全文获取类型
收费全文 | 594篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
化学 | 466篇 |
晶体学 | 3篇 |
力学 | 14篇 |
数学 | 55篇 |
物理学 | 70篇 |
出版年
2020年 | 7篇 |
2019年 | 5篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 23篇 |
2012年 | 26篇 |
2011年 | 29篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 29篇 |
2007年 | 33篇 |
2006年 | 37篇 |
2005年 | 23篇 |
2004年 | 26篇 |
2003年 | 17篇 |
2002年 | 30篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 16篇 |
1986年 | 10篇 |
1985年 | 24篇 |
1984年 | 19篇 |
1983年 | 4篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 13篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1968年 | 2篇 |
1964年 | 2篇 |
1935年 | 2篇 |
排序方式: 共有608条查询结果,搜索用时 15 毫秒
1.
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
2.
Yoshikazu Takada 《Annals of the Institute of Statistical Mathematics》1998,50(2):325-335
This paper gives a condition which implies the nonexistence of parametric statistical procedures with bounded risk or error performance characteristics. Many examples for which such a condition is satisfied are considered. 相似文献
3.
The engineering of many modern electronic devices demands control over a crystal down to the thickness of a single layer of atoms—and future demands will be even more challenging. Such control is achieved by the method of crystal growth known as epitaxy, and that makes this method the subject of intense study. More than that, recent advances are revolutionizing our knowledge of how surfaces grow. In fact, growing surfaces show a beautifully rich variety of phenomena, many of which are only now beginning to be uncovered. In the past few years many surface imaging techniques have been used to give us a close look at how crystals grow—while they are growing. The purpose of this article will be to illustrate some of the ways real surfaces grow and change as revealed by some of the latest in situ microscopic imaging technologies.
It is often said that crystal growth is more of an art than a science. Here we will show that it is emphatically both. 相似文献
4.
5.
Masahiro Nakao Chikako Yamazaki Hiroshi Tominaga Takako Yamaguchi Yoshikazu Fujita 《Analytical sciences》2006,22(2):313-316
A simple and highly sensitive spectrophotometric method for the determination of anthracycline anticancer agents, such as Daunorubicin hydrochloride (DAU), was established by using aluminum(III) and Chromazurol S (CAS) in a nonionic surfactant micellar medium. In the case of determination of DAU, the apparent molar absorptivity was 1.3 x 10(5) dm3 mol(-1) cm(-1) at 615 nm. Beer's law was obeyed in the concentration range of 0.028 - 2.82 microg ml(-1) for DAU. Owing to no need for solvent extraction, this method could be applied to assays of DAU and related drugs in pharmaceutical preparations. 相似文献
6.
7.
8.
9.
Meso- and dl-1,2-diarylethylenediamines (14 species) were evaluated for pre-column fluorescence derivatization reagents in the high-performance liquid chromatographic determination of catecholamines (norepinephrine, epinephrine and dopamine) in human urine and plasma. Of the compounds, meso-1,2-bis(4-methoxyphenyl)ethylenediamine was most preferable for all the catecholamines in terms of sensitivity and selectivity. The detection limit for each catecholamine is approximately 0.5 fmol in a 50-microliters injection volume. 相似文献
10.
A sensitive assay for acyl CoA-cholesterol acyltransferase (EC 2.3.1.26) in rat liver microsomal and mitochondrial preparations is described. The lowered cholesterol concentration in the enzyme reaction with oleoyl CoA is determined spectrofluorimetrically by using the cholesterol oxidase/peroxidase/p-hydroxyphenylpropionic acid system. The assay requires as little as 20 μg of protein in the enzyme preparation. 相似文献