大陆大气本底基准研究

国家社会公益类研究重点项目“大陆大气本底基准研究”2006年8月通过由国家科技部基础司组织的验收。验收专家组认为项目观测数据资料、数据质量的总体水平达到国际先进水平，对瓦里关山NOy的观测和本底地区气溶胶理化特性方面有价值的发现。     

光纤耦合微通道反应系统原位监测海水氨氮和亚硝酸盐的研究

原位监测海水中氨氮（NH3-N）和亚硝酸盐（${rm{NO}}_2^- $）对于水体富营养化评价十分重要。针对现有的氨氮、亚硝酸盐原位监测仪器难以在同一检测模块中分别实现荧光和分光光度分析,仪器高效集成及利用受到限制等问题,本文基于光纤耦合微通道反应系统,通过光波长切割、光纤波导和微通道反应 Z 型检测池等技术集成和条件优化,提出了在同一光纤偶联微反应系统中实现氨氮荧光分析和亚硝酸盐分光光度分析的原位测定技术。结果表明,该技术实现了荧光和可见光光度法的模式切换并可分别测定NH3-N和${rm{NO}}_2^- $;在恒温条件下,NH3-N测定荧光信号漂移小于−2.0%,${rm{NO}}_2^- $测定吸光度稳定;不同的盐度对氨氮和亚硝酸盐测定影响较小;不同浊度下氨氮测定误差为−6.6%～2.5%,浊度补偿校正后${rm{NO}}_2^-$测定误差小于0.1%。将该仪器应用于养殖海水中开展氨氮和亚硝酸盐的原位分析,仪器原位监测值与实验室方法测定值相符合。本文所提出的技术在同一模块中分别实现了氨氮和亚硝酸盐的荧光和分光光度两种模式的原位监测,为海水营养盐原位监测仪器的集成化设计提供了新的思路。     

Review of Digital Elevation Model （DEM） Based Research on China Loess Plateau

Introduction The Loess Plateau is located in the upper and middle reaches of the Yellow River, among the western Taihang Mt, eastern Riyue-Helan Mt, northern Qinling Mt, and southern Yinsan Mt (from 100°54′to 114°33′E and 33°43′to 41°31′N; Figure 1). It covers a total area of 624,000 km2. The Loess Plateau of China has drawnworldwide attention in geographical research for its unique morphological features, abundant nature resources, most serious soil erosion, as well as its pot…     

A two-way nested-grid ocean-circulation model for the Meso-American Barrier Reef System

A two-way nested-grid ocean-circulation model is developed for the Meso-American Barrier Reef System (MBRS), using a newly developed two-way interactive nesting technique. The unique feature of this new nesting technique is its use of the semi-prognostic method (Sheng et al. 2001) to exchange information between different grids through the model momentum equations. The nested-grid model for the MBRS has a fine-resolution inner model embedded in a coarse-resolution outer model. The outer model is the western Caribbean Sea model developed by Sheng and Tang (2003), with a horizontal resolution of roughly 19 km. The inner model domain covers the northwest Caribbean Sea (NWCS) between 79°W and 89°W and between 15.5°N and 22°N, with a horizontal resolution of roughly 6 km. The nested-grid ocean model is initialized with the January mean temperature and salinity and forced by the monthly mean COADS (comprehensive ocean-atmosphere data set) wind stress and surface heat flux. The model sea-surface salinity is restored to the monthly mean climatology. The nested-grid model is integrated for 2 years and the second-year model results are presented in this paper. The model-calculated annual-mean near-surface currents over the NWCS agree reasonably well with the time-mean near-surface currents inferred by Fratantoni (2001) from trajectories of the satellite-tracked 15-m drogued drifters in the 1990s. The two-way nested model is also used to quantify the role of local wind stress, local density gradients and boundary forcings of the outer model in driving the annual-mean circulation in the region.Responsible Editor: Phil Dyke     

河东煤田地史—热史模拟与煤变质演化

河东煤田是华北石炭二叠纪重要煤田之一．本文采用盆地数值模拟方法,建立了煤田地史一热史模型,恢复了煤变质演化历程,总结出煤级分布规律。     

Palaeoceanological significance of Holocene ostracean banks in Tianjin area

On the basis of the study of ostracean banks in Tianjin area, the present study recognized that the ostracean banks at Ninghe County in Tianjin area are well developed along the west coast of the Bohai Sea; they consist of thanato-coenose and taphocoenose from Crassistrea gigars and C. revularis. From the 14C datings it can be known that the banks had formed from early Middle-Holocene and continued up to over 2 ka BP (14C age). The top has different reliefs . Although there is an effect of spatial shift of estuary position, the top is only distributed in the range of-0. 50--2. 50 m(Huanghai elevation minus National elevation system). The banks cannot explain the sea-level fluctuation. As the string ostracean banks are distributed near E-W direction, it suggests that the direction of tidal currents was then similar to that of the present day.     

云南小江流域泥石流堆积扇研究

泥石流堆积扇是判别泥石流性质、发育阶段和危险度的重要依据。通过对小江流域泥石流堆积扇的调查和观测,阐述了泥右流堆积过程和扇形地形成模式,并对泥石流扇群横向、平面组合类型及变形方式进行了分析。研究结果表明:小江流域泥石流堆积扇发育典型,类型齐全,扇群组合复杂,且呈现一定的规律性。     

Matched field localization based on CS-MUSIC algorithm

The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered. A matched field localization algorithm based on CS-MUSIC (Compressive Sensing Multiple Signal Classification) is proposed based on the sparse mathematical model of the underwater positioning. The signal matrix is calculated through the SVD (Singular Value Decomposition) of the observation matrix. The observation matrix in the sparse mathematical model is replaced by the signal matrix, and a new concise sparse mathematical model is obtained, which means not only the scale of the localization problem but also the noise level is reduced; then the new sparse mathematical model is solved by the CS-MUSIC algorithm which is a combination of CS (Compressive Sensing) method and MUSIC (Multiple Signal Classification) method. The algorithm proposed in this paper can overcome effectively the difficulties caused by correlated sources and shortness of snapshots, and it can also reduce the time complexity and noise level of the localization problem by using the SVD of the observation matrix when the number of snapshots is large, which will be proved in this paper.     

中国东北耕地物候期对气候变化的响应(英文)

We investigated the responses of cropland phenophases to changes of agricultural thermal conditions in Northeast China using the SPOT-VGT Normalized Difference Vegetation Index (NDVI) ten-day-composed time-series data, observed crop phenophases and the climate data collected from 1990 to 2010. First, the phenological parameters, such as the dates of onset-of-growth, peak-of-growth and end-of-growth as well as the length of the growing season, were extracted from the smoothed NVDI time-series dataset and showed an obvious correlation with the observed crop phenophases, including the stages of seedling, heading, maturity and the length of the growth period. Secondly, the spatio-temporal trends of the major thermal conditions (the first date of ≥10℃, the first frost date, the length of the temperature-allowing growth period and the accumulated temperature (AT) of ≥10℃) in Northeast China were illustrated and analyzed over the past 20 years. Thirdly, we focused on the responses of cropland phenophases to the thermal conditions changes. The results showed that the onset-of-growth date had an obvious positive correlation with the first date of ≥10℃ (P < 0.01), especially in the northern part of the Songnen Plain, the eastern part of the Sanjiang Plain and the middle and eastern parts of Jilin Province. For the extracted length of growing season and the observed growth period, notable correlations were found in almost same regions (P < 0.05). However, there was no obvious correlation between the end-of-growth date and the first frost date in the study area. Opposite correlations were observed between the length of the growing season and the AT of ≥10℃. In the northern part of the Songnen Plain, the eastern part of the Sanjiang Plain and the middle part of Jilin and Liaoning Provinces, the positive correlation coefficients were higher than the critical value of 0.05, whereas the negative correlation coefficients reached a level of 0.55 (P < 0.05) in the middle and southern parts of Heilongjiang Province and some parts of the Sanjiang Plain. This finding indicated that the crop growth periods were shortened because of the elevated temperature; in contrast, the extended growth period usually meant a crop transformation from early- or middle-maturing varieties into middle or late ones.     

枣庄煤田太原组煤中微量元素地球化学特征

采用中子活化法测定了山东枣庄煤田晚古生代太原组高硫煤层中的微量元素质量分数 ,用数理统计方法取得了高硫煤中微量元素的浓度分布范围、平均值和变异系数 ,用逐步聚类分析法和相关分析法分析了微量元素的共生组合关系 ,并用扫描电镜 -能谱分析了不同煤岩组分的微量元素浓度 ,在此基础上结合形态硫分析结果和沉积相分析结果 ,讨论了高硫煤中微量元素的富集因素、聚集机理和成因背景 ,指出受海水影响的沼泽沉积环境不但对煤中形态硫的分布和含量有控制作用 ,同时对煤中微量元素的浓度和共生组合特点也有影响。太原组高硫煤中的微量元素按其成因可分成两组 ,一组是陆源碎屑富集型 ,其含量直接与煤中灰分产率呈正相关关系 ;另一组为盆地内部沉积 -生物作用富集型元素 ,海水的入侵和盆地介质的停滞还原条件和陆源碎屑物质输入量的减少最有利于沉积 -生物作用型元素的富集 ,并以有害元素 Cu、As、 U、 Pb、 Mo、 Sr和 Co的富集为特征。煤中黄铁矿及其他硫化物是许多有害元素的重要载体 ,充分凝胶化的富氢镜质体比其他组分承载和吸附有更多的有害元素。深入研究不同煤层的有害元素的有机亲和性有利于指导煤的合理利用和采用有效的有害元素的去除措施 ,以利于煤的有效和洁净利用