A simulation study of protons heated by left/right-handed Alfvén waves generated by electromagnetic proton-proton instability

Most protons in the solar wind belong to one of two different populations,the less dense beam protons and the denser core protons.The beam protons,with a velocity of(1-2)VA(VA is the local Alfvén speed),always drift relative to the core protons;this kind of distribution is unstable and stimulates several kinds of wave mode.In this study,using a 2D hybrid simulation model,we find that the original right-handed elliptically polarized Alfvén waves become linearly polarized,and eventually become right-handed and circularly polarized.Given that linearly polarized waves are a superposition of left-handed and right-handed waves,cyclotron resonance in the right-handed/left-handed component heats beam/core protons perpendicularly.The resonance between beam protons and right-handed polarized waves is stronger when the beam relative density is lower,resulting in more dramatic perpendicular heating of beam protons,whereas the situation is reversed when the beam relative density is larger.     

皮肤T细胞淋巴瘤局部用药和物理治疗的研究进展

皮肤T细胞淋巴瘤(cutaneous T cell lymphoma,CTCL)大多属于惰性淋巴瘤,病情进展缓慢,患者确诊时多处于疾病早期。局部用药和物理治疗在CTCL治疗中占重要地位,包括局部外用皮质类固醇激素、免疫抑制剂、维A酸,放疗及光疗等。近年来,有研究对CTCL传统局部用药和物理治疗方法的有效性和安全性进行了重新评估。同时,新型CTCL局部用药和物理治疗策略也不断涌现,如局部外用他扎罗汀、瑞喹莫特,紫外线A联合新型光敏剂的光化学疗法和光动力治疗等。本文对CTCL局部用药和物理治疗的研究进展作一综述。     

带有Lévy跳的随机捕食-食饵系统动力学行为

研究带有Lévy跳的随机捕食-食饵模型的动力学行为.主要通过构造恰当的Lyapunov函数,使用It公式证明了系统全局正解的存在唯一性,给出了系统随机持久、灭绝的充分条件,通过数值模拟进一步说明了所得理论结果的正确性.     

明代地方官府赋役核算体系的早期发展

明洪武到弘治年间,州县官府的赋役管理从基本不依赖核算向需要且能够进行核算的状态转变。洪武、永乐时期,在官府体系内部,只有田赋被部分地纳入核算管理,其他赋役征发则完全或绝大部分无法计量,也没有计划性。宣德以降,地方官员吸收民间粮里阶层分担赋役负担的经验,在此基础上进行旨在“均平”的改革,以确保赋役的可持续征发。在探索均平之道的过程中,不同地方官员多采取量化赋役负担、预定征收计划、将派征对象标准化并进行摊派核算的方式。其中,田赋额等开始扮演摊派对象的角色。这开启了州县层面赋役征收核算体系的发展之路,也导致府、州、县与户、工等部及布政使司之间产生了赋役核算信息不对称,出现了二重会计结构。     

Bolzano's Theorems for Holomorphic Mappings

The existence of a zero for a holomorphic functions on a ball or on a rectangle under some sign conditions on the boundary generalizing Bolzano's ones for real functions on an interval is deduced in a very simple way from Cauchy's theorem for holomorphic functions.A more complicated proof,using Cauchy's argument principle,provides uniqueness of the zero,when the sign conditions on the boundary are strict.Applications are given to corresponding Brouwer fixed point theorems for holomorphic functions.Extensions to holomorphic mappings from Cn to Cn are obtained using Brouwer degree.     

Option Pricing and Hedging under a Markov Switching Lévy Process Model

In this paper,we consider a Markov switching Lévy process model in which the underlying risky assets are driven by the stochastic exponential of Markov switching Lévy process and then apply the model to option pricing and hedging.In this model,the market interest rate,the volatility of the underlying risky assets and the N-state compensator,depend on unobservable states of the economy which are modeled by a continuous-time Hidden Markov process.We use the MEMM(minimal entropy martingale measure) as the equivalent martingale measure.The option price using this model is obtained by the Fourier transform method.We obtain a closed-form solution for the hedge ratio by applying the local risk minimizing hedging.     

热奈特的类文本理论及其效应

杰拉德·热奈特的类文本理论受到中西方学界的关注与重视,一些学者对该理论进行了一定的补充和修正工作,也有不少学者将其用于文学研究。类文本理论视阈下,文学研究的对象为环绕于文本边缘的类文本要素,如作者的署名、序言、献词、题记、版权页信息等。将作者重新纳入批评视野,类文本理论有效修正了文本理论将文本与作者相割裂的不当做法;将出版商引入批评框架,类文本理论不仅拓展了传统文学批评体系,还起到限制读者过度阐释的目的。同时,类文本理论促进了叙事学的进一步发展,使文学研究从文本中心走向文本边缘,并将文学的内部研究和外部研究相结合,从而推进了文学批评理论的发展。鉴于类文本与文本的互存关系,某些类文本和文本之间的界限模糊不清,它们在具备类文本属性的同时,又不乏文本的属性,而这一特性又恰恰佐证了类文本之于文本而存续的重要性。     

掺钼尾矿氯氧镁水泥免烧砖的制备

以商洛钼尾矿为试验矿样,以氯氧镁水泥为胶凝材料,进行了制砖研究。通过Mg O、Mg Cl2和钼尾矿等的混合,经搅拌、振动后制备免烧砖,研究了波美度和钼尾矿掺加量对免烧砖性能的影响,并分析了尾矿对免烧砖性能影响的机理。研究结果表明,当卤水波美度为28%,尾矿掺加量为80%时,性能较好,其28d的抗折强度和抗压强度分别为3.35MPa和9.28MPa。     

鄂尔多斯盆地地层水的配伍性研究

通过对中国图书馆分类法和中国科学院图书馆图书分类法及测绘学叙词表等相关资料的分析,确定本体中的类和定义类的语义关系,基于Protégé工具构建测绘学科信息公共本体、测绘学科分类—中图法本体及测绘学科分类—科图法本体,在构建的本体基础上基于Oracle 11g语义技术构建测绘学科分类本体库,为进一步语义检索提供基础.