Factors controlling suspended sediment yield during runoff events in small headwater catchments of the Basque Country

For the first time in the Basque Country, turbidity (NTU), discharge (l/s) and precipitation (mm) have been continuously monitored in the gauging stations located at the outlet of three catchments (Aixola, Barrendiola and Añarbe) since October 2003. In this study, several data sets derived from flood events were used to develop turbidity and suspended sediment relationships for the three catchments separately, and so to estimate continuous suspended sediment concentration (SSC). Linear relationships are found in Barrendiola and Añarbe, and two curvilinear relationships for Aixola owing to changing sediment sources in the catchment. Several event (discharge, precipitation and suspended sediment concentration) and pre-event (discharge and precipitation) factors are calculated for all the events registered. With them correlation matrixes were developed for each catchment. Although some differences are found between catchments good correlation between precipitation (P), discharge (Q) and suspended sediment (SS) variables is found in general. Pre-event conditions are also well correlated with Q and SS variables in Barrendiola (higher regulation capacity) and Añarbe (larger area) but not in Aixola (“flash floods”). SSC-discharge evolutions through the events were also analysed. For Aixola four different types of hysteretic loops were observed: single lined, clockwise, counter-clockwise and eight-shaped; while for Barrendiola and Añarbe just clockwise loops were observed.     

Phylogenetic and structural studies of a novel equine papillomavirus identified from aural plaques

Papillomaviruses (PVs) infect a wide range of animal species and show great genetic diversity. To date, excluding equine sarcoids, only three species of PVs were identified associated with lesions in horses: Equus caballus papillomavirus 1 (EcPV1-cutaneous), EcPV2 (genital) and EcPV3 (aural plaques). In this study, we identified a novel equine PV from aural plaques, which we designated EcPV4. Cutaneous samples from horses with lesions that were microscopically diagnosed as aural plaques were subjected to DNA extraction, amplification and sequencing. Rolling circle amplification and inverse PCR with specific primers confirmed the presence of an approximately 8 kb circular genome. The full-length EcPV4 L1 major capsid protein sequence has 1488 nucleotides (495 amino acids). EcPV4 had a sequence identity of only 53.3%, 60.2% and 51.7% when compared with the published sequences for EcPV1, EcPV2 and EcPV3, respectively. A Bayesian phylogenetic analysis indicated that EcPV4 clusters with EcPV2, but not with EcPV1 and EcPV3. Using the current PV classification system that is based on the nucleotide sequence of L1, we could not define the genus of the newly identified virus. Therefore, a structural analysis of the L1 protein was carried out to aid in this classification because EcPV4 cause lesion similar to the lesion caused by EcPV3. A comparison of the superficial loops demonstrated a distinct amino acid conservation pattern between EcPV4/EcPV2 and EcPV4/EcPV3. These results demonstrate the presence of a new equine PV species and that structural studies could be useful in the classification of PVs.     

轮系运动分析的构件元法

用构件元的概念推导了轮系中齿轮与系杆的构件元,特别是推导出用齿数表示的雅可比元,分析了轮系中的封闭环,总结出3种轮系基本封闭环.通过引入有效因子,可用雅可比元按基本封闭环建立整个轮系的雅可比矩阵,求解线性方程组,就得出各构件的角速度.提出的方法无需区分基本轮系,无需绘制箭头,具有极强的模块性,手工计算和计算机自动求解都非常方便,适用于各类复杂轮系.     

含复铰连杆机构的拓扑表示与其回路自动分

提出用"复合铰链零错位"分析机构结构的方法.先将复合铰链错位成相互距离为零的运动副,建立拓扑图和对应的关联矩阵,确定树及余树,通过矩阵计算求出基本回路矩阵,并进而求出完全回路矩阵.将错位的复合铰链重新合并,根据回路的权排序,再按回路的相互独立性和回路连通性找出优选的独立回路.研究表明,复合铰链零错位后绘制的拓扑图简洁、直观,关联矩阵的建立以及分析回路的算法通用,便于应用在计算机自动结构分析与运动分析程序中.     

Monitoring and analysis of suspended sediment transport dynamics in the Carapelle torrent (Southern Italy)

In Northern Puglia watershed's high rates of suspended sediment loads occur along the hydrographic network during intense rainfall events. In order to monitor this phenomenon an automated station, equipped with a turbidity probe, has been set up in the Carapelle torrent.     

Relationships among rainfall, runoff, and suspended sediment in a small catchment with badlands

The Araguás Catchment of the Central Spanish Pyrenees has been monitored since 2004 to study weathering, erosion, and the hydrological and sediment response to rainfall events in order to understand the hydromorphological dynamics of a badland area in a relatively humid environment. This small catchment (0.45 km²) shows highly active processes of physical and chemical weathering related to seasonal variations in temperature and moisture. Erosion and sediment transport are widely studied in badlands within Mediterranean environments because they represent the dominant sediment source. To obtain information about suspended sediment and discharge, a gauging station was installed within the Araguás Catchment during the summer of 2005. The aim of this work is to determine the relationships among rainfall, runoff, and suspended sediment in this badland area. Towards this goal, we analyze the relationships between suspended sediment concentration and discharge during rainfall events.From a hydrological viewpoint, the Araguás Catchment reacts to all rainfall events with torrential flow being the most characteristic hydrological response. The results obtained between October 2005 and April 2007 reveal extremely high concentrations of suspended sediment, with values frequently exceeding 100 g l^{<modINS>−<!--[/INS]"> 1} and reaching a maximum of 1200 g l^{<modINS>−<!--[/INS]"> 1}. Three different types of hysteretic loops were observed: clockwise (22 events, 28%), counter-clockwise (27 events, 34%), and figure-eight (12 events, 15%). Moreover, 23% of events were classified as complex hysteretic loops and removed from the analysis due to their complexity. Clockwise hysteretic floods are characterized by their long duration and the highest hydrological and sedimentological responses; counter-clockwise hysteretic floods are characterized by their short duration and moderate hydrological and sediment responses; finally, figure-eight hysteretic floods are related to multiple peaks in suspended sediment, coinciding with oscillations in discharge associated with the highest rainfall intensities within each event and moderate hydrological and sediment responses.     

弓齿滚筒式割前脱粒装置的试验研究

本文在对比各种滚简式割前脱粒装置特点的基础上,选择、试验了不加气吸的下脱式弓齿滚筒脱粒装置。试验表明,本装置对霜前、霜后较难脱的粳稻均有较强的脱粒能力,总损失在2％以上,功率比较特别低,为0.83～1.12HP/kg/s,为传统型脱粒装置的1/5.5,轴流型的1/10,夹持半喂入型的1/3.6。它的主要缺点是断穗率过高,并且在茎杆中央带小量穗头。文章对试验重复次数的合理选择,从置信区间的角度进行了探讨,认为以5次为宜,代替了通常的3次。     

Factors controlling hydro-sedimentary response during runoff events in a rural catchment in the humid Spanish zone

In Galicia (NW Spain) studies on the suspended sediment (SS) transported in river catchments are scarce. Using a dataset comprising three hydrological years (2004/05–2006/07) in the Corbeira catchment (NW Spain), the relationships between rainfall, runoff and SS are analysed at event scale. The catchment was instrumented to measure rainfall, water level and SS in the stream. Several event (rainfall, discharge and SS concentration and load) and pre-event (rainfall and discharge) variables were calculated for all the events analysed. Correlation matrices were developed using these data. Discharge characteristics and rainfall depth showed good correlations with SS concentration and load. Suspended sediment and discharge relationships were also examined. In most of the events, the SS peak preceded peak discharge (clockwise hysteresis), implying that zones near the stream are the main sediment source areas.     

Seismic Performance Research on Beam-column Joint of Tall Steel Framed Structure with BRB

Using nonlinear finite element software ABAQUS to analyze and numerically simulate the beam-column joint of high-rise steel framed structure with BRB and with ordinary support. Analyzed and compared the seismic impact on frame joint with the two support. For the beam-column joint with BRB, conduct its parameter analysis about the yield strength of the supporting inner core, the size and thickness of the gusset plate, and the length of the stiffener on the gusset plate. The results showed that the BRB has the good performance of energy-consuming with the constrains come from the wrapped steel and concrete. And with the yield's reduction in strength of the supporting inner core, the increase in the scale and thickness of the gusset plate, as well as the increase in the length of the stiffener on the gusset plate, the hysteresis curve of the beam-column joint display more fuller, which have better seismic performance.