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排序方式: 共有126条查询结果,搜索用时 15 毫秒
61.
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63.
R.R. Reddy Y. Nazeer Ahammed K. Rama Gopal D. Baba Basha 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,85(1):105-113
The experimental potential energy curves for the electronic ground states of molecules like CO+, CH and CH+ observed in comets are constructed by using the Rydberg-Klein-Rees method as modified by Vanderslice et al. The ground state dissociation energies are determined by curve fitting technique using the five parameter Hulburt-Hirschfelder (H-H) function. The estimated dissociation energies are 8.33±0.19, 3.48±0.903 and for CO+, CH and CH+, respectively. These values are in good agreement with the literature values. Estimated dissociation energies of CO+, CH and CH+ are used in the relation given by Gaydon and ionization potentials are evaluated for CO and CH molecules. The estimated ionization potentials are 14.03 and , respectively for CO and CH. The Franck-Condon factors and r-centroids for the band system of - of CO+ molecule have been calculated employing an approximate analytical methods of Jarmain and Fraser. The absence of the bands in this system is explained. 相似文献
64.
S. K. Shahenoor Basha G. Sunita Sundari K. Vijay Kumar M. C. Rao 《Polymer Science Series A》2017,59(4):554-565
Solid polymer electrolyte films were prepared by adding Al2O3 particles to poly(vinylpyrrolidone)-MgCl2 ? 6H2O salt using solution cast technique. Various analytical techniques have been applied to characterize the prepared polymer films such as XRD, SEM, UV–Vis spectroscopy and AC conductivity. The structural analysis of pure poly(vinylpyrrolidone) complexed with MgCl2 ? 6H2O salt showed orthorhombic lattice structure indicating its semi-crystalline nature. SEM analysis reveals the heterogeneous phase of nanocomposite polymer electrolyte systems. The conductivity of Al2O3 doped poly(vinylpyrrolidone) based solid polymer electrolyte was found to be 1.22 × 10–6 S/cm at room temperature for 85: 15 weight composition. Electrochemical cell has been fabricated with the configuration Mg+/(PVP + MgCl2 ? 6H2O + Al2O3)/(I2 + C + electrolyte) and its discharge characteristics were studied for a constant load of 100 kΩ. Various cell parameters such as open-circuit voltage, short circuit current, energy density and power density were calculated for the prepared samples. 相似文献
65.
Ch. Subramanyam Sk. Thaslim Basha G. Madhava Sk. Nayab Rasool Sk. Adam S. Durga Srinivasa Murthy 《Phosphorus, sulfur, and silicon and the related elements》2017,192(3):267-270
A facile synthesis of novel α-aminophosphonates 5a-j was accomplished by condensation of imines (3a-j) with diethyl phosphite (4) in ethanol at 50–60°C using easily recoverable and reusable catalyst, tetramethyl guanidine (TMG) via pudovik reaction in high yields. All the title compounds were characterized by spectral and elemental analysis. They were further screened for their abilities towards in vitro antibacterial, antifungal and antioxidant activities. The compounds 5g, 5d, 5f exhibited good antibacterial and antifungal activities compared to the standard bactericide, Penicillin and fungicide, Griseofulvin, respectively. The compounds 5h, 5i, 5g, and 5c exhibited good antioxidant activity compared to the standard ascorbic acid. 相似文献
66.
A variety of novel 5‐substituted pyridine 2 carboxamides were designed and synthesized using both normal and solvent‐free microwave (MW) irradiation techniques. The results revealed that MW protocol proceeded smoothly under mild reaction conditions in short reaction times, thus avoiding the use of toxic organic solvents. Structural elucidation of the synthesized compounds was carried out on the basis of various spectroscopic methods, such as 1H NMR, 13C NMR, LCMS, and IR. The synthesized compounds were evaluated for their in vitro antimicrobial activity (MIC) using the agar disk diffusion method. Among the various synthetic compounds, compound 3b showed higher potential activity against Escherichia coli than the other compounds. The order of activity against E. coli of the studied compounds is 3b > 3e > 3g > 3h > 3d > 3c > 3a > 3f . Additionally, 2D and 3D structural features of the synthesized derivatives were recognized by the 3D‐QSAR model. This validated model exhibited good internal (r2, 0.924) and external prediction (r2pred, 0.851) correlation. The results of QSAR studies concluded that Alog P, the number of hydrogen bond acceptors, and the number of rotatable bonds were necessary features for the activity of the pyridine carboxamide derivatives. 相似文献
67.
Basha MT Chartres JD Pantarat N Ali MA Mirza AH Kalinowski DS Richardson DR Bernhardt PV 《Dalton transactions (Cambridge, England : 2003)》2012,41(21):6536-6548
The iron coordination and biological chemistry of a series of heterocyclic dithiocarbazate Schiff base ligands is reported with regard to their activity as Fe chelators for the treatment of Fe overload and also cancer. The ligands are analogous to tridentate heterocyclic hydrazone and thiosemicarbazone chelators we have studied previously which bear NNO and NNS donor sets. The dithiocarbazate Schiff base ligands in this work also are NNS chelators and form stable low spin ferric and ferrous complexes and both have been isolated. In addition an unusual hydroxylated ligand derivative has been identified via an Fe-induced oxidation reaction. X-ray crystallographic and spectroscopic characterisation of these complexes has been carried out and also the electrochemical properties have been investigated. All Fe complexes exhibit totally reversible Fe(III/II) couples in mixed aqueous solvents at potentials higher than found in analogous thiosemicarbazone Fe complexes. The ability of the dithiocarbazate Schiff base ligands to mobilise Fe from cells and also to prevent Fe uptake from transferrin was examined and all ligands were effective in chelating intracellular Fe relative to known controls such as the clinically important Fe chelator desferrioxamine. The Schiff base ligands derived from 2-pyridinecarbaldehyde were non-toxic to SK-N-MC neuroepithelioma (cancer) cells but those derived from the ketones 2-acetylpyridine and di-2-pyridyl ketone exhibited significant antiproliferative activity. 相似文献
68.
The dc conductivity of semiconducting cobalt-phosphate glasses has been measured at temperatures ranging from 213 to 530 K. Four bulk samples of CoO-P2O5 glasses of different compositions were produced by melting dry mixtures of analytical reagent grades of CoO and P2O5 at temperatures between 1200-1250 °C for 2 h using a press-quenching method from glass melt. Samples were annealed at 400 °C for 1 h. The dc conductivity was found to be dependent on the CoO content in the glass. At temperatures from 213 to 444 K, however, both Mott's variable-range hopping (VRH) and the Greaves' intermediate range hopping models are found to be applicable. VRH at this range of temperatures is attributed to large values of the disorder energy of these glasses. 相似文献
69.
Long TR Faisal S Maity PK Rolfe A Kurtz R Klimberg SV Najjar MR Basha FZ Hanson PR 《Organic letters》2011,13(8):2038-2041
Soluble, high-load ring-opening metathesis polymerization (ROMP)-derived oligomeric triazole phosphates (OTP) are reported for application as efficient triazolating reagents of nucleophilic species. Utilizing a "Click"-capture, ROMP, release protocol, the efficient and purification-free, direct triazolation of N-, O-, and S-nucleophilic species was successfully achieved. A variety of OTP derivatives were rapidly synthesized as free-flowing solids on a multigram scale from commercially available materials. 相似文献
70.
B. Krishna Kumar A. Krishnamoorthy S. Pavai Madheswari S. Sadiq Basha 《Queueing Systems》2007,56(3-4):133-141
A transient solution is obtained analytically using continued fractions for the system size in an M/M/1 queueing system with catastrophes, server failures and non-zero repair time. The steady state probability of the system
size is present. Some key performance measures, namely, throughput, loss probability and response time for the system under
consideration are investigated. Further, reliability and availability of the system are analysed. Finally, numerical illustrations
are used to discuss the system performance measures.
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