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141.
Xiao-Ping Rao Yong Wu Zhan-Qian Song Shi-Bin Shang 《Journal of chemical crystallography》2010,40(4):328-331
Abstract
The title compound (C46H72N4O2, M r = 713.08) [systematic name: 1-isopropyl-3-((1R,4aS,10aR)-7-isopropyl-1, 4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl)urea] is a new derivative of dehydroabietic acid. It crystallized in the orthorhombic system, space group P2121 21 with cell dimensions of a = 9.5950(19) ?, b = 18.740(4) ?, c = 24.654(5) ?, V = 4,433.0(16) ?3, Z = 4, D c = 1.068 g/cm3, λ = 0.71073 ?, μ = 0.07 mm−1, F(000) = 1,568, final R = 0.0777 and wR = 0.1731 for 2,048 observed reflections with I > 2σ(I). Two crystallorgraphically independent molecules with different conformations co-exist in the structure. Each molecule exhibit classic tricyclic hydrophenanthrene structure, the two cyclohexane rings form a trans ring junction with chair and half-chair conformations, respectively. The crystal is stabilized by intermolecule hydrogen bonds and the molecules are in a head–tail zigzag arrangement. 相似文献142.
143.
Ting Liu Xian Chen Cheng-Yi Hong Xiao-Ping Xu Huang-Hao Yang 《Mikrochimica acta》2014,181(7-8):731-736
Electrochemiluminescence (ECL) integrates the advantages of electrochemical detection and chemiluminescent techniques. The method has received particular attention because it is highly sensitive and selective, has a wide linear range but low reagent costs. The use of nanomaterials with their unique physical and chemical properties has led to new kinds of biosensors that exhibit high sensitivity and stability. Compared to other nanomaterials, DNA nanostructures are more biocompatible, more hydrophilic, and thus less prone to nonspecific adsorption onto the electrode surface. We describe here a label-free and ultrasensitive ECL biosensor for detecting a cancer-associated microRNA at a femtomolar level. We have designed two auxiliary probes that cause the formation of a long-range self-assembly in the form of a μm-long 1-dimensional DNA concatamer. These can be used as carriers for signal amplification. The intercalation of the ECL probe Ru(phen)3 2+ into the grooves of the concatamers leads to a substantial increase in ECL intensity. This amplified sensor shows high selectivity for discriminating complementary target and other mismatched RNAs. The biosensor enables the quantification of the expression of microRNA-21 in MCF-7 cells. It also displays very low limits of detection and provides an alternative approach for the detection of RNA or DNA detection in diagnostics and gene analysis. Figure
The long-range self-assembly DNA concatamers were used as carriers for signal amplification by the intercalation of numerous ECL probe (Ru(phen)3 2+) into the grooves of the DNA concatamers. Such signal amplification strategy lead to a substantial increase in ECL intensity and sensitivity. 相似文献
144.
Reactions of isocyanides with 2-mercaptobenzothiazole and 2-mercaptobenzoxazole afforded a series of compounds containing formamidine framework in moderate to high yields. These organic transformations were performed under mild and catalyst-free conditions. In addition to promoting the reactions, the use of ultrasound irradiation also allowed the process to be carried out under air atmosphere. A possible reaction mechanism was proposed based on the experimental results. 相似文献
145.
Zhang CL Ding XP Hu ZF Wang XT Chen LL Qi J Yu BY 《Chemical & pharmaceutical bulletin》2011,59(5):541-545
An on-line HPLC-diode array detection-flow injection chemiluminescence (HPLC-DAD-FICL) method was applied to estimate the difference of Puerariae lobatae and Puerariae thomsonii. Their chemical and active profiles could be obtained by HPLC-DAD-FICL in one run. Seventeen compounds in two species were tentatively identified by HPLC-electrospray ionization-MS (HPLC-ESI-MS) method. The main antioxidants were rapidly screened by active fingerprints coupled with MS data. Similarity and Hierarchical clustering analysis (HCA) were used to distinguish different samples. The results suggested that the chemical fingerprints of 16 batches of samples were similar by similarity evaluation, while HCA could discriminate the two species. The active fingerprints of Puerariae lobatae and Puerariae thomsonii were significantly different. More antioxidants were found in Puerariae lobatae than in Puerariae thomsonii. Main antioxidants, including 3'-hydroxypuerarin, genistein 8-C-glycoside-xyloside, puerarin, 6″-O-xylosylpuerarin, mirificin and daidzein in two species, may be reasonable markers for the discrimination of the two species. The integrated fingerprint based on the chemical and active characteristics may provide an objective quality evaluation for Puerariae lobatae and Puerariae thomsonii. 相似文献
146.
By systematically varying the geometric length and electronic properties of the second ligating ligands of halogen (Cl(-), Br(-), and I(-)) and pseudohalogen (CN(-), SCN(-), and N(3)(-)) anions, we synthesized 11 isomeric/isostructural copper(I) complexes: [Cu(2)(L3-3)I](n) (1), [Cu(2)(L4-4)Br](n) (2-Br), [Cu(2)(L4-4)Cl](n) (2-Cl), [Cu(2)(L3-4)(CN)](n) (3), [Cu(2)(L3-3)(CN)](n) (4), [Cu(3)(L4-4)(CN)(2)](n) (5), {[Cu(2)(L4-4)Br](2)·CuBr}(n) (6-Br), {[Cu(2)(L4-4)Cl](2)·CuCl}(n) (6-Cl), [Cu(2)(L4-4)(SCN)](n) (7α-SCN), [Cu(2)(L4-4)(SCN)](n) (7β-SCN), and [Cu(2)(L4-4)(N(3))](n) (7α-N(3)). These structures are based on a series of isomeric pyridylpyrazole ligands, namely, 3,5-bis(3-pyridyl)-1H-pyrazole (HL3-3), 3-(3-pyridyl)-5-(4-pyridyl)-1H-pyrazole (HL3-4), and 3,5-bis(4-pyridyl)-1H-pyrazole (HL4-4), and their structural features range from 1-D (1), 2-D (2), and 3-D noninterpenetration (3), to 3-D 2-fold interpenetration (4 and 5), to 3-D self-catenation (6 and 7), exhibiting a trend from simple to complex with dimension expansion and an interpenetrating degree increase. The five most complex structures (6 and 7) with self-catenated networks are based on 2-fold interpenetrated networks linked via appropriate second ligating spacers (Cl(-), Br(-), SCN(-), and N(3)(-)), representing a strategy to construct self-catenated coordination polymers through cross-linking interpenetrated frameworks. Moreover, these complexes exhibit strong photoluminescence, which is mainly ascribed to Cu(I)-related charge transfers (MLCT, MC, and MMLCT) regulated by the electronic properties of halogen or pseudohalogen. The topological evolution and luminescence variation presented in this work open an avenue to understanding the luminescence origin and the structure-property relationship of luminescent coordination polymers. 相似文献
147.
New tribenzotriquinacene (TBTQ) hosts bearing six-fold peripheral benzofuran functionalization have been synthesized. The three polycondensed arene wings were shown to operate optically independently and to generate deeply bowl-shaped C(3v)-symmetrical frameworks that act as relatively weak hosts toward C(60), as revealed by (1)H NMR spectroscopy. 相似文献
148.
149.
Live morphological analysis of taxol-induced cytoplasmic vacuolization [corrected] in human lung adenocarcinoma cells 总被引:1,自引:0,他引:1
Taxol (paclitaxel), one of the most active cancer chemotherapeutic agents, can cause programmed cell death (PCD) and cytoplasmic vacuolization. The objective of this study was to analyze the morphological characteristics induced by taxol. Human lung adenocarcinoma (ASTC-a-1) cells were exposed to various concentration of taxol. CCK-8 was used to assay the cell viability. Atomic force microscopy (AFM), plasmid transfection and confocal fluorescence microscopy were performed to image the cells morphological change induced by taxol. Fluorescence resonance energy transfer (FRET) was used to monitor the caspase-3 activation in living cells during taxol-induced cell death. Cells treated with taxol exhibited significant swelling and cytoplasmic vacuolization which may be due to endoplasmic reticulum (ER) vacuolization. Caspase-3 was not activated during taxol-induced cytoplasmic vacuolization and cell death. These findings suggest that taxol induces caspase-3-independent cytoplasmic vacuolization, cell swelling and cell death through ER vacuolization. 相似文献
150.