圆弧逼近平面曲线原理在轨道车辆下盖板成型中的应用

通过几何作图、代数计算结合数控折弯机工作原理,将圆弧逼近平面曲线原理应用至轨道车辆下盖板的压型加工。提供了一套简单、实用的计算公式,能够在精度要求的范围内计算出拟合圆弧数量、确定数控折弯机参数,生产出合格零件。     

两串联排队系统逗留时间的泛函重对数律

本文考虑了两服务台串联排队系统,证明了重话务条件下逗留时间的泛函重对数率。逗留时间指的是一个顾客从到达系统到离开系统的时间,泛函重对数率基于更新过程的强逼近。     

基于填充函数法的光滑分段半监督支持向量机

构造一个光滑分段函数,以逼近梯度直推式支持向量机模型中的不可微项,得到一种新的光滑分段半监督支持向量机模型。根据新模型的非凸特性,采用无参数填充函数法对其求解,以此避免参数调节的复杂过程,减小计算量.采用UCI数据库中不同规模的数据集,对新模型进行训练和测试,结果表明新模型可降低向量机的平均误分率,提高其分类性能。     

High mass loading Ni4Co1-OH@CuO core-shell nanowire arrays obtained by electrochemical reconstruction for alkaline energy storage

The design of three-dimensional(30)core-shell hetercistructures is an efficient method to achieve high mass specific capacity of electroactive materials under high mass loading.In this work,porous Ni₄Co1-0H nanosheets with a mass loading of 7.7 mg·cm^-2 are obtained by using Ni₄Cor(NO₃)₂(0H)₄ supported on the CuO nanowires as precursors via an unavoidable electrochemically induced phase reconstruction.During the electrochemical reconstruction process,the N03-anions in Ni₄Cor(N0₃)₂(0H)₄ are easily replaced by OH-anions in the electrolyte.The phase reconstruction is accompanied by the decrease of ionic diffusion.:resistance and the increase of pore volume,and the shift of binding energy.The obtained Ni4Co1-0H nanosheets show a high:mass specific capacity of 363.6 mAh·g^-1 at 5 mA·cm^-2.The as-fabricated alkaline hybrid supercapacitor and Ni-Zn battery deliver high energy density of 293.1 and 604.9 Wh·kg^-1,respectively,indicating.excellent alkaline energy storage performance.     

Recent developments of infrared photodetectors with lowdimensional inorganic nanostructures

Low-dimensional inorganic nanostructures such as quantum dots as well as one-and two-dimensional nanostructures are widely studied and already used in high-performance infrared photodetectors.These structures feature large surface-to-volume ratios,tunable light absorption,and electron-limiting effects.This article reviews the state-of-the-art research of low-dimensional inorganic nanostructures and their application for infrared photodetection.Thanks to nano-structuring,a narrow bandgap,hybrid systems,surface-plasmon resonance,and doping,many common semiconductors have the potential to be used for infrared detection.The basic approaches towards infrared detection are summarized.Furthermore,a selection of very important and special nanostructured materials and their remarkable infrared-detection properties are introduced(e.g.,black phosphorus,graphene-based,MoX₂-based,Ⅲ-Ⅶ group).Each section in this review describes the corresponding photosensitive properties in detail.The article concludes with an outlook of anticipated future developments in the field.     

Orderly defective superstructure for enhanced pseudocapacitive storage in titanium niobium oxide

Artificial defect engineering in transition metal oxides is of important terms for numerous applications.In the present work,we proposed an in-situ gas reduction strategy to introduce ordered defects into titanium niobium oxide embedding on vapor grew carbon fibers(Ti₂Nb₁₀O_29-x@VGCFs).High-resolution transmission electron microscopy(HRTEM)and fast Fourier transform(FFT)simulation indicate that the ordered oxygen defects locate at interval layers,which leads to a new superstructure in Ti₂Nb₁₀O₂₉.The ordered defects could provide extra active sites for lithium-ion storage and modulate ionic migration,resulting an enhanced pseudocapacitive performance.In addition,the excellent structural stability of the superstructure was proved by in-situ HRTEM under a harsh electrochemical process.Our work provides a directly observation of orderly defective superstructure in transition metal oxide,and its functionality on electrochemistry was revealed.     

组合赋权的TOPSIS在冲击地压危险性评价中的应用

为了合理准确地评价煤矿冲击地压危险性,在现有评价冲击地压危险性实例的基础上,从煤矿地质因素和开采因素2个方面,选取10个主要的影响指标,利用熵权法和指标相关性权重法分别计算影响冲击地压危险性的各评价指标权重,再根据组合赋权的方法得出各指标的综合权重,构建基于逼近理想解理论的冲击地压危险性评价模型。以重庆砚石台煤矿为例,选取20组评价冲击地压危险性样本数据进行分析,确定评价冲击地压危险性的最优和最劣状况,然后计算出各个评价方案与最优和最劣状况的距离,最后综合最优与最劣距离,确定评价对象的相对贴近度。应用结果表明:评价结果与实际情况一致,且该模型相较其他模型的评价结果更加科学准确,表明该方法有良好的实用价值。