| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Lu, Guangyue, et al.
(författare)
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Enhanced interleaved partitioning PTS for peak-to-average power ratio reduction in OFDM systems
- 2006
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 42:17, s. 983-984
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Tidskriftsartikel (refereegranskat)abstract
- The independence of the candidates generated in the existing interleaved partitioning partial transmit sequences (IP-PTS) is first investigated. The result shows that these candidates are not fully independent, which leads to performance inferior to the adjacent partitioning PTS (AP-PTS) in which all the generated candidates are mutually independent. To improve the performance of the IP-PTS in peak-to-average power ratio reduction, a novel type of phase sequences for IP-PTS is proposed that can be used to produce fully independent candidates so that IP-PTS can achieve similar performance to AP-PTS, while keeping low complexity.
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| 3. |
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| 6. |
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| 7. |
- Lu, Guangyue, et al.
(författare)
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Peak-to-average power ratio reduction in OFDM using cyclically shifted phase sequences
- 2007
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Ingår i: IET communications. - : Institution of Engineering and Technology (IET). - 1751-8628. ; 1:6, s. 1146-1151
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Tidskriftsartikel (refereegranskat)abstract
- Two approaches for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) are proposed that are relied on a set of cyclically shifted phase sequences (CSPS) and implemented using the time domain circular convolution. After multiplying CSPS with the frequency domain data, the signal candidates can be expressed as weighted sum of the circularly shifted OFDM time domain data in the first method, which is called CSPS method. In the second method, weighted coefficients for generating the signal candidates in CSPS method are optimally selected to improve its performance; thus, the second method is referred to as optimised CSPS (OCSPS) method. The performances of the CSPS and OCSPS methods are evaluated using simulated data and compared with those of selective mapping (SLM) and partial transmit sequences (PTS). The simulation results show that both the CSPS and OCSPS methods can reduce the PAPR effectively, and that the OCSPS performs even better than the CSPS. The OCSPS can achieve the same performance as compared to the PTS. A distinct feature of the proposed methods is that only one inverse discrete Fourier transform is needed, and thus, the candidates can be calculated in time domain directly.
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| 8. |
- Lu, Ping, et al.
(författare)
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A 5.4GHz 90-nm CMOS digitally controlled LC oscillator with 21% tuning range, 1.1MHz resolution, and 180dB FOM
- 2008
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Konferensbidrag (refereegranskat)abstract
- A 5.4 GHz digitally controlled oscillator (DCO) has been implemented in a 90-nm CMOS process. It has three different frequency control words, coarse, medium, and fine. The coarse control bank uses MIM capacitors and differential MOS switches. The other banks use MOS varactors. The phase noise was measured at the output of an on-chip divide by 2 circuit. It is -132 dBc/Hz at 3 MHz offset from the 2.7 GHz carrier. The power consumption of the oscillator is 7.8 mW from a 1.2 V supply, resulting in a figure of merit (FOM) of 182 dB. The worst case FOM is 180 dB over the 21% tuning range.
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| 9. |
- Lu, Ping, et al.
(författare)
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A 5.4GHz wide tuning range CMOS PLL using an auto-calibration multiple-pass ring oscillator
- 2009
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Ingår i: [Host publication title missing]. - 9781424449408 ; , s. 39-42
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Konferensbidrag (refereegranskat)abstract
- A 5.4GHz multiple-pass ring voltage controlled oscillator (VCO) based phase-locked loop (PLL) is described. For the sake of active devices’ sensitivity to process and temperature regarding ring oscillators, an effective automatic frequency calibration scheme is proposed. A new process-independent differential to single (DTOS) is used to adjust control voltage range and loop gain. The chip is implemented in 0.18-um CMOS process and achieves phase noise of -100dBc/Hz@1MHz and a 40% tuning range.
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| 10. |
- Lu, Ping, et al.
(författare)
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A 5GHz 90-nm CMOS all digital phase-locked loop
- 2009
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Ingår i: ; , s. 65-68
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Konferensbidrag (refereegranskat)abstract
- An all digital phase-locked loop (ADPLL) has been implemented in a 90-nm CMOS process. It uses a phase frequency detector (PFD) connected to two time-to-digital converters (TDC). To save power the TDCs use uneven delay time in the delay line cells. An automatic tuning bank controller selects active bank of the digitally controlled oscillator (DCO), which features three separate tuning banks. The PLL achieves a phase noise of -125 dBc/Hz at 1 MHz offset from a divided-by-2 carrier frequency of 2.58 GHz. The core area is 0.33 mm2 and the current consumption is 30 mA from a 1.2 V supply.
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| 11. |
- Wei, Jian-Feng, et al.
(författare)
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Formation of Kv2.1-FAK complex as a mechanism of FAK activation, cell polarization and enhanced motility
- 2008
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 217:2, s. 544-557
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Tidskriftsartikel (refereegranskat)abstract
- Focal adhesion kinase (FAK) plays key roles in cell adhesion and migration. We now report that the delayed rectifier Kv2.1 potassium channel, through its LD-like motif in N-terminus, may interact with FAK and enhance phosphorylation of FAK(397) and FAK(576/577) Overlapping distribution of Kv2.1 and FAK was observed on soma and proximal dendrites of cortical neurons. FAK expression promotes a polarized membrane distribution of the Kv2.1 channel. In Kv2.1-transfected CHO cells, formation of the Kv2.1-FAK complex was stimulated by fibronectin/integrin and inhibited by the K channel blocker tetraethylammonium (TEA). FAK phosphorylation was minimized by shRNA knockdown of the Kv2.1 channel, point mutations of the N-terminus, and TEA, respectively. Cell migration morphology was altered by Kv2.1 knockdown or TEA, hindering cell migration activity. In wound healing tests in vitro and a traumatic injury animal model, Kv2.1 expression and co-localization of Kv2.1 and FAK significantly enhanced directional cell migration and wound closure. It is suggested that the Kv2.1 channel may function as a promoting signal for FAK activation and cell motility.
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| 14. |
- Zhang, Xiang, et al.
(författare)
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Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group
- 2008
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Ingår i: Applied organometallic chemistry. - : Wiley. - 0268-2605 .- 1099-0739. ; 22:10, s. 592-597
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Tidskriftsartikel (refereegranskat)abstract
- Chiral pyrrolidine SalenMn(III) complexes with an anchored functional group at the N-aza-substituent in the pyrrolidine backbone were synthesized, and used as catalysts for asymmetric epoxidation of substituted chromenes. The complex 1 with an anchored imidazole as acceptor could effectively catalyze epoxidation of substituted chromenes in the absence of expensive additive 4-phenyl pyridine N-oxide (PPNO) by the coordination of the anchored organic base to the central manganese ion. Complexes 2 and 3 with a quaternary ammonium salt unit at the Naza-substituent in the pyrrolidine backbone displayed higher activities than Jacobsen catalyst and the analogous complex 4 without anchored functional group in the aforementioned reaction.
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| 15. |
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| 16. |
- Zhu, Yinian, et al.
(författare)
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Strain-insensitive and high-temperature long-period gratings inscribed in photonic crystal fiber
- 2005
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Ingår i: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 30:4, s. 367-369
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Tidskriftsartikel (refereegranskat)abstract
- We fabricate and demonstrate strain-insensitive and high-temperature long-period gratings in endlessly single-mode photonic crystal fiber by use of focused pulses of a CO2 laser and a periodic stress relaxation technique without geometrical deformation and elongation of the fiber. The thermal dependence of mode coupling at 1299.59 nm is 10.9 pm/°C from 24 to 992 °C, whereas the coefficient of strain sensitivity is −0.192 pm/??-0.192 pm/−0.192 pm/?? up to the maximum strain of 2.74%?2.74%−0.192 pm/?. It is found for what is believed to be the first time that, in contrast with the traditional fiber case, the coupling resonance shifts toward shorter wavelengths under applied strain, indicating that the refractive index of the core is decreased as a result of the rebuilding of tension attributed to the stress-elastic effect, and the cladding modes is highly dispersive because of airholes arranged in the fiber cladding.
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