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Structures with varying dampers have been widely designed and constructed for earthquake resistance. However, the residual seismic performance of these damped structures could not be guaranteed after being exposed to a fire because both the primary structure and dampers are vulnerable to high temperatures. The postfire residual seismic performance is an important design index for damped structures whereas no research has been done so far to determine such residual performance. Therefore, this study serves as the first attempt by exploiting the widely constructed RC frame structure with commonly investigated metallic yielding dampers (MYDs) as an example to investigate its residual seismic performance after being exposed to a fire. One story of a RC office building is employed as the single-degree-of-freedom (SDOF) analytical model, and then the mechanical and geometric parameters of MYDs are derived via the design method from the perspective of the uniform damping ratio. In addition, the gas temperature of the natural fire curves is determined according to current European standards, and 16 representative fire scenarios are selected. Moreover, the residual material properties and residual performance of the primary structure as well as MYD are investigated and expressed in mathematical forms. Thereon, the linear forms of the restoring forces of the primary structure and MYD are obtained by utilizing the equivalent linearization method, and the motion-governing and energy-conservation equations are established. Furthermore, the methodology for the parametric analysis is put forward, and the residual seismic performance of the fire-damaged damped structure is derived quantitatively, which is also verified via time-domain analysis with recorded ground motions. The results show that the seismic performance of the SDOF concrete structure with MYD can be reduced significantly by fire damage. [ABSTRACT FROM AUTHOR]

A field research was conducted in the Agricultural High-tech Demonstration Park in Horqin District of Tongliao, Inner Mongolia, using the maize variety Nonghua 101 with two cropping modes, including strip-till with staggered planting (seeding strip tillage, 15 cm + 45 cm narrow-double row staggered sowing, TGCW) and conventional tillage with equal row space (rotary tillage with row space of 60 cm, CK), and three planting densities (67,500 plants hm-2, 82,500 plants hm-2, and 97,500 plants hm-2) in 2017 and 2018 to study the effect of strip-till with staggered planting on regulating spring maize yield formation and coordination characteristics of shoot-root in irrigation areas of Xiliao river plain. The model of that strip-till with staggered planting enhanced maize yield by 13.1% and 13.8% in 2017 and 2018, under the planting density 82,500 plants hm-2 compared with CK, respectively. The strip-till with staggered planting showed a distinct advantage on the amount and rate of dry matter accumulation after silking, which obviously delayed the senility of leaves in later growth stage, meanwhile, compared with CK, the light transmittance significantly increased in or above panicle layers. The leaf area index, net photosynthetic rate and population photosynthetic potential in the model of strip-till with staggered planting were higher than those in CK in late growth stage. At later growing stage, the strip-till with staggered planting had significantly higher root dry weight than CK in different soil layers, with the highest root ratio in 20-60 cm, especially under higher planting density. The grain yield against per unit of root weight at silking and root-shoot ratio at maturity had a distinct advantage. In conclusion the strip-till with staggered planting combined with high planting density can increase light transmission rate in above-spike layer in late growing stage, alleviate leaf area decline, increase production capacity, facilitate root growth and increase root ratio in deeper soil layers. Shoot-root coordination under dense planting is one of the main reasons facilitating yield increase of spring maize in irrigation areas of Xiliao river plain. [ABSTRACT FROM AUTHOR]

A simulation model for maize spike differentiation and phenophase was established by analysis of temperatures and illumination treatments effects on maize growth and development process based on physiological development time constancy. Specific Bata function was applied in the model to calculate the daily thermal effect, and Gaussian function for photoperiodic effects. Temperature sensitivity, photoperiod sensitivity, intrinsic earliness and filling fractions which are genetic coefficients used to express genetic differences of maize development process. The model was tested at different growth stages and nitrogen factor was corrected by the actual nitrogen content, the critical nitrogen content and the lowest nitrogen content of plant. Results demonstrated that the absolute simulation error on growth stages (including emergence, jointing, silking, filling and maturity) and tassel and ear differentiation stages (including growing tip lengthening, spikelet differentiation, floret differentiation stage and sexual organ development) in different maize (Zea mays L.) cultivars was between 0-5 d, and the root mean square error was found less than 3.5 d. The proposed model demonstrated that the mechanism is rational and practical. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Horizontal gene transfer, unlike vertical gene transfer, is a means of genetic communication in bacteria. In the special polluted environment, horizontal transfer of polluted-degrading gene has significant functions. Study on horizontal transfer of degrading gene in polluted environment may deepen our understanding of the mechanism of bacterial adaptation to the organic-polluted environment. In the practical application in bioremediation, horizontal transfer of degrading gene can be regulated to promote degrading ability of microorganisms. In this article, we will review the advances in the study on mechanisms of genetic interactions among bacteria, the effect of degrading gene transfer in contaminated environment on microorganisms'adaptation to contaminated environment and the degradation of the pollutants.