Noble gases

惰性气体
  • 文章类型: Journal Article
    通过应用基于Numerov方法的Fortran程序,我们重新研究了弱约束同核和异核惰性气体对的振动本征态的数值解。谐波,伦纳德-琼斯(LJ),和改进的Lennard-Jones(ILJ)势能模型已经实现,以表示势能曲线(PECs)。在实验数据上测试了获得的振动能谱,并在CCSD(T)/CBS水平上进行了精确的从头算计算。在ILJ势模型中可以准确地再现振动特征值和特征函数。此外,从计算的范德华(vdW)络合物的寿命考虑,ILJ而不是标准的LJ势模型的实现通过提供更有代表性的原子轨迹对系统动力学有重大影响,当函数被纳入力场分子动力学(MD)模拟。总的来说,ILJ函数是表示振动运动和确定弱约束系统振动能级的最适合的潜在模型,在平衡条件和非平衡条件下。
    We revisit the numerical solutions of vibrational eigenstates of weakly bound homonuclear and heteronuclear noble gas pairs by applying a Fortran program based on the Numerov method. The harmonic, Lennard-Jones (LJ), Morse, Tang-Toennies (TT), and Improved Lennard-Jones (ILJ) potential models have been implemented to represent the potential energy curves (PECs). The obtained vibrational energies spectrum was tested on the experimental data and accurate ab initio calculations at CCSD(T)/CBS level. The vibrational eigenvalues and eigenfunctions can be reproduced accurately within the ILJ potential model. Moreover, considering the calculated lifetime of van der Waals (vdW) complexes, the implementation of ILJ rather than standard LJ potential model has a significant impact on the systems dynamics by providing more representative atomic trajectories when the function is incorporated in force fields for molecular dynamics (MD) simulations. Overall, the ILJ function is the best suited potential model for the representation of vibrational motions and the determination of vibrational energy levels of weakly bound systems, both at equilibrium and non-equilibrium conditions.
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  • 文章类型: Journal Article
    本研究旨在使用快速准确的操作员分裂方法(OSM)研究惰性气体如何影响肺泡和静脉血液的分压。与以前的复杂方法不同,如有限元法(FEM),OSM有效地将控制方程分离成较小的子问题,有助于更好地了解惰性气体的运输和毛细血管与周围组织之间的交换。控制方程用全隐式有限差分法(FDM)离散化,这使得能够使用更大的时间步长。该模型采用偏微分方程,考虑到血液中的对流扩散和仅在组织中的扩散。这项研究探讨了初始动脉压的影响,呼吸频率,血流速度,溶解度,以及血液和组织中惰性气体分压的扩散率。此外,分析麻醉惰性气体和氧气对静脉血液分压的影响。模拟结果表明,麻醉惰性气体的高溶解度和扩散性导致其在血液和组织中的长期存在,导致静脉血分压降低。这些发现增强了我们对惰性气体与肺泡/静脉血相互作用的理解,对医学诊断和治疗有潜在影响。
    This study aims to investigate how inert gas affects the partial pressure of alveolar and venous blood using a fast and accurate operator splitting method (OSM). Unlike previous complex methods, such as the finite element method (FEM), OSM effectively separates governing equations into smaller sub-problems, facilitating a better understanding of inert gas transport and exchange between blood capillaries and surrounding tissue. The governing equations were discretized with a fully implicit finite difference method (FDM), which enables the use of larger time steps. The model employed partial differential equations, considering convection-diffusion in blood and only diffusion in tissue. The study explores the impact of initial arterial pressure, breathing frequency, blood flow velocity, solubility, and diffusivity on the partial pressure of inert gas in blood and tissue. Additionally, the effects of anesthetic inert gas and oxygen on venous blood partial pressure were analyzed. Simulation results demonstrate that the high solubility and diffusivity of anesthetic inert gas lead to its prolonged presence in blood and tissue, resulting in lower partial pressure in venous blood. These findings enhance our understanding of inert gas interaction with alveolar/venous blood, with potential implications for medical diagnostics and therapies.
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  • 文章类型: Journal Article
    尽管最近取得了进展,缺血性心脏病构成了持续的全球挑战,驱动显著的发病率和死亡率。对治疗解决方案的追求导致了诸如缺血预处理等策略的出现,后处理,和远程调理以掩护心脏免受心肌缺血/再灌注毁伤(MIRI)。这些缺血调理方法,之前应用,之后,或者离受影响的器官一定距离,激发未来的治疗策略,包括药理调理。气体发射器,包括一氧化氮,硫化氢,二氧化硫,还有一氧化碳,在生理和病理过程中发挥关键作用,表现出共同的特征,如平滑肌松弛,抗凋亡作用,和抗炎特性。尽管高浓度存在潜在风险,生理水平的气体传递剂诱导血管舒张和促进心脏保护作用。惰性气体,特别是氩气,氦气,还有氙气,通过减少细胞死亡表现出器官保护特性,尽可能减小梗死面积,并增强缺血后器官的功能恢复。惰性气体的保护作用似乎取决于它们对控制细胞存活的分子途径的调节,导致促凋亡和抗凋亡作用。在惰性气体中,氦和氙在心脏保护领域特别有前途。本概述综合了我们目前对气体发射器和惰性气体在MIRI和心脏保护方面所起作用的理解。此外,我们强调了未来潜在的发展,包括利用惰性气体和气体发射器供体分子来推进心脏保护策略。
    Despite recent progress, ischemic heart disease poses a persistent global challenge, driving significant morbidity and mortality. The pursuit of therapeutic solutions has led to the emergence of strategies such as ischemic preconditioning, postconditioning, and remote conditioning to shield the heart from myocardial ischemia/reperfusion injury (MIRI). These ischemic conditioning approaches, applied before, after, or at a distance from the affected organ, inspire future therapeutic strategies, including pharmacological conditioning. Gasotransmitters, comprising nitric oxide, hydrogen sulfide, sulfur dioxide, and carbon monoxide, play pivotal roles in physiological and pathological processes, exhibiting shared features such as smooth muscle relaxation, antiapoptotic effects, and anti-inflammatory properties. Despite potential risks at high concentrations, physiological levels of gasotransmitters induce vasorelaxation and promote cardioprotective effects. Noble gases, notably argon, helium, and xenon, exhibit organ-protective properties by reducing cell death, minimizing infarct size, and enhancing functional recovery in post-ischemic organs. The protective role of noble gases appears to hinge on their modulation of molecular pathways governing cell survival, leading to both pro- and antiapoptotic effects. Among noble gases, helium and xenon emerge as particularly promising in the field of cardioprotection. This overview synthesizes our current understanding of the roles played by gasotransmitters and noble gases in the context of MIRI and cardioprotection. In addition, we underscore potential future developments involving the utilization of noble gases and gasotransmitter donor molecules in advancing cardioprotective strategies.
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  • 文章类型: Journal Article
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  • 文章类型: Case Reports
    归因于传统污染源,包括盐水,对于确定补救方案和分配责任很重要。为了做出合理的补救决定,有必要区分地下来源,例如泄漏石油和天然气(“O&G”)井或自然向上的流体迁移,从表面释放。虽然表面和地下释放的化学特征可能相似,它们有望压印特定的溶解惰性气体特征,由地下泄漏中陆源惰性气体的积累或表面释放后惰性气体的重新平衡引起。我们证明,只有历史性的地表释放影响了在废弃的O&G井附近被盐水污染的监测井中地下水的溶解惰性气体特征,而不是井中的地下泄漏。升高的盐水浓度与较低的陆源氦浓度有关,表明在释放过程中表面与大气氦的重新平衡。地球物理调查表明,油井表层土壤的盐度升高,进一步支持了对惰性气体数据的解释。消除地下泄漏是羽流来源的可能性对于在现场选择适当的补救措施至关重要,否则,这可能包括不必要和昂贵的重新放弃。这项研究表明,使用惰性气体分析来比较地下水中盐水污染的潜在来源,并排除地下泄漏作为油田的潜在来源。
    Attributing the sources of legacy contamination, including brines, is important to determine remediation options and to allocate responsibility. To make sound remediation decisions, it is necessary to distinguish subsurface sources, such as leaking oil and gas (\"O&G\") wells or natural upward fluid migrations, from surface releases. While chemical signatures of surface and subsurface releases may be similar, they are expected to imprint specific dissolved noble gas signatures, caused by the accumulation of terrigenic noble gases in subsurface leaks or re-equilibration of noble gases following surface releases. We demonstrate that only a historic surface release influenced the dissolved noble gas signature of groundwater in monitoring wells contaminated with brine near an abandoned O&G well, rather than subsurface leakage from the well. Elevated brine concentrations were associated with lower terrigenic helium concentrations, indicating re-equilibration with atmospheric helium at the surface during the release. Geophysical surveying indicating elevated salinity in surficial soils upgradient of the wells further supported the interpretation of the noble gas data. Eliminating the possibility that subsurface leakage was the source of the plume was critical to selecting the proper remedial action at the site, which otherwise may have included an unnecessary and costly well re-abandonment. This study demonstrates the use of noble gas analysis to compare potential sources of brine contamination in groundwater and to exclude subsurface leakage as a potential source in an oilfield.
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  • 文章类型: Journal Article
    This work originated from the demand presented by an electric power transmission company and addresses a possible solution for the sector by exploring alternatives to extend the flight time of drones in the inspection of transmission lines. This original article demonstrates the use of the electromagnetic field of a transmission line to generate useful electrical power at the terminals of a bulb containing argon gas. It is an unprecedented application in power transmission. In this work, the tests based on a proof of concept are documented, where the results obtained were satisfactory and still allowed to connect an LED through the constructed arrangement. It is observed that the continuity of this research can provide scalability for applications whose main source of ion excitation is given from the energy dissipated as electric field loss in high-voltage lines.
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  • 文章类型: Journal Article
    惰性气体,氧-氢同位素比,和离子成分在三个采样点测量(KUM,OTN,和ASO)从2013年12月到2021年7月。3个采样点的3He/4He值在整个观测期内保持稳定在3-4Ra范围内,这表明向含水层供应深层气体是稳定的。KUM和OTN的4He/20Ne值表明,相对于KUM和OTN的深层流体,向含水层的地表源流体供应减少。相比之下,在ASO网站中,提供给含水层的表层和深层流体都很稳定。δD-δ18O关系表明向KUM和OTN含水层供应了深层水,但不向ASO含水层供应。然而,在整个观测期间,δD-δ18O关系保持稳定,表明三个站的深层水供应稳定。在整个观察期间,在狭窄的范围内绘制了三个采样点的Li/Cl和1/Cl关系,表明地下水补给是稳定的。在任何数据中都没有观察到由于2016年熊本地震而引起的尖峰和阶跃变化。这些结果表明,KUM和OTN含水层不断地从熊本地区下方的流体富集区供应深层流体,只有深层气体被供应到ASO含水层。我们还证实,这些供应条件没有受到2016年熊本地震或随后的余震活动的影响。
    Noble gases, oxygen-hydrogen isotope ratios, and ion compositions were measured at three sampling points (KUM, OTN, and ASO) from December 2013 to July 2021. The 3He/4He values at the three sampling points remained stable in the range of 3-4 Ra throughout the observation period, suggesting that the supply of deep-seated gases to the aquifer was stable. The 4He/20Ne values of KUM and OTN indicate that the supply of surface-source fluids to the aquifer decreased relative to that of deep-seated fluids at KUM and OTN. In contrast, in the ASO site, both the surface- and deep-seated fluids supplied to the aquifer were stable. The δD-δ18O relationship indicated the supply of deep-seated water to the KUM and OTN aquifers but not to the ASO aquifer. Nevertheless, the δD-δ18O relationship remained stable throughout the observation period, suggesting that the supply of deep-seated water to the three stations was stable. The Li/Cl and 1/Cl relationships for the three sampling points were plotted within a narrow range throughout the observation period, suggesting that the groundwater recharge was stable. Neither spikes nor step changes owing to the 2016 Kumamoto earthquake were observed in any of the data. These results indicate that the KUM and OTN aquifers are constantly supplied with deep fluids from the fluid-rich zone beneath the Kumamoto region, and that only deep-seated gas was supplied to the ASO aquifer. We also confirmed that these supply conditions were unaffected by the 2016 Kumamoto earthquake or the subsequent aftershock activity.
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  • 文章类型: Journal Article
    使用时间分辨透射电子显微镜(TEM)研究了惰性气体元素的单原子动力学,通过直接观察可以更深入地了解化学键,反应性,和纳米尺度的物质状态。我们报告了由封装在单壁碳纳米管((Kr@C60)@SWCNT)中的内面富勒烯组成的纳米级系统,能够按需输送和释放氪原子,在电子束(原位)或热(非原位)的作用下,通过主体富勒烯笼的聚结。通过能量色散X射线光谱(EDS)研究了Kr原子的状态和动力学,电子能量损失谱(EELS),和X射线光电子能谱(XPS)。使用像差校正的高分辨率TEM(AC-HRTEM)精确测量Kr原子位置,像差校正扫描TEM(AC-STEM),和单原子光谱成像(STEM-EELS)。电子束驱动2Kr@C120胶囊的形成,其中鉴定了范德华斯Kr2和瞬时共价[Kr2]+键合态。热聚结导致形成更长的聚结嵌套纳米管,其中包含更松散结合的Krn链(n=3-6)。在某些情况下,通过STEM分析确认了Kr原子位置的离域为向一维(1D)气体的过渡,因为Kr原子在长时间内只被限制在一个平移自由度,退火良好,嵌套纳米管。通过拉曼光谱研究了这种嵌套的纳米管结构。该材料代表在环境条件下稳定的高度压缩和尺寸约束的1D气体。直接原子级成像揭示了这种惰性气体元素的难以捉摸的键合态和以前从未见过的一维气态物质,证明TEM是在单原子水平上发现化学的强大工具。
    Single-atom dynamics of noble-gas elements have been investigated using time-resolved transmission electron microscopy (TEM), with direct observation providing for a deeper understanding of chemical bonding, reactivity, and states of matter at the nanoscale. We report on a nanoscale system consisting of endohedral fullerenes encapsulated within single-walled carbon nanotubes ((Kr@C60)@SWCNT), capable of the delivery and release of krypton atoms on-demand, via coalescence of host fullerene cages under the action of the electron beam (in situ) or heat (ex situ). The state and dynamics of Kr atoms were investigated by energy dispersive X-ray spectroscopy (EDS), electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS). Kr atom positions were measured precisely using aberration-corrected high-resolution TEM (AC-HRTEM), aberration-corrected scanning TEM (AC-STEM), and single-atom spectroscopic imaging (STEM-EELS). The electron beam drove the formation of 2Kr@C120 capsules, in which van der Waals Kr2 and transient covalent [Kr2]+ bonding states were identified. Thermal coalescence led to the formation of longer coalesced nested nanotubes containing more loosely bound Krn chains (n = 3-6). In some instances, delocalization of Kr atomic positions was confirmed by STEM analysis as the transition to a one-dimensional (1D) gas, as Kr atoms were constrained to only one degree of translational freedom within long, well-annealed, nested nanotubes. Such nested nanotube structures were investigated by Raman spectroscopy. This material represents a highly compressed and dimensionally constrained 1D gas stable under ambient conditions. Direct atomic-scale imaging has revealed elusive bonding states and a previously unseen 1D gaseous state of matter of this noble gas element, demonstrating TEM to be a powerful tool in the discovery of chemistry at the single-atom level.
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  • 文章类型: Journal Article
    在地球化学和宇宙化学中大多数相关样品中,惰性气体是非常稀有的元素。对化学家来说,惰性气体可能也看起来相当无聊,因为它们不形成任何稳定的化合物。然而,正是它们的稀有性和化学惰性使惰性气体在非常广泛的领域中具有多功能元素,比如海洋学,气候学,环境科学,陨石研究,摇滚约会,早期太阳系和早期地球历史,和许多其他人。到目前为止,质谱是惰性气体地球化学和宇宙学的主要分析工具,部分原因是稀有气体的稀有性通常使研究人员能够在同一样品中识别出不同来源的不同稀有气体“成分”,从而识别出不同的同位素组成。本文试图通过选定的示例说明惰性气体质谱在地球科学中的广泛应用。
    Noble gases are very rare elements in most relevant samples in geochemistry and cosmochemistry. Noble gases may perhaps also look rather boring to chemists, as they do not form any stable compounds. However, it is just their rarity and chemical inertness which makes noble gases versatile elements in a very wide range of fields, such as oceanography, climatology, environmental sciences, meteorite studies, rock dating, early solar system and early Earth history, and many others. Mass spectrometry is by far the main analytical tool in noble gas geochemistry and cosmochemistry, partly because the rarity of noble gases often allows researchers to recognize in the same sample different noble gas \"components\" of different origin and hence different isotopic composition. This contribution attempts to illustrate the wide range of applications of noble gas mass spectrometry in the Earth sciences with selected examples.
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  • 文章类型: Journal Article
    酸性矿山排水污染会影响生态系统以及用于家庭和市政目的的地下水的可用性。沃德外面的杰克船长超级基金网站,博尔德县,科罗拉多,美国,拥有一个排水的矿井,该矿井通过安装液压舱壁进行了补救,以防止酸性矿井排水进入附近的LefthandCreek。在2020年矿井工作中蓄水期间,水稳定同位素的多样化和新颖数据集,硫酸盐,和碳(δ2H,δ18OH2O,δ18OSO4,δ34S,δ13CDIC),稀土元素,收集环境示踪剂(稀有气体和氚)以了解地下水的补给和混合,硫化物氧化和水-岩相互作用的机制,以及修复对水文地球化学系统的影响。水同位素表明,远离矿井的地下水具有季节性变化的补给源,而矿井内的水具有独特的组成,时间变化最小。硫酸盐同位素表明,硫化物氧化既发生在矿山工作中,也发生在邻近的火成岩堤防中。并且硫化物氧化可以在以三价铁作为氧化剂的低价条件下发生。碳同位素跟踪酸性水的中和和系统的碳质量预算。稀土元素确证了稳定的同位素,表明地下水分区,并进一步说明了矿山工作中矿物风化的增强。环境示踪剂表明现代和现代前地下水的混合,并告知时间表可能需要积极补救。这些数据集一起为废弃矿场的类似调查提供了有用的模板,其中物理混合过程,溶质负载源,或补救时间框架很重要。
    Contamination from acid mine drainage affects ecosystems and usability of groundwater for domestic and municipal purposes. The Captain Jack Superfund Site outside of Ward, Boulder County, Colorado, USA, hosts a draining mine adit that was remediated through emplacement of a hydraulic bulkhead to preclude acid mine drainage from entering nearby Lefthand Creek. During impoundment of water within the mine workings in 2020, a diverse and novel dataset of stable isotopes of water, sulfate, and carbon (δ2H, δ18OH2O, δ18OSO4, δ34S, δ13CDIC), rare earth elements, and environmental tracers (noble gases and tritium) were collected to understand groundwater recharge and mixing, mechanisms of sulfide oxidation and water-rock interaction, and the influence of remediation on the hydrologic and geochemical system. Water isotopes indicate that groundwater distal from the mine workings has seasonally variable recharge sources whereas water within the workings has a distinctive composition with minimal temporal variability. Sulfate isotopes indicate that sulfide oxidation occurs both within the mine workings and in adjacent igneous dikes, and that sulfide oxidation may occur under suboxic conditions with ferric iron as the oxidant. Carbon isotopes track the neutralization of acidic waters and the carbon mass budget of the system. Rare earth elements corroborate stable isotopes in indicating groundwater compartmentalization, and additionally illustrate enhanced mineral weathering in the mine workings. Environmental tracers indicate mixing of modern and pre-modern groundwater and inform timelines that active remediation may be needed. Together these datasets provide a useful template for similar investigations of abandoned mine sites where physical mixing processes, sources of solute loading, or remediation timeframes are of importance.
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