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11.
用PowerPoint制作出的幻灯片简洁明快、条理清晰,而且PowerPoint简单易用,非常适合教师上课使用,成为教师制作多媒体课件的工具之一(在我校大部分教师采用PowerPoint制作多媒体课件).在制作多媒体课件过程中,结合适当的媒体技术(动画、声音、文字)不仅能提高课件的直观生动性,激发学生学习兴趣,同时有助于学生对课堂知识的当堂消化和理解,加深记忆.通过我校开展多媒体教学多年的实践发现:对医科学生的基础课、专业基础课和专业课教学中广泛涉及的机能性、原理性的知识适当采用动画其教学效果是传统教学方法无法比拟的.在众多的动画媒体中(avi、mov、mpg、swf、gif、ram等),Flash动画(swf文件)以其作品容量小(单个swf文件通常不到100 K)、质量高和丰富的交互性,特别是近年推出的Flash5同时能结合视频和音频,成为目前最为流行的二维动画.不仅为网页制作增添了活力,同时也为多媒体制作提供了有效的手段,既精巧又实用,素有"闪客"、"动画精灵"之美誉,越来越受到人们的青睐.如果要把Flash制作好的动画插入到PowerPoint制作的课件中,将会使PowerPoint单调的动画增色不少,使课件更具魅力.为此,我校专门开展了一系列Flash动画制作讲座,广大教师都能结合本专业制作Flash动画.如何将Flash动画加入到PowerPoint中,不少教师都是直接通过"超级连接"导入Flash课件,放映时总会出现讨厌的警告信息和警告声音提示,点击确定后打开Flash课件,有时打开的Flash课件窗口还要重新调整,使用十分不便.如何才能更恰当地引入Flash动画呢?不少杂志刊物和网上发表过类似文章,但大都比较复杂,而且在使用中特别是在PowerPoint中放映Flash动画偶尔会出现这样和那样的问题,这也是我们教学工作中经常遇到的问题,具有一定的普遍性.经过与教师们的众多交流和笔者平时反复摸索,找到了较为简便有效的方法,写出来与大家分享. 相似文献
12.
Su Nee Tan Daniel Fornasiero Rossen Sedev John Ralston 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):307-315
The foam behaviour of low molecular weight polypropylene glycols (PPG) was investigated as a function of concentration and molecular weight (190–2000 g mol−1). For each polypropylene glycol, foam stability increases with concentration and passes through a maximum, beyond which foamability is suppressed as the solubility limit of the glycol is exceeded and droplets of glycol form. Light-scattering data as well as static and dynamic surface tension results provide the key information leading to these interpretations. A maximum in foamability was observed for the PPG molecules with increasing molecular weight (caused by a change in molecular conformation at the interface). This suppresses the Marangoni effect and leads to a decrease in foam stability. 相似文献
13.
14.
K. Venkatakrishnan B.K.A. Ngoi P. Stanley L.E.N. Lim B. Tan N.R. Sivakumar 《Applied Physics A: Materials Science & Processing》2002,75(4):493-496
Photomasks are the backbone of microfabrication industries. Currently they are fabricated by a lithographic process, which
is very expensive and time consuming since it is a multi-step process. These issues can be addressed by fabricating photomasks
by direct femtosecond laser writing, which is a single-step process and comparatively cheaper and faster than lithography.
In this paper we discuss our investigations on the effect of two types of laser writing techniques, namely front- and rear-side
laser writing, with regard to the feature size and the edge quality of a feature. It is proved conclusively that for the patterning
of masks, front-side laser writing is a better technique than rear-side laser writing with regard to smaller feature size
and better edge quality. Moreover the energy required for front-side laser writing is considerably lower than that for rear-side
laser writing.
Received: 22 May 2001 / Accepted: 14 September 2001 / Published online: 17 October 2001 相似文献
15.
The new phenylpropanoid diglycoside ligusinenoside A ( 1 ), and the two new 8,4′‐oxyneolignan(‘8‐O‐4′‐neolignan’) diglycosides ligusinenosides B ( 2 ) and C ( 3 ), together with nine known compounds, were isolated from the rhizomes of Ligusticum sinensis Oliv. The structures of 1 – 3 were elucidated on the basis of spectroscopic analyses. 相似文献
16.
17.
建立一个描述低能电子在多元多层介质中散射的物理模型,运用MonteCarlo方法模拟低能电子在靶体胶衬底中的复杂散射过程,在此基础上通过大量计算研究入射束能、胶层厚度、衬底材料等不同曝光条件对抗蚀剂沉积能密度分布的影响,获得沉积能分布规律:适量的低束能、薄胶层、低原子序数衬底可以使前散射电子对胶中沉积能密度分布的贡献增大、背散射电子的贡献减小,从而提高曝光分辨率.
关键词:
电子束曝光
MonteCarlo方法
低能电子散射
能量沉积 相似文献
18.
It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network: trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space: tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal. 相似文献
19.
Chirped fiber grating was used in dispersion compensator. We tried to use the same phase mask to write fiber grating of different wavelength with two methods to reduce the price of the fiber grating. 相似文献
20.
Using the theoretically calculated point-defect total-energy values of Baraff and Schlüter in GaAs, anamphoteric-defect model has been proposed by Walukiewicz to explain a large number of experimental results. The suggested amphoteric-defect system consists of two point-defect species capable of transforming into each other: the doubly negatively charged Ga vacancyV
Ga
2–
and the triply positively charged defect complex (ASGa+V
As)3+, with AsGa being the antisite defect of an As atom occupying a Ga site andV
As being an As vacancy. When present in sufficiently high concentrations, the amphoteric defect systemV
Ga
2–
/(AsGa+V
As)3+ is supposed to be able to pin the GaAs Fermi level at approximately theE
v
+0.6 eV level position, which requires that the net free energy of theV
Ga/(AsGa+V
As) defect system to be minimum at the same Fermi-level position. We have carried out a quantitative study of the net energy of this defect system in accordance with the individual point-defect total-energy results of Baraff and Schlüter, and found that the minimum net defect-system-energy position is located at about theE
v
+1.2 eV level position instead of the neededE
v
+0.6 eV position. Therefore, the validity of the amphoteric-defect model is in doubt. We have proposed a simple criterion for determining the Fermi-level pinning position in the deeper part of the GaAs band gap due to two oppositely charged point-defect species, which should be useful in the future. 相似文献