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排序方式: 共有923条查询结果,搜索用时 125 毫秒
911.
Ya. V. Lubyanskiy A. D. Bondarev I. P. Soshnikov N. A. Bert V. V. Zolotarev D. A. Kirilenko K. P. Kotlyar N. A. Pikhtin I. S. Tarasov 《Semiconductors》2018,52(2):184-188
In the work we investigate synthesis of aluminum nitride films using reactive ion plasma deposition in oxygen/nitrogen gas mixture for application as optical elements for power semiconductor lasers. The experimental refractive index of synthesized AlNO films is dependent on oxygen composition and is decreasing in diapason from 1.76 to 2.035 at elevation of the oxygen fraction.It is shown that the AlN films synthesized by pure nitrogen plasma are polycrystalline and textured. The oxygen presence in discharging gas results to growth of amorphous phase of the AlNO film. 相似文献
912.
Kaneko K Inoke K Freitag B Hungria AB Midgley PA Hansen TW Zhang J Ohara S Adschiri T 《Nano letters》2007,7(2):421-425
Colloidal cerium oxide (CeO2) nanocrystals prepared by hydrothermal synthesis were characterized by high-resolution transmission electron microscopy (HRTEM) and three-dimensional electron tomography (3D-ET). HRTEM images of individual CeO2 nanocrystals were then simulated by Blochwave and multislice simulations to determine the atomic arrangement and terminating atoms. The edge length distributions were between 5.0 and 8.0 nm with an average edge length of 6.7 nm. The HRTEM images showed that the CeO2 particles were slightly truncated revealing {220} facets. 3D-ET revealed that the CeO2 nanocrystals exposed predominantly {200} cubic facets. The nanocrystals were truncated at the corners exposing {111} octahedral facets and at the edges {220} dodecahedral facets. Furthermore, 3D-ET revealed the presence of some tetragonal-shaped CeO2 nanocrystals. 相似文献
913.
Julander A Westberg H Engwall M van Bavel B 《The Science of the total environment》2005,350(1-3):151-160
Twelve air samples were collected from an electronic recycling facility in Sweden representing three different dust fractions; respirable, total and inhalable dust. Four samples were collected from each fraction. The highest concentration of polybrominated diphenyl ether (PBDE) #209 (ten bromine atoms) was found in the samples from the inhalable dust fraction (ID), which was 10 times higher than for the "total dust" fraction (TD). The concentration ranges were 157.6-208.6; 13.9-16.7; and 2.8-3.3 ng/m3 for inhalable, total and respirable fractions, respectively. The second most abundant PBDE congener was PBDE #183 (seven bromine atoms), followed by the second most abundant substance 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in all samples. In addition, decabromodiphenyl ethane (DeBDethane) was tentatively identified in five of the samples. Because of the large differences in air concentrations between the three fractions in ID, TD and RD, it is suggested that the inhalable instead of "total dust" fraction should be used to assess air concentrations, in particular for the larger and higher brominated flame retardants (BFRs). 相似文献
914.
Natalie Pilote John Endacott Kimberly Miller Gretchen Peterson Robert PoolmanAuthor vitae 《World Patent Information》2011,33(4):340-344
To address a broad company wide education initiative to train non-patent associates on intellectual property related issues, a customized patent information training program targeting discovery chemists was created and implemented.An electronic survey was designed to identify training needs for specific skills pertaining to patents and the patenting process, searching and retrieving patent information, and interpreting search results. From the results of the survey, a training program consisting of several modules was developed and marketed globally through the corporate intranet and by using targeted emails. The modules were a series of classroom based training classes that covered the topics of most interest: a) understanding patent families and legal status, b) differences between different types of patent searches, and c) strengths and attributes of different patent databases. The success of the program was clearly evident based on the high response rate, the positive feedback received and by it stimulating communication and collaboration between patent analysts and discovery chemists.Key determining factors in ensuring the success of the program were the support of the training effort by management, face-to-face communication and making the attendees feel that they were contributing to the long term success of the training program. 相似文献
915.
Martin G Biryukov SV Schmidt H Steiner B Wall B 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(3):658-661
SPUDT cells including two fingers are only known thus far for so-called NSPUDT directions. In that case, usual solid-finger cells are used. The purpose of the present paper is to find SPUDT cell types consisting of two fingers only for pure mode directions. Two-finger (TF) cells for pure mode directions on substrates like 128°YX LiNbO(3) and YZ LiNbO(3) were found by means of an optimization procedure. The forward direction of a TF-cell SPUDT on 128°YX LiNbO(3) was determined experimentally. The properties of the new cells are compared with those of conventional SPUDT cells. The reflectivity of TF cells on 128°YX LiNbO(3) turns out to be two to three times larger than that of distributed acoustic reflection transducer (DART) and Hanma-Hunsinger cells at the same metal layer thickness. 相似文献
916.
917.
918.
Graph-based optimization of five-axis machine tool movements by varying tool orientation 总被引:1,自引:0,他引:1
Denys Plakhotnik Bert Lauwers 《The International Journal of Advanced Manufacturing Technology》2014,74(1-4):307-318
There is a relatively vast class of tool path optimization methods that minimize cost functions depending on a whole tool path. In these methods, cost functions are usually limited to convex function because the used optimization approaches cannot either handle nonsmooth functions or perform with an acceptable computational time. This paper describes a developed optimization method that finds a sequence of tool orientations that can minimize various cost functions including displacement of machine rotary axes. Every posture, tool feasible orientation can be represented in discrete fashion as nodes of a directed graph in which the edge weights denote an objective. Shortest paths are sought iteratively by applying Dijkstra’s algorithms and narrowing intervals of feasible tool orientations around the previous solution. The developed algorithm is a derivative-free optimization method working in a linear time. 相似文献
919.
Bert Berkley 《印刷技术》2006,(33)
今天,我想讲以下四个议题:直邮信函的优势,全球信封制造业和印刷业的竞争和变化,美国兴德信封公司的发展历史,以及全球信封联盟(GEA)在全球范围内开展一场提高直邮信函的使用量及其价值的运动. 相似文献
920.
A. E. Zhukov A. R. Kovsh A. Yu. Egorov N. A. Maleev V. M. Ustinov B. V. Volovik M. V. Maksimov A. F. Tsatsul’nikov N. N. Ledentsov Yu. M. Shernyakov A. V. Lunev Yu. G. Musikhin N. A. Bert P. S. Kop’ev Zh. I. Alferov 《Semiconductors》1999,33(2):153-156
A method is proposed to increase the emission wavelength from structures grown on GaAs substrates by inserting a strained
InAs quantum dot array into an external InGaAs quantum well. The dependence of the luminescence peak position on the active
region design was investigated for structures grown by this method. Room-temperature photo-and electroluminescence spectra
in the 1.3-μm wavelength range are compared.
Fiz. Tekh. Poluprovodn. 33, 180–183 (February 1999) 相似文献