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101.
Dr. Erli Lu Dr. Oliver J. Cooper Dr. Jonathan McMaster Dr. Floriana Tuna Prof. Eric J. L. McInnes Dr. William Lewis Prof. Alexander J. Blake Prof. Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2014,53(26):6696-6700
We report the uranium(VI) carbene imido oxo complex [U(BIPMTMS)(NMes)(O)(DMAP)2] ( 5 , BIPMTMS=C(PPh2NSiMe3)2; Mes=2,4,6‐Me3C6H2; DMAP=4‐(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two‐electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T‐shaped motif with respect to the carbene, which is consistent with an inverse trans‐influence. Complex 5 reacts with tert‐butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPMTMS)(O)2(DMAP)2] ( 6 ). 相似文献
102.
Two‐Electron Reductive Carbonylation of Terminal Uranium(V) and Uranium(VI) Nitrides to Cyanate by Carbon Monoxide 下载免费PDF全文
Peter A. Cleaves Dr. David M. King Dr. Christos E. Kefalidis Prof. Laurent Maron Dr. Floriana Tuna Prof. Eric J. L. McInnes Dr. Jonathan McMaster Dr. William Lewis Prof. Alexander J. Blake Prof. Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2014,53(39):10412-10415
Two‐electron reductive carbonylation of the uranium(VI) nitride [U(TrenTIPS)(N)] ( 2 , TrenTIPS=N(CH2CH2NSiiPr3)3) with CO gave the uranium(IV) cyanate [U(TrenTIPS)(NCO)] ( 3 ). KC8 reduction of 3 resulted in cyanate dissociation to give [U(TrenTIPS)] ( 4 ) and KNCO, or cyanate retention in [U(TrenTIPS)(NCO)][K(B15C5)2] ( 5 , B15C5=benzo‐15‐crown‐5 ether) with B15C5. Complexes 5 and 4 and KNCO were also prepared from CO and the uranium(V) nitride [{U(TrenTIPS)(N)K}2] ( 6 ), with or without B15C5, respectively. Complex 5 can be prepared directly from CO and [U(TrenTIPS)(N)][K(B15C5)2] ( 7 ). Notably, 7 reacts with CO much faster than 2 . This unprecedented f‐block reactivity was modeled theoretically, revealing nucleophilic attack of the π* orbital of CO by the nitride with activation energy barriers of 24.7 and 11.3 kcal mol?1 for uranium(VI) and uranium(V), respectively. A remarkably simple two‐step, two‐electron cycle for the conversion of azide to nitride to cyanate using 4 , NaN3 and CO is presented. 相似文献
103.
Oliver J. Cooper Dr. David P. Mills Dr. Jonathan McMaster Dr. Floriana Tuna Prof. Eric. J. L. McInnes Dr. William Lewis Prof. Alexander J. Blake Dr. Stephen T. Liddle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7071-7083
Treatment of [K(BIPMMesH)] (BIPMMes={C(PPh2NMes)2}2?; Mes=C6H2‐2,4,6‐Me3) with [UCl4(thf)3] (1 equiv) afforded [U(BIPMMesH)(Cl)3(thf)] ( 1 ), which generated [U(BIPMMes)(Cl)2(thf)2] ( 2 ), following treatment with benzyl potassium. Attempts to oxidise 2 resulted in intractable mixtures, ligand scrambling to give [U(BIPMMes)2] or the formation of [U(BIPMMesH)(O)2(Cl)(thf)] ( 3 ). The complex [U(BIPMDipp)(μ‐Cl)4(Li)2(OEt2)(tmeda)] ( 4 ) (BIPMDipp={C(PPh2NDipp)2}2?; Dipp=C6H3‐2,6‐iPr2; tmeda=N,N,N′,N′‐tetramethylethylenediamine) was prepared from [Li2(BIPMDipp)(tmeda)] and [UCl4(thf)3] and, following reflux in toluene, could be isolated as [U(BIPMDipp)(Cl)2(thf)2] ( 5 ). Treatment of 4 with iodine (0.5 equiv) afforded [U(BIPMDipp)(Cl)2(μ‐Cl)2(Li)(thf)2] ( 6 ). Complex 6 resists oxidation, and treating 4 or 5 with N‐oxides gives [{U(BIPMDippH)(O)2‐ (μ‐Cl)2Li(tmeda)] ( 7 ) and [{U(BIPMDippH)(O)2(μ‐Cl)}2] ( 8 ). Treatment of 4 with tBuOLi (3 equiv) and I2 (1 equiv) gives [U(BIPMDipp)(OtBu)3(I)] ( 9 ), which represents an exceptionally rare example of a crystallographically authenticated uranium(VI)–carbon σ bond. Although 9 appears sterically saturated, it decomposes over time to give [U(BIPMDipp)(OtBu)3]. Complex 4 reacts with PhCOtBu and Ph2CO to form [U(BIPMDipp)(μ‐Cl)4(Li)2(tmeda)(OCPhtBu)] ( 10 ) and [U(BIPMDipp)(Cl)(μ‐Cl)2(Li)(tmeda)(OCPh2)] ( 11 ). In contrast, complex 5 does not react with PhCOtBu and Ph2CO, which we attribute to steric blocking. However, complexes 5 and 6 react with PhCHO to afford (DippNPPh2)2C?C(H)Ph ( 12 ). Complex 9 does not react with PhCOtBu, Ph2CO or PhCHO; this is attributed to steric blocking. Theoretical calculations have enabled a qualitative bracketing of the extent of covalency in early‐metal carbenes as a function of metal, oxidation state and the number of phosphanyl substituents, revealing modest covalent contributions to U?C double bonds. 相似文献
104.
105.
Sharples JW Zheng YZ Tuna F McInnes EJ Collison D 《Chemical communications (Cambridge, England)》2011,47(27):7650-7652
The synthesis, structure and magnetic properties of two isostructural heptametallic lanthanide discs are reported, showing single molecule magnet (SMM) behaviour with a large energy barrier for the dysprosium analogue and a large magnetocaloric effect (MCE) for the gadolinium analogue. 相似文献
106.
Eli MooreSteven J. McInnes Andrew VogtNicolas H. Voelcker 《Tetrahedron letters》2011,52(18):2327-2329
Here, we investigate the catalytic activity of various copper (Cu)-loaded poly(amido amine) (PAMAM) dendrimers towards the Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC). Reactivity is tested on a model reaction between azido propanol and propargyl alcohol in aqueous solution. We observe significantly faster conversion using PAMAM dendrimers as macromolecular Cu(I) ligands compared to traditional small molecular ligand systems, and demonstrate that the macromolecular catalyst can be removed by ultrafiltration. 相似文献
107.
108.
Alvarez CS Bashall A McInnes EJ Layfield RA Mole RA McPartlin M Rawson JM Wood PT Wright DS 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(11):3053-3060
The ion-contact complexes [{(eta(5)-Cp)(2)Mn(eta(2):eta(5)-Cp)K}(3)]x0.5 THF (1x0.5 THF) and [{(eta(2)-Cp)(2)(eta(2);eta(5)-MeCp)MnK(thf)}]x2 THF (2x2 THF) and ion-separated complexes [Mg(thf)(6)][(eta(2)-Cp)(3)Mn](2) (3), [Mg(thf)(6)][(eta(2)-Cp)(eta(2)-MeCp)(2)Mn)](2)x0.5 THF (4x0.5 THF), [Mg(thf)(6)][(eta(2)-MeCp)(3)Mn)](2)x0.5 THF (5x0.5 THF) and [Li([12]crown-4)](5)[(eta-Cp)(3)Mn](5) (6) (Cp=C(5)H(5), CpMe=C(5)H(4)CH(3)), have been prepared and structurally characterised. The effects of varying the Cp and CpMe ligands in complexes 1-5 have been probed by variable-temperature magnetic susceptibility measurements and EPR spectroscopic studies. 相似文献
109.
A sample of the liverwort Cephaloziella varians was collected on 1 January 1999 at Rothera Point on the Wright Peninsula, Adelaide Island, western Antarctic Peninsula and was partially dried and then frozen at -80 degree C. The sample was rapidly defrosted to c. 10 degree C after six years and two months of storage at this temperature. Nematodes, tardigrades and a bdelloid rotifer present in the sample were found to have survived. Of the 159 nematodes recovered from the sample, 49 (31%) were alive: of the tardigrades and rotifers, two of 15 (13%) and one of 48 (2%) had survived, respectively. A Chi-square test showed that there was a significant association between nematode taxon and survival: a greater proportion of Coomansus gerlachei individuals were alive than of Rhyssocolpus paradoxus. A Chi-square test also showed that there was a significant association between phylum and survival: a significantly greater proportion of nematodes or tardigrades were alive than of bdelloid rotifers. We conclude that Antarctic soil metazoans are capable of surviving long-term exposure to low sub-zero temperatures and that there may be taxon-specific effects of freezing on survival. 相似文献
110.
Nicholas A. Zia Carleen Cullinane Jessica K. Van Zuylekom Kelly Waldeck Lachlan E. McInnes Gojko Buncic Mohammad B. Haskali Peter D. Roselt Rodney J. Hicks Paul S. Donnelly 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15133-15136
Molecules containing lysine‐ureido‐glutamate functional groups bind to the active site of prostate specific membrane antigen, which is overexpressed in prostate cancer. To prepare copper radiopharmaceuticals for the diagnosis and therapy of prostate cancer, macrobicyclic sarcophagine ligands tethered to either one or two lysine‐ureido‐glutamate functional groups through an appropriate linker have been prepared. Sarcophagine ligands can be readily radiolabeled with positron‐emitting copper‐64 at room temperature. The bivalent agent, in which two targeting groups are tethered to a single copper complex, dramatically outperforms the monomeric agent with respect to tumor uptake and retention. The high tumor uptake, low background, and prolonged tumor retention, even at 24 hours post injection, suggest the bivalent agent is a promising diagnostic for prostate cancer and could be used for prospective dosimetry for therapy with a copper‐67 variant. 相似文献