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1.
A mathematical model of laser beam treatment of double layer alloys (Ni/Fe, Al/Fe and Cr/Fe systems) describing the effect of laser beam on different physical and geometrical parameters of coated layer system has been adapted. The numerical solutions of the non-homogeneous heat-transport differential equation could estimate the temperature of the treated region.The suggested model allows investigation of the temperature distribution as a function of treated surface and laser parameters. The physical parameters of the treated materials were taken as functions of temperature due to the change in the temperature of the treated double layer materials. 相似文献
2.
铂(Ⅳ)—钼酸盐—丁基罗丹明B缔合显色反应的研究 总被引:7,自引:0,他引:7
本文研究在聚乙烯醇(PVA)存在下,铂与钼酸铵和丁基罗丹明B(BRB)形成离子缔合物,该缔合物的最大吸收位于570nm,摩尔吸光系数ε值为9.26×10~5L·mol~(-1)·cm~(-1),服从比耳定律范围0~3.0μg Pt/25ml,缔合物至少稳定3周。测定铂的条件为C_(HClO_4)=1.4mol/L,C_(MoO_4~(2-)=1.1×10~(-3)mol/L,C_(BRB)=3.8×10~(-5)mol/L,0.08%PVA。考察了40多种共存离子的影响,除形成杂多酸的元素外,大多数不干扰。本法已用于催化剂和某些铂矿中铂的测定,结果较满意。 相似文献
3.
Cyclohexanone and morpholine in the presence of KSF under azeotropic distillation gave 1-morpholinocyclohexene which is alkylated or acylated in situ without isolation of the enamine. The overall yield of these Stork's reactions are better or equivalent to those obtained by isolation of the enamine. 相似文献
4.
It is shown that an n × n matrix of continuous linear maps from a pro-C^*-algebra A to L(H), which verifies the condition of complete positivity, is of the form [V^*TijФ(·)V]^n i,where Ф is a representation of A on a Hilbert space K, V is a bounded linear operator from H to K, and j=1,[Tij]^n i,j=1 is a positive element in the C^*-algebra of all n×n matrices over the commutant of Ф(A) in L(K). This generalizes a result of C. Y.Suen in Proc. Amer. Math. Soc., 112(3), 1991, 709-712. Also, a covariant version of this construction is given. 相似文献
5.
6.
An adsorbent for the high-performance affinity chromatography of antisteroid antibodies was prepared, based on a commercial pre-packed column. The column contained activated microparticulate silica beads bearing epoxide functions, on which the steroid dexamethasone was covalently linked. The column was used successfully for the rapid and complete isolation of several hundred microgram amounts of specific antidexamethasone antibodies from rabbit antisera. The practical aspects of the purification procedure, especially the optimization of the washing and of the elution steps, are detailed. Despite non-biospecific elution with 20% acetonitrile in an acidic buffer, the purification yield was very satisfactory and the biological activity of the purified immunoglobulins appeared excellent. 相似文献
7.
In this paper, we prove the global existence of smooth solutions to the three‐dimensional incompressible magnetohydrodynamical system with initial data close enough to the equilibrium state, (e3,0). Compared with previous works by Lin, Xu, and Zhang and by Xu and Zhang, here we present a new Lagrangian formulation of the system, which is a damped wave equation and which is nondegenerate only in the direction of the initial magnetic field. Furthermore, we remove the admissible condition on the initial magnetic field, which was required in the earlier works. By using the Frobenius theorem and anisotropic Littlewood‐Paley theory for the Lagrangian formulation of the system, we achieve the global L1‐in‐time Lipschitz estimate of the velocity field, which allows us to conclude the global existence of solutions to this system. In the case when the initial magnetic field is a constant vector, the large‐time decay rate of the solution is also obtained.© 2016 Wiley Periodicals, Inc. 相似文献
8.
Models for weather and climate prediction are complex, and each
model typi-cally has at least a small number of phenomena that are
poorly represented, such as perhaps the Madden-Julian Oscillation
(MJO for short) or El Ni\~{n}o-Southern Oscillation (ENSO for short)
or sea ice. Furthermore, it is often a very challenging task to
modify and improve a complex model without creating new
deficiencies. On the other hand, it is sometimes possible to design
a low-dimensional model for a particular phenomenon, such as the MJO
or ENSO, with significant skill, although the model may not
represent the dynamics of the full weather-climate system. Here a
strategy is proposed to mitigate these model errors by taking
advantage of each model''s strengths. The strategy involves
inter-model data assimilation, during a forecast simulation, whereby
models can exchange information in order to obtain more faithful
representations of the full weather-climate system. As an initial
investigation, the method is examined here using a simplified
scenario of linear models, involving a system of stochastic partial
differential equations (SPDEs for short) as an imperfect tropical
climate model and stochastic differential equations (SDEs for short)
as a low-dimensional model for the MJO. It is shown that the MJO
prediction skill of the imperfect climate model can be enhanced to
equal the predictive skill of the low-dimensional model. Such an
approach could provide a route to improving global model forecasts
in a minimally invasive way, with modifications to the prediction
system but without modifying the complex global physical model
itself. 相似文献
9.
10.