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411.
From primitive wood to nowadays fossil fuels such as coal, oil and natural gas, it can be seen that the forms of energy becomes more and more diverse and the core trend of decarburization is also obvious (the rate of the element of H to C ranging from 1/10, 1/2-1, 2, to 4 in wood, coal, oil and natural gas, respectively). Although the content of C in current main fuels becomes less and less, the excess exploitation and extensive utilization of various fossil fuels are widely recognized to be responsible for the deterioration of the environment (greenhouse effect, acid rain, photochemical pollution, etc.). With the roar consumption of energy to maintain the development of human society and taking the environmental problems into consideration, it is inevitable to develop renewable energy containing more H and less C as possible. Under these circumstances, the development of H2 energy is the certain and ultimate choice for its high energy per unit, diversity resources, no pollution to environment and ideal renewable utilization cycle. There are so many methods and ways were employed to develop HE energy, such as electrolysis, methane stream reforming process, coal gasification, etc., but there lies two main problems in current methods and ways, those are the cost of bulk of first energy to extract HE from fossil raw materials and still facing the problems of C deposition (carbon dioxide). Consequently, if considering the cost and environmental issues, the development of HE energy must resort to renewable energy sources such as solar energy, wind energy to extract HE from water. Based on this context, the development of HE energy by semiconductor photocatalyst to split water into HE and O2 under the irradiation of solar energy, photocatalysis process in short word, is one of the most promising ways. In this review, the importance and necessity to develop hydrogen energy were intensively studied based on the relationship between energy consumption and environment effect. Then the current ways and methods to develop hydrogen were reviewed, especially the state-of-the-art photocatalysis process (from the semiconductor photocatalyst materials perspective).  相似文献   
412.
黄冠星  孙继朝 《地下水》2007,29(4):30-31,39
在系统收集整理中国北方河北平原、太原盆地、鄂尔多斯盆地以及银川平原的地下水氢氧同位素资料基础上,依据同位素形成演化相似性原理,对比分析同位素组成得出:深层地下水是在过去更寒冷的气候条件下形成;研究区的大气降水不但在现代气候条件下存在大陆效应和高程效应,而且在 25 kaB.P.以来的古气候条件下也存在大陆效应和高程效应;古气候条件下各盆地平原之间的蒸发强度的差异可能比现代气候条件下各盆地平原之间的蒸发强度的差异大.  相似文献   
413.
王广  李立武 《岩矿测试》2006,25(4):311-314
利用岩石热脱气单体碳/氢同位素组成分析装置,通过高温热解、分步加热的方法,对山东蓬莱第四纪碱性玄武岩全岩流体组分中氢同位素进行了同位素质谱分析,得到了流体组分中热解H2及CH4的δD值。在15个样品中,热解H2及CH4的δD值变化相对较小,说明热解H2和烃的来源比较单一。  相似文献   
414.
Abstract. The Onsen site is an active submarine hydrothermal system hosted by the Desmos caldera in the Eastern Manus Basin, Papua New Guinea. The hydrothermal fluid is very acidic (pH=1.5) and abundant native sulfur is deposited around the vent. The δ34S values of native sulfur range from -6.5 to -9.3 %o. δ34S values of H2S and SO4 in the hydrothermal fluid are -4.3 to -9.9 %o and +18.6 to +20.0 %o, respectively. These δ34S values are significantly lower than those of the other hydrothermal systems so far reported. These low δ34S values and the acidic nature of the vent fluids suggest that volcanic SO2 gas plays an important role on the sulfur isotope systematic of the Onsen hydrothermal system. Relationship among the δ34S values of S-bearing species can be successively explained by the model based on the disproportionation reaction starting from the volcanic SO2 gas. The predicted δ34S values of SO2 agree with the measured whole rock δ34S values. δD and δ18O values of clay minerals separated from the altered rock samples also suggest the contribution of the magmatic fluid to the hydrothermal system. Present stable isotopic study strongly suggests that the Onsen hydrothermal site in the Desmos caldera is a magmatic submarine hydrothermal system.  相似文献   
415.
Rainwater is a major source of dissolved iron to much of the world's oceans, including regions where iron may be a limiting nutrient for marine phytoplankton primary production. Rainwater iron is therefore potentially important in regulating global photosynthetic uptake of CO2, and hence climate. Two rainwater addition bioassay experiments (2% rain) conducted at the Bermuda Atlantic Time-series Station (BATS) during March 2000 using 50 or 100 nM FeCl2 or FeCl3 in synthetic rain (pH 4.5 H2SO4) showed an increase in chlorophyll a 50% greater than controls after three days. Addition of 20 μM hydrogen peroxide, a typical rainwater concentration at BATS, completely removed the chlorophyll a increase with both forms of iron additions, suggesting stimulation of phytoplankton growth by rainwater iron can be limited by rainwater H2O2. In laboratory experiments using Gulf Stream seawater, iron-enriched (100 nM Fe(III)) synthetic rain was mixed with seawater in a 5% rain 95% seawater ratio. Dissolved iron concentrations increased two times above concentrations predicted based on dilution alone. The increase in soluble iron probably resulted from release from seawater particles and was maintained for more than 24 hours. No increase was observed in controls that did not have iron added to the synthetic rain, or with synthetic rainwater containing both added iron and H2O2. The increase in iron concentration above that predicted by dilution indicates rain may have a larger effect on seawater iron concentrations than that calculated for rainwater iron addition alone.  相似文献   
416.
雄鲁摩铜多金属矿床产于沉积岩中,生成工业意义矿床主体的改造期石英中的流体包裹体显微测温、成分分析以及氢氧同位素研究结果表明,雄鲁摩铜多金属矿床的流体为具有中低温、中低盐度和中低密度特征的富钠氯化物型热卤水,成矿流体水来源于与围岩发生了同位素交换的演化大气降水,形成于浅成低压的较酸性还原环境。  相似文献   
417.
刘广志 《探矿工程》2004,31(1):7-10
为适应广大科技工作者了解国外新能源的发展态势,从而关注我国新能源发展前景,集中编辑了有关生物质能、生物柴油、太阳能、风能、地热、氢能等多种新能源的国内外发展态势,分析了各自的开发利用潜力和前景,以供大家借鉴,有利于开展某些项目的研发。相信不久的将来,我国新能源事业,能尽快走上“快车道”、“高速路”。  相似文献   
418.
Sichuan Basin is one of the most important marine–salt forming basins in China. The Simian and Triassic have a large number of evaporites. The Triassic strata have found a large amount of polyhalite and potassium-rich brine. However, no soluble potassium salt deposit were found. In this study, the halite in well Changping 3 which is located at the eastern part of the Sichuan basin was studied using the characteristics, hydrogen and oxygen isotopes of the fluid inclusion in halite to reconstruct the paleoenvironment. The salt rocks in well Changping 3 can be divided into two types: grey salt rock and orange salt rock. The result shows that the isotopic composition of the halite fluid inclusion is distinct from the global precipitation line reflecting that the salt formation process is under strong evaporation conditions and the climate is extremely dry. At the same time, compared with the hydrogen and oxygen isotopes of brine in the Sichuan Basin and the hydrous isotope composition of the inclusions in the salt inclusions of other areas in China, it is shown that the evaporation depth of the ancient seawater in the Sichuan Basin was high and reached the precipitation of potassium and magnesium stage.  相似文献   
419.
雷新勇 《矿床地质》1994,13(4):322-330
本文通过试验路研究,提出交通事故多发段沥青路面抗滑表层做法的一些具体意见,包括结构类型、材料要求和施工要点。试验路观测表明,抗滑表层对减少交通事故有明显作用,供应用参考。  相似文献   
420.
王义文 《地质与资源》1993,2(3):169-180
华北地台与金矿床有关的花岗岩,其岩浆水以δD值较低为特征(-120‰——85‰),古老结晶基底变质水同样亦以贫δD为特征(-95‰)。中国不同类型金矿床成矿流体具有多来源多成因特征,但最突出的特征是皆在不同程度上混有大气降水成分。中国东部金矿床成矿流体δD在地理分布上表现出明显的纬度效应和海岸效应,且与我国中生代大气降水等值线一致。借助被加热循环的大气降水使矿源层(岩)中的成矿物质活化和再富集是金矿成矿的一种具有普遍意义的成矿方式。  相似文献   
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