364 research outputs found
EUV/Soft X-Ray Interference Lithography
Based on the coherent radiation from an undulator source, extreme UV interference lithography (EUV-IL) technology is considered as the leading candidate for future nodes of high-volume semiconductor manufacturing. The throughput of this technique is much higher than that of traditional lithography methods such as e-beam lithography (EBL) and laser interference lithography (LIL). Different types of interference schemes based on reflection mirrors and transmission diffraction masks have been described in this chapter. Achromatic Talbot lithography (ATL) and the soft X-ray interference lithography (SXIL) with different photon energies have also been developed to produce highly dense, high-resolution periodic nanostructures. Two scan-exposure techniques, one is the method employing the broadband Talbot effect and the other based on the multi-grating EUV-IL with an order sorting aperture (OSA), have been used to obtain periodic nanostructures over large areas. Applications of EUV-IL on EUV-resist testing and nano-science have been illustrated
Optimal Allocation of Virtual Inertia and Droop Control for Renewable Energy in Stochastic Look-Ahead Power Dispatch
To stabilize the frequency of the renewable energy sources (RESs) dominated
power system, frequency supports are required by RESs through virtual inertia
emulation or droop control in the newly published grid codes. Since the
long-term RES prediction involves significant errors, we need online configure
the frequency control parameters of RESs in a rolling manner to improve the
operation economics under the premise of stabilizing system frequency. To
address this concern, this paper proposes a frequency constrained stochastic
look-ahead power dispatch (FCS-LAPD) model to formulate the frequency control
parameters of RESs and Energy Storage Systems (ESSs) as scheduling variables,
which can optimally allocate the virtual inertia and droop coefficient of RESs
and ESSs. In this FCS-LAPD model, the uncertainties of RESs are characterized
using Gaussian Mixture Model (GMM). The required reserves are determined by
frequency control parameters, and the reserve cost coefficients are adjusted
properly to allocate the reserves according to the predicted power generation.
Due to the nonlinearity of the frequency nadir constraint, a convex hull
approximation method is proposed to linearize it with guaranteed feasibility.
The proposed FCS-LAPD is ultimately cast as an instance of quadratic
programming and can be efficiently solved. Case studies on modified IEEE 24-bus
system and a provincial power system in China are conducted to show the
effectiveness of the proposed model
Human SFMBT is a transcriptional repressor protein that selectively binds the Nâterminal tail of histone H3
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116313/1/feb2s0014579307006746.pd
Factors on perceived waiting time and implications on passengersâ satisfaction with waiting time
In order to explore the influence factors on perceived waiting time, a multiple linear regression model is used to quantitatively describe the relationship between perceived waiting time and various factors. The model is established with 234 data, which is surveyed with questionnaire in three stops in Harbin, China. The results show that several certain factors (âtrip purpose-to whereâ, âpresence of a companion-weather have a companion or notâ, âhaving a timing device-weather have a timing device or notâ, âriding frequency-how many times to take one line per weekâ and âwaiting behavior-what to do when wait for a busâ) have significant influence on perceived waiting time, which confirms previous findings and supports transferability of results. The significance of âwaiting mood-how about the mood when wait for a busâ and âreserved waiting time-how long will waitâ are confirmed for the first time in this study. In contrast to previous studies, âwaiting time interval-what time of one dayâ is a negative variable and socioeconomic variables are non-significant. And it is found that the relationship between perceived waiting time and passengersâ satisfaction with waiting time follows a decreasing exponential distribution. With this model, the variation trend of the section, where passengersâ satisfaction value is larger than 0, is obviously steeper than the section less than 0. Such result proves that passengersâ mood with short time are more sensitive than with longer waiting time. And the borderline perceived waiting time, distinguishing satisfied from dissatisfied passengers, is proved to be 7.87 minutes when assignment interval of satisfaction is (-25,25], when satisfaction is positive (larger than 0), the accuracy is 70.30%, while the accuracy is 82.71% for negative satisfaction (less than 0)
Indium Phosphide Bismide
Indium phosphide bismide is a new member to the dilute bismide family. Since the first synthesis by molecular beam epitaxy (MBE) in 2013, it has cut a figure for its abnormal properties comparing with other dilute bismides. Bismuth (Bi) incorporation is always a difficulty for epitaxial growth of dilute. In this chapter, it shows how to regulate MBE growth parameters and their influence on Bi incorporation in InP1âxBix. Structural, electronic and optical properties are systematically reviewed. Thermal annealing to study Bi thermal stability and its effect on physical properties is performed. InP1âxBix shows strong and broad photoluminescence at room temperature, which is a potential candidate for fabricating super-luminescence diodes applied for enhancing spatial resolution in optical coherence tomography. Quaternary phosphide bismide, including InGaPBi and InAlPBi, is briefly introduced in this chapter
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