Temporal electronic structure of non-resonant Raman excited virtual state of P-nitroaniline by 514 nm excitation via bond polarisabilities

We have studied the temporal bond polarisabilities of para-nitroaniline from the Raman intensities by the algorithm proposed by Wu et al. in 1987 (Tian B, Wu G, Liu G 1987 J. Chem. Phys. 87 7300). The bond polarisabilities provide much information concerning the electronic structure of the non-resonant Raman excited virtual state. At the initial moment by the 514.5 nm excitation, the tendency of the excited electrons (mapped out by the bond polarisabilities) is to spread to the molecular periphery, and the electronic structure of the Raman virtual state is close to the pseudo-quinonoidic state. When the final stage of relaxation is approached, the bond polarisabilities of those peripheral bonds relax faster than those closer to the molecular core, the phenyl ring. The molecule is in the benzenoidic form as demonstrated by the bond polarisabilities after relaxation.     

2010年玉树Ms7.1地震前的重力变化

利用中国地壳运动观测网络1998—2008年绝对重力和相对重力观测资料,获得了玉树地震区域重力场及其动态变化,从动态的观点研究了2010年4月14日玉树Ms7.1地震前区域重力场演化特征及其与地震活动的关系。结果表明：1)重力变化与甘孜 玉树断裂构造活动存在密切的空间联系,重力测量较好地反映了伴随活动断层的物质迁移和构造变形引起的地表重力变化效应;2)区域重力场动态图像较完整地反映了2010年4月14日玉树7.1级地震孕育、发生过程中出现的流动重力观测得到的异常前兆信息;3)玉树震中附近重力点值时序变化累积量超过80× 10^-8 ms-2,较好地反映了玉树地震前重力测点随时间的剧烈波动性上升变化。     

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The Characteristic Patterns of Macrofaunal Fouling Assemblages in Nearshore Waters of the South China Sea

The spatio-temporal patterns of macrofaunal fouling assemblages were quantitatively investigated in the nearshore waters of the South China Sea. The work was undertaken by deploying seasonal panels at two sites (H-site, L-site) for one year, and the fouling communities on the panels were examined and analyzed. The results indicated that species composition of assemblages was obviously different between the two sites. At both sites the assemblages were characteristic with solitary dominant species throughout the year, with Amphibalanus reticulates dominating at H-site and Hydroides elegans at L-site. Shannon index and biomass of the assemblages varied with depth and season at both sites. At H-site the total biomass in summer and autumn were significantly higher than those in spring and winter, while at L-site the assemblage biomass also differed significantly among the four seasons, and the greatest biomass occurred at the depth of 2.0 m in winter. The abundance of all seasonal samples in non-metric multidimensional scaling was clustered as one group at L-site and three groups at H-site. The environmental factors were more likely to be related to the variation of fouling assemblages. Furthermore, it also suggests that in tropical seas the integrated adaptability would qualify a species for dominating a fouling assemblage despite its short life cycle, rather than the usually assumed only species with long life span. This study reveals the complexity and characteristic dynamics of macrofaunal fouling assemblages in the tropical habitats, and the results would provide valuable knowledge for biodiversity and antifouling research.     

基于CEEMDAN的GNSS变形监测去噪方法

为了提高GNSS变形监测数据去噪的有效性和可靠性,提出一种自适应完备集合经验模态分解(complete ensemble empirical mode decomposition with adaptive noise, CEEMDAN)去噪方法。首先将GNSS变形序列经CEEMDAN分解为若干特征模态函数;其次引入排列熵理论确定高低频分界值K,利用小波分析对高频分量进行去噪,去噪后与低频分量重构得到去噪序列;最后通过仿真和实测边坡GNSS变形监测数据,利用信噪比、均方根误差、相关系数等指标对比分析CEEMDAN、EMD和小波去噪方法。结果表明,CEEMDAN方法的去噪效果和精度优于EMD和小波去噪方法,证明了本文所提方法的有效性和可靠性。     

GIS与土壤溶质运移模型结合研究进展

地理信息系统对土壤溶质模型研究而言,使用者的要求与GIS所能提供的功能之间,还存在巨大的差距。出于对环境问题的关注,土壤中水分及溶质运移的规律及其对环境的影响,成为当前研究的热点。随着对土壤溶质运移模型研究的深入,一方面由于田间土壤特性具有很大的空间变异;另一方面,在实际应用中,往往溶质运移的宏观特征而非微观特征,具有更重要的意义。将溶质运移模型与GIS技术结合,定量研究空间尺度的溶质运移,成为溶质运移研究的必然发展趋势。由于计算机软硬件技术的发展,GIS正处于一个高速发展的时期。将GIS与溶质运移模型相结合,或者进一步,以GIS理论和技术为基础,建立基于GIS的溶质运移模型,将对溶质运移的规律及其对环境的影响,做出更深入和准确的描述。     

Analysis Of The Disappearing Filament And Flare Of 7 May 1992

By using Yohkoh soft X-ray data, H filtergrams, and radio data, the activation of the disappearing filament and the flare eruption on 7 May 1992 have been studied. Main conclusions are as follows: (1) the emergence of new magnetic flux tends to affect the pre-existing X-ray loops, which usually appear in arcades spanning H filament, changing the magnetic environment of the filament, and then enhance the current in the filament. Therefore newly emerging flux plays a fundamental role in the destabilization of this filament. (2) According to the H data and the rising motion of the filament, the corresponding current variation in the filament has been calculated. It seems that the current interruption may be a possible trigger mechanism for this filament disappearance. (3) The magnetic field strength and the energy flux of energetic electrons in the source region of microwave bursts have been estimated by using the microwave spectrum. During the main phase, the mean magnetic strength and the energy flux of energetic electrons are about 300–400 G and 1×1011 erg cm–2 s –1, respectively. (4) The energy provided by reconnection of the current sheet and the total energy of the current filament are estimated and we show that there is enough energy stored in the filament to feed the 7 May, 1992 flare.     

步云山自然保护区生态功能价值研究

以可持续发展为目标,以生态学原理为标准,通过对保护区涵养水量、森林价值以及生态足迹三方面的研究和计算,系统分析了步云山自然保护区的生态功能,指出保护区在规划过程中存在的问题,提出相应解决办法的依据。     

基于地价模拟的同城化空间格局研究——以南京、扬州同城化为例

为进一步适应区域协同背景下的国土空间规划需要,基于地价梯度模型和空间插值方法,以地价为指示指标,对南京、扬州同城化空间格局进行模拟,以揭示同城化空间格局演化的一般规律。结果表明：（1）以城际铁路为代表的快速交通对同城化推动效应明显,以南京为代表的强中心城市辐射范围扩大,扬州等弱中心城市辐射范围相对收缩。（2）不同时速城际铁路对同城化空间格局影响的一般规律为：时速越快,中心城市辐射强度越高,同城化程度越高;同一时速下,距中心城市越近,同城化程度越高;时速提升存在边际效应,表现为城际铁路对中心城市辐射范围的扩张有阈值极限。（3）随着中心城市互动的日益紧密,同城化空间格局将沿着单轴、多轴、网络形态逐渐演进,应进一步发挥中心城市、次级城市、城镇组团比较优势,形成分工明确、资源共享的同城化网络。     

Late Carboniferous-Early Permian Sequence Stratigraphy and Depositional Evolution in the Northeast Ordos Basin,North China

<正>Sequence stratigraphical analysis was applied to the Upper Carboniferous-Lower Permian sedimentary succession of the northeastern Ordos Basin,north China based on data acquired from ten entire logging curves and eight outcrops.The facies framework of the lithostratigraphical unit,the Taiyuan Formation comprises seven facies in two facies associations,varying from fluvio-delta to shelf-barrier islands.The facies are presented within a chronostratigraphical framework,linked by systems tract,which in turn are limited by flooding surfaces and sequence boundaries.Six third-order depositional sequences are recognised,bounded by six type 2 unconformities.An upwards-shallowing epicontinental sea sedimentary model is created,which consists of a sandstone,coal seam and carbonate succession.