Excellent destabilization effect and ideal desorption temperature in the hydride Mg2FeH6 substituted with yttrium; a first principles study

We investigated some properties of the hydride Mg₂FeH₆ substituted with yttrium by a first principles calculation. Some experimental results showed that 4d transition metal, yttrium serves as a good catalyst for magnesium based hydrogen storage alloys, but there are a few theoretical studies about magnesium based hydrides substituted with it. Mg₂FeH₆ is regarded as a cheaper material than pure MgH₂, while it is crystalized into Fm3m structure (space group 225). Although it has high hydrogen storage capacity, many investigations have not been devoted to it due to its extremely high thermodynamic stability. The yttrium substituted Mg₂FeH₆ exhibits very low energy of formation, and its desorption temperature, 75 °C is very suitable for practical hydrogen storage applications. Our results showed that Mg₂FeH₆ is destabilized effectively by yttrium substitution and introducing vacancy defects has additive effect to the improvement of dehydrogenation performance.     

Application of Vis–NIR hyperspectral imaging in classification between fresh and frozen-thawed pork Longissimus Dorsi muscles

Fresh and frozen-thawed (F-T) pork meats were classified by Vis–NIR hyperspectral imaging. Eight optimal wavelengths (624, 673, 460, 588, 583, 448, 552 and 609 nm) were selected by successive projections algorithm (SPA). The first three principal components (PCs) obtained by principal component analysis (PCA) accounted for over 99.98% of variance. Gray-level-gradient co-occurrence matrix (GLGCM) was applied to extract 45 textural features from the PC images. The correct classification rate (CCR) was employed to evaluate the performance of the partial least squares-discriminate analysis (PLS-DA) models, by using (A) the reflected spectra at full wavelengths and (B) those at the optimal wavelengths, (C) the extracted textures based on the PC images, and (D) the fused variables combining spectra at the optimal wavelengths and textures. The results showed that the best CCR of 97.73% was achieved by applying (D), confirming the high potential of textures for fresh and F-T meat discrimination.     

基于IEEE802.16d的OFDM基带系统实验

根据通信协议IEEE802.16d,通过simulink仿真实现符合协议标准的发射和接收系统,模拟原始数据经过OFDM调制,在AWEG信道中传播,解调后得到的星座图和误码率都达到了良好的效果。该试验平台简单明了的描述了OFDM基带系统,有助于未来进一步的研究,而OFDM作为后3G的核心技术,使得该平台的实验价值不容忽视。     

Dissolved organic carbon dynamics in the upper rhone: The influence of side-arms?

Dissolved organic carbon (DOC) dynamics were investigated over a two year period in the Upper Rhǒne River to examine the role of side-arms in providing DOC to the main channel in relation to discharge fluctuations, especially floods. Concentrations of DOC are shown to remain low in space and in time (average 1.5 mg ^?1) and to be more related to global hydrological events (precipitation) than to any local flushing for backwaters during floods. The results do not support the general assumption that side-arms are the providers of DOC to the main channel.     

Technology transfer projects in developing countries—furthering the Project Management perspectives

This paper attempts to broaden the analysis of the technology transfer phenomenon by refocusing research attention on the level of performance assessment of technology transfer projects. An holistic evaluation framework based on the considerations of an extended Project Life Cycle model is proposed to overcome some of the shortcomings of conventional approaches to project evaluation. This also reinforces the need for open systems thinking in assessing and managing risk of technology transfer projects. The discussion is based on two case studies which articulate the experiences with two integrated mechanisms of technology transfer used in Algeria from 1965 to 1990: turnkey and “product-in-hand”. The aim is to gain a better understanding of the processes of technology transfer and to contribute to the improvement of associated managerial practices in developing economies.     

Silver impregnation applied to striated muscle: The sarcoplasmic reticulum

The classical black reaction developed by Camillo Golgi is shown to impregnate the tubules and fenestrations of the sarcoplasmic reticulum (SR) in striated muscle. This is a double impregnation of chromate and silver, which usually fills extracellular spaces. The method is difficult insofar as long incubation times are required, and location of the successfully “stained” SR in plastic-embedded tissue blocks is unpredictable. The light microscope is absolutely necessary to find the good regions which can then be cut from the blocks in 1-μm-thick sections and examined in the electron microscope. Stereo pairs give the best results since these resolve overlap problems common to thick sections. A variety of artifacts are illustrated which can help avoid erroneous interpretations. The Golgi-“stained” SR shows this elusive network with unsurpassed contrast and should benefit the morphological studies of muscle-membrane enthusiasts.     

两个重组质粒在快生型大豆根瘤菌中的稳定性的比较

将两个复制子相同的重组质粒导入快生型大豆根瘤菌中，考察了得到的转移接合子在培养和共生条件下的稳定性。发现带有质粒ＲＫ２ ｐａｒ基因的重组质粒ｐＴ２ＴＸ３Ｋ在快生型大豆根瘤菌中无论在培养还是共生条件下都可以稳定存在，而不带有该基因的重组质粒ｐＣＫ３在两种条件下都有一定程度的丢失。     

用奇异模型描述的受限机器人的学习控制

本文了一类受限机器人的迭代学习控制方案，控制器的设计是基于机器人模型的降阶形式。在存在有界未知干扰的情况下，对末端操纵器受线性、无摩擦约束面的受限机器人。本文给出的控制方案保证了机器人系统的完全运动跟踪，同时保证了力跟踪误差有界的，且界的大小是可调节的。     

溪洛渡水电站三维施工总布置设计研究

结合溪洛渡水电站工程,基于12dModel软件,利用三维数字化地形图,以及AutoCAD、3DSMAX及Photoshop等软件,实现工程量自动交互计算及三维施工总布置模型制作的设计全过程。给出了具体步骤和溪洛渡水电站的施工总布置图。     

混合集成型光学拾音器的设计与制作

通过混合集成型结构光学拾音器的光学设计和芯片设计，制作了包含微光学棱镜，光电探测器和信号放大电路的混合集成型光学拾音器。经过测试，发现有较好的信号输出特性，表明混合集成型光学拾音器已基本研制成功。