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Journal of Radioanalytical and Nuclear Chemistry - Polonium is rapidly emerging as an international environmental health concern primarily because of the recent rise in hydraulic fracturing... 相似文献
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Ariadna Lázaro Cristina Balcells Dr. Josefina Quirante Prof. Josefa Badia Prof. Laura Baldomà Dr. Jas S. Ward Prof. Kari Rissanen Dr. Mercè Font-Bardia Prof. Laura Rodríguez Dr. Margarita Crespo Prof. Marta Cascante 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1947-1952
Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide variety of tumours. Nevertheless, the acquisition of platinum resistance is utterly common, ultimately cornering conventional platinum drugs to only palliative in many patients. Thus, encountering alternatives that are both effective and non-cross-resistant is urgent. In this work, we report the synthesis, reduction studies, and luminescent properties of a series of cyclometallated (C,N,N′)PtIV compounds derived from amine–imine ligands, and their remarkable efficacy at the high nanomolar range and complete lack of cross-resistance, as an intrinsic property of the platinacycle, against multiplatinum-resistant colorectal cancer (CRC) and castration-resistant prostate cancer (CRPC) metastatic cell lines generated for this work. We have also determined that the compounds are effective and selective for a broader cancer panel, including breast and lung cancer. Additionally, selected compounds have been further evaluated, finding a shift in their antiproliferative mechanism towards more cytotoxic and less cytostatic than cisplatin against cancer cells, being also able to oxidize cysteine residues and inhibit topoisomerase II, thereby holding great promise as future improved alternatives to conventional platinum drugs. 相似文献
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Dr. Renata Kaczmarek Samuel Ward Dipra Debnath Taisiya Jacobs Alexander D. Stark Dariusz Korczyński Prof. Dr. Anil Kumar Prof. Dr. Michael D. Sevilla Dr. Sergey A. Denisov Dr. Viacheslav Shcherbakov Dr. Pascal Pernot Prof. Dr. Mehran Mostafavi Prof. Dr. Roman Dembinski Prof. Dr. Amitava Adhikary 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(43):9495-9505
The directionality of the hole-transfer processes between DNA backbone and base was investigated by using phosphorodithioate [P(S−)=S] components. ESR spectroscopy in homogeneous frozen aqueous solutions and pulse radiolysis in aqueous solution at ambient temperature confirmed initial formation of G.+-P(S−)=S. The ionization potential of G-P(S−)=S was calculated to be slightly lower than that of guanine in 5′-dGMP. Subsequent thermally activated hole transfer from G.+ to P(S−)=S led to dithiyl radical (P-2S.) formation on the μs timescale. In parallel, ESR spectroscopy, pulse radiolysis, and density functional theory (DFT) calculations confirmed P-2S. formation in an abasic phosphorodithioate model compound. ESR investigations at low temperatures and higher G-P(S−)=S concentrations showed a bimolecular conversion of P-2S. to the σ2-σ*1-bonded dimer anion radical [-P-2S 2S-P-]− [ΔG (150 K, DFT)=−7.2 kcal mol−1]. However, [-P-2S 2S-P-]− formation was not observed by pulse radiolysis [ΔG° (298 K, DFT)=−1.4 kcal mol−1]. Neither P-2S. nor [-P-2S 2S-P-]− oxidized guanine base; only base-to-backbone hole transfer occurs in phosphorodithioate. 相似文献
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Madison J. Sowden Dr. Jas S. Ward Prof. Michael S. Sherburn 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):4174-4182
The first general preparative access to compounds of the 2,3-diethynyl-1,3-butadiene (DEBD) class is reported. The synthesis involves a one-pot, twofold Sonogashira-type, Pd0-catalyzed coupling of two terminal alkynes and a carbonate derivative of a 2-butyne-1,4-diol. The synthesis is broad in scope and members of this structural family are kinetically stable enough to be handled using standard laboratory techniques at ambient temperature. They decompose primarily through heat-promoted cyclodimerizations, which are impeded by alkyl substitution and accelerated by aryl or alkenyl substitution. An iterative sequence of these unprecedented Sonogashira-type couplings generates a new type of expanded dendralene. A suitably substituted DEBD carrying two terminal alkyne groups undergoes Glaser–Eglinton cyclo-oligomerization to produce a new class of expanded radialenes, which are chiral due to restricted rotation about their 1,3-butadiene units. The structural features giving rise to atropisomerism in these compounds are distinct from those reported previously. 相似文献
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Caitlin E. Shields Dr. Xue Wang Dr. Thomas Fellowes Rob Clowes Dr. Linjiang Chen Prof. Graeme M. Day Prof. Anna G. Slater Dr. John W. Ward Dr. Marc A. Little Prof. Andrew I. Cooper 《Angewandte Chemie (International ed. in English)》2023,62(34):e202303167
Hydrogen-bonded organic frameworks (HOFs) with low densities and high porosities are rare and challenging to design because most molecules have a strong energetic preference for close packing. Crystal structure prediction (CSP) can rank the crystal packings available to an organic molecule based on their relative lattice energies. This has become a powerful tool for the a priori design of porous molecular crystals. Previously, we combined CSP with structure-property predictions to generate energy-structure-function (ESF) maps for a series of triptycene-based molecules with quinoxaline groups. From these ESF maps, triptycene trisquinoxalinedione (TH5) was predicted to form a previously unknown low-energy HOF (TH5-A) with a remarkably low density of 0.374 g cm−3 and three-dimensional (3D) pores. Here, we demonstrate the reliability of those ESF maps by discovering this TH5-A polymorph experimentally. This material has a high accessible surface area of 3,284 m2 g−1, as measured by nitrogen adsorption, making it one of the most porous HOFs reported to date. 相似文献
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Santos Jovy Ann Simon Paulo Bernot Anthony R. Babasi Christopher Ward Patrick A. Hwang Son-Jong Zidan Ragaiy Teprovich Joseph A. 《Journal of Solid State Electrochemistry》2021,25(4):1441-1452
Journal of Solid State Electrochemistry - In this work, we evaluate the electrochemical properties of MBH4-C60 (M = Li+, Na+) nanocomposites for potential use as a solid-state electrolyte in... 相似文献
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An efficient approach for the synthesis of monosubstituted aromatic compounds relying on a ring-closing metathesis followed by spontaneous 1,2-elimination is presented. The efficiency for late-stage functionalization is highlighted in various solvents (up to 920 TON). This approach is compatible with strained cycles and other multiple bonds in the substrate. 相似文献
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Maria Rubega Emanuela Formaggio Franco Molteni Eleonora Guanziroli Roberto Di Marco Claudio Baracchini Mario Ermani Nick S. Ward Stefano Masiero Alessandra Del Felice 《Entropy (Basel, Switzerland)》2021,23(5)
Stroke is the commonest cause of disability. Novel treatments require an improved understanding of the underlying mechanisms of recovery. Fractal approaches have demonstrated that a single metric can describe the complexity of seemingly random fluctuations of physiological signals. We hypothesize that fractal algorithms applied to electroencephalographic (EEG) signals may track brain impairment after stroke. Sixteen stroke survivors were studied in the hyperacute (<48 h) and in the acute phase (∼1 week after stroke), and 35 stroke survivors during the early subacute phase (from 8 days to 32 days and after ∼2 months after stroke): We compared resting-state EEG fractal changes using fractal measures (i.e., Higuchi Index, Tortuosity) with 11 healthy controls. Both Higuchi index and Tortuosity values were significantly lower after a stroke throughout the acute and early subacute stage compared to healthy subjects, reflecting a brain activity which is significantly less complex. These indices may be promising metrics to track behavioral changes in the very early stage after stroke. Our findings might contribute to the neurorehabilitation quest in identifying reliable biomarkers for a better tailoring of rehabilitation pathways. 相似文献