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991.
Improved partial response maximum likelihood method combining modulation code for signal waveform modulation multi-level disc 下载免费PDF全文
In this paper, we describe an improved adaptive partial response maximum likelihood (PRML) method combining modulation code tbr signal waveform modulation multi-level disc. This improved adaptive PRML method employs partial response equalizer and adaptive viterbi detector combining modulation code. Compared with the traditional adaptive PRML detector, the improved PRML detector additionally employs illogical sequence detector and corrector. Illogical sequence detector and corrector can aw)id the appearance of illogical sequences effectively, which do not follow the law of modulation code for signal waveform modulation multi-level disc, and obtain the correct sequences. We implement the improved PRML detector using a DSP and an FPGA chip. The experimental results show good performance. The higher efficient and lower complexity can be obtained by using the improved PRML method than by using the previous PRML method. Meanwhile, resource utilization of the improved PRML detector is not changed, but the bit error rate (BER) is reduced by more than 20%. 相似文献
992.
Li‐Hong Zhang Tao Jiang Dr. Lian‐Bin Wu Dr. Jun‐Hua Wan Dr. Chih‐Hsien Chen Dr. Yong‐Bing Pei Dr. Hua Lu Yuan Deng Gao‐Feng Bian Prof. Hua‐Yu Qiu Prof. Guo‐Qiao Lai 《化学:亚洲杂志》2012,7(7):1583-1593
A series of linear 2,5‐tetraphenylsilole‐vinylene‐type polymers were successfully synthesized for the first time. The tetraphenylsilole moieties were linked at their 2,5‐positions through a vinylene bridge with p‐dialkoxybenzenes to obtain polymer PSVB and with 3,6‐carbazole to obtain polymer PSVC . For comparison, 2,5‐tetraphenylsilole‐ethyne‐type polymer PSEB was also synthesized, in which the vinylene bridge of PSVB was replaced with an ethyne bridge. Very interestingly, the bridging group (vinylene or ethyne) had a significant effect on the photophysical properties of the corresponding polymers. The fluorescence peak of PSEB at 504 nm in solution originated from the emission of its silole moieties, whereas PSVB and PSVC emitted yellow light and no blueish–green emission from the silole moieties was observed, thus demonstrating that the emissions of PSVB and PSVC were due to their polymer backbones. More importantly, the 2,5‐tetraphenylsilole‐ethyne polymer exhibited a pronounced aggregation‐enhanced emission (AEE) effect but the 2,5‐tetraphenylsilole‐vinylene polymer was AEE‐inactive. Moreover, both AEE‐active 2,5‐tetraphenylsilole‐ethyne polymer and AEE‐inactive 2,5‐tetraphenylsilole‐vinylene polymers were successfully applied as fluorescent chemosensors for the detection of explosive compounds. 相似文献
993.
994.
Most of the existing color image watermarking schemes was designed to mark grayscale images or use the color components, which ignore the significant correlation between different color channels. Recently, several approaches were developed to process the color channels intrinsically, but they always cannot counterattack geometric distortions. It is a challenging work to design a robust color image watermarking scheme against geometrical distortions. In this paper, we propose a geometric correction based robust color image watermarking approach using quaternion Exponent moments (QEMs). The novelty of our approach is that (1) the QEMs are derived to deal with the color images in a holistic manner, and (2) the QEMs are exploited for estimating the geometric distortions parameters in order to permit watermark extraction. Experimental results confirm the validity of our approach and its higher robustness against geometrical distortions compared to alternative watermarking methods in the literature. 相似文献
995.
Journal of Solid State Electrochemistry - V2O5 nanobelt-carbonized bacterial cellulose (V2O5-CBC) nanocomposite was synthesized via a hydrothermal process in a single step. The prepared samples... 相似文献
996.
997.
Nonlinear Dynamics - This study significantly extends the development of an initialization methodology for designing multilayer feedforward neural networks, aimed primarily at modeling nonlinear... 相似文献
998.
Ya Jun Yang Ya Nan Yang Jian Shuang Jiang Zi Ming Feng Hong Yan Liu Xian Dao Pan Pei Cheng Zhang 《中国化学快报》2010,21(8):902-904
<正>A series of heterocycle-substituted phthalimide derivatives were synthesized.Structurally diverse derivatives with heterocyclic rings,including furan,imidazo[1,2-a]pyridine,1,3,4-thiadiazine,imidazo[2,1-b][1,3,4]thiadiazine,pyrazole,1,2,4-triazolo[3,4- b][1,3,4]thiadiazine,thiazole and thiazoline,were obtained by the reactions ofα-bromoketone intermediate with various nucleophiles containing oxygen,nitrogen and sulfur atom.Their cytotoxic activity was also evaluated against five human cancer cell lines in vitro. 相似文献
999.
1000.
Liulin Wang Buxiang Chen Pingping Peng Wenbo Hu Zhipeng Liu Xiaohua Pei Weihong Zhao Chengwu Zhang Lin Li Wei Huang 《中国化学快报》2017,28(10):1965-1968
Monitoring mitochondrial derived copper(Ⅱ) in live cells is highly demanded, but accurately detecting is unmet due to the interference with cytoplasmic copper(Ⅱ). Herein, we have reported the design,synthesis and characterization of photocontrollable fluorogenic probe, M_(Cu)~(-3), which is equipped with a photo-labile group(nitrobenzyl group) and mitochondria targeting unit(triphenylphosphonium salt).This novel probe showed an intense fluorescence enhancement in response to copper(Ⅱ) without interference from other metal cations in the biological condition(p H 6–9). The detection limit is 1.7 ×10~(-7) mol/L in HEPES buffer. The confocal fluorescence imaging results demonstrated M_(Cu)~(-3) can visualize mitochondrial copper(Ⅱ) in live mammalian cells. The clear advantage of our photocontrollable method is successful to avoid the influence of cytoplasmic copper(Ⅱ) during mitochondria specific detection. 相似文献