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High pressure die casting (HPDC) Mg alloy has a hetero-structure in which the microstructures gradually coarsen from the casting surface to the interior, leading to the different elastic–plastic (E-P) transitional behaviors among the layers. In this paper, we quantitively determined the diverse E-P transitions among the HPDC layers and related them to the microstructural evolution. To investigate independently the E-P transitional behavior of the layer, the surface, middle, and central layers were deliberately sliced in sequence from the casting surface to the interior of the HPDC Mg-4Al-5.7RE (in wt.%) component. The onset and the end of E-P transition in each layer were quantitively determined by cyclic tensile test and Kocks-Mecking analysis, respectively. It was found that the plastic deformation for all layers occurred in the first unloading loop near zero strain, indicating the start of the E-P transition. With increasing strain, the E-P transition ended first in the middle layer at 0.0081 strain due to the lowest fraction of the second phases and ended last at the small-grained surface layer at 0.0090 strain. Excluding the twinning-dependent anelastic strain, the E-P transitions ended in advance at the strains of 0.0059 and 0.0062 in the middle and surface layer, respectively. A combination of cyclic tensile test and Kocks-Mecking analysis provided a method to quantitively determine the diverse E-P transitions among the HPDC layers resulted from the hetero-structure regarding grains, the second phases, and twins.

Particle simulation has been widely used in studying plasmas. The technique follows the motion of a large assembly of charged particles in their self-consistent electric and magnetic fields. Plasmons, collective oscillations of the free electrons in conducting media such as metals, are connected to plasmas by very similar physics, in particular, the notion of collective charge oscillations. In many cases of interest, plasmons are theoretically characterized by solving the classical Maxwell’s equations, where the electromagnetic responses can be described by bulk permittivity. That approach pays more attention to fields rather than motion of electrons. In this work, however, we apply the particle simulation method to model the kinetics of plasmons, by updating both particle position and momentum (Newton–Lorentz equation) and electromagnetic fields (Ampere and Faraday laws) that are connected by current. Particle simulation of plasmons can offer insights and information that supplement those gained by traditional experimental and theoretical approaches. Specifically, we present two case studies to show its capabilities of modeling single-electron excitation of plasmons, tracing instantaneous movements of electrons to elucidate the physical dynamics of plasmons, and revealing electron spill-out effects of ultrasmall nanoparticles approaching the quantum limit. These preliminary demonstrations open the door to realistic particle simulations of plasmons.

AIDS/HIV is a serious life-threatening and public health problem that urges for new antiviral drugs to control. A bis-indole alkaloid voacamine has been isolated from Voacanga africana Stapf. In this study, voacamine 1H and 13C chemical shift assignments were redetermined using 1D and 2D NMR; 1H NMR and 13C NMR chemical shifts were accurately assigned. Absolute configuration was confirmed by single-crystal X-ray diffraction analysis with Cu Kα radiation, and in vitro antiviral activity against HIV via effecting the binding affinity with gp120 based on SPRi experiment was testified. This study supports the potential value of voacamine as a natural agent against AIDS/HIV.

本文报道1例扁桃体周围脓肿穿刺术后继发颈动脉假性动脉瘤的患者诊治过程。患者男，23岁，因“扁桃体周围脓肿穿刺术后6 d，术后出现咽痛、吞咽痛、呼吸困难加重2 d”就诊。经颈动脉数字减影血管造影术明确诊断为颈内动脉假性动脉瘤，之后行选择性动脉栓塞并成功治愈，随访3年患者无咽痛及出血，无神经系统后遗症。.

本文报道了1例急性髓系白血病诱导化疗后继发颌面部侵袭性毛霉菌病的患者。患者女，46岁，全身乏力20余天，持续高热10余天，临床诊断为急性髓系白血病，首次诱导化疗第3天继发鼻脑型毛霉菌病，外科清创及抗真菌药物联合治疗后局部感染程度未见明显减轻，半年后因全身感染、多器官衰竭死亡。.

本文报道了1例因挖耳勺刺入过深导致镫骨前庭脱位的患者，女，48岁，因鼓膜穿透伤后眩晕伴恶心呕吐1 d入院，结合患者症状、体征及影像学检查诊断为外伤性镫骨前庭内脱位（左侧），予以减轻水肿及抗眩晕、止吐等对症治疗后症状完全缓解。随访3个月无异常。.

3He enrichment is one distinctive feature of impulsive solar energetic particle events. This study is designed to investigate the process of plasma wave–particle resonance, which plays a key role in selectively accelerating heavy ions. We apply a 1.5 dimensional particle-in-cell simulation to model the electron-beam–plasma interaction that generates electron and ion cyclotron waves, namely proton and 4He cyclotron waves, whose dispersions are dependent on the magnetization parameter α = ω pe/Ωce and the temperature ratio τ = T e /T p . The background particles, e.g., 3He and 4He, resonate with the excited cyclotron waves and experience selective heating or acceleration. Specifically, the resonant modes of 3He ions lead to a more effective acceleration rate compared to those of the 4He ions. The simulation results provide a potential solution for understanding the abundance of heavy ions in the solar wind.

Aims. The present study aims to shed light on our understanding of the radiation processes of solar radio bursts associated with nonthermal electron propagation in the corona and interplanetary space. Methods. We performed 2.5-dimensional particle-in-cell (PIC) simulations to investigate the plasma emission excited by a relativistic electron beam using different pitch angles in the magnetized plasma. Results. Langmuir waves at the fundamental and harmonic frequencies were excited via the energy dissipation of the electron beam. For the first time, the backward Langmuir waves up to the third harmonic frequencies were reproduced in the cases of large pitch angles, likely arising from the relecting and scattering of density fluctuations to the Langmuir waves during electrom beam-plasma interaction. Electromagnetic (EM) waves were generated via the mode conversion of electrostatic (ES) waves and the nonlinear wave coupling. Specifically, the harmonic EM emission comes from the coupling of forward and backward Langmuir waves, namely, L + L′ → 2H, while the higher harmonic EM emissions generally come from the coupling of the Langmuir wave and lower-order harmonic EM wave, namely, L + (n − 1)H → nH. When the electron beam exhibits a large pitch angle, another possible mechanism for the third harmonic EM emission might be the coalescence of three ES waves, namely, L + L′ + L″ → 3H.

Previous studies showed that the subchannel codes need most CPU time to solve the matrix formed by the conservation equations. Traditional matrix solving method such as Gaussian elimination method and Gaussian-Seidel iteration method cannot meet the requirement of the computational efficiency. Therefore, a new algorithm for solving the block penta-diagonal matrix is designed based on Stone's incomplete LU (ILU) decomposition method. In the new algorithm, the original block penta-diagonal matrix will be decomposed into a block upper triangular matrix and a lower block triangular matrix as well as a nonzero small matrix. After that, the LU algorithm is applied to solve the matrix until the convergence. In order to compare the computational efficiency, the new designed algorithm is applied to the ATHAS code in this paper. The calculation results show that more than 80 % of the total CPU time can be saved with the new designed ILU algorithm for a 324-channel PWR assembly problem, compared with the original ATHAS code.

We investigate intense broadband terahertz radiation generation based the interaction of high intensity ultrashort laser with solid plasma. THz pulse with electric field of hundreds of MV/cm are generated using laser with intensity of about 1018 W/cm2. Theoretical model, simulations agree well with experiments, and reveal that the THz radiation is coherent transition radiation by hot electrons produced in laser-plasma interaction. We have studied both planar and nanorod array targets, latter of which efficiently enhance the intensity and directionality of the THz source.

Broadband THz radiation with electric field up to hundreds of MV/cm is achieved using femtosecond laser interaction with solid target. Particle-in-cell simulations reveal that the THz pulses are coherent transition radiation (CTR) of hot electrons produced in laser-plasma interaction. Due to the square law dependence of CTR energy on the electron number, laser-plasma based strong THz sources can reach unprecedented intensity comparing to other methods. Besides planar targets, nano-grating targets have also been investigated, which improve the THz sources both in intensity and directionality. Theory model and simulations agree very well with experimental observations.

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with length 5 \mu m, a maximum 13.8 times enhancement in the THz pulse energy (in $\leq$ 20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies ($\leq$ 20THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20 - 200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets of length 60 \mu m . Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results., Comment: 14 pages, 5 figure

The cooling system for the solar simulator was introduced, which contained wind-cooling system, water-cooling system, and refrigeration system. Then the numerical simulation of the wind-cooling system was numerical simulated. The solar simulator with 13 xenon lamp was modeled, and the flow and the heat transfer in the solar hood was simulated by the FLUENT. The flow field in the solar hood was studied, especially the flow near the xenon lamp and the collector. The result showed that the velocity of the most area in the solar hood was slow, but the area near the xenon lamp, because the flow area suddenly decreases, the velocity of the gas increased significantly, which is conducive to the heat exchange between the xenon lamp and the gas. The temperature of the xenon lamp was lower than 328 K, and the velocity on the surface of the xenon lamp was higher than 17 m/s, which met the operating requirement of the xenon lamp, and the temperature of the collector was lower than 308 K, and meet the operating requirement of the collector.

To study the expression of ALK protein in pulmonary adenocarcinoma as detected by Ventana immunohistochemistry, with correlation of clinicopathologic features.Immunohistochemical study for ALK protein using Ventana ALK (D5F3) kit was carried in 7 371 pulmonary adenocarcinoma samples. The clinicopathologic features were subsequently analyzed.ALK fusion protein was detected in 446 of the 7 371 lung adenocarcinoma samples studied (6.05%). The ALK positivity rate in small biopsy samples was higher than that in surgical specimens [9.02% (153/1 696) versus 5.16% (293/5 675); P0.01]. ALK fusion protein expression correlated with patient age, sample type and smoking history. ALK positivity rate in each age group increased with younger patient age. ALK positivity rate was 45.45% (10/22) in patients younger than 30 years old. The positivity rate of ALK fusion protein in adenocarcinoma in-situ, minimally invasive adenocarcinoma and invasive adenocarcinoma was 0, 0.48% (2/418) and 5.63% (291/5 165), respectively. The differences of ALK positivity rate amongst different subtypes had statistical significance (P0.01). Invasive mucinous adenocarcinoma had highest ALK positivity rate, followed by invasive adenocarcinoma with predominantly solid pattern.ALK fusion protein is more often found in young patients with pulmonary adenocarcinoma, especially in those younger than 30 years old. ALK fusion protein is rarely expressed in early-stage pulmonary adenocarcinoma. Invasive mucinous adenocarcinoma and invasive adenocarcinoma with solid pattern have higher ALK positivity rate than other adenocarcinoma subtypes.

Broadband terahertz (THz) radiation with extremely high peak power, generated by the interaction of a femtosecond laser with a thin solid target, has been investigated via particle-in-cell simulations. The spatial (angular) and temporal profiles of the THz radiation reveal that it is caused by the coherent transition radiation emitted when laser-produced hot electrons pass through the front or rear surface of the target. Dependence of the THz radiation on laser and target parameters is studied; it is shown to have a strong correlation with hot electron production. The THz radiation conversion efficiency can be as high as a few times 10^{-3}. This radiation is not only a potentially high power THz source, but may also be used as a unique diagnostic of hot electron generation and transport in relativistic laser-solid interactions.

We achieved broadband terahertz radiation with extreme high peak power by femtosecond laser interaction with thin solid foil via particle-in-cell simulations. The angular distribution, temporal profile and spectra of the radiation are studied and reveal that it is coherent transition radiation emitted by hot electrons which are produced in laser plasma interaction and crossing the target surfaces. The THz radiations are emitted to the broad space, strongest along the target surface and weakest in a direction between the target normal and specular reflection direction. Under laser with different peak intensities from 1017 to 1019 W/cm2, the angular distribution of the radiations does not change much. Intensity of the THz radiation is explored and shows close correlation to the target and laser parameters. Conversion efficiency of the THz radiation can be as high as a few times of 10−3. A theory model is given, as well as comparison with recent experimental observations.

A wakefield driven by a short intense laser pulse in a perpendicularly magnetized underdense plasma is studied analytically and numerically for both weakly relativistic and highly relativistic situations. Owing to the DC magnetic field, a transverse component of the electric fields associated with the wakefield appears, while the longitudinal wave is not greatly affected by the magnetic field up to 22 Tesla. Moreover, the scaling law of the transverse field versus the longitudinal field is derived. One-dimensional particle-in-cell simulation results confirm the analytical results. Wakefield transmission through the plasma-vacuum boundary, where electromagnetic emission into vacuum occurs, is also investigated numerically. These results are useful for the generation of terahertz radiation and the diagnosis of laser wakefields.

The laser wakefield structure in a magnetized underdense plasma is studied analytically and numerically. Because of the DC magnetic field perpendicular to the laser propagation direction, an electromagnetic component appears in addition to the normal electrostatic component. This electromagnetic component can transmit partially into vacuum at the plasma–vacuum boundary as shown by particle-in-cell simulation. It is found that the emission has components both at the fundamental plasma frequency and its harmonics if the wakefield is driven at a high amplitude. Comparing with the emission at the plasma frequency, the harmonic emission depends weakly upon the density profile at plasma–vacuum boundary and it can pass through the boundary almost without energy loss, providing a new method for the diagnostic of wakefields.

Irradiated by femtosecond laser pulses with different energies, opened cone targets behave very differently in the transmission of incident laser pulses. The targets, each with an opening angle of 71? and an opening of 5 ?m, are fabricated using standard semiconductor technology. When the incident laser energy is low and no pre-plasma is generated on the side walls of the cones, the cone target acts like an optical device to reflect the laser pulse, and 15% of the laser energy can be transmitted through the cones. In contrast, when the incident laser energy is high enough to generate pre-plasmas by the pre-pulse of the main pulse that fills the inner cone, the cone with the plasmas will block the transmission of the laser, which leads to a decrease in laser transmission compared with the low-energy case with no plasma. Simulation results using optical software in the low-energy case, and using the particle-in-cell code in the high-energy case, are primarily in agreement with the experimental results.

The thermal regulation of a shroud has been widely applied in the thermal vacuum testing of spacecraft. The shroud is flooded with fluid, where the temperature is controlled to a specified range, so that the temperature of the test specimen can be changed with the shroud and maintained at a certain value as designed. A numerical model of temperature in the thermal regulation system is established and the heat transfer among fluids, the shroud and the test specimen are analyzed. A combination of heat radiation, heat conduction, and heat convection are realized based on the fuzzy control theory. When a test prototype is built, the test results show that the temperature range of the shroud can be steadily controlled between -75°C and 155°C, and the temperature of the test specimen can be stably controlled at any value in the range of -50°C–120°C. The over control of temperature is less than 1°C, and the temperature stability is less than ±0.5°C.

Numerical self-heating and thermalization are two unphysical artifacts in particle-in-cell (PIC) simulations due to the implicit assumptions used in the numerical method. Numerical self-heating in plasma simulations can typically be suppressed by using higher order finite-difference methods, field smoothing and particle weighting schemes. On the other hand, numerical thermalization is associated with the granularity of the particles that introduces relaxation in the velocity distribution functions (i.e. the particle velocity distribution approaches Maxwellian). In 2D collisionless plasma simulations, the rate of relaxation has been shown to be proportional to 1/N D , where N D is the number of particles per Debye length1. This scaling has been illustrated to be true in several previous works using electrostatic PIC codes.

Terahertz (THz) radiation provides very wide and promising applications in fields of information, non-invasive imaging, and fundamental science. The community seeks strong THz sources nowadays to access the applications from linear to non-linear range. By using an ultrashort laser illuminating a solid target, we obtain THz pulses as strong as over 100MV/cm1 with half-cycled shape. The THz pulses are emitted in both forward and backward directions and subsequent secondary pulses are generated. The primary pulses are attributed to coherent transition radiation from hot electrons passing through the vacuum-target interfaces and secondary pulses are generated by refluxing electrons dragged back by sheath field.

Summary form only given. Particle-in-Cell (PIC) simulation is a powerful and extensively used tool for plasma studies. We have recently developed our own PIC code at IHPC. In the code, we have implemented both explicit and implicit algorithms1 for Maxwell solver. The explicit scheme is efficient for short simulations, while the implicit scheme is more superior in term of numerical noise suppression. This allows us to choose the most efficient algorithm depending on the size and nature of the problem. Other improvements to the algorithm includes a modification to the “zig-zag” scheme2 for current calculation applicable to any order of particle weighting and the implementation of coulomb collisions to model collisional damping in plasmonic nanostructures, which can essentially be treated as micro plasmas.

Summary form only given. THz radiation has wide applications in physics, chemistry, information, security and biology. Applications and studies in the nonlinear regime require strong THz radiation sources. Here, we demonstrate intense half cycle THz radiations produced by ultrashort laser solid targets interactions in both forward and backward direction via particle-in-cell simulations. Radiations with intensity higher than 1014W/cm2 near the target surface with the duration approximates that of the incident laser can be obtained by hundreds of TW lasers. Simulations suggest that the radiations are transition radiation1 induced by hot electrons generated in laser plasma interactions crossing the front and back surface of the target. An overall picture of intense THz generation by laser solid interactions will be presented. Our simulations results are highly consistent with observations from related experiments by other authors2, 3.

Summary form only given. The propagation of a large flux of laser generated mildly relativistic electrons in warm resistive plasma is one of the most important problems for the fast ignition scenario of laser inertial confinement fusion. At the initial stage of propagation, the beam induces a return current in the plasma so that the beam-plasma system is unstable to three well known instabilities[1], i.e., the two-stream instability (TSI), the filamentation instability (FI), and the oblique instability (OI). The three instabilities are supposed to be the critical issues for the beam transport. We investigate these issues by both particle-in-cell (PIC) simulations and analytic kinetic theory[2].

Turbulence in fluids is a ubiquitous, fascinating, and complex natural phenomenon that is not yet fully understood. Unraveling turbulence in high density, high temperature plasmas is an even bigger challenge because of the importance of electromagnetic forces and the typically violent environments. Fascinating and novel behavior of hot dense matter has so far been only indirectly inferred because of the enormous difficulties of making observations on such matter. Here, we present direct evidence of turbulence in giant magnetic fields created in an overdense, hot plasma by relativistic intensity (10 18 W/cm 2 ) femtosecond laser pulses. We have obtained magneto-optic polarigrams at femtosecond time intervals, simultaneously with micrometer spatial resolution. The spatial profiles of the magnetic field show randomness and their k spectra exhibit a power law along with certain well defined peaks at scales shorter than skin depth. Detailed two-dimensional particle-in-cell simulations delineate the underlying interaction between forward currents of relativistic energy “hot” electrons created by the laser pulse and “cold” return currents of thermal electrons induced in the target. Our results are not only fundamentally interesting but should also arouse interest on the role of magnetic turbulence induced resistivity in the context of fast ignition of laser fusion, and the possibility of experimentally simulating such structures with respect to the sun and other stellar environments.

Interactions of 100-fs laser pulses with solid targets at intensities of 10(18) W/cm(2) and resultant terahertz (THz) radiation are studied under different laser contrast ratio conditions. THz emission is measured in the specular reflection direction, which appears to decrease as the laser contrast ratio varies from 10(-8) to 10(-6). Correspondingly, the frequency spectra of the reflected light are observed changing from second harmonic dominant, three-halves harmonic dominant, to vanishing of both harmonics. Two-dimensional particle-in-cell simulation also suggests that this observation is correlated with the plasma density scale length change. The results demonstrate that the THz emission is closely related to the laser-plasma interaction processes. The emission is strong when resonance absorption is a key feature of the interaction, and becomes much weaker when parametric instabilities dominate.

We report a plasma-based strong THz source generated in intense laser-solid interactions at relativistic intensities > 10(18) W/cm(2). Energies up to 50 mu J/sr per THz pulse is observed when the laser pulses are incident onto a copper foil at 67.5 degrees. The temporal properties of the THz radiation are measured by a single shot, electro-optic sampling method with a chirped laser pulse. The THz radiation is attributed to the self-organized transient fast electron currents formed along the target surface. Such a source allows potential applications in THz nonlinear physics and provides a diagnostic of transient currents generated in intense laser-solid interactions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729874]

Based on fully kinetic model using drift-Maxwellian distributions and taking into account the transverse electrostatic field (TEF), it is shown that the current-filamentation instability (CFI) grows unexpectedly with the plasma temperature. The growth is attributed to the decreasing of the TEF as the plasma becomes hot. In the low-temperature plasma regime where the TEF is strong, it is identified that the TEF can dominate over the thermal pressure in suppressing the CFI. Since the TEF originates from the temperature difference between the beam and the plasma, the plasma temperature plays a significant role for the development of the CFI and the quasistatic magnetic fields in a hot-beam warm-plasma system. Particle-in-cell simulations verify the above results.

Resonance absorption in relativistic laser-plasma interaction is studied via two-dimensional particle-in-cell simulation. As the laser intensity increases from the linear regime, the absorption rate first decreases due to relativistic modulation of the electron plasma oscillations excited at the mode conversion layer. However, the trend reverses after a critical intensity. The reversal can be attributed to the fact that the relativistic critical layer depends on the local intensity of the laser pulse, so that instead of occurring in a thin layer, resonance absorption occurs in a plasma bulk region, leading absorption rate increase. The reflected-light spectrum also shows broadening and splitting of the harmonics at high laser intensities, which can be attributed to critical-surface oscillations driven by the laser ponderomotive force.

To study the age-related changes of atropine (Atr), scopolamine (Sco), anisodine (AT3), and anisodamine (Ani) on behaviors and memories.The behaviors and memories were measured with open-field test and step-through task. M-cholinergic receptors were determined by [3H] quinuclidinyl benzilate ([3H] QNB).During acquisition session (d 1) the 18-, 28-, and 38-d-old mice pretreated with Atr, Sco, and AT3 (0.02, 0.2, 2, or 20 mg.kg-1, i.p.) in open-field test showed increase in walking counts by 26%-42%, but decrease in rearing, grooming, and defecating counts for 50%-92%, 67%-100%, and 75%-100%, respectively. On recall session (d 2) the walking and rearing behaviors in the 18- and 28-d-old mice receiving Atr, Sco, and AT3 on d 1 were higher than those in the mice receiving saline. But a lower grooming behavior on d 2 was found in the mice receiving the drugs on d 1. On d 1 Ani 20 mg.kg-1 reduced the rearing behavior by 50% in 18-d-old mice and defecation by 33%-36% in 18- and 28-d-old mice. All the 4 belladonna alkaloids increased the number of avoidance-response errors and decreased the retention latencies in step-through task. Bmax of [3H] QNB binding sites in frontal cortex and hippocampus regions in the 38-d-old mice increased 7% and 23% vs in the mice of 18 d of age, respectively.1) The effects of the belladonna alkaloids on behaviors and memories in adult mice were weaker than those in young mice. 2) The belladonna alkaloids-induced amnesia on passive avoidance-response in step-through was more sensitive than behavioral changes and amnesia on open-field. 3) According to the lowest effective doses which insulted the behaviors or memories in young mice, Sco was about 10, 100, and 1000 times more potent than Atr, AT3, and Ani, respectively.

The general oblique instability for a relativistic electron beam propagating through a warm and resistive plasma is investigated fully kinetically by a variable rotation method. Analysis shows that the electrostatic part of the oblique instability is attenuated and eventually stabilized by collisional effects. However, the electromagnetic part of the oblique instability (EMOI) is enhanced. Since the current-filamentation instability as a special case of the EMOI has a larger growth rate, it becomes dominant in the collisional case as shown in our two-dimensional particle-in-cell simulations. While the beam diverges in the collisionless case, it can become magnetically collimated in the collisional case due to stabilization of the electrostatic instabilities when the initial beam spreading angle is less than certain magnitude such as a dozen degrees. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4736980]

The effect of minor addition of 3d transition metals on the formation enthalpy (△H) and electronic structure of MgH2 have been studied using first-principle calculations, and considering the phonon-calculated zero point energy. The results indicate that the partial substitution of Mg atoms by 3d transition metal atoms increases the formation enthalpy of MgH2. Both formation enthalpy and Mulliken population analysis showed that the ability to destabilize MgH2 generally increases with the atomic number, except Mn and Zn, which have half-filled and completely filled 3d orbital states. The destabilization of MgH2 by partially alloying 3d elements was due to relatively stronger covalent bonds between 3d elements and the H atom, and a weaker ionic bond between Mg and H in the alloyed material with respect to pure MgH2. Based on electronic structure analyses, MgH2 and MgH2 alloyed with Ti, Fe, and Zn show no spin magnetism, while MgH2 alloyed with Sc, V, Cr, Mn, Co, Ni, and Cu show spin magnetism. In the MgH2-3d...

Using opened reentrant cone silicon targets, we have demonstrated the effect of micro focusing of fast electrons generated in intense laser-plasma interactions. When an intense femtosecond laser pulse is focused tightly onto one of the side walls of the cone, fast electron beam emitted along the side wall is observed. When a line focus spot, which is long enough to irradiate both of the side walls of the cone simultaneously, is used, two electron beams emitted along each side wall, respectively, are observed. The two beams should cross each other near the open tip of the cone, resulting in micro focusing. We use a two-dimensional Particle-In-Cell code to simulate the electron emission both in opened and closed cone targets. The simulation results of the opened cone targets are in agreement with the experimental observation while the results of the closed cone targets do not show the micro focusing effect.