外来入侵物种的危害及防治对策

在查阅大量文献资料基础上，综合阐述外来入侵物种的来源、生物学特征、入侵的过程与机制及其危害，结合外来入侵物种的现状提出外来入侵物种的生物安全管理措施及防治对策。     

外来入侵物种的危害及防治对策

在查阅大量文献资料基础上，综合阐述外来入侵物种的来源、生物学特征、入侵的过程与机制及其危害，结合外来入侵物种的现状提出外来入侵物种的生物安全管理措施及防治对策。     

阻击外来物种入侵

外来物种入侵是当今世界最棘手的三大生态环境难题之一,外来物种入侵引起的灾害比比皆是,如何阻击外来物种入侵,已成为当前科学研究的一个热点。国家环保总局有关负责人近日也提出警告:外来物种入侵正成为威胁我国生物多样性与生态环境的重要因素之一,在我国几乎所有类型的生态系统中都出现了外来有害物种的危害。据统计,松材线虫、湿地松粉蚧、松突圆蚧、美国白蛾、松干蚧等森林入侵害虫严重发生与危害的面积在我国每年已达150万公顷左右。美洲斑潜蝇、马铃薯甲虫、非洲大蜗牛等农业入侵的害虫近年来每年严重发生的面积达到140万至160万公顷。入侵我国东北、华北、华东、华中的豚草,入侵西南地区的紫茎泽兰和飞机草,入侵广东的薇甘菊,在我国华东、华中、华南、西南地区作饲料引进的空心莲子草与水葫芦,沿海省区引进的大米草等的蔓延,对本地生物多样性和农业生产造成了巨大威胁,已经到了难以控制的局面。这些物种疯长成灾,侵入草场、林地和荒地,很快形成单种优势群落,导致原有植物群落的衰退。     

秦皇岛市外来入侵物种的调查分析

采用实地考察、文献词研与专家咨询相结合的方法,对秦皇岛市外来入侵物种的种类、来源地、入侵途径以及对生态环境的影响等进行了系统调查。结果表明,秦皇岛市外来入侵物种共计32科67种。其中,外来入侵植物22科57种;外来入侵动物10科10种。分析了外来物种的入侵途径和入侵危害,提出了应采取的必要防范和控制措施。     

生物入侵的危害

生物入侵是指生物由原生存地经自然或人为的途径进入到另一个新环境，并在当地的自然或人为生态系统中定居、自行繁殖和扩散，最终明显影响当地生态环境，损害当地生物多样性，破坏农林牧渔业生产、危害人类健康的现象。生物入侵已成为当前全球性的环境问题。据统计，美国每年因外来物种入侵造成的经济损失高达１５００亿美元，印度每年的损失为１３００亿美元，南非为８００亿美元。我国每年仅几种主要外来入侵物种造成的经济损失就达５７４亿元人民币。生物入侵的危害不仅仅是经济损失，更严重的是在以下几个方面。一是外来入侵物种会造成…     

外来物种对中国的影响和立法研究

防治外来物种入侵、维护生物多样性,是各国政府必须解决的一项重要课题.然而,我国防治外来物种入侵的法律法规却存在明显的缺陷,对外来物种入侵方面的立法也相当滞后,这种现状难以适应中国环境保护、经济和社会和谐发展的需要,也难以符合我国生物多样性保护的要求.因此,尽快建立和完善相关的法律制度来确立我国防治外来物种入侵的法律体系将有重要意义.针对我国目前的现状,提出防治外来物种入侵立法的意见和建议,以期通过法律手段有效地防治外来物种的入侵,并促进我国对防治外来物种入侵的相关立法.     

外来海洋生物的入侵及其生态危害

一提到生物入侵,很多人就会问,外来生物和外来入侵生物有何区别?外来入侵生物究竟有何危害?对此,请看看科学家是如何解释的。外来物种和外来入侵物种的区别外来生物物种是指当地历史上从来没有分布的、而是被人类直接或间接引入的生物物种。在外来生物物种当中,有一些生物物种被引入之后,由于环境适宜、没有天敌等原因,通过迅速繁殖与当地生物物种产生激烈的竞争,以至剥夺当地物种的生存空间和食物资源,最终排挤和消灭掉被竞争的当地物种,破坏当地的生态平衡。这些极具侵略性的外来生物物种就被称之为“外来入侵物种”或“外来入侵生物”或…     

外来种入侵与生态安全

世界的生物多样性正受到严重威胁，其中，生物入侵已成为威胁生物多样性的重要因素之一，近年来，外来种入侵对我国生物多样性的危害日益加剧，已经危及到我国的生态安全，为此从介绍与外来种入侵有关的概念入手，分析了外来种入侵的途径，生物入侵对我国生态环境、生物多样性（包括物种多样性和遗传多样性）、经济及社会的严重影响，提出在外来种入侵的防治和管理方面，应根据我国国情和目前生物入侵的实际状况，加强国家能力、研究能力和监管能力建设，确保我国的生态安全。     

我国公布首批16种危害极大的外来入侵物种名单

近年来,外来入侵物种已对我国生物多样性和生态环境造成了严重的危害,同时造成了巨大的经济损失。为此国家环保总局公布了首批入侵我国的外来物种名单。国家林业局日前也成立了“国家林业局防止外来林业有害生物入侵管理办公室”。国家环保总局这次共公布了16种外来入侵物种,分     

生物入侵的现状及防治对策

本文探讨了生物入侵的概念以及入侵的途径 ,生物入侵的危害 ,文中列举了我国多个典型的入侵物种实例 ,接着提出了一些针对生物入侵的防治方法及对策。相信随着国人生态意识的不断加强以及国家有关法规的不断完善 ,我国的外来物种入侵问题将会一个个得到解决 ,威胁本地生物多样性的那些外来物种终会得到有效的控制。     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~