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921.
Irina Glazova Larisa Smirnova Sergey Zaitsev Alexander Avdoshin Vladimir Naumov 《Supramolecular chemistry》2019,31(6):412-423
Our team conducted theoretical calculations and experimental studies of interpolymer interactions in insulin-chitosan complexes based on the spatial orientation of chitosan and insulin macromolecules using Langmuir film balance at various pH values. The most optimal conditions for interpolymer interactions between insulin and chitosan chains occur at pH value of 5.4, which corresponds to the isoelectric point of insulin. For the similar pH values of 4.2 and 6.0, the free energy of coordination between chitosan and insulin was estimated by molecular dynamic simulations as of 1.1 and 5.8 kcal mol?1, respectively. 相似文献
922.
从含4,4'-二吡啶胺结构单元的双(二吡啶胺) 桥联配体出发,采用溶剂热法合成了两个结构新颖的配位聚合物:[CdL1Br2]n?7.5nH2O (L1 = N,N,N′,N′-四(4-吡啶)-1,4-苯二胺) (1)和[Cu2L2(μ1,1,3-SCN)2]n?nMeOH (L2 = N,N-二(2-吡啶)-N',N'-二(4-吡啶)-1,4-苯二胺) (2),对它们进行了元素分析、红外光谱等表征,并用X-射线单晶衍射测定了其晶体结构。单晶测试结果显示,配合物1中配体L1的四个吡啶N原子均参与配位,桥联了4个Cd原子,每个Cd原子与四个吡啶 N 原子和两个溴配位,形成六配位的八面体构型。通过这些配位作用,最终形成包含 Kagome 结构的三维超分子网络。配合物2 是由一维柱状 {Cu(SCN)}n 链通过 L2 桥联生成的二维结构。有趣的是,L2中具有螯合能力的2,2'-二吡啶胺单元并未参与配位,只有4,4'-二吡啶胺单元中的两个吡啶N原子分别与一个 Cu(I) 配位,连接了相邻两条平行的{Cu(SCN)}n 链,生成二维结构。 相似文献
923.
The review summarizes data on synthesis and structure of rhenium chalcocyanide cluster onions [ Re6X8(CN)6]4-f (X = S, Se, Te) belonging to a new class of inorganic compounds. Two main groups of such compounds are considered: salts
with an island structure and polymer compounds. Various factors governing the type of structure and the dimensionality of
the polymer compounds are analyzed, including the nature of the chalcogen atom in the cluster anion, preferable coordination
of the transition metal cation, and the size of additional charge-compensating cations. Crystal-chemical approaches to design
of complex salts based on octahedral rhenium chalcocyanide cluster anions are formulated.
Translated fromZhurnal Strukturnoi Khimii, Vol. 41, No. 3, pp. 609-638, May–June, 2000. 相似文献
924.
925.
Yun Shan Peng Han Sheng Xu Pance Naumov S. Shanmuga Sundara Raj Hoong‐Kun Fun Ibrahim Abdul Razak Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1386-1388
The title compound, C10H9NO2Se, crystallizes as flat molecules linked by selenium–oxygen interactions [Se?O = 3.189 (4) Å] into a linear chain along the a axis of the triclinic cell. The bond dimensions that are derived from ab initio geometry optimization calculations are similar to those determined from the diffraction measurements. 相似文献
926.
Using the model of an infinite one-dimensional periodic layered structure, we consider the possibilities of controlling dispersion properties and transmission spectra of hybrid optical components consisting of photonic band-gap structures filled with a resonant gas. It is shown that the combination of resonance-enhanced gas dispersion with the dispersion of a photonic band-gap structure may give rise to new features in the dispersion and transmission of hybrid spectral elements. These effects can be employed to create narrowband filters and ultrarefractive prisms with controllable parameters. 相似文献
927.
A. A. Samokhvalov T. I. Arbuzova N. A. Viglin S. V. Naumov I. B. Smolyak A. V. Korolev N. I. Lobachevskaya 《Physics of the Solid State》2000,42(4):719-721
The problem of localized superconductivity has motivated the preparation of Mg1−x
CuxO solid solutions with NaCl structure and 0.01≤x≤0.20, as well as a study of the magnetization and magnetic susceptibility χ in the 2–400 K temperature range and in magnetic fields of up to 5 T. The temperature dependence of χ is described for all
compositions by the Curie-Weiss law, χ = C/(T − θ), where the constant C is close to the value calculated for each composition for μeff = 1.7–1.9μB, and θ is close to zero. For T < 30 K, χ(T) deviates for all compositions toward lower χ, which can be attributed to magnetic ordering of exchange-coupled clusters
in the solid solution. At T∼320–330 K, an anomaly of a diamagnetic type, i.e., a decrease of χ by 6–30% of its paramagnetic value, has been observed
for all compositions against the background of the generally paramagnetic χ(T). A discussion is presented of alternative reasons for this anomaly and of its possible connection with localized superconductivity.
__________
Translated from Fizika Tverdogo Tela, Vol. 42, No. 4, 2000, pp. 701–703.
Original Russian Text Copyright ? 2000 by Samokhvalov, Arbuzova, Viglin, Naumov, Smolyak, Korolev, Lobachevskaya. 相似文献
928.
In this paper,we study and analyze the regularized least squares for function-on-function regression model.In our model,both the predictors(input data)and respo... 相似文献
929.
Naumov P Sakurai K Asaka T Belik AA Adachi S Takahashi J Koshihara SY 《Inorganic chemistry》2006,45(13):5027-5033
The structural grounds of the decrease of point and lattice symmetries coupled with switching of the exchange interaction in single crystals of a highly strained, coordinationally unsaturated bisdiaminecopper(II) cation are described. The combined magnetic susceptibility and X-ray diffraction results indicate that the interplay between the inherent vibronic instability and ligand-field strain imposed by moderately flexible, coordinationally shielding ligands enables effective switching of the pseudo-Jahn-Teller d9 centers between states with different exchange interaction in the low-temperature regime and valence orbital orientation and coordination geometry in the high-temperature regime. Within the low-temperature hysteresis region, the phase transition can also be induced by excitation of the ligand-to-metal charge-transfer bands, resulting in overall shrinkage of the lattice. The compound is a prototype of weakly electronically coupled one-dimensional Jahn-Teller systems, which can undergo phase transitions induced by light, in addition to heating, cooling, and change of pressure, and it represents a prospective basis for the design of switching materials capable of multimode external control. 相似文献
930.
N. I. Solin S. V. Naumov S. V. Telegin A. V. Korolev 《Journal of Experimental and Theoretical Physics》2017,125(6):1096-1101
It is established that excess oxygen content δ influences the exchange bias (EB) in layered GdBa-Co2O5 + δ cobaltite. The EB effect arises in p-type (δ > 0.5) cobaltite and disappears in n-type (δ < 0.5) cobaltite. The main parameters of EB in GdBaCo2O5.52(2) polycrystals are determined, including the field and temperature dependences of EB field H EB , blocking temperature T B , exchange coupling energy J i of antiferromagnet–ferromagnet (AFM–FM) interface, and dimensions of FM clusters. The training effect inherent in systems with EB has been studied. The results are explained in terms of exchange interaction between the FM and AFM phases. It is assumed that the EB originates from the coexistence of Co3+ and Co4+ ions that leads to the formation of monodomain FM clusters in the AFM matrix of cobaltite. 相似文献