本征α－Si∶H MIS结构电导机制

利用本征α－Ｓｉ：Ｈ薄膜材料制成了Ａｌ－Ｓｉ（１－ｘ）Ｎｘ－ａ－Ｓｉ：Ｈ金属－绝缘体－半导体结构，用高精度差分电容谱仪在５０℃和暗背景条件下测量了这种结构的变频电容谱及变频电导谱。讨论了该ＭＩＳ结构中可能存在的电导机制，计算了禁带态能谱并根据修正后的实验结果得到了其俘获电子的时间常数及截面。     

A Chemical thinning technique for transmission electron microscopy cross-sectional samples

An essentially chemical thinning method for cross-sectional electron microscopy samples is described. This method can give cross-sectional samples in less than three hours without ion milling. This technique has been applied to a silicon wafer that had been amorphized by ion implantation and then partially annealed. An amorphous silicon layer as thin as 200 A was observed.     

圆柱截面法轮胎模具非线性文字加工研究

根据轮胎模具文字特点,选择圆柱截面法作为轮胎模具非线性文字加工的路径规划算法,详细分析了圆柱截面法的算法过程.验证结果表明,圆柱截面法加工轮胎表面文字具有计算更简单、工件加工程序更简洁及精度更高等优点.对轮胎模具这种类型的工件加工来说,圆柱截面法具有很好的工程适应性.     

错位环轧工艺

错位环轧工艺是在环件外周的适当位置安置两个辗压轮,同时在环件内孔的两辗压轮与环件接触处之间的近中部位置错位安置一个芯辊,外周的大辗压轮由电动机拖动旋转,它带动环件、芯辊和小辗压轮旋转,构成环轧,外周的两个辗压轮和内孔中的芯辊,在径向发生相向连续的进给运动的过程中,保持内外三个轧辊的错位状态,在此状态下,它们的径向压力难以穿透环件的壁厚,环件壁厚处于未锻透的状态,在轧制过程中,环件的断面面积变化不大,在咬入条件满足时,环件外周及内孔表面的局部连续受压,迫使环件外周表层金属发生轴向流动变形,去充填模具型腔,形成与模具型腔相对应的较复杂的断面形状。     

一种通用的公路隧道洞口噪声预报模式

研究了单车在隧道内行驶时,隧道尺寸对洞口噪声的影响.重点讨论了横截面和隧道长度等对洞口噪声级的影响,并给出了一个对矩形和半圆形截面隧道通用的洞口噪声预报模式.     

内螺纹异型管横截面面积的理论计算

根据内螺纹异型管纵截面不直观参数来计算其横截面面积的理论计算方法,可大大减化生产中取样、刨标样、称重等多项程序,且与标样称重计算法所得数值相差不大。该计算方法切实可行。     

纯滚动式绕弯工艺分析与实验研究

为研究一种纯滚动式绕弯成形工艺,采用实验方法研究工艺系统中各个几何参数和工艺参数对于烧结式微热管弯曲中横截面畸变的影响机制。实验结果表明:靠模距弯曲起始线的尺寸越小、模具孔尺寸越小、弯曲角度越小、弯曲角速度越小、相对弯曲半径越大,则弯曲时横截面畸变越小;反之横截面畸变则越大。实验中优化出各个几何参数和工艺参数的最优值。同时该弯管工艺系统能成倍的提高弯管效率。     

How price responsive is industrial demand for natural gas in the United States?

Our panel data analysis of the price responsiveness of industrial demand for natural gas in the United States utilizes five parametric specifications and 10,944 monthly observations for the lower 48 states in 2001–2019 to document statistically significant (p-value ≤ 0.05) static own-price elasticity estimates of −0.027 to −0.062, short-run −0.029 to −0.125, and long-run −0.060 to −0.179. These estimates with relatively small absolute values support the continuation of energy efficiency standards and demand-side-management programs for deep decarbonization. Further, diverse price responsiveness among heterogeneous industrial customers suggests using demand-response programs to efficiently allocate the limited supply available during a natural gas shortage.     

First-order generalised beam theory for arbitrary orthotropic materials

This paper presents the formulation of a Generalised Beam Theory (GBT) developed to analyse the structural behaviour of composite thin-walled members made of laminated plates and displaying arbitrary orthotropy. The main concepts and procedures involved in the available isotropic first-order GBT are revisited and adapted/modified to account for the specific aspects related to the member orthotropy. In particular, the orthotropic GBT fundamental equilibrium equations and corresponding boundary conditions are derived and their terms are physically interpreted, i.e., associated with the member mechanical properties. Moreover, different laminated plate material behaviours are dealt with and their influence on the GBT equations is investigated. Finally, in order to clarify the concepts involved in the formulated GBT and illustrate its application and capabilities, a thin-walled orthotropic beam is analysed and the results obtained are thoroughly discussed.     

How price responsive is commercial electricity demand in the US?

We use monthly data for the lower 48 states in the US and 30-year period of 1991–2020 to estimate commercial electricity demand’s price responsiveness. Our key findings are: (1) the US commercial electricity demand’s statistically significant (p-value ≤ 0.05) own-price elasticity estimates are between ? 0.03 and ? 0.08; and (2) the size of these estimates has been slowly declining over time. Hence, price-induced conservation is unlikely effective, at least in the immediate future, to materially reduce the US commercial electricity consumption, thus justifying continuation of energy efficiency standards and demand side management programs.