我国水产动物营养研究与渔用饲料的发展战略研究

对我国未来15年水产动物营养研究与渔用饲料开发的展战略进行了探讨.分析了本领域国内外的研究现状及发展方向;指出了我国与发达国家之间存在的差距.最后,提出了21世纪我国水产动物营养与饲料研究的任务及关键技术.     

航天器舱自动化布局设计的若干科学问题

航天器(卫星、飞船等)舱自动化布局设计在数学上属组合最优化、Packing、NPC问题,在工程上属概念设计和方案设计问题.存在的主要困难是:布局问题描述复杂,建模和求解困难,既要解决数学上的组合爆炸问题,又要解决工程系统的复杂性问题,以达到工程上的实用.在综述国内外有关进展的基础上,介绍了该课题组近15年来的阶段性研究进展,重点讨论:(1)模型和求解算法;(2)干涉计算;(3)布局拓扑模式;(4)布局方案评价;(5)工程实用化等5个关键科学问题.     

水产动物幼体开食饲料的开发和应用

水产动物幼体的开食饲料,又称微粒子人工饲料,是水产动物幼体在各个不同发育阶段人工配制的初始微型适口饲料,一般要求粒径在50—500微米之间,其浮游性(比重)要能自由调节,投于水中营养成份不易     

线粒体DNA多态分析在动物遗传育种研究中的应用

综述了近二十年来线粒体ＤＮＡ多态分析在动物分类、进化、亲缘关系和育种等方面的研究进展，并对线粒体ＤＮＡ多态分析在畜牧业上的应用前景作了展望。     

东海区典型断面营养盐潜在性富营养化评价

根据1989年至2010年丰水期东海区3条断面表层营养盐调查结果,分析近20年来东海典型断面丰水期无机氮、活性磷酸盐、硅酸盐长期变化。结果表明:(1)1989-2010年东海区表层水体中无机氮从1996年开始波动浓度范围明显增大,无机氮的最大浓度增加到1989年的2.15~5.94倍,平均值浓度为1989年的1.80~6.75倍;(2)活性磷酸盐在1989-2010年呈现历年增大的变化趋势。活性磷酸盐的平均浓度是1989年的1.44~9.22倍,在2005年达到最高;(3)硅酸盐的浓度在0.00~107.17μmol/L,波动较大,除了2002年最大浓度骤降外,整体基本呈现上升趋势;(4)从总体上看,除长江口附近3-5个测站外,表层水体基本为贫营养,总体上营养水平很低,水质质量较好。     

植酸酶在水产养殖中的应用(综述)

从植酸酶对水产动物生长性能、磷及其它矿物质生物利用、水产动物饲料营养消化率、水产动物体成分、水产动物血液生化指标等的影响和降低磷酸二氢钙用量,减少环境污染方面综述了新型饲料添加剂植酸酶的作用。探讨了水产饵料中添加植酸酶的最适添加量问题和植酸酶的活性问题。从提高水产动物饲料利用率;减少环境污染,保护生态平衡等方面阐述了植酸酶在水产养殖中的应用前景。     

1960—2011年秦岭南北地表干湿变化时空特征

运用P-M模型、气候倾向率及相关分析等方法,分析秦岭南北近52年地表干湿变化特征及其影响因素.结果表明:(1)潜在蒸散量(ET0)和干燥度指数(I)均呈现由南向北逐渐增加的空间分布型式;(2)ET0呈下降趋势,降速为-0.314mm/a(P0.05),其中1993年之前下降趋势显著,为-2.699mm/a(P0.01);(3)I呈缓慢上升趋势,增速为0.022/10a,在空间上呈现中部下降、两侧上升的分布型式,上升和下降趋势区域分别占62.62%和37.38%;(4)各年代干湿分界线变化显著,20世纪90年代最干旱,21世纪干燥程度有所缓解;(5)秦岭南北地表干湿状况及干湿分界线的变化主要归因于相对湿度、日照时数及降水量的变化.     

英汉动物喻体的差异及文化内涵

世界上所有的语言中都有以动物作喻体的比喻,英汉两种语言也不例外。本文通过对英汉两种语言中“动物”喻体的比较来探讨英汉两种文化的异同。全文分为四个部分:(1)喻体相同,喻义也相同;(2)喻体相同,喻义不同;(3)喻体不同,喻义相同;(4)英、汉两种语言都具有自己民族文化个性特色的“动物”喻体。     

水产养殖业中应用的几种新型消毒剂

近年来,随着集约化水产养殖方式的日益普及,养殖水域受到了严重的污染。各种病原微生物在水体中大量繁殖,导致水产动物细菌、病毒性疾病流行,严重阻碍了水产养殖业的健康发展,于是,消毒剂使成了抑制杀灭水体原微生物的主要手段。近十几年来,水产养殖业普遍使用含氯消毒剂,基本上为漂     

左旋肉碱对机体物质代谢及运动能力的影响研究进展

L-肉碱(即左旋肉碱L-carnitine)是机体内一种具有多种生理功能的氨基酸类物质,对机体血浆肉碱含量、肌肉酶活性以及更为重要的脂类代谢过程具有重要的调节作用,早期的研究主要关注补充L-肉碱后可以增强机体的耐力运动表现,近十年来对于L-肉碱作为肌肉能源选择以及生理功能调节者的重要作用的研究提出了许多富有见解的新观点;L-肉碱在通过线粒体膜转运脂肪酸的过程中发挥着重要的作用,在血浆中确实发现了血浆肉碱含量增加的情况。虽然一些研究表明,相对于运动能力而言,在口服肉碱后,并没有显示出其对健康人群机体物质代谢及健康状况会产生不可或缺的影响,但是绝大多数研究表明,L-肉碱可以帮助特定的人群在运动能力表现上达到一个较高的水平。     

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.     

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