Ratio Of Ions Research Articles

Engineering atomic size mismatch in Pr3+, La3+ codoped Lu3Al5O12 garnet single crystals for tailored structure and functional properties

This study provided the first in-depth investigation of the effects of large dopant incompatibility (Pr3+ and La3+ ions) on the small host lattice element (Lu3+) in Lu3Al5O12 (LuAG) single crystal. The growth of such complex crystals from the melt presented many challenges. By engineering the ionic radius ratio of RE- and M-site cations, a single-crystal phase stabilized by configurational entropy was achieved. This investigation elucidated the crystallization behavior of configurationally disordered rare-earth aluminum garnet oxide (Lu1−x−yPrxLay)3Al5O12 from the melt and characterized its functional properties, including microstructural, optical, photoluminescence, and scintillation properties, between 5 and 300 K. Relaxation of the imposed strain energy led to local perturbations and destabilization of the garnet structure. Multielemental EDS mapping, micro-Raman spectroscopy, and thermoluminescence revealed the mechanism by which atomic size mismatch drove a smooth transition from the garnet to the perovskite phase in high entropy garnets. The optical, photoluminescence, and scintillation measurements provided fundamental insights into property changes driven by incompatibility doping. Standard and modified Judd-Ofelt theory analysis of absorption spectra determined the phenomenological Judd-Ofelt parameters Ωλ and radiative lifetimes. Atomic size mismatch engineering offers a promising approach to overcoming the limitations of conventional eutectic synthesis methods.

Modulated dust-ion-acoustic waves result from Earth's magnetosphere and lunar ionosphere interactions

The Earth's magnetosphere's modulational amplitude dust-ion-acoustic waves are studied. When the moon passes through the Earth's magnetotail, its dust grains may interact, causing these waves. The theoretical plasma model for this study includes positive ionospheric ion fluids, isothermal electrons, and fluid-negative dust grains on the moon. A perturbation technique derived the nonlinear Schrödinger equation, which exhibited dispersion and nonlinear effects. The nonlinear and dispersion term coefficients' polarity may predict stable and unstable pulse domains. A numerical study was performed to identify unstable pulse domains and their connections with bright and rogue unstable modes. The effects of critical plasma conditions on these pulses' basic features have been studied. This study showed that increasing the ratio of ions to electrons temperature and density reduces system nonlinearity. Consequently, shorter unstable pulses are formed. Amplification of plasma unstable waves results in an increase in their intensity and energy, potentially impacting any device traveling through the area of impact.

Seasonal variations and water chemical control mechanism of water quality in a suburban river near a coal city: a case study in the Xinbian River of Suzhou City, Anhui Province, China

Abstract To study the seasonal change rules of water quality indicators and water chemical control mechanisms in the nearby city river Xinbian River, in Suzhou City, Anhui Province, China, nine points were selected and periodically sampled for 12 months. Totally 108 water samples were collected, and basic physical–chemical indicators and routine ions (e.g., Ca2+, Mg2+, Na+, K+, SO42−, Cl−, F−, NO3−, CO32−, and HCO3−) were measured. Piper diagram, Gibbs diagram, and ion ratio method were used. The result shows that the seasonal and upstream-to-downstream variations in pH were less varied, whereas the fluctuation in dissolved oxygen was large. Four ions, namely, SO42-, F−, Cl−, and Na+ generally first decreased overall and then changed from spring to winter. The maximum contents of SO42- (406.03 mg/L), Cl− (250.22 mg/L), and Na+ (269.99 mg/L) in single water samples appeared at the S9 sampling point (Suzhou control gate) in March 2020. The dominant hydrochemical types in summer were Na–Ca–HCO3 and Na–Mg–SO4, while Na–Mg–SO4 and Na–Mg–HCO3 were the main hydrochemical types in the other seasons. The control factors of water chemical composition vary according to the season. However, rock weathering (e.g., silicate dissolution) is the dominant control factor of water chemistry in the studied river section.

Biomineralization of Human Genomic DNA into ZIF-8, a Zeolite-Like Metal-Organic Framework.

We studied human genomic DNA isolated from lymphocytes of peripheral blood of healthy volunteers using Proba-NK kit (DNA-Technology LLC, Russia). Genomic DNA purity and concentration was estimated spectrophotometrically at 260/280 nm using Tecan Infinity 200 Pro plate reader (Tecan Instruments, Austria). ZIF-8 was synthesized in the physiological conditions (37°C) by mixing zinc salt and 2-methylimidazole aqueous solutions at different molar ratios. Human genomic DNA was encapsulated into ZIF-8 in similar conditions. The obtained MOF and DNA@ZIF-8 composite were studied using X-ray powder diffraction at the Phaser D2 XRPD device (Bruker, USA), and the specific surface area was estimated using Autosorb iQ porosimetry analyzer (Quantachrome, USA). The encapsulated DNA was quantified by dissolving DNA@ZIF-8 composite in the citrate buffer. DNA integrity was assessed by real-time allele-specific PCR (AS-PCR) using the kits for single nucleotide polymorphisms (Lytech, Russia) at the Quantstudio 6 Pro PCR machine (Thermo Scientific, USA). In case of using the kits with electrophoretic detection, the amplification was performed on the thermal cycler T100 (Thermo Scientific, USA). The polymer ZIF-8 and DNA@ZIF-8 composite were obtained at different molar ratios of zinc ions and 2-methylimidazole. We characterized their structure and specific surface area. Genomic DNA biomineralization efficacy was found to be about 7-8%. PCR indicated the integrity of non-selectively chosen loci within the biomineralized DNA. The study confirmed the possibility of human genomic DNA encapsulation into ZIF-8 metal-organic framework. After the biomineralization, DNA was found to preserve feasibility to be used in studies to investigate genetic constructs.

Controllable synthesis of CeFeO3/Fe+2Fe2+3O4/C composites with improved microwave absorption performances

Magnetic-dielectric component modulation and heterogeneous interface engineering have been acknowledged as a highly potent strategy for the effective development of lightweight and broad-spectrum electromagnetic wave (EMW) absorbers. In this investigation, a series of carbon-based Ce/Fe-MOF derivatives were successfully synthesized via the carbonization process of Ce/Fe-MOF precursors. The EMW absorption characteristics of these derivatives were investigated by manipulating the metal ion ratio and the pyrolysis temperature. Notably, the Ce/Fe-MOF-700 composite, derived from the calcination of Ce/Fe-MOF with a molar ratio of Ce/Fe of 1:2 at 700 °C, demonstrated an impressive minimum reflection loss value of −44.6 dB at 1.38 mm. Furthermore, it exhibited an efficient absorbing bandwidth (EAB) of 6.88 GHz at a thinner coating thickness ranging from 1.38 to 1.8 mm. This remarkable ability of these materials to attenuate EMW can be ascribed to the heightened conductivity dissipation, polarization dissipation, magnetic dissipation, and enhanced impedance matching achieved by these materials. The findings of this study provide a novel point of reference for the design of lightweight and broad-spectrum EMW absorbing materials.

Reservoirs and Hydrogeochemical Characterizations of the Yanggao Geothermal Field in Shanxi Province, China

Geothermal water is the product of deep circulation within the crust, and the understanding of its hydrogeochemical process can provide effective information for integrated research on its circulation pattern and formation mechanism. Based on the geothermal geological conditions of the Yanggao geothermal field, this study analyzed water samples from thermal springs and geothermal wells in the geothermal field, ascertaining their hydrochemical components, along with their hydrogen and oxygen isotopes. Using methods like piper diagrams, ionic component ratio characterization, Na–K–Mg equilibrium diagrams, and reverse path simulations, this study elucidated the recharge source of geothermal water in the study area, revealed the water–rock interactions the geothermal water experienced, and evaluated the geothermal reservoir temperatures. The results show that the geothermal water has hydrochemical types of Na–Cl–HCO3 and Na–HCO3–Cl, and is primarily recharged by the atmospheric precipitation in the northern mountainous area. The geothermal water has experienced extended water runoff and deep thermal circulation, and its hydrochemical composition primarily results from the weathering and dissolution of silicate rocks and evaporites. The major hydrogeochemical processes of the geothermal water involve the dissolution of calcite, dolomite, gypsum, and kaolinite. In addition, the canon-exchange also changes the chemical component of the geothermal water. The SiO2 Geothermometer, a multimineral equilibrium diagram, and the silica–enthalpy model reveal the presence of deep and shallow geothermal reservoirs in the study area, which exhibit temperatures of 73 °C and ranging from 125 to 150 °C, respectively. The open geothermal reservoir environment results in the mixing of geothermal water and cold water, with shallow and deep geothermal water mixing with cold water at ratios of 57% and 76%, respectively.

Cs+ Extraction from Chloride-Rich Brine Solutions Using the Calixarene Crown Ether MAXCalix

ABSTRACT We have developed an extraction method for the retrieval of Cs+ from chloridecontaining salt brine solutions. We employ the calixarene crown ether known as MAXCalix as the extractant, which exhibits a remarkable selectivity for Cs+ over Na+, K+, Mg2+ and Ca2+, with separation factors ranging from 100 to 104. The efficiency of the extraction strongly depends on the chloride concentration in the aqueous phase. Notably, when the chloride concentration reaches 4 mol L−1, we achieve a Cs+ distribution ratio of 7.9. Accordingly, the retrieval of Cs+ from the organic phase is achieved when the HCl concentration is maintained at a low level. In multicomponent chloride brine solutions, the distribution ratios for Cs+ are somewhat lower, yet still fall within the range of 4–6. Nevertheless, these ratios remain favorable for separation purposes. Additionally, the distribution ratios of Na+, K+, Mg2+, and Ca2+ offer insights into the coordination chemistry of MAXCalix. Our experimental data indicate a correlation between ionic size and distribution ratio. Cs+ forms the strongest complex, followed by K+ and Na+, while Mg2+ and Ca2+ exhibit minimal extraction, potentially due to interactions with the diluent. These findings may open new approaches for the development of a decontamination strategy tailored to address salts and brine solutions contaminated with Cs-137.

Fresh and recirculated submarine groundwater discharge zones along the central west coast of India

The study area receives an average of 2840.0 mm of rainfall within four months every year. A portion of the rainwater is flown to the sea as surface water, and the other part is percolated into the bottom as groundwater. In coastal aquifers, the groundwater is transported to the sea due to a hydraulic gradient, and it contains a significant quantity of dissolved materials and nutrients. SGD processes impact the ocean productivity, mangrove and coral growth, local acidification and many. To isolate the SGD on the central west coast of India, different data was referred. The GWL concerning MSL contributed significantly to demarcating the SGD zones by considering the positive (>0 m) and negative (<0 m) values of GWL concerning above MSL. Thermal images for SST of pre-monsoon and post-monsoon periods of 2020 exhibit cooler surrounded by warmer, which might be the SGD buffering zones in the off-central west coast of India. By considering the results from GWL and SST, 8 SGD beach sites were identified for the further particularized study. The water samples were collected in March 2022, and analyzed using standard procedures and instruments. Fresh and mixing (recirculated) zones have been isolated by piper, hydrochemical facies evolution, and Ca2++Mg2+/K++Na + Vs log Cl− ionic ratio plots. The aquifer water chemical elements are converting possibly due to ionic exchange processes. The decrease in salinity and conductivity observed in the pore water just below the seawater might be due to the influence of freshwater inputs, helping to isolate the fresh SGD and recirculated SGD zones in the study area. Among 8 sites, 3 were found to be fresh SGD sites and 5 were noticed to be mixing/recirculated SGD sites. Most of these Beaches are bounded by hills, which helps to lead the SGD along the central west coast of India.

Spatial Distribution of Arsenic in the Aksu River Basin, Xinjiang, China: The Cumulative Frequency Curve and Geostatistical Analysis

The quality of drinking water is crucial for human health and the sustainable development of societies. The Aksu River Basin, a typical inland river system, has areas where groundwater arsenic levels exceed safe drinking water standards (i.e., arsenic concentrations greater than 10 μg/L). Identifying the causes of high arsenic levels in the basin’s groundwater requires further study. Analyzing the hydrogeochemical composition of the Aksu River basin helps us to understand the spatial distribution of groundwater environments and locate areas with dangerously high arsenic levels. In this research, we collected 196 groundwater samples from along the river. Out of these, 38 samples had arsenic levels above 10 μg/L, which represents 19.4% of the total samples collected. By examining the slope changes in the cumulative frequency curves of major ion ratios and employing geostatistics (specifically, the Kriging interpolation), and taking into account the environmental characteristics of the entire basin, we divided the study area into five sub-regions (Zone I through Zone V). The geostatistical analysis showed a significant spatial variability in groundwater arsenic levels, with a clear spatial correlation. Our findings demonstrate that arsenic concentrations in the Aksu River basin’s groundwater vary widely, with Zones II and III—mainly located in the northeastern part of the basin and in Awat County—being hotspots for high-arsenic water. Factors such as a weak reducing environment, intense evaporation, strong cation exchange, and the low-permeability recharge of surface water contribute to the accumulation of arsenic in the basin’s groundwater. The results of this study are vital for assessing the risk of arsenic contamination in groundwater in similar basins and for identifying critical areas for further investigation and research.

NOx formation mechanism of plasma assisted ammonia combustion: A reactive molecular dynamics study

The effects of ionization ratio (α) on the reaction rate of NH3 combustion and the formation characteristics of NOx are studied by ReaxFF MD, and the formation mechanism of NOX in plasma assisted NH3 combustion are analyzed from the molecular level. It is found that the maximum growth rate of NOX gradually slows down with increasing reaction system temperature. The plasma promotes NOX formation at the initial stage of NH3 combustion, and when the nitrogen-containing radicals are consumed, the non-nitrogen-containing components will inhibit NO formation. When the α is 25%, the NH3 reaction rate reduces slightly. This is attributed that the proportion of NH2/H is the larger at this lower α. The plasma effect at lower α = 25% enhances the N2 formation path from NH3 by the primary reaction pathway of NH3→NH2→NH→NNH→N2, and the intermediate NH consumes some of the NO to form N2 by NH + NO↔HN2O and HN2O↔N2+OH. As α increases to 50%, the plasma leads to the direct generation of NO from NH by NH + OH↔H2NO and H2NO + O↔H2O + NO, which makes the maximum of NO increase.

Development of a Semi-Dry Method for Measuring Drug Permeation into Skin Using an Electric Facial Care Device and Iontophoresis

Introduction: Percutaneous drug delivery systems are attractive not only as a therapeutic strategy but also for cosmetic treatment. Iontophoresis is a well-recognized method for promoting transdermal absorption of ionized compounds. Franz cells are generally used to estimate drug permeation of skin by iontophoresis. However, methods using Franz cells are less versatile; for instance, the method is unsuited for use with a portable electric facial care device having a working probe of a certain size and weight. In this study, we constructed a semi-dry apparatus for use with an electric facial care device. Methods: The apparatus has a multilayer structure consisting of mouse skin and 3 filter papers, modeled after the Franz cell. The skin permeation of the drug edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) was then measured using this apparatus. Results: Edaravone permeation depended on working time, drug concentration, and ionization ratio of edaravone when iontophoresis was carried out with an electric facial care device. Furthermore, glycyrrhizic acid, α-tocopheryl phosphate, retinoic acid, and ascorbyl palmitate, which are recognized as functional cosmetic materials, also permeated the skin by applying iontophoresis with the device. Conclusion: These results suggest that the developed measuring apparatus is applicable for use with a portable electric facial care device and that iontophoresis using a portable electric facial care device is potentially useful in the cosmetic field.

Arsenic geochemical species modeling, prediction, and bioavailability in groundwaters of the Oban Massif, southeastern Nigeria

To ascertain the distribution patterns, source identification, chemical speciation, and bioavailability of arsenic in basement aquifers, 64 groundwater samples were analyzed using hydrochemical and geochemical modeling. It was determined that important ion geochemistry, hydrogeochemical facies, and basic hydrogeochemical parameters are interdependent. Arsenic (As) concentrations varied from 0.001 mg/l to 0.03 mg/l, with a mean of 0.007 mg/l. The results of 4.68% of samples were higher than the allowable level of 0.01 mg/l, i.e., groundwater arsenic levels are not dangerous. Significant ion concentrations decreased from dry to rainy seasons suggesting that ionic concentrations generated by silicate weathering in aquifers became diluted. Abundance trends in metal concentration during the dry and rainy seasons were Fe &gt; Mn &gt; Zn &gt; Ni &gt; Cu &gt; As &gt; Pb &gt; Cd and Fe &gt; Zn &gt; Mn &gt; Ni &gt; Pb &gt; Cu &gt; As &gt; Cd, respectively. Of the two hydrochemical facies discovered, the predominant one was the main alkaline-earth-bicarbonate facies [Ca-(Mg)-HCO3] typical of basement terrains, suggesting the fundamental stage of groundwater evolution. Plots of ionic ratios, metal loads, and principal component analyses showed that ionic concentrations are controlled by geology. Geochemical modeling revealed the presence of aqueous arsenic species, which are the less dangerous arsenates at unsaturated levels and do not currently pose a concern.

Hydrogeochemical characterization, quality assessment, and potential nitrate health risk of shallow groundwater in Dongwen River Basin, North China.

Assessing groundwater geochemical formation processes and pollution circumstances is significant for sustainable watershed management. In the present study, 58 shallow groundwater samples were taken from the Dongwen River Basin (DRB) to comprehensively assess the hydrochemical sources, groundwater quality status, and potential risks of NO3- to human health. Based on the Box and Whisker plot, the cation's concentration followed the order of Ca2+ > Mg2+ > Na+ > K+, while anions' mean levels were HCO3- > SO42- > NO3- > Cl-. The NO3- level in groundwater samples fluctuated between 4.2 and 301.3mg/L, with 67.2% of samples beyond the World Health Organization (WHO) criteria (50mg/L) for drinking. The Piper diagram indicated the hydrochemical type of groundwater and surface water were characterized as Ca·Mg-HCO3 type. Combining ionic ratio analysis with principal component analysis (PCA) results, agricultural activities contributed a significant effect on groundwater NO3-, with soil nitrogen input and manure/sewage inputs also potential sources. However, geogenic processes (e.g., carbonates and evaporite dissolution/precipitation) controlled other ion compositions in the study area. The groundwater samples with higher NO3- values were mainly found in river valley regions with intense anthropogenic activities. The entropy weight water quality index (EWQI) model identified that the groundwater quality rank ranged from excellent (70.7%) and good (25.9%) to medium (3.4%). However, the hazard quotient (HQ) used in the human health risk assessment (HHRA) model showed that above 91.38% of groundwater samples have a NO3- non-carcinogenic health risk for infants, 84.48% for children, 82.76% for females, and 72.41% for males. The findings of this study could provide a scientific basis for the rational development and usage of groundwater resources as well as for the preservation of the inhabitants' health in DRB.

Therapeutic drug monitoring of clozapine in human serum by high-throughput paper spray mass spectrometry

IntroductionMonitoring the atypical antipsychotic drug clozapine is crucial to ensure patient safety. This article showcases a high-throughput analytical method for measuring clozapine and its primary metabolite norclozapine (N-desmethylclozapine) in serum using paper spray mass spectrometry (PS-MS). ObjectivesThis study aimed to assess the viability of a PS-MS method for the rapid measurement of clozapine and norclozapine in human serum samples as an alternative to liquid chromatography mass spectrometry (LC-MS). MethodsSerum samples were processed by protein precipitation followed by deposition of the supernatant containing labelled internal standards onto paper spray substrates mounted in cartridges. Analytes were then analyzed using a triple quadrupole mass spectrometer equipped with a commercial paper spray ionization source. The results obtained from the patient samples were compared to those from a validated LC-MS assay. ResultsPS-MS calibrations for clozapine and norclozapine were linear (R2 > 0.99) over five days. Between-run precision was below 8 %, and within-run precision did not exceed 10 %. When compared to a validated LC-MS method, the mean bias for 39 patient samples was −9% for clozapine and −1% for norclozapine, with no outliers. Mass spectrometry ion ratio comparisons indicated no interference for patient samples above the lower limit of quantification. There was less than 7 % change in the measured concentrations of both analytes over five days for samples dried on paper substrates. Notably, virtually no maintenance of the MS source was required during this study. ConclusionThis study illustrates the potential of PS-MS for serum drug monitoring in the clinical laboratory.

The Effect of the Chemical Composition on Mechanical Properties of CMAS Diopside Glass Ceramics

Molecular dynamics simulations were performed on CaO-MgO-Al2O3-SiO2 (CMAS) diopside glass ceramics (GCs) to study the effect of nanocrystal on glass and the effect of chemical composition on mechanical properties. Under tensile loading, the GCs demonstrated that the strength lay between its glass and ceramic counterparts and maintained considerable ductility. Moreover, high Mg/Ca ion ratios are conductive to both the strength and ductility of GCs. In addition, Al ions should be avoided as far as possible since they would promote fracture. After analyzing the shear strain and displacement vector map for ion structures, we found that the presence of nanocrystal in glass changes the original deformation pattern and led to the deformation concentration surrounding the nanocrystal. A high Mg/Ca ion ratio would make the deformation more homogeneous, while a high Ca/Mg ion ratio would aggregate the deformation in the glass region near the nanocrystal. The existence of Al ions near the interface between glass and crystal would promote the formation of voids.

Chemical Characteristics and Genetic Analysis of Karst Groundwater in the Beijing Xishan Area

As an important water supply source in Beijing， karst groundwater has played an irreplaceable role in the security of urban water supply and ecological environment protection in the past 70 years. The Xishan karst groundwater system， located in the upper reaches of western Beijing， belongs to ecological conservation areas. There are several centralized water supply fields in this area. In this study， the Xishan karst groundwater system was taken as the research object. A total of 120 karst groundwater samples in this area were investigated by using statistical analysis， ion ratio， and principal component analysis （PCA） methods to explore the spatial distribution characteristics and formation mechanism of groundwater hydrochemistry. The research results showed that： ① the groundwater quality of the Xishan system was generally good， with the characteristics of neutral pH and low salinity. A total of 84.17% of the water samples were classified as hard water. The chemical type of groundwater was mainly HCO3-Ca·Mg. ② The chemical composition of groundwater was mainly affected by the water-rock interaction， and the weathering source of rock was mainly the dissolution of carbonate. ③ The results of principal component analysis showed that 34.41% of the chemistry formation of groundwater could be explained by carbonate dissolution， 27.33% by rock salt and evaporate dissolution， 11.76% by aquifer sediment dissolution， and 10.30% by domestic sewage discharge. From the recharge area to the runoff area and then to the discharge area， the TH and TDS gradually increased. Coal mining drainage and human activities were the main factors that caused groundwater degradation and variable hydrochemical types in the piedmont. In the future， it is necessary to further strengthen environmental governance， control point and non-point source pollution， and continuously monitor key areas to provide scientific support for ecological and environmental protection.

Hydrochemical Characteristics and Its Origin of Surface Water and Groundwater in Dianbu River Basin

Chaohu lake is a key water body for water pollution prevention and treatment in our country. However， it has been at a higher eutrophication level recently. Here， the surface water and groundwater in the Dianbu River Basin， a secondary tributary of Chaohu Lake， were taken as the research object. In order to test the hydrochemical composition and hydrogen and oxygen isotope values of different water bodies， 30 groups of surface water samples， 36 groups of groundwater samples， 16 groups of hydrogen and oxygen stable isotope samples， and 18 groups of groundwater hydrogen and oxygen stable isotope samples were collected in August 2021 （wet season）， November 2021 （normal season）， and February 2022 （dry season）. The seasonal and spatial variation characteristics were analyzed to explore the hydrochemical characteristics and formation mechanism of water bodies by means of mathematical statistics， Piper triangular diagram， Gibbs figures， and ion ratios. The following results were obtained： ① precipitation was the main source of surface water and groundwater in Dianbu River Basin， and the evaporation fractionation effect of surface water was more significant than that of groundwater. At different periods， the surface water was more enriched with stable isotopes of hydrogen and oxygen than groundwater. The stable isotopes of hydrogen and oxygen in water showed seasonal variation， relative enrichment in the wet season， and depletion in the dry season. ② Both surface water and groundwater in the Dianbu River Basin were weakly alkaline， and the concentration of ions in surface water was significantly lower than that in groundwater. Ca2+ and Na+ were the main cations in surface water， Ca2+ was the main cation in groundwater， and the dominant anion in all water was HCO3-. The hydrochemical typology of surface water was mainly HCO3·Cl-Na·Ca， and that of groundwater was mainly HCO3-Na·Ca. ③ The concentrations of the main hydrochemical indexes of surface water and groundwater showed certain seasonal and spatial differences. From the wet season to the dry season， the concentrations of TDS， K+， Na+， Ca2+， Mg2+， Cl-， and SO42- in surface water showed an increasing trend on the whole. The concentrations of Na+， Ca2+， and Mg2+ in groundwater showed little change but increased slightly， whereas the concentrations of Cl-， SO42-， and NO3- showed an increasing trend on the whole. The concentrations of Cl-， SO42-， and NO3- in the water showed relatively large seasonal fluctuations. From upstream to downstream， the concentrations of the main hydrochemical indexes in surface water first decreased and then increased， among which the concentration of NO3- increased the most. The concentrations of the main hydrochemical indexes of groundwater in the direction of runoff changed little overall， but the concentration in the discharge area was higher than that in the recharge area. ④ The formation of hydrochemical characteristics of the water was mainly controlled by water-rock interaction but was also influenced by human factors. The water-rock action was mainly the weathering dissolution of silicate rock， salt rock， and carbonate rock. Man-made pollutants such as sewage from a sewage treatment plant， domestic sewage， and feces had obviously changed the hydrochemical characteristics of the local water. ⑤ Compared with that in 2016， the concentration of NO3- in surface water showed a certain degree of reduction. The nitrogen pollution control work carried out by the local government had achieved certain results， but it was still necessary to strengthen the pollution prevention and control of sewage and feces in the downstream of the Dianbu River， some tributaries （such as the Dingguang River and Maqiao River）， and some residential areas.

Hydrochemical Characteristics and Genesis Mechanism of Groundwater in the Dry Period in the Zhangjiakou Area

In order to better support the construction of the capital water conservation functional area and ecological environment support area， research on the chemical characteristics of groundwater and its formation mechanism in the dry period in the Zhangjiakou area can provide a great reference for the rational development and utilization of groundwater resources. A total of 41 groups of groundwater samples were collected， and the hydrochemical types， composition characteristics， and control factors of groundwater in the study area were analyzed by using the combined method of descriptive statistical analysis， Piper triplot， correlation analysis， Gibbs plot， and ion ratio. The results showed that the groundwater in the study area was weakly alkaline， with the total hardness and ρ（TDS） ranging from 105.00 mg·L-1 to 1 433.00 mg·L-1 and 137.00 mg·L-1 to 2 286.00 mg·L-1， respectively. The total hardness and TDS mass concentrations of groundwater in the Bashang area were higher than those in the Baxia area. HCO3- and Na+ were the main dominant anions and cations in the groundwater in the study area. The highest overstandard rate of the main components in groundwater was that of total hardness （36.59%）. The overstandard rate and maximum excess multiple of each component in groundwater in the Bashang area were greater than those in the Baxia area. HCO3-Ca·Mg·Na was the main type of groundwater hydrochemistry in the study area， and there was little difference between the Bashang area and the Baxia area. SO42-， Cl-， HCO3-， Na+， and Mg2+ contributed the most to TDS. The chemical characteristics of groundwater were affected by weathering and filtration of rock minerals such as salt rock， albite， and dolomite； cation exchange； and human activities. Evaporative crystallization and atmospheric precipitation contributed to a small part of the main ion source of groundwater in the area. The effect of human activities on groundwater in the Bashang area was greater than that in the Baxia area， and NO3- mainly originated from agricultural activities.

Study on inverse geochemical modeling of hydrochemical characteristics and genesis of groundwater system in coal mine area - a case study of Longwanggou Coal Mine in Ordos Basin.

The exploitation of coal resources has disturbed the equilibrium of the original groundwater system, resulting in a perturbation of the deep groundwater dynamic conditions and hydrochemical properties. Exploring the formation of mine water chemistry under the conditions of deep coal seam mining in the Ordos Basin provides a theoretical basis for the identification of sources of mine water intrusion and the development and utilization of water resources. This paper takes Longwanggou Coal Mine as the research area, collects a total of 106 groups of water samples from the main water-filled aquifers, comprehensively uses Piper trilinear diagram, Gibbs diagram, ion correlation, ion ratio coefficient and mineral saturation index analysis, and carries out inverse geochemical modeling with PHREEQC software, so as to analyze the hydrochemical characteristics and causes of the main water-filled aquifers in deep-buried coal seams in the research area. The results show that the main hydrochemical processes in the study area are leaching and cation exchange, and the groundwater is affected by carbonate (calcite, dolomite), silicate (gypsum) and evaporite. Calculations of mineral saturation indices and PHREEQC simulations have led to the conclusion that the dissolution of rock salt and gypsum in groundwater accounts for most of the ionic action. Na+, Cl- and SO42- are mainly derived from the dissolution of rock salt and gypsum minerals, while Ca2+ and Mg2+ are mostly derived from the dissolution of dolomite and calcite. The results of the inverse geochemical modeling are consistent with the theoretical analysis.

The impact of neutral beam parameters on current drive and neutron yield in DEMO-FNS tokamak

DEMO-FNS (DEMO Fusion Neutron Source) will be a hybrid reactor designed to combine fusion and fission technologies. In a hybrid reactor the power is mainly produced by a fission blanket which is exposed to the neutron flux generated by confined fusion plasma used as a Fusion Neutron Source (FNS). The steady-state operation of the FNS is easier to achieve as compared to pure fusion reactors, allowing the FNS to be more compact. The DEMO-FNS will produce 40 MW of fusion power. The neutral beam injectors (NBI) are designed to provide a steady state plasma heating, rotation, fueling, current drive and neutron generation in DEMO-FNS. Four injector units will deliver 30 MW power in deuterium with energy Eb = 500 keV. The NBI concept and main components are inspired from ITER HNBI design implementing acceleration of negative ions with their neutralization on gas.The high density of injected power in DEMO-FNS leads to a very specific operation scenario with ahigher ratio of high-energy ions in the plasma with respect to conventional tokamaks, where the mainpart of neutron flux will result from fusion between hot-tail ions and relatively coldbackground. The current drive and neutron yield produced by the tangentially injected beam in asteady-state operation are strongly affected by magnetic configuration and plasma kineticprofiles. The fast ions deposition and performance in plasma are limited by the losses associatedwith the neutral beam shape and aiming. The main channels of direct beam losses includeshine-through losses, as well as fast ion orbital losses. The detailed evaluation of NB parametersand geometry effects is a necessary step of scenario optimization.BTR code (Beam Transmission or, in earlier versions, Beam Transmission with Reionization) is intended for injector beamlines study, and BTR detailed beam model can be also applied to perform a detailed analysis of beam losses and performance in plasma. The analysis of beam in plasma shows the ways towards higher values of beam driven current (NBCD) and neutral yield; the beam-in-plasma behaviour can be tuned for a given tokamak configuration. The NB tracing model workflow is implemented in the BTOR suite (Beam in TORoids). The results for DEMO-FNS are compared with the NBI performance in ITER tokamak, as both machines are beam-driven and implement a similar NBI concept.