The sources of sodium escaping from Io revealed by spectral high definition imaging

On Jupiter's moon Io, volcanic plumes and evaporating lava flows provide hot gases to form an atmosphere that is subsequently ionized. Some of Io's plasma is captured by the planet's strong magnetic field to form a co-rotating torus at Io's distance; the remaining ions and electrons form Io's ionosphere. The torus and ionosphere are also depleted by three time-variable processes that produce a banana-shaped cloud orbiting with Io, a giant nebula extending out to about 500 Jupiter radii, and a jet close to Io. No spatial constraints exist for the sources of the first two; they have been inferred only from modelling the patterns seen in the trace gas sodium observed far from Io. Here we report observations that reveal a spatially confined stream that ejects sodium only from the wake of the Io-torus interaction, together with a visually distinct, spherically symmetrical outflow region arising from atmospheric sputtering. The spatial extent of the ionospheric wake that feeds the stream is more than twice that observed by the Galileo spacecraft and modelled successfully. This implies considerable variability, and therefore the need for additional modelling of volcanically-driven, episodic states of the great jovian nebula.     

基于结构状态方程的结构参数和荷载识别方法

基于结构状态方程进行结构参数和荷载的共同识别。以结构参数修正因子为优化变量,由测得的结构动态响应结构和构造的系统矩阵计算相应的未知荷载。通过最小化实测结构响应与给定的修正因子下的计算结构响应间的距离来识别未知量。其中给定修正因子的系统矩阵由虚拟变形方法构造,并通过一个桁架结构的数值算例验证了该方法的有效性。     

不锈钢冶炼粉尘中锌还原的研究

直接还原回收有价金属处理不锈钢冶炼粉尘过程中,锌在冶炼系统中不断循环积聚,可从收尘系统中分离出高含锌粉尘,然后采用CO在等离子炉中选择性还原回收锌.作者研究了反应温度、粉尘给料速度、粉尘给料量与还原剂CO量比等对锌还原挥发率的影响,建立了还原过程的数学模型.研究结果表明还原温度对粉尘中锌的还原影响很大,升高温度有利于锌的还原,但当温度超过1 228.2 ℃时,进一步升高温度不会明显提高锌的还原率,高的锌还原率的获得还应通过降低给料速度和控制给料比来实现;在1 400 ℃,给料速度为50 g/min,给料比为4.5∶1时,锌还原率可达99.98%;ZnFe2O4在高温下可分解,在还原过程进行前将粉尘中ZnFe2O4分解可显著提高锌的还原挥发率.     

Alcaloïde des Canneberges du Nouveau-Brunswick

Summary A new alkaloid C₂₀H₂₂O₂N₂ (cannagunine) obtained from canadian Vaccinium Oxycoccus is shown to have structure 1. The structure of this compound was supported by NMR-, SM-, IR- and UV-spectra.     

Alkaloids of Cranberries

Résumé Une étude à l'aide de spectroscopie de masse et de spectroscopie r.m.n., ainsi que de dégradations, a permi l'identification de la structure de quelques bases isolées de feuilles de canneberges et leur classification parmi les alkaloids de la famille indolique.     

Fruit bats as reservoirs of Ebola virus

The first recorded human outbreak of Ebola virus was in 1976, but the wild reservoir of this virus is still unknown. Here we test for Ebola in more than a thousand small vertebrates that were collected during Ebola outbreaks in humans and great apes between 2001 and 2003 in Gabon and the Republic of the Congo. We find evidence of asymptomatic infection by Ebola virus in three species of fruit bat, indicating that these animals may be acting as a reservoir for this deadly virus.     

Alkaloids of cranberries V

Resumé La séparation de trois nouveaux alcaloïdes de canneberges — cannivonines1, 2 et3—a été effectuée à l'aide de solvants appropriés et de la chromatographie sur couche mince préparative. Une identification des structures des trois alcaloïdes est proposée.