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排序方式: 共有289条查询结果,搜索用时 15 毫秒
1.
Kondakov N. N. Mel´nikova T. M. Chekryzhova T. V. Mel´nikova M. V. Zinin A. I. Torgov V. I. Chizhov A. O. Kononov L. O. 《Russian Chemical Bulletin》2015,64(5):1142-1148
Russian Chemical Bulletin - Terminal disaccharide fragment of phenolic glycolipid from Mycobacterium leprae (PGL-I) was synthesized as a glycoside with 4-(2-aminoethoxy)phenyl aglycon. The obtained... 相似文献
2.
Jean Ravez Re´gnault Von Der Mu¨hll Paul Hagenmuller 《Journal of solid state chemistry》1975,14(1):20-24
Au sein d'un re´seau de type BaFeF5 des chai?nes d'octae`dres fluore´sa`sommets communs peuvent disparai?tre en donnant naissance a des canaux dont l'occupation partielle ou totale par des files de cations Sr2+ et de couples d'anions F?, conduit respectivement aux phases Sr3(FeF6)2 ou Sr5T3F19 (T = Cr, Co, Ga). Une discussion cristallochimique permet d'expliquer l'existence d'un domaine de solutions solides au sein du diagramme ternaire SrF2BaF2FeF3. 相似文献
3.
Thomas Andre´s Wolcan Ezequiel Fe´liz Mario R. Capparelli Alberto L. 《Transition Metal Chemistry》1997,22(6):541-544
The kinetics of the complexation of NiII by pteroylglutamic acid have been studied in the 545 ∘C range, the ionic strength
(0.6 M) being regulated with KNO3, in the 5.5–7.0pH range, using the stopped-flow method. Under the experimental conditions
two processes were observed. The faster process was detected in the millisecond range and is associated with the reaction
between NiII and the ligand. The slower is observed within a few seconds. Complementary equilibrium studies were made at 25
∘C. The results are consistent with the formation of a 1:1 complex between the reactants, and a mechanism is proposed to account
for the observed behaviour. Equilibrium constants for the NiII plus pteroylglutamic acid system, as well as activation parameters,
are reported.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
The intermolecular potential energy surface (PES) of Ar interacting with the acetylene cation in its (2)Pi(u) ground electronic state is characterized by infrared photodissociation (IRPD) spectroscopy and quantum chemical calculations. In agreement with the theoretical predictions, the rovibrational analysis of the IRPD spectrum of C(2)H(2) (+)-Ar recorded in the vicinity of the antisymmetric CH stretching fundamental (nu(3)) is consistent with a vibrationally averaged T-shaped structure and a ground-state center-of-mass separation of R(c.m.) = 2.86 +/- 0.09 A. The nu(3) band experiences a blueshift of 16.7 cm(-1) upon complexation, indicating that vibrational excitation slightly reduces the interaction strength. The two-dimensional intermolecular PES of C(2)H(2) (+)-Ar, obtained from coupled cluster calculations with a large basis set, features strong angular-radial coupling and supports in addition to a global pi-bound minimum also two shallow side wells with linear H-bound geometries. Bound state rovibrational energy level calculations are carried out for rotational angular momentum J = 0-10 (both parities) employing a discrete variable representation-distributed Gaussian basis method. Effective spectroscopic constants are determined for the vibrational ground state by fitting the calculated rotational energies to the standard Watson A-type Hamiltonian for a slightly asymmetric prolate top. 相似文献
5.
A. Marti´n-Esteban P. Fernández C. Cámara 《Analytical and bioanalytical chemistry》1997,357(7):927-933
Immunoaffinity techniques have been widely used for the determination of different analytes in the medical field. However
the use of antibodies immobilized in an appropriate support material to preconcentrate pesticides from environmental samples
is only recent. The production of antibodies, election of supports, antibody immobilization procedures, elution of analytes
from immunosorbents and the more recent applications in the field of pesticide analysis are reviewed. The present review concludes
that immunosorbents have great potential and discusses the present limitations and expected future trends.
Received: 29 July 1996 / Accepted: 14 August 1996 相似文献
6.
Flow injection system with gas diffusion for the sequential determination of total nitrogen and phosphorus in vegetables 总被引:1,自引:0,他引:1
Jose´ L. F. C. Lima Antoacutenio O. S. S. Rangel M. Renata S. Souto 《Analytical and bioanalytical chemistry》1997,358(5):657-662
A flow injection system was developed for the sequential determination of total nitrogen and phosphorus in digests of vegetables
using potentiometric and spectrophotometric detection systems, respectively. A tubular ammonium selective electrode with a
sensor system composed of nonactin/monactin in tris(2-ethylhexyl) phosphate was used. The selectivity limitations of this
electrode were overcome by the inclusion of a gas-diffusion unit in the system that separated ammonium from the rest of the
sample matrix and allowed the determination of total nitrogen and phosphorus by the partition of the sample plug between two
streams.
The results obtained with the developed FIA system were in good agreement with those of the reference methods. Sampling rates
from 40 to 60 samples per hour and relative standard deviations below 3.5% were achieved.
Received: 17 October 1996/Revised: 21 November 1996/Accepted: 27 November 1996 相似文献
7.
Karl Pays Caroline Mabille Véronique Schmitt Fernando Leal-Calderon J´erôme Bibette 《Journal of Dispersion Science and Technology》2013,34(1-3):175-186
This paper aims to review the various degradation pathays of emulsions. Aging of emulsions may proceed through three distinct microscopic mechanisms: diffusion or permeation, dewetting, and coalescence, each one being associated with a very characteristic growth scenario. We show within this context how double emulsions are a unique tool to complete the basic understanding of emulsion metastability. 相似文献
8.
N. S. Emel´yanova N. Yu. Shmatko N. A. Sanina S. M. Aldoshin 《Russian Chemical Bulletin》2017,66(10):1842-1846
Possible reactions of the mononuclear iron nitrosyl complex [Fe(SC(NH2)2)2(NO)2]Сl?H2O in an aqueous solution were studied using quantum chemical modeling. The electronic structures of the possible intermediates were examined by the NBO and AIM methods. The substitution of the thio ligand in the iron—sulfur nitrosyl complex by a water molecule and the formation of dimeric intermediate complexes were found to facilitate the NO-donation process. 相似文献
9.
Prozorova G. F. Korzhova S. A. Pozdnyakov A. S. Emel´yanov A. I. Ermakova T. G. Dubrovina V. I. 《Russian Chemical Bulletin》2015,64(6):1437-1439
Russian Chemical Bulletin - The water-soluble nanocomposite with the uniform distribution of silver nanoparticles in polymer matrix was synthesized on the basis of poly-1-vinyl-1,2,4-triazole.... 相似文献
10.
Ukhin L. Yu. Kuz´mina L. G. Alexeenko D. V. Belousova L. V. Morkovnik A. S. Shepelenko E. N. Podshibyakin V. A. Borodkin G. S. Dmitrieva O. I. 《Russian Chemical Bulletin》2019,68(12):2290-2297
Russian Chemical Bulletin - New potentially bioactive derivatives comprising spatially hindered pyrocatechol linked to hydrazine, acid hydrazides (including isoniazid), and acetylcysteine by a... 相似文献