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991.
Meng-Xing Huang Yan-Quan Chen Run-Duo Liu Yue Huang Chen Zhang 《Molecules (Basel, Switzerland)》2022,27(11)
Dipyridamole, apart from its well-known antiplatelet and phosphodiesterase inhibitory activities, is a promising old drug for the treatment of pulmonary fibrosis. However, dipyridamole shows poor pharmacokinetic properties with a half-life (T1/2) of 7 min in rat liver microsomes (RLM). To improve the metabolic stability of dipyridamole, a series of pyrimidopyrimidine derivatives have been designed with the assistance of molecular docking. Among all the twenty-four synthesized compounds, compound (S)-4h showed outstanding metabolic stability (T1/2 = 67 min) in RLM, with an IC50 of 332 nM against PDE5. Furthermore, some interesting structure–activity relationships (SAR) were explained with the assistance of molecular docking. 相似文献
992.
Yi-Lin He Pei-Zhi Huang Hong-Ying Yang Wei-Jiao Feng Zhao-Cai Li Kun Gao 《Molecules (Basel, Switzerland)》2022,27(11)
Two new neolignans jatrolignans, C (1) and D (2), a pair of epimers, were isolated from the whole plants of Jatropha curcas L. (Euphorbiaceae). Their structures were determined with HRESIMS, IR, and NMR data analysis, and electronic circular dichroism (ECD) experiments via a comparison of the experimental and the calculated ECD spectra. Their antichlamydial activity was evaluated in Chlamydia abortus. They both showed dose-dependent antichlamydial effects. Significant growth inhibitory effects were observed at a minimum concentration of 40 μM. 相似文献
993.
Developing low-cost and high-activity transition metal oxide electrocatalysts for an efficient oxygen evolution reaction (OER) at a large current density is highly demanded for industrial application and remains a big challenge. Herein, we report vertically aligned cobalt doped Ni–Fe based oxide (Co–NiO/Fe2O3) arrays as a robust OER electrocatalyst via a simple method combining hydrothermal reaction with heat treatment. Density functional theory calculation and XRD Rietveld refinement reveal that Co preferentially occupies the Ni sites compared to Fe in the Ni–Fe based oxides. The electronic structures of the Co–NiO/Fe2O3 could be further optimized, leading to the improvement of the intrinsic electronic conductivity and d-band center energy level and the decrease in the reaction energy barrier of the rate-determining step for the OER, thus accelerating its OER electrocatalytic activity. The Co–NiO/Fe2O3 nanosheet arrays display state-of-the-art OER activities at a large current density for industrial demands among Fe–Co–Ni based oxide electrocatalysts, which only require an ultra-low overpotential of 230 mV at a high current density of 500 mA cm−2, and exhibit superb durability at 500 mA cm−2 for at least 300 h without obvious degradation. The Co–NiO/Fe2O3 nanosheet arrays also have a small Tafel slope of 33.9 mV dec−1, demonstrating fast reaction kinetics. This work affords a simple and effective method to design and construct transition metal oxide based electrocatalysts for efficient water oxidation.Co–NiO/Fe2O3 nanosheets featuring Co substitution on Ni sites can effectively regulate electronic structures and exhibit high OER activities with low overpotential (η500 = 230 mV), small Tafel slope (33.9 mV dec−1) and superb durability for 300 h. 相似文献
994.
Yixuan Tang Shihui Huang Xingxing Chen Junzhang Huang Qianwen Lin Lei Huang Shuping Wang Qihua Zhu Yungen Xu Yi Zou 《Molecules (Basel, Switzerland)》2022,27(19)
Protein arginine methyltransferases 5 (PRMT5) is a clinically promising epigenetic target that is upregulated in a variety of tumors. Currently, there are several PRMT5 inhibitors under preclinical or clinical development, however the established clinical inhibitors show favorable toxicity. Thus, it remains an unmet need to discover novel and structurally diverse PRMT5 inhibitors with characterized therapeutic utility. Herein, a series of tetrahydroisoquinoline (THIQ) derivatives were designed and synthesized as PRMT5 inhibitors using GSK-3326595 as the lead compound. Among them, compound 20 (IC50: 4.2 nM) exhibits more potent PRMT5 inhibitory activity than GSK-3326595 (IC50: 9.2 nM). In addition, compound 20 shows high anti-proliferative effects on MV-4-11 and MDA-MB-468 tumor cells and low cytotoxicity on AML-12 hepatocytes. Furthermore, compound 20 possesses acceptable pharmacokinetic profiles and displays considerable in vivo antitumor efficacy in a MV-4-11 xenograft model. Taken together, compound 20 is an antitumor compound worthy of further study. 相似文献
995.
996.
p-Tolyl-substituted ladder-type oligo(p-phenylene)s containing three, four, and five phenylene rings were readily synthesized. The uniform aryl substitution of these systems allowed us to determine the coplanarity of the pi-conjugated backbones crystallographically. The intramolecular annulations eliminate almost all of the conformational disorder and enhance the degree of pi-conjugation of the backbones, resulting in significant red shifts in the absorption and emission maxima and lower oxidation potentials in the higher homologues. [structure: see text] 相似文献
997.
Huang XJ Im HS Yarimaga O Kim JH Lee DH Kim HS Choi YK 《The journal of physical chemistry. B》2006,110(43):21850-21856
Carboxylated single-walled carbon nanotubes (SWCNT) chemically assembled on gold substrate was employed as netlike electrode to investigate the charge-transfer process and electrode process kinetics using uric acid as an example. The electrochemical behavior of uric acid in carboxylated SWCNT system was investigated using cyclic voltammetry, chronoamperometry, and single potential time-based techniques. The properties of raw SWCNT electrode were also studied for comparison purpose. Uric acid has better electrochemical behavior whereas ascorbic acid has no effective reaction on the carboxylated SWCNT electrode. Cyclic voltammograms indicate that the assembled carboxylated SWCNT increases more active sites on electrode surface and slows down the electron transfer between the gold electrode and uric acid in solution. The charge-transfer coefficient (alpha) for uric acid and the rate constant (k) for the catalytic reaction were calculated as 0.52 and 0.43 s(-1), respectively. The diffusion coefficient of 0.5 mM uric acid was 7.5 x 10(-6) cm2 x s(-1). The results indicate that electrode process in the carboxylated SWCNT electrode system is governed by the surface adsorption-controlled electrochemical process. 相似文献
998.
Wu XL Qiu T Hu DS Huang GS Yuan RK Siu GG Chu PK 《The Journal of chemical physics》2006,125(5):054713
Efficient resonant electron transfer from the surface bonding structure to the conduction band of quantum confined Si nanocrystals is observed by Si nanocrystals in a toluene suspension. Based on the electron transfer mechanism, the enhancement of photoluminescence originates from the band-to-band recombination in the p-type Si nanocrystals suspended in a toluene solution. The energy levels of the electrons in the Si nanocrystals chemisorbed with toluene molecules are calculated using the method of linear combination of atomic orbitals, and the characteristics of the obtained density of states is in good agreement with the observed photoluminescence properties. 相似文献
999.
The gemini surfactant sodium 4,8-dioctyl-3,9-dioxo-6-hydroxy-4,8-diaza-1,11-undecanedicarboxylate (SDUC), bearing two carboxylic headgroups and two hydrocarbon chains, has been synthesized, and its self-organization characteristics at strong basic and neutral environments have been studied. The results reveal that a transition from micelles to vesicles in SDUC aqueous solution occurs when the pH drops from 12.0 to 7.0. When a small amount of Cu(2+) ion is added to the SDUC solutions at both pH 12.0 and 7.0, remarkable transformations were observed within the SDUC aggregate structures. At pH 12.0, micelles transform into vesicles as Cu(2+) is added, while the vesicles of SDUC are formed at pH 7.0 and these small vesicles tend to fuse into larger ones slowly. Moreover, these SDUC vesicles at pH 7.0 undergo a relatively fast fission process when Cu(2+) is added in. An attempt has been made to explain the mechanism of these transformations. 相似文献
1000.
Axially substituted tin phthalocyanines, namely dichloride-tetra-(pentyloxy) tin (IV) phthalocyanine 3 and its dimmer di-cyanine 4 were synthesized. The catalytic effect of H2O-free CaCl2 in quinoline was used for condensation of dihydroxy tin phthalocyanine 3 to the cofacially array dimmer 4. Their structures were characterized by UV-vis, IR, elemental analysis, MS, as well as 1HNMR spectroscopy. 相似文献