共查询到19条相似文献，搜索用时 50 毫秒
1.
粉煤灰是燃煤火力发电厂的废弃物,由大小不等、结构疏松的非晶质玻璃相球形颗粒组成,其主要化学成分是铝硅酸盐,具有来源广和成本低等特点。在水热条件下,Holler和Wirsching首先利用粉煤灰与碱（NaOH或KOH）作用合成了沸石。针对油田封堵油层孔隙即改善注水井吸水效果的实际需求,在总结和吸取粉煤灰和沸石颗粒封堵油层孔隙矿场施工成功经验和不足基础上,探索了水热条件下粉煤灰部分转化为沸石的配方组成和工艺条件,研究了改性粉煤灰组成和外观结构特征,评价了改性粉煤灰的封堵效果,分析了改性粉煤灰封堵作用机理。研究结果对改善油层孔隙封堵效果、提高油田注水效率具有重要应用价值。 相似文献
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海水化学组成的特点之一,是它受生物学过程的影响。海洋生物通过合成、代谢和分解作用来影响海水的化学组成,使海水获得本底有机组份。有机组份的存在使海水成份更趋复杂化,它所赋予海水的一些新的性质可以在化学物理和生物学等诸方面反映出来。有机物质影响海水的颜色和透明度,使海水具有起泡性质;吸附于海-空界面的有机微层,对于海洋 相似文献
3.
应用生物标志化合物长链烯酮不饱和比值 Uk37估算冲绳海槽 2万年以来古海水表层温度 ,其波动范围在 1 5.9～ 2 6.2℃之间 ,平均为 2 2 .9℃。并与常用的浮游有孔虫转换函数测算的表层海水温度进行对照 ,结果与冬季表层水温 ( 2 2 .0℃ )相近 ,Uk37值指示的古海水温度与季节有关 ,主要反映在冬季。在沉积物中还检出了另一类生物标志化合物甾、萜类等 ,对它们的组成进行了地球化学研究 ,结果表明 :冲绳海槽沉积物中有机质具有多源性特点 ,由陆源碎屑、生物碎屑和火山碎屑共同组成 ;该海域沉积有机质的成熟度不高 ,沉积环境具有强的还原性。 相似文献
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Li/Fe摩尔比和表面活性剂浓度对水热合成α-LiFeO2的影响 总被引：1，自引：0，他引：1
以α-FeOOH、LiOH·H2O、十六烷基三甲基溴化铵(CTAB)和十二烷基苯磺酸钠(SDBS)为原料,采用水热法合成了α-LiFeO2粉体,利用X射线衍射仪(XRD)、冷场发射扫描电子显微镜(SEM)对粉体的物相和微观形貌进行了表征,研究了不同Li/Fe摩尔比及CTAB浓度对α-LiFeO2物相形成和微观形貌的影响.结果表明:当Li/Fe摩尔比为30:1,反应温度为210℃,反应时间为6 h时,可得到纯相α-LiFeO2,随着Li/Fe摩尔比的减少,有杂相α-Fe2O3和Li0.5Fe2.5O4生成;表面活性剂CTAB和SDBS对水热合成α-LiFeO2的物相组成没有影响,但对其微观形貌的影响较大.其中,CTAB主要起到了控制粉体粒径大小的作用,而SDBS除了降低粉体粒径外,还影响到了粉体的微观形貌.随着体系SDBS浓度的增大.粉体经历了多面体、层状和类球形3种形貌,并且平均尺寸降至0.3μm左右. 相似文献
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纳米ZnO-La_2O_3固体碱的制备及其催化废弃煎炸油制备生物柴油 总被引：1，自引：0，他引：1
本文采用共沉淀法,以草酸铵为沉淀剂制备了ZnO-La2O3固体碱,并将其应用于催化废弃煎炸油与甲醇的酯交换反应制备生物柴油,通过X射线衍射(XRD)、电感耦合等离子体原子发射光谱(ICP-AES)以及扫描电子显微镜(SEM)对催化剂的组成和形貌进行表征。结果表明:700℃煅烧制备的催化剂具有较好的催化活性,催化剂是由ZnO和La2O3组成,锌镧摩尔比为3∶1,粒径在100nm左右。该催化剂用量5%(为油的质量)、醇油摩尔比36∶1、200℃反应3h,得到的脂肪酸甲酯(FAME)产率达到91.6%;催化剂经过洗涤和干燥,无需活化可继续使用,连续使用第四次后,脂肪酸甲酯的产率仍保持在80%以上。 相似文献
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本文报导了在多聚磷酸作用下,0,0’-邻苯二酚二乙酸同三聚甲醛缩聚生成具有对钾离子吸着作用的树脂的反应。探讨了摩尔配比、反应温度和反应时间等影响树脂性能的因素。提出了合成0,0’-邻苯二酚二乙酸—甲醛树脂的最宜条件: CH_2O:CDAH_2=1:4(摩尔); (CH_2O+CDAH_2):PPA=1:4(重量); 温度=120—130℃;时间=1小时。树脂产率为84—91％。树脂在380PPm氯化钾水溶液中(相当于海水中的钾离子浓度)对钾离子的吸着容量是28—30毫克钾离子/克(干树脂)[动态法]。富集因数是73—78。 相似文献
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盐水闪蒸技术广泛应用于海水淡化及海洋温差能发电,含盐质量分数、给盐液温度和闪蒸压力对闪蒸汽化率和热效率有很大影响。在质量分数为3.5%～20%、给盐液温度为30～95℃和闪蒸压力为1～30 kPa的范围内,对NaCl溶液闪蒸汽化率和热效率等闪蒸效率特性进行了定量计算研究,研究得到了盐水含盐质量分数、给盐液温度和闪蒸压力对闪蒸汽化率以及热效率影响的规律。结果表明,降低含盐质量分数,提高给盐液温度,降低闪蒸压力可提高闪蒸汽化率与热效率;含盐质量分数越高,造成的热损失越大,而提高给盐液温度会增大热损失。 相似文献
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采用2种不同的合成路线制备出CePO4,利用非均相成核法和sol-gel法实现了CePO4对ZrO2的包覆,探讨了室温和600 ℃煅烧后粉体的包覆结果,通过SEM,TEM和XRD手段研究了合成产物和包覆产物的形貌及物相结构.实验结果表明,利用非均相成核法室温下可以实现六方CePO4纤维对ZrO2的包覆,经过600 ℃煅烧,形成六方CePO4包覆ZrO2的核-壳结构;利用sol-gel法在室温下可形成CePO4前驱体对ZrO2的包覆,经过600 ℃煅烧,包覆层CePO4由无定形态逐渐向晶态转变,形成单斜CePO4对ZrO2的包覆. 相似文献
11.
Tsutomu Ikeda 《Journal of Oceanography》2013,69(3):339-355
Respiration and ammonia excretion data and chemical composition data [water content, ash, carbon (C), nitrogen (N) and C:N ratios] of 18–32 amphipods (hyperiids and gammarids) from the epipelagic through bathypelagic zones of the world’s oceans were compiled. The independent variables including body mass, habitat temperature and mid-sampling depth were all significant predictors of respiration, accounting for 65–83 % of the variance in the data, while the former two variables were significant predictors of ammonia excretion, accounting for 64–77 % of the variance. Atomic O:N ratios (respiration:ammonia excretion) ranged from 11 to 74 (median 21.5). C composition was negatively correlated with habitat temperature, but water contents, ash, N, and the C:N ratio were uncorrelated with the three independent variables. As judged by C:N ratios, protein was considered to be the major organic component of most pelagic amphipods. However, some amphipods from >500 m depth exhibited high C:N ratios (>10) suggesting a large deposition of lipids in the body. Comparison of the present results with global bathymetric models of euphausiids and pelagic copepods revealed that respiration rates of the pelagic amphipods were near-equal to the rates of euphausiids but greater than the rates of pelagic copepods, reflecting taxon-specific body morphology and swimming behavior among the three taxa. As a marked feature of body chemical composition, the pelagic amphipods exhibited extremely high ash content (mean 25 % of DM) due to their possession of a robust exoskeleton. 相似文献
12.
大连大魏家滨海岩溶区海水入侵化学过程 总被引：9，自引：1，他引：9
通过不同比例的海水与淡水的混合作用及其混合水对碳酸盐岩的混合溶蚀作用的室内模拟实验，对滨海岩溶区海水入侵过程中的化学过程和水-岩作用进行了研究。在海水入侵过程中，海水与淡水的混合作用是以机械混合为基础的复杂化学过程；过渡带混合水对围岩(碳酸盐岩)的混合溶蚀作用则是以分子扩散和表面反应为主的复杂化学过程；而混合水与岩溶空间内的松散沉积物间的各种离子交换作用主要是阳离子交换吸附。室内模拟试验和野外实测地下水化学组分剖面资料对应说明，淡水、海水界面之间的过渡带中部区的混合溶蚀作用最强，亦可能是岩溶最发育的部位。 相似文献
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To understand the source and nature of the ore-forming fluids of the Edmond hydrothermal field on the Central Indian Ridge, we studied the He-Ar isotope composition and fluid inclusions of the hydrothermal precipitates.Our results show that the sulfide samples contain noble gases He, Ne, Kr, and Xe with their abundances in between those of air-saturated water(ASW) and mid-ocean ridge basalt(MORB). The ~3He/~4He ratio varies from1.3 to 8.7 R_a(n=10, average: 5.1 R_a), whereas the ~(40)Ar/~(36) Ar ratio is from 285.3 to 314.7(n=10, average: 294.8). These results suggest that the He was derived from a mixture of MORB with variable amounts of seawater, but the Ar in the ore-forming fluids trapped in the sulfides is predominantly derived from seawater. The fluid inclusions of barite have a wide range of homogenization temperatures and salinities varying from 163°C to 260°C and 2.6 wt%to 8.5 wt% Na Cl equiv., respectively. It is suggested that the ore-forming fluids were produced by phase separation, which agreed with the present-day vent fluid study. 相似文献
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A triaxial system is designed with a temperature range from-20 ℃ to 25 ℃ and a pressure range from 0 MPa to 30 MPa in order to improve the understanding of the mechanical properties of gas hydrate-bearing sediments.The mechanical properties of synthetic gas hydrate-bearing sediments (gas hydrate-kaolin clay mixture) were measured by using current experimental apparatus.The results indicate that:(1) the failure strength of gas hydrate-bearing sediments strongly depends on the temperature.The sediment’s strength increases with the decreases of temperature.(2) The maximum deviator stress increases linearly with the confining pressure at a low-pressure stage.However,it fluctuates at a high-pressure stage.(3) Maximum deviator stress increases with increasing strain rate,whereas the strain-stress curve has no tremendous change until the axial strain reaches approximately 0.5%.(4) The internal friction angles of gas hydrate-bearing sediments are not sensitive to kaolin volume ratio.The cohesion shows a high kaolin volume ratio dependency. 相似文献
15.
西南印度洋中脊热液产物稀土元素组成变化及其来源 总被引：1，自引：1，他引：0
对西南印度洋中脊热液区不同热液产物稀土元素(REE)进行了分析,探讨了热液产物形成过程中稀土元素组成变化及其来源。研究结果表明:不同热液产物稀土元素总量变化范围从3.47×10-7到4.80×10-5,轻重稀土比值(LREE/HREE)从2.06到6.16,表明轻重稀土有较大程度分异,δEu异常(δEu=0.86~3.88)和δCe异常(δCe=0.40~0.86)显示热液产物中REE呈Eu富集和Ce亏损特征。稀土元素球粒陨石标准化模式呈现两种类型:(1)呈轻微富集LREE的平坦模式,REE大于2×10-5;(2)呈显著富集LREE和正Eu异常模式,REE小于5×10-7。模式1类似于洋壳火山岩REE配分模式,而模式2与西南印度洋中脊黑烟囱REE模式相似,也与典型洋中脊热液喷口流体和硫化物LREE富集和正Eu异常模式类似。热液产物中稀土元素含量变化和模式特征以及Mg与LREE极强正相关关系可能反映了西南印度洋中脊硫化物形成在热液流体与海水混合沉淀的初始阶段,后期经历了广泛的热液流体再循环和海水蚀变过程。 相似文献
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The ratio of dissolved cadmium (Cd) to phosphate (PO4) in the subtropical coastal area of Ishigaki Island, Okinawa, Japan, was investigated. Twenty vertical seawater samplings
were carried out once a month from May 2008 to January 2010. In order to examine how the Cd/PO4 ratio in seawater varies with the oceanographic conditions (i.e., the water temperature–salinity characteristics), the water
masses at the study sites were classified into two types: group 1 with a water temperature of >25°C and a salinity range of
34.0–34.4, and group 2 with a water temperature of <25°C and a salinity of >34.4. A different phytoplankton assemblage was
observed in each water mass defined. Different Cd/PO4 ratios were obtained for the two water mass types, due to the differences between the types in terms of the environmental
conditions such as the water temperature–salinity (T–S) characteristics and phytoplankton assemblages, as well as possible variations in the concentrations of dissolved iron, zinc,
manganese, and CO2 in seawater in each water mass. 相似文献
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Along a north-south transect (9.69°N to 55.01°S) in the southwestern Indian Ocean during the Indian Pilot Expedition to Southern Ocean (PESO), the oxygen isotopic analysis of planktic foraminifera (Globigerina bulloides) from 23 surface sediment samples was carried out to assess the relationship between isotopic composition of G. bulloides and the prevailing physical (seawater temperature and salinity) conditions of the ambient seawater. An increasing trend in the δ18O value is noticed towards higher latitude. Apparently such an increase in δ18O values is inversely related to the temperature changes along the transect. However, slight mismatch is observed at a few stations due to calcification out of optimum conditions or due to the salinity changes. The preliminary results of the present study, if extended to the subsurface sediments coupled with other parameters, may contribute to the reconstruction of the paleohydrography of the region, especially the position of various seawater fronts during the geologic past albeit with areal limitation. 相似文献
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