全文获取类型
收费全文 | 2532篇 |
免费 | 89篇 |
国内免费 | 15篇 |
专业分类
化学 | 1876篇 |
晶体学 | 24篇 |
力学 | 49篇 |
综合类 | 1篇 |
数学 | 181篇 |
物理学 | 505篇 |
出版年
2022年 | 18篇 |
2021年 | 25篇 |
2020年 | 39篇 |
2019年 | 33篇 |
2018年 | 34篇 |
2017年 | 27篇 |
2016年 | 61篇 |
2015年 | 54篇 |
2014年 | 62篇 |
2013年 | 108篇 |
2012年 | 156篇 |
2011年 | 133篇 |
2010年 | 87篇 |
2009年 | 78篇 |
2008年 | 170篇 |
2007年 | 149篇 |
2006年 | 139篇 |
2005年 | 150篇 |
2004年 | 127篇 |
2003年 | 103篇 |
2002年 | 107篇 |
2001年 | 60篇 |
2000年 | 38篇 |
1999年 | 34篇 |
1998年 | 30篇 |
1997年 | 21篇 |
1996年 | 35篇 |
1995年 | 34篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 20篇 |
1991年 | 23篇 |
1989年 | 13篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 20篇 |
1985年 | 29篇 |
1984年 | 27篇 |
1983年 | 15篇 |
1982年 | 29篇 |
1981年 | 21篇 |
1980年 | 19篇 |
1979年 | 37篇 |
1978年 | 23篇 |
1977年 | 26篇 |
1976年 | 25篇 |
1975年 | 22篇 |
1974年 | 13篇 |
1973年 | 14篇 |
1969年 | 10篇 |
排序方式: 共有2636条查询结果,搜索用时 781 毫秒
1.
Watanabe Sou Senzaki Tatsuya Shibata Atsuhiro Nomura Kazunori Takeuchi Masayuki Nakatani Kiyoharu Matsuura Haruaki Horiuchi Yusuke Arai Tsuyoshi 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(3):1273-1277
Journal of Radioanalytical and Nuclear Chemistry - Extraction chromatography flow-sheet employing octyl(phenyl)-N,N-diisobutylcarbonoylmethylphosphine oxide and bis(2-ethylhexyl) hydrogen phosphate... 相似文献
2.
HPLC with fluorescence detection assay of perampanel,a novel AMPA receptor antagonist,in human plasma for clinical pharmacokinetic studies
下载免费PDF全文
![点击此处可从《Biomedical chromatography : BMC》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Perampanel (Fycompa®), a novel α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptor antagonist, is registered for the adjunctive treatment of patients (aged ≥12 years) with refractory partial‐onset seizures. To support therapeutic drug monitoring, a simple high‐performance liquid chromatography (HPLC) assay with fluorescence detection was developed to determine perampanel concentrations in human plasma and validated to support clinical trials. Human plasma samples (1.0 mL) were processed by liquid extraction using diethyl ether, followed by chromatographic separation on a YMC Pack Pro C18 column (150 × 4.6 mm i.d., 5 µm) with isocratic elution of acetonitrile–water–acetic acid–sodium acetate (840:560:3:1.8, v/v/v/w) at a flow rate of 1.0 mL/min. Column eluent was monitored at excitation and emission wavelengths of 290 and 430 nm, respectively. The assay was linear (range 1.0–500 ng/mL) and this could be extended to 25 µg/mL by 50‐fold dilution integrity. No endogenous peaks were detected in the elution of analytes in drug‐free blank human plasma from six individuals and no interference was observed with co‐medications tested. Intra‐ and inter‐batch reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. Validation data demonstrated that our assay is simple, selective, reproducible and suitable for therapeutic drug monitoring of perampanel. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
3.
Behavior of fine crystalline particles of W5Si3 on a beta-Si3N4 substrate at high temperatures was observed by an in situ heating experiment in a transmission electron microscope. Some of the fine particles of W5Si3 moved in a to-and-fro manner. 相似文献
4.
Akira Yanagisawa Prof. Dr. Takahiro Suzuki Takanori Koide Shogo Okitsu Takayoshi Arai Prof. Dr. 《化学:亚洲杂志》2008,3(10):1793-1800
A Barbier‐type regioselective propargylation of aldehydes and ketones with (3‐bromobut‐1‐ynyl)trimethylsilane has been achieved using reactive barium as a low‐valent metal in THF. Especially in the case of ketones, the corresponding homopropargylic alcohols form almost exclusively. In the reaction of α,β‐unsaturated carbonyl compounds, only 1,2‐adducts have been observed. This method is also applicable to propargylation of imines, and the corresponding homopropargylic amines are obtained regiospecifically in good yields with diastereomeric ratios of up to 87:13. 相似文献
5.
Oscillation is found in many biological systems, and among them the enzymatic oscillatory reaction has been well studied using an enzyme solution. We show in this study for the first time that oscillation occurs when catalase is immobilized to controlled pore glass (CPG). The oscillatory wave mode changes with the distance among the CPG, electrode, or dialysis membrane. The lower substrate concentration results in oscillation with a longer period. This tendency agrees with a previous study using an enzyme solution. Furthermore, we show that the oscillation occurs when no dialysis membrane is used. These results show the wider applicability of the system to analysis or novel device fabrication. 相似文献
6.
Squier (1987) showed that if a monoid is defined by a finite complete rewriting system, then it satisfies the homological
finiteness condition FP3, and using this fact he gave monoids (groups) which have solvable word problems but cannot be presented by finite complete
systems. In the present paper we show that a monoid cannot have a finite complete presentation if it contains certain special
elements. This observation enables us to construct monoids without finite complete presentation in a direct and elementary
way. We give a finitely presented monoid which has (1) a word problem solvable in linear time and (2) linear growth but (3)
no finite complete presentation. We also give a finitely presented monoid which has (1) a word problem solvable in linear
time, (2) finite derivation type in the sense of Squier and (3) the property FP∞, but (4) no finite complete presentation. 相似文献
7.
Sohei Okazaki Noriaki Okazaki Hidetaka Sugaya Ryota Takahashi Yuji Matsumoto Hideomi Koinuma Tetsuya Hasegawa 《Applied Surface Science》2006,252(7):2615-2621
We developed a scanning microwave microscope (SμM) designed for high-throughput electric-property screening as well as for rapid construction of electronic phase diagrams at low temperatures. As a sensor probe, we used a high-Qλ/4 coaxial cavity resonator to which a thin needle with ball-tip end was attached. The sensor module was mounted on the low-temperature XYZ stage, which allowed us to map out the change of resonance frequency and quality factor due to the local tip-sample interaction at low temperatures. From the measurements of combinatorial thin films, such as Ti1−xCoxO2−δ and Nd0.9Ca0.1Ba2Cu3O7−δ (NCBCO), it was demonstrated that this SμM system has enough performance for the high-throughput characterization of sample conductance under variable temperature conditions. 相似文献
8.
Low-loss and rugged distal tips for CO2 laser have been proposed and fabricated based on a commercially available stainless steel (St) pipe. A method of smoothening the inner surface of the St pipe with a rough inner surface is put forward. Fabrication parameters, transmission properties, and mechanical strength of the cyclic olefin polymer-coated silver hollow St distal tip are experimentally discussed. 相似文献
9.
10.