Objective: The strong electric field radiation under atmospheric pressure to the rice 6 the influence of DNA methyla-tion.Methods: Under atmospheric pressure at the same time,based on the different strength(and in the same strength,in different time) radiation Guodao 6 seed,the application of DNA methylation sensitive amplification polymorphism(methylation sensitive amplification polymorphism,MSAP) technology,the research in different radiation condition,the rice genome DNA methylation level and difference.Results: All the strong electric field radiation treatment group methylation level than the control group did not radiation reduced,and ra-diation time and strength about.All cell DNA methylation,half methylation amplification sites accounted for the proportion of amplifica-tion sites for: 12.89% ~ 13.62%,3.36% ~ 4.63%,with the increase of radiation intensity and time reduced.Conclusions: The strong elec-tric field radiation kingdom rice 6 rice genome DNA methylation is parent changed obviously variation that strong electric field can cause apparent genetic variation,and the rules for the research laid the foundation for discussion,and rice methylation on rice growth control molecular mechanism provides the help.

Large flow relief valve is an important part of hydraulic support,which can protect hydraulic support from high pressure damage.To obtain dynamic characteristics of relief valve,a test system of high pressure and large relief valve using a accumulator as a power source is proposed,its operating principle and measurement and control system are also described.Experiment result indicates that accumulator taking replace of large flow hydraulic pump can realize fast loading,and provide step input with large flow for relief valve,and test system satisfies test requirement of dynamic characteristics of large flow relief valve.

Clay is an excellent material in reducing radon emissions and health risks from uranium tailings.The compactness and moisture content of clay covered on uranium tailings can be altered on site.The effectiveness of earthen thickness for Radon attenuation depends on the compactness and moisture content of clay.When the moisture content of clay is greater than the "classic moisture content",the moisture content will decrease instead with the increase of compactness.The relations between radon attenuation efficiency,compactness,moisture content and thickness of clay are nonlinear.By analyzing these relations,geotechnical parameters are optimized to achieve an optimal effect on clay covering.

In this paper,different from the traditional structure of the Fresnel phase correction plate,a new focus antenna with dual focus structure used for the millimeter-wave imaging is presented.The new type of FZP antenna,in comparison with ellipsoidal reflector antenna,take the advantages of design simplicity,as well as focusing performance is superior.

In order to improve cartridge valve response speed,Working principle of cartridge valve is introduced,and the model of cartridge valve is simulated by AMESim software,drawing conclusions to improve cartridge valve response speed.The results show that stroke of main cartridge valve and the damping between main cartridge calve and pilot-operated valve effect hard to dynamic properties of cartridge valve;and closure time of main cartridge valve has been shorten from 0.341 s to 0.087 s,the effect of optimization is evidential,and have some guidance to improve response speed of cartridge valve.

Dynamic characteristics are important performance indexes of the large flux relief valve in the hydraulic support. After introducing the dynamic characteristics and demands of the relief valve,the working principle of a quickly loading testing system applying accumulators as power source for large flux relief valve was described. In addition,the simulation and analysis on the model of the testing system were carried out by AMESim software,which provides theoretical references for the design and optimization of the system of testing for the large flux relief valve.

The construction steps of using soils to cover decommissioning uranium tailings and the method of controlling compactness are introduced.The relation of compactness of soils and radon mi-tigation efficiency is analyzed theoretically.The calculated value is verified by the value measured in the field.

Wireless channel modeling and simulation have always been difficulties in the design on mobile communication systems.Base on the physical mechanism of wave propagation,this paper proposes a channel models based on cluster of illumination-multi-path component cluster.The simulation and analysis the identity of this model are also made.

Now the water hydraulic drive technology using water as the hydraulic medium receives more and more attentions.Water hydraulic motors,the executing components of the hydraulic system,receive increasing attention.The current situation of research and development for the water hydraulic motor both at home and abroad was analyzed.Several kinds of typical water hydraulic motors using tap water or sea water as the working media were introduced.The key works to be done in the research of water hydraulic motor were analyzed which were distribution mode,sealing and leakage,wearing,corroding and cavitation.

动态性能是煤矿液压支架用大流量安全阀的重要性能指标.该文阐述了现有的几种大流量安全阀的试验方法的原理及其特点,如落锤冲击系统、大流量泵供液系统、爆破冲击加载系统、伺服液压冲击系统和快速加载系统.通过对比分析,指出蓄能器为动力源的快速加载系统成本低、体积小、耗能少,是一种值得研究推广的试验方法.