Chromospheres, transition regions, and coronas

The increase in temperature outward from the surface of a stellar photosphere can be understood by looking at the local energy balance. The relatively high-density stellar photosphere is cooled effectively by radiative energy loss penetrating the optically thin corona. For the low-density chromosphere and corona, if the energy input cannot be balanced by radiative energy losses, the temperature will rise steeply, possibly up to 1 million degrees or more. Coronal heating and emission appear to be strongly influenced by magnetic fields, leading to large differences in x-ray emission for otherwise similar stars. Comparatively small variations are seen in the overall chromospheric emission of stars. Chromospheres are probably mainly heated by shock-wave energy dissipation, modified by magnetic fields.     

Slipping magnetic reconnection in coronal loops

Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments.     

Coronal transverse magnetohydrodynamic waves in a solar prominence

Solar prominences are cool 10(4) kelvin plasma clouds supported in the surrounding 10(6) kelvin coronal plasma by as-yet-undetermined mechanisms. Observations from Hinode show fine-scale threadlike structures oscillating in the plane of the sky with periods of several minutes. We suggest that these represent Alfvén waves propagating on coronal magnetic field lines and that these may play a role in heating the corona.     

Alfven waves in the solar corona

Alfvén waves, transverse incompressible magnetic oscillations, have been proposed as a possible mechanism to heat the Sun's corona to millions of degrees by transporting convective energy from the photosphere into the diffuse corona. We report the detection of Alfvén waves in intensity, line-of-sight velocity, and linear polarization images of the solar corona taken using the FeXIII 1074.7-nanometer coronal emission line with the Coronal Multi-Channel Polarimeter (CoMP) instrument at the National Solar Observatory, New Mexico. Ubiquitous upward propagating waves were seen, with phase speeds of 1 to 4 megameters per second and trajectories consistent with the direction of the magnetic field inferred from the linear polarization measurements. An estimate of the energy carried by the waves that we spatially resolved indicates that they are too weak to heat the solar corona; however, unresolved Alfvén waves may carry sufficient energy.     

The Elemental Composition of the Corona of Procyon: Evidence for the Absence of the FIP Effect

The chemical composition of the solar corona is not the same as that of the underlying photosphere. In the corona, elements with a first ionization potential (FIP) of /=10 electron volts (for example, oxygen, neon, and sulfur) by factors of 3 to 10 with respect to the photosphere. The origin of this FIP effect is unknown. The launch of the Extreme Ultraviolet Explorer Satellite (EUVE) opened up the spectroscopic capability required to determine elemental abundances in the coronae of other stars. Spectroscopic observations of the corona of the nearby F5 IV star Procyon obtained with EUVE have yielded estimates of the relative abundances of high- and low-FIP species. The results provide evidence that Procyon, unlike the sun, does not exhibit the FIP effect. Whether the sun or Procyon is more typical of the general late-type stellar population is of fundamental interest to the physics of stellar outer atmospheres and has a bearing on the origin of cosmic rays.     

Fine thermal structure of a coronal active region

The determination of the fine thermal structure of the solar corona is fundamental to constraining the coronal heating mechanisms. The Hinode X-ray Telescope collected images of the solar corona in different passbands, thus providing temperature diagnostics through energy ratios. By combining different filters to optimize the signal-to-noise ratio, we observed a coronal active region in five filters, revealing a highly thermally structured corona: very fine structures in the core of the region and on a larger scale further away. We observed continuous thermal distribution along the coronal loops, as well as entangled structures, and variations of thermal structuring along the line of sight.     

Soft X-ray Images of the Solar Corona with a Normal-Incidence Cassegrain Multilayer Telescope

High-resolution images of the sun in the soft x-ray to extreme ultraviolet(EUV) regime have been obtained with normal-incidence Cassegrain multilayer telescopes operated from a sounding rocket in space. The inherent energy-selective property of multilayer-coated optics allowed distinct groups of emission lines to be isolated in the solar corona and the transition region. The Cassegrain telescopes provided images in bands centered at 173 and 256 angstroms. The bandpass centered at 173 angstroms is dominated by emission from the ions Fe IX Fe X. This emission is from coronal plasma in the temperature range 0.8 x 10(6) to 1.4 x 10(6)K. The images have angular resolution of about 1.0 to 1.5 arc seconds, and show no degradation because of x-ray scattering. Many features of coronal structure, including magnetically confined loops of hot plasma, coronal plumes, polar coronal holes, faint structures on the size scale of supergranulation and smaller, and features due to overlying cool prominences are visible in the images. The density structure of polar plumes, which are thought to contribute to the solar wind, has been derived from the observations out to 1.7 solar radii.     

Solar wind origin in coronal funnels

The origin of the solar wind in solar coronal holes has long been unclear. We establish that the solar wind starts flowing out of the corona at heights above the photosphere between 5 megameters and 20 megameters in magnetic funnels. This result is obtained by a correlation of the Doppler-velocity and radiance maps of spectral lines emitted by various ions with the force-free magnetic field as extrapolated from photospheric magnetograms to different altitudes. Specifically, we find that Ne7+ ions mostly radiate around 20 megameters, where they have outflow speeds of about 10 kilometers per second, whereas C3+ ions with no average flow speed mainly radiate around 5 megameters. Based on these results, a model for understanding the solar wind origin is suggested.     

不同加热温度对兔肉肉质的影响

试验选择65、75、85、95℃4个加热梯度,一个未加热组作为对照,考察兔肉不同加热温度蒸煮损失、肉色、pH值及剪切力的变化情况。试验结果表明随温度升高蒸煮损失显著上升,pH值呈上升趋势但不同温度加热样品之间差异不显著;加热样品肉色与对照样品肉色差异显著,但是各加热组之间的肉色差异不大;剪切力有增大趋势,75℃加热组与85℃加热组差异不显著,其他各组均有明显差异。结论是,兔肉在加热温度不断升高的过程中,肉品质逐渐下降,不同的加热温度明显地对兔肉品质产生不同程度的影响。     

Electron Plasma Oscillations Associated with Type III Radio Bursts

Plasma wave electric field measurements with the solar orbiting Helios spacecraft have shown that intense (approximately 10 millivolts per meter) electron plasma oscillations occur in association with type III solar radio bursts. These observations confirm the basic mechanism, proposed in 1958, that type III radio emissions are produced by intense electron plasma oscillations excited in the solor corona by electrons ejected from a solar flare.     

Chromospheric anemone jets as evidence of ubiquitous reconnection

The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection.     

3种淡水鱼血浆中游离磷脂的有效性测定

[目的]检测鲤鱼、鲫鱼和鲶鱼3种淡水鱼血浆中游离磷脂的有无,为探索3种淡水鱼凝血现象的生理机制奠定基础。[方法]采用加热兔脑磷脂凝血有效性试验检测加热磷脂的活性,将80℃水浴加热20min后的兔脑磷脂分别加入兔的少血小板血浆、鲤鱼、鲫鱼和鲶鱼的无细胞血浆,测定各血浆加热磷脂的活化部分凝血酶原时间（APTT）。[结果]各试验动物血浆加热磷脂的APTT平均值与对照间差异不显著（P〉0.05）,说明其凝血功能未发生变化;鲤鱼、鲫鱼和鲶鱼的CFP和家兔的不同稀释倍数的PPP的混合血浆平均凝固时间与对照间存在极显著差异（P〈0.01）。[结论]鲤鱼、鲫鱼和鲶鱼的CFP中不含游离的磷脂,它们CFP在无磷脂存在的条件下也可以发生凝固。     

Solar wind outflow and the chromospheric magnetic network

Observations of outflow velocities in coronal holes (regions of open coronal magnetic field) have recently been obtained with the Solar and Heliospheric Observatory (SOHO) spacecraft. Velocity maps of Ne7+ from its bright resonance line at 770 angstroms, formed at the base of the corona, show a relationship between outflow velocity and chromospheric magnetic network structure, suggesting that the solar wind is rooted at its base to this structure, emanating from localized regions along boundaries and boundary intersections of magnetic network cells. This apparent relation to the chromospheric magnetic network and the relatively large outflow velocity signatures will improve understanding of the complex structure and dynamics at the base of the corona and the source region of the solar wind.     

Chromospheric alfvenic waves strong enough to power the solar wind

Alfvén waves have been invoked as a possible mechanism for the heating of the Sun's outer atmosphere, or corona, to millions of degrees and for the acceleration of the solar wind to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the solar atmosphere. We used images of high temporal and spatial resolution obtained with the Solar Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the solar surface and the corona, is permeated by Alfvén waves with strong amplitudes on the order of 10 to 25 kilometers per second and periods of 100 to 500 seconds. Estimates of the energy flux carried by these waves and comparisons with advanced radiative magnetohydrodynamic simulations indicate that such Alfvén waves are energetic enough to accelerate the solar wind and possibly to heat the quiet corona.     

短期氟哌啶醇、利培酮、阿立哌唑作用对小鼠糖脂代谢及行为学影响

探究不同抗精神病药物(APDs)短期作用对MK801诱导的精神分裂症模型小鼠体质量、摄食、糖脂代谢以及动物行为学的影响.将60只雄性昆明小鼠随机分成5组,分别给予连续7 d的生理盐水, MK801, MK801加氟哌啶醇(2.0 mg/kg)(HAL), MK801加利培酮(1.0 mg/kg)(RIS), MK801加阿立哌唑(4.0 mg/kg)(ARI)处理.结果显示, MK801诱导的精神分裂症模型组自发活动(旷场实验)较正常组显著增加.模型组小鼠体质量、摄食及糖脂代谢参数均无显著性变化.加入APDs处理后,与模型组比较, 3种药物均能显著降低小鼠的自发活动,该参数与血脂中的甘油三酯(TG)和总胆固醇(TC)的浓度呈显著的负相关;此外, TG浓度还与肝脏组织中重要的转录因子SREBP1c的表达增加呈显著的正相关,与组蛋白受体H_1R的表达增加也呈显著的正相关.其中,利培酮表现出较强的引发代谢紊乱的趋势,该药物促进了肝脏组织中SREBP1c和SREBP-2以及H_1R的表达显著升高.因此得出,在APDs短期作用下,阿立哌唑无明显糖脂代谢紊乱,具有安全性高、不良反应小的特点.氟哌啶醇的过度镇静效应,可能是这类药物诱发一定程度的代谢性副反应的主要原因;而利培酮作为临床治疗重型精神疾病的一线用药,能较好地发挥疗效,但因其与其他靶点的亲和效应,可能引起更为严重的代谢紊乱副反应,并独立于体质量的增加.     

Direct high-temperature ohmic heating of metals as liquid pipes

When a sufficiently high electric current is passed through a liquid metal, the electromagnetic pressure pinches off the liquid metal and interrupts the flow of current. For the first time the pinch effect has been overcome by use of centrifugal acceleration. By rotation of a pipe of liquid metal, tin or bismuth or their alloys, at sufficiently high speed, it can be heated electrically without intermission of the electric current. One may now heat liquid metallic substances, by resistive (ohmic) heating, to 5000 degrees K and perhaps higher temperatures.     

加热方式对白鲢鱼糜类素材凝胶形成能力的影响(英文)

以白鲢鱼糜,鱼糜 大豆蛋白复合素材为实验对象,研究了水浴、微波以及微波与水浴联合的三种不同加热方式对样品凝胶形成能力的影响,并通过电镜实验对样品微观结构加以观察,从而考察样品凝胶特性与微观结构的相关性。结果表明:(1)在达到相同凝胶强度的条件下,微波加热较传统水浴加热在处理时间上明显缩短,且微波加热由于具有瞬时升温的特点从而未出现水浴加热中存在的中温凝胶劣化现象。(2)在相近温度下,加热方式对单一鱼糜样品为微波水浴联合加热的样品凝胶强度最大,其次是微波单独加热,水浴加热最小,而对鱼糜大豆蛋白复合样品而言,微波单独加热的样品凝胶强度最大,其次是微波水浴联合加热,水浴加热最小。(3)不同凝胶样品微观结构的电镜实验显示微波加热比水浴加热下样品的组织结构更均匀致密,这与样品的凝胶强度的差异性相一致。     

加热方式对白鲢鱼糜类素材凝胶形成能力的影响

以白鲢鱼糜,鱼糜 大豆蛋白复合素材为实验对象,研究了水浴、微波以及微波与水浴联合的三种不同加热方式对样品凝胶形成能力的影响,并通过电镜实验对样品微观结构加以观察,从而考察样品凝胶特性与微观结构的相关性。结果表明:(1)在达到相同凝胶强度的条件下,微波加热较传统水浴加热在处理时间上明显缩短,且微波加热由于具有瞬时升温的特点从而未出现水浴加热中存在的中温凝胶劣化现象。(2)在相近温度下,加热方式对单一鱼糜样品为微波水浴联合加热的样品凝胶强度最大,其次是微波单独加热,水浴加热最小,而对鱼糜大豆蛋白复合样品而言,微波单独加热的样品凝胶强度最大,其次是微波水浴联合加热,水浴加热最小。(3)不同凝胶样品微观结构的电镜实验显示微波加热比水浴加热下样品的组织结构更均匀致密,这与样品的凝胶强度的差异性相一致。     

地源热泵在日光温室中的应用

介绍了一种新型加热方式-地源热泵,并在顺义三高建造了地源热泵加热温室,对其加热效果进行了试验。测试结果表明,室外、试验温室与对照温室夜间平均温度分别为-7.9℃、14.4℃和8.7℃,加温效果明显。地源热泵加热与传统燃煤锅炉相比,平均节能为29.6%。     

草鱼肌原纤维蛋白加热过程中理化特性的变化

考察草鱼肌原纤维蛋白在加热过程中各理化特性的变化规律和机理。结果表明:随着温度的上升,浊度呈S型曲线增加,48℃时上升迅速;黏度呈反S型曲线下降,46℃时下降剧烈;Ca2+-ATPase活性下降,在36～42℃略有上升,46℃时完全失活;总巯基含量从40℃开始显著下降,60～70℃时下降显著。分别于45、55和65℃恒温加热,Ca2+-ATPase活性和黏度随时间延长而下降,浊度上升,温度越高变化越显著;大于50℃恒温加热,总巯基随时间延长而显著下降。草鱼肌原纤维蛋白的DSC扫描图谱在46.37℃和62.59℃出现2个焓变点。SDS-PAGE电泳表明草鱼肌原纤维蛋白在加热过程中(大于45℃)产生了二硫键,说明草鱼肌球蛋白在加热过程中发生了构象变化和分子聚集从而导致了肌原纤维蛋白的热变性。