Upconversion emission of a Er3+-doped glass microsphere under 633 nm excitation (vol 35, pg 353, 2004)

　

半导体纳米结构物理性质的理论研究--2004年国家自然科学二等奖获奖项目介绍

半导体纳米结构是纳米材料的一个重要组成部分,纳米结构的电子和光子器件将成为下一代微电子和光电子器件的核心.半导体纳米结构有多种多样,如自组织量子点、纳米晶体、硅团簇、量子结构等,它们可以制成各种纳米电子学器件.根据以上几类半导体纳米结构,文章介绍的获奖项目提出了研究半导体纳米结构电子结构的四个理论,并利用这些理论研究了它们的电子态和物理性质,发现了许多新的效应.这些理论包括

我国半导体科学领域基础研究迈入新阶段--国家自然科学基金半导体学科2004年申请概况分析

2004年国家自然科学基金委员会半导体学科受理的面上项目申请数终于有了突破,文中介绍了2004年半导体学科基金申请与资助概况,分析半导体学科受理申请的近期动态,介绍学科拟采取的对策,并附2004年半导体学科批准资助的面上项目及重点项目,供广大科研人员参考.

1973年至2004年贵州喀斯特山区石漠化风险格局的变化——以普定后寨地下河流域中下游为例

以贵州省普定后寨地下河流域中下游为例,采用景观生态学的研究方法,利用多时相多数据源的遥感影像(1973年的航片、1995年的TM影像及2004年的SPOT-5影像),从不同等级石漠化风险的角度分析了研究区近30多年来的石漠化风险格局变化的特征,以期了解喀斯特高原山区的石漠化变化特征规律。结果表明:从景观水平上来看,整个区域的景观正在向程度更高的石漠化风险的方向发展,表现为极低度石漠化风险斑块的面积呈现出逐渐减少的趋势,而高度和极高度石漠化风险斑块的面积却呈现出不断增加的趋势;从斑块类型水平上来看,不同等级的石漠化风险斑块的变化差异明显,在变化幅度和变化趋势上都存在差异,其中极低度石漠化风险斑块面积变化最为明显,呈现出大幅度的下降,而变化最不明显的是低度石漠化风险斑块,无明显的增减趋势。

大连市2000～2004年农业生态系统能值分析

能值为环境、资源、人类劳务、信息和发展决策的分析评价提供了新尺度。为了更好地评价大连市农业种植业对太阳能资源的利用情况和大连市农业的可持续发展情况,本文在简单阐述能值分析理论基础上,运用能值分析方法,计算分析大连市2000年到2004年农业生态系统的能值投入与产出,并根据实际情况构建了能值分析指标体系。从净能值产出率和环境负荷力角度来量化分析大连市农业系统的发展状况。结果表明:从2000年到2004年,大连市农业生态系统净能值产出率分别为9.48、9.24、8.52、8.00和7.59,环境负荷力分别为10.21、11.49、6.26、10.41和9.03。大连市农业生态系统发展整体处于较好态势,但对环境的压力较大,应进一步加大其高科技含量的能值投入,以促进农业系统的更好发展。

基于遥感-过程耦合模型的1988～2004年青海三江源区净初级生产力模拟

三江源区不仅是地处青藏高原的全球气候变化的敏感区,也是我国甚至亚洲最重要河流的上游关键源区。作为提供物质基础的植被净初级生产力(Netprimaryproduction,NPP),是评价生态系统状况的重要指标。该文应用已在碳通量观测塔验证,扩展到区域水平的遥感-过程耦合模型GLOPEM-CEVSA,以空间插值的气象数据和1km分辨率的AVHRR遥感反演的FPAR数据为模型主要输入,模拟并分析了1988～2004年该区NPP时空格局及其控制机制。结果表明,该区植被平均NPP为143.17gC·m–2·a–1,呈自东南向西北逐渐降低的空间格局,其中,以森林NPP最高(267.90gC·m–2·a–1),其次为农田(222.94gC·m–2·a–1)、草地(160.90gC·m–2·a–1)和湿地(161.36gC·m–2·a–1),荒漠最低(36.13gC·m–2·a–1)。其年际变化趋势在空间上呈现出明显的差异,西部地区NPP表现为增加趋势,每10a增加7.8～28.8gC·m–2;而中、东部表现为降低趋势,每10a降低13.1～42.8gC·m–2。根据显著性检验,NPP呈增加趋势(趋势斜率b>0),显著性水平高于99%和95%的区域占研究区总面积的13.43%和20.34%,主要分布在西部地区;NPP呈降低趋势(趋势斜率b<0),显著性水平高于99%和95%的区域占研究区面积的0.75%和3.77%,主要分布在中、东部地区,尤以该区长江和黄河等沿线区分布更为集中,变化显著性也更高。三江源NPP的年际变化趋势的气候驱动力分析表明,整个区域水平上该地区植被生产力受气候变化的主导,西部地区暖湿化趋势,造成了该地区生产力较为明显的、大范围的增加趋势;但东、中部地区则主要受人类活动的影响,特别是长江、黄河等河流沿线,是人类居住活动密集的地区,造成这些地区放牧压力较大、草地退化严重,而该地区暖干化趋势加剧了这一过程。

Ecological environment changes in Daya Bay, China, from 1982 to 2004

Data collected from 12 marine monitoring stations in Daya Bay from 1982 to 2004 reveal a substantial change in the ecological environment of this region. The average N/P ratio increased from 1.377 in 1985 to 49.09 in 2004. Algal species changed from 159 species of 46 genera in 1982 to 126 species of 44 genera in 2004. Major zooplankton species went from 46 species in 1983 to 36 species in 2004. The annual mean biomass of benthic animals was recorded at 123.10 gm(2) in 1982 and 126.68 g m(2) in 2004. Mean biomass and species of benthic animals near nuclear power plants ranged froth 317.9 g m(2) in 1991 to 45.24 g m(2) in 2004 and from 250 species in 1991 to 177 species in 2004. A total of 12-19 species of hermatypic corals and 13 species of mangrove plants were observed in Daya Bay from 1984 to 2002. 2008 Elsevier Ltd. All rights reserved.

Preliminary study on different nutrient pools supplies for the phytoplankton growth in the Jiaozhou Bay in China in the fall of 2004

The source and significance. of two mitrients, nitrogen. and phosphorous, were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay in autumn 2004. This modified dilution method accounted for the phytoplankton growth rate, microzooplankton grazing mortality rate, the external nutrient pools, as well as nutrient supplied through remineralization by microzooplankton. The results indicated that the phytoplankton net growth rate increased in turn from inside the bay, to outside the bay, to in the Xiaogang Harbor. The phytoplankton, maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d(-1) outside the bay, 0.42 and 0.32 d(-1) inside the bay and 0.98 and 0.62 d(-1) in the harbor respectively. Outside the bay, the remineralized nitrogen (K-r = 24.49) had heavy influence on the growth of the phytoplankton. Inside the bay, the remineralized phosphorus(K-r = 3.49) strongly affected the phytoplankton growth. In the harbor, the remineralized phosphorus (K-r = 3.73) was in larger demand by phytoplankton growth. The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure, microzooplankton grazing mortality rates and environmental conditions. It is revealed that, nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.

On the crangonidae (Crustacea : Decapoda : Caridea) of the Philippines from the PANGLAO 2004 and PANGLAO 2005 expeditions

Eleven species of the caridean family Crangonidae are reported from the material collected by the Philippine PANGLAO 2004 and PANGLAO 2005 expeditions. Although they have been reported from the Philippines before, all the species have their colouration described and illustrated here for the first time.

Dinâmica espaço temporal das queimadas na Amazônia Legal nos anos de 2003 e 2004.

2005

Relatório de Atividades do Convênio de Cooperação Geral entre a Embrapa Monitoramento por Satélite e o Ministério da Defesa (Exército) - 2004.

2005

IV Plano Diretor da Embrapa Monitoramento por Satélite: 2004 - 2007.

Plano Diretor; Embrapa Monitoramento por Satélite