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- Author or Editor: H. M. Liu x
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Abstract
In this paper, a brief survey of hydrogen production methods is presented with a focus on S-I cycle. Based on heat duty data of sulfuric acid decomposition in S-I cycle, optimization models are developed to explore the minimum utility consumption and the minimum number of heat exchangers. Finally an optimal heat exchanger network for S-I thermochemical cycle is defined by a mixed integer optimization model.
Abstract
The complex of [Tb2(o-MBA)6(PHEN)2] (o-MBA: o-methylbenzoate and PHEN:1,10-phenanthroline) were synthesized and characterized by elemental analysis and IR spectroscopy. The thermal behavior of [Tb2(o-MBA)6(PHEN)2] in dynamic nitrogen atmosphere was investigated by TG-DTG techniques. The thermal decomposition process of the [Tb2(o-MBA)6(PHEN)2] occurred in three consecutive stages at Tp 294, 427 and 512C. The kinetic parameters and mechanisms of first decomposition stage from analysis of the TG-DTG curves were obtained by the Malek method.
Abstract
The thermal decomposition of Eu2(BA)6(bipy)2 (BA=C2H5N– 2, benzoate; bipy=C10H8N2, 2,2'-bipyridine)and its kinetics were studied under the non-isothermal condition by TG-DTG, IR and SEM methods. The kinetic parameters were obtained from analysis of the TG-DTG curves by the Achar method, the Madhusudanan-Krishnan-Ninan (MKN) method, the Ozawa method and the Kissinger method. The most probable mechanism function was suggested by comparing the kinetic parameters. The kinetic equation for the first stage can be expressed as: dα/dt=Aexp(–E/RT)3(1–α)2/3.
Abstract
The uranium(VI) accumulation was studied in detail by using the biomass of mangrove endophytic fungus Fusarium sp.#ZZF51 from the South China Sea. The uranium(VI) biosorption process onto the tested fungus powders was optimized at pH 4.0, adsorption time 60 min, and uranium(VI) initial concentration 50 mg L−1 with 61.89% of removal efficiency. According to Fourier transform infrared spectra for the tested fungus before and after loaded with uranium(VI), the results showed that both of hydroxyl and carboxyl groups acted as the important roles in the adsorption process. In addition, the experimental data were analyzed by using parameter and kinetic models, and it was obtained that the Langmuir isotherm model and the pseudo-second-order kinetic model provided better correlation with the experimental data for adsorption of uranium(VI).
Abstract
Samarium-153-EDTMP (ethylene diamine tetramethylene phosphonate), for its promising biological properties, has been proved as a palliating therapeutic agent for boné cancer in human beings. In this article, we present the results on synthesis and structure analysis of Samarium-153-EDTMP. In a basic medium,153Sm-EDTMP can be readily prepared with a complexing yield not less than 98%, and it is confirmed that the ratio of the ligand to Sm is 1
1, and the charge of153Sm-EDTMP is negative two.
Shenqi Fuzheng Injection (SFI) is a traditional Chinese medicine injection, widely used to enhance immune function of clinical cancer patients undergoing chemotherapy. In this study, a high-performance liquid chromatography-diode array detection-evaporative light scattering detection (HPLC-DAD-ELSD) method was established for quality control of SFI, which could simultaneously semiquantitatively reflect the constituents displayed in the chromatographic profile of SFI. The relative retention time and relative peak areas of the 21 common peaks related to the reference peak were calculated. The validity and advantage of this method were validated by systematically comparing chromatograms of 10 batches of SFI samples with the analytical methods of principal component analysis and angle cosine method recommended by the State Food and Drug Administration of China. Moreover, a total of 21 constituents of SFI were identified or tentatively characterized in the fingerprint via ultrafast liquid chromatography-diode array detection-quadrupole time-of-flight (UFLC-DAD-Q-TOF) tandem mass spectrometry technique on the basis of the retention time, ultraviolet spectra, fragmentation patterns, and reported literatures. All the results proved that the technique was useful in comprehensive quality evaluation of SFI and further study.
Summary
Harmaline and harmine accounted for more than 70% in composition in extracts of P. harmala. More attention, however, should be paid to the other alkaloids which would be favorable or unfavorable to the efficacy and safety of the products. It was necessary to determine these trace alkaloids in the extracts; thereafter, most of them have been characterized. Diglycoside vasicine, vasicine, vasicinone, harmalol, harmol, tetrahydroharmine, 8-hydroxy-harmine, ruine, harmaline, and harmine were separated and identified with reference substances and characteristic MS spectra in extracts by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) and high-performance liquid chromatography (HPLC). Three trace alkaloids, vasicine, harmalol, and harmol were determined using the developed chromatographic separation method subsequently. The average contents of vasicine, harmalol, and harmol in extracts of ten batches were 2.53 ± 0.73, 0.54 ± 0.19, and 0.077 ± 0.03%, respectively. The total content of the three alkaloids was 3.23 ± 0.90% (from 1.81 to 4.48%). For rough estimation of all the relative alkaloids except of harmaline and harmine, the average total areas of all peaks in extracts varied from 4.35 to 26.64% detected at 220, 254, 265, 280, and 380 nm, respectively. The results indicated that area normalization method was powerless for the quality evaluation for traditional herb medicine consisting of numerous compounds with highly differential features. It might be concluded that LC-MS or HPLC could be utilized as a qualitative and quantitative analytical method for quality control of the extracts from seeds of P. harmala L.
Abstract
The complex of [Tb2(p-ClBA)6(PHEN)2] [(p-ClBA: p-chlorobenzoate and PHEN: 1,10-phenanthroline) was prepared and characterized by elemental analysis and IR spectroscopy. The thermal behavior of [Tb2(p-ClBA)6(PHEN)2] in dynamic nitrogen atmosphere was investigated by TG-DTG, SEM and IR techniques. By the kinetic method of processing thermal analysis data put forward by Malek et al., it is defined that the kinetic model for the first-step thermal decomposition is SB(m,n). The activation energy E and the pre-exponential factor lnA for this step reaction are 164 kJ mol-1 and 32.80, respectively. The lifetime equation at mass loss of 10% was deduced as lnτ=(-33.0569+20512.36/T by isothermal thermogravimetric analysis.
