Evidence for the Retrograde Accretion onto Supermassive Black Holestwo

Recently, Sloan Digital Sky Survey successfully carried out the reverberation mapping of a sky area, aiming to test the R ? L relation that has been already widely used. Here, R is the responsivity-weighted radius of the broad line region, and L is the optical luminosity at 5100 Å. Two results have been obtained from the data in the first year: (1) The time lags of AGNs (Active Galactic Nuclei) with a high accretion rate are much shorter than that estimated from the R ? L relation, which confirmed the results of reverberation mapping observations made by the Lijiang 2.4 meter telescope. (2) Some AGNs with a lower accretion rate also have very short time lags. The shortening of the time lags of the AGNs with a low accretion rate is caused by the retrograde accretion of black holes. This result has verified from observations the theoretical prediction made by Wang et al. (2014). The discovery of the black holes with a retrograde accretion has important significance, it indicates that the cosmological evolution of the black holes in quasars is implemented via the inherently random accretion.     

A comparative study of fish community in four main estuaries of China southeastern coastal areas and their adjacent waters

Based on literature and survery data of fish composition collected by bottom trawl investigation from 2006 to 2007 infour main estuaries of China southeastern coastal areas and their adjacent waters,changes of the taxonomic diversity across spatialand temporal scales of fish community were analyzed by taxonomic diversity indices.The results are as follows:a total number of1397 fish species(including some freshwater species),belonging to 2 classes,42 orders,186 families and 593 genera,were collected inthe studied sea areas.The species richness increased with lower latitudes,particularly so with Perciformes.There were 339 fish spe-cies in the Yangtze River Estuary and adjacent waters,belonging to 2 classes,31 orders,101 families and 231 genera.There were 535fish species in the Minjiang River Estuary and adjacent waters,belonging to 2 classes,33 orders,133 families and 323 genera.A totalnumber of 803 fish species were collected in the Jiulongjiang River Estuary and adjacent waters,which belonged to 2 classes,35 orders,155 families and 419 genera.And 1021 fish species which belonged to 2 classes,32 orders,153 families,and 466 genera were collectedin the Pearl River Estuary and adjacent waters.The numbers of orders and families of fish species from the northern to the southern wa-ters first increased and then decreased.The average variation in taxonomic distinctness(Λ+)gradually decreased with lower latitudes inthe four estuaries and adjacent waters.There were no significant differences in the average taxonomic distinctness(△+)among the fourestuaries and adjacent waters,and fish fauna were closely related with each other,and all of them belonged to the same zoogeographicalfauna(Indian-Malaysia fauna).Fish composition in the Minjiang River Estuary and adjacent waters was more similar to that in the Jiu-longjiang River Estuary and adjacent waters among the four estuaries.Compared with the historical data,the average taxonomic dis-tinctness of fish community showed a great decrease in the Minjiang River Estuary and the Jiulongjiang River Estuary and their adjacentwaters.     

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取土器几何尺寸对饱和软黏土样结构的扰动研究

基于颗粒流软件模拟,以吹填淤泥为例,分析了取土器的内径、切角、壁厚等尺寸参数对高黏性软土微观动力学特性的影响;通过分层方法,比较了7组土样层间颗粒特征拐点的运动行为。模拟结果表明:土样的颗粒在底部形成对流位移场,对流处上方颗粒主要受拉膨胀,对流处下方颗粒主要受压收缩,由此造成孔隙率的规律变化和层理的弯曲变形。7组参数对应土样的孔隙率曲线与初始孔隙率曲线的交点同颗粒位移场的对流位置存在协同关系。土样层理表现为向下弯曲变形,层间颗粒位移行为存在特征拐点,拐点之间颗粒扰动行为不明显;反之,颗粒扰动行为较大,这种变形特征可拟合为下开口的旋转抛物面,且曲面方程的曲面形状拟合系数a值能初步评估7组土样的扰动程度。层间特征拐点的连线可再拟合为旋转抛物面,抛物面体积与土样体积的比值可用来评估土样的原状性。     

Optical monitoring and IDV analysis of the blazars S50716+714 and 3C 273

S50716+714 and 3C 273 are frequently studied blazars,which show obvious optical variabilities with different timescales.Using the 1.0 m telescope at the Yunnan ...     

数字化城市管理系统基础框架数据库建设方法研究

结合郑州数字化城市建设工程的实施,制定了数字化城市建设中基础框架数据库建设的技术路线,采用基于AutoCAD平台一体化制作DLG及城市管理专题数据的方法。结果证明该方法可以整合数据生产,有效避免数据的冗余和矛盾,提高生产效率和数据质量,取得了良好效果。     

鱼塭产斑节对虾(Penaeus monodon)催熟繁殖技术研究

以综合催熟措施和移植精荚手术相结合的技术方法,解决了鱼塭产斑节对虾催熟效应期长,产卵率低,易蜕壳失去精荚等难题。使用 ２７８ 尾雌虾,催熟率达９０％ 以上,在４０ ｄ 内共产卵６０８ 尾次,卵量１８ ５３０ 万粒,孵出无节幼体１１ ９９８ 万尾,平均孵化率 ６４．７％ ,平均每尾雌虾孵出无节幼体 ４３．１ 万尾,育成商品虾苗 １ ０２８．５ 万尾,育苗平均成活率 １３．６％ ,试养成活率５７．１％     

浅谈广西经济与矿业的发展

文章分析了广西经济和矿业现状及发展关系,矿业主要包括前期矿产勘查业和后期矿产采选业两部分。按照正常的工业化进程,轻工业发展转向重工业发展,首先是从勘查和开发矿产资源发展矿业开始的。根据广西的工业结构处于重工业化向高加工化演进阶段必然导致原材料工业（钢铁、有色冶金、化工等）资本投入加大,这就要求有足够的矿物原料保障供给。因此,广西的经济发展和工业结构演进是加速矿业发展的有利时期和条件,。     

从萤石资源看丽水发展氟化工前景

本文从萤石资源的分布特点、开发利用状况、国内外市场需求及资源保证程度等不同角度进行综合全面分析预测,阐述了丽水地区发展氟化学工业的可行性。     

Characteristics and variations of the East Asian monsoon system and its impacts on climate disasters in China

Recent advances in studies of the structural characteristics and temporal-spatial variations of the East Asian monsoon （EAM） system and the impact of this system on severe climate disasters in China are reviewed. Previous studies have improved our understanding of the basic characteristics of horizontal and vertical structures and the annual cycle of the EAM system and the water vapor transports in the EAM region. Many studies have shown that the EAM system is a relatively independent subsystem of the Asian- Australian monsoon system, and that there exists an obvious quasi-biennial oscillation with a meridional tripole pattern distribution in the interannual variations of the EAM system. Further analyses of the basic physical processes, both internal and external, that influence the variability of the EAM system indicate that the EAM system may be viewed as an atmosphere-ocean-land coupled system, referred to the EAM climate system in this paper. Further, the paper discusses how the interaction and relationships among various components of this system can be described through the East Asia Pacific （EAP） teleconnection pattern and the teleconnection pattern of meridional upper-tropospheric wind anomalies along the westerly jet over East Asia. Such reasoning suggests that the occurrence of severe floods in the Yangtze and Hualhe River valleys and prolonged droughts in North China are linked, respectively~ to the background interannual and interdecadal variability of the EAM climate system. Besides, outstanding scientific issues related to the EAM system and its impact on climate disasters in China are also discussed.