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51.
《China Geology》2022,5(4):722-733
Global energy structure is experiencing the third transition from fossil energy to non-fossil energy, to solve future energy problems, cope with climate change, and achieve net-zero emissions targets by 2050. Hydrogen is considered to be the most potential clean energy in this century under the background of carbon neutrality. At present, the industrial methods for producing hydrogen are mainly by steam-hydrocarbon (such as coal and natural gas) reforming and by electrolysis of water, while the exploration and development of natural hydrogen had just started. According to this literature review: (1) Natural hydrogen can be divided into three categories, including free hydrogen, hydrogen in inclusions and dissolved hydrogen; (2) natural hydrogen could be mainly from abiotic origins such as by deep-seated hydrogen generation, water-rock reaction or water radiolysis; (3) natural hydrogen is widely distributed and presents great potential, and the potential natural hydrogen sources excluding deep source of hydrogen is about (254±91)×109 m3/a according to a latest estimate; (4) at present, natural hydrogen has been mined in Mali, and the exploration and development of natural hydrogen has also been carried out in Australia, Brazil, the United States and some European countries, to find many favorable areas and test some technical methods for natural hydrogen exploration. Natural hydrogen is expected to be an important part of hydrogen energy production in the future energy pattern. Based on a thorough literature review, this study introduced the origin, classification, and global discovery of natural hydrogen, as well as summarized the current global status and discussed the possibility of natural hydrogen exploration and development, aiming to provide reference for the future natural hydrogen exploration and development.©2022 China Geology Editorial Office. 相似文献
52.
为明晰济南四大泉群水化学动态变化特征及成因,利用离子比例系数、PHREEQC模拟以及氢氧同位素反演等方法分析各泉群水化学成分特征及其形成过程。研究表明:(1)四大泉群阳离子Ca2+为优势离子,阴离子HCO3-为优势离子;(2)潭西泉和珍珠泉水化学类型稳定,而趵突泉和黑虎泉由HCO3—Ca型变为HCO3·SO4—Ca型;(3)四大泉群受地表水、寒武系凤山组-奥陶系岩溶水以及寒武系张夏组岩溶水混合补给,其中趵突泉、黑虎泉接受寒武系凤山组-奥陶系岩溶水补给占比略大,而潭西泉、珍珠泉接受寒武系张夏组岩溶水补给占比略大;黑虎泉滞留时间最短,循环交替强烈;(4)水岩相互作用强弱程度导致泉群水化学成分差异,溶解沉淀作用强度整体大于阳离子交换作用。趵突泉阳离子交换作用强度最弱,黑虎泉伴随有去白云化作用,潭西泉和珍珠泉水化学作用及强度类似,进一步印证潭西泉和珍珠泉有相同的补给来源及运移机制。该研究成果对水资源合理利用和岩溶大泉的保护具有重要意义。 相似文献
53.
降水是干旱区水文循环研究不可缺少的水文要素,为了揭示我国西北地区大气降水的氢氧同位素时空分布特征,合理开展不同尺度水文循环研究和建立对比标准,系统搜集分析了乌鲁木齐、银川、张掖、兰州、平凉、西安和拉萨七个地区多年大气降水的氢氧同位素数据资料。分析结果表明:乌鲁木齐、银川、张掖和兰州四个地区的δ18O值夏半年明显高于冬半年,从全年尺度上来看只是受到了温度效应的影响;而位于关中盆地的西安地区则由于复杂的水汽来源,冬半年表现出受温度效应的控制,夏半年转为雨量效应控制为主。平凉地区δ18O与其它海拔相近地区(如兰州)相比5~9月份均偏负,这与平凉地区较弱的城市热岛效应有关。西北地区大气降水δD和δ18O的变化范围均在全球大气降水的变化范围之内,除平凉和拉萨外,其它几个地区大气降水线方程的斜率和截距均小于全球大气降水线,说明这些地区的降水是在干旱环境下经历较强程度的蒸发条件下进行的,且在降水过程中还可能受到了局地二次蒸发凝结等水汽循环的影响。而该区域大气降水的氘盈余(d值)表现出冬半年高、夏半年低的特点,表明冬半年和夏半年水汽来源不同或者水源地的蒸发条件不同。 相似文献
54.
文章通过80组不同地热田的样品,分析总结了北京地区地热水资源氘过量参数的特征:(1)地热水的平均δ值为5.4,常温地下水的平均d值为6.04,热水的d值与氚值都较低,水岩作用所导致的氧同位素交换比冷水更容易进行;(2)地下热水的氢和氧同位素组成具有明显的热交换趋势,d值随地下水年龄增大而递增,当地热水年龄为(12.76±0.13)ka时,d值为11.2,而当地热水年龄为(38.96±0.63)ka,d值为14.6;(3)在同一地区,d值随着地下水埋深加大而减小,埋深为125.13 m时d值为5.72,埋深为3221 m时,d值为3.03;(4)从补给源到排泄区,地下水的d值应逐渐降低,其中北部补给区平均d值为7.31,北京断陷盆地平均d值为5.68,南部凤河营地区仅为-9.20;补给源区与排泄区水的d的差值越大,地下水的运动速度越慢;(5)当Eh小于200 m V时,北京地区地下热水的d值随着Eh值的降低而减少,如在桐热-7中,氧化还原电位为-326 m V,d值为-9.20,而在TR-43中氧化还原电位为158 m V,d值为7.48;当Eh大于200 m V时,地下热水的d值随着Eh值的降低而增加,但增幅较小。 相似文献
55.
56.
57.
Patrick Petitjean 《Astrophysics and Space Science》2002,281(1-2):467-470
I describe briefly the status of an ongoing mini-survey for molecular hydrogen in high-redshift Damped Lyman-α systems using
UVES at the VLT. H2 is detected in about 30% of the cases. When H2 is not detected the molecular fraction f = 2N(H2)/(2N(H2)+N(HI) is smaller than 10-5. Therefore, most of the DLA systems arise in warm (T > 3000 K) and diffuse neutral gas embedded in a strong UV flux. The very recent detection of HD molecules in a Damped Lyman-α
system at z
abs = 2.337 demonstrates the possibility to discuss the high redshift chemistry.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
58.
In the last few years, deuterium has been the focus of a high level of laboratory activity that was sparked by a disagreement
on the experimental value of the maximum compression along the Hugoniot.
Astrophysically, the uncertainty in the EOS of hydrogen is most consequential in models of the interiors of Jupiter and Saturn
since a significant fraction of their mass falls in the region where the EOS uncertainty is largest. We present a study of
the range of interior structures allowed by the shock-compression experiments on deuterium and constrained by astrophysical
observations of the two planets. We find that the EOS uncertainty must be reduced to less than 3% along the planet’s isentrope
to get good interior models of Jupiter.
These models provide values for the mass of a core of heavy elements (other than H and He) and the total mass of heavy elements
in these planets. The amount and distribution of heavy elements are quite sensitive to the EOS of hydrogen and constitute
important clues to their formation process. 相似文献
59.
Deprit and Miller have conjectured that normalization of integrable Hamiltonians may produce normal forms exhibiting degenerate equilibria to very high order. Several examples in the class of coupled elliptic oscillators are known. In order to test the utility of normalization as a detector of integrability we normalize, to high order, a perturbed Keplerian system known to have several integrable limits; the generalized van der Waals Hamiltonian for a hydrogen atom. While the separable limits give rise to high order degeneracy we find a non-separable, integrable limit for which the normal form does not exhibit degeneracy. We conclude that normalization may, in certain cases, indicate integrability but is not guaranteed to uncover all integrable limits. 相似文献
60.
Guangyou?ZhuEmail author Shuichang?Zhang Yingbo?Liang Jinxing?Dai Jian?Li 《中国科学D辑(英文版)》2005,48(11):1960-1971
The northeastern area of Sichuan Basin, southwestern China, is the area with the maximal reserve of natural gas containing
higher hydrogen sulphide (H2S) that has been found among the petroliferous basins of China, with the proven and controlled gas reserve of more than 200
billion cubic meters. These gas pools, with higher H2S contents averaging 9%, some 17%, are mainly distributed on structural belts of Dukouhe, Tieshanpo, Luojiazhai, Puguang,
etc., while the oolitic-shoal dolomite of the Triassic Feixianguan Fm. (T1f) is the reservoir. Although many scholars regard the plentiful accumulation of H2S within the deep carbonate reservoir as the result of Thermochemical Sulfate Reduction (TSR), however, the process of TSR
as well as its residual geological and geochemical evidence is still not quite clear. Based on the carbon isotopic analysis
of carbonate strata and secondary calcite, etc., together with the analysis of sulfur isotopes within H2S, sulphur, gypsum, iron pyrites, etc., as well as other aspects including the natural gas composition, carbon isotopes of
hydrocarbons reservoir petrology, etc., it has been proved that the above natural gas is a product of TSR. The H2S, sulphur and calcite result from the participation of TSR reactions by hydrocarbon gas. During the process for hydrocarbons
being consumed due to TSR, the carbons within the hydrocarbon gas participate in the reactions and finally are transferred
into the secondary calcite, and become the carbon source of secondary calcite, consequently causing the carbon isotopes of
the secondary calcite to be lower (−18.2‰). As for both the intermediate product of TSR, i.e. sulfur, and its final products,
i.e. H2S and iron pyrites, their sulfur elements are all sourced from the sulfate within the Feixianguan Fm. During the fractional
processes of sulfur isotopes, the bond energy leads to the 32S being released firstly, and the earlier it is released, the lower δ 34S values for the generated sulphide (H2S) or sulfur will be. However, for the anhydrite that participates in reactions, the higher the reaction degree, the more
32S is released, while the less 32S remains and the more δ 34S is increased. The testing results have proved the process of the dynamic fractionation of sulfur isotopes. 相似文献