974 research outputs found
Antenna Pattern Multiplexing for Enhancing Path Diversity
In this chapter, we show the concept of antenna pattern multiplexing (APM), which enhances path diversity gain and antenna pattern diversity reception in multipath rich fading environment. We discuss the types of antennas that achieve the APM, i.e., generating time-varying antenna pattern and the benefits of reducing antenna size and hardware cost. When electronically steerable passive array radiator (ESPAR) antenna is used, the benefits can be maximised. A model of receiving process is proposed for analysing the ergodic capacity of multiple-input multiple-output (MIMO) systems using APM. We derive a model of received signals to analyse the system performance. The received signal in matrix form includes an equivalent channel matrix, which is a product of antenna pattern matrix, the channel coefficient vector for each output. Numerical results in terms of ergodic capacity show the comparable performances of the proposed MIMO with APM to the conventional MIMO systems; in particular, the number of arrival paths and the number of antenna pattern are sufficiently large. Also the ergodic capacity can be equivalent to that of the conventional MIMO systems when the average SNR per antenna pattern is constant among the virtual antennas
Single cell analysis of neutrophils NETs by Microscopic LSPR imaging system
A simple microengraving cell monitoring method for neutrophil extracellular traps
(NETs) released from single neutrophils has been realized using a polydimethylsiloxane (PDMS)
microwell array (MWA) sheet on a plasmon chip platform. An imbalance between NETs formation
and the succeeding degradation (NETosis) are considered associated with autoimmune disease and
its pathogenesis. Thus, an alternative platform that can conduct monitoring of this activity on single
cell level at minimum cost but with great sensitivity is greatly desired. The developed MWA
plasmon chips allow single cell isolation of neutrophils from 150 μL suspension (6.0 × 105 cells/mL)
with an efficiency of 36.3%; 105 microwells with single cell condition. To demonstrate the utility of
the chip, trapped cells were incubated between 2 to 4 h after introducing with 100 nM phorbol 12-
myristate 13-acetate (PMA) before measurement. Under observation using a hyperspectral imaging
system that allows high-throughput screening, the neutrophils stimulated by PMA solution show a
significant release of fibrils and NETs after 4 h, with observed maximum areas between 314–758
μm2. An average absorption peak wavelength shows a redshift of Δλ = 1.5 nm as neutrophils release
NETs
Electron emission from conduction band of diamond with negative electron affinity
Experimental evidence explaining the extremely low-threshold electron
emission from diamond reported in 1996 has been obtained for the first time.
Direct observation using combined ultraviolet photoelectron spectroscopy/field
emission spectroscopy (UPS/FES) proved that the origin of field-induced
electron emission from heavily nitrogen (N)-doped chemical vapour deposited
(CVD) diamond was at conduction band minimum (CBM) utilising negative electron
affinity (NEA). The significance of the result is that not only does it prove
the utilisation of NEA as the dominant factor for the extremely low-threshold
electron emission from heavily N-doped CVD diamond, but also strongly implies
that such low-threshold emission is possible from other types of diamond, and
even other materials having NEA surface. The low-threshold voltage, along with
the stable intensity and remarkably narrow energy width, suggests that this
type of electron emission can be applied to develop a next generation vacuum
nano-electronic devices with long lifetime and high energy resolution.Comment: 17 pages, 4 figures, Phys. Rev. B in pres
Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide
The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule
Vsop2/Astro-G Project
We introduce a new space VLBI project, the Second VLBI Space Observatory
Program (VSOP2), following the success of the VLBI Space Observatory Program
(VSOP1). VSOP2 has 10 times higher angular resolution, up to about 40 micro
arcseconds, 10 times higher frequency up to 43 GHz, and 10 times higher
sensitivity compared to VSOP1. Then VSOP2 should become a most powerful tool to
observe innermost regions of AGN and astronomical masers. ASTRO-G is a
spacecraft for VSOP2 project constructing in ISAS/JAXA since July 2007. ASTRO-G
will be launched by JAXA H-IIA rocket in fiscal year 2012. ASTRO-G and
ground-based facilities are combined as VSOP2. To achieve the good observation
performances, we must realize new technologies. They are large precision
antenna, fast-position switching capability, new LNAs, and ultra wide-band down
link, etc.. VSOP2 is a huge observation system involving ASTRO-G, ground radio
telescopes, tracking stations, and correlators, one institute can not prepare a
whole system of VSOP2. Then we must need close international collaboration to
get sufficient quality of resultant maps and to give a sufficient quantity of
observation time for astronomical community. We formed a new international
council to provide guidance on scientific aspects related of VSOP2, currently
called the VSOP2 International Science Council (VISC2).Comment: 10 pages, 9 figures, proceedings of The Universe under the Microscope
Astrophysics at High Angular Resolutio
Traditional and Innovative Approaches to Legal Reform: 'The New Company Law'
In this paper, we have distinguished three different positions along the reform strategy spectrum of company law. The first position is located on the left side of the spectrum and closest to stasis - where virtually no effective legal changes can occur and where only the idea of reform clashes with legal tradition and standardization pressures. An example of a jurisdiction that takes this position is Germany. Along or near the mid-point of the spectrum, company law changes are less impeded by tradition and standardization factors, but more influenced by interest group pressures. We see England occupying this position. Japan can be seen as a more adaptable jurisdiction located toward the right end of the spectrum and therefore better able to create and introduce more functional legal rules and institutions that turn the traditional view of company law around. It is submitted that Singapore is located on the right side of the spectrum as its legislature is aware of the need to adapt the legal system to international business practices in order to develop a distinct jurisprudence, acclaimed for its efficiency and integrity, which is set apart from the English legal system.Length: 36 pages
シロイヌナズナの維管束幹細胞分化におけるBES1転写因子ファミリーの機能解析
学位の種別: 課程博士審査委員会委員 : (主査)東京大学准教授 阿部 光知, 東京大学教授 平野 博之, 東京大学教授 塚谷 裕一, 東京大学准教授 伊藤 恭子, 東京大学教授 福田 裕穂University of Tokyo(東京大学
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