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991.
992.
993.
Abdallah Al Amrani 《代数通讯》2013,41(6):1591-1614
994.
Computational schemes for the collocation method and the mechanical quadrature method for the approximate solution of systems of singular integro-differential equations with a Cauchy kernel are elaborated. The case where the systems of equations are defined on an arbitrary smooth closed contour of a complex plane is examined. The methods researched are based on Fejér points. Estimates of the rate of convergence in Lebesgue space are obtained. 相似文献
995.
996.
Nagaraja SreeHarsha Jagadeesh G. Hiremath Rajesh Kumar Aitha Abraham J. Domb Bandar E. Al‐Dhubiab Chandramouli Ramnarayanan Abdullah Mossa Alzahrani Katharigatta N. Venugopala Sabah H. Akrawi Mahesh Attimarad Anroop B. Nair 《先进技术聚合物》2019,30(10):2613-2622
This research presents a thin‐film hydration‐solvent evaporation method to formulate the paclitaxel loaded poly (DL lactic acid co castor oil) 4:6 with poloxamer‐F68 cylindrical shape nanoparticles. The particles were less than 250 nanometers (nm) in size, with an average width of 60 nm and an average length of 100 nm. The percent yield, encapsulation efficiency (EE), and percent drug loading (DL) were detected. This approach produces drug loading values between 5% and 20% w/w. X‐ray powder diffraction (XRD) identified the physicochemical properties of nanoparticles differential scanning calorimetry (DSC) and Fourier‐transform infrared spectroscopy (FTIR). The investigation shows that the drug is molecularly dispersed in polymers or given in an amorphous or semicrystalline state. Horizontal water bath shaker technology considered the in vitro release of PTX loaded nanoparticles under sink conditions. Poly (DL lactic acid co castor oil) 4:6 nanoparticles exhibited a sustained release analysis. At the end of 30 hours, the percent cumulative drug release from the formulations was between 74.52% and 92.87% for F1 and F4. In vitro cytotoxicity assays indicate that PTX having p (DLLA:CO60:40) nanoparticles have a higher cytotoxic effect on MCF‐7/ADR. 相似文献
997.
A new organotin complex derived from propyl gallate and 1,10‐phenanthroline was designed, synthesized and characterized using spectroscopic and elemental analytical methods. The underlying mechanisms of the anticancer action of the tin complex were further elucidated by evaluating its in vitro DNA interaction and the regulating signaling pathways. Our results showed that the tin complex could effectively activate DNA strand breaks in MCF‐7 cells in a dose‐dependent manner after cellular internalization. Phosphorylation of a DNA damage marker, histone H2A.X (Ser139), was thus upregulated in treated cells. Additionally, our results indicate that p53 is phosphorylated in response to DNA damage, and that this phosphorylation may be involved in the subsequent induction and activation of p53. In vitro DNA binding of the complex in Tris–HCl buffer was studied using various biophysical methods, revealing that the tin complex binds to DNA non‐covalently via electrostatic interaction. The higher Kb value of the complex suggested greater DNA binding propensity. Further, to evaluate the mode of action at the molecular level, interaction studies of the tin complex with nucleotide (5′‐GMP) were carried out. The complex exhibits DNA cleavage activity with supercoiled pBR322 in the presence of different activators. The complex cleaves DNA efficiently via oxidative cleavage pathway. Molecular docking studies were performed to understand the binding mode of the tin complex with DNA (PDB ID: 1BNA). 相似文献
998.
Aysun Ipek Paksoy Cansu Yassi Akdag Burcu Selen Caglayan Ahmet Erhan Aksoylu 《国际化学动力学杂志》2019,51(2):138-145
Carbon dioxide reforming of methane (CDRM) is an effective route to utilize CO2 and CH4, the most abundant, thermodynamically stable and hazardous greenhouse gases. To overcome the economical impediments to favor CDRM's industrial applicability, its mechanistic features need to be revealed both for developing efficient catalysts and optimizing operational conditions. In this context, this work aims to obtain power-law type CDRM kinetic expressions over 5%Co–2%Ce/ZrO2 and 10%Co–2%Ce/ZrO2 catalysts and compare and analyze mechanistic routes to elucidate the effect of the Co:Ce ratio on kinetics. The empirical power-law type rate expressions were estimated with the reaction orders of 1.63 and 1.12 for CH4 and 0.29 and –0.12 for CO2 for 5%Co–2%Ce/ZrO2 and 10%Co–2%Ce/ZrO2 catalysts, respectively. Limited CH4 activation and, thus, carbon formation due to low Co loading lead to accumulation of surface oxygen on ZrO2 as redox ability of Ce becomes suppressed. This causes higher CO2 activation barrier. The presence of H2 in the feed slows down mechanistic steps involving CHx. The reactions including CH4 activation, most probably reversible direct CH4 dissociation, are found to be rate determining. 相似文献
999.
Balandin S. F. Donchenko V. A. Zemlyanov Al. A. Myshkin V. F. Khan V. A. Abramova E. S. 《Russian Physics Journal》2019,62(5):735-740
Russian Physics Journal - Results of measurements of the conductivity and electric field strength in the laser radiation propagation channel and near it are presented. An experimental setup and... 相似文献
1000.
Nashwa El‐Metwaly Ismail Althagafi Hanadi A. Katouah Jabir H. Al‐Fahemi Tahani M. Bawazeer Abdalla M. Khedr 《应用有机金属化学》2019,33(9)
New VO (II)‐thaizolyl hydrazine complexes were synthesized and characterized by analytical, spectral and theoretical techniques. Bi‐nuclear complexes were suggested for all synthesizes upon neutral poly‐dentate mode of bonding. UV–Vis and EPR spectra, proposed two structural geometries as, square‐planer and octahedral. TGA confirmed the contribution of solvent molecules through physical and/or coordinate‐bonding. XRD parameters calculated, displayed outstanding nanometer‐sizes for all nano‐crystalline compounds, which suffering slight imperfections. Also, SEM images showed, spherical‐shape that observed for most topographic particulates. Conformational study executed for all new synthesizes, demonstrated their optimized structural‐forms. Furthermore, important physical parameters were computed that predict essential characteristics as, biological efficiency. Predictable parameters as softness and electrophilicity, point to priority of VO (II)‐4d complex. Genotoxic study, was already examined, for all new synthesizes, against CT‐DNA and displayed complete deterioration for DNA, by influence of most tested compounds. Moreover, MOE‐docking technique, was executed against receptors of Y‐family DNA‐polymerase (4irk) and Key‐Enzyme Linking‐Metabolic Inflammation (4cyf). This docking study displayed the following ascending order; VO (II)‐4c,4irk ? VO (II)‐4d,4cyf ? VO (II)‐4c, 4cyf ? VO (II)‐4b, 4cyf, based on scoring‐energy values. This study concluded with promising prediction of these complexes in relation to DNA‐polymerase as well as inflammation enzyme that compared with known anti‐inflammatory drug (meloxicam). 相似文献