic silica deposition (or to a change in the influence of microbial activity on silica accumulation); (ii) cessation of the formation of cherts enriched in organic matter, which was synchronized with land colonization by organisms in the Devonian, and (iii) an explosive style of global silica accumulation related to the appearance and development of diatoms, which correlates with appearance of angiosperm plants in tropical forests.     

A vision for Iran’s fuel cell and hydrogen development

Hydrogen combined with fuel cell (FC) technology has been widely discussed as a long-term fuel option to address environmental and energy security concerns. Iran, despite outlining a long-term plan to develop its renewable energies’ (REs) infrastructures, is faced with difficulties in deploying fuel cell hydrogen (FCH). These obstacles—led by lack of adequate funding—have caused a slowdown in the government-driven initiatives in recent years, thus resulting in projects delays and suspensions. This paper focuses on current status of Iran’s FCH within and among leading and neighboring countries. Barriers and challenges of the three main actors (government, university, and industry) on Iran’s FCH development are analyzed and then supported with a policy perspective. It is shown that the government obligations play a significant role to overcome these obstacles and also act as the main driving force to perform the required actions. The paper also proposes strategic measures in a short-, medium-, and long-term framework to promote the technology in Iran in hopes of a clear national policy and a proper vision. It is shown that the responsibility for the short- and medium-term actions lies predominantly upon the government while it will be fully devolved to the private sector in the long term.     

Environmental geoinformaicts of fast growing Himalaya’s foothill towns and surrounding: concept and implementation

Himalaya foothill zone have fragile geo-environment due to active tectonics and dynamic hydrological process and its associated reshaped geomorphology. Rapid urbanization and development of new colonies leads to high rate of land use change and natural resource degradation since last three decades which has been accumulating the fragility of the area. Consequently entire Himalaya foothill zone requires a comprehensive local level geo-environmental appraisal for effective sustainable development planning of the region. Keep in view this; the Ramnagar Himalayan Foothill area (RHFA) in district Nainital, Uttarakhand (India) has been selected for the case illustration. The main objective of the study was to develop a GIS database on Ramnagar environmental geo-informatics (REGI) to facilitate all the concern line departments to implement their socioeconomic developmental activities in the most suitable and safe places throughout the study area. REGI suggests, although landscape of the study area have few favorable conditions for the inhabitant (i.e. maximum proportion (92 %) of the study area enjoys sub-tropical to sub-temperate climatic conditions, easy approachable, thick vegetation cover, rich water resources) but the active tectonics and dynamic hydrological process and its associated reshaped geomorphology poses a stressed geo-environment which need to be consider to formulate a decision support system (DSS) for sustainable development planning.     

A. V. Peyve — the founder of the concept of deep faults

The further development of Peyve’s concept of deep faults in the Earth’s crust and brittle part of the lithosphere is discussed. Three aspects are accentuated in this paper: (1) the modern definition of the term deep fault; (2) the parameters of deep faults as ruptures of the geological medium and three-dimensional, often boundary, geological bodies; and (3) reactivation of deep faults, including the development of this process in real time. Peyve’s idea of deep faults readily fitted into the concept of new global tectonics (plate tectonics). This was facilitated, first of all, by the extensive efforts made to elaborate Peyve’s ideas by a large group of researchers at the Geological Institute of the Russian Academy of Sciences (GIN RAS) and other scientists. At present, the term deep fault has been extended and transformed to cover three-dimensional geological bodies; the geological and geophysical properties and parameters of these bodies, as well as their reactivation (recurrent activation) in real time, have been studied.     

Supercontinent tectonics and biogeochemical cycle： A matter of ‘life and death＇

<正>The formation and disruption of supercontinents have significantly impacted mantle dynamics,solid earth processes,surface environments and the biogeochemical cycle.In the early history of the Earth,the collision of parallel intra-oceanic arcs was an important process in building embryonic continents.Superdownwelling along Y-shaped triple junctions might have been one of the important processes that aided in the rapid assembly of continental fragments into closely packed supercontinents. Various models have been proposed for the fragmentation of supercontinents including thermal blanket and superplume hypotheses.The reassembly of supercontinents after breakup and the ocean closure occurs through "introversion","extroversion" or a combination of both,and is characterized by either Pacific-type or Atlantic-type ocean closure.The breakup of supercontinents and development of hydrothermal system in rifts with granitic basement create anomalous chemical environments enriched in nutrients, which serve as the primary building blocks of the skeleton and bone of early modern life forms. A typical example is the rifting of the Rodinia supercontinent,which opened up an N—S oriented sea way along which nutrient enriched upwelling brought about a habitable geochemical environment.The assembly of supercontinents also had significant impact on life evolution.The role played by the Cambrian Gondwana assembly has been emphasized in many models,including the formation of 'Trans-gondwana Mountains' that might have provided an effective source of rich nutrients to the equatorial waters,thus aiding the rapid increase in biodiversity.The planet has witnessed several mass extinction events during its history,mostly connected with major climatic fluctuations including global cooling and warming events,major glaciations,fluctuations in sea level,global anoxia,volcanic eruptions, asteroid impacts and gamma radiation.Some recent models speculate a relationship between superplumes,supercontinent breakup and mass extinction.Upwelling plumes cause continental rifting and formation of large igneous provinces.Subsequent volcanic emissions and resultant plume-induced "winter" have catastrophic effect on the atmosphere that lead to mass extinctions and long term oceanic anoxia.The assembly and dispersal of continents appear to have influenced the biogeochemical cycle,but whether the individual stages of organic evolution and extinction on the planet are closely linked to Solid Earth processes remains to be investigated.     

Influence of Marble’s Texture on its Mechanical Behavior

This research work studied the influence of texture on the mechanical properties of crystalline rocks at the scale of the laboratory sample. The experiments were performed on a marble varying in texture, so that the study was conducted on homogeneous (entirely xenoblastic or totally granoblastic) and heterogeneous (mix of the two textures) specimens. The mechanical behavior of the homogeneous and heterogeneous samples was investigated with static and dynamic, destructive and nondestructive tests, in natural conditions, at the laboratory temperature, and at higher temperatures. The specimens were heated to 100, 200, and 300 °C, in order to examine the effect of heating temperature on the elastic modulus and P-waves velocity. As a result, the pure granoblastic marble exhibits values of the elastic modulus, P-waves velocity, and strengths, both in natural conditions and on heated specimens, lower than xenoblastic samples. Such different behavior can be explained by a higher grain boundaries porosity of the granoblastic marble. On heterogeneous samples, only the Rock Impact Hardness Number (RIHN) appears able to highlight the dependence of the mechanical properties on the rock texture. In particular, the impact strength improves with increasing the percentage of xenoblastic texture inside the specimen.     

Diffusion of China’s coal-fired power generation technologies: historical evolution and development trends

Natural Hazards - With increasing environmental pressure and the promotion of structural reforms on the supply side, a trend of transformation and upgrading is inevitable in coal-fired power...     

Solidification of the Earth’s core: The main energy source in the formation of trappean provinces and flood basalts

The discovery of a layer of increased density in the liquid core at the boundary with the solid core gives grounds to suggest that solidification of the solid core occurs with an increase in total core volume and is accompanied by an increase in internal pressure in the core. This makes it possible to suggest a translational mechanism of energy transfer from the core to the Earth’s surface. It is suggested that the restoration of lithostatic equilibrium occurs via rising of a column of mantle material, uplift as result of elastic mantle deformation of the boundary of the transition layer at a depth of 420 km, and the formation of rising at the surface.     

Model or measurements? A discussion of the key issue in Chapman and Pollack’s critique of Hamza et al.’s re-evaluation of oceanic heat flux and the global power

Chapman and Pollack (C and P)[2007, Int J Earth Sci] criticize Hamza et al. [2007, Int J Earth Sci] for using actual heat flux measurements in young oceanic crust instead of values from 1-D cooling models. The rationalization of C and P and previous authors is that hydrothermal circulation causes the discrepancy between model and measurement. However, the discrepancy between model values and measured heat flux exists over the entire ocean floor and is opposite to the perturbations that hydrothermal circulation would superimpose on a conductive system [Hofmeister and Criss (2005) Tectonophysics 409:199–203]. The error lies in force-fitting a 1-D cooling model to the 3-D oceanic crust [Hofmeister and Criss (2005) Tectonophysics 395:159–177]. Shortcomings of the 1-D model include mathematical errors, such as use of volumetric rather than linear thermal expansivity to describe contraction which, by assumption, is limited only to the Z -direction [Hofmeister and Criss (2006) Tectonophysics]. This 3× error, traceable to McKenzie and Sclater [1969, Bull Vocanol 33–1:101–118], accidentally provides good agreement of model values with globally averaged seafloor depths for young, but not old ages, and is the sole rationale for using the simplistic cooling model. There is no justification for selective substitution of erroneous 1-D model values for measurements only for the younger half of the 3-D oceanic crust, as stridently and arbitrarily promoted by C and P. Hamza et al. [2007, Int J Earth Sci], in contrast, use the scientific method, which calls for discarding models that do not well describe physical phenomena. The remainder of this report summarizes the shortcomings of cooling models, particularly the half-space cooling (HSC) model touted by C and P, and explains how hydrothermal circulation affects heat flux. We focus on the basics, as these have been misunderstood. With the key issues of C and P being erroneous, it is not necessary to address their remaining comments, many of which enumerate the vote for an imagined, gargantuan circulation of hot fluid through oceanic basins that is somehow warmed without removing heat from the rocks. The use of “consensus” to belittle valid challenge is the enemy of the scientific method.     

Genesis of volatile components at Saturn’s regular satellites. Origin of Titan’s atmosphere

Jupiter’s and Saturn’s regular satellites, which posses much ice, are currently thought to have been formed during the early evolution of the Solar System in circumplanetary protosatellite disks. Two of Saturn’s regular satellites—Titan and Enceladus—were experimentally proved to contain, along with water, other volatile components: molecular nitrogen, and methane (which are the major components of Titan’s atmosphere) and various nitrogen and carbon compounds in water plumes of Enceladus. The protomaterial of these rocky–icy satellites was formed in the outer regions of the gas–dust circumsolar nebula, and its closest analogue currently accessible to study is cometary material. The paper presents a review of experimental data on the chemical and isotopic composition of cometary material as possible sources of volatile components on Titan and Enceladus and model evaluations of temperatures in the circumsolar gas–dust protoplanetary disk and Jupiter’s and Saturn’s protosatellite disks during various evolutionary episodes of the solar system. The P–T parameters of the origin of the protomaterial of Jupiter’s and Saturn’s regular satellites were proved to have been remarkably different, and hence, the material of Europa, a Jupiter’s regular satellite, cannot contain any volatile components other than water, in contrast to Titan and Enceladus. This conclusion is supported by experimental data. Cometary material is likely genetically related to the material of Saturn’s regular satellites Titan and Enceladus. The paper presents results of thermodynamic simulation of the evolution of the chemical and phase composition of Saturn’s satellites and suggests a model for the origin of Titan’s nitrogen–methane atmosphere.     

Distribution and Collection of China’s Dinosaurs

<正>It is estimated that the world has discovered more than1000 species and 800 genera of dinosaurs.Chinese scientists have named more than 170 species of dinosaurs,with 17 genera and 44 species of dinosaur egg fossils,35genera and 39 species of dinosaur footprints,since their first discovery in China in 1902.China has dinosaur occurrences from the Upper Triassic to the Upper     

Local mineral equilibrium in metamorphism: development of D. Korzhinskii’s ideas (on 110th anniversary of D.S. Korzhinskii)

In 1950, D. Korzhinskii hypothesized that minerals in metamorphic reactions can be in local equilibrium. Proceeding from this idea, G. Fisher and R. Joesten later developed a realistic model of metamorphism kinetics. The model included diffusive mass transport in intergranular fluid controlled by the concentrations of components and chemical potential gradients, local-equilibrium reactions between minerals and pore fluid, mass balance of components, etc. The Korzhinskii–Fisher–Joesten model can provide clues to the duration of metamorphic events as inferred from mineral chemistry, free energy of phases, and rock textures and structures. The respective modeling of metamorphic reactions, with regard to spatial distribution of mineral grains, has implications for the transport and balance of chemical components. The balance of components (except volatiles) is restricted to domains of hundredth fractions of a cubic millimeter to several cubic meters. This may be the minimum size of an elementary domain in which minerals are in local equilibrium.     

Aeolian desertification and its causes in the Zoige Plateau of China’s Qinghai–Tibetan Plateau

Studies and efforts to control aeolian desertification in China have focused on the arid and semiarid lands in the north. However, the aeolian desertification that is occurring on the high-altitude Qinghai–Tibetan Plateau, which has a cold and humid climate, has received attention only in recent years. In this paper, we report the results of monitoring this aeolian desertification between 1975 and 2005 and of our analysis of its causes on the Zoige Plateau, which is located in the northeastern part of China’s Qinghai–Tibetan Plateau. Aeolian desertified lands expanded at a compound annual rate of 4.07% between 1975 and 2005. They expanded most rapidly between 1975 and 1990, at an annual rate of 7.73%. Factors responsible for this expansion include increasing temperature, decreasing precipitation, over-grazing, drainage of water systems, and land reclamation for agriculture. Increasing temperature, over-grazing, and the drainage of water systems were the key factors. The climatic variations between 1975 and 2005 were not sufficient by themselves to lead to aeolian desertification. Human disturbances such as over-grazing and drainage of water systems must thus have been primarily responsible for the observed changes, and human behavior must be adjusted to control the expansion of aeolian desertification and rehabilitate the desertified lands.     

A Mesozoic Pompeii: History of the Jehol Biota’s Rise and Fall

The Jehol fauna was initially represented by a bony fish, concostracan and an insect, as a Lycoptera davidi–Eosestheria–Ephemeropsis trisetalis association, but since the researches of recent decades, the Jehol Biota is now completely different from the past low-diversity, and encompasses a native terrestrial biota that includes many well-preserved vertebrates, invertebrates and plants. There are more than 20 important biological categories, thousands of taphonomically unusual fossils, especially noted for the wide variety of biological tissues. The Jehol Biota has caused a sensation in the world with its wide distribution, large quantity, great variety, fine preservation and detailed information, which records the rise and fall of the numerous taxa, and provides significant evidence for three origins: of birds, eutherian mammals, and angiosperms. The Jehol Biota is a highlight of basic scientific research in China, and we honor it as a world–class fossil treasury and “a Mesozoic Pompeii”.