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1.
NO 2 $$ {\mathrm{NO}}_2 $$ is a traffic-related air pollutant. Ground NO 2 $$ {\mathrm{NO}}_2 $$ monitoring stations measure NO 2 $$ {\mathrm{NO}}_2 $$ concentrations at certain locations and statistical predictive methods have been developed to predict NO 2 $$ {\mathrm{NO}}_2 $$ as a continuous surface. Among them, ensemble tree-based methods have shown to be powerful in capturing nonlinear relationships between NO 2 $$ {\mathrm{NO}}_2 $$ measurements and geospatial predictors but it is unclear if the spatial structure of NO 2 $$ {\mathrm{NO}}_2 $$ is also captured in the response-covariates relationships. We dive into the comparison between spatial and nonspatial data models accounting for prediction accuracy, model interpretation and uncertainty quantification. Moreover, we implement two new spatial and a nonspatial methods that have not been applied to air pollution mapping. We implemented our study using national ground station measurements of NO 2 $$ {\mathrm{NO}}_2 $$ in Germany and the Netherlands of 2017. Our results indicate heterogeneous levels of importance of modeling the spatial process in different areas. The prediction intervals predicted with ensemble tree-based methods are more satisfactory than the geostatistical methods. The two new methods implemented each obtained better prediction accuracy compared to the original ensemble tree-based and stacking methods. The probabilistic distribution of the spatial random field estimated by the geostatistical methods could provide useful information for analyzing emission sources and the spatial process of observations.  相似文献   

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The p‐regions is a mixed integer programming (MIP) model for the exhaustive clustering of a set of n geographic areas into p spatially contiguous regions while minimizing measures of intraregional heterogeneity. This is an NP‐hard problem that requires a constant research of strategies to increase the size of instances that can be solved using exact optimization techniques. In this article, we explore the benefits of an iterative process that begins by solving the relaxed version of the p‐regions that removes the constraints that guarantee the spatial contiguity of the regions. Then, additional constraints are incorporated iteratively to solve spatial discontinuities in the regions. In particular we explore the relationship between the level of spatial autocorrelation of the aggregation variable and the benefits obtained from this iterative process. The results show that high levels of spatial autocorrelation reduce computational times because the spatial patterns tend to create spatially contiguous regions. However, we found that the greatest benefits are obtained in two situations: (1) when ; and (2) when the parameter p is close to the number of clusters in the spatial pattern of the aggregation variable.  相似文献   

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The boron stable isotope ratio δ11B of 12 water samples representative of three chemical facies (fresh Na‐bicarbonate, brackish Na‐chloride, saline, and brine Ca‐chloride) has been analyzed. Interpretation of the δ11B data, along with the chemical compositions, reveals that Na‐carbonate waters from the Northern Apennine are of meteoric origin, with boron contributions from clay desorption and mixing with seawater‐derived fluids of Na‐chloride or Ca‐chloride compositions. The comparison of our new results with the literature data on other sedimentary basins of Mediterranean, and worldwide, confirms the contribution of Na‐bicarbonate waters to the genesis of mud volcano fluids. The Na‐chloride sample of Salvarola (SAL), which may represent the end‐member of the mud volcanoes, and the Ca‐chloride brine water from Salsomaggiore (SM) indicate boron release from clays compatible with the diagenetic process. The empirical equation: relating boron concentration and the stable isotope composition of the fluids observed in this study and the literature is proposed to trace the effect of diagenesis in sedimentary basins. A geothermometer associated to the diagenetic equation is also proposed: The application of this equation to obtain reservoir temperatures from δ11B compositions of waters should be carefully evaluated against the results obtained from other chemical and isotopic geothermometers from other basins around the world.  相似文献   

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Experimental studies reveal complex dissolution behavior of quartz in aqueous NaCl solutions at high temperature and pressure, involving variation from salting‐in to salting‐out that changes with temperature, pressure, and salt concentration. The behavior is not explainable by traditional electrostatic theory. An alternative hypothesis appeals to complexing of SiO2 with NaCl and can explain the observations. However, the hypothesis of complexing, as previously applied, is inadequate in several respects: it neglects polymerization of solute silica, regards the SiO2‐NaCl hybrid complex(es) as anhydrous, which seems unlikely, and invokes an incorrect stoichiometry of the hydrated silica monomer, now known to be Si(OH)4?2H2O. These neglected features can be incorporated into the complexing model in a revised formulation based on a simple thermodynamic analysis using existing quartz solubility data. The analysis leads to a quasi‐ideal solution model with silica monomers, dimers, and two distinct hydrous SiO2‐NaCl hybrid complexes with overall NaCl:H2O = 1:6, one Na‐bearing and one Cl‐bearing. Their (equal) molar concentrations (Xhc) are governed by a pressure‐ and temperature‐dependent equilibrium constant, , where aNacl and are the respective activities of the solvent components. The stability of the hybrid complexes (i.e., their concentration) is very sensitive to H2O activity. The entire set of experimental quartz‐solubility data at 700°C, 1–15 kbar, is reproduced with high fidelity by the expression (P is pressure in kbar), including the transition from low‐pressure salting‐in to high pressure salting‐out. The results indicate that hybrid SiO2‐NaCl complexes are the main hosts for dissolved silica at NaCl concentrations greater than 6 wt%, which are likely common in crustal fluids. At higher temperatures, approaching the critical end point in the system SiO2‐H2O, the model becomes progressively inaccurate, probably because polymers higher than the dimer become significant as SiO2 concentration increases.  相似文献   

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Interpreting the behaviours of nomadic groups from the archaeological record is particularly challenging owing to the ephemeral remains produced by their lifestyle. As such, human burials – even from isolated contexts – provide a wealth of information about these transient groups. Stable carbon and nitrogen isotope analysis of a series of human skeletal remains (n = 22) from isolated burials were utilized to reconstruct the diet of historic (ca. 13th–19th century CE) Bedouin from the Khirbat al‐Mudayna vicinity in modern‐day Jordan. Carbon isotope values ranging from −17.7 to −12.5‰ point to variable dietary contributions from both C3‐ and C4‐based foods, while corresponding faunal δ13C ratios ( = −19.0 ± 1.7‰, 1σ) exhibit depletion in 13C characteristic of a predominantly C3 diet. While mean human δ15N values ( = 12.7 ± 1.9‰, 1σ) may suggest that the majority of protein consumed by these nomads came from animal and not plant sources, elevated δ15N ratios in some fauna may be indicative of 15N‐enriched soils as reported in some arid desert environments. Considerable variability in both δ13C and δ15N values also points to differences in individual life histories and subsistence economies over time. Despite a lack of temporal cohesion, these data illustrate the information that can be gleaned from the isolated interments of nomadic or semi‐nomadic individuals. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

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The identification of substantively similar policy proposals in legislation is important to scholars of public policy and legislative politics. Manual approaches are prohibitively costly in constructing datasets that accurately represent policymaking across policy domains, jurisdictions, or time. We propose the use of an algorithm that identifies similar sequences of text (i.e., text reuse), applied to legislative text, to measure the similarity of the policy proposals advanced by two bills. We study bills from U.S. state legislatures. We present three ground truth tests, applied to a corpus of 500,000 bills. First, we show that bills introduced by ideologically similar sponsors exhibit a high degree of text reuse, that bills classified by the National Conference of State Legislatures as covering the same policies exhibit a high degree of text reuse, and that rates of text reuse between states correlate with policy diffusion network ties between states. In an empirical application of our similarity measure, we find that Republican state legislators introduce legislation that is more similar to legislation introduced by Republicans in other states, than is legislation introduced by Democratic state legislators to legislation introduced by Democrats in other states.   相似文献   

8.
D. Reeves  D. H. Rothman 《Geofluids》2014,14(2):128-142
The formation of porous weathering rinds (layers of chemical alteration) on the exterior of rocks is a consequence of dissolution and precipitation of minerals occurring at the mineral–fluid interface within the pores. The speed at which the developed rind advances is controlled by both kinetic reaction rates and the transport of reaction products away from the pore spaces into the outside fluid. We show, using both reaction‐diffusion theory and numerics, that under diffusion limitations, the weathering rate depends on the size and curvature of the sample. This leads to a relationship between rind thickness, δ, and age, t. As the rind thickens, the result in three dimensions differs substantially from the one‐dimensional result of . We describe the conditions under which the one‐dimensional and diffusion‐limited approximations apply and how they evolve as the rock weathers. Under chemical kinetic limitations, the rind advances at a constant rate, /dt = v. We defend the application of a spherical approximation to irregular non‐spherical rocks and apply our results to field observations reported in the literature to show consistency with established methods. Finally, we argue that the variability in size, as well as in mineralogy, over ensembles of grains contributes to heterogeneous weathering rates. We demonstrate that this heterogeneity can contribute to the aging, or gradual decrease with time, of weathering rates previously observed in laboratory and field measurements.  相似文献   

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L. Wang  Y. Cheng  W. Li 《Geofluids》2014,14(4):379-390
This study assesses the displacement of coalbed methane by CO2 migration along a fault into the coal seam in the Yaojie coalfield. Coal and gas samples were collected continuously at various distances in NO.2 coal seam from F19 fault. Vitrinite reflectance, maceral, and pore distributions and proximate analysis of fourteen coal samples were performed. Gas components, concentrations, carbon isotopes of 28 gas samples were determined. We examined the coal–gas trace characteristics of coalbed methane displaced away from the fault by CO2 injection after geological ages. From east to west, away from the F19 fault, the CO2 concentration decreased, whereas the CH4 concentration increased gradually. The δ13C values for CO2 varied between ?9.94‰ and 1.12‰, suggesting a metamorphic origin. A wider range of values (from ?9.94‰ to 20‰) was associated with the mixing of microbial carbon dioxide, isotopic fractionation during CO2 migration through the microporous structures of coals, and/or carbon isotope fractionation during gas–water exchange and dissolution of CO2. Away from the F19 fault, the volumes of micropores, mesopores and macropores decrease gradually. The Dubinin–Radushkevich (DR) micropore volume decreased from 0.0059 to 0.0037 cmg‐1, and the mesopore and macropore volumes decreased from 0.066 to 0.026 cmg‐1. The CO2 injection can mobilize aromatic hydrocarbons and mineral matter from coal matrix, resulting in the decrease in the absorption peak intensity for coal samples after supercritical CO2 treatment, which indicates that chemical reactions occur between coal and CO2, not only physical adsorption.  相似文献   

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BOOK REVIEWS     
Book reviewed in this article: Palestinian Rights: Affirmation and Denial. Edited by Ibrahim Abu-Lughod A Mediterranean Society: The Jewish Community of the Arab World as Portrayed in the Documents of the Cairo Geniza , Volume 4: Daily Life. By S. D. Goitein The Arabic Book. By Johannes Pedersen The Early Islamic Conquests. By Fred McGraw Donner The Islamic Impact. Edited by Yvonne Yazbeck Haddad, Byron Haines and Ellison Findly Persian Miniature Painting: and its Influence on the art of Turkey and India [The British Library Collections]. By Norah M. Titley Essays in Islamic Art and Architecture [Islamic Art and Architecture, Vol. I]. Edited by Abbas Daneshvari Architecture and Community: Building in the Islamic World Today. [The Aga Khan Award for Architecture.] Edited by Renata Holod with Darl Rastorfer Islam and Ownership. By Seyyed Mahmood Taleqani Society and Economics in Islam: Writings and Declarations of Ayatullah Sayyid Mahmud Taleghani. Translated from the Persian by R. Campbell Equality, Efficiency, and Property Ownership in the Islamic Economic System. By Akhtar A. Awan. Lanham Crime and Corrections: An Al-Islamic Perspective. By Sidney R. Sharif The Qur'ān and Its Interpreters. Vol. I. By Mahmoud M. Ayoub 'Ulum al-Qur'ān: An Introduction to the Sciences of the Qur'ān. By Ahmad von Denffer Ibn Taymiyyah's Ethics—The Social Factor. By Victor E. Makari Shāh Wal?-Allāh And His Times. By Saiyid Athar Abbas Rizvi Islamic Theology and Philosophy: Studies in Honor of George F. Hourani. Edited by Michael E. Marmura Religion, My Own. The Literary Works of Naj?b Ma fūz. By Mattityahu Peled L'Orient dèchirè entre I'Est et L'Ouest (1955–1982). By Simon Jargy The Reflowering of Malaysian Islam: Modern Religious Radicals and Their Roots. By Judith Nagata Muslim Sects and Divisions. The section on Muslim sects in Kitāb al-Milal wa'I-Ni al by Mu ammad b. 'Abd al-Kar?m Shahrastān? (d. 1153) . By A. K. Kazi and J. G. Flynn Muslim Intellectual Responses to “New Order” Modernization in Indonesia. By Muhammad Kamal Hassan Social history of Timbuktu: the role of Muslim scholars and notables 1400–1900. By Elias N. Saad Religion and Politics in Muslim Society : Order and Conflict in Pakistan. By Akbar S. Ahmed Baba of Karo: A Woman of the Muslim Hausa. By Mary F. Smith  相似文献   

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Factual differences between the Periplus and Pliny about Roman trade with India reveal a time gap which indicates a date for the Periplus of circa 45 AD. In the light of this, a number of conclusions concerning Arabia in the 1st century AD can be drawn, in particular that awr Rūnī is not the site of Moscha, while the historical background in the Persian Gulf can be more readily understood. Points touched on concerning the sea routes to India and Italian mediaeval versions of Ptolemy's map of Arabia are discussed more fully in two appendices.  相似文献   

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Porous synthetic quartzites and amphibolites, each with faceted pore walls, were synthesized and evaluated to examine the permeability of pore networks similar to those of the lower crust and mantle. Quartzite with a fluid in equilibrium with an Mg–clinopyroxene contained connected networks of pores with a dihedral angle of 30° bounded by walls that were 10–50% faceted. The relationship of their permeability (k) to porosity (φ) is approximated by the previously determined relationship for relatively nonfaceted synthetic quartzite Amphibolite with an HF fluid contained fluorotremolite and a connected network of pores bounded by walls exhibiting 78–90% faceting. These materials showed much lower k for a given φ, with an apparent permeability threshold at φc = 0.04. A curve fit to these data yields The results suggest that moderate faceting has little effect on the transmission of fluids through rocks, but extensive faceting significantly alters permeability. This difference is most likely produced through isolation of the fluid to the grain corners at low φ with extensive faceting. Rocks with pores that tend toward faceting may impede the flow of fluids and melt.  相似文献   

13.
Although a Māhāyana sūtra, the clearly contains a number of elements that seem to presage the “tantric” phase in Indian Buddhism. In particular, the sūtra contains four components worthy of note: elaborate scenes detailing what can best be understood as , a soteriology based on absolute faith in the spiritual guides, a strong insinuation of organisational esotericism, and the hint of sexual yoga. After briefly summarising some recent scholarship on the , the author addresses each of the four “proto‐tantric” components in detail. Following this, the author concludes with the suggestion that despite the inherent difficulties in developing a relative chronology of Indian Buddhist literature, close readings such as provided in this article may be useful in generating data sets, which can then be used to relate Indian Buddhist texts to each other.  相似文献   

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Various thermodynamic properties of H2O that are defined as pressure or temperature derivatives of some other variable, such as isothermal compressibility (β, pressure derivative of density), isobaric thermal expansion (α, temperature derivative of density), and specific isobaric heat capacity (cf, temperature derivative of enthalpy), all show large magnitudes near the critical point, reflecting large variations in fluid density and specific enthalpy with small changes in temperature and pressure. As a result, mass (related to fluid density) and energy (related to fluid enthalpy) transport in this PT region are sensitive to changing PT conditions. Addition of NaCl to H2O causes the region of anomalous behavior, here defined as the critical region, to migrate to higher temperatures and pressures. The critical region is defined as that region of PT space in which the dimensionless reduced susceptibility  ≥ 0.5. When NaCl is added to H2O, the critical region migrates to higher temperature and pressure. However, the absolute magnitudes of thermodynamic properties that are defined as temperature and/or pressure derivatives (α, β, and cf) all decrease with increasing salinity. Thus, the mass and energy transporting capacities of hydrothermal fluids in the critical region become less sensitive to changing PT conditions as the salinity increases. For example, quartz solubility can be described as a function of fluid density, and because density becomes less sensitive to changing PT conditions as salinity increases, quartz solubility also becomes less sensitive to changing PT conditions as fluid salinity increases. Similarly, fluxibility describes the ability of a fluid to transport heat by buoyancy‐driven convection, and fluxibility decreases with increasing salinity. Results of this study show that the mass and energy transport capacity of fluids in the Earth's crust are maximized in the critical region and that the sensitivity to changing PT conditions decreases with increasing salinity.  相似文献   

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The excavation and palaeoanthropological analysis of the early Upper Palaeolithic site of Dolní V stonice II has yielded a series of incomplete and isolated human remains, comprising cranial vaults, teeth (including a series from an infant), ribs, arm bones, hand phalanges, leg bones, tarsals, metatarsals and pedal phalanges. Morphologically and morphometrically the elements are similar to those from buried individuals at Dolní V stonice I and II and Pavlov I, as well as to other European early Upper Palaeolithic human remains. They differ principally in the high percentage of cortical areas of the distal humerus and femur. The Dolní V stonice 36 infant's teeth may well derive from an undisturbed burial with in situ bone destruction. Geological processes are unlikely to have produced the taphonomic patterns observed, and the preservation and damage patterns of the elements (other than Dolní V stonice 36) suggest that the original bodies were processed by some combination of scavenging agents. Moreover, the original number of burials at Dolní V stonice II may have been greater than the four currently known.  相似文献   

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