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981.
报道了在兰州重离子加速器国家实验室电子回旋共振离子源原子物理实验平台上,用高电荷态40Arq+(1≤q≤12)离子作用于半导体Si固体表面时的电子发射产额实验测量.实验中,通过改变炮弹离子的电荷态和引出电压选取其不同的势能和动能,系统地研究了入射离子势能沉积和与其在固体中的电子能损对表面电子发射产额的贡献.结果表明,作为引起表面电子发射的两个主要因素,单离子的电子发射产额与炮弹离子在固体表面的势能沉积和电子能损都有近似的正比关系. 相似文献
982.
983.
Diamond film was deposited in CH4 and H2 gas mixture with a small amount of N2 by microwave plasma assisted chemical vapor deposition (MPCVD). Scanning electron microscopy, Raman spectroscopy and transmission electron microscopy were applied to characterize the film. The results showed that the growth of grains are different the central region and the edge. In the central region, diamond grains nucleated with a density as high as 4.8×108 cm-2 and were preferential in 〈001〉 orientation. The inner grains formed an area without stacking faults,which was surrounded by a rim with a high density of stacking faults. A growth model was suggested to interpret the morphological feature and the behavior of preferential growth. At the edge, the grains were identified to be 6H polytypes of diamond and a new twin relationship of grains was found. Besides, the effect of the N dopant on the growth behavior of the diamond film deposited by MPCVD was discussed in connection with the growth rate of the film.
关键词:
金刚石
结构表征
透射电子显微镜
多型金刚石 相似文献
984.
M. Janda V. Martišovitš M. Morvová Z. Machala K. Hensel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(2):309-315
Motivated by experimental investigations of electrical discharges in N2/CO2/H2O, Monte Carlo (MC) electron dynamics simulations in atmospheric
N2/CO2 mixtures were performed. The goal was to obtain electron energy distribution functions (EEDFs), mean free path, drift velocity,
collision frequency and mean energy of electrons,
rate coefficients of electron-impact reactions, ionisation and attachment coefficients, as functions of the reduced electric
field strength (E/N) and of the concentration of individual gas components. The results obtained by MC simulations were fitted
with polynomials of up to the 3rd order with reasonable accuracy for E/N above 80 Td.
The studied parameters below 80 Td were strongly non-linear as functions of E/N. This is mostly due to the influence of elastic
collisions of electrons with CO2 molecules prevailing in CO2-dominant mixtures for E/N < 40 Td, and vibrational excitation collisions of N2 species prevailing in N2-dominant mixtures for E/N from 40 to 80 Td. The effect of these electron-impact processes was specific for each of the studied
parameters. 相似文献
985.
R. M. Movsessyan A. S. Sahakyan M. A. Chalabyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2007,42(6):268-270
The scattering of nonspin-polarized electrons on a heterostructure containing a magnetic element (a nonmagnetic barrier adjoining a magnetic one from left or right, or a magnetic well between two nonmagnetic barriers) is considered. The transmission coefficients and degrees of the spin polarization of electrons transmitted through these structures are obtained. 相似文献
986.
O. Kavatsyuk C. Mazzocchi Z. Janas A. Banu L. Batist F. Becker A. Blazhev W. Brüchle J. Döring T. Faestermann M. Górska H. Grawe A. Jungclaus M. Karny M. Kavatsyuk O. Klepper R. Kirchner M. La Commara K. Miernik I. Mukha C. Plettner A. Płochocki E. Roeckl M. Romoli K. Rykaczewski M. Schädel K. Schmidt R. Schwengner J. Żylicz 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):319-325
The β decay of the very neutron-deficient isotope 101Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors
for γ-ray spectroscopy. Based on the β-delayed proton data the production cross-section of 101Sn in the 50Cr + 58Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of 101Sn was measured to be 1.9(3)s. For the first time β-delayed γ-rays of 101Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in 101In. The results for the 101Sn decay as well as those from previous work on the 103Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction
in the 88Sr to 132Sn model space. 相似文献
987.
成功研制了测量绝缘体二次电子发射系数的测量装置,该装置主要由栅控电子枪系统、真空系统和电子采集系统组成,测量装置产生的原电子流的能量范围为0.8~60 keV。采用单脉冲电子枪法,测量了原电子能量范围为0.8~45 keV的多晶MgO的二次电子发射系数。测量中,收集极(偏置盒)离材料表面设置为约35 mm,偏置电压设置为 45 V。测量得到:用磁控溅射法制备的MgO的二次电子发射系数最大值约为2.83,处于 2~26范围内,其对应的原电子能量约为980 eV。这表明该装置测量的绝缘体二次电子发射系数是可信的,但用磁控溅射法制备的MgO的二次电子发射系数较低,这可能是制备MgO时引入了过多的杂质在MgO二次电子发射体里面所引起的。 相似文献
988.
989.
990.
研究了基于InP基的In0.65Ga0.35As/In0.52Al0.48As赝型高迁移率晶体管材料中纵向磁电阻的Shubnikov-deHaas(SdH)振荡效应和霍耳效应,通过对纵向磁电阻SdH振荡的快速傅里叶变换分析,获得了各子带电子的浓度,并因此求得了各子带能级相对于费米能级的位置.联立求解Schrdinger方程和Poisson方程,自洽计算了样品的导带形状、载流子浓度分布以及各子带能级和费米能级位置.理论计算和实验结果很好符合.实验和理论计算均表明,势垒层的掺杂电子几乎全部转移到了量子阱中,转移率在95%以上. 相似文献