直流电法在水文地质勘查中的应用研究     

张玉池 《矿产与地质》1998,12(6):421-426

直流电法主要有电阻率法（联合剖面法和电测深法）和充电法,广泛应用于工程地质和水文地质勘察中,如地基勘察,水库涌水处理,矿山岩溶水测量等。直流电法能有效地圈定含水体的位置,确定其产状,特别是选择的方法组合应用效果更佳,为工程水文地质提供准确的资料。  相似文献   

关于我国电力建设问题     

陆大道 《云南地理环境研究》1990,2(1):10-13

本文在分析我国能源资源分布特点,总结过去电力建设经验的基础上,通过水、火电全面经济效益比较,认为,在我国具体的国情和国力条件下,今后必须贯彻优先开发水能的方针,并提出了因地制宜发展水电建设应注意做好的四项工作。  相似文献   

The adoption of sustainable innovations: Driven by symbolic and environmental motives     

《Global Environmental Change》2014

Critical to the environmental success of sustainable innovations is the adoption by consumers. The consensus is that instrumental shortcomings of sustainable innovations inhibit their adoption. However, we argue that the adoption of sustainable innovations does not exclusively depend on their instrumental attributes. In addition, people may be motivated to adopt sustainable innovations because of their positive environmental and symbolic attributes, that is, they benefit the environment and can be used to signal positive characteristics to oneself and others. We studied the significance of instrumental, environmental and symbolic attributes for the adoption of two sustainable innovations: electric cars (Study 1) and local renewable energy systems (Study 2), following two methods. Results showed that when asked directly, participants claimed that instrumental and environmental attributes are most important for their decision to adopt sustainable innovations, while symbolic attributes were rated as less important. Interestingly, evaluations of the symbolic and environmental attributes of sustainable innovations, but not evaluations of their instrumental attributes, predicted different indicators of adoption (i.e., interest in, the acceptability of, and intention to adopt these sustainable innovations), suggesting that the significance of symbolic motives for adopting sustainable innovations may not be recognized by consumers. Moreover, favorable evaluations of symbolic attributes particularly enhanced interest in and acceptability of sustainable innovation when participants evaluated the instrumental attributes more negatively, but not when instrumental attributes were evaluated relatively positively. This suggests that the instrumental drawbacks of sustainable innovations may sometimes strengthen their positive signal, which can promote interest in sustainable innovations.  相似文献   

热液矿床中萤石的稀土元素地球化学及其地质意义     

孙海瑞  黄智龙  周家喜  冷成彪  甘婷 《岩石矿物学杂志》2014,33(1):185-193

萤石是许多热液矿床中重要的脉石矿物,其稀土元素含量及相关参数（如∑REE、LREE/HREE、Eu/Eu^*、Ce/Ce^*、Y/La、Tb/Ca-Tb/La图解等）,能为揭示成矿流体性质、来源与演化,建立成矿模式,评价区域成矿潜力等提供重要信息。然而,随着微区分析技术的日趋成熟,原位实测数据显示,萤石中微量元素（包括稀土元素）的分配在显微尺度上可能具有不均一性,致使依据萤石溶液法获得的稀土元素含量所反映地质信息的可靠性受到质疑。因此,在应用萤石稀土元素地球化学探讨相关地质问题前,有必要加强萤石微观结构的观察和配套的流体包裹体以及相关同位素组成分析。本文在综述萤石稀土元素地球化学研究基础上,初步探讨了影响萤石稀土元素不均一分配的主要机制,以期为萤石稀土元素在热液矿床成因研究中的应用提供借鉴。  相似文献   

Dynamics of volcanic eruptions: Understanding electric signatures for activity monitoring     

《Comptes Rendus Geoscience》2015,347(3):112-123

Aside common methods as seismology, ground deformation, and geochemistry, electromagnetic and especially electric ones can efficiently be applied for imaging and monitoring active volcanoes and hydrothermal systems that most often control the initial eruptive phase. Surveys and mappings image ground fluids flow, faults systems, and structural interfaces with anomalies up to several hundred of mV. Reiteration of surveys highlights time and spatial evolution. Continuous networks must extend surveys when the activity becomes stronger. Resolution in the data can reach a few microvolts as compared to the tens of millivolts for surveys. Observations made on several volcanoes definitively show that electric signals, up to some tens of millivolts, may appear some hours to a few weeks before ground deformation and seismicity, and are related to some extent to the location of the future activity. These transient signals may have a relationship with those recorded aboard satellites. Both of them appear during the transition period between the “fatigue” and the “dynamical” stages, which announces accelerating and irreversible processes.  相似文献   

电力系统潮流量的微机快速跟踪测量     

王筱珍 《广东海洋大学学报》1995,(2)

提出了一种电力系统潮流量的快速跟踪测量方法，其响应时间只有一个采样时间间隔。实验表明，其准确度可满足实用要求。  相似文献   

Simulation of Titan haze formation using a photochemical flow reactor: The optical constants of the polymer     

Buu N. Tran  James P. Ferris  Peter D. Persans 《Icarus》2003,165(2):379-390

Solar UV is the principal energy source impinging the atmosphere of Titan while the energy from the electrons in Saturn's magnetosphere is less than 0.5% of the UV light. Titan haze analogs were prepared by the photolysis of a mixture of gases that simulate the composition of its atmosphere (nitrogen, methane, hydrogen, acetylene, ethylene, and cyanoacetylene). The real (n) and imaginary (k) parts of the complex refractive index of haze analogs formed from four different gas mixtures were calculated from the spectral properties of the solid polymer in UV-visible, near infrared and infrared wavelength spectral regions. The value of n was constant at 1.6±0.1 throughout the 0.2-2.5 μm region. The variation of k with wavelength for the values derived for Titan has a lower error than the absolute values of k so the more significant comparisons are with the slopes of the k(λ) plots in the UV-VIS region. Three of the photochemical Titan haze analogs had slopes comparable to those derived for Titan from the Voyager data (Rages and Pollack, 1980, Icarus 41, 119-130; McKay and Toon, 1992, in: Proceedings of the Symposium on Titan, in: ESA SP, Vol. 338, pp. 185-190). The slopes of the k(λ) plots for haze analogs prepared by spark discharge (Khare et al., 1984, Icarus 60, 127-137) and plasma discharge (Ramirez et al., 2002, Icarus 156, 515-529) were also comparable to Titan's. These finding show that the k(λ) plots do not differentiate between different laboratory simulations of atmospheric chemistry on Titan in the UV-VIS near IR region (0.2-2.5 microns). There is a large difference between the k(λ) in the infrared between the haze analogs prepared photochemically and analogs prepared using a plasma discharges (Khare et al., 1984, Icarus 60, 127-137; Coll et al., 1999, Planet. Space Sci. 47, 1331-1340; Khare et al., 2002, Icarus 160, 172-182). The C/N ratio in the haze analog prepared by discharges is in the 2-11 range while that of the photochemical analogs is in the 18-24 range. The use of discharges and UV light for initiating the chemistry in Titan's atmosphere is discussed.  相似文献   

In situ measurements of contributions to the global electrical circuit by a thunderstorm in southeastern Brazil     

Jeremy N. Thomas  Robert H. Holzworth  Michael P. McCarthy 《Atmospheric Research》2009,91(2-4):153-160

The global electrical circuit, which maintains a potential of about 280 kV between the earth and the ionosphere, is thought to be driven mainly by thunderstorms and lightning. However, very few in situ measurements of electrical current above thunderstorms have been successfully obtained. In this paper, we present dc to very low frequency electric fields and atmospheric conductivity measured in the stratosphere (30–35 km altitude) above an active thunderstorm in southeastern Brazil. From these measurements, we estimate the mean quasi-static conduction current during the storm period to be 2.5 ± 1.25 A. Additionally, we examine the transient conduction currents following a large positive cloud-to-ground (+ CG) lightning flash and typical − CG flashes. We find that the majority of the total current is attributed to the quasi-static thundercloud charge, rather than lightning, which supports the classical Wilson model for the global electrical circuit.  相似文献   

Analysis of microsecond- and submicrosecond-scale electric field pulses produced by cloud and ground lightning discharges     

Amitabh Nag  Brian A. DeCarlo  Vladimir A. Rakov 《Atmospheric Research》2009,91(2-4):316-325

We examined microsecond- and submicrosecond-scale pulses in electric field records of cloud and cloud-to-ground lightning discharges acquired in summer 2006, in Gainesville, Florida. A total of 12 cloud and 12 ground flashes were analyzed in detail, with the electric field record length being 96 or 200 ms and sampling interval being 4 or 10 ns. The majority of pulses in both cloud and ground discharges analyzed in this study were associated with the initial breakdown process and were relatively small in amplitude and duration. The typical durations were an order of magnitude smaller than tens of microseconds characteristic of “classical” preliminary breakdown pulses. We estimated that 26% of the pulses in the 12 cloud discharges and 22% of the pulses in the 12 cloud-to-ground discharges had total durations less that 1 µs.  相似文献   

电场时序差分在雷电预警中的有效性分析   总被引：6，自引：3，他引：3  

王强  王建初  顾宇丹 《气象科学》2009,29(5):657-663

目前国内应用地面大气电场仪进行雷电预警一般使用阈值法,这一方法直接使用电场观测值的多重阈值来进行预警,在实际应用中容易出现误报和漏报的现象.本文通过对晴天大气电场和雷暴天气大气电场分析了大气电场时序差分的基本特征,并结合SAFIR3000闪电定位观测数据,对典型雷暴过程下的电场时序差分进行了深入分析.本文还选取了有雷暴发生和无雷暴发生的预警应用个例进行了分析,分析结果表明电场时序差分的应用能在一定程度上提高雷电预警的效率.  相似文献