Search

The questions of application of nanomaterials in mechanical engineering are considered. Concept of electrochemical processing products in mechanical engineering with the use of a solid nanodisperse phase is defined. The characteristics and methods of application in the processes of electrodeposition of carbon nanomaterials are determined. The results of experimental investigations of electrolytic chrome plating with multi-walled carbon nanotubes of the "Taunit" series are presented.

The questions of the application of nanomaterials in mechanical engineering are considered. The concept of electrochemical processing products in mechanical engineering with the use of a solid nanodisperse phase is defined. The characteristics and methods of application in the processes of electrodeposition of carbon nanomaterials are determined. The results of experimental investigations of electrolytic chrome plating with multi-walled carbon nanotubes of the "Taunit" series are presented.

Amorphous metal alloys have unique properties and are widely used. The unique properties of such materials are accompanied by problems of mechanical strength. The existing methods of their processing are not unambiguous and require a certain approach. In practice, laser technologies allow us to optimize the complex properties of such materials. The selection of optimal processing modes, including the influence of the gas phase, allows you to locally affect the material, increase the microhardness in certain areas. The absence of the influence of the processing medium on the mechanical properties is confirmed. Local impact on the surface sample also leads to an increase in crack resistance. In general, nanosecond laser exposure can be an effective tool for controlling the mechanical characteristics of an amorphous nanocrystalline material.

The ability to control the mechanical properties of metal alloys is an urgent task in materials science. For formation of certain operational properties, in most cases, it is enough to treat the working surface of the product by laser radiation. Classical processing methods are ineffective in relation to multicomponent amorphous-nanocrystalline metallic alloys. This is due to their limited use. Usually, this treatment leads to the loss of unique properties the amorphous-nanocrystalline material. Increasing crack resistance and microhardness is not an easy problem. The structure of an amorphous nanocrystalline material can be destroyed under the action of laser processing. Laser nanosecond treatment, as result of a complex effect on the surface, slightly affects the structure of material. The treated material is characterized by increased microhardness and crack resistance, while at the same time such changes may be controlled.

One of the most important purposes of materials science is the ability to govern the physical properties of materials characterized by different structures. The strength properties of nanostructured metal alloys do not always meet the exploitation requirements. The set of properties of such materials is stable within narrow limits: temperature, mechanical, and corrosion conditions. Traditional processing modes are ineffective for such materials. Attempts to use them often lead to the loss of unique physical and chemical properties. The most effective methods of processing such materials are associated with the use of laser radiation. The laser pulse has a number of features, including a complex effect on the surface layers of the material. Spot and short irradiation with high-energy rays can preserve the unique physical properties of samples as a whole and improve strength indicators without destroying the structure of the material as a whole.

A series of new fine‐tunable monodentate phosphite and phosphoramidite ligands based on carboranes have been synthesized and used for asymmetric Rh‐catalyzed hydrogenation of prochiral olefins with the result of up to 99.8% ee. Dependence of the enantioselectivity on the electron‐withdrawing or electron‐donating properties of the carboranyl substituent has been studied. Chirality, 2009. © 2008 Wiley‐Liss, Inc.

A scheme of an iodine laser with two different intracavity space -- time modulators based on electrooptic PLZT ceramics is experimentally studied. It is shown that lasing can occur in different angular directions with the use of both modulators. The output laser energy is 10 mJ with a pulse duration of 200 us and a beam divergence of 6.3 x 10-4 rad. The laser field of view (5.1 x 10-3 rad) consists of a discrete set of 8 x 8 directions.

Novel P,P‐bidentate diamidophosphite ligands (I) are synthesized and applied to Pd‐catalyzed asymmetric allylic substitutions with amines or dimethyl malonate.

Two new chiral binaphthol derivatives are synthesized and used as ligands in transition metal‐catalyzed hydrogenation, allylic alkylation and allylic amination reaction.

The first pincer‐type phosphodiamidite ligand is synthesized and applied as catalyst ligand in the Pd‐catalyzed enantioselective allylic sulfonylation of ester and carbonate (I) and in the Pd‐catalyzed deracemization of compound (Ib).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

For Abstract see ChemInform Abstract in Full Text.