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Journal of Environmental Sciences 2008年第8期20卷 998-1005页

作者： li, Chunping li, Guoxue LUO, Yiming li, yanfu HUANG, Jian College of Resource and Environment Science China Agriculture University Beijing 100094 China Beijing Solid Waste Administration Department Beijing 100067 China Institute of Desert Meteorology China Meteorological Administration Urumqi 830002 China

Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management *** provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW *** wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results of...

关键词： municipal solid waste(MSW) transfer stations(TSs) pollutant monitoring environmental quality fuzzy mathematics

A study on limit velocity and its mechanism and implications for alluvial rivers

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International Journal of Sediment Research 2016年第3期31卷 205-211页

作者： Yanhong Jia Zhaoyin Wang Xiangmin Zheng yanfu li East China Normal University State Key Laboratory of Hydroscience and Engineering of Tsinghua University Nanjing Hydraulic Research Institute

Observations from field investigations showed that flow velocity greater than 3 m/s rarely occurs in nature,and high flow velocity stresses the bio-community and causes instability to the *** alluvial rivers without strong human disturbance,the flow velocity varies within a limited range,generally below 3 m/s,while the discharge and wet area may vary in a range of several *** phenomenon was studied by analyzing hydrological data,including daily average discharge,stage,cross sections,and sediment concentration,collected from 25 stations on 20 rivers in China,including the Yangtze,Yellow,Songhua,Yalu,Daling,and liaohe *** cross-sectional average velocity was calculated from the discharge and wet area using the continuity *** alluvial rivers,the wet cross section may self-adjust in accordance with the varying flow discharge so that the flow velocity does not exceed a limit *** general,the average velocity increases with the discharge increase at low *** the discharge exceeds the discharge capacity of the banks,any further increase in discharge does not result in a great increase in *** average velocity approaches an upper limit as the discharge *** limit velocity,in most cases,is less than 3 m/*** activities,especially levee construction,disturb the limit velocity law for alluvial *** these cases,the average velocity may be approximately equal to or higher than the limit *** limit velocity law has profound morphological and ecological implications on alluvial rivers and requires further *** should be trained and managed by mimicking natural processes and meeting the limit velocity law,so as to maintain ecologically-sound and morphological stability.

关键词： limit velocity Alluvial river Self-adjustment Wet area Human activity

Impacts of artificially planted vegetation on the ecological restoration of movable sand dunes in the Mugetan Desert,northeastern Qinghai-Tibet Plateau

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International Journal of Sediment Research 2017年第2期32卷 277-287页

作者： yanfu li Zhiwei li Zhaoyin Wang Wenlong Wang Yanhong Jia Shimin Tian Nanjing Hydraulic Research Institute State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering School of Hydraulic Engineering Changsha University of Science &TechnologyKey Laboratory of Water Sediment Sciences and Water Disaster Prevention of Hunan Province State Key Laboratory of Hydroscience and Engineering Tsinghua University Institute of Soil and Water Conservation Chinese Academy of SciencesNorthwest Sci-Tech University of Agriculture and Forestry East China Normal University Key Laboratory of Yellow River Sediment MWRInstitute of Hydraulic ResearchYRCC

Controlling desertification is an important ecological target for the Qinghai-Tibet Plateau of China,where studies on impacts of vegetation restoration measures on sandy soil improvement are still *** Mugetan Desert in Guinan County,Qinghai Province,northeastern Qinghai-Tibet Plateau is a representative ecological restoration *** impacts of artificial vegetation on the ecological restoration and its properties are studied by using field investigation and sample testing including contents of the surface layer and the vegetation composition of movable,semi-fixed,and fixed sand *** demonstrate that the moss crust has formed on the surface of a sand dune which has become fixed after 30 years under the impact of artificial vegetation(*** poplar).Meanwhile,the clay minerals,organic matter,and other soil available nutrients have markedly increased.A correlation has been found between these materials,i.e.,clay minerals and organic matter content increasing with silt and clay increases with reduction in sand *** addition,soil nutrient were positively correlated with the increase of plant *** the current meteorological conditions,the artificial vegetation is helpful for the stabilization of sand dune and the ecological restoration in the Mugetan Desert.

关键词： Desertification Sand dune Artificial vegetation Ecological restoration Biological crusting layer Soil available nutrients

Low-Complexity Detection and Decoding Scheme for LDPC-Coded MLC NAND Flash Memory

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China Communications 2018年第6期15卷 58-67页

作者： Xusheng lin Guojun Han Shijie Ouyang yanfu li Yi Fang School of Information Engineering Guangdong University of Technology National Mobile Communications Research Laboratory Southeast University

With the development of manufacture technology, the multi-level cell(MLC)technique dramatically increases the storage density of NAND flash memory. As the result,cell-to-cell interference(CCI) becomes more serious and hence causes an increase in the raw bit error rate of data stored in the ***, low-density parity-check(LDPC)codes have appeared to be a promising solution to combat the interference of MLC NAND flash memory. However, the decoding complexity of the sum-product algorithm(SPA) is extremely high. In this paper, to improve the accuracy of the log likelihood ratio(LLR) information of each bit in each NAND flash memory cell, we adopt a non-uniform detection(N-UD) which uses the average maximum mutual information to determine the value of the soft-decision reference ***, with an aim to reduce the decoding complexity and improve the decoding performance, we propose a modified soft reliabilitybased iterative majority-logic decoding(MSRBI-MLGD) algorithm, which uses a non-uniform quantizer based on power function to decode LDPC codes. Simulation results show that our design can offer a desirable trade-off between the performance and complexity for high-column-weight LDPC-coded MLC NAND flash memory.

关键词： Cell-to-cell interference(CCI) LDPC codes MLC NAND flash memory non-uniform detection(N-UD) modified soft reliability-based iterative majority-logic decoding(MSRBI-MLGD) algorithm

Slope Debris Flows in the Wenchuan Earthquake Area

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Journal of Mountain Science 2010年第3期7卷 226-233页

作者： li yanfu WANG Zhaoyin SHI Wenjing WANG Xuzhao State Key Laboratory of Hydroscienee and Engineering Tsinghua University Beijing 100084 China Beijing Institute of Geology for Mineral Resources Beijing 100012 China

Avalanches and landslides,induced by the Wenchuan Earthquake on May 12,2008,resulted in a lot of disaggregated,solid material on slopes that could be readily mobilized as source material for debris *** triggered numerous slope debris flows with great damage to highways and rivers over the subsequent two *** debris flows(as opposed to channelized debris flows) are defined as phenomena in which high-concentration mixtures of debris and water flow down slopes for short distances to highways and river *** on field investigations and measurements of 19 slope debris flows,their main characteristics and potential mitigation strategies were *** rainfall intensity is the main triggering *** rainfall intensities for simultaneous occurrence of single,several and numerous slope debris flow events were 20 mm/day,30mm/day,and 90 mm/day,*** investigations also revealed that slope debris flows consist of high concentrations of cobbles,boulders and *** are two-phase debris *** liquid phase plays the role of lubrication instead of transporting *** particles collide with each other and consume a lot of *** velocities of slope debris flows are very low,and their transport distances are only several tens of *** debris flows may be controlled by construction of drainage systems and by reforestation.

关键词： Slope debris flow rainfall intensity Wenchuan Earthquake landslide avalanche

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基于深度学习的工业装备PHM研究综述

振动．测试与诊断 2022年第5期42卷 835-847,1029页

作者：李彦夫韩特清华大学工业工程系北京100084

随着物联网和通信技术的快速发展,现代工业装备海量运行数据被实时监测传输,推动装备服役阶段的故障预测与健康管理进入大数据时代。面对具有不确定性强、价值密度低及多源异构特点的装备运行大数据,传统浅层模型算法存在难以自主挖掘... 详细信息

随着物联网和通信技术的快速发展,现代工业装备海量运行数据被实时监测传输,推动装备服役阶段的故障预测与健康管理进入大数据时代。面对具有不确定性强、价值密度低及多源异构特点的装备运行大数据,传统浅层模型算法存在难以自主挖掘数据蕴含特征、对装备健康状态表征能力弱的先天不足。近年来,作为机器学习领域的研究热点,深度学习理论得到了学术界与工业界的广泛关注,相关的工业装备故障预测与健康管理(prognostics and health management,简称PHM)研究与应用层出不穷,为解决大数据背景下的故障预测与健康管理难题提供了新的思路和技术手段。为此,笔者回顾了工业装备故障预测与健康管理技术发展历程;从异常检测、故障诊断以及故障预测3个方面综述了深度学习已取得的研究成果;讨论了深度学习在当下工业装备故障预测与健康管理中的热点话题;分析了该研究方向在工程实际中面临的挑战,并探讨应对这些挑战的有效措施和未来发展趋势。

关键词：工业装备深度学习故障诊断故障预测与健康管理

维普期刊数据库博看期刊

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列车车轮多边形磨损及其噪音研究综述

振动．测试与诊断 2019年第6期39卷 1143-1152,1355页

作者：李彦夫门天立清华大学工业工程系

介绍了近年来国内外关于列车出现的车轮多边形磨损及其产生噪音的研究概况,解释了车轮多边形磨损的相关概念和定义,列出了多边形磨损产生的原因以及多边形磨损与噪音之间的关系。国内外关于车轮多边形磨损的相关研究,主要集中于车轮多... 详细信息

介绍了近年来国内外关于列车出现的车轮多边形磨损及其产生噪音的研究概况,解释了车轮多边形磨损的相关概念和定义,列出了多边形磨损产生的原因以及多边形磨损与噪音之间的关系。国内外关于车轮多边形磨损的相关研究,主要集中于车轮多边形磨损对轮轨动力学的影响、车轮多边形磨损的产生和发展机理以及车轮多边形磨损的检测和评估三方面。笔者从车辆振动产生的噪音、车轮多边形磨损产生的振动和车轮多边形磨损产生的噪音三方面对噪音、振动与车轮多边形磨损之间的关系进行了综述,总结了国内外关于列车维修方面的研究进展,为发生车轮多边形磨损的列车检修提供建议。

关键词：列车多边形磨损噪音相关关系

酶解核桃蛋白制备ACE抑制肽及其功能特性研究

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中国食品学报 2015年第2期15卷 79-85页

作者：姜莉徐怀德李艳伏西北农林科技大学食品科学与工程学院陕西杨凌712100

对木瓜蛋白酶酶解核桃蛋白制备ACE抑制肽条件进行优化,测定不同条件下酶解液的抗ACE功能特性。用葡聚糖凝胶G-25分离活性肽段,测定其ACE抑制率。结果表明：酶解条件是：酶用量6 000 U/g底物、底物质量分数3%、p H 7.5、温度50℃,酶解240... 详细信息

对木瓜蛋白酶酶解核桃蛋白制备ACE抑制肽条件进行优化,测定不同条件下酶解液的抗ACE功能特性。用葡聚糖凝胶G-25分离活性肽段,测定其ACE抑制率。结果表明：酶解条件是：酶用量6 000 U/g底物、底物质量分数3%、p H 7.5、温度50℃,酶解240 min。此时酶解液的ACE抑制率较高,达88.86%。通过葡聚糖凝胶分离并与已知标准品对照,木瓜蛋白酶酶解核桃蛋白产物高ACE抑制率的活性肽段集中在分子质量612~307u范围,其抑制率为93.56%。

关键词：核桃蛋白酶解物多肽 ACE抑制率

Fluvial diversity in relation to valley setting in the source region of the Yangtze and Yellow Rivers

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Journal of Geographical Sciences 2013年第5期23卷 817-832页

作者： YU Guo-an liU Le li Zhiwei li yanfu HUANG Heqing Gary BRIERLEY Brendon BLUE WANG Zhaoyin PAN Baozhu Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China School of Environment University of Auckland Private Bag 92019 Auckland New Zealand Changjiang River Scientific Research Institute Wuhan 430010 China

The spatial distribution of valley setting （laterally-unconfined, partly-confined, or confined） and fluvial morphology in the source region of the Yangtze and Yellow Rivers is contrasted and analyzed. The source region of the Yangtze River is divided into 3 broad sections （I, II and III） based on valley setting and channel gradient, with the upstream and downstream sections being characterized by confined （some reaches partly-confined） valleys while the middle section is characterized with wide and shallow, laterally-unconfined valleys. Gorges are prominent in sections I and III, while braided channel patterns dominate section II. By contrast, the source region of the Yellow River is divided into 5 broad sections （sections I-V） based on valley characteristics and channel gradient. Sections I, II and IV are alluvial reaches with mainly laterally-unconfined （some short reaches partly-confined） valleys. Sections III and V are mainly confined or partly-confined. Greater morphological diversity is evident in the source region of the Yellow River relative to the upper Yangtze River. This includes braided, anabranching, anastomosing, meandering and straight alluvial patterns, with gorges in confined reaches. The macro-relief （elevation, gradient, aspect, valley alignment and confinement） of the region, linked directly to tectonic movement of the Qinghai-Tibet Plateau, tied to climatic, hydrologic and biotic considerations, are primary controls upon the patterns of river diversity in the region.

关键词： valley setting fluvial morphology river patterns spatial distribution source region of the Yangtze and Yellow Rivers

股价动态偏离程度、股价动态回归速度与投资收益研究

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金融理论与实践 2021年第6期 84-93页

作者：李彦甫成都工业学院经济与管理学院四川成都611830

上市公司股价与内在价值之间出现的动态偏离与回归是一个在股票市场中普遍存在的情况。在现有文献中首创了全新方法,专注于对股价动态偏离程度与股价动态回归速度展开研究,并对投资收益进行探讨。得出了一系列结论:股价在牛市、熊市中... 详细信息

上市公司股价与内在价值之间出现的动态偏离与回归是一个在股票市场中普遍存在的情况。在现有文献中首创了全新方法,专注于对股价动态偏离程度与股价动态回归速度展开研究,并对投资收益进行探讨。得出了一系列结论:股价在牛市、熊市中均存在明显的向下偏离状况,周期性行业受市场行情影响明显且更易出现向上偏离,股价偏离程度受过去与未来预期基本面影响明显;在牛市与向上偏离期间股价回归速度更快,在上/下偏离期间基本面状况对股价回归速度具有负/正面影响,偏离程度越大,则股价回归速度越慢,且回归周期越长。

关键词：股票市场股价动态偏离程度股价动态回归速度投资收益