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1.
The LiPO3-Y(PO3)3 system has been studied for the first time. Microdifferential thermal analysis (μ-DTA), infrared spectroscopy (IR) and X-ray diffraction were used to investigate the liquidus and solidus relations. The only new compound observed within this system is LiY(PO3)4, melting incongruently at 1104 K. An eutectic appears at 4±1 mol% Y(PO3)3 at 933 K. LiY(PO3)4 crystallizes in the monoclinic system C2/c with a unit cell: a=16.201(4) Å, b=7.013(2) Å, c=9.573(2) Å, β=125.589(9)°, Z=4 and V=884.5 Å3, which is isostructural to LiNd(PO3)4. The infrared absorption spectrum indicates that this salt is a chain polyphosphate. 相似文献
2.
Elbasuney Sherif Hamed Abdelaziz Yehia M. Ramzy Hesham Abdelgawad Ahmed Gobara Mohamed Mokhtar Mohamed 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(9):3665-3676
Journal of Inorganic and Organometallic Polymers and Materials - Surface oxygen of oxide catalyst has low coordination number; they are negatively charged. Surface oxygen can act active site for... 相似文献
3.
This paper is concerned with partial-information mixed optimal stochastic continuous–singular control problem for mean-field stochastic differential equation driven by Teugels martingales and an independent Brownian motion, where the Teugels martingales are a family of pairwise strongly orthonormal martingales associated with Lévy processes. The control variable has two components; the first being absolutely continuous, and the second singular. Partial-information necessary and sufficient conditions of optimal continuous–singular control for these mean-field models are investigated. As an illustration, this paper studies a partial-information linear quadratic control problem of mean-field type involving continuous–singular control. 相似文献
4.
Behrooz Safarinejadian Mojtaba Asad Mokhtar Sha Sadeghi 《International journal of control》2016,89(11):2277-2296
In the present paper, the identification and estimation problem of a single-input–single-output (SISO) fractional order state-space system will be addressed. A SISO state-space model is considered in which parameters and also state variables should be estimated. The canonical fractional order state-space system will be transformed into a regression equation by using a linear transformation and a shift operator that are appropriate for identification. The identification method provided in this paper is based on a recursive identification algorithm that has the capability of identifying the parameters of fractional order state-space system recursively. Another subject that will be addressed in this paper is a novel fractional order Kalman filter suitable for the systems with coloured measurement noise. The promising performance of the proposed methods is verified using two stable fractional order systems. 相似文献
5.
Mohamed Jleli Mokhtar Kirane Bessem Samet 《Computers & Mathematics with Applications》2019,77(3):740-751
We, first, consider the quantum version of the nonlinear Schrödinger equation where , is the principal value of , is the -derivative with respect to , is the Laplacian operator in , , , and is a complex-valued function. Sufficient conditions for the nonexistence of global weak solution to the considered equation are obtained under suitable initial data. Next, we study the system of nonlinear coupled equations
6.
Rachid Benkadja Mokhtar Benhadouga Abdelhalim Benkadja 《Bulletin of Engineering Geology and the Environment》2013,72(3-4):523-531
Due to the semi-arid climate, scarcity of vegetation, the presence of a sometimes steep slope, Algeria is vulnerable to soil erosion that threatens its socio-economic development. In the watershed of K’sob, transport of suspended sediment by rivers is a disturbing phenomenon due to siltation to 80 % of the dam at the outlet. Data of suspended sediment concentrations are closely related to liquid discharge (Q). Models of solid discharge (Qs) according to the equation Qs = aQb were used to perform qualitative and quantitative analysis of suspended sediment. Different scales of analysis helped identify and explain conclusively seasonal models. Sediment production is very high in the fall. In the spring, despite the increase in discharge, it is less significant. In summer, during a period of disappearance of vegetation cover, highly loaded floods are sometimes observed. Currently, millions of cubic meters of sediments are dredged each year. This large volume is an economic, environmental and ecological problem. To remedy this, an experimental study of manufacturing brick has been proposed with 65 % of sediment, 25 % of dune sand used as an additive and 10 % water. The shrinkage is minimal for a solid brick fabricated to 800 °C during 6 h of cooking. The mechanical tests carried out on the brick exhibit acceptable values of compression strength, mass density and water absorption. The study of the evolution of these parameters for different pressing intensities (13.2–20–30 and 40 kN) at different ages (4, 14, 21, and 28 days) shows that the solid brick acquires its resistance only after 21 days. 相似文献
7.
Laabaissi T. Benhiba F. Rouifi Z. Rbaa M. Oudda H. Zarrok H. Lakhrissi B. Guenbour A. Warad I. Zarrouk A. 《Protection of Metals and Physical Chemistry of Surfaces》2019,55(5):986-1000
Protection of Metals and Physical Chemistry of Surfaces - New benzodiazepine derivatives, namely 8-Chloro-1,2,3,4,10,11-hyxahydrospiro[cyclohexane-1,11-dibenzo[1,4]diazipine] and... 相似文献
8.
Katabathini Narasimharao Maqsood Ahmad MalikMohamed M. Mokhtar Sulaiman N. BasahelShaeel A. Al-Thabaiti 《Ceramics International》2014
Sulfated TiO2 nanotubes and a series of iron oxide loaded sulfated TiO2 nanotubes catalysts with different iron oxide loadings (1 wt%, 3 wt%, 5 wt% and 7 wt%) were prepared and calcined at 400 °C. The physico-chemical properties of the catalysts were studied by using XRD, N2-physisorption, Raman spectroscopy, SEM-EDX, TEM, XPS, and pyridine adsorption using FTIR and H2-TPR techniques. It was observed that iron oxide was highly dispersed on the sulfated TiO2 nanotube support due to its strong interaction. The activity of these catalysts in the catalytic removal of NO with propane was also studied in the temperature range of 300–500 °C. Highest activity (90% NO conversion) was observed with 5 wt% iron oxide supported on sulfated TiO2 catalyst at 450 °C. Selective catalytic reduction of NO activity of the catalysts was correlated with iron oxide loading, reducibility, and the Brönsted and Lewis acid sites of the catalysts. The catalyst also showed good stability under studied reaction conditions that no deactivation was observed during the 50 h of reaction. 相似文献
9.
This paper describes an experimental study of hydrodynamic lubrication in wire drawing in which different types of lubricants (straight oils, emulsions and grease) are used. The experiments were conducted on a specially designed laboratory wiredrawing test rig, to assess the frictional force and film thickness, while drawing an aluminium wire at different speeds. Hydro-dynamic performance, including frictional force and film thickness, were measured and plotted graphically, showing lubricant and drawing speed as the main influences. Results indicate that the frictional force decreased and the oil film thickness increased using straight oils with high viscosity at high drawing speed. 相似文献
10.