射电望远镜控制系统中的数据传输序列化分析

控制系统能衔接、集成和管理射电望远镜的软硬件系统。控制系统的序列化工具可以将射电望远镜的不同设备、操作系统、编程语言和网络之间传输的信息进行编码和解码,增强系统之间数据的传输效率。分析和比较了3款二进制序列化工具Msgpack,Protobuf和Flatbuffers的编码原理及特性,并通过一个实例测试了它们的序列化数据大小、序列化时间和中央处理器利用率。结果表明,Msgpack的综合性能优于Protobuf和Flatbuffers,适用于周期长、需求易变的射电望远镜系统之间传输信息的编码和解码。     

Joint exploration of regional importance of possibilistic and probabilistic uncertainty in stability analysis

Stability analysis generally relies on the estimate of failure probability P. When information is scarce, incomplete, imprecise or vague, this estimate is imprecise. To represent epistemic uncertainty, possibility distributions have shown to be a more flexible tool than probability distributions. The joint propagation of possibilistic and probabilistic information can rely on more advanced techniques such as the classical random sampling of the cumulative probability distribution F and of the intervals from the possibility distributions π. The imprecise probability P is then associated with a random interval, which can be summarized by a pair of indicators bounding it. In the present paper, we propose a graphical tool to explore the sensitivity on these indicators. This is conducted by means of the contribution to sample probability of failure plot based on the ordering of the randomly generated levels of confidence associated with the quantiles of F and to the α-cuts of π. This presents several advantages: (1) the contribution of both types of uncertainty, aleatoric and epistemic, can be compared in a unique setting; (2) the analysis is conducted in a post-processing step, i.e. at no extra computational cost; (3) it allows highlighting the regions of the quantiles and of the nested intervals which contribute the most to the bounds of P. The method is applied on two case studies (a mine pillar and a steep slope stability analysis) to investigate the necessity for extra data acquisition on parameters whose imprecision can hardly be modelled by probabilities due to the scarcity of the available information (respectively the extraction ratio and the cliff geometry).     

一种新型绳索钻具打捞器

绳索钻具打捞器在地质勘探取心过程中有着相当重要的作用,不论是取心还是深孔投放钻具都要用到打捞器,这就要求打捞器在投放过程中有极高的可靠性,保证脱卡器能够顺利脱卡。同时打捞器在被提出钻外后要求有很高的安全性,保证不会空中脱钩伤人。本文所述的一种新型绳索打捞器具有较高的可靠性和安全性,并且兼具重锤的功能,无需打钻过程中投放重锤,可以大大提高钻探效率。     

河南嵩县石盘钼矿床地质特征及区域找矿潜力分析

石盘钼矿是近年来在豫西钼多金属成矿带上发现的一个中型钼矿床。矿体产于燕山期合峪花岗岩体内外接触带,特别是岩体周边同期不同次的岩体侵入区域、岩体顶面的凸起部位是矿体赋存的有利部位。文章在讨论矿床成矿地质背景、矿床地质特征的基础上,对矿床成因及控矿因素、区域找矿潜力及找矿标志进行了探讨,指出了该类矿床的进一步找矿方向。     

青海省都兰县洪利铅锌矿床地质特征及找矿标志

青海省都兰县洪利铅锌矿床地处华南板块与柴达木盆地南缘的接合部,位于东昆中断裂带内,总体构造线走向为NW-SE向,构造形迹以断裂、褶皱为主,矿区断裂构造发育,按其走向可划分为2组,即NW,NE向断裂。其中NW向断裂为区内主干断裂,略具规模,控矿明显,为区内主要的导、控矿构造,洪利铅锌矿床即受其控制。次为NE向断裂,但规模不大,且对矿体具错断和破坏作用。区内岩浆活动多集中于晋宁期和华力西期,成矿地质条件较好。受后期构造活动影响,造成了该矿床由于矽卡岩化与热液蚀变在空间上的叠加而使其矿化特征的复杂多变。通过详细的野外观察和室内分析共圈出锌多金属矿体2个,磁铁矿体6个,金矿体2个,铁矾帽9个。根据围岩蚀变、矿体走向、分布特征及其与岩性、构造的关系,可分为南、北2个矿段,初步划分了Ⅰ,Ⅱ,Ⅲ条矿化带。研究认为铁矾帽、磁异常、地球化学、矽卡岩化、热液蚀变及角岩化是该区的主要找矿标志,其中铁矾帽系该矿区找矿的直接标志。     

Optimizing alginate beads for the immobilisation of Phaeodactylum tricornutum in estuarine waters

This study addresses the influence of calcium as hardening agent, on alginate gel bead stability and suitability for the growth of Phaeodactylum tricornutum Bohlin (Bacillariophyceae) in estuarine waters. Alginate beads produced with 1, 2, 4, 5 and 6% of CaCl₂ solutions were investigated for stability and suitability for growth of P. tricornutum cells, under mean salinity 27, at 220 and 440 rpm stirring laboratory conditions, and in devices placed under in situ estuarine conditions. Gel stability and suitability for cell growth were evaluated through bead diameter, bead disruption, dissolution and loss of spherical shape, cell viability and specific growth rates. Beads gelled with 5% CaCl₂ were found the most suitable to sustain gel stability and cell growth in the estuarine waters. These beads were surveyed during dredging operations in the Tagus estuary, both in situ and in estuarine water under laboratory conditions, showing significantly lowered growth rates possibly due to Mn, Co and As accumulated in the cells. Results confirmed that the monitoring tool presented is reliable and effective for the assessment of anthropogenic impacts.     

连续造斜绳索取心钻具造斜机构的设计与试验

根据钻杆抗弯强度的限制,确定连续造斜绳索取心钻具的造斜能力在0．2°-0．5°／m。为满足绳索取心的要求,设计造斜机构采用偏心轴承结构。分别利用几何分析法与极限曲率法对造斜结构的造斜能力进行理论计算。实验结果表明,该造斜机构能够达到设计造斜能力,用纵横弯曲梁法的计算造斜率与实钻造斜率较为吻合。     

SA75+5绳索取心钻具在第三系煤田地质勘探中的应用

针对宝山-振兴煤田第三系煤田地质勘探中地层松散,易坍塌、掉块、缩径的问题,采用普通双管和普通绳索取心钻进,各有利弊,而将SA75绳索取心钻具钻头、扩孔器加大到Φ80 mm,并采取相应的钻孔、取心技术措施,取得了质量高、效率高、效益好的成果。     

Was FLK North levels 1–2 a classic “living floor” of Oldowan hominins or a taphonomically complex palimpsest dominated by large carnivore feeding behavior?

From excavation at FLK North levels 1–2 in 1960–1962, Mary Leakey reported approximately 1200 Oldowan artifacts and 3300 large mammal fossils as a hominin “living floor”. Preliminary taphonomic analysis by Bunn seemed supportive, based on the presence of some cut-marked bones, the concentration of several dozen bovid individuals, and the relative abundance of limbs and mandibles over other axial elements. Recent taphonomic analysis of Leakey's entire fossil assemblage by Domínguez-Rodrigo and Barba, however, documents a minor hominin role at the site, contrasted to the dominant role of carnivores. Felids brought prey animals; hyenas scavenged from abandoned felid meals. At different times, hominins butchered several bovids and discarded artifacts at this dynamic location. Since 2006, renewed excavations at FLK North and other sites by the Olduvai Paleoanthropology and Paleoecology Project (TOPPP) have expanded artifact and fossil samples and implemented new analytical approaches to clarify taphonomic histories of the Olduvai paleolandscape. At FLK North, > 1000 new large mammal fossils from levels 1 to 2 show minimal butchery evidence amid abundant evidence of carnivore gnawing/fracture, rodent gnawing, and sediment abrasion. To help guide future excavation and analyses, we have developed several alternative working hypotheses of site formation.     

龙永煤田绳索取心钻进工艺技术研究

龙永煤田地质构造复杂,岩性倾角变化大,断层破碎带多,在应用金刚石绳索取心工艺钻进时,常常存在着掉块、坍塌和漏失现象,造成孔内事故多,钻进效率低等问题。通过反复的实践研究,总结出根据不同的地层特性,选择适宜的钻孔口径、钻具级配和钻头型号,配制不同的冲洗液;针对地层的漏失特点和漏失量的大小,采用不同的堵漏材料的技术措施,从而初步解决了在该区钻进时遇到的技术难点,减少了孔内事故的发生,将钻月效率由430m提高到603m,取得了良好的经济效益。