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111.
Background
Antiproliferative factor (APF) is a sialoglycopeptide elevated in the urine of patients with interstitial cystitis—a chronic, painful bladder disease. APF inhibits the proliferation of normal bladder epithelial cells and cancer cells in vitro, presumably by binding to its cellular receptor, cytoskeleton associated-protein 4 (CKAP4); however, the biophysical interaction of APF with CKAP4 has not been characterized previously. In this study, we used surface plasmon resonance (SPR) to explore the binding kinetics of the interaction of APF and as-APF (a desialylated APF analogue with full activity) to CKAP4.Results
We immobilized non-glycosylated APF (TVPAAVVVA) to the Fc1 channel as the control and as-APF to Fc2 channel as the ligand in order to measure the binding of CKAP4 recombinant proteins encompassing only the extracellular domain (Aa 127–602) or the extracellular domain plus the transmembrane domain (Aa 106–602). Positive binding was detected to both CKAP4126–602 and CKAP4106–602, suggesting that as-APF can bind specifically to CKAP4 and that the potential binding site(s) are located within the extracellular domain. To identify the primary APF binding site(s) within the CKAP4 extracellular domain, deletion mutants were designed according to structural predictions, and the purified recombinant proteins were immobilized on a CM5 chip through amine-coupling to measure as-APF binding activity. Importantly, both CKAP4127–360 and CKAP4361–524 exhibited a fast association rate (k on ) and a slow dissociation rate (k off ), thus generating high binding affinity and suggesting that both regions contribute relatively equally to overall as-APF binding. Therefore, two or more as-APF binding sites may exist within the Aa 127–524 region of the CKAP4 extracellular domain.Conclusions
We determined that the CKAP4127–360 and CKAP4361–524 mutants exhibit improved binding activity to as-APF as compared to the full-length extracellular domain, making it possible to detect low concentrations of as-APF in urine, thereby establishing a foundation for a non-invasive diagnostic assay for IC. Further, these data have revealed novel APF binding site(s) suggesting that targeting this region of CKAP4 to inhibit APF binding may be a useful strategy for treating IC-related bladder pathology.112.
Sonia Keunchkarian Pablo J. Lebed Brenda B. Sliz Cecilia B. Castells Leonardo G. Gagliardi 《Analytica chimica acta》2014
One of the main steps in the manufacture of robust and efficient packed capillary microcolumns for electro- and capillary chromatography is the generation of porous devices to retain the packed beds. Frits based on sintered silica particles have been found to give the best results in terms of mechanical resistance and efficiency. The conventional procedure to produce these kinds of frits consists in a radial heating of the packed material with either a flame or an electrical resistance, but the frits thus obtained have many drawbacks as a result of the procedure rather than the silica per se as the base material. In the present work we investigated a new approach to produce silica-based retaining devices involving the frontal exposure of a short silica-particle bed packed at the end of a capillary tube. The capillary is radially insulated and frontally exposed to the heat of a muffle oven, generating a transfer of heat that is not radial but rather throughout the capillary axis. This procedure resulted in substantial advantages: an improved radial homogeneity, a protection of the external polyimide, and a generation of extremely short (400–600 μm) frits that were highly permeable and avoided bubble formation. 相似文献
113.
Sonia Fiorilli Dario Caldarola Hao Ma Barbara Onida 《Journal of Sol-Gel Science and Technology》2011,60(3):260-265
Silica spheres with uniform size of 230–250 nm were functionalized with sulfonic groups and bi-functionalized with carboxylic and sulfonic groups via a co-condensation route, by adding the organosilanes (3-(triethoxysilyl)mercaptopropyl and 4-(triethoxysilyl)butyronitrile) to a pre-hydrolized TEOS solution. The conversion of mercapto and cyano groups to, respectively, sulfonic and carboxylic groups was carried out by treating both the samples with nitric acid solution. The presence of alkyl-SO3H and alkyl-COOH species at the silica surface in an approximate molar ratio of 1:1 was assessed by TG and NMR. FT-IR spectroscopy showed that both Brønsted acidic groups are accessible and give proton-transfer reaction to ammonia with the formation of ammonium ion. Sulfonic groups react irreversibly with ammonia at room temperature at variance with carboxylic groups which give a reversible proton-transfer, in agreement with the stronger Brønsted acidity of the former. 相似文献
114.
Sonia Aguado-Ullate Octavio González-del Moral Alberto Hernán-Gómez Miguel Mena Cristina Santamaría 《Journal of organometallic chemistry》2011,696(25):4011-4017
The ability of the oxonitride [{Ti(η5-C5Me5)(μ-O)}3(μ3-N)] (1) to act as an organometallic ligand has been studied from both theoretical and experimental points of view. DFT calculations have allowed understanding the electronic structure of 1, and rationalizing its chemical behavior by comparison with the electronic structures of isoelectronic species [{Ti(η5-C5Me5)(μ-O)}3(μ3-CH)] and [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)]. Reactions of 1 with different inorganic molecules such as [Mo(CO)3(1,3,5-Me3C6H3)] or AlEt3 have confirmed the possibility of 1 to act as a tridentate or monodentate ligand to give the [{(CO)3Mo}(μ3-O)3{Ti3(η5-C5Me5)3(μ3-N)}] (2) and [{Et3Al}(μ3-O){(μ-O)2Ti3(η5-C5Me5)3(μ3-N)}] (3) complexes, respectively. Surprisingly, reactions of 1 with [M(CO)6] (M = Cr, Mo, W) complexes led to activate the μ3-N unit in 1 to afford the new compounds [Ti3(η5-C5Me5)3(μ-O)4{(NC)M(CO)5}]2 [M = Cr (4), Mo (5), W (6)]. Molecular structures of complexes 2-6 have been established by single crystal X-ray analysis. 相似文献
115.
Ayesha Kausar Sonia Zulfiqar Liaquat Ali Muhammad Ilyas Sarwar 《Monatshefte für Chemie / Chemical Monthly》2011,17(3):201-209
Abstract
New diacid dichlorides bearing phenyl thiourea groups were prepared by a facile synthetic approach and characterized using spectroscopic and elemental analyses. A series of novel aromatic and semiaromatic polyamides were prepared via a condensation route from the synthesized diacid dichlorides with 4,4′-oxydianiline. The polymers were characterized by FT-IR, 1H NMR, 13C NMR, and their physical properties, including their solution viscosities, solubilities and thermal properties, were studied too. Polyamides with phenyl thiourea moieties in the backbone showed good solubilities in amide solvents such as DMAc, DMF, DMSO, and NMP. All of the synthesized polymers had η inh values of 0.042–0.053 dm3/g, and were obtained in quantitative yield. GPC measurements of the synthesized polyamides indicated M w values of 64,759–86,172. The crystallinity of the polymers was evaluated via their X-ray diffraction patterns. Their glass transition temperatures were found to be 218–229 °C. Furthermore, thermogravimetric analysis indicated that the polymers were thermally stable in the range 300–398 °C in a N2 atmosphere. 相似文献116.
Santos Fustero Javier MoscardóMaría Sánchez-Roselló Sonia FloresMarta Guerola Carlos del Pozo 《Tetrahedron》2011,67(38):7412-7417
The organocatalytic synthesis of quinolizidine alkaloids (+)-myrtine, (−)-lupinine, and (+)-epiepiquinamide is described. It involved, as the key step, an enantioselective intramolecular aza-Michael reaction (IMAMR) catalyzed by Jørgensen catalyst I, affording the common precursor with high enantioselectivity. This compound was subsequently transformed into the three alkaloids in a highly diastereoselective manner. 相似文献
117.
Martínez-Salvador S Forniés J Martín A Menjón B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(29):8085-8097
The homoleptic, square‐planar organoplatinum(II) compound [NBu4]2[Pt(CF3)4] ( 1 ) undergoes oxidative addition of CF3I under mild conditions to give rise to the octahedral organoplatinum(IV) complex [NBu4]2[Pt(CF3)5I] ( 2 ). This highly trifluoromethylated species reacts with Ag+ salts of weakly coordinating anions in Me2CO under a wet‐air stream to afford the aquo derivative [NBu4][Pt(CF3)5(OH2)] ( 4 ) in around 75 % yield. When the reaction of 2 with the same Ag+ salts is carried out in MeCN, the solvento compound [NBu4][Pt(CF3)5(NCMe)] ( 5 ) is obtained in around 80 % yield. The aquo ligand in 4 as well as the MeCN ligand in 5 are labile and can be cleanly replaced by neutral and anionic ligands to furnish a series of pentakis(trifluoromethyl)platinate(IV) compounds with formulae [NBu4][Pt(CF3)5(L)] (L=CO ( 6 ), pyridine (py; 7 ), tetrahydrothiophene (tht; 8 )) and [NBu4]2[Pt(CF3)5X] (X=Cl ( 9 ), Br ( 10 )). The unusual carbonyl–platinum(IV) derivative [NBu4][Pt(CF3)5(CO)] ( 6 ) is thermally stable and has a νCO of 2194 cm?1. The crystal structures of 2? CH2Cl2, 5 , [PPh4][Pt(CF3)5(CO)] ( 6′ ), and 7 have been established by X‐ray diffraction methods. Compound 2 has shown itself to be a convenient entry to the chemistry of highly trifluoromethylated platinum compounds. To the best of our knowledge, compounds 2 and 4 – 10 are the organoelement compounds with the highest CF3 content to have been isolated and adequately characterized to date. 相似文献
118.
Geagea R Ladeira S Mazières S Destarac M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(13):3718-3725
Molybdenum and chromium pentacarbonyldiphenylphosphinocarbodithioate complexes have been prepared in a one‐pot reaction from the corresponding metallocarbonyldiphenylphosphine. The complexes have been characterised by IR, 1H, 31P and 13C NMR spectroscopies and by mass spectrometry. The solid‐state structures of [Cr(CO)5{PPh2CS2CH(Ph)CH3}] ( 1 ) and [Mo(CO)5{PPh2CS2CH(Ph)CH3}] ( 2 ) are reported. Compounds 1 and 2 are isostructural and crystallise in the triclinic P$\bar 1Molybdenum and chromium pentacarbonyldiphenylphosphinocarbodithioate complexes have been prepared in a one-pot reaction from the corresponding metallocarbonyldiphenylphosphine. The complexes have been characterised by IR, (1)H, (31)P and (13)C?NMR spectroscopies and by mass spectrometry. The solid-state structures of [Cr(CO)(5){PPh(2)CS(2)CH(Ph)CH(3)}] (1) and [Mo(CO)(5){PPh(2)CS(2)CH(Ph)CH(3)}] (2) are reported. Compounds 1 and 2 are isostructural and crystallise in the triclinic P1 space group. These new organometallic compounds are highly efficient reversible chain-transfer agents for reversible addition-fragmentation chain-transfer (RAFT) polymerisation of styrene (St) and n-butyl acrylate (nBA), with controlled number-average molar mass values and narrow dispersities (<1.2). The controlled character of the polymerisation was further exemplified by the synthesis of St and nBA diblock copolymers. 相似文献
119.
Boronate ureas are introduced as a new class of noncovalent catalysts for conjugate addition reactions with enhanced activity. Through intramolecular coordination of the urea functionality to a strategically placed Lewis acid, rate enhancements up to 10 times that of more conventional urea catalysts are observed. The tunable nature of boronate ureas is a particularly attractive feature and enables the rational design of catalysts for optimal performance, in terms of both activity and stereocontrol, in new bond-forming processes. 相似文献
120.