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排序方式: 共有282条查询结果,搜索用时 15 毫秒
81.
K. Nagaiah V. Naveen Kumar R. Srinivasa Rao B. V. S. Reddy A. V. Narsaiah J. S. Yadav 《合成通讯》2013,43(22):3345-3352
The imines were generated in situ from carbonyl compounds and amines, which undergo smooth reduction with sodium borohydride in an ionic liquid/H2O solvent system. The reaction conditions were very mild and neutral to afford the corresponding highly functionalized amines in excellent yields. 相似文献
82.
In this paper, we implement a fully phase-encrypted memory system using cascaded extended fractional Fourier transform (FRT). We encrypt and decrypt a two-dimensional image obtained from an amplitude image. The full phase image to be encrypted is fractional Fourier transformed three times and random phase masks are placed in the two intermediate planes. Performing the FRT three times increases the key size, at an added complexity of one more lens. The encrypted image is holographically recorded in a photorefractive crystal and is then decrypted by generating through phase conjugation, the conjugate of the encrypted image. A lithium niobate crystal has been used as a phase contrast filter to reconstruct the decrypted phase image, alleviating the need of alignment in the Fourier plane making the system rugged. 相似文献
83.
Polymer blended films of polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):lithium perchlorate (LiClO4) embedded with silver (Ag) nanofiller in different concentrations have been synthesized by a solution casting method. The semi-crystalline nature of these polymer films has been confirmed from their X-ray diffraction (XRD) profiles. Fourier transform infrared spectroscopy (FTIR) and Raman analysis confirmed the complex formation of the polymer with dopant ions. Dispersed Ag nanofiller size evaluation study has been done using transmission electron microscopy (TEM) analysis. It was observed that the conductivity increases when increasing the Ag nanofiller concentration. On the addition of Ag nanofiller to the polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ electrolyte system, it was found to result in the enhancement of ionic conductivity. The maximum ionic conductivity has been set up to be 1.14?×?10?5 S cm?1 at the optimized concentration of 4 wt% Ag nanofiller-embedded (45 wt%) polyethylene oxide (PEO)?+?(45 wt%) polyvinyl pyrrolidone (PVP):(10 wt%) Li+ polymer electrolyte nanocomposite at room temperature. Polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ +Ag nanofiller (4 wt%) cell exhibited better performance in terms of cell parameters. This is ascribed to the presence of flexible matrix and high ionic conductivity. The applicability of the present 4 wt% Ag nanofiller-dispersed polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ polymer electrolyte system could be suggested as a potential candidate for solid-state battery applications. Dielectric constants and dielectric loss behaviours have been studied. 相似文献
84.
Dr. Kenkera Rayappa Naveen Dr. Rajendra Kumar Konidena P. Keerthika 《Chemical record (New York, N.Y.)》2023,23(11):e202300208
Since their first demonstration, thermally activated delayed fluorescence (TADF) materials have been emerged as the most promising emitters because of their promising applications in optoelectronics, typified by organic light-emitting diodes (OLEDs). In which, the rigid oxygen bridged boron acceptor-featured ( DOBNA ) emitters have gained tremendous impetus for OLEDs, which is ascribed to their excellent external quantum efficiency (EQE). However, these materials often displayed severe efficiency roll-off and poor operational stability. Therefore, there needs to be a comprehensive understanding of the aspect of the molecular design and structure-property relationship. To the best of our knowledge, there is no detailed review on the structure-function outlook of DOBNA -based emitters emphasizing the effect of the nature of donor units, their number density, and substitution pattern on the physicochemical properties, excited state dynamics and OLED performance were reported. To fill this gap, herein we presented the recent advancements in DOBNA -based acceptor featured TADF materials by classifying them into several subgroups based on the molecular design i. e. donor-acceptor (D−A), D−A-D, A−D-A, and multi-resonant TADF (MR-TADF) emitters. The detailed design concepts, along with their respective physicochemical and OLED performances were summarized. Finally, the prospective of this class of materials in forthcoming OLED displays is also discussed. 相似文献
85.
Dr. Qiang Wen Dr. Naveen Malik Dr. Yoseph Addadi Maren Weißenfels Vivek Singh Dr. Linda J. W. Shimon Dr. Michal Lahav Prof. Milko E. van der Boom 《Angewandte Chemie (International ed. in English)》2023,62(4):e202214041
In this study, the precise positioning and alignment of arrays of two different guest molecules in a crystalline host matrix has been engineered and resulted in new optically active materials. Sub-nm differences in the diameters of two types of 1D channels are sufficient for size-selective inclusion of dyes. Energy transport occurs between the arrays of different dyes that are included in parallel-positioned nanochannels by Förster resonance energy transfer (FRET). The color of individual micro-sized crystals are dependent on their relative position under polarized light. This angular-dependent behavior is a result of the geometrically constrained orientation of the dyes by the crystallographic packing of the host matrix and is concentration dependent. 相似文献
86.
Kingshuk Panda Kalichamy Alagarasu Poonam Patil Megha Agrawal Ashwini More Naveen V. Kumar Prathama S. Mainkar Deepti Parashar Sarah Cherian 《Molecules (Basel, Switzerland)》2021,26(10)
Dengue virus (DENV), a member of the family Flaviviridae, is a threat for global health as it infects more than 100 million people yearly. Approved antiviral therapies or vaccines for the treatment or prevention of DENV infections are not available. In the present study, natural compounds were screened for their antiviral activity against DENV by in vitro cell line-based assay. α-Mangostin, a xanthanoid, was observed to exert antiviral activity against DENV-2 under pre-, co- and post-treatment testing conditions. The antiviral activity was determined by foci forming unit (FFU) assay, quantitative RT-PCR and cell-based immunofluorescence assay (IFA). A complete inhibition of DENV-2 was observed at 8 µM under the co-treatment condition. The possible inhibitory mechanism of α-Mangostin was also determined by docking studies. The molecular docking experiments indicate that α-Mangostin can interact with multiple DENV protein targets such as the NS5 methyltransferase, NS2B-NS3 protease and the glycoprotein E. The in vitro and in silico findings suggest that α-Mangostin possesses the ability to suppress DENV-2 production at different stages of its replication cycle and might act as a prophylactic/therapeutic agent against DENV-2. 相似文献
87.
M Gnaneswara Reddy Naveen Kumar R B C Prasannakumara N G Rudraswamy K Ganesh Kumar 《理论物理通讯》2021,73(4):45002
This research work explores the effect of hybrid nanoparticles on the flow over a rotating disk by using an activation energy model. Here, we considered molybdenum disulfide and ferro sulfate as nanoparticles suspended in base fluid water. The magnetic field is pragmatic normal to the hybrid nanofluid flow direction. The derived nonlinear ordinary differential equations are nondimensionalized and worked out numerically with the help of Maple software by the RKF-45method. The scientific results for a non-dimensionalized equation are presented for both nanoparticle and hybrid nanoparticle case. Accoutrements of various predominant restrictions on flow and thermal fields are scanned. Computation estimation for friction factor, local Nusselt number and Sherwood number are also executed. Results reveal that the reduction of the heat transfer rate is greater in hybrid nanoparticles when compared to nanoparticles for increasing values of Eckert Number and the thermal field enhances for the enhanced values of volume fraction. 相似文献
88.
Nivedita Rathnakar Desai Krishnaswamy Gurunathan Parameshwar Adimule Suchetan Aruna Kumar Doyjide Basappa Shivalingegowda Naveen Neratur Krishnappagowda Lokanath Swamy Sreenivasa 《Research on Chemical Intermediates》2017,43(11):6131-6154
The present work reports the synthesis of novel 2-(4-(4-substitutedphenylsulfonyl) piperazin-1-yl) quinolone-3-carbaldehyde derivatives, namely, 2-(4-tosylpiperazin-1-yl)quinoline-3-carbaldehyde (4a), 2-(4-(4-nitrophenylsulfonyl)piperazin-1-yl)quinoline-3-carbaldehyde (4b) and 2-(4-(4-tert-butylphenylsulfonyl) piperazin-1-yl)quinoline-3-carbaldehyde (4c). These compounds have been characterized by FT-IR, 1H-NMR, 13C-NMR and LCMS. Further, the structures of compounds 4b and 4c have been elucidated by single crystal X-ray diffraction studies. The asymmetric unit of 4b contains two molecules (A and B) and that of 4c contains one. The piperazine ring in both the molecules 4b and 4c has chair conformation and the aldehyde group is twisted with respect to the quinoline group, respectively, by 13.3 (3)°, 18.2 (3)° and 11.2 (3)° in Molecule A & B of 4b and 4c due to the bulky piperazinyl group present in the ortho position. The crystal structures of both features interactions of the type C-H…O, C-H…πaryl and πaryl… πaryl, leading to a three-dimensional (3D) supramolecular architecture in 4b and a one-dimensional (1D) architecture in 4c. The various intermolecular interactions exhibited in 4b and 4c are well supported by Hirshfeld surface and fingerprint plots analysis. Further, the three compounds were evaluated for their in-silico antimicrobial activity. In-silico molecular docking studies were carried out in order to know the binding modes of the synthesized compounds with DNA Gyrase A and N-myristoyltranferase as target proteins for antibacterial and antifungal docking studies, respectively. 相似文献
89.
Naveen Kumar Prashant Raj Pananghat Balanarayan 《International journal of quantum chemistry》2020,120(7):e26137
The spatio-temporal localization of a system in the presence of an oscillating electric field for a symmetric double-well potential is examined via numerical simulations of the time-dependent Schrödinger equation. For an initial state with equal probability densities in both the wells, stabilized localization atop the barrier can be achieved on a periodic high-frequency driving. The barrier localization is characterized using Shannon information entropies in position and momentum spaces, defined as Sρ = − ∫ |ψ|2 ln |ψ|2 dx and Sγ = − ∫ |ϕ|2 ln |ϕ|2 dp , where ψ and ϕ refer to position and momentum space wave functions, respectively. The information entropy sum, Sρ + Sγ, goes through a minimum indicating the formation of the barrier-localized state, when the peak intensity of the oscillating field is reached. The generalized uncertainty via the Białynicki-Birula-Mycielski inequality ( Sρ + Sγ ≥ 1 + lnπ ) is saturated upon this minimization. This serves as a signature of the formation of the barrier-atop localized state, in terms of Shannon entropies of measurable densities. 相似文献
90.
Parsharamulu Rayam Naveen Polkam Naveen Kuntala Venkanna Banothu Hasitha Shilpa Anantaraju Yogeeswari Perumal Sridhar Balasubramanian Jaya Shree Anireddy 《Journal of heterocyclic chemistry》2020,57(3):1071-1082
In the present study, we report design, synthesis and screening of new novel 5-substituted-2-mercapto-1,3,4-oxadiazole analogues appended to oxaprozin for their in vitro anticancer and antibacterial activity. The synthesised compounds were characterized using various spectroscopic techniques. Furthermore, the structure of 5b (2-(2-[4,5-diphenyloxazol-2-yl]ethyl)-5-(ethylthio)-1,3,4-oxadiazole) was unequivocally confirmed by X-ray analysis. Among the series 5c (2-(2-[4,5-diphenyloxazol-2-yl]ethyl)-5-(propylthio)-1,3,4-oxadiazole) showed most promising anticancer activity against A549 cancer cell line and all the reported analogues manifested satisfactory safety profiles against human normal cell line HEK293T. The products exhibited good antibacterial activity and among the tested 5j (2-(2-[4,5-diphenyloxazol-2-yl]ethyl)-5-([4-fluorobenzyl]thio)-1,3,4-oxadiazole) exhibited most potent. 相似文献