广东省智能网工程建设

本文介绍了广东省智能网的组网方案及所能提供的业务,并论述了智能网工程建设,安装维护以及与广东省现有移动通信网联网中存在的一些问题。     

Magnetocaloric properties of DyCo2−xGax alloys

The influence of the substitution of Ga atoms for Co atoms in DyCo₂ compounds on magnetocaloric properties has been investigated. A series of DyCo_2−xGa_x alloys with x=0, 0.03, 0.06, 0.1, 0.15, and 0.2 was prepared by the arc-melting method for this investigation. Experimental results revealed that the Ga substitution for Co in DyCo₂ can form a single phase with the cubic Laves phase structure up to x=0.2. As the Ga content x increases, the lattice parameter and the Curie temperature T_c increases from 143 to 196 K linearly. The maximum magnetic entropy changes in a low field change of 0-1.5 T, increasing from 8.24 to 10.61 J/K kg when the Ga content x increases from 0 to 0.03, but decreasing gradually to 3.51 J/K kg as the Ga content further increases to x=0.2. All the samples show a relatively large magnetic entropy change with very small hysteresis loss.     

RE2Ti2O7(RE=Gd,Y,Ho,Er)的结构、机械性能及热学性质的第一性原理研究(英文)

本文利用第一性原理和准谐近似的方法研究了一系列钛酸盐烧绿石,即RE₂Ti₂O₇（RE=Gd,Y,Ho,Er）的结构、机械性能及热学性质。研究结果表明,在基态下RE₂Ti₂O₇具有良好的抗压、抗剪切能力。并且,由于这些化合物的齐纳指数接近于1,可近似地看作各向同性材料。此外,计算得到的热膨胀系数在高温区与实验值符合得较好。在500~1 500 K温度区间内,平均热膨胀系数为（10.4~13.1）×10-6 K-1。基于Slack模型,我们还计算了这些材料的晶格热导率,当温度等于1 000 K时,这四种物质的热导率在区间（1.5~4.9）W·m-1·K-1内。     

Nd-Fe-B/FeCo多层纳米复合膜的结构和磁性

制备了Nd₂₈Fe₆₆B₆/Fe₅₀Co₅₀多层纳米复合磁性薄膜，对溅射态和650℃退火处理15 min试样的相成分分析和微结构的观察显示，溅射态薄膜呈非晶态，经650℃退火处理15 min后，薄膜主要相成分为硬磁性Nd₂Fe₁₄B相和软磁性相FeCo(110)相.Nd₂Fe₁₄B相呈柱状，其易磁化c轴垂直于膜面，尺寸约10 nm.在硬磁性相和软磁性相之间存在少量富Nd相和非晶态，富Nd相大小约7 nm.磁性测量和分析表明，1)该系列薄膜退火态具有垂直于膜面的磁晶各向异性.2)对于固定厚度(10 nm)层Nd-Fe-B和不同厚度(t_FeCo=1—100 nm)层FeCo多层纳米复合膜,剩磁随软磁相FeCo 厚度的增加快速增加，而矫顽力则减小.当t_FeCo=5 nm时，最大磁能积达到200 kJ/m³. 3)硬磁相Nd-Fe-B层和软磁相FeCo层之间交换耦合导致剩磁和磁能积增强. 关键词： Nd-Fe-B/FeCo多层纳米复合膜 交换耦合 磁各向异性     

Synthesis,structure characterization,and gas sensitive properties of a copolymer of aniline with phenol

A new kind of conductive copolymers of aniline with phenol was designed and synthesized by using oxidation polymerization and the results showed that the apparent inherent conductivities of the copolymers are in the range of 10^?2 to 10^?10 S/cm which covers from conductors to insulators. The results showed that the conductivity of the copolymers strongly depends on synthesis conditions, such as reaction time, molar ratios of oxidizer to monomers and aniline to phenol, concentrations of reactants, and reaction temperature. Compared to the conventional (co)polymers of aniline and its derivatives, the magnitudes of the reversible conductivity changes are very significant, about two orders, and get to the maximum readings in about 5 min when they are exposed to ammonia gas, hydrochloric acid gas, and a various vapors of organic compounds, such as methanol, alcohol, acetone, benzene, toluene, chloroform, carbon tetrachloride, etc. It should be noted that with the introduction of the weak acidic structural units into the polyaniline chains, the copolymers are reversibly responded to both acidic and basic gases promptly. Copyright © 2009 John Wiley & Sons, Ltd.     

Surface characterization of 7S and 11S globulin powders from soy protein examined by X-ray photoelectron spectroscopy and scanning electron microscopy

In this study the surface composition of 7S and 11S globulin powders from soybean proteins by aqueous buffer and reverse micelle extractions had been examined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Analysis by XPS revealed that the O and N atomic percentage of 7S and 11S globulin surfaces from bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelle was higher than from aqueous buffer, but the C atomic percentage was lower. The O/C ratio of the 7S globulin powder from aqueous buffer and reverse micelle was similar while significant differences were obtained in the O/C ratio of the 11S globulin powder, N/C atom ratios of the 7S and 11S globulin powders and high-resolution XPS C 1s, N 1s, O 1s spectra. Powder microstructure after reverse micelle treatment showed the presence of small pores, indicating the effect of reverse micelle on the 7S and 11S globulin structure. The obtained results indicated that the reverse micelle could affect the C, O and N components on the surface of soybean proteins.     

Optimization of a Multiplex PCR Assay for Detecting Transgenic Soybean Components in Feed Products

A multiplex polymerase chain reaction (m-PCR) assay was developed for the simultaneous detection of multiple components of genetically modified (GM) soybean. It uses two sets of primers (I, lectin1/35S/CP4; II, lectin2/35S/CP4) specific for a soybean reference gene, the 35S promoter, and an event-specific gene. Amplified fragments of 118, 414, 195, and 320 bp were easily detected by agarose gel electrophoresis and were positively confirmed by sequencing. Primer set concentrations and annealing temperatures in the m-PCR were optimized. The optimized m-PCR conditions were obtained for primer set I at a ratio of 1:2:3 and a 59.2 °C annealing temperature and set II at the same ratio and 58.6 °C, 60.3 °C, and 61.2 °C annealing temperatures. The sensitivities of the two m-PCR primer sets (I and II) were 0.25% and 0.5%, respectively. The results showed that this m-PCR assay provides rapid, reliable, and effective identification of multiple components of GM soybean in feed.     

Expeditious one-pot synthesis of C3-piperazinyl-substituted quinolines: key precursors to potent c-Met inhibitors

An effective one-pot synthesis of quinolines bearing diverse C3-piperazinyl functions was developed by using a modified Friedl?nder's protocol. The method not only enables the synthesis of our early reported c-Met inhibitor on a large scale, but also provides a way to generate novel multi-substituted quinolines for further structure-activity relationship (SAR) study.     

Synthesis and characterization of Li1.05Co1/3Ni1/3Mn1/3O1.95X0.05 (X = Cl,Br) cathode materials for lithium-ion battery

In order to improve the thermal stability and dynamic performance of LiCo_1/3Ni_1/3Mn_1/3O₂ materials, Cl-doped and Br-doped materials were synthesized via the co-precipitation method. The morphology, structure, electrochemical performance and thermal stability were characterized by environment scanning electron microscopy (ESEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), charge–discharge cycling and differential scanning calorimetry (DSC). Results show that all materials had a stable layered structure with α-NaFeO₂ and that Cl-doping slightly increased the size of grains. Both Cl-doping and Br-doping improved the high rate of discharge capacity, cycle-life performance and thermal stability, but Cl-doping was better than Br-doping in improving the material structure stability, dynamic performance and thermal stability.     

若丹明类荧光探针的合成与应用研究进展

本文综述了近年来若丹明类荧光染料的研究状况.首先,介绍了若丹明衍生物的结构特征,然后以其修饰位置为线索,详细地介绍了该类化合物的合成,总结了其修饰策略及结构与功能之间的联系,强调了它们在环境分析和生物标记领域的应用.以供读者了解若丹明荧光探针的合成及其在蛋白质、DNA等生物标记领域和金属离子检测领域的应用时参考.