全文获取类型
收费全文 | 186篇 |
免费 | 36篇 |
专业分类
化学 | 18篇 |
物理学 | 204篇 |
出版年
2021年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2011年 | 2篇 |
2010年 | 8篇 |
2009年 | 33篇 |
2008年 | 28篇 |
2007年 | 31篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有222条查询结果,搜索用时 15 毫秒
121.
A Laser-Diode-Pumped Widely Tunable Single-Longitude-Mode Tm:YAP Laser at Room Temperature 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A laser-diode-pumped widely tunable single-longitude-mode TIn:YAP laser in 2μm eye-safe region is built. Con- tinuous tanable range from 1899nm to 2025nm is achieved with the maximum laser output power of 225mW at 1989 am. In addition, the TIn:YAP laser operating under multimode and slngle-mode conditions is discussed. 相似文献
122.
KITAZAWA Tazuko MIYANISHI Shintaro MURAKAMI Yoshiteru KOJIMA Kunio TAKAHASHI Akira 《中国物理快报》2007,24(10):2827-2829
We observe surface plasmon polariton (SPP) refraction on a metal heterostructured sample with a scattered-type scanning near-field optical microscope (SNOM). The sample consists of AI and Au in-plane whose boundary is smooth enough with proper etching time. SPPs excited on the AI film travel to the boundary and a portion of SPPs propagates into the Au film. In addition, interference fringes appear in the SNOM image bent at the boundary. The result is analysed with effective index method and the refracted angle is explained by Shell's law. 相似文献
123.
Near-Field Birefringence Response of Liquid Crystal Molecules in Thickness Direction of Liquid Crystal Thin Film Orientated by Shear Force
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jing QIN Norihiro UMEDA 《中国物理快报》2007,24(10):2906-2909
Information of molecular orientation in nematic liquid crystal (LC) is attractive and important for applications in the field of display devices. We demonstrate a novel method using a birefringence scanning near-field optical microscope (Bi-SNOM) with a probe which is inserted into the LC thin film to detect the molecular orientation from its birefringence responses in the thickness direction of the LC thin film. The probe is laterally vibrated when going forward into the LC thin film, and the retardation and azimuth angle are recorded as the probe going down. Firstly, the thickness of the LC thin film is measured by the shear force detection. Since the shear force acts as a stimulation to reorientate the LC molecules above the substrate surface, we can detect the molecular orientation caused by a polyimide alignment substrate and the effect to molecular orientation caused by vibration of fibre probe. As a result, the orientation profiling of the LC film in depth direction is obtained in both the cases that the direction of probe vibrating is vertical/parallel to the rubbing direction of the alignment film. Furthermore, the thickness of completely orientated layers just above the substrate surface can also be obtained by either vibrating probe or no-vibrating probe. Ultimately, the LC thin film can be modelled in thickness direction from all the results using this method. 相似文献
124.
Bastiaan L. Duivelshof Amarande Murisier Julien Camperi Szabolcs Fekete Alain Beck Davy Guillarme Valentina D'Atri 《Journal of separation science》2021,44(1):35-62
Fc‐Fusion proteins represent a successful class of biopharmaceutical products, with already 13 drugs approved in the European Union and United States as well as three biosimilar versions of etanercept. Fc‐Fusion products combine tailored pharmacological properties of biological ligands, together with multiple functions of the fragment crystallizable domain of immunoglobulins. There is a great diversity in terms of possible biological ligands, including the extracellular domains of natural receptors, functionally active peptides, recombinant enzymes, and genetically engineered binding constructs acting as cytokine traps. Due to their highly diverse structures, the analytical characterization of Fc‐Fusion proteins is far more complex than that of monoclonal antibodies and requires the use and development of additional product‐specific methods over conventional generic/platform methods. This can be explained, for example, by the presence of numerous sialic acids, leading to high diversity in terms of isoelectric points and complex glycosylation profiles including multiple N‐ and O‐linked glycosylation sites. In this review, we highlight the wide range of analytical strategies used to fully characterize Fc‐fusion proteins. We also present case studies on the structural assessment of all commercially available Fc‐fusion proteins, based on the features and critical quality attributes of their ligand‐binding domains. 相似文献
125.
R.C. Santana R.O. Cunha K.D. Ferreira R. Calvo 《Journal of Physics and Chemistry of Solids》2007,68(4):586-593
We investigated the crystal growth, electron paramagnetic resonance (EPR) and optical absorption spectra of l-threonine doped with Cu2+. The quality, size and habit of the single crystals grown from aqueous solution by the slow solvent evaporation and by the cooling methods vary when the impurities are introduced during the growth process. The variations with the magnetic field orientation of the EPR spectra of single-crystal samples at room temperature and 9.77 GHz in three crystal planes (ab, bc and ac) show the presence of copper impurities in four symmetry-related sites of the unit cell. These spectra display well resolved hyperfine couplings of the of Cu2+ with the ICu= of the copper nuclei. Additional hyperfine splittings, well-resolved only for specific orientations of the magnetic field, indicate that the copper impurity ions in the interstitial sites have two N ligands with similar hyperfine couplings. The principal values of the g and ACu tensors calculated from the EPR data are g1=2.051(1), g2=2.062(2), g3=2.260(2), ACu,1=16.9(5)×10−4 cm−1, ACu,2=21.8(6)×10−4 cm−1, ACu,3=180.0(5)×10−4 cm−1. The principal directions corresponding to g3 and to ACu,3 are coincident within the experimental errors, reflecting the orientation of the bonding planes of the copper ions in the crystal. The values of the crystal field energies are evaluated from the optical absorption spectrum, and the crystal field and bonding parameters of the Cu impurities in the crystal are calculated and analyzed. The EPR and optical absorption results are discussed in terms of the crystal structure of l-threonine and the electronic structure of the Cu2+ ions, and compared with data reported for other systems. The effects of the impurities in the growth and habit of the crystals are also discussed. 相似文献
126.
O. Casel D. Woll M. A. Tremont H. Fuchs R. Wallenstein E. Gerster P. Unger M. Zorn M. Weyers 《Applied physics. B, Lasers and optics》2005,81(4):443-446
We report the generation of blue 489-nm picosecond laser pulses by intracavity second-harmonic generation in a mode-locked optically pumped InGaAs vertical-external-cavity surface-emitting laser. Mode locking achieved by a semiconductor saturable absorber mirror generated 5.8-ps-long sech2-shaped pulses at an emission wavelength of 978 nm and a repetition rate of 1.88 GHz. Intracavity frequency doubling in a 5-mm-long lithium triborate crystal generated blue picosecond pulses with a spectral width of 0.15 nm and an average output power of up to 6 mW. 相似文献
127.
Correlation between Zero-Field Splitting and Site Distortions of Cr^3+ Ions in NH4Cl:Cr^3+ System: a Complete Energy Matrix Study
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A theoretical method for investigating the inter-relation between the electronic and molecular structures of 3d^3 configuration ions in a tetragonal ligand field is established on the basis of the 120 × 120 complete energy matrices. Using this method, the local structure parameters of two tetragonal Cr^3+ centers in the NH4 Cl:Cr^3+ system are determined, Furthermore, the relations between the molecular symmetry and the ligand field symmetry are discussed. 相似文献
128.
Theoretical Investigations on the Off-Center Displacement of Co2+ in SrO by Analyzing Its Anisotropic g Factors
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The off-center displacement of Co^2+ ion in SrO crystal is investigated by analyzing its anisotropic g factors gx, gy and gz through diagonalization of the 6 × 6 energy matrix within ^4T1 ground state for a 3d^7 ion under rhombic symmetry. In the matrix, the contributions from the admixtures of various J(= 1/2, 3/2, 5/2) states and the fourth-order term Dn of rhombic crystal-fields and the ligand orbitals and spin-orbit coupling interactions, which are usually ignored in the previous studies, are considered. Both g factors (gx = 4.172, gy = 5.004 and gz = 2.133) and the off-displacement value (△ R ≈ 0.023 am) show good agreement with the experimental data. 相似文献
129.
Maolu Du 《Journal of magnetism and magnetic materials》2009,321(2):95-98
In this paper, a Spin-Hamiltonian theory of orbital near-degenerate state in tetragonal field is presented. For orbital doublet 2E, which is an orbital degenerate state in the cubic field and is a near-degenerate state in the tetragonal field, we obtain the cubic invariant form and the tetragonal invariant form of the Spin-Hamiltonian. In case of near-degeneracy (tetragonal splitting is very small) two additional g-factors are introduced to investigate Zeeman-splitting for tetragonal field. The two additional g-factors g2z and g2xy describe the magnetic interest between A1g and B1g states for a parallel magnetic field with z-axis and a perpendicular magnetic field with z-axis, respectively. The theory is based on the time-reversal invariant and the point-group symmetry invariant. The theoretical method can also be used for other orbital degenerate states 2S+1Γ including and Γ=T1 or T2 and can be used for other point-group symmetry. 相似文献
130.
Souha Kammoun Hajer Souissi Ramzi Maalej Mohamed Dammak Mohamed Kamoun 《Journal of luminescence》2009,129(5):411-415
The experimental studies have provided evidence of the occurrence of transitions from the 3T1g(3F) ground state to the crystal-field levels 3T2g(3F), 3T1g(3P) and 3A2g(3F) for the V3+ centres in Al2O3 crystal; and from the 3A2g(3F) ground state to the crystal-field levels 3T2g(3F), 3T1g(3F) and 3T1g(3P) for the Ni2+ centres in LiNbO3 crystal (levels are assigned to irreps of the Oh point symmetry group). Using the experimental spectroscopic data, theoretical calculations of the crystal-field levels of V3+:Al2O3 and Ni2+:LiNbO3 are carried out based on the Racah theory. The observed crystalline-field splittings of the V3+ and Ni2+ terms were accounted for using a C3 symmetry Hamiltonian. The spin-orbit interaction was taken into account in this work. The Racah, crystal-field and spin-orbit parameters, which fit experimental and theoretical energy levels, have been reliably obtained. A good agreement between the theoretical and experimental results for the energy levels of V3+:Al2O3 and Ni2+:LiNbO3 has been obtained. 相似文献