全文获取类型
收费全文 | 83篇 |
免费 | 0篇 |
专业分类
化学 | 32篇 |
力学 | 1篇 |
物理学 | 50篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 2篇 |
1998年 | 1篇 |
1995年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有83条查询结果,搜索用时 19 毫秒
1.
Shashilov VA Ermolenkov VV Levitskaia TG Lednev IK 《The journal of physical chemistry. A》2005,109(32):7094-7098
Deep UV resonance Raman spectroscopy was used for characterizing ligand-metal ion complexes. The obtained results demonstrated a strong intrinsic sensitivity and selectivity of a Raman spectroscopic signature of a bicyclic diamide, a novel chelating agent for lanthanides and actinides (Lumetta, G. J.; Rapko, B. M.; Garza, P. A.; Hay, B. P.; Gilbertson, R. D.; Weakley, T. J. R.; Hutchison, J. E. J. Am. Chem. Soc. 2002, 124, 5644). Molecular modeling, which included structure optimization and calculation of Raman frequencies and resonance intensities, allowed for assigning all strong Raman bands of the bicyclic diamide as well as predicting the band shifts observed because of complex formation with metal ions. A comparative analysis of Raman spectra and the results of the molecular modeling could be used for elucidating the structure of complexes in solution. 相似文献
2.
3.
A novel approach utilizing automated Raman microspectroscopic mapping for gunshot residue (GSR) detection was investigated. A well-established technique for GSR recovery (tape lifting) was utilized for GSR particle collection. Uncontaminated samples of the substrate (tape), organic GSR (OGSR), and inorganic GSR (IGSR) particles were characterized to generate three respective Raman spectroscopic training sets. Automated Raman mapping was used to rapidly collect spectra over areas of the tape substrate populated with GSR particles. Raman spectra collected from the maps were classified against the training sets via partial least squares discriminant analysis (PLS-DA) to determine if GSR was present. We report the application of Raman chemical mapping as a proof of concept for the positive detection of GSR particles of varying morphologies. The estimated size of GSR particles, which could be readily detected by this method, is about 3.4 μm. The efficiency of the classification was quantitated with rates of true positives and negatives. Validation studies scrutinizing the practicality of this approach as a viable tool for potential forensics investigations are currently in progress. Figure
The figure illustrates a novel approach for the recovery and identification of gunshot residue on adhesive tape. The emerging approach combines tape lifting and a rapid, non-destructive Raman spectroscopic scanning over the tape, which was used for collecting GSR from a surface of interest. Detection of GSR is achieved through multivariate classification of mapping spectra against a known training set. 相似文献
4.
Abdullahi Garba USMAN Selin IIK Sani Isah ABBA Filiz MERL 《Turkish Journal of Chemistry》2020,44(5):1339
Isoquercitrin is a flavonoid chemical compound that can be extracted from different plant species such as Mangifera indica (mango), Rheum nobile , Annona squamosal , Camellia sinensis (tea), and coriander ( Coriandrum sativum L.). It possesses various biological activities such as the prevention of thromboembolism and has anticancer, antiinflammatory, and antifatigue activities. Therefore, there is a critical need to elucidate and predict the qualitative and quantitative properties of this phytochemical compound using the high performance liquid chromatography (HPLC) technique. In this paper, three different nonlinear models including artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and support vector machine (SVM),in addition to a classical linear model [multilinear regression analysis (MLR)], were used for the prediction of the retention time (tR) and peak area (PA) for isoquercitrin using HPLC. The simulation uses concentration of the standard, composition of the mobile phases (MP-A and MP-B), and pH as the corresponding input variables. The performance efficiency of the models was evaluated using relative mean square error (RMSE), mean square error (MSE), determination coefficient (DC), and correlation coefficient (CC). The obtained results demonstrated that all four models are capable of predicting the qualitative and quantitative properties of the bioactive compound. A predictive comparison of the models showed that M3 had the highest prediction accuracy among the three models. Further evaluation of the results showed that ANFIS–M3 outperformed the other models and serves as the best model for the prediction of PA. On the other hand, ANN–M3proved its merit and emerged as the best model for tR simulation. The overall predictive accuracy of the best models showed them to be reliable tools for both qualitative and quantitative determination. 相似文献
5.
A. M. Blik A. M. Gorin S. V. Donskov V. N. Kolosov A. A. Lednev V. A. Lishin Yu. V. Mikhailov V. A. Polyakov V. D. Samoylenko A. E. Sobol V. P. Sugonyaev G. V. Khaustov 《Physics of Atomic Nuclei》2008,71(12):2124-2128
An experiment performed with the GAMS-4π spectrometer resulted in observing 235 ± 45 events of the decay η′ → 3π 0. The respective charge-exchange reaction at a momentum of 32.5 GeV/c was used as a source of η′ mesons. The decay branching ratio was found to be Br(η′ → 3π 0) = (1.8 ± 0.4) × 10?3. The slope parameter of the square of the respective matrix element in the linear approximation proved to be β = ?0.59 ± 0.18. 相似文献
6.
V. I. Boyarintsev A. K. Lednev A. S. Prudnikov A. S. Savin E.O. Savina 《Fluid Dynamics》2004,39(6):972-978
The data of a laboratory experiment to observe the small perturbations of a free surface by a thin hydrofoil profile moving horizontally in water are presented and compared with the calculation results obtained for a hydrofoil modeled by a system of distributed sources and sinks within the framework of the small-wave approximation.Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, 2004, pp. 145–152.Original Russian Text Copyright – 2004 by Boyarintsev, Lednev, Prudnikov, Savin, and Savina. 相似文献
7.
Raman spectroscopy was used to study trends in chemical composition of bones in a burial environment. A turkey bone was sectioned
and buried for short intervals between 12 and 62 days. Buried sections were analyzed using Raman microspectroscopy with 785 nm
excitation. The results indicate that chemical changes in bone due to soil bacteria are time-dependent. Spectroscopic trends
within buried bone segments were correlated to burial duration. A preliminary model was constructed using peak integration
of Raman bands. Data collected within buried bone segments fit very well in this model. The model constructed is sensitive
to changes in bone composition in a scale of days. This study illustrates the great potential of Raman spectroscopy as a non-destructive
method for estimating the burial duration of bone for forensic purposes. 相似文献
8.
F. Binon A. M. Blik S. V. Donskov S. Inaba V. N. Kolosov A. A. Lednev V. A. Lishin Yu. V. Mikhailov J. P. Peigneux V. A. Polyakov S. A. Sadovsky V. D. Samoilenko A. E. Sobol J. P. Stroot V. P. Sugonyaev K. Takamatsu T. Tsuru I. Fujii G. V. Khaustov H. Shimizu Y. Yasu 《Physics of Atomic Nuclei》2005,68(6):960-973
The ηη system produced in charge-exchange π ? p interaction at a momentum of 32.5 GeV/c is studied in an experiment performed with the GAMS-4π spectrometer at the 70-GeV accelerator of the Institute for High-Energy Physics (IHEP, Protvino). A partial-wave analysis is performed in the mass range between 1.1 and 3.9 GeV for ?t <0.2 (GeV/c)2, S, D, G, and J waves being taken into account in this analysis. The S wave has a complicated structure, displaying peaks at about 1.5 and 1.7 GeV. These peaks are associated with the f 0(1500) and f 0(1710) mesons. One of the solutions (preferable one) involves the f 0(2200) and f 2(1950) resonances. The mass region above 2.4 GeV is dominated by the G wave. A broad state of mass about 3 GeV and width 0.7 GeV is found in the J wave. The parameters of the resonances in question and their production cross sections are measured. 相似文献
9.
D. Alde F. G. Binon M. Boutemeur C. Bricman A. V. Dolgopolov S. V. Donskov M. Gouanere S. Inaba A. V. Inyakin V. A. Kachanov G. V. Khaustov T. Kinashi E. A. Knapp M. Kobayashi A. A. Kondashov A. V. Kulik G. L. Landsberg A. A. Lednev V. A. Lishin T. Nakamura J. P. Peigneux S. A. Polovnikov V. A. Polyakov M. Poulet Yu. D. Prokoshkin S. A. Sadovsky V. D. Samoylenko P. M. Shagin A. V. Shtannikov A. V. Singovsky J. P. Stroot V. P. Sugonyaev K. Takamatsu T. Tsuru 《Zeitschrift fur Physik C Particles and Fields》1995,66(3):379-383
A partial-wave analysis of the ω ωπ0-system produced in the π- p→ωπ0 n reaction at 38 GeV/c beam momentum has been performed. A new 5?- meson state,ρ 5(22350), with a massM=2330±35 MeV and a width Γ=400±100 MeV, is observed. The analysis also confirms the 1?- ρ(2150) meson, a radial-orbital excitation of the ρ(770), observed earlier by the GAMS Collaboration. 相似文献
10.
W.D. Apel K.H. Augenstein E. Bertolucci S.V. Donskov A.V. Inyakin V.A. Kachanov R.N. Krasnokutsky M. Kruger G. Leder A.A. Lednev I. Mannelli Yu.V. Mikhailov H. Müller G.M. Pierazzini Yu.D. Prokoshkin M. Quaglia H. Schneider A. Scribano M.L. Vincelli 《Physics letters. [Part B]》1978,72(4):500-502
The invariant mass spectrum of neutral final states produced in π?p charge-exchange scattering at 40 GeV/c has been studied, searching for heavy particles decaying in 2γ. A peak is observed around 2.85 GeV/c2. The cross section of the reaction π?p→X(2.85)+n, times the branching ratio of the X→2γ decay, is measured to be . 相似文献