大气压氦等离子体射流传输及作用目标时空动态研究

在惰性气体为工作气体条件下,大气压等离子体射流通常是由具有周期传输特性的电离波组成.在大气压的条件下,基于时空分辨图像技术,研究了施加电压、电压脉冲宽度及气体流量对大气压纳秒脉冲氦等离子体射流传输及作用目标过程的时空动态特性的影响.实验结果表明电离波在空间中及作用表面后的传输行为受到了放电参数的显著影响.电离波喷出管口后,在潘宁电离和管口极化电场的共同作用下,电离波呈加速传输,之后其传输行为受到残余电荷、气体通道的建立和外加电场的共同作用影响.电离波与目标表面相互作用过程中,因表面极化电荷作用,其总电场矢量方向的改变造成了电离波在临近目标表面时发生“偏移”.

物质的六种形态

到目前为止,人类已发现或探知了六种形态的物质……了解和掌握并运用这些物质形态为我们服务,将推动人类社会的发展.

合肥“新水稻”总理很称赞离子束研究惠及水稻、西瓜

2月28日，位于合肥科学岛上的中科院合肥物质研究院等离子体所传出好消息：由该所科技工作者主持的“十五”国家科技攻关项目、离子束应用技术研究课题通过了中科院和安徽省科技厅组织的专家验收。该项目四个课题中的部分课题将对我国农业产生巨大推动作用，国务院总理温家宝非常重视，还对此作出批示。

LHC／ALICE及其光子探测

大型强子对撞机（LHC）上的大型离子对撞机实验（ALICE）将致力于TeV能区重离子碰撞，探测夸克退禁闭的新物质形态——夸克-胶子等离子体（QGP），探索宇宙诞生之初的物态性质。本文介绍其上的新一代电磁谱仪ALICE光子探测器（PHOS），它将用于铅-铅碰撞实验中测量直接光子和衰变光子产物，诊断夸克物质的电磁信号。束流测试结果显示，ALICE光子谱仪——PHOS将能够高效探测0．5～100GeV／c的光子。

Lixiviation of Open-Coast Dumping Site and Pollution of Water and Soils of Edea Industrial Zone（Littoral-Cameroon）

The nexus between water, food and energy is one of the most fundamental relationships and challenges for society. Indeed, seepage of wastes stored into dumping sites of Edea township, favor their lixiviation. Soluble components of matter are slowly dissolves, drained by meteoric water and flowed into tail bay vicinity. Knowledge of trace and toxic metal concentrations in the biotic matrices is important for assessing the effects of pollutants and the risk of exposure. In this study, A1, Mn, Cd, Cr, Cu, Pb and Zn were quantified respectively in 33 samples of soil and water, using ICP-MS （Inductively Coupled Plasma Mass Spectrometry）, Pb were found between 1.38-88.28 mg/L. Higher concentrations of Al were found in Alucam industrial wastes （315,502.33 mg/kg）, and in Hysacam domestic wastes （54,126.93 mg/kg）. Concentrations of Cd （1.955 mg/kg）, Pb （469.00 mg/kg） and Zn （853.00 rng/kg） are higher in domestic wastes. The ones of Mn （696.96 mg/kg） and Cu （1,320.10 mg/kg） are higher in industrial wastes. Higher concentrations of Pb and Cu let assume that it is a risk of poisoning relative to these elements around this area. These findings illustrate that lixiviation of dumping wastes has great influence on water and soils pollutions of the study ecosystem.

Physiological traits of rice seedlings in response to inorganic arsenic

The aim of our study was to better understand the different responses of rice seedling to different species of inorganic arsenic As203 （As（Ill）） and Na2HAsO4 （As（V））. Our results indicate that the biomass of rice seedling decreased as arsenic concentration increased, with the decrease being more significant at higher arsenic concentrations. In addition, the analysis of superoxide dimutase （SOD）, peroxidase （POD）, and catalase （CAT） in rice roots and leaves showed that the activity of these three enzymes significantly decreased in rice tissues, especially in rice roots, as arsenic concentration was increased,. Further, the uptake and utilization efficiencies of N, P, and K were found to decrease as arsenic concentration was increased. However, the uptake and utilization efficiencies of P and K were mainly affected by As（IlI）, whereas those of N were mainly affected by As（V）. Inductively coupled plasma-mass spectrometry （ICP-MS） was used to assay arsenic accumulation in rice tissues; the results indicate that the arsenic content in rice tissues was enhanced when arsenic concentration was increased, especially in rice roots after arsenic treatment.

Simultaneous determination of Repaglinide and Irbesartan in biological plasmas using micellar enhanced excitation-emission matrix fluorescence coupled with ATLD method

A highly sensitive and selective 3D excitation-emission fluorescence method has been proposed to rapidly quantify the combined antidiabetics Repaglinide(Re) and Irbesartan(Ir) in rat and human plasmas with the aid of second-order calibration method based on alternating trilinear decomposition(ATLD) method. Re and Ir with weak fluorescence can be endowed with strong fluorescent property by changing the microenvironment in samples and improving the fluorescence quantum yield by using an appropriate micellar enhanced surfactant. The enhanced excitation-emission matrix fluorescence of Re and Ir can be accurately resolved and can simultaneously attain the optimal concentration even in the presence of a potentially strong intrinsic fluorescence from complex biological matrices, such as rat and human plasmas, by using the ATLD method, which completely exploits the "second-order advantage". The average recoveries of Re and Ir obtained from ATLD with the factor number of 3(N=3) were 101.0%±4.3% and 99.1%±4.1% for rat plasma and 100.5%±5.4% and 97.1%±3.6% for human plasma. Several statistical methods, including Student's t-test, figures of merit, and elliptical joint confidence region, have been utilized to evaluate the accuracy of the proposed method. Results show that the developed method can maintain second-order advantage in simultaneous determinations of the weak fluorescent analytes of interest in different biological plasma matrices.

Plasmon-enhanced polymer bulk heterojunction solar cells with solution-processable Ag nanoparticles

We report the plasmon-enhanced polymer bulk-heterojunction solar cells with Ag nanoparticles (AgNPs) obtained via chemical method. Here, the AgNPs films with different particle densities are introduced between the poly (3,4-ethylene dioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) buffer layer and the poly (3-hexythiophene):[6,6]-phenyl-c61 butyric acid methyl ester (P3HT: PCBM) layer. By improving the optical absorption of the active layer owing to the localized surface plasmons, the power conversion efficiency of the solar cells is increased compared with the control device. It is shown that the efficiency of the device increases with the density of AgNPs. For the device employing higher density, the resulted power conversion efficiency is found to increase from 2.89% to 3.38%, enhanced by 16.96%.

Numerical experiments of disturbance to the solar atmosphere caused by eruptions

Despite extensive research on various global waves in solar eruptions, debate continues on the intrinsic nature of them. In this work, we performed numerical experiments of the coronal mass ejection with emphases on the associated large-scale MHD waves. A fast-mode shock forms in front of the flux rope during the eruption with a dimming region following it, and the development of a three-component structure of the ejecta is observed. At the flank of the flux rope, the slow-mode shock and the velocity vortices are also invoked. The dependence of the eruption energetics on the strength of the background field and the coronal plasma density distribution is apparent： the stronger the background field is, and/or the lower the coronal plasma density is, the more energetic the eruption is. In the lower Alfven speed environment, the slow mode shock and the large scale velocity vortices may be the source of the EIT wave. In the high Alfvdn speed environment, on the other hand, the echo due to the reflection of the fast shock on the bottom boundary could be so strong that its interaction with the slow mode shock and the velocity vortices produces the second echo propagating downward and causing the secondary disturbance to the boundary surface. We suggest that this second echo, together with the slow shock and the velocity vortices, could constitute a possible candidate of the source for the EIT wave.

Origin and structures of solar eruptions Ⅰ: Magnetic flux rope

Coronal mass ejections(CMEs) and solar flares are the large-scale and most energetic eruptive phenomena in our solar system and able to release a large quantity of plasma and magnetic flux from the solar atmosphere into the solar wind. When these high-speed magnetized plasmas along with the energetic particles arrive at the Earth, they may interact with the magnetosphere and ionosphere, and seriously affect the safety of human high-tech activities in outer space. The travel time of a CME to 1 AU is about 1–3 days, while energetic particles from the eruptions arrive even earlier. An efficient forecast of these phenomena therefore requires a clear detection of CMEs/flares at the stage as early as possible. To estimate the possibility of an eruption leading to a CME/flare, we need to elucidate some fundamental but elusive processes including in particular the origin and structures of CMEs/flares. Understanding these processes can not only improve the prediction of the occurrence of CMEs/flares and their effects on geospace and the heliosphere but also help understand the mass ejections and flares on other solar-type stars. The main purpose of this review is to address the origin and early structures of CMEs/flares, from multi-wavelength observational perspective. First of all, we start with the ongoing debate of whether the pre-eruptive configuration, i.e., a helical magnetic flux rope(MFR), of CMEs/flares exists before the eruption and then emphatically introduce observational manifestations of the MFR. Secondly, we elaborate on the possible formation mechanisms of the MFR through distinct ways. Thirdly, we discuss the initiation of the MFR and associated dynamics during its evolution toward the CME/flare. Finally, we come to some conclusions and put forward some prospects in the future.

Laser-driven plasma collider for nuclear studies

A novel method of initiating nuclear fusion reactions in a full plasma environment was suggested, and a proof-of-concept experiment was carried out with the D ＋D → n＋3He reaction. In this new approach, two plasma jets generated by high-intensity lasers collide headon-head. The center-of-mass energy of the nuclei increases accordingly, and therefore, reaction products can be significantly enhanced, especially in the sub-Coulomb barrier ranges. As a result of the fusion reaction, up to - 7.6 ×105 neutrons had been observed. This new type of ＂plasma collider＂ could provide an innovative tool to study nuclear reactions under astrophysical conditions.

Recent advances in solar storm studies in China

"Solar storm" has been commonly accepted by academic community and the public as a very popular scientific term. It is avivid description of violent ejections of a huge amount of magnetized plasma from the Sun as strong flare/CMEs, which sweepover into interplanetary space, develop, and affect our space environment. The solar storm could bring us disastrous spaceweather, destroy crucial technology, and cause a large-scale blackout. It is one of the natural disasters faced by modern humanbeings. Here we first briefly summarize the observational features of solar storms and introduce some key issues, and then wefocus on major advances in observational studies. We mainly introduce the efforts made by the Chinese scientists and comment on the challenges and opportunities that they are facing. In this era when scientific breakthroughs in solar storm studiescrucially depend on space-borne devices and large-aperture ground-based telescopes, the Chinese solar research communityneeds to develop its own major observational facilities and improve space weather forecasting abilities.