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排序方式: 共有151条查询结果,搜索用时 15 毫秒
121.
A novel MB‐SWNT‐sol‐gel nanocomposite material was prepared by the sol‐gel process incorporating a redox mediator and carbon nanotubes. The electrocatalytic properties of the nanomaterial based sensor toward NADH oxidation were studied by electrochemical measurements. Significant enhancement of oxidation current is obtained at electrodes modified by MB‐SWNT‐sol‐gel in comparison with the analogous carbon black and/or graphite composite modified electrode. The usefulness of the nanocomposite material as a matrix for immobilizing enzymes is also demonstrated. Analytical parameters of D ‐lactate biosensors with and without SWNT in the hybrid film were compared demonstrating that performance of the biosensor was significantly improved when introducing SWNT. 相似文献
122.
Adina?Lumini?a?Sasulbsasu@yahoo.com" title="sasu@math.uvt.ro lbsasu@yahoo.com" itemprop="email" class="gtm-email-author">Email author 《Integral Equations and Operator Theory》2007,58(1):133-152
The purpose of this paper is to give new and general characterizations for uniform dichotomy and uniform exponential dichotomy
of evolution families on the real line. We consider two general classes denoted
and
and we prove that if V,W are Banach function spaces with
and
, then the admissibility of the pair
for an evolution family
implies the uniform dichotomy of
. In addition, we consider a subclass
and we prove that if
, then the admissibility of the pair
implies the uniform exponential dichotomy of the family
. This condition becomes necessary if
. Finally, we present some applications of the main results. 相似文献
123.
Adina Rotar Richard A. Varga Klaus Jurkschat Cristian Silvestru 《Journal of organometallic chemistry》2009,694(9-10):1385-1392
Hypercoordinated diorganotin(IV) dichloride, [2-(Et2NCH2)C6H4]2SnCl2 (1), was prepared by reacting [2-(Et2NCH2)C6H4]Li with SnCl4. Halide-exchange reactions between 1 and the appropriate potassium halides gave [2-(Et2NCH2)C6H4]2SnX2 [X = F (2), Br (3), I (4)]. Reaction of 1 with excess of Na2S gave the cyclo-[{2-(Et2NCH2)C6H4}2SnS]2 (5). The solution behavior of the title compounds in solution was investigated by multinuclear (1H, 13C, 19F and 119Sn) NMR spectroscopy, including variable temperature studies. Single-crystal X-ray diffraction analysis revealed for all compounds intramolecular N → Sn coordination thus resulting in distorted octahedral (C,N)2SnX2 configurations. Planar chirality is observed as result of the non-planarity of the SnC3N rings; all compounds, however, crystallizing as racemates. The isomers are linked by extensive hydrogen bonds to give different supramolecular architectures in the crystals of compounds 1, 3 and 4. 相似文献
124.
Dr. Lucia Flamigni Adina I. Ciuciu Prof. Dr. Heinz Langhals Bernd Böck Prof. Dr. Daniel T. Gryko 《化学:亚洲杂志》2012,7(3):582-592
A couple of corrole–perylene carboximide dyads ( C2‐PIa and C2‐PIx ) have been synthesized and their photoreactivity has been evaluated. We aimed at obtaining better performances for photoinduced charge separation, both in terms of efficiency and in terms of lifetime, with respect to formerly studied systems. The energy level of the charge‐separated state was tuned by selecting perylene and corrole components with diverse redox and spectroscopic properties. High spectroscopic energy levels of the perylene carboximide derivatives (PIs) allow a fast charge separation to be maintained in competition with an energy‐transfer process from the PI to the corrole unit. Yields and lifetimes of charge separation in toluene are, respectively, 75 % and 2.5 μs for C2‐PIa and 65 % and 24 ns for C2‐PIx . The results and the effect of solvent polarity are discussed in the framework of current energy‐ and electron‐transfer theories. 相似文献
125.
Lucica Viorica Ababei Angela Kriza Adina Magdalena Musuc Cristian Andronescu Elena Adina Rogozea 《Journal of Thermal Analysis and Calorimetry》2010,101(3):987-996
New complexes of 2-benzoyl-pyridil-isonicotinoylhydrazone (L) with Cu(II), Co(II), Ni(II) and Mn(II), having formula of type
[ML2] SO4·xH2O (M = Cu2+, Co2+, Ni2+, x = 2 and M = Mn2+, x = 3), have been synthesised and characterised. All complexes were characterised on the basis of elemental analyses, IR spectroscopy,
UV–VIS–NIR, EPR, as well as thermal analysis and determination of molar conductivity and magnetic moments. The thermal behaviour
of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry
(DSC). The structure of L hydrazone was established by X-ray study on single crystal. The ligand works as tridentate NNO,
being coordinated through the azomethine nitrogen, the pyridine nitrogen and carbonylic oxygen. Heats of decomposition, ΔH, associated with the exothermal effects were also determined. 相似文献
126.
Angela Kriza Mariana Loredana Dianu Cristian Andronescu Adina Elena Rogozea Adina Magdalena Musuc 《Journal of Thermal Analysis and Calorimetry》2010,100(3):929-935
New copper (II) complexes of Schiff bases with 1,2-di(imino-2-aminomethylpyridil)ethane with the general composition CuLX m (H2O) x , [L = Schiff base, X = Cl?, Br?, NO3 ?, ClO4 ?, CH3COO?, m = 2; X = SO4 2?, m = 1] were prepared by template synthesis. The complexes were characterized by elemental analysis, conductivity measurements, magnetic moments, IR, UV–VIS and EPR spectra. The thermal behavior of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Infrared spectra of all complexes are in good agreement with the coordination of a neutral tetradentate N4 ligand to the cooper (II) through azomethinic and pyridinic nitrogen. Magnetic, EPR and electronic spectral studies show a monomeric distorted octahedral geometry for all Cu(II) complexes. Conductance measurements suggest the non-electrolytic nature of the compounds, except for copper (II) nitrate and perchlorate complexes which are 1:2 electrolytes. Heats of decomposition, ΔH, associated with the exothermal effects were also determined. 相似文献
127.
T. Morozan 《随机分析与应用》2013,31(5):915-931
An input-output linear time-varying discrete system with statedependent noise and mean square exponential stable evolution is considered. It is proved that if the norm of the input-output operator is less than γ then a corresponding parametrized by γ Riccati equation has a unique global bounded and stabilizing solution. An application to the estimate of a stability radius is given 相似文献
128.
Lazar AN Dupont N Navaza A Coleman AW 《Chemical communications (Cambridge, England)》2006,(10):1076-1078
Two trimeric units of calix[4]arene di-methoxycarboxylic acid form a six-pointed star architecture that, in turn, generates triple helical aquatubes which intermesh between themselves by aromatic-aromatic interdigitation of the macrocycle. 相似文献
129.
Lazar AN Coleman AW Terenzi S Strazewski P 《Chemical communications (Cambridge, England)》2006,(1):63-65
Amphiphilic peptidyl-RNA conjugates, molecules that mimic natural peptidyl-transfer RNA, are capable of self-assembling on glass substrates as vesicles and supported bilayers. 相似文献
130.
The aim of this paper is to obtain necessary and sufficient conditions for uniform exponential trichotomy of evolution families
on the real line. We prove that if p ∈ (1,∞) and the pair (Cb(R,X),Cc(R,X)) is uniformly p-admissible for an evolution family ={U(t,s)}t≥s then is uniformly exponentially trichotomic. After that we analyze when the uniform p-admissibility of the pair (Cb(R, X), Cc(R, X)) becomes a necessary condition for uniform exponential trichotomy. As applications of these results we study the uniform
exponential dichotomy of evolution families. We obtain that in certain conditions, the admissibility of the pair (Cb(R,X),Lp(R,X)) for an evolution family ={U(t,s)}t≥s is equivalent with its uniform exponential dichotomy. 相似文献