双频激电在某铁矿勘查中的应用效果

双频激电方法轻便、快速、抗干扰能力强、稳定性好、观测精度高,本文通过实例阐明双频激电法在交通不便,地形复杂的山区找矿中的应用效果。     

双频激电法在新疆金沙滩金矿勘查中的应用

新疆金沙滩金矿普查区以往的物探资料相对缺乏,这与该区较为困难的接地条件有关。相对而言,双频激电法具有受电流变化影响小、抗干扰能力强等优点,对该类地区的物探找矿具有一定的适用性。文章主要阐述了双频激电中梯扫面和双频激电测深在新疆金沙滩金矿普查区的应用;并通过视幅频率的数据处理,综合分析双频激电中梯平面、剖面异常特征和双频激电测深断面特征,进一步明确找矿范围,查明矿(化)体的赋存部位、分布规模等,实现找矿目标。     

双频激电法在西藏抱布德铅锌矿勘探中的应用

抱布德矿区为班公湖—怒江缝合带和拉竹龙—金沙江缝合带成矿区域上一个典型铅锌矿床。本文对双频激电法应用在铅锌矿找矿中的效果进行了分析探讨,认为抱布德矿区内物探异常具有较高视幅频率、视电阻率的特点,一般找矿价值较高。据此研究成果,成功在矿区圈定激电异常区域,并为钻探工作提供技术支撑,使矿区找矿成果达到了中型铅锌矿床规模(矿石资源量266. 27万t)。同时也说明高海拔区域采用双频激电法找铅多金属矿床也可以取得较好的效果。     

双频激电法在坦桑尼亚汉德尼金矿勘查中的应用

汉德尼(Handeni)金矿是近年来在坦桑尼亚绿岩带中发现的大型金矿床,矿区地形复杂、植被繁茂,物性测试显示含金的硫化物地质体具有高极化的特征。双频激电法具有受电流变化影响小、设备轻便等优点。文章主要阐述了双频激电法在该矿区的应用,通过对视幅频率的数据处理,综合分析双频激电平面、剖面和测深断面异常特征,查明矿(化)体的赋存部位、分布规模等,进一步明确找矿范围。     

甘肃河西某石墨矿激电特征及找矿预测

石墨矿产在国民经济发展和现代化建设中占有重要的地位,近年全国掀起了勘查石墨矿的热潮。本文介绍了激发极化法在甘肃某石墨矿勘查中的成功应用效果。工作中利用激电中梯测量圈定了有利激电异常区,以激电测深法大致查明了激电异常体的空间分布特征。结合地质、钻探验证资料就找矿效果进行了初步探讨,总结提出了地质、地球物理找矿标志,初步建立了该区石墨矿勘查地质—地球物理找矿模型。     

激电中梯在内蒙古某金属矿勘查中的应用

介绍了激电中梯法在内蒙古某金属矿勘查中的具体应用,通过分析该矿区已有的地质、地球物理资料以及对野外测量数据的处理解释,共圈定3个激电异常区,并对异常进行了定性解释,推测了该区内极化体的分布情况,为后续找矿工作指明了方向。     

激发极化法在门坎哨金矿勘查中的应用

激发极化法在以低阻高极化为特征的金矿找矿中是一种有效方法。文章对门坎哨区金矿的激电资料进行了综合整理和研究,分析了该区金矿的激电异常特征,结合物性资料研究了该区矿化与其围岩的区分,制定了相应的工作方案,取得了较好的找矿效果。     

激发极化法在云南大宝山铜矿勘查中的应用效果

云南维西大宝山铜矿区通过近年的地质勘查,探明的铜资源量已达中型规模。文章介绍了激发激化法原理及采集参数,简述了激电中梯和激电测深两种物探方法在铜矿勘探中的综合应用。通过物探工作圈定了长约数千米的激电异常带,并选择了大宝山铜矿101、91、104剖面为实例进行异常解释推断,并结合钻孔资料对异常进行了验证。激发极化法的应用使该地区找矿评价取得了良好的效果。     

综合物探在广东石寨矽卡岩型铅锌多金属矿应用

石寨矿区属矽卡岩型铅锌多金属矿,矿区内已发现2条铅锌多金属矿脉,赋存于矽卡岩带中。在矿区采用磁法与电法组合的综合物探方法追索矿脉,通过分析磁异常和激电异常,明确了找矿靶区,确定了有利的找矿部位,经过钻孔验证,在激电测深异常位置控制到矿脉。综合物探方法在矿区取得了良好的找矿效果。     

河南宅延多金属矿磁异常区找矿前景

豫西宅延M-158航磁异常历经多次查证,找矿均未取得实质性进展。本文从航磁异常、地磁异常、重力异常、激电异常特征及该区最新地质成果等方面对前人工作成果进行分析总结,结合邻近老里湾、中河大型银矿区找矿成果,认为宅延磁异常可能为银、铅、锌及铁磁性矿物等多金属矿引起的综合异常,圈出了2处铅锌找矿靶区,为该区最终取得找矿突破提供了必要的地质地球物理依据。     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

浅谈建筑施工临时用电安全

针对由于建筑施工临时用电安全管理的不完善和不规范操作而导致大量工伤事故频频发生的问题,为消除用电安全隐患,对建筑施工临时用电安全管理进行了归纳和分析,并提出了整改意见,以确保现场人员及电气设备的安全运行。     

谈城市历史保护规划的误区

由于缺乏起码的历史文化知识,忽视历史文化遗产的保护,错误的决策导致了建设性的破坏,要加强城市保护的教育,培养合格人才。     

浅谈我国工程项目建设成本控制存在的问题

结合目前我国施工企业工程项目成本管理现状,对工程项目成本管理过程中存在的问题进行了较详细的分析,并提出了一些解决问题的办法,以做好项目成本控制工作,进而增强企业经济实力。     

Perchlorate exposure in lactating women in an urban community in New Jersey

Perchlorate is most widely known as a solid oxidant for missile and rocket propulsion systems although it is also present as a trace contaminant in some fertilizers. It has been detected in drinking water, fruits, and vegetables throughout New Jersey and most of the United States. At sufficiently high doses, perchlorate interferes with the uptake of iodine into the thyroid and may interfere with the development of the skeletal system and the central nervous system of infants. Therefore, it is important to quantify perchlorate in breast milk to understand potential perchlorate exposure in infants. In this study we measured perchlorate in breast milk, urine, and drinking water collected from 106 lactating mothers from Central New Jersey. Each subject was asked to provide three sets of samples over a 3-month period. The average ± SD perchlorate level in drinking water, breast milk, and urine was 0.168 ± 0.132 ng/mL (n = 253), 6.80 ± 8.76 ng/mL (n = 276), and 3.19 ± 3.64 ng/mL (3.51 ± 6.79 μg/g creatinine) (n = 273), respectively. Urinary perchlorate levels were lower than reference range values for women of reproductive age (5.16 ± 11.33 μg/g creatinine, p = 0.03), likely because of perchlorate secretion in breast milk. Drinking water perchlorate levels were ≤ 1.05 ng/mL and were not positively correlated with either breast milk or urine perchlorate levels. These findings together suggest that drinking water was not the most important perchlorate exposure source for these women. Creatinine-adjusted urine perchlorate levels were strongly correlated with breast milk perchlorate levels (r = 0.626, p = < 0.0005). Breast milk perchlorate levels in this study are consistent with widespread perchlorate exposure in lactating women and thus infants. This suggests that breast milk may be a source of exposure to perchlorate in infants.     

瓷砖放射性研究

通过对瓷砖放射性抽样检测,得到了瓷砖放射性质量状况,与过去检测数据相比较,初步研究发现放射性有增大的趋势。