hydrogen

氢气
  • 文章类型: Journal Article
    二氧化钛是通过使用溶胶-凝胶法水解异丙醇钛(IV)合成的,在中性或基本条件下,并在微波辅助溶剂热反应器和/或高温炉中加热。使用X射线衍射法测定制备的样品的相组成。通过低温氮吸附/解吸研究确定比表面积和孔体积。通过光催化还原二氧化碳测试样品的光活性。使用气相色谱法分析气相的组成,和氢,碳氧化物,甲烷被识别出来了.研究了pH和热处理对二氧化碳光还原过程中二氧化钛基材料物理化学性质的影响。发现在中性环境中制备的光催化剂显示出较高的氢含量,一氧化碳,与在基本条件下获得的光催化剂相比,气相中的甲烷。在使用在微波反应器中加热的光催化剂的过程中检测到最高量的氢气,和双重加热的光催化剂。
    Titanium dioxide was synthesized via hydrolysis of titanium (IV) isopropoxide using a sol-gel method, under neutral or basic conditions, and heated in the microwave-assisted solvothermal reactor and/or high-temperature furnace. The phase composition of the prepared samples was determined using the X-ray diffraction method. The specific surface area and pore volumes were determined through low-temperature nitrogen adsorption/desorption studies. The photoactivity of the samples was tested through photocatalytic reduction of carbon dioxide. The composition of the gas phase was analyzed using gas chromatography, and hydrogen, carbon oxide, and methane were identified. The influence of pH and heat treatment on the physicochemical properties of titania-based materials during photoreduction of carbon dioxide have been studied. It was found that the photocatalysts prepared in neutral environment were shown to result in a higher content of hydrogen, carbon monoxide, and methane in the gas phase compared to photocatalysts obtained under basic conditions. The highest amounts of hydrogen were detected in the processes using photocatalysts heated in the microwave reactor, and double-heated photocatalysts.
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  • 文章类型: Journal Article
    CO的优先氧化(CO-PROX)在净化燃料电池的氢气以避免CO分子引起的催化剂中毒方面具有重大意义。传统的粉末催化剂面临诸多挑战,包括高压降,聚集趋势,热点地层,质量和传热效率差,热稳定性不足。因此,陶瓷整体式催化剂,以其优异的热稳定性而闻名,高表面积,和优越的传质和传热特性,正在获得越来越多的研究关注。这篇综述考察了CO-PROX中陶瓷整体式催化剂的最新研究,强调活性位点的监管(例如,贵金属,如Pt和Au,以及CuO和CeO2等非贵金属),整体结构,和涂层策略。此外,结构-催化性能关系,以及不同陶瓷整体式催化剂在实际应用中的潜力和局限性,正在讨论。最后,重点介绍了整体式催化剂在CO-PROX反应中的挑战和未来的研究前景。
    Preferential oxidation of CO (CO-PROX) has tremendous significance in purifying hydrogen for fuel cells to avoid catalyst poisoning by CO molecules. Traditional powder catalysts face numerous challenges, including high pressure drop, aggregation tendency, hotspot formation, poor mass and heat transfer efficiency, and inadequate thermal stability. Accordingly, ceramic monolithic catalysts, known as their excellent thermal stability, high surface area, and superior mass and heat transfer characteristics, are gaining increasing research attention. This review examines recent studies on ceramic monolithic catalysts in CO-PROX, placing emphasis on the regulation of active sites (e.g., precious metals like Pt and Au, and non-precious metals like CuO and CeO2), monolith structures, and coating strategies. In addition, the structure-catalytic performance relationships, as well as the potential and limitations of different ceramic monolithic catalysts in practical application, are discussed. Finally, the challenges of monolithic catalysts and future research prospects in CO-PROX reactions are highlighted.
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  • 文章类型: Journal Article
    高温超导体(HTS)是飞机推进广泛电气化的推动者。的确,如果用于电机,HTS材料可以大大提高其在功率重量比方面的性能。在超导电机的不同拓扑结构中,基于HTS主体的通量调制机因其紧凑性和重量轻而受到关注。这种机器是在空中客车公司领导的FROST(磁通屏障旋转超导拓扑)项目中提出的,目的是开发新技术,作为国际政策驱动的脱碳目标的一部分。机器的转子将容纳大的环段形HTS主体以增加输出功率。然而,这些散装的性质是鲜为人知的,几乎没有在文献中进行过研究。在这种情况下,目前的工作旨在在FROST的框架内部分填补这种稀缺性。因此,对11种大型REBaCuO散装的性能和均匀性进行了彻底的表征。其中十块将用于机器原型中,最初保留第十一批作为备用。对11个块进行第一组表征。对于这套,估计了被困场映射和临界电流。然后,随后对第十一批进行了一系列深入的表征。它包括临界电流测量,X射线衍射,和扫描电子显微镜在不同位置从散装切出的不同毫米大小的样品。X射线衍射和扫描电子显微镜显示主体内部的弱氧化区域,解释了超导性能的局部下降或损失。目的是确定在所有散装物上测量的被困场中发现的不均匀性的原因,牺牲其中一个,这里是备用的。为了获得更清晰的图像,然后,使用从各种小样本的表征中获得的实验数据,对数值模型进行了阐述,以重现第十一块的现场图。结论是,进一步的表征,包括各种散货的统计数据,仍然需要了解被困场不均匀性的根本原因。尽管如此,所有的散装提出了足够的电流密度,可用于建设拟议的机器。
    High temperature superconductors (HTSs) are enablers of extensive electrification for aircraft propulsion. Indeed, if used in electrical machines, HTS materials can drastically improve their performance in terms of the power-to-weight ratio. Among the different topologies of superconducting electrical machines, a flux modulation machine based on HTS bulks is of interest for its compactness and light weight. Such a machine is proposed in the FROST (Flux-barrier Rotating Superconducting Topology) project led by Airbus to develop new technologies as part of their decarbonization goals driven by international policies. The rotor of the machine will house large ring-segment-shaped HTS bulks in order to increase the output power. However, the properties of those bulks are scarcely known and have barely been investigated in the literature. In this context, the present work aims to fill out partially this scarcity within the framework of FROST. Thus, a thorough characterisation of the performances and homogeneity of 11 large REBaCuO bulks was carried out. Ten of the bulks are to be utilized in the machine prototype, originally keeping the eleventh bulk as a spare. A first set of characterisation was conducted on the eleven bulks. For this set, the trapped field mapping and the critical current were estimated. Then, a series of in-depth characterisations on the eleventh bulk followed. It included critical current measurement, X-ray diffraction, and scanning electron microscopy on different millimetre-size samples cut out from the bulk at various locations. The X-ray diffraction and scanning electron microscopy showed weakly oxygenated regions inside the bulk explaining the local drop or loss in superconducting properties. The objective was to determine the causes of the inhomogeneities found in the trapped field measured on all the bulks, sacrificing one of them, here the spare one. To help obtain a clearer picture, a numerical model was then elaborated to reproduce the field map of the eleventh bulk using the experimental data obtained from the characterisation of its various small samples. It is concluded that further characterisations, including the statistics on various bulks, are still needed to understand the underlying reasons for inhomogeneity in the trapped field. Nonetheless, all the bulks presented enough current density to be usable in the construction of the proposed machine.
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  • 文章类型: Journal Article
    这项研究介绍了一种氢传感器,该传感器由使用称为射频共溅射(RF共溅射)的技术沉积的氧化镁锌(MgZnO)薄膜制成。分别使用氧化镁(MgO)和氧化锌(ZnO)靶来沉积MgZnO薄膜,试验不同的沉积时间和功率水平。当暴露于浓度为百万分之1000(ppm)的氢气时,传感器表现最佳(达到2.46的感测响应)。在300°C的温度下,当MgZnO膜厚度为432纳米(nm)时,出现了该峰值性能。最初,传感器的响应性随着薄膜厚度的增加而增加。这是因为较厚的薄膜倾向于具有更多的氧空位,这些是在传感器功能中起作用的缺陷。然而,膜厚度进一步增加超过最佳点损害性能。这归因于薄膜内晶粒的生长,这阻碍了它的有效性。使用X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)对MgZnO薄膜的质量进行了全面表征。这些技术为薄膜的晶体结构和形态提供了有价值的见解,影响其作为氢传感器性能的关键因素。
    This research introduces a hydrogen sensor made from a thin film of magnesium zinc oxide (MgZnO) deposited using a technique called radiofrequency co-sputtering (RF co-sputtering). Separate magnesium oxide (MgO) and zinc oxide (ZnO) targets were used to deposit the MgZnO film, experimenting with different deposition times and power levels. The sensor performed best (reaching a sensing response of 2.46) when exposed to hydrogen at a concentration of 1000 parts per million (ppm). This peak performance occurred with a MgZnO film thickness of 432 nanometers (nm) at a temperature of 300 °C. Initially, the sensor\'s responsiveness increased as the film thickness grew. This is because thicker films tend to have more oxygen vacancies, which are imperfections that play a role in the sensor\'s function. However, further increases in film thickness beyond the optimal point harmed performance. This is attributed to the growth of grains within the film, which hindered its effectiveness. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) were employed to thoroughly characterize the quality of the MgZnO thin film. These techniques provided valuable insights into the film\'s crystal structure and morphology, crucial factors influencing its performance as a hydrogen sensor.
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  • 文章类型: Journal Article
    嗜热产乙酸细菌作为生物技术应用如合成气发酵的有希望的候选细菌引起了人们的注意。微生物电合成和甲醇转化。这里,我们旨在从不同的环境中分离和表征新型的嗜热乙酸原。通过基于16SrRNA基因的细菌群落分析监测异养和自养乙酸原的富集。通过基因组和生理分析分离并表征了七个新的Moorella菌株。在自养生长过程中,两种Moorellahumerferrea分离株显示出相当大的差异。将M.humeroperreaLNE分离物(DSM117358)发酵成一氧化碳(CO),而M.humeroperreaOCP分离物(DSM117359)通过水煤气变换反应将CO转化为氢气和二氧化碳(H2CO2)。从活性炭燃烧堆的覆盖土壤中分离出另一种一氧化碳养氢Moorella菌株,并被提议为新型物种Moorellacarbonis的类型菌株(ACPsT)(DSM116161T,CCOS2103T)。其余四个新菌株与Moorellathermocetica相关,并显示,与DSM2955T型应变一起,除乙酸盐外,从H2CO2中生产少量乙醇。对新型Moorella菌株的生理分析揭示了分离株特异性差异,这大大增加了对嗜热乙酸原的知识基础,以供将来应用。
    Thermophilic acetogenic bacteria have attracted attention as promising candidates for biotechnological applications such as syngas fermentation, microbial electrosynthesis, and methanol conversion. Here, we aimed to isolate and characterize novel thermophilic acetogens from diverse environments. Enrichment of heterotrophic and autotrophic acetogens was monitored by 16S rRNA gene-based bacterial community analysis. Seven novel Moorella strains were isolated and characterized by genomic and physiological analyses. Two Moorella humiferrea isolates showed considerable differences during autotrophic growth. The M. humiferrea LNE isolate (DSM 117358) fermented carbon monoxide (CO) to acetate, while the M. humiferrea OCP isolate (DSM 117359) transformed CO to hydrogen and carbon dioxide (H2 + CO2), employing the water-gas shift reaction. Another carboxydotrophic hydrogenogenic Moorella strain was isolated from the covering soil of an active charcoal burning pile and proposed as the type strain (ACPsT) of the novel species Moorella carbonis (DSM 116161T and CCOS 2103T). The remaining four novel strains were affiliated with Moorella thermoacetica and showed, together with the type strain DSM 2955T, the production of small amounts of ethanol from H2 + CO2 in addition to acetate. The physiological analyses of the novel Moorella strains revealed isolate-specific differences that considerably increase the knowledge base on thermophilic acetogens for future applications.
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  • 文章类型: Journal Article
    迈克尔·J·福克斯基金会资助帕金森病的研究已经有35年了。但还没有找到治疗方法.这是由于现代医学治疗发展背后的哲学问题。在本文中,我们将介绍一种可以解决中枢神经系统药物所有问题的物质“智能医学”。该物质是最小的双原子分子,氢分子.由于它们的大小,氢分子可以很容易地穿透细胞膜并进入大脑。在帕金森病患者的中脑,芬顿反应产生的羟基自由基引起多巴胺氧化的连锁反应,但是进入中脑的氢可以将羟基自由基转化为水分子,并抑制多巴胺的氧化。在本文中,我们专注于神经系统疾病的病因,尤其是帕金森病,并提出了一个案例,其中氢气吸入可以改善帕金森氏病的症状,如身体弯曲和手颤抖。我们自信地说,如果迈克尔·J·福克斯遇到了可以用分子氢实现的“智能医学”,他不会是一个“幸运的人”,而是一个“超级幸运的人”。\"
    The Michael J. Fox Foundation has been funding research on Parkinson\'s disease for 35 years, but has yet to find a cure. This is due to a problem with the philosophy behind the development of modern medical treatments. In this paper, we will introduce \"smart medicine\" with a substance that can solve all the problems of central nervous system drugs. The substance is the smallest diatomic molecule, the hydrogen molecule. Due to their size, hydrogen molecules can easily penetrate the cell membrane and enter the brain. In the midbrain of Parkinson\'s disease patients, hydroxyl radicals generated by the Fenton reaction cause a chain reaction of oxidation of dopamine, but hydrogen entering the midbrain can convert the hydroxyl radicals into water molecules and inhibit the oxidation of dopamine. In this paper, we focus on the etiology of neurological diseases, especially Parkinson\'s disease, and present a case in which hydrogen inhalation improves the symptoms of Parkinson\'s disease, such as body bending and hand tremor. And we confidently state that if Michael J. Fox encountered \"smart medicine\" that could be realized with molecular hydrogen, he would not be a \"lucky man\" but a \"super-lucky man.\"
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  • 文章类型: Journal Article
    通过在氩气介质中负载由纤维材料构成的竹炭床的介质阻挡放电(DBD),研究了一种将水蒸气有效转化为氢气的新方法。在三个不同的反应器中测量氢气生产率:无负载DBD(N-DBD),竹炭(BC)床DBD(BC-DBD),和装载有石英棉(QW)的BDBD(QC-DBD)。还在各种流速的QC-DBD中研究了BC与QW的质量比和相对湿度对氢生产率的影响。通过扫描电子显微镜分析了反应过程和机理,X射线光电子能谱,N2物理吸附实验,红外光谱,和光发射光谱学。通过将BC加载到纤维结构材料中以激活反应分子并捕获DBD反应器中的含O基团,开发了一种新的反应途径。在5kV的施加电压下,氢生产率达到17.3g/kWh,流量为4升/分钟,QC-DBD中的相对湿度(RH)为100%,BC与QW的质量比为3.0。
    A new method of efficiently transforming water vapor into hydrogen was investigated by dielectric barrier discharge (DBD) loaded with bamboo carbon bed structured by fibrous material in an argon medium. Hydrogen productivity was measured in three different reactors: a non-loaded DBD (N-DBD), a bamboo carbon (BC) bed DBD (BC-DBD), and a quartz wool (QW)-loaded BC DBD (QC-DBD). The effects of the quality ratio of BC to QW and relative humidity on hydrogen productivity were also investigated in QC-DBD at various flow rates. The reaction process and mechanism were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, N2 physisorption experiments, infrared spectroscopy, and optical emission spectroscopy. A new reaction pathway was developed by loading BC into the fibrous structured material to activate the reaction molecules and capture the O-containing groups in the DBD reactor. A hydrogen productivity of 17.3 g/kWh was achieved at an applied voltage of 5 kV, flow rate of 4 L/min, and 100% relative humidity (RH) in the QC-DBD with a quality ratio of BC to QW of 3.0.
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  • 文章类型: Journal Article
    (1)背景:用于评估氢代谢机制的血液生物标志物的多样性限制了对其改善运动表现的影响的全面理解。本研究使用代谢组学方法评估了富氢气体(HRG)对短跑间歇运动后代谢物的影响,旨在阐明其潜在的作用机制。(2)方法:10名健康成年男性在HRG或安慰剂(空气)吸入60分钟后参加了WingateSprint间隔测试(SIT)。在气体吸入之前和之后以及完成SIT之后,收集静脉血液样品用于代谢组学分析。(3)结果:与安慰剂相比,HRG吸入显著提高平均功率,疲劳指数,以及第四次冲刺的峰值时间,并显着降低了峰值功率的衰减值,平均力量,以及在第一和第四之间达到峰值的时间。代谢组学分析强调了乙酰肉碱的显着上调,丙酰基-L-肉碱,次黄嘌呤,和黄嘌呤吸入HRG,富集途径分析表明,HRG可能通过增强辅酶A合成促进脂肪动员,促进甘油磷脂代谢,抑制胰岛素水平。(4)结论:在SIT之前吸入HRG可增强终末期无氧冲刺能力并减轻疲劳。代谢组学分析表明,HRG可能通过加速脂肪氧化来增强间歇阶段的ATP恢复,为后期冲刺提供更多的能量补充。
    (1) Background: The diversity of blood biomarkers used to assess the metabolic mechanisms of hydrogen limits a comprehensive understanding of its effects on improving exercise performance. This study evaluated the impact of hydrogen-rich gas (HRG) on metabolites following sprint-interval exercise using metabolomics approaches, aiming to elucidate its underlying mechanisms of action. (2) Methods: Ten healthy adult males participated in the Wingate Sprint-interval test (SIT) following 60 min of HRG or placebo (air) inhalation. Venous blood samples were collected for metabolomic analysis both before and after gas inhalation and subsequent to completing the SIT. (3) Results: Compared with the placebo, HRG inhalation significantly improved mean power, fatigue index, and time to peak for the fourth sprint and significantly reduced the attenuation values of peak power, mean power, and time to peak between the first and fourth. Metabolomic analysis highlighted the significant upregulation of acetylcarnitine, propionyl-L-carnitine, hypoxanthine, and xanthine upon HRG inhalation, with enrichment pathway analysis suggesting that HRG may foster fat mobilization by enhancing coenzyme A synthesis, promoting glycerophospholipid metabolism, and suppressing insulin levels. (4) Conclusions: Inhaling HRG before an SIT enhances end-stage anaerobic sprint capabilities and mitigates fatigue. Metabolomic analysis suggests that HRG may enhance ATP recovery during interval stages by accelerating fat oxidation, providing increased energy replenishment for late-stage sprints.
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  • 文章类型: Journal Article
    缺血/再灌注损伤(IRI)是与各种临床疾病相关的发病率和死亡率的重要因素。包括急性冠脉综合征,中风,和器官移植。在缺血期间,发生了严重的缺氧损伤,导致细胞功能障碍和组织损伤。矛盾的是,再灌注可以通过产生活性氧和诱导炎症级联反应来加剧这种损伤。IRI的广泛临床后遗症需要开发治疗策略以减轻其有害作用。这已成为基础科学和转化科学正在进行的研究工作的基石。这篇综述研究了分子氢在不同器官中对IRI的使用,并探讨了其作用的潜在机制。分子氢是一种具有抗炎作用的选择性抗氧化剂,细胞保护,和信号调制特性。在不同的模型中,它已被证明在减轻IRI方面是有效的,包括心力衰竭,脑中风,移植,和手术干预。氢气通过不同的机制减少IRI,比如抑制氧化应激和炎症,ATP产量的提高,减少钙超载,调节细胞死亡,等。仍需要进一步的研究以将分子氢的使用整合到临床实践中。
    Ischemia/reperfusion injury (IRI) represents a significant contributor to morbidity and mortality associated with various clinical conditions, including acute coronary syndrome, stroke, and organ transplantation. During ischemia, a profound hypoxic insult develops, resulting in cellular dysfunction and tissue damage. Paradoxically, reperfusion can exacerbate this injury through the generation of reactive oxygen species and the induction of inflammatory cascades. The extensive clinical sequelae of IRI necessitate the development of therapeutic strategies to mitigate its deleterious effects. This has become a cornerstone of ongoing research efforts in both basic and translational science. This review examines the use of molecular hydrogen for IRI in different organs and explores the underlying mechanisms of its action. Molecular hydrogen is a selective antioxidant with anti-inflammatory, cytoprotective, and signal-modulatory properties. It has been shown to be effective at mitigating IRI in different models, including heart failure, cerebral stroke, transplantation, and surgical interventions. Hydrogen reduces IRI via different mechanisms, like the suppression of oxidative stress and inflammation, the enhancement of ATP production, decreasing calcium overload, regulating cell death, etc. Further research is still needed to integrate the use of molecular hydrogen into clinical practice.
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  • 文章类型: Journal Article
    化学浴沉积(CBD)工艺使得能够在具有可定制形态的各种衬底上沉积ZnO纳米线(NW)。然而,富含氢的CBD环境引入了许多与氢相关的缺陷,无意间掺杂ZnONWs并增加其电导率。基于氧的等离子体处理可以改变这些缺陷的性质和数量,可能为特定应用定制ZnONW特性。这项研究考察了平均离子能量对暴露于低压氧等离子体的ZnONWs中氧空位(VO)和氢相关缺陷形成的影响。使用X射线光电子能谱(XPS),5K阴极发光(5KCL),和拉曼光谱,建立了对氧离子能量对缺陷和缺陷络合物形成的影响的全面理解。一系列缔合和解离反应表明,控制等离子体工艺参数,特别是离子能量,至关重要。XPS数据表明,增加离子能量可以通过增加VO的量和有利于羟基吸附来增强费米能级钉扎。扩大电荷载流子的耗尽区。5KCL和拉曼光谱进一步证明了通过改变氧离子能量来调节ZnONW物理性质的潜力,影响各种供体和受体型缺陷复合物。这项研究强调了通过修改等离子体工艺参数在低温下调节ZnONW性能的能力,为在柔性和/或透明衬底上制造的各种纳米级工程器件提供了新的可能性。
    The chemical bath deposition (CBD) process enables the deposition of ZnO nanowires (NWs) on various substrates with customizable morphology. However, the hydrogen-rich CBD environment introduces numerous hydrogen-related defects, unintentionally doping the ZnO NWs and increasing their electrical conductivity. The oxygen-based plasma treatment can modify the nature and amount of these defects, potentially tailoring the ZnO NW properties for specific applications. This study examines the impact of the average ion energy on the formation of oxygen vacancies (VO) and hydrogen-related defects in ZnO NWs exposed to low-pressure oxygen plasma. Using X-ray photoelectron spectroscopy (XPS), 5 K cathodoluminescence (5K CL), and Raman spectroscopy, a comprehensive understanding of the effect of the oxygen ion energy on the formation of defects and defect complexes was established. A series of associative and dissociative reactions indicated that controlling plasma process parameters, particularly ion energy, is crucial. The XPS data suggested that increasing the ion energy could enhance Fermi level pinning by increasing the amount of VO and favoring the hydroxyl group adsorption, expanding the depletion region of charge carriers. The 5K CL and Raman spectroscopy further demonstrated the potential to adjust the ZnO NW physical properties by varying the oxygen ion energy, affecting various donor- and acceptor-type defect complexes. This study highlights the ability to tune the ZnO NW properties at low temperature by modifying plasma process parameters, offering new possibilities for a wide variety of nanoscale engineering devices fabricated on flexible and/or transparent substrates.
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