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An efficient method for preparation of semiconductor quantum rod films for robust lasing in a cylindrical microcavity is reported. A capillary tube, serving as the laser cavity, is filled with a solution of nanocrystals and irradiated with a series of intense nanosecond laser pulses to produce a nanocrystal film on the capillary surface. The films exhibit intense room‐temperature lasing in whispering‐gallery modes that develop at the film–capillary interface as corroborated from the spacing detected for the lasing modes. Good lasing stability is observed at moderate pump powers. The method was applied successfully to several quantum‐rod samples of various sizes. 相似文献
3.
Mike Yonker 《世界电子元器件》2006,(10):18-20,22
概述
自从20世纪40年代黑白广播电视问世以来,电视已走过了一个漫长的发展历程。我们经历了彩色电视与数字广播电视在画质方面的创新,以及在信号传输方式上的不断进步,如从有线到卫星再到HD等。每项新技术的推出都使电视的受欢迎程度与日俱增,并都能为观众带来更为丰富的节目内容。目前,电视正在迎来它的另一个全新的发展阶段:移动数字电视。 相似文献
4.
2006年8月31日,NTT DoCoMo开始在日本东京的中心地带提供HSDPA服务,NEC为该服务提供了惟一的一款终端,支持最高可达3.6Mbit/s的数据下载,这一速度10倍于以前FOMA手机可支持的速度。NTT DoCoMo的用户使用HSDPA服务,不需要支付额外的费用。这一举措使原本已经非常激烈的日本三大移动运营商之间的竞争又步入了一个新阶段。KDDI对此做出回应,宣布将在今年12月份推出世界上第一个商用的EV-DO Rev.A服务,KDDI目前已经推出了两款支持该服务的终端。K DDI过去所取得的成功在很大程度上归功于其采用了CDMA,这使得KDDI有效地将… 相似文献
5.
Predicting Forest Age Classes from High Spatial Resolution Remotely Sensed Imagery Using Voronoi Polygon Aggregation 总被引:1,自引:0,他引:1
Efficient identification of forest age is useful for forest management and ecological applications. Here we propose a user-assisted method for determining forest age using high spatial resolution remotely sensed imagery. This method requires individual trees to be extracted from imagery and represented as points. We use a local maximum filter to generate points that are converted to Voronoi polygons. Properties of the Voronoi polygons are correlated with forest age and used to aggregate points (trees) into areas (stands) based on three forest age classes. Accuracy of the aggregation ranges from approximately 68% to 78% and identification of the mature class is more consistent and accurate than the younger classes. 相似文献
6.
Disciplinary and linguistic considerations for academic Web linking: An exploratory hyperlink mediated study with Mainland China and Taiwan 总被引:4,自引:0,他引:4
The Web has become an important means of academic information exchange and can be used to give new insights into patterns
of informal scholarly communication. This study develops new methods to examine patterns of university Web linking, focusing
on Mainland China and Taiwan, and including language considerations. Multiple exploratory investigations into Web links were
conducted between universities in these two places. Firstly, inlinks were counted to each university Web site from its national
peers using four alternative Web document models. The results were shown to correlate significantly with research productivity
in Taiwan but not in the Mainland, although in the latter case less reliable institutional data could have been the cause.
For Taiwan, this is the first evidence of a scholarly association with academic linking for a non-English speaking region.
It was then ascertained that the same link counts associated more strongly with scientific than social scientific research
productivity in Taiwan. This confirms the general assumption of greater Web use by the hard sciences. We then investigated
Taiwan-Mainland university cross-links, and found that although English is extensively used on the Web, there was no evidence
that it was the language of preference for informal scholarly communication between the two areas.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Lewis Gloria J.; Greenburg Sharon L.; Hatch David B. 《Canadian Metallurgical Quarterly》1988,19(1):81
We report the results of the first national survey of psychologists in private practice regarding their participation in peer consultation groups. The sample (71% return) was drawn from 800 randomly selected psychologists listed in the National Register of Health Service Providers in Psychology. We found that 23% of the sample currently belonged to peer consultation groups, and 24% had belonged in the past. Of those not currently in groups, 61% expressed the desire to belong if one were available. There were virtually no significant demographic differences between current members and nonmembers. We examined the following group characteristics: formation, length of existence, size, membership, leadership, theoretical orientation, range of experience, time and place, content, and group process. Groups tended to be small, informal, and leaderless; however, we found great variation among groups on all dimensions. Findings also showed a high degree of satisfaction with membership. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.