全文获取类型
收费全文 | 216篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 123篇 |
晶体学 | 2篇 |
力学 | 4篇 |
数学 | 7篇 |
物理学 | 85篇 |
出版年
2022年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 9篇 |
2012年 | 7篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 14篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有221条查询结果,搜索用时 31 毫秒
111.
We found both nucleation-growth-type and spinodal-decomposition-type transformation from one liquid state to another in a "molecular liquid," triphenyl phosphite (TPP). Binodal and spinodal temperatures of this transition at ambient pressure were determined by the characteristics of morphological evolution, domain-growth kinetics, and rheological evolution. Furthermore, a distinct thermal signature of the glass transition of a second liquid was also detected in addition to that of an ordinary liquid. These findings strongly suggest the existence of a liquid-liquid transition; more precisely, a transformation of one supercooled liquid to a glassy state of another liquid, in TPP. 相似文献
112.
113.
Weiwu Ren Regine Gries Catherine McCaughey Nathan Derstine Santosh K. Alamsetti Kenji L. Kurita Lorna Tu Prof. Roger G. Linington Prof. Robert Britton Prof. Gerhard Gries 《Angewandte Chemie (International ed. in English)》2018,57(36):11618-11622
Yellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald‐faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic–electroantennographic detection (GC‐EAD), isolated the compounds that elicited responses from male antennae by high‐performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC‐MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)‐3,7‐dimethyldeca‐2,7‐diendioic acid (termed here maculatic acid A) and (2Z,7E)‐10‐methoxy‐3,7‐dimethyldeca‐10‐oxo‐deca‐2,7‐dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald‐faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets. 相似文献
114.
Abbott T Akiba Y Beavis D Bloomer MA Bond PD Chasman C Chen Z Chu YY Cole BA Costales JB Crawford HJ Cumming JB Debbe R Engelage J Fung SY Gushue S Hamagaki H Hansen O Hayano RS Hayashi S Homma S Huang HZ Ikeda Y Juricic I Kang J Katcoff S Kaufman S Kimura K Kitamura K Kurita K Ledoux RJ Levine MJ Miake Y Morse RJ Moskowitz B Nagamiya S Olness J Parsons CG Remsberg LP Sakurai H Sarabura M Stankus P Steadman SG Stephans GS Sugitate T Tannenbaum MJ van Dijk JH Videbaek F Vient M Vincent P 《Physical review D: Particles and fields》1992,45(11):3906-3920
115.
Kiyoshi Shibata Takayuki Yamamoto Masahiko Kurita Hiroshi Kimura Akira Tsuchida Tsuneo Okubo 《Colloid and polymer science》2006,284(6):688-693
Fluorescence light emitted from photoexcited rhodamine 6G (R6G) doped in colloidal crystals of exhaustively deionized colloidal silica suspension is partially trapped within a crystal cage. This photon trapping is caused by Bragg reflection in crystal lattices. The photon trapping efficiencies were quantitatively examined as a function of the thickness of measurement cell. The efficiency increased from about 40 to 60% as the cell thickness increased from 1 to 10 mm for an R6G concentration of 5×10−6 mol/L. This result is attributed to an increase in the number of crystal layers perpendicular to the observation direction; these are formed in the cell with a large optical path length. On the other hand, the trapping efficiencies were constant irrespective of the angle between the incident and observed light of the cylindrical cells. The constant efficiencies are attributed to the fact that the heterogeneous crystal layers around the inner cell wall have the same thickness. 相似文献
116.
Shigeru Shimizu Yujirou Aiki Hiroki Ikake Kimio Kurita 《Journal of Polymer Science.Polymer Physics》1999,37(16):2195-2199
Segment‐segment interaction of poly(methylmethacrylate) in t‐butyl alcohol‐water mixtures in poor solvent regime was studied. From the small‐angle X‐ray scattering measurements of semidilute solution range, the binary and ternary cluster integrals of polymer segments were determined from concentration dependence of the correlation length at various temperatures just above the upper critical solution temperature. We have calculated the contributions of the segment–segment interaction to the entropy and enthalpy from the measured temperature dependence of these interaction parameters and found that both quantities are negative and decrease with decreasing t‐butyl alcohol content. FT‐IR absorption peak of carbonyl group of poly(methylmethacrylate) shifts to the lower frequency with increasing water content. The implications of these findings are discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2195–2199, 1999 相似文献
117.
118.
Thermochromic and magnetic properties of an organic radical, 1,3,5-trithia-2,4,6-triazapentalenyl (TTTA) crystal were investigated through polarized reflection and EPR measurements. TTTA shows a first-order magnetic phase transition with a wide thermal hysteresis loop near room temperature. The high temperature (HT) phase is paramagnetic due to a uniform one-dimensional stacking of the radical molecules, while the low temperature (LT) phase is diamagnetic due to strong dimerization along the stacking direction. The colors of the HT and LT phases are purple and green, respectively, and both phases show a strong dichroism. We also found that part of the LT phase changes to the HT phase by laser light irradiation. The experimental results suggest the possibility of optical control of magnetic bistabitity in TTTA crystal. 相似文献
119.
Pressure-induced phase transition of anatase titanium dioxide was investigated by Raman, absorption spectroscopy and X-ray diffraction. The change in Raman and absorption spectra with pressure revealed that the transition from anatase to high pressure phase with f -PbO 2 structure (TiO 2 -II) occurred in the pressure range of 4.0-4.6 GPa for a single crystal. The X-ray powder diffraction patterns indicate the presence of superstructural lattice of anatase at pressures more than 3 GPa. The superstructure of anatase disappears on the release of the pressure. A sluggish transition to the high pressure phase is also observed. The anatase coexists with the high pressure phase at 5.2 GPa. The difference in the results between optical spectroscopy (single crystal) and X-ray diffraction (powder) will be due to crystalinity of the sample. 相似文献
120.
Shunsuke Takahashi Shohei Kawasaki Koji Yamaguchi Hidefumi Miyata Hirofumi Kurita Takeshi Mizuno Shun-ichi Matsuura Akira Mizuno Masahiko Oshige Shinji Katsura 《Journal of fluorescence》2013,23(4):635-640
We developed two labeling methods for the direct observation of single-stranded DNA (ssDNA), using a ssDNA binding protein and a ssDNA recognition peptide. The first approach involved protein fusion between the 70-kDa ssDNA-binding domain of replication protein A and enhanced yellow fluorescent protein (RPA-YFP). The second method used the ssDNA binding peptide of Escherichia coli RecA labeled with Atto488 (ssBP-488; Atto488-IRMKIGVMFGNPETTTGGNALKFY). The labeled ssλDNA molecules were visualized over time in micro-flow channels. We report substantially different dynamics between these two labeling methods. When ssλDNA molecules were labeled with RPA-YFP, terminally bound fusion proteins were sheared from the free ends of the ssλDNA molecules unless 25-mer oligonucleotides were annealed to the free ends. RPA-YFP-ssλDNA complexes were dissociated by the addition of 0.2 M NaCl, although complex reassembly was possible with injection of additional RPA-YFP. In contrast to the flexible dynamics of RPA-YFP-ssλDNA complexes, the ssBP-488-ssλDNA complexes behaved as rigid rods and were not dissociated even in 2 M NaCl. 相似文献