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41.
A. Cecal A. Gulea V. Rudic I. Palamaru D. Humelnicu K. Popa 《Isotopes in environmental and health studies》2013,49(3):327-331
Abstract Using different algea types the bioaccumulation of UO2 2+ and Th4+ ions from experimental residual wastes of nuclear facilities was investivated. The retaining degree of these ions on microbiological sorbents decreases as: Scenedesmus quadricauda > Porphyridium cruentum > Spirulina platensis > Calothrix sp.2 > Calothrix sp.1 for UO2 2+ and Porphyridium cruentum > Spirulina platensis > Scenedesmus quadricauda for Th 4+. For the same algae it was observed that the retaining degree is much higher for UO2 2+ than for Th4+, probably due to the different linking degrees of hydrolysed species of these ions on the macromolecular compounds of the living cells through the chemical functional groups. 相似文献
42.
Thomas E. Murphy Halil Berbero?lu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(18):2826-2834
This paper reports a numerical study coupling light transfer with photosynthetic rate models to determine the size and microorganism concentration of photobioreactors based on the pigmentation of algae to achieve maximum productivity. The wild strain Chlamydomonas reinhardtii and its transformant tla1 with 63% lower pigmentation are used as exemplary algae. First, empirical models of the specific photosynthetic rates were obtained from experimental data as a function of local irradiance using inverse methods. Then, these models were coupled with the radiative transfer equation (RTE) to predict both the local and total photosynthetic rates in a planar photobioreactor (PBR). The optical thickness was identified as the proper scaling parameter. The results indicated that under full sunlight corresponding to about 400 W/m2 photosynthetically active irradiation, enhancement of PBR productivity up to 30% was possible with tla1. Moreover, under similar irradiation, optical thicknesses above 169 and 275 for the wild strain and tla1, respectively, did not further enhance PBR productivity. Based on these results guidelines are provided for maximizing PBR productivity from a light transport perspective. 相似文献
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Isao Shitanda Kazutake Takada Yasuyuki Sakai Tetsu Tatsuma 《Analytica chimica acta》2005,530(2):191-197
Unicellular microalga Chlorella vulgaris was entrapped in an alginate gel or a polyion complex membrane immobilized directly on the surface of a transparent indium tin oxide electrode. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine), 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU), toluene and benzene, were evaluated as inhibition ratios of the reduction current. The concentrations that give 50% inhibition of the oxygen reduction current (IC′50) for atrazine, DCMU, toluene and benzene were 2.0, 0.05, 1550 and 3000 μmol dm−3, respectively. There was a good correlation between these data and those of the conventional standard growth test. In comparison with the conventional algal biosensors based on the Clark-type oxygen electrode, the present sensor is much smaller and less expensive, and its assay time is much shorter (≤200 s). 相似文献
46.
激发光强和激发持续时间是快速光脉冲藻类光合作用测量方法的关键实验条件.通过光脉冲激发实验,定量分析了不同平均激发光强下还原态初级电子受体的比例和发生再氧化的初级电子受体的比例.结果表明:快速光脉冲激发的最佳平均光强为30 000μmol quanta·m-2·s-1,最佳激发持续时间为70μs;30 000μmol quanta·m-2·s-1平均激发光强能够在70μs内还原96.08%的初级电子受体,且仅9.81%的初级电子受体发生了再氧化. 相似文献
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Myriam El Ati-Hellal Gaetane Lespes Mohamed Dachraoui 《International journal of environmental analytical chemistry》2013,93(10):733-742
Optimal conditions of headspace solid-phase microextraction followed by gas chromatography coupled to pulsed flame photometric detection (SPME–GC–PFPD) have been investigated to validate the analysis of 11 organotin compounds in plant matrices including methyl-, butyl-, and phenyltin compounds. The extraction of organotin compounds from vegetal matrices has been carried out using optimized conditions of HCl-based extraction. The use of headspace SPME to preconcentrate the analytes allowed most of the detection limits to be obtained sub-0.5?ng(Sn)?g?1. The precision evaluated using RSD with six replicates ranges between 5 and 10% (except for triphenyltin: 17%). The accuracy of the method was validated on spiked or polluted vegetal samples taken from Bizerte Lagoon (Tunisia) and by comparison with classical liquid–liquid extraction (LLE). These results highlight the suitability of the selected method for organotin control in complex environmental matrices such as aquatic plants. 相似文献
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Electrothermal atomic absorption spectrometry was used for the determination of Cd, Pb, As and Se in the whole blood, serum, hair reference standard materials and the samples of algae collected at the coastal Estonian regions of Baltik sea. Instead of tedious and time-consuming experimental comparison of various chemical modifiers, theoretical consideration of the problem was applied for choosing the most prospective one (colloidal Pd) for solution of the given task. The experimental data obtained proved correctness of the choice. Pure standard solutions in diluted nitric acid were used for construction of the calibration graphs. The same experimental conditions were applied for each analyte for calibration solutions and all samples studied. In spite of very limited optimization procedures used, all the values obtained agree well with the corresponding reference values. Accuracy of the analysis of the algae samples was checked by recoveries of the spikes that were in the region 91-109%. Detection limits reached are 0.021, 1.2, 0.62 and 1.1 ng ml−1 for Cd, Pb, As and Se, respectively, in digests of biological samples. 相似文献
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Three different methods, i.e. a biosensor method, a voltammetric method and a spectrophotometric method, have been used to evaluate the total antioxidant capacity of certain types of algae. In the final evaluation of the data also the variation in time of the antioxidant capacity of cultivated algae was considered and some experimental factors, such as the use of different solvent mixtures to extract the antioxidant substances contained in the algae, were discussed. 相似文献