检索结果-南通市图书馆

component Matching Based on Low Bypass Ratio Mixed Exhaust Turbofan Engine

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2018年第S1期35卷 9-15页

作者： Zheng Xilong Wu Tieying Ji Honghu College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics

In order to study component matching which exists in off-design situation at the initial design stage of turbine engine,by establishing performance analysis model of low bypass ratio mixed flow turbofan engine and components characteristic data,and by applying Newton-Raphson method to solve the nonlinear equations of offdesign points in flying envelop,the factors which affect matching between engine components are *** results show that low pressure turbine(LPT)must not operate in a critical condition,and the partial derivative(slope)of pressure ratio to similitude mass flow ratio of working point in LPT characteristic map affects the stability of *** smaller the slope is,the more stable the engine *** addition,the engine is more stable when the fan characteristic map is steep.

关键词： turbofan engine low bypass ratio off-design component matching OOP performance analysis

component temperatures inversion for remote sensing pixel based on directional thermal radiation model

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2000年第S1期43卷 41-47页

作者：王锦地李小文孙晓敏刘强 1. Research Center for Remote Sensing and GIS Beijing Normal University 100875 Beijing China 2. Center for Remote Sensing Boston University 02215 Boston MA USA 3. Institute of Geography Chinese Academy of Sciences 100101 Beijing China 4. Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China

When the remote sensing pixel is composed of multiple components and a non-isothermal surface, its directional signature of thermal-infrared radiation is mainly determined by the 3D structure of the pixel. In this paper, we present our simple directional thermal radiation model to describe the relation between the pixel thermal emission and the pixel’s component parameters, and invert the model to get the component temperatures. For the inversion algorithm, we focus on how to use the information of given observations in a more effective way. The information content in data space and parameter space is defined, and the transferring of information content in inversion procedure is studied. Our forward model and inversion method are validated using indoor directional measurement data.

关键词： model inversion component temperature information content.

"Metrology is a key component of the industrial value-added chain":an interview with *** Osten

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第10期11卷 2288-2293页

作者： Shuai Ding Light Publishing Group Changchun Institute of OpticsFine Mechanicsand PhysicsChinese Academy of Sciences3888 Dong Nan Hu Road130033 ChangchunChina

Short Bio:Dr.,*** Osten received the MSc/Diploma in Physics from the Friedrich-Schiller-University Jena in *** 1979 to 1991 he was working at the Academy of Sciences in Berlin in several institutes making investigatio... 详细信息

关键词： metrology component interview

Multi-response optimization of Ti-6A1-4V turning operations using Taguchi-based grey relational analysis coupled with kernel principal component analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2019年第2期7卷 142-154页

作者： Ning Li Yong-Jie Chen Dong-Dong Kong School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 People's Republic of China

Ti-6A1-4V has a wide range of applications, especially in the aerospace field;however, it is a difficultto- cut material. In order to achieve sustainable machining of Ti?6A1-4V, multiple objectives considering not only economic and technical requirements but also the environmental requirement need to be optimized simultaneously. In this work, the optimization design of process parameters such as type of inserts, feed rate, and depth of cut for Ti-6A1-4V turning under dry condition was investigated experimentally. The major performance indexes chosen to evaluate this sustainable process were radial thrust, cutting power, and coefficient of friction at the toolchip interface. Considering the nonlinearity between the various objectives, grey relational analysis (GRA) was first performed to transform these indexes into the corresponding grey relational coefficients, and then kernel principal component analysis (KPCA) was applied to extract the kernel principal components and determine the corresponding weights which showed their relative importance. Eventually, kernel grey relational grade (KGRG) was proposed as the optimization criterion to identify the optimal combination of process parameters. The results of the range analysis show that the depth of cut has the most significant effect, followed by the feed rate and type of inserts. Confirmation tests clearly show that the modified method combining GRA with KPCA outperforms the traditional GRA method with equal weights and the hybrid method based on GRA and PCA.

关键词： Ti-6A1-4V Taguchi method Grey relational analysis (GRA) Kernel principal component analysis (KPCA) Multi-response optimization

Highly efficient green InP-based quantum dot light-emitting diodes regulated by inner alloyed shell component

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第7期11卷 1454-1463页

作者： Peng Yu Sheng Cao Yuliang Shan Yuhe Bi Yaqi Hu Ruosheng Zeng Bingsuo Zou Yunjun Wang Jialong Zhao School of Physical Science and Technology MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and MaterialsGuangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning 530004China Suzhou Xingshuo Nanotech Co. Ltd.(Mesolight)Suzhou 215123China

InP-based quantum dot light-emitting diodes(QLEDs),as less toxic than Cd-free and Pb-free optoelectronic devices,have become the most promising benign alternatives for the next generation lighting and ***,the development of green-emitting InP-based QLEDs still remains a great challenge to the environmental preparation of InP quantum dots(QDs)and superior device ***,we reported the highly efficient green-emitting InP-based QLEDs regulated by the inner alloyed shell *** on the environmental phosphorus tris(dimethylamino)phosphine((DMA)3P),we obtained highly efficient InP-based QDs with the narrowest full width at half maximum(~35 nm)and highest quantum yield(~97%)by inserting the gradient inner shell layer ZnSe_(x)S_(1-x)without further *** importantly,we concretely discussed the effect and physical mechanism of ZnSe_(x)S_(1-x)layer on the performance of QDs and QLEDs through the characterization of structure,luminescence,femtosecond transient absorption,and ultraviolet photoelectron *** demonstrated that the insert inner alloyed shell ZnSe_(x)S_(1-x)provided bifunctionality,which diminished the interface defects upon balancing the lattice mismatch and tailored the energy levels of InP-based QDs which could promote the balanced carrier *** resulting QLEDs applying the InP/ZnSe_(0.7)S_(0.3)/ZnS QDs as an emitter layer exhibited a maximum external quantum efficiency of 15.2%with the electroluminescence peak of 532 nm,which was almost the highest record of InP-based pure green-emitting *** results demonstrated the applicability and processability of inner shell component engineering in the preparation of high-quallity InP-based QLEDs.

关键词： diodes quantum component

Two-phase flow component fraction measurement using gamma-ray attenuation technique

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2017年第6期28卷 196-202页

作者： Mohsen Sharifzadeh Hosein Khalafi Hosein Afarideh Ehsanallah Noori Radiation Application Research School Nuclear Science and Technology Research Institute Department of Energy Engineering and Physics AmirKabir University of Technology Nuclear Science and Technology Research Institute Plasma Research School Nuclear Science and Technology Research Institute

Multiphase flow meters as the potential alternatives to separation and metering techniques have been in rapid development since 1980 *** its field operation,the instrument should be calibrated in a standard *** spite of the known medium and large scale facilities all over the world,we developed a laboratory scale instrument for component fraction *** has a two-phase flow homogenizer loop with the clamp-on potential of the meters to provide a regime independent *** is capable of delivering a complete homogenization by γ-ray *** an error of±5%in component fraction measurements,this instrument is appropriate for testing and calibrating other meters.

关键词： component fraction measurement Homogenization MATLAB-Based algorithm Pencilbeam collimation Gamma-ray attenuation

Dimensioning a stockpile operation using principal component analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1485-1494页

作者： Siyi Li Marco de Werk Louis St-Pierre Mustafa Kumral Department of Mining and Materials Engineering McGill University

Mineral processing plants generally have narrow tolerances for the grades of their input raw materials,so stockpiles are often maintained to reduce material variance and ensure ***,designing stockpiles has often proven difficult when the input material consists of multiple sub-materials that have different levels of variances in their *** this paper,we address this issue by applying principal component analysis(PCA)to reduce the dimensions of the input *** study was conducted in three ***,we applied PCA to the input data to transform them into a lower-dimension space while retaining 80% of the original ***,we simulated a stockpile operation with various geometric stockpile configurations using a stockpile simulator in *** used the variance reduction ratio as the primary criterion for evaluating the efficiency of the ***,we used multiple regression to identify the relationships between stockpile efficiency and various design parameters and analyzed the regression results based on the original input variables and principal *** results showed that PCA is indeed useful in solving a stockpile design problem that involves multiple correlated input-material grades.

关键词： bed-blending mining stockpile principal component analysis multiple regression

Crustal structure study based on principal component analysis of receiver functions

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2019年第7期62卷 1110-1124页

作者： Jianyong ZHANG Ling CHEN Xu WANG State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences

The receiver function(RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths, whereas structural variations(such as dipping discontinuities or anisotropy) can be constrained through analysis of waveform dependence on the backazimuth of both the radial and tangential RFs. However, it is often difficult to directly extract information about structural variations from the waveform of RF, due to the common presence of noise in real data. In this study, we proposed a new method to derive structural variation information for individual stations by applying principal component analysis(PCA) to RFs sorted by back-azimuth. In this method(termed as RF-PCA), a set of principal components(PCs), which are uncorrelated with each other and reflect different characteristics of the RF data, were extracted and utilized separately to reconstruct new RFs. Synthetic tests show that the first PC of the radial RFs contains the average structural information of the crust beneath the corresponding station, and the second PC of the radial RFs and the first PC of the tangential RFs both reflect the variations of the crustal structure. Our synthetic modeling results indicate that the new RF-PCA method is valid for a variety of synthetic models with intra-crustal dipping discontinuities and/or anisotropy. We applied this method to the real data from a broadband temporary seismic station(s233) in the central part of the Sichuan Basin. The results suggest that the RF data can be best explained by the presence of two nearly parallel dipping discontinuities within the crust. Combining with previous logging data, seismic exploration and deep sounding observations, we interpret the shallow dipping discontinuity as the top boundary of the Precambrian crystalline basement of the Sichuan Basin and the deep one corresponding to the Conrad interface between the upper a

关键词： Principal component analysis Receiver function Crustal structure Dipping discontinuity Anisotropy Sichuan Basin

LOW TEMPERATURE THERMAL DEBINDING BEHAVIOR OF WAX-BASED MULTI-component BINDER FOR TUNGSTEN HEAVY ALLOY

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第1期9卷 95-100页

作者： Fan, Jinglian Huang, Baiyun Qu, Xuanhui Li, Yiming Central South Univ of Technology Changsha China

１ＩＮＴＲＯＤＵＣＴＩＯＮＰｏｗｄｅｒｉｎｊｅｃｔｉｏｎｍｏｕｌｄｉｎｇ（ＰＩＭ）ｉｓａｎｅｗｐｒｏｃｅｓｓｆｏｒｍａｎｕｆａｃｔｕｒｉｎｇｎｅａｒｎｅｔｓｈａｐｅｐａｒｔｓｗｉｔｈａｄｖａｎｔａｇｅｓｏｆｌｏｗｃｏ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＰｏｗｄｅｒｉｎｊｅｃｔｉｏｎｍｏｕｌｄｉｎｇ（ＰＩＭ）ｉｓａｎｅｗｐｒｏｃｅｓｓｆｏｒｍａｎｕｆａｃｔｕｒｉｎｇｎｅａｒｎｅｔｓｈａｐｅｐａｒｔｓｗｉｔｈａｄｖａｎｔａｇｅｓｏｆｌｏｗｃｏｓｔ，ｈｉｇｈｐｅｒｆｏｒｍａｎｃ...

关键词： thermal debinding multi component binder tungsten heavy alloy