全文获取类型
收费全文 | 390篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
化学 | 210篇 |
晶体学 | 12篇 |
力学 | 4篇 |
数学 | 22篇 |
物理学 | 152篇 |
出版年
2023年 | 4篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 24篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 17篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 7篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 5篇 |
1955年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有400条查询结果,搜索用时 15 毫秒
101.
Kapil Parihar Surya Shekhar Daga Umema Ahmed G. K. Mathur Supriya Kumari Jyoti Kumawat Mahipal Singh Sankhla 《Macromolecular Symposia》2024,413(1):2300056
Accurate gender determination is crucial in many scientific disciplines, especially in prenatal diagnosis of X-linked diseases and forensic investigations. Today, molecular techniques, especially typing for a length variation in the X–Y homologous amelogenin gene (AMEL X and AMEL Y), are used for gender assignation. This amelogenin is an integral part of most PCR multiplex kits for gender determination marker, but in 1998 there was a report of two normal males being typed as female with this marker. Subsequently, a small number of males with amelogenin deleted genes have been reported in various populations but little data are available characterizing these deletions. This review aims to explore possible relationships among the AMEL Y deleted samples and Y-chromosome microsatellite haplotypes. Also, attempts are made to determine the frequency of males with AMEL Y deleted gene in various countries across the globe. Although some studies have shown that males with AMEL Y deleted gene are extremely rare in most populations, typing an additional gender-determining locus should be considered in forensic investigations where the reference sample is of unknown gender. 相似文献
102.
Ashok Kumar Ashoke Chandra Deb S. K. Mukerjee V. N. Vaidya D. D. Sood 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(1):375-377
Solvent extraction of plutonium(VI) from nitric acid (1 to 5M) into 20% and 30% TBP in dodecane saturated with uranium(VI)
(0% to 80%) has been studied. For a particular nitric acid concentration, the distribution coefficient (K
d
) is found to decrease with the increase in saturation of organic phase with uranium(VI). At a fixed organic phase the saturationK
d
increased with increase in nitric acid concentration, however, the magnitude of this increase inK
d
decreased with the increase in saturation. 相似文献
103.
Structures of complexes formed in aqueous solutions by some anionic polyelectrolytes (double and single stranded (ds and ss)
DNA, poly(vinyl sulfonate) (PVS), and poly(styrene sulfonate) (PSS)) with a cationic surfactant system consisting of cetyltrimethylammonium
bromide (CTAB) and sodium 3-hydroxy-2-naphthoate (SHN) have been determined using small angle X-ray diffraction. All complexes
are found to have a two-dimensional (2-D) hexagonal structure at low SHN concentrations. Analysis of the diffraction data
shows that the ds DNA—CTAB complex has an intercalated structure, with each DNA strand surrounded by three cylindrical micelles.
On increasing SHN concentration, DNA—CTAB—SHN complexes exhibit a hexagonal-to-lamellar transition, whereas PVS complexes
show a hexagonal → centered rectangular → lamellar transition. PSS complexes show yet another sequence of structures. These
results indicate the significant influence of the chemical nature of the polyelectrolyte on the structure of the complexes. 相似文献
104.
A detailed theoretical study of the low-temperature lattice specific heat of Ni-based dilute alloys has been carried out.
Lattice Green’s function method has been used to calculate the local density of states of substitutional impurities and lattice
specific heat in different alloys. The resonance condition has been investigated for possible occurrence of resonance modes.
Except in NiCr and NiMn, low-frequency resonance modes have been obtained in all the alloys. However, no localized mode was
obtained. The impurity-induced increase in lattice specific heat is explained on the basis of the obtained resonance modes.
The calculation shows an excellent agreement with the measured lattice specific heat in these alloys 相似文献
105.
Kapil Ahuja Layne T. Watson Stephen C. Billups 《Computational Optimization and Applications》2008,41(3):363-375
Probability-one homotopy algorithms have strong convergence characteristics under mild assumptions. Such algorithms for mixed
complementarity problems (MCPs) have potentially wide impact because MCPs are pervasive in science and engineering. A probability-one
homotopy algorithm for MCPs was developed earlier by Billups and Watson based on the default homotopy mapping. This algorithm
had guaranteed global convergence under some mild conditions, and was able to solve most of the MCPs from the MCPLIB test
library. This paper extends that work by presenting some other homotopy mappings, enabling the solution of all the remaining
problems from MCPLIB. The homotopy maps employed are the Newton homotopy and homotopy parameter embeddings. 相似文献
106.
Motivated by recent observations of rheochaos in sheared wormlike micelles, we study the coupled nonlinear partial differential equations for the hydrodynamic velocity and order-parameter fields in a sheared nematogenic fluid. In a suitable parameter range, we find irregular, dynamic shear banding and establish by decisive numerical tests that the chaos we observe in the model is spatiotemporal in nature. 相似文献
107.
108.
P. C. Sood 《Zeitschrift für Physik A Hadrons and Nuclei》1983,310(1-2):95-97
The band-head energies of the two-quasiparticle states expected in the doubly odd deformed nucleus170Ho are calculated for a zero range residual interaction. The results are compared with the available experimental information. It is concluded that the ground state has the Nilsson configuration 6+{7/2?[523↑] p }+5/2[512↑] n being the 2.76m isomer whereas the 43s isomer is the 1+ ∑=0 state arising from the same configuration and lies at about 100 keV excitation energy in agreement with the experiment. The first excited state in this nucleus is predicted to be the 4?{3/2+[411↑] p +5/2?[521↑] n } state close to the ground state with the corresponding 1? ∑=0 member expected to appear well above the 1+ isomer. 相似文献
109.
A generalized VMD mechanism, implemented through the OPC model, is proposed for E1 and M1 decays of mesons wherein the photon couples to two infinite sequences of radial excitations of 3S1 and 3D1 states. The results reveal good accord with data under the conventional assignments, with a parameter signifying a reduced magnetic coupling of ψ-ions with c quarks. 相似文献
110.