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61.
Poly(ethylene glycol) dimethacrylate (PEGDMA) and methacrylic acid (MAA) based micro and nanoparticles were prepared and evaluated as a carrier for oral delivery of insulin. PEGDMA was synthesized by esterification reaction of the PEG4000 with MAA in the presence of an acid catalyst. Particles of different size were prepared by emulsion polymerization reaction using different concentration of sodium lauryl sulphate (SLS) as an emulsifying agent. Synthesized copolymeric particle were characterized by attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), scanning electron microscopy, and acid value. The mean particle diameter of the polymeric micro and nanoparticles at various physiologically relevant pH values was measured using dynamic light scattering. Insulin loading efficiency of the particles was found to be directly proportional to the particle size and inversely proportional to the acid value of the particles. In vitro insulin release studies from various insulin loaded particles were performed by simulating the gastrointestinal tract conditions using HPLC. At pH 2.5, the release of insulin from polymeric particles was observed in the range of 5–8% while a significant higher release (20–35%) was observed at pH 7.4 during first 15 min of in vitro release. Largest size copolymeric particles of 8.3 µm also showed the highest efficiency to reduce the blood glucose level in diabetic rabbits. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
62.
The nanocrystalline mordenite (MOR) type zeolite materials with initial chemical composition Na(2)O:Al(2)O(3):10SiO(2):48H(2)O have been synthesized under hydrothermal conditions. MOR1 and MOR2 are spherically shaped nanocrystals, whereas MOR3 and MOR4 have rod-like morphology. This paper reports the sorption characteristics of MOR analogues for Th(IV) and Eu(III) removal from aqueous nuclear waste. Sorption of Th(IV) and Eu(III) on MOR1, MOR2, MOR3 and MOR4 in a single component system with varying initial metal ion concentration, solution pH, contact times, sorbent dose and temperatures has also been investigated. Further, the Langmuir and Freundlich sorption models have been applied to describe equilibrium isotherms at different temperatures. The adsorption capacity increases largely with increasing solution pH and temperature of the system. Specific surface area and pore volume have been investigated by Brunauer-Emmett-Teller (BET) method. The N(2) adsorption isotherm presents a type IV isotherm with narrow hysteresis loop which indicates the presence of mesopores related to inter-particle voids. Thermodynamic results indicate that the sorption follows an endothermic physisorption process. It has been found that these exchangers have good sorption capacity and out of which MOR4 has highest sorption capacity. Thus, nanocrystalline MOR4 is proved to be good sorbent for both Th(IV) and Eu(III). 相似文献
63.
R. Ruhela J.N. SharmaB.S. Tomar M.S. MuraliR.C. Hubli A.K. Suri 《Tetrahedron letters》2011,52(30):3929-3932
A novel multidentate ligand N,N,N′,N′-tetra(2-ethylhexyl) dithiodiglycolamide DTDGA has been synthesized and studied for its extraction behavior towards various elements present in high level liquid waste (HLW). The extractant showed remarkable extractability and selectivity for palladium vis a vis other metal ions present in HLW. The distribution ratio as well as the separation factor for palladium was found to be the highest reported so far thus making this extractant one of the most promising candidates for effective separation of palladium from HLW. 相似文献
64.
Tomar V Roberts TF Abbott NL Hernández-Ortiz JP de Pablo JJ 《Langmuir : the ACS journal of surfaces and colloids》2012,28(14):6124-6131
A continuum theory is used to study the interactions between nanoparticles suspended in nematic liquid crystals. The free energy functional that describes the system is minimized using an Euler-Lagrange approach and an unsymmetric radial basis function method. It is shown that nanoparticle liquid-crystal mediated interactions can be controlled over a large range of magnitudes through changes of the anchoring energy and the particle diameter. The results presented in this work serve to reconcile past discrepancies between theoretical predictions and experimental observations, and suggest intriguing possibilities for directed nanoparticle self-assembly in liquid crystalline media. 相似文献
65.
R. Ruhela S. PanjaB.S. Tomar M.A. MahajanR.M. Sawant S.C. TripathiA.K. Singh P.M. GandhiR.C. Hubli A.K. Suri 《Tetrahedron letters》2012,53(40):5434-5436
A novel extractant, namely, Benzodioxodiamide (BenzoDODA) has been synthesized and evaluated for its extraction behaviour towards plutonium and other elements present in the spent nuclear fuel. High separation factors for plutonium over other elements were observed, indicating the high selectivity of the extractant for plutonium. The extractant is quite promising for the selective separation of plutonium from dissolver solution and various acidic waste streams. 相似文献
66.
Ram Niranjan R.K. Rout B.S. Tomar P.S. Ramanjaneyulu D.B. Paranjape T.C. Kaushik 《Physics letters. A》2018,382(46):3365-3368
Pulsed neutrons generated in a plasma focus device are used for the thermal neutron activation analysis (TNAA) of selected three elements having widely different half-lives varying from a few seconds to a few days [Dysprosium (Dy), Manganese (Mn) and Gold (Au)]. Neutron pulse having strength of neutrons/pulse with a pulse width of is produced by “MEPF-12” device operated at a filling gas (deuterium + 0.5% krypton) pressure of 3 mbar. The fast 2.45 MeV D–D neutrons are thermalized before irradiating the sample. The decay gammas from the radioisotopes 165mDy (), 56Mn (), and 198Au () produced via reactions, 164Dy()165mDy, 55Mn() 56Mn, and 197Au() 198Au respectively are counted off-line in a lead shielded well type NaI(Tl) detector coupled to a calibrated 2048 channel analyzer. The values of half-lives evaluated from the measured decay gammas, , and respectively for the radioisotopes of Dy, Mn and Au, are seen to be close to the values reported in literature. 相似文献
67.
A plane longitudinal displacement wave is made incident upon a chiral slab of uniform thickness, interposed between two different semi-infinite micropolar elastic solids. The amplitude ratios of various reflected and refracted waves are obtained using the two possible sets of boundary conditions. The variations of various amplitude ratios with the angle of incidence as well as with the frequency are depicted graphically, for a specific problem. The effect of chirality parameter and the thickness of the chiral slab on these amplitude ratios have been noticed. Results of some earlier researchers have also been reduced as special cases of present formulation. 相似文献
68.
The after effects of β− -decay on time differential perturbed angular correlation (TDPAC) spectra of II–VI semiconductor CdS have been studied using
β− -emitting111Ag as well as111mCd as probe nuclei. The TDPAC spectrum of111Ag in CdS exhibits a time dependent interaction indicating that the preceding β− -decay leaves the daughter nucleus in an excited state. The recovery time (τg) of the probe atom was found to be 16±6 ns while Abragam and Pound's relaxation time (τkr) was found to be 9±2 ns. The results show that β− -decay does change the chemical environment around the probe atom. 相似文献
69.
Eight supramolecular assemblies of benzene-1,3,5-tricarboxylic acid (H3BTC) and benzene-1,2,4,5-tetracarboxylic acid (H4BTtC) with reduced Schiff base of flexible backbone having phenolic and pyridyl groups, i.e., 1,2-bis(2-hydroxybenzylamino)ethane, 1,3-bis(2-hydroxybenzylamino)propane, 1,4-bis(2-hydroxybenzylamino)butane and 1,4-bis(4-pyridinylmethylamino)butane have been constructed by proton transfer reaction. H3BTC forms host–guest type assemblies with amines having phenolic functionality, while a layered structure was obtained with pyridyl functionalized amine. H4BTtC also formed host–guest assemblies with the diamines where reduced Schiff base acts as host and acid moiety acts as the guest. Different conformations of the diamines were observed in these assemblies. Theoretical studies were performed to analyze the effect of varied chain lengths of diamines on hydrogen bond interaction energy of the adducts. 相似文献