用泻利盐矿和卤水制备硫酸镁工艺探究

以盐田泻利盐矿和卤水为原料,通过兑卤、热溶、结晶法制备硫酸镁。探究了各工艺因素对产物收率及纯度的影响,找到了较佳的工艺条件;在此基础上进行粗镁精制,得到纯度99%以上的硫酸镁。     

中朝地台东北缘3km深度地震层析成像的地质解释

利用本区丰富的地质,人工地震探测资料,对３ｋｍ深度层析成象成果进行了分析对比,结果表明：（１）３Ｋｍ深度速度值与人工地震探测所获地震波速值吻合较好;（２）３ｋｍ深度速度分布与该深度处的岩石介质分布有较好的对应关系,高速区对应地层主要为太古界－下元古界变质岩和地槽区的古生界浅变质岩,低速区对应主要为中生界火山,碎屑岩,燕山期花岗岩体和盖层性质的中元古－古代界沉积岩。（３）层析成象结果可划分深度不同的     

黔中息烽磷矿床成矿环境、成矿作用及成矿模式探讨*

息烽磷矿是贵州地区震旦纪陡山沱期磷矿的重要组成部分,以矿层厚、品位高、断裂构造发育、叠层石丰富而独具特色。通过对矿床地质特征及矿床地球化学特征综合研究认为,从陡山沱组底到顶气候经历温湿—干热—湿热变化,海平面对应经历了海进—海退—海进,其内的磷块岩和磷质岩是在热水沉积作用、生物作用和正常海水沉积作用等共同作用下形成于前滨—临滨环境。综合以上,反演息烽陡山沱期成矿过程,发现矿床经历了“海进—海退—海进”三阶段成矿,在陡山沱早期海进阶段形成下矿层,随后的海退阶段和海进阶段形成上矿层。空间上,2矿层之间夹白云岩,且交于靠黔中古陆一侧,当第2次海进越过第1次海进的前滨—临滨位置后,只形成上矿层,是开阳、息烽磷矿床1层矿体形成的对应部位。瓮福磷矿床有2层矿体,对应处于经历了“三阶段成矿”的前滨—临滨部位,且瓮福磷矿成矿时的位置高程明显低于息烽磷矿、息烽磷矿略低于开阳磷矿,通过岩性特征对比,与实际基本吻合。因此,在对陡山沱期的磷矿进行成矿预测和找矿勘查中,与息烽磷矿床相似的黔中及附近区域的动态前滨—临滨环境,均为磷矿床的找矿靶区,利用“三阶段成矿”形成相交的2矿层特点,可高效对已知矿床、矿化点和前滨—临滨带周围进行成矿预测。     

论城市地理信息系统的标准化问题

本文阐述了城市地理信息系统标准化的必要性,国内外城市地理信息系统标准的研制现状,城市地理信息系统标准化的基本原则及城市地理信息系统标准化设计等几项内容,旨在和读者达成共识;建设城市地理信息系统时,必须注重标准化设计。且文中给出了与城市地理信息系统相关的标准,供读者参考。     

Adaptability of ESR dating of fault gouge in aseismic region: A case study on Hangzhou region, China

ESR dating has been widely used in seismic assessment. In this paper, we collected fault gouge samples systematically for ESR (Electron Spin Resonance) dating, and sediment samples of overlying strata, and offset strata for OSL (Optically Stimulated Luminescence) dating along Xiaoshan-Qiuchuan fault (XQF) trending NE-SW, Xiaofeng-Sanmen fault (XSF) trending NW-SE, and Changhua-Putuo fault (CPF) trending E-W. In the same fault outcrop, the ESR data of fault gouge is greater than the OSL data of the strata of...     

不同周期气压波对钻孔体应变仪观测结果的影响

应用相关分析与谱分析方法,研究了天津宝坻、北京东三旗和河北张家口台2003～2006年钻孔体应变与气压之间的关系。分析结果表明,同一台站不同周期的气压波与体应变具有不尽相同的关系,如宝坻台年周期体应变与气压负相关,回归系数为-13.35×10-11/Pa,滞后气压变化62.15天;月周期和日、半日周期体应变与气压均呈同步、线性、正相关关系,回归系数平均值分别为7.489×10-11/Pa和6.301×10-11/Pa。不同台站日、半日周期和月周期气压波对体应变的影响较为接近,而与年周期相比差异较大。根据岩石力学和弹性力学原理,进一步探讨了不同周期气压波与体应变相关性存在差异的原因。     

我国大陆6级地震平静后首次强地震的短期预测实验

自2005年4月8日西藏仲巴6.7级地震后,我国大陆出现了历史上少有的6级地震平静.截止到2007年4月初,6级地震平静达730多天,这一现象引起了众多专家的高度关注,将在何时、何处打破这种平静一时成为关注的焦点.依据我国大陆形变异常分布特征,作者分别于2007年4月18日和4月27日试验性地提出了<东部地区短期地震危险性分析意见>及西北地区5月份存在发生6级地震可能性的预测意见.两次预测实验结果尽管都不是很准确,但对于揭示地壳形变观测本质及探索地震预测新方法等都是有意义的.     

Ultradeep diamonds originate from deep subducted sedimentary carbonates

Diamonds are renowned as the record of Earth’s evolution history. Natural diamonds on the Earth can be distinguished in light of genetic types as kimberlitic diamonds (including peridotitic diamonds and eclogitic diamonds), ultrahigh-pressure metamorphic diamonds and ophiolitic diamonds. According to the inclusion mineralogy, most diamonds originated from continental lithospheric mantle at depths of 140–250 km. Several localities, however, yield ultradeep diamonds with inclusion compositions that require a sublithospheric origin (>~250 km). Ultradeep diamonds exhibit distinctions in terms of carbon isotope composition, N-concentration, mineral inclusions and so on. The present study provides a systematic compilation concerning the features of ultradeep diamonds, based on which to expound their genesis affinity with mantle-carbonate melts. The diamond-parental carbonate melts are proposed to be stemmed from the Earth’s crust through subduction of oceanic lithosphere. Ultradeep diamonds are classified into a subgroup attaching to kimberlitic diamonds grounded by formation mechanism, and present connections in respect of carbon origin to eclogitic diamonds, ultrahigh-pressure metamorphic diamonds and ophiolitic diamonds.     

Using a global reference sample set and a cropland map for area estimation in China

A technically transparent and freely available reference sample set for validation of global land cover mapping was recently established to assess the accuracies of land cover maps with multiple resolutions. This sample set can be used to estimate areas because of its equal-area hexagon-based sampling design. The capabilities of these sample set-based area estimates for cropland were investigated in this paper. A 30-m cropland map for China was consolidated using three thematic maps (cropland, forest and wetland maps) to reduce confusion between cropland and forest/wetland. We compared three area estimation methods using the sample set and the 30 m cropland map. The methods investigated were: (1) pixel counting from a complete coverage map, (2) direct estimation from reference samples, and (3) model-assisted estimation combining the map with samples. Our results indicated that all three methods produced generally consistent estimates which agreed with cropland area measured from an independent national land use dataset. Areas estimated from the reference sample set were less biased by comparing with a National Land Use Dataset of China (NLUD-C). This study indicates that the reference sample set can be used as an alternative source to estimate areas over large regions.     

Rainfall interception by tree crown and leaf litter: An interactive process

Rainfall interception research in forest ecosystems usually focuses on interception by either tree crown or leaf litter, although the 2 components interact when rainfall occurs. A process‐based study was conducted to jointly measure rainfall interception by crown and litter and the interaction between the 2 interception processes for 4 tree species (Platycladus orientalis and Pinus tabulaeformis represented needle‐leaf species, and Quercus variabilis and Acer truncatum represented broadleaf species) at 3 simulated rainfall intensities (10, 50, and 100 mm hr^?1). Results indicated that (a) crown and litter interception processes incorporated 3 phases: the dampening phase, the steady saturation phase, and the postrainfall drainage phase, but the dampening phase for litter interception usually lasted 30 min longer than for crown interception; (b) the maximum and minimum interception storage (C _max and C _min ) for the crown were 0.63 and 0.36 mm on average, and litter C _max and C _min were 5.38 and 2.36 mm, respectively; (c) generally, crown and litter C _max and C _min increased when gross precipitation increased significantly (p  < .05) from 10 to 100 mm; and (4) crown C _max and C _min for needle‐species were 1.8 and 1.2 times larger than broadleaf species, whereas broadleaf litter showed the opposite, its C _max and C _min were 2.0 and 1.6 times larger than needle‐leaf litter on average; however, no significant differences were observed in crown and litter C _max and C _min between species on per leaf area and litter thickness basis. Results were normalized by total leaf area and litter thickness to provide a way to scale up from young trees to mature forests. Overall, rainfall interception was affected by biotic and abiotic factors together and could be quantified via multiple linear regression functions.