The present study examined the effects of hypergravity exposure on the developing brain and specifically explored the possibility that these effects are mediated by altered thyroid status. Thirty-four timed-pregnant Sprague-Dawley rats were exposed to continuous centrifugation at 1.5 G (HG) from gestational Day 11 until one of three key developmental points: postnatal Day (P) 6, P15, or P21 (10 pups/dam: 5 males/5 females). During the 32-day centrifugation, stationary controls (SC, n = 25 dams) were housed In the same room as HG animals. Neonatal body, forebrain, and cerebellum mass and neonatal and maternal thyroid status were assessed at each time point. The body mass of centrifuged neonates was comparatively lower at each time point. The mass of the forebrain and the mass of the cerebellum were maximally reduced In hypergravlty-exposed neonates at P6 by 15.9% and 25.6%, respectively. Analysis of neonatal plasma suggested a transient hypothyroid status, as indicated by Increased thyroid stimulating hormone (TSH) level (38.6%)at P6, while maternal plasma TSH levels were maximally elevated at P15 (38.9%). Neither neonatal nor maternal plasma TH levels were altered, suggesting a moderate hypothyroid condition. Thus, continuous exposure of the developing rats to hypergrav-Ity during the embryonic and neonatal periods has a highly significant effect on the developing forebrain and cerebellum and neonatal thyroid status (P < 0.05, Sonferronl corrected). These data are consistent with the hypothesized role of the thyroid hormone In mediating the effect of hypergravity In the developing central nervous system and begin to define the role

Each transport mode owns itself technical economy. On the basis of multiple transport mode selection, the paper presents the route optimization model for single-task from one origination to one destination in the fourth party logistics, and gives the solution of Genetic Algorithms. In the algorithms, a length-variant encoding scheme of round number is adopted to represent the selected route, and idea that keeps the best individual is used. The results of experiments show that Genetic Algorithms can solve the route optimization problem based on the selection of multiple transport modes in the fourth party logistics conveniently and effectively.

With the rapid economic and social development of China, the attention to environment issue is higher and higher. Current, toxic and hazardous substances polycyclic aromatic hydrocarbons (PAHs) has been detected in the air, water, sediments of the river (or lake) and soil. Part of these PAHs come from (1) volatile of PAHs in solids phase or liquids phase in raw coal ,(2) raw coal incomplete combustion (3) PAHs hydrolyze in a reducing atmosphere. As the basis of PAHs discharging in the process of coal using, it is necessary to summary extraction, purification, analysis of the PAHs in raw coal, conclude species and content of PAHs in raw coal, analysis the impact factors of PAHs distribution, discovered the deficiencies in current research and the future research direction.

A key issue in the wave equation simulation of seismic records is the boundary conditions. Due to computer memory and computation and other restrictions, can only be solved on a limited area, which will cause the introduction of an artificial reflector. So as to simulation of seismic wave propagation in an infinite medium, the boundary conditions must be constructed so that the interface of the reflection as little as possible. In 2.5D VTI media feature analysis absorbing boundary of higher order velocity-stress staggered-grid finite difference method are established. The mixed boundary of the feature analysis absorbing boundary plus damping attenuation condition is used in 2.5 D VTI numerical simulations, simulation results show that this method is an efficient absorption and attenuation boundary conditions.

The earth filtering is inevitably in seismic wave propagation and the parameters to represent earth filter intensity is the absorption coefficient and the Q value. Using zero-offset vsp's down-going direct wave to estimated Q value is considered the most reliable way to extract stratigraphic quality factor Q value. We used Ken 71 well zero-offset VSP down-going direct wave with the centroid frequency shift method to estimate layer Q value. First, by processing the zero-offset VSP data, we separated down-going-direct wave and up-going wave. Then, we analysis and calculated the layer-velocity and layer Q value using down-going wave. At last, we made the bridge comparison chart by the up-going-wave processed. The bridge comparison chart compared with the layer-velocity and layer-Q value, results show that the corresponding relations are very good.