RFID技术原理及其射频天线设计

首先简要介绍RFID技术的基本工作原理,说明射频天线是RFID系统设计的技术关键,然后介绍了几种基本的RFID射频天线及其工作原理,并针对普遍使用的偶极子天线在RFID系统中方向性上的不足提出改进,最后,给出一个具有全向收发功能的RFID天线设计.通过设计仿真工具模拟仿真,并进行实际样品测试,获得较满意的设计结果.     

Research on the magnetic material of Sm-Fe matrix nitrides

In this paper, the types of Sm-Fe matrix compounds and their correlations are introduced, and progress of research on the magnetic materials of Sm-Fe matrix nitrides is also reviewed. Possible research trends of future permanent magnetic materials of SmFe matrix nitrides are briefly predicted.     

Composition of sandstone and heavy minerals implies the provenance of Kuqa Depression in Jurassic, Tarim basin, China

The petrological characteristics and heavy mineral assembly of the Jurassic System in Kuqa Basin are consistent with the tectonic evolution, which is the major factor controlling the filling process of Kuqa Basin. Controlled by the source areas at the both sides of the Basin, the matrixes are dominated by sedimentary rock, high-grade metamorphic rock, acid magmatic rock, and the highest heavy mineral assemblage of zircon-garnet-magnetite in the content. According to heavy mineral indexes, the Jurassic strata can be classified into three rhythmic units of heavy mineral. The lower sequence contains abundant heavy minerals and relatively high content of detritus and its matrixes primarily came form the recycling orogen. The assemblage of “zircon-garnet-magnetite” indicates that the sedimentary area in the early evolution period of the basin is relatively near the provenance. The middle sequence is different from the lower sequence in the heavy mineral assemblage and has the different characteristics from that of source rock. The heavy mineral assemblage is “garnet-zircon” with the highest content of garnet and its main matrices are the high-grade metamorphic rock, acid magmatic rock and hydrothermal vein at the northeastern edge of the basin. The middle and upper sequences are characterized by the clast provenance, which is primarily from the recycling orogen at the northern edge of the basin and secondarily from the southern uplift. As a result of the two provenances, the strata with apparent changes of heavy mineral assemblage and index better coincides with the interfaces of the secondary strata sequences, which reflects the denudation history and the filling process of the orogen at the northern edge of the basin.     

新型氮支套索冠醚的合成及络合阳离子的电导特征

以苯氧乙醇为起始剂合成了两种新型氮支套索冠醚：N-苯氧乙基单氮杂-18-冠-6（18CE）与N-苯氧乙基单氮杂-15-冠-5（15CE），通过红外光谱、核磁共振氢谱、紫外光谱和元素分析表征了新冠醚及其中间体的结构，测试了18CE与15CE络合阳离子对溶液电导率的影响。     

氨氮对厌氧颗粒污泥产甲烷活性的影响

利用取自ABR反应器中的厌氧颗粒污泥,通过间歇试验,研究了不同浓度氨氮对厌氧污泥产甲烷活性的影响以及活性恢复情况。实验结果表明:氨氮对厌氧颗粒污泥产甲烷活性的影响具有多重性,当氨氮浓度分别为0.2 g/L和0.4 g/L时,表现为促进产甲烷作用,二者的产甲烷能力分别比参考体系提高5%和10%;当氨氮浓度为0.8 g/L时,开始表现为抑制产甲烷作用,抑制程度为7%;并且随着氨氮浓度提高到2 g/L、3 g/L、4 g/L,厌氧颗粒污泥的产甲烷活性分别下降20%、28%、45%。此外,研究表明,氨氮影响产甲烷活性的浓度范围与具体的操作条件,如温度、pH值、碱度及污泥浓度等因素有关。     

基于信息博弈的多源信息融合方法

针对多传感器信息融合系统中的信息冲突,结合博弈论的原理,在考虑信息冲突环境下局中人最优策略和最优支付的情况下,提出了求解信息冲突环境的信息博弈融合方法.首先通过信息熵的形式将多信息器表示成多源信息,并将多源信息的信息冲突过程抽象成为信息博弈过程,多传感器系统通过信息博弈的过程实现整个系统的信息收益最大化.通过对空调机调速器运行工况评价的实验分析,证实该方法在保持调节性能的同时,能从冗余的多源信息角度对系统的被控参数做出调整,各种动态品质特性优于传统的方法.     

Synthesis of TiO2 nanotubes film and its light scattering property

TiO2 nanotubes with diameters of 10 nm and lengths up to 600 nm were fabricated by directly using commercial TiO2 powders P25 as the precursors via sonication-hydrothermal combination approach. TiO2 nanotubes were characterized by means of X-ray powder diffractometer （XRD）, scanning electron microscope （SEM）, selected area electron diffraction pattern （SAED） and transmission elec- tron microscope （TEM）. The light scattering property of film electrodes modified with TiO2 nanotubes was studied and revealed that TiO2 nanotubes can be used as the light scattering centers to increase the light absorption in dye-sensitized solar cells. The TiO2 nanotubes film electrodes mixed with 10% small nanoparticles TiO2 had both strong light scattering property and fine mechanical characteristics, and this kind of electrodes can be used as electrodes in improving the conversion efficiencies of dye-sensitized solar cells.     

Tin Oxide and Carbon Composite （Sn6O4（OH）4/AG） as the Anode in a Lithium Ion Battery

A tin oxide and carbon composite （Sn6O4（OH）4/AG） with a Sn content of 0.15-0.30 was prepared by chemical deposition at normal pressures and temperatures. The structures of the artificial graphite （AG）, the Sn6O4（OH）4, and the Sn6O4（OH）4JAG were analyzed using X-ray diffraction. The electrochemical lithiation was investigated by measuring the galvanostatic charge and discharge ratio. The electrochemical capacities of the three materials during the first discharge were 310 mAh/g （AG）, 616 mAh/g （Sn6O4（OH）4/AG）, and 1090 mAh/g （Sn6O4（oa）4）. The discharge capacity of the Sn6O4（OH）4/AG was larger than the simple sum of the capacities provided by AG and Sn6O4（OH）4 with the same content. The cyclic performance of Sn6O4（OH）4/AG was also better than that of Sn6O4（OH）4 for voltages of 0 to 3 V. The results imply that the interaction between Sn and C in Sn6O4（OH）4/AG is very strong and effectively inhibits the volume expansion of the Sn.     

Study on molecular interaction between NifA and NifL of Pseudomonas stutzeri A1501 by using the yeast two-hybrid system

Pseudomonas stutzeri AI501 (formerly Alcaligenes faecalis A1501), which was isolated from rice paddies in South China in 1980, can colonize tightly on rhizoplane of the host plants or invade the roots of plants for growth and nitrogen fixation. But A1501 can fix nitrogen only under the micro-aerobic and nitrogen-free conditions. The oxygen concentration and the availability of fixed nitrogen are therefore important factors in the regulation of nitrogenase biosynthesis of associative nitrogen-fixing bacteria.     

Functional identification of gene cluster for the aniline metabolic pathway mediated by transposable element

A convenient and widely applicable method has been developed to clone aniline metabolic gene cluster in this study. Three positive recombinant plasmids pDA1, pDB2 and pDB11 were cloned from genomic library of aniline degradation strain AD9. The result of aniline dioxygenase （AD） activity and catechol 2,3-oxygenase （C230） activity assay showed that pDA1 and pDB11 contain aniline dioxygenase genes and catechol 2,3-dioxygenase genes, respectively. The sequence analysis of the total 24.7-kb region revealed that this region contains 25 ORFs, of which 17 genes involve metabolism of aniline. In the gene cluster, the first five genes （tadQTA1A2B） and the subsequent gene （tadR1） were predicted to encode a multi-component aniline dioxygenase and a LysR-type regulator, respectively, while the others （tadD1C1D2C2EFGIJKL） were expected to encode metacleavage pathway enzymes for catechol degradation. The gene cluster was surrounded by two IS1071 sequences.