Wednesday, December 29, 2010

Morphology-Controlled Synthesis and Novel Microwave Absorption Properties of Hollow Urchinlike α-MnO2 Nanostructures

Morphology-Controlled Synthesis and Novel Microwave Absorption Properties of Hollow Urchinlike α-MnO2 Nanostructures: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp106652x

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Controlled Synthesis of ZnO Nanostructures: The Role of Source and Substrate Temperatures

Controlled Synthesis of ZnO Nanostructures: The Role of Source and Substrate Temperatures: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp110416v

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Doping Cu in Semiconductor Nanocrystals: Some Old and Some New Physical Insights

Doping Cu in Semiconductor Nanocrystals: Some Old and Some New Physical Insights: "
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Journal of the American Chemical Society
DOI: 10.1021/ja1089809

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Electrochemical Deposition of Eu3+-Doped CeO2 Nanobelts with Enhanced Optical Properties

Electrochemical Deposition of Eu3+-Doped CeO2 Nanobelts with Enhanced Optical Properties: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp1070924

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Employing Heavy Metal-Free Colloidal Quantum Dots in Solution-Processed White Light-Emitting Diodes

Employing Heavy Metal-Free Colloidal Quantum Dots in Solution-Processed White Light-Emitting Diodes: "
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Nano Letters
DOI: 10.1021/nl1021442

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The Different Nature of Band Edge Absorption and Emission in Colloidal PbSe/CdSe Core/Shell Quantum Dots

The Different Nature of Band Edge Absorption and Emission in Colloidal PbSe/CdSe Core/Shell Quantum Dots: "
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ACS Nano
DOI: 10.1021/nn102980e

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Fe3O4@organic@Au: core-shell nanocomposites with high saturation magnetisation as magnetoplasmonic MRI contrast agents

Fe3O4@organic@Au: core-shell nanocomposites with high saturation magnetisation as magnetoplasmonic MRI contrast agents: "


Eric D. Smolensky, Michelle C. Neary, Yue Zhou, Thelma S. Berquo, Valerie C. Pierre

(Communication from Chem. Commun.)

Eric D. Smolensky, Chem. Commun., 2011, DOI: 10.1039/c0cc03746j

To cite this article before page numbers are assigned, use the DOI form of citation above.


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Meanings, news of China’s new rare earths quotas don’t agree

Meanings, news of China’s new rare earths quotas don’t agree: "
Chinese rare earth exports, 2009-2011, in metric tons:




























|  2009/H1:21,728 tons ||| 2010/H1:22,282 tons ||| 2011/H1:14,446 tons
|  2009/H2:28,417 tons 2010/H2:7,976 tons | 2011/H2:?
Total:50,145 tons 30,258 tons ?


First the good news: China appears to be increasing rare earth export quotas for the first half of 2011 - compared to the second half of 2010 – by over 80%. The bad news: The new quotas represent a 35% drop compared to the same period in 2010, and a 33% drop compared to the first half of 2009.

In other words, the short term may be a small improvement over the previous six months, but nevertheless a change that is not inconsistent with recent declines in the output of rare earth elements from China.

Where China ultimately is going with these REE quotas in 2011 isn’t clear, nor does recent history provide any clear cut guide. For example, quotas in 2009/H2 actually increased by 31% over 2009/H1 (28,417 metric tons versus 21,728 tons, for a year total of 50,145 tons).

The influential Bloomberg New Service reported on the quota this morning, headlining (and inaccurately reporting the numbers - Bloomberg editors don’t read their own archive) the story as an 11% cut.

On the other hand, one of the writers at the Rare Metal Blog took the “glass half full” approach with the story, “China INCREASES export quota by 82%” (emphasis in the original).

Traders on some stock exchanges thought they could read China’s mind and early in the day share in U.S. mining company Molycorp shot up by about 12% compared to the previous day’s closing price.

But, according to a New York Times story posted this afternoon (with accurate numbers), China apparently wants to head off some of the gloom:


“In what seemed to be an effort to reassure traders and users of rare earths, the commerce ministry said in a follow-up statement late Tuesday on its Web site that it had not decided what the total export quotas would be for all of 2011 … The ministry said on Tuesday night that companies should not make guesses about the total export quotas for next year based on the initial reductions issued earlier in the day.

“We will be considering the production of rare earths in China, domestic demand and sustainable development needs to determine” the full quotas for the entire year, the ministry Web site quoted its foreign trade department director as saying, without naming the director.”

Apparently the reassurance worked: Molycorp’s closing stock price was a decline of 6%

Although some speculate about economic and business decisions are behind these moves, Chinese officials have recently been saying that environmental concerns are a factor in making quota decisions. Again, from the NYT:


“Until a few months ago, Chinese officials said that their rare earth policies were aimed at forcing foreign industries to move high-tech factories to China so as to have access to Chinese rare earths. But as trade frictions have increased, they have given greater emphasis to environmental concerns.

A Chinese official said on Tuesday that pollution worries about rare earth mining were sincere.

‘The government is paying more attention to environmental protection, and is retiring older facilities and older technologies,’ said the official, who insisted on anonymity because of the political implications of rare earth policies, and declined to discuss specifics of the quotas.’

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Wednesday, December 15, 2010

Direct Hydrothermal Synthesis and Physical Properties of Rare-Earth and Yttrium Orthochromite Perovskites

Direct Hydrothermal Synthesis and Physical Properties of Rare-Earth and Yttrium Orthochromite Perovskites: "
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Chemistry of Materials
DOI: 10.1021/cm102925z

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Bright and Compact Alloyed Quantum Dots with Broadly Tunable Near-Infrared Absorption and Fluorescence Spectra through Mercury Cation Exchange

Bright and Compact Alloyed Quantum Dots with Broadly Tunable Near-Infrared Absorption and Fluorescence Spectra through Mercury Cation Exchange: "
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Journal of the American Chemical Society
DOI: 10.1021/ja108482a

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Unique Temperature Dependence and Blinking Behavior of CdTe/CdSe (Core/Shell) Type-II Quantum Dots

Unique Temperature Dependence and Blinking Behavior of CdTe/CdSe (Core/Shell) Type-II Quantum Dots: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp109229u

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Size-Dependent Surface Effects on the Photoluminescence in ZnO Nanorods

Size-Dependent Surface Effects on the Photoluminescence in ZnO Nanorods: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp106990a

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Biphasic Synthesis of Au@SiO2 Core−Shell Particles with Stepwise Ligand Exchange

Biphasic Synthesis of Au@SiO2 Core−Shell Particles with Stepwise Ligand Exchange: "
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Langmuir
DOI: 10.1021/la102630y

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Fast and facile synthesis of silica coated silver nanoparticles by microwave irradiation

rFast and facile synthesis of silica coated silver nanoparticles by microwave irradiation: "Publication year: 2010
Source: Journal of Colloid and Interface Science, In Press, Accepted Manuscript, Available online 13 December 2010
Newaz Mohammed, Bahadur , Takeshi, Furusawa , Masahide, Sato , Fumio, Kurayama , Iqbal Ahmed, Siddiquey , ...
A novel, fast and facile microwave technique has been developed for preparing monodispersed silica coated silver (Ag@SiO2) nanoparticles. Without using any other surface coupling agents such as 3-aminopropyltrimethoxysilane (APS) or polymer such as polyvinyl pyrrolidone (PVP), Ag@SiO2 nanoparticles could be easily prepared by microwave irradiation of a mixture of colloidal silver nanoparticles, tetraethoxysilane (TEOS) and catalyst for only 2 min. The thickness of silica shell could be conveniently controlled in the range of few nanometers (nm) to 80 nm by changing the concentration of TEOS. Transmission electron microscopy (TEM) and UV-visible spectroscopy were employed to characterize the morphology and optical...
Silica coated silver nanoparticles with different silica-shell thickness were prepared by a novel, fast and facile microwave (MW) technique. Prepared particles were functionalized with different groups for many applications.
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Friday, December 03, 2010

High Up-Conversion Efficiency of YVO4:Yb,Er Nanoparticles in Water down to the Single-Particle Level

High Up-Conversion Efficiency of YVO4:Yb,Er Nanoparticles in Water down to the Single-Particle Level: "
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The Journal of Physical Chemistry C
DOI: 10.1021/jp107900z

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Controlled synthesis of Co3O4 nanocubes under external magnetic fields and their magnetic properties

Controlled synthesis of Co3O4 nanocubes under external magnetic fields and their magnetic properties: "


Mingsheng Wang, Lingkun Zeng, Qianwang Chen

(Paper from Dalton Trans.)

Mingsheng Wang, Dalton Trans., 2011, DOI: 10.1039/c0dt00946f

To cite this article before page numbers are assigned, use the DOI form of citation above.


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