法国吕兹那克滑石矿石的处理

1.概况吕兹那克滑石矿在阿里埃日省(法国),位于图卢兹南面约120公里处的比利牛斯—阿里埃日中心,座落在圣—巴泰勒米高地上。矿床海拔1500～1800米。选矿厂在矿床山脚下,位于吕兹那克的阿里埃日山谷,海     

Identification of male-specific chiral compound from the sugarcane weevil Sphenophorus levis

Comparative gas chromatographic analyses of airborne volatiles produced by males and females of the sugarcane weevil Sphenophorus levis, showed one male-specific compound. Gas chromatography–mass spectrometry data indicated an aliphatic alcohol that was identified as 2-methyl-4-octanol. Both optical isomers were synthesized in five steps by employing commercially available (R)- and (S) -2,2-dimethyl-1,3-dioxolane-4-methanol as starting material. Enantiomeric resolution by gas chromatography with a chiral column demonstrated that the natural alcohol possessed the S configuration. Preliminary indoor observations suggested that the alcohol elicited aggregation behavior among adults. The same compound has been previously described as an aggregation pheromone in several other curculionid species.     

Identification of Male-Produced Aggregation Pheromone of the Curculionid Beetle <Emphasis Type="Italic">Sternechus subsignatus</Emphasis>

Analyses of the headspace volatiles produced by males and females of Sternechus subsignatus Boheman (Coleoptera: Curculionidae) revealed seven male-specific compounds. The major component was (E)-2-(3,3-dimethylcyclohexylidene)-ethanol, and the minor components were 1-(2′-hydroxyethyl)-1-methyl-2-isopropenylcyclobutane (grandisol), 7-methyl-3-methyleneoct-6-en-1-ol, (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol, (Z)- and (E)-2-(3,3-dimethylcyclohexylidene)-acetaldehyde, and (E)-2-(3,3-dimethylcyclohexylidene) acetic acid. The latter compound is described for the first time as a natural product. Only four of the seven identified compounds showed electrophysiological activity. Enantioselective gas chromatography showed that the natural grandisol is the (1R,2S)-stereoisomer. The major component, (E)-2-(3,3-dimethylcyclohexylidene)-ethanol, attracted S. subsignatus in olfactometer bioassays. Studies are in progress to evaluate the biological activity of the major component and the EAD-active mixture under field conditions.     

Tuning the dimensionality of ZnO nanowires through thermal treatment: an investigation of growth mechanism

ABSTRACT: In this study we synthesized various dimensionalities of ZnO nanowires using the Ti-grid assisted chemical vapor deposition process. Energy dispersive x-ray spectroscopic mapping technique accompanied with a lattice diffusion model was used to characterize the growth mechanism. A diffusion ratio was obtained to describe the mechanism based on short-circuit- and lattice- diffusion of Zn ions from the Zn base film is then proposed for the growth of ZnO nanowires. The tunable dimensionalities of ZnO nanowires allow us to modify the morphology of ZnO nanocrystals by developing well controlled potential applications.     

Ambulatory assessment of ankle and foot dynamics

Ground reaction force (GRF) measurement is important in the analysis of human body movements. The main drawback of the existing measurement systems is the restriction to a laboratory environment. This paper proposes an ambulatory system for assessing the dynamics of ankle and foot, which integrates the measurement of the GRF with the measurement of human body movement. The GRF and the center of pressure (CoP) are measured using two six-degrees-of-freedom force sensors mounted beneath the shoe. The movement of foot and lower leg is measured using three miniature inertial sensors, two rigidly attached to the shoe and one on the lower leg. The proposed system is validated using a force plate and an optical position measurement system as a reference. The results show good correspondence between both measurement systems, except for the ankle power estimation. The root mean square (RMS) difference of the magnitude of the GRF over 10 evaluated trials was (0.012 +/- 0.001) N/N (mean +/- standard deviation), being (1.1 +/- 0.1)% of the maximal GRF magnitude. It should be noted that the forces, moments, and powers are normalized with respect to body weight. The CoP estimation using both methods shows good correspondence, as indicated by the RMS difference of (5.1 +/- 0.7) mm, corresponding to (1.7 +/- 0.3)% of the length of the shoe. The RMS difference between the magnitudes of the heel position estimates was calculated as (18 +/- 6) mm, being (1.4 +/- 0.5)% of the maximal magnitude. The ankle moment RMS difference was (0.004 +/- 0.001) Nm/N, being (2.3 +/- 0.5)% of the maximal magnitude. Finally, the RMS difference of the estimated power at the ankle was (0.02 +/- 0.005) W/N, being (14 +/- 5)% of the maximal power. This power difference is caused by an inaccurate estimation of the angular velocities using the optical reference measurement system, which is due to considering the foot as a single segment. The ambulatory system considers separate heel and forefoot segments, thus allowing an additional foot moment and power to be estimated. Based on the results of this research, it is concluded that the combination of the instrumented shoe and inertial sensing is a promising tool for the assessment of the dynamics of foot and ankle in an ambulatory setting.