Some popular neutral extractants (PSO-petroleum sulfoxide, DOSO-di-n-octyl sulfoxide, TBP-tributylphosphate etc.) were chosen
as synergist to study the synergistic effect on the extraction reaction with HBMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione)
for U(VI), and the synergistic separation ability of HBMPPT for U(VI) and Th(IV). The synergistic extraction ability shown
by the studied systems for U(VI) is as follows: PSO>DOSO>TBP, and the same sequence was also verified for the separation coefficient
of U(VI) and Th(IV). The synergistic complexes may be presented as: UO2NO3·BMPPT·S and UO2(BMPPT)2·S for U(VI) (S is PSO, DOSO or TBP).
Non-isothermal crystallization kinetics of polypropylene (PP), m-isopropenyl-α,α-dimethyl-benzyl isocyanate grafted PP (PP-g-m-TMI), and styrene(St), as comonomer, together with m-TMI grafted PP (PP-g-(St-m-TMI)) was investigated by using differential scanning calorimetry (DSC) under different cooling rates. The crystallization
rates of all samples increased with increasing cooling rate. The relation of the half time of crystallization (t1/2) of the three samples, t1/2(PP-g-(St-m-TMI)) < t1/2(PP-g-m-TMI) < t1/2(PP), implying the introduction of St could effectively improve the degree of grafting of m-TMI, resulting in crystallization temperature increased, and the crystallization rate was the fastest. Three methods, namely,
the Avrami, the Ozawa, and the Mo, were used to describe the crystallization process of the three samples under non-isothermal
conditions. The Avrami and Ozawa neglected the secondary crystallization that follows primary crystallization. The Mo method
can successfully describe the overall non-isothermal crystallization process of all the samples. It has been found that the
F(T)(PP-g-(St-m-TMI)) < F(T)(PP-g-m-TMI) < F(T)(PP), also meaning that the crystallization rate of PP-g-(St-m-TMI) and PP-g-m-TMI were faster than that of PP. The activation energy (ΔE) for non-isothermal crystallization of all samples was determined by using the Kissinger method. The result showed that the
lower value of ΔE for crystallization obtained for PP-g-m-TMI and PP-g-(St-m-TMI) confirmed the nucleating effect of St and m-TMI on crystallization of PP.
The extractant HBMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) was synthesized from HBMPP. Its m.p. was
106–108°C. The synergistic extraction of U(VI) and Th(IV) from nitric acid solution by HBMPPT and TOPO in toluene was studied.
The extraction ability of HBMPPT was not so high as that of its parent (HBMPP), but when a little tri-n-octylphosphine oxide
(TOPO) was added the ability to extract U(VI) and Th(IV) was seriously improved. The synergistic extracted complexes may be
presented as UO2NO3·BMPPT·TOPO and UO2(BMPPT)2·TOPO for U(VI), and Th(NO3)3·BMPPT·TOPO and Th(NO3)2(BMPPT)2·TOPO for Th(IV) respectively.
Authors:C. Li, X. Ma, A. Wang, E. Nevo, and G. Chen
The aerial surface of land plants is protected by a cuticle against abiotic and biotic stresses. A better understanding of the determinants of cuticle formation and function has the potential to contribute to the breeding of more drought tolerant and disease resistant crop varieties. Two doubled haploid (DH) mapping populations, Steptoe × Morex populations and OWB-dominant × recessive populations were exploited to genetically position homologs of a set of known cuticle-associated genes. These genes were also placed on a consensus map, BinMap2005, which includes 27 eceriferum (cer) loci. Of the 49 known cuticle-associated genes, 21 identified a homolog in barley, and of these, 14 were mapped. There was a complete linkage between HvCER6 and cer-zg, suggesting the possibility that HvCER6 is the candidate gene of CER-ZG. Positioning known cuticle-associated genes on a consensus map containing cuticle mutant loci may guide the selection of candidate genes for cuticle mutants, and thus facilitate the isolation of cuticle-associated genes in barley.
Authors:Zhang Yuanxun, Li Deyi, Ma Jixiao, and Huang Qiren
Bone mineral density (BMD) determination has been performed in 210 selected Shanghai residents of both sexes of age range 15–50 using Hologic QDR-2000 dual energy X-ray absorptiometry (DEXA). The results showed that in female groups the peak value of L1-L4 BMD was 1.023 g/cm2 at the age of 31–35, but in the male groups it was 0.971 g/cm2 aged 26–30 and the peak period lasted till the group aged 46–50. The similar conclusion has also obtained by further statistics.
The title compound 3,3-dinitroazetidinium (DNAZ) 3,5-dinitrosalicylate (3,5-DNSA) was prepared and the crystal structure has
been determined by a four-circle X-ray diffractometer. The thermal behavior of the title compound was studied under a non-isothermal
condition by DSC and TG/DTG techniques. The kinetic parameters were obtained from analysis of the TG curves by Kissinger method,
Ozawa method, the differential method and the integral method. The kinetic model function in differential form and the value
of Ea and A of the decomposition reaction of the title compound are f(α)=4α3/4, 130.83 kJ mol−1 and 1013.80s−1, respectively. The critical temperature of thermal explosion of the title compound is 147.55 °C. The values of ΔS≠, ΔH≠ and ΔG≠ of this reaction are −1.35 J mol−1 K−1, 122.42 and 122.97 kJ mol−1, respectively. The specific heat capacity of the title compound was determined with a continuous Cp mode of mircocalorimeter. Using the relationship between Cp and T and the thermal decomposition parameters, the time of the thermal decomposition from initiation to thermal explosion (adiabatic
time-to-explosion) was obtained.
Authors:Lin Sun, Xiangsheng Wang, Jichun Li, An Ma, and Hongchen Guo
Four series of nano-sized HZSM-5 zeolite catalysts were prepared with different steaming and HNO3 leaching processes. These samples were studied by XRD, NH3-TPD, FT-IR, n-hexane and cyclohexane adsorption, and fixed-bed aromatization of C4 liquefied petroleum gas (C4 LPG). Results show that, with the steaming temperature increasing, the acidity of catalyst decreased gradually, which was attributed to the removal of Al species from the framework of the zeolite. When steaming is combined with acid leaching, we found that acid leaching-steam catalysts exhibit stronger acidity than steam-acid leaching catalysts. Besides, acid leaching also played an important role in enhancing the diffusibility of catalysts. Catalysts which underwent acid leaching twice exhibit the best microporous diffusibility. Through correlating the acidity and diffusibility of the catalysts with their aromatization performance, it is found that the product distribution of aromatization is mainly determined by catalyst acidity rather than diffusibility. On the other hand, the average coking speed of the catalysts is not only influenced by the acidity of the catalyst, but also by its microporous diffusibility. The improvement of microporous diffusibility remarkably favors suppressing the coking deactivation of nano-sized ZSM-5 zeolite in C4 LPG aromatization.
Authors:Xinfang Mao, Zhongyuan Liu, Honglei Li, Ji Ma, and Fuchun Zhang
Many ectotherms organisms produce antifreeze proteins (AFPs), also known as thermal hysteresis proteins (THPs), which can lower the freezing temperature of body liquids without significantly affecting the melting point. In this article, thermal hysteresis activity (THA) of ApAFP752 from the desert beetle Anatolica polita was measured with differential scanning calorimetry (DSC). When the ice fraction was less than 25.3%, a delay in the onset temperature of refreezing was observed, indicating that the ApAFP752 solution has thermal hysteresis effect. When the amount of ice in the solution was less than 5.1%, THA of the ApAFP752 reached as high as 0.76 °C. THA of ApAFP752 was concentration-dependent. Hydrophilic ability of ApAFP752 was evaluated by thermal gravimetry (TG). The results of TG showed that ApAFP752 has strong hydrophilicity. The secondary structure of ApAFP752 was studied with circular dichroism (CD). The CD spectrum from 190 to 240 nm indicated a well-defined secondary structure consisting of 11.1% α-helix, 53.6% β-sheet, 8.3% turn, and 27.0% random coil.
Authors:Ruimin Ma, Qiangbin Dai, Chaoqun Ni, and Xuelu Li
Author co-citation analysis (ACA) is an important method for discovering the intellectual structure of a given scientific
field. Since traditional ACA was confined to ISI Web of Knowledge (WoK), the co-citation counts of pairs of authors mainly
depended on the data indexed in WoK. Fortunately, Google Scholar has integrated different academic databases from different
publishers, providing an opportunity of conducting ACA in wider a range. In this paper, we conduct ACA of information science
in China with the Chinese Google Scholar. Firstly, a brief introduction of Chinese Google Scholar is made, including retrieval
principles and data formats. Secondly, the methods used in our paper are given. Thirdly, 31 most important authors of information
science in China are selected as research objects. In the part of empirical study, factor analysis is used to find the main
research directions of information science in China. Pajek, a powerful tool in social network analysis, is employed to visualize
the author co-citation matrix as well. Finally, the resemblances and the differences between China and other countries in
information science are pointed out.
Authors:Tingting Zhang, Wanting Yin, Bo Jin, Tong Li, and Chen Ma
A sensitive, stability-indicating reversed-phase high-performance liquid chromatography with diode array detection (HPLC–DAD) method has been developed for the determination of TBI-166 and its 10 kinds of related impurities. Chromatographic separation was achieved on a Kromasil ODS column (250 mm × 4.6 mm, 5 μm), with a gradient elution of the mobile phase system consisting of acetonitrile and 1% ammonium formate solution (with 0.2% formic acid). The flow rate was 1.0 mL/min, and the detection wavelength was set at 251 nm. The method was validated according to the International Conference on Harmonization (ICH) guidelines with respect to selectivity, linearity, limits, accuracy, precision, and robustness. The calibration curves were linear from LOQ to 150% of the specification limit of impurity with correlation coefficients not less than 0.999. The limits of quantitation were between 0.123 and 0.257 μg/mL. Accuracy for the related substances was estimated by the recovery ranged from 94.6% to 111.2%. The method was proved to be reliable for the determination of related substances in TBI-166 bulk drug, which is essential and important in the quality control.