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- Author or Editor: Li'an Wang x
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Abstract
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.
Abstract
Backgrounds and aims
Family dysfunction is a significant risk factor for adolescent problematic gaming, yet few studies have investigated the bidirectional relations between changes in family dysfunction and adolescent problematic gaming and potential mediating mechanisms. This study thus examined the bidirectional relations between family dysfunction and adolescent problematic gaming and the mediating role of self-concept clarity within this relation.
Methods
Participants included 4,731 Chinese early adolescents (44.9% girls; M age = 10.91 years, SD = 0.72) who were surveyed at four time points 6 months apart.
Results
Random intercept cross-lagged panel modeling found (a) family dysfunction directly predicts increased problematic gaming, (b) adolescent problematic gaming directly predicts increased experience of family dysfunction, (c) family dysfunction indirectly predicts problematic gaming via self-concept clarity, and (d) adolescent problematic gaming indirectly predicts family dysfunction via self-concept clarity.
Discussion and conclusions
The present study suggests that adolescents may be trapped in a vicious cycle between family dysfunction and problematic gaming either directly or indirectly through impairing their self-concept clarity. Findings indicate fostering youth self-concept clarity is essential to break the vicious circle between dysfunctional experiences in the family and problematic gaming among adolescents.
To investigate porcine circovirus type 2b (PCV2b) transmission by contact and vertical infection in Kunming mice (an outbred mouse stock deriving from Swiss albino mice with a high ratio of gene heterozygosis), four mice in cage 6 were inoculated with PCV2b and 25 mice without any treatment were placed into cages 1 to 5 (five mice in each cage). Seven days after being infected, the PCV2-binoculated mice were co-mingled with non-inoculated mice from cages 1 to 5 successively at 7, 14, 21, 28 and 35 days post infection (dpi), respectively, for 3 days. In addition, eleven pregnant mice were injected with PCV2b. Samples were collected from non-inoculated mice and three newborn mice from each litter for PCV2b detection by polymerase chain reaction (PCR) and immunohistochemistry (IHC). The PCR results showed that PCV2b transmission rate among mice in cages 1, 2, 3, 4 and 5 was 0/5, 2/5, 5/5, 5/5 and 1/5, respectively. PCV2b antigen signals generally appeared in most organs of the non-inoculated mice in which viruses were detected by PCR. PCV2b DNA was also detected in newborn mice of PCV2b-infected litters, and viral antigen signals were observed in their organs as well. PCV2b was transmitted in Kunming mice by contact, and it also caused vertical infection through the placenta.
Molecular markers are important tools that have been used to identify the short arm of rye chromosome 1R (1RS) which contains many useful genes introgressed into wheat background. Wheat expressed sequence tag (EST) sequences are valuable for developing molecular markers since ESTs are derived from gene transcripts and more likely to be conserved between wheat and its relative species. In the present study, 35 sequence-tagged site (STS) primers were designed based on EST sequences distributed on homology group 1 chromosomes of Triticum aestivum and used to screen specific markers for chromosome 1RS of Secale cereale . Two primer pairs different from the early studies, STS WE3 , which amplified a 1680-bp and a 1750-bp fragment, and STS WE126 , which produced a 850-bp fragment from rye genome, were proved to be specific to chromosome 1RS since the corresponding fragments were only amplified from 1R chromosome addition line and wheat-rye lines with chromosome 1RS, but not from wheat-rye 2R-7R chromosome addition lines and the other lines lacking chromosome 1RS. Eleven wheat-rye lines derived from ‘Xiaoyan 6’ and ‘German White’ were used to test the presence of specific markers for 1RS. The specific fragments of 1RS were amplified in 4 wheat-rye lines, but not in the other lines. The testing results using EST-STS markers of 1RS were consistent with those obtained from fluorescence in situ hybridization (FISH), suggesting that these markers specific to 1RS could be used in marker-assisted selection (MAS) for incorporating 1RS into wheat cultivars in breeding.
Two new y-type HMW-GSs in Ae. tauschii , 1Dy12.1* t and 1Dy12.2 t with the mobility order of 1Dy12.2 t > 1Dy12.1* t > 1Dy12.1 t >1Dy12, were identified by both SDS-PAGE and MALDI-TOF-MS. Molecular cloning and sequencing showed that the genes encoding subunits 1Dy12.1* t and 1Dy12.2 t had identical nucleotide acid sequences with 1,947 bp encoding a mature protein of 627 residues. Their deduced molecular weights were 67,347.6 Da, satisfactorily corresponding to that of 1Dy12.2 t subunit determined by MALDI-TOF-MS (67,015.7 Da), but was significantly smaller than that of the the 1Dy12.1* t subunit (68,577.1 Da). Both subunits showed high similarities to 1Dy10, suggesting that they could have a positive effect on bread-making quality. Interestingly, the expressed protein of the cloned ORF from accessions TD87 and TD130 in E. coli co-migrated with subunit 1Dy12.2 t , but moved slightly faster than 1Dy12.1* t on SDS-PAGE. The expressed protein in transgenic tobacco seeds, however, had the same mobility as the 1Dy12.1* t subunit, as confirmed by both SDS-PAGE and Western blotting. Although direct evidence of phosphoprotein could not be obtained by specific staining method, certain types of post-translational modifications (PTMs) of the 1Dy12.1* t subunit could not be excluded. We believe PTMs might be responsible for the molecular weight difference between the subunits 1Dy12.1* t and 1Dy12.2 t .
Abstract
The fractional cumulative yields (FCY) of133mTe and133gTe in the spontaneous fission of252Cf were measured for the first time by a radiochemical method. The values ofFCY are 0.533±0.014 and 0.291±0.042 for133mTe and133gTe, respectively. The isomeric state to ground state fractional independent yield (FIY) ratio of133Te,R, was found to be 3.5. The root-mean-square angular momentum of the primary fragment corresponding to the fission product133Te, Jr.m.s.=8.8h, was estimated according to a simple one-parameter statistical model. The fractional cumulative yields from this work together with other literature data in the mass region A=131–141 are compared with the 
normal
yields given by the empiricalZ
p model by Whhl. It suggests that both theN=82 neutrons shell and nucleus pairing effects are not apparent for the spontaneous fission of252Cf.
