bluuebunny/crossref_metadata_2025_split huggingface dataset:
The fractal dimension of Islamic and Persian four-folding gardens
Authors: Patuano Agnès , Lima M. Francisca 
Published: March 2021

AbstractSince Benoit Mandelbrot (1924–2010) coined the term “fractal” in 1975, mathematical theories of fractal geometry have deeply influenced the fields of landscape perception, architecture, and technology. Indeed, their ability to describe complex forms nested within each other, and repeated towards infinity, has allowed the modeling of chaotic phenomena such as weather patterns or plant growth. Some human-designed patterns such as the ones developed by Islamic cultures have been found to follow similar principles of hierarchy, symmetry, and repetition. However, the application of these principles in the design of gardens is an underexplored field. This paper presents a comparative exploration of the four-fold garden design model—the chahár-bágh—typical of Persian and Islamic garden design by analyzing two case studies: Taj Mahal and Isfahan’s city plan. This four-fold pattern is known to not only have a religious reading but to be also linked with ideals of fair distribution. Using an innovative compositional fractal analysis inspired by architecture, our results demonstrate that these gardens contain a high level of self-replication and scale invariance and that they exhibit a high fractal dimension. The novel application of this method of analysis to historical landscape plans allows us to assess to what extent fractal concepts were already in use before the European Renaissance and Mandelbrot’s explorations, and to speculate on their symbolism in the context of Islamic and Persian garden design. Specifically, we conclude that the fractal characteristics of these gardens might be intended as a representation of the infinite divine but also of principles of fairness and equality. Moving forward, this approach could be applied to design spaces, namely in the infrastructural design of the urban fabric, which are both meaningful and environmentally just.
The discharge selectivity in an atmospheric pressure helium–argon dielectric barrier discharge
Authors: Huo W. G. , Li X. , Lin J. S. , Guo Y. T. , Wang Y. X. , Xia Y. , Zhang M. 
Published: March 2021

In this paper, an atmospheric pressure polyethylene terephthalate dielectric barrier discharge is produced in a helium–argon mixture. The influences of the electrode voltage on the discharge mode are experimentally investigated. The results show that, at a fixed argon content of 50%, the discharge transits from local uniform, through the isolated pattern, to whole uniform with the increase in the electrode voltage. Both the peak value of current pulse and argon spectra (696.54, 763.13, 772.09, 811.17, and 911.81 nm) intensities are captured to clarify the characteristics of the discharge mode transition. The different discharge characteristic regions are obtained by varying the argon content. In addition, the influence of the argon content on the above-mentioned argon spectra intensities is also researched. The spectra intensities enhance at 696.54, 763.13, and 772.09 nm but weaken at 811.17 and 911.81 nm with the increase in the argon content when the discharge operates in the whole uniform mode. The physical reasons for these results are discussed.
Synthesis and biological activity of aza and deaza analogues of purine nucleosides
Authors: Matyugina Elena S. , Kochetkov Sergey N. , Khandazhinskaya Anastasia L. 
Published: March 2021

Abstract

Analogues and derivatives of nucleic acid components have been used as key drugs in different areas of medicine over the past decades. The replacement of one or more nitrogen atoms of the heterocyclic base with a CH group affords deazapurine nucleoside analogues, and the replacement of the methine group with a nitrogen atom gives azapurine derivatives. A combination of aza and deaza moieties in the purine base leads to aza(deaza)-modified bases. Some nucleoside analogues were found to exhibit pronounced anticancer and antiviral activity. The synthesis and evaluation of biological activity of aza- and deazapurine nucleoside analogues have attracted interest from researchers four decades ago. This review describes and integrates the studies concerning certain aspects of the synthesis and(or) activity of various representatives of this class of compounds. The structure–biological activity relationships are analyzed. The successful approaches to the design of aza- and deazapurine nucleoside analogues are considered. A comparison is given for the methods of chemical and enzymatic synthesis of these compounds.
The bibliography includes 161 references.
Genomic analysis of the brassica pathogen turnip mosaic potyvirus reveals its spread along the former trade routes of the Silk Road
Authors: Kawakubo Shusuke , Gao Fangluan , Li Shifang , Tan Zhongyang , Huang Ying-Kun , Adkar-Purushothama Charith Raj , Gurikar Chennappa , Maneechoat Phoowanarth , Chiemsombat Pissawan , Aye Seint San , Furuya Naruto , Shevchenko Oleksiy , Špak Josef , Škorić Dijana , Ho Simon Y. W. , Ohshima Kazusato 
Published: March 2021

Significance
Our article presents the most comprehensive reconstruction of the evolutionary and phylogeographic history of a major plant pathogen of brassica vegetables in Eurasia. Sampling across such a large landmass poses considerable challenges, and our study attempts to describe the spatial and temporal patterns of migration for a plant pathogen on a large scale. Our phylogeographic and molecular clock analyses show that the migration pathways of turnip mosaic potyvirus retrace some of the historical trade arteries of the Silk Road. This study demonstrates how a comprehensive genetic analysis can provide a large-scale view of the epidemiology and human-mediated spread of a plant pathogen across centuries of evolutionary history.
Micro-businesses in the Mountains of Northern Albania
Authors: Woodward Simon 
Published: March 2021

Abstract
Parts of Northern Albania are still hard to get to, but adventure tourism has been making significant inroads, year by year, up until 2019. Two entrepreneurial villages, in particular, have led the way. Over 20 guest-houses have already opened, providing accommodation and food to travellers.

Information

Adapted from ‘Chapter 12: Destination Management: Case Study: Developing Rural Tourism in Northern Albania’. In: Robinson P., Lück M. and Smith S. (eds)
Tourism 2nd Edition
. CAB International, pp. 274-276.

© CAB International 2021
Application of multi-active center organic quinone molecular functionalized graphene in fully pseudocapacitive asymmetric supercapacitors
Authors: Hou Lijie , Kong Chao , Hu Zhongai , Wu Bowan , Han Yanxia 
Published: March 2021

Abstract
5, 7, 12, 14-pentacenetetrone (PT), polycyclic quinone derivatives, are rich in carbonyl, which were investigated as a novel organic electrode material for supercapacitors. PT with a π conjugated system, is a flat molecule, generating strong π–π interactions between molecules. PT molecules were uniformly fixed on conductive reduced graphene oxide (rGO) through π–π interaction by one-step solvothermal method, forming a three-dimensional cross-linked PT@rGO hydrogel. This composite structure was conducive to reducing the charge transfer resistance and promoting the Faraday reaction of electrode, which achieved the superposition of electric double-layer capacitance and pseudocapacitance. Appropriate organic molecular loading can effectively improve electrochemical performance. The optimal PT@rGO electrode material displayed the specific capacitance of 433.2 F g−1 at 5 mV s−1 with an excellent rate capability in 1 mol l−1 H2SO4 electrolyte. Finally, the fully pseudocapacitive asymmetric supercapacitor has been assembled by using PT@rGO as positive electrode and benz[a]anthracene-7,12-quinone (BAQ) modified rGO(BAQ/rGO)as negative electrode, which exhibited the good energy storage performance in a cell voltage of 1.8 V.
Gravitational waves as a big bang thermometer
Authors: Ringwald Andreas , Schütte-Engel Jan , Tamarit Carlos 
Published: March 2021

Abstract
There is a guaranteed background of stochastic gravitational
waves produced in the thermal plasma in the early universe. Its
energy density per logarithmic frequency interval scales with the
maximum temperature Tmax which the primordial plasma
attained at the beginning of the standard hot big bang era. It
peaks in the microwave range, at around 80
GHz [106.75/g*s(Tmax)]1/3, where g*s(Tmax) is the effective number of entropy degrees of freedom in
the primordial plasma at Tmax. We present a
state-of-the-art prediction of this Cosmic Gravitational Microwave
Background (CGMB) for general models, and carry out calculations for
the case of the Standard Model (SM) as well as for several of its
extensions. On the side of minimal extensions we consider the
Neutrino Minimal SM (νMSM) and the SM-Axion-Seesaw-Higgs
portal inflation model (SMASH), which provide a complete and
consistent cosmological history including inflation. As an example
of a non-minimal extension of the SM we consider the Minimal
Supersymmetric Standard Model (MSSM). Furthermore, we discuss the
current upper limits and the prospects to detect the CGMB in
laboratory experiments and thus measure the maximum temperature and
the effective number of degrees of freedom at the beginning of the
hot big bang.
Inpainting CMB maps using partial convolutional neural networks
Authors: Montefalcone Gabriele , Abitbol Maximilian H. , Kodwani Darsh , Grumitt R.D.P. 
Published: March 2021

Abstract
We present a novel application of partial convolutional neural networks (PCNN) that can inpaint masked images of the cosmic microwave background. The network can reconstruct both the maps and the power spectra to a few percent for circular and irregularly shaped masks covering up to 10% of the image area. By performing a Kolmogorov-Smirnov test we show that the reconstructed maps and power spectra are indistinguishable from the input maps and power spectra at the 99.9% level. Moreover, we show that PCNNs can inpaint maps with regular and irregular masks to the same accuracy. This should be particularly beneficial to inpaint irregular masks for the CMB that come from astrophysical sources such as Galactic foregrounds. The proof of concept application shown in this paper shows that PCNNs can be an important tool in data analysis pipelines in cosmology.
Parameters estimation and strong gravitational lensing of nonsingular Kerr-Sen black holes
Authors: Ghosh Sushant G. , Kumar Rahul , Islam Shafqat Ul 
Published: March 2021

Abstract
The recent time witnessed a surge of interest in strong gravitational lensing by black holes is due to the Event Horizon Telescope (EHT) results, which suggest comparing the black hole lensing in both general relativity and heterotic string theory. That may help us to assess the phenomenological differences between these models. Motivated by this, we consider gravitational lensing by the nonsingular Kerr-Sen black holes, which encompass Kerr black holes as a particular case, to calculate the light deflection coefficients p and q in strong-field limits, while the former increases with increasing parameters k and charge b, later decrease. We also find a decrease in the light deflection angle αD, angular position θ∞ decreases more slowly and impact parameter for photon orbits um more quickly, but angular separation s increases more rapidly with parameters b and k. We compare our results with those for Kerr black holes, and also the formalism is applied to discuss the astrophysical consequences in the case of the supermassive black holes NGC 4649, NGC 1332, Sgr A* and M87*. In turn, we also investigate the shadows of the nonsingular Kerr-Sen black holes and show that they are smaller and more distorted than the corresponding Kerr black holes and nonsingular Kerr black holes shadows. The inferred circularity deviation Δ C≤ 0.10, for the M87* black hole shadow, put constraints on the nonsingular Kerr-Sen black hole parameters (a, k) and (a, b). The maximum shadow angular diameter for b=0.30M and k=0.30M are, respectively, θd=35.3461 μas and θd=35.3355 μas. We also estimate the parameters associated with nonsingular Kerr-Sen black holes using the shadow observables.
A semi-analytic model for the study of 1/1 resonant dynamics of the planar elliptic restricted co-orbital problem
Authors: Li Miao , Huang Yu-Kun , Gong Sheng-Ping 
Published: March 2021

Abstract
Mean motion resonances (MMRs) are widespread in our Solar System. Moreover, resonant dynamics has always been an essential topic in planetary research. Recently, the research about exoplanets and the potential Planet Nine with large eccentricity has given rise to our interests in the secular dynamics inside MMRs in the elliptic model. In this paper, we study the fixed points of the averaged Hamiltonian and the long-term stable regions of the 1/1 resonance (or co-orbital motion) in the elliptic restricted three-body problem (ERTBP) systematically. Numerical integrations prove those test particles trapped in “apsidal co-rotation”, where both the resonant angle ϕ
res and the secular angle ⧍ϖ (or apsidal longitude differences) librate simultaneously, always survive the long-term simulations. Furthermore, utilizing a semianalytical method based on the adiabatic approach, three families of long-term fixed points of the averaged Hamiltonian of the planar ERTBP inside the 1/1 resonance have been found. We call them QS-points, Hpoints, and T-points here, whose values of the (ϕ
res, ⧍ϖ) are (0°, 180°), (180°, 0°), and (± 60°, ± 60°), respectively. All the fixed points of the averaged Hamiltonian of the co-orbital motion in the ERTBP are presented in the e-e′ plane (′ represents the elements of the planet in this paper). We find that QS-points and T-points always exist for the arbitrary eccentricity of a planet, while H-points only exist for the cases of low e′ and very high e. Furthermore, we measure the libration width in terms of eccentricity, ⧍e, around these stable equilibrium points in the e-⧍ϖ phase-space portraits. The “apsidal co-rotation” around all the stable equilibrium points is presented in the e-e′ plane. All these results are effectively confirmed by numerical experiments. The long-term stable zones around these periodic orbits in the e-e′ plane are significant for the research of the co-orbital motion in the ERTBP. Above all, these practical approaches that we proposed can also be used to study the secular dynamics of other MMRs.
Collapsing index: a new method to identify star-forming cores based on ALMA images
Authors: Yue Nan-Nan , Gao Yang , Li Di , Pan Liu-Bin 
Published: March 2021

Abstract
Stars form through the gravitational collapse of molecular cloud cores. Before collapsing, the cores are supported by thermal pressure and turbulent motions. A question of critical importance for the understanding of star formation is how to observationally discern whether a core has already initiated gravitational collapse or is still in hydrostatic balance. The canonical method to identify gravitational collapse is based on the observed radial density profile, which would change from Bonnor-Ebert type toward power laws as the core collapses. In practice, due to the projection effect, the resolution limit and other caveats, it has been difficult to directly reveal the dynamical status of cores, particularly in massive star forming regions. We here propose a novel, straightforward diagnostic, namely, the collapsing index (CI), which can be modeled and calculated based on the radial profile of the line width of dense gas. A meaningful measurement of CI requires spatially and spectrally resolved images of optically thin and chemically stable dense gas tracers. ALMA observations are making such data sets increasingly available for massive star forming regions. Applying our method to one of the deepest dense-gas spectral images ever taken toward such a region, namely, the Orion molecular cloud, we detect the dynamical status of selected cores. We observationally distinguished a collapsing core in a massive star forming region from a hydrostatical one. Our approach would help significantly improve our understanding of the interaction between gravity and turbulence within molecular cloud cores in the process of star formation.
Research on the panel adjustment method of an active main reflector for a large radio telescope
Authors: Sun Zheng-Xiong , Wang Jin-Qing , Yu Lin-Feng , Gou Wei , Wang Guang-Li 
Published: March 2021

Abstract
The surface accuracy of a large parabolic antenna is an important indicator to evaluate the quality of the antenna. It not only directly affects the antenna’s aperture efficiency, thereby determining the shortest wavelength that the antenna can work, but also affects the main lobe width and side lobe structure of the antenna pattern. Microwave holography is an important method for parabolic antenna profile detection. In this article we adopt a new algorithm to adjust the panels for the large radio telescope with an active main reflector through the TM65 m antenna’s aperture phase profile. The panels of the TM65 m radio telescope is in a radial pattern with 14 rings. Each corner of the panel is fixed on the screw of the actuator to move up and down, and the adjacent corners of the four panels share an actuator. We use the method of plane fitting to calculate the adjustment value of every panel’s corner. But one actuator, which simultaneously controls the common corner of the adjacent panels, will have different adjustment values according to the different plane fitting equation based on adjacent panels. In this paper, the adjustment value of the adjacent panels’crosspoints are constrained to be equal to the constraint condition to calculate each actuator’s adjustment value of the TM65 m radio telescope. Through multiple adjustments and application of the new algorithms, the accuracy of the TM65 m antenna reflector profile has been improved from the original 0.28 mm to the current 0.19 mm.
New observations and transit solutions of the inflated exoplanets HAT-P-40b and HAT-P-51b
Authors: Kjurkchieva Diana P. , Petrov Nikola I. , Popov Velimir A. 
Published: March 2021

Abstract
We present high-precision photometric observations of the transiting exoplanets HAT-P-40b and HAT-P-51b by the Rozhen 2-m telescope. The newly-observed transit of HAT-P-40b is the first one with a complete curve. The orbital periods of the two targets were improved. We modeled the observed transits and found bigger stellar radii than those derived from the stellar models. The planet radii of HAT-P-40b and HAT-P-51b obtained from our transit solutions are bigger than the values calculated by the empirical relations for Jupiter-mass and Saturn-mass planets respectively. Their values reveal the highly-inflated nature of the two targets, especially that of HAT-P-51b. We established that the best transit solutions correspond to a quadratic limb-darkening law. The fitted limb-darkening coefficients of HAT-P-40 are close to the theoretical ones while those of HAT-P-51 are a little different. The precise astrometric Gaia distances of the two targets are smaller by 6%-7% than the calculated values from the stellar models. We propose the Gaia distances to be used for improvement of the stellar models as well as for more reliable calculation of the parameters of the known exoplanets.
Discovery of Four New Clusters in the Cygnus Cloud
Authors: Qin Song-Mei , Li Jing , Chen Li , Zhong Jing 
Published: March 2021

Abstract
We report the discovery of four new open clusters (named QC 1, QC 2, QC 3 and QC 4) in the direction of Cygnus Cloud and select their members based on five astrometric parameters (l, b, ϖ,

μ
α
*

, μδ
) of Gaia DR2. We also derive their astrophysical parameters for each new cluster. Structure parameters are generated by fitting the radial density distribution with a King’s profile. Using solar metallicity, we performed isochrone-fitting on their purified color-magnitude diagrams (CMDs) to derive the age of the clusters. The known cluster NGC 7062 in an adjacent area is chosen to verify our identification process. The estimated distance, reddening and age of NGC 7062 are in good agreement with the literature.
Van der Waals heterojunction ReSe2/WSe2 polarization-resolved photodetector
Authors: Tian Xiaoyu , Liu Yushen 
Published: March 2021

Abstract
Polarization-resolved photodetectors, a significant branch of photodetection, can more effectively distinguish the target from the background by exploiting polarization-sensitive characteristics. However, due to the absence of intrinsic polarized absorption properties of many materials, there is still a great challenge to develop the high-performance polarization-resolved photodetectors. Here, we report a van der Waals heterojunction (vdWH) ReSe2/WSe2 photodetector, which performs a high responsivity of ~0.28 A/W and a high detectivity of 1.1 × 1012 Jones under the illumination of 520 nm laser at room temperature. Remarkably, scanning photocurrent mapping (SPCM) measurements demonstrate the photoresponse of devices closely depend on the polarized angle of the incident light, indicating the effective polarized light detection. This work paves the way to develop high-performance polarization-resolved photodetectors based on two-dimensional (2D) materials.
Resonant enhancement of magnetic damping driven by coherent acoustic phonons in thin Co2FeAl film epitaxied on GaAs
Authors: Song Lin , Yan Wei , Wang Hailong , Zhao Jianhua , Zhang Xinhui 
Published: March 2021

Abstract
The magnetic dynamics of a thin Co2FeAl film epitaxially grown on GaAs substrate was investigated using the time- resolved magneto-optical Kerr measurement under an out-of-plane external field. The intrinsic magnetic damping constant, which should do not vary with the external magnetic field, exhibits an abnormal huge increase when the precession frequency is tuned to be resonant with that of the coherent longitudinal acoustic phonon in the Co2FeAl/GaAs heterostructure. The experimental finding is suggested to result from the strong coherent energy transfer from spins to acoustic phonons via magnetoelastic effect under a resonant coupling condition, which leads to a huge energy dissipation of spins and a greatly enhanced magnetic damping in Co2FeAl. Our experimental findings provide an experimental evidence of spin pumping-like effect driven by propagating acoustic phonons via magnetoelastic effect, suggesting an alternative approach to the possible long-range spin manipulation via coherent acoustic waves.
Synthesis and Study of the fluorescent properties of 4-hydroxy-coumarin derivatives
Authors: Al-Majedy Yasameen K. , Ibraheem Hiba H. , Shamel Shemaa , Al-Amiery Ahmed A. 
Published: March 2021

Abstract
On the other hand the synthesis and fluorescent characteristics of some 4-hydroxy-coumarin are given. When tetrabutylbromide is present in water, 4-hydroxy-coumarin condensation with 4-nitrobenzaldehyde results in a fairly good yield of 3, 3’-(4-nitrophenyl) methylene) bis(4-hydroxy-2H-chromen-2-one)1. Additionally compound 1 on methyl bromoacetate therapy supplied compound 2 then this compound condensation with hydrazinhydrate supplies compound 3. IR, 1H-NMR, 13C-NMR verified the structures of all synthesized compounds. Experimental fluorescent results revealed significant photoluminescent characteristics. The luminescent character ristics of all synthesized compounds are determined to exhibit strong blue-green fluorescent characteristics to widely used in various applications because of their beneficial properties.