Russian Tea Trade in Hankou during Second Half of 19th Century: Production of Brick Tea

This article addresses the issue of producing the socalled “brick tea” in China at Russian factories during the second half of the 19th century. Compressed teas constituted the second largest group after looseleaf teas highlighted in prerevolutionary Russian literature, sources, and statistics among Chinese teas exported to the Russian market. The study explores aspects of brick tea production that have been least covered in previous historiography. These include issues related to the procurement of raw materials for further pressing at Russian factories, pricing strategies for this product, and the accompanying competition. The experience of utilizing hydraulic presses for more efficient tea production, as well as the dynamics and volumes of brick tea production, are examined. The research revealed that in the latter half of the 19th century, Russian entrepreneurs in Hankou successfully organized the process of fabricating pressed teas, thereby contributing to the strengthening and further development of Russo-Chinese relations. Documents from central Russian archives were utilized in this study, enabling the unveiling of many previously unexplored aspects of the history of Russo-Chinese trade

Study of magnetic ordering in a multisublattice Ising model in terms of static fluctuation approximation

In terms of the static fluctuational approximation previously developed by the authors, a closed set of equations was found for finding all necessary thermodynamic characteristics (including the calculation of two-particle correlation functions) of a multisublattice Ising model with an arbitrary interaction between spins over the entire temperature range. Magnetic ordering on a simple-cubic magnetic lattice is investigated with allowance for the nearest and next-nearest neighbors. Closed equations were obtained for binary correlation functions of a given system

Magnetic properties of magnetoactive spin clusters

A simple model is proposed for describing magnetic properties of magnetoactive nanoclusters, which permits exact analytic solution. Exact expressions are obtained for thermodynamic characteristics of the model, which hold in the entire range of temperatures, magnetic fields, and interaction parameters. It is found that in the case of easy-axis anisotropy, the field dependence of magnetization of a nanocluster consisting of N particles with a spin of 1/2 has [N/2] fractional plateaus ([⋯] is the integer part) corresponding to polarized phases with ruptures singlet pairs. A nonmonotonic behavior observed for the magnetic susceptibility of an easy-plane cluster is typical of gap magnets. The spin gap between the ground state and excited states is proportional to the anisotropy parameter. © 2010 Pleiades Publishing, Ltd

Turkic-Chinese Relations in East and Central Asia in VI—VIII Centuries

The article deals with the problem of trade relations between the Turkic Qaghanates and China in the VI—VIII centuries. At that time, the zone of contact between steppe Mongolia and the northern Chinese borders became a place of active trade exchange, in which nomads, Chinese, and Sogdians participated. The purpose of the article is to analyze trade relations along the territory of contact between China and the Turkic Qaghanate in the VI—VIII centuries and to identify the economic significance of the Turkic-Chinese frontier for international trade relations in the Central Asian region. As a result of the analysis, it was shown that the strengthening of the influence of the Turks and China in Central Asia contributed to the establishment of stable trade along the Silk Road. Based on the analysis of Chinese sources, it was revealed that Chinese silk and Turkic horses have become the main goods involved in the exchange in the frontier zone. As a result, the authors conclude that trade along the frontier zone stimulated the entire system of trade relations in Central Asia. China’s need for nomadic horses led to huge shipments of silk fabrics to the steppe. The Turkic qaghans sold the accumulated silk to the Sogdians, who distributed it in the markets of the Central Asian region, sent it to Iran and Byzantium. Thus, due to trade, a symbiosis of China and the steppe region was created, international contacts intensified

Thermodynamics of Ising rare-earth magnet in the static fluctuation approximation

The authors obtain the closed self-consistent system of equations for calculation of the desired thermodynamic values of the Ising magnet with arbitrary spin and in presence of the single-ion anisotropy in the frame of the original static fluctuation approach (SFA). The essence of the SFA is based on accurate calculations of fluctuations of a molecular field. As an example the complete analysis of the critical behavior of the Ising magnet with spin S = 1 (Blume-Capiel model) is shown. The expressions for the phase transitions lines of the first and the second order are found. In addition, the coordinates of the tricritical point for some types of cubic lattices are found also. © 2014 Pleiades Publishing, Ltd

The NMR line shape of a system of nuclear spins with equal spin-spin coupling constants

We obtain an expression for the NMR line at low temperatures for a system of nuclear spins described by a Hamiltonian with equal spin-spin coupling constants. We show that in the case of "easy axis" anisotropy, the line has a logarithmic low-frequency singularity and an exponentially decreasing high-frequency asymptotic behavior at the temperature of an anomalous peak of heat capacity. In the case of "easy plane" anisotropy, the line has the traditional Gaussian form. We discuss the possibility of using NMR data to discover specific thermodynamic and magnetic properties of the considered model system. © 2011 MAIK/Nauka

Multiple-trapping model of dielectric relaxation of the ice I<inf>h</inf>

© 2017 Author(s). A microscopic theory of dielectric relaxation of the hexagonal ice (I h ) is proposed based on the multiple-trapping model. The theory explains the distinctive peculiarities of the relaxation time temperature behavior and the peak broadening parameter in a wide temperature range from the unified positions

Thermodynamic and magnetic properties of the finite spin complexes of the Ising type

In the frame of the static fluctuation approximation (SFA) the analysis of the thermodynamic and magnetic properties of the finite spin clusters in the 1D Ising model is performed It has been shown that under the influence of the magnetic impurity that forms the fixed value of the magnetization on the ends of spin complex the total magnetic ordering of the whole chain becomes possible. The results obtained in the frame of this model can open a way to understanding of magnetic properties of a wide class of the finite cluster systems. © 2014 Elsevier B.V

Ising model with competing axial interactions in the static fluctuation approximation

An original method, namely, the static fluctuation approximation (SFA) was used to study the thermodynamics of an Ising model with competing interactions between the nearest and next-nearest layers in the presence of an applied magnetic field. Three magnetically ordered phases (ferromagnetic, metamagnetic, and modulated) meeting at a multicritical point (the Lifshitz point) are shown to exist. Asymptotic expressions near the Lifshitz point for transition lines and the line of tricritical points are obtained. The modulated structure near the critical surface is shown to be a distorted sinusoidal wave with a period determined by the ratio γ of the competing interactions; in a zero magnetic field, only odd higher harmonics are present, whereas in a nonzero applied magnetic field, both even and odd harmonics exist. The nth-order harmonic asymptotically depends on the nth power of the fundamental harmonic. Expressions for correlation functions that correctly describe the modulated phase and exhibit characteristic oscillations are obtained