90 research outputs found
Π‘Π’Π Π£ΠΠ’Π£Π Π Π ΠΠΠΠΠ’Π ΠΠΠΠ«Π Π‘ΠΠΠΜΠ‘Π’ΠΠ ΠΠΠ€ΠΠΠ’ΠΠ ΠΠ ΠΠ ΠΠΠΠ¦Π Π‘ΠΠΠΠΠΠΠΠΠ«Π₯ ΠΠΠΠ‘Π’ΠΠ ΠΠ ΠΠΠΠΠ―
Comprehensive studies of the structure and electronic properties of defects occurring on the connection boundary of disarranged nβtype Si(001) wafers have been made by the methods of transmission electron microscopy, deep level transient spectroscopy (DLTS) and photoluminescence. The main revealed defects are two types of dislocation structure: orthogonal dislocation network composed of two screw dislocation families and zigzag mixed dislocations. The dislocation structures observed are sources of intense luminescence whose spectra are appreciably different from the standard dislocation luminescence spectra at all the investigated misfit angles of the Si bonded wafers. We show that an increase of the misfit angle results in a strong transformation of the dislocation luminescence spectra consisting in changes of the form of the spectra and a decrease in the integral luminescence intensity. In the samples in question the DLTS method revealed the presence of deep centers the concentration of which increased with increasing of twist misorientation of bonded wafers. It has been established that the deep centers are related to the dislocation structures observed by means of transmission electron microscopy.Β ΠΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ ΠΏΡΠΎΡΠ²Π΅ΡΠΈΠ²Π°ΡΡΠ΅ΠΈΜ ΡΠ»Π΅ΠΊΡΡΠΎΠ½- Π½ΠΎΠΈΜ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ, Π½Π΅ΡΡΠ°ΡΠΈΠΎΠ½Π°ΡΠ½ΠΎΠΈΜ ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΠΈΠΈ Π³Π»ΡΠ±ΠΎΠΊΠΈΡ
ΡΡΠΎΠ²Π½Π΅ΠΈΜ ΠΈ ΡΠΎΡΠΎΠ»ΡΠΌΠΈΠ½Π΅ΡΡΠ΅Π½ΡΠΈΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΠΊΠΎΠΌ- ΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΡΡΠΊΡΡΡΡ ΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΡΡ
ΡΠ²ΠΎΠΈΜΡΡΠ² Π΄Π΅ΡΠ΅ΠΊΡΠΎΠ², Π²ΠΎΠ·- Π½ΠΈΠΊΠ°ΡΡΠΈΡ
Π½Π° Π³ΡΠ°Π½ΠΈΡΠ΅ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ ΡΠ°Π·ΠΎΡΠΈΠ΅Π½ΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΏΠ»Π°ΡΡΠΈΠ½ Si(001) nβΡΠΈΠΏΠ° ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌΠΈ Π²ΡΡΠ²Π»Π΅Π½Π½ΡΠΌΠΈ Π΄Π΅- ΡΠ΅ΠΊΡΠ°ΠΌΠΈ ΡΠ²Π»ΡΡΡΡΡ Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΡΠ΅ ΡΡΡΡΠΊΡΡΡΡ Π΄Π²ΡΡ
Π²ΠΈΠ΄ΠΎΠ²: ΠΎΡΡΠΎΠ³ΠΎΠ½Π°Π»ΡΠ½Π°Ρ ΡΠ΅ΡΠΊΠ° Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΈΜ, ΡΠΎΡΡΠΎΡΡΠ°Ρ ΠΈΠ· Π΄Π²ΡΡ
ΡΠ΅ΠΌΠ΅ΠΈΜΡΡΠ² Π²ΠΈΠ½ΡΠΎΠ²ΡΡ
Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΈΜ, ΠΈ Π·ΠΈΠ³Π·Π°Π³ΠΎΠΎΠ±ΡΠ°Π·Π½ΡΠ΅ ΡΠΌΠ΅ΡΠ°Π½Π½ΡΠ΅ Π΄ΠΈΡ- Π»ΠΎΠΊΠ°ΡΠΈΠΈ. ΠΡΡΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΠΌΡΠ΅ Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΡΠ΅ ΡΡΡΡΠΊΡΡΡΡ ΡΠ²Π»ΡΡΡΡΡ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠΎΠΌ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΠΈΜ Π»ΡΠΌΠΈΠ½Π΅Ρ- ΡΠ΅Π½ΡΠΈΠΈ, ΡΠΏΠ΅ΠΊΡΡ ΠΊΠΎΡΠΎΡΠΎΠΈΜ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΎΡΠ»ΠΈΡΠ°Π΅ΡΡΡ ΠΎΡ ΡΡΠ°Π½Π΄Π°ΡΡΠ½ΠΎΠ³ΠΎ ΡΠΏΠ΅ΠΊΡΡΠ° Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΈΜ Π»ΡΠΌΠΈΠ½Π΅ΡΡΠ΅Π½ΡΠΈΠΈ ΠΏΡΠΈ Π²ΡΠ΅Ρ
ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΡ
ΡΠ³Π»Π°Ρ
ΠΏΠΎΠ²ΠΎΡΠΎΡΠ½ΠΎΠΈΜ ΡΠ°Π·ΠΎΡΠΈΠ΅Π½ΡΠ°ΡΠΈΠΈ ΠΏΠ»Π°ΡΡΠΈΠ½ Si. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΈ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠΈ ΡΠ³Π»Π° ΡΠ°Π·ΠΎΡΠΈΠ΅Π½- ΡΠ°ΡΠΈΠΈ ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΠΈΡ ΡΠΈΠ»ΡΠ½Π°Ρ ΡΡΠ°Π½Ρ- ΡΠΎΡΠΌΠ°ΡΠΈΡ ΡΠΏΠ΅ΠΊΡΡΠΎΠ² Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΈΜ Π»ΡΠΌΠΈΠ½Π΅ΡΡΠ΅Π½ΡΠΈΠΈ, ΠΊΠΎΡΠΎΡΠ°Ρ Π·Π°ΠΊΠ»ΡΡΠ°Π΅ΡΡΡ Π² ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΡΠΎΡΠΌΡ ΡΠΏΠ΅ΠΊΡΡΠΎΠ² ΠΈ ΡΠΌΠ΅Π½Ρ- ΡΠ΅Π½ΠΈΠΈ ΠΈΠ½ΡΠ΅Π³ΡΠ°Π»ΡΠ½ΠΎΠΈΜ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ Π»ΡΠΌΠΈΠ½Π΅ΡΡΠ΅Π½ΡΠΈΠΈ. ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ Π½Π΅ΡΡΠ°ΡΠΈΠΎ- Π½Π°ΡΠ½ΠΎΠΈΜ ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΠΈΠΈ Π³Π»ΡΠ±ΠΎΠΊΠΈΡ
ΡΡΠΎΠ²- Π½Π΅ΠΈΜ Π² ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΡ
ΠΎΠ±ΡΠ°Π·ΡΠ°Ρ
Π²ΡΡΠ²Π»Π΅Π½ΠΎ Π½Π°Π»ΠΈΡΠΈΠ΅ Π³Π»ΡΠ±ΠΎΠΊΠΈΡ
ΡΠ΅Π½ΡΡΠΎΠ², ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°- ΡΠΈΡ ΠΊΠΎΡΠΎΡΡΡ
Π²ΠΎΠ·ΡΠ°ΡΡΠ°Π΅Ρ Ρ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ ΡΠ³Π»Π° ΡΠ°Π·ΠΎΡΠΈΠ΅Π½ΡΠ°ΡΠΈΠΈ ΠΏΠ»Π°ΡΡΠΈΠ½. Π£ΡΡΠ°- Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½Π½ΡΠ΅ Π³Π»ΡΠ±ΠΎΠΊΠΈΠ΅ ΡΠ΅Π½ΡΡΡ ΡΠ²ΡΠ·Π°Π½Ρ Ρ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΠΌΡΠΌΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΡΠΎΡΠ²Π΅ΡΠΈΠ²Π°ΡΡΠ΅ΠΈΜ ΡΠ»Π΅ΠΊΡΡΠΎΠ½- Π½ΠΎΠΈΜ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΡΠΌΠΈ ΡΡΡΡΠΊΡΡΡΠ°ΠΌΠΈ.
ChemInform Abstract: The Role of Metal-Oxygen Intermediates in Biological and Chemical Monooxygenation of Alkanes
Metallocavitins as Advanced Enzyme Mimics and Promising Chemical Catalysts
The supramolecular approach is becoming increasingly dominant in biomimetics and chemical catalysis due to the expansion of the enzyme active center idea, which now includes binding cavities (hydrophobic pockets), channels and canals for transporting substrates and products. For a long time, the mimetic strategy was mainly focused on the first coordination sphere of the metal ion. Understanding that a highly organized cavity-like enzymatic pocket plays a key role in the sophisticated functionality of enzymes and that the activity and selectivity of natural metalloenzymes are due to the effects of the second coordination sphere, created by the protein framework, opens up new perspectives in biomimetic chemistry and catalysis. There are two main goals of mimicking enzymatic catalysis: (1) scientific curiosity to gain insight into the mysterious nature of enzymes, and (2) practical tasks of mankind: to learn from nature and adopt from its many years of evolutionary experience. Understanding the chemistry within the enzyme nanocavity (confinement effect) requires the use of relatively simple model systems. The performance of the transition metal catalyst increases due to its retention in molecular nanocontainers (cavitins). Given the greater potential of chemical synthesis, it is hoped that these promising bioinspired catalysts will achieve catalytic efficiency and selectivity comparable to and even superior to the creations of nature. Now it is obvious that the cavity structure of molecular nanocontainers and the real possibility of modifying their cavities provide unlimited possibilities for simulating the active centers of metalloenzymes. This review will focus on how chemical reactivity is controlled in a well-defined cavitin nanospace. The author also intends to discuss advanced metalβcavitin catalysts related to the study of the main stages of artificial photosynthesis, including energy transfer and storage, water oxidation and proton reduction, as well as highlight the current challenges of activating small molecules, such as H2O, CO2, N2, O2, H2, and CH4
Hydrophobic association of Fe(III) protoporphyrin IX with cyclodextrins and their derivatives
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