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91.
用磁园二色谱和光吸收谱对α-NiSO4.6H2O晶体进行了测量和研究,实验结果表明在λ=185~3300nm范围内存在一系列吸收结构,其中三个主要主要吸收带结构分别对应于晶体中Ni离子基态到有关激发态的d-d跃迁,对它们进行了初步指认,实验中观测到红带的λ=654nm和λ=713nm两结构间存在一系列弱的结构峰,它们主要与自旋轨道耦合相互作用结果有关,在磁园二色谱中还观测到λ=585nm的强吸收峰 相似文献
92.
A. Borghesi B. Guizzetti L. Nosenzo E. Reguzzoni A. Stella F. Levy 《Il Nuovo Cimento D》1984,4(2):141-152
Summary The main structures of interband spectra of Ti1−x
Hf
x
Se2 crystals (0≤x≤0.3 andx=1) have been investigated by means of thermoreflectance from 1 to 9 eV. New indications about the correspondence of the interband
spectra of TiSe2 and HfSe2 are given. Detailed data at intermediate stoichiometries, which give also evidence of possible bowing effects, are reported
and discussed. No relevant effect of the 200 K phase transition in TiSe2 is observable above 2 eV.
Riassunto Sono state studiate, mediante la tecnica della termoriflettanza, le principali strutture dello spettro interbanda dei cristalli Ti1−x Hf x Se2 (0≤x≤0.3 ex=1), fra 1 e 9 eV. Si sono così ottenute nuove indicazioni circa la corrispondenza fra gli spettri interbanda del TiSe2 e dell'HfSe2. Si riportano in dettaglio e discutono i dati di termoriflettanza a valori intermedi dix con evidenza di possibili effetti di ?bowing?. Non sono stati osservati apprezzabili effetti della transizione di fase a 200 K ad energie superiori a 2 eV.
Резюме Исследуются главные особенности междузонных спектров кристаллов Ti1−xHf x Se2 (0≤x≤0.3 иx=1) с помощью техники термоотражения в области от 1 до 9 эВ. Приводятся новые данные о соответствии между междузонными спектрами TiSe2 и HfSe2. Подробно обсуждаются данные при промежуточных значенияхx. Не наблюдаются заметные эффекты фазового перехода при 200 К в TiSe2 при энергиях выше 2 эВ.相似文献
93.
Themelis Andreas Stella Lorenzo Patrinos Panagiotis 《Computational Optimization and Applications》2022,82(2):395-440
Computational Optimization and Applications - Although the performance of popular optimization algorithms such as the Douglas–Rachford splitting (DRS) and the ADMM is satisfactory in convex... 相似文献
94.
Giroussi ST Voulgaropoulos AN Ayiannidis A 《Analytical and bioanalytical chemistry》1996,356(7):452-455
A selective, sensitive and reliable voltam- metric method for the simultaneous determination of MoS2-4 and MoO2-4 has been developed. The reduction of HgMoS4 at –0.43 V and the reduction of Mo as complex of MoO2-oxine2 at –0.63 V in acetate buffer at pH 4.9 are utilized for the simultaneous determination by differential pulse cathodic stripping voltametry (DPCSV). Cadmium and lead form complexes with MoS2-4, but do not interfere with the determination. The limit of detection is 0.59 g/l Mo for MoS2-4 and 1.8 g/l Mo for MoO2-4. The R.S.D at a concentration level of 20 g/l is 4.7% for MoO2-4 and 3.6% for MoS2-4. The method is applied to spiked blood plasma samples for the determination of free tetrathiomolybdates and molybdates. Additionally, labile tetrathiomolybdates and molybdates can be determined in spiked blood plasma after treatment of the sample with 0.15 mol/lKCN and ultrafiltration. 相似文献
95.
Constantine KL Mueller L Huang S Abid S Lam KS Li W Leet JE 《Journal of the American Chemical Society》2002,124(25):7284-7285
Nocathiacin I (BMS-249524) is a highly cross-linked thiazolyl peptide that displays potent activity against Gram-positive bacteria, including a number of antibiotic-resistant strains. This natural product contains 10 chiral centers. NMR studies have been performed to characterize the solution structure of nocathiacin I. A uniformly 13C,15N-labeled sample was used to obtain NMR assignments. Restrained simulated annealing calculations were performed by using accurately determined NOE distance restraints. All of the chiral centers were allowed to float during the simulated annealing protocol. Two clusters of structures were obtained that satisfy the NOE restraints very well and that are reasonably consistent with vicinal J-coupling constants. Within each cluster, all 10 chiral centers are uniquely defined. The two clusters are effectively mirror images of each other: all chiral centers that have the R(S) configuration in one cluster have the S(R) configuration in the other. The single threonine residue in nocathiacin I was subsequently determined to be l-threonine by chiral capillary electrophoresis, allowing the absolute configurations of all 10 chiral centers to be defined. 相似文献
96.
The Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR) was formally established by Australia, China, Japan, South Korea, Singapore, Taiwan, and Thailand in 2006. Its objective is to strengthen the collaboration, as well as the inter-communication, among the synchrotron radiation facilities and to promote synchrotron radiation sciences and accelerator-based research in the Asia-Oceania region. Regular meetings have been organized to uphold its objective. The first scientific meeting of AOFSRR took place at KEK, Japan, in 2006. Member countries have been taking turns to organize meetings: Taiwan (NSRRC, 2007), Australia (Australian Synchrotron, 2008), China (SSRF, 2009), South Korea (POSTEC, 2010), Thailand (SLRI, 2012), and Japan (SPring-8, 2013). In 2014, the National Synchrotron Radiation Research Center (NSRRC) hosted the Eighth Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR 2014) from September 15th to 18th in Hsinchu, Taiwan. The NSRRC is located in the Hsinchu Science Park, within an hour's drive from Taipei, the largest city in Taiwan. Hsinchu is a city not only composed of historical landmarks but also the heartland of high-tech semiconductor industries in Taiwan. 相似文献
97.
Stella Maragkaki Panagiotis C. Lingos George D. Tsibidis George Deligeorgis Emmanuel Stratakis 《Molecules (Basel, Switzerland)》2021,26(23)
The efficiency of light coupling to surface plasmon polariton (SPP) represents a very important issue in plasmonics and laser fabrication of topographies in various solids. To illustrate the role of pre-patterned surfaces and impact of laser polarisation in the excitation of electromagnetic modes and periodic pattern formation, Nickel surfaces are irradiated with femtosecond laser pulses of polarisation perpendicular or parallel to the orientation of the pre-pattern ridges. Experimental results indicate that for polarisation parallel to the ridges, laser induced periodic surface structures (LIPSS) are formed perpendicularly to the pre-pattern with a frequency that is independent of the distance between the ridges and periodicities close to the wavelength of the excited SPP. By contrast, for polarisation perpendicular to the pre-pattern, the periodicities of the LIPSS are closely correlated to the distance between the ridges for pre-pattern distance larger than the laser wavelength. The experimental observations are interpreted through a multi-scale physical model in which the impact of the interference of the electromagnetic modes is revealed. 相似文献
98.
Yasser H. Ochoa-Muoz Ruby Mejía de Gutirrez Jorge E. Rodríguez-Pez Isabel Grcia Stella Vallejos 《Molecules (Basel, Switzerland)》2022,27(9)
In this work, the gas-sensing functionality of porous ceramic bodies formed by the slip casting technique was studied using perovskite nanoparticles of an MSnO3 system (M = Ba, Ca, Zn) synthesized by a chemical route. The performance and reliability of the sensitive materials in the presence of different volatile organic compounds (acetone, ethanol, and toluene), and other gases (CO, H2 and NO2) were analysed. The ZnSnO3, BaSnO3, and CaSnO3 sensors showed sensitivities of 40, 16, and 8% ppm−1 towards acetone, ethanol, and toluene vapours, respectively. Good repeatability and selectivity were also observed for these gaseous analytes, as well as excellent stability for a period of 120 days. The shortest response times were recorded for the ZnSnO3 sensors (e.g., 4 s for 80 ppm acetone) with marked responses to low concentrations of acetone (1000 ppb). These results are attributed to the porosity of the sensitive materials, which favours the diffusion of gases, induces surface defects, and provides greater surface area and good sensitivity to acetone, as is seen in the case of ZnSnO3. 相似文献
99.
Moulton SE Barisci JN Bath A Stella R Wallace GG 《Langmuir : the ACS journal of surfaces and colloids》2005,21(1):316-322
The adsorption of Immunoglobulin G on a titanium dioxide (TiO(2)) electrode surface was investigated using (125)I radiolabeling and electrochemical impedance spectroscopy (EIS). (125)I radiolabeling was used to determine the extent of protein adsorption, while EIS was used to ascertain the effect of the adsorbed protein layer on the electrode double layer capacitance and electron transfer between the TiO(2) electrode and the electrolyte. The adsorbed amounts of Ig.G agreed well with previous results and showed approximately monolayer coverage. The amount of adsorbed protein increased when a positive potential was applied to the electrode, while the application of a negative potential resulted in a decrease. Exposure to solutions of Ig.G resulted in a decrease of the double layer capacitance (C) and an increase in the charge-transfer resistance (R(2)) at the electrode solution interface. As more Ig.G adsorbed onto the electrode surface, the extent of C and R(2) variation increased. These capacitance and charge-transfer resistance variations were attributed to the formation of a proteinaceous layer on the electrode surface during exposure. 相似文献
100.
In this issue of Chemistry & Biology, Blankman et al. identify new enzymes hydrolyzing the endocannabionoid 2-arachidonoyl glycerol (2-AG), increasing the complexity of endocannabinoid signaling in the brain, but also pinpointing additional therapeutic targets. 相似文献