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91.
C.A. Cody R.C. Levitt Rampur S. Viswanath Philip J. Miller 《Journal of solid state chemistry》1978,26(3):281-291
The infrared and Raman spectra of alkali hydrogen selenites [(MHSeO3), where M = Li, Na, K, or Cs], selenous acid (H2Seo3), and their deuterated analogs have been recorded and interpreted. The internal mode frequencies observed in sodium hydrogen selenite, selenous acid, and sodium trihydrogen selenite are used to generate general valence force constants for HSeO?3 and H2SeO3 under the assumption of Cs geometry for each species. Calculations of observed deuterium frequency shifts are made to aid in the assignments of the various internal modes. A low-temperature proton-triggered phase transition is observed in CsHSeO3 and is confirmed in KHSeO3. A discussion of the effects of proton order and disorder upon the selenite frequencies is also presented. 相似文献
92.
Getzler YD Mahadevan V Lobkovsky EB Coates GW 《Journal of the American Chemical Society》2002,124(7):1174-1175
A new highly active and selective catalyst for the synthesis of beta-lactones from CO and epoxides is reported. The catalyst, [(N,N'-bis(3,5-di-tert-butylsalicylidene) phenylenediamino)Al(THF)2][Co(CO)4] ([(salph)Al(THF)2][Co(CO)4]) is easily prepared from the corresponding (salph)AlCl and NaCo(CO)4. At 50 degrees C and 880 psi of CO, the catalyst (1 mol %) carbonylates epoxides such as propylene oxide, 1-butene oxide, epichlorohydrin, and isobutylene oxide to the lactones beta-butyrolactone, beta-valerolactone, gamma-chloro-beta-butyrolactone, and beta-methyl-beta-butyrolactone in high yield. (R)-Propylene oxide was carbonylated to (R)-beta-butyrolactone with retention of stereochemistry. 相似文献
93.
Erioglaucine A, Eriogreen B, Patent Blue and Xylene Cyanol FF work satisfactorily for the titration of Sb(III) with Ce(IV) in 1-2N sulphuric acid medium with iodine as catalyst. In hydrochloric acid medium the colour of the oxidized dye is very evanescent but is very much improved in intensity and stability by the addition of manganese(II) sulphate; no catalyst is needed. 相似文献
94.
95.
Vinod Viswanath Vincent Vineeth Leo S. Sabna Prabha C. Prabhakumari M.S. Jisha 《Natural product research》2016,30(2):223-227
The chemical nature of the polyphenols of cashew kernel testa has been determined. Testa contains tannins, which present large molecular complexity and has an ancient use as tanning agents. The use of tannins extracted from cashew testa, considered in many places as a waste, grants an extra value to the cashew. In this work we have analysed through high performance liquid chromatography, infrared spectroscopy (FT-IR) and thermo gravimetric analysis the average molecular weight, main functional groups and thermal properties of tannins extracted from Anacardium occidentale L. The results of these analyses are compared with the commercial grade tannic acid. The FT-IR spectra showed bands characteristic of C = C, C–C and OH bonds. This important bioactive compound present in the cashew nut kernel testa was suggested as an interesting economical source of antioxidants for use in the food and nutraceutical industry. 相似文献
96.
J. Thimmasetty C. V. S. Subrahmanyam P. R. Sathesh Babu M. A. Maulik B. A. Viswanath 《Journal of solution chemistry》2008,37(10):1365-1378
The solubility behavior of pimozide in individual solvents ranging from nonpolar to highly polar was studied. For understanding
the solute-solvent interactions, the partial solubility parameters concept was utilized. Solutions containing excess drug
were shaken in a water bath for 72 hours at 25 °C. After the solutions attained equilibrium, they were filtered and analyzed
for drug content. A multiple regression method, using extended Hansen’s partial solubility parameters, was applied to verify
the solubilities of pimozide in pure polar and nonpolar solvents and to predict its solubility in untested solvents. The three-parameter
approach and the Flory-Huggins size correction term ‘B’ give predictions of solubilities with correlations up to 97%. The four-parameter approach involving proton-donor and proton-acceptor
parameters was also used in fitting the solubility data. The correlations are appreciable (94%). Further, the ‘B’ term coupled with four-parameter approach was examined in order to improve the data representation, and resulted in a 1%
improvement (98%) in the correlation when compared to the Flory-Huggins size-correction method. The solubility parameter obtained
by this method is 10.43 H which is closer to the values obtained by theoretical methods, such as Fedors’ and Hoy’s. The resulting
partial solubility parameters are δ
2d
=8.85 H, δ
2p
=2.17 H, δ
2a
=3.15 H, and δ
2b
=4.08 H, which give insights into the interaction capability of pimozide and are consistent with its chemical structure. Pimozide
is a Lewis base as its δ
2b
>δ
2a
. The total solubility parameter of pimozide is assigned at 10.43 H. This work demonstrates for the first time the validity
of the four-parameter approach coupled with the Flory-Huggins size-correction term and therefore the result is interesting. 相似文献
97.
Vijayan Thamilarasan Venkatesan Sethuraman Kasi Gopinath Chinnasamy Balalakshmi Marimuthu Govindarajan Ramzi A. Mothana Nasir A. Siddiqui Jamal M. Khaled Giovanni Benelli 《Journal of Cluster Science》2018,29(2):375-384
In this study, chitosan nanoparticles (CH-NPs) were synthesized using Penaeus semisulcatus shrimp shells and characterized using UV–Vis and FT-IR spectroscopy, as well as XRD and HR-TEM analyses. CH-NPs were investigated for growth inhibition properties against selected species of bacterial and fungal pathogens, showing performances higher or comparable over positive controls, respectively. Furthermore, CH-NPs were tested on three important mosquito vectors, achieving LC50 from 12.27 to 14.62 µg/ml. In addition, CH-NPs were evaluated using in vitro plant tissue culture by rooting gel method, to enhance the vegetative growth of the medicinal plant species Sphaeranthus indicus. With the simple technique presented here, large-scale industrial production of CH-NPs is possible. They can be used to develop pesticides highly effective against mosquito vectors of high medical and veterinary importance, as well as for plant tissue culture and food packaging applications. 相似文献
98.
Growth of good quality InGaN multiple quantum wells by MOCVD 总被引:1,自引:0,他引:1
Annamraju Kasi Viswanath J. I. Lee S. T. Kim Dongho Kim 《Journal of Crystal Growth》2004,260(3-4):322-326
We report the optical properties of the blue emitting LED material that belongs to the III–V nitrides family. Quantum wells of InGaN were grown by metal organic chemical vapor deposition. Sapphire was used as the substrate material. Continuous wave and time resolved luminescence experiments were conducted in the temperature range of liquid helium to room temperature. Very intense blue luminescence was observed upto the room temperature. From the very broad linewidth of the emission it was concluded that the compositional fluctuations were dominant. At very low temperatures the lifetimes were found to be somewhat longer than the free exciton case which indicated the localization of excitons at potential fluctuations in the InGaN lattice. 相似文献
99.
Joachim Stolze V. S. Viswanath Gerhard Müller 《Zeitschrift für Physik B Condensed Matter》1992,89(1):45-55
Time-dependent spin autocorrelation functions and their spectral densities for the semi-infinite one-dimensionals=1/2 XY and XXZ models atT= are determined in part by rigorous calculations in the fermion representation and in part by the recursion method in the spin representation. Boundary effects yield valuable new insight into the different dynamical processes which govern the transport of spin fluctuations in the two models. The results obtained for theXXX model bear the unmistakable signature of spin diffusion in the form of a squareroot infrared divergence in the spectral density.From April 1 to September 30, 1992 also at Institut für Physik Universität Augsburg, W-8900 Augsburg, Federal Republic of Germany 相似文献
100.
Santhosh Reddy Kasi Reddy Surendrababu Manabolu Surya Mustafa Shaik Phani Raja Kanuparthy 《Transition Metal Chemistry》2016,41(5):517-523
Pyridyl–tetrazole ligands 2-(5-(pyridin-2-yl)-1H-tetrazol-1-yl)acetamide (L1), 2-(5-(pyridin-2-yl)-2H-tetrazol-2-yl)acetamide (L2), 2-(5-(pyridin-2-yl)-1H-tetrazol-1-yl)acetohydrazide (L3) and 2-(5-(pyridin-2-yl)-2H-tetrazol-2-yl)acetohydrazide (L4) have been prepared and coordinated with CuCl2·2H2O to furnish the corresponding complexes [Cu(L1) 2 ]–[Cu(L4) 2 ]. EPR spectra of the complexes are characteristic of square planar geometries, with nuclear hyperfine spin 3/2. DNA-binding studies using UV–Vis absorption spectroscopy, viscosity and thermal denature studies revealed that all of these complexes are avid binders of calf thymus DNA. The antioxidant properties of the free ligands and the Cu(II) complexes were investigated using the p-nitrosodimethyl aniline hydroxyl radical scavenging method, and [Cu(L4) 2 ] was found to show the highest activity. 相似文献