排序方式： 共有144条查询结果，搜索用时 15 毫秒
121.
The paper reviews a number of challenges associated with reducing degradation and its related emissions through national approaches
to REDD+ under UNFCCC policy. It proposes that in many countries, it may in the short run be easier to deal with the kinds
of degradation that result from locally driven community over-exploitation of forest for livelihoods, than from selective
logging or fire control. Such degradation is low-level, but chronic, and is experienced over very large forest areas. Community
forest management programmes tend to result not only in reduced degradation, but also in forest enhancement; moreover they
are often popular, and do not require major political shifts. In principle these approaches therefore offer a quick start
option for REDD+. Developing reference emissions levels for low-level locally driven degradation is difficult however given
that stock losses and gains are too small to be identified and measured using remote sensing, and that in most countries there
is little or no forest inventory data available. We therefore propose that forest management initiatives at the local level,
such as those promoted by community forest management programmes, should monitor, and be credited for, only the net increase
in carbon stock over the implementation period, as assessed by ground level surveys at the start and end of the period. This
would also resolve the problem of nesting (ensuring that all credits are accounted for against the national reference emission
level), since communities and others at the local level would be rewarded only for increased sequestration, while the national
reference emission level would deal only with reductions in emissions from deforestation and degradation. 相似文献
122.
Proteomics is a new and promising approach to evaluate potential effects of pollution. In order to investigate if there is a direct link between the protein expression profiles obtained by the SELDI-TOF MS technology and effects observed at the organism level in fish, plasma samples from unexposed and 20 ppb alkylphenol exposed female Atlantic cod (Gadus morhua) with high phenotypic variation in gonadosomatic index (GSI) were analyzed by SELDI-TOF MS. Principle component analysis (PCA) showed that the major proteomic variation present in the dataset (i.e. 23.6%) could be significantly correlated to the individual variation in GSI, which indicates that SELDI-TOF MS data can reflect effects observed at higher levels of organization in fish. Further exploration of the other principal components revealed an additional proteomic pattern specific for the alkylphenol exposed females. Hence, this study supports the usefulness of SELDI-TOF MS as a proteomic tool in ecotoxicological research. 相似文献
123.
124.
125.
利用文中所提出的指示方法勘查盲矿体是一项新而有效的技术。该方法的依据是：由于岩浆、热液及构造作用，使得矿质及其有关的脉体物质活化、迁移、在上覆岩体中发生部分再沉积。 相似文献
127.
Brown MM Williams TD Chipman JK Katsiadaki I Sanders M Craft JA 《Marine environmental research》2008,66(1):127-130
128.
一、地调机构的产生及其规模一个国家的经济发展,离不开自然资源,而自然资源的有效开发利用需要系统的自然地理和历史的信息。十八世纪工业革命带来的通讯、交通和产业的迅猛发展增加了对未开垦的美洲、澳洲、非洲的开发呼声,为促进当地勘查业的发展,满足市场需求,必须开展地质填图以搞清矿产资源的分布,而在欧洲工业发展则要求 相似文献
130.