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161.
High-speed all-optical logic circuits have attracted much attention because of their important roles in signal processing in next-generation optical networks.The digital encoder is widely used in binary calculation,multiplexing,demultiplexing,address recognition and data encryption.A priority encoder allows the existence of multiple valid inputs simultaneously,identifies the priority of the request signals and encodes the priority.We propose and experimentally demonstrate an all-optical 4-bit priority encoder for return-to-zero signals at 40 Gbit/s based on cross-gain modulation in semiconductor optical amplifiers.Detuning fil-ters after semiconductor optical amplifiers are employed to improve the output performance.Correct logic bit sequences and clear open eye patterns with extinction ratios exceeding 10 dB are achieved. 相似文献
162.
It is difficult to date pyroclastic rocks, for almost all the dating methods, due to the multiple sources during their formation. ^40Ar/^39gAr incremental heating results on groundmass selected from the samples show that the age spectra are meaningless geologically. However, singe crystal total fusions of CO2 lasing on the sanidine separates could yield rational 4^40Ar/^39Ar results and distinguish their sources in this study. Timing on three formations of the Moshishan Group, after avoiding the exotic and altered grains by lasing on the single sanidine separate, was reported in this paper. The lowermost portion of the Chawan Formation gives an age of 113.7±0.3 Ma; the lower part of the Xishantou Formation was formed 116.4±0.4 Ma ago and the bottom of the Gaowu Formation took its shape at 118.4±0.4 Ma. These new ages are much younger than the previous ones, suggesting that these thick volcanic formations had been formed in very short durations. 相似文献
163.
In order to develop highly secure database systems to meet the requirements for class B2, the BLP (Bell-LaPudula) model is extended according to the features of database systems. A method for verifying security model for database systems is pro- posed. According to this method, an analysis by using Coq proof assistant to ensure the correctness and security of the extended model is introduced. Our formal security model has been verified secure. This work demonstrates that our verification method is effective and sufficient. 相似文献
164.
Copper/liquid microcapsule composite coatings with polyvinyl alcohol (PVA), gelatin or methyl cellulose (MC) as shell materials were prepared by electrodeposition. The influence of shell materials on the corrosion resistance of the composite coatings in 0.1 M H2SO4 was investigated by means of electrochemical techniques, scanning electron microscopy (SEM), and energy dispersion spectrometry (EDS). The results show that the participation of microcapsules can enhance the corrosion resistance of the composite coatings compared with the traditional copper layer. Based on the analysis of electrochemical test results, the release ways of microcapsules were deduced. Gelatin and MC as the shell materials of microcapsules are easy to release quickly in the composite coating. On the contrary, the releasing speed of PVA microcapsules is relatively slow due to their characteristics. 相似文献
165.
人工智能技术在仪器与测量中的应用 总被引:5,自引:0,他引:5
分析了与人工智能技术相关的人工神经网络和模糊逻辑的基本要领和重要方法,根据传感器增强、数据融合和系统辨识、控制等相关领域的几个成功案例,分析了它们的技术优越性和可行性,并展示了人工智能技术在仪器和测量中的应用前景。 相似文献
166.
PEI FuPing XU WenLiang YANG DeBin ZHAO QuanGuo LIU XiaoMing HU ZhaoChu 《科学通报(英文版)》2007,52(7):942-948
Zircon LA-ICP MS U-Pb dating of six metamorphic rocks and a metagranite (breccia) from southern basement of the Songliao Basin are reported in order to constrain the formation ages of basement. The basement metamorphic rocks in the Songliao Basin mainly consist of metagabbro (L45-1), amphibolite (SN117), metarhyolitical tuff (G190), sericite (Ser) schist (N103), chlorite (Chl) schist (T5-1), biotite (Bi)-actinolite (Act)-quartz (Q) schist (Y205), and metagranite (L44-1). The cathodoluminesence (CL) images of the zircons from metagabbro (L45-1) and metagranite (L44-1) indicate that they have cores of magmatic origin and rims of metamorphic overgrowths. Their U-Pb isotopic ages are 1808±21 Ma and 1873±13 Ma, respectively. The zircons with oscillatory zoning from amphibolite (SN117) and Chl schist (T5-1), being similar to those of mafic igneous rocks, yield ages of 274 ± 3.4 Ma and 264 ± 3.2 Ma, re-spectively. The zircons from metarhyolitical tuff (G190) and Ser schist (N103) display typical magmatic growth zoning and yield ages of 424 ± 4.5 Ma and 287 ± 5.1Ma, respectively. Most of zircons from Bi-Act-Q schist (Y205) are round in shape and different in absorption degree in the CL images, implying their sedimentary detritals. U-Pb dating yield concordant ages of 427 ± 3.1Ma, 455 ± 12 Ma, 696 ± 13 Ma, 1384±62 Ma, 1649±36 Ma, 1778±18 Ma, 2450±9 Ma, 2579±10 Ma, 2793±4 Ma and 2953±14 Ma. The above-mentioned results indicate that the Precambrian crystalline basement (1808―1873 Ma) exists in the southern Songliao Basin and could be related to tectonic thrust, and that the Early Paleozoic (424―490 Ma) and Late Paleozoic magmatisms (264―292 Ma) also occur in the basin basement, which are consistent with the ages of the detrital zircons from Bi-Act-Q schist in the basement. 相似文献
167.
LEI WanHua LIU HuiXue ZHONG LiJun YANG XiaoDa WANG Kui 《科学通报(英文版)》2007,52(20):2775-2781
Several vanadium compounds have been known for the hypoglycemic and anticancer effects. However, the mechanisms of the pharmacological and toxicological effects were not clear. In this work, we in- vestigated the potential targets of vanadium in mitochondria. Vanadyl ions were found to bind to mi- tochondria from rat liver with a stoichiometry of 244±58 nmol/mg protein and an apparent dissocia- tion constant (Kd) of (2.0±0.8)×10·16 mol/L. Using size exclusion chromatography, a vanadium-binding protein was isolated and identified to be the 60-kDa heat shock protein (HSP60) by mass spectrometry analysis and immunoassays. Additionally, binding of vanadyl ions was found to result in depolymeri- zation of homo-oligomeric HSP60 (GroEL). HSP60 is an indispensable molecular chaperone and in- volved in many kinds of pathogenesis of inflammatory and autoimmune diseases, e.g. type 1 diabetes. Our results suggested that HSP60 could be a novel important target involved in the biological and/or toxicological effects of vanadium compounds. 相似文献
168.
Robust fuzzy filterings for a class of nonlinear stochastic systems with infinite Markov jump are explored based on T-S fuzzy model approach in this paper. First of all, the exponentially mean square stable filter with a prescribed H∞ performance is designed via linear matrix inequalities(LMIs). Secondly, H2/H∞ fuzzy filtering is solved in terms of LMIs by minimizing the estimation error energy under the worst case fuzzy disturbance. The corresponding fuzzy filter parameters can be received by convex optimization algorithms. And lastly, two illustrative examples are performed to manifest the validity of the proposed methods. 相似文献
169.
170.
The reverse construction and analysis of the networks of molecular interactions are essential for understanding their functions
within cells. In this paper, a logic network model is constructed to investigate the complicated regulation mechanism of shoot
genes of Arabidopsis Thaliana in response to stimuli. The dynamics of the complicated logic network is analyzed, discussed,
and simulated. The simulation results show that the logic network of the active genes of shoot eventually evolves into eleven
attractors under the stimuli, including five 1-periodic and six 2-periodic attractors. Our work provides valuable reference
and guidance for biologists to understand and explain Arabidopsis’ response to external stimuli by experiments. 相似文献