Microwave Sintering and Optical Properties of Sm3+-Activated KSrPO4 Phosphors

The microwave sintering and photoluminescence properties of KSr_1?x PO₄:xSm³⁺ phosphors have been investigated. KSrPO₄ phosphates activated by various concentrations of Sm³⁺ ions (x = 0.007, 0.009, 0.01, 0.03) were microwave sintered at 1200°C for 3 h under air atmosphere. x-Ray diffraction patterns showed that all phosphor samples exhibited a single phase without any extraneous phases. Scanning electron microscopy images showed that the particle size increased with the Sm³⁺ concentration and that the particle morphology was fine and uniform. The photoluminescence results showed that a concentration quenching effect occurred when the concentration of Sm³⁺ ions reached x = 0.01. Decay time measurement results showed that the lifetime decreased gradually from 3.12 ms to 2.34 ms as the Sm³⁺ concentration increased. All the chromaticity (x, y) values of the microwave-sintered KSrPO₄:Sm³⁺ phosphors were located in the red region (0.57, 0.41).     

冻结肉类食品远红外辐射加热解冻的可行性研究

低温冻藏食品在利用之前必须经过解冻。解冻方法和装置的研究是食品冻藏技术的难题，各国都在不断地研究开发。本文介绍了肉类食品解冻的要求，进行了红外辐射加热解冻的模拟实验后，初步得出单独应用远红外辐射加热技术解冻实用价值不大的结论，指出一般红外烤箱不宜用作冻结食品的解冻。     

A Gauss-Newton-like optimization algorithm for“weighted” nonlinear least-squares problems

The Gauss-Newton algorithm is often used to minimize a nonlinear least-squares loss function instead of the original Newton-Raphson algorithm. The main reason is the fact that only first-order derivatives are needed to construct the Jacobian matrix. Some applications as, for instance multivariable system identification, give rise to “weighted” nonlinear least-squares problems for which it can become quite hard to obtain an analytical expression of the Jacobian matrix. To overcome that struggle, a pseudo-Jacobian matrix is introduced, which leaves the stationary points untouched and can be calculated analytically. Moreover, by slightly changing the pseudo-Jacobian matrix, a better approximation of the Hessian can be obtained resulting in faster convergence     

Detection of Carbon Dioxide in Air Using Difference-Frequency Generation Based Infrared Spectrometer

Spectroscopic detection of carbon dioxide (CO₂) in ambient air was performed using a continuous-wave mid-infrared spectrometer based on difference-frequency generation in an AgGaS₂ crystal. Significant improvement in nonlinear optical frequency conversion efficiency was achieved by Gaussian beam optical design consideration. CO₂ concentration was determined from direct-absorption spectral measurement.     

Multihour engineering and traffic routing optimization in hierarchical telephone networks

Classical hierarchical routing in telephone networks is extended to a wider class called out-of-chain routing in such a way that some useful properties of hierarchical routing are retained. This new routing pattern offers more potential paths than the fixed hierarchical one and can be introduced as a dynamic routing where the fixed alternate sequences change at some predetermined instants during the day. The effect of this new routing pattern on the network performances is examined. The main topic of this paper is to present heuristic methods used to optimise such routings in large networks. We show on artificial networks that the throughput of a given network can be significantly improved by suitable routing choices. We demonstrate that the integration of routing changes within a multihour dimensioning process is possible but the lack of realistic data does not permit at this time to quantify the value of routing optimization on real networks.     

14C labelling of lignins of normal and bm3 maizes for fermentation studies

[U-¹⁴C] phenylalanine (phe*) and [O¹⁴CH₃] sinapic acid (sin*) were infused into the cut ends of normal and bm3 maizes (anthesis stage) under or above the last node or at mid-internode, with or without the leaf, in light or in darkness. Radioactivity was measured in the organs, and in phenolic constituents of the cell wall and saponified residues of the bases and tops of the apical inter-node. In both maize genotype labelled under the node the radioactivity was distributed more evenly in the organs with sin* than with phe*. Infusion above the node and at mid-internode greatly increased radioactivity in the bases and tops, respectively. Removal of the leaf only slightly increased the radioactivity, mainly in the bases, and no clear-cut effect of darkness was observed. Phe* labelled the phenolic acids and the three lignin units, but the syringyl units of bm3 maize were only slightly labelled. Sin* specifically labelled the syringyl units, which represented the least condensed fraction of lignins. Both the native and labelled lignins were highly alkali soluble. There were differences in lignin biogenesis between the bases and tops, and between normal and bm3 maizes. The newly formed lignins were slightly different from the native lignins but had similar types of heterogeneity, with variations in the internode and between genotypes similar to those in native lignins. Provided due allowance is made for the distinguishing characteristics of newly formed lignins, the [¹⁴C-lignin] cell walls, which are strongly labelled on complementary structures, seem suitable model substrates for fermentation studies.     

An integrated on chip organic optical source based on electrochemiluminescence

We report here on an original “glass-PDMS-glass” electrochemiluminescence optofluidic device that integrates 32 electrodes on a large surface. This organic electrically powered light source has been integrated on chip using an alternative process based on a photopatternable silicone resist. Under a continuous flow rate, this device allows electrogenerated chemiluminescence for several minutes which would be very useful for future μTAS systems.     

Détermination des perturbations induites aux extrémités d’une ligne blindée soumise à une excitation ponctuelle de courant

This article allows the determination of the induced perturbations at the ends of the coaxial line in wide frequency band enough. The perturbation source is a current direct point injection into the cable screen in any position. For this, we have applied the theory of the state variables, with foundation of the quasi-TEM approximation, in order to simulate the coaxial line above a ground level that has a finished conductivity. This allows us to supply the current and voltage expressions at the ends of the line as their analytic forms for any conditions of charge. Next, the elaborate objective is to verify experimentally on concrete applications if the test obtained results confirm the theoretical expectations supplied by calculation code finalizing.