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91.
根据CRRES卫星上MICS离子成分探测器的观测资料以及前人有关AMPTE卫星的观测数据,研究了地磁活动和太阳活动性对环电流成分以及各种环电流离子的最大通量位置的影响. 观测表明相对于地磁平静时期,在地磁活动的活跃时期,环电流中O+、He++和He+离子的数密度和能量密度占环电流总数密度和总能量密度的份额增加,相反H+离子所占的比例却明显减少. 太阳活动极大年时环电流中H+离子丰度比极小年时低,而O+和He++离子的丰度却比太阳活动极小年时高. 卫星数据观测还表明,在地球磁暴期间,环电流中O+离子和He+离子的最大通量位置会随着地磁的活动径向移动,平均来看太阳活动极大年的能量粒子最大数密度位置距离地球比极小年时约小0.5RE (RE 为地球半径).  相似文献   
92.
93.
This article reports a preliminary research on silicate-incorporated hydroxyapatite as a new environmental mineral used to remove cadmium ions from aqueous solutions. The silicate-incorporated hydroxyapatite was prepared by coprecipitation and calcining, and silicate was incorporated into the crystal lattice of hydroxyapatite by partial substitution of phosphate. The amount of cadmium ions removed by silicate-incorporated hydroxyapatite was significantly elevated, which was 76% higher than that of pure hydroxyapatite. But the sorption behavior of cadmium ions on silicate-incorporated hydroxyapatite was similar to that of pure hydroxyapatite. Morphological study revealed that silicate incorporation confined the crystal growth and increased the specific surface area of hydroxyapatite, which were in favor of enhancing the cadmium ion sorption capacity of the samples. Incorporation of silicate into hydroxyapatite seems to be an effective approach to improve the environmental property of hydroxyapatite on removal of aqueous cadmium ions.  相似文献   
94.
通过对大磨曲家金矿床不同类型矿石、蚀变岩中石英单矿物流体包裹体群体气液相成分,探讨金成矿流体由高温到低温流体成分演化与金成矿过程,结果证实:流体包裹体气相成分以H2O为主,其次为CO2,其余为CH4,C2H6,H2S,少量样品检测到少量N2和Ar2.流体包裹体液相成分中,阳离子主要为Na 和K ,Ca2 次之,少数样品检测到Mg抖;阴离子主要为Clˉ和SO42-,Fˉ含量也较高.高温阶段CO2含量缓慢降低,CH4 C2H6总量变化较大;低温阶段CO2含量快速降低,H2S含量缓慢降低,CH4 C2H6总量呈现增加趋势.由高温阶段到低温阶段K 含量降低,Na 含量增加,Ca2 变化不明显;阴离子组成SO42-含量急剧降低,Fˉ含量缓慢增加,Cl-含量快速增加.成矿流体稳定同位素组成δD水(SMOW)为-106.48‰~-95.52‰,δ18O石()(SM()w)为10.64‰~12.68‰,换算与之平衡δ18O水(SMOw)为1.88‰~5.78‰,δ13Cco2(PDB)为-6.264‰~-4.271‰.稳定同位素组成说明大磨曲家金矿床成矿流体可能为深部来源,可能与地幔排气和矿区内煌斑岩岩浆活动有关.  相似文献   
95.
Removal of Lead,Copper, Zinc and Cadmium from Water Using Phosphate Rock   总被引:2,自引:0,他引:2  
Removal of Pb^2+, Cu^2+, Zn^2+ and Cd^2+ from aqueous solutions by sorption on a natural phosphate rock (FAP) was investigated. The effects of the contact time and initial metal concentration were examined in the batch method. The percentage sorption of heavy metals from solution ranges generally between 50% and 99%. The amount of sorbed metal ions follows the order Cu〉Pb〉Cd〉Zn. Heavy metal immobilization was attributed to both surface complexation of metal ions on the surface of FAP grains and partial dissolution and precipitation of a heavy metal-containing phosphate. The very low desorption ratio of heavy metals further supports the effectiveness of FAP as an alternative and low-cost material to remove toxic Pb^2+, Cu^2+, Zn^2+ and Cd^2+ from polluted waters.  相似文献   
96.
The Sipadan island is the only oceanic island found in Malaysia, and is popularly known for its beautiful corals and diving activities. The aquifer of the island is affected by seawater intrusion associated with groundwater exploitation. Geologically, the aquifer is composed of several series of Quaternary bioherm facies, and its recharge merely depends on rainfall. This research attempts to understand the chemical changes of the groundwater attributed to the salinization processes based on major ion composition (Ca^2+, Mg^2+, Na^+, K^+, HCO, SO, Cl^-). The initial assessments were done in years 1993 - 1994, followed by subsequent assessment in years 2004-2005. Methods of analyses were adopted from APHA (1995). The hydrogeochemical saturation indices (SI) were computed using the PHREEQC program in order to assess the state of equilibrium between groundwater and the minerals present. The results of analyses indicated that the groundwater has been highly enriched in Na^+, SO and CI, reflecting an encroachment of saline water into the aquifer. The groundwater facies can be classified as sodium chloride (Na-Cl) water type. There are positive correlations (moderate to strong), except HCO3^-, between the studied parameters. The weak and inconsistent correlation of HCO3^- with the cations and anions related to dissolved salts suggests that saltwater intrusion has an insignificant impact on the chemistry of HCO3^- in the groundwater. Strong correlations (r 〉0.70) exist among the major elements (Na^+, Mg^2+, K^+, Cl^- and SO4^-) and salinity (EC). These relationships clearly identify the main elements contributing to the groundwater salinity and their tendency to depict a similar trend of salinization pattern. Chloride has a major influence on the salinity of groundwater based on the positive and strong correlation that exist between Cl^- and EC (r=0.97).  相似文献   
97.
硫酸型酸雨沉降至地表经石灰土缓冲后,参与碳酸盐岩溶蚀及对岩溶碳汇的影响尚不明确,严重制约了我国岩溶碳汇效应的准确评估。本研究通过设置不同土层厚度条件下pH 4.5的硫酸型酸雨淋滤实验,以明确石灰土对硫酸型酸雨的缓冲过程及关键控制因素。结果表明:石灰土对酸雨的缓冲作用主要发生在表层(10 cm),淋出液中Ca2+、Mg2+、${\rm{HCO}}_3^{-}$含量在淋溶初期均表现快速降低,当淋溶量(土壤水达饱和后)为1 020 mL时Ca2+、Mg2+、${\rm{HCO}}_{{3}}^{-}$淋失量趋于稳定,稳定淋失量分别为20 mg·L−1、6 mg·L−1、40 mg·L−1。淋出液中被酸雨H+交换出的Ca2+、Mg2+仅占很小一部分,土壤水溶性Ca2+、Mg2+是淋出液中Ca2+、Mg2+的主要部分,开放系统中,大气和土壤CO2溶于降雨形成H2CO3不仅增加碳汇,且H2CO3解离产生的H+交换土壤中交换态Ca2+、Mg2+,造成Ca2+、Mg2+的淋失量不容忽视。不同厚度石灰土中交换性钙镁可缓冲酸雨容量均大于土壤碳酸钙矿物可缓冲容量,前者是后者的1.17~1.59倍。相同酸度、同一降雨量(土壤水达饱和后)下土壤盐基离子参与酸雨缓冲产生的碳汇量约为碳酸盐矿物风化缓冲产生碳汇量的2.1倍,不同厚度(≥10 cm)石灰土产生的碳汇量大致相等。根据本次实验及桂林市降雨数据计算,桂林市质纯石灰岩风化残积土壤区(土层厚度≥10 cm),土壤盐基离子参与酸雨缓冲每年可产生0.59 ~0.93 mol·m−2的碳汇通量。  相似文献   
98.
An electrically based ion spectrometer is described, capable of measuring particle sizes and mobilities from molecular ions (small ions) to aerosol particles across a size range of 0.4 to 30 nm in diameter. It consists of a single cylindrical capacitor divided into three electrically insulated sections. The current arriving at the central section is measured by an electrometer and represents the ion flux over a known range of mobilities determined by the applied voltage. The applied voltage is scanned in steps to measure the ion fluxes over a large number of overlapping mobility ranges. The recorded signal and the response function of the instrument are unfolded using a maximum entropy procedure to give a high-resolution measured mobility spectrum. The maximum entropy approach offers a considerable improvement over traditional aspiration collectors and can approach the resolution of a drift tube system. In this way, the spectrometer successfully overcomes the diffusion limit to small ion resolution. Illustrative spectra are shown, demonstrating for the first time the presence of some resolved structure within the small ion spectrum at the highest mobilities. It is demonstrated that the actual mobility spectrum of small ions falls in the range 0.8–2.0 × 10−4 m2 V−1 s−1. This represents a narrower range than that previously measured which is attributed to improved spectral resolution in the present work.  相似文献   
99.
Snowpacks samples were colleted from two glaciers: Baishui No.1 glacier and Hailuogou No.1 glacier in June, 2006. The method of sea-salt ions tracer, correlation analysis and trend analysis were used in this research in order to confirm the source of main ions, it is indicated that Na+ is mainly from marine moisture and other ions mainly originate from land dust. The non-marine source percent of Cl-, NO-3, SO2-4, K+, Ca2+ and Mg2+ is 52%, 99%, 100%, 98%, 99.9% and 83%, respectively, in Hailuogou No.1 glacier, while the corresponding value in Baishui No.1 glacier is 68%, 99%, 100%, 98%, 99% and 59%. The non-marine source of ions is from dust of Central Asia arid regions carried by westerly circulation and the plateau borne-areas with Qinghai-Tibet Plateau winter monsoon in two glacial areas. How-ever, the import of local dust in glacial area has made a great contribution to ions concentra-tion in Baishui No.1 glacier, which accounts for the reason why the ions concentration in Bai-shui No.1 glacier is much higher than that of Hailuogou No.1 glacier. It is obvious that the source of each ion is different between Hailuogou No.1 glacier and Baishui No.1 glacier. There are three reasons which can explain it: firstly, the difference in the internal environment of glacial area, such as lithology, mountain-valley wind system, topographical relief and so on; secondly, the influence exerted by ions elution in snowpacks section, and ions elution in Hailuogou No.1 glacier is very strong; and thirdly, the difference caused due to varying ions transporting styles, deposition modes, chemical characteristics and post-ions-deposition process.  相似文献   
100.
为研究Mg2+、Cl−和${\rm{SO}}_4^{2-} $三种可溶盐离子对高含盐水泥土强度的影响,通过室内不同龄期水泥土无侧限抗压强度试验,分析可溶盐离子含量变化对水泥土强度的影响及其变化规律,并利用X射线衍射(XRD)和环境扫描电镜(ESEM),研究可溶盐离子对高含盐水泥土的微观结构和化学组分的影响,从宏微观的角度揭示可溶盐离子与水泥土之间的作用机理。研究结果表明:Mg2+、Cl−和${\rm{SO}}_4^{2-} $三种可溶盐离子对试块的强度有不同程度的负作用,且随可溶盐离子含量的增加,负作用越明显;造成这种现象的原因主要在于,高含量的可溶盐离子参与反应,消耗C-S-H和C-A-H凝胶,生成M-S-H、M-A-H和大量结晶物,M-S-H和M-A-H分散于C-S-H和C-A-H凝胶中,降低水泥土的胶结力,使得高含盐水泥土强度降低。  相似文献   
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