oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Error Probability of DPPM UWB Systems over Nakagami Fading Channels with Receive Diversity  [cached]
Zhang Hao,Lu Ting-ting,Wang Jing-jing,Gulliver TAaron
EURASIP Journal on Wireless Communications and Networking , 2011,
Abstract: We consider differential-pulse position modulation (DPPM) in an ultra wideband (UWB) communication system. A typical format for a DPPM signal in a UWB system is derived from that of a pulse position modulation (PPM) signal. The error probabilities of a UWB DPPM system with receive diversity over additive white Gaussian noise (AWGN) and Nakagami fading channels are derived. Both single-user and multiuser environments are considered. Performance results are presented which show that the frame error rate (FER) with DPPM is better than that with PPM, and the FER performance can be improved significantly by receive diversity.
Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) complexes on porous vycor glass
Gimenez, Iara de Fátima;Alves, Oswaldo Luiz;
Journal of the Brazilian Chemical Society , 2004, DOI: 10.1590/S0103-50532004000500005
Abstract: porous vycor glass (pvg) is used as a matrix for immobilization of complexes containing metal-metal bonds: [pd2cl2(dppm)2], [pd2(sncl3)cl(dppm)2 ] and [pd2(sncl3)2(dppm)2]. the high reactivity of the metal-metal bonds in insertion reactions with small molecules such as co and so2 is preserved in the pore medium, and is reversible under vacuum. 31p mas-nmr and raman spectra indicate that there is a range of interactions between the glass and the adsorbed molecules as a result of the availability of different groups in the molecules and of the irregular pore topology as well. the static character of the molecules in the restrictive pore environment precludes motions such as flipping of the ring pd2p4c2 between boat and chair conformations and rotation of the phenyl rings, and the molecules may present a range of conformations.
膦桥双核银配合物[Ag(dppm)NO3]2的合成与结构  [PDF]
张鹏,黄明生,张颖,郑兰荪,杨华惠
化学学报 , 1991,
Abstract: [Ag(dppm)NO3]2晶体属单斜晶系,空间群Cc。单胞参数a=1.2704(1),b=1.7028(2),c=2.2634(5)nm;β=100.66(1)°;Z=4;V=4.8117nm^3;Dc=1.530g·cm^-^3。两个双齿膦配体dppm连续两个银离子形成一个扭曲八元环。Ag-Ag间距离为0.3089nm,硝酸根以不对称配位方式与银离子配位,结构测定的最后偏离因子R=0.050。
Magnetic properties of Co/Cu/Py antidot films  [PDF]
J. C. Denardin,E. Burgos,R. Lavín,S. Vojkovic,J. Briones,M. Flores
Physics , 2014, DOI: 10.1109/TMAG.2014.2331973
Abstract: The magnetic properties of ordered nanoscale Co/Cu/Py multilayer antidot films with different pore sizes prepared on top of nanoporous alumina membranes are presented. By using Co and Py films separated by a Cu thin layer, and tuning the pore diameters of the NAMs we were able to play with the coercivity of the films and observe stepped magnetization curves, as a consequence of the different coercivities of the Co and Py films. The magnetic properties of the multilayer antidots have been measured and compared with results obtained for antidots of Cu/Py. The magnetization reversal process that occurs in each individual layer and in the multilayer was studied by means of micromagnetic simulations.
Ag~+[Ag_2~ⅡAg_4~ⅢO_8]NO_3~-的晶体结构
周公度
科学通报 , 1962,
Abstract: Ag~ Ag_2~ⅡAg_4~ⅢO_8]NO_3~-晶体系电解硝酸银溶液时所得的阳极氧化产物。Braekken 等曾测定过这个立方晶体的晶胞常数。Noyes 等研究过它的组成和电化学性质。而及给出了晶体的空间群为 O_h~5-F_m3_m。他们根据粉末图和单晶体衍射图的强度数据,给出晶胞中各个原子的参数值如下:Ag~(1)(1/2,1/2,1/2);Ag~(2)(1/4,1/4,0);NO_3~-(0,0,0);O(x,x,x),x=3/8。从这些参数值中可以引出 Ag~(2)-()系按 dSp~2杂化轨道所成的共面键,键长为2.12(?),而 Ag~(1)和 O 原子按离子键结合,配位数为8,距离为2.26(?),而NO_3~-离子的空间取向尚未确定。有关 Ag~ Ag_2~ⅡAg_4~ⅢO_8]NO_3~-晶体以往研究工作的进展情况,和其他高价银盐的结构化学,最近已由 McMillan 加以总结。
一种硫膦混配无限链状聚合物[Ag4(N,S:mbo)4(μ-dppm)2]n的合成和晶体结构
肖文,康北笙,邓良容,张华新,王修建
自然科学进展 , 2001,
Abstract: 报道了含双(二苯基膦基)甲烷(dppm)和2-巯基苯并恶唑(Hmbo)的银配合物,即硫膦混配无限链状聚合物Ag4(N,S:mbo)4(μ-dppm)2]n的合成及单晶结构,讨论了配合物的组装过程及配体(Hmbo)与金属的配位方式.
Targeted Disruption of py235ebp-1: Invasion of Erythrocytes by Plasmodium yoelii Using an Alternative Py235 Erythrocyte Binding Protein  [PDF]
Solabomi A. Ogun ,Rita Tewari,Thomas D. Otto,Steven A. Howell,Ellen Knuepfer,Deirdre A. Cunningham,Zhengyao Xu,Arnab Pain,Anthony A. Holder
PLOS Pathogens , 2011, DOI: 10.1371/journal.ppat.1001288
Abstract: Plasmodium yoelii YM asexual blood stage parasites express multiple members of the py235 gene family, part of the super-family of genes including those coding for Plasmodium vivax reticulocyte binding proteins and Plasmodium falciparum RH proteins. We previously identified a Py235 erythrocyte binding protein (Py235EBP-1, encoded by the PY01365 gene) that is recognized by protective mAb 25.77. Proteins recognized by a second protective mAb 25.37 have been identified by mass spectrometry and are encoded by two genes, PY01185 and PY05995/PY03534. We deleted the PY01365 gene and examined the phenotype. The expression of the members of the py235 family in both the WT and gene deletion parasites was measured by quantitative RT-PCR and RNA-Seq. py235ebp-1 expression was undetectable in the knockout parasite, but transcription of other members of the family was essentially unaffected. The knockout parasites continued to react with mAb 25.77; and the 25.77-binding proteins in these parasites were the PY01185 and PY05995/PY03534 products. The PY01185 product was also identified as erythrocyte binding. There was no clear change in erythrocyte invasion profile suggesting that the PY01185 gene product (designated PY235EBP-2) is able to fulfill the role of EBP-1 by serving as an invasion ligand although the molecular details of its interaction with erythrocytes have not been examined. The PY01365, PY01185, and PY05995/PY03534 genes are part of a distinct subset of the py235 family. In P. falciparum, the RH protein genes are under epigenetic control and expression correlates with binding to distinct erythrocyte receptors and specific invasion pathways, whereas in P. yoelii YM all the genes are expressed and deletion of one does not result in upregulation of another. We propose that simultaneous expression of multiple Py235 ligands enables invasion of a wide range of host erythrocytes even in the presence of antibodies to one or more of the proteins and that this functional redundancy at the protein level gives the parasite phenotypic plasticity in the absence of differences in gene expression.
ZnCl2·2Py,CdCl2·2Py和HgCl2·2Py13C-NMR研究  [PDF]
韩秀文,纪涛,程国宝,杨振云,胡皆汉
科学通报 , 1981,
Abstract: 我们对吡啶(Py)及其氯化锌(ZnCl2·2Py)、氯化镉(CdCl2·2Py)和氯化汞(HgCl2·2Py)三种络合物进行了13C-NMR研究。络合物的化学位移(δ)和耦合常数(1JC-H均有变化,反映了络合后吡啶环的电子云密度有改变。
Post py w hepatologii dzieci cej
Jerzy Socha,Irena Jankowska,Joanna Paw?owska,Danuta Celińska-Cedro
Pediatria Wspó?czesna , 2000,
Abstract: Autorzy przedstawiaj post py w diagnostyce i leczeniu wybranych jednostek chorobowych z zakresu hepatologii dzieci cej. Post p, jaki dokona si w zakresie genetyki, immunologii, diagnostyki laboratoryjnej i obrazowej, chirurgii oraz histopatologii, przyczyni si do rozpoznania dotychczas nieznanych chorób w troby oraz wprowadzenia nowych metod leczenia, m.in. zabiegu przeszczepiania w troby w przypadku niewydolno ci tego narz du.
Time-Resolved Spin Torque Switching and Enhanced Damping in Py/Cu/Py Spin-Valve Nanopillars  [PDF]
N. C. Emley,I. N. Krivorotov,A. G. F. Garcia,O. Ozatay,J. C. Sankey,D. C. Ralph,R. A. Buhrman
Physics , 2005, DOI: 10.1103/PhysRevLett.96.247204
Abstract: We report time-resolved measurements of current-induced reversal of a free magnetic layer in Py/Cu/Py elliptical nanopillars at temperatures T = 4.2 K to 160 K. Comparison of the data to Landau-Lifshitz-Gilbert macrospin simulations of the free layer switching yields numerical values for the spin torque and the Gilbert damping parameters as functions of T. The damping is strongly T-dependent, which we attribute to the antiferromagnetic pinning behavior of a thin permalloy oxide layer around the perimeter of the free layer. This adventitious antiferromagnetic pinning layer can have a major impact on spin torque phenomena.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.