声光双稳态混沌系统参数调制通信

文中我们针对声光双稳态混沌系统提出了参数调制的方法实现保密通信,计算研究表明,参数调制虽然对混沌系统有一定的改变,但并不改变该系统的伪随机的特性,我们还计算模拟了该方法,并讨论了对其的影响因素。

漫话年夜饭

除夕之夜，城乡人民家家都要吃年夜饭，这已是流传几千年的民间习俗了。除夕之夜，就是将辞去的一年腊月三十的晚上，即“月穷岁尽之日”。“除夕”是旧岁至此而除，来年另换新岁的意思。唐骆宾王的《西京守岁》诗中曰：“夜将寒色去，年共晓光新”，也是说除旧市新，希望桌年过上新的美好的日子。除夕之夜吃年夜饭，一是驱邪祈平安，二是家庭宴会；也叫“团年”或“分岁”，俗称“

Relatedness between catalytic effect of activated carbon and passivation phenomenon during chalcopyrite bioleaching by mixed thermophilic Archaea culture at 65°C

The relatedness between catalytic effect of activated carbon and passivation phenomenon during chalcopyrite bioleachingby mixed thermophilic Archaea culture(Acidianus brierleyi,Metallosphaera sedula,Acidianus manzaensis and Sulfolobusmetallicus)at65°C was studied.Leaching experiments showed that the addition of activated carbon could significantly promote thedissolution of chalcopyrite for both bioleaching and chemical leaching.The results of synchrotron-based X-ray diffraction,ironL-edge and sulfur K-edge X-ray absorption near edge structure spectroscopy indicated that activated carbon could change thetransition path of electrons through galvanic interactions to form more readily dissolved secondary mineral chalcocite at a low redoxpotential(?400mV)and then enhanced the copper dissolution.Jarosite accumulated immediately in the initial stage of bioleachingwith activated carbon but copper dissolution was not hindered.However,much jarosite precipitated on the surface of chalcopyrite inthe late stage of bioleaching,which might account for the decrease of copper dissolution rate.More elemental sulfur(S0)was alsodetected with additional activated carbon but the mixed thermophilic Archaea culture had a great sulfur oxidation activity,thus S0waseliminated and seemed to have no significant influence on the dissolution of chalcopyrite.

Electrochemical study on semiconductive properties of the passive film on rebar in concrete

The electrochemical behavior of metallic passive film on rebar in concrete is characterized by its semiconductive nature. The charge distribution at the interface between a semiconductor and an electrolyte is often determined by measuring the capacitance of the space-charge layer （Csc） as a function of the electrode potential （E）. When the space charge-layer serves as the depletion layer, the relation of Csc^-2 vs E resembles a Mott-Schottky plot （M-S plot）. The semiconductive properties of the passive film on rebar in concrete were analyzed with M-S plots to study the effect of chloride ions and mineral admixtures on rebar passive films. Some rebar electrodes were immersed in simulated concrete pore solutions, while others were embedded in concrete with/without mineral admixtures. In saturated Ca（OH）, solutions, the relation of Csc^-2-E of rebar electrodes shows linear MottSchottky relationship indicating that the passive film on rebar is a highly disordered n-type semiconductor, with donor density （ND） in the order of 10^26m^-3. After adding chloride ions （Cl wt%〈0.2%） in system solutions, the M-S plot slopes significantly decreased and ND increased, suggesting that chloride ion will cause passive film corrosion and breakdown. The M-S plots of the passive film on rebar electrodes embedded in concrete were similar to those immersed in simulated system solution. However, ND of those in concrete with mineral admixtures tended to be a little smaller, indicating that introducing proper quantity admixtures into concrete could make the rebar passive film have a thicker space-charge layer and therefore a thicker passive film layer.

Formation of passivation film during pyrrhotite bioleached by pure L. ferriphilum and mixed culture of L. ferriphilum and A. caldus

Bioleaching and electrochemical experiments were conducted to evaluate pyrrhotite dissolution in the presence of pure L.ferriphilum and mixed culture of L. ferriphilum and A. caldus. The results indicate that the pyrrhotite oxidation behavior is the preferential dissolution of iron accompanied with the massive formation of sulfur in the presence of L. ferriphilum, which significantly hinders the leaching efficiency. Comparatively, the leaching rate of pyrrhotite distinctly increases by 68% in the mixed culture of L. ferriphilum and A. caldus at the 3rd day. But, the accumulated ferric ions and high p H value produced by bioleaching process can give rise to the rapid formation of jarosite, which is the primary passivation film blocking continuous iron extraction during bioleaching by the mixed culture. The addition of A. caldus during leaching by L. ferriphilum can accelerate the oxidation rate of pyrrhotite, but not change the electrochemical oxidation mechanisms of pyrrhotite. XRD and SEM/EDS analyses as well as electrochemical study confirm the above conclusions.

Surface modification toward luminescent and stable silica-coated quantum dots color filter

A highly pixelated and luminescent silica-coated quantum dot color filter(QDCF)was achieved by surface conjugation with epoxy functional group.Epoxy-functionalized silica-coated quantum dots(QDs)can be thoroughly mixed with SU-8 photoresist up to 25 wt.%without aggregation.The quantum yield(QY)of the silica-coated QDCF can be significantly improved from 19.3%to 36.5%after epoxy treatment.The pristine QDCF experienced a 40%QY decrease,while the epoxied silica-coated QDCF maintained its luminescence even after irradiation(300 mW cm 2@450 nm)for over 25 days.The well-controlled epoxy cap plays a critical role in attaining the ideal optical properties of the QDCF.