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61.
对聊古一井数字化氡观测资料进行分析研究的结果显示,科学合理的气水分离装置对于获得真实可靠的观测结果具有重要作用;保障仪器的正常工作状态。是数字化氡观测的重要环节之一。聊古一井数字化氡的变化特征主要受气温,气压和井压的影响。分析和排除这些因素的影响是数字化观测资料分析应用的基础。  相似文献   
62.
小波变换在前兆观测资料分析中的应用   总被引:4,自引:3,他引:4  
由于数字化前兆具有高精度特点,因此,如何分离数字化前兆中的高频与低频信息,以及如何识别地震前兆的趋势异常与短期异常,是数字化前兆资料分析应用中的一个重要问题。本文给出了小波变换应用于正常的数字化前兆资料高频与低频信息的分离方法,并实际应用于地震前兆观测资料的处理,结合实例给出了地震前兆的趋势异常与短期异常的识别思路,从而为数字化前兆的趋势异常与短期异常的识别提供了一种新的有效方法。  相似文献   
63.
2003年5月初至2003年10月下旬,聊古一井气体总量现明显的低值异常过程,在对上述异常变化进行现场分析落实的基础上,结合对聊古一井水化学测项投测以来地震异常特征和聊古一井水化学测项前兆意义的分析结果,认为聊古一井气体总量的异常变化属场兆异常,可作为该井周围不同地震构造带上发生5级以上地震的一种判据。聊古一井气体总量异常过程较好地对应了2003年11月25日山西洪洞发生的5.0级地震。  相似文献   
64.
山东地区水化学短临跟踪标志体系的研究   总被引:1,自引:0,他引:1  
耿杰  王忠民  张昭栋 《地震研究》2000,23(3):346-355
在系统整理山东地区水化学观测资料的基础上,对山东菏泽5.9级地震、苍山5.2级地震及大同6.1级地城才南黄海5.3级地震前的地震异常特征了分析和总结,认为水化学多组分的同步异常变化,反映了震源应力场孕育过程,具有统一的物理力学机制,是震前源兆异常的重要标志。这异常基本同步出现,相互印证,增强了异常的可信度,为短临异常的判定提供了较为充分的依据。某一井孔水化学多组分出现同步异常变化,预示位于井孔同  相似文献   
65.
Concentrations of polychlorinated dibenzo-p-dioxins (dioxins)(PCDDs) and polychlorinated dibenzofurans (PCDFs)(furans) in sediments from Port Jackson ranged from 32 to 4352 pg WHO-TEQ DF g(-1)dw with a mean of 712 pg g(-1)dw. Maximum total dioxins plus furans concentrations in this sediment was 6,290,000 pg g(-1)dw, which is the highest recorded in Australia and among the highest reported for sediment globally. Permanent bans were placed on fin fishing and prawn trawling in February, 2006 for the whole estuary, based on dioxin tissue burdens. A distinct congener profile corresponded to chemicals known to have been produced by industry on the shores of Homebush Bay in the upper estuary. These chemicals are being dispersed extensively and exceed pre-anthropogenic concentrations in even distant, less developed parts of the harbour. Remediation of sediments is currently being undertaken, with the intention of containing dispersion of dioxins and reducing body burdens in fin fish and prawn populations.  相似文献   
66.
The marine ecosystem of the Pearl River Delta, located on the southern coast of China, has been heavily exploited following the rapid economic growth that has occurred since the 1980s. This investigation aimed to elucidate trace organic contamination in marine biota inhabiting the Pearl River Delta area. Biota samples, including green-lipped mussels (Perna viridis), oysters (Crassostrea rivularis) and shrimp (Penaeus orientalis) were sampled from 16 stations fringing the Estuary. Elevated concentrations (on a dry weight basis) of polycyclic aromatic hydrocarbons (27.8–1041.0 ng/g), petroleum hydrocarbons (1.7–2345.4 μg/g), polychlorinated biphenyls (2.1–108.8 ng/g), DDTs (1.9–79.0 ng/g), and hexachlorocyclohexanes (n.d.–38.4 ng/g) were recorded. A human health risk assessment was conducted to estimate the risk to local residents associated with the consumption of biota collected from the Pearl River Estuary. The results indicated that PCBs were at levels that may cause deleterious health effects in populations that consume large amounts of seafood. However, it would be instructive to establish health criteria for trace organic contaminants that are specific to the local populations, in order to derive a more accurate and relevant health risk assessment.  相似文献   
67.
Mussels (Mytilus edulis) were continuously exposed to dispersed crude oil (0.015-0.25 mg/l) for 7 months covering the whole gamete development cycle. After 1 month exposure to 0.25 mg oil/l, the level of alkali-labile phosphates (ALP) and the volume density of atretic oocytes in female gonads were higher than those in the gonads of control females, indicating that oil affected the level of vitellogenin-like proteins and gamete development. Spawning of mussels was induced after 7 months oil exposure. Parental oil exposure did not affect subsequent fertilization success in clean seawater but this was reduced in 0.25 mg oil/l. Parental exposure to 0.25 mg oil/l caused both slow development and a higher percentage of abnormalities in D-shell larvae 2 days post-fertilization; reduced growth 7 days post-fertilization. These effects were greatly enhanced when larval stages were maintained at 0.25 mg oil/l. Similar studies are warranted for risk assessment prognosis.  相似文献   
68.
环渤海地区断层气CO2监测网观测结果的初步分析   总被引:4,自引:0,他引:4  
耿杰  薛革  魏焕  王忠民 《华南地震》2000,20(1):28-32
为了进一步强化环渤海地震重点监视区的短临监测和预报。在分析山东环渤海地区第四系活动断裂分布特征的基础上,1998年3月下旬在渤海南岸的潍坊、烟台、威海3地市的10个县区,沿活动断裂布设了10个断层气二氧化碳观测点。根据CO2监测网一年来的观测结果,把这些观测点分为3类,结果表明,断层气CO2监测网对其300Km范围内的 4级以上地震具有较强的映震能力。  相似文献   
69.
70.
Coral species composition of drilled cores from emergent bank reefs, and coral cover of the surface of old and living reefs located along the coast of the state of Bahia, Eastern Brazil, revealed that there is a marked change in the occurrence of the major building coral species in different time intervals of the reef structure, as well as in the living surface of reefs located in two different geographical sites. Holocene core sections from two reef areas (12 degrees 40'S-38 degrees 00'W and 18 degrees 00'S-39 degrees 00'W) have as major reef builders, on its topmost core interval (3 to 4 ky old), the endemic coral Mussismilia braziliensis Verrill, 1868, which also dominate on the 2.5-3.5 ky old surfaces of truncated reef tops. At the base of the cores (the 2m lower interval, older than 4 ky BP), another endemic coral Mussismilia harttii Verrill, 1868 is the dominant reef component. The relative abundance of M. braziliensis on the living surfaces of shallow reefs from both areas, shows that in the southern area, it is up to 98% on reefs located 60 km off the coast, in depths between 3 and 4m, but do not exceed 1.3% on the surface of the northern reefs located 1-2 km off the coast in depths 4-5m. The Holocene falling sea level that occurred along the coast of Brazil since 5.1 ky BP, causes an increasing runoff into the area of coastal reefs. This phenomenon may have affected the nearshore reef building fauna, replacing a more susceptive coral fauna with one better adapted to low light levels and higher sediment influx. The high turbidity associated with early Holocene shelf flooding, should also be responsible for the absence of M. braziliensis during the initial stages of reef buildup in Brazil. At the present time, the rapidly increasing human pressure, due to changes in land uses of the coastal zone (increasing sedimentation rate, nutrification of coastal waters, industrial pollution) and underwater practices, such as overfishing and an intense tourism, is aggravating the recovery capacity of this already naturally threatened coral community. If this situation coupled with increasing sea surface temperature persists, modern coral reef growth, in Brazil cannot be maintained and the major reef building coral species of the reefs in Bahia, a remnant endemic coral fauna will very soon appear in the list of endangered species.  相似文献   
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