用次级束流对硅望远镜的时间和能量定标

利用95MeV/u的^(16)O束产生的次级束流对半导体硅探测器进行了时间和能量定标。实验结果表明,由于次级束流提供的次级粒子种类多,飞行距离长,因此,能给探测器带来非常精确的定标。

Study of the Biochemical Composition of Senegalese Mango Varieties Intended for Export and Local Consumation

Biochemical characterization was carried out on five mango varieties grown in Senegal, two of which are intended for export (Kent and Keitt) and three to local consumption, on the one hand, and to national marketing, on the other. It can be seen that the flavanols composition is between “0.74 ± 0.03 mg/100 g” to “4.70 ± 0.33 mg/100 g” and the total polyphenols composition is “265.83 ± 33.70 mg gallic acid/100 g” to “834.29 ± 25.78 mg gallic acid/100 g”. This analysis shows that the variety Bk is richer in polyphenols followed by the variety Dr then Knt and finally the lowest proportions are noted with the varieties Kt and SL. The analysis of antioxidant activity shows us percentages ranging from “4.16% ± 2.68% inhibition” to “50.21% ± 3.91% inhibition”. It was noted that the SL and Knt varieties give the highest inhibition percentages of “50.21 ± 3.91” and “33.97 ± 0.36” respectively. Variety Bk gives the lowest percentage followed by variety Kt. The Dr variety is the richest in flavonoids “11.75 ± 0.27” followed by the SL variety “11.27 ± 0.10” and the lowest composition is noted in the Knt variety “1.91 ± 0.04”. For total sugars, the most important contents are found in the varieties: Bk “12.71 ± 0.32 mg/100 g” followed by Dr “11.5 ± 0.33 mg/100 g” and SL “9.86 ± 0.06 mg/100 g”. This time the variety Kt stands out with also important proportions. For quantification, there is a slight difference in the values obtained for the different varieties studied. However, the highest values are observed in local varieties: “0.36 ± 0.06 g/100 g” for Bk and Dr followed by SL “0.31 ± 0.01 g/100 g”. The study of the mineral composition shows that the local varieties are the richest and the Knt variety is the poorest. The difference in composition noted within the same variety can be explained by the fact that some varieties have an advanced maturity compared to others.

Study of the Variation in Total and Reducing Sugars Contents According to the Variety and According to the Position Where the Fruit (Mango) Was Harvested from Five Mango Varieties Exploited in Senegal

In this study, the results show that total sugar contents depend on the variety and the position where the fruit (mango) has been harvested. This variation in total sugar contents is observed according to the following varieties: the Bk (Boukodiekhal) variety (bottom position 45 mg/100 mL) then Bk (intermediate and bottom position 40 mg/100 mL) and with the Dr (Diourou) variety the content according to the intermediate position is 63 mg/100 mL while the content according to its bottom position is 56 mg/100 mL. The same is observed for variety Knt (Kent). For the variety factor, we see that the Dr and Sl (Sierra Leone) varieties are the richest in total sugars. Compared to the variation in reducing sugar content, the effect of position is less pronounced. Nevertheless, the statistical results show that the contents vary according to the varieties. There is a very significant variation in reducing sugar content between certain varieties. The variety Kt (Keitt) (45 mg/100 mL) is the richest in reducing sugars but compared to the lower position of the variety Bk, they are statistically identical. Variety Knt remains the poorest in reducing sugars 20 mg/ 100 mL.

Reaction Plane Determination for ^(64)Zn+^(27)Al Collisions at Intermediate Energy

The collective flow for 64Zn+27Al system is measured at intermediate energyby using a 4π multidetector array in conjunction with an array of Si telescopes.Theevents have been sorted versus the impact parameter by means of global variables.Three methods of reaction plane determination are compared:sphericity tensor method,transverse momentum analysis,and azimuthal correlation method.For this system,thetransverse momentum analysis method is the best one.

Metallic nanostructures for efficient LED lighting

Light-emitting diodes(LEDs)are driving a shift toward energy-efficient illumination.Nonetheless,modifying the emission intensities,colors and directionalities of LEDs in specific ways remains a challenge often tackled by incorporating secondary optical components.Metallic nanostructures supporting plasmonic resonances are an interesting alternative to this approach due to their strong light–matter interaction,which facilitates control over light emission without requiring external secondary optical components.This review discusses new methods that enhance the efficiencies of LEDs using nanostructured metals.This is an emerging field that incorporates physics,materials science,device technology and industry.First,we provide a general overview of state-of-the-art LED lighting,discussing the main characteristics required of both quantum wells and color converters to efficiently generate white light.Then,we discuss the main challenges in this field as well as the potential of metallic nanostructures to circumvent them.We review several of the most relevant demonstrations of LEDs in combination with metallic nanostructures,which have resulted in light-emitting devices with improved performance.We also highlight a few recent studies in applied plasmonics that,although exploratory and eminently fundamental,may lead to new solutions in illumination.

Recent advances in development of vertical-cavity based short pulse source at 1.55 μm

This paper reviews and discusses recent developments in passively mode-locked vertical external cavity surface emitting lasers （ML-VECSELs） for short pulse generation at 1.55 gin. After comparing ML- VECSELs to other options for short pulse generation, we reviewed the results of ML-VECSELs operating at telecommunication wavelength and point out the chal- lenges in achieving sub-picosecond operation from a ML- VECSEL at 1.55 gm. We described our recent work in the VECSELs and semiconductor saturable absorber mirrors （SESAMs）, their structure design, optimization and characterization, with the goal of moving the pulse width from picosecond to sub-picosecond.