| 1. |
- Feng, Zhenhua, et al.
(författare)
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SNR equalized optical direct-detected OFDM transmission with CAZAC equalization
- 2015
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Ingår i: CLEO. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- 50Km SSMF optical direct-detected OFDM transmission with Constant Amplitude Zero Auto Correlation Sequence (CAZAC) equalization is experimentally demonstrated with over 15dB power budget. 2.5dB enhancement in sensitivity has been achieved simultaneously with 3dB PAPR suppression.
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| 2. |
- Bai, Ru, et al.
(författare)
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The NF-κB-modulated miR-19a-3p enhances malignancy of human ovarian cancer cells through inhibition of IGFBP-3 expression
- 2019
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Ingår i: Molecular Carcinogenesis. - : Wiley. - 0899-1987 .- 1098-2744. ; 58:12, s. 2254-2265
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian cancer is the most lethal gynecologic malignancy due to the lack of symptoms until advanced stages, and new diagnosis and treatment strategy is in urgent need. In this study, we found higher expression of miR-19a-3p in ovarian cancer tissues compared with that in the adjacent normal tissues. By chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) analysis, we showed that nuclear factor-kappaB (NF-κB) binds to the promoter of miR-19a-3p, leading to reduced expression in ovarian cancer cells. Further study indicated that miR-19a-3p inhibits the expression of insulin-like growth factor binding protein-3 (IGFBP-3), resulting in enhanced growth and migration of ovarian cancer cells in vitro and tumor growth in vivo. These results showed that miR-19a-3p enhances the oncogenesis of ovarian cancer through inhibition of IGFBP-3 expression, and which can be inhibited by NF-κB, suggesting an NF-κB/miR-19a-3p/IGFBP-3 pathway in the oncogenesis of ovarian cancer, which expands our understanding of ovarian cancer and they may contribute to the development of new diagnosis and treatment of ovarian cancer.
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| 3. |
- Feng, Zhenhua, et al.
(författare)
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Digital Domain Power Division Multiplexing DDO-OFDM Transmission with Successive Interference Cancellation
- 2016
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Ingår i: 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO). - Washington, D.C. : IEEE conference proceedings.
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Konferensbidrag (refereegranskat)abstract
- Two independent 2.5-Gb/s DDO-OFDM signals are simultaneously transmitted over 25km SMF using digital domain power division multiplexing and successive interference cancellation. With optimized power division ratio and enhanced SD-FEC, the spectral efficiency can be doubled.
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| 4. |
- Feng, Zhenhua, et al.
(författare)
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Performance-Enhanced Direct Detection Optical OFDM Transmission With CAZAC Equalization
- 2015
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 27:14, s. 1507-1510
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Tidskriftsartikel (refereegranskat)abstract
- Direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) transmission with constant amplitude zero autocorrelation (CAZAC) sequence equalization is proposed and experimentally demonstrated. Simulation results show that more than 2-dB peak-to-average power ratio (PAPR) reduction can be realized using CAZAC equalization, and 50-km standard single mode fiber (SSMF) transmission of 4.11-Gb/s QPSK-OFDM can be achieved with bit-error rate (BER) under forward error correction limit. Transmission performance of QPSK-based DDO-OFDM system is analyzed in both OB2B configuration and fiber link with and without CAZAC equalization. More than 2.5-dB optical receiver sensitivity improvements can be obtained thanks to the PAPR reduction enjoyed by CAZAC equalization. Signal-to-noise ratio for every subcarrier derived from error vector magnitude is estimated and its flatness is confirmed to be much improved with CAZAC equalization. The performance improvements brought by CAZAC equalization can be extended to other modulation formats, and 8.22-Gb/s 16-quadratic-amplitude modulation-OFDM signals transmission using CAZAC equalization is demonstrated with over 1.5 dB enhancement in receiver sensitivity.
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| 5. |
- Jiang, Tao, et al.
(författare)
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Investigation of DC-Biased Optical OFDM With Precoding Matrix for Visible Light Communications : Theory, Simulations, and Experiments
- 2018
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Ingår i: IEEE Photonics Journal. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1943-0655. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Orthogonal frequency-division-multiplexing (OFDM) technology is widely used in visible light communication (VLC) to achieve high data rate transmission. However, the traditional direct-current (DC)-biased optical OFDM (DCO-OFDM) VLC systems suffer from the high peak-to-average power ratio (PAPR) which causes signal clipping distortion, and, thus, performance degradation. Furthermore, severe high-frequency fading due to the limited system bandwidth results in poor bit error rate (BER) performance. Precoding matrix (PM) techniques have been proposed to enhance the performance of VLC OFDM transmission, but a little or no work has been carried out in investigating the theory of PM used in OFDM VLC systems. In this paper, we aim to reveal the theory of PM-DCO-OFDM for a VLC system. To figure out the intrinsic laws of a PM method, we investigate the principles of PAPR reduction, clipping distortion optimization, and signal-to-noise ratio (SNR) distribution equalization. Based on the analysis of PAPR, we theoretically proved the simplicity of PM as a method to reduce the possibility of high PAPR by improving the autocorrelation performance of input symbols. The clipping distortion could be improved due to the reduction of high PAPR. Moreover, the relatively uniform SNR distribution can be achieved by PM through equalizing the clipping and channel noise, which is beneficial to improve the BER performance in high-frequency constrained systems. However, the PM method used in a DCO-OFDM VLC system should consider the transmitting power, modulation format, and transmission distance as a whole to achieve the transmission performance improvement. The simulation results demonstrate the complementary cumulative distribution function of PAPR can be reduced similar to 3 dB, while the performance of clipping distortion power and clipping error probability are significantly improved. Furthermore, experiment is carried out with results showing that the PM method can improve the BER performance in the case that VLC OFDM transmission has enough transmitting power, but with the low transmitting power, the PM also can damage the BER performance. The simulation and experiment results are consistent with our theoretical analysis.
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| 6. |
- Liu, Zhenhua, et al.
(författare)
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A Rapid Prototyping Technique for Microfluidics with High Robustness and Flexibility
- 2016
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 7:11
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Tidskriftsartikel (refereegranskat)abstract
- In microfluidic device prototyping, master fabrication by traditional photolithography is expensive and time-consuming, especially when the design requires being repeatedly modified to achieve a satisfactory performance. By introducing a high-performance/cost-ratio laser to the traditional soft lithography, this paper describes a flexible and rapid prototyping technique for microfluidics. An ultraviolet (UV) laser directly writes on the photoresist without a photomask, which is suitable for master fabrication. By eliminating the constraints of fixed patterns in the traditional photomask when the masters are made, this prototyping technique gives designers/researchers the convenience to revise or modify their designs iteratively. A device fabricated by this method is tested for particle separation and demonstrates good properties. This technique provides a flexible and rapid solution to fabricating microfluidic devices for non-professionals at relatively low cost.
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| 7. |
- Radamson, Henry H., et al.
(författare)
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State of the Art and Future Perspectives in Advanced CMOS Technology
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:8
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Forskningsöversikt (refereegranskat)abstract
- The international technology roadmap of semiconductors (ITRS) is approaching the historical end point and we observe that the semiconductor industry is driving complementary metal oxide semiconductor (CMOS) further towards unknown zones. Today's transistors with 3D structure and integrated advanced strain engineering differ radically from the original planar 2D ones due to the scaling down of the gate and source/drain regions according to Moore's law. This article presents a review of new architectures, simulation methods, and process technology for nano-scale transistors on the approach to the end of ITRS technology. The discussions cover innovative methods, challenges and difficulties in device processing, as well as new metrology techniques that may appear in the near future.
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| 8. |
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| 9. |
- Wang, Zhihang, 1989, et al.
(författare)
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Chip-scale solar thermal electrical power generation
- 2022
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Ingår i: Cell Reports Physical Science. - : Elsevier BV. - 2666-3864. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for alternative compact technologies that can derive and store energy from the sun, especially the large amount of solar heat that is not effectively used for power generation. Here, we report a combination of solution- and neat-film-based molecular solar thermal (MOST) systems, where solar energy can be stored as chemical energy and released as heat, with microfabricated thermoelectric generators to produce electricity when solar radiation is not available. The photophysical properties of two MOST couples are characterized both in liquid with a catalytical cycling setup and in a phase-interconvertible neat film. Their suitable photophysical properties let us combine them individually with a microelectromechanical ultrathin thermoelectric chip to use the stored solar energy for electrical power generation. The generator can produce, as a proof of concept, a power output of up to 0.1 nW (power output per unit volume up to 1.3 W m−3). Our results demonstrate that such a molecular thermal power generation system has a high potential to store and transfer solar power into electricity and is thus potentially independent of geographical restrictions.
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| 10. |
- Wu, Zhenhua, et al.
(författare)
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Valley-Dependent Brewster Angles and Goos-Hanchen Effect in Strained Graphene
- 2011
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Ingår i: Physical Review Letters. - 1079-7114. ; 106:17
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate theoretically how local strains in graphene can be tailored to generate a valley-polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys (K or K') show different Brewster-like angles and Goos-Hanchen shifts, exhibiting a close analogy with light propagating behavior. In a strain-induced waveguide, electrons in K and K' valleys have different group velocities, which can be used to construct a valley filter in graphene without the need for any external fields.
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| 11. |
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| 12. |
- Xu, Wenchao, et al.
(författare)
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Viscosity-difference-induced asymmetric selective focusing for large stroke particle separation
- 2016
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Ingår i: Microfluidics and Nanofluidics. - : Springer Science and Business Media LLC. - 1613-4982 .- 1613-4990. ; 20:9
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Tidskriftsartikel (refereegranskat)abstract
- We developed a new approach for particle separation by introducing viscosity difference of the sheath flows to form an asymmetric focusing of sample particle flow. This approach relies on the high-velocity gradient in the asymmetric focusing of the particle flow to generate a lift force, which plays a dominated role in the particle separation. The larger particles migrate away from the original streamline to the side of the higher relative velocity, while the smaller particles remain close to the streamline. Under high-viscosity (glycerol-water solution) and low-viscosity (PBS) sheath flows, a significant large stroke separation between the smaller (1.0 mu m) and larger (9.9 mu m) particles was achieved in a sample microfluidic device. We demonstrate that the flow rate and the viscosity difference of the sheath flows have an impact on the interval distance of the particle separation that affects the collected purity and on the focusing distribution of the smaller particles that affects the collected concentration. The interval distance of 293 mu m (relative to the channel width: 0.281) and the focusing distribution of 112 mu m (relative to the channel width: 0.107) were obtained in the 1042-mu m-width separation area of the device. This separation method proposed in our work can potentially be applied to biological and medical applications due to the wide interval distance and the narrow focusing distribution of the particle separation, by easy manufacturing in a simple device.
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