低频标准振动台失真度及测量

波形失真度是衡量标准振动台技术性能的一个重要指标,为了规范它的测量方法及所用仪器,对低频标准振动台的低频失真度进行了分析,对失真度测量方法进行了实验研究,提出了低频失真度的表述方法及合格界限.经大量的实验验证,提供了失真度的测量方法及所用仪器.为低频标准振动台技术指标检定规程的制定、规范失真度的测试方法提供了参考依据.     

建立中国城市的实体地域概念

本文总结了我国在城市的行政地域与景观地域严重背离的情况下，继续使用行政地域区分城乡的种种弊端，认为解决这一问题于关键在于建立适合中国特点又具有国际可比性的城市实体地域概念，以此作为城乡划分及统计的地域基础，文章提出以下限人口规模、非农化水平和人口密度三个指标定义城市实体地域，并在大量实证研究的基础上，通过对中国城市空间形态的分类，提出了一套完整的划分实体地域的方法和工作程序。     

Effects of Updated RegCM4 Land Use Data on Near-Surface Temperature Simulation in China

Biogeophysical effects of land use and land cover (LULC) changes play a significant role in modulating climate on various spatial scales. In this study, a set of recent LULC products with a spatial resolution of 500 m was developed in China for update in RegCM4 (regional climate model version 4). Two sets of comparative numerical experiments were conducted to study the effects of LULC changes on near-surface temperature simulation. The results show that after LULC changes, areas of crops and mixed woodlands as well as urban areas increase over entire China, accompanied with greatly expanded mixed farming and forests/field mosaics in southern China, and reduced areas of 1) irrigated crops and short grasses in northern China and the Tibetan Plateau, and 2) semi-desert and desert in northwestern China. Improvements in the LULC data clearly result in more accurate simulations of the near-surface temperature. Specifically, increasing latent heat and longwave albedo due to enhanced LULC in certain areas lead to reduction in land surface temperature (LST), while changes in shortwave albedo and sensible heat also exert a great influence on the LST. Overall, these parameter adjustments reduce the biases in near-surface temperature simulation.     

大兴安岭北部冻土中CO分布研究

冻土中的甲烷作为重要的温室气体得到了广泛研究, 而CO作为一种具有间接温室效应的气体,目前的研究还非常少.调查了大兴安岭北部兴安落叶松林地冻土中CO气体的分布, 发现非过火区CO浓度普遍在21～117 mL·m-3, 过火区在0～15 mL·m-3;夏季CO浓度阴坡在8～221 mL·m-3, 阳坡在0～85 mL·m-3. 在0～75 cm深度 CO浓度有逐渐上升趋势;较平缓的阴坡CO浓度明显高于较陡峭的阳坡;适当降雨有利于CO气体的产生, 大雨或连续阴雨天气不利于CO的产生, 大雨后1～2 d内CO浓度较高, 并且在不同地理位置有不同的观测结果. CO、 CH4作为可燃性气体, 对森林火灾有何影响, 还需要做进一步研究.     

通过椭球变换建立区域独立坐标系的方法

阐述了应用椭球变换建立区域独立坐标系的方法。以某山区道路为例,分别运用椭球膨胀法、椭球平移法、椭球变形法建立区域独立坐标系,对这些方法建立的独立坐标系的投影变形值进行了分析,比较了3种方法的特点。     

昌都地区盐泉水化学特征与找钾研究

昌都地区发育有大量的膏盐、白云石及菱镁矿,研究其区域成钾潜力意义重大。在对昌都盆地蒸发岩矿点实地考察过程中,共采集12个盐泉水样及2个泉水样。通过常微量元素及水化学特征系数研究,查明研究区盐泉水水化学类型为氯化物型和硫酸钠亚型,属于岩盐溶滤成因,溶滤了大量的石盐和少量的碳酸盐岩及硫酸盐岩,纳西盐井盐泉水同时还受深部循环水的影响。昌都地区盐泉水样中Na、Cl含量及矿化度由北向南逐渐降低,Br、Li、B含量较低,整体上呈现以贡觉为中心,向北、向南逐渐增高的变化趋势。研究区盐泉水具有内陆盐湖性质,北部含盐地层更具海相成因特征,盆地由北至南从海相沉积环境逐渐过渡为内陆海沉积环境,受陆表水影响愈大。研究表明,类乌齐含盐地层经历了最强烈的浓缩蒸发及岩盐溶滤作用,其浓缩阶段晚于纳西及贡觉含盐带,其成钾潜力同样也优于纳西及贡觉含盐带,可作为钾盐矿异常点。贡觉和纳西含盐地层在不同程度上受到了陆表水的影响。综合对比前人研究成果,发现囊谦—昌都—兰坪盆地自北向南,成钾潜力逐渐变优。     

Using lithium isotopes to quantitatively decode continental weathering signal: A case study in the Changjiang (Yangtze River) Estuary

As the key link connecting the earth's spheres, continental weathering plays an important role in regulating the global biogeochemical cycle and long-term climate change. Siliciclastic sediments derived from large river basins can record continental weathering and erosion signals, and are thus widely used to investigate weathering processes. However, sediment grain size, hydrodynamic sorting and sedimentary recycling complicate the interpretation of sediment weathering proxies. This study presents elemental and lithium isotope compositions of estuarine surface sediments(SS) and suspended particulate matters(SPM) collected from the Changjiang(Yangtze River) Estuary. Based on a simple mass balance model, the proportions of different end-members(i.e., igneous rocks, modern weathering products and inherited weathering products) in sediments were quantitatively calculated and thus the silicate weathering process can be estimated. Overall, the sediments in the Changjiang Estuary are mainly eroded from un-weathered rock fragments(60%), while modern weathering products account for less than40%. The fine-grained SPM contain more shale components(52–66%), and the modern weathering products account for 21–40%. Comparatively, the coarse-grained surface sediments contain more un-weathered igneous rock fragments(63–84%) and less modern weathering products(only 4–18%). The comparison of δ7 Li values with the weathering proxy(Chemical Index of Alteration, CIA) suggests that sediment weathering intensity declines with increasing proportion of un-weathered igneous rock fragments. Additionally, the occurrence of inherited weathering products(i.e., shale) in modern sediments makes it a challenge to simply use CIA and δ7 Li as indicators of weathering intensity. This study confirms that fine-grained particles are more suitable for tracing contemporary weathering process, albeit with the influence of sedimentary recycling. Lithium isotopes combining with the mass balance model can quantitatively constrain the continental weathering processes in large river basins.     

初夏孟加拉湾对流云团北上低纬高原的初步研究

分析2000—2001年初夏(5—6月)孟加拉湾对流云团活动特征及其北上的环流背景以及与西太平洋副热带高压的关系。结果表明：初夏孟湾对流云团活动对低纬高原的初夏降水有明显影响；孟湾北部及其东部海域和沿岸是对流云团北上频数最多的地区；下风方伴随风速大值区的西南气流有利于孟湾云团北上；孟湾云团北上与西太平洋副热带高压的活动和位置关系密切。     

横向非均匀介质Q值层析成像方法、软件及应用

Q值结构对了解地壳的非弹性性质、地壳内部构造、热活动状态、地壳介质非均匀性以及断层分布有着非常重要的意义。编写了基于吸收特征时间t*的二维横向非均匀Q值层析成像人机交互软件,可以方便快捷地计算深地震测深资料的振幅谱并通过拟合振幅谱得到反映地震波衰减的t*。利用t*通过二维Q值层析成像方法得到Q值结构。实际观测资料处理结果表明,文中给出的方法和软件是有效且可行的。     

中国资源规制的概念、框架和实践(英文)

当前我国经济增长模式对自然资源的依赖程度过高,已经引起了严重的经济和社会问题,尤其是自然资源约束的变化威胁着未来我国区域经济的可持续发展。根据我国自然资源的制度基础及经济条件,本文提出了资源规制的概念。资源规制是政府规制在自然资源领域的应用,其目的在于调节和控制区域发展,是政府对资源勘查、开发、利用、经营和保护等行为的约束。资源规制包括了两层涵义:一是对自然资源的管理,二是以自然资源为工具对区域经济和社会发展的调控。我国资源规制的基本框架主要由法律规制、规划规制、标准规制和具体的指标规制四个层次构成,而其他的社会参与、监督、监测、评价和奖惩对于资源规制框架的构建也是必不可少的。从资源类型来看,我国的资源规制主要集中在对水资源、土地资源、能源资源和环境资源的规制上,而对于海洋资源、矿产资源和森林资源的规制力度则较弱。总体来说,我国的资源法律规制、规划规制和标准规制的基本体系已经基本形成,并取得了较好的效果。而具体的指标规制则较为分散和破碎,建立完善的资源规制体系仍任重道远。