全文获取类型
收费全文 | 52篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
化学 | 29篇 |
晶体学 | 1篇 |
数学 | 4篇 |
物理学 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有57条查询结果,搜索用时 31 毫秒
11.
Clemens Schmetterer Divakar Rajamohan Herta Silvia Effenberger Hans Flandorfer 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(10):i65-i67
Dinickel ditin zinc, Ni2Sn2Zn, crystallizes in the cubic space group , with a lattice parameter of a = 8.845 (1) Å and with all atoms occupying special positions. The crystal structure exhibits pronounced similarities with that of the quaternary compound Ni5.20Sn8.7Zn4.16Cu1.04. It shares structural features with other compounds in the Ni–Sn–Zn system, such as Ni5Sn4Zn and Ni3Sn2. 相似文献
12.
Divakar Vishwanath Swamy S. Girimanchanaika Dukanya Dukanya Shobith Rangappa Ji-Rui Yang Vijay Pandey Peter E. Lobie Basappa Basappa 《Molecules (Basel, Switzerland)》2022,27(3)
Novel PARP inhibitors with selective mode-of-action have been approved for clinical use. Herein, oxadiazole based ligands that are predicted to target PARP-1 have been synthesized and screened for the loss of cell viability in mammary carcinoma cells, wherein seven compounds were observed to possess significant IC50 values in the range of 1.4 to 25 µM. Furthermore, compound 5u, inhibited the viability of MCF-7 cells with an IC50 value of 1.4µM, when compared to Olaparib (IC50 = 3.2 µM). Compound 5s also decreased cell viability in MCF-7 and MDA-MB-231 cells with IC50 values of 15.3 and 19.2 µM, respectively. Treatment of MCF-7 cells with compounds 5u and 5s produced PARP cleavage, H2AX phosphorylation and CASPASE-3 activation comparable to that observed with Olaparib. Compounds 5u and 5s also decreased foci-formation and 3D Matrigel growth of MCF-7 cells equivalent to or greater than that observed with Olaparib. Finally, in silico analysis demonstrated binding of compound 5s towardsthe catalytic site of PARP-1, indicating that these novel oxadiazoles synthesized herein may serve as exemplars for the development of new therapeutics in cancer. 相似文献
13.
Palaniswami Ravi Soundar Divakar 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):323-336
Sterically controlled styrene-acrylonitrile (SAN)copolymers were prepared by inclusion polymerizationusing molar equivalents of -cyclodextrin(-CD) and its derivative. Comonomercompositions, reactivity ratios, monomer sequence andaverage styrene and acrylonitrile sequence lengthswere determined using 13C NMR spectroscopy. Themolecular weight of the polymers prepared increasedwith decreasing -CD concentration, but wasfound to be less than the control. With increase inthe styrene: -CD ratios the averageacrylonitrile sequence length and run number of thepolymers increased. The glass transition temperature(g) also increased along with the meltingtemperature (m) of the polymers at higherstyrene:-CD ratios. 相似文献
14.
Palaniswamy Ravi Soundar Divakar 《Journal of inclusion phenomena and macrocyclic chemistry》2001,39(1-2):27-33
Stereoselective hydrogenation of thymol over Rh/alumina in the presence of various equivalents of -cyclodextrin (-CD) and itsderivatives in the solid state was studied. Hydrogenation of thymol in the absence of -CD gave 76.8% epimeric alcohols with a menthol/neomenthol (M/N) ratio of 5.6 and an alcohol/ketone ratio of 4.5, whereas the presence of 0.1 equivalent (to thymol) of -CD gave rise to 94.6% of epimeric alcohols with a M/N ratio of 6.3 and an alcohol/ketone ratio of 45.4. The effect of -cyclodextrin and its derivatives on the modification of the yield and the proportion of epimeric alcohols formed were found to be the salient features of this investigation. Inclusion complexation of thymol by -CD studied by UV-Visible spectroscopyindicated a 2:1 stoichiometry ofthymol: -CD complex with a binding constant value of 480 ±40 M-2. 相似文献
15.
Soundar Divakar 《Journal of inclusion phenomena and macrocyclic chemistry》1993,15(4):305-316
The structure of the inclusion complex formed between naringin (naringenin-7-O--neohesperidoside) and-cyclodextrin (BCD) was studied in detail by UV and NMR spectroscopic techniques and potentiometry. A binding constant value of 1016±150M–1 was arrived at from UV studies. Potentiometric studies showed that pK values of 4-OH and 5-OH were affected by and-cyclodextrins. One-dimensional difference NOE and spin-lattice relaxation time (T
1) measurements indicated that the aglycone protion was affected more than the neohesperidoside portion. TheT
1 values analysed for local motions indicated that
c
values of complexed naringin was higher than that of free naringin. The internal rotation calculated for different groups showed
i
values for the phenolic and dihydrobenzopyran portion decrease by a factor of 2. Also a value of 0.12–0.17 observed for the aglycone portion indicated that the coupling between guest and host is weak. All the studies have shown that the disposition in which the phenol group at 2 is inside the BCD cavity with 4-keto and 5-OH hydrogen bonded to the secondary hydroxyl groups at the rim of the wider end of the BCD cavity is the most probable one. 相似文献
16.
17.
A Fast and Facile Fabrication of PTFE Based Superhydrophobic and Ultra Wideband Angle Insensitive Anti‐Reflection Coatings (Phys. Status Solidi RRL 6/2018)
下载免费PDF全文
![点击此处可从《固体物理学:研究快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
18.
Zotkin DN Duraiswami R Grassi E Gumerov NA 《The Journal of the Acoustical Society of America》2006,120(4):2202-2215
An efficient method for head-related transfer function (HRTF) measurement is presented. By applying the acoustical principle of reciprocity, one can swap the speaker and the microphone positions in the traditional (direct) HRTF measurement setup, that is, insert a microspeaker into the subject's ear and position several microphones around the subject, enabling simultaneous HRTF acquisition at all microphone positions. The setup used for reciprocal HRTF measurement is described, and the obtained HRTFs are compared with the analytical solution for a sound-hard sphere and with KEMAR manikin HRTF obtained by the direct method. The reciprocally measured sphere HRTF agrees well with the analytical solution. The reciprocally measured and the directly measured KEMAR HRTFs are not exactly identical but agree well in spectrum shape and feature positions. To evaluate if the observed differences are significant, an auditory localization model based on work by J. C. Middlebrooks [J. Acoust. Soc. Am. 92, 2607-2624 (1992)] was used to predict where a virtual sound source synthesized with the reciprocally measured HRTF would be localized if the directly measured HRTF were used for the localization. It was found that the predicted localization direction generally lies close to the measurement direction, indicating that the HRTFs obtained via the two methods are in good agreement. 相似文献
19.
Ramaswamy Ravichandran Soundar Divakar 《Journal of inclusion phenomena and macrocyclic chemistry》1993,16(3):201-208
Studies on the effect of-cyclodextrin (BCD) and its derivatives on the selectivity in hydroxymethylation of guaiacol by formaldehyde was carried out. Fairly high selectivity with respect to isovanillyl alcohol formation was achieved. Significantly, the selectivity-enhancing effects of 2,6-di-O-methyl-BCD was much larger, giving rise to 22% more of isovanillyl alcohol formation than BCD and its polymer. UV, fluorescence,1H-NMR spectroscopic and potentiometric studies were also carried out to determine the orientation of guaiacol inside the BCD cavity. 相似文献
20.
Ramaswamy Ravichandran Soundar Divakar 《Journal of inclusion phenomena and macrocyclic chemistry》1998,30(3):253-270
The disposition of cholesterol inside the -cyclodextrin cavity(-CD) was deduced from oxidation of cholesterol secondary alcoholgroups by Ca(OCl)2 and H2O2 in thepyridine–acetic acid system. The amount of cholest-4-ene-3-one formedwas found to be proportional to the concentration of -cyclodextrin,resulting in 56.1% of ketone. The oxidation rate was enhanced by-cyclodextrin and its methyl, polymer and 1 : 1copper(II)–-cyclodextrin derivatives. Detailed investigationsinvolving UV-visible, 13C- and 1H-NMR(T1, 1D NOE and ROESY) spectroscopic studies were carried out.A binding constant value of 15,385 ± 1500 M-2 wasobtained for the 2 : 1heptakis-2,6-di-O-methyl--cyclodextrin(DM-CD) : cholesterolcomplex in chloroform from UV studies. Proton and solid state13C-CP MAS spectra of the -CD–cholesterol mixtureshowed large magnitude shifts for the protons from the wider end of the-CD cavity as well as those of ring A and ring B of cholesterol. Both1D NOE and ROESY measurements indicated the proximity between ring A andring B protons of cholesterol and the wider end protons of -CD andDM-CD. Besides, analysis of c,i and tau;m from T1measurements showed not only a lowering of rotational motions but a value of 0.016–0.048 for some of the cholesterol protons, typical of aweak complex. Based on these studies, a probable structure for the 2 : 1complex involving two molecules of -CD/DM-CD was proposed withportions of ring A and ring B being present inside the wider end of the-CD/DM-CD cavity and ring D and the side chain attached atposition 17, projecting into the wider end of the secondCD/DM-CD molecule. 相似文献