Late-time photometry of two nearby type II-P supernovae： 2004dj and 2004et

We present late-time photometry for two bright type II-P supernovae （SNe） 2004dj and 2004et, extending over 400 d after the explosion, which are measured with a set of intermediate-band filters that have the advantage of tracing the strength variations of some spectral features. Although these two SNe II-P exhibit similar photometric evolution at earlier times, they diverge during the nebular phase. SN 2004dj shows a slow late-time decline rate with - 0.7 ±0.1 mag （100d）^-1 during the period ranging from t ≈ 200 - 300 d after the explosion, while SN 2004et shows a much faster decline rate at a comparable phase, e.g., 1.3 ± 0.1 mag （100d）^-1. The steeper decay rate seen in SN 2004et is likely due to dust formation in the explosion ejecta. Based on intermediate-band photometry, we derived the evolution of the feature lines [e.g., Hα] of SNe 2004dj and 2004et which are similar in flux at comparable phases but perhaps with significantly different decay rates. The origin of the observed variations in the continuum and the feature lines is briefly discussed.     

Comportement d'une source karstique soumise à une sécheresse prolongée : la source Bittit (Maroc)

The behaviour of a karstic spring (Bittit spring, Middle Atlas, Morocco) subjected to a prolonged drought (>20 yr), is analysed using spring hydrographs analysis methods and correlation and spectral methods. Two series of discharges, corresponding to a normal rainfall period and a drought period, are analysed. The results show that the karstic system is inertial, with very significant storage. However, in spite of the great regulating capacity of the storage, the long drought period significantly reduced the spring discharges, due to less diversified inputs, and to the karstic system storage depletion. To cite this article: F. Amraoui et al., C. R. Geoscience 336 (2004).     

Sodic Pyroxene and Sodic Amphibole as Potential Reference Materials for In Situ Lithium Isotope Determinations by SIMS

Two large pegmatitic crystals of sodic pyroxene (aegirine) and sodic amphibole (arfvedsonite) from the agpaitic igneous Ilímaussaq Complex, south Greenland were found to be suitable as reference materials for in situ Li isotope determinations. Lithium concentrations determined by SIMS and micro‐drilled material analysed by MC‐ICP‐MS generally agreed within analytical uncertainty. The arfvedsonite crystal was homogeneous with [Li] = 639 ± 51 μg g^?1 (2s, n = 69, MC‐ICP‐MS and SIMS results). The aegirine crystal shows strongly developed sector zoning, which is a common feature of aegirines. Using qualitative element mapping techniques (EPMA), the homogeneous core of the crystal was easily distinguished from the outermost sectors of the crystals. The core had a mean [Li] of 47.6 ± 3.6 μg g^?1 (2s, n = 33) as determined by SIMS. The seven micro‐drilled regions measured by solution MC‐ICP‐MS returned slightly lower concentrations (41–46 μg g^?1), but still overlap with the SIMS data within uncertainty. Based on MC‐ICP‐MS and SIMS analyses, the variation in δ⁷Li was about 1‰ in each of the two crystals, which is smaller than that in widely used glass reference materials, making these two samples suitable to serve as reference materials. There was, however, a significant offset between the results of MC‐ICP‐MS and SIMS. The latter deviated from the MC‐ICP‐MS results by ?6.0 ± 1.9‰ (2s) for the amphibole and by ?3.9 ± 1.9‰ (2s) for the aegirine. This indicates the presence of a significant matrix effect in SIMS determinations of Li isotopes for amphibole and pyroxene relative to the basalt glasses used for calibration. Based on the MC‐ICP‐MS results, mean δ⁷Li values of +0.7 ± 1.2‰ (2s, n = 10) for the arfvedsonite crystal and of ?3.7 ± 1.2‰ (2s, n = 7) for the core of the aegirine crystal were calculated. Adopting these values, SIMS users can correct for the specific IMF (instrumental mass fractionation) of the ion probe used. We propose that these two crystals serve as reference materials for in situ Li isotope determinations by SIMS and pieces of these two crystals are available from the first author upon request.     

A New Family of Sauropod Dinosaur from the Upper Cretaceous of Tianzhen, Shanxi Province, China

A new gigantic sauropod, Huabeisaurus allocates gen. et sp. nov., about 20 m in length and 5 m in height, was discovered in the Upper Cretaceous Huiquanpu Formation, Tianzhen County, Shanxi Province. It is notably different from Diplodocidae, Titanosauridae and Nemegtosauridae in the following aspects: the teeth are strong, peg-like with a length ratio of the tooth crown to tooth root at about 3 to 1; the cervical vertebrae are long with forked spines; the spines in dorsal vertebrae are relatively high, unbifiarcated; the caudal vertebrae are amphicoelous, with anterior neural spines and unbifurcated spines and chevrons; the femur is straight and long, narrow and flat and the tibia and fibula are long and flat. These characters show that the described genus should represent a new family, Huabeisauridae fam. nov. The discovery enriches the sauropod dinosaur record in China, and is quite significant to the study of the taxonomy, evolution, migration, extinction and palaeobiogeographic provincialism of the     

Tourism and Land Transformation:A Case Study of the Li River Basin,Guilin,China

Land-use change is intertwined with tourism because land is used as a resource for human activities.Land-use change also provides an opportunity to evaluate the status of the ecoenvironment.Understanding the relationship between tourism and land use change would help to predict the effect of tourism on land use and encourage sustainable tourism development.Using the Li River Basin as a case study,a hybrid approach using multilevel modeling and logistic regressions was employed to analyze the distribution of land-usechange between 1989 and 2010 to examine potential driving factors.Results reveal that rapid tourism development and construction expansion expose this area to risk of deforestation and forest degradation.Construction increased by 141% between 1989 and 2000 and by 195% between 2000 and 2010.The primary driving force for construction expansion shifted from population growth between 1989 and 2000 to investment growth after 2000.New construction primarily occurred on crop and woodlands areas,with shares of 81.25% and 6.38%,respectively,between 1989 and 2000,and with shares of 57.79% and 15.29%,respectively,between 2000 and 2010.Moreover,these drastic increases in construction also led to frequent transitions between croplands,woodlands,and grasslands.Traits including distances to urban areas and roads and scenic locations exerted significant effects on land-use change.Woodland regrowth in the areas thatsurround scenic locations consisted of fluctuating woodlands,whereas stable woodland regrowth was often absent in these areas.Likewise,permanent woodland clearing tended to be closed to near scenic locations.That is,construction at scenic locations negatively affected forest conservation in the Li River Basin.     

中国洞穴龙虱一新属种——（鞘翅目，龙虱科，水龙虱亚科，碧龙虱族）

龙虱是一类水生甲虫,营捕食性生活。真洞穴龙虱种类不多,在中国仅记录2种。本文基于采自中国广西壮族自治区环江毛南族自治县文雅村岩律洞（干燥岩洞）一个雌性标本,描述了龙虱科一新属种——田氏华龙虱（Sinoporus tianmingyii gen. ＆ sp. nov.）。新属具有地下龙虱类特征：成虫浅色,相对柔软,无复眼和后翅。新属与已知龙虱区别如下：（1） 身体侧缘近平行;（2） 鞘翅缘折近基部具明显斜脊;（3） 鞘翅具缘缝;（4） 前足和中足腿节具长刚毛; （5） 各跗节无游泳毛。田氏华龙虱（Sinoporus tianmingyii gen. ＆ sp. nov.）.主要特征：身体卵形,背腹平坦,浅黄褐色。体长1.8 mm,最大宽度0.8 mm。头部略窄于前胸背板,两侧平行,具有密集的微网纹。触角11节,末节纺锤形。下颚须4节,末节膨大;下唇须3节,末节膨大。前胸背板两侧平行,具微网纹及稀疏的细刻点。鞘翅无微网纹,具有不规则的密刻点列。前胸腹板、中胸腹板及后胸腹板翼具有较密集的刻点。前胸腹板有密集的短白毛;前胸腹板突端部尖锐,中间具纵脊。后胸腹板翼窄。腹部第2、3节间在侧部分节不明显。前、中足腿节背面有长毛,无短刚毛;后足腿节无长毛;后足胫节细长,后足第一跗节与后两节之和等长。检视标本：正模：♀（中山大学生物博物馆）,中国广西环江县文雅村岩律洞,25.2239° N, 108.2956° E,396 m,10.xi.2009,采集人：Louis Deharveng & Anne Bedos。     

A New Genus of Psittacosauridae (Dinosauria: Ornithopoda) and the Origin and Early Evolution of Marginocephalian Dinosaurs

An almost complete juvenile dinosaur skull with lower jaw was discovered from the Early Cretaceous Yixian Formation in Beipiao, Liaoning Province, China. Here, the specimen is described and a cladistic analysis is performed in order to find its phylogenetic relationships. The result shows that this specimen represents a new genus of Psittacosauridae, Hongshanosaurus houi, gen. et sp. nov., and confirms the monophyletic status for Ceratopsia and Marginocephalia. However, Heterodontosaurus is found to be the sister taxon to Marginocephalia, rather than a basal Omithopoda.     

富阳市万市镇十字街岩溶塌陷路基稳定性评价与治理设计探讨

浙江富阳市万市镇十字街位于岩溶塌陷区内,周围环境要求高。经过地质调查、地基稳定性分析和治理方案比选,采用高压喷射注浆法对岩溶塌陷路基进行治理,取得了良好效果。     

宁武煤田平朔矿区9号煤中锂的富集机理

从宁武煤田平朔矿区的9号煤中共采了58个煤样,通过光学显微镜、逐级化学提取、SEM-EDX分析、X射线粉末衍射和ICP-MS技术对这些样品进行分析。结果表明9号煤中Li的平均含量达到152 mg/kg,9号煤的点储量为36.7亿吨,Li O2的量达119.5万吨,也就是说煤层中锂的储量约为55.8万吨;逐级化学提取过程的结果表明,Li的富集主要与无机物有关,只有约5.5%的锂具有有机亲和力,这些无机矿物是高岭石、勃姆石、绿泥石族矿物、石英、方解石、黄铁矿以及无定形粘土状矿物等,在含锂煤层中,锂可能被粘土矿物吸附;根据古地理研究,9号煤中锂的最初来源可能是阴山古陆,盆地北部本溪组中的铝土矿可能是锂的直接来源。