全文获取类型
收费全文 | 227篇 |
免费 | 10篇 |
专业分类
化学 | 149篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 17篇 |
物理学 | 66篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 20篇 |
2007年 | 11篇 |
2006年 | 14篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1958年 | 1篇 |
1957年 | 1篇 |
1955年 | 2篇 |
1953年 | 2篇 |
1952年 | 1篇 |
排序方式: 共有237条查询结果,搜索用时 15 毫秒
31.
Hong WK Rairakhwada D Seo PS Park SY Hur BK Kim CH Seo JW 《Applied biochemistry and biotechnology》2011,164(8):1468-1480
In the present study, a novel oleaginous Thraustochytrid containing a high content of docosahexaenoic acid (DHA) was isolated
from a mangrove ecosystem in Malaysia. The strain identified as an Aurantiochytrium sp. by 18S rRNA sequencing and named KRS101 used various carbon and nitrogen sources, indicating metabolic versatility. Optimal
culture conditions, thus maximizing cell growth, and high levels of lipid and DHA production, were attained using glucose
(60 g l−1) as carbon source, corn steep solid (10 g l−1) as nitrogen source, and sea salt (15 g l−1). The highest biomass, lipid, and DHA production of KRS101 upon fed-batch fermentation were 50.2 g l−1 (16.7 g l−1 day−1), 21.8 g l−1 (44% DCW), and 8.8 g l−1 (40% TFA), respectively. Similar values were obtained when a cheap substrate like molasses, rather than glucose, was used
as the carbon source (DCW of 52.44 g l−1, lipid and DHA levels of 20.2 and 8.83 g l−1, respectively), indicating that production of microbial oils containing high levels of DHA can be produced economically when
the novel strain is used. 相似文献
32.
CeO2-deposited mesoporous silica nanoparticles were synthesized as a probe to determine carcinoembryonic antigen (CEA) in serum by inductively coupled plasma-mass spectrometry (ICP-MS). The prepared mesoporous nanoparticles were modified and tagged to the target for sandwich-type immunoassay. Fe3O4 magnetic nanoparticles (MNPs) were also synthesized and immobilized with antibody to extract the target biomarker. The calibration curve of the synthesized CeO2-deposited silica nanoparticles, which was plotted by the signal ratio of 140Ce/57Fe measured by ICP-MS vs. the concentration of CEA, showed excellent linearity and sensitivity owing to the signal amplification and low spectral interference. Under optimal conditions, the sandwich-type analytical method was applied to determine CEA in serum spiked in the range of 0.001–5 ng mL−1 and showed a limit of detection of 0.36 ng mL−1. Since the deposited CeO2 in the mesoporous silica layer can be substituted by other metal compounds, various kinds of metal-deposited nanoparticles can be prepared as probe materials for multiplex detection in bioanalysis. 相似文献
33.
Poly(dimethyl dipropargylmalonate) synthesized in scCO2 contained more than 95% five-membered rings, i.e., highly regular polyene was produced, which shows carbon dioxide as a reaction medium plays a significant role in determining a highly selective polymer structure. 相似文献
34.
T. Hur J. A. Manson L. H. Sperling 《Journal of Polymer Science.Polymer Physics》1989,27(11):2251-2268
Network formation (branching) theory was used to examine the relationships between network structure and concomitant sound and vibration damping. For a series of model polyether-based polyurethane networks with varying stoichiometry and composition, the glass transition temperature Tg, was found to increase with increasing concentration of elastically active network chains, EANCs, as well as the ratio of branch OH group concentration to the total OH group concentration ρ. The values of (tan δ)max, the peak height of tan δ at Tg, linearly decrease with increasing concentration of EANCs, regardless of the ρ values. However, the loss area (LA), equal to the integral of the linear loss modulus-temperature curve, is independent of the concentration of EANCs and/or ρ. Utilizing group contribution analysis techniques, the value of the main chain -O- group contribution, LA-O-, is 19.1 GPa·K/g, a rather large value. This finding gives insight into why polyether urethanes are preferred for many damping applications. 相似文献
35.
36.
Jiang S Kim MG Kim SJ Jung HS Lee SW Noh do Y Sadowsky MJ Hur HG 《Chemical communications (Cambridge, England)》2011,47(28):8076-8078
Shewanella oneidensis MR-1 rapidly accumulates long, extracellular, U(VI) nanowires composed of polycrystalline chains of discrete meta-schoepite (UO(3)·2H(2)O) nanocrystallites. The production of uranium(VI) nanowires could provide a novel strategy for remediation of uranium contamination in sediments and aquifers, as well as the recovery of uranium in manufacturing processes. 相似文献
37.
Vera Mikyoung Hur 《Archive for Rational Mechanics and Analysis》2008,188(2):213-244
The solitary water wave problem is to find steady free surface waves which approach a constant level of depth in the far field.
The main result is the existence of a family of exact solitary waves of small amplitude for an arbitrary vorticity. Each solution
has a supercritical parameter value and decays exponentially at infinity. The proof is based on a generalized implicit function
theorem of the Nash–Moser type. The first approximation to the surface profile is given by the “KdV” equation. With a supercritical
value of the surface tension coefficient, a family of small amplitude solitary waves of depression with subcritical parameter
values is constructed for an arbitrary vorticity. 相似文献
38.
39.
Plasma Chemistry and Plasma Processing - Two dielectric barrier discharge reactors, based on L-shaped electrodes, were designed and fabricated for in-line surface treatment of polyimide (PI)... 相似文献
40.
Self-consistent field theory investigation of directed self-assembly in cylindrical confinement 下载免费PDF全文