The goal of this work is to obtain optimal hole shape for minimum stress concentration in two-dimensional finite plates using
parameterized geometry models. The boundary shape for a hole is described by two families of smooth curves: one is a “generalized
circular” function with powers as two parameters; the other one is a “generalized elliptic” function
a and b are ellipse axes) with powers as two parameters and one of the ellipse axes as the third parameter. Special attention is
devoted to the practicability of parameterized equations and the corresponding optimal results under the condition with and
without the curvature radius constraint. A number of cases were examined to test the effectiveness of the parameterized equations.
The numerical examples show that extremely good results can be obtained under the conditions with and without curvature radius
constraint, as compared to the known solutions in the literature. The geometries of the optimized holes are presented in a
form of compact parametric functions, which are suitable for use and test by designers. It is anticipated that the implementation
of the suggested parameterized equations would lead to considerable improvements in optimizing hole shape with high quality. 相似文献
Phosphofructokinase purified from mantle tissue of the sea mussel Mytilus galloprovincialis, was phosphorylated "in vitro" by the catalytic subunit of cyclic AMP-dependent protein kinase. The incorporation of phosphate gave rise to an activation of the enzyme by increasing its affinity for fructose-6-phosphate, by decreasing its sensitivity to the inhibition by ATP and by enhancing the effect of allosteric activators (5'-AMP and fructose-2,6-bisphosphate). In addition, the effects of phosphorylation on the catalytic activity are pH-dependent. 相似文献
Computational Visual Media - In this paper, we tackle the challenging problem of point cloud completion from the perspective of feature learning. Our key observation is that to recover the... 相似文献
Applied Intelligence - Implicit discourse relation classification is one of the most challenging tasks in discourse parsing. Without connectives as linguistic clues, classifying discourse relations... 相似文献
In this study, we report the results of an investigation into the sintering temperature dependence of magnetic and transport properties for GdBaCo2O5 + δ synthesized through a sol-gel method. The lowering of sintering temperature leads to the increase of oxygen content and the reduction of grain size. The increase of oxygen content results in the enhancement of magnetic interactions and the weakening of Coulomb repulsion effect, while the reduction of grain size improves the magnetoresistance effect. Metal-insulator transition accompanied with spin-state transition is observed in all samples. 相似文献
The purpose of this study is to analyze the environmental pollution effects elicited by industrial agglomeration and to devise necessary changes before and after China going into the New Normal, a contemporary phase of less rapid but more sustainable economic development. An empirical model is constructed based on the Copeland–Taylor model, and empirical research is conducted using statistical panel data derived from 285 Chinese cities between 2003 and 2014. To study the relationship between industrial agglomeration and industrial pollutant emission both before and after the ‘New Normal,’ the sample data are divided into two time periods: 2003–2008 and 2009–2014. Estimated results are as follows. First, industrial agglomeration exacerbates industrial pollution levels overall although the negative environmental effect of industrial agglomeration is weakened following China’s entry into the New Normal phase of economy. Second, both the interaction term of industrial agglomeration and foreign direct investment (FDI) and the interaction term of industrial agglomeration and environmental regulation are negatively related to industrial agglomeration. These findings indicate that FDI and environmental regulation can indirectly reduce industrial pollutant emissions by way of industrial agglomeration. 相似文献
This paper describes an inverse procedure to determine the constitutive constants and the friction conditions in the machining processes using Finite Elements (FE) simulations. In general, the FE modeling of machining processes is an effective tool to analyze the materials machinability under different cutting conditions. However, the use of reliable rheological and friction models represents the basis of a correct numerical investigation. The presented inverse procedure was based on the numerical results obtained using a commercial FE code and was developed considering a specific optimization problem, in which the objective functions that have to be minimized is the experimental/numerical error. This problem was performed by a routine developed in a commercial optimization software. In order to verify the goodness and the robustness of the methodology, it was applied on a Super Duplex Stainless Steel (SDSS) and on an Austenitic Stainless Steel (AUSS) orthogonal machining processes. This work, then, was focused on the identification of the Johnson-Cook (JC) coefficients (A,B,C, n and m) and on the calibration of a Coulomb friction model, in the specific cases of the SAF2507 SDSS and of an AISI 316 Based AUSS Alloy (AISI 316 ASBA). The identification phases were performed considering forces and temperatures experimental data, collected in two specific experimental tasks in which different orthogonal cutting tests were carried out under different cutting parameters conditions. 相似文献
A facile one-step approach to synthesize various phase-separated porous, raspberry-like, flower-like, core–shell and anomalous nanoparticles and nanocapsules via 1,1-diphenylethene (DPE) controlled soap-free emulsion copolymerization of styrene (S) with glycidyl methacrylate (GMA), or acrylic acid (AA) is reported. By regulating the mass ratio of S/GMA, transparent polymer solution, porous and anomalous P(S-GMA) particles could be produced. The P(S-GMA) particles turn from flower-like to raspberry-like and then to anomalous structures with smooth surface as the increase of divinylbenzene (DVB) crosslinker. Transparent polymer solution, nanocapsules and core–shell P(S-AA) particles could be obtained by altering the mole ratio of S/AA; anomalous and raspberry-like P(S-AA) particles are produced by adding DVB. The unpolymerized S resulted from the low monomer conversion in the presence of DPE aggregates to form nano-sized droplets, and migrates towards the external surfaces of the GMA-enriched P(S-GMA) particles and the internal bulk of the AA-enriched P(S-AA) particles. The nano-sized droplets function as in situ porogen, porous P(S-GMA) particles and P(S-AA) nanocapsules are produced when the porogen is removed. This novel, facile, one-step method with excellent controllability and reproducibility will inspire new strategies for creating hierarchical phase-separated polymeric particles with various structures by simply altering the species and ratio of comonomers. The drug loading and release experiments on the porous particles and nanocapsules demonstrate that the release of doxorubicin hydrochloride is very slow in weakly basic environment and quick in weakly acidic environment, which enables the porous particles and nanocapsules with promising potential in drug delivery applications.