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91.
The reaction of 7,7a,8,9,10,12-hexahydrobenzo[h]pyrrolo [1,2-b]isoquinoline-7,10-dione 2 with sodium azide in sulfuric acid afforded the unexpected cyano derivative 5 . The proposed structure for 5 is supported by 13C nmr, 1H nmr and HMBC spectra. 相似文献
92.
Lincker F Bourgun P Masson P Didier P Guidoni L Bigot JY Nicoud JF Donnio B Guillon D 《Organic letters》2005,7(8):1505-1508
[reaction: see text] The synthesis and photonic and liquid-crystalline properties of a novel oligo biphenylene vinylene (OBV) chromophore with an extended pi-electron system are reported; the compound exhibits high fluorescence, a large two-photon absorption cross-section, and two- and three-dimensional liquid-crystalline mesophases. 相似文献
93.
取代聚苯胺的聚集态结构 总被引:3,自引:0,他引:3
环取代基及掺杂对聚苯胺分子链结构产生影响的同时也对大分子聚集态结构产生影响.通过对聚合物膜的XRD、SEM研究,表明在所合成的环取代聚苯胺衍生物中,聚合物的结晶性依POT(聚邻甲苯胺)、PDMAn(聚 2,5 二甲氧基苯胺)、PmClAn(聚间氯苯胺)顺序增加;与本征态的比较,质子酸掺杂后聚合物的结晶性有所提高.POT基本上表现出了非晶聚合物的性质; PDMAn具有同质多晶的结构特征,但结晶度较低; PmClAn表现出了典型高分子晶体性质,符合单斜晶系的特征(晶胞参数为a=0.679 nm, b=2.304 nm, c=0.5734 nm, α=90°, β=100.9°, γ=90°).采用HyperChem程序包中的MM+分子力学方法对1H NMR和XRD实验结果进行结构优化,确定了苯式结构/醌式结构为3/2的PmClAn大分子链的构象. 相似文献
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Jean-Baptiste Baugros Cécile Cren-Olivé Barbara Giroud Jean-Yves Gauvrit Pierre Lantéri Marie-Florence Grenier-Loustalot 《Journal of chromatography. A》2009,1216(25):4941-4949
The study proposes an analytical method to quantify 10 alkylphenols and 12 pesticides at ultra-trace levels by liquid chromatography in reverse mode coupled to positive electrospray ionisation–tandem mass spectrometry. The extraction procedure from environmental solids was optimised by pressurised liquid extraction using acetonitrile:isopropanol (1:1, v/v). The influence of several extraction experimental factors, temperature, pressure, duration and number of cycles, related to the PLE was investigated by an original and efficient chemometric approach. The optimised extraction method (80 °C, 40 bar, 10 min, 1 cycle) exhibited recoveries between 67 and 127% with RSD mostly under 13%. The whole method was applied to real samples: sludge, suspended materials, atmospheric fallouts and roof deposit. Pollutant levels were between 1 μg kg−1 and 5.9 mg kg−1. 相似文献
98.
Max Schütz Christian Gemel Maximilian Muhr Christian Jandl Samia Kahlal Jean-Yves Saillard Roland A. Fischer 《Chemical science》2021,12(19):6588
Cluster growth reactions in the system [Cu5](Mes)5 + [Al4](Cp*)4 (Mes = mesitylene, Cp* = pentamethylcyclopentadiene) were explored and monitored by in situ LIFDI-MS and 1H-NMR. Feedback into experimental design allowed for an informed choice and precise adjustment of reaction conditions and led to isolation of the intermetallic cluster [Cu4Al4](Cp*)5(Mes) (1). Cluster 1 reacts with excess 3-hexyne to yield the triangular cluster [Cu2Al](Cp*)3 (2). The two embryonic [Cu4Al4](Cp*)5(Mes) and [Cu2Al](Cp*)3 clusters 1 and 2, respectively, were shown to be intermediates in the formation of an inseparable composite of the closely related clusters [Cu7Al6](Cp*)6 (3), [HCu7Al6](Cp*)6 (3H) and [Cu8Al6](Cp*)6 (4), which just differ by one Cu core atom. The radical nature of the open-shell superatomic [Cu7Al6](Cp*)6 cluster 3 is reflected in its reactivity towards addition of one Cu core atom leading to the closed shell superatom [Cu8Al6](Cp*)6 (4), and as well by its ability to undergo σ(C–H) and σ(Si–H) activation reactions of C6H5CH3 (toluene) and (TMS)3SiH (TMS = tris(trimethylsilyl)).Cu/Al cluster growth reactions leading to open- and closed-shell superatoms are investigated. Therein, LIFDI-MS is presented as a powerful technique for the in situ detection of cluster identities and reactivity patterns. 相似文献
99.
Christelle Machon Lars Petter Jordheim Jean-Yves Puy Isabelle Lefebvre Charles Dumontet Jérôme Guitton 《Analytical and bioanalytical chemistry》2014,406(12):2925-2941
An analytical method coupling online solid-phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC-MS/MS) was developed to quantify 16 endogenous nucleoside mono- and triphosphates in cellular samples. Separation was achieved on a porous graphitic carbon (PGC) column without ion-pairing agent in the mobile phase. Low levels of the ion-pairing agent diethylamine (DEA) added to the reconstitution solution were necessary to prevent peak tailing of nucleoside triphosphates. The mass spectrometer, a triple quadrupole with an electrospray ionisation source, was operated in positive mode. Two multiple reaction monitoring (MRM) segments were programmed, each an internal standard. Extraction and separation of nucleoside mono- and triphosphates were obtained within 20 min. The total duration of a single run was 37 min. Calibration curves, performed with labelled nucleotides added to the sample matrix, ranged from 0.29 to 18.8 pmol injected for deoxyribonucleotides and from 3.9 to 3,156 pmol for ribonucleotides. Accuracy did not deviate more than ?14.6 and 10.2 % from nominal values for all compounds at all levels. CV results were all lower than 17.0 % for the LLOQ level and 14.6 % for the other levels. Quality control (QC) samples were also in agreement with acceptance criteria, except for the lower QC of GMP. Ion suppression, matrix effect, extraction recoveries and stability were assessed. After validation, the method was applied to the evaluation of the effects of gemcitabine and hydroxyurea on nucleotide pools in Messa cells. 相似文献
100.