“Exact” Frequency-Dependent Rays in Acoustic Media and Their Properties

Doklady Earth Sciences - The numerical algorithm for tracing “exact” frequency-dependent rays, which makes it possible to trace these rays in arbitrary media is proposed. In addition, a...     

Engaging a temporal–spatial stretch: An inquiry into the role of the state in cultivating and claiming the Chinese knowledge diaspora

This paper examines the role of the state in cultivating and claiming the Chinese knowledge diaspora for development, focusing on the Chinese–German academic space. It calls for a temporal–spatial stretch in conceptualising the state in this policy arena. The spatial stretch broadens the usual analysis of the state to go beyond the sending nation-state framework. It illustrates that the state, rather than functioning as a unitary body, comprises different agencies and exists in a multiplicity of forms. Examples demonstrate that the Chinese state at various geographical levels and localities as well as states in other countries engage with one another in making and tapping the Chinese knowledge diaspora. The temporal stretch necessitates an extension of our analytical optic from the conventional focus on how the state claims the diaspora ‘out there’ towards recognising its important role in the strategic and selective production of the diaspora. Furthermore, this paper calls for a higher sensitivity to other temporal characteristics in state policies and practices. Moving away from an expectation of a permanent return of its talents overseas, the Chinese state has turned to the ‘diaspora option’, which refers to regulating and tapping the potential of the Chinese knowledge network that contributes from afar and/or circulates transnationally. Other mechanisms to control the temporality of knowledge diaspora engagement will also be illustrated. Finally, the paper provides an analysis of the complex, sometimes collaborative while other times competitive relationship, between the Chinese and German states in producing and regulating the Chinese knowledge diaspora.     

Mesozoic “Red Beds” and its Evolution in the Hefei Basin

The Hefei Basin is the largest basin in the North China landmass with complete and well-preserved Mesozoic and Cenozoic strata. In the basin there developed a suite of extremely thick “red beds” in the Mesozoic. Owing to complex evolution processes and a lack of paleontological traces, there have been controversies regarding the division and correlation of this suite of red beds. Based on results obtained in recent years in drilling, seismic and surface geological investigations and in consideration of relationships between seismic sequences and regional tectonic events, as well as evidence in paleontology, petrology and isotopic dating, this paper preliminarily puts forward the following ideas about the sequence stratigraphic framework of the continental “red beds” in the Hefei Basin. (1) The Zhougongshan Formation and the Yuantongshan Formation have similar lithologic, geophysical and paleontological characteristics, so we incorporate them into a single formation, called the Yuantongshan Formation, and the original Zhougongshan and Yuantongshan Formations are regarded as the upper and the lower parts of the newly defined Yuantongshan Formation. Its age is the Middle Jurassic; (2) the Zhuxiang Formation belongs to the Upper Jurassic Series and (3) the age of the Xiangdaopu Formation is the Lower Cretaceous. Furthermore, signatures of depositional evolution are analyzed in the paper based on features of seismic reflection, outcrops and drilling data. The Early and Middle Jurassic is characterized by a foreland basin, which is influenced mainly by uplift and longitudinal compression of the Dabieshan Mountains; the Lower Jurassic System has a relatively small depositional area; the Middle Jurassic strata are distributed extensively over the whole basin, marking the summit of basin development; a flexure basin is characteristic of the Late Jurassic, manifesting a joint effect of the Dabieshan and Zhangbaling Mountains with the former being more significant. In the Early Cretaceous, the Xiangdaopu Formation was distributed in the Daqiao depression, evidently affected by extension of the Tanlu fault; in the Late Cretaceous, the Hefei Basin was subjected to dismembering and the Zhangqiao Formation was distributed in the east-west direction along the downthrown side of the fault.     

Minerals in nature and “on Paper”: History of the commissions on new minerals in Russia and IMA and principles of classification and nomenclature of minerals

This paper reviews the history of the foundation of the Commission on New Minerals in Russia (1956) and the same Commission of the International Mineral Association (IMA). The terms mineral species, subspecies, and variety are considered. The nomenclature of mineral groups of lovozerite, eudialyte, and apatite is given as examples of using a root name and its suffixes.     

Water Resources Issues and Control Policy Recommendations in the Process of “Industrialization,Urbanization and Agricultural Modernization” in Henan Province

In the process of “industrialization, urbanization, and agricultural modernization”（he-rein--after referred to shortly as “IUAM”）in Henan province, water resources issues have caused deterioration of water environments and water attenuation. These are the region''s most common and prominent issues, caused by improper activities, water environmental conflict and ignoring the results of local water environment carrying capacity. This environmental problem is getting worse and worse, seriously restricting the region’s “IUAM” healthy development. According to coor-dinated development between “IUAM” and water resources bearing capacity, we carry out the environmental management of water resources policy research and design and put forward some corresponding policies and proposals.     

Water Security and the Countermeasures in South Asia Based on the “Belt and Road” Initiative

South Asia is the subregion of Asia with the most neighbors of China. Although the high mountains in the Great Himalayas spatially separate South Asia from East Asia along the border of China’s autonomous region of Tibet, the geographical items such as mountains and rivers link the countries in South Asia with China, resulting in a special and complex geopolitical environment and relationship. In this geopolitical relationship, the transboundary rivers are becoming a key issue of this region in an era of increasing water stress. Depleted and degraded transboundary water supplies have the potential to cause social unrest and spark conflict within and between countries in South Asia, and complicate the geopolitical relationship among them. In addition, the increasing impacts from climate change and human activities will definitely bring many transboundary eco-environmental issues in this region, projecting a big challenge to regional stability and development. The key issues related to the water resources supplement and exploration require the transboundary rivers to be a positive role in regional water resources utility and exploration, and the result will definitely affect regional relationship and water security. How to handle these issues and challenges will be a question for the countries in this region with a long time. Currently, the “Belt and Road” Initiative represents an opportunity to build a shared vision for common prosperity through regional cooperation and is a way to inject new positive energy into world peace and development. In the light of this, the countries with transboundary rivers in South Asia must come together to construct a cooperative mechanism of water security, and adopt a win-win cooperation for the use of transboundary rivers under the principles of “equal”, “equitable” and “reasonable”.     

Migmatization and “secondary” granitic magmas: effects of emplacement and crystallization of “primary” granitoids in Southern Bohemia,Austria

The Sauwald and Mühl zones of the prebatholithic, Moldanubian, middle crust in northern Austria contain metapelites and metaluminous to weakly peraluminous metagreywackes, respectively. Both zones were affected by low-pressure, high-temperature metamorphism and anatexis. The metapelites of the Sauwald zone became in-situ diatexites, probably by fluid-absent reactions involving the breakdown of muscovite and the partial breakdown of biotite. The biotite-plagioclase-quartz gneisses of the Mühl zone experienced only slight melting. Following this event, and while the mid crust was still hot, additional heat was locally advected into the Mühl zone by the intrusion of the Weinsberg granite. This brought about fluid-present partial melting of the biotite-plagioclasequartz gneisses, producing relatively large volumes of metaluminous to weakly peraluminous, I-type Schlieren granite. This cool, wet, restite-rich magma remained close to its site of generation. Thus, infracrustal I-type granitoids may be formed anywhere in the crust, and not always at high T. Under special circumstances the heat and fluids from granitic magmas can spawn secondary granites. Also, relatively low initial ⁸⁷Sr/⁸⁶Sr values (of around 0.707) in I-type rocks do not necessarily indicate either lower crustal magma sources or mixing with mantle-derived magma. The Weinsberg granite magma came from the lower crust (P probably <700 MPa), where widespread fluid-absent breakdown of biotite-plagioclase-quartz assemblages occurred. The necessary high heat flow was probably provided by newly underplated mafic magmas. However, these seem not to have mixed or mingled with the crustally derived Weinsberg magmas. Deep equivalents of the Mühl-zone metagreywackes may have formed the Weinsberg protolith. Fluid-absent experiments show that the melting temperature probably exceeded 850°C and that a garnet-bearing, orthopyroxene-rich residue should be present in the lower crust. Fluid-present experiments demonstrate that the availability of free H₂O can radically alter the characteristics of the partial melts, from apparent S-type mineralogy (with fluid-absent melting) to I-type mineralogy (with wet melting).     

Problems of soil and groundwater pollution in the disposal of “marble” slurries in NW Sicily

This work deals with disposal of slurries generated during the cutting and polishing processes of slabs of decorative sedimentary carbonate rocks in the north western Sicily. At present, they are used as fillers of dismantled quarries near the sawmills and, as a final step of reclamation, are covered with earth layers. In spite of such inexpensive solution, there is lack of knowledge about the composition of the waste. In order to assess if there is any threat for the environment and to suggest indications for alternative solutions, such as recycling or inactivation processes, the slurries were analysed by XR diffraction, simultaneous thermal analysis, ICP/MS, ionic chromatography, FTIR, UV-Vis, COD and TOC measurements, grain size analysis. Results indicate that the slurries can threaten the groundwater, because of the high chemical oxygen demand; furthermore they can modify the mechanism of groundwater recharge, because of their grain size distribution. Some laboratory tests show that, even in very aggressive conditions, the solid pollutants persist in the waste and slowly release into water the products of their degradation. The slurry therefore should be subjected to inactivation treatment before disposal or, alternatively, recycled as secondary raw material for a suitable process.     

“Water Consumption” in the Diagenetic Stage and Its Petroleum Geological Significance

Inspired from the anomaly of low pressure in the middle and deep reservoir of the Paleogene in the Jiyang depression, this paper theoritically discusses＂waterconsumption＂of the principal mineral alteration during the diagenetic stage. The preliminary research result shows that ＂water consumption＂ of mineral alteration in the diagenetic stage can make formation water greatly decrease. Relevant formations will be in the stage of low pressure without supply of exterior liquid. Pressure differences between the relevant formations and wall rocks make hydrocarbons enter easily to form the effective reservoir.     

Opportunities and challenges in rebuilding tornado-impacted Greensburg,Kansas as “stronger,better, and greener”

A May 2007 tornado destroyed 95% of aging, declining Greensburg, Kansas. The city took the opportunity to build back “stronger, better, and greener,” enforcing upgraded codes, requiring city-owned buildings to meet LEED Platinum level standards, and recommending energy-efficiency housing in a new Sustainable Comprehensive Plan. Using information collected from surveys of Greensburg tornado survivors, interviews, and publications, we examined the housing-related recovery, including the emergency provision of temporary shelter and rebuilding permanently. Although temporary shelter kept residents nearby for rebuilding, given the gap between insurance policy limits on the aging housing stock and rebuilding costs, housing affordability is a critical issue in Greensburg’s recovery. Local, state, and federal support have made construction of municipal buildings at LEED Platinum level and some affordable and green housing projects possible. However, far greater public and private sector funding for affordable workforce housing, in conjunction with broader economic and job development, is needed.     

Effect of Al source and alkali activation on Pb and Cu immobilisation in fly-ash based “geopolymers”

Solidification/stabilisation technologies are attracting great interest from mining and energy industries alike, to solve their pressing waste disposal problems. “Geopolymers”, in particular, are becoming one of the more popular solidification/stabilisation methods since they can be applied to a variety of waste sources at low cost, yielding added-value products. However, the effect of Al source on the solidification/stabilisation of heavy metals within fly ash-based Geopolymers, has received little attention. This study examines the effect of variable Al source and alkali-activator on the final properties of fly ash-based Geopolymers as characterised by compressive strength testing, infrared and X-ray diffraction analyses. Leaching tests were performed to determine the efficiencies of Pb and Cu immobilisation, which were compared to the initial properties of the Al source (e.g. particle size, cation exchange capacity, total extractable cation concentration and suspension yield stress). It was observed that Pb was generally better immobilised than Cu. In addition, the total extractable cation concentration of the Al source greatly affected the efficiency of Pb immobilisation while the physical properties of the Al source (suspension yield stress and eventual compressive strength) determined the efficiencies of Cu immobilisation. For both metals, NaOH activation was the most favourable method for metal immobilisation, however, a clear mechanism of adsorption remains elusive.     

“Source-Diagenesis-Accumulation” enrichment and accumulation regularity of marine shale gas in southern China

After the breakthrough of shale gas exploration and development in the Ordovician Wufeng Formation (Fm.) and Silurian Longmaxi Fm. of Chongqing Jiaoshiba area, Changning-Weiyuan area, etc. in Sichuan basin, a series of discovery and breakthrough were obtained by China Geological Survey in the Cambrian Niutitang Fm. and Sinian Doushantuo Fm. shale of the areas with complicated structure outside Sichuan basin. Based on the understanding of the law of shale gas enrichment in Longmaxi Fm. in the basin, this paper puts forward three elements of the formation and enrichment of shale gas, which are the “Source”, the “Diagenesis” and the “Accumulation”, after deeply studying the law shale gas enrichment and accumulation in Sinian-Cambrian reservoir of the complex structure area outside the basin. The “Source” means the sedimentary environment and petrological characteristics of organic shale. The “Diagenesis” means the basin tectonic subsidence and hydrocarbon generation and expulsion process of organic matter. The “Accumulation” means the tectonic uplift and shale gas preservation. It is proposed that the Sinian-Cambrian and Ordovician-Silurian black shale series in the middle and upper Yangtze region of southern China were both formed in the deep-water shelf environment of rift trough and foreland basin respectively. The dessert intervals were formed in the strong reduction environment under transgressive system tract. The shale lithology belongs to calcium-siliceous and charcoal-siliceous respectively. Based on the summary of structural evolution in Yangtze area, the correlation of structural burial depth with shale diagenesis and the coupling evolution of organic matter with pore structure are discussed. Combining with structural styles, the preservation conditions of shale gas are discussed. Five types of shale gas reservoir control models are further described. Two types of future exploration directions, which are reverse fault syncline and paleo-uplift margin in complex structural area outside the basin, are proposed.     

Making the landscape “home”: Narratives of bushfire and place in Australia

This study investigated how the meaning of ‘home’ influences the social construction of bushfire in two Australian communities at high risk. An increasing number of Australians are living in proximity to areas of high bushfire risk due to climate, vegetation and demographic changes. Land and Fire Management Agencies recognise an urgent need to understand what motivates residents to take action to mitigate bushfire risk, and individual decisions whether or not to evacuate when bushfire is imminent. In bushfire policy and management, the home is considered to be synonymous with the house and associated built structures. Using a combination of visual and ethnographic research methods, we ‘mapped’ residents’ understanding of ‘home’. The findings suggest that the concept of ‘home’ embraces more than the private spaces of house and garden. Landscape practices such as gardening with indigenous plant species, ecological restoration, and habitual walking extend the home territory beyond the house and garden and into public landscapes. Physical elements of the landscape such as mountains and locally significant species of trees form part of the ‘imaginary’ of home. These findings are important to the on-going study of the meaning of home. The implications are also significant for land and bushfire managers as they suggest that community education programs that focus solely on the house may fail to connect with people’s wider sense of home in the landscape.     

Jurassic Tectonic Revolution in China and New Interpretation of the “Yanshan Movement”

With acquisition and accumulation of new data of structural geological investigations and high-resolution isotopic dating data, we have greatly improved our understanding of the tectonic events occurring in eastern China during the period from the Late Jurassic to Early Cretaceous and may give a new interpretation of the nature, timing and geodynamic settings of the “Yanshan Movement”. During the Mid-Late Jurassic （165±5 Ma）, great readjustment of plate amalgamation kinematics took place in East Asia and the tectonic regime underwent great transformation, thus initiating a new tectonic regime in which the North China Block was the center and different plates converged toward it from the north, east and southwest and forming the “East Asia convergent” tectonic system characterized by intracontinental subduction and orogeny. As a consequence, the crustal lithosphere of the East Asian continent thickened considerably during the Late Jurassic, followed immediately by Early Cretaceous substantial lithospheric thinning and craton destruction featured by drastic lithospheric extension and widespread volcano-magmatic activities, resulting in a major biotic turnover from the Yanliao biota to Jehol Biota. Such a tremendous tectonic event that took place in the continent of China and East Asia is the basic connotation of the “Yanshan Movement”. In the paper, according to the deformation patterns, geodynamic settings and deep processes, the “Yanshan Movement” is redefined as the Late Jurassic East Asian multi-directional plate convergent tectonic regime and its associated extensive intracontinental orogeny and great tectonic change that started at -165±5 Ma. The substantial lithospheric attenuation in East China is considered the post-effect of the Yanshanian intracontinental orogeny and deformation.     

Native Ta and in from a probe of regolith AS “Luna-24”

Doklady Earth Sciences -     

“Yes to Peace”? Environmental peacemaking and transboundary conservation in Central America

The use of transboundary conservation as tools for improving interstate relations has become a widely supported initiative in nature conservation. The rationale follows the environmental peacemaking hypothesis, which argues that seemingly neutral environmental issues can provide a sound basis for cooperation between states. The paper investigates the hypothesis’ premise through the case of International System of Protected Areas for Peace (Si-A-Paz), a transboundary protected area shared by Costa Rica and Nicaragua. In recent years, both countries have been involved in a number of border conflicts within Si-A-Paz and linked to the use of the San Juan River, contested land areas, and oil resources. The case of Si-A-Paz shows that transboundary environmental issues can provide arguments for maintaining or even strengthening conflicts rather than fostering peace between states. The case also shows the emergence of environmental issues as a new arena for geopolitical play, where actors not only justify their actions through an environmental discourse but also, the environmental discourse is stretched to include a variety of issues through which actors can obtain international support. The events in Nicaragua and Costa Rica raise questions about the role of transboundary conservation as a peacebuilding tool.     

Juxtaposing Pakistani diaspora policy with migrants’ transnational citizenship practices

Through a juxtaposition of diaspora policy with migrants’ transnational citizenship practices, this article explores how peoplehood, nationhood and citizenship are articulated, justified and enacted. The article draws on the politico-spatial context of Norwegian-Pakistani transnational social space, analyzing the Pakistani Origin Card (POC), remittances and return mobilities as transnational citizenship practices. The elusiveness of residency becomes apparent, underscoring the salience of territoriality, for both diaspora strategies and transnational citizenship practices, involving the co-constitution of formal membership and everyday citizenship practices. Through this overlaps, frictions and disruptions in conceptions of citizenship and of nationhood are revealed, underscoring their non-static nature. Whilst questions of who is included within the people are more commonly approached from the vantage point of immigration contexts, they share key tenets of struggles over conceptualizations of citizenship, and more plural ideologies of nationhood, in emigration contexts, exposed by a juxtaposition of diaspora policies and migrants’ transnational citizenship practices.     

“Differentiated citizenship” and the persistence of informal rural credit systems in Amazonia

In the Brazilian Amazon, the long-distance river trading system known as aviamento has linked commodity producers in remote areas to markets in urban centers since the colonial period. Based on a case study from the rural municipality of Lábrea, this article explores continuities and changes in river trading from the point view of riverine residents and river traders. Geographic isolation and seasonal productive needs continued people’s dependence on river traders in 2008–2009, but they had greater choices due to increased access to information, mobility, and alternate markets. Expanded citizenship rights provided access to the vote and to education and other government services, but in a “differentiated” manner that still excluded many rural Amazonians. Given that agroindustry is currently the economic focus for Amazonian development, instead of forest product extraction, these rural producers continued to be forced to rely on informal river traders to meet their needs.     

“In situ” visualization of phase states and transformations of hydrocarbons in water-oil mixtures at high and ultrahigh temperatures and pressures

Doklady Earth Sciences -