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裂缝性致密砂岩储层声波测井数值模拟 被引量:1
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作者 龚丹 章成广 《石油天然气学报》 CAS CSCD 2016年第2期28-35,共8页
目前,用来评价致密砂岩储层有效性的测井方法主要有常规测井、成像测井及声波测井3种。由于裂缝性致密砂岩储层的裂缝宽度一般小于100μm,常规测井和成像测井对微裂缝难以进行有效识别,而声波测井可通过斯通利波衰减系数等参数对微... 目前,用来评价致密砂岩储层有效性的测井方法主要有常规测井、成像测井及声波测井3种。由于裂缝性致密砂岩储层的裂缝宽度一般小于100μm,常规测井和成像测井对微裂缝难以进行有效识别,而声波测井可通过斯通利波衰减系数等参数对微裂缝进行定性甚至定量识别。通过数值模拟计算,对含有裂缝的致密储层井孔声场进行研究,掌握裂缝对井内声场的影响规律,对于声波测井数据处理及解释具有重要意义。应用三维交错网格应力一速度有限差分方法,模拟了含有倾斜薄裂缝的孔隙介质地层中点声源所激发的井孔声场问题。针对单条水平裂缝,确定了不同裂缝宽度(20-1000μm)对斯通利波识别微裂缝的影响,即裂缝宽度越大,波形振幅越小;裂缝宽度较小时(裂缝宽度小于100μm),波形幅度对裂缝宽度的变化非常敏感,递减非常快:裂缝宽度越大时,斯通利波衰减系数越大。此外,还计算了孔隙介质地层不同孔隙度条件下斯通利波、横波、纵波幅度及衰减系数与裂缝宽度的关系,即孔隙度越大,斯通利波、横波、纵波幅度越小,衰减系数越大。 展开更多
关键词 声波测井 斯通利波 裂缝性致密砂岩 数值模拟 测井响应特征
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An overview on ethical issues about sperm donation 被引量:9
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作者 dan gong Yu-Lin Liu +2 位作者 Zhong Zheng Yi-Fei Tian Zheng Li 《Asian Journal of Andrology》 SCIE CAS CSCD 2009年第6期645-652,共8页
Beyond the scientific progress in assisted reproductive technologies (ART), it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered ... Beyond the scientific progress in assisted reproductive technologies (ART), it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered and discussed by government and non-governmental agencies, the public, media and academic institutions in many countries. Recommendations and guidelines concerning sperm donation issues vary from country to country and between professional groups within countries. This paper attempts to present an overview of findings and reports from various agencies concerning the ethics of sperm donation. The following topics are considered: limiting the number of donor offspring; minimizing risk of infection and genetics from sperm donors; age requirements for sperm donors; and anonymity versus non-anonymity of sperm donors. The diversity of policies shows that each country has its unique set of guidelines tailored toward its own specific needs. Similarly, countries designing their own procedures and guidelines concerning reproductive medicine must tailor them toward their own needs and practical considerations. In China's Mainland, the anonymous policy for sperm donation should still be carried out, and the number of donor offspring should be revaluated. ART procedures must be conducted in a way that is respectful of those involved. Ethical principles must respect the interests and welfare of persons who will be born as well as the health and psychosocial welfare of all participants, including sperm donors. 展开更多
关键词 ETHICS DONOR sperm bank sperm donation
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Recent advances in alkaline hydrogen oxidation reaction 被引量:3
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作者 Lixin Su dan gong +2 位作者 Yiming Jin Dean Wu Wei Luo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第3期107-122,I0004,共17页
The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR ... The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR kinetics in alkaline is two to three orders of magnitude slower than that in acid.More critically,fundamental understanding of the sluggish kinetics derived from the p H effect is still debatable.In this review,the recent development of understanding HOR mechanism and rational design of advanced HOR electrocatalysts are summarized.First,recent advances in the theories focusing on fundamental understandings of HOR under alkaline electrolyte are comprehensively discussed.Then,from the aspect of intermediates binding energy,optimizing hydrogen binding energy(HBE)and increasing hydroxyl binding energy(OHBE),the strategies for designing efficient alkaline HOR catalysts are summarized.At last,perspectives for the future research on alkaline HOR are pointed out. 展开更多
关键词 Hydrogen oxidation reaction Hydrogen evolution reaction Alkaline electrolyte AEMFC Binding energy
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