A Possible Cause of the Diminished Solar Wind During the Solar Cycle 23 – 24 Minimum

Interplanetary magnetic field and solar wind plasma density observed at 1 AU during Solar Cycle 23?–?24 (SC-23/24) minimum were significantly smaller than those during its previous solar cycle (SC-22/23) minimum. Because the Earth’s orbit is embedded in the slow wind during solar minimum, changes in the geometry and/or content of the slow wind region (SWR) can have a direct influence on the solar wind parameters near the Earth. In this study, we analyze solar wind plasma and magnetic field data of hourly values acquired by Ulysses. It is found that the solar wind, when averaging over the first (1995.6?–?1995.8) and third (2006.9?–?2008.2) Ulysses’ perihelion (\({\sim}\,1.4~\mbox{AU}\)) crossings, was about the same speed, but significantly less dense (\({\sim}\,34~\%\)) and cooler (\({\sim}\,20~\%\)), and the total magnetic field was \({\sim}\,30~\%\) weaker during the third compared to the first crossing. It is also found that the SWR was \({\sim}\,50~\%\) wider in the third (\({\sim}\,68.5^{\circ}\) in heliographic latitude) than in the first (\({\sim}\,44.8^{\circ}\)) solar orbit. The observed latitudinal increase in the SWR is sufficient to explain the excessive decline in the near-Earth solar wind density during the recent solar minimum without speculating that the total solar output may have been decreasing. The observed SWR inflation is also consistent with a cooler solar wind in the SC-23/24 than in the SC-22/23 minimum. Furthermore, the ratio of the high-to-low latitude photospheric magnetic field (or equatorward magnetic pressure force), as observed by the Mountain Wilson Observatory, is smaller during the third than the first Ulysses’ perihelion orbit. These findings suggest that the smaller equatorward magnetic pressure at the Sun may have led to the latitudinally-wider SRW observed by Ulysses in SC-23/24 minimum.     

青海省化隆地区镁铁-超镁铁质侵入岩含矿特点与成矿规律

铁质系列的镁铁-超镁铁质侵入岩具有镍矿成矿专属性,但并非所有的类似侵入岩都含矿,根据镁铁-超镁铁质侵入岩含矿特点可总结成矿规律,有效指导区域找矿实践。青海省化隆地区发育114个镁铁-超镁铁质侵入岩体,其含矿性特点与成矿规律是制约该岩带找矿突破的关键因素。本文通过对区内裕龙沟、亚曲、阿什贡及下什堂等岩体地质特征、年代学、岩石地球化学特征及区域对比分析研究,发现这些岩体具有相近的成岩时代,集中于436~449 Ma,可能是同一构造背景的产物。S同位素、Re-Os同位素及Sr-Nd同位素共同揭示了岩体的母岩浆来自一个曾被交代富集的地幔源区,其εNd(t)=-7.74~+8.36,初步表明其岩浆源区应该位于软流圈地幔,并混有一部分被俯冲板片交代的地幔楔物质。而这种交代富集事件可能与祁连、柴北缘在早古生代期间大规模的俯冲有关,是弧岩浆作用的成矿表现。化隆群富硅地层S的混入为硫化物的不混溶创造了条件,致使岩浆中熔离出的硫化物液滴聚集,侵位到理想空间形成不同品位不同类型的铜镍矿体。岩相分异充分、橄榄石富集、基性程度较高的侵入岩体相对易形成镍矿体,对青海省化隆地区镁铁-超镁铁质岩体的含矿性评价具有重要指示作用。     

南祁连化隆地区镁铁-超镁铁质侵入岩地质、地球化学特征与铜镍成矿

南祁连化隆地区的镁铁-超镁铁质侵入岩带是青海省重要的含镍矿岩带,铁质系列良好的岩相分异及较高的Ni、Cu、Co元素含量表现出了很好的成矿条件与找矿潜力。通过对区内裕龙沟、亚曲、阿什贡及下什堂等岩体地质特征、岩石地球化学特征及区域对比分析研究,表明稀土元素的球粒陨石和微量元素的原始地幔蛛网图表现出轻稀土元素相对富集的右倾模式,并且富集大离子亲石元素(Sr、Rb、Ba)、相对亏损高场强元素(Nb、Ta、Hf、Zr)。γOs值表现为大的正值且变化范围较大(+80~+1183),连同普遍存在的Nb、Ta亏损,进一步说明可能也与地壳同化混染密切相关。这些表明带内岩体的母岩浆来自一个曾被交代富集的地幔源区,其εNd(t)=-7.74~+8.36,这些共同表明其岩浆源区应该位于软流圈地幔,并混有一部分被俯冲板片交代的地幔楔物质。而这种交代富集事件可能与祁连、柴北缘在早古生代期间大规模的板片俯冲有关。化隆群富硅地层为硫化物的不混溶创造了同化混染的条件,并最终导致富硅物质的加入,致使岩浆中硫化物的不混溶作用发生,从而可形成不同品位不同类型的岩浆铜镍硫化物矿床。     

云南耿马县勐简铅锌银矿特征及成矿规律

勐简铅锌银矿近矿围岩为古生界孟定街群(Pzmb),矿体呈似层状、脉状赋存于北东东向断裂破碎带中,为中—低温热液充填型矿床。     

面向相似材料模型的数据处理软件的研究

工业测量系统具有高精度、简单便捷、应用广泛等优点,但在开采沉陷方面的应用尚处于研究的初级阶段。数字工业近景摄影测量系统是工业测量系统中的一种,基于该系统的相似材料模型观测方法是开采沉陷模拟研究领域一项重大的技术革新,但工业测量系统的海量数据、数据间的关系等一系列的问题急需解决,因此面向相似材料模型的观测数据处理软件的开...     

基于三维TIN的非地面点云剔除方法研究

三维激光扫描仪对地面进行扫描时,会产生很多非地面点,即噪声点,对后续研究带来很多不便.针对这一问题,提出两种基于三维TIN的非地面点云剔除方法,分别是根据判断相邻三角形法向量的夹角以及构建局部平面的方法,介绍两种剔除方法的原理及实现过程,以拟合局部平面的方法进行实例分析,得出剔除结果.     

2010年7—8月东北地区强降雨过程分析和预报技术探讨

2010年7月19日至8月底,我国东北地区的吉林省和辽宁省先后共出现10次强降雨过程,造成严重洪涝灾害,降雨具有过程频繁、降水量大、落区重复的特点。利用地面、高空、卫星、雷达等常规观测资料和地面区域站资料及T639、NCEPFNL业务全球分析资料针对上述特点进行了分析。结果表明：稳定而异常的环流形势导致了较强偏南暖湿气流与冷空气在吉林中东部和辽宁中东部交汇,形成持续不断的降雨过程。造成强降雨的主要高空系统有低涡（切变）北上类和冷涡（低槽）东移类,两类的环流形势特点、水汽来源、冷空气作用不尽相同。两类系统的个例分析表明,降雨云团反复生成并经过同一地区是造成较大累积降雨量的主要原因。两个个例的对流云团生成机制不同,7月20日过程对流云团发生于沿低空急流带上超地转偏差风辐合区、高空冷锋前部的上升运动区和位势不稳定区,7月27日夜间过程的上升运动主要是近地层锋面抬升即冷暖空气辐合的结果;生成后对流系统的移动方向可用Corfidi向量法判断。上述分析结果对东北暴雨预报具有参考价值,分析方法同样也适用于我国其他各地的暴雨分析和预报。     

Purification and characterization of cold-active endo-1,4-β-glucanase produced by Pseudoalteromonas sp. AN545 from Antarctica

A bacterium hydrolyzing carboxymethylcellulose, isolated from Antarctic sea ice, was identified as Pseudoalteromonas sp. based on 16S rDNA gene sequences and named as Pseudoalteromonas sp. AN545. The extracellular endo-1,4-β-glucanase AN-1 was purified successively by ammonium sulfate precipitation, DEAE-Sepharose ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The molecular mass of AN-1 was estimated to be 47.5 kDa utilizing SDS-PAGE and gel chromatography analysis. AN-1 could hydrolyze caboxymethylcellulose, avicel and β-glucan, but not cellobiose, xylan and p-Nitrophenyl-β-D-glucopyranoside. The optimal temperature and pH for the β-glucanase activity of AN-1 were determined to be at 30°C and pH 6.0, respectively. AN-1 was stable at acidic solutions of pH 5.0-6.5 and temperatures below 30°C for 1 h. Moreover, the specific activity was enhanced by Ca2+ and Mg2+, and inhibited by Cu2+. The kinetic parameters Michaelis constant (Km) and maximum velocity (Vmax) of AN-1 were 3.96 mg/mL and 6.06×10-2 mg/(min·mL), respectively.     

青海省化隆县下什堂岩体地质-地球化学特征及其含矿性研究

作者近几年在青海省化隆地区开展了岩浆型铜镍矿资源潜力评价,重点对下什堂岩体进行了实地调查和研究.岩体地质特征、岩石地球化学特征及区域对比分析表明,下什堂岩体为一铁质系列的超基性-基性岩杂岩体,岩体分异好,有用元素Ni、Cu、Co丰度高,系有利成矿岩体;元素丰度和相关性揭示,该岩体在岩浆成岩演化过程中,硫逸度对元素富集起...     

论苗族传统知识在贵州麻山石漠化灾变救治中的价值

20世纪中期以来,麻山喀斯特山区随着周边社会环境的巨变,这些巨变冲击了麻山地区生态系统的脆弱环节,使麻山地区石漠化灾变日趋扩大。国家从20世纪60年代开始虽经多方救治,成效甚微。我们在对苗族生计方式的田野调查后发现,生息在这里的苗族积累有高效利用与精心维护喀斯特生态系统的经验和技能,发掘和利用苗族传统的地方性知识和技能,在石漠化灾变救治中具有不可替代的特殊价值。