甘新交界红柳河地区海西期构造演化特征

据岩石组合、基本层序特征 ,结合生物化石鉴定和同位素测年结果 ,红柳河地区海西期物质建造由红柳河群海相碎屑岩、碳酸盐岩、火山岩建造和陆相磨拉石建造组成 ,主期变形形成主干褶皱———红柳河向斜及伴生构造 ,变形机制为纵弯褶皱作用兼具一定压扁特点 ,总挤压收缩率达 40 %～ 70 % ,反映了造山后强烈陆内收缩变形特点。构造演化时限为 35 6～ 2 5 6Ma。     

The invasion of the intertidal canopy-forming alga Fucus serratus L. to southwestern Iceland: Possible community effects

The intertidal serrated wrack, Fucus serratus L. (Fucales: Phaeophyceae), has become an abundant canopy-forming alga along a ca. 100 km stretch of shore in southwestern Iceland in the last century. Its distribution has not changed noticeably since a survey in 1975/1976. Many experimental studies have shown that canopy-forming algae can have profound effects on the community structure. Although such experiments involving F. serratus are few it was decided to test predictions from these experiments on a geographical scale by comparing community compositions within the area where F. serratus is a dominant algae (since at least 1975/1976) with an adjacent area of similar size where F. serratus is absent (with a single exception without consequences). The work is based on measurements on some 372 stations in the F. serratus area, termed region A, and 227 stations from the F. serratus-free area, termed region B. Percentage cover of algae and sessile invertebrates was estimated on 2 m² on each station and animals collected from 800 cm² from each station. The vertical distribution of F. serratus was most similar to that of Fucus distichus and the two species often grew intermingled on the lower part of the shore. F. serratus appeared to have reduced the cover of F. distichus in the lowermost part of the shore, while having little or no effect on other canopy-forming species. The low abundance of Semibalanus balanoides in the F. serratus area (region A) is in line with experiments showing detrimental effect on this barnacle by whiplash of F. serratus. In general algal grazers were more abundant in region A, consistent with the greater attractiveness of F. serratus than other canopy-forming species to grazers, although this may be partly explained by the abundance of understorey algae in region A.     

Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core,and selected auxiliary records

The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ¹⁸O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi‐parameter annual layer counting provides an age of 11 700 calendar yr b2 k (before AD 2000) for the base of the Holocene, with a maximum counting error of 99 yr. A proposal that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene–Holocene boundary have also been recognised. Copyright © 2008 John Wiley & Sons, Ltd.     

Nudging of vertical profiles of meteorological parameters in one-dimensional atmospheric model: A step towards improvements in numerical simulations

In this article, we describe a simple yet effective method for insertion of observational datasets in a mesoscale atmospheric model used in one-dimensional configuration through Nudging. To demonstrate the effectiveness of this technique, vertical profiles of meteorological parameters obtained from GLASS Sonde launches from a tiny island of Kaashidhoo in the Republic of Maldives are injected in a mesoscale atmospheric model — Advanced Regional Prediction System (ARPS), and model simulated parameters are compared with the available observational datasets. Analysis of one-time nudging in the model simulations over Kaashidhoo show that incorporation of this technique reasonably improves the model simulations within a time domain of +6 to +12 Hrs, while its impact on +18 Hrs simulations and beyond becomes literally null.     

长江口管理界线的现状和分析

自然界河海相互关系非常密切.河海交互的河口海域,既不可同于一般典型河流,也不同于一般典型海洋.河口地区有着自身特有的现象和规律,这些特殊的现象和规律,不仅使许多河流研究者痴迷,也使许多海洋学家难以释怀.引发长江口河海划界之事或之争最初是在20世纪80年代中期,缘于河口选划海洋倾倒区,确定<海洋环境保护法>在河口区适用的地理范围.1993年财政部、国家海洋局颂布<国家海域使用管理暂行规定>,上海市出现了执行该规定的适用地理范围问题的不同意见,再次引发长江口河海划界之争.2001年12月市政府批准的<上海市海洋功能区划>虽然涵盖了长江口,但由于水务和海洋部门在长江口海域使用管理问题上争执不下,影响了上海海域使用管理工作的推进.2002年1月1日<海域管理法>施行后,长江口河海之争峰烟越燃越旺,直至现在,这一问题也没有很好解决.管理长江口海域的政府部门众多,它们在长江口海域的工作界线不同,对长江口海域的认识也很难统一意见.河口区是河海相互作用的交汇区,很难按照自然属性在河口区划出一条河海分界线,从自然科学研究角度出发也无必要划定一条河海分界线.就海洋与水行政管理部门的工作范围和工作衔接问题提出一些看法,首先是解决河海划界问题的3条基本原则:有利于经济社会发展和维护社会主义法制统一;尊重和考虑历史与现状,不纠缠细节,不排斥对方,具体问题具体分析解决;建立海洋与水行政部门之间的协调机制,以"非排他性原则"作好长江口海域权属管理的职能分工、协同配合与有机衔接.在此基础上,提出解决河海划界问题的3点办法.有关河口海域管理问题,要解决好不同部门管理上的地理范围重叠交叉和法律关系上的职能各有分工、不能相互取代、互相排斥的问题,在管理地理范围有交叉重叠的河口海域时,各自依法履行职责,共同监督管理.有关海岸带滩涂的管理问题,应以海岸线为界,在城市化地区应以一线海堤为界,海岸线或一线海堤以下滩涂的开发利用,纳入海域使用管理;海岸线以上的高滩涂,按地方滩涂管理条例进行管理.有关长江河口区的海域使用管理问题,海洋和水利行政主管部门应依据法律和各自的职责,共同监督管理,并对管理的具体做法提出4点建议.     

An Efficient Model for Transient Surface Waves in Both Finite and Infinite Water Depths

A numerical model is developed to simulate fully nonlinear extreme waves in finite and infinite water-depth wave tanks. A semi-mixed Eulerian-Lagrangian formulation is adopted and a higher-order boundary element method in conjunction with an image Green function is used for the fluid domain. The boundary values on the free surface are updated at each time step by a fourth-order Runga-Kutta time-marching scheme at each time step. Input wave characteristics are specified at the upstream boundary by an appropr...     

Characteristics of turbulent boundary layers over a rough bed under saw-tooth waves and its application to sediment transport

A large number of studies have been done dealing with sinusoidal wave boundary layers in the past. However, ocean waves often have a strong asymmetric shape especially in shallow water, and net of sediment movement occurs. It is envisaged that bottom shear stress and sediment transport behaviors influenced by the effect of asymmetry are different from those in sinusoidal waves. Characteristics of the turbulent boundary layer under breaking waves (saw-tooth) are investigated and described through both laboratory and numerical experiments. A new calculation method for bottom shear stress based on velocity and acceleration terms, theoretical phase difference, φ and the acceleration coefficient, a_c expressing the wave skew-ness effect for saw-tooth waves is proposed. The acceleration coefficient was determined empirically from both experimental and baseline k–ω model results. The new calculation has shown better agreement with the experimental data along a wave cycle for all saw-tooth wave cases compared by other existing methods. It was further applied into sediment transport rate calculation induced by skew waves. Sediment transport rate was formulated by using the existing sheet flow sediment transport rate data under skew waves by Watanabe and Sato [Watanabe, A. and Sato, S., 2004. A sheet-flow transport rate formula for asymmetric, forward-leaning waves and currents. Proc. of 29th ICCE, ASCE, pp. 1703–1714.]. Moreover, the characteristics of the net sediment transport were also examined and a good agreement between the proposed method and experimental data has been found.     

中华人民共和国省级行政区域界线详图集的编制

阐述《中华人民共和国省级行政区域界线详图集》编制的意义,介绍该图集编制的工艺流程,讨论其专题要素编绘的工艺。     

Consolidation solution of soil around a permeable pipe pile

Abstract

In practice, how to quickly improve the bearing capacity of piles in a short time is of great significance. In view of this, a technique of setting grooves and installing PVDs (prefabricated vertical drains) at the surface of the pile is proposed in this investigation to accelerate the consolidation of the surrounding soil. A radial and circular consolidation model is established for permeable piles. The finite cosine transform, finite Weber transform, and discretization method are used to obtain a semi-analytical solution for the consolidation model with a mixed drainage boundary condition at the surface of the pile. The sensitivity of the consolidation process to the strip number and the width of PVDs is discussed. The results show that the technique of installing PVDs in piles could potentially improve the bearing capacity. When the area of drainage channels is fixed, the bearing capacity of permeable piles can be more effectively improved by using a higher strip number of PVDs and a smaller PVD width.     

乌鲁木齐市城区和郊区气温分布及廓线特征

利用乌鲁木齐市5座100 m气象塔10层气温观测资料，通过统计方法详细分析了乌鲁木齐市城区和郊区近地层不同高度气温季节变化和日变化特征。研究表明：乌鲁木齐市四季均存在逆温，北郊逆温最明显。近地层100 m内主城区气温日较差较小，约为3.5～5.5 ℃；郊区气温日较差较大，约为4.2～7.0 ℃。夏季郊区气温高于城区，冬季北郊气温最低、南郊最高；白天大气基本上为超绝热不稳定状态，夜间城区气温高于郊区。春、秋季，白天城区和郊区温差小、夜间大，且愈近地面温差愈大；春季城区与南郊温差可达2.4 ℃、秋季可达3 ℃。城区和郊区各季节各层最高气温与最低气温出现时间几乎不同步达到。夏季、秋季、冬季和春季最高气温分别约在17:00～18:10、16:00～17:20、14:30～15:50（北郊滞后1.5 h）、17:00～18:00（南郊提前1.5 h）出现，最低气温分别约在7:10～8:20、8:00～9:00、冬季为多个时段（这与出现逆温有关）、7:30～8:40出现。