Publications

Science in the Future of India

India has voted for Science. In May, half a billion people cast their ballots, and they decisively favored spurring the development of the world's second most populous nation. The reelected Prime Minister Manmohan Singh and his new coalition government have made a commitment to reduce poverty and disease, create employment, and stimulate rural and industrial development. Attaining these goals will require substantial new investments in science and technology (S&T) plus much greater investments in human capital.

Improved method for the synthesis of alkyl azides

No abstract is provided for this article.

Structure and Electron‐Transport Properties of Anion‐Deficient MoTe₂: A Combined Experimental and Theoretical Study

We present experimental measurements and first‐principles theoretical analysis of high‐temperature electron‐transport properties of polycrystalline Te‐deficient 2H‐ and 1T′‐MoTe 2– x . Electron transport measurements in the temperature range 300–673 K show that polycrystalline 2H‐MoTe 2– x exhibits two regimes of activated conduction: hopping of defect‐induced localized carriers at lower temperatures and an extended state conduction at higher temperatures. Its Seebeck coefficient changes from p‐type to n‐type around 497 K peaking near 370 K, which is ascribed to mixed conduction of carriers. In contrast, 1T′‐MoTe 2– x exhibits metallic conduction up to 300 K beyond which conductivity slightly increases due to thermal excitation of the minority carriers. 2H‐ and 1T′ forms of MoTe 2– x exhibit thermal conductivity with opposite temperature‐dependence due to dominant electronic thermal conductivity in the latter. Using first‐principles calculations based on density functional theory, we determine the nature of defect states associated with Te‐vacancies in 2H‐, 1T′‐ and Td‐MoTe 2– x . The defect bands associated with Te vacancies appear within the gap of 2H‐MoTe 2 and in the pseudo gap of 1T′‐MoTe 2 , thereby reducing the bandgap of the former and making the latter more metallic. These defect states are crucial to understanding the observed trends in the temperature‐dependent transport properties of Te‐deficient 2H‐ and 1T′‐MoTe 2– x .

Synthesis pharmacological activities and physico chemical properties of 4 substituted amino and n 4 arylpiperazinyl and aminocarbonyl 2 3 polymethylenequinolines

The Hierarchy of Open‐Framework Structures in Metal Phosphates and Oxalates.

No abstract is provided for this article.

Infrared Spectra of Organic Azides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfrared Spectra of Organic AzidesEugene. Lieber, C. N. R. Rao, T. S. Chao, and C. W. W. HoffmanCite this: Anal. Chem. 1957, 29, 6, 916–918Publication Date (Print):June 1, 1957Publication History Published online1 May 2002Published inissue 1 June 1957https://pubs.acs.org/doi/10.1021/ac60126a016https://doi.org/10.1021/ac60126a016research-articleACS PublicationsRequest reuse permissionsArticle Views7710Altmetric-Citations121LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Solar Photochemical Reduction and Oxidation of Water and Related Aspects

Conversion of solar energy to useful chemicals has become necessary for finding solutions to energy and environmental issues. One of the means is to use of solar energy for the reduction of water to generate hydrogen or for the reduction of CO[Formula: see text] to useful chemicals. In spite of substantial effort, the discovery of stable and efficient photocatalysts remains a challenge, although some encouraging results have been reported. In this article, we provide a brief perspective of the current status of solar water splitting and reduction of CO[Formula: see text].

Effect of Y substitution in La-Ca-Mn-O perovskites showing giant magnetoresistance

Substitution of yttrium (${\mathrm{Y}}^{3+}$) in La-Ca-Mn-O perovskites of the ${\mathrm{ABO}}_{3}$ structure markedly affects the crystal structure and lattice constants as well as the resistivity (\ensuremath{\rho}), ferromagnetic transition temperature (${\mathit{T}}_{\mathit{c}}$), and the temperature corresponding to the insulator-metal-like transition (${\mathit{T}}_{\mathit{p}}$). The two important parameters which control the electronic transport and the magnetic behavior are the ${\mathrm{Mn}}^{4+}$ content and the effective radius of the A-site cation. The substitution by Y, which changes the A-site radius, is compared to pressure effect. For certain Y concentrations we observe substantial enhancement of the negative magnetoresistance at temperatures T${\mathit{T}}_{\mathit{c}}$ and a large positive magnetoresistance at T\ensuremath{\gg}${\mathit{T}}_{\mathit{c}}$. \textcopyright{} 1996 The American Physical Society.

XPES and UVPES studies of iron oxides

X-Ray and uv photoelectron spectra of FeO, Fe2O3, and Fe3O4 have been studied along with those of a few model compounds. It has been possible to assign distinct bands due to Fe2+ and Fe3+ in the 3d, 3p, 3s, and 2p bands of Fe3O4. The spectra of Fe3O4 do not show major changes through the Verwey transition.

Hydrogen sensors based on ZnO nanoparticles

Hydrogen sensing characteristics of thick films of nanoparticles (∼35nm diameter) of ZnO, 3% Co doped ZnO, 1% Pt-impregnated ZnO and 1% Pt-impregnated 3% Co–ZnO have been investigated. The last composition exhibits the highest sensitivity for 10–1000ppm H2, reaching values upto 1700 as well as good response and recovery times at 125°C or lower. The sensor is not affected significantly upto 50% relative humidity.

CCDC 221335: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Evidence for supramolecular organization of alkane and surfactant molecules in the process of forming mesoporous silica

No abstract is provided for this article.

Buckminsterfullerene, C60: Improved synthesis, electron microscopy, electron states, anions and related aspects

No abstract is provided for this article.

ChemInform Abstract: Zirconia Nanotubes.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Organically Templated Linear and Layered Iron Sulfates.

For Abstract see ChemInform Abstract in Full Text.

Superconductivity in the Bi2(Ca, Sr)n+1CunO2n+4 (n=1, 2, or 3) series: Synthesis, characterization and mechanism

The n=1, 2 and 3 members of the Bi2(Ca, Sr)n+1CunO2n+4 series of superconductors have been synthesized and characterized by a variety of techniques including electrical resistivity, magnetic susceptibility and non-resonant microwave absorption. Based on studies with a number of compositions, the T c ranges for the n=1, 2 and 3 members are suggested to be 60±20 K, 82±8 K, and 107±3 K, the rather broad ranges arising from differences in sample stoichiometry and homogeneity. Electron spectroscopic studies show that Cu is mainly in the 2 + and 1 + states suggesting the importance of oxygen holes.

CCDC 683698: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Core–shell nanoparticles based on an oxide metal: ReO₃@Au (Ag) and ReO₃@SiO₂(TiO₂)

Core–shell nanoparticles based on metallic ReO3 nanoparticles have been prepared for the first time. The nanoparticles with the metallic shell viz. ReO3@Au and ReO3@Ag were prepared by the reduction of metal salts over ReO3 nanoparticle seeds. ReO3@SiO2 and ReO3@TiO2 core–shell nanoparticles were prepared by the hydrolysis of the organometallic precursors over the ReO3 nanoparticles. The core–shell nanoparticles have been characterized by transmission electron microscopy, optical absorption spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and Raman spectroscopy. The ReO3@Au and ReO3@Ag core–shell nanoparticles show composite plasmon absorption bands comprising contributions from both ReO3 and Au (Ag) whereas ReO3@SiO2 and ReO3@TiO2 show shifts in the plasmon bands depending on the refractive index of the shell material.