67 research outputs found

    Real estate rental market: a 10-year bibliometricbased review

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    The real estate rental market (RERM) is considered to have an important role in the entire real estate market. It refers to a property composed of land and its buildings, including the natural resources that can be rented or leased. Previous researches show that most developed countries have experienced the historical process of passively renting, actively buying, and actively renting. Moreover, academic interest in the impact of different sectors of the RERM has been reviewed increasingly over the past decade. However, previous studies provide limited insights into a comprehensive review of the RERM. Based on a 10-year database of 790 articles collected from the Web of Science, a comprehensive literature review is presented to discover the knowledge structure of RERM using CiteSpace software. First, this study recognizes the cluster of the articles, and discusses six major clusters in detail. Next, this study has identified four research trends that emerged during the past decade. To reveal the differences between the studies in the United States (US), China and the United Kingdom (UK), this study compares their publication scales and co-word networks. Finally, this study suggests six meaningful future research directions

    Revisiting the ground state of CoAl2_2O4_4: comparison to the conventional antiferromagnet MnAl2_2O4_4

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    The A-site spinel material, CoAl2O4, is a physical realization of the frustrated diamond-lattice antiferromagnet, a model in which is predicted to contain unique incommensurate or `spin-spiral liquid' ground states. Our previous single-crystal neutron scattering study instead classified it as a `kinetically-inhibited' antiferromagnet, where the long ranged correlations of a collinear Neel ground state are blocked by the freezing of domain wall motion below a first-order phase transition at T* = 6.5 K. The current paper expands on our original results in several important ways. New elastic and inelastic neutron measurements are presented that show our initial conclusions are affected by neither the sample measured nor the instrument resolution, while measurements to temperatures as low as T = 250 mK limit the possible role being played by low-lying thermal excitations. Polarized diffuse neutron measurements confirm reports of short-range antiferromagnetic correlations and diffuse streaks of scattering, but major diffuse features are explained as signatures of overlapping critical correlations between neighboring Brillouin zones. Finally, and critically, this paper presents detailed elastic and inelastic measurements of magnetic correlations in a single-crystal of MnAl2O4, which acts as an unfrustrated analogue to CoAl2O4. The unfrustrated material is shown to have a classical continuous phase transition to Neel order at T_N = 39 K, with collective spinwave excitations and Lorentzian-like critical correlations which diverge at the transition. Direct comparison between the two compounds indicates that CoAl2O4 is unique, not in the nature of high-temperature diffuse correlations, but rather in the nature of the frozen state below T*. The higher level of cation inversion in the MnAl2O4 sample indicates that this novel behavior is primarily an effect of greater next-nearest-neighbor exchange.Comment: 13 pages, 8 figures, acccepted for publication in Physical Review

    Unusual double-peak specific heat and spin freezing in a spin-2 triangular lattice antiferromagnet FeAl2_{2}Se4_{4}

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    We report the properties of a triangular lattice iron-chalcogenide antiferromagnet FeAl2_{2}Se4_{4}. The spin susceptibility reveals a significant antiferromagnetic interaction with a Curie-Weiss temperature {\Theta}CW_{CW} ~ -200K and a spin-2 local moment. Despite a large spin and a large |{\Theta}CW_{CW}|, the low-temperature behaviors are incompatible with conventional classical magnets. No long-range order is detected down to 0.4K. Similar to the well-known spin-1 magnet NiGa2_{2}S4_{4}, the specific heat of FeAl2_{2}Se4_{4} exhibits an unusual double-peak structure and a T2^{2} power law at low temperatures, which are attributed to the underlying quadrupolar spin correlations and the Halperin-Saslow modes, respectively. The spin freezing occurs at ~ 14K, below which the relaxation dynamics is probed by the ac susceptibility. Our results are consistent with the early theory for the spin-1 system with Heisenberg and biquadratic spin interactions. We argue that the early proposal of the quadrupolar correlation and gauge glass dynamics may be well extended to FeAl2_{2}Se4_{4}. Our results provide useful insights about the magnetic properties of frustrated quantum magnets with high spins.Comment: 7 pages, 4 figure

    Magnetic Ordering in the Ising Antiferromagnetic Pyrochlore Nd2ScNbO7

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    The question of structural disorder and its effects on magnetism is relevant to a number of spin liquid candidate materials. Although commonly thought of as a route to spin glass behavior, here we describe a system in which the structural disorder results in long-range antiferromagnetic order due to local symmetry breaking. Nd2_2ScNbO7_7 is shown to have a dispersionless gapped excitation observed in other neodymium pyrochlores below TN_N = 0.37 K through polarized and inelastic neutron scattering. However the dispersing spin waves are not observed. This excited mode is shown to occur in only 14(2) \% of the neodymium ions through spectroscopy and is consistent with total scattering measurements as well as the magnitude of the dynamic moment 0.26(2) μB\mu_B. The remaining magnetic species order completely into the all-in all-out Ising antiferromagnetic structure. This can be seen as a result of local symmetry breaking due disordered Sc+3^{+3} and Nb+5^{+5} ions about the A-site. From this work, it has been established that B-site disorder restores the dipole-like behaviour of the Nd+3^{+3} ions compared to the Nd2_2B2_2O7_7 parent series

    Spin-phonon scattering-induced low thermal conductivity in a van der Waals layered ferromagnet Cr2_2Si2_2Te6_6

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    Layered van der Waals (vdW) magnets are prominent playgrounds for developing magnetoelectric, magneto-optic and spintronic devices. In spintronics, particularly in spincaloritronic applications, low thermal conductivity (κ\kappa) is highly desired. Here, by combining thermal transport measurements with density functional theory calculations, we demonstrate low κ\kappa down to 1 W m1^{-1} K1^{-1} in a typical vdW ferromagnet Cr2_2Si2_2Te6_6. In the paramagnetic state, development of magnetic fluctuations way above Tc=T_\mathrm{c}= 33 K strongly reduces κ\kappa via spin-phonon scattering, leading to low κ\kappa \sim 1 W m1^{-1} K1^{-1} over a wide temperature range, in comparable to that of amorphous silica. In the magnetically ordered state, emergence of resonant magnon-phonon scattering limits κ\kappa below \sim 2 W m1^{-1} K1^{-1}, which would be three times larger if magnetic scatterings were absent. Application of magnetic fields strongly suppresses the spin-phonon scattering, giving rise to large enhancements of κ\kappa. Our calculations well capture these complex behaviours of κ\kappa by taking the temperature- and magnetic-field-dependent spin-phonon scattering into account. Realization of low κ\kappa which is easily tunable by magnetic fields in Cr2_2Si2_2Te6_6, may further promote spincaloritronic applications of vdW magnets. Our theoretical approach may also provide a generic understanding of spin-phonon scattering, which appears to play important roles in various systems.Comment: 14 pages, 6 figures, accepted for publication in Advanced Functional Material

    Thermal and electrostatic tuning of surface phonon-polaritons in LaAlO<sub>3</sub>/SrTiO<sub>3</sub> heterostructures

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    Phonon polaritons are promising for infrared applications due to a strong light-matter coupling and subwavelength energy confinement they offer. Yet, the spectral narrowness of the phonon bands and difficulty to tune the phonon polariton properties hinder further progress in this field. SrTiO3 – a prototype perovskite oxide - has recently attracted attention due to two prominent far-infrared phonon polaritons bands, albeit without any tuning reported so far. Here we show, using cryogenic infrared near-field microscopy, that long-propagating surface phonon polaritons are present both in bare SrTiO3 and in LaAlO3/SrTiO3 heterostructures hosting a two-dimensional electron gas. The presence of the two-dimensional electron gas increases dramatically the thermal variation of the upper limit of the surface phonon polariton band due to temperature dependent polaronic screening of the surface charge carriers. Furthermore, we demonstrate a tunability of the upper surface phonon polariton frequency in LaAlO3/SrTiO3 via electrostatic gating. Our results suggest that oxide interfaces are a new platform bridging unconventional electronics and long-wavelength nanophotonics.</p

    Association of GALC, ZNF184, IL1R2 and ELOVL7 With Parkinson’s Disease in Southern Chinese

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    Study Objectives: The aim of the study was to investigate the relationship between 22 single nucleotide polymorphisms (SNPs) and Parkinson’s disease (PD) in the Chinese population.Methods: A total of 250 PD patients and 240 healthy controls were recruited. The SNaPshot technique and the polymer chain reaction were used to detect 22 SNPs.Results: rs8005172 of GALC, rs9468199 of ZNF184 and rs34043159 of IL1R2, were associated with PD (rs8005172: p = 0.009, OR = 0.69, allele model, p = 0.010, additive model, p = 0.015, OR = 2.17, dominant model; p = 0.020, OR = 2.11, dominant model after adjustment; p = 0.036, OR = 1.47, recessive model after adjustment; rs9468199: p = 0.008, OR = 1.52, allele model, p = 0.008, additive model, p = 0.007, OR = 0.22, recessive model, p = 0.005, OR = 0.20, recessive model after adjustment; rs34043159: p = 0.034, OR = 1.31, allele model, p = 0.036, additive model).Conclusion: Our study revealed that GALC, ZNF184, and IL1R2 were associated with PD in the southern Chinese population. GALC was also associated with LOPD. ELOVL7 and ZNF184 were associated with EOPD. In addition, trends of association to PD, between SATB1, NMD3, and FGF20, were also found.Statement of Significance: Genetic play an important role in the pathogenesis factors of Parkinson’s disease (PD). We found that GALC, ZNF184, and IL1R2 were associated with PD. GALC was also associated with late onset of PD, while ELOVL7 and ZNF184 were associated with early onset PD. This study is the first to find an association between GALC, ZNF184, and rs2280104 with PD

    The application and progress of tissue engineering and biomaterial scaffolds for total auricular reconstruction in microtia

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    Microtia is a congenital deformity of the ear with an incidence of about 0.8–4.2 per 10,000 births. Total auricular reconstruction is the preferred treatment of microtia at present, and one of the core technologies is the preparation of cartilage scaffolds. Autologous costal cartilage is recognized as the best material source for constructing scaffold platforms. However, costal cartilage harvest can lead to donor-site injuries such as pneumothorax, postoperative pain, chest wall scar and deformity. Therefore, with the need of alternative to autologous cartilage, in vitro and in vivo studies of biomaterial scaffolds and cartilage tissue engineering have gradually become novel research hot points in auricular reconstruction research. Tissue-engineered cartilage possesses obvious advantages including non-rejection, minimally invasive or non-invasive, the potential of large-scale production to ensure sufficient donors and controllable morphology. Exploration and advancements of tissue-engineered cartilaginous framework are also emerging in aspects including three-dimensional biomaterial scaffolds, acquisition of seed cells and chondrocytes, 3D printing techniques, inducing factors for chondrogenesis and so on, which has greatly promoted the research process of biomaterial substitute. This review discussed the development, current application and research progress of cartilage tissue engineering in auricular reconstruction, particularly the usage and creation of biomaterial scaffolds. The development and selection of various types of seed cells and inducing factors to stimulate chondrogenic differentiation in auricular cartilage were also highlighted. There are still confronted challenges before the clinical application becomes widely available for patients, and its long-term effect remains to be evaluated. We hope to provide guidance for future research directions of biomaterials as an alternative to autologous cartilage in ear reconstruction, and finally benefit the transformation and clinical application of cartilage tissue engineering and biomaterials in microtia treatment

    Bioengineered MSC-derived exosomes in skin wound repair and regeneration

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    Refractory skin defects such as pressure ulcers, diabetic ulcers, and vascular ulcers represent a challenge for clinicians and researchers in many aspects. The treatment strategies for wound healing have high cost and limited efficacy. To ease the financial and psychological burden on patients, a more effective therapeutic approach is needed to address the chronic wound. MSC-derived exosomes (MSC-exosomes), the main bioactive extracellular vesicles of the paracrine effect of MSCs, have been proposed as a new potential cell-free approach for wound healing and skin regeneration. The benefits of MSC-exosomes include their ability to promote angiogenesis and cell proliferation, increase collagen production, regulate inflammation, and finally improve tissue regenerative capacity. However, poor targeting and easy removability of MSC-exosomes from the wound are major obstacles to their use in clinical therapy. Thus, the concept of bioengineering technology has been introduced to modify exosomes, enabling higher concentrations and construction of particles of greater stability with specific therapeutic capability. The use of biomaterials to load MSC-exosomes may be a promising strategy to concentrate dose, create the desired therapeutic efficacy, and maintain a sustained release effect. The beneficial role of MSC-exosomes in wound healing is been widely accepted; however, the potential of bioengineering-modified MSC-exosomes remains unclear. In this review, we attempt to summarize the therapeutic applications of modified MSC-exosomes in wound healing and skin regeneration. The challenges and prospects of bioengineered MSC-exosomes are also discussed
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