The origin of strain patterns resulting from contemporaneous deformation and metamorphism in the Sambagawa metamorphic belt

Abstract The magnitudes of plastic strains of 104 metacherts were determined from the deformed shape of initially spherical radiolarians in the Sambagawa high- P type metamorphic belt of Western Shikoku, Japan. The strain magnitude increases with increasing metamorphic temperature from several per cent to 250%. The a₂/a₃ ratio of strain ellipsoids in the higher metamorphic grades decreases with increasing metamorphic grade while the a₁/a₂ ratio increases rapidly. The long axis of the strain ellipsoid for every grade is nearly parallel to the length of the metamorphic belt, suggesting that the flow direction of the synmetamorphic deformation was uniform along the belt. A map of strain zones within the Sambagawa high- P type metamorphic belt reveals that the metamorphic belt underwent a progressive bulk inhomogeneous shear deformation and that the high-grade zones represent a deep-seated boundary shear zone on the accretionary wedge between a subducting oceanic plate and the immobile rigid continental plate.     

气象服务产业化、商品化趋势及其对策

20世纪50年代以来,大气科学的发展和新科技在气象实践中的运用,不同程度地提高着气象成果的多样性、专业性、应用性和有效性,从而创造了气象成果产业化、商品化的物质技术条件;社会生产和居民生活对气象成果更为多样的、专一的需要,形成了气象成果产业化、商品化的市场条件。我国气象服务有偿化的发展已成为趋势;但从社会需求与气象服务自身现状考察,认真转变观念、积极调整结构、大力拓展市场、深化基础研究乃是加速气象成果产业化、商品化趋势的基本对策。     

An alternative deduction of the hill-type surfaces of the spatial 3-body problem

In the present paper, inequalities stronger than Sundman's and the best possible zero velocity surfaces of the spatial 3-body problem first obtained by Saari (1987) are deduced using a modified version of the transformation developed by Zare (1976). The notion of inertia ellipsoid is used to show the equivalence of the present authors' result to that of Saari's.     

Volatile Organic Compounds in the Po Basin. Part B: Biogenic VOCs

Measurements of volatile organic compounds (VOCs) were performed in the Po Basin, northern Italy in early summer 1998, summer 2002, and autumn 2003. During the three campaigns, trace gases and meteorological parameters were measured at a semi-rural station, around 35 km north of the city center of Milan. Bimodal diurnal cycles of isoprene with highest concentrations in the morning and evening were found and could be explained by the interaction of emissions, chemical reactions, and vertical mixing. The diurnal cycle could be qualitatively reproduced by a three-dimensional Eulerian model. The nighttime decay of isoprene could be attributed mostly to reactions with NO₃, while the decay of the isoprene oxidation products could not be explained with the considered chemical reactions. Methanol reached very high mixing ratios, up to 150 ppb. High concentrations with considerable variability occurred during nights with high relative humidities and low wind speeds. The origin of these nighttime methanol concentrations is most likely local and biogenic but the specific source could not be identified.     

The amino acid composition of estuarine colloidal material

Amino acids were determined in estuarine colloidal and particulate material from near surface waters ranging from fresh to brackish water (12 g kg^?1 salinity). The hydrolizable amino acids and associated ammonia account for an average of 80% of the nitrogen present in colloidal samples, and approximately 75% of the nitrogen from particulate fractions of the same samples. The relative proportions of these amino acids are similar to those of a cultured estuarine diatom. There are no significant amounts of D amino acids, or non-protein amino acids characteristic of bacteria in sediments and soil. A single deep-water sample (25 m) shows some evidence of bottom mud resuspension by the presence of a possible aspartic acid-hydroxyproline dimer.     

Observations and modelling of the travel time delay and leading negative phase of the 16 September 2015 Illapel,Chile tsunami

The systematic discrepancies in both tsunami arrival time and leading negative phase (LNP) were identified for the recent transoceanic tsunami on 16 September 2015 in Illapel, Chile by examining the wave characteristics from the tsunami records at 21 Deep-ocean Assessment and Reporting of Tsunami (DART) sites and 29 coastal tide gauge stations. The results revealed systematic travel time delay of as much as 22 min (approximately 1.7％ of the total travel time) relative to the simulated long waves from the 2015 Chilean tsunami. The delay discrepancy was found to increase with travel time. It was difficult to identify the LNP from the near-shore observation system due to the strong background noise, but the initial negative phase feature became more obvious as the tsunami propagated away from the source area in the deep ocean. We determined that the LNP for the Chilean tsunami had an average duration of 33 min, which was close to the dominant period of the tsunami source. Most of the amplitude ratios to the first elevation phase were approximately 40％, with the largest equivalent to the first positive phase amplitude. We performed numerical analyses by applying the corrected long wave model, which accounted for the effects of seawater density stratification due to compressibility, self-attraction and loading (SAL) of the earth, and wave dispersion compared with observed tsunami waveforms. We attempted to accurately calculate the arrival time and LNP, and to understand how much of a role the physical mechanism played in the discrepancies for the moderate transoceanic tsunami event. The mainly focus of the study is to quantitatively evaluate the contribution of each secondary physical effect to the systematic discrepancies using the corrected shallow water model. Taking all of these effects into consideration, our results demonstrated good agreement between the observed and simulated waveforms. We can conclude that the corrected shallow water model can reduce the tsunami propagation speed and reproduce the LNP, which is observed for tsunamis that have propagated over long distances frequently. The travel time delay between the observed and corrected simulated waveforms is reduced to <8 min and the amplitude discrepancy between them was also markedly diminished. The incorporated effects amounted to approximately 78％ of the travel time delay correction, with seawater density stratification, SAL, and Boussinesq dispersion contributing approximately 39％, 21％, and 18％, respectively. The simulated results showed that the elastic loading and Boussinesq dispersion not only affected travel time but also changed the simulated waveforms for this event. In contrast, the seawater stratification only reduced the tsunami speed, whereas the earth's elasticity loading was responsible for LNP due to the depression of the seafloor surrounding additional tsunami loading at far-field stations. This study revealed that the traditional shallow water model has inherent defects in estimating tsunami arrival, and the leading negative phase of a tsunami is a typical recognizable feature of a moderately strong transoceanic tsunami. These results also support previous theory and can help to explain the observed discrepancies.     

漳江口红树林国家级自然保护区海产品产量产值研究

2006年全年对福建漳江口红树林国家级自然保护区红树林主要分布地竹塔村辖区内的海产品类型、产量和价格进行了逐日统计。结果表明:2006年竹塔村滩涂海产品总产量为529956kg(1589.9kg/hm2),远高于一般的红树林。其中缢蛏苗和缢蛏成品的产量最高,分别为312468kg(937.4kg/hm2)和123376kg(370.1kg/hm2),占总产量的59.0%和23.3%。泥蚶、锯缘青蟹成品和泥螺分别占总产量的12.2%、2.3%和2.0%。缢蛏苗以冬季(1月和12月)的产量最高;锯缘青蟹苗年产量为2.59尾/m2,高峰期出现在6月至11月。2006年竹塔村红树林滩涂海产品总产值为1388.0万元(4.17万元/hm2)。研究结果可为红树林生态系统服务功能的评价和红树林的科学管理提供基础数据。     

UCX数码航摄在大比例尺3D产品生产中的应用

数码航摄技术在大比例尺3D产品开发中的应用日益广泛,UCX数码航摄系统成像分辨率较高,成为目前国内数字化测绘应用较多的主导设备。本文结合石狮工程实践,利用UCX数码航摄系统获取的影像数据生产制作3D数字产品,探讨了基于UCX数码航摄大比例尺3D产品的实现方法、技术路线、作业流程及全程质量控制。     

几内亚BOKE558铝土矿勘探独立坐标系的建立及转换研究

建立地方独立坐标系的主要元素是中央子午线、投影面和参考椭球。建立独立坐标系有三种方法：中央子午线移到城市或工程建设地区中央,归化高程面提高到该地区的平均高程面;采用抵偿高程面;只移动中央子午线。以工程实例得出国家坐标系与地方独立坐标系之间转换的可靠、简便方法。     

开发地理信息服务新产品,实现空间数据增值

回顾了北京市测绘设计研究院20年来地理信息产业的发展,分析了建设地理信息产品的种类和策略。提出建立基础地理信息框架数据、相关委办局专业地理信息产品、国家专项调查地理信息产品的发展思路,建议重视用户需求调研,与相关地理信息用户建立战略合作伙伴关系,保证产品质量,实现地理信息产品持续更新。