ALBERT

Description: To substitute for petroleum, Fischer-Tropsch synthesis (FTS) is an environmentally benign process to produce synthetic diesel (n-paraffin) from syngas. Industrially, the synthetic gasoline (iso-paraffin) can be produced with a FTS process followed by isomerization and hydrocracking processes over solid-acid catalysts. Herein, we demonstrate a cobalt nano-catalyst synthesized by physical-sputtering method that the metallic cobalt nano-particles homogeneously disperse on the H-ZSM5 zeolite support with weak Metal-Support Interactions (MSI). This catalyst performed the high gasoline-range iso-paraffin productivity through the combined FTS, isomerization and hydrocracking reactions. The weak MSI results in the easy reducibility of the cobalt nano-particles; the high cobalt dispersion accelerates n-paraffin diffusion to the neighboring acidic sites on the H-ZSM5 support for isomerization and hydrocracking. Both factors guarantee its high CO conversion and iso-paraffin selectivity. This physical-sputtering technique to synthesize the supported metallic nano-catalyst is a promising way to solve the critical problems caused by strong MSI for various processes. Scientific Reports 3 doi: 10.1038/srep02813

Description: Organic Letters DOI: 10.1021/ol400213f

Description: Aiming at strong coupling and nonlinear dynamic equations for a space-based observation satellite, a sliding mode controller with feed-forward compensation is proposed in this paper. The theorem of moment of momentum is applied to formulate the exact nonlinear dynamic equations of a multibody satellite. On this basis, sliding-mode control-based, dual-loop forward-feed compensation control is used to control the attitude of the space-based observation microsatellite. By comparing with the conventional control method, simulation results demonstrate that the proposed control method has superior performance in terms of suppression from external disturbances and vibration. Better dynamic and static performance indices than the conventional control method are achieved.

Description: The Extraordinary Magnetoresistance (EMR) effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal. The underlying principle of this phenomenon is a change of the current path in the hybrid structure upon application of a magnetic field, due to the Lorentz force. Specifically, the ratio of current, flowing through the highly conducting metal and the poorly conducting semiconductor, changes. The main factors for the device’s performance are: the device geometry, the conductivity of the metal and semiconductor, and the mobility of carriers in the semiconductor. Since the discovery of the EMR effect, much effort has been devoted to utilize its promising potential. In this review, a comprehensive overview of the research on the EMR effect and EMR devices is provided. Different geometries of EMR devices are compared with respect to MR ratio and output sensitivity, and the criteria of material selection for high-performance devices are discussed.

Description: Anticholinesterase pesticides have been widely used in agricultural and domestic settings and can be detected in the environment after long-term use. Although the acute toxic effects of chlorpyrifos and carbaryl have been well described, little is known about the chronic toxicity of the pesticides mixture. To investigate their chronic neurotoxicity, Wistar rats were exposed to chlorpyrifos, carbaryl, and their mixture (MIX) for 90 consecutive days. The activities of serum cholinesterase (ChE) as well as acetylcholinesterase (AChE) and neuropathy target esterase (NTE) in nerve tissues were determined. Furthermore, the histopathological examination was carried out. The results showed that ChE activity significantly decreased in all treated rats except the rats treated with low dose carbaryl. Treatment with middle- and high-dose chlorpyrifos and MIX in rats significantly inhibited AChE activity in the central nervous tissues, whereas treatment with carbaryl alone did not. In sciatic nerve, AChE activity was significantly inhibited by high-dose carbaryl and MIX, but not by chlorpyrifos alone. No significant NTE inhibition was observed in all treatment groups. Histopathological examination revealed that both chlorpyrifos and MIX treatment induced hippocampal damage. However, no obvious hippocampal damage was found in carbaryl-treated rats. Carbaryl and MIX, but not chlorpyrifos alone, induced pathological damage of sciatic nerve. Taken together, all of the results indicated that chlorpyrifos and carbaryl have different toxicological target tissues in nervous system and showed corresponding effects in the nervous tissues, which may reflect the different sensitivity of central and peripheral nervous tissues to different pesticides individually and in combination. © 2013 Wiley Periodicals, Inc. Environ Toxicol 2013.

Description: Tracking moving targets in complex scenes using an active video camera is a challenging task. Tracking accuracy and efficiency are two key yet generally incompatible aspects of a Target Tracking System (TTS). A compromise scheme will be studied in this paper. A fast mean-shift-based Target Tracking scheme is designed and realized, which is robust to partial occlusion and changes in object appearance. The physical simulation shows that the image signal processing speed is 〉 50 frame/s.

Description: The new secoiridoid sulfonates 1 – 3 were isolated from the 50% EtOH/H 2 O extract of the sulfiting-processed Lonicera japonica Flos ( LJF ) by semi-prep. HPLC, and their structures were identified on the basis of mass spectrometry and NMR spectroscopy. HPLC and LC-DAD-MS/MS analyses of the different samples of LJF obtained by various process techniques suggested that the sulfur fumigation led to the decrease of secologanic acid ( 4 ) and the formation of secologanic acid-derived sulfonate 1 and its derivatives 2, 2a , and 3 in the crude materials, which revealed that sulfur fumigation, the traditional process technique, could alter the phytochemical profiles of some Chinese herbal medicines.

Description: Organic Letters DOI: 10.1021/ol3006437

Description: We use a conditional averaging approach to estimate the parameters of a land surface water and energy balance model and then use the estimated parameters to partition net radiation into latent, sensible, and ground heat fluxes and precipitation into evapotranspiration and drainage plus runoff. Through conditional averaging of the modeled fluxes with respect to soil moisture and temperature, we write an objective function that approximates the temperature- and moisture-dependent errors of the modeled fluxes in terms of atmospheric forcing (e.g., precipitation and radiation), surface states (moisture (S) and temperature (Ts)), and model parameters. The novelty of the approach is that the error term is estimated without comparison to measured fluxes. Instead, it is inferred from the deviation of the conditionally averaged tendency terms (expectation $E\left[ {\left. {{{{\rm{d}}S} \mathord{\left/ {\vphantom {{{\rm{d}}S } {{\rm{d}}t}}} \right. \kern-\nulldelimiterspace} {{\rm{d}}t}}} \right|_s } \right]$ and expectation $E\big[ {\left. {{{{\rm{d}}T_s } \mathord{\left/ {\vphantom {{{\rm{d}}T_s } {{\rm{d}}t}}} \right. \kern-\nulldelimiterspace} {{\rm{d}}t}}} \right|_{T_s } } \big]$) from zero since each of these terms equals zero in stationary systems but diverges from zero in the presence of misspecified parameters. Minimization of the approximated error yields parameters for model applications. This strategy was previously studied for simple water balance models using soil moisture conditional averaging. Here we extend the idea to include energy balance fluxes and surface temperature conditioning. The method is tested at two AmeriFlux sites, Vaira Ranch (California) and Kendall Grassland (Arizona). The estimated fluxes (using only observed forcing and state variables) are in reasonable agreement with field measurements. Because this method is based on conditional averages, it can be applied to situations with subsampled or missing data; that is, continuous integration in time is not required.

Description: Author(s): Jian Sun, Dennis D. Klug, Chris J. Pickard, and Richard J. Needs We use a combination of a searching method and first-principles electronic structure calculations to predict novel structures of carbon monoxide (CO) which are energetically more stable than the known structures. The most stable forms of CO at zero pressure consist of metallic polycarbonyl chains wi... [Phys. Rev. Lett. 106, 145502] Published Fri Apr 08, 2011