全文获取类型
收费全文 | 68篇 |
免费 | 4篇 |
专业分类
化学 | 17篇 |
力学 | 1篇 |
数学 | 8篇 |
物理学 | 46篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有72条查询结果,搜索用时 31 毫秒
41.
The dynamics of 90-degree interphase domain walls during a first-order Morin-type spin-reorientation phase transition is studied
theoretically. It is shown that an oscillatory motion of the walls with an amplitude that depends linearly on the field amplitude,
as well as a drift motion of the wall at a velocity proportional to the square of the field amplitude, are driven by an external
oscillating magnetic field. Drift of the entire domain structure as a whole is predicted to be possible.
Fiz. Tverd. Tela (St. Petersburg) 41, 274–282 (February 1999) 相似文献
42.
Hebah Muhsien Sabiah AL Ubeed Ronald B. H. Wills Jayani Chandrapala 《Molecules (Basel, Switzerland)》2022,27(5)
The traditional Cannabis plant as a medicinal crop has been explored for many thousands of years. The Cannabis industry is rapidly growing; therefore, optimising drying methods and producing high-quality medical products have been a hot topic in recent years. We systemically analysed the current literature and drew a critical summary of the drying methods implemented thus far to preserve the quality of bioactive compounds from medicinal Cannabis. Different drying techniques have been one of the focal points during the post-harvesting operations, as drying preserves these Cannabis products with increased shelf life. We followed or even highlighted the most popular methods used. Drying methods have advanced from traditional hot air and oven drying methods to microwave-assisted hot air drying or freeze-drying. In this review, traditional and modern drying technologies are reviewed. Each technology will have different pros and cons of its own. Moreover, this review outlines the quality of the Cannabis plant component harvested plays a major role in drying efficiency and preserving the chemical constituents. The emergence of medical Cannabis, and cannabinoid research requires optimal post-harvesting processes for different Cannabis strains. We proposed the most suitable method for drying medicinal Cannabis to produce consistent, reliable and potent medicinal Cannabis. In addition, drying temperature, rate of drying, mode and storage conditions after drying influenced the Cannabis component retention and quality. 相似文献
43.
44.
Ateyyah M. AL‐Baradi Matthew Mears Richard A. L. Jones Mark Geoghegan 《Journal of Polymer Science.Polymer Physics》2012,50(18):1286-1292
We describe an investigation of fluorescence correlation spectroscopy into the diffusion of fluorescein‐tagged dextran (FDEX) in a poly(methacrylic acid) (PMAA) hydrogel. The temperature dependence of FDEX diffusion is shown to follow Zimm behavior in pure water, and the decrease in the diffusion coefficient when in the PMAA hydrogel has been modeled. The addition of acid and alkali (HCl and NaOH, respectively) not only control the swelling and collapse of the hydrogel but also reveal a strong pH dependence of the dextran diffusion coefficient, which shows a (nonmonatonic) increase with pH. The addition of NaCl and CaCl2 salts similarly showed evidence of network swelling, most notably at low salt concentration, but also that the diffusion coefficient within the gel at these low concentrations is larger than that in the equivalent solution without the hydrogel, indicating that the combination of hydrogel and salt works to increase the diffusion coefficient above that in pure water. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
45.
I. I. Davidenko A. Stupakiewicz A. Maziewski A. L. Sukstanskii 《Physics of the Solid State》1997,39(10):1630-1632
Experimental study of domain-wall deformation in Co-doped YIG epitaxial films under irradiation by linearly polarized light
is reported. A simple theoretical model offering explanation for the observed effects as due to the onset of photo-induced
anisotropy in the illuminated volume of the film is proposed. The experimental results are described quantitatively within
the model.
Fiz. Tverd. Tela (St. Petersburg) 39, 1824–1827 (October 1997) 相似文献
46.
Sukstanskii AL Bretthorst GL Chang YV Conradi MS Yablonskiy DA 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2007,184(1):62-71
In the framework of a recently proposed method for in vivo lung morphometry, acinar lung airways are considered as a set of randomly oriented cylinders covered by alveolar sleeves. Diffusion of (3)He in each airway is anisotropic and can be described by distinct longitudinal and transverse diffusion coefficients. This macroscopically isotropic but microscopically anisotropic model allows estimation of these diffusion coefficients from multi b-value MR experiments despite the airways being too small to be resolved by direct imaging. Herein a Bayesian approach is used for analyzing the uncertainties in the model parameter estimates. The approach allows evaluation of relative errors of the parameter estimates as functions of the "true" values of the parameters, the signal-to-noise ratio, the maximum b-value and the total number of b-values used in the experiment. For a given set of the "true" diffusion parameters, the uncertainty in the estimated diffusion coefficients has a minimum as a function of maximum b-value and total number of data points. Choosing the MR pulse sequence parameters corresponding to this minimum optimizes the diffusion MR experiment and gives the best possible estimates of the diffusion coefficients. The mathematical approach presented can be generalized for models containing arbitrary numbers of estimated parameters. 相似文献
47.
48.
Imran Ali Zeid A. AL‐Othman Norikaju Nagae Vinay D. Gaitonde Kamlesh K. Dutta 《Journal of separation science》2012,35(23):3235-3249
New generation columns, i.e. packed with superficially porous silica particles are available as trade names with following manufacturers: Halo, Ascentis Express, Proshell 120, Kinetex, Accucore, Sunshell, and Nucleoshell. These provide ultra‐fast HPLC separations for a variety of compounds with moderate sample loading capacity and low back pressure. Chemistries of these columns are C8, C18, RP‐Amide, hydrophilic interaction liquid chromatography, penta fluorophenyl (PFP), F5, and RP‐aqua. Normally, the silica gel particles are of 2.7 and 1.7 μm as total and inner solid core diameters, respectively, with 0.5‐μm‐thick of outer porous layer having 90 Å pore sizes and 150 m2/g surface area. This article describes these new generation columns with special emphasis on their textures and chemistries, separations, optimization, and comparison (inter and intra stationary phases). Besides, future perspectives have also been discussed. 相似文献
49.
We discuss here a method for the extraction of the singularparts of a variety of problems involving singular integrands.The method is based on the systematic use of a partial fractionidentity; we give here applications to numerical quadratureand to the solution of singular integral equations of variouskinds. 相似文献
50.