全文获取类型
收费全文 | 125篇 |
免费 | 0篇 |
专业分类
化学 | 100篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 6篇 |
物理学 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 15 毫秒
101.
Understanding speech in background noise, talker identification, and vocal emotion recognition are challenging for cochlear implant (CI) users due to poor spectral resolution and limited pitch cues with the CI. Recent studies have shown that bimodal CI users, that is, those CI users who wear a hearing aid (HA) in their non-implanted ear, receive benefit for understanding speech both in quiet and in noise. This study compared the efficacy of talker-identification training in two groups of young normal-hearing adults, listening to either acoustic simulations of unilateral CI or bimodal (CI+HA) hearing. Training resulted in improved identification of talkers for both groups with better overall performance for simulated bimodal hearing. Generalization of learning to sentence and emotion recognition also was assessed in both subject groups. Sentence recognition in quiet and in noise improved for both groups, no matter if the talkers had been heard during training or not. Generalization to improvements in emotion recognition for two unfamiliar talkers also was noted for both groups with the simulated bimodal-hearing group showing better overall emotion-recognition performance. Improvements in sentence recognition were retained a month after training in both groups. These results have potential implications for aural rehabilitation of conventional and bimodal CI users. 相似文献
102.
Vidya Shivatare 《Molecular physics》2014,112(18):2397-2406
We applied the two-colour resonant two-photon ionisation and mass-analysed threshold ionisation techniques to record the vibrationally resolved spectra of the selected rotamers and 35Cl and 37Cl isotopologues of 4-chloro-3-fluorophenol in the electronically excited S1 and cationic ground D0 states. The band origins of the S1 ← S0 electronic transition and the adiabatic ionisation energies of the cis and trans rotamers of 4-chloro-3-fluorophenol are determined to be 35,233 ± 2 and 35,405 ± 2 cm?1, and 69,334 ± 5 and 69,460 ± 5 cm?1, respectively. The electronic transition energies and general spectral features of the two isotopologues are nearly identical. Most of the observed active vibrations result from the in-plane ring deformation and substituent-sensitive motions. The experimental data show that the frequency difference in the observed active vibrations of the rotamers and isotopologues depends on the nature, vibrational pattern, location, and relative orientation of the substituents. 相似文献
103.
Trisheteroarylmethanes are interesting molecules for the construction of three dimensionally complex systems. From this vantage point, we studied electrophilic substitution reactions on tris-2-thienylmethane and tris-2-furylmethane. During the bromination reaction, we have isolated the tris-bromosubstituted tris-2-thienylmethane in the former case and brominated furanones in the latter case, which may be of synthetic and biological importance. 相似文献
104.
The interaction of D-glucose with alkali halide in aqueous and formmide solutions has been studied by employing conductance
measurements. Our results showed a break at the saturation temperature indicating a transition in the conductance values.
This behaviour is explained in terms of solute-solvent interactions involved in the electrolyte-solvent-nonelectrolyte systems. 相似文献
105.
Synthesis and characterisation of CoII,NiII and CuII complexes of a tridentate N5 macrocyclic ligand
Vidya B. Rana Suraj P. Ratra Dharam P. Singh Mahendra P. Teotia 《Transition Metal Chemistry》1985,10(3):115-116
Summary A novel tridentate macrocyclic ligand was synthesised by the reaction of 2,6-dipicolinic acid hydrazide and 2,3-butanedione.
Complexes with CoII, NiII and CuII are five-coordinate trigonal bipyramidal on the basis of analyses, electrical conductance, magnetic, electronic and infrared
spectral studies. I.r. studies reveal that the ligand coordinates through the pyridine nitrogen and the amido-nitrogen. 相似文献
106.
Summary Picolinic acid hydrazide (PH) and isonicotinic acid hydrazide (INH) react with acetylacetone to form complexes, containing open chain tetradentate ligands, through anin situ process in the presence of nickel and copper salts. The complexes were isolated and characterised as five-coordinate with the aid of analyses, magnetic, e.s.r., electronic and i.r. spectral studies.Attempts to obtain the free ligand were unsuccessful, but its solid complexes can be isolated. Acetylacetonebispicolinoyl hydrazone Ac(PH)2 coordinates through azomethine and pyridine nitrogen atoms while acetylacetonebisisonicotinoyl hydrazone Ac(INH)2 does so through azomethine nitrogens and amido oxygen atoms, giving rise to complexes of the MAc(PH)2X or MAc(INH)2X type where X=Cl, Br, NO3 or NCS and M=nickel(II) and copper(II). Magnetic, e.s.r. and electronic spectra are consistent with five coordinate geometries incorporating one anion on the axial positions. Various ligand field parameters have been calculated and the amount of distortion assessed in terms of DT/DQ. The metal-ligand vibrations in the far i.r. are discussed. 相似文献
107.
Peter D. Friedman Vidya D. Vadakoot William J. MeyerJr Steven Carey 《Experiments in fluids》2007,42(5):751-759
Experimental simulations were carried out to investigate the onset of instability in negatively buoyant fountains by injecting
glycerin–water mixtures into silicon oil. The transition from a stable to an unstable fountain structure is primarily governed
by the Richardson number, and to a lesser extent, Reynolds number, viscosity ratio, Weber number and vent geometry. Transition
nominally occurs at a Ri = 1.0. For a fountain issuing from a cylindrical pipe, the major effect of the Reynolds number is in determining whether
or not the fountain is laminar or turbulent. The Reynolds number effect can be largely accounted for by basing a corrected
Richardson number on the root mean square of the mean velocity. Viscosity ratio deviating from unity has the effect of stabilizing
the flow structure and thereby reducing the transition Richardson number. Similarly, interfacial tension stabilizes the flow
pattern resulting in a trend of increasing transition Richardson number with increasing Weber number. The results are valid
in rectangular vents if the Richardson number and Reynolds number are based on the hydraulic diameter. 相似文献
108.
A DMAP catalyzed tandem addition-cyclization-dehydration sequence involving dimethyl acetylenedicarboxylate and β-ketoesters leading to polysubstituted benzene/biaryl derivatives is presented. 相似文献
109.
ZnSe films were pulse-electrodeposited on conducting glass substrates with and without the addition of phosphotungstic acid.
X-ray diffraction studies indicated the formation of single phase cubic ZnSe. Addition of phosphotungstic acid resulted in
films with nanocrystallites. The band gap of the films was found to increase due to addition of phosphotungstic acid. The
films had a crystallite size of the order of 15nm and a surface roughness of 1.8nm. Laser Raman studies exhibited the LO phonon
peaks of ZnSe. The films were found to possess a slight excess of Se as evident from the energy dispersive X-ray analysis
measurements. 相似文献
110.
Thorat Vidya Soudamini N. Sengupta Arijit Mishra R. K. Kumar Amar Kaushik C. P. 《Journal of Radioanalytical and Nuclear Chemistry》2019,320(3):627-631
Journal of Radioanalytical and Nuclear Chemistry - A simple, simultaneously multi-elemental, ICP-AES based method was optimized to characterize nuclear high level waste solutions from different... 相似文献