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循环张拉作用下新型多节泡土钉抗拔性能现场试验研究 被引量:1
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作者 叶新宇 时一帆 +3 位作者 李煜 张升 田奔 刘蔚 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第3期1037-1046,共10页
新型多节泡土钉具有拉拔硬化特征,相比传统土钉,其在土质边坡中抗拔性能更优。为了探究实际工况条件下新型多节泡土钉的边坡加固性能,并与传统土钉进行比较,开展7组新型多节泡土钉及传统土钉现场循环张拉试验,研究注浆工艺、节泡间距及... 新型多节泡土钉具有拉拔硬化特征,相比传统土钉,其在土质边坡中抗拔性能更优。为了探究实际工况条件下新型多节泡土钉的边坡加固性能,并与传统土钉进行比较,开展7组新型多节泡土钉及传统土钉现场循环张拉试验,研究注浆工艺、节泡间距及埋深对土钉抗拔力及其发挥速率的影响规律,进而探明了每一循环下土钉弹、塑性拉拔位移占比,并分析其内在机理。试验结果表明:循环张拉作用下,注浆工艺对土钉的抗拔力影响显著,采用改进式压密注浆工艺和直接压密注浆工艺的土钉抗拔力远远超出传统注浆工艺,且初期的拉拔硬化现象更明显。采用改进式压密注浆工艺的土钉抗拔力发挥速率最快,直接压密注浆工艺次之,传统注浆工艺最小。从总体趋势上看,新型多节泡土钉抗拔力发挥速率在降低,传统土钉抗拔力发挥速率在升高。采用改进式压密注浆工艺虽然不能提升土钉弹性拉拔位移的占比,却能显著提高极限抗拔力;节泡间距对多节泡土钉抗拔力和抗拔力发挥速率影响较小,主要受到土钉周围土体强度的影响;埋深影响多节泡土钉的极限抗拔力,埋深越大,极限抗拔力和初始抗拔力发挥速率越大,同时抗拔力发挥速率随拉拔位移递减的趋势也更加明显。研究成果对提高新型多节泡土钉加固性能和优化工程应用提供指导。 展开更多
关键词 土钉 拉拔硬化 循环张拉 节泡 现场试验
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滤泡调节性T细胞在眼肌型重症肌无力中的研究进展 被引量:4
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作者 吴娜 胡裕翔 +5 位作者 许晓璇 晏立 程艺 饶杰 吴雅俊 吴晓蓉 《中国医学科学院学报》 CAS CSCD 北大核心 2020年第3期383-387,共5页
重症肌无力(MG)是由抗体介导、对T细胞依赖及不同补体参与共同发挥作用导致的自身免疫性疾病。眼肌型重症肌无力(OMG)是MG中的一种类型,其症状仅局限于眼外肌。新近研究表明,包括OMG在内的多种自身免疫性疾病的发生发展都与滤泡调节性T... 重症肌无力(MG)是由抗体介导、对T细胞依赖及不同补体参与共同发挥作用导致的自身免疫性疾病。眼肌型重症肌无力(OMG)是MG中的一种类型,其症状仅局限于眼外肌。新近研究表明,包括OMG在内的多种自身免疫性疾病的发生发展都与滤泡调节性T细胞(Tfr细胞)的表达失衡密切相关。因此,对Tfr细胞的探讨或许可作为眼OMG相关性研究的一个新切入点。本文总结了Tfr细胞在OMG免疫学发病机制中的研究进展。 展开更多
关键词 眼肌型重症肌无力 调性T细胞 辅助性T细胞 生发中心 机制
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不同注浆工艺下土钉的现场拉拔试验
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作者 李煜 张升 +4 位作者 叶新宇 刘玮 时一帆 李柔锋 田奔 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第7期2690-2700,共11页
针对传统注浆工艺下土钉注浆控制难、抗拔性能不佳的问题,开展不同注浆工艺的土钉现场抗拔对比试验,探究传统注浆工艺、改进式压密注浆工艺以及分步改进式压密注浆(预注浆+改进式压密注浆)3种工艺下土钉抗拔性能及荷载传递规律,并将多... 针对传统注浆工艺下土钉注浆控制难、抗拔性能不佳的问题,开展不同注浆工艺的土钉现场抗拔对比试验,探究传统注浆工艺、改进式压密注浆工艺以及分步改进式压密注浆(预注浆+改进式压密注浆)3种工艺下土钉抗拔性能及荷载传递规律,并将多节泡土钉抗拔力现场试验结果与理论模型计算结果进行对比分析。研究结果表明:注浆工艺对土钉的抗拔力影响显著,改进式压密注浆工艺和分步改进式压密注浆工艺下的土钉抗拔力是传统注浆工艺下的2倍以上,且拉拔初期的硬化现象更明显;改进式压密注浆工艺下土钉的轴力在节泡段变化显著,节泡端抗力占总抗拔力的75%左右;分步改进式压密注浆工艺下土钉轴力后段变化趋势与改进式压密注浆工艺下的土钉轴力变化趋势相似,其前段变化趋势与传统注浆工艺下土钉轴力的变化规律一样,呈线性减小,土钉端反力与侧摩擦力基本相等,且出现抗拔力软化时对应的拉拔位移最大;在3种注浆工艺下,土钉侧摩擦力都是靠近拉拔端最先屈服,且直径越大的节泡段提供的侧摩擦力越大。抗拔力理论模型能够基本反映不同注浆工艺下土钉在现场应用的抗拔规律,可为多节泡土钉的现场应用提供理论参考。 展开更多
关键词 土钉 注浆工艺 节泡 土工织物 抗拔力
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应用于压密注浆土钉的土工织物反滤性能试验研究 被引量:2
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作者 彭锐 张升 +2 位作者 叶新宇 雷宇 李煜 《岩土力学》 EI CAS CSCD 北大核心 2022年第S01期339-347,共9页
针对现有乳胶膜压密注浆土钉的潜在缺陷,提出了采用土工织物替代乳胶膜改进该土钉的新思路。基于自研的土工织物反滤性能测定装置,开展了一系列水泥浆液反滤试验,研究了水灰比、浆液体积和注浆压力对土工织物反滤性能的影响。并且,对反... 针对现有乳胶膜压密注浆土钉的潜在缺陷,提出了采用土工织物替代乳胶膜改进该土钉的新思路。基于自研的土工织物反滤性能测定装置,开展了一系列水泥浆液反滤试验,研究了水灰比、浆液体积和注浆压力对土工织物反滤性能的影响。并且,对反滤前后浆液成型的试块进行了强度试验。试验结果表明:随水灰比的增加,浆液最终滤出质量、反滤结束时间和质量流量都相应增加,但反滤结束时间的增量会逐渐减小;浆液体积的变化不会影响质量流量的变化,而反滤结束时间与浆液体积呈线性增加的关系;随注浆压力的增加,浆液质量流量逐渐增加。同时,土工织物撑开面积的增加率与注浆压力呈线性增加的关系;采用土工织物替代乳胶膜后,节泡内浆液水灰比明显减小,强度得到显著提高。研究能为土工织物改进新型压密注浆土钉的应用奠定基础。 展开更多
关键词 压密注浆土钉 节泡 土工织物 水灰比 浆液体积 注浆压力
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High Efficiency of Propagation for Sagittaria sagittifolia Using a Temporary Immersion Bioreactor System 被引量:1
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作者 Meiping Gao Zhicheng Lin +7 位作者 Cong Luo Zhang Chi Zhihuan Mo Fanglian He Wen Jiang Lijuan Chen Xinhua He Shaolong Wei 《Journal of Agricultural Science and Technology(A)》 2016年第3期161-170,共10页
Although several studies have reported on the propagation of the Sagittaria sagittifolia to date, none of these methods have efficiently achieved the mass production of these plants. The present study aimed to investi... Although several studies have reported on the propagation of the Sagittaria sagittifolia to date, none of these methods have efficiently achieved the mass production of these plants. The present study aimed to investigate the propagation and growth of S. sagittifolia using a temporary immersion bioreactor system (TIBS) compared with conventional semi-solid and liquid culture. The effect of different immersion frequencies and immersion times together with supplementation of various plant growth regulators to the Murashige and Skoog (MS) medium was evaluated on shoot proliferation and plant growth. The results showed that the higher immersion frequency (every 6 h) and shorter immersion time (3 min and 10 rain) in medium containing 4 mg/L BA and 0.1 mg/L NAA produced the highest multiplication rate (23), which are significantly higher than conventional semi-solid (3.6) and liquid (4.5) method, and the best plant growth parameter. While, the lower immersion frequency and longer immersion time (30 rain every 12 h and 60 min every 24 h) induced vitrification and pollution rate in shoot tips 16.6% and 19%, 42% and 37%, respectively. There is distinct decrease in pollution rate (8.3%) in TIBS (10 min every 6 h) compared with the conventional semi-solid and liquid cultures. Medium containing 4 mg/L BA and 0.5 mg/L NAA using 10 min immersion every 6 h showed satisfaction at the rooting stage, with high shoot proliferation rate (21.6), 100% rooting and 94% plant survival. Therefore, applying TIBS in S. sagittifolia is an efficient method for scaling up the production of plantlets with high quality seedlings. 展开更多
关键词 Sagittaria sagittifolia temporary immersion bioreactor system proliferation and growth root formation.
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A Study on the Architectural Application of Aerogel 被引量:6
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作者 Young Cheol Kwon 《Journal of Civil Engineering and Architecture》 2013年第12期1494-1500,共7页
As the building energy saving is more and more important, high-performing insulation like aerogel will be required in buildings to improve their thermal environment and to save building energy. This study conducted th... As the building energy saving is more and more important, high-performing insulation like aerogel will be required in buildings to improve their thermal environment and to save building energy. This study conducted the literature survey on the aerogel blanket and presents the architectural application considering its high-insulating property. If aerogel is applied to a building as an envelope insulation, its thickness could be reduced to as half as that of existing insulation such as polystyrene foam board or glassfiber. Currently, aerogel is largely used as a thermal breaker in thermal bridges in buildings. It is still too expensive to be used as a main insulation of whole building envelopes. Thanks to the advantages of aerogel blanket such as low thermal conductivity, broad temperature range for use, excellent water repellent property and fire resistance, easiness of moving and applying, it has much possibility in the respect of its building application. 展开更多
关键词 INSULATION AEROGEL thermal conductivity aerogel blanket.
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Acupuncture combined with vesiculating cupping for 110 patients with rheumatoid arthritis 被引量:4
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作者 刘一儒 乔圣茜 《World Journal of Acupuncture-Moxibustion》 CSCD 2015年第4期38-42,共5页
Objective To explore the clinical efficacy of acupuncture combined with vesiculating cupping in treatment of rheumatoid arthritis(RA). Methods A total of 110 patients with RA were randomly divided into an acupunctur... Objective To explore the clinical efficacy of acupuncture combined with vesiculating cupping in treatment of rheumatoid arthritis(RA). Methods A total of 110 patients with RA were randomly divided into an acupuncture combined with vesiculating cupping group(group A) and an acupuncture combined with non-vesiculating cupping group(group B). Treatment was conducted once a day in two groups, and ten days were considered as one course of treatment. The total effective rate was observed after treatment for three courses. Results The difference in cured and markable effective rate of group A and group B was obviously significant [81.82%(45/55) vs 18.18%(10/55), P〈0.01], the difference in total effective rate of group A and group B was significant [96.36%(53/55) vs 69.09%(38/55), P〈0.05], indicating that the efficacy in group A was significantly superior to that of group B. Conclusion Acupurcture combined with vesiculating cupping therapy achieves more satisfactory efficacy on RA compared with acupuncture combined with nonvesiculating cupping therapy. 展开更多
关键词 Rheumatoid arthritis ACUPUNCTURE CUPPING vesiculating therapy
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