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用有限拉莫尔半径(FLR)修正的相对论色散关系进行了数值模拟，研究了电子回旋波在高温、高密等离子体的功率沉积，并将计算结果与应用弱相对论Fokker-Planck方程得到的结果进行了比较。结果表明，在高温、高密等离子体中，波功率的吸收非常集中；平行折射率、极向发射位置和发射波频率的变化都会影响波功率沉积的大小和分布；平行折射率变大后，FLR效应会使波的阻尼减少。     

Catalysis, by amorphous carbon, of H2 attack on oxidized U-0.1 wt% Cr surfaces

Amorphous carbon, evaporated on a thin oxide layer covered U-0.1 wt% Cr sample, was proven to significantly catalyze H₂ reaction with the metal. A hydride was formed preferentially on the carbon-covered surface, for vacuum pretreatment temperatures of 150 and 190 °C and hydrogen reactions of 150 and 90 °C, respectively. Dependence of the reaction rate on the thickness of the layer was observed.     

A study on microstructures and properties of P/M valve seats of hot forging by laser irradiation

A CO₂ laser was used as heating source for hot forging. Powder/metallurgy (P/M) valve seats for car engine was studied by this novel process. The effects of compression ratio and tempering temperature followed by laser irradiation on the microstructures and mechanical properties were investigated. It was indicated that the amount of the recrystallized grains increased with increasing compression ratio, especially when the compression ratio was above a certain value (18.70%), resulting in more refined grains. Good properties including density, radial crushing strength and hardness can be obtained by optimizing processing parameters.     

Microexplosion of an emulsion droplet during Leidenfrost burning

An experimental study has been made of the microexplosion of an emulsion droplet on a hot surface during Leidenfrost burning. Photographic observation is used to study how the emulsion droplet behaves and what happens inside the droplet and to measure the waiting time for the onset of microexplosion. Weibull analysis was used to obtain the distribution function of the waiting time for the onset of microexplosion and to derive the formula for the rate of microexplosion as a function of water volume and emulsion temperature. The base fuels employed were n-decane, n-dodecane, n-tetradecane, and n-hexadecane. The results show that the increase in emulsion temperature with lapse of time results in the agglomeration and coalescence of microdroplets of base fuel dispersed in the continuous phase of water inside the emulsion droplet, terminated by the complete separation of the two phases. At the end of the phase separation process, an opaque water droplet is formed in the central core and is enveloped by the transparent shell of base fuel. Preferential evaporation of the base fuel occurs after the phase separation. The volume of the base fuel decreases while the water volume remains constant. The onset of the microexplosion of an emulsion droplet burning on the hot surface is classified by the wearout type of the Weibull distribution. The waiting time for the onset of the microexplosion decreases with increases in the normal boiling point of base fuel, initial water content, ambient pressure, and test surface temperature. The rate of microexplosion increases with the lapse of time and with increased normal boiling point of the base fuel. The rate of microexplosion increases linearly with increasing water volume in the emulsion droplet and decreases exponentially with the inverse of emulsion temperature.     

Particle accelerator physics and technology for high energy density physics research

Interaction phenomena of intense ion- and laser radiation with matter have a large range of application in different fields of science, extending from basic research of plasma properties to applications in energy science, especially in inertial fusion. The heavy ion synchrotron at GSI now routinely delivers intense uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Our simulations show that the new accelerator complex FAIR (Facility for Antiproton and Ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. A natural example of hot dense plasma is provided by our neighbouring star the sun, and allows a deep insight into the physics of fusion, the properties of matter at high energy density, and is moreover an excellent laboratory for astroparticle physics. As such the sun's interior plasma can even be used to probe the existence of novel particles and dark matter candidates. We present an overview on recent results and developments of dense plasma physics addressed with heavy ion and laser beams combined with accelerator- and nuclear physics technology.     

Hot electron plasmas trapped in helical magnetic surfaces

Experimental studies on nonneutral (pure electron) plasmas of finite temperature, trapped in helical closed magnetic surfaces have been conducted. The helical electron plasmas are produced with thermal electrons launched from the outside of the last closed flux surface (LCFS). About 150 μs after the electron injection, the plasmas reach equilibrium state. Around the LCFS, a steep gradient of plasma space potential φ _s is formed. The corresponding radial electric field is about 2.5 kV/m. On the other hand, around the magnetic axis of helical magnetic surfaces, φ _s is almost constant, indicating that there are little electrons there. The volume-averaged electron density is on the order of 10¹³ m^–3, smaller than the Brillouin density limit. The confinement time seems to be limited by a disruptive instability, and is so far about 1.5 ms.      

Microstructure analysis on IN 718 alloy round rod by FEM in the hot continuous rolling process

Based on physical metallurgy rules and experiential equations, models for microstructure analysis on IN 718 alloy in the round rod hot continuous rolling process has been developed using the finite element method (FEM) on the software ANSYS/LS-DYNA. The dynamic and metadynamic recrystallization models in and after deformation, the grain growth models in the compensated reheating process for IN 718 alloy are regressed, and corresponding processes are involved in these models. For a real rolling practice, the calculated central grain sizes were examined and are in good agreement with the measured ones. The element in the center of the workpiece is a typical one possessing the maximum of the effective strain, the temperature and the grain size in the rolling process. In the hot continuous rolling process, the relationship between the final grain size of the typical element and the inlet velocity of the first stand has been regressed by FE analysis, and the lower rolling speed is beneficial to the grain refinement.     

飞秒激光烧蚀硅表面产生微纳结构过程中激光脉冲数目的影响

为了研究飞秒激光脉冲数目与硅表面形貌之间的关系,在相同的SF6气体氛围下,改变照射硅表面的飞秒激光脉冲数,发现在飞秒激光照射下由硅表面形成的微型锥状尖峰的高度与飞秒激光脉冲数呈现一种非线性关系.通过对该关系的研究有利于找出在制造具有较高吸收效率的高微型锥状尖峰的"黑硅"的实验条件,有利于基于"黑硅"材料的光电器件转化效...     

火焰原子吸收光谱法测定温泉水中金属元素的含量

采用火焰原子吸收光谱法测定了奇村、顿村温泉水中9种金属元素Ca、Mg、Fe、Cu、Zn、Pb、Mn、Cr、Cd的含量,研究了测定不同元素的仪器最佳工作条件、方法的准确性和精密度。结果表明,该方法的加标回收率为98.10%—104.29%,相对标准偏差（n=9）为0.056%—3.32%,检出限为0.0015—0.1571mg/L。测定方法简单易行,方便准确。