Coprecipitation of metal ions into calcite: an estimation of partition coefficients based on field investigation

Trace elements(and their isotopes)in carbonates are commonly used to reconstruct paleoenvironment and paleoclimate.Understanding the processes and mechanisms of element incorporation into carbonates is thus crucial for using such geochemical parameters as paleoclimate proxies.In contrast to laboratory-based experimental results,the partitioning of trace metals between solid and solution phases in natural carbonate precipitation systems has rarely been reported.In this study,we investigated the partition coefficients of metal ions between solid and solution in the channel of the natural Baishuitai travertine system,Yunnan,China.Our results show that the partition coefficients of Li+,Na+,Mg2+,Sr2+and Ba2+are<1,that of Ni2+is approximately 1,and those of Co2+,Mn2+,Zn2+and Cu2+are>1,consistent with the results found in previous experimental studies.Although the substitution for Ca2+is likely the main uptake process of these metals into calcite,depending on their ionic radius and charge,trace elements may also be incorporated by adsorption or physical entrapment.Our study shows that unlike laboratory experiments performed under specific conditions,the partitioning of metals between two phases in the natural travertine system could be controlled by several,even multiple,environmental factors(e.g.,carbonate deposition rate,temperature,and pH),which should be taken into account when using trace metals(and their isotopes)in carbonate archives as a paleoclimate proxy.

区域场地土壤跨介质污染物多源清单:中国场地土壤污染防治的新策略

China has experienced rapid economic development and industrialization during the past four decades,leading to widespread distribution of various types of industrial facilities[1].With the understanding of soil contamination induced by industrial sites and rapid urbanization,abandoned industrial sites are generally reclassified for urban land[2].The remained brownfield sites(the sites of abandoned,idle,or under used industrial and commercial facilities where expansion or redevelopment is hindered by environmental contamination)exhibit great health risks to the residents due to that pollutants were continuously discharged intothe surrounding environments[3].

Three Dimensional Metal-Surface Processing Parameter Generation Through Machine Learning-Based Nonlinear Mapping

The accuracy and efficiency of three-dimensional(3D)surface forming,which directly affects the cycle and quality of production,is important in manufacturing.In practice,given the uncertainty of metal plate springback,an error exists between the actual plate and the target surface,which creates a nonlinear mapping from computer aided design models to bending surfaces.Technicians need to reconfigure parameters and process a surface multiple times to delicately control springback,which greatly wastes human and material resources.This study aims to address the springback control problem to improve the efficiency and accuracy of sheet metal forming.A basic computation approach is proposed based on the DeepFit model to calculate the springback value in 3D surface bending.To address the sample data shortage problem,we put forward an advanced approach by combining a deep learning model with case-based reasoning(CBR).Next,a multi-model fused bending parameter generation framework is devised to implement the advanced springback computation approach through surface data preprocessing,CBR-based model matching,convolution neural network-based machining surface generation,and bending parameter generation with a series of model transformations.Moreover,the proposed approaches and the framework are verified by considering saddle surface processing as an example.Overall,this study provides a new idea to improve the accuracy and efficiency of surface processing.

Mass-independent fractionation of even mercury isotopes

Practically all physical, chemical, and biological processes can induce mass-dependent fractionation of mercury(Hg) isotopes. A few special processes such as photochemical reduction of Hg(II) and photochemical degradation of methylmercury(Me Hg) can produce massindependent fractionation(MIF) of odd Hg isotopes(oddMIF), which had been largely reported in variable natural samples and laboratory experiments, and was thought to be caused by either nuclear volume effect or magnetic isotope effect. Recently, intriguing MIF of even Hg isotopes(evenMIF) had been determined in natural samples mainly related to the atmosphere. Though photo-oxidation in the tropopause(inter-layer between the stratosphere and the troposphere) and neutron capture in space were thought to be the possible processes causing even-MIF, the exact mechanism triggering significant even Hg isotope anomaly is still unclear. Even-MIF could provide useful information about the atmospheric chemistry and related climate changes, and the biogeochemical cycle of Hg.

Healthcare data analytics:using a metadata annotation approach for integrating electronic hospital records

The data in electronic medical records(EMR)are complex in structure.They are independent,yet related to each other.In order to improve information access through the use of EMR,annotating work on these data is necessary.The annotation on metadata,the resource data which contain a meta-model of the database,is the basis of the annotating work if a semi-automated or an automated annotating approach which aims at making the database more accessible is expected.In this study,a method has been proposed to transform the terms which cannot be matched directly by changing them literally but maintaining their semantics,and then annotating them indirectly.After the transforming work,a refinement method which is reducible to phrase sense disambiguation(PSD)is employed to ensure accuracy.A pilot study on a hospital database has been conducted to test the accuracy and effectiveness of the proposed method.

Geochronology and Petrogenesis of Mafic-Intermediate Intrusions on the Northern Margin of the Central Tianshan(NW China): Implications for Tectonic Evolution

Late Paleozoic mafic-intermediate intrusions are widespread in the central Tianshan belt, but their tectonic settings remain controversial. Petrogenesis of these intrusions can provide insights into the tectonic evolution of the belt and its adjacent areas. This study presents new whole-rock geochemical and zircon U-Pb geochronology and Hf isotopic data for the Yaxi diorite and Qianzishan gabbro on the northern margin of the central Tianshan(NW China). Zircon U-Pb dating yielded the magma crystallization ages of 313±4 and 295±4 Ma for the Yaxi diorite and Qianzishan gabbro, respectively. They have lower Mg# values, Ni and Cr contents than typical mantle-derived primary melt, with negative correlations between MgO, TFeO and SiO2 contents, indicating clinopyroxene and olivine fractionation during magma evolution. They are characterized by enrichment of large ion lithophile elements(e.g., Rb, Ba and Sr) and depletion of high field strength elements(e.g., Nb, Ta and Ti) with high Ba/Th and Rb/Y, suggesting that their mantle sources had been metasomatized by slab-derived fluids. In addition, the Qianzishan gabbro has high Al2 O3 contents(19.54 wt.%–20.88 wt.%) and positive Eu anomalies(Eu/Eu*=1.09–1.42), which can be attributed to accumulation of plagioclase. Geochemical and zircon Hf isotopic compositions reveal that both the Yaxi diorite and Qianzishan gabbro were derived from depleted lithospheric mantle in the spinel stability field with insignificant crustal contamination. In association with previous investigations, we suggest that the Yaxi and Qianzishan intrusions were emplaced in a subduction-related environment, which means that the subduction of the Junggar Ocean lasted at least to the earliest Permian.

A linked data-based approach for clinical treatment selecting support

Treatment plan selection is a complex process because it sometimes needs sufficient experience and clinical information.Nowadays it is even harder for doctors to select an appropriate treatment plan for certain patients since doctors might encounter difficulties in obtaining the right information and analyzing the diverse clinical data.In order to improve the effectiveness of clinical decision making in complicated information system environments,we first propose a linked data-based approach for treatment plan selection.The approach integrates the patients’clinical records in hospitals with open linked data sources out of hospitals.Then,based on the linked data net,treatment plan selection is carried on aided by similar historical therapy cases.Finally,we reorganize the electronic medical records of 97 colon cancer patients using the linked data model and count the similarity of these records to help treatment selecting.The experiment shows the usability of our method in supporting clinical decisions.

South-hemispheric marine aerosol Hg and S isotope compositions reveal different oxidation pathways

Particle-bound mercury(PBM)records the oxidation of elemental mercury,of which the main oxidation pathways(Br∙/Cl∙/OH∙/O3)remain unclear,especially in the Southern Hemisphere.Here,we present latitudinal covariations of Hg and Sisotopic anomalies in cross-hemispheric marine aerosols that evidence an equator-to-poleward transition of Hg oxidants from OH∙/O3 in tropics to Br∙/Cl∙in polar regions highlighting thus the presence of distinct oxidation processes producing PBM.The correlations between Hg,S and O-isotopic compositions measured in PBM,sulfates and nitrates respectively within the aerosols highlight the implication of common oxidants in their formations at different latitudes.Our results open a new window to better quantify the present-day atmospheric Hg,S and N budgets and to evaluate the influences of aerosols on climate and ecosystems once the isotopic fractionations associated with each process have been determined.

Healthcare data analysis system for regional medical union in smart city

Regional medical unions are practical approaches to deal with the cases that patients crowd in Grade 3 Class A general hospitals in metropolitan cities such as Shanghai,in China.However,electronic medical data analysis exists challenges when patients are referred among different hospitals in the regional medical unions during treatment procedures.In smart cities,demands for medical services provided by smart devises,complicate the environment of medical data analysis.In order to tackle the above problems,in this paper,a healthcare data analysis system for regional medical union is designed to support doctors from different hospitals to assess health conditions of patients in an overall data view.Behaviour patterns are mined from physiological index values.Tags are generated from social networks data to find the hot topics concerned by people living in common region.Experiments are given to illustrate the feasibility of the system in supporting healthcare data analysis.