一种基于稀疏正则化的地下水点污染源识别法

提出了一种基于稀疏正则化的方法识别地下水点污染源。首先,对地下水一维对流-弥散方程时域有限元格式进行拉普拉斯变换得到频域方程,然后建立以l1范数项为约束的地下水点污染源识别问题的目标函数,从而克服空间分布稀疏的点污染源识别问题的不适定性;接着,利用交替优化法进行迭代求解。研究结果表明,所提方法能在噪声条件下有效识别地下水点污染源的位置和强度变化。     

用脉冲谱-优化法求解对流-扩散方程源项控制反问题

作者曾撰文求解了对流-扩散方程边界条件控制反问题，可根据下游河道的环境容量反求上游边界的限制浓度，作为确定排放标准的参考．在此基础上，本文求解对流-扩散方程的另一类反问题——源项控制反问题，并考虑了水流自净能力；作为典型的算例，可根据下游河道的环境容量反求散布在上游河道中的若干个污染源的限制强度．本文的成果与前文的成果相结合，可基本解决一维河道的污染源控制问题．解算方法仍为作者在前文中提出的脉冲谱-优化法，但本文导出了目标泛函对未知源项的变分的解析表达式．计算结果表明，用脉冲谱-优化法求解源项控制反问题，避免了传统的“试错法”，求解所需的信息少，计算精度高、速度快，能一次解出若干个污染点源的限制强度，在环境水力学领域有广泛的实用意义，也可用于泥沙悬移质控制问题．     

一类热传导方程非线性源项识别问题

利用单调性估计方法证明了一类热传导方程非线性源项识别问题的可识别性，并运用函数逼近理论，把对非线性源项的识别问题转化成一常系数参数识别问题；给出了一种对非线性源项识别的可实现的线性迭代算法及相应的数值实例。     

大沽夹河流域水环境评价及污染防治对策

根据1998年至2002年犬沽夹河流域水环境质量监测资料，选取CODCr、BOD5、总磷（TP）、氨氮（NH3-N）、总氮（TN）、pH和溶解氧（DO）7项评价指标。对犬沽夹河流域水环境质量现状进行了评价．结果表明，大活夹河水质污染严重，主要污染物为总氮．根据流域水质污染的特征和存在的问题，提出强化面源削减、城市污水集中处理、严格控制增加新污染源、进行面源污染控制量化研究四方面的综合防治时策．     

时间模上二阶3－点边值问题的两个正解

运用Avery—Henderson锥上的不动点定理，讨论了时间模上的二阶非线性动力学方程3-点边值问题{y^△ （t）＋a（t）f（y（t））=O，t∈[t1,t3] T，y^△（t1）=0，y（t3）=βy（t2）至少有两个正解的存在性．其中T是一个时间模，0≤t1〈t2〈t3,0〈β〈1．     

大冶市水环境污染源调查及防治

为全面了解大冶市水环境污染源情况,分别对大冶市点污染源和面污染源进行调查,采用产排污系数法、间接估算法和源强系数修正法等方法对污染物入河量进行核算。结果表明：大冶市面源污染对水环境造成的危害与点污染源相当,当地生活污水处理率较低,畜禽养殖与农田径流污染未能得到有效控制。针对上述结果提出相应保护水环境的防治措施建议：（1）从严控制面源污染;（2）强化环保基础设施建设;（3）调整产业结构,实施矿业经济转型。     

含弱阻尼和源项的非线性波方程的初边值问题

研究了含弱阻尼和源项的非线性波方程初边值问题．利用势阱理论和凹方法，证明当初始能量E（0）满足0〈E（O）〈d时（其中d为势阱深度）整体解的不存在性．     

波动方程反移动源问题

考虑三维波动方程的反移动源问题,其移动源项为F(x,t)=f (x-a(t))g(t).波场在可测量球面上的Dirichlet数据已知,利用Fourier变换将波动方程问题转化为频域的Helmholtz方程,建立了源项与观测数据的积分等式.利用Fourier逆变换和一阶微分方程解的存在唯一性定理,证明了轨迹函数a(t)的存在唯一性.最后,利用积分不等式来分析反演a(t)的稳定性.     

一阶非线性时滞微分方程周期解的存在性

考虑具有周期系数的一阶非线性时滞微分方程M’（t）=（p（t）/（q（t）＋M（t-mw）^n＋1-β（t）M（t），t≥0得到了方程的正周期解M（t）存在的充分条件．利用Mathin连续性定理，得到了方程的正周期解M（t）存在的充分条件．     

三维双曲方程非齐次边值问题的推广型LOD有限差分格式

针对三维非齐次双曲方程第一边值问题提出了一种新型的LOD有限差分格式,此格式能够将高维问题完全分解为一系列一维问题进行求解,克服了LOD格式源项难以分解、过渡层条件不易确定的缺陷．证明了该LOD有限差分格式按照离散L^2模具有二阶收敛精度,与抛物型方程相比,源项的扰动达到了△t^4,从而使△t的取法有更大的灵活性．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that