由分段供水向全天候供水的可行性研究 --以赵各庄矿为例     

曹永祥  戚春前 《中国煤田地质》2004,16(Z1):40-42

根 据 开 滦 集 团 赵 各 庄 矿 业 公 司 水 文 地 质 情 况 和 居 民 用 水 的 现 状 ,提 出 全 天 供 水 的 新 观 念 ,即 将 全 年 需 集 中强 排 的 水量 变 为 人 们日 常 生 活 的用 水 量 ,既 解 决 了 分 时 间 段 供 水 给 职 工 生 活 造 成 的 不 便 ,提 高 了 人 们 的 生 活 质 量 ,又 合理 的 利用 了水 资 源,而且 还可 以 降低 奥灰 水 对安 全生 产 的威 胁。  相似文献   

徐州地区下古生界碳酸盐岩的碳、氧同位素研究   总被引：12，自引：2，他引：12  

桑树勋  郑永飞张华徐磊  范炳恒 《岩石学报》2004,20(3):707-716

在已有的对徐州地区下古生界碳酸盐岩详细岩石学研究基础上，系统测试了碳酸盐岩方解石和白云石的碳、氧同位素组成特征；地球化学和岩石学研究相结合，综合提取了碳酸盐岩碳、氧同位素组成的沉积、成岩地质信息；初步探讨了同位素组成的地层变化及其意义。研究结果表明：碳酸盐岩碳同位素组成特征可以指示沉积环境及其演化，开阔陆表海、灰质障壁砂坝、局限陆表海、潮下带、潮渠、藻坪诸沉积相间碳酸盐岩的δ^13C值表现出规律性变化，碳同位素组成变化曲线上的显著正偏移与海侵有关；碳酸盐岩氧同位素组成对成岩环境及其演化有明显响应，淡水成岩环境、潮上成岩环境、潮间成岩环境、潮下成岩环境和埋藏成岩环境具有不同的碳酸盐岩氧同位素组成特征；徐州地区大北望寒武系剖面地层界线附近都有碳、氧同位素组成变化的特征显示，研究工作证实了徐州地区下古生界同位素地层划分的可行性。  相似文献   

P–T–f_O2 controls on a partly inverse chromite-bearing ultramafic intrusive: an evaluation from the Sukinda Massif, India     

Tapan Pal  Sachinath Mitra 《Journal of Asian Earth Sciences》2004,22(5):483

The chromites from the alpine type ultramafic intrusive of Sukinda, India, display a typical partly inverse spinel form and occur in two distinct zones: Brown Ore Zone (BOZ) and Grey Ore Zone (GOZ). The host ultramafites are mostly altered and are represented by the serpentinite, tremolite-talc(chlorite) schist, talc-serpentine schist and chlorite rock. The less altered variants are dunite, harzburgite and websterite. A dyke of orthopyroxenite runs through the main ultramafic body.The composition of olivine (Fo₉₂), orthopyroxene (En_92–89) and Al₂O₃ contents of the parental liquid (10.40–11.45%) determined from chromites, suggest that the parent melt is of boninitic affinity. The chemical plot of TiO₂ content against cr# of chromites corroborates a boninitic parental melt. The Fe–Mg partitioning in olivine and chromite depicts the temperature for chromitites as 1200 °C. A compositional plot of mg# and cr# suggests crystallization at high pressure conditions, corresponding to the kimberlite xenolith field. From the P–T diagram of pyrolite melting and mineral assemblage, the pressure of crystallization is stipulated to be ≥1.2 GPa. The f_O2 values estimated from Fe³⁺/Cr+Al+Fe³⁺ ratios range from 10^−8.3 to 10^−9.3 for the GOZ and 10^−7.1 to 10^−7.3 for the BOZ. The f_O2 values together with the pressure range suggest crystallization at upper mantle conditions. The heterogeneity in chemical composition and f_O2 conditions for the GOZ and BOZ could be linked to heterogeneity in the upper mantle.  相似文献   

Holocene hydrographical changes of the eastern Laptev Sea (Siberian Arctic) recorded in δO profiles of bivalve shells     

Thomas Mueller-Lupp  Henning A. Bauch 《Quaternary Research》2004,61(1):32-41

Oxygen isotope profiles along the growth axis of fossil bivalve shells of Macoma calcarea were established to reconstruct hydrographical changes in the eastern Laptev Sea since 8400 cal yr B.P.. The variability of the oxygen isotopes (δ¹⁸O) in the individual records is mainly attributed to variations in the salinity of bottom waters in the Laptev Sea with a modern ratio of 0.50‰/salinity. The high-resolution δ¹⁸O profiles exhibit distinct and annual cycles from which the seasonal and annual salinity variations at the investigated site can be reconstructed. Based on the modern analogue approach oxygen isotope profiles of radiocarbon-dated bivalve shells from a sediment core located northeast of the Lena Delta provide seasonal and subdecadal insights into past hydrological conditions and their relation to the Holocene transgressional history of the Laptev Sea shelf. Under the assumption that the modern relationship between δ¹⁸O_w and salinity has been constant throughout the time, the δ¹⁸O of an 8400-cal-yr-old bivalves would suggest that bottom-water salinity was reduced and the temperature was slightly warmer, both suggesting a stronger mixture of riverine water to the bottom water. Reconstruction of the inundation history of the Laptev Sea shelf indicates local sea level ∼27 m below present at this time and a closer proximity of the site to the coastline and the Lena River mouth. Due to continuing sea level rise and a southward retreat of the river mouth, bottom-water salinity increased at 7200 cal yr B.P. along with an increase in seasonal variability. Conditions comparable to the modern hydrography were achieved by 3800 cal yr B.P.  相似文献   

Variability of the Intertropical Convergence Zone recorded in coral isotopic records from the central Indian Ocean (Chagos Archipelago)     

Miriam Pfeiffer  Wolf-Christian Dullo  Anton Eisenhauer 《Quaternary Research》2004,61(3):245-255

We have analyzed the stable oxygen isotopic composition of two Porites corals from the Chagos Archipelago, which is situated in the geographical center of the Indian Ocean. Coral δ¹⁸O at this site reliably records temporal variations in precipitation associated with the Intertropical Convergence Zone (ITCZ). Precipitation maxima occur in boreal winter, when the ITCZ forms a narrow band across the Indian Ocean. The Chagos then lies within the center of the ITCZ, and rainfall is strongly depleted in δ¹⁸O. A 120-yr coral isotopic record indicates an alternation of wet and dry intervals lasting 15 to 20 yr. The most recent 2 decades are dominated by interannual variability, which is tightly coupled to the El Niño-Southern Oscillation (ENSO). This is unprecedented in the 120 yr of coral record. As the ITCZ is governed by atmospheric dynamics, this provides evidence of a major change in the coupled ENSO-monsoon system.  相似文献   

环境同位素记录中共生碳酸盐氧同位素分馏差值的影响          下载免费PDF全文

曾承  余俊清 《盐湖研究》2004,12(2):14-18

湖泊化学沉积碳酸盐δ18O是研究区域气候演变的重要环境指标之一。青海湖等闭流湖泊的研究结果证实,在对δ18O环境记录进行共生碳酸盐氧同位素分馏效应校正时,应依据具体情况,采用0-1‰的分馏差值。由高温实验结果推断出的常温分馏差值(4‰-7‰)不能被应用到自然条件下湖泊共生碳酸盐氧同位素分馏效应的校正。  相似文献   

Respiratory adaptations to oxygen lack in three species of Glossiphoniidae (Hirudinea) in Lake Esrom, Denmark     

Bettina Pohle  Kirsten Hamburger   《Limnologica》2005,35(1-2):78-89

The weight-specific respiration rate (μl O₂ mg⁻¹ AFDW h⁻¹) of three species of leech from Lake Esrom, Denmark, Glossiphonia concolor, G. complanata and Helobdella stagnalis was measured in a closed stirred chamber with a micro electrode. At declining oxygen concentration (mg O₂ l⁻¹) all three species expressed moderate ability to regulate respiration, in G. concolor and G. complanata down to 2 mg O₂ l⁻¹, in H. stagnalis down to 0.75 mg O₂ l⁻¹. Survival in anoxia was measured in closed bottles. The time to 50% survival (LD₅₀) was 30 days in G. concolor at 20 °C and 30 and 4 days in H. stagnalis at 10 and 20 °C, respectively. The results were discussed in relation to habitat and spatial distribution of the three species in the lake.  相似文献   

Continuous Multi‐probe Measurements in Fastflowing Waters Using a Hydrographic Slot     

Bernhard Karrasch  Michael Herzog 《洁净——土壤、空气、水》2005,33(2):165-169

Taking continuous spatiotemporal in situ measurements with multi‐probes in fast‐flowing waters/rivers can be problematic because the sensors may be damaged by high shear forces and flotsam. To protect the multi‐probe and to enable easy access for the maintenance and calibration of the sensors, a special multi‐probe holder fixed in a hydrographic slot was developed. The validation of the probe system revealed a “memory effect” at short time scales (< 10 s) within sharp gradients caused by the overflow container of the multi‐probe rack keeping the sensors submerged in the sample water. Continuously recorded data (conductivity, temperature, pH, oxygen concentration and saturation, as well as in vivo fluorescence of chlorophyll‐a) from a research cruise on board the RV ALBIS along the river Elbe (river km 309) and entering the river Saale are presented. This river stretch upstream of the city of Magdeburg to the mouth of the Saale tributary was found to have a complex physicochemical character, which is attributable to the long mixing process of water from the river Saale and the river Elbe.  相似文献   

Environmental significance of C/C and O/O ratios of modern land-snail shells from the southern great plains of North America     

Meena Balakrishnan  James L. Theler  Don G. Wyckoff 《Quaternary Research》2005,63(1):15-30

¹³C/¹²C and ¹⁸O/¹⁶O ratios of aragonite shells of modern land snails from the southern Great Plains of North America were measured for samples from twelve localities in a narrow east-west corridor that extended from the Flint Hills in North Central Oklahoma to the foothills of the Sangre de Cristo Mountains in Northern New Mexico, USA. Across the study area, shell δ¹⁸O values (PDB scale) ranged from −4.1‰ to 1.2‰, while δ¹³C values ranged from −13.2‰ to 0.0‰. δ¹⁸O values of the shell aragonite were predicted with a published, steady state, evaporative flux balance model. The predicted values differed (with one exception) by less than 1‰ from locality averages of measured δ¹⁸O values. This similarity suggests that relative humidity at the time of snail activity is an important control on the δ¹⁸O values of the aragonite and emphasizes the seasonal nature of the climatic information preserved in the shells. Correlated δ¹³C values of coexisting Vallonia and Gastrocopta suggest similar feeding habits and imply that these genera can provide information on variations in southern Great Plains plant ecology. Although there is considerable scatter, multispecies, transect average δ¹³C values of the modern aragonite shells are related to variations in the type of photosynthesis (i.e., C₃, C₄) in the local plant communities. The results of this study emphasize the desirability of obtaining isotope ratios representing averages of many shells in a locale to reduce possible biases associated with local variations among individuals, species, etc., and thus better represent the “neighborhood” scale temporal and/or spatial environmental variations of interest in studies of modern and ancient systems.  相似文献   

兰州大学(盘旋路校区)2003年生态足迹调查分析   总被引：11，自引：2，他引：11  

蒋莉  陈治谏  沈兴菊 《地理与地理信息科学》2005,21(2):82-85

人均消费产品的数量是计算区域人均生态足迹关键和基础的一步。通过实地问卷调查，运用自下而上法收集资料，计算小尺度生态足迹。兰州大学(盘旋路校区)2003年的生态足迹计算结果为：人均生态足迹0．892hm^2，男、女生的人均生态足迹分别为0．976hm^2和0．788hm^2。这些数据与全国或者西部的人均生态足迹相比明显偏低，但总生态足迹为4119．3hm^2，是校园面积的73．7倍。因此，应合理利用自然资源，减少学生的生态足迹，真正做到可持续发展。  相似文献