Reliability analysis of laterally loaded piles using response surface methods

Response surface methods have been applied to the reliability analysis of laterally loaded piles. Beam elements and a series of discrete springs are used to model the pile–soil system. The pile head displacement and the maximum bending moment in the piles are used as the performance criteria in this study. It is shown in the illustrative example that the CDF and PDF curves of the pile head displacement and the maximum bending moment in the pile obtained from the proposed methods are in good agreement with Monte Carlo simulation. The failure probabilities of the pile under specified performance criteria, the probabilistic responses of the pile-soil system, and the effect of pile-soil parameters to the failure probability of the pile are also studied.     

颜色传感器TCS230在单片机平台上的应用实现

TCS230是RGB彩色光/频率转换器。本文通过其滤光选择功能,借助单片机设计出对于三基色测量的步骤和方法,阐述了以AT89S52为核心的,能测量出颜色的具体算法,且进一步给出了相应的硬件设计电路、软件流程图和测试程序清单。最后给出的实现HSC模型算法的程序,具有通用性、能广泛应用于颜色测量和相关的三维数据的处理。     

黄土类土渗透溶滤变形机制及影响因素

通过对河南省黄土类土渗透溶滤变形机理的研究 ,阐明黄土类土渗透溶滤变形与土中易溶盐含量等因素的关系。黄土类土溶滤变形实质上是由于环境水对土中易溶盐淋滤而产生的变形。     

VC++6.0下用中断实现转速实时测量

本文介绍了在Windows98下利用VxD技术编写中断处理程序．并且利用VC 6．0的多线程技术实现转速的实时测量，并实现了数据存储、再现功能，可用于数据采集，实时控制等领域。     

Performance Analysis of Incremental Amplify-and-Forward Relaying Protocols with Nth Best Partial Relay Selection Under Interference Constraint

In this paper, we investigate two incremental amplify-and-forward relaying protocols in cognitive underlay networks. In the proposed protocols, whenever the secondary destination cannot receive the secondary source’s signal successfully, it requests a retransmission from one of M secondary relays. In the first protocol, we assume that a secondary relay with the Nth best channel gain to the secondary source is used to forward the received signal to the secondary destination. In the second protocol, relying on the quality of channels between the secondary relay and secondary destination and between the secondary relay and primary user, the Nth best relay is chosen for the retransmission. We derive exact closed-form expressions of the outage probability and average number of time slots for both protocols over Rayleigh fading channel. Finally, these mathematical expressions are then verified by Monte Carlo simulations.     

Early identification of technological convergence in numerical control machine tool: a deep learning approach

Scientometrics - The importance of technology convergence of multidisciplinary knowledge has increased recently, and it is a crucial way to spur emerging technologies. Therefore, to understand and...     

Electro-Photoluminescence Color Change for Deformable Visual Encryption

Although structural coloring and photoluminescence (PL) have been investigated for radiation-responsive color change, electroluminescence (EL) has not been used for the radiation-responsive system. An electro-photoluminescence (EPL) color change is presented here. The phosphors in the alternating current electroluminescence (ACEL) act simultaneously as electro-luminophores and photo-luminophores. The EPL chromaticity is systematically investigated depending on the ACEL frequency and UV intensity. It is found that the PL variation depending on UV intensity is the mechanism of the EPL color change. It is revealed that EL and PL can be controlled independently in the low electric field so that the EPL chromaticity can be adjusted by a linear combination of the EL color and the PL color. The EPL color-changing device is used as a deformable visual encryption system and a soft skin for a soft robotic rover, imitating the concealment and signaling functions in nature.     

Heavy Water Additive in Formamidinium: A Novel Approach to Enhance Perovskite Solar Cell Efficiency

Heavy water or deuterium oxide (D₂O) comprises deuterium, a hydrogen isotope twice the mass of hydrogen. Contrary to the disadvantages of deuterated perovskites, such as shorter recombination lifetimes and lower/invariant efficiencies, the serendipitous effect of D₂O as a beneficial solvent additive for enhancing the power conversion efficiency (PCE) of triple-A cation (cesium (Cs)/methylammonium (MA)/formaminidium (FA)) perovskite solar cells from ≈19.2% (reference) to 20.8% (using 1 vol% D₂O) with higher stability is reported. Ultrafast optical spectroscopy confirms passivation of trap states, increased carrier recombination lifetimes, and enhanced charge carrier diffusion lengths in the deuterated samples. Fourier transform infrared spectroscopy and solid-state NMR spectroscopy validate the N–H₂ group as the preferential isotope exchange site. Furthermore, the NMR results reveal the induced alteration of the FA to MA ratio due to deuteration causes a widespread alteration to several dynamic processes that influence the photophysical properties. First-principles density functional theory calculations reveal a decrease in PbI₆ phonon frequencies in the deuterated perovskite lattice. This stabilizes the PbI₆ structures and weakens the electron–LO phonon (Fröhlich) coupling, yielding higher electron mobility. Importantly, these findings demonstrate that selective isotope exchange potentially opens new opportunities for tuning perovskite optoelectronic properties.     

Strain gradient differential quadrature finite element for moderately thick micro-plates

In this study, we integrate the advantages of differential quadrature method (DQM) and finite element method (FEM) to construct a C¹-type four-node quadrilateral element with 48 degrees of freedom (DOF) for strain gradient Mindlin micro-plates. This element is free of shape functions and shear locking. The C¹-continuity requirements of deflection and rotation functions are accomplished by a fourth-order differential quadrature (DQ)-based geometric mapping scheme, which facilitates the conversion of the displacement parameters at Gauss-Lobatto quadrature (GLQ) points into those at element nodes. The appropriate application of DQ rule to non-rectangular domains is proceeded by the natural-to-Cartesian geometric mapping technique. Using GLQ and DQ rules, we discretize the total potential energy functional of a generic micro-plate element into a function of nodal displacement parameters. Then, we adopt the principle of minimum potential energy to determine element stiffness matrix, mass matrix, and load vector. The efficacy of the present element is validated through several examples associated with the static bending and free vibration problems of rectangular, annular sectorial, and elliptical micro-plates. Finally, the developed element is applied to study the behavior of freely vibrating moderately thick micro-plates with irregular shapes. It is shown that our element has better convergence and adaptability than that of Bogner-Fox-Schmit (BFS) one, and strain gradient effects can cause a significant increase in vibration frequencies and a certain change in vibration mode shapes.