scholarly journals Growth of width-controlled nanowires MnO2 from mesoporous carbon and investigation of their properties

2006 ◽  
Vol 21 (11) ◽  
pp. 2847-2854 ◽  
Author(s):  
Shenmin Zhu ◽  
Xiaolin Wang ◽  
Wei Huang ◽  
Deyue Yan ◽  
Honghua Wang ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
Magnetic Transition ◽  
Reaction System ◽  
Ferromagnetic State ◽  
Ultrasonic Waves ◽  
Controlled Synthesis ◽  
One Dimensional ◽  
System A ◽  
20 Nm ◽  
Resultant Material

One-dimensional α-MnO2 nanowires with a controlled width of 10–20 nm have been developed by means of ultrasonic waves from mesoporous carbon using KMnO4 as the precursor. The formation mechanism has been proposed based on the results. A peak around 100 K was detected in the temperature-dependence of magnetization curve, indicating the ferromagnetic state in nanocomposite mesoporous carbon-MnO2, which is in agreement with the transition temperature found from the magnetization versus applied magnetic field curve. The magnetization versus temperature curve of the obtained MnO2 nanowires showed a magnetic transition at about 50 K, illustrating that a parasitic ferromagnetic component is composed on the antiferromagnetic structure of MnO2. The advantage of the method reported here is that phase-controlled synthesis of α-MnO2 nanowires was implemented regardless of pH, temperature, and types of ions in the reaction system. A major advantage of this approach is the efficient, fast, and reproducible control of width and the facile strategy to synthesize nanowires MnO2, in addition to the high purity of the resultant material.

PMA-b-PAA-controlled synthesis of one-dimensional CaCO3 superstructures

2010 ◽  
Vol 46 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Chao You ◽  
Qiang Zhang ◽  
Yun Zhao ◽  
Qingze Jiao
Keyword(s):  
Controlled Synthesis ◽  
One Dimensional

Mesoporous carbon nanotubes for use as support in catalysis and as nanosized reactors for one-dimensional inorganic material synthesis

2003 ◽  
Vol 254 (2) ◽  
pp. 345-363 ◽  
Author(s):  
Jean-Mario Nhut ◽  
Laurie Pesant ◽  
Jean-Philippe Tessonnier ◽  
Gauthier Winé ◽  
Jean Guille ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Carbon ◽  
Inorganic Material ◽  
Material Synthesis ◽  
One Dimensional

Size and shape-controlled synthesis of Ru nanocrystals

2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Linlin Xu ◽  
Jun Yang
Keyword(s):  
Noble Metal ◽  
Chemical Properties ◽  
Controlled Synthesis ◽  
One Dimensional ◽  
Size And Shape ◽  
The Past ◽  
Metal Nanomaterials ◽  
Shape Controlled ◽  
Synthetic Approaches ◽  
Coherent Picture

Abstract Mastery over the size/shape of nanocrystals (NCs) enables control of their properties and enhancement of their usefulness for a given application. Within the past decades, the development of wet-chemistry methods leads to the blossom of research in noble metal nanomaterials with tunable sizes and shapes. We herein would prefer to devote this chapter to introduce the solution-based methods for size and shape-controlled synthesis of ruthenium (Ru) NCs, which can be summarized into five categories: (i) Synthesis of spherical Ru NCs; (ii) synthesis of one-dimensional (1D) Ru NCs, e.g. wires and rods; (iii) synthesis of two-dimensional (2D) Ru NCs, e.g. nanoplates; (iv) synthesis of Ru NCs with hollow interiors and (v) synthesis of Ru NCs with other morphologies, e.g. chains, dendrites and branches. We aim at highlighting the synthetic approaches and growth mechanisms of these types of Ru NCs. We also introduce the detailed characterization tools for analysis of Ru NCs with different sizes/shapes. With respect to the creation of great opportunities and tremendous challenges due to the accumulation in noble metal nanomaterials, we briefly make some perspectives for the future development of Ru NCs so as to provide the readers a systematic and coherent picture of this promising field. We hope this reviewing effort can provide for technical bases for effectively designing and producing Ru NCs with enhanced physical/chemical properties. Graphical Abstract: The solution-based methods for size and shape-controlled synthesis of ruthenium nanocrystals as well as the mechanisms behind them are extensively reviewed.

scholarly journals Critical flow and dissipation in a quasi–one-dimensional superfluid

2015 ◽  
Vol 1 (4) ◽  
pp. e1400222 ◽  
Author(s):  
Pierre-François Duc ◽  
Michel Savard ◽  
Matei Petrescu ◽  
Bernd Rosenow ◽  
Adrian Del Maestro ◽  
...  
Keyword(s):  
Power Law ◽  
Capillary Flow ◽  
Three Dimensional ◽  
Universality Class ◽  
Superfluid State ◽  
One Dimensional ◽  
Flow Experiment ◽  
20 Nm ◽  
Bulk Behavior ◽  
Superfluid Velocity

In one of the most celebrated examples of the theory of universal critical phenomena, the phase transition to the superfluid state of 4He belongs to the same three-dimensional (3D) O(2) universality class as the onset of ferromagnetism in a lattice of classical spins with XY symmetry. Below the transition, the superfluid density ρs and superfluid velocity vs increase as a power law of temperature described by a universal critical exponent that is constrained to be identical by scale invariance. As the dimensionality is reduced toward 1D, it is expected that enhanced thermal and quantum fluctuations preclude long-range order, thereby inhibiting superfluidity. We have measured the flow rate of liquid helium and deduced its superfluid velocity in a capillary flow experiment occurring in single 30-nm-long nanopores with radii ranging down from 20 to 3 nm. As the pore size is reduced toward the 1D limit, we observe the following: (i) a suppression of the pressure dependence of the superfluid velocity; (ii) a temperature dependence of vs that surprisingly can be well-fitted by a power law with a single exponent over a broad range of temperatures; and (iii) decreasing critical velocities as a function of decreasing radius for channel sizes below R ≃ 20 nm, in stark contrast with what is observed in micrometer-sized channels. We interpret these deviations from bulk behavior as signaling the crossover to a quasi-1D state, whereby the size of a critical topological defect is cut off by the channel radius.

Integration of one-dimensional equations of motions

2020 ◽  
pp. 79-90
Author(s):  
Gleb L. Kotkin ◽  
Valeriy G. Serbo
Keyword(s):  
Potential Energy ◽  
Field Change ◽  
One Dimensional ◽  
System A ◽  
Small Correction ◽  
The Law ◽  
The One ◽  
The Given ◽  
Equations Of Motions

If the potential energy is independent of time, the energy of the system remains constant during the motion of a closed system. A system with one degree of freedom allows for the determination of the law of motion in quadrature. In this chapter, the authors consider motion of the particles in the one-dimensional fields. They discuss also how the law and the period of a particle moving in the potential field change due to adding to the given field a small correction.

scholarly journals HST-FGS Astrometry of the Low Mass Binary L722-22

1999 ◽  
Vol 172 ◽  
pp. 405-407
Author(s):  
L.G. Taff ◽  
John L. Hershey
Keyword(s):  
Main Sequence ◽  
Hubble Space Telescope ◽  
Brown Dwarf ◽  
One Dimensional ◽  
Photographic Images ◽  
System A ◽  
Data Points ◽  
Low Mass ◽  
The Masses ◽  
M Dwarf

The M dwarf L722-22 (= LHS 1047) was discovered to be a binary system by Ianna 20 years ago. The analysis of the ground- based data indicated a mass 0.06M⊙ for the secondary. This is below the nominal stellar mass limit of 0.08M⊙. The importance of potential “brown-dwarf” candidates, and the fact that the masses of both components place them near the end of the main sequence, made this system a prime object for further, intensive, study.This close (separation 0."3), faint (V = 11.m5, 14.m4) binary was near the limit for ground-based work. The residuals of an individual night’s photographic data were typically at the 50% level. Also, the photographic images are completely blended. The few one-dimensional speckle data points yielded a merged, asymmetric image profile. Finally, this system is too faint for HIPPARCOS. Our proposal for Hubble Space Telescope Fine Guidance Sensor (FGS) observing was approved in 1992.

REACTION-FRONT DYNAMICS IN A+B→C WITH INITIALLY-SEPARATED REACTANTS

Fractals ◽  
1993 ◽  
Vol 01 (03) ◽  
pp. 405-415 ◽  
Author(s):  
S. HAVLIN ◽  
M. ARAUJO ◽  
H. LARRALDE ◽  
A. SHEHTER ◽  
H.E. STANLEY
Keyword(s):  
Reaction Front ◽  
Reaction Rate ◽  
Reaction System ◽  
Diffusion Reaction ◽  
Dimensional System ◽  
Scaling Exponent ◽  
One Dimensional ◽  
Recent Developments ◽  
The One ◽  
Front Dynamics

We review recent developments in the study of the diffusion reaction system of the type A+B→C in which the reactants are initially separated. We consider the case where the A and B particles are initially placed uniformly in Euclidean space at x>0 and x<0 respectively. We find that whereas for d≥2 a single scaling exponent characterizes the width of the reaction zone, a multiscaling approach is needed to describe the one-dimensional system. We also present analytical and numerical results for the reaction rate on fractals and percolation systems.

High index, reactive facet-controlled synthesis of one-dimensional single crystalline rare earth hydroxide nanobelts

CrystEngComm ◽  
2011 ◽  
Vol 13 (17) ◽  
pp. 5367 ◽  
Author(s):  
Liap Tat Su ◽  
Jun Ye ◽  
Siva Krishna Karuturi ◽  
Lijun Liu ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Index ◽  
Controlled Synthesis ◽  
Single Crystalline ◽  
One Dimensional
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