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酸碱药对甘草-马钱子配伍汤液沉积相态释放特性研究 被引量:7
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作者 郭玉岩 高滔 +5 位作者 李春城 魏宇欣 邵爽 孙爽 杨大宇 吕邵娃 《中草药》 CAS CSCD 北大核心 2022年第10期3000-3005,共6页
目的探讨甘草-马钱子配伍汤液沉积相态的释放行为,为甘草-马钱子配伍减毒提供科学参考。方法建立沉积相态释放测定HPLC法,通过体外释放实验,追踪沉积相态在蒸馏水、人工胃液、人工肠液等不同介质中主成分的释放行为,并对其释放结果进行... 目的探讨甘草-马钱子配伍汤液沉积相态的释放行为,为甘草-马钱子配伍减毒提供科学参考。方法建立沉积相态释放测定HPLC法,通过体外释放实验,追踪沉积相态在蒸馏水、人工胃液、人工肠液等不同介质中主成分的释放行为,并对其释放结果进行拟合研究分析。结果甘草酸、马钱子碱以及士的宁在人工肠液中的释放量较大,且马钱子碱>甘草酸>士的宁。马钱子碱和甘草酸均与一级动力学模型拟合结果最佳,士的宁与Higuchi模型拟合结果最佳。结论甘草-马钱子沉积相态主要毒效成分呈现出难溶性骨架材料缓释制剂的释放特性,毒(效)成分士的宁可能以沉积共聚体形式存在,在体释放呈缓释行为而减毒;同时,甘草酸的释放对减毒增效起到协同作用。 展开更多
关键词 酸碱药对 甘草 马钱子 配伍汤液 体外释放 沉积相态 减毒
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风化型稀土矿的矿石性质研究 被引量:11
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作者 梁国兴 池汝安 朱国才 《稀土》 EI CAS CSCD 北大核心 1997年第5期5-9,共5页
本文研究分析了产于我国两类特有的风化型稀土矿矿石性质。发现风化淋积型稀土矿中稀土赋存是以羟基水合离子吸附在粘土矿物上,矿石具有含水多样性,酸碱缓冲性,吸附稀土离子的化学稳定性和可交换性,稀土配分类型多样性及铈亏效应。... 本文研究分析了产于我国两类特有的风化型稀土矿矿石性质。发现风化淋积型稀土矿中稀土赋存是以羟基水合离子吸附在粘土矿物上,矿石具有含水多样性,酸碱缓冲性,吸附稀土离子的化学稳定性和可交换性,稀土配分类型多样性及铈亏效应。黑色风化矿泥中稀土是以胶态沉积相均匀分散在Mn-Fe氧化物表面赋存,矿石是非晶相的含稀土泥状集合体,稀土配分是典型的轻稀土配分选择型。 展开更多
关键词 风化湘积型 风化型 稀土矿 矿石性质 沉积相
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Ecological Responses to Holocene Millennial-Scale Climate Change at High Altitudes of East and Central Asia: A Case Study of Picea/Abies Pollen Changes in Lacustrine Sediments 被引量:2
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作者 LI Yu ZHANG Cheng-qi ZHOU Xue-hua 《Journal of Mountain Science》 SCIE CSCD 2014年第3期674-687,共14页
Ecosystem response to climate change in high-altitude regions is a focus on global change research. Picea/Abies forests are widely distributed at high altitudes of East and Central Asia, and their distribution changes... Ecosystem response to climate change in high-altitude regions is a focus on global change research. Picea/Abies forests are widely distributed at high altitudes of East and Central Asia, and their distribution changes are sensitive to climate change. Humidity is an important climatic factor that affects high-altitude ecosystems; however, the relationship between distribution changes of Picea/Abies forests and millennial-scale variability of humidity is still not dear. Palynological records can provide insights into millennial-scale paleovegetation changes, which have been successfully used to reconstruct past climate change in East and Central Asia. In this study, we synthesized 24 Picea/Abies pollen and humidity/moisture changes based upon Holocene lake records in East and Central Asia in order to explore the response of high-latitude ecosystem to millennial-scale climate change. The changing pattern of Holocene lacustrine Picea/Abies pollen in arid Central Asia differs from that of monsoonal East Asia, which can be due to different millennial-scale climate change patterns between monsoonal and arid Central Asia. Then, the relationship between changes in Picea/Abies pollen and humidity/moisture conditions was examined based on a comparison of pollen and humidity/moisture records. The results indicate that millennial-scale Picea/Abies distribution changes aremainly controlled by moisture variability at high altitudes, while the temperature effect plays a minor role in Picea/Abies distribution changes. Moreover, this research proves that lacustrine Picea/Abies pollen can be used as an indicator of millennial-scale humidity/moisture evolution at high altitudes in East and Central Asia. 展开更多
关键词 Lake sediments Palynological records High-altitude regions Picea/Abies Asian summermonsoon MILLENNIAL-SCALE Climate change
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