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11.
Thirty four distinct composition series arising out of the 32 crystallographic double point groups are employed to re-derive
in a simple and elegant fashion all the 169 distinct colour symmetry groups generated by the 32 double point groups, exploiting
the idea of colour generators. The advantage of the method employed and some possible applications of these colour groups
are discussed. The resulting colour groups are tabulated. 相似文献
12.
Mahesh Kumar Mohana K. RajpalkeBasanta Roul Thirumaleshwara N. BhatNeeraj Sinha A.T. KalghatgiS.B. Krupanidhi 《Applied Surface Science》2011,257(6):2107-2110
Ultra thin films of pure silicon nitride were grown on a Si (1 1 1) surface by exposing the surface to radio-frequency (RF) nitrogen plasma with a high content of nitrogen atoms. The effect of annealing of silicon nitride surface was investigated with core-level photoelectron spectroscopy. The Si 2p photoelectron spectra reveals a characteristic series of components for the Si species, not only in stoichiometric Si3N4 (Si4+) but also in the intermediate nitridation states with one (Si1+) or three (Si3+) nitrogen nearest neighbors. The Si 2p core-level shifts for the Si1+, Si3+, and Si4+ components are determined to be 0.64, 2.20, and 3.05 eV, respectively. In annealed sample it has been observed that the Si4+ component in the Si 2p spectra is significantly improved, which clearly indicates the crystalline nature of silicon nitride. The high resolution X-ray diffraction (HRXRD), scanning electron microscopy (SEM) and photoluminescence (PL) studies showed a significant improvement of the crystalline qualities and enhancement of the optical properties of GaN grown on the stoichiometric Si3N4 by molecular beam epitaxy (MBE). 相似文献
13.
The transport coefficients for the nine point groups
—which represent the symmetry groups of the quasicrystals in two and three dimensions—have been evaluated and tabulated in
this work, employing group-theoretical methods. 相似文献
14.
Dr. Srivari Chandrasekhar Kakita Veera Mohana Rao Mallikanti Seenaiah Police Naresh Ambure Sharada Devi Dr. Bharatam Jagadeesh 《化学:亚洲杂志》2014,9(2):457-461
Hybrid peptidic oligomers comprising natural and unnatural amino acid residues that can exhibit biomolecular folding and hydrogen‐bonding mimicry have attracted considerable interest in recent years. While a variety of hybrid peptidic helices have been reported in the literature, other secondary structural patterns such as γ‐turns and ribbons have not been well explored so far. The present work reports the design of novel periodic γ‐turns in the oligomers of 1:1 natural‐α/unnatural trans‐β‐norborenene (TNAA) amino acid residues. Through DFT, NMR, and MD studies, it is convincingly shown that, in the mixed conformational pool, the heterogeneous backbone of the hybrid peptides preferentially adopt periodic 8‐membered (pseudo γ‐turn)/7‐membered (inverse γ‐turn) hydrogen bonds in both polar and non‐polar solvent media. It is observed that the stereochemistry and local conformational preference of the β‐amino acid building blocks have a profound influence on accessing the specific secondary fold. These findings may be of significant relevance for the development of molecular scaffolds that facilitate desired positioning of functional side‐chains. 相似文献
15.
Mahesh Kumar Basanta Roul Thirumaleshwara N. Bhat Mohana K. Rajpalke Neeraj Sinha A. T. Kalghatgi S. B. Krupanidhi 《Journal of nanoparticle research》2011,13(3):1281-1287
One of the scientific challenges of growing InN quantum dots (QDs), using Molecular beam epitaxy (MBE), is to understand the
fundamental processes that control the morphology and distribution of QDs. A systematic manipulation of the morphology, optical
emission, and structural properties of InN/Si (111) QDs is demonstrated by changing the growth kinetics parameters such as
flux rate and growth time. Due to the large lattice mismatch, between InN and Si (~8%), the dots formed from the Strannski–Krastanow
(S–K) growth mode are dislocated. Despite the variations in strain (residual) and the shape, both the dot size and pair separation
distribution show the scaling behavior. We observed that the distribution of dot sizes, for samples grown under varying conditions,
follow the scaling function. 相似文献
16.
K Rama Mohana Rao 《Pramana》1990,35(2):141-149
A flow chart (inverted ‘tree’) for generating and identifying the 58 magnetic and 18 polychromatic point groups using a classification
for the 32 generating crystallographic point groups is suggested. The idea of colour generator is explored for generating
the colour symmetry point groups. The advantages in presenting the identification of colour groups through a tree are discussed. 相似文献
17.
Vignesh Nayak Mannekote Shivanna Jyothi Prof. R Geetha Balakrishna Dr. Mahesh Padaki Prof. Ahmad Fauzi Ismail 《ChemistryOpen》2015,4(3):278-287
Herein we present a new approach for the complete removal of CrVI species, through reduction of CrVI to CrIII, followed by adsorption of CrIII. Reduction of chromium from water is an important challenge, as CrIV is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSf < PSf/TiO2 < PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of CrVI to CrIII through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced CrIII species are adsorbed onto the CS layer via complexation to give chromium-free water. 相似文献
18.
19.
Selvaraj Mohana Roopan F. Nawaz Khan Jong Sung Jin R. Senthil Kumar 《Research on Chemical Intermediates》2011,37(8):919-927
Montmorillonite K10 efficiently catalyzed a one pot–three component cyclocondensation of isatoic anhydride, NH4OAc and aromatic/heteroaromatic aldehydes under ambient conditions to produce the corresponding 2-substituted-2,3-dihydroquinazolin-4(1H)-ones
in good yields. The 2-(2-chloroquinolin-3-yl)-2,3-dihydroquinazolin-4(1H)-ones 3a–d were screened for their antitumor activity against Ehrlich Ascites Carcinoma tumor cells 相似文献
20.
Marimuthu M Kandasamy K Ahn CG Sung GY Kim MG Kim S 《Analytical and bioanalytical chemistry》2011,401(5):1645-1653
Complementary metal oxide semiconductor (CMOS)-based image sensors have received increased attention owing to the possibility
of incorporating them into portable diagnostic devices. The present research examined the efficiency and sensitivity of a
CMOS image sensor for the detection of antigen–antibody interactions involving interferon gamma protein without the aid of
expensive instruments. The highest detection sensitivity of about 1 fg/ml primary antibody was achieved simply by a transmission
mechanism. When photons are prevented from hitting the sensor surface, a reduction in digital output occurs in which the number
of photons hitting the sensor surface is approximately proportional to the digital number. Nanoscale variation in substrate
thickness after protein binding can be detected with high sensitivity by the CMOS image sensor. Therefore, this technique
can be easily applied to smartphones or any clinical diagnostic devices for the detection of several biological entities,
with high impact on the development of point-of-care applications. 相似文献