The design of low-wear friction materials

The relation between the elastoplastic characteristics of the friction surface and contact pressure is analyzed on the basis of the molecular-mechanical theory of friction. A criterion for predicting certain physico-mechanical properties necessary to ensure high wear resistance over a broad temperature interval is proposed.State Scientific-Research Institute of Machine Science, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 298–302, March–April, 1969.     

On the cyclotron resonance at skipping orbits in electron liquid

The possibility of the surface cyclotron waves propagation in metals with noncylindrical Fermi surface, placed in a weak magnetic field, is shown in the degenerate electron liquid theory case. Connected with the Fermi liquid constantA the contribution of such waves in the surface impedance of metals is calculated.     

Nonlinear interaction of the radiation with the pondermotive force deformated plasmas

The interaction of the powerful p-polarised radiation with the plasmas is studied. It is obtained the picture of the space and time evolution of the electromagnetic field in the plasmas and the picture of the particle's redistribution connected with the ponderomotive force of the plasma field and with the hydrodynamic motion as well. The dynamics of the electromagnetic field absorption and the distribution of the absorbed energy between the cold and hot electrons are investigated. The role of such general processes in the effect of second harmonic generation is demonstrated.     

Friction properties of styrene-ε-caprolactam graft copolymers

The friction properties of styrene--caprolactam graft copolymers have been investigated in the atmosphere, in a vacuum, and in the presence of ionizing radiation.Mekhanika Polimerov, Vol. 4, No. 3, pp. 559–562, 1968     

Transport in Porous Media Contents of Volume 43

Volume Contents

Transport in Porous Media Contents of Volume 43     

炔酰胺类缩合剂研究进展

缩合剂是指用于促成羧酸与胺或者醇直接缩合构建酰胺键或酯键的一类试剂的总称.由于酰胺和酯的重要性,缩合剂的开发成为了学术界与工业界广泛关注的一个重要研究方向.多肽合成就是α-氨基酸在缩合剂的作用下反复形成酰胺键的过程,因此,缩合剂在多肽合成中发挥着至关重要的作用.当前多肽合成所使用的试剂和技术大多是20世纪50~80年代发展起来的,这些试剂和技术的天生弊端逐渐显现出来.比如传统多肽缩合剂过度活化α-氨基酸而诱发的外消旋化和其它副反应导致的副产物成为药物多肽生产过程中一个极为关切的问题.另外固相多肽合成的低原子经济性给可持续发展带来了极大的挑战.这些问题只能依靠原始创新的颠覆性技术和全新的缩合方法来解决.我们课题组致力于通过发展新试剂和新反应来解决多肽与蛋白质化学合成领域的难题.本文系统介绍了我们发展的一种结构全新的炔酰胺类缩合试剂及其在酰胺、酯、大环内酯、多肽、硫代多肽合成中的应用研究进展.     

On the separation of variables in the theory of the ion-acoustic turbulence spectrum

The independence of the ion-acoustic turbulence spectrumof the constant of separation of variables, i.e., the wave vector magnitude and angle, in solving the integral equation defining the fluctuation intensity N(k) is proved.     

A new method of high-speed cellular protein separation and insight into subcellular compartmentalization of proteins

Transglutaminase (TGM)-2 is a ubiquitous protein with important cellular functions such as regulation of cytoskeleton, cell adhesion, apoptosis, energy metabolism, and stress signaling. We identified several proteins that may interact with TGM-2 through a discovery-based proteomics method via pull down of flag-tagged TGM-2 peptide fragments. The distribution of these potential binding partners of TGM-2 was studied in subcellular fractions separated by density using novel high-speed centricollation technology. Centricollation is a compressed air-driven, low-temperature stepwise ultracentrifugation procedure where low extraction volumes can be processed in a relatively short time in non-denaturing separation conditions with high recovery yield. The fractions were characterized by immunoblots against known organelle markers. The changes in the concentrations of the binding partners were studied in cells expressing short hairpin RNA against TGM-2 (shTG). Desmin, mitochondrial intramembrane cleaving protease (PARL), protein tyrosine kinase (NTRK3), and serine protease (PRSS3) were found to be less concentrated in the 8.5%, 10%, 15%, and 20% sucrose fractions (SFs) from the lysate of shTG cells. The Golgi-associated protein (GOLGA2) was predominantly localized in 15% SF fraction, and in shTG, this shifted to predominantly in the 8.5% SF and showed larger aggregations in the cytosol of cells on immunofluorescent staining compared to control. Based on the relative concentrations of these proteins, we propose how trafficking of such proteins between cellular compartments can occur to regulate cell function. Centricollation is useful for elucidating biological function at the molecular level, especially when combined with traditional cell biology techniques.     

Crystal Structure of Mercury 7-Amylthio-8-mercaptoquinolinate Hg[C9H5(SC5H11)NS]2 and the Structure of the 7-Amylthio-8-mercaptoquinoline Ligand

Mercury 7-amylthio-8-mercaptoquinolinate Hg[C9H₅(SC5H₁₁)NS]₂ has been synthesized and studied by X-ray diffraction. The crystals are triclinic: a = 8.980(2) Å, b = 9.298(2) Å, c = 18.909(4) Å, α = 93.66(2)°, β = 98.00(2)°, γ = 62.25(2)°, V = 1383.7(5) ų, ρ_calcd = 1.74 g/cm³, Z = 2, space group P1?. The structure is formed by neutral asymmetric complexes in which two 7-amylthio-8-mercaptoquinoline ligands coordinate, in a bidentate fashion (N,S), a mercury atom (Hg-S, 2.363(2) and 2.376(2) Å; Hg-N, 2.436(6) and 2.466(7) Å). The coordination polyhedron of mercury, which is a “swing” (2S+2N), has an SHgS bond angle equal to 173.5(1)°. Some structural features of the ligands in mercury, zinc and copper 7-amylthio-8-mercaptoquinolinates are discussed.