3,253 research outputs found
Income Distribution and Public Transfers as Social Safety Nets in Korea
Using 5-year balanced household panel data, this paper shows that the inequality of per capita income in Korea aggravated during the financial crisis in 1998. The decomposition analysis of income inequality by factor component shows that the dominant positive effect on the income inequality is by the asset income. Next is the wage income, followed by the other income. Furthermore, this paper shows that social safety net programs were not yet in place during the initial period of the crisis. Public transfers were not effective social safety net devices and did not contribute in decreasing income inequality. Private transfers, on the other hand, were effective devices and narrowed the disparity in household income.
Temperature-dependent evolutions of excitonic superfluid plasma frequency in a srong excitonic insulator candidate, TaNiSe
We investigate an interesting anisotropic van der Waals material,
TaNiSe, using optical spectroscopy. TaNiSe has been
known as one of the few excitonic insulators proposed over 50 years ago.
TaNiSe has quasi-one dimensional chains along the -axis. We have
obtained anisotropic optical properties of a single crystal TaNiSe
along the - and -axes. The measured - and -axis optical
conductivities exhibit large anisotropic electronic and phononic properties.
With regard to the -axis optical conductivity, a sharp peak near 3050
cm at 9 K, with a well-defined optical gap ( 1800
cm) and a strong temperature-dependence, is observed. With an increase
in temperature, this peak broadens and the optical energy gap closes around
325 K(). The spectral weight redistribution with respect to the
frequency and temperature indicates that the normalized optical energy gap
() is . The
temperature-dependent superfluid plasma frequency of the excitonic condensation
in TaNiSe has been determined from measured optical data. Our
findings may be useful for future research on excitonic insulators.Comment: 17 pages, 5 figure
Synergistic multi-doping effects on the Li7La3Zr2O12 solid electrolyte for fast lithium ion conduction.
Here, we investigate the doping effects on the lithium ion transport behavior in garnet Li7La3Zr2O12 (LLZO) from the combined experimental and theoretical approach. The concentration of Li ion vacancy generated by the inclusion of aliovalent dopants such as Al(3+) plays a key role in stabilizing the cubic LLZO. However, it is found that the site preference of Al in 24d position hinders the three dimensionally connected Li ion movement when heavily doped according to the structural refinement and the DFT calculations. In this report, we demonstrate that the multi-doping using additional Ta dopants into the Al-doped LLZO shifts the most energetically favorable sites of Al in the crystal structure from 24d to 96 h Li site, thereby providing more open space for Li ion transport. As a result of these synergistic effects, the multi-doped LLZO shows about three times higher ionic conductivity of 6.14 × 10(-4) S cm(-1) than that of the singly-doped LLZO with a much less efforts in stabilizing cubic phases in the synthetic condition
Searching for Exotic Spin-Dependent Interactions with Diamond-Based Vector Magnetometer
We propose a new method to search for exotic spin-spin interactions between
electrons and nucleons using a diamond-based vector magnetometer. The vector
magnetometer can be constructed from ensembles of nitrogen-vacancy centers
along different axes in a diamond. The nuclear spins of
nitrogen-vacancy centers in the same diamond can be polarized through the
dynamic nuclear polarization method to serve as spin sources. With the vector
magnetometer, the sought-after exotic interactions can be distinguished from
the magnetic dipole-dipole interaction. For the axion-mediated interaction , new upper bounds of the coupling are
expected within the force range from 10 nm to 100 m. For the -mediated interaction , new upper bounds of the coupling are expected within the force range from 10 nm to 1 cm.
The new upper bounds for and are both expected to be more
than 5 orders of magnitude more stringent than existing constraints at the
force range of 1 m with the total measurement time of one day
Point Clouds Are Specialized Images: A Knowledge Transfer Approach for 3D Understanding
Self-supervised representation learning (SSRL) has gained increasing
attention in point cloud understanding, in addressing the challenges posed by
3D data scarcity and high annotation costs. This paper presents PCExpert, a
novel SSRL approach that reinterprets point clouds as "specialized images".
This conceptual shift allows PCExpert to leverage knowledge derived from
large-scale image modality in a more direct and deeper manner, via extensively
sharing the parameters with a pre-trained image encoder in a multi-way
Transformer architecture. The parameter sharing strategy, combined with a novel
pretext task for pre-training, i.e., transformation estimation, empowers
PCExpert to outperform the state of the arts in a variety of tasks, with a
remarkable reduction in the number of trainable parameters. Notably, PCExpert's
performance under LINEAR fine-tuning (e.g., yielding a 90.02% overall accuracy
on ScanObjectNN) has already approached the results obtained with FULL model
fine-tuning (92.66%), demonstrating its effective and robust representation
capability
Improvement of dye-sensitized solar cells toward the broader light harvesting of the solar spectrum
Dye-sensitized solar cells (DSSCs) have been extensively evolved for the past two decades in order to improve their cell performance. From the commercialization point of view, the overall solar to electrical energy conversion efficiency should compete with other solar cells. But, due to structural restrictions of DSSC using the liquid electrolyte and a space requirement between two electrodes, the direct tandem construction of DSSCs by stacking of repeating units is highly limited. In this feature article, important research trials to overcome these barriers and a recent research trend to improve the light harvesting strategies mainly panchromatic engineering, various tandem approaches such as parallel tandem, series tandem, p-n tandem etc., have been briefly reviewed.close271
Graphene nanocomposites modified electrochemical aptamer sensor for rapid and highly sensitive detection of prostate specific antigen
Prostate specific antigen (PSA) is a widely used marker for the diagnosis of prostate cancer, and the increasing attention has been attracted on the development of rapid assay using biosensing technology. However, it remains challenging for the sensitive and selective detection of PSA in clinical samples. Here, we report a label-free microfluidic paper-based analytical device for highly sensitive electrochemical detection of PSA. The paper device was fabricated with wax printing to generate hydrophobic and hydrophilic layers for the construction of microfluidic channel, followed by screen-printing of three electrodes including working, counter and reference electrode. Gold nanoparticles (AuNPs)/reduced graphene oxide (rGO)/thionine (THI) nano composites were synthesized and characterized, which were coated onto working electrodes for the immobilization of DNA aptamer probe. THI servers as the electrochemical mediator to transduce the biological recognition between DNA aptamer and PSA, and the excellent conductivity of AuNPs and rGO also play a significant role of electron transfer, leading to a sensitive detection for PSA, able to detect PSA as low as 10 pg mL , with a linear range from 0.05 to 200 ng mL . We demonstrated that our electrochemical sensor for the detection of clinical serum samples, indicating that our sensor would provide a new platform for low cost, sensitive and point-of-care diagnosis of prostate cancer
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