Ordovician Proto–basin in South China and its Tectonic Implications: Evidence from the Detrital Zircon U–Pb Ages of the Ordovician in Central Hunan, China

Caledonian orogeny is another important tectonic event in South China Block after the breakup of the Rodinia supercontinent. With a view to constrain the tectonic evolution and proto–basin in South China, this paper reports the geochemical and zircon U-Pb dating data of the Ordovician strata in central Hunan, South China. Geochemical features and paleocurrent directions suggest that the lower Ordovician deposited in a passive continental margin basin with a provenance of quartzose components and showing an affinity with the Yangtze Block. U-Pb age data for 260 detrital zircons from upper Ordovician identify three major age populations as: 900–1200 Ma, 1400–1800 Ma and 2400–2700 Ma. The detrital zircon age spectrum as well as the paleocurrent directions suggest that upper Ordovician deposited in a foreland basin and showing a close affinity with the Cathaysia Block. It is also suggest that the lower Ordovician continuously accepted the mineral from the Yangtze Block, whereas the provenance of the upper Ordovician sedimentary basin changed from the Yangtze Block to the Cathaysia Block. This change implies a tectonic movement, which caused the transformation of the proto–basin in the Hunan area in SCB from passive continental margin basin to foreland basin probably took place during late Ordovician. This fact also demonstrate that the Caledonian orogeny in South China Block began no later than 453 Ma, and a new crustal evolution model is proposed.     

井-孔联合微震技术在工作面底板破坏深度监测中的应用

准确预测底板采动破坏深度是承压水上采煤底板水害防治中的一个关键问题,对于防治水方案的制定至关重要。根据山西保德煤矿的地质特征与工作面布置特点,采用高精度井-孔联合微震监测技术,对81307工作面底板破坏深度开展实时监测。利用锤击方法,标定了定位参数,验证了定位精度,确保微震监测系统的定位精度能够满足防治水要求,监测期间工作面回采600 m。监测结果表明:底板破坏深度为30 m,其中在81308二号回风巷下方破坏较深,81307一号回风巷下方破坏只有15 m,工作面超前破坏距离为25 m,监测结果与相邻81306工作面利用压水试验测量的底板破坏深度基本一致。研究表明,井-孔联合微震监测技术可以获得工作面底板破坏深度及其空间分布特征,更好地为煤矿防治水服务。      

用模糊综合评判法优选大射电望远镜候选台址

贵州大射电望远镜候选台址优选,需综合考虑喀斯特洼地几何条件、工程条件、地质条件、气象条件和无线电环境等因素.因上述各因素具复杂性、模糊性和难量化性等特点,本文采用模糊综合评判法进行大射电望远镜候选台址优选.经研究,大射电望远镜候选台址优评价指标可取"长短轴比、最小挖填方率、最适宜口径、洼地闭合情况、岩体结构、地质灾害、洼底水文条件、交通状况"等8个参数,综合评判结果集为"好、较好、一般、差".采用专家评定法和降半梯形分布相结合的隶属度评价模型,共选出38个大射电望远镜候选台址.它们集中分布于三大区域内:一是以平塘、紫云、惠水、罗甸、荔波为中心区域;二是以普定、安顺、镇宁为中心区域;三是以安龙、兴义和关岭为中心区域.     

Growth performance,digestive enzyme activities and serum nonspecific immunity of the red tilapia ( Oreochromis mossambicus × Oreochromis niloticus ) fed diets supplemented with ultrafine powder of Enteromopha prolifera

Journal of Oceanology and Limnology - The present study evaluated effects of ultrafine powder of the green macroalgae Enteromopha prolifera as dietary supplement on growth performance, digestive...     

基于B/S架构的陕西省博物馆管理信息平台的实现

陕西省历史文化悠久,在陕西省境内存在各级各类博物馆近250余处。为了对陕西省境内的博物馆进行有效的管理,需要建立直观高效的管理信息平台。在本项目中,依托陕西省第一次可移动文物普查项目,利用地理空间信息技术,建立了基于B/S架构的陕西省管理信息平台,能够对陕西省博物馆信息进行科学、高效的管理。     

复方中草药对珍珠龙胆石斑鱼生长、非特异性免疫及消化酶活性的影响

中草药含有多种活性物质,具有抗病助长无残留等特性,在国内外被广泛使用。本试验采用单因素试验设计方法,研究复方中草药（由黄芪、党参、大黄等12种中草药组合而成）不同剂量对珍珠龙胆石斑鱼（Epinephelus lanceolatus ♂×Epinephelus fuscoguttatus♀）生长性能、非特异性免疫及消化酶活性的影响。以初始体质量（19.16±0.25） g,体长为（10.63±0.56） cm的珍珠龙胆石斑鱼为试验对象,在基础饲料中分别添加0、0.4%、0.8%、1.2%、1.6%和2%复方中草药连续饲喂珍珠龙胆28 d。结果显示,该种复方中草药在添加剂量1.6%以内时,能有效降低石斑鱼的饵料系数（P<0.05）,对石斑鱼的增重率和特定生长率影响不显著（P>0.05）,但能显著提高石斑鱼血清中总蛋白含量（TP）、碱性磷酸酶（AKP）、酸性磷酸酶（ACP）以及总超氧化物歧化酶（T-SOD）活性（P<0.05）。对血清中非特异性免疫酶活性影响结果表明,中草药添加剂量在0.8%和1.2%时能很好地提高石斑鱼的免疫能力。石斑鱼肠道中的脂肪酶、胰蛋白酶活性受该种复方中草药的影响显著（P<0.05）,在添加量为1.2%以内显著提高了肠道中脂肪酶活性,胰蛋白酶活性和肠道总蛋白含量,而对淀粉酶活性影响不明显（P>0.05）,中草药对珍珠龙胆石斑鱼肠道消化酶活性的影响在添加剂量为1.2%时尤为明显。综合石斑鱼的生长、非特异性免疫和消化性能结果,认为该种复方中草药的最适添加量为1.2%左右。     

不同浓度氨氮胁迫下长蛸(Octopus minor)的半致死浓度和急性毒性评估

作为重要的水质参数,高浓度的氨氮对水生动物产生有害影响。氨氮的安全浓度对海水养殖物种至关重要。本文采用静水法,在盐度30.0±1.0, pH 7.8±0.2,温度20.8±0.5°C条件下,以荣成月湖海区的长蛸(Octopus minor)成体为研究对象,分析了水体氨氮对其急性毒性作用。通过预实验获得长蛸成体可耐受的浓度范围,从中选取浓度0(对照)、87.0、124.5、143.5、180.3、204.0、242.5mg/L等7个浓度梯度测定长蛸成体耐受性,采用概率单位法、寇氏法和线性回归法分别计算48h、72h和96h的半致死浓度(LC50)。实验结果显示,氨氮毒性效应随着浓度和胁迫时间的增长而增加,氨氮胁迫48h、72h和96h的半致死浓度分别为187.93、154.61和124.92mg/L (χ2检验P0.05);显示氨氮对长蛸成体具有显著毒性作用。与其他水生动物相比,长蛸对于氨氮的耐受性较强,对氨氮毒性的自我调节能力较强,具体的调节机制有待进一步研究。     

Seismic wave input method for three-dimensional soil-structure dynamic interaction analysis based on the substructure of artificial boundaries

Earthquake Engineering and Engineering Vibration - The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a...     

Discrete Element Modeling of Tangjiagou Two-Branch Rock Avalanche Triggered by the 2013 Lushan MW6.6 Earthquake, China

Two branches of Tangjiagou rock avalanche were triggered by Lushan earthquake in Sichuan Province, China on April 20^th, 2013. The rock avalanche has transported about 1 500 000 m³ of sandstone from the source area. Based on discrete element modeling, this study simulates the deformation, failure and movement process of the rock avalanche. Under seismic loading, the mechanism and process of deformation, failure, and runout of the two branches are similar. In detail, the stress concentration occur firstly on the top of the mountain ridge, and accordingly, the tensile deformation appears. With the increase of seismic loading, the strain concentration zone extends in the forward and backward directions along the slipping surface, forming a locking segment. As a result, the slipping surface penetrates and the slide mass begin to slide down with high speed. Finally, the avalanche accumulates in the downstream and forms a small barrier lake. Modeling shows that a number of rocks on the surface exhibit patterns of horizontal throwing and vertical jumping under strong ground shaking. We suggest that the movement of the rock avalanche is a complicated process with multiple stages, including formation of the two branches, high-speed sliding, transformation into debris flows, further movement and collision, accumulation, and the final steady state. Topographic amplification effects are also revealed based on acceleration and velocity of special monitoring points. The horizontal and vertical runout distances of the surface materials are much greater than those of the internal materials. Besides, the sliding duration is also longer than that of the internal rock mass.     

张家港市天气与道路交通安全的关系

对张家港市2010—2012年每日气象要素和交通事故数据进行了统计和分析。结果表明,在张家港市这个中国东部沿海发达地区典型的县级市里,交通事故的发生与节气、大风、降雨、积雪、能见度和温度等气象现象和要素都有着一定的内在关系。天气对道路交通安全的影响,不仅表现在对道面客观通行状况的影响,也表现在天气变化对驾驶员心理的间接影响。如果充分利用气象预报为交通服务,就能在很大程度上减少交通事故的发生概率。