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1.
T. Kalpana Y. Gandhi V. Sudarsan M. Piasecki V. Ravi Kumar N. Veeraiah 《Luminescence》2016,31(7):1358-1363
BaO‐B2O3‐P2O5 glasses doped with a fixed concentration of Tb3+ ions and varying concentrations of Al2O3 were synthesized, and the influence of the Al3+ ion concentration on the luminescence efficiency of the green emission of Tb3+ ions was investigated. The optical absorption, excitation, luminescence spectra and fluorescence decay curves of these glasses were recorded at ambient temperature. The emission spectra of terbium ions when excited at 393 nm exhibited two main groups of bands, corresponding to 5D3 → 7Fj (blue region) and 5D4 → 7Fj (green region). From these spectra, the radiative parameters, viz., spontaneous emission probability A, total emission probability AT, radiative lifetime τ and fluorescent branching ratio β, of different transitions originating from the 5D4 level of Tb3+ ions were evaluated based on the Judd‐Ofelt theory. A clear increase in the quantum efficiency and luminescence of the green emission of Tb3+ ions corresponding to 5D4 → 7F5 transition is observed with increases in the concentration of Al2O3 up to 3.0 mol%. The improvement in emission is attributed to the de‐clustering of terbium ions by Al3+ ions and also to the possible admixing of wave functions of opposite parities. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
A series of non‐aqueous electrolytes were prepared by dissolving lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) in triglyme and tetraglyme (Gx, x = 3 and 4), respectively, with varied molar ratios. With the electrolytes the cycling performance of Li‐O2 batteries showed a strong dependence on the molar ratios between LiTFSA and Gx. It was found that the molar ratio of 1 to 5 was critical for the cycling‐performance of Li‐O2 batteries. High stability over 20 discharge–recharge cycles at 500 mA/gcarbon and in an O2 flow was obtained in LiTFSA‐(Gx)5 (x = 3 and 4). The discharge product at cathode could be directly detected and identified as the dominant crystalline product Li2O2 on the 1st and 20th discharged electrodes using X‐ray diffraction technique (XRD), which indicates rechargeability and feasibility of the electrolytes LiTFSA‐(Gx)5 (x = 3 and 4) for Li‐O2 batteries. At 1000 mA/gcarbon their capacities could be stabilized for 10 cycles. To our knowledge, this behavior of dependence of cycling performance of Li‐O2 batteries on the concentration of Li salts is presented here for the first time, and it may be extended to other Li salts and solvents and suggest a new route for screening cycling‐stable electrolytes for Li‐O2 batteries. 相似文献
3.
Omid Baziar Hamid Gholamhosseinian Seyed Amir Aledavood Mahboubeh Sadeghi 《Reports of Practical Oncology and Radiotherapy》2022,27(3):571
BackgroundTo investigate dose distribution of the 5cm spherical applicator of the INTRABEAM™ intraoperative radiation therapy (IORT) device via thermoluminescence dosimeters (TLDs) and Radiographic films. Independent dose distribution assessment of IORT devices is considered important. Several methods are described for this purpose, including TLDs and films. However, Radiographic films are not routinely used.Materials and methodsTwenty TLDs were used for depth dose measuring and evaluating the isotropy in water. Additionally, the isotropy was assessed separately via Radiographic films in air by drawing isodose curves.ResultsTLD measurements showed a steep dose decline which the relative average dose of 0.94 at the applicator surface reduced to 0.32, 0.13, and 0.07 at 1, 2, and 3 cm depths in water, respectively. Some remarkable isodose curves prepared using Radiographic films showed forward anisotropy of the 5 cm applicator.ConclusionA very steep dose decline and approximately isotropic dose distribution of the 5 cm applicator were observed via TLD measurements. Radiographic films showed acceptable potential for drawing dose distribution maps. However, they should be applied in more various radiation setups to be implemented more confidently. 相似文献
4.
All‐solid‐state Li‐ion batteries based on Li7La3Zr2O12 (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li+ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li‐garnet, c‐Li6.25Al0.25La3Zr2O12, all‐solid‐state batteries running safely with a full ceramics setup, exemplified with the anode material Li4Ti5O12. Novel strategies to design an enhanced Li+ transfer at the electrode–electrolyte interface using an interface‐engineered all‐solid‐state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all‐solid‐state Li‐ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all‐solid‐state Li‐ion batteries based on garnet‐type cubic LLZO structures. 相似文献
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Xiao-Xue Wang De-Hui Guan Cheng-Lin Miao Jia-Xin Li Jian-You Li Xin-Yuan Yuan Xin-Yue Ma Ji-Jing Xu 《Liver Transplantation》2024,14(5):2303829
Rechargeable lithium–oxygen batteries (LOBs) are considered to be one of the most promising energy storage systems. However, the use of reactive lithium (Li) metal and the formation of Li dendrites during battery operation would lead to serious safety concerns, especially when flammable liquid electrolytes are utilized. Herein, superior metal–organic framework (MOF) glass-based solid-state electrolytes (SSEs) is developed for stable all-solid-state LOBs (SSLOBs). These non-flammable and boundary-free MOF glass SSEs are capable of suppressing the dendrite growth and exhibiting long-term Li stripping/plating stability, contributing to superior Li+ conductivity (5 × 10−4 S cm−1 at 20 °C), high Li+ transference number (0.86), and good electrochemical stability. It is discovered that discharge product deposition behavior in the solid-solid interface can be well regulated by the ion/electron mixed conducted cathode fabricated with MOF glass SSEs and electronic conductive polymers. As a result, the SSLOBs can be stably recharged for 400 cycles with a low polarization gap and deliver a high capacity of 13552 mAh g−1. The development of this proposed MOF glass displays great application potential in energy storage systems with good safety and high energy density. 相似文献
7.
Michael Heitkamp Olen R. Brown 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,676(3):345-349
Niacin significantly reduced the bacteristatic effect of 1 mM paraquat for Escherichia coli. Without niacin (an intermediate in the salvage pathway for pyridine nucleotide coenzyme biosynthesis), the NAD concentration was decreased rapidly and significantly in E. coli during paraquat poisoning. Niacin prevented the decline in NAD in paraquat-poisoned cells; quinolinate (an intermediate in de novo NAD biosynthesis prior to the entry point of niacin) did not. These data suggest that paraquat poisons the de novo pathway of pyridine nucleotide coenzyme biosynthesis. Similar consequences have been reported to result from hyperbaric oxygen poisoning of E. coli; thus, there is growing evidence for a common mechanism of toxicity for hyperoxia and paraquat. 相似文献
8.
Metal‐Ion Batteries: Open‐Structured V2O5·nH2O Nanoflakes as Highly Reversible Cathode Material for Monovalent and Multivalent Intercalation Batteries (Adv. Energy Mater. 14/2017)
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Huali Wang Xuanxuan Bi Ying Bai Chuan Wu Sichen Gu Shi Chen Feng Wu Khalil Amine Jun Lu 《Liver Transplantation》2017,7(14)
9.
Huali Wang Xuanxuan Bi Ying Bai Chuan Wu Sichen Gu Shi Chen Feng Wu Khalil Amine Jun Lu 《Liver Transplantation》2017,7(14)
The high‐capacity cathode material V2O5·n H2O has attracted considerable attention for metal ion batteries due to the multielectron redox reaction during electrochemical processes. It has an expanded layer structure, which can host large ions or multivalent ions. However, structural instability and poor electronic and ionic conductivities greatly handicap its application. Here, in cell tests, self‐assembly V2O5·n H2O nanoflakes shows excellent electrochemical performance with either monovalent or multivalent cation intercalation. They are directly grown on a 3D conductive stainless steel mesh substrate via a simple and green hydrothermal method. Well‐layered nanoflakes are obtained after heat treatment at 300 °C (V2O5·0.3H2O). Nanoflakes with ultrathin flower petals deliver a stable capacity of 250 mA h g?1 in a Li‐ion cell, 110 mA h g?1 in a Na‐ion cell, and 80 mA h g?1 in an Al‐ion cell in their respective potential ranges (2.0–4.0 V for Li and Na‐ion batteries and 0.1–2.5 V for Al‐ion battery) after 100 cycles. 相似文献
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Lynn Trahey Naba K. Karan Maria K. Y. Chan Jun Lu Yang Ren Jeffrey Greeley Mahalingam Balasubramanian Anthony K. Burrell Larry A. Curtiss Michael M. Thackeray 《Liver Transplantation》2013,3(1):75-84
It has become clear that cycling lithium‐oxygen cells in carbonate electrolytes is impractical, as electrolyte decomposition, triggered by oxygen reduction products, dominates the cell chemistry. This research shows that employing an α‐MnO2/ramsdellite‐MnO2 electrode/electrocatalyst results in the formation of lithium‐oxide‐like discharge products in propylene carbonate, which has been reported to be extremely susceptible to decomposition. X‐ray photoelectron data have shown that what are likely lithium oxides (Li2O2 and Li2O) appear to form and decompose on the air electrode surface, particularly at the MnO2 surface, while Li2CO3 is also formed. By contrast, cells without α‐MnO2/ramsdellite‐MnO2 fail rapidly in electrochemical cycling, likely due to the differences in the discharge product. Relatively high electrode capacities, up to 5000 mAh/g (carbon + electrode/electrocatalyst), have been achieved with non‐optimized air electrodes. Insights into reversible insertion reactions of lithium, lithium peroxide (Li2O2) and lithium oxide (Li2O) in the tunnels of α‐MnO2, and the reaction of lithium with ramsdellite‐MnO2, as determined by first principles density functional theory calculations, are used to provide a possible explanation for some of the observed results. It is speculated that a Li2O‐stabilized and partially‐lithiated electrode component, 0.15Li2O·α‐LixMnO2, that has Mn4+/3+ character may facilitate the Li2O2/Li2O discharge/charge chemistries providing dual electrode/electrocatalyst functionality. 相似文献
11.
Arati Duragkar Aarti Muley N.R. Pawar Vibha Chopra N.S. Dhoble O.P. Chimankar S.J. Dhoble 《Luminescence》2019,34(7):656-665
Thermoluminescence (TL) materials exhibit a wide range of applications in different areas such as personal dosimetry, environmental dosimetry, medical research etc. Doping of different rare earth impurities in different hosts is responsible for changing the properties of materials useful for various applications in different fields. These materials can be irradiated by different types of beams such as γ‐rays, X‐rays, electrons, neutrons etc. Various radiation regimes, as well as their dose–response range, play an important role in thermoluminescence dosimetry. Several TL materials, such as glass, microcrystalline, nanostructured inorganic materials and recently developed materials, are reviewed and described in this article. 相似文献
12.
Maria Diaz‐Lopez Philip A. Chater Pierre Bordet Melanie Freire Christian Jordy Oleg I. Lebedev Valerie Pralong 《Liver Transplantation》2020,10(7)
The irreversible loss of lithium from the cathode material during the first cycles of rechargeable Li‐ion batteries notably reduces the overall cell capacity. Here, a new family of sacrificial cathode additives based on Li2O:Li2/3Mn1/3O5/6 composites synthesized by mechanochemical alloying is reported. These nanocomposites display record (but irreversible) capacities within the Li–Mn–O systems studied, of up to 1157 mAh g?1, which represents an increase of over 300% of the originally reported capacity in Li2/3Mn1/3O5/6 disordered rock salts. Such a high irreversible capacity is achieved by the reaction between Li2O and Li2/3Mn1/3O5/6 during the first charge, where electrochemically active Li2O acts as a Li+ donor. A 13% increase of the LiFePO4 and LiCoO2 first charge gravimetric capacities is demonstrated by the addition of only 2 wt% of the nanosized composite in the cathode mixture. This result shows the great potential of these newly discovered sacrificial additives to counteract initial losses of Li+ ions and improve battery performance. 相似文献
13.
Song-Lin Tian Li-Na Song Li-Min Chang Wan-Qiang Liu Huan-Feng Wang Ji-Jing Xu 《Liver Transplantation》2024,14(9):2303215
The high overpotential caused by the slow kinetics of oxygen reduction (ORR) and oxygen evolution (OER) has greatly limited the practical application of lithium-oxygen (Li−O2) batteries. The adoption of force-field-assisted system based on a newly developed piezocatalysis is promising in reducing the overpotential. Herein, a force-assisted Li−O2 battery is first established by employing MoS2/Pd nanocomposite cathode, in which the piezoelectric polarization as well as built-in electric field are formed in MoS2 piezoelectric catalyst under ultrasound activation, leading to the continuously separated electrons and holes to enhance the ORR and OER kinetics. Moreover, the introduction of Pd can promote the electrons transfer and further inhibit the complexation of electron–hole pairs, contributing to enhanced catalytic activity in the decomposition/generation of discharge products, resulting in reduced discharge/charge overpotentials. Thus, the force-assisted MoS2/Pd-based Li−O2 battery is capable of adjusting the output and input energies by the assisted ultrasonic wave. An ultra-low charging platform of 2.86 V and a high discharging platform of 2.77 V are achieved. The proposed unique force-assisted strategy can also be applied to lithium carbon dioxide battery system through the effective reduction and separation of CO2 and CO32−, providing significant insights in achieving efficient energy conversion for metal−air batteries. 相似文献
14.
Joonhyeon Kang Jinyoung Kim Sangheon Lee Sungun Wi Chunjoong Kim Seungmin Hyun Seunghoon Nam Yongjoon Park Byungwoo Park 《Liver Transplantation》2017,7(19)
This paper introduces oxygen‐deficient black TiO2 with hierarchically ordered porous structure fabricated by a simple hydrogen reduction as a carbon‐ and binder‐free cathode, demonstrating superior energy density and stability. With the high electrical conductivity derived from oxygen vacancies or Ti3+ ions, this unique electrode features micrometer‐sized voids with mesoporous walls for the effective accommodation of Li2O2 toroid and for the rapid transport of reaction molecules without the electrode being clogged. In the highly ordered architecture, toroidal Li2O2 particles are guided to form with a regular size and separation, which induces the most of Li2O2 external surface to be directly exposed to the electrolyte. Therefore, large Li2O2 toroids (≈300 nm) grown from solution can be effectively charged by incorporating a soluble catalyst, resulting in a very small polarization (≈0.37 V). Furthermore, disordered nanoshell in black TiO2 is suggested to protect the oxygen‐deficient crystalline core, by which oxidation of Ti3+ is kinetically impeded during battery operation, leading to the enhanced electrode stability even in a highly oxidizing environment under high voltage (≈4 V). 相似文献
15.
Lithium‐Ion Batteries: Breathable Carbon‐Free Electrode: Black TiO2 with Hierarchically Ordered Porous Structure for Stable Li–O2 Battery (Adv. Energy Mater. 19/2017)
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Joonhyeon Kang Jinyoung Kim Sangheon Lee Sungun Wi Chunjoong Kim Seungmin Hyun Seunghoon Nam Yongjoon Park Byungwoo Park 《Liver Transplantation》2017,7(19)
16.
Daiane de Lima Alves Menezes Katia Cristina Zanatta Enderson Sérgio Bannwart Eduardo Antonelli Maurício Rodriguez Chialanza Germán Azcune José Ezequiel De Souza Seila Rojas de Souza 《Luminescence》2024,39(4):e4732
In the present work, glass samples in the (100 − x)B2O3–xLi2O binary system, with x varying from 30 to 50 mol%, were prepared using the conventional melting and moulding method, with the main objective of evaluating the thermoluminescence response when exposing these materials to ultraviolet (UV) radiation. Complementary analysis based on density, optical absorption on the UV–visible region (UV–vis absorbance), Fourier transform infrared spectroscopy on the medium region, X-ray diffraction, and differential thermal analysis measurements were performed. Thermoluminescence measurements of vitreous samples showed glow curves with at least one peak with a maximum temperature of ~170°C after exposure to UV radiation in the temperature range 50–250°C. Samples were also exposed to beta radiation in the temperature range 25–275°C, also showing single peaks with a maximum temperature of ~150°C. 相似文献
17.
Yilong Ma Yafang Shang Danye Zhu Caihong Wang Zhifeng Zhong Ziyang Xu 《Phytochemical analysis : PCA》2016,27(3-4):153-157
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Li3PO4 phosphor was prepared using a modified solid‐state diffusion technique. In this work, photoluminescence, lyoluminescence and mechanoluminescence studies were carried out in a Li3PO4 microcrystalline powder doped with different rare earths. In photoluminescence studies, characteristic emission of Ce and Eu was observed. The lyoluminescence glow curves of Li3PO4 microcrystals show that lyoluminescence intensity initially increases with time and then decreases exponentially. The decay time consists of two components for all masses. The dependence of decay time, especially the longer component, on mass has been investigated. Experiments on γ‐irradiated crystals have proved that the light emission originates from the recombination of released F‐centres with trapped holes (V2‐centres) at the sulfuric acid–solid interface. Incorporation of bivalent alkali in solid lithium phosphate leads to an enhancement of lyoluminescence. A possible explanation for the experimental results has been attempted. The phosphor has a mechanoluminescence single glow peak. Mechanoluminescence intensity under various loading conditions was investigated. It is observed that mechanoluminescence intensity increases with increasing impurity concentration and increasing piston impact velocity. The results may be considered as only being of academic interest in solid‐state materials. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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目前,磷酸钙骨水泥因其具有优良的生物性能已被广泛用于骨组织工程,但它自固化后只是形成具有微孔和封闭气孔的致密块体,其孔径尺寸和连通性仍远达不到骨组织工程的最佳要求.本研究采用α-TCP为原料,以过氧化氢作为发泡剂,使用模具插针法制得一种具有大孔径和中空管的多孔磷酸钙骨水泥材料.孔径达到900μm,孔隙率为50.67%,抗折强度达到5.84MPa.通过扫描电镜照片观察和分析微观结构.结果表明,通过这种方法可以制得具有理想孔径尺寸和连通性的多孔磷酸钙骨水泥,可以说,这为制备用于骨组织工程的多孔磷酸钙骨水泥创造了一种新的方法. 相似文献