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.     

塑性应变极限状态下I形和矩形管截面变形分析

通常在钢结构弹塑性设计中会假设大多数受压横截面中具有"全塑性铰"。基于平衡条件提出的用于计算塑性极限状态下结构内力的公式,不能计算出这种极限状态下各种内力组合下结构的整体变形。针对矩形管截面和双轴对称I形截面的弹塑性分析提出一个简单模型。该模型考虑了横截面塑性应变极限状态下的结构整体变形(轴向变形和弯曲曲率)与相应内力(轴力和弯矩)的关系。利用这个模型可以对横截面延性进行真实的评估。     

短鞘丝匀度的判知

本文阐述了利用无鞘丝截面非常扁平的特征判断短鞘丝匀度的若干方法。认为短鞘丝匀度可根据生丝非常扁平、其直径离散性大等特征进行判知。     

Characteristics of cross-sectional atom probe analysis on semiconductor structures

The laser-assisted Atom Probe has been proposed as a metrology tool for next generation semiconductor technologies requiring sub-nm spatial resolution. In order to assess its potential for the analysis of three-dimensional semiconductor structures like FinFETs, we have studied the Atom Probes lateral resolution on a silicon, silicon-germanium multilayer structure. We find that the interactions of the laser with the semiconductor materials in the sample distort the sample surface. This results in transient errors of the measured dimensions of the structure. The deformation of the sample furthermore leads to a degradation of the lateral resolution. In the experiments presented in this paper, the Atom Probe reaches a lateral resolution of 1-1.8 nm/decade. In this paper we will discuss the reasons for the distortions of the tip and demonstrate that with the present state of data reconstruction severe quantification errors limit its applicability for the quantitative analysis of heterogeneous semiconductor structures. Our experiments show that reconstruction algorithms taking into account the time dependent nanostructure of the tip shape are required to arrive at accurate results.     

Active vibration control of doubly tapered thin-walled beams using piezoelectric actuation

This paper deals with a study of the modeling and open/closed-loop vibrational behavior of cantilevered beams of non-uniform cross-sections featuring non-classical properties such as transverse shear, anisotropy and heterogeneity of their constituent materials. The active feedback control capability is based upon the implementation of adaptive materials, consisting of piezoelectric layers that are bonded or embedded into the host structure and fully distributed along the entire beam span. As a result of the converse piezoelectric effect considered in conjunction with the out-of-phase activation, a boundary moment is induced at the beam tip. A combined dynamic feedback control law relating the piezoelectrically induced boundary bending moment to the various kinematical response quantities is implemented, and its effects upon the closed-loop eigenfrequencies are investigated. The results obtained reveal the high efficiency of the control methodology adopted towards enhancement of the vibrational behavior of these structures, and emphasize, in this context, the implications of the non-uniformity of the beam cross-sections considered in conjunction with other non-classical effects.     

Localization of dielectric breakdown defects in multilayer ceramic capacitors using 3D X-ray imaging

In this article, a non-destructive method using 3D X-ray imaging to find dielectric breakdown defects in multilayer ceramic capacitors (MLCCs) aged by high temperature and high voltage in an accelerated test is presented. In total, 64 aged samples were investigated using 2D X-ray imaging and half of them were further analysed with 3D X-ray imaging. Miniscule dielectric breakdown defects located in the MLCC active region are extremely difficult to identify solely using cross-section analysis or 2D X-ray imaging. In this study, the information provided by the 3D X-ray analysis was used to localize the defects for cross-section analysis. Cross-section analysis was performed to verify the dielectric breakdowns and their locations. 3D X-ray imaging is an effective method for detecting dielectric breakdown defects in MLCCs due to its short analysis time and high accuracy. This further facilitates failure analysis processes by providing the required grinding depth in cross-section analysis procedures.     

Investigation of through-plane morphologies of multiblock copolymers based on poly(arylene ether sulfone)s

Through-plane morphologies of multiblock copolymers based on poly(arylene ether sulfone)s were investigated by transmission electron microscopy (TEM) and through-plane conductivity measurements using a 4-probe method. The measured results showed that proton conductivity increased with a longer block length and that the optimal block length ranged from 5 to 7 K. TEM cross-sectional images also supported these results, indicating that a block length of 10 K is too well organized to conduct through-plane ion carriers.     

绕弱轴的循环弯矩作用下高厚比较大的H型钢—柱试验研究

对恒定轴力和绕弱轴循环弯矩共同作用下的9根高厚比较大的H型钢梁-柱进行了试验研究。考虑横截面的不同类别,翼缘和腹板选择不同的宽厚比,并提出一套可靠的试验方案。试验结果表明,局部屈曲在所有未发生整体屈曲的试件的破坏中占主导地位。对于绕弱轴的弯曲,H型钢件表现出良好的塑性变形能力,由此可判定现行规范中H型钢的分类方法不适用于绕弱轴弯曲的情况。此外,研究发现,翼缘或腹板的宽厚比以及轴向力的比例对滞回特性的影响互相依赖,因此应视为交互作用。     

Design of a prompt-gamma neutron activation analysis system on China Advanced Research Reactor

In this paper,computational methods are used to optimize the design of a prompt-gamma neutron activation analysis(PGNAA) system on China Advanced Research Reactor(CARR).Approaches are adopted for obtaining accurate neutron beam parameter and saving the computing time.For the radiation shielding design,the optimizing factors include the cost,weight,volume,machining convenience and background radiation at the detector position.Low background spectrum and high sensitivity are expected.The simulation results...     

A new cross-section generation model in the FAST code system and its application to gas- and sodium-cooled Generation IV fast reactors

The cross-section generation scheme employed in the 3D spatial kinetics PARCS code included in the FAST code system being used and developed at the Paul Scherrer Institute (PSI) is currently based on region-wise macroscopic cross-sections for reference conditions and their first-order derivatives with respect to the state variables. Since for some transients, feedback effects may likely not in this way be precisely approximated in their interrelations, this standard method was recently complemented for (hex, z) geometry by a more rigorous cross-section representation scheme. The main idea behind the new approach within the FAST code system is that of preparing sets of microscopic cross-sections for a studied design. The full library consisting of such isotopic tables is generated based on using the ECCO cell code of the code system ERANOS developed by the French Atomic Energy Commission (CEA) for a suitable range of temperatures and background cross-sections (σ₀) on a common grid. In the paper, this σ₀-model is described. In addition, within a detailed verification study needed due to its complexity, it is extensively compared to the standard method for both steady-state and transient conditions. Thereby use is made of current Generation IV fast-spectrum concepts. Reactivity and power evolution indicate overall good agreement of the two methods. Such a good consistence in various transient situations for systems characterized by different neutron spectra gives a large degree of confidence in the correct implementation and suitability of the microscopic cross-section methodology. Therefore, besides for the safety analysis of advanced fast-spectrum core concepts in general, it is foreseen, within the FAST code system, to use the σ₀-model for the assessment of uncertainty propagations in transient calculations in conjunction with the available ERANOS isotopic covariance matrices. The new development makes it also in principle possible to use the PARCS code as a reactor kinetics solver for severe accident analysis, allowing through the use of microscopic cross-sections to account for relocation of the core material during the accident.