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41.
In this paper the singularly perturbed initial boundary value problems for the nonlocal reaction diffusion system are considered. Unsing the iteration method and the comparison theorem, the existence, uniqueness and its asymptotic behavior of solution for the problem are studied. 相似文献
42.
A series of substituted benzimidazoles, benzothiazoles, and benzoxazoles was synthesized by combining 1,2-phenylenediamine, 2-aminothiophenol, or 2-aminophenol with aryl, heteroaryl, aliphatic, α,β-unsaturated aldehydes in the presence of nano ceria (CeO2) as an efficient heterogeneous catalyst. 相似文献
43.
Materials that can recognize the changes in their local environment and respond by altering their inherent physical and/or chemical properties are strong candidates for future “smart” technology materials. Metal–organic frameworks (MOFs) have attracted a great deal of attention in recent years owing to their designable architecture, host–guest chemistry, and softness as porous materials. Despite this fact, studies on the tuning of the properties of MOFs by external stimuli are still rare. This review highlights the recent developments in the field of stimulus‐responsive MOFs or so‐called smart MOFs. In particular, the various stimuli used and the utility of stimulus‐responsive smart MOFs for various applications such as gas storage and separation, sensing, clean energy, catalysis, molecular motors, and biomedical applications are highlighted by using representative examples. Future directions in the developments of stimulus‐responsive smart MOFs and their applications are proposed from a personal perspective. 相似文献
44.
We have investigated the superconducting properties of the Bi1.7 Pb0.3Sr2Ca2−xCe
x
Cu3O10+δ system with x=0.00, 0.02, 0.04, 0.08 and 0.1 by X-ray diffraction and magnetic susceptibility. The substitution of Ce for Ca has been found
to drastically change the superconducting properties of the system. X-ray diffraction studies on these compounds indicate
decrease in the c-parameter with increased substitution of Ce at Ca site and volume fraction of high T
c (2 : 2 : 2 : 3) phase decreases and low T
c phase increases. The magnetic susceptibility of this compound shows that the diamagnetic on set superconducting transition
temperature (onset) varies from 109 K to 51 K for x=0.00, 0.02, 0.04, 0.08 and 0.1. These results suggest the possible existence of Ce in a tetravalent state rather than a trivalent
state in this system; that is, Ca2+ → Ce4+ replacement changes the hole carrier concentration. Hole filling is the cause of lowering T
c of the system. 相似文献
45.
A Nitro‐Functionalized Metal–Organic Framework as a Reaction‐Based Fluorescence Turn‐On Probe for Rapid and Selective H2S Detection
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Dr. Sanjog S. Nagarkar Aamod V. Desai Dr. Sujit K. Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(28):9994-9997
The toxic gas H2S has recently emerged as one of the important signaling molecules in biological systems. Thus understanding the production, distribution, and mode of action of H2S in biological system is important, but the fleeting and reactive nature of H2S makes it a daunting task. Herein we report a biocompatible, nitro‐functionalized metal–organic framework as reaction‐based fluorescence turn‐on probe for fast and selective H2S detection. The selective turn‐on performance of MOF remains unaffected even in presence of competing biomolecules. 相似文献
46.
S Chanda Sarmishtha Bhattacharyya Tumpa Bhattacharjee SS Ghugre Swapan Kumar Basu S Muralithar RP Singh B Mukherjee RK Bhowmik SN Ray 《Pramana》2001,57(1):175-179
The high spin states in N=80 139Pr have been investigated by in-beam γ-spectroscopic techniques following the reaction 130Te (14N, 5n) reaction at E=75 MeV, using a gamma detector array, consisting of seven 23% compton-suppressed high purity germanium detectors and a multiplicity
ball of fourteen bismuth germanate elements. Based on γ-γ coincidence data, the level scheme of 139Pr has been considerably extended up to 7.2 MeV excitation. Tentative spin-parity assignments are done for the newly proposed
levels on the basis of the DCO ratios corresponding to strong gates and the available information from the earlier light ion
experiments. 相似文献
47.
48.
A Raghava Rao SS Ramana Reddy K Premchand K L Narasimham K Parthasaradhi V Lakshminarayana 《Pramana》1982,18(3):271-278
The values of incoherent scattering functions are determined experimentally for 145 keV gamma rays in elements Au, Ag and
Y at scattering angles 40°, 70° and 100°, using a x-ray gamma coincidence technique. The corresponding theoretical values
are obtained from the tabulations of Hubbellet al, and computed from the models of Jauch and Rohrlich and Shimizuet al. A comparison between the theoretical and experimental results showed that the non-relativistic approach adopted in the theory
of Shimizuet al is inapplicable to the present cases. A gross agreement is noticed between the present experimental results and the other
theoretical values. 相似文献
49.
Tomohiro Ogawa Kazuki Takahashi Sanjog S. Nagarkar Koji Ohara You-lee Hong Yusuke Nishiyama Satoshi Horike 《Chemical science》2020,11(20):5175
High proton conducting electrolytes with mechanical moldability are a key material for energy devices. We propose an approach for creating a coordination polymer (CP) glass from a protic ionic liquid for a solid-state anhydrous proton conductor. A protic ionic liquid (dema)(H2PO4), with components which also act as bridging ligands, was applied to construct a CP glass (dema)0.35[Zn(H2PO4)2.35(H3PO4)0.65]. The structural analysis revealed that large Zn–H2PO4−/H3PO4 coordination networks formed in the CP glass. The network formation results in enhancement of the properties of proton conductivity and viscoelasticity. High anhydrous proton conductivity (σ = 13.3 mS cm−1 at 120 °C) and a high transport number of the proton (0.94) were achieved by the coordination networks. A fuel cell with this CP glass membrane exhibits a high open-circuit voltage and power density (0.15 W cm−2) under dry conditions at 120 °C due to the conducting properties and mechanical properties of the CP glass.A proton-conducting coordination polymer glass derived from a protic ionic liquid works as a moldable solid electrolyte and the anhydrous fuel cell showed I–V performance of 0.15 W cm−2 at 120 °C. 相似文献
50.
Ovechkina EE Gaysinskiy V Miller SR Brecher C Lempicki A Nagarkar VV 《Radiation measurements》2007,42(4-5):541-544
Despite the acknowledged advantages of CsI:Tl in many scintillator applications, a characteristic property that undermines its use in high-speed radiographic and radionuclide imaging is the presence of a strong afterglow component in its scintillation decay. This causes pulse pileup in high count-rate applications, reduced energy resolution in radionuclide imaging, and reconstruction artifacts in computed tomography applications. The research outlined here addresses the specific issue of suppressing the afterglow in CsI:Tl crystals by modifying them with codopants. In previous work we reported that one specific codopant, Eu(2+), was particularly effective in this regard, lowering the normalized intensity of the afterglow in the time range of 10 mus - 100 ms by almost two orders of magnitude compared to conventional material. We also found, however, that the extent of the suppressive effect was significantly influenced by the presence of additional additives, some of which were inadvertently introduced by the very material that provided the primary Eu codopant itself. The effects of these secondary codopants, which include elemental iodine and various oxidic species, are addressed in the present investigation. 相似文献