页岩气运移过程中的碳同位素分馏:机理、表征及意义

页岩原位含气量和吸附气/游离气比例是页岩气资源评价的2个关键参数,因此受到了广泛关注.然而,业已提出评价上述关键参数的多种方法均未得到广泛认可.甲烷在运移过程中的碳同位素分馏效应为有效区分不同赋存状态气体(吸附气、游离气)运移过程并最终确定这2个参数提供了全新的途径.文章通过页岩气运移模拟实验发现,页岩气解析/生产过程中甲烷碳同位素分馏存在4个阶段:游离气压差渗流阶段(Ⅰ)、吸附-游离转换阶段(Ⅱ)、吸附气解吸阶段(Ⅲ)和浓度差扩散阶段(Ⅳ).解耦实验揭示了甲烷运移过程中各单一作用(压差渗流、吸附-解吸和扩散)的碳同位素分馏效应.结合Amoco曲线拟合法和碳同位素分馏方法,文章进一步评价了页岩气解析/生产过程中吸附气/游离气比例动态变化,结果表明:第Ⅰ阶段产出的气体主要为游离气,甲烷碳同位素值(δ13C1)基本保持不变,且与气源值(13C10)相近;第Ⅱ阶段,游离气比例降低,吸附气比例增加,δ13C1值逐渐变轻;随着游离气的大量消耗,吸附气占据主导地位(接近100%),碳同位素分馏进入第Ⅲ阶段,δ13C1值逐渐变重;第Ⅳ阶段,残留在页岩基质内的吸附气在浓度差作用下向外扩散,该阶段δ13C1值再次变轻并最终稳定在一个较轻值.此外,文章还建立了定量描述页岩气解吸与扩散的动力学模型.

Studies on developing a safe-management standard system for Chinese biosafety laboratories

Standardization management is one of the key prerequisites to guarantee the effective and safe functioning of high-level biosafety laboratories.Since the outbreak of SARS,increasing numbers of biosafety laboratory levels have been established in China.Therefore,creating a specialized and standardized management system for biosafety laboratories has become necessary and is a core concern.This paper describes the current status of Chinese standards for biosafety management and analyzes its relation to other laboratory biosafety standard systems in developed countries.Based on the analysis on developing a biosafety laboratory,a laboratory biosafety standard system framework was developed,and a policy environment for building the system was suggested with the aim of promoting the promulgation of specific biosafety standards and securing the effective functioning of high-level biosafety laboratories.

转录因子禽类红细胞增多症病毒E26癌基因同系物1是一种新型的盐敏感性高血压肾损害介质

转录因子E26特异转录序列（E26transforma—tion—specificsequence，ETS）1是一种调节多种基因表达的转录因子，包括生长因子、趋化因子以及黏附分子。最近的研究显示血管紧张素（angiotensin，Ang）Ⅱ可增强ETS-1在肾小球内的表达，并且抑制ETS-1可改善AngⅡ引起的纤维化和促炎症效应。