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111.
112.
Li‐Chai Chen I‐Li Chen Chih‐Chiang Huang Chang‐Hui Liao Jhy‐Yih Chen Tai‐Chi Wang 《中国化学会会志》2010,57(6):1331-1340
Some oxime‐containing 3,4‐dihydroquinolin‐2(1H)‐one derivatives were synthesized and evaluated for their antiplatelet and antiproliferative activities. These compounds were synthesized via alkylation of hydroxyl precursors followed by the reaction with NH2OH. The preliminary assays indicated that (Z)‐7‐[2‐(4‐fluorophenyl)‐2‐(hydroxyimino)ethoxy]‐3,4‐dihydroquinolin‐2(1H)‐one (13c) is the most active against U46619 induced platelet aggregation with an IC50 value of 3.51 μM. For the inhibition of AA‐induced aggregation, (E)‐6‐[2‐(hydroxyimino)propoxy]‐3,4‐dihydroquinolin‐2(1H)‐one (15 ) is the most potent with an IC50 value of 1.85 μM. These oxime‐containing 3,4‐dihydroquinolin‐2(1H)‐one derivatives were inactive against thrombin induced platelet aggregation with an IC50 value of greater than 26.78 μM. For the antiproliferative activity, most of these oxime‐containing 3,4‐dihydroquinolin‐2(1H)‐one derivatives were inactive while (Z)‐7‐[2‐(hydroxyimino)‐2‐(naphthalen‐2‐yl)ethoxy]‐3,4‐dihydroquinolin‐2(1H)‐one (13a) exhibited only marginal activities with GI50 value of 7.63, 7.34 and 6.36 μM against the growth of NPC‐TW01, NCI‐H661, and Jurkat respectively. 相似文献
113.
Optimized structures and photophysical properties of mer- and fac-Alq3 have been generated by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Investigating the substitution effect in the Alq3 derivatives, the role of the electron-donating (CH3- and NH2-) and electron-withdrawing (F-, CN-, NO2- and phenyl-) groups with 2- to 7-substitution have been analyzed. According to the calculation results, the 4- and 5- substituted Alq3 exhibit an apparent spectral shift relative to the non-substituted Alq3. The HOMO, LUMO, Eg (the energy gap between LUMO and HOMO), (maximum absorption wavelength) and f (the relative oscillator strength) of mer-Alq3 with the 4- or 5-phenyl substitution on the quinoline ligand in the ground electronic state were calculated by using the DFT/B3LYP/6-31G(d) and TD-DFT methods. 5-phenyl substituted mer-Alq3 with an electron-donating substituent showed an increase in the π-delocalization as compared to the 4-phenyl substituted mer-Alq3 derivatives. Similarly, 4-phenyl substituted mer-Alq3 with electron-withdrawing substituents also exhibits increased π-delocalization in the pyridine ring as compared to the non-substituted Alq3. Replacing the CH group at the 4, 5 and 4,5 positions of the quinoline ligand of mer-Alq3 with the aza group (nitrogen atom) gives three Alq3 analogous: AlX3, Al(NQ)3 and Al(NX)3; the calculated energy gap Eg of these derivatives decreases in the order Al(NQ)3>Al(NX)3>AX3. Four quinoline with group III metals Mq3 complexes were investigated for the photophysical properties; the calculated energy gap Eg decreases in the order Tlq3>Inq3>Gaq3>Alq3. The photophysical properties of 4-hydroxy-8-methyl-1,5-naphthyridine (mND) chelated with group III metals (MmND3 complexes) were investigated also; their calculated Eg have the opposite order as those of Mq3 complexes. 相似文献
114.
115.
Yun Long ZHANG Liang Ren ZHANG* Zhen Jun YANG Ji Mei MIN Li He ZHANG* Yang LU Ning Bo GONG Qi Tai ZHENG National Research Laboratory of Natural Biomimetic Drugs Peking University Beijing Institue of Materia Medica Chinese 《中国化学快报》2001,(5)
Tubercidin (4-amino-7--D-riobofuranosyl-7-H-pyrrolo[2,3-d]pyrimidine) 1, an antibio-tic substance produced in the culture broth of Streptomyces tubericidus1, is an adenosine analog in which N-7 is replaced by a carbon atom. It has attracted much attention due to the biological activities for the growth inhibition of certain tumors, and many derivatives of tubercidin have been synthesized2-5.For the synthesis of tubercidin analogs, 4-chloro-7-H-pyrrolo[2,3-d]pyrimidine-2,3,5-tri-O-acetyl--D-r… 相似文献
116.
In this study, we detail a method for estimating the flux-averaged solid fraction of a steady granular flows moving down an
inclined rectangular chute using velocity measurements from along the perimeter cross section, combined with knowledge of
the mass flow rate through the cross section. The chute is 5 cm wide and 150 cm long with an adjustable inclination angle.
Four inclination angles, from 27° to 36° at 3° intervals, are tested. This angle range overlaps the internal friction angle
of the glass beads, which are 4 mm nominal in diameter. Two slender mirrors are installed at the top and the bottom of the
transparent chute to reflect images of the flow down the chute of the two surfaces. This allows photographic recording of
the flow with a PIV imaging system and measurement of the flow depth. The mass flow rate can be calibrated simultaneously
by collecting the accumulated mass at the chute exit. A linear interpolation scheme is proposed to interpolate the volume
flow rate in each section of the chute. Sensitivity analysis suggests that the relative standard deviation of this scheme
is about ±6%, i.e., the resultant solid volume fraction is only moderately dependent on the interpolation scheme for the tested
cases. This is further confirmed by a direct intercepting method. Compared to the sophisticated magnetic resonance imaging
(MRI) or the radioactive positron emission particle tracking (PEPT) methods, the present method is verified as a cost-effective
and nonhazardous alternative for ordinary laboratories. Two distinct groups of streamwise dependence of the solid fractions
are found. They are separated by the inclination angle of the chute and agreed with the internal friction angle. In the experiments
using the two smaller inclination angles, the solid fraction ratios are found to be linear functions of the streamwise distance,
while for the two larger inclination angles, the ratios have a nonlinear concave shape. All decrease with growing downstream
distance. 相似文献
117.
Dopamine was electrochemically oxidized in aqueous solutions and in the organic solvents N,N‐dimethyl‐formamide and dimethylsulfoxide containing varying amounts of supporting electrolyte and water, to form dopamine ortho‐quinone. It was found that the electrochemical oxidation mechanism in water and in organic solvents was strongly influenced by the buffering properties of the supporting electrolyte. In aqueous solutions close to pH 7, where buffers were not used, the protons released during the oxidation process were able to sufficiently change the localized pH at the electrode surface to reduce the deprotonation rate of dopamine ortho‐quinone, thereby slowing the conversion into leucoaminochrome. In N,N‐dimethylformamide and dimethylsulfoxide solutions, in the absence of buffers, dopamine was oxidized to dopamine ortho‐quinone that survived without further reaction for several minutes at 25 °C. The voltammetric data obtained in the organic solvents were made more complicated by the presence of HCl in commercial sources of dopamine, which also underwent an oxidation process. 相似文献
118.
119.
槲皮素修饰的从层脂膜作为研究抗病毒药物的一种模型体系,用循环伏安法测定了槲皮素在脂膜界面上的氧化还原性质和配位性质。在电位扫描过程中,微量铜离子能催化槲皮素的氧化,当双层脂膜的两侧存在着合适的氧化还原偶时,就会产生跨膜的电子传递。 相似文献
120.
Simultaneous two-dimensional imaging of an unburnt area and a reacting area was performed using laser-induced fluorescence. Acetone was added to fuel as a tracer, and OH radical was used as a marker of the reacting area. A narrow band tunable KrF excimer laser (248 nm) was employed to excite acetone and OH simultaneously. Two intensified CCD cameras with different wavelength filters were used to detect these two kinds of species respectively. Detecting 294-314 nm (A-X (3, 2), etc.) for OH and 335-410 nm for acetone, we obtained images of each species without interference of a signal from the other. The method was also successfully applied to flames in a pressurized combustion chamber under the pressure of 0.5 MPa. 相似文献