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高速铁路箱型路基动力响应分析

铁道标准设计 2025年第1期69卷 57-66页

作者：刘晶磊周玮浩张伯扬刘佳凡张业荣河北建筑工程学院河北张家口075000 河北省土木工程诊断、改造与抗灾重点实验室河北张家口075000 河北省寒冷地区交通基础设施工程技术创新中心河北张家口075000

为研究高速铁路箱型路基在列车荷载作用下的动力响应问题,采用数值模拟方法建立轨道-路基-地基三维有限元模型,分析箱型路基的动应力、动位移和加速度的分布规律,并与常规填土路基进行对比。结果表明,列车荷载作用下的动力响应时程曲线... 详细信息

为研究高速铁路箱型路基在列车荷载作用下的动力响应问题,采用数值模拟方法建立轨道-路基-地基三维有限元模型,分析箱型路基的动应力、动位移和加速度的分布规律,并与常规填土路基进行对比。结果表明,列车荷载作用下的动力响应时程曲线周期性变化明显,不同车厢相邻2个转向架产生叠加效应,随深度增加叠加效应减弱,且发生时间滞后约0.1 s。动力响应沿深度分布,主要呈递减趋势。箱型路基内,竖向动应力和加速度衰减率分别可达60%、75%以上。动力响应沿横向分布,在支承层范围内,横向分布差异较小,顶板竖向动位移最大差值仅为0.008 mm,而范围外则变化迅速。动力响应沿横向分布,主要呈“马鞍”形和“U”形分布,在支承层边缘下方、竖板和顶、底板连接处以及底板边缘均出现峰值,存在应力集中效应。路基表面最大动应力为39.6 kPa,最大动位移为0.165 mm,路基内最大动应力为100.6 kPa,满足设计要求。与常规填土路基相比,箱型路基竖向动应力的衰减率更大,可达到95%,且加速度较小,对动荷载的吸收和耗散作用更显著。箱型路基与常规路基表面竖向动位移幅值分别为0.165 mm、0.329 mm,最大差值为0.036 mm、0.189 mm。箱型路基动位移更小,横向分布更均匀,整体性更好。

关键词：高速铁路箱型路基数值模拟动应力动位移加速度

面向处理器微架构设计空间探索的加速方法综述

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计算机研究与发展 2025年第1期62卷 22-57页

作者：王铎刘景磊严明玉滕亦涵韩登科叶笑春范东睿处理器芯片全国重点实验室(中国科学院计算技术研究所) 北京100190 中国科学院大学计算机科学与技术学院北京100049 中国移动研究院北京100053

中央处理器是目前最重要的算力基础设施.为了最大化收益,架构师在设计处理器微架构时需要权衡性能、功耗、面积等多个目标.但处理器运行负载的指令多,单个微架构设计点的评估耗时从10 min到数十小时不等.加之微架构设计空间巨大,全设计... 详细信息

中央处理器是目前最重要的算力基础设施.为了最大化收益,架构师在设计处理器微架构时需要权衡性能、功耗、面积等多个目标.但处理器运行负载的指令多,单个微架构设计点的评估耗时从10 min到数十小时不等.加之微架构设计空间巨大,全设计空间暴力搜索难以实现.近些年来许多机器学习辅助的设计空间探索加速方法被提出,以减少需要探索的设计空间或加速设计点的评估,但缺少对加速方法的全面调研和系统分类的综述.对处理器微架构设计空间探索的加速方法进行系统总结及分类,包含软件设计空间的负载选择、负载指令的部分模拟、设计点选择、模拟工具、性能模型5类加速方法.对比了各加速方法内文献的异同,覆盖了从软件选择到硬件设计的完整探索流程.最后对该领域的前沿研究方向进行了总结,并放眼于未来的发展趋势.

关键词：处理器微架构设计设计空间探索性能模型负载选择软件模拟

Efficient Preference Clustering via Random Fourier Features

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Big Data Mining and Analytics 2019年第3期2卷 195-204页

作者： Jingshu liu Li Wang jinglei liu College of Data Science Taiyuan University of TechnologyJinzhong 030600China School of Computer and Control Engineering Yantai UniversityYantai 264005China

Approximations based on random Fourier features have recently emerged as an efficient and elegant method for designing large-scale machine learning *** approaches using the Nystr?m method,which randomly samples the training examples,we make use of random Fourier features,whose basis functions(i.e.,cosine and sine)are sampled from a distribution independent from the training sample set,to cluster preference data which appears extensively in recommender ***,we propose a two-stage preference clustering *** this framework,we make use of random Fourier features to map the preference matrix into the feature matrix,soon afterwards,utilize the traditional k-means approach to cluster preference data in the transformed feature *** with traditional preference clustering,our method solves the problem of insufficient memory and greatly improves the efficiency of the *** on movie data sets containing 100000 ratings,show that the proposed method is more effective in clustering accuracy than the Nystr?m and k-means,while also achieving better performance than these clustering approaches.

关键词： random Fourier features matrix decomposition similarity matrix Nystrom method preference clustering

Circular RNAs and human glioma

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Cancer Biology & Medicine 2019年第1期16卷 11-23页

作者： jinglei liu Kun Zhao Nunu Huang Nu Zhang Department of Neurosurgery The First Affiliated Hospital of Sun Yat-sen University Guangdong Provincial Key Laboratory of Brain Function and Disease

As a newly discovered type of RNA, circular RNAs(circRNAs) are widespread throughout the eukaryotic genome. The expression of circRNAs is regulated by both cis-elements and trans-factors, and the expression pattern of circRNAs is cell type-and diseasespecific. Similar to other types of non-coding RNAs, functions of circRNAs are also versatile. CircRNAs have been reported previously to function as microRNA(miRNA) sponges, protein sponges, coding RNAs or scaffolds for protein ***, several circRNAs have been reported to play important roles in human malignancies, including glioma. Here, we reviewed several reports related to circRNAs and glioma, as well as the potential diagnostic and therapeutic applications of circRNAs in brain cancer. In general, some circRNAs, such as circSMARCA5 and circCFH, are found to be expressed in a gliomaspecific pattern, these circRNAs may be used as tumor biomarkers. In addition, some circRNAs have been found to play oncogenic roles in glioma(e.g., circNFIX and circNT5E), whereas others have been reported to function as tumor suppressors(e.g.,circFBXW7 and circSHPRH). Furthermore, circRNA is a good tool for protein expression because of its higher stability compared to linear RNAs. Thus, circRNAs may also be an ideal choice for gene/protein delivery in future brain cancer therapies. There are some challenges in circRNA research in glioma and other diseases. Research related to circRNAs in glioma is comparatively new and many mysteries remain to be solved.

关键词： Circular RNA glioma miRNA sponge translation protein scaffold miRNA target

Kinetic Study of SiO_2/S Coating Deposition by APCVD

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Journal of Materials Science & Technology 2007年第4期23卷 535-540页

作者： Jianxin ZHOU Hong XU Li ZHANG jinglei liu Xuegui QI Bo PENG State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

To alleviate catalytic coking on the inner surface of radiant tube for ethylene production in petrochemical plants,SiO2/S coatings were deposited on HP40 alloy specimens using dimethyldisulfide （DMDS） and tetraethoxysilane （TEOS） by atmospheric pressure chemical vapor deposition （APCVD）. A two-dimension mathematical model was made to predict the growth rate of SiO2/S coating and to study the effects of deposition parameters on the deposition rate. The results show that the predicted deposition rate is in good agreement with the experimental one. The deposition rate mainly depends on the concentrations of precursors in the total gas flow, concentrations of intermediates on the deposition surface, total gas flow rate and deposition temperature. The weight of SiO2/S coating linearly increases with the deposition time. When the gas flow rate is below 0.3 m/s, the rate-limiting step of SiO2/S coating deposition is the diffusions of ***, the surface reactions of intermediates will be the rate-limiting step after the gas flow rate is above 0.3 m/s. When the deposition temperature is below 780℃, the rate-limiting step of SiO2/S coating deposition mainly depends on the surface reactions of intermediates. When the deposition temperature is above 780℃,the rate-limiting step depends on the diffusions of intermediates. The deposition rate increases with increasing the concentrations of the intermediates. However, when the partial pressures of the intermediates reach 8 Pa,the deposition rate keeps constant.

关键词： APCVD SiO2/S coating Mathematical model HP40 steel Kinetics

Deformation Processed Cu-15 wt pct Cr Composite Synthesized by Hot Hydrostatic Extrusion of Mechanical Milled Powders

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Journal of Materials Science & Technology 2003年第5期19卷 507-508页

作者： jinglei liu, Zuyan liu and Erde WANGSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

A novel technique was developed for the preparation of Cu-15 wt pct Cr composite with high strength and conductivity. The composite powders with refined microstructure and curly lamellae strengthening phase was first prepared by mechanical milling in favorite milling time and then were hot hydrostatic extruded after pre-densification with sintering or hot pressing. It was shown that the extrusion densified the composite powders well and at the same time the chaos curled strengthening phase was aligned into lines and further deformed as strengthening ribbons. The deformation processed Cu-15 wt pct Cr composite prepared by this technique is of superior conductivity, strength and thermal stability.

关键词： Mechanical milling Hydrostatic extrusion Deformation processed composite Copper-base composite

Targeting circular RNAs as a therapeutic approach: current strategies and challenges

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Signal Transduction and Targeted Therapy 2021年第6期6卷 1718-1731页

作者： Alina T.He jinglei liu Feiya Li Burton B.Yang Sunnybrook Research Institute TorontoONCanada Department of Bioinformatics ATCGene IncGuangzhouChina Department of Laboratory Medicine and Pathobiology University of TorontoTorontoONCanada

Significant progress has been made in circular RNA(circRNA)research in recent *** evidence suggests that circRNAs play important roles in many cellular processes,and their dysregulation is implicated in the pathogenesis of various *** are highly stable and usually expressed in a tissue-or cell type-specific ***,they are currently being explored as potential therapeutic ***-of-function and loss-of-function approaches are typically performed using circRNA expression plasmids and RNA interference-based strategies,*** strategies have limitations that can be mitigated using nanoparticle and exosome delivery ***,recent developments show that the cre-lox system can be used to knockdown circRNAs in a cell-specific *** still in the early stages of development,the CRISPR/Cas13 system has shown promise in knocking down circRNAs with high specificity and *** this review,we describe circRNA properties and functions and highlight their significance in *** summarize strategies that can be used to overexpress or knockdown circRNAs as a therapeutic ***,we discuss major challenges and propose future directions for the development of circRNA-based therapeutics.

关键词： therapeutic specificity circular

Tubes with coated and sintered porous surface for highly efficient heat exchangers

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Frontiers of Chemical Science and Engineering 2018年第3期12卷 367-375页

作者： Hong Xu Yulin Dai Honghai Cao jinglei liu Li Zhang Mingjie Xu Jun Cao Peng Xu Jianshu liu State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China Wuxi Chemical Equipment Co. Ltd Wuxi 214131 China Department of Material Science and Engineering University of California in Irvin CA 92697 USA

Surface modification is a direct and effective way to enhance the efficiency of heat exchangers. Surface modification by forming a microporous coated layer can greatly enhance the boiling heat transfer and thus achieve a high performance. In this paper, we systematically investigate the boiling behavior on a plain surface with/ without sintered microporous coatings of copper powder. The results demonstrated that the sintered surface has a better performance in nucleate boiling due to the increased nucleation sites. The superheat degree is lower and the bubble departure diameter is larger for the sintered surface than for the plain surface, so the heat can be carried away more efficiently on the sintered surface. In addition, the heat transfer capacity on the sintered surface depends on both the powder size and the coating thickness for a high flux tube. The optimum heat transfer capacity can be obtained when the thickness of the microporous coating layer is 3-5 times of the sintered powder diameter. As a result, the heat transfer coefficient tube can be up to 3 times higher for the tube with a sintered surface than that with a plain surface, showing a pronounced enhancement in heat transfer and a high potential in chemical engineering industry application.

关键词： microporous coating layer surface modification boiling enhancement sintering

Current approaches to reduce or eliminate mitochondrial DNA mutations

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Science China(Life Sciences) 2016年第5期59卷 532-535页

作者： Liang Yang Tingfang Mei Xiaobing Lin Haite Tang Yi Wu Rui Wang jinglei liu Zahir Shah Xingguo liu Key Laboratory of Regenerative Biology Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine South China Institute for Stem Cell Biology and Regenerative Medicine Guangzhou Institutes of Biomedicine and Health Chinese Academy of Sciences

Mitochondrial DNA （mtDNA） mutations have been impli- cated in a broad range of disorders which severely affect human health （Wallace, 1999）. Some drugs have been developed to slow down pathological changes of mitochon- drial disorders. However, there is no effective treatment for patients with mtDNA mutations, mtDNA is less protected and has fewer repair mechanisms than nuclear DNA （nDNA）. Such a reality results in a much higher mutation rate in mtDNA than that in nDNA. The mixture of mutated mtDNA versus wild-type mtDNA is known as hetero- plasmy. Mitochondrial threshold effect refers to the fact that mtDNA mutation must accumulate to high proportions （60%-90%） before respiratory activity is affected （Schon et al., 2012）. It is feasible to selectively reduce the levels of mu- tated mtDNA while sparing wild-type mtDNA to skew this ratio back to a healthier range. Here, we describe the link between mtDNA mutation and mitochondrial diseases, and we summarize several newly developed approaches with regard to the reduction or elimination of mtDNA mutation in mammals. These methods include nuclear gene modula- tion, molecular approaches targeting mutated mtDNA, mtDNA replacement, and induced pluripotent stem cell （iPSC） modeling. These various methods have their own advantages and limitations.

关键词：线粒体DNA突变基因突变 mtDNA突变线粒体疾病人类健康核DNA 多能干细胞病理变化