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81.
Abdul Ahad Khan Zeshan Zada Ali H. Reshak Muhammad Ishaq Sabeen Zada Muhammad Saqib Muhammad Ismail Muhammad Fazal-ur-Rehman Ghulam Murtaza Shafqat Zada Muhammad M. Ramli 《Molecules (Basel, Switzerland)》2022,27(20)
Our study used the full-potential linearized augmented plane waves (FP-LAPW) method to conduct a first-principles evaluation of the structural, electronic, and magnetic properties of ThMn2X2 (X = Si and Ge) compounds. To establish theoretical dependability with the currently available experimental results, computations for the structural findings of ternary intermetallic thorium (Th)-based compounds were achieved using the generalized gradient approximation in the scheme of Perdew–Burke–Ernzerhof (PBE–GGA) potential, while the generalized gradient approximation plus the Hubbard U (GGA + U) approach was employed to improve the electrical and magnetic properties. In contrast with both the paramagnetic (PM) and antiferromagnetic (AFM) phases, the ThMn2X2 compounds were optimized in a stable ferromagnetic (FM) phase, which was more suited for studying and analyzing magnetic properties. The electronic band structures (BS) and the density of state (DOS) were computed using the two PBE–GGA and GGA + U approximations. The thorium (Th)-based ThMn2X2 compound has full metallic character, due to the crossing and overlapping of bands across the Fermi level of energy, as well as the absence of a gap through both spin (up and down) channels. There was a significant hybridization between (Mn-d and (X = Si and Ge)-p states of conduction band with Th-f states in the valence band. The total magnetic moment of ThMn2Si2 in the ferromagnetic phase was 7.94534 μB, while for ThMn2Ge2 it was 8.73824 μB with a major contribution from the Mn atom. In addition, the ThMn2Ge2 compound’s total magnetic moment confirmed that it exhibits higher ferromagnetism than does the ThMn2Si2 compound. 相似文献
82.
83.
Muhammad Iqbal Saqib Ali Manzar Sohail Muhammad N. Tahir Paul A. Anderson 《中国化学会会志》2019,66(12):1619-1627
Two new copper(II) carboxylate complexes with 2,2′‐bipyridine and para‐nitrophenyl acetate (complex 1 ) and phenyl acetate (complex 2 ) have been synthesized; isolated in quantitative yield; and characterized using fourier‐transform infrared spectroscopy (FT‐IR), electron paramagnetic resonance, absorption spectroscopy, electrochemistry, and powder and single crystal X‐ray diffraction (XRD) techniques. Being mononuclear, the geometry around copper in complex 1 is a Jahn–Teller distorted octahedral, while complex 2 is binuclear with slightly distorted square pyramidal geometry around both copper ions. Powder XRD indicated several peaks in spectra of both complexes, which coincided with their theoretical spectra. FT‐IR results of the carboxylate stretching frequency were in accordance with the single crystal structure data. Electron paramagnetic resonance spectra of complexes 1 and 2 yielded g┴ values of 2.06161 and 2.24623 and 1.94959, respectively, indicating a localized electron in b1 (d x2–y2‐orbital). Ultra‐violet (UV)–visible spectroscopy and electrochemistry helped in characterization, as well as in deoxyribonucleic acid (DNA)‐binding ability of the complexes, yielding DNA‐binding constant values = 1.351 × 104 and 1.361 × 104 and 1.820 × 104 and 2.426 × 104 M?1, respectively, for complexes 1 and 2 . The complexes demonstrate good biological potential. 相似文献
84.
Sadiq-ur-Rehman Muhammad Aziz Choudhary Moazzam H. Bhatti Saqib Ali 《Journal of the Iranian Chemical Society》2012,9(1):35-45
A new series of di- and tri-organotin(IV) compounds with the general formula R4?n SnL n , where R?=?Me (1,2), Et (3), n-Bu (4,5), n-Oct (6), Ph (7) and L?=?(E)-3-(4-methoxyphenyl)-2-(4-chlorophenyl)-2-propenoate, were synthesized by reaction of silver salt of ligand or ligand acid with diorganotin dichloride/oxide and triorganotin chloride in 2:1 and 1:1 molar ratio, respectively. These compounds were characterized by elemental analyses, FT-IR, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry. The spectroscopic results revealed that all the diorganotin(IV) compounds possess trigonal bipyramidal structures in solution and octahedral geometry in the solid state around the tin atom. A linear polymeric trigonal bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non-coordinating solvents has been proposed for the triorganotin(IV) compounds. All synthesized compounds were tested in vitro against a number of microorganisms to assess their biocidal activity. These studies revealed that ligand acid and some of its organotin compounds show promising activity against different strains of bacteria and fungi but lowered than reference drugs. 相似文献
85.
Masood Parvez Moazzam Hussain Bhatti Saqib Ali Muhammad Mazhar Sajid Iqbal Qureshi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):327-328
The Sn atom in the crystal structure of the title compound,catena‐poly[trimethyltin‐μ‐[(2,5‐dioxo‐2,5‐dihydropyrrol‐1‐yl)acetato‐O:O′]], [Sn(CH3)3(C6H4NO4)], adopts a distorted trigonal bipyramidal coordination geometry with three methyl groups defining the trigonal plane [mean Sn—C 2.117 (11) Å] and the axial positions occupied by O atoms from different carboxylate groups, with significantly different Sn—O bond lengths [2.207 (5) and 2.358 (6) Å]. The structure forms a polymeric chain of complex molecules linked via carboxylate moieties. 相似文献
86.
The second order elliptic equation, which is also know as the diffusion-convection equation, is of great interest in many branches of physics and industry. In this paper, we use the weak Galerkin finite element method to study the general second order elliptic equation. A weak Galerkin finite element method is proposed and analyzed. This scheme features piecewise polynomials of degree $k\geq 1$ on each element and piecewise polynomials of degree $k-1\geq 0$ on each edge or face of the element. Error estimates of optimal order of convergence rate are established in both discrete $H^1$ and standard $L^2$ norm. The paper also presents some numerical experiments to verify the efficiency of the method. 相似文献
87.
Muhammad Danish M. Nawaz Tahir Sabiha Ghafoor Nazir Ahmad Saqib Ali Edward R. T. Tiekink 《Journal of chemical crystallography》2011,41(9):1365-1369
Abstract
The structure of n-Bu2Sn(2-methyl-3,5-dinitrobenzoato)2 (1) presents a rare structural motif for compounds with the general formula R 2Sn(O2CR′)2 which almost exclusively adopt skew-trapezoidal bipyramidal geometries. By contrast, the structure of (1) is polymeric with the polymer backbone comprising eight-membered {SnOCO}2 rings linked at the pivotal tin atoms. The coordination geometry is octahedral trans-C2O4. The relationship between structural motifs for R 2Sn(O2CR′)2 is discussed. Compound (1) crystallizes in the monoclinic space group P21/c with a = 5.0114(2) ?, b = 13.7120(5) ?, c = 19.5956(7) ?, β = 91.385(2)o, and Z = 2. 相似文献88.
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
89.
Maity PK Rolfe A Samarakoon TB Faisal S Kurtz RD Long TR Schätz A Flynn DL Grass RN Stark WJ Reiser O Hanson PR 《Organic letters》2011,13(1):8-10
A monomer-on-monomer (MoM) Mitsunobu reaction utilizing norbornenyl-tagged (Nb-tagged) reagents is reported, whereby purification was rapidly achieved by employing ring-opening metathesis polymerization, which was initiated by any of three methods utilizing Grubbs catalyst: (i) free catalyst in solution, (ii) surface-initiated catalyst-armed silica, or (iii) surface-initiated catalyst-armed Co/C magnetic nanoparticles. 相似文献
90.
A series of organotin(IV) thiocarboxylates have been synthesized with the general formula R2SnL2 and R3SnL (R = Ph2(I), Me3(II), n‐Bu3(III), Ph3(IV), Cy3(V), Me2(VI), n‐Bu2(VII), and L = piperidine‐1‐thiocarboxylic acid) in anhydrous toluene under the reflux conditions. The complexes were characterized by microanalysis, IR, 1H and 13C NMR, mass spectrometry, and XRD. NMR data revealed that thiocarboxylic acid acts as bidentate, and complexes exhibit the four‐coordinated geometry in solution state. In solid state, diorganotin complexes exhibit the hexa‐coordinated geometry whereas the triorganotin(IV) compounds show the five‐coordinated geometry. These complexes were also tested for their antimicrobial activity along with the ligand against different animals, plant pathogens, and Artemia salina. All complexes with few exceptions show high activity as compared to the ligand. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:664–674, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20380 相似文献