全文获取类型
收费全文 | 193篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
化学 | 147篇 |
物理学 | 55篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2013年 | 5篇 |
2012年 | 11篇 |
2011年 | 21篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 12篇 |
2007年 | 13篇 |
2006年 | 19篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 7篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有202条查询结果,搜索用时 31 毫秒
31.
Maity P Wakabayashi T Ichikuni N Tsunoyama H Xie S Yamauchi M Tsukuda T 《Chemical communications (Cambridge, England)》2012,48(49):6085-6087
Organogold clusters Au(54)(C(2)Ph)(26) were selectively synthesized by reacting polymer-stabilized Au clusters (1.2 ± 0.2 nm) with excess phenylacetylene in chloroform. 相似文献
32.
Shigeki Ohsugi Yoshio Kitaoka Masaki Azuma Yoshie Fujishiro Mikio Takano Takashi Nagata Hirokazu Fujino Jun Akimitsu 《Hyperfine Interactions》2001,133(1-4):157-162
Cu nuclear magnetic resonance (NMR) spectra of impurities (Zn, Ni, and La)-doped spin-1/2 Heisenberg ladder compounds SrCu2O3 (Sr123) are broadened with Curie-like temperature (T) dependence. The spectra have been successfully fit by using a quasi-one-dimensional (Q1D) staggered polarization (SP) model. Such a SP has also revealed in Cu NMR measurements of Sr14–x
Ca
x
Cu24O41 (Cax) with hole-doped ladders. The origin of possible 3D antiferromagnetic (AF) long-range ordering in (Zn and Ni)-doped Sr123 and Cax around x=12 at low T is considered to be similar. Once unpaired spins S
0's are induced and 3D interlayer interaction occurs, the localized spins couple in the whole system. 相似文献
33.
J. Akimitsu H. Okajima A. Yamashita K. Ishii T. Yokoo T. Nagata M. Uehara R. Kadono K. Nagamine N. Kobayashi Z. Hiroi M. Takano H. Takahashi N. Mori K. Kinoshita 《Hyperfine Interactions》1997,104(1-4):43-48
We report here the two current topics in the ladder compounds.
1. The new ladder compound LaCuO2.5 recently discovered by Hiroi and Takano shows a clear sign of magnetic long range order at around 125 K observed by μ+SR technique. This result demonstrates that the ground state of LaCuO2.5 is not a spin liquid state, but a magnetically ordered state.
2. Superconductivity has been found in the ladder material (Sr,Ca)14Cu24O41 under high pressure between 3 GPa and 4.5 GPa. The superconducting transition temperatures Tc (onset) are 12 K and 9 K at 3 GPa and 4.5 GPa, respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
34.
35.
Patterned magnetic media have been considered as one of the promising candidates for future ultra-high-density magnetic recording. In this paper, a new kind of patterned medium based on hexagonal ferrite have been studied. We have successfully fabricated strontium ferrite dot arrays by electron beam lithography. Their magnetic properties are evaluated by magnetic force microscopy (MFM) and superconducting quantum interference device (SQUID). The results show the dot arrays have perpendicular anisotropy. Dots with the lateral size larger than 500 nm show multidomain magnetization configuration in the initial magnetization state. However, with dot size decreased to 500 nm, all the dots have single-domain configuration both in the initial magnetization state and remanent magnetization state. 相似文献
36.
The fluorescence excitation spectrum, the MPI spectrum, and the absorption spectrum of acetylene due to the à 1Au←
transition were observed in a gas and in a supersonic jet. A sudden decrease in the fluorescence quantum yield Φf was found above the V4 K2 (46339 cm−1) vibronic sublevel. The decrease is due to predissociation into C2H + H. AK and J dependence on Φf was also found. 相似文献
37.
Okamoto A Tanaka K Fukuta T Saito I 《Journal of the American Chemical Society》2003,125(31):9296-9297
We report a novel method for base detection using a base-discriminating fluorescent (BDF) nucleoside. We developed BDF probes containing methoxybenzodeazaadenine MDA and methoxybenzodeazainosine MDI, which give strong fluorescence only when the base on the complementary strand is cytosine and thymine, respectively. Thus, the MDA- and MDI-containing ODNs can be used as a very effective BDF probe for the detection of single base alterations, such as SNPs and point mutations. The present method using BDF probes is a very powerful tool for SNP typing that does not require any enzymes and time-consuming steps, and can avoid hybridization errors. In addition, a combination of MDA- and MDI-containing BDF probes facilitates the T/C SNP typing of a heterozygous sample. 相似文献
38.
39.
40.
Dr. José I. Urgel Dr. Marco Di Giovannantonio Guido Gandus Qiang Chen Dr. Xunshan Liu Dr. Hironobu Hayashi Dr. Pascal Ruffieux Prof. Dr. Silvio Decurtins Dr. Akimitsu Narita Dr. Daniele Passerone Prof. Dr. Hiroko Yamada Shi-Xia Liu Prof. Dr. Klaus Müllen Dr. Carlo A. Pignedoli Prof. Dr. Roman Fasel 《Chemphyschem》2019,20(18):2360-2366
On-surface synthesis is a unique tool for growing low-dimensional carbon nanomaterials with precise structural control down to the atomic level. This novel approach relies on carefully designed precursor molecules, which are deposited on suitable substrates and activated to ultimately form the desired nanostructures. One of the most applied reactions to covalently interlink molecular precursors is dehalogenative aryl-aryl coupling. Despite the versatility of this approach, many unsuccessful attempts are also known, most of them associated to the poor capability of the activated precursors to couple to each other. Such failure is often related to the steric hindrance between reactants, which may arise due to their coplanarity upon adsorption on a surface. Here, we propose a copolymerization approach to overcome the limitations that prevent intermolecular homocoupling. We apply the strategy of using suitable linkers as additional reactants to the formation of fully conjugated polycyclic nanowires incorporating non-benzenoid rings. 相似文献