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   138篇
  免费   1篇
化学   78篇
力学   3篇
数学   16篇
物理学   42篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2018年   3篇
  2017年   4篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   3篇
  2012年   4篇
  2011年   8篇
  2010年   5篇
  2009年   11篇
  2008年   8篇
  2007年   6篇
  2006年   8篇
  2005年   3篇
  2004年   4篇
  2003年   1篇
  2002年   1篇
  2001年   3篇
  2000年   3篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   4篇
  1992年   1篇
  1990年   1篇
  1987年   4篇
  1986年   7篇
  1985年   4篇
  1984年   11篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1977年   1篇
  1975年   1篇
  1973年   6篇
  1972年   3篇
  1966年   1篇
  1965年   1篇
  1896年   1篇
排序方式: 共有139条查询结果,搜索用时 15 毫秒
81.
We report on a narrowband 5 W cw fiber laser incorporating a point-by-point fiber Bragg grating inscribed into the core of a Yb(3+)-doped double-clad fiber. The laser featured excellent long-term wavelength and power stability (0.3%), as well as a very narrow (15 pm) linewidth, when passive temperature stabilization of the grating was implemented.  相似文献   
82.
We used metastatic variant of B16 melanoma (B16F1) to study lung colonization galectin-3-deficient (gal-3−/−) C57BL/6 mice. In vivo study showed that compared with gal-3+/+ mice, gal-3−/−mice exhibited resistance to lung colonization of B16F1 melanoma cells (p < 0.03). In vitro assays showed higher number of attached malignant cells in the tissue section derived from gal-3+/+ mice (p < 0.001) and tumor specific cytotoxicity of lymphoid cells of tumour inoculated gal-3−/− suggesting that galectin-3 is considered as therapeutic target.  相似文献   
83.
A quantum phase amplifier operated in the spatial domain can improve the signal-to-noise ratio in imaging beyond the classical limit. The scaling of the signal-to-noise ratio with the gain of the quantum phase amplifier is derived from classical information theory.  相似文献   
84.
The motivation behind mathematically modeling the human operator is to help explain the response characteristics of the complex dynamical system including the human manual controller. In this paper, we present two different fuzzy logic strategies for human operator and sport modeling: fixed fuzzy-logic inference control and adaptive fuzzy-logic control, including neuro-fuzzy-fractal control. As an application of the presented fuzzy strategies, we present a fuzzy-control based tennis simulator.  相似文献   
85.
Oil-filled silica nanocapsules consisting of a hydrophobic liquid core and a silicate shell have been shown to efficiently extract hydrophobic compounds from aqueous media. With a view toward quantifying the selectivity of these systems, a series of electrochemical and spectroscopic measurements was performed. Uptake and kinetics experiments were carried out through electrochemical measurements by using solutions of lipophilic electroactive molecules of different sizes and with different affinities for silica. Other solutions with fluorescent probes were used for spectrophotometry measurements. In this work we report the environment where the lipophilic compounds studied end up after absorption and the kinetics of their uptake by the oil-filled silica nanocapsules with different shell thicknesses.  相似文献   
86.
This paper presents the generalized Fourier series solution for the transverse vibration of a beam subjected to a viscous boundary. The model of the system produces a non-self-adjoint eigenvalue-like problem which does not yield orthogonal eigenfunctions; therefore, such functions cannot be used to calculate the coefficients of expansion in the Fourier series. Furthermore, the eigenfunctions and eigenvalues are complex valued. Nevertheless, the eigenfunctions can be utilized if the space of the operator is extended and a suitable inner product is defined. The methodology presented in this paper utilizes Hilbert space methods and is applicable in general to other problems of this type. As an adjunct to the theoretical discussion, the results from numerical simulations are presented.  相似文献   
87.
Hamlat  S.  Thompson  P.  Rinker  M.  St-Amant  N.  Pan  P.  Peters  K.  Dagher  E.  Jovanovic  S.  Sauvé  K. 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):325-335
Journal of Radioanalytical and Nuclear Chemistry - Radiological impact to members of the public living around the Canadian Nuclear Power Plants (NPPs) was assessed using environmental monitoring...  相似文献   
88.
The objective of this study was to determine if topical anesthesia to the larynx and pharynx affects vocal fold motion during dynamic voice evaluation with transnasal flexible endoscopy. Transnasal dynamic laryngeal examinations of 10 patients with no voice complaints were evaluated by five blinded fellowship-trained laryngologists. Each patient was examined before and after application of topical anesthetic. Reviewers rated briskness of right and left vocal fold movement and longitudinal tension on a visual analogue scale. Statistical comparisons were made between individual subject scores before and after anesthetic application. Inter-rater reliability was also assessed. No statistical difference was observed between subject scores before and after anesthetic application. Average intraclass correlation coefficients were 0.643 and 0.591 for pre- and postanesthesia scores, respectively. Application of topical anesthesia to the larynx and pharynx does not affect vocal fold motion.  相似文献   
89.
Hot-wire anemometer measurements, using two types of probes, are reported for wall boundary layer flows with particular attention being given to the near-wall region and to measurements at high Reynolds numbers up to R 15,000. To obtain accurate near-wall measurements, the influence of wall proximity on hot-wire readings was eliminated by using a highly insulating wall material. Measurements were carried out with a single hot-wire boundary layer probe to obtain the longitudinal velocity informatemperature-wake sensor for the cross flow tion and a hot-wire, information.The results provided in the paper include measurements of averaged properties like mean velocity, rms-quantities of velocity fluctuations, probability density distributions etc. Conditional averages are also provided in order to yield information related to coherent flow structures present in boundary layer flows. It is shown that these structure remain present up to the highest Reynolds number investigated in the present study. The conditionally averaged data provide quantitative information on the mechanisms that are involved in the production of turbulence in boundary-layer flows.  相似文献   
90.
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