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Whole-rock geochemistry and zircon trace element, U Pb and Hf isotopic data for Upper Permian volcanic ash at Shangsi show a significant change in source from the Emeishan Large Igneous Province (LIP) to a convergent plate margin magmatic arc. The lower stratigraphic samples display high Al2O3/TiO2 ratios, strong negative Eu anomalies, and no depletion in high field strength elements. Zircons with ages of ca. 260 Ma from these ashes have a geochemical affinity to within-plate-type magmas and with felsic ignimbrites from the uppermost part of the Emeishan volcanic succession at Binchuan. These features, combined with relatively high eHf(t) values and low Th/Nb ratios in the zircons, imply a late-stage felsic volcanic origin related to Emeishan LIP. The upper stratigraphic samples at Shangsi display significant depletion in Nb and Ti; zircons separated from these volcanic ashes are chemically similar to those from arc-related/orogenic rocks, indicative of a magmatic arc source. Combined with published high-precision CA-TIMS data for these volcanic ash layers, the Emeishan volcanism can be constrained to between ca. 260–257.8 Ma. The age of Emeishan volcanism is consistent with the Wuchiapingian climate cooling event, supporting a potential linkage between these two phenomena.

This study investigated variations in air quality by evaluating trace gases, inhalable particulate matter (PM_(10)), and associated trace elements at three sites in Panzhihua (a mining city located in Panxi Rift Valley, Southwest China) between January and December 2014. The concentrations of 19 trace elements in PM_(10) were determined through inductively coupled plasma mass spectrometry. Single particle morphology and chemical composition were determined through scanning electron microscopy with energy-dispersive X-ray analysis to identify their possible sources. Mean sulfur dioxide, nitrogen dioxide, and carbon monoxide concentrations were highest near the steel smelting district, whereas ozone concentrations were highest in the residential region. Annual mean concentrations of PM_(10) at three sites were 129.4, 165.5, and 187.2 μg m^(-3); all these exceed the annual mean (70.0 μg m^(-3)) of the National Ambient Air Quality Standard. In addition, the concentrations of trace elements in PM_(10) exhibited significant spatial and seasonal variations at the three sites. The mean concentrations of trace elements in PM_(10) were in the order of Fe ＞ Ti ＞ Zn ＞ Pb ＞ Cu ＞ Mn ＞ Ba ＞ V ＞ Cr ＞ Ni ＞ Sr ＞ Bi ＞ Cd ＞ As ＞ Co ＞ Sb ＞ Sc ＞ TI ＞ U. The enrichment factor values of the trace elements suggested that anthropogenic activities were the dominant sources of As, Cd, Sb, Ti, TI, Zn, Cu, Pb, and Bi. Particle morphology and chemical composition analysis revealed five major particle types, namely aluminosilicate, Fe-containing, mineral, soot, and Ca-containing particles.

This research was supported by the Open Fund (PLC201404) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology), the National Natural Science Foundation of China (41502109), Project funded by China Postdoctoral Science Foundation (2015 M582528) and the Fundamental Research Funds for the Central Universities, Chengdu University of Technology. Claystone beds directly below and above the Emeishan basalts in SW China formed around the Guadalupian-Lopingian (G-L) boundary. Zircons from both levels give U–Pb ages of ~ 260 Ma, and are identical within-error to ages reported for the Emeishan Large Igneous Province (LIP). The claystones lack Nb-Ta anomalies on primitive mantle normalized elemental diagrams; zircons from these claystones have a geochemical affinity to within-plate-type magmas. These features, combined with the strong negative Eu anomalies in the zircons and high Al2O3/TiO2 ratios, indicate that claystones around the G-L boundary have a silicic volcanic component related to Emeishan LIP. Zircons from the underlying claystone bed have much higher U/Yb and Th/Nb ratios and lower εHf(t) values than those overlying the LIP, suggesting that early-stage silicic volcanic rocks had a higher crustal contamination or assimilation during magmatic processes. In terms of stratigraphic correlation, our data demonstrate that silicic eruptions occurred not only at the end, but also at the beginning of the Emeishan LIP, and the overall duration of the main basaltic phase was short (< 1 m.y). Postprint

Landscape pattern change will cause flow and change of energy, material and nutrient between different units of land, and can cause regional ecological processes and systems functional changes. As the capital city of Yunnan Province and the southwest gateway to China, Kunming city landscape structure takes place significant changes under the high-intensity human disturbance, then the environmental effects are certainly very obvious. Based on the past two decades land cover changes of Kunming, study applies 10 types of landscape indices on class level and landscape level, analyzes the landscape changes of forest, grass land, water area, farm land, residential surface, industrial land and bare land from year 1990 to 2010, then explores the various types of spatial and temporal evolution of the landscape, the regional landscape effects on the ecosystem, and provides a scientific reference for understanding the trend of ecological environment and promoting the coordinated development of regional economy and environment.

An isothermal dissolution method was employed to investigate the phase equilibrium at 308 K of the mixed aqueous system containing lithium, magnesium, sulfate, and borate. The solid phases of the invariant points were confirmed with the X-ray diffraction method. The stable phase diagram, the water content diagram, and the diagrams of the physicochemical properties versus the composition of the solution have been constructed. The system contained two invariant points (noted as E1 and E2), five univariant curves, and four crystallization fields corresponding to single salts epsomite (MgSO4·7H2O), hungchaoite (MgB4O7·9H2O), lithium sulfate monohydrate (Li2SO4·H2O), and lithium borate trihydrate (Li2B4O7·3H2O). Invariant points E1 and E2 are of commensurate invariant points. The crystallization fields decrease in the sequence MgB4O7·9H2O, Li2B4O7·3H2O, Li2SO4·H2O, and MgSO4·7H2O, which was contrary with the solubility of the salts. Compared with the temperature at 298 K, the crystallization area of salts MgB4...

The solid–liquid equilibrium of reciprocal quaternary system Cd2+, K+//Cl–, SO42––H2O at 298 K was studied by an isothermal solution saturation method. Experimental results indicate that there are nine univariant curves F2E2, F4E4, E2E1, F3E1, E1E3, F5E3, F1E3, F6E4, and E4E2, four invariant points E1, E2, E3, and E4, and six crystallization fields in the reciprocal quaternary system. There are two double salts existing in the reciprocal quaternary system. The crystallization zones of equilibrium solid phases are K2SO4 (F2E2F4), KCl (F4E2E1F3), CdCl2·H2O (F5E3F1), Cd3KCl7·4H2O (F3E1E3F5), 3CdSO4·8H2O (F1E3E1E2F2), and KCdCl3 (E1E2E4F6F3). The point E1 represents the equilibrium of the three-solid phase KCl + Cd3KCl7·4H2O + 3CdSO4·8H2O. The eutectic point E2 represents the equilibrium of the three-solid phase K2SO4 + KCl + 3CdSO4·8H2O. The eutectic point E3 represents the equilibrium of three-solid phase Cd3KCl7·4H2O + CdCl2·H2O + 3CdSO4·8H2O. The other eutectic point E4 represents the equilibrium of the t...

Static adsorption experiments were conducted to understand the impact of soil surface charge characteristics, such as pH, AEC and CECp values, on migration behavior of radioactive Uranium, Strontium and Cesium. The results demonstrate that distribution coefficient of Uranium (U-Kd value) increases with decreasing initial pH of solution, and increases with increasing AEC values for acidic clay and silty clay that were studied; distribution coefficients of Strontium and Cesium appear to be positively correlated with CECp values of and total contents of montomorillonite and illite in the soil.

Advantages and disadvantages of natural shields in a very low level waste (VLLW) disposal area were studied with regard to the adsorption and fixation capability of the natural shields against radioactive elements Uranium, Strontium and Cesium, with the understanding of the hydrogeological and geochemical characteristics of the surrounding area. Necessity of establishing geochemical engineering shield in the disposal area is discussed based on the understanding of the inadequacy of the natural shields against Uranium and Strontium. A physical chemistry model involving three-fold of shields suitable for the disposal area is proposed with integrated consideration of the results from efficacy and endurance experiments on the natural shield.

To explore the effect of logfO2(g), pH, uranium concentration, phosphate concentration and NaCl concentration on the predominance diagrams of dissolved uranium species and formation of solid phases containing uranium in the U-PO43--NaCl-H2O system at 25 °CandPCO2=10-3.5MPa, the thermodynamic model of this system was constructed. Based on the results of calculation, the logfO2(g)-pH diagrams were drawn. It can be found that: 1) the formation of uraninite needed enough reductive condition (about logfO2(g) < -50 ), while the formation of Na-Autunite needed the strict pH range (54O9(C). 3)The independent increasing of uranium concentration can lead to more kinds of uranium species.4) The variance of NaCl concentration had little impact on the formation of solid phases containing uranium.

Land-use planning has triggered debates on social and environmental values, in which two key questions will be faced: one is how to see different planning simulation results instantaneously and apply the results back to interactively assist planning work; the other is how to ensure that the planning simulation result is scientific and accurate. To answer these questions, the objective of this paper is to analyze whether and how a bridge can be built between qualitative and quantitative approaches for land-use planning work and to find out a way to overcome the gap that exists between the ability to construct computer simulation models to aid integrated land-use plan making and the demand for them by planning professionals. The study presented a theoretical framework of land-use planning based on scenario analysis (SA) method and multiagent system (MAS) simulation integration and selected freshwater wetlands in the Sanjiang Plain of China as a case study area. Study results showed that MAS simulation technique emphasizing quantitative process effectively compensated for the SA method emphasizing qualitative process, which realized the organic combination of qualitative and quantitative land-use planning work, and then provided a new idea and method for the land-use planning and sustainable managements of land resources.

Solid-liquid equilibrium of ternary system Cd2+, Na+//Cl−-H2O at 298 K were studied by an isothermal solution saturation method. Experimental results indicate that there are three univariant curves AE, EF, and FB, two invariant points E, F, and three crystallization fields in the ternary system. The ternary system has one double salt Na2CdCl4 · 3H2O. The crystallization zones of equilibrium solid phases are CdCl2 · H2O (AEG field), Na2CdCl4 · 3H2O (EFM field), and NaCl (FBN field), respectively. The composition of the invariant point E is CdCl2 · H2O and Na2CdCl4 · 3H2O of which content was 52.70 and 4.11%, respectively. The composition of the invariant point F is Na2CdCl4 · 3H2O and NaCl of which content was 27.92 and 14.95%, respectively. The density of solution in the ternary system show regular changes along with the increased cadmium concentration. The results indicated that CdCl2 · H2O possessed the highest solubility among those three salts, which means a strong transfer of Cd ion and a high pollution risk of soil environment. And the solubility of NaCl would be restrained as the three salts existing together.

Metastable equilibrium solubilities and such physico-chemical properties as densities, conductivity, pH, refractive index and viscosity of the solution for the quaternary system Li2B4O7+Na2B4O7+K2B4O7+H2O at 15 °C were determined experimentally. According to the experimental data, the metastable equilibrium phase diagram was plotted. In the metastable phase diagram, there are one invariant point, three univariant curves, and three fields of crystallization: Li2B2O4·16H2O, Na2B4O7·10H2O, and K2B4O7·4H2O. Potassium borate (K2B4O7·4H2O) has the smallest crystallization field and sodium borate (borax) has the biggest one. Also, the relationship diagram between the properties and the ion concentration of solution was constructed. It can be seen from the relationship diagram that the metastable equilibrium solution density values, viscosity values and refractive index values are increased apparently with the rise of lithium borate concentration, reaching the maximum values at invariant point F. Electrical conductivity values and pH values, however, fall down with the rise of ion concentration on the whole.

An experimental study on phase equilibria at 288 K in the quinary system Li+ + Na+ + K+ + SO42- + B4O72- + H2O was performed using the isothermal evaporation method. Equilibrium solubility and density of the solution were measured. The equilibrium phase diagram for the solution saturated with the salt Li2B2O4·16H2O was constructed. The phase diagram of this system consists of 7 invariant points, 14 univariant curves, and 8 crystallization fields corresponding to potassium tetraborate pentahydrate (K2B4O7·5H2O), borax (Na2B4O7·10H2O), potassium sulfate, lithium sulfate monohydrate (Li2SO4·H2O), sodium sulfate, lithium−potassium sulfate double salt (Li2SO4·K2SO4), lithium−sodium sulfate double salt (Li2SO4·Na2SO4), and potassium−sodium sulfate double salt (3K2SO4·Na2SO4). There are three kinds of double salts formed in the system. The crystallization forms of lithium and potassium borate were K2B4O7·5H2O and Li2B2O4·16H2O, respectively, which are different from the usual forms of K2B4O7·4H2O and Li2B4O7·3H2...

Ten trace elements in the inhalable particles (PM10) at Panzhihua, a Southwestern China mining city, were studied for characteristics and human health risks of particulate toxic metal(loid)s at two industrial sites and one urban residential site during April 2014 through January 2015. Average concentrations of PM10 at three sites were 127.2, 172.0 and 187.5 µg m−3, respectively, which all greatly exceeded the national ambient air quality standard (70.0 µg m−3 annual average). Zn, Pb, Cu, and Mn were the most abundant trace elements among the studied metals in PM10. Particulate metal(loid)s' pollution was very serious, in which As, Cd, Ni, Co, Cu, and Mn in PM10 greatly exceeded their respective thresholds. Results of a health risk assessment indicated that Cr posed a major carcinogenic health risk to both children and adults, whereas Mn had a non-carcinogenic risk. Other toxic metals were within the safe levels.