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大柳沟—玉带湾一带石墨矿床地质特征及成因探讨
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作者 允跃 谭均 《中国非金属矿工业导刊》 2024年第1期39-46,61,共9页
大柳沟—玉带湾一带石墨矿床位于华北陆块北缘蒙西南至冀北石墨矿化带中东段,赋存在古元古代中期红旗营子岩群太平庄岩组地质构造相对稳定地段,该组至少有两套集中分布的石墨含矿层。矿床受后期断层控制,位于断层上盘。矿石自然类型:主... 大柳沟—玉带湾一带石墨矿床位于华北陆块北缘蒙西南至冀北石墨矿化带中东段,赋存在古元古代中期红旗营子岩群太平庄岩组地质构造相对稳定地段,该组至少有两套集中分布的石墨含矿层。矿床受后期断层控制,位于断层上盘。矿石自然类型:主要为含石墨黑云二长变粒岩夹含石墨黑云斜长片麻岩、长英质细脉混合质含石墨绿泥云母石英片岩和含石墨透闪绿泥片岩等。含石墨岩系具孔兹岩系特征。矿床总体呈似层状,矿体分布较为集中,矿床平均品位较低,正目石墨含量较高。矿床开发条件中等。矿床外围及深部还有找矿潜力。是典型的区域变质及混合岩化作用形成的大型晶质石墨矿床,系有机成因。 展开更多
关键词 晶质石墨矿 特征 成因 大柳沟—玉带湾
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全氟庚烷作为纸张脱酸载体的安全有效性研究 被引量:1
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作者 张玉芝 徐森 +2 位作者 何子晨 云悦 章月 《中华纸业》 CAS 2022年第18期29-32,共4页
近现代纸质文献脱酸过程中所使用的溶剂需要谨慎、科学。总览既有的脱酸用溶剂体系,氟碳溶剂被视为良好的脱酸用溶剂。人工模拟常用的脱酸过程,使用全氟庚烷作为纸张脱酸用溶剂,并对酸化纸张进行处理,并将处理前后纸张在(105±2)℃... 近现代纸质文献脱酸过程中所使用的溶剂需要谨慎、科学。总览既有的脱酸用溶剂体系,氟碳溶剂被视为良好的脱酸用溶剂。人工模拟常用的脱酸过程,使用全氟庚烷作为纸张脱酸用溶剂,并对酸化纸张进行处理,并将处理前后纸张在(105±2)℃条件下进行干热老化。考察处理前后纸张的酸度情况、机械性能、颜色变化等,从而确定全氟庚烷作为脱酸载体在近现代纸质文献脱酸过程中的使用安全性。利用全氟庚烷-氢氧化镁体系对酸化的纸质文献进行脱酸处理。经处理后,纸张的pH值和碱储量有很好的提升,可见全氟庚烷作为脱酸载体可用于文献脱酸。 展开更多
关键词 氟碳溶剂 全氟庚烷 纸质文献 安全性 有效性
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EVALUATION OF NEUROPROTECTIVE EFFECTS OF LONG-TERM LOW DOSE HORMONE REPLACEMENT THERAPY ON POSTMENOPAUSAL WO-MEN BRAIN HIPPOCAMPUS USING MAGNETIC RESONANCE SCANNER 被引量:1
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作者 Ling Hu yun yue +5 位作者 Ping-ping Zuo Zheng-yu Jin Feng Feng Hui You Ming-li Li Qin-sheng Ge 《Chinese Medical Sciences Journal》 CAS CSCD 2006年第4期214-218,共5页
To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters... To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters. Methods A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [ estradiol (E2 ) 0. 5-1.0 mg and progesterone 0.5-2.0 mg, once a day ] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay (ELISA). The gene types of apolipoprotein E (ApoE) were measured by polymerase chain reaction, and the subjects with susceptible genes ( ApoE ε3/ε4) of Alzheimer's disease (AD) were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging (MRI), and results in two groups were analyzed by statistical method. Results Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher (P 〈0. 05) except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups The results of hippocampus MRI for the subjects with susceptible genes ApoE ε3/ε4 (HRT group 14 cases, control group 11 cases) showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group (0. 406 ± 0.028) was signiticantlyhigher than control gronp (0.369±0.031, P〈0.05). Theresults of ^1H MRS for the subjects with susceptible genes ApoE ε3/ε4 ( HRT group 12 cases, control group 11 cases) showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group ( 1.54±0. 08 ) were significantly higher than control group ( 1.45±0. 13, P 〈 0. 05). Conclusions For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE ε3/ε3 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD. 展开更多
关键词 long-term low dose hormone replacement therapy ESTROGEN apolipoprotein E HIPPOCAMPUS magnetic resonance spectroscopy
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