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In this article, we investigate the impacts of jump intensity on the volatility of futures in the oil futures market using the heterogeneous autoregressive model of realized range-based volatility (HAR-RRV) and its extended model. We present several interesting and notable findings. First, short-term investors have larger influences on oil futures price volatility. In addition, negative returns are significant, but the effects of jumps and their intensity (probability) appear to not be significant during the in-sample period. Second, the out-of-sample results statistically support that our proposed models are able to achieve higher forecast accuracy than that of the benchmark in both the statistical and economic senses, especially when including the combination of significant jumps and jump intensity. Third, our findings are strongly robust in various checks, such as different forecasting windows, sampling frequencies, and volatility measures.

This paper aims to identify the most informative determinant in forecasting crude oil market volatility. We use a new GARCH-class model based on mixed data sampling regression and the dynamic model averaging combination method to examine the predicting power of the determinants. We integrate both the global economic policy uncertainty (GEPU) indices and several national economic policy uncertainty (EPU) indices with traditional determinants, such as global oil demand, supply, and speculation. Our analysis suggests that the EPU indices comprehensively integrate the information contained in other determinants. Specifically, GEPU indices and the U.S.’s EPU index have superior predictive powers for West Texas Intermediate spot oil volatility. This finding highlights the importance of EPU indices, implying that they are key factors to consider when determining crude oil market volatility.

In China, the social risks associated with housing demolition increasingly challenge the success of urban redevelopment projects. In practice, these risks are interacting and are associated with various stakeholders. Previous studies have largely focused on risk identification and evaluation without giving sufficient consideration to stakeholders and their linkages with risks. Therefore, we used social network analysis to investigate social risks related to housing demolition, from a stakeholder perspective. Stakeholder-associated risks and their interrelations were investigated based on a literature analysis and interviews with key stakeholders. Using a network analysis we identified critical risks and their corresponding stakeholders. Social security schemes, efficient financial management, multi-dimensional impact assessments, policy analyses and adherence to laws, and public participation were proposed to mitigate risks. The effectiveness of these solutions was quantified based on a network simulation. This study contributes to the body of knowledge on social risk management via linking social risks with stakeholders.

As a response to climate change, low carbon development has attracted a growing public attention. It is urgent to implement low carbon economy through technological innovation so that carbon emissions can be reduced effectively. The synergy and cooperation amongst the participants is required due to various challenges such as: multi-participants, multi-objectives and multi-technologies. These present significant challenges to the low carbon technology (LCT) innovation development. The objective of this study is to identify the relevant driving forces of LCT innovation and their interaction in the construction industry. This paper firstly analyzes the interrelationships of the participants via a methodology of system dynamics (SD) and questionnaire survey. The main driving forces and related influential factors are highlighted by means of a deductive method. Moreover, a SD model is established to examine the driving forces where government and private firms all play a role. The results show that LCT integration driving forces are significantly influenced by the continuous changes of a particular low carbon project as well as the number of participating enterprises. All the driving forces reflect an increasingly level of effectiveness. According to the model simulation, it will take a long period of time to transform traditional projects to low carbon projects. China needs at least 21 years that the quantity of low carbon buildings exceeds that of traditional ones. As a result, the building and construction industry is facing a significant challenge in terms of carbon emissions reduction. The numbers of enterprises participating in LCT innovation will not always increase with the enhancement of driving forces. Rather, it will keep at a stable level after a certain growth. A particular one single driving force has limited impact on the growth of low carbon projects and participating enterprises. System integration plays a crucial role to achieve the low carbon development.

The Bayan Obo deposit in Inner Mongolia, North China Craton (NCC) is the largest rare-earth element (REE) resource in the world. Due to the complex element and mineral compositions and the activity of several geological events, the ore-forming mechanism is still controversial. Previous models are reviewed here to provide information for further investigation on the Bayan Obo deposit. In this study, we summarize all different types of Fe-REE-Nb mineralization using field observations and microscope work, in which we recognize 9 types of Fe-REE-Nb ores in the Bayan Obo ore district. By compiling and re-evaluating a large number of published geochemical data, this paper provides solid evidence that the Bayan Obo deposit formed through interaction between sedimentary rocks and carbonatite magmatism. From the results of our review, it can be conjectured that the formation of iron ores was originated from sedimentation (Pt1), whereas the formation of REE mineralized dolomite might be related to interaction and reaction between the carbonatite magmas and/or associated fluids with sedimentary carbonate rocks, with the REE-bearing carbonatite magmas having undergone intense fractionation enrichment process. The C-O-S-Fe-Mg isotopes indicate that the REE-Nb mineralization was derived from metasomatism (fenitic alteration) of sedimentary carbonate. A new model is proposed for this unique REE-Nb mineralization, which is related to the subduction of Siberian Craton beneath the North China Craton since Early Paleozoic period. We interpret that the Bayan Obo Fe-REE-Nb ore deposits and their massive barren host, H8 dolomite, were generated as a result of interaction of fluids expelled from a subcontinental lithospheric mantle (SCLM)-derived carbonatite magma with sedimentary carbonates.

Last decades have witnessed growing public concerns on sustainable development in China arguably due to the social and environmental issues associated with the rapid urbanization. As a result, sustainable neighborhood development has attracted an increasing level of attention from both industry and government. A number of factors exist that may impede the development of sustainable neighborhoods. This study aims to explore the inter-relationship amongst various barriers to sustainable neighborhood development with consideration given to the complex nature of the system. A hierarchical structural model is developed via interpretative structural modeling, which is followed by a classification via Matrice d’Impacts Croises Multiplication Appliquee a un Classeement (MICMAC) analysis. The complex inter-relationships among various barriers to the sustainable neighborhood developments are examined. The most influential barriers are identified, i.e. unsustainable urbanization mode, lack of supporting policy, lack of national standards and assessment tools, and unsustainable planning. Top priorities can be assigned to deal with these issues properly to facilitate the development of sustainable neighborhoods. This informs the urban policy making process as well as industry practices.

Innovation has been valued as a main driving force of social development, and the need for environmental protection has further raised green innovation development. Previous studies have confirmed that industrial agglomeration has an innovation spillover effect, and furthermore it varies with different agglomeration modes. However, the addition of environmental regulation could exert effects on the innovation spillover of industrial agglomeration. Based on Chinese provincial panel data from 2003 to 2017, this paper tested the effect of different agglomeration modes on green technology innovation (green process innovation and green product innovation) under environmental regulation. Research found that: when industrial agglomeration promotes green technology innovation, environmental regulation will inhibit agglomeration innovation; when industrial agglomeration hinders green technology innovation, environmental planning will promote agglomeration innovation. The regional difference of cluster development are obvious in China, and the effect of agglomeration innovation in different regions is also different. In the implementation of environmental regulation for each region, it is necessary to combine the current situation of cluster development to effectively promote green technology innovation.

The Bayan Obo Fe–REE–Nb deposit is a world-largest REE deposit in Inner Mongolia, North China Craton. It also contains large Fe and Nb reserves. The REE ore body is hosted in H8 dolomite of the Bayan Obo Group. Depositional time and genesis of H8 dolomite are still controversial in addressing the genesis of the REE deposit. In this study, Pb–Pb age and geochemical features of carbonate minerals in H8 dolomite have been studied, providing constraints to genesis of H8 dolomite and the REE deposit. Results of Pb–Pb dating from unmetamorphosed and non-mineralized domains of the H8 dolomite well constrain the depositional age as 1619 ± 150 Ma, which is earlier than both REE ore and carbonatite dykes in the Bayan Obo region. This indicates that REE mineralization has characteristics of epigenetic origin. Geochemical data of carbonate minerals in H8 dolomite have low REE contents, distinctly distinguished from those carbonatitic dykes. However, the fine-grained H8 dolomite whole rocks have high REE contents, similar to those carbonatitic dykes. Mineral analysis suggests a close relationship between REE mineralization and calcite carbonatite dykes and related-derived fluids, which could transport a large amounts of REE. Integrated with these new geochronological and geochemical data, we draw conclusion that the Bayan Obo Group was a Proterozoic depositional succession, REE mineralization is as result of sedimentary carbonate rocks once being metasomatised by fluids derived from regional REE-rich calcite carbonatitic magma at depth.

Sharing economy represents a new business model in which the access to goods, services, spaces, and other assets can be shared or obtained. Sharing economy firms have been able to achieve global levels of success at an unprecedented space. It is acknowledged by the public and enterprises due to intensive utilization of resources. In order to help enterprises understand and clarify the resources efficiency improvement mechanism of environmental impact during the promotion of the sharing economy model in operation, this paper explores the evolutionary history and value chain of different bicycle consumption pattern, then employs a queuing theory to discuss the feasibility of the sharing bicycle company recycle system from the perspective of value chain and analyzes the approach to improve the efficiency of recycling system. It creates a model against current traditional recycling mechanism which contains production, consumption and recycling process with a queuing theory as a base. Related cost and benefit calculation are analyzed based on an example simulation, an empirical application in two sharing bicycle companies are discussed as well. Result shows that, if the ration of operating cost of each recycle station and the average reduction cost each bicycle recycle can meet a range between the average number of bicycles in recycle station and the average number of bicycles waiting to be recycled, the sharing bicycle resource recycle efficiency can be improved, accordingly, it can not only alleviate the urban environmental problems as it allows idle assets to gain more usage but also generate more frequent economic activity, the bicycle companies have a value adding in sharing bicycle operation from the efficiency improvement. The comparison between two major sharing bicycle enterprises (OFO and Mobike) with two different schemes in China indicates that the model with self-source of damaged bicycles recycling are more beneficial than the model with the public help of the damaged bicycles recycling.

The Bayan Obo deposit in the Inner Mongolia, North China Craton, is the largest rare-earth element (REE) resource in the world. The deposit is hosted in Mesoproterozoic sediments of the Bayan Obo Group, the lithological sequence of which has been divided into seventeen units (H1–H17). The REE mineralization is mainly concentrated in the H8 dolomite unit, and therefore the depositional age of this unit is important in addressing the debate over the genesis of the REE–Fe–Nb ore deposit. Here we present U–Pb and Hf model ages of zircons from the adjacent H9 slate. Our data suggest that the H9 slate formed at 1505 ± 12 Ma and the H8 dolomite was deposited during the Mesoproterozoic. We also present Ar–Ar ages of riebeckite in veins cutting the H8 dolomite and biotite in the ore bodies which show 389.5 ± 3.0 Ma and 289.1 ± 1.8 Ma, respectively. The U–Pb measurements from overgrowth zircon in H9 slate give an age of 518.8 ± 7.5 Ma. These new age data indicate that the Bayan Obo deposit was disturbed during thermal events at 520 Ma to 390 Ma, generating a second phase of REE–Nb mineralization. The δ7Li values of the REE mineralized dolomite are similar to those of carbonatite dykes. Combined with ɛNd features, we provide geochemical evidences that REE mineralized dolomite has undergone fluid interaction. Results reveal that the carbonatite magmatism occurred within the Bayan Obo rift at ca. 1.2 Ga, provided the primary source for REE–Nb mineralization or to fertilize the Bayan Obo crust, and the later was remobilized during the Caledonian to generate the second phase of mineralization within a convergent plate margin regime.

Risk measurement has both theoretical and practical significance in risk management. Using daily sample of 10 international stock indices, firstly this paper models the internal structures among different stock markets with C-Vine, D-Vine and R-Vine copula models. Secondly, the Value-at-Risk (VaR) and Expected Shortfall (ES) of the international stock markets portfolio are forecasted using Monte Carlo method based on the estimated dependence of different Vine copulas. Finally, the accuracy of VaR and ES measurements obtained from different statistical models are evaluated by UC, IND, CC and Posterior analysis. The empirical results show that the VaR forecasts at the quantile levels of 0.9, 0.95, 0.975 and 0.99 with three kinds of Vine copula models are sufficiently accurate. Several traditional methods, such as historical simulation, mean-variance and DCC-GARCH models, fail to pass the CC backtesting. The Vine copula methods can accurately forecast the ES of the portfolio on the base of VaR measurement, and D-Vine copula model is superior to other Vine copulas.

This article examined the literatures enlisted in the database of SCI and SSCI on the topics with regard to green technology and low carbon technology innovation from 1994 to 2010. It intends the service with the purpose of helping researchers and practitioners understand what issues or subjects have been addressed in green and low carbon technology innovation and initiate a journey for the next generation of sustainable‐oriented research. Some critical discussion and conclusion are as follows: (1) it shows a positive journey of green and low carbon technology innovation. The research of Western Europe and North America is highly advanced compared to other developing countries, especially in terms of new resource and renewable energy technology innovation. (2) The empirical research, such as sample survey and field study with primary data, is prevalent and preponderating over other methods (conceptual, qualitative and formal models research). (3) The research subjects are multi-perspective and multi-disciplinary, covering environment science, management, energy and fuels, economics and social behavior. So far the research fields mainly focus on technology adoption, diffusion, transfer, policy making or implementation, and advanced technology development. New vibrancy of advanced theoretical and methodological research is particularly needed, especially for low carbon technology innovation trajectory, performance evaluation, government policy instrument and multi-level cooperation among enterprises, governments and NGOs. (4) The local governments and NGOs have played a key role on the promotion of low carbon techniques particularly in developing countries such as China. (5) Green and low carbon technology innovation cannot be isolated from the policy or regulation regime, and is becoming a new underpin of current sustainable development coupled with social energy system contributing to control the climate change.

Geochemical characteristics of different dolomites in the Bayan Obo giant REE–Nb–Fe deposit in Inner Mongolia have been studied. Intensively REE-mineralized dolomites (total REE over 800 ppm) show similar geochemical characteristics to associated carbonatite dykes, with Ba, Th, REE enrichments and Sr, Nb, Ti, Cu depletions, which is different from those of dolomites in the deposit with low REE contents (total REE less than 800 ppm). The low REE dolomites display some transitional characteristics between carbonatite dyke and sedimentary carbonate, with La depletion and Nb enrichment. This indicates that the genesis of the REE-mineralized dolomites might be related to both carbonatite magma and sedimentary carbonates. Sulfur isotope data indicates two sulfur sources, a mantle source (δ34S c.a. 0‰) and seawater (δ34S c.a. +25‰). It is proposed that mineralized dolomites in the Bayan Obo giant REE–Nb–Fe deposit are the product of sedimentary carbonate hydrothermally metasomatised by carbonatite magma and/or associated fluids. These dolomites formed the large-scale rare earth mineralization in the unique Bayan Obo REE–Nb–Fe deposit.

The Bayan Obo giant REE–Nb–Fe deposit in Inner Mongolia is the most famous and largest REE deposit in the world. Its genesis has been long disputed. Carbonate rocks of this deposit are divided into four categories based on their texture, mineral assemblage and geological occurrence: (1) Sedimentary limestone and dolostone, (2) Deformed mineralized coarse-grained dolomite marble, (3) Fine-grained dolomite marble, and (4) Carbonatite dykes. In this study, major and trace elements of different dolomite marbles are analyzed by XRF and ICP-AES and mineral compositions are analyzed by EPMA. Results show that major, trace and rare earth elements of coarse-grained dolomite marble samples are comparable to those of sedimentary carbonate rocks. In comparison, geochemical features of the fine-grained dolomite marbles are comparable with those of carbonatites. The SrO and MnO concentrations analyzed by EPMA in carbonate minerals from fine-grained dolomite marble are similar to carbonatite, and where least altered, carbonates from coarse-grained dolomite marble retain SrO signatures of sedimentary carbonates. We find that coarse-grained dolomite marbles are the result of weak mineralization of sedimentary carbonate rocks, and fine-grained dolomite marbles are the product of intensive mineralization by REE-rich fluids derived from carbonatitic magma. Moreover, SrO content in carbonate minerals is a more sensitive indicator than MnO to distinguish carbonatite from sedimentary carbonate rock in the Bayan Obo REE–Nb–Fe deposit.

The distribution of dissolved (D) and acid-dissolvable (AD) Fe, Ni, Cu and Pb in the upper water column (0–300mdepth)was determined in the Australian sector of the Southern Ocean (140°E meridian) during three cruises conducted between November 2001 and March 2002. For Ni and Cu, therewas no significant difference in concentration between dissolved and acid-dissolvable species. DNi and DCu showed significant (P = 0.01) positive correlations with silicate, phosphate and nitrate, reflecting their strong nutrient-type behaviour. For Fe and Pb, the acid-dissolvable concentration mostly exceeded the dissolved concentration, reflecting the importance of labile particulate species for these elements. DPb decreased between January and February in the Polar Frontal Zone and in Antarctic continental shelf water. ADPb maxima occurred in the Antarctic Zone, resulting in a maximum AD/D ratio of 7. The mean DFe concentration in the surface mixed layer was 0.3 nM in the sub-Antarctic zone, 0.4 nM in the Polar Frontal Zone, 0.5 nM in the Antarctic Zone and increased southward beyond the Antarctic Divergence and towards the continent. DFe did not show a clear temporal change in its horizontal distribution, which was in contrast to the other nutrients and trace metals. ADFe substantially increased in Antarctic continental shelf water where the AD/D ratio reached 11. The following conclusions can be drawn from these data. (1) Ni and Cu exist exclusively as dissolved species and their distributions are mainly controlled by their biogeochemical cycling, similar to those of the major nutrients. (2) Pb is dominated by particulate species. The distribution of DPb is temporally and spatially variable due to a sporadic source and strong scavenging. (3) DFe is rather a minor fraction of total Fe in Antarctic continental shelf water where shelf sediments and Antarctic sea-ice appear to be strong sources for Fe. There is substantial temporal variation in the supply of Fe to the upper water column. DFe in the mixed layer of the open Southern Ocean is maintained at low concentrations throughout summer due to uptake by phytoplankton and scavenging.