Investigation of multiple heterogeneous relationships using a q-rung orthopair fuzzy multi-criteria decision algorithm

Neural Computing and Applications - Q-rung orthopair fuzzy (q-ROF) set is one of the powerful tools for handling the uncertain multi-criteria decision-making (MCDM) problems, various MCDM methods...     

磷在钢回火脆性发展时的非平衡偏聚及钼的影响

用俄歇能谱仪和扫描电镜研究了中碳钢和含钼中碳钢在回火脆性发展过程中Ｐ在晶界上的偏聚。发现在４８０ ℃回火时,两种钢均在晶界出现Ｐ的浓度峰值。含钼中碳钢中的Ｍｏ 减小了晶界断裂比例,但并不改变Ｐ的浓度峰值。同时还观察了Ｓ、Ｃ、Ｍｏ 等组元在晶界的偏聚。Ｐ在晶界的浓度峰值可以用磷－空位复合体的非平衡偏聚机制加以解释。     

Dynamic behavior of nanometer-scale amorphous intergranular film in silicon nitride by in situ high-resolution transmission electron microscopy

We report about the dynamic behavior of a nanometer-scale amorphous intergranular film (IGF) in a Si₃N₄ ceramic by an in situ heating experiment in a high-resolution transmission electron microscopy (HRTEM). During the experiment the IGF gradually vanishes at 820 °C accompanied by the formation of crystal planes within the IGF. The IGF reappears after cooling back to room temperature. The results cannot be explained within the framework of a force balance model. We argue that the dynamic behavior of the IGF in our experiment originates from the open system observed.     

干涉量对HI-LEX复合材料紧固系统疲劳寿命的影响

本文通过采用拉一拉疲劳循环对三种不同规格HI-LEX复合材料紧固系统进行疲劳寿命试验,研究不同干涉量对其疲劳寿命的影响.最终得到此种复合材料干涉配合连接的最佳干涉量范围,并拟合出该复合材料紧固件系统随干涉量变化的接头疲劳寿命曲线.     

巴基葱及其电学特性研究

利用直流弧光放电法制备了巴基葱,高分辨透射电子显微镜分析表明这种巴基葱为空心椭球形,由11层富勒烯组成。利用超高真空原子力显微镜和扫描隧道显微镜研究了巴基葱在高定向石墨基底上的行为和电学特性。巴基葱的扫描隧道谱结果表明,巴基葱的电学特性介于石墨和单层富勒烯之间。     

Pt nanoparticles modified Au dendritic nanostructures: Facile synthesis and enhanced electrocatalytic performance for methanol oxidation

A facile and simple method is presented for the synthesis of bimetallic composites, Pt nanoparticles modified dendritic Au nanostructures (PtNPs/DGNs), in which dendritic Au was deposited on a glassy carbon electrode via a potentiostatic method and sphere-like Pt nanoparticles were decorated on Au substrates through a chemical reduction reaction. The compositions, morphologies, and structures of the PtNPs/DGNs were characterized by X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. Results indicated that bimetallic composites were successfully synthesized and spherical Pt nanoparticles were dispersed evenly on dendritic Au substrates. The number of Pt nanoparticles on Au surface was regulated by controlling the chemical reduction deposition time, allowing the electrocatalytic properties of the composite towards methanol oxidation to be tuned. Electrochemical measurements, including cyclic voltammetry and chronoamperometry, were performed to investigate the electrochemical properties and electrocatalytic behaviors of the PtNPs/DGNs towards methanol oxidation. Pt nanoparticles partially covered dendritic Au exhibited dramatically enhanced electrocatalytic activity (3.947 mA cm^?2), which was 2.65 times that of commercial carbon-supported Pt nanoparticles (1.487 mA cm^?2), along with much improved poisoning tolerance (current decline: 70.85% vs 99.36%). These enhanced performances were likely caused by the large active electrochemical area of the bimetallic nanocomposites and the change in the electronic structure of Pt when the Au surface was modified with fewer Pt nanoparticles.     

A decision-making algorithm for online shopping using deep-learning–based opinion pairs mining and q-rung orthopair fuzzy interaction Heronian mean operators

In the process of online shopping, consumers usually compare the review information of the same product in different e-commerce platforms. The sentiment orientation of online reviews from different platforms interactively influences on consumers’ purchase decision. However, due to the limitation of the ability to process information manually, it is difficult for a consumer to accurately identify the sentiment orientation of all reviews one by one and describe the process of their interactive influence. To this end, we proposed an online shopping support model using deep-learning–based opinion mining and q-rung orthopair fuzzy interaction weighted Heronian mean (q-ROFIWHM) operators. First, in the proposed method, the deep-learning model is used to automatically extract different product attribute words and opinion words from online reviews, and match the corresponding attribute-opinion pairs; meanwhile, the sentiment dictionary is used to calculate sentiment orientation, including positive, negative, and neutral sentiments. Second, the proportions of the three kinds of sentiments about each attribute of the same product are calculated. According to the proportion value of attribute sentiment from different platforms, the sentiment information is converted into multiple cross-decision matrices, which are represented by the q-rung orthopair fuzzy set. Third, considering the interactive characteristics of decision matrix, the q-ROFIWHM operators are proposed to aggregate this cross-decision information, and then the ranking result was determined by score function to support consumers' purchase decisions. Finally, an actual example of mobile phone purchase is given to verify the rationality of the proposed method, and the sensitivity and the comparison analysis are used to show its effectiveness and superiority.     

A new interpretation of temper embrittlement dynamics by non-equilibrium segregation of phosphor in steels

A new interpretation of temper embrittlement dynamics is proposed, which is based on the diffusion of phosphor atoms to grain boundaries by the complex of phosphor atom-vacancy. The dynamics of temper embrittlement in a medium-carbon Cr steel during 538°C tempering was carefully examined. The results show that the dependence of 50% fracture appearance transition temperature (FATT) on tempering time has a maximum, which can be satisfactorily elucidated by diffusion of the complex of phosphor atom-vacancy. However, the dependence of hardness on tempering duration decreases all the time. The fracture morphology was observed by scanning electron microscopy (SEM), the variation of intergranular fracture ratio also has a maximum during tempering treatment at 538°C, which is at the near same time as the one in the dynamic of temper embrittlement. The concentration of phosphor on grain boundary was measured by Auger electron microscopy (AES).     

煤气化给煤机给煤量控制系统改造

分析煤气化装置称重给煤机频繁故障原因,提出改进方案,将现场控制改为中控DCS控制,消除现场环境对给煤控制系统的影响。改造实施后效果明显,节约大量维护费用。     

In Situ Study of γ‐TiAl Lamellae Formation in Supersaturated α2‐Ti3Al Grains

In situ heating transmission electron microscopy (TEM) was used to investigate the initial stage of γ‐TiAl lamellae formation in an intermetallic Ti–45Al–7.5Nb alloy (in at.%). The material was heat treated and quenched in a non‐equilibrium state to consist mainly of supersaturated, ordered α₂‐Ti₃Al grains. Subsequently, specimens were annealed inside a TEM up to 750 °C. The in situ TEM study revealed that ultra‐fine γ‐TiAl laths precipitate in the α₂‐matrix at ≈730 °C which exhibit the classical Blackburn orientation relationship, i.e. (0001)α₂//(111)γ and [$11{\bar {2}}0$ ]α₂//<110]γ. The microstructural development observed in the in situ TEM experiment is compared to results from conventional ex situ TEM studies. In order to investigate the precipitation behavior of the γ‐phase with a complementary method, in situ high energy X‐ray diffraction experiments were performed which confirmed the finding that γ‐laths start to precipitate at ≈730 °C from the supersaturated α₂‐matrix.