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排序方式: 共有237条查询结果,搜索用时 140 毫秒
101.
Qinyu Song Dr. Olaf Stefanczyk Guanping Li Dr. Kunal Kumar Kazuki Nakamura Dr. Koji Nakabayashi Prof. Shin-ichi Ohkoshi 《欧洲无机化学杂志》2023,26(30):e202300482
The spin-crossover (SCO) and charge-transfer (CT) phenomena, the switching processes between two distinguishable magnetic states, are promising for developing materials capable of sophisticated memory and sensing functionalities. The majority of SCO systems are based on iron(II) complexes. However, cobalt(II)-2,2′:6′,2′′-terpyridine (terpy) systems emerge as a promising alternative. In this work, new complex salts [CoII(terpy)2]2[MoIV(CN)8] ⋅ 15H2O, Co2Mo (H2O), and [CoII(terpy)2]3[WV(CN)8]2 ⋅ 12H2O, Co3W2 (H2O) were synthesized and physiochemically characterized. Structural studies for both compounds revealed [Co(terpy)2]2+ layers pillared by octacyanidometallate anions and completed with water molecules between them. Magnetic studies confirmed that the (de)solvated phases of both complexes exhibit partial SCO on the cobalt(II) centers: CoII−LS (SCo(II)-LS=1/2)↔CoII−HS (SCo(II)-HS=3/2). Moreover, handling dehydrated samples in a high-humidity environment leads to partial recovery of previous magnetic properties via humidity-induced SCO for Co2Mo : CoII−HS→CoII−LS, and the new phenomenon of isothermal humidity-activated charge-transfer-induced spin transition, which we define here as HACTIST, for Co3W2 : CoII−HS⋅⋅⋅WV (SCo(II)-HS=3/2 and SW(V)=1/2)→CoIII−LS⋅⋅⋅WIV (SW(IV)=0 and SCo(III)-LS=0). These comprehensive studies shed light on the water-solvation-dependent spin transitions in Co(II)-octacyanidometallate(IV/V) complexes. 相似文献
102.
K. Kunal M. Paluch C. M. Roland J. E. Puskas Y. Chen A. P. Sokolov 《Journal of Polymer Science.Polymer Physics》2008,46(13):1390-1399
The influence of molecular weight, M, on the fragility and fast dynamics in polyisobutylene (PIB) was studied using dielectric and mechanical relaxation spectroscopies, calorimetry, and Raman spectroscopy. The measurements indicate a decrease in fragility with increasing M for shorter chains, in the range of M where Tg is M‐dependent. Such behavior is not observed for other polymers and is at odds with traditional theoretical models that predict an increase in fragility with chain length. These results confirm the unusual character of PIB, as evident in various properties including extremely low gas permeability, a low fragility, and a segmental relaxation spectrum much broader than expected for a low‐fragility material. The reason for this anomalous behavior remains unclear, but might be related to the symmetric structure of the PIB repeat unit, together with comparable flexibility of both structural components, the backbone and side groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1390–1399, 2008 相似文献
103.
Pain Puspak Das Kunal Sadhu Arindam Kanjilal Maitreyi Ray De Debashis 《International Journal of Theoretical Physics》2019,58(9):3118-3137
International Journal of Theoretical Physics - Information processing and conventional computing are usually resource constrained; evermore they need to operate in a physically suspicious... 相似文献
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An analytical model for subthreshold current and subthreshold swing of short-channel triple-material double-gate (TM-DG) MOSFETs is presented in this paper. Both the drift and diffusion components of current densities are considered for the modeling of subthreshold current. Virtual cathode concept of DG MOSFETs is utilized to model the subthreshold swing of TM-DG MOSFETs. The effect of different length ratios of the three channel regions under three different gate materials of device on the subthreshold current and subthreshold swing of the short-channel TM-DG MOSFETs have been discussed. The dependencies of subthreshold current and subthreshold swing on various device parameters have been studied. The simulation data obtained by using the commercially available 2D device simulation software ATLAS™ has been used to validate the present model. 相似文献
108.
Karan Singh Vinayak Suneel Kumar 《The European Physical Journal A - Hadrons and Nuclei》2012,48(7):1-7
One-neutron knockout reactions in a 9Be target have been investigated at relativistic energies, near 700 MeV/u, for a set of sd-shell, neutron-rich nuclei. The experiment was performed in the FRS spectrometer, at GSI. ??-ray measurements were carried out by means of the MINIBALL ??-ray spectrometer and allowed the determination of partial cross-sections and branching ratios corresponding to the final states of the emerging knockout fragments. Experimental results are presented for 17C, 19N, 21O and 25F projectiles. The role of excited states of the N ? 1 fragments in the composition of the ground state of these neutron-rich projectiles is outlined in this work. 相似文献
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Costunolide and dehydrocostus lactone are two guianolide sesquiterpene lactones present in abundance in Saussurea costus, a plant popularly known as `costus' and renowned throughout the world for its medicinal properties. A simple densitometric
TLC method for simultaneous quantification of costunolide and dehydrocostus lactone, without derivatization, has been developed
as an alternative to gas chromatography. The method enables rapid, sensitive, and reproducible simultaneous analysis of a
variety of samples. The method was validated for precision, repeatability, and accuracy in accordance with ICH guidelines.
Amounts of costunolide and dehydrocostus lactone in different samples of costus, estimated by use of this method, were in
the range 0.46 to 1.00% and 0.81 to 1.21%, respectively. The proposed method is simple, precise, specific, sensitive, and
accurate and can be used by the herbal drug industry for routine quality control of the crude drug costus. 相似文献