全文获取类型
收费全文 | 216篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
化学 | 202篇 |
晶体学 | 3篇 |
力学 | 4篇 |
物理学 | 20篇 |
出版年
2023年 | 2篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 11篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 20篇 |
2005年 | 14篇 |
2004年 | 23篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有229条查询结果,搜索用时 140 毫秒
71.
72.
Naoto Koizumi Shigenobu Suzuki Yukiya Ibi Yasuhiko Hayasaka Yusuke Hamabe Takayoshi Shindo Muneyoshi Yamada 《Journal of synchrotron radiation》2012,19(1):74-83
In situ Co K‐edge quick‐EXAFS (QEXAFS) coupled with temperature‐programmed oxidation as well as ex situ XAFS was applied to investigating the mechanism for enhancing the dispersion of Co3O4 nanoparticles in a calcined Co/SiO2 Fischer–Tropsch synthesis catalyst prepared by adding triethylene glycol (TEG) to a Co(NO3)2.6H2O impregnating solution. Ex situ Co K‐edge XAFS indicated that, regardless of whether the catalysts were prepared with or without using TEG, the hexaaqua Co (II) complex was formed in impregnated samples which then underwent the dehydration process to some extent during the subsequent drying step at 393 K. In situ QEXAFS and ex situ EXAFS results also indicated that small oxide clusters were formed in the TEG‐modified catalyst calcined at ~400–470 K which interacted with polymer species derived from TEG. Since the Fischer–Tropsch synthesis activity of the TEG‐modified catalyst increased with an increase in the calcination temperature in a similar temperature range [Koizumi et al. (2011), Appl. Catal. A, 395 , 138–145], it was suggested that such an interaction enables the clusters to be distributed over the support surface uniformly, resulting in enhancing their dispersion. After combustion of polymer species, Co3O4‐like species were formed, and agglomeration of the Co3O4‐like species at high calcination temperatures was suppressed by the addition of TEG to the impregnating solution. It was speculated that the addition of TEG induced the formation of some surface silicate which worked as an anchoring site for Co3O4 and Co0 nanoparticles during calcination and H2 reduction, respectively. 相似文献
73.
74.
75.
[NiFe]Hydrogenase from Citrobacter sp. S‐77 Surpasses Platinum as an Electrode for H2 Oxidation Reaction 下载免费PDF全文
Dr. Takahiro Matsumoto Shigenobu Eguchi Dr. Hidetaka Nakai Prof. Takashi Hibino Dr. Ki‐Seok Yoon Prof. Seiji Ogo 《Angewandte Chemie (International ed. in English)》2014,53(34):8895-8898
Reported herein is an electrode for dihydrogen (H2) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S‐77 ([NiFe]S77). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe]S77 or Pt) at 50 mV in a hydrogen half‐cell. The [NiFe]S77 electrode is also stable in air and, unlike Pt, can be recovered 100 % after poisoning by carbon monoxide. Following characterization of the [NiFe]S77 electrode, a fuel cell comprising a [NiFe]S77 anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt. 相似文献
76.
High‐Throughput Development of a Hybrid‐Type Fluorescent Glutamate Sensor for Analysis of Synaptic Transmission 下载免费PDF全文
Dr. Kenji Takikawa Dr. Daisuke Asanuma Dr. Shigeyuki Namiki Hirokazu Sakamoto Tetsuro Ariyoshi Naoya Kimpara Prof. Kenzo Hirose 《Angewandte Chemie (International ed. in English)》2014,53(49):13439-13443
Fluorescent sensors are powerful tools for visualizing cellular molecular dynamics. We present a high‐throughput screening system, designated hybrid‐type fluorescence indicator development (HyFInD), to identify optimal position‐specific fluorophore labeling in hybrid‐type sensors consisting of combinations of ligand‐binding protein mutants with small molecular fluorophores. We screened sensors for glutamate among hybrid molecules obtained by the reaction of four cysteine‐reactive fluorescence probes with a set of cysteine‐scanning mutants of the 274 amino acid S1S2 domain of AMPA‐type glutamate receptor GluA2 subunit. HyFInD identified a glutamate‐responsive probe (enhanced glutamate optical sensor: eEOS) with a dynamic range >2400 %, good photostability, and high selectivity. When eEOS was specifically tethered to neuronal surfaces, it reliably visualized the spatiotemporal dynamics of glutamate release at single synapses, revealing synapse‐to‐synapse heterogeneity of short‐term plasticity. 相似文献
77.
The EMF and voltage-current characteristics for a galvanic cell with the configuration Na vapor (P1)/sodium beta-alumina/Na vapor (P2) were studied. It was verified that the EMF followed the Nernst relation over a wide pressure range. For example, when P1 = 2 × 10-2 mm Hg and beta-alumina temperature = 340°C, the measured EMF agreed with the calculated value in P2 range from 10-5 to 10-2 mm Hg. At lower pressure range, the measured EMF showed a negative deviation. Coexisting argon gas did not influence the cell EMF characteristic. In an atmosphere containing oxygen, the measured EMF was very high at first. Then it decreased and finally approached a value which agreed with the Nernst equation after several hours. At low beta-alumina temperatures, current saturation was observed in the voltage versus current relation with the anode on the P2 side. Although the sodium pressure could be determined from saturating current measurement, the measurable pressure range was narrower than that for EMF measurement. At high beta-alumina temperature, current saturation was not clear. Values of 6 × 10-6 (Ω cm)-1 for the electron conductivity and 6 × 10-10 (Ω cm)-1 for the hole conductivity at 340° were obtained for beta-alumina from the voltage-current characteristics at low sodium pressure. 相似文献
78.
79.
80.
Hayashi Y Regnier T Nishiguchi S Sydnes MO Hashimoto D Hasegawa J Katoh T Kajimoto T Shiozuka M Matsuda R Node M Kiso Y 《Chemical communications (Cambridge, England)》2008,(20):2379-2381
Herein, we describe an efficient strategy for the total synthesis of (+)-negamycin using commercially available achiral N-Boc-2-aminoacetaldehyde as starting material with 42% overall yield for a limited number of steps. 相似文献