全文获取类型
收费全文 | 522篇 |
免费 | 18篇 |
国内免费 | 2篇 |
专业分类
化学 | 341篇 |
晶体学 | 4篇 |
力学 | 6篇 |
数学 | 21篇 |
物理学 | 170篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 21篇 |
2021年 | 17篇 |
2020年 | 24篇 |
2019年 | 21篇 |
2018年 | 20篇 |
2017年 | 27篇 |
2016年 | 32篇 |
2015年 | 17篇 |
2014年 | 30篇 |
2013年 | 40篇 |
2012年 | 33篇 |
2011年 | 30篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 13篇 |
2007年 | 7篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 12篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1916年 | 2篇 |
排序方式: 共有542条查询结果,搜索用时 15 毫秒
1.
4-Hydroxybenzofuran-3-ones show a large bathochromic shift in UV spectrum on the addition of sodium acetate. Such a large shift is not observed in 6-hydroxycompounds. 相似文献
2.
P. N. Tandon V. S. Patil A. K. Grover R. G. Pillay H. G. Devare 《Hyperfine Interactions》1983,16(1-4):709-712
A new class of magnetic system RuxFeySi, has been identified in which the hyperfine field at Fe, as sensed by57Fe Mossbauer effect, is seen to evolve at a characteristic temperature far below the bulk magnetic ordering temperatures. 相似文献
3.
V.S. Patil R.G. Pillay A.K. Grover P.N. Tandon H.G. Devare 《Solid State Communications》1983,48(11):945-947
A ternary system consisting of Ru, Fe and Si is identified in which the hyperfine field at Fe is seen to evolve at a characteristic temperature, T1, far below the magnetic ordering temperature, Tm. It is speculated that the magnetic ordering at Tm is itinerant and T1 corresponds to the localization of the majority spin electrons at the Fe atoms. 相似文献
4.
S. Sarkar A. D. Thakur C. V. Tomy G. Balakrishnan D. McK Paul S. Ramakrishnan A. K. Grover 《Pramana》2006,66(1):193-207
New experimental data are presented on the scan rate dependence of the magnetization hysteresis width ΔM(H) (∞ critical current densityJ
c(H)) in isothermalMH scans in a weakly pinned single crystal of Ca3Rh4Sn13, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). We observe an interesting
modulation in the field dependence of a parameter which purports to measure the dynamical annealing of the disordered bundles
of vortices injected through the sample edges towards the destined equilibrium vortex state at a givenH. These data, in conjunction with the earlier observations made while studying the thermomagnetic history dependence inJ
c(H) in the tracing of the minor hysteresis loops, imply that the partially disordered state heals towards the more ordered state
between the peak field of the SMP anomaly and the onset field of the PE. The vortex phase diagram in the given crystal of
Ca3Rh4Sn13 has been updated in the context of the notion of the phase coexistence of the ordered and disordered regions between the
onset field of the SMP anomaly and the spinodal line located just prior to the irreversibility line. A multi-critical point
and a critical point in the (H,T) region of the Bragg glass phase have been marked in this phase diagram and the observed behavior is discussed in the light
of recent data on multi-critical point in the vortex phase diagram in a single crystal of Nb. 相似文献
5.
CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
6.
Massless Dirac fermions in monolayer graphene exhibit total transmission when normally incident on a scalar potential barrier, a consequence of the Klein paradox originally predicted by O Klein for relativistic electrons obeying the 3 + 1 dimensional Dirac equation. For bilayer graphene, charge carriers are massive Dirac fermions and, due to different chiralities, electron and hole states are not coupled to each other. Therefore, the wavefunction of an incident particle decays inside a barrier as for the non-relativistic Schr?dinger equation. This leads to exponentially small transmission upon normal incidence. We show that, in the presence of magnetic barriers, such massive Dirac fermions can have transmission even at normal incidence. The general consequences of this behavior for multilayer graphene consisting of massless and massive modes are mentioned. We also briefly discuss the effect of a bias voltage on such magnetotransport. 相似文献
7.
Ionics - A novel, simple, sensitive, and highly selective omeprazole sensor based on the synergistic effect of polyaniline (PANI) and multiwalled carbon nanotubes (MWCNTs) has been developed. The... 相似文献
8.
Fernandes Patrick F. Bhasin Hinaly Kashyap Priyanka Mishra Divya R. 《Journal of fluorescence》2022,32(4):1279-1288
Journal of Fluorescence - A new tri-naphthoylated Cyclotriveratrylene molecule has been synthesized for the rapid and sensitive detection of 4-nitrotoluene (4-NT) among various nitro aromatic... 相似文献
9.
This paper describes the heavy ion-induced effects on the electrical characteristics of reactively sputtered ZrO2 and Al2O3 high-k gate oxides deposited in argon plus nitrogen containing plasma. Radiation-induced degradation of sputtered high-k dielectric ZrO2/Si and Al2O3/Si interface was studied using 45?MeV Li3+ ions. The devices were irradiated with Li3+ ions at various fluences ranging from 5?×?109 to 5?×?1012?ions/cm2. Capacitance–voltage and current–voltage characteristics were used for electrical characterization. Shift in flat band voltage towards negative value was observed in devices after exposure to ion radiation. Post-deposition annealing effect on the electrical behavior of high-k/Si interface was also investigated. The annealed devices showed better electrical and reliability characteristics. Different device parameters such as flat band voltage, leakage current, interface defect density and oxide-trapped charge have been extracted.The surface morphology and roughness values for films deposited in nitrogen containing plasma before and after ion radiation are extracted from Atomic Force Microscopy. 相似文献
10.