A Study of Chinese Second-year English Majors’ Code Switching Phenomenon in Comprehensive English Course from the Perspective of Interlanguage

The paper analyzes functions and influencing factors of second-year English majors’ code switching in Comprehensive English Course on the basis of the interlanguage theory and other SLA (second language acquisition) models, i.e. Krashen’s Comprehensible Input Hypothesis and Affective Filter Hypothesis, Long’s Interaction Hypothesis and Swain’s Comprehensible Output Hypothesis

Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes

BACKGROUND: Transposons, i.e. transposable elements (TEs), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. To address the general issue of whether transposons mediate genomic changes in environment-adaptation genes, we scanned two alleles per each of the six xenobiotic-metabolizing Helicoverpa zea cytochrome P450 loci, including CYP6B8, CYP6B27, CYP321A1, CYP321A2, CYP9A12v3 and CYP9A14, for the presence of transposon insertions by genome walking and sequence analysis. We also scanned thirteen Drosophila melanogaster P450s genes for TE insertions by in silico mapping and literature search. RESULTS: Twelve novel transposons, including LINEs (long interspersed nuclear elements), SINEs (short interspersed nuclear elements), MITEs (miniature inverted-repeat transposable elements), one full-length transib-like transposon, and one full-length Tcl-like DNA transpson, are identified from the alleles of the six H. zea P450 genes. The twelve transposons are inserted into the 5'flanking region, 3'flanking region, exon, or intron of the six environment-adaptation P450 genes. In D. melanogaster, seven out of the eight Drosophila P450s (CYP4E2, CYP6A2, CYP6A8, CYP6A9, CYP6G1, CYP6W1, CYP12A4, CYP12D1) implicated in insecticide resistance are associated with a variety of transposons. By contrast, all the five Drosophila P450s (CYP302A1, CYP306A1, CYP307A1, CYP314A1 and CYP315A1) involved in ecdysone biosynthesis and developmental regulation are free of TE insertions. CONCLUSION: These results indicate that TEs are selectively retained within or in close proximity to xenobiotic-metabolizing P450 genes

Ultrasonic-Assisted Dyeing of Poplar Veneer

This study introduces poplar veneer ultrasonic-assisted dyeing. Response-surface methodology was adopted to perform optimum analysis of effects of ultrasonic dyeing on poplar veneer. Results demonstrated that ultrasound increased dye uptake under optimal conditions (210-W ultrasonic power, 57-min assisted dyeing time, and 30-kHz ultrasonic frequency using a dye concentration with mass fraction of 0.52% at 72°C). Under these optimal conditions, dye uptake can reach 42.4%. Compared with nonultrasonic dyeing technologies, ultrasonic dyeing technology for poplar veneer developed in this study increased dye uptake 11.2%

Acidity and catalytic activity of zeolite catalysts bound with silica and alumina

Zeolites ZSM-5 (SiO2/Al2O3=30~280) and Y(SiO2/Al2O3=5.2~80) are bound with silica gel (Ludox HS-40 and Ludox AS-40) and alumina (γ- Al2O3 and boehmite) by different binding methods, namely, gel-mixing, powder-mixing and powder-wet-mixing methods. The acidities of the bound catalysts and the zeolite powder are determined by NH3-TPD and FTIR. The textures of these catalysts are analyzed on a BET machine with nitrogen as a probe molecule. The micropore surface area and micropore volume are determined by t-plot method. Micropore volume distribution is determined by Horvath-Kawazoe approach with a cylindrical pore model. Mesopore volume distribution is determined by BJH method from the nitrogen desorption isotherm. Silica from the binder may react with extra-framework alumina in zeolites to form a new protonic acid. SiO2-bound catalysts have less strong acidity, Bronsted acidity and Lewis acidity than the zeolite powder. Also, the strength of strong acid sites of the zeolites is reduced when silica is embedded. Micropore surface area and micropore volume are reduced by about 19% and 18%, respectively, indicating some micropores of ZSM-5 are blocked on binding with silica. SiO2-bound ZSM-5 catalysts have less catalytic activity for butane transformation (cracking and disproportionation) and ethylene oligomerization than ZSM-5 powder. When alumina is used as a binder, both the total acid sites and Lewis acid sites are increased. Micropore surface area and micropore volume of ZSM-5 powder are reduced by 26% and 23%, respectively, indicating some micropores of ZSM-5 are blocked by the alumina binder. Alumina-bound catalysts showed a lower activity for butane transformation and ethylene oligomerization than ZSM-5 powder. Alkaline metals content in the binder is a crucial factor that influences the acidity of a bound catalyst. The metal cations neutralize more selectively Bronsted acid sites than Lewis acid sites. Alkaline metal cations in the binder and micropore blockage cause the bound catalysts to have a lower catalytic activity than the zeolite powder

Cd2+-induced Conformational Change Of A Synthetic Metallopeptide: Slow Metal Binding Followed By A Slower Conformational Change

A two-stranded a-helical coiled coil was prepared having a Cys(4) metal-binding site within its hydrophobic interior. The addition of Cd2+ results in the incorporation of 2 equiv of metal ion, which is accompanied by a conformational change of the peptide, as observed by circular dichroism (CID) spectroscopy. Isothermal titration calorimetry (ITC) shows that the addition of Cd2+ is accompanied by two thermodynamic events. A comparison of the time dependence of the ITC behavior with those of the UV absorption and CID behavior allows the assignment of these events to a preliminary endothermic metal-binding step followed by a slower exothermic conformational change

Study on China's Regional Carbon Emission Factors: The case of Chongqing City

AbstractLow-carbon development has become a hot issue concerned by the whole world. Governments respectively introduced the country's low-carbon strategy and action. China has put forward a series of obligatory targets and has issued a provincial area “twelfth five-year” carbon intensity reduction target. How to coordinate the contradiction between economic growth and environmental constraints, and formulating corresponding low-carbon development path and the supporting measures, has become one of the problems to be solved. Considering the regional resource endowment, stage of economic development, energy structure, industrial structure, technical development level and other factors, this article constructs the model of regional carbon emission factors, the paper takes Chongqing of China as an example. The research results show that: The major contribution of elements, in turn, is the improvement of technology energy efficiency, the optimization of energy structure, and the adjustment of industrial structure. Based on this, this paper puts forward the corresponding low-carbon development policies according to the results of analysis, from the aspects such as energy structure, industrial structure, and technological progress and so on

CO2 Emission Reduction Potential in China's Electricity Sector: Scenario Analysis Based on LMDI Decomposition

AbstractThe CO2 emission reduction from China's electricity sector will matter not only for China but impact the result of the global action on climate change. This paper firstly analyzed the main factors that affect the CO2 emission in accordance with the LMDI decomposition model. Then three scenarios were assumed based on the main factors to explore the CO2 reduction potential. Furthermore, LMDI method was used again to measure the contribution of each factor to CO2 emission reduction potential in the future. The results showed that the CO2 emission will continue to grow in the three scenarios from 2010 to 2020, with an annual growth rate of 10.7%, 6.5% and 4.5%, respectively. The active low carbon policies taken on the driving factors will contribute to 2701Mt - 3688Mt CO2 emission reduction. The share of low-carbon power generation and thermal power generation efficiency are most important factors for emission reduction. However, in the long run, low-carbon power generation will contribute more. Terminal electricity consumption is always the most important factor driving CO2 emission up. Finally, policies for low-carbon development of China's electricity sector are proposed based on the analysis results

Effects of mycorrhizal fungi on plant growth, nutrient absorption and phytohormones levels in tea under shading condition

High temperature and strong light could induce bitterness and astringency of tea (Camellia sinensis (L.) O. Kuntze) in summer. Arbuscular mycorrhizal (AM) fungus and shading could change tea growth surroundings and improve its quality. The present study evaluated the inoculated effects of an arbuscular mycorrhizal fungus (AMF), Glomus etunicatum, on plant growth, root morphology, leaf nutrient status, phytohormones and the relative expression of root CsCPC, CsTTG1, CsAUX1, CsYUCCA1, CsNCED2, CsGA3OX1, CsDWF4 and CsAOS genes in Camellia sinensis  ‘Xinyang population’ seedlings in sands under shading conditions. After 14 weeks of AMF inoculation, root mycorrhizal colonization ranged from 18.5% to 48.00%. AMF inoculation and shading heavily increased plant height, shoot and root biomass, total root length and volume, leaf nutrients content (except Fe), respectively. Both mycorrhizal inoculation and shading significantly increased root hair growth respectively, in company with up-regulation gene CsCPC and down-regulation gene CsTTG1. Root auxin level and its transport gene CsAUX1 was both up-regulated by mycorrhizal inoculation and shading. Interestingly, auxin biosynthesis gene CsYUCCA1 has not been affected, which suggested that both mycorrhizal and shading mainly regulate auxin transport but not biosynthesis pathway. The contents of gibberellin (GA) and brassinosteroid (BR) in root were notably increased by mycorrhizal inoculation and shading, accompanied with up-regulation of its biosynthesis genes, CsGA3OX1 and CsDWF4. With regard to the growth inhibiting phytohormones abscisic acid (ABA) and jasmonic acid (JA), mycorrhizal inoculation and shading significantly decreased their levels in root, in company with down-regulation of biosynthesis genes, CsNCED2 and CsAOS. These results implied that both AMF inoculation and shading could enhance the tea plant stress resistance and increase nutrient absorption, root biomass and the contents of root phytohormones by up-regulating its transport and biosynthesis pathway