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1.
We describe here a simple set-up for X-ray diffraction under high pressure using a diamond anvil cell employing a sealed tube. The set-up works in angular dispersive geometry and is built using rather common components that are available in a research laboratory. We show that using this set-up one can routinely acquire good-quality data for the determination of structural properties under pressure and the equations of state. Technical details are presented along with examples of experimental results for sodium chloride and LiV2O4. 相似文献
2.
It is proposed to construct a spallation neutron source (SNS) at Centre for Advanced Technology (CAT) based on a 1 GeV proton
synchrotron with 100 MeV H− LINAC as injector. Additionally, the LINAC can form the first 100 MeV part of a 1 GeV proton LINAC to be built in future
for accelerator driven system (ADS) applications. We are exploring a configuration of the 100 MeV LINAC which will consist
of an H− ion source, a 4–6 MeV RFQ followed either by a 20 MeV drift tube LINAC (DTL) and 100 MeV separated function drift tube LINAC
(SDTL) or a coupled cavity drift tube LINAC (CCDTL) structure. In this paper, we present the results of our preliminary physics
design studies of the RFQ-SDTL, RFQ-CCDTL and RFQ-DTL-SDTL configurations. The design of the 4.5 MeV RFQ is discussed along
with the matching sections between the RFQ-SDTL/DTL and RFQ-CCDTL. The choice of the accelerator configuration and that of
various parameters of the individual accelerator structures under consideration are discussed. The design objectives are to
arrive at a configuration which eases heat removal for CW operation and which is less prone to halo formation in order to
reduce the beam loss at higher energies. 相似文献
3.
M K Parida Nita Sinha B Adhikary B Allanach A Alok K S Babu B Brahmachari D Choudhury E J Chun P K Das A Ghosal D Hitlin W S Hou S Kumar H N Li E Ma S K Majee G Majumdar B Mishra G Mohanty S Nandi H Pas M K Parida S D Rindani J P Saha N Sahu Y Sakai S Sen C Sharma C D Sharma S Shalgar N N Singh S Uma Sankar N Sinha R Sinha F Simonetto R Srikanth R Vaidya 《Pramana》2006,67(5):849-860
This is the report of flavor physics and model building working group at WHEPP-9. While activites in flavor physics have been
mainly focused on B-physics, those in model building have been primarily devoted to neutrino physics. We present summary of working group discussions
carried out during the workshop in the above fields, and also briefly review the progress made in some projects subsequently. 相似文献
4.
Bogdan Nita 《General Relativity and Gravitation》2003,35(10):1865-1868
Algebraically special gravitational fields are described using algebraic and differential invariants of the Weyl tensor. A type III invariant is also given and calculated for Robinson-Trautman spaces. 相似文献
5.
I. Lacatusu N. Badea R. Nita M. Giurginca D. Bojin I. Iosub A. Meghea 《Journal of Physical Organic Chemistry》2009,22(11):1015-1021
Sol–gel chemistry can be easily modified to the changing needs of society to produce fine‐tuned sol–gel nanostructured materials for relevant applications. In this context, there is an increasing need for natural and versatile raw materials as well as biocompatible compounds that could be extensively used as biomarkers for bioimaging in diagnosis or therapy. Silica‐based materials are widely used in the field of biomedicine due to their chemical inertness and biocompatibility. In the present paper, orange peel extract was immobilized inside inorganic silica and hybrid silica‐silsesquioxane polymeric networks. Silica and organo‐modified silica matrices were synthesized through a templated sol–gel route of TEOS and an organosilsesquioxane (octaisobutyltetracyclo[7.3.3.15,11] octasiloxane‐endo‐3,7‐diol), with D ‐glucose as template, and for comparison a non‐ionic surfactant (tetraethylene glycol mono‐hexadecyl ether) was also used. The bioactive properties of the molecules from orange peel extract were preserved after immobilization in both silica and silica‐silsesquioxane networks. Moreover, the fluorescence properties were amplified by 10–20 times more than the native orange peel extract. The structural properties of the final materials have been studied by FT‐IR, UV–Vis‐NIR, and fluorescence spectroscopy. Dynamic light scattering measurements and transmission electron microscopy were used to estimate the size and morphology of the hybrid materials with orange peel extract immobilized in silica networks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
7.
Cleaves HJ Michalkova Scott A Hill FC Leszczynski J Sahai N Hazen R 《Chemical Society reviews》2012,41(16):5502-5525
Life is believed to have originated on Earth ~4.4-3.5 Ga ago, via processes in which organic compounds supplied by the environment self-organized, in some geochemical environmental niches, into systems capable of replication with hereditary mutation. This process is generally supposed to have occurred in an aqueous environment and, likely, in the presence of minerals. Mineral surfaces present rich opportunities for heterogeneous catalysis and concentration which may have significantly altered and directed the process of prebiotic organic complexification leading to life. We review here general concepts in prebiotic mineral-organic interfacial processes, as well as recent advances in the study of mineral surface-organic interactions of potential relevance to understanding the origin of life. 相似文献
8.
Karácsony O Deschamps JR Trammell SA Nita R Knight DA 《Molecules (Basel, Switzerland)》2012,17(5):5724-5732
The synthesis of a new 2,2'-bipyridyl functionalized oligovinylenephenylene (OVP-5) containing a methyl protected thiol using Heck coupling and the Horner-Wadsworth-Emmons reaction and is described. A key step involving a diisopropylcarbodiimide promoted dehydration of a stable β-hydroxyphosphonate intermediate was identified. The structure of precursor E-(4-(4-bromostyryl)phenyl)(methyl)sulfane was determined using X-ray crystallography. 相似文献
9.
Cimpoesu F Ito S Shimotani H Takagi H Dragoe N 《Physical chemistry chemical physics : PCCP》2011,13(20):9609-9615
Analysis of IR and Raman spectra of Ar@C(60) and Kr@C(60) shows that the incorporation of noble gas atoms causes a blue shift of low energy vibrations, which have radial character, and a red shift of higher energy ones which have a tangential character movement. The mechanism of these phenomena is explained on the basis of ab initio numerical experiments with DFT and MP2 procedures. Methodological discussions are advanced, altogether with a scheme for the estimation of the van der Waals interaction between fullerene and noble gas, based on the frequency shifts. 相似文献
10.
Aurica P. Chiriac Loredana E. Nita Manuela T. Nistor 《Journal of polymer science. Part A, Polymer chemistry》2011,49(7):1543-1551
The study reports the synthesis of a copolymer based on 2‐hydroxyethyl methacrylate and 3,9‐divinyl‐2,4,8,10‐tetraoxaspiro[5.5]undecane (U) acquired through radical polymerization in the presence of 2,2′‐azobis(2‐methylpropionitrile). The attempt was to have a solid content as high as 10 wt %. The polymerization process was conducted in the presence of a classic ionic surfactant—sodium lauryl sulfate—and comparatively using two variants of protective colloid β‐cyclodextrin and poly(aspartic acid), respectively. The prepared dispersions were characterized from the viewpoint of their hydrodynamic radius, zeta potential, and conductivity evolution during syntheses. The mean particle size and size distribution and zeta potential and conductivity were also evaluated for the synthesized polymeric particles. The compositions of the polymers were confirmed by FTIR and 1H NMR spectra, and also, the thermal stability of the polymeric compounds was evaluated. SEM and AFM investigations of the polymer morphology are also presented. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献