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三维虚拟 T 型接头双作用激光焊接装备功能综合演示系统开发
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作者 武大伟 苏长青 刘迎春 《电子乐园》 2018年第9期11-11,共1页
本文从 T 型接头双作用激光焊接装备的应用特点出发,对其技术特点和应用需求进行了研究,对三维虚拟 T 型接头双作用激光 焊接系统的开发意义进行了讨论,后对三维虚拟 T 型接头双作用激光焊接装备综合演示功能实现方法进行了分析。
关键词 t接头双作用激光焊接 三维虚拟 综合演示系统开发
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带电组氨酸侧链与DNA碱基间非键作用强度的理论研究 被引量:3
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作者 李蕾 李书实 王长生 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2017年第1期56-62,共7页
采用MP2方法和6-31+G(d,p)基组优化得到了带有一个正电荷的组氨酸侧链与4个DNA碱基间形成的18个氢键复合物的气相稳定结构,从文献中获取了组氨酸侧链与DNA碱基间形成的12个堆积和T型复合物的气相稳定结构,使用包含基组重叠误差(BSSE)校... 采用MP2方法和6-31+G(d,p)基组优化得到了带有一个正电荷的组氨酸侧链与4个DNA碱基间形成的18个氢键复合物的气相稳定结构,从文献中获取了组氨酸侧链与DNA碱基间形成的12个堆积和T型复合物的气相稳定结构,使用包含基组重叠误差(BSSE)校正的MP2方法和aug-cc-pVTZ基组及密度泛函理论M06-2X-D3方法和aug-cc-pVDZ基组计算了这些复合物的结合能.研究结果表明,包含BSSE校正的M06-2X-D3方法和aug-cc-pVDZ基组能够给出较准确的结合能;气相条件下,组氨酸侧链与同种DNA碱基间的离子氢键作用明显强于堆积作用和T型作用,组氨酸侧链最易通过离子氢键与胞嘧啶C和鸟嘌呤G作用形成氢键复合物,组氨酸与胞嘧啶C和鸟嘌呤G间的T型作用强于与腺嘌呤A和胸腺嘧啶T间的离子氢键作用;水相条件下,组氨酸侧链与同种DNA碱基间的离子氢键作用仍明显强于堆积作用和T型作用,组氨酸侧链更易与胞嘧啶C和鸟嘌呤G相互作用形成氢键复合物,但是最强的组氨酸侧链与胞嘧啶C间的T型作用明显弱于与腺嘌呤A和胸腺嘧啶T间的离子氢键作用,说明水相条件下组氨酸侧链与DNA碱基间主要通过离子氢键作用形成氢键复合物. 展开更多
关键词 组氨酸侧链 DNA碱基 离子氢键作用 堆积作用 t型作用
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柴达木地块寒武纪变质作用——来自相平衡模拟和独居石U-Pb年代学的约束 被引量:1
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作者 滕霞 张建新 +4 位作者 毛小红 路增龙 周桂生 武亚威 郭祺 《岩石学报》 SCIE EI CAS CSCD 北大核心 2022年第11期3247-3258,共12页
柴达木地块位于青藏高原东北缘的祁连-阿尔金-昆仑早古生代造山系之中,它的西段出露一套(超)高温变质岩组合:变泥质岩、长英质片麻岩、基性麻粒岩、钙硅酸盐岩、含橄榄石大理岩及少量Mg-Al麻粒岩。本文以相平衡模拟和独居石U-Pb年代学... 柴达木地块位于青藏高原东北缘的祁连-阿尔金-昆仑早古生代造山系之中,它的西段出露一套(超)高温变质岩组合:变泥质岩、长英质片麻岩、基性麻粒岩、钙硅酸盐岩、含橄榄石大理岩及少量Mg-Al麻粒岩。本文以相平衡模拟和独居石U-Pb年代学为主要手段,限定柴西缘变泥质岩的变质作用P-T-t轨迹。变泥质岩记录了顺时针P-T轨迹,其中,压力峰期条件约为0.89GPa和800℃,温度峰期条件约为0.64GPa和825℃,退变质条件为0.58GPa和800℃至0.37±0.05GPa和702±50℃。变泥质岩的独居石U-Pb年龄集中在517~496Ma之间,三个样品的加权平均年龄分别为508±2Ma(MSWD=2.0)、506±1Ma(MSWD=1.7)、506±1Ma(MSWD=1.3)。本文将其解释为独居石的形成年龄,并认为独居石主要形成于退变质过程中的残留熔体结晶阶段(0.58GPa和800℃左右)。结合已有的工作可以得出,柴达木地块西段麻粒岩相变质作用具有顺时针P-T轨迹和1000~1300℃/GPa的峰期T/P值,并且在高温变质条件(>800℃)持续了超过30Myr。该类高T/P型变质作用最有可能发生在大型碰撞造山带内,可以与冈瓦纳大陆内部的晚泛非期的高T/P型变质作用对比,很可能是与冈瓦纳大陆最终拼合有关的晚泛非期造山事件的体现。 展开更多
关键词 柴达木地块 变泥质岩 t/P变质作用 相平衡模拟 独居石年代学
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希夏邦马峰地区始新世地壳加厚和隆升过程 被引量:3
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作者 王佳敏 侯康师 +1 位作者 李潇丽 吴福元 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第5期1429-1445,共17页
中新世中期之前喜马拉雅山脉的隆升历史和深部动力机制,还存在极大的争议、缺乏基本的数据约束。喜马拉雅造山带核部高级变质岩的埋藏和折返过程可以约束地壳加厚和山脉隆升过程,但是现有的变质记录主要为渐新世晚期-中新世中期,始新世... 中新世中期之前喜马拉雅山脉的隆升历史和深部动力机制,还存在极大的争议、缺乏基本的数据约束。喜马拉雅造山带核部高级变质岩的埋藏和折返过程可以约束地壳加厚和山脉隆升过程,但是现有的变质记录主要为渐新世晚期-中新世中期,始新世变质作用的分布范围、形成过程和地质意义仍然未被充分挖掘。本文首先厘定了希夏邦马峰(8027m)山体的基本岩石组成:下部为高喜马拉雅正/副片麻岩,上部为肉切村群变粒岩及贯入其中的淡色花岗岩席。进一步对1964年希夏邦马峰登山科考采集的眼球状片麻岩进行了变质作用相平衡模拟和独居石微区原位U-Th-Pb定年,确定了始新世变质记录的P-T-t演化轨迹:M1阶段中P/T型变质压力峰期,条件为~1.0GPa、~740℃(~22℃/km),变质年龄为~37Ma;后近等温降压至M2阶段低P/T型变质温度峰期,条件为0.5~0.4GPa、~760℃(45~57℃/km),变质年龄为~25Ma;在~18Ma左右冷却至固相线以下。希夏邦马峰~37Ma的中P/T型变质和地壳加厚事件与北喜马拉雅穹隆、高喜马拉雅主体、前陆飞来峰等地区的记录一致(40~37Ma,20~25℃/km),表明印度-亚洲初始碰撞约20Myr后中上地壳被堆叠埋藏至>33km以下,发生了广泛的整体性加厚和深熔作用。该事件与喜马拉雅内陆残留海最终退却的时间吻合,是喜马拉雅山脉初始隆升的诱因。喜马拉雅山脉不是晚新生代以来隆升的,而是经历了自始新世中期以来的长期地壳堆叠和隆升过程。 展开更多
关键词 喜马拉雅 初始隆升 地壳加厚 中P/t变质作用 独居石U-th-Pb岩石年代学
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Function of Helper T Cells in the Memory CTL-mediated Anti-tumor Immunity
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作者 高丰光 Germain J.P.Fernendo 刘文军 《Journal of Microbiology and Immunology》 2004年第1期50-55,共6页
To investigate the role of CD4 + helper T (Th) cells in the memory CTL-mediated anti-tumor immunity, the RAG-1 gene knock out mice were adoptively transferred with OT-1 cells to generate the memory CTL, the C57BL/6 mi... To investigate the role of CD4 + helper T (Th) cells in the memory CTL-mediated anti-tumor immunity, the RAG-1 gene knock out mice were adoptively transferred with OT-1 cells to generate the memory CTL, the C57BL/6 mice immunized with the epitope peptide of OVA specific Th cells and with different adjuvants were adoptively transferred with these memory-CTLs, and then the animals were challenged with tumor cells EG7. It was found that although the simple immunization of mice with the epitope peptide of the OVA specific Th cells could generate more effect CTL, but this effect was not so strong enough to resist completely the challenges with tumor cells. Nevertheless, the memory CTL-mediated anti-tumor immune effect required the helps of Th1 and Th2 cells. The cross-regulation between Th1 and Th2 cells seemed to be beneficial for the host to generate more effector CTL for mounting an efficient anti-tumor response. It concluded that the interaction between Th1 and Th2 cells might be more important than the single subset of Th cells in the memory CTL-mediated anti-tumor immune response. More attention should be paid in this regard for the future studies. 展开更多
关键词 Memory t cells Helper t cells tRANSGENIC CD44
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Protective effects of Yindanxinnaotong capsule in a rat model of myocardial ischemia/reperfusion injury 被引量:23
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作者 Wandan Wang Lan Wang +5 位作者 Hongjun Yang Jianlu Wang Xiaojie Yin Haiyu Xu Long Cheng Rixin Liang 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2014年第6期699-709,共11页
OBJECTIVE: To investigate the effects of Yindanxinnaotong capsule(YDXNTC) and main components compatibility and ratios on myocardium against ischemia/reperfusion injury and the effect's underlying mechanism.METHOD... OBJECTIVE: To investigate the effects of Yindanxinnaotong capsule(YDXNTC) and main components compatibility and ratios on myocardium against ischemia/reperfusion injury and the effect's underlying mechanism.METHODS: Myocardial ischemia/reperfusion injury(MIRI) was induced by ischemia for 30 min and reperfusion for 30 min. Electrocardiogram data and coronary flow were recorded, and superoxide dismutase(SOD), malondialdehyde(MDA), lactate dehydrogenase, creatine kinase-MB, cardiac troponin T and I(cT nT, cT n I) and interleukin-1β, interleukin-8,interleukin-18(IL-1β, IL-8, IL-18) in myocardium were measured. Hypoxia/reoxygenation and hydrogen peroxide(H2O2) injury were induced by hypoxia for 3 h/reoxygenation for 2 h, and 100 μM H2O2 for 1 h, respectively, in vitro rat myocardial cells(H9c2). Cell viability, SOD, MDA, cT nT and inflamma-tory factors(IL-1β, IL-8 and IL-18) were determined,and Toll-like receptor 4(TLR-4) expression was measured by western blotting.RESULTS: In the isolated heart experiment, elevated heart function, coronary flow and SOD levels,and decreased MDA levels and inflammatory factors were noted in the YDXNTC, main components and main components compatibility groups. Ventricular tachycardia/ventricular fibrillation occurrence decreased in the ginkgo biloba extract(GBE),and GBE and salvia miltiorrhiza ethanol extract compatibility(SM-E, GSEC) groups. Lactic dehydrogenase levels decreased in the YDXNTC and aqueous extract of salvia miltiorrhiza(SM-H) groups. Creatine kinase-MB decreased with GBE, SM-E, SM-H and GSEC treatment, and cT n I and cT nT levels decreased with GSEC. In the in vitro cell study,YDXNTC and main components ratios improved cell viability and SOD levels, and suppressed MDA,cT nT and inflammatory factors. TLR-4 expression was down-regulated.CONCLUSION: YDXNTC and main components compatibility showed protective effects on MIRI in this rat model and in vitro study. Regulating the Toll-like receptor signaling pathway may affect the mechanism. 展开更多
关键词 Myocardial ischemia REPERFUSION Components compatibility Yindanxinnaotong cap-sule
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