scholarly journals Получение атомарно-чистых и структурно-упорядоченных поверхностей эпитаксиальных пленок CdTe для последующей эпитаксии

2021 ◽  
Vol 55 (9) ◽  
pp. 748
Author(s):  
А.С. Тарасов ◽  
Н.Н. Михайлов ◽  
С.А. Дворецкий ◽  
Р.В. Менщиков ◽  
И.Н. Ужаков ◽  
...  
Keyword(s):  
Isopropyl Alcohol ◽  
State Change ◽  
Surface Chemical ◽  
Surface Enrichment ◽  
Treatment Results ◽  
Elemental Tellurium ◽  
Native Oxides ◽  
Two Stages ◽  
Temperature Heating ◽  
Cdte Surface

In this work, atomically clean and structurally ordered surface of CdTe epitaxial layer after storage in air by treatment in isopropyl alcohol saturated with vapors of hydrochloric acid, and further temperature heating in an ultrahigh vacuum, was obtained. CdTe surface chemical treatment results in the removal of native oxides and surface enrichment with elemental tellurium. Heating in vacuum leads to the tellurium desorption and the appearance of a Te-stabilized CdTe surface. During heating in vacuum, two stages of surface state change are observed (~125°С and ≤250°С). At Т>250°С, elemental tellurium is desorbed and a Te-stabilized structure (1x1) CdTe(013) is formed.

Operation Experiences with Biological Phosphorus Removal at the Sewage Treatment Plants of Berlin (West)

1991 ◽  
Vol 24 (7) ◽  
pp. 133-148 ◽  
Author(s):  
A. Peter ◽  
F. Sarfert
Keyword(s):  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Chemical Precipitation ◽  
Biological Phosphorus Removal ◽  
Treatment Results ◽  
Sewage Treatment Plants ◽  
Research Activities ◽  
Two Stages ◽  
The Given ◽  
Biological Phosphorus

In investigations concerning sludge bulking in Berlin enhanced biological phosphorus removal was first observed unexpectedly. Because since 1986 an officially preset limit of 2 mg TP/l must be kept in all Berlin wastewater discharges it was decided to explore the capabilities of the observed mechanism under the specific circumstances of the exciting two large treatment plants in Ruhleben (240,000 m3/d) and Marienfelde (100,000 m3/d). For this purpose some of the existing units at both plants were equipped with anaerobic zones which were generated mainly by process modifications. Additionally stage one of the Ruhleben plant was altered completely in order to investigate the combination of biological phosphorus and nitrogen removal as a special pilot study in three parallel trains. The research activities and treatment results gained in each of the two stages of the Ruhleben and in the Marienfelde plant are reported in detail. For example BOD-related phosphorus removal rates were obtained ranging from 2.3-4.5 mg TP per 100 mg BOD removed. It must be stressed that all examinations were performed on full-scale conditions. At present the given limit of 2 mg TP/l in the Ruhleben plant is met without any chemical precipitation at least on average. From the beginning biological phosphorus removal will be integrated into further projected extensions.

In-Situ Processing of Silicon Dielectrics by Rapid Thermal Processing: Cleaning, Growth, and Annealing

1987 ◽  
Vol 92 ◽  
Author(s):  
J. Nulman
Keyword(s):  
Thermal Processing ◽  
Silicon Surface ◽  
Rapid Thermal Processing ◽  
Oxide Growth ◽  
Surface Chemical ◽  
Native Oxides ◽  
Wafer Cleaning ◽  
In Situ Processing ◽  
Kinetics Of

ABSTRACTThe in-situ processing of silicon dielectrics by rapid thermal processing (RTP) is described. RTP includes here three basic sequentially performed processes: wafer cleaning, oxidation and annealing. The insitu cleaning allows for reduction of chemical and native oxides and silicon surface chemical polish, resulting in interface density of states as low as 5×l09 cm-2eV-1. Kinetics of oxide growth indicates an activation energy of 1.4 eV for the initial linear oxidation rate.

scholarly journals CLINICAL USE OF ORTHO-SUV TRANSOSSEOUS HEXAPOD IN TREATMENT OF LOWER LIMB FALSE JOINTS

2016 ◽  
Vol 1 (4) ◽  
pp. 78-84
Author(s):  
Тишков ◽  
Nikolay Tishkov ◽  
Пусева ◽  
Marina Puseva ◽  
Рудаков ◽  
...  
Keyword(s):  
Lower Limb ◽  
Soft Tissues ◽  
Varus Deformity ◽  
Valgus Deformity ◽  
Treatment Results ◽  
Second Stage ◽  
Working Age ◽  
Hip Deformity ◽  
The Moment ◽  
Two Stages

We studied the use of Ortho-SUV hexapod in the treatment of 15patients with lower limb false joints. All patients were at active working age – from 22 to 50years. In 12patients, the period from the moment of trauma was 1 to 3years, in 3patients – 3 to 6years. 5patients had femoral false joints, 10patients – shin false joints. In 98% of cases, the formation of false joints was caused by inadequate treatment of initial trauma. In 100% of cases, false joint localized at diaphyseal level and was accompanied with shortening of injured segment for 2.5±1.0cm in 13patients, and for 0.5 and 0.8cm in 2cases. We also registered recurvatum and valgus deformity in 5patients, recurvatum and varus deformity in 8patients, and antecurvatum and varus deformity in 2patients. Combined contracture in knee and ankle joint was found in 90% of patients. Using combined transosseous osteosynthesis along with Ortho-SUV hexapod allowed us to correct hip deformity for 35±10days and ankle deformity – for 20±5days on the average. When shortening of femoral bone for more than 5.0cm, the deformity was corrected in two stages. At the first stage, we reconstructed the length of a segment using methods of transosseous osteosynthesis at discrete-continuum distraction. At the second stage, we corrected deformity using Ortho-SUV hexapod within specified time limits. Duration of femoral and shin false joint consolidation was 194±16days. We registered inflammatory complications in the areas of transosseous elements contacting soft tissues in 3(0.2%)patients. These complications didn’t have an effect on the treatment results.

scholarly journals SYNTHESIS AND STUDY OF GAS-SENSITIVE NANOSTRUCTURES OF THE Zn-Sn-O SYSTEM

2021 ◽  
pp. 910-918
Author(s):  
Светлана Сергеевна Налимова ◽  
Замир Валериевич Шомахов ◽  
Ксения Николаевна Пунегова ◽  
Андрей Андреевич Рябко ◽  
Александр Иванович Максимов
Keyword(s):  
Photoelectron Spectroscopy ◽  
Composite Structures ◽  
Isopropyl Alcohol ◽  
Zinc Oxide Nanorods ◽  
Aqueous Alcohol ◽  
Surface Chemical ◽  
Electron Density Redistribution ◽  
X Ray ◽  
Aqueous Alcohol Solution ◽  
Oxide Nanorods

Наностержни оксида цинка синтезированы гидротермальным методом. Проведена обработка полученных образцов в водно-спиртовом растворе станната калия и мочевины при 170°С в течение 30 и 60 минут. В результате получены наноструктуры Zn - Sn - O. Химический состав поверхности образцов ZnO и Zn - Sn - O исследован с помощью рентгеновской фотоэлектронной спектроскопии. Проанализирована их чувствительность к парам изопропилового спирта (1000 мд) при температурах 120 °С, 180°С, 250 °С. Показано перераспределение электронной плотности при формировании композитных наноструктур Zn - Sn - O, проявляющееся в химическом сдвиге пиков O1s и Zn2p. Это свидетельствует о перестроении химических связей при замещении атомов цинка оловом. Обнаружено, что чувствительность композитных структур к парам изопропилового спирта значительно превышает чувствительность ZnO во всем исследуемом температурном диапазоне. Улучшение газочувствительных свойств связано с наличием в образцах системы Zn - Sn - O поверхностных центров различного типа, принимающих участие в адсорбции и окислении изопропилового спирта. Zinc oxide nanorods were synthesized by the hydrothermal method. The obtained samples were processed in an aqueous-alcohol solution of potassium stannate and urea at 170 °C during different times. As a result, Zn - Sn - O nanostructures were obtained. The surface chemical composition of ZnO and Zn - Sn - O was studied using the X-ray photoelectron spectroscopy. Its sensitivity to vapors of isopropyl alcohol (1000 ppm) at 120 °C, 180 °C, 250 °C was analyzed. The electron density redistribution during the Zn - Sn - O composite nanostructures formation manifests itself in the chemical shift of the O1s and Zn2p peaks. It confirm the rearrangement of chemical bonds when zinc atoms are replaced by tin ones. It was found that the sensitivity of composite structures to isopropyl alcohol vapors significantly exceeds that of ZnO in the entire temperature range under study. The improvement of gas-sensitive properties is associated with the presence of various types of surface centers in the Zn - Sn - O samples that participate in the adsorption and oxidation of isopropyl alcohol.

Dissolution kinetics of cerussite in an alternative leaching reagent for lead

2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Qi-Cheng Feng ◽  
Shu-Ming Wen ◽  
Yi-Jie Wang ◽  
Qin-Bo Cao ◽  
Wen-Juan Zhao
Keyword(s):  
Dissolution Kinetics ◽  
Product Layer ◽  
Surface Chemical ◽  
Surface Chemical Reaction ◽  
Mixed Control ◽  
Shrinking Core ◽  
Two Stages ◽  
Kinetics Of ◽  
And Diffusion ◽  
Rate Controlling Step

AbstractThe dissolution kinetics of cerussite was investigated using methanesulphonic acid (MSA) as an alternative leaching reagent. The effects of particle size, stirring speed, acid concentration, and reaction temperature on the lead dissolution rate were determined. The dissolution process followed the kinetic law of the shrinking-core model, and a corresponding mixed control model was found suitable for representing the rate-controlling step. The mixed kinetic model comprised two stages: surface chemical reaction (283 K to 303 K) and diffusion through the product layer (303 K to 323 K). The activation energies of these sequential stages were 43.20 kJ mol

Altered Fine Structure of B Lymphocytes Correlated with Defective Terminal Differentiation

1973 ◽  
Vol 31 ◽  
pp. 386-387
Author(s):  
Dale E. Bockman ◽  
L. Y. Frank Wu ◽  
Alexander R. Lawton ◽  
Max D. Cooper
Keyword(s):  
Immune Deficiency ◽  
B Lymphocytes ◽  
Plasma Cells ◽  
Present Report ◽  
Specific Antigen ◽  
Terminal Differentiation ◽  
Second Stage ◽  
Two Stages ◽  
Deficiency Diseases ◽  
Cell Line Generation

B-lymphocytes normally synthesize small amounts of immunoglobulin, some of which is incorporated into the cell membrane where it serves as receptor of antigen. These cells, on contact with specific antigen, proliferate and differentiate to plasma cells which synthesize and secrete large quantities of immunoglobulin. The two stages of differentiation of this cell line (generation of B-lymphocytes and antigen-driven maturation to plasma cells) are clearly separable during ontogeny and in some immune deficiency diseases. The present report describes morphologic aberrations of B-lymphocytes in two diseases in which second stage differentiation is defective.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

Analytical Electron Microscopy of Ion-Implanted Metals

1985 ◽  
Vol 43 ◽  
pp. 282-285
Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing
Keyword(s):  
Electron Microscopy ◽  
Ion Implantation ◽  
Friction And Wear ◽  
Analytical Electron Microscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Near Surface ◽  
The Past ◽  
Analytical Electron ◽  
Property Changes

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.

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