全文获取类型
收费全文 | 166篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
化学 | 151篇 |
数学 | 7篇 |
物理学 | 17篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 11篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1965年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有175条查询结果,搜索用时 15 毫秒
101.
Aysu Yarman Thomas Nagel Nenad Gajovic‐Eichelmann Anna Fischer Ulla Wollenberger Frieder W. Scheller 《Electroanalysis》2011,23(3):611-618
We report on the redox behaviour of the microperoxidase‐11 (MP‐11) which has been electrostatically immobilized in a matrix of chitosan‐embedded gold nanoparticles on the surface of a glassy carbon electrode. MP‐11 contains a covalently bound heme c as the redox active group that exchanges electrons with the electrode via the gold nanoparticles. Electroactive surface concentration of MP‐11 at high scan rate is between 350±50 pmol cm?2, which reflects a multilayer process. The formal potential (E°′) of MP‐11 in the gold nanoparticles‐chitosan film was estimated to be ?(267.7±2.9) mV at pH 7.0. The heterogeneous electron transfer rate constant (ks) starts at 1.21 s?1 and levels off at 6.45 s?1 in the scan rate range from 0.1 to 2.0 V s?1. Oxidation and reduction of MP‐11 by hydrogen peroxide and superoxide, respectively have been coupled to the direct electron transfer of MP‐11. 相似文献
102.
103.
Abstract The cross section for atomic displacement has been determined at 7.5°K by means of electrical resistivity measurements in electron irradiated aluminium up to transferred energies of 1100 eV. These data and those from the literature have been evaluated with respect to the displacement function (DF). Below 200 eV the DF could be derived from the data with sufficient accuracy by solving the integral equation which describes the displacement cross section. Above 200 eV a family of non-linear and linear DF's has been found which fits the data within the experimental error. From the linear DF's one obtains an average threshold energy of (62±6) eV according to Kinchin and Pease. 相似文献
104.
Abstract The heating of various materials by X-ray pulses is studied. The relaxation of the excited electron subsystem of the material is investigated. A method for calculation of temperature distributions in the bulk of the material is developed and applied to different materials. The pulse length dependence has also been studied. 相似文献
105.
106.
107.
108.
Antonietta Pepe Lu Zhao Juha Koikkalainen Jarmo Hietala Ulla Ruotsalainen Jussi Tohka 《Magnetic resonance imaging》2013
The study of the structural asymmetries in the human brain can assist the early diagnosis and progression of various neuropsychiatric disorders, and give insights into the biological bases of several cognitive deficits. The high inter-subject variability in cortical morphology complicates the detection of abnormal asymmetries especially if only small samples are available. This work introduces a novel automatic method for the local (vertex-level) statistical shape analysis of gross cerebral hemispheric surface asymmetries which is robust to the individual cortical variations. After segmentation of the cerebral hemispheric volumes from three-dimensional (3D) T1-weighted magnetic resonance images (MRI) and their spatial normalization to a common space, the right hemispheric masks were reflected to match with the left ones. Cerebral hemispheric surfaces were extracted using a deformable model-based algorithm which extracted the salient morphological features while establishing the point correspondence between the surfaces. The interhemispheric asymmetry, quantified by customized measures of asymmetry, was evaluated in a few thousands of corresponding surface vertices and tested for statistical significance. 相似文献
109.
Dr. Manfred Eggersdorfer Dr. Dietmar Laudert Dr. Ulla Létinois Dr. Tom McClymont Dr. Jonathan Medlock Dr. Thomas Netscher Priv.‐Doz. Dr. Werner Bonrath 《Angewandte Chemie (International ed. in English)》2012,51(52):12960-12990
The discovery of vitamins as essential factors in the diet was a scientific breakthrough that changed the world. Diseases such as scurvy, rickets, beriberi, and pellagra were recognized to be curable with an adequate diet. These diseases had been prevalent for thousands of years and had a dramatic impact on societies as well as on economic development. This Review highlights the key achievements in the development of industrial processes for the manufacture of eight of the 13 vitamins. 相似文献
110.
Halthur TJ Claesson PM Elofsson UM 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):11065-11071
The buildup of biodegradable poly(L-glutamic acid) (PGA) and poly(L-lysine) (PLL) multilayers on silica and titanium surfaces and the immobilization of enamel matrix derivate (EMD) protein was followed by utilizing in situ ellipsometry, quartz crystal microbalance with dissipation, and dual-polarization interferometry (DPI). The use of the relatively new DPI technique validated earlier published ellipsometry measurements of the PLL-PGA polypeptide films. The hydrophobic aggregating EMD protein was successfully immobilized both on top of and within the multilayer structures at pH 5.0. DPI measurements further indicated that the immobilization of EMD is influenced by the flow pattern during adsorption. The formed polypeptide-EMD multilayer films are of interest since it is known that EMD is able to trigger cell response and induce biomineralization. The multilayer films thus have potential to be useful as bioactive and biodegradable coatings for future dental implants. 相似文献