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Study on the Ring Eulargment Reaction:Synthesis of 7,8,13,13a-tetrahydroisoindolo[1,2-b][3]benzazepine and 5,6,8,9,14,14a-hexahydroisoquino[1,2-b][3]benzazepine

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Chinese Chemical Letters 2001年第1期12卷 7-10页

作者： yu xin LIU Xiao tian LIANG Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical College 1 Xian NongTan StreetBeijing 100050

A new approach to the synthesis of 7,8,13,13a-tetrahydroisoindolo[1,2-b] [3]benzazepine 5 and 5,6,8,9,14,14a-hexahydroisoquino[1,2-b][3]benzazepine 9 and related compounds is described as using ring expansion of N-he... 详细信息

关键词： Isoindolo[1,2-b]benzazepines Isoquino[1,2-b]benzazepines Ring enlargement Synthesis

2016年深圳市某街道噪声作业工人职业禁忌证检出结果

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职业与健康 2018年第7期34卷 986-988页

作者：邱星元边寰锋邱奕冰余新天深圳市宝安区沙井预防保健所职业卫生科广东深圳518104

目的了解深圳市某街道噪声作业工人职业禁忌证检出情况,为职业病防治工作提供依据。方法采用判断抽样方法,以深圳市某街道18 881名噪声作业工人及862例噪声职业禁忌证工人为研究对象,收集工人职业健康检查结果并进行统计分析。结果 201... 详细信息

目的了解深圳市某街道噪声作业工人职业禁忌证检出情况,为职业病防治工作提供依据。方法采用判断抽样方法,以深圳市某街道18 881名噪声作业工人及862例噪声职业禁忌证工人为研究对象,收集工人职业健康检查结果并进行统计分析。结果 2016年深圳市某街道噪声作业工人的职业禁忌证检出率为4.5%,上岗前噪声作业工人的职业禁忌证检出率(7.4%)高于在岗期间(2.5%)(P<0.01);男性工人的检出率(5.3%)高于女性(2.6%)(P<0.01);上岗前和在岗期间噪声作业工人的职业禁忌证检出率均随着年龄的增加而逐渐升高(均P<0.01);噪声联合其他危害因素组的检出率(4.9%)高于单纯噪声组(4.3%)(P<0.05)。结论深圳市某街道噪声作业工人的禁忌证发生情况不容乐观,开展噪声作业工人的职业健康检查有利于早期发现职业禁忌证,保护工人的身体健康;应重视男性、年龄较大以及接触噪声联合其他危害因素工人的职业健康检查,预防职业性噪声聋的发生。

关键词：噪声职业健康检查职业禁忌证性别年龄

DNA methylation and demethylation link the properties of mesenchymal stem cells: Regeneration and immunomodulation

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World Journal of Stem Cells 2020年第5期12卷 351-358页

作者： tian-Yi xin Ting-Ting yu Rui-Li Yang Department of Orthodontics Peking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijing 100081China

Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial *** have attracted increasingly more attention over the years due to their regenerative capacity and function in *** foundation of tissue regeneration is the potential of cells to differentiate into multiple cell lineages and give rise to multiple tissue *** addition,the immunoregulatory function of MSCs has provided insights into therapeutic treatments for immune-mediated *** methylation and demethylation are important epigenetic mechanisms that have been shown to modulate embryonic stem cell maintenance,proliferation,differentiation and apoptosis by activating or suppressing a number of *** most studies,DNA hypermethylation is associated with gene suppression,while hypomethylation or demethylation is associated with gene *** dynamic balance of DNA methylation and demethylation is required for normal mammalian development and inhibits the onset of abnormal ***,the exact role of DNA methylation and demethylation in MSC-based tissue regeneration and immunomodulation requires further *** this review,we discuss how DNA methylation and demethylation function in multi-lineage cell differentiation and immunomodulation of MSCs based on previously published ***,we discuss the implications of the role of DNA methylation and demethylation in MSCs for the treatment of metabolic or immune-related diseases.

关键词： Mesenchymal stem cells DNA methylation and demethylation Multi-lineage differentiation Regeneration Immunomodulation Immune disease

Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions

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Acta Mechanica Sinica 2016年第1期32卷 75-82页

作者： Lu tian Li-Hong Chen Qiang Chen Feng-Quan Zhong xin-yu Chang State Key Laboratory of High-Temperature Gas DynamicsInstitute of Mechanics Chinese Academy of SciencesBeijing 100190China

A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a cru- cial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distrib- utions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions （isolator entrance Mach number： 1.5-3.5）. Results show that different opti- mal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets.

关键词： Dual-mode scramjet Engine performance Thrust Optimization Heat release distribution Simulatedannealing algorithm

A Survey of Visual Analytic Pipelines

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Journal of Computer Science & Technology 2016年第4期31卷 787-804页

作者： Xu-Meng Wang tian-Ye Zhang yu-xin Ma Jing Xia Wei Chen State Key Laboratory of Computer Aided Design and Computer Graphics Zhejiang University Hangzhou 310058 China Innovation Joint Research Center for Cyber-Physical-Society System Zhejiang University Hangzhou 310058 China

Visual analytics has been widely studied in the past decade. One key to make visual analytics practical for both research and industrial applications is the appropriate definition and implementation of the visual analytics pipeline which provides effective abstractions for designing and implementing visual analytics systems. In this paper we review the previous work on visual analytics pipelines and individual modules from multiple perspectives： data, visualization, model and knowledge. In each module we discuss various representations and descriptions of pipelines inside the module, and compare the commonalities and the differences among them.

关键词： visual analytics pipeline visualization model knowledge

Evolution model for scientific collaboration network with local-world information

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 15-20,31页

作者： tian Sheng-wen LIAO Jian-xin WANG Jing-yu QI Qi State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications School of Information and Electrical Engineering Ludong University

In order to reveal the intrinsic properties of scientific collaboration networks, a new local-world evolution model on a scientific collaboration network is proposed by analysing the network growth mechanism. The act degree as the measurement of preferential attachment is taken, and the local-world information of nodes is taken into account. Analysis and simulation show that the node degree and the node strength obey the power-law distribution. Low average path length and high clustering coefficient are approved. Experiment indicates that the model can depict efficiently the topological structure and statistical characteristics of real-life scientific collaboration networks.

关键词： scientific collaboration network evolution model local-world information scale-flee act degree

Objectness Region Enhancement Networks for Scene Parsing

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Journal of Computer Science & Technology 2017年第4期32卷 683-700页

作者： xin-yu Ou Ping Li He-Fei Ling Si Liu tian-Jiang Wang School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China Institute of Information Engineering Chinese Academy of Sciences Beijing 100091 China Cadres Online Learning Institute of yunnan Province Yunnan Open University Kunming 650223 China

Semantic segmentation has recently witnessed rapid progress, but existing methods only focus on identifying objects or instances. In this work, we aim to address the task of semantic understanding of scenes with deep learning. Different from many existing methods, our method focuses on putting forward some techniques to improve the existing algorithms, rather than to propose a whole new framework. Objectness enhancement is the first effective technique. It exploits the detection module to produce object region proposals with category probability, and these regions are used to weight the parsing feature map directly. 'Extra background' category, as a specific category, is often attached to the category space for improving parsing result in semantic and instance segmentation tasks. In scene parsing tasks, extra background category is still beneficial to improve the model in training. However, some pixels may be assigned into this nonexistent category in inference. Black-hole filling technique is proposed to avoid the incorrect classification. For verifying these two techniques, we integrate them into a parsing framework for generating parsing result. We call this unified framework as Objectness Enhancement Network (OENet). Compared with previous work, our proposed OENet system effectively improves the performance over the original model on SceneParse150 scene parsing dataset, reaching 38.4 mIoU (mean intersection-over-union) and 77.9% accuracy in the validation set without assembling multiple models. Its effectiveness is also verified on the Cityscapes dataset.

关键词： objectness region enhancement black-hole filling scene parsing instance enhancement objectness region proposal

适变与应变:“十五五”时期人口发展规划的新格局、新挑战及其实践路径

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河北学刊 2025年第1期45卷 130-139页

作者：陆杰华冯雨欣北京大学中国社会与发展研究中心北京大学社会学系

“十五五”时期是中国基本实现社会主义现代化承上启下的关键时期,同时也是人口发展深度转型的重要节点。“十五五”人口发展规划的制定必须准确识别人口规模、结构、素质、分布等要素呈现的趋势性变化,及时把握当前人口发展的潜在机遇... 详细信息

“十五五”时期是中国基本实现社会主义现代化承上启下的关键时期,同时也是人口发展深度转型的重要节点。“十五五”人口发展规划的制定必须准确识别人口规模、结构、素质、分布等要素呈现的趋势性变化,及时把握当前人口发展的潜在机遇和堵点难点,根据人口发展新格局适时调整应变思路,不断推进人口自身均衡发展,以及人口与经济社会、资源环境的协调发展。从长远来看,人口发展规划的制定还需要纵向锚定人口高质量发展的战略目标,形成应对未来人口发展新变化的超前预案。

关键词： “十五五” 人口发展规划人口高质量发展适变与应变

Adsorption desulfurization of model gasoline by metal–organic framework Ni3（BTC）2

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Journal of Energy Chemistry 2019年第5期28卷 8-14页

作者： Fuping tian Qiaofeng Ru Chenxia Qiao xin Sun Cuiying Jia yu Wang Yifu Zhang School of Chemistry & State Key Laboratory of Fine Chemicals Dalian University of Technology

This work presented the synthesis of Ni-based metal-organic framework material with a paddle-wheel structure Ni3(BTC)2 (Ni-BTC) and its application in thiophene (TP) adsorption from gasoline distillate by batch method. Adsorption isotherms of TP, cyclohexene, and toluene in cyclohexane onto Ni-BTC were conducted at 298-308 K to interpret the different effect of cyclohexene and toluene on TP adsorption. The results showed that, compared w让h cyclohexene, toluene addition in model gasoline led to a more evident decline in sulfur capacity of Ni-BTC, which is opposite to isostructural HKUST-1. The adsorption isotherms of TP, cyclohexene and toluene fit Langmuir model, S-type model and Temkin model well, respectively, indicating that the adsorption mechanisms of TP and the two competitors are different from one another The adsorption capacities on Ni-BTC followed the order of cyclohexene < toluene < TP at the same equilibrium concentrations, implying the order of the adsorption affinities, which is in good agreement with the different extent of influence by the two competitors. The enthalpy of TP adsorption on Ni-BTC was estimated to be -80.01 kj/mol, almost twice that on HKUST-1. The poor reusability of Ni-BTC in batch experiment, which is owing to its sensitivity to the air, can be prevented from regenerating used Ni-BTC in fixed-bed reactor by N2 flow. The difference between Ni-BTC and HKUST-1 in maximum adsorption capacity (q0),△H of TP adsorption, and stability demonstrates that the central metal in isostructural MOFs plays a key role in adjusting the desulfurization performance, which may open up a potential avenue for the development of MOF-based adsorbents with superior desulfurization performance.

关键词： Adsorption Desulfurization Ni3(BTC)2 Thiophene Toluene Cyclohexene