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971.
Shuyue He Xiaoyan Cui Afsar Khan Yaping Liu Yudan Wang Qimin Cui Tianrui Zhao Jianxin Cao Guiguang Cheng 《Molecules (Basel, Switzerland)》2021,26(12)
Anneslea fragrans Wall., commonly known as “Pangpo Tea”, is traditionally used as a folk medicine and healthy tea for the treatment of liver and intestine diseases. The aim of this study was to purify the antioxidative and cytoprotective polyphenols from A. fragrans leaves. After fractionation with polar and nonpolar organic solvents, the fractions of aqueous ethanol extract were evaluated for their total phenolic (TPC) and flavonoid contents (TFC) and antioxidant activities (DPPH, ABTS, and FRAP assays). The n-butanol fraction (BF) showed the highest TPC and TFC with the strongest antioxidant activity. The bio-guided chromatography of BF led to the purification of six flavonoids (1–6) and one benzoquinolethanoid (7). The structures of these compounds were determined by NMR and MS techniques. Compound 6 had the strongest antioxidant capacity, which was followed by 5 and 2. The protective effect of the isolated compounds on hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells revealed that the compounds 5 and 6 exhibited better protective effects by inhibiting ROS productions, having no significant difference with vitamin C (p > 0.05), whereas 6 showed the best anti-apoptosis activity. The results suggest that A. fragrans could serve as a valuable antioxidant phytochemical source for developing functional food and health nutraceutical products. 相似文献
972.
Yulin Ren Sijin Wu Joanna E. Burdette Xiaolin Cheng A. Douglas Kinghorn 《Molecules (Basel, Switzerland)》2021,26(12)
Digoxin is a cardiac glycoside long used to treat congestive heart failure and found recently to show antitumor potential. The hydroxy groups connected at the C-12, C-14, and C-3′a positions; the C-17 unsaturated lactone unit; the conformation of the steroid core; and the C-3 saccharide moiety have been demonstrated as being important for digoxin’s cytotoxicity and interactions with Na+/K+-ATPase. The docking profiles for digoxin and several derivatives and Na+/K+-ATPase were investigated; an additional small Asn130 side pocket was revealed, which could be useful in the design of novel digoxin-like antitumor agents. In addition, the docking scores for digoxin and its derivatives were found to correlate with their cytotoxicity, indicating a potential use of these values in the prediction of the cancer cell cytotoxicity of other cardiac glycosides. Moreover, in these docking studies, digoxin was found to bind to FIH-1 and NF-κB but not HDAC, IAP, and PI3K, suggesting that this cardiac glycoside directly targets FIH-1, Na+/K+-ATPase, and NF-κB to mediate its antitumor potential. Differentially, digoxigenin, the aglycon of digoxin, binds to HDAC and PI3K, but not FIH-1, IAP, Na+/K+-ATPase, and NF-κB, indicating that this compound may target tumor autophagy and metabolism to mediate its antitumor propensity. 相似文献
973.
Zhang Wenyao Zhang Zhizhong Jin Wenqi Zhang Ruonan Cheng Meng Yang Zhihua Pan Shilie 《中国科学:化学(英文版)》2021,64(9):1498-1503
The introduction of oxofluoride anion into anionic group assists to tune optical properties owing to the change of coordination,electronegativity,and according anionic framework.Here,we proposed a rational design of new compounds by fluorine-driven structure and optical property evolution.A new borophosphate Ba_2BP_3O_(11)with the monoclinic space group P2_1/c has been synthesized in the sealed system.Ba_2BP_3O_(11)exhibits a rare P–O–P bridge formation,which is the first example in alkaline-earth metal borophosphates.By further substituting[BO_4]~(3-)with[BO_3F]~(4-),the first alkaline-earth metal/lead fluoroborophosphates M_2BP_2O_8F (M=Ba and Pb) with the same space group were designed.Since the scissors effect of fluorine,in M_2BP_2O_8F (M=Ba and Pb),a BO_3F tetrahedron corner-sharing with three PO_4tetrahedra forms 1D chains along the b-axial direction,which are filled by MO_n(M=Ba/Pb,n=5,6,8) distorted polyhedra.The first principles calculation shows that the borophosphate Ba_2BP_3O_(11)has a birefringence about 0.013@1,064 nm,while the fluoroborophosphates M_2BP_2O_8F (M=Ba and Pb) have the values of 0.035 and 0.043@1,064 nm,respectively.Such an apparent enhancement in birefringence is derived from synergies of the oxyfluoride and cation.The introduction of fluorine-containing heteroanionic groups provides a feasible strategy to design novel promising optical materials. 相似文献
974.
Cheng Fei Xu Yunfei Lv Zhenfei Huang Zhaohui Fang Minghao Liu Yan’gai Wu Xiaowen Min Xin 《Journal of Thermal Analysis and Calorimetry》2021,146(5):2089-2099
Journal of Thermal Analysis and Calorimetry - In this study, we focus on important global issue containing both environmental pollution control and energy saving. High density polyethylene (HDPE)... 相似文献
975.
Díaz-Díaz Ana María López-Beceiro Jorge Li Yanchun Cheng Yi Artiaga Ramón 《Journal of Thermal Analysis and Calorimetry》2021,145(6):3125-3132
Journal of Thermal Analysis and Calorimetry - A model is proposed to fit differential scanning calorimetry (DSC) isothermal crystallization curves obtained from the molten state at different... 相似文献
976.
Yuan Liu Ting Lin Cui Cheng Qiaowen Wang Shujin Lin Chun Liu Xiao Han 《Molecules (Basel, Switzerland)》2021,26(4)
Cyclodextrins (CDs) are a series of cyclic oligosaccharides formed by amylose under the action of CD glucosyltransferase that is produced by Bacillus. After being modified by polymerization, substitution and grafting, high molecular weight cyclodextrin polymers (pCDs) containing multiple CD units can be obtained. pCDs retain the internal hydrophobic-external hydrophilic cavity structure characteristic of CDs, while also possessing the stability of polymer. They are a class of functional polymer materials with strong development potential and have been applied in many fields. This review introduces the research progress of pCDs, including the synthesis of pCDs and their applications in analytical separation science, materials science, and biomedicine. 相似文献
977.
978.
Shufang Ren Runyan Feng Shounian Cheng Qingtao Wang Zhixiang Zheng 《Electroanalysis》2021,33(6):1471-1483
Ti3C2TX MXene was synthesized by exfoliating pristine Ti3AlC2 phase with hydrofluoric acid. The simple methods of mechanical mixing and drop-casting of Ti3C2TX and MWCNTs were carried out to prepare sensing electrode of Ti3C2TX/MWCNTs/GCE. The composite and topography, especially the surface functional groups of Ti3C2TX/MWCNTs were analyzed by XRD, SEM, FTIR, XPS, and Raman spectrum. The results turned out that Ti3C2TX was characteristic by accordion-like 2D nanostructure with the surfaces terminated with −OH, −F, and =O. When combining with acid pretreated, the interaction between the functional groups of Ti3C2TX and MWCNTs facilitated the convenience and reproducibility of the robust modified electrodes and could make Ti3C2TX/MWCNTs/GCE possess good synergistic catalytic acceleration by increasing the electron transfer efficiency as well as adsorption and aggregation of MOP analyte onto the electrode surface. Versatile electrochemical measurements of CV, DPV and EIS were used to investigate the electrochemical performance of Ti3C2TX/MWCNTs/GCE sensing platform. The linear detection range is 0.01–100 μM with the limit of detection of 0.0092 μM (S/N=3). The sensor has good stability, repeatability, reproducibility and anti-interference. In the detection of serum and urine samples, it has a good recovery rate. 相似文献
979.
980.
PengXiang Zhang GuFan Yin YuYan Wang Bin Cui Feng Pan Cheng Song 《中国科学:物理学 力学 天文学(英文版)》2016,59(8):687511
Manipulation of antiferromagnetic (AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moments of FeMn up to 15 nm, using an ionic liquid to exert a substantial electric-field effect. The manipulation is demonstrated by the modulation of exchange spring in [Co/Pt]/FeMn system, where AFM moments in FeMn pin the magnetization rotation of Co/Pt. By carrier injection or extraction, the magnetic anisotropy of the top layer in FeMn is modulated to influence the whole exchange spring and then passes its influence to the [Co/Pt]/FeMn interface, through a distance up to the length of exchange spring that fully screens electric field. Comparing FeMn to IrMn, despite the opposite dependence of exchange bias on gate voltages, the same correlation between carrier density and exchange spring stiffness is demonstrated. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics. 相似文献