| 1. |
- Li, Guoqiang, et al.
(author)
-
Orbital scale lake evolution in the Ejina Basin, central Gobi Desert, China revealed by K-feldspar luminescence dating of paleolake shoreline features
- 2018
-
In: Quaternary International. - : Elsevier BV. - 1040-6182 .- 1873-4553. ; 482, s. 109-121
-
Journal article (peer-reviewed)abstract
- The Ejina Basin in the central Gobi Desert contains the terminal lakes of the Heihe River. Paleoenvironmental changes in the basin are important since its deposits are a significant source of Northern Hemisphere dust. In this study we employed a K-feldspar pIRIR dating technique to date shoreline features <= 940 m at multiple locations in the Ejina Basin similar to 45-50 m above the modern basin floor. Internal checks of luminescence characteristics were employed to test the reliability of the pIRIR dating. In combination with our previously reported stratigraphy and chronology of shorelines at <= 927 m in the Ejina Basin, these results imply that a paleolake was present in the basin prior to similar to 350 ka. Other high stands in the basin occurred at similar to 320-310 ka, 240-180 ka, 120-80 ka, and similar to 5 ka, corresponding to MIS 9, MIS 7, MIS 5 and the mid Holocene (MIS 1), respectively, indicating a strong link with glacial-interglacial cycles. Extensions of the East Asian Summer Monsoon (EASM) during interglacial periods, possibly interacting with the Westerlies, apparently caused higher precipitation and lake formation. The impact of orbital eccentricity on the EASM/Westerlies appears to be responsible for the formation of major lake/desert cycles on the northeastern margin of the Tibetan Plateau.
|
|
| 2. |
- Li, Junhao, et al.
(author)
-
Full-color enhanced second harmonic generation using rainbow trapping in ultrathin hyperbolic metamaterials
- 2021
-
In: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
-
Journal article (peer-reviewed)abstract
- Though metamaterials enhance nonlinear light-matter interactions due to their resonant features, these materials typically show a narrow spectral bandwidth. Here, the authors report broadband enhanced second-harmonic generation in patterned multilayer hyperbolic metamaterial arrays. Metasurfaces have provided a promising approach to enhance the nonlinearity at subwavelength scale, but usually suffer from a narrow bandwidth as imposed by sharp resonant features. Here, we counterintuitively report a broadband, enhanced second-harmonic generation, in nanopatterned hyperbolic metamaterials. The nanopatterning allows the direct access of the mode with large momentum, rendering the rainbow light trapping, i.e. slow light in a broad frequency, and thus enhancing the local field intensity for boosted nonlinear light-matter interactions. For a proof-of-concept demonstration, we fabricated a nanostructured Au/ZnO multilayer, and enhanced second harmonic generation can be observed within the visible wavelength range (400-650 nm). The enhancement factor is over 50 within the wavelength range of 470-650 nm, and a maximum conversion efficiency of 1.13x10(-6) is obtained with a pump power of only 8.80 mW. Our results herein offer an effective and robust approach towards the broadband metasurface-based nonlinear devices for various important technologies.
|
|
| 3. |
- Li, Xinghao, et al.
(author)
-
Porous organic polycarbene nanotrap for efficient and selective gold stripping from electronic waste
- 2023
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 14
-
Journal article (peer-reviewed)abstract
- The role of N-heterocyclic carbene, a well-known reactive site, in chemical catalysis has long been studied. However, its unique binding and electron-donating properties have barely been explored in other research areas, such as metal capture. Herein, we report the design and preparation of a poly(ionic liquid)-derived porous organic polycarbene adsorbent with superior gold-capturing capability. With carbene sites in the porous network as the “nanotrap”, it exhibits an ultrahigh gold recovery capacity of 2.09 g/g. In-depth exploration of a complex metal ion environment in an electronic waste-extraction solution indicates that the polycarbene adsorbent possesses a significant gold recovery efficiency of 99.8%. X-ray photoelectron spectroscopy along with nuclear magnetic resonance spectroscopy reveals that the high performance of the polycarbene adsorbent results from the formation of robust metal-carbene bonds plus the ability to reduce nearby gold ions into nanoparticles. Density functional theory calculations indicate that energetically favourable multinuclear Au binding enhances adsorption as clusters. Life cycle assessment and cost analysis indicate that the synthesis of polycarbene adsorbents has potential for application in industrial-scale productions. These results reveal the potential to apply carbene chemistry to materials science and highlight porous organic polycarbene as a promising new material for precious metal recovery.
|
|
| 4. |
- Zhao, Peiyu, et al.
(author)
-
Stable lithium metal anode enabled by high-dimensional lithium deposition through a functional organic substrate
- 2020
-
In: Energy Storage Materials. - : Elsevier BV. - 2405-8297. ; 33, s. 158-163
-
Journal article (peer-reviewed)abstract
- The growth of lithium dendrites severely restricts the development of lithium metal batteries. In order to achieve the goal of dendrites-free lithium in principle, it is crucial and urgent to control nucleation and growth of lithium. Here, a functional organic layer of perylene-3, 4, 9, 10-tetracarboxydiimide-lithium (PTCDI-Li) is built on the lithium anode surface by in-situ chemical reaction of PTCDI and Li metal. PTCDI-Li, with high surface energy (-10.19 eV) and low diffusion barrier (0.89 eV), efficiently promotes disk-shaped high-dimensional nucleation by regulation of lithium ion flux upon lithium plating, leading to a dendrites-free morphology. When operating under a relatively high current density of 10 mA cm−2, the Li | Li symmetrical cells with PTCDI-Li exhibit outstanding cyclic stability for 300 hours with ultralow overpotential of 400 mV, superior to the most of the reported lithium anode. The corresponding PTCDI-Li batteries show high specific capacity and enhanced cycle life. We anticipate that this strategy of regulation of lithium deposition from one-dimensional to high-dimensional opens a new horizon in the development of dendrites-free Li anodes.
|
|
| 5. |
- Li, Guohui, et al.
(author)
-
Localized Bound Multiexcitons in Engineered Quasi-2D Perovskites Grains at Room Temperature for Efficient Lasers
- 2023
-
In: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:20
-
Journal article (peer-reviewed)abstract
- Reducing the excitation threshold to minimize the Joule heating is critical for the realization of perovskite laser diodes. Although bound excitons are promising for low threshold laser, how to generate them at room temperature for laser applications is still unclear in quasi-2D perovskite-based devices. In this work, via engineering quasi-2D perovskite PEA2(CH3NH3)n-1PbnBr3n+1 microscopic grains by the anti-solvent method, room-temperature multiexciton radiative recombination is successfully demonstrated at a remarkably low pump density of 0.97 µJ cm−2, which is only one-fourth of that required in 2D CdSe nanosheets. In addition, the well-defined translational momentum in quasi-2D perovskite grains can restrict the Auger recombination which is detrimental to radiative emission. Furthermore, the quasi-2D perovskite grains are favorable for increasing binding energies of excitons and biexcitons and so as the related radiative recombination. Consequently, the prepared phase quasi-2D perovskite film renders a threshold of room-temperature stimulated emission as low as 13.7 µJ cm−2, reduced by 58.6% relative to the amorphous counterpart with larger grains. The findings in this work are expected to facilitate the development of solution-processable perovskite multiexcitonic laser diodes.
|
|
| 6. |
- Li, Linlin, et al.
(author)
-
A Novel Picornavirus Associated with Gastroenteritis
- 2009
-
In: Journal of Virology. - 0022-538X .- 1098-5514. ; 83:22, s. 12002-12006
-
Journal article (peer-reviewed)abstract
- A novel picornavirus genome was sequenced, showing 42.6%, 35.2%, and 44.6% of deduced amino acid identities corresponding to the P1, P2, and P3 regions, respectively, of the Aichi virus. Divergent strains of this new virus, which we named salivirus, were detected in 18 stool samples from Nigeria, Tunisia, Nepal, and the United States. A statistical association was seen between virus shedding and unexplained cases of gastroenteritis in Nepal (P = 0.0056). Viruses with approximately 90% nucleotide similarity, named klassevirus, were also recently reported in three cases of unexplained diarrhea from the United States and Australia and in sewage from Spain, reflecting a global distribution and supporting a pathogenic role for this new group of picornaviruses.
|
|
| 7. |
- Wang, Sen, et al.
(author)
-
ATAC-seq reveals the roles of chromatin accessibility in the chondrocytes of Kashin-Beck disease compared with primary osteoarthritis
- 2023
-
In: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 14
-
Journal article (peer-reviewed)abstract
- Objective: This study aimed to investigate the roles of accessible chromatin in understanding the different pathogeneses between Kashin-Beck disease (KBD) and primary osteoarthritis (OA).Methods: Articular cartilages of KBD and OA patients were collected, and after tissue digestion, primary chondrocytes were cultured in vitro. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) was performed to compare the accessible chromatin differences of chondrocytes between KBD and OA groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were executed for the promoter genes. Then, the IntAct online database was used to generate networks of significant genes. Finally, we overlapped the analysis of differentially accessible region (DAR)-associated genes and differentially expressed genes (DEGs) obtained from whole-genomic microarray.Results: We obtained 2,751 total DARs, which contained 1,985 loss and 856 gain DARs and belonged to 11 location distributions. We obtained 218 motifs associated with loss DARs, 71 motifs associated with gain DARs, 30 motif enrichments of loss DARs, and 30 motif enrichments of gain DARs. In total, 1,749 genes are associated with loss DARs, and 826 genes are associated with gain DARs. Among them, 210 promoter genes are associated with loss DARs, and 112 promoter genes are associated with gain DARs. We obtained 15 terms of GO enrichment and 5 terms of KEGG pathway enrichment from loss DAR promoter genes, and 15 terms of GO enrichment and 3 terms of KEGG pathway enrichment from gain DAR promoter genes. We obtained CAPN6 and other 2 overlap genes from loss DARs-vs-down DEGs, AMOTL1 from gain DARs-vs-down DEGs, EBF3 and other 12 overlap genes from loss DARs-vs-up DEGs, and ADARB1 and other 10 overlap genes from 101 gain DARs-vs-up DEGs. These overlap genes were built into 4 gene interaction networks.Conclusion: FGF7, GPD1L, NFIB, RUNX2, and VCAM1 were the overlapped genes from the DAR-associated genes and DEGs. These genes were associated with the abnormal chondrocyte function, which may play crucial roles in different processes between KBD and OA in the way of accessible chromatin.
|
|
| 8. |
- Xie, Li, et al.
(author)
-
Characterization of dry biopotential electrodes
- 2013
-
In: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. - 9781457702167 ; , s. 1478-1481
-
Conference paper (peer-reviewed)abstract
- Driven by the increased interest in wearable long-term healthcare monitoring systems, varieties of dry electrodes are proposed based on different materials with different patterns and structures. Most of the studies reported in the literature focus on proposing new electrodes and comparing its performance with commercial electrodes. Few papers are about detailed comparison among different dry electrodes. In this paper, printed metal-plate electrodes, textile based electrodes, and spiked electrodes are for the first time evaluated and compared under the same experimental setup. The contact impedance and noise characterization are measured. The in-vivo electrocardiogram (ECG) measurement is applied to evaluate the overall performance of different electrodes. Textile electrodes and printed electrodes gain comparable high-quality ECG signals. The ECG signal obtained by spiked electrodes is noisier. However, a clear ECG envelope can be observed and the signal quality can be easily improved by backend signal processing. The features of each type of electrodes are analyzed and the suitable application scenario is addressed.
|
|
| 9. |
- Zhao, Kefan, et al.
(author)
-
High-Quality Solution-Processed Quasi-2D Perovskite for Low-Threshold Lasers
- 2024
-
In: ACS Applied Materials and Interfaces. - 1944-8244. ; 16:17, s. 22361-22368
-
Journal article (peer-reviewed)abstract
- Spin-coated quasi-two-dimensional halide perovskite films, which exhibit superior optoelectronic properties and environmental stability, have recently been extensively studied for lasers. Crystallinity is of great importance for the laser performance. Although some parameters related to the spin-coating process have been studied, the in-depth understanding and effective control of the acceleration rate on two-dimensional perovskite crystallization during spin-coating are still unknown. Here we investigate the effect of solvent evaporation on the microstructure of the final perovskite films during the spin-coating process. The crystallization quality of the film can be significantly improved by controlling solvent evaporation. As a result, the prepared quasi-2D perovskite film exhibits a stimulated emission threshold (pump: 343 nm, 6 kHz, 290 fs) of 550 nm as low as 16.2 μJ/cm2. Transient absorption characterization shows that the radiative biexciton recombination time is reduced from 738.5 to 438.3 ps, benefiting from the improved crystallinity. The faster biexciton recombination significantly enhanced the photoluminescence efficiency, which is critical for population inversion. This work could contribute to the development of low-threshold lasers.
|
|
| 10. |
- Zheng, Linlin, et al.
(author)
-
Design and implementation of a fully reconfigurable chipless RFID tag using inkjet printing technology
- 2008
-
In: Proceedings - IEEE International Symposium on Circuits and Systems. - 9781424420780 ; , s. 1524-1527
-
Conference paper (peer-reviewed)abstract
- In this paper, a novel fully reconfigurable chipless RFID tag has been presented. 8-bit data are encoded by impedance mismatches along transmission line. Inkjet printing is used to reconfigure for special tag IDs. By integrating inkjet printing technology, printable tags are not only economically feasible but also technically efficient. The remarkable idea has been successfully validated both by simulation and experimental measurements.
|
|
