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141.
Ardisiacrispin D–F (1–3), three new 13,28 epoxy bridged oleanane-type triterpenoid saponins, together with four known analogues (4–7) were isolated from the roots of Ardisia crispa. The structures of 1–7 were elucidated based on 1D and 2D-NMR experiments and by comparing their spectroscopic data with values from the published literatures. Ardisiacrispin D–F (1–3) are first examples that the monosaccharide directly linked to aglycone C-3 of triterpenoid saponins in genus Ardisia are non-arabinopyranose. In the present paper, all compounds are evaluated for the cytotoxicity against three cancer cell lines (HeLa, HepG2 and U87 MG) in vitro. The results show that compounds 1, 4 and 6 exhibited significant cytotoxicity against Hela and U87 MG cells with IC50 values in the range of 2.2 ± 0.6 to 9.5 ± 1.8 µM. The present investigation suggests that roots of A. crispa could be a potential source of natural anti-tumor agents and their triterpenoid saponins might be responsible for cytotoxicity. 相似文献
142.
Yabin Song Yongqiang Deng Huiqiang Wang Zhuchun Bei Hongjing Gu Hui Zhao Hong Wang Dongna Zhang Likun Xu Baogang Wang Yuhuan Li Hongquan Wang 《Molecules (Basel, Switzerland)》2022,27(3)
COVID-19 has spread around the world and caused serious public health and social problems. Although several vaccines have been authorized for emergency use, new effective antiviral drugs are still needed. Some repurposed drugs including Chloroquine, Hydroxychloroquine and Remdesivir were immediately used to treat COVID-19 after the pandemic. However, the therapeutic effects of these drugs have not been fully demonstrated in clinical studies. In this paper, we found an antimalarial drug, Naphthoquine, showed good broad-spectrum anti-coronavirus activity. Naphthoquineinhibited HCoV-229E, HCoV-OC43 and SARS-CoV-2 replication in vitro, with IC50 = 2.05 ± 1.44 μM, 5.83 ± 0.74 μM, and 2.01 ± 0.38 µM, respectively. Time-of-addition assay was also performed to explore at which stage Naphthoquine functions during SARS-CoV-2 replication. The results suggested that Naphthoquine may influence virus entry and post-entry replication. Considering the safety of Naphthoquine was even better than that of Chloroquine, we think Naphthoquine has the potential to be used as a broad-spectrum drug for coronavirus infection. 相似文献
143.
詹涌强 《高等学校计算数学学报》2021,43(1):16-27
1 引言
在渗流、扩散、热传导等领域中经常会遇到求解二维抛物型方程的初边值问题
{(6)u/(6)=a((6)2u/(6)x2+(6)2u/(6)y2), 0<x,y<L,t>0,a>0u(x, y, 0) =φ(x, y), 0 ≤ x, y ≤ L (1)u(0,y,t) =f1(y,t),u(L,y,t) =f2... 相似文献
144.
Wenbo Yang Peng Liu Ying Chen Qingyu Lv Zhongtian Wang Wenhua Huang Hua Jiang Yuling Zheng Yongqiang Jiang Liping Sun 《Molecules (Basel, Switzerland)》2022,27(1)
Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacteria associated with urinary tract infection (UTI). UPEC can cause UTI by adhering to and invading uroepithelial cells. Fimbriae is the most important virulence factor of UPEC, and a potentially promising target in developing novel antibacterial treatments. In this study, the antibacterial properties and effects of the compound dictamnine, extracted from the traditional Chinese medicine Cortex Dictamni, on the bacterial morphology, cell adhesion, and invasion of UPEC were studied. Dictamnine exhibited no obvious antibacterial activity against UPEC, but significantly impeded the ability of UPEC to adhere to and invade uroepithelial cells. RT-qPCR analysis showed that treatment downregulated the expression of type 1 fimbriae, P fimbriae, and curli fimbriae adhesion genes, and also downregulated adhesion-related receptor genes of uroepithelial cells. Transmission electron microscopy showed that dictamnine destroyed the structure of the fimbriae and the surface of the bacteria became smooth. These results suggest that dictamnine may help to prevent UTI by simultaneously targeting UPEC fimbriae and urothelial adhesin receptors, and may have a potential use as a new anti-UPEC drug. 相似文献
145.
木文提出一种利用正弦型位相光栅的衍射特性实现图象密度分离,再假彩色合成获得密度假彩色编码的新方法,并给出了实验结果 相似文献
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Yongqiang Ma Jinshan Li Zhenai Xuan Runchang Liu 《Journal of organometallic chemistry》2001,620(1-2):235-242
A series of novel arylantimony(V) triphenylgermanylpropionates with the formula (Ph3GeCHR1CHR2CO2)nSbAr(5−n) (R1=H, Ph; R2=H, CH3; n=1, 2) were synthesized and characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and mass spectroscopy. The crystal structures of Ph3GeCH(Ph)CH2CO2SbPh4 and [Ph3GeCH2CH(CH3)CO2]2Sb(4-ClC6H4)3 were determined by X-ray diffraction. The in vitro antitumor activities of some selected compounds against five cancer cells are reported. 相似文献