296 research outputs found
Growth of graphene on 6H-SiC by molecular dynamics simulation
Classical molecular-dynamics simulations were carried out to study epitaxial
growth of graphene on 6H-SiC(0001) substrate. It was found that there exists a
threshold annealing temperature above which we observe formation of graphitic
structure on the substrate. To check the sensitivity of the simulation results,
we tested two empirical potentials and evaluated their reliability by the
calculated characteristics of graphene, its carbon-carbon bond-length, pair
correlation function, and binding energy.Comment: 7 pages, 5 figure
ΠΡΠΎΠ΅ΠΊΡ ΡΠ΅Ρ Π° ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ ΠΏΠΎΡΠΎΡΠΊΠΎΠΎΠ±ΡΠ°Π·Π½ΠΎΠ³ΠΎ ΡΠ°Π½ΡΠ°Π»Π° Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΌΠ°Π³Π½ΠΈΠΉΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΏΠ΅Π½ΡΠ°ΠΎΠΊΡΠΈΠ΄Π° ΡΠ°Π½ΡΠ°Π»Π°, ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΡΡ 40 Ρ/Π³ΠΎΠ΄ ΠΏΠΎ ΡΠ°Π½ΡΠ°Π»ΠΎΠ²ΠΎΠΌΡ ΠΏΠΎΡΠΎΡΠΊΡ
Π Π΄Π°Π½Π½ΠΎΠΌ Π΄ΠΈΠΏΠ»ΠΎΠΌΠ½ΠΎΠΌ ΠΏΡΠΎΠ΅ΠΊΡΠ΅ Π±ΡΠ»Π° ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π° Π°ΠΏΠΏΠ°ΡΠ°ΡΡΡΠ½ΠΎ-ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΡ
Π΅ΠΌΠ° ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ ΠΏΠΎΡΠΎΡΠΊΠΎΠΎΠ±ΡΠ°Π·Π½ΠΎΠ³ΠΎ ΡΠ°Π½ΡΠ°Π»Π° Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΌΠ°Π³Π½ΠΈΠΉΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΏΠ΅Π½ΡΠ°ΠΎΠΊΡΠΈΠ΄Π° ΡΠ°Π½ΡΠ°Π»Π°, ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΡΡ 40 Ρ/Π³ΠΎΠ΄ ΠΏΠΎ ΡΠ°Π½ΡΠ°Π»ΠΎΠ²ΠΎΠΌΡ ΠΏΠΎΡΠΎΡΠΊΡ. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π΅ Π΄Π°Π½Π½ΡΡ
ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΡΠ½ΡΡ
Π±Π°Π»Π°Π½ΡΠΎΠ² Π±ΡΠ»ΠΎ ΠΏΠΎΠ΄ΠΎΠ±ΡΠ°Π½ΠΎ ΠΎΡΠ½ΠΎΠ²Π½ΠΎΠ΅ ΠΈ Π²ΡΠΏΠΎΠΌΠΎΠ³Π°ΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΠΎΠ±ΠΎΡΡΠ΄ΠΎΠ²Π°Π½ΠΈΠ΅ Π΄Π»Ρ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΠΉΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ. ΠΡΠ½ΠΎΠ²Π½ΡΠΌ Π°ΠΏΠΏΠ°ΡΠ°ΡΠΎΠΌ Π²ΡΠ±ΡΠ°Π½Π° ΡΡΡΠ°Π½ΠΎΠ²ΠΊΠ° ΡΡΠ΅ΡΠ½Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠ°Π΄Π΅Π½ΠΈΡ Π΄Π»Ρ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΎΠΊΡΠΈΠ΄Π° ΡΠ°Π½ΡΠ°Π»Π° ΠΌΠ°Π³Π½ΠΈΠ΅ΠΌ Π²ΡΡΠΎΡΠΎΠΉ 2,6 ΠΌ, Π΄ΠΈΠ°ΠΌΠ΅ΡΡ-0,25 ΠΌ. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΠΎΠ΄ΠΎΠ±ΡΠ°Π½Π½ΠΎΠ³ΠΎ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΠ±ΠΎΡΡΠ΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½ ΡΠ΅Ρ
ΠΌΠ°Π³Π½ΠΈΠΉΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ. ΠΡΠ» ΠΏΡΠΎΠΈΠ·Π²Π΅Π΄Π΅Π½ ΡΠ°ΡΡΠ΅Ρ Π·Π°ΡΠ°Π±ΠΎΡΠ½ΠΎΠΉ ΠΏΠ»Π°ΡΡ ΡΠ°Π±ΠΎΡΠ½ΠΈΠΊΠΎΠ². Π Π°ΡΡΡΠΈΡΠ°Π½Π° ΡΠ΅Π±Π΅ΡΡΠΎΠΈΠΌΠΎΡΡΡ ΠΊΠΎΠ½Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»ΡΠΏΡΠΎΠ΄ΡΠΊΡΠ°. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΏΡΠ½ΠΊΡΡ ΡΠΎΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎΡΡΠΈ.In the diploma project was proposed an instrumentation-technological scheme for the processing of obtaining powdered tantalum by means of magnesium-thermal reduction of tantalum pentoxide, with a capacity of 40 tons per year for tantalum powder. Based on the data of material balances, the main and auxiliary equipment for magnesium-thermal recovery was selected. Was chosen the main device - cramped fall installation to carry out the reduction of tantalum oxide with magnesium 2.6 m in height,diameter-0.25 m. On the basis of the selected auxiliary equipment, was made a plan of the working area .The calculation of the personnel number of the personnel, the basic wage fund, the cost of the final semi-product has been made. Was introduced with the main points of social responsibility
Lectin prospecting in Colombian Labiatae. A systematic-ecological approach. - II
This is the second study of lectin and mucilage detection in Labiatae nutlets from
Colombia. It was carried out on 31 taxa belonging to 7 genera in which no previous
studies have been carried out in this field. A differential response was observed
in the group of genera and species studied in terms of mucilage presence as well
as lectin activity which consistently increased following extract treatment with
Pectinex. Lectin activity was detected in 28 species, being important (greater than
60% activity) in at least 75% of them. Genera such as Hyptis, Scutellaria, Aegiphila
and Lepechinia, whilst not presenting mucilage, did present lectin activity, having
high activity in most cases. By contrast, Salvia (in all sections studied) presented
mucilage and important lectin activity.Este es el segundo estudio sobre la presencia de mucΓlagos y lectinas en nΓΊculas
de Labiadas colombianas. Se llevΓ³ a cabo en 31 taxones, pertenecientes a siete
gΓ©neros, sobre los cuales no se disponΓa de informaciΓ³n en este campo. Se observΓ³
una respuesta diferencial en los gΓ©neros y especies en lo relativo a la presencia
de mucΓlago y a la actividad de lectina que se incrementΓ³ de manera consistente
despuΓ©s de tratar los extractos con Pectinex. Se detectΓ³ actividad de lectina en 28
especies, siendo muy importante (mayor del 60%) en al menos 75% de ellas. Aunque
los gΓ©neros Hyptis, Scutellaria, Aegiphila y Lepechinia no presentaron mucΓlago,
su actividad de la lectina fue alta. Por el contrario Salvia (en todas las secciones
estudiadas) presentΓ³ mucΓlago y una actividad importante de lectina.Peer reviewe
Highly variable AFLP and S-SAP markers for the identification of βMalbecβ and βSyrahβ clones
The retrotransposon-based sequence-specific amplification polymorphism (S-SAP) and the amplified fragment length polymorphism (AFLP) marker systems were used to assess the clonal variation of 14 βSyrahβ and 22 βMalbecβ (Vitis vinifera L.) clones. The utility of S-SAP markers was compared to that of AFLP markers. On the basis of our results, S-SAP is more informative marker system and showed higher average number of polymorphic bands per cultivar group than AFLP. Relationships among clones were analyzed by cluster analysis using unweighted pair-groups using arithmetic averages and in both cases revealed well defined groups of clones, in which βMalbecβ clones were separated from βSyrahβ clones. High variability of some clones could also be seen within these clusters. The different levels of polymorphism for βMalbecβ and βSyrahβ obtained in this study suggest that βMalbecβ exhibits a higher mutation frequency than βSyrahβ. Our results indicate that higher proportion of polymorphic bands in S-SAP makes it a less labour-intensive and more efficient approach for developing markers for clonal identification.
Experimental researches of mechanoelectrical transformations in tashtagolsky iron-ore field rock
Physical modeling in lab is approach of definition of main mechanical transformations behaviours inrock massive for choice of electromagnetical signals optimum characteristics and parameters ofelectomagnetical emission for developed approach of crush burst estimate. It is support connection betweenmechanoelectrical transformations characteristics and stress strain state of researched object. Physical modelingof mechanoelectrical transformations in the lab was made under a press by axial quasistatic compression of rockspecimen up to destruction. During stressing applied injections of specimens using determined acoustic signals. For researches used model and real specimens of Tashtagolsky iron-ore field rock, such as ore and matrix rock
ΠΠ½ΡΠ΅ΡΠ°ΠΊΡΠΈΠ²Π½Π°Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ, ΠΏΠΎΠ»ΡΡΠ°Π΅ΠΌΡΡ ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²ΠΎΠΌ Π»Π°Π·Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠ½ΠΈΡΠΎΡΠ° Π² ΡΠ΅ΠΆΠΈΠΌΠ΅ ΡΠ΅Π°Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ
Π Ρ
ΠΎΠ΄Π΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎ Π±ΡΠ»ΠΎ ΡΠΎΠ·Π΄Π°ΡΡ ΡΡΡΡΠΎΠΉΡΡΠ²ΠΎ ΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΠ±ΡΠ΅ΠΊΡΠ° Π² ΡΠΈΡΡΠ΅ΠΌΠ΅ Π»Π°Π·Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠ½ΠΈΡΠΎΡΠ°.
Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΎΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ² ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΠ΅Π·ΠΊΠΎΡΡΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π΅ Π²ΡΠ±ΡΠ°Π½Π½ΠΎΠ³ΠΎ ΠΌΠ΅ΡΠΎΠ΄Π° Π±ΡΠ» ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½ Π°Π»Π³ΠΎΡΠΈΡΠΌ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΎΠΊΡΡΠΈΡΠΎΠ²ΠΊΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ. Π’Π°ΠΊΠΆΠ΅ Π±ΡΠ» ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½ Π°Π»Π³ΠΎΡΠΈΡΠΌ ΡΠΈΡΡΠ΅ΠΌΡ ΡΠ»Π΅ΠΆΠ΅Π½ΠΈΡ Π·Π° ΠΎΠ±ΡΠ΅ΠΊΡΠΎΠΌ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Π°Π»Π³ΠΎΡΠΈΡΠΌΠ° Π½ΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΊΡΠΎΡΡΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ΄Π°Π»ΠΎΡΡ ΡΠ½ΠΈΠ·ΠΈΡΡ ΠΈΡΠΊΠ°ΠΆΠ΅Π½ΠΈΡ, Π²Π½ΠΎΡΠΈΠΌΡΠ΅ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠΎΠΉ Π»Π°Π·Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠ½ΠΈΡΠΎΡΠ° ΠΈ Π°ΠΊΡΠΈΠ²Π½ΠΎΠΉ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΠ΅Π΄ΠΎΠΉ, ΠΈ ΠΎΡΠ³Π°Π½ΠΈΠ·ΠΎΠ²Π°ΡΡ ΡΠΈΡΡΠ΅ΠΌΡ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΎΠΊΡΡΠΈΡΠΎΠ²ΠΊΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ ΠΈ ΡΠΈΡΡΠ΅ΠΌΡ ΡΠ»Π΅ΠΆΠ΅Π½ΠΈΡ, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΡΡ ΠΎΡΡΠ»Π΅ΠΆΠΈΠ²Π°ΡΡ ΠΏΠ΅ΡΠ΅ΠΌΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΎΠ±ΡΠ΅ΠΊΡΠ° Π½Π°Π±Π»ΡΠ΄Π΅Π½ΠΈΡ Ρ ΡΠΎΡΠ½ΠΎΡΡΡΡ Π΄ΠΎ 1 ΠΏΠΈΠΊΡΠ΅Π»Ρ.In the study, it was necessary to create a device object positioning system for the laser monitor.
The study surveyed algorithms determine the sharpness of the image. Based on the selected method algorithm for automatic focus of the image was developed. There was also designeded a tracking system for the object of the algorithm based on normalized cross-correlation method. The study was able to reduce the distortions introduced by the optical system of the laser and monitor the active optical medium, and to organize a system of auto focus and image tracking system to track the movement of the object of observation up to 1 pixel
Cystic lymph node metastases of squamous cell carcinoma of Waldeyer's ring origin
We analysed in a retrospective study the frequency of cystic lymph node (LN) metastases in neck dissection specimens of 123 patients with primary squamous cell carcinoma (SCC) arising in the palatine tonsils (62 M/14 F), the base of the tongue (38 M/5 F) and the nasopharynx (2 M/2 F). Eighty-two per cent of patients had metastases (64 tonsillar SCC, 33 base of tongue SCC and all four nasopharynx SCC) in 368 LN of a total 2298 sampled LN. Thirty-nine per cent of patients had exclusively solid metastases and 37% of patients had exclusively cystic metastases. A total of 62 patients had some signs of cyst formation in one or more metastatically affected LN (27 with only histological evidence of cyst formation with luminal diameters < 5 mm, 35 with clinically detectable cyst with luminal diameter > 5 mm). Cystic metastases were more common in patients with SCC of the base of the tongue (P = 0.005), while solitary clinically evident cystic metastasis with lumina > 5 mm were found exclusively in tonsillar carcinoma (P = 0.024). In comparison with solid metastases, cyst formation was associated with N-categories (N2b and N3, P = 0.005) in SCC of the base of the tongue origin. No such association was observed for tonsillar SCC (P = 0.65). The primary mechanism of cyst formation was cystic degeneration. Β© 1999 Cancer Research Campaig
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