Macrobioerosion and Microbioerosion in Marine Molluscan Shells from Holocene and Modern Beaches (39°−40°S, South of Buenos Aires Province, Argentina)

The marine sediments of the area of Verde Peninsula-Jabali Island(39°28′S/62°19′W-40°28′S/62°11′W) Holocene in age(3-2 ky),and modern beaches contain a significant amount of bioeroded mollusc shells.Fifteen sites were analyzed,in which 20.11%of the mollusc shells(2168 valves) presented bioerosion traces,in 54 species(30 bivalves and 24 gastropods).Fourteen ichnogenera were reported:Entobia,Maeandropoiydora,Iramena,Caulostrepsis,Pennatichnus,Pinaceocladichnus,Trypanites,and Gastrochaenolites(Domichnia),Gnathichnus and Radulichnus(Pascichnia),Finichnus and Centrichnus(Fixichnia),Oichnus(Praedicnia)(macrobioerosion),y Semidendrina(microbioerosion),the latter is first reported in mollusc shells in Argentina.Eleven ichnospecies were identified Finichnus peristroma,Maeandropoiydora sulcans,Gnathichnus pentax,Pinaceocladichnus onubensis,Caulostrepsis taeniola,Centrichnus eccentricus,Radulichnus inopinatus,Oichnus simplex,Oichnus paraboloides,Oichnus gradatus,and Gastrochaenolites torpedo(lithic remains).The dominant ichnogenera in the Holocene deposits are Iramena,Entobia and Oichnus.The same ichnogenera are constant with different abundance in the modern beaches,and increasing representation of Pinaceocladichnus and Pennatichnus.The dominant ichnofacies in the Holocene deposits is Trypanites,revealing a benthonic marine community composed of cheilostome bryzoans,clionaid sponges,predator gastropods,regular echinoids,polychaete annelids,bivalves,thallophytas and fungi.Generally,the area was described as a sublittoral,low-energy,stable environment with high rate of oxygenation,and sandy bottoms,with rocky bottoms at Villalonga locality.     

A New Species Group in the Genus Tanytarsus van der Wulp(Diptera:Chironomidae)Based on a Fossil Record from Baltic Amber

<正>A new fossil chironomid,Tanytarsus serafini,found in Baltic amber is described and illustrated based on adult males.The new species and similar extant species of the genus Tanytarsus van der Wulp are compared. Due to several distinct characters of wing,legs and hypopygium,a new species group for Tanytarsus serafini is proposed,and its diagnostic features are evaluated.     

Fossil Hydrophilid Beetles (Coleoptera: Hydrophilidae) of the Late Oligocene Rott Formation (Germany)

<正>Fossil water scavenger beetles(Coleoptera:Hydrophilidae)of the latest Oligocene Rott Formation are revised,based on the examination of the type specimens,as well as numerous additional material from Statz(Los Angeles)and Kastenholz(Bonn)collections.Seven hydrophilid species are recognized,five of which are reliably attributed to the following genera:Berosus morticinus(von Heyden and von Heyden,1866),Paracymus excitatus (von Heyden and von Heyden,1866),Paracymus sp.,Hydrobiomorpha fraterna(von Heyden,1859),and Hydrophilus rottensis(Statz,1939).Coccinella? protogaeae Germar 1837 is attributed to the subtribe Hydrophilina, and Cymbiodyta? austera Statz 1939 to the subfamily Hydrophilinae.Hydrous ebeninus Statz 1939 and Paracymus excitatus(form 3)are excluded from the Hydrophiloidea.Berosus capitatus Statz 1939 is synonymized with Berosus morticinus,and Hydrous neptunus von Heyden and von Heyden 1866 with Hydrobiomorpha fraterna.Lectotypes of Philydrus morticinus von Heyden and von Heyden 1866 and Hydrous ebeninus Statz 1939 are designated.The significance of the hydrophilid fossils for paleoecological reconstructions of the former Rott Lake is briefly discussed.     

叶尔羌河流域水文特性分析

介绍了叶尔羌河流域基本情况，根据流域内主要控制站的多年水文资料，从降水、蒸发、径流、洪水、泥沙、冰情、水质等方面对流域的水文特性进行了分析。     

1918年广东南澳大地震的类型和区域构造应力场分析

1918年2月13日14时07分在广东南澳东北侧海中发生的7.3级地震,是本世纪我国东南诸省(台湾除外)的最大地震,波及粤、闽、赣、浙、台、苏、沪、皖、鄂、湘、桂等省市自治区,震中烈度十度,造成相当大的破坏和伤亡。重新查阅上海保存的地震记录,发现在次日04时25分又发生一次7.0级地震和一系列小于6级的余震。两次大震的震级相近,所释放的能量占整个地震序列总能量的99.4%。因此,这次地震属双震型。利用丰富的宏观资料绘制了该次地震的等震线图,求得了该次地震的震源机制解,判定该次地震是由于泉州——汕头断裂带左旋走向滑动的结果。     

基于模式参数化方案的塔中地区临界起沙阈值分析

利用2009年7月4日~29日塔中野外试验观测数据,基于MARTICORENA和SHAO提出的2种起沙模式参数化方案,初步探讨塔中地区不同沙尘天气临界起沙风速,所得结论如下：（1）非沙尘天气,沙尘撞击颗粒数≤ 10 000;扬沙天气,10 001 ≤沙尘撞击颗粒数≤ 20 000;沙尘暴天气,沙尘撞击颗粒数≥ 20 001。（2）基于MARTICORENA起沙参数化方案,临界起沙风速的平均值为4.88 m·s^-1,基于SHAO起沙参数化方案,临界起沙风速的平均值为6.24 m·s^-1,临界起沙风速在非沙尘天气最大,在沙尘暴天气最小。（3）在观测期间沙尘水平通量为732.9 kg·m^-1,其中非沙尘天气125.2 kg·m^-1,扬沙天气80.9 kg·m^-1,沙尘暴天气526.8 kg·m^-1,SHAO起沙参数化方案适合估算总沙尘水平通量以及非沙尘和扬沙天气的沙尘水平通量,MARTICORENA起沙参数化方案适合估算沙尘暴天气沙尘水平通量。     

塔克拉玛干沙漠夏季晴空对流边界层大涡模拟

为了探索塔克拉玛干沙漠夏季晴空对流边界层湍流结构和热对流运动规律,利用沙漠腹地探空及地表通量观测资料,开展了晴空对流边界层的大涡模拟研究。结果表明：（1）沙漠夏季晴空条件下,对流边界层湍能主要由地表热力浮力对流产生,机械剪切对边界层湍能的贡献较小,小尺度湍涡对湍能的耗散随高度呈减弱趋势,边界层湍能变化呈现间歇性特点。（2）沙漠夏季晴空边界层中存在着有组织的热对流泡现象,热泡最大上升速度可超过4.0 m·s^-1;沙漠热对流运动一般呈羽状和网状分布特征,在上升运动区周围伴随有大片的下沉辐散区域。（3）地表感热和逆温层顶盖强度是控制和影响沙漠对流边界层发展的两个重要因素,感热增大,对流边界层变暖且高度升高;感热减小,对流边界层变冷且高度降低。在感热不变的条件下,逆温层顶盖强度越强,越不利于对流边界层发展,反之则相反。     

塔克拉玛干沙漠腹地冬季积雪下垫面地表反照率及土壤温湿度变化特征

利用塔克拉玛干沙漠大气环境观测试验站西站10 m梯度探测系统气象和辐射观测数据,分析了塔中积雪下垫面地表反照率、土壤温度、土壤湿度的变化特征及其相互关系。结果表明：塔中积雪覆盖期间地表反照率0.18~0.97,日均值为0.60;有积雪覆盖的地表反照率日变化更偏向反"J"型,呈现出上午大于傍晚的形态,平均早晚较差为0.13;积雪使0~40 cm深度土壤温度下降,积雪消融后土壤湿度增大使各层土壤温度趋于接近,并使0、10、20 cm深度的土壤温度日变幅呈减小趋势,减小幅度分别为41%、39%、39%;积雪地表反照率与地表温度表现出负相关关系,反照率越高地表温度越低,二者相关系数为-0.71;积雪地表反照率与5 cm深度土壤湿度负相关,高地表反照率对应低土壤湿度,低地表反照率对应高土壤湿度,二者相关系数为-0.74。     

新疆人口分布与经济发展不一致性时空演变分析

利用人口分布与经济发展的不一致性指数和空间自相关模型,从时空角度出发,对1993,2003,2014年新疆人口分布与经济发展的不一致性现象的空间分布及地域关联性进行分析。结果表明:1 1993—2014年新疆人口分布与经济发展呈现严重的不平衡,二者之间存在错位现象,人口集聚高于经济集聚成为主要特征。人口的空间分布与区域经济之间关系有所协调,但仍具有不均衡性。2新疆人口经济不一致性地域分异明显,各类型区在空间分布上存在集聚性。3新疆人口分布与经济发展的不一致性存在正的、显著的空间自相关性,且这种相关性有增强的趋势。局部空间自相关分析下,全疆人口分布与经济发展的不一致性从东到西形成了"低-低""不显著""高-高"平行分布的集聚格局,且"低-低"与"高-高"的分布格局具有背向性,新疆人口经济不一致性的现状正在逐步改善。     

VARIABILITY OF DIURNAL TEMPERATURE RANGE IN EAST AFRICA DURING 1921–2010

This study investigates the long-term spatiotemporal variability of diurnal temperature range(DTR) in East Africa(EA). The study carries out non-parametric trend analysis of gridded DTR monthly data sourced from Climatic Research Unit(CRU). The DTR exhibits mixed signals in space and time over EA. The DTR correlates negatively with rainfall over EA. Reduction in DTR coincides with the summer season in the northern and southern hemispheres respectively, suggesting the influence of cloud cover on it. There was a non-uniform pattern of DTR changes across the region with time. Lake Victoria basin recorded the highest warming rates. The Indian Ocean coast recorded the least spatiotemporal variability in DTR. A reduction in DTR is evident in the two seasons: hot and cold. The start of the study period; 1921—1930, was the coolest decade in the study period. Most parts of EA recorded negative DTR anomalies in 1961—1970. The overall reduction in DTR throughout the study period highlights the ongoing warming which is a global phenomenon. There remains need for investigating the causation of the observed DTR variability for effective monitoring of the variability in future.