不同模式对虾养殖水体中硝酸盐和亚硝酸盐的变化特征及其影响因素

于2001年10月15～19日在广西海洋研究所曲湾养殖基地,选择养殖南美白对虾(Penaeus vannamei)的8个封闭式的工厂化养殖池和4个开放式的水泥底普通养殖池,连续5d取样分析不同模式、不同密度、不同面积养殖水体中硝酸盐和亚硝酸盐的变化及其与环境因子之间的关系。结果表明,工厂化养殖水体中,硝酸盐和亚硝酸盐含量显著偏高,平均值分别为11．31mg／L和4．70mg／L;硝酸盐和亚硝酸盐含量随时间增加而升高,随养殖面积增大而下降。普通养殖水体中,硝酸盐和亚硝酸盐含量显著偏低,平均值分别为0．017mg／L和0．060mg／L,硝酸盐和亚硝酸盐含量在时间变化上无明显规律性。养殖水体中硝酸盐和亚硝酸盐含量与COD呈显著的正相关,与叶绿素a含量呈显著负相关关系,突出体现化学作用的输入影响及生物吸收的输出影响。     

台风对封闭式工厂化虾池生态系统中水环境因子的影响

于2003年7月23～29日台风发生期间在广西海洋研究所对虾工厂化养殖基地现场测定养殖水温、pH值和化学耗氧量(COD),采样分析养殖水体的无机氮(DIN)、无机磷(DIP)及叶绿素a(chl.a)含量,并对水温、pH值、COD、DIN、DIP、chl.a间进行相关性分析,研究封闭式工厂化虾养殖生态系中环境因子的变化状况及其影响因素.结果表明:台风气候对该生态系中的水环境因子影响较大,一方面既导致了浮游植物的快速削减,也导致了pH值的明显下降;另一方面又导致了COD的显著增加和DIN、DIP的明显上升.台风期间养成密度大的养殖池中,环境因子之间多具有显著的相关性;养成密度小的养殖池中,环境因子之间的相关性较差.显然,虾池生态系中水环境功能的优劣对对虾的养成质量及抵抗自然灾害具有至关重要的作用,而虾池有机物的及时清除以及水环境因子的适时调控也是重要的一环.     

关于指数丢番图方程x2+by=cz

设m是偶数,r是奇数;又设Ur、Vr是适合Vr＋Ur√-1=（m＋√-1）^r的整数．笔者证明了：当a=｜Vr｜,b=｜Ur｜,c=m^2＋1,r=3（mod4）,m〉r／π且m是2的方幂时,指数丢番图方程仅有正整数解．     

大规格凡纳滨对虾健康养殖试验

为寻找出一条适合广西北海地区高产、稳产、高效益、可持续发展的大规格对虾养殖模式,通过凡纳滨对虾（Litopenaeus vanmamei）无公害健康养殖试验,获得了显著效果。养殖池1口,面积0．2hm^2,放养虾苗的体长0．8～1．0cm,共8万尾。经136d养殖,获对虾1403．7kg,平均7018．5kg／hm^2,规格37．4尾／kg,成活率65．6％。产值44918元,扣除生产成本25854元,获利19064元,平均每公顷获利95322元。     

凡纳滨对虾养殖早期水体中氮磷营养盐变化规律研究

为探讨凡纳滨对虾养殖早期水体中主要营养盐含量及其变化,测定了对虾池水体中的氨氮、硝酸盐、亚硝酸和磷酸盐。结果显示,氨氮浓度变化范围：0．3-0．02mg／L,硝酸盐浓度变化范围：0．29-8．68mg／L,亚硝酸盐浓度变化范围：0．15-8．50mg/L,磷酸盐浓度变化范围：004-1．10mg／L。在养殖早期水体中,氨氮浓度呈波动变化,硝酸盐、亚硝酸盐和磷酸盐含量相对稳定。     

标准型绝对值函数的分段函数形式及应用

获得了化标准型函数 y=｜｜x｜-a｜=y=｜…｜｜x｜-a｜…-a｜（a〉0,n∈N）分段函数的一般解析式，举例说明了化标准型绝对值函数为分段函数形式的数学应用。     

乌龙茶覆盖遮荫技术的研究

进行了夏季乌龙茶园不同遮荫度遮荫的生态生理生化效应及其对茶树生长、产量和品质的影响研究．结果表明：与不遮荫的对照处理相比，遮荫后，(1)树冠层的白昼平均温度、日极端最高温度和温度日较差分别下降了1．47～4．29℃、3．95～7．26℃和3．33～8．44℃；白昼平均相对湿度、日极端最低相对湿度分别增加了4．31％～12．31％和3．27％～12．62％，相对湿度日较差减少了3．58％～12．94％．(2)夏、暑梢1芽3叶含水率分别增加了4．57％～6．47％和2．24％～2．78％．(3)夏、暑梢叶绿素总量分别增加了0．5983～0．7019mg／dm^2和0．3480～0．6050mg／dm^2．增幅达41．70%～48．92％和52．38％～91．06％；叶绿素a增加38．96％～47．25％和50．94％～72．52％；叶绿素b增加了43．83％～54．58％和67．98％～155．81％；叶绿素a、b比值下降了0．1042～0．1868和1．10～3．54．(4)茶叶中茶多酚和咖啡碱含量明显降低，氨基酸含量明显提高，粗纤维含量显减少．儿茶素组份得以优化．(5)适度遮荫有利于提高夏暑茶的产量和品质．     

带有临界Sobolev和Hardy项的半线性椭圆方程的解（I）

设Ω包含R^N是有界光滑区域，0 ∈Ω ,N≥3,2^＊：=2N/N-2,0≤s〈2,2^＊（s）：=2（N-s）/N-2,2〈r〈2^＊（s）．对于满足一定条件的参数λ和μ，证明了带Diriehlet边界条件的奇异椭圆问题-△u-μu/｜x｜^2=｜u｜^2＋-2u＋λ｜u｜^r-2/｜x｜^1u的一些重要性质．     

一类带有Hardy项和Sobolev—Hardy临界指数椭圆方程的非平凡解

研究了一类带有Hardy项和Sobolev—Hardy临界指数的椭圆方程{-△u-u＋h（x）/｜x｜2u=｜u｜2·（s）-2/｜x｜s u＋λ｜u｜q-2 u,x∈Ω; u=0,x∈ Ω。通过运用变分方法和精确估计得到了非平凡解u∈D 1,2（Ω）的存在性．其中：Ω R N（N≥3）是一个有界光滑区域,0∈Ω,λ〉0,u∈R,0≤s〈2．     

一类p-Laplace发展方程解的存在性

研究了一类p—Laplace发展方程ut=div（｜▽u｜^p-2▽u）＋au∫Ωu^q（x,t）dx在一个有界域Ω R^N（N〉2）解的存在性,其中Δp=div（｜▽u｜^p-2▽u）,P〉1,r,q〉0．证明了当r,q≥1时,方程的解唯一存在;而在r〈1或者q〈1时局部解存在,但唯一性未必成立．     

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.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with