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排序方式: 共有162条查询结果,搜索用时 15 毫秒
1.
2.
Subhajit Chakraborty Risov Das Mohd Riyaz Kousik Das Ashutosh Kumar Singh Debabrata Bagchi Chathakudath P. Vinod Sebastian C. Peter 《Angewandte Chemie (International ed. in English)》2023,62(9):e202216613
We present surface reconstruction-induced C−C coupling whereby CO2 is converted into ethylene. The wurtzite phase of CuGaS2. undergoes in situ surface reconstruction, leading to the formation of a thin CuO layer over the pristine catalyst, which facilitates selective conversion of CO2 to ethylene (C2H4). Upon illumination, the catalyst efficiently converts CO2 to C2H4 with 75.1 % selectivity (92.7 % selectivity in terms of Relectron) and a 20.6 μmol g−1 h−1 evolution rate. Subsequent spectroscopic and microscopic studies supported by theoretical analysis revealed operando-generated Cu2+, with the assistance of existing Cu+, functioning as an anchor for the generated *CO and thereby facilitating C−C coupling. This study demonstrates strain-induced in situ surface reconstruction leading to heterojunction formation, which finetunes the oxidation state of Cu and modulates the CO2 reduction reaction pathway to selective formation of ethylene. 相似文献
3.
Israr U. Hassan Hiba Salim Gowhar A. Naikoo Tasbiha Awan Riyaz A. Dar Fareeha Arshad Mohammed A. Tabidi Ratnesh Das Waqar Ahmed Abdullah M. Asiri Ahsanulhaq Qurashi 《Journal of Saudi Chemical Society》2021,25(5):101228
The remarkable significance of electrode materials in industrial processes, energy, sustainability and diabetes monitoring has captivated scientists to develop advance nanomaterials for the benefit of life across the globe. Here in, the recent developments in nanostructured porous metal and metal oxide composite materials for supercapacitor applications and non-enzymatic glucose sensors (NEGS) has been extensively discussed. The essential and active electrode materials from the research and application perspective has been emphasized in detail. We have also evaluated the worthiness, taxonomical classification, efficiency, specific capacitance and sensitivity of these materials for the aforementioned potential applications. Eventually, we concluded the review by providing the aspect ratio, surface morphology, particle size and specific surface area of these materials that plays an indispensable role for their promising potential applications. 相似文献
4.
A. Indrasena Sd. Riyaz Prema L. Mallipeddi P. Padmaja B. Sridhar P.K. Dubey 《Tetrahedron letters》2014
A series of indolylidinepyrazolones were synthesized using a simple, green, and effective route and evaluated as anti-bacterial agents. The compounds were further studied via structure-guided docking study. One of the compounds exhibiting H-bonding interactions with conserved residue Arg144 turned out to be the most potent compound of the series. The minimum inhibitory concentration values ranged from 50 to 25 μg/mL against Staphylococcus aureus in their anti microbial evaluation. 相似文献
5.
On doubling metric measure spaces endowed with a strongly local regular Dirichlet form, we show some characterisations of pointwise upper bounds of the heat kernel in terms of global scale-invariant inequalities that correspond respectively to the Nash inequality and to a Gagliardo–Nirenberg type inequality when the volume growth is polynomial. This yields a new proof and a generalisation of the well-known equivalence between classical heat kernel upper bounds and relative Faber–Krahn inequalities or localised Sobolev or Nash inequalities. We are able to treat more general pointwise estimates, where the heat kernel rate of decay is not necessarily governed by the volume growth. A crucial role is played by the finite propagation speed property for the associated wave equation, and our main result holds for an abstract semigroup of operators satisfying the Davies–Gaffney estimates. 相似文献
6.
Performance of a polymer flood process requires the knowledge of rheological behavior of the polymer solution and reservoir
properties such as rock wettability. To provide a better understanding of effects of polymer chemistry and wettability on
the performance of a polymer flood process, a comprehensive experimental study was conducted using a two-dimensional glass
micromodel. A series of water and polymer flood processes were carried out at different polymer molecular weights, degrees
of polymer hydrolysis, and polymer concentrations in both water-wet and oil-wet systems. Image processing technique was applied
to analyze and compare microscopic and macroscopic displacement behaviors of polymer solution in each experiment. From micro-scale
observations, the configuration of connate water film, polymer solution trapping, flow of continuous and discontinuous strings
of polymer solution, piston-type displacement of oil, snap-off of polymer solution, distorted flow of polymer solution, emulsion
formation, and microscopic pore-to-pore sweep of oil phase were observed and analyzed in the strongly oil-wet and water-wet
media. Rheological experiments showed that a higher polymer molecular weight, degree of hydrolysis, and concentration result
in a higher apparent viscosity for polymer solution and lower oil–polymer viscosity ratio. It is also shown that these parameters
have different impacts on the oil recovery in different wettabilities. Moreover, a water-wet medium generally had higher recovery
in contrast with an oil-wet medium. This experimental study illustrates the successful application of glass micromodel techniques
for studying enhanced oil recovery (EOR) processes in five-spot pattern and provides a useful reference for understanding
the displacement behaviors in a typical polymer flood process. 相似文献
7.
Abstract Novel, diethyl 1-(isothiocyano)alkylphosphonates 3 have been efficiently synthesized via a one-pot reaction of diethyl 1-azidoalkylphosphonates 1 with triphenylphosphine, followed by in situ transformation of thus formed phosphazenes 2 with carbon disulfide. Application of the title compounds in the synthesis of diethyl (N-phenylthioureido)- and (benzothiazol-2-ylamino)methylphosphonates was also described. 相似文献
8.
Petr Vlček Vladimír Raus Miroslav Janata Jaroslav Kříž Antonín Sikora 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):164-173
Here, we present the first example of application of single‐electron transfer living radical polymerization (SET‐LRP) process to a controlled grafting of cellulose esters, cellulose diacetate (CDA), and cellulose acetate butyrate (CAB). The cellulose ester macroinitiators with various functionality densities have been prepared by acylation of the backbones with 2‐bromoisobutyryl (BrIB) and dichloroacetyl (DCA) groups, respectively. Methacrylate monomers were polymerized using DCA‐functionalized macroinitiators in the presence of pentamethyldiethylene triamine as a ligand. At 30 °C, the reaction is rather slow, reaching about 10% conversion after 3 to 6 h of polymerization, whereas the higher temperature (60 °C) perceptibly speeds up the polymerization so that methyl methacrylate (MMA) conversion is ~30% after 5 h. Graft copolymers with random‐type and diblock‐type grafts having amphiphilic character were also synthesized. For acrylate grafting (BuA and t‐BuA), BrIB‐functionalized macroinitiators are more convenient in a combination with a low concentration of Cu(0) and Me6TREN as a ligand and polymerization is detectably faster even at the lower temperature than that of MMA. Kinetic studies show “living” character of both the graftings. Important advantages of SET‐LRP, compared with classic ATRP, are (i) higher polymerization rate, (ii) lower extent of recombination of the growing grafts and (iii) negligible coloration of the products with catalytic residua, so that the prepared polymers do not require additional careful purification. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
9.
Ali Maghzi Ali Mohebbi Riyaz Kharrat Mohammad Hossein Ghazanfari 《Transport in Porous Media》2011,87(3):653-664
It is well known that the oil recovery is affected by wettability of porous medium; however, the role of nanoparticles on
wettability alteration of medium surfaces has remained a topic of debate in the literature. Furthermore, there is a little
information of the way dispersed silica nanoparticles affect the oil recovery efficiency during polymer flooding, especially,
when heavy oil is used. In this study, a series of injection experiments were performed in a five-spot glass micromodel after
saturation with the heavy oil. Polyacrylamide solution and dispersed silica nanoparticles in polyacrylamide (DSNP) solution
were used as injected fluids. The oil recovery as well as fluid distribution in the pores and throats was measured with analysis
of continuously provided pictures during the experiments. Sessile drop method was used for measuring the contact angles of
the glass surface at different states of wettability after coating by heavy oil, distilled water, dispersed silica nanoparticles
in water (DSNW), polyacrylamide solution, and DSNP solution. The results showed that the silica nanoparticles caused enhanced
oil recovery during polymer flooding by a factor of 10%. The distribution of DSNP solution during flooding tests in pores
and throats showed strong water-wetting of the medium after flooding with this solution. The results of sessile drop experiments
showed that coating with heavy oil, could make an oil-wet surface. Coating with distilled water and polymer solution could
partially alter the wettability of surface to water-wet and coating with DSNW and DSNP could make a strongly water-wet surface. 相似文献
10.
The spectrum and properties of the excited states of the nucleon are still poorly established despite decades of study. These proceedings describe new measurements of pseudo-scalar meson photoproduction at the Crystal Ball at MAMI, employing a new large acceptance nucleon recoil polarimeter. The double- and single-polarisation observables obtained will provide valuable and unique data to be used as part of the world effort to improve our knowledge of this fundamental spectrum. 相似文献