Measurement of phosphorus segregation in silicon at the atomic-scale using STM

In order to fabricate precise atomic-scale devices in silicon using a combination of scanning tunnelling microscopy (STM) and molecular beam epitaxy it is necessary to minimize the segregation/diffusion of dopant atoms during silicon encapsulation. We characterize the surface segregation/diffusion of phosphorus atoms from a $\delta$-doped layer in silicon after encapsulation at 250$^{\circ}$C and room temperature using secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES), and STM. We show that the surface phosphorus density can be reduced to a few percent of the initial $\delta$-doped density if the phosphorus atoms are encapsulated with 5 or 10 monolayers of epitaxial silicon at room temperature. We highlight the limitations of SIMS and AES to determine phosphorus segregation at the atomic-scale and the advantage of using STM directly

Topological phases of a dimerized Fermi–Hubbard model for semiconductor nano-lattices

Motivated by recent advances in fabricating artificial lattices in semiconductors and their promise for quantum simulation of topological materials, we study the one-dimensional dimerized Fermi–Hubbard model. We show how the topological phases at half-filling can be characterized by a reduced Zak phase defined based on the reduced density matrix of each spin subsystem. Signatures of bulk–boundary correspondence are observed in the triplon excitation of the bulk and the edge states of uncoupled spins at the boundaries. At quarter-filling, we show that owing to the presence of the Hubbard interaction the system can undergo a transition to the topological ground state of the non-interacting Su–Schrieffer–Heeger model with the application of a moderate-strength external magnetic field. We propose a robust experimental realization with a chain of dopant atoms in silicon or gate-defined quantum dots in GaAs where the transition can be probed by measuring the tunneling current through the many-body state of the chain

Anatomical studies No. 52. Two cases of false masculine hermaphroditism in cattle (Path. nos. 5018 and 11125)

The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.No abstract available

Anatomical studies, no. 48 : on a case of brachygnathia superior in an ox

No abstract available.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn2015mn201

Anatomical studies, No. 61. A comparison of two of the so-called Zebus

Summarising the position we have: Resemblances. 1. Both Zebu types originated in Asia. 2. Externally: (a) They have a coffin-shaped head with convex profile; (b) the dewlap is prominent; (c) the hump is well marked, but not characteristic, for it occurs also in the Sanga type. 3. Internally: (a) The thoracic vertebrae from No. 6 backwards have bifid spines. 4. Both have adapted themselves well to unfavourable environmental conditions, e.g. poor pasture, and parasites. Differences. 1. Origin: Lateral-horned Zebu originate from a pure parent stock while Shorthorned Zebu are a derived type arising through intermixture of Lateralhorned Zebu and Brachyceros. 2. Arrival in Africa: Lateral-horned Zebu arrived in pre-Christian times while Shorthorned Zebu arrived in Christian times. 3. Distribution in Africa: Lateral-horned Zebu are scattered and mainly south of the Zambesi River while Shorthorned Zebu form compact groups chiefly in East Africa, north of the Zambesi River. 4. Horns: Lateral-horned Zebu have horns which are oval in cross-section, long and laterally placed while Shorthorned Zebu have horns which are circular at the base, short to medium length and upright. 5. Hump: Lateral-horned Zebu have cervico-thoracic humps which are muscular while Shorthorned Zebu have thoracic humps which are musculo-fatty.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Studies on sex physiology. XI. The relationship between a corpus luteum verum and the corresponding pregnant horn

No abstract available.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Anatomical studies no. 62. On the effect of debudding on skull conformation

It is possible by the operation of debudding to alter the conformation of the skull in such a marked fashion as not to be able to recognise the original type.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format