Serials of halloysite nanotubes/polystyrene (HNTs/PS) nanocomposites with different contents of organo-modified halloysite
nanotubes (organo-HNTs) were successfully prepared by the in situ bulk polymerization of styrene with the organo-HNTs as macromonomers.
The percentage of grafting (PG%) of more than 230% was achieved, calculated from the results of the thermogravimetric analysis
(TG). The TG results also showed that the thermal stabilities of the HNTs/PS nanocomposites prepared via the bulk polymerization
were better than the pure polystyrene. And the maximum thermal degradation temperature of the nanocomposites increased with
the increasing of the amount of the HNTs fillers added.
The effect of short-term higher ambient temperature (HT) and continuous vibration (CV) treatment was comparatively characterized by sensory evaluation and chemical analysis. Results of quantitative descriptive analysis of modified frequency (MF) showed that HT causes both in red wine and white wine a decrease of fruity and floral characters, an unbalance of taste, and a shortness of aftertaste length. CV wine showed very close sensory characters to control in most terms evaluated. Seventy-four volatile compounds were quantitative analysed by solid phase microextractiongas chromatography-mass spectrometry, and the principal component analysis (PCA) was conducted on the 23 volatiles of highest odour activity value (OAV). The concentrations of potential fruity and floral aroma attributors like isoamyl acetate, ethyl butanoate, ethyl 2-methylbutanoate, ethyl hexanoate, ethyl octanoate, β-damascenone, and linalool were lower in HT wine than that in original wine and CV wine.
Authors:P. Zhao, Q. Hu, T. Rose, G. Nimz, and M. Zavarin
99Tc and 129I are important contributors to risk assessment due to their long half-lives and high mobility as aqueous anionic species.
We analyzed 99Tc and 129I in groundwater samples in and near 11 underground nuclear tests and in melt glass and rock samples retrieved from the Chancellor
test cavity, Nevada Test Site. The 129I/127I ratio ranges from 10−3 to 10−6 in cavity water and 10−4 to 10−9 in satellite wells. The 99Tc concentration ranges from 3 to 10−4 Bq/l in cavity waters and from 0.3 to 10−4 Bq/l in satellite wells. Downstream migration is apparent for both radionuclides. However, it is affected by both retardation
and initial distribution. In-situ 99Tc and 129I Kds calculated using rubble and water concentrations are 3 to 22 ml/g and 0 to 0.12 ml/g, respectively, and are suggestive of
mildly reducing conditions. 129I distribution in the melt glass, rubble and groundwater of the Chancellor test cavity is 28%, 24% and 48%, respectively,
for 99Tc, it is 65%, 35% and 0.3%, respectively. Our partitioning estimates differ from those of underground tests in French Polynesia,
implying that fission product distribution may vary from test to test. Factors that may influence this distribution include
geologic conditions (e.g., lithology, water and CO2 content) and the cooling history of the test cavity.
Authors:S. Song, Y. Tao, L. Zhao, P. Liu, and Y. Wu
Barley yellow dwarf virus-GAV (BYDV-GAV) is one of the most serious viruses on wheat in China. In this study, five BYDV-GAV isolates collected from five regions in Northwestern China were sequenced. The complete genome sequences generated in this study along with nine genome sequences of BYDV-GAV isolates available in GeneBank were compared and analyzed. The comparative analysis indicated that the complete genomes of BYDV-GAV showed a low level of genetic diversity with nucleotide sequence identities ranging between 97.0% and 99.7%, and the RNA-dependent RNA polymerase gene (ORF1 + ORF2) was the most variable within the complete genome. Phylogenetic analysis indicated that the BYDV-GAV isolates in Northwestern China could be divided into two groups. In addition, two potential recombination events were detected among the 14 BYDV-GAV isolates. This study provided a detailed description of molecular characterization of BYDV-GAV in Northwestern China based on the complete genome sequences, which increased the understanding of genetic diversity of barley yellow dwarf viruses.
In the present paper, various formulae for evaluating critical buckling strain of bending pipeline are analyzed on basis of its actual nature, available test data or finite element calculation results. The available test data is from different resources, it provides a more objective comparison; Especially, the experimental bending buckling data of Corona et al. and Kyriakides et al. for Al-6061-T6 aluminum pipes with various D/t value, as well as the prediction of Minnaar’s FEM regressive formula for high grade steel pipe are reanalyzed to check the reasonability of the plastically elliptical cross-section model. It shows that the consequence of the plastically elliptical cross-section model is more reasonable than others for the critical buckling strain prediction of a pipe bending in most cases.
Authors:Hou-yin Zhao, Yan Cao, Song P. Sit, Quentin Lineberry, and Wei-ping Pan
The pyrolysis behavior of bitumen was investigated using a thermogravimetric analyzer–mass spectrometer system (TG–MS) and a differential scanning calorimeter (DSC) as well as a pyrolysis-gas chromatograph/mass spectrometer system (Py-GC/MS). TG results showed that there were three stages of weight loss during pyrolysis—less than 110, 110–380, and 380–600 °C. Using distributed activation energy model, the average activation energy of the thermal decomposition of bitumen was calculated at 79 kJ mol−1. The evolved gas from the pyrolysis showed that organic species, such as alkane and alkene fragments had a peak maximum temperature of 130 and 480 °C, respectively. Benzene, toluene, and styrene released at 100 and 420 °C. Most of the inorganic compounds, such as H2, H2S, COS, and SO2, released at about 380 °C while the CO2 had the maximum temperature peaks at 400 and 540 °C, respectively. FTIR spectra were taken of the residues of the different stages, and the results showed that the C–H bond intensity decreased dramatically at 380 °C. Py-GC/MS confirmed the composition of the evolved gas. The DSC revealed the endothermic nature of the bitumen pyrolysis.
Authors:H. W. Zhao, Y. L. Geng, H. Zhu, P. Yang, and J. Q. Yu
Seven compounds, including two flavanones, dihydrokaempferol (1) and naringenin (2), and five terpenoids, boscartol A (3), 3,7-dioxo-tirucalla-8,24-dien-21-oic acid (4), 3α-acetoxyl-7-oxo-tirucalla-8,24-dien-21-oic acid (5), 11-keto-β-boswellic acid (6), and acetyl-11-keto-boswellic acid (7), have been purified by high-speed counter-current chromatography (HSCCC) from olibanum. For the separation, from 250 mg of the crude extract, 3.1 mg of 1 (95.2% purity), 2.7 mg of 2 (96.1% purity), 9.1 mg of 3 (96.7% purity), 4.5 mg of 4 (95.3% purity), 5.4 mg of 5 (96.3% purity), 48.1 mg of 6 (96.8% purity), and 45.5 mg of 7 (98.1% purity) were obtained by HSCCC with petroleum ether–ethyl acetate–methanol–water (1:0.8:1.1:0.6, v/v). The structures of these seven compounds were elucidated by a combination of electrospray ionization mass spectrometry (ESI–MS) and extensive nuclear magnetic resonance (NMR) spectroscopic.
Authors:Sh. Luo, M. Pu, J. Quao, Zh. Liu, Ch. Zhang, P. Zhao, Y. Fu, and H. Deng
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 11, and the charge of153Sm-EDTMP is negative two.
Authors:W. J. Duan, Q. Liu, R. X. Zhao, Y. Mu, L. P. Guo, D. P. Li, and X. Wang
A method was developed for the preparative separation of two alkaloids from the crude extract of the radix of Rauvolfia verticillata (Lour.) Baill. in a single run. The two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (5:5:2:8, v/v), where triethylamine (40 mmol/L) was added to the upper organic phase as the stationary phase and hydrochloric acid (10 mmol/L) was added to the lower aqueous phase as the mobile phase, was selected for this separation by pH-zone-refining counter-current chromatography (PZRCCC). For the preparative separation, the apparatus was rotated at a speed 850 rpm, while the mobile phase was pumped into the column at 2 mL/min. As a result, 112 mg of reserpine and 21 mg of yohimbine were obtained from 3 g of crude extract in a single run. The analysis of the isolated compounds was determined by high-performance liquid chromatography (HPLC) at 230 nm with purities of over 91.0%, and the chemical identification was carried out by the data of electrospray ionization–mass spectrometry (ESI–MS) and nuclear magnetic resonance (NMR) spectroscopy. The technique introduced in this paper is an efficient method for preparative separation of reserpine and yohimbine from devil pepper radix. It will be beneficial to utilize medicinal materials and also useful for the separation, purification, and pharmacological study of Chinese herbal ingredients.
Authors:J. L. Zhao, L. Zou, L. Y. Zhong, L. X. Peng, P. L. Ying, M. L. Tan, and G. Zhao
This study was to examine the effects of four fungal polysaccharides, namely exo-polysaccharide (EPS), water-extracted mycelia polysaccharide (WPS), sodium hydroxideextracted mycelia polysaccharide (SPS), and hydrochloric-extracted mycelia polysaccharide (APS) obtained from the endophytic fungus Bionectra pityrodes Fat6, on the sprout growth and flavonoids production of Fagopyrum tataricum. Without obvious changes in the appearance of the sprouts, the exogenous polysaccharide elicitors notably stimulated the sprout growth and functional metabolites accumulation, and the stimulation effect was mainly depended on the polysaccharide species along with its treatment dose. With application of 150 mg/l of EPS, 150 mg/l of WPS and 200 mg/l of SPS, the total rutin and quercetin yield of buckwheat sprouts was effectively increased to 49.18 mg/(100 sprouts), 50.54 mg/(100 sprouts), and 52.27 mg/(100 sprouts), respectively. That was about 1.57- to 1.66-fold in comparison with the control culture of 31.40 mg/(100 sprouts). Moreover, the present study revealed the accumulation of bioactive flavonoids resulted from the stimulation of the phenylpropanoid pathway by fungal polysaccharide treatments. It could be an efficient strategy for improving the nutritional and functional quality of tartary buckwheat sprouts applied with specific fungal elicitors.