Poly[[diaqua-μ3-citrato-praseodymium(III)] monohydrate]

In the coordination polymer, {[Pr(C6H5O7)(H2O)2]·H2O}n, seven of the nine coordination sites of the monocapped square-anti­prismatic geometry are occupied by three O atoms of the same citrate trianion (an O atom of the hy­droxy unit and the formally single-bond O atoms from two carboxyl units). Two other coordination sites are occupied by the O atoms of a chelating carboxyl unit of another citrate; one of these atoms is additionally involved in bridging. The seventh coordination site is occupied by the O atom of the formally double-bond O atom of a neighboring citrate. The remaining two coordination sites are occupied by water mol­ecules. The citrate functions in a μ3-bridging mode, connecting the metal atoms into a ribbon structure parallel to [010]. The structure is consolidated into a three-dimensional network by O—H⋯O hydrogen bonds

Hot stamping of an Al-Li alloy: a feasibility study

The feasibility of forming a third generation aluminium-lithium alloy (AA2060) into a complex shaped panel component, was studied by using an advanced forming technology called solution heat treatment, cold die forming and in-die quenching (HFQa) process. The main challenges using HFQ technology to form complex shaped AA2060 component was to find out optimum forming parameters, such as forming temperature, forming speed, lubrication condition and blank holding force. In this paper, the optimum forming temperature was mainly concerned. The flow stresses of AA2060 were obtained at different temperatures ranging from 350 to 520 °C at the strain rate of 2 s−1. The suitable temperature to achieve the adequate ductility was found at 470 °C. By forming the AA2060 blanks at the optimum forming temperature, experimental results exhibited the feasibility for forming complex-shaped AA2060 components. The formed components were analysed through strain measurements. The post-form mechanical properties of AA2060 were assessed using hardness and tensile tests

Reducing Computational Workload Of Electromagnetic Scattered Fields From Electrically Large Quadratic Surface At High Frequency

We use the numerical steepest descent path (NSDP) method to calculate the highly oscillatory physical optics (PO) scattered fields on electrically large quadratic surfaces. The resultant phase behaviors of PO integrands are elliptic and hyperbolic on parabolic and saddle quadratic patches, respectively. The proposed method relies on deforming the integration path of the PO integral into the NSDPs on the complex plane. Numerical results of the PO scattered fields on these smooth conducting quadratic surfaces illustrate that the proposed NSDP method gains high accuracy while the workload is frequency independent. © 2013 IEEE

The Fast Contour Deformation Method For Calculating The High Frequency Scattered Field From The Fock Current On The Convex Scatterer

In this paper, the Fock current from the 3-D convex cylinder is considered. By using the incremental length diffraction coefficient technique (ILDC), the resultant high frequency scattered fields are expressed in terms of the Fock current from convex scatterer. To efficiently solve the scattered fields, we propose the efficient NSDP method. Numerical examples from the convex cylinder scatterer illustrate that the proposed NSDP method for calculating the high frequency scattered fields could achieve the frequency independent computational workload and error controllable accuracy

An Efficient Numerical Contour Deformation Method For Calculating Electromagnetic Scattered Fields From 3-D Convex Scatterers

We consider the accuracy improvement of the high frequency scattered fields from 3-D convex scatterers. The Fock currents from the convex scatterers are carefully studied. Furthermore, we propose the numerical contour deformation method to calculate the Fock currents with frequency independent workload and error controllable accuracy. Then, by adopting the Fock currents and the incremental length diffraction coefficient (ILDC) technique, the scattered fields are clearly formulated. Compared to physical optics (PO) scattered fields from 3-D convex sphere, numerical results demonstrate significant accuracy enhancement of the scattered field via the Fock current approach

Calculating The Scattered Fields From The Fock Currents Of The 3-D Convex Scatterers By The Incremental Length Diffraction Technique

In this work, we consider the accuracy improvement of the high frequency scattered fields from the 3-D convex scatterers with the aid of the Fock current and the incremental length diffraction coefficient (ILDC) technique. To efficiently calculate the Fock currents, we adopt the numerical contour deformation method. Then, by using the Fock currents and the ILDC technique, high frequency scattered fields are clearly formulated. Compared to the PO scattered fields from the 3-D convex sphere, numerical results demonstrate significant accuracy enhancement of the scattered field via the Fock current