首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
  免费   0篇
化学   1篇
数学   1篇
物理学   4篇
  2018年   1篇
  2010年   1篇
  2008年   1篇
  1998年   1篇
  1985年   1篇
  1983年   1篇
排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
2.
Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documented subjective vocal changes or documented single cases without detailed, baseline voice assessments. The impact on laryngeal function of women taking these androgenic treatments requires further detailed, objective assessment. The need for increased awareness of the actions of androgenic hormones on womns' voices, and the benefits of a thorough voice assessment are discussed.  相似文献   
3.
The development of variable-angle synchronous scanning (v.a.s.s.) in fluorescence spectrometry is reported, based on a computer-aided spectrofluorimeter. The technique permits a linear path to be scanned at any preselected angle through the emission-excitation matrix defined by (Iem, λem, λex), by effectively scanning the emission and the excitation monochromators at different speeds under computer control. When applied to pharmaceutical dosage forms, v.a.s.s. gave good selectivity for chlorpromazine in the presence of its principal degradation product, chlorpromazine sulphoxide, and for oxytetracycline in the presence of the additives vitamin C, thiamine, nicotinamide and riboflavin. Good calibration linearity, precision and recovery were observed for both principal drug components. The angle of the scan trajectory can also be varied continuously through the emission-excitation matrix, to describe any desired path under computer control. This novel technique of non-linear v.a.s.s. can provide an improved method for generating diagnostic profiles of drugs, degradation products and metabolites.  相似文献   
4.
A precise measurement of the neutron decay β asymmetry A? has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A? = -0.119?66±0.000?89{-0.001?40}{+0.001?23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275?90{-0.004?45}{+0.004?09}.  相似文献   
5.
Bao H  Allen J  Pattie R  Vance R  Gu M 《Optics letters》2008,33(12):1333-1335
A fast handheld two-photon fiber-optic fluorescence endoscope for three-dimensional (3D) in vivo cellular imaging is developed. The compact handheld probe of the two-photon endoscope can simply be placed into contact with the target tissue to reveal clear 3D surface and subsurface histological images without biopsy. The new system has, to the best of our knowledge, the largest field of view (FOV) of 475 microm x 475 microm and a 3D imaging volume larger than 475 microm x 475 microm x 250 microm. A real-time two-photon fluorescence image is displayed at 0.4 mm(2)/s. The lateral and axial resolutions of the two-photon fluorescence endoscope are better than 1 and 14.5 microm, respectively.  相似文献   
6.
A set of vertices S is said to dominate the graph G if for each v ? S, there is a vertex uS with u adjacent to v. The smallest cardinality of any such dominating set is called the domination number of G and is denoted by γ(G). The purpose of this paper is to initiate an investigation of those graphs which are critical in the following sense: For each v, uV(G) with v not adjacent to u, γ(G + vu) < γ(G). Thus G is k-y-critical if γ(G) = k and for each edge e ? E(G), γ(G + e) = k ?1. The 2-domination critical graphs are characterized the properties of the k-critical graphs with k ≥ 3 are studied. In particular, the connected 3-critical graphs of even order are shown to have a 1-factor and some stringent restrictions on their degree sequences and diameters are obtained.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号