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71.
We try to establish the commonalities and leadership in the cryptocurrency markets by examining the mutual information and lead-lag relationships between Bitcoin and other cryptocurrencies from January 2019 to June 2021. We examine the transfer entropy between volatility and liquidity of seven highly capitalized cryptocurrencies in order to determine the potential direction of information flow. We find that cryptocurrencies are strongly interrelated in returns and volatility but less in liquidity. We show that smaller and younger cryptocurrencies (such as Ripple’s XRP or Litecoin) have started to affect the returns of Bitcoin since the beginning of the pandemic. Regarding liquidity, the results of the dynamic time warping algorithm also suggest that the position of Monero has increased. Those outcomes suggest the gradual increase in the role of privacy-oriented cryptocurrencies. 相似文献
72.
In the Raman spectra of silicon nanocrystals a new anomalous component was detected. Close to the usual first order Raman peak situated for a bulk crystal at 521 cm−1 at room temperature, two peaks arise shifting towards lower energy and demonstrating a huge temperature increase, as measured by the ratio of the Stokes/anti-Stokes peak intensities. This behavior is dependent on the laser power and on the morphology of the nanocrystals. We can exclude, however, confinement effects, although surface enhanced phonon modes could be responsible of such superheating. Alternative explanations are also suggested and discussed. 相似文献
73.
Rafal Kruszynski Agata Trzesowska‐Kruszynska 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(12):o624-o629
The 2‐aminobenzothiazole sulfonation intermediate 2,3‐dihydro‐1,3‐benzothiazol‐2‐iminium monohydrogen sulfate, C7H7N2S+·HSO4−, (I), and the final product 2‐iminio‐2,3‐dihydro‐1,3‐benzothiazole‐6‐sulfonate, C7H6N2O3S2, (II), both have the endocyclic N atom protonated; compound (I) exists as an ion pair and (II) forms a zwitterion. Intermolecular N—H...O and O—H...O hydrogen bonds are seen in both structures, with bonding energy (calculated on the basis of density functional theory) ranging from 1.06 to 14.15 kcal mol−1. Hydrogen bonding in (I) and (II) creates DDDD and C(8)C(9)C(9) first‐level graph sets, respectively. Face‐to‐face stacking interactions are observed in both (I) and (II), but they are extremely weak. 相似文献
74.
Agata Siwek Joanna Stefaska Irena Wawrzycka‐Gorczyca Monika Wujec 《Heteroatom Chemistry》2010,21(3):131-138
A series of s‐triazoles and thiohydantoines were synthesized by dehydrocyclization of 1‐substituted‐4‐ethoxycarbonylmethylthiosemicarbazides. The molecular structure proposed for s‐triazoles was confirmed by the X‐ray crystal structure analysis of one compound that was prone to crystallization. All compounds were tested in vitro for their antibacterial activity. Some of them showed low levels of activity against Gram‐positive species, MIC range 100–400 μg/mL or higher. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:131–138, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20597 相似文献
75.
Agata Wawrzyczak Jacek Kos Izabela Nowak Beata Czarnecka 《Molecules (Basel, Switzerland)》2021,26(17)
The surface properties of three commercial ionomer glass powders, i.e., Fuji IX, Kavitan Plus and Chemadent G-J-W were studied. Samples were analyzed by X-ray fluorescence spectroscopy (XRF), and the density was determined by gas pycnometry. Morphology was studied using scanning electron microscopy (SEM) and laser diffraction (LD) technique, whereas low-temperature nitrogen sorption measurements determined textural parameters like specific surface area and pore volume. Thermal transformations in the materials studied were evaluated by thermogravimetric analysis (TGA), which was carried out in an inert atmosphere between 30 °C and 900 °C. XRF showed that Fuji IX and Kavitan Plus powders were strontium-based, whereas Chemadent G-J-W powder was calcium-based. Powders all had a wide range of particle sizes under SEM and LD measurements. Specific surface areas and pore volumes were in the range 1.42–2.73 m2/g and 0.0029 to 0.0083 cm3/g, respectively, whereas densities were in the range 2.6428–2.8362 g/cm3. Thermogravimetric analysis showed that the glass powders lost mass in a series of steps, with Fuji IX powder showing the highest number, some of which are attributed to the dehydration and decomposition of the polyacrylic acid present in this powder. Mass losses were more straightforward for the other two glasses. All three powders showed distinct losses at around 780 °C and 835 °C, suggesting that similar dehydration steps occur in all these glasses. Other steps, which differed between glass powders, are attributed to variations in states of water-binding on their surfaces. 相似文献
76.
Recent interest in the role of quantum mechanics in the primary events of photosynthetic energy transfer has led to a convergence of nonlinear optical spectroscopy, condensed matter and quantum physics on the topic of energy‐transfer dynamics in pigment‐protein complexes. The convergence of these communities has unveiled a mismatch between the background and terminology of the respective fields. To make connections, a pedagogical guide to understanding the basics of two‐dimensional spectra is provided aimed at researchers with a background in quantum mechanics and condensed matter. 相似文献
77.
A major challenge in the area of DNA detection is the development of rapid methods that do not require polymerase chain reaction
(PCR) amplification of the genetic sample. The PCR amplification step increases the cost of the assay, the complexity of the
detection, and the quantity of DNA required for the assay. In this context, methods that are able to perform DNA analyses
with ultrasensitivity have recently been investigated with the aim of developing new PCR-free detection protocols. Functionalized
gold nanoparticles have played a central role in the development of such methods. Here, possibilities offered by functionalized
gold nanoparticle in the ultrasensitive detection of DNA are discussed. The different functionalization protocols available
for gold nanoparticles and the principal DNA detection methods that are able to detect DNA at the femtomolar to attomolar
level are presented. 相似文献
78.
Iterative operations on microdroplets and continuous monitoring of processes within them; determination of solubility diagrams of proteins 总被引:1,自引:0,他引:1
ME Dolega S Jakiela M Razew A Rakszewska O Cybulski P Garstecki 《Lab on a chip》2012,12(20):4022-4025
We demonstrate a technique for controlling the content of multiple microdroplets in time. We use this system to rapidly and quantiatively determine the solubility diagrams of two model proteins (lysozyme and ribonuclease A). 相似文献
79.
Andrzej Kudelski Marcin Pisarek Agata Roguska Marcin Hodyski Maria Janik‐Czachor 《Journal of Raman spectroscopy : JRS》2012,43(10):1360-1366
Silver nanoparticles deposited on various ‘inert’ porous materials (mainly Al2O3 and TiO2) are often used as substrates for surface‐enhanced Raman scattering (SERS) measurements. In this study, we used the sputter deposition technique to cover tubular arrays of Al2O3 and TiO2 with Ag nanoparticles. Raman spectra of pyridine (as a probe molecule) and of two selected dyes (5‐(4‐dimethylaminobenzylidene)rhodanine and 5‐(4‐(dimethylamino)benzylidene)‐3‐(3‐methoxypropyl)rhodanine) adsorbed on fabricated Ag/TiO2‐n/Ti and Ag/Al2O3‐n/Al substrates were measured. We found that the SERS spectra of pyridine adsorbed on Ag nanoparticles deposited on an Al2O3‐n/Al substrate are distinctly different from those measured for an Ag/TiO2‐n/Ti composite. Similar effects were observed for dyes adsorbed on the surface of both composites. The spectral differences between two kinds of composites (Ag/TiO2‐n/Ti and Ag/Al2O3‐n/Al) are discussed in terms of (1) the modified electronic structure of the Ag nanoparticles due to their interaction with different substrate materials and (2) the different atomic topology of the metal particles thus deposited on the surfaces of the substrates. Composite samples were also studied with the aid of scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to reveal their characteristic morphological and chemical features. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
80.
Monika Skwira Agata Jakóbik-Kolon Jerzy Ciba 《Central European Journal of Chemistry》2012,10(2):300-304
A soil incubation and shot-term plant growth experiment was conducted to study the effect of ferruginous mineral application
on exchangeable Al immobilization. The mineral containing mainly siderite was mixed at various rates with A-horizon soil and
incubated at 80% humidity for 45 days. Following the incubation, a short-term plant growth test was carried out using mung beans. The ferruginous mineral application into tested soil resulted in a reduction of the exchangeable aluminum concentration
and soil acidity. An increase in root growth and stalk length, as well as a general improvement of plant condition was observed
in the case of ferruginous mineral application. This observation was confirmed by chemical analysis of roots and stalks. The
greatest amount of essential elements: calcium and magnesium and the lowest amount of aluminum were determined in green part
of mung beans sown in the soil with addition of 2% ferruginous mineral.
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