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941.
Denys V. Shevchenko Volodymyr N. Kokozay Roman I. Zubatyuk Brian W. Skelton 《Inorganica chimica acta》2005,358(13):3889-3904
A series of new heterometallic CuIIZnII and NiIIZnII complexes with N- and N,O open-chain multidentate ligands (L1 = 4,6,6-trimethyl-1,9-diamino-3,7-diazanon-3-ene; L2 = 3,7-bis(2-aminoethyl)-1,3,5,7-tetraazabicyclo[3.3.1]nonane; L3 = 1,15-dihydroxy-7,9,9-trimethyl-3,6,10,13-tetraazapentadec-6-ene and L4 = 1-hydroxy-9-oxy-4,6,6-trimethyl-3,7-diazanon-3-ene) have been prepared through the “direct template synthesis” approach, which is a combination of classical template reactions of amines with acetone/formaldehyde and the “direct synthesis” method based on using elemental metals as starting materials. There is a significant decrease in the reaction time when the “direct synthesis” method is used compared to the conventional template condensation methods. X-ray crystallographic analyses of the complexes with the general formula M(L)ZnX4 and [CuL4ZnCl3]2 (M = Cu2+, Ni2+; L = L1-L3; X = Cl−, NCS−) reveal the presence of long intermolecular distance interactions, such as semi-coordination, S?S and H-bonding, in their crystal organization. 相似文献
942.
We report the synthesis of the Schiff base ligands, 4-[(4-bromo-phenylimino)-methyl]-benzene-1,2,3-triol (A1), 4-[(3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,2,3-triol (A2), 3-(p-tolylimino-methyl)-benzene-1,2-diol (A3), 3-[(4-bromo-phenylimino)-methyl]-benzene-1,2-diol (A4), and 4-[(3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,3-diol (A5), and their Cd(II) and Cu(II) metal complexes, stability constants and potentiometric studies. The structure of the ligands and their complexes was investigated using elemental analysis, FT-IR, UV-Vis, 1H and 13C NMR, mass spectra, magnetic susceptibility and conductance measurements. In the complexes, all the ligands behave as bidentate ligands, the oxygen in the ortho position and azomethine nitrogen atoms of the ligands coordinate to the metal ions. The keto-enol tautomeric forms of the Schiff base ligands A1-A5 have been investigated in polar and non-polar organic solvents. Antimicrobial activity of the ligands and metal complexes were tested using the disc diffusion method and the strains Bacillus megaterium and Candida tropicalis.Protonation constants of the triol and diol Schiff bases and stability constants of their Cu2+ and Cd2+ complexes were determined by potentiometric titration method in 50% DMSO-water media at 25.00 ± 0.02 °C under nitrogen atmosphere and ionic strength of 0.1 M sodium perchlorate. It has been observed that all the Schiff base ligands titrated here have two protonation constants. The variation of protonation constant of these compounds was interpreted on the basis of structural effects associated with the substituents. The divalent metal ions of Cu2+ and Cd2+ form stable 1:2 complexes with Schiff bases.The Schiff base complexes of cadmium inhibit the intense chemiluminescence reaction in dimethylsulfoxide (DMSO) solution between luminol and dioxygen in the presence of a strong base. This effect is significantly correlated with the stability constants KCdL of the complexes and the protonation constants KOH of the ligands; it also has a nonsignificant association with antibacterial activity. 相似文献
943.
Jin Zhao 《Inorganica chimica acta》2005,358(14):4201-4207
A series of compounds of the type CpMoR(CO)3 and RCpMo(CO)3CH3 (R = (CH2)3Si(OMe)3 or CH2Si(OEt)3), containing a (CH2)nSi(OR)3 functionality as a side chain, either fixed to the metal itself or to the cyclopentadienyl ligand are prepared and spectroscopically characterized. These molecules are applicable as precursors for both homogeneous and heterogeneous phase catalysts. Their homogeneous catalytic activity in the olefin epoxidation is in the same order of magnitude as that of their methyl and chloro analogues of the types CpMo(CO)3R and CpMo(CO)3Cl. 相似文献
944.
Michael T. Gamer 《Inorganica chimica acta》2005,358(14):4172-4176
New homoleptic diphosphanylamido compounds of the lanthanides, [Ln{N(PPh2)2}3] (Ln = Sm, Gd, Dy), were synthesized and characterized by single crystal X-ray diffraction in the solid state and partly by NMR in solution. In the solid state the complexes solely show a η2-coordination of the {(Ph2P)2N}− ligand. The dependence of the Ln-N and the Ln-P bond distance on the ion radius of the center metal was investigated. 相似文献
945.
Vieites M Otero L Santos D Toloza J Figueroa R Norambuena E Olea-Azar C Aguirre G Cerecetto H González M Morello A Maya JD Garat B Gambino D 《Journal of inorganic biochemistry》2008,102(5-6):1033-1043
In the search for new therapeutic tools against Chagas’ disease (American Trypanosomiasis) two series of new platinum(II) complexes with bioactive 5-nitrofuryl containing thiosemicarbazones as ligands were synthesized, characterized and in vitro evaluated. Most of the complexes showed IC50 values in the μM range against two different strains of Trypanosoma cruzi, causative agent of the disease, being as active as the anti-trypanosomal drug Nifurtimox. In particular, the coordination of L3 (4-ethyl-1-(5-nitrofurfurylidene)thiosemicarbazide) to Pt(II) forming [Pt(L3)2] lead to almost a five-fold activity increase in respect to the free ligand. Trying to get an insight into the trypanocidal mechanism of action of these compounds, DNA and redox metabolism (intra-parasite free radical production) were evaluated as potential parasite targets. Results suggest that the complexes could inhibit parasite growth through a dual mechanism of action involving production of toxic free radicals by bioreduction and DNA interaction. 相似文献
946.
Nociceptin/orphanin FQ (N/OFQ) and nocistatin are two neuropeptides originated from the same precursor prepronociceptin/orphanin FQ (ppN/OFQ). N/OFQ is the endogenous ligand of the NOP receptor, while the target of action of nocistatin is still unknown. N/OFQ modulates various biological functions, including anxiety. Conversely, nocistatin either behaves as a functional N/OFQ antagonist or evokes per se effects opposite to those of N/OFQ. Here we investigated the interaction between the anxiolytic-like effects of N/OFQ and the anxiogenic-like action of nocistatin with those evoked by GABAA receptor ligands in the mouse elevated plus maze. The anxiogenic-like effects of the GABAA receptor antagonist pentylenetetrazol (20 mg/kg; intraperitoneal, i.p.) were abolished by the co-treatment with N/OFQ (10 pmol; intracerebroventricular, i.c.v.) while potentiated by the administration of nocistatin (0.01 pmol; i.c.v.). The anxiolytic-like effects of the benzodiazepine receptor agonist diazepam (0.75 mg/kg, i.p.) were reversed by nocistatin (0.1 pmol; i.c.v.), whereas signs of sedation were observed when mice were co-treated with diazepam and N/OFQ (3 pmol). Interesting enough, the i.p. treatment with flumazenil (1 mg/kg) blocked the anxiolytic-like effects of N/OFQ (10 pmol; i.c.v.), but not the anxiogenic effect elicited by nocistatin. Collectively, our findings suggest that the effects on anxiety elicited by pentylenetetrazol and diazepam can be counteracted or potentiated in the presence of N/OFQ and nocistatin. In addition, the effects on anxiety of N/OFQ, but not nocistatin, appear to be dependent on the benzodiazepine site of the GABAA receptor. 相似文献
947.
Agnes RS Ying J Kövér KE Lee YS Davis P Ma SW Badghisi H Porreca F Lai J Hruby VJ 《Peptides》2008,29(8):1413-1423
Prolonged opioid exposure increases the expression of cholecystokinin (CCK) and its receptors in the central nervous system (CNS), where CCK may attenuate the antinociceptive effects of opioids. The complex interactions between opioid and CCK may play a role in the development of opioid tolerance. We designed and synthesized cyclic disulfide peptides and determined their agonist properties at opioid receptors and antagonist properties at CCK receptors. Compound 1 (Tyr-c[d-Cys-Gly-Trp-Cys]-Asp-Phe-NH(2)) showed potent binding and agonist activities at delta and mu opioid receptors but weak binding to CCK receptors. The NMR structure of the lead compound displayed similar conformational features of opioid and CCK ligands. 相似文献
948.
Shoichi Katsuta Yudai Iwabe Yayoi Kato Yoshihiro Kudo Yasuyuki Takeda 《Inorganica chimica acta》2008,361(1):103-108
The solvent extraction properties of macrocyclic trinuclear organometallic complexes, [(p-cymene)Ru(pyO2)]3 and [Cp∗Rh(pyO2)]3, for Li+, Na+, and K+ picrates have been investigated in a dichloromethane-water system at 25 °C. The extraction rates of the alkali metal picrates with these macrocyclic complex ligands are unusually slow; the shaking times required to attain equilibrium are at least 1 h for [(p-cymene)Ru(pyO2)]3 and 20-40 h for [Cp∗Rh(pyO2)]3. From analysis of the equilibrium data, the extraction constants (Kex = [ML+A−]o/[M+][L]o[A−]; M+ = alkali metal ion, L = macrocyclic ligand, A− = picrate ion, o = organic phase) have been determined. The log Kex value varies in the sequences, Li+ (5.72) > Na+ (4.50) > K+ (2.88) for [(p-cymene)Ru(pyO2)]3 and Li+ (4.79) > Na+ (2.70) ≈ K+ (2.69) for [Cp∗Rh(pyO2)]3. The Kex values of 6,6-dibenzyl-14-crown-4 (DBz14C4), which is one of the best Li+-selective crown ethers, have also been determined for comparison. It is revealed that [Cp∗Rh(pyO2)]3 is much superior to DBz14C4 both in the extractability for Li+ and the selectivity for Li+ over Na+. 相似文献
949.
Maria Caporali 《Inorganica chimica acta》2008,361(11):3017-3023
New palladium(II) complexes containing the water soluble aminophosphine PTN ligand (PTN = 7-phospha-3,7-dimethyl-1,3,5-triazabicyclo[3.3.1]nonane) in 1:1 and 1:2 ratio Pd/PTN ligand, respectively, were prepared and fully characterised by mono and bidimensional 31P, 1H and 13C NMR techniques showing that PTN can adopt both κ1-P and κ2-P,N coordination modes. The complexes with Pd/PTN ratio 1:2 are highly soluble in water at room temperature. Suitable crystals for X-ray structure determination were obtained for the neutral complex κ2-P,N-Pd(PTN)(OAc)2 (1) and for the monocationic complex [Pd(κ2-P,N-PTN)(κ1-P-PTN)Cl][PF6] (5). 相似文献
950.
Aldona Beganskiene 《Inorganica chimica acta》2008,361(5):1349-1356
New t-butyl-aryl thioethers where the aryl group is 2,6-bis(phosphino)phenyl have been synthesized. The syntheses were completed via sequential ortho-lithiations of t-butylphenylsulfide, followed by chlorophosphine (ClPR2) quenches; symmetric (2,6-bis(diphenylphosphino)phenyl, (4a)) and unsymmetric (2-diisopropylphosphino-6-diphenylphosphino)phenyl, (4b) aryl groups were obtained. Treatment of 4a with Li or Na naphthalenide yielded 2,6-bis(diphenylphosphino)thiophenol 5. Reactions of 4a or 5 with NiCl2 · 6H2O yielded nickel bis(phosphinothiophenolate) 6. Compounds 4a,b, 5 and 6 were characterized by 1H and 31P NMR, and by mass-spectrometry. In addition, 4a, 5 and 6 were characterized by single crystal X-ray diffraction methods. 相似文献