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101.
Jung-Hoon Choi In-Hak Cho Hee-Chul Eun Hwan-Seo Park Yung-Zun Cho Ki-Rak Lee Geun-Il Park Song-Hyun Kim Chang-Ho Shin Jong-Kyung Kim 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1731-1738
The pyrochemical process, which uses a dry method to recycle used nuclear fuel generates waste LiCl–KCl salt containing radioactive lanthanide elements. To reuse LiCl–KCl salt, the lanthanide elements are separated through a precipitation method promoted by oxygen sparging and the separated fission product of lanthanide oxide should be fabricated into durable wasteforms sustainable for several 1,000 years to store in a final geological repository. Herein, we report the fabrication of a borosilicate glass based wasteform with a glass matrix of SiO2–Al2O3–B2O3 having a high waste loading of 50 wt% lanthanide oxide. Th physical properties of four kinds of wasteforms having a different lanthanide oxide waste composition were evaluated. To investigate the long-term physical stability of each sample having 50 wt% lanthanide oxide waste loading, time–temperature–transformation (TTT) test was conducted at 500 and 700 °C for 60 and 180 h, and the physical properties were evaluated after each TTT test. 相似文献
102.
Moonyong Shin Myeong Hak Kim Tae-hwan Ha Jongho Jeon Kyoo-Hyun Chung Jin Seuk Kim Young Gyu Kim 《Tetrahedron》2014
Propellanes and azapropellanes are attractive compounds for their unique structure and valuable applications but there are few synthetic studies for highly N-substituted azapropellanes. Several novel derivatives of 2,4,6,8,10-pentaaza[3.3.3]propellane, such as 3, 4, and 5 were successfully synthesized from readily available diethyl tartrate. Most of the synthetic steps were efficient. Their propellane structures were established by spectroscopic data and confirmed with single crystal X-ray analyses. 相似文献
103.
The (132R)-methoxycarbonyl group of methyl pheophorbide a, one of the chlorophyll-a derivatives, was converted to a methyl group through methylation at the C132 position followed by removal of the methoxycarbonyl group. The methylation of the C132 carboanion gave a 4:1 mixture of methyl 132-methyl-pheophorbide a and its 132-epimer. The successive pyrolysis of the major methylated product afforded methyl (132R)-methyl-pyropheophorbide a with a small amount of its (132S)-epimer. The substitution effects at the C132 position including stereochemistry were discussed on the basis of 1D/2D NMR, UV–vis absorption, and circular dichroism spectroscopic analyses as well as molecular modeling simulation. 相似文献
104.
Tae Kyu Kim Euh Duck Jeong Chae Young Oh Min Seob Shin Jong-Pil Kim Ok-Sang Jung Hongsuk Suh Fazlur Rahman Nawaz Khan Myung Ho Hyun Jong Sung Jin 《Chemical Papers》2011,65(6):863-872
A series of neutral gelators and cationic amphiphiles derived from 1,2 diphenylethylenediamine (I) and 1,2-cyclohexanediamine (II) was synthesised. Helical silica nanotubes were prepared utilising these organic gelators through sol-gel polycondensation
of tetraethoxy silane, (TEOS-silica source). Right- and left-handed helical nanotubes respectively were obtained from a 1:
1 mass mixture of optically active, (1S,2S)-III-(1S,2S)-V neutral gelator and (1S,2S)-IV-(1S,2S)-VI cationic amphiphile and a 1: 1 mass mixture of optically active, (1R,2R)-III-(1R,2R)-V neutral gelator and (1R,2R)-IV-(1R,2R)-VI cationic amphiphile, indicating that the handedness of the helical nanotubes varied with the change in the neutral gelator
precursors used. The nanotubes were characterised by SEM images. 相似文献
105.
Young Hee Choi Seul Oh Seo-Hyun Yoon Tae-Eun Kim Namyi Gu Eun Young Kim Han Kyong Kim Kyung-Sang Yu In-Jin Jang Sang-Goo Shin Joo-Youn Cho 《Chromatographia》2011,73(3-4):273-280
A simultaneous simple, rapid, and sensitive LC?CMS?CMS method was developed and validated for the determination of HM30181A, [2-(2-{4-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-ethyl]-phenyl}-2H-tetrazol-5-yl]-4,5-dimethoxy-phenyl]amide, as a P-glycoprotein inhibitor and its two metabolites, M1 and M2, in human plasma using docetaxel as an internal standard (IS). The analytes were extracted from 200???L of biological sample by liquid?Cliquid extraction using 1?mL of methyl-t-butyl ether. Chromatographic separation was carried on a Luna C8 column at 30???C with mobile phase consisting of distilled water with 0.1% formic acid and acetonitrile (75:25, v/v) at a flow rate of 0.7?mL?min?1 for human plasma samples. The method was linear over concentration ranges of 0.5?C50, 0.1?C10, and 0.1?C10?ng?mL?1 for HM30181A, M1, and M2, respectively, in human plasma. The values of coefficient variation for the assay precision were <12.5, <9.10, and <9.96% for HM30181A, M1, and M2, respectively, in human plasma. The values of accuracy were 93.0?C108, 94.7?C104%, and 95.7?C105% for HM30181A, M1, and M2, respectively, in human plasma. This method is simple, sensitive, and applicable for the pharmacokinetic studies of HM30181A and its metabolites in humans. 相似文献
106.
Brison J Benoit DS Muramoto S Robinson M Stayton PS Castner DG 《Surface and interface analysis : SIA》2011,43(1-2):354-357
Time of flight secondary ion mass spectrometry 2D images and molecular depth profiles of human HeLa cells treated with bromodeoxyuridine (BrdU) were acquired in the dual beam mode (Bi(3) (+) analysis beam, C(60) (+) etching beam). Several preparation protocols were investigated and were compared to a simple wash-and-dry method. The feasibility of using C(60) to clean the samples prior to imaging with Bi was also investigated quantitatively by calibrating full depth profiles of the cells using atomic force microscopy. BrdU was used as a marker for the cell nucleus, facilitating identification and localization of sub-cellular features during depth profiling. Results show that C(60) can be used to remove the surface contamination and to access different layers within the cells for 2D imaging. For a 1 nA, 10 keV C(60) (+) beam incident at 45° and rastered over a 500 × 500 μm(2) area, ~1 nm of biological material was sputtered every second. Our results show that HeLa cells were completely removed after etching with 1.3×10(15) C(60) (+) ions per cm(2), giving an average etching rate of 3.9 nm for every 10(13) C(60) per cm(2) at 10 keV and 45° incidence. 相似文献
107.
Shin‐Yuh Chern Jeng‐Haur Horng Shih‐Han Chen 《Surface and interface analysis : SIA》2011,43(12):1509-1513
In this study, a numerical thermal model is developed for sliding block contact under various loads, sliding velocities and surface roughness. The temperature distributions are shown for perfectly insulated thermal conditions along noncontact surfaces. For a particular five‐peaks contact model, the maximum temperature at the central peak is slightly lhigher than the others. The temperature profile decreases as the distance to the symmetry axis increases, and then decreases dramatically at the noncontact area. It is clear to see that the maximum temperature locates at the symmetry central peak of the asperity contact area instead of the leading head of the smooth surface. The maximum temperature rise parameter increases as the pressure, sliding velocity and asperity roughness increased or conductivity decreased. This phenomenon becomes obvious for cases at high pressure, velocity and roughness and low conductivity. Particularly, the influence of roughness is not significant for low velocity. Similar results are found for the maximum temperature rise parameter difference between peaks or peaks/valleys. The simulation results of this asperity surface sliding block contact model are able to provide essential information for the components of microelectro—mechanical systems (MEMS) and biochemical reaction mechanism. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
108.
109.
The substitution of a small amount of Ga in the high-voltage spinel cathode LiMn1.5Ni0.42Ga0.08O4 leads to superior cyclability at room temperature and 55 °C along with higher rate capability with conventional electrolytes compared to that found with the LiMn1.5Ni0.5O4 cathode. The superior performance is attributed to the segregation of the inert Ga3+ ions to the surface during the synthesis process, providing a robust, more stable interface with the electrolyte at the high operating voltage (~ 4.7 V), along with the stabilization of the spinel structure with a disordering of the cations in the octahedral sites. 相似文献
110.