全文获取类型
收费全文 | 8360篇 |
免费 | 1308篇 |
国内免费 | 516篇 |
专业分类
化学 | 302篇 |
晶体学 | 1篇 |
力学 | 194篇 |
综合类 | 114篇 |
数学 | 213篇 |
物理学 | 2187篇 |
综合类 | 7173篇 |
出版年
2025年 | 2篇 |
2024年 | 122篇 |
2023年 | 192篇 |
2022年 | 205篇 |
2021年 | 267篇 |
2020年 | 223篇 |
2019年 | 192篇 |
2018年 | 123篇 |
2017年 | 199篇 |
2016年 | 229篇 |
2015年 | 317篇 |
2014年 | 598篇 |
2013年 | 486篇 |
2012年 | 538篇 |
2011年 | 539篇 |
2010年 | 565篇 |
2009年 | 557篇 |
2008年 | 636篇 |
2007年 | 513篇 |
2006年 | 425篇 |
2005年 | 411篇 |
2004年 | 367篇 |
2003年 | 354篇 |
2002年 | 276篇 |
2001年 | 302篇 |
2000年 | 235篇 |
1999年 | 192篇 |
1998年 | 143篇 |
1997年 | 179篇 |
1996年 | 145篇 |
1995年 | 113篇 |
1994年 | 92篇 |
1993年 | 72篇 |
1992年 | 86篇 |
1991年 | 70篇 |
1990年 | 55篇 |
1989年 | 52篇 |
1988年 | 37篇 |
1987年 | 29篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1978年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
33.
采用多聚螯合物酶联抗体交联磁性纳米乳胶的脂联素免疫透射比浊法检测了血清中脂联素. 发现多聚螯合物酶上含有大量HRP酶, 可以极大地放大检测信号; 在优化条件下, 免疫比浊信号强度在脂联素0.005~0.2ng?mL-1范围内变化时, 并随着ADPN浓度的增加呈线性关系(R2=0.998), 检出限为2 pg?mL-1. 该方法能成功用于血清样本中脂联素的检测. 相似文献
34.
35.
生物学一条被勘察了无数次的信号通路可能还藏有不为人知的功能:防止蛋白生产线出现瓶颈效应。大肠杆菌需摄入含碳丰富的养分才能生长,并按照固定的顺序选择碳源。例如,当葡萄糖充足时,它就会停止合成用来运输和分解其他碳源(如乳糖或麦芽糖)的酶。20世纪40年代,剑桥大学生化学家Helen Epps和Ernest Gale观察到此现象,并将它命名为葡萄糖效应。现在知道其他糖类也能触发类似的响应,它们被统称为分解代谢抑制效应。 相似文献
36.
Neural Signal Tuned by Random Long-range Connections in Coupled FitzHugh-Nagumo Neurons Systems
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigate the effect of random long-range connections on signal propagation in an array of coupled FitzHugh- Nagumo (FHN) neurons. The neural network can be obtained by randomly adding a small fraction of shortcuts in an originally locally coupled one-dimensional chain. It is shown that when the first neuron is subjected to external stimuli, it fires and excites its connected neighbours, such that the neural signal may propagate along the chain favoured by the shortcuts. Moreover, there exists an optimal number of shortcuts which can lead to the most synchronous behaviour. In addition, how the region of the fraction of shortcuts varies with the coupling strength is also discussed. These results suggest that topological disorder in the neural network may play a vital role in helping information processing in living systems. 相似文献
37.
We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0=1+Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states. 相似文献
38.
39.
Unlike usual celestial gravitational waves, the relic gravitational waves (RGWs) form random signals in curved spacetime background. We calculate the energy-momentum pseudo-tensor of a certain component of the RGWs propagating along arbitrary directions in Cartesian coordinates. It is found that the energy density of RGWs is positive definitely, and the momentum density components have reasonable behaviour. Such results may provide a theoretical basis for the detection of RGWs. 相似文献
40.
XIE Bosun 《声学学报:英文版》2006,25(4):330-341
From the point of spatial sampling, spatial interpolation of HRTFs (head-related transfer functions) and signal mixing for multichannel (surround) sound are analyzed. First, it is proved that they are mathematically equivalent. Different methods for HRTFs interpolation are equivalent to different signal mixing methods for multichannel sound. Then, a stricter derivation for the signal mixing of multichannel sound and the law of sine for stereophonic sound is given. It is pointed out that trying to reconstruct lateral HRTFs by adjacent linear interpolation is wrong. And for accurate sound image localization, the conventional equation of adjacent linear interpolation of HRTFs is revised. At last, it is also pointed out that some methods used in the analysis of HRTFs and multichannel sound can be used for reference mutually. 相似文献