Monodomain theory: experimental verification

The Néel thermal-activation theory of remanence in monodomain grains has been verified quantitatively in experiments on four ferrite micropowders and two natural rocks. Magnetization and demagnetization curves of thermal, isothermal, viscous, and anhysteretic remanences can all be predicted with reasonable accuracy when the Neél theory is generalized to include effects of grain interaction. Results with the natural materials indicate that interacting, single-domain grains or regions are the carriers of the magnetically hard natural remanence of some paleomagnetic rocks.     

Magnetite: Behavior near the Single-Domain Threshold

Maximum values for the single-domain threshold d(0) and superpara-magnetic threshold d(8) in pure magnetite are found to be 570+/-50 and 350+/-50 angstroms, respectively. Particles larger than do but smaller than about 0.25 micron have size-dependent saturation remanences and coercive forces like those of multidomain particles, but intense and stable thermoremanent magnetization like that of single-domain particles. The presence of magnetite grains in this size range could account for the essentially single-domain character of stable natural remanence in many volcanic and intrusive rocks.     

Magnetic dynamo in the moon: a comparison with the Earth

The assumption that the moon had an internal magnetic field produced in the same way as the geomagnetic field requires that the moon rotated faster than the angular velocity at which it would break up. This suggests that a lunar dynamo is not a tenable explanation for the magnetic remanence observed on the moon.     

The remanent magnetization of lunar soils

The magnetic material in the lunar soils makes them potentially strong carriers of remanence and magnetically viscous. The soils therefore block remanence in the temperature range of the lunar diurnal cycle. This remanence is stable against alternating-field demagnetization. A mechanism whereby such hard natural remanent magnetization may be acquired by material buried in the regolith is proposed.     

Electrical manipulation of magnetization reversal in a ferromagnetic semiconductor

We report electrical manipulation of magnetization processes in a ferromagnetic semiconductor, in which low-density carriers are responsible for the ferromagnetic interaction. The coercive force HC at which magnetization reversal occurs can be manipulated by modifying the carrier density through application of electric fields in a gated structure. Electrically assisted magnetization reversal, as well as electrical demagnetization, has been demonstrated through the effect. This electrical manipulation offers a functionality not previously accessible in magnetic materials and may become useful for reversing magnetization of nanoscale bits for ultrahigh-density information storage.     

婚内强迫性交行为的刑法学分析

婚内强迫性交行为指婚姻关系存续期间,丈夫以暴力、胁迫或者其他手段,违背妻子意志,强迫妻子性交的行为,包括婚内一般强迫性交行为和婚内严重强迫性交行为。婚内强迫性交行为不等同于婚内强迫性行为和婚内强奸。婚内一般强迫性交行为由婚姻法和伦理道德调整;对婚内严重强迫性交行为,刑法可以明确规定为犯罪,罪名可确定为婚内强奸罪,并根据情节的严重程度适用不同的法定刑。     

木材结合水扩散的非平衡态热力学研究

本文从非平衡热力学观点,推导了驱动力和通量的普遍表达式,并与Siau等所得到的结果作了比较,简单评述了关于木材中结合水扩散过程的研究,主要侧重于驱动力和通量讨论的进展。内容涉及木材水分输运中驱动力、化学势、蒸汽相的作用以及等温和非等温扩散模型。     

Hematite: intrinsic and defect ferromagnetism

Both intrinsic (spin-canted) ferromagnetism and defect ferromagnetism occur in hematite. Because defect ferromagnetism is sensitive to structure, it is altered by stress or heating and could give spurious paleomagnetic information. Annealing experiments now suggest that the defect remanence of fine-grain hematites and red sediments, unlike that of single crystals, is magnetically softer than the spin-canted remanence and can be erased by partial demagnetization.     

Magnetic properties of lunar samples

The magnetic properties of samples of rock, fines, and magnetic separate from the fines from Apollo 11 have been measured. Native iron, or possibly nickel-iron, of submicroscopic particle size is the most important constituent, with minor contributions from ilmenite, paramagnetic iron minerals, and other iron-titanium oxides. The remanent magnetization of a sample of the micro-breccia rapidly acquires a viscous magnetization and does not appear to have a significant stable remanence. The crystalline sample has a weak natural remanence showing some stability.     

Laser-selective demagnetization: a new technique in paleomagnetism and rock magnetism

Laser-selective demagnetization (LSD) enables the determination of the magnetic moment associated with individual mineral grains in thin sections of rock. Small volumes can be demagnetize with laser pulses directed through the optics of a microscope, permitting resolution of remanence components in individual mineral grains. LSD of mafic granulite samples revealed two paleomagnetic directional components of opposite polarity: one resided in coarse magnetite, the other in ilmenohematite-hemoilmenite exsolution intergrowths and fine magnetite indusions in clinopyroxene. These directions are consistent with those inferred from bulk demagnetization techniques, but LSD permits direct identification of the remanence carriers. The ability to discriminate magnetization components in different generations of a single mineral and to define intergrain magnetic moment distributions are significant advantages of LSD.     

分子动力学模拟高温高压下水的粘度

由于高温高压的极端条件实验室很难实现,因此应用分子动力学方法模拟计算水在高温高压下的粘度成为一种重要的手段。模拟实验基于分子动力学方法,针对水分子的特殊结构,引入Ewald法求长程作用力和四元素法,采用等温等压条件,最终模拟得到不同温度、压强下水的粘度并与实验值进行比较分析。     

Chemico-Viscous Remanent Magnetization in the Fe3O4-yFe2O3 System

The chemical remanent magnetization (CRM) acquired when single-domain size magnetite (Fe(3)0(4)) oxidizes to maghemite (gammaFe(2)O(3)) in a 50-microtesla field at a series of 13 temperatures from 1000 to 6560C is of similar intensity to viscous remanent magnetization (VRM) acquired under the same field and temperature conditions by unoxidized magnetite. The remanences of the oxidized and unoxidized phases also have similar resistances to demagnetization. These similarities imply that the remanence of the oxidized material is a chemico-viscous remanent magnetization (CVRM) having some of the characteristics of both classic growth CRM and thermally activated VRM. At low temperatures in partially oxidized grains, VRM of the magnetite core and growth CRM of the maghemite surface layer contribute about equally to CVRM. Near the Curie point, intensity of CVRM increases to a Hopkinson-type peak. High-temperature CVRM is more resistant to demagnetization than the thermoremanent magnetization (TRM) produced from cooling through the Curie point.     

生物炭与小球藻联合吸附重金属的效果

[目的]研究生物炭与小球藻对水体中重金属单独及联合吸附特性。[方法]以小麦秸秆生物炭和小球藻为吸附剂,进行了不同添加量的生物炭对Pb的吸附等温试验,小球藻对Pb等温吸附试验,以及生物炭和小球藻联合吸附Pb的等温吸附试验。[结果]生物炭与小球藻对Pb的等温吸附曲线均符合Langmuir方程。当生物炭添加量为50 mg/L时,吸附量最大,为203.339 mg/g;小球藻添加量为500 mg/L时最大吸附量为67.851 mg/g;生物炭和小球藻联合吸附的最大吸附量为79.144 mg/g。[结论]生物炭联合小球藻用于吸附Pb的最大吸附量高于单独吸附。     

对赫钦斯通识教育大学理念的再认识

美国著名的高等教育理论家和实践家赫钦斯针对当时盛行的实用主义教育思潮之弊端,提出了一整套以通识教育为核心的高等教育思想。他认为通识教育是整个社会教育尤其是大学教育的基础,它对抽绎永恒人性,培养学生良好个性,加强大学凝聚力等方面都起着积极的作用。主张大学应担负起引导社会前进的职责,而不应为迎合市民大众的浅近需要而盲目地随波逐流。认为大学教育的目标应执着“人性”而非着眼“人力”。赫钦斯的高等教育理念对美国乃至世界高等教育的发展产生深远影响,对当今我国高等教育改革与发展仍具有积极的启示和借鉴意义。     

Stable magnetic remanence in antiferromagnetic goethite

Goethite, known to be antiferromagnetic, acquires thermoremanent magnetization at its Neel temperature of 120 degrees C. This remanence, extremely stable, is due to the presence of unbalanced spins in the antiferromagnetic structure; the spins may result from grain size, imperfections, or impurities.     

汽车发电机抛负载电压的分析与估算

分析了汽车发电机抛负载电压的形成过程及其与发电机的相电动势、激磁电流和转速之间的关系，汽车发电机抛负载电压包含两个部分，且均由定子绕组本身产生．其一为定子绕组中负载电流突变产生的自感电动势，其特点是持续时间短，危害较小；其二为在激磁磁场作用下定子绕组产生的感应电动势经整流后得到的电压，其特点是电压持续时间长，危害较大，最后推导了发电机磁路在未饱和及饱和时抛负载电压的计算公式，并给出了相应的实例分析。     

现状特点与制约因素分析:贵州农村劳动力转移

农村劳动力非农就业问题一直是困扰贵州省农村发展中的一个重要问题。笔者通过对贵州省农村劳动力现状的分析，指出农村劳动力外出转移所带来的如促进农民增收、抑制城乡差距扩大、减轻对土地的压力、提高了农村劳动者素质等积极影响；同时也分析了不利因素的影响如经济水平低下、城镇化发展滞后、劳动者素质偏低、保守的文化、政策和体制的制约等。提出了提高农村劳动力素质、完善劳动力转移市场、加快制订劳动法、进行体制创新等改善农村劳动力外出的一些政策建议。     

洱海流域生态文明建设的法治保障

洱海流域生态文明建设过程中,形成的“大理模式”,是地方政府自上而下主导的管理模式,通过政府强制力保障实施的政府治理模式。洱海流域生态文明建设取得良好效果,与“大理模式”分不开,但现阶段仍存在着公众参与度不高、生态保护执法尚不规范、审判人员的环境专业素养不高和环境损害司法鉴定成本较大等问题。通过分析洱海流域生态文明法治建设的现状与存在的问题,构建了洱海流域生态文明建设的法治保障体系。在洱海流域生态文明建设的过程中,应推进生态文明建设的法治化,健全生态环境执法体制机制,加强生态环境司法保护,提高司法公信力。     

Phyllosticta capitalensis粉末菌剂对孔雀石绿染料的 吸附动力学分析

将富含多糖的内源真菌Phyllosticta capitalensis的粉末菌剂作为生物吸附剂,对孔雀石绿染料废水进行吸附处理.分别考察了粉末剂量、孔径大小、染料的初始浓度、pH值、背景离子强度和金属离子等因素对P.capitalensis粉末菌剂吸附孔雀石绿染液的影响.通过对实验数据进行吸附动力学和等温吸附模型的拟合,以及对吸附前后的吸附剂进行红外光谱扫描,探究P.capitalensis粉末菌剂对孔雀石绿染料的吸附机理.结果表明:粉末菌剂的最大单位吸附量为19.61 mg·g-1.当pH=6时吸附效果更佳,且在一定范围内粉末菌剂的粒径越大,染料浓度越高,吸附效果越好.而较高的离子强度与金属离子对P.capitalensis粉末菌剂吸附孔雀石绿溶液则起一定的抑制作用.动力学和等温吸附模型拟合分析表明该实验吸附过程符合准二级动力学吸附模型与Koble-Corrigan等温吸附模型,说明该吸附过程属于多层化学吸附,红外光谱扫描结果表明是粉末菌剂中的多糖羟基和羰基与染料发生反应.     

Magnetic studies of lunar samples

The remanent magnetismn of a lunar type C breccia sample includes a large viscous component with a time constant of several hours, and a high coercivity remanence, possibly acquired by impact processes on the lunar surface. Ilmenite(?) and metallic iron in breccias, and ferrous and metallic iron in glass beads separated from lunar fines (type D) were identified by high-field and low-temperature experiments. The iron appears to occur in a wide range of grain sizes including the single domain and multidomain states.