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Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of Chinese Geriatrics Society,beijing Hypertension Association,National Clinical Research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina Chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

Characterization on Laser Melting Deposition of Metallic Components

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稀有金属材料与工程 2011年第S3期40卷 27-32页

作者： Zhang Yongzhong1, Shi Likai1, Li Guowei2, Xi Mingzhe3 1 General Research Institute for Non-ferrous Metals, beijing 100088, china 2 Nantong entry-exit inspection and quarantine Bureau, Nantong 226005, china 3 Yanshan University, Qinhuangdao 066004, china Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China Nantong entry exit Inspect & quarantine Bur Nantong 226005 Peoples R China Yanshan Univ Qinhuangdao 066004 Peoples R China

Laser melting deposition process (LMD) is an advanced computer-aided laser additive manufacturing process (LAM). This process can produce net-shape components with fully dense microstructure and good properties based on a computer aided design (CAD) model by using a high power laser to melt the injected powders and re-solidify them in a layered way. It presents obvious superiority in direct manufacturing components with small-lot, repairing high-value components with good performance, and integrated fabricating new materials and composite structure. Deep understanding the melting process, alloying and reaction within the molten pool, solidification behavior, as well as formation and control of residual stress and defects during deposition are crucial to successful application.

关键词： laser melting deposition solidified microstructure residual stress defects interface flexible manufacturing

Characterization of In-situ Titanium Matrix Composites Prepared by Laser Melting Deposition

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稀有金属材料与工程 2011年第S3期40卷 33-37页

作者： Zhang Yongzhong1, Sun Jingchao1, Huang Can1, Li Guowei2 1 General Research Institute for Non-ferrous Metals, beijing 100088, china 2 Nantong entry-exit inspection and quarantine Bureau, Nantong 226005, china Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China Nantong entry exit Inspect & quarantine Bur Nantong 226005 Peoples R China

Preliminary characterization of microstructure and mechanical properties of (TiB+TiC)/TC4 and TiC/Ti60 in-situ titanium matrix composites prepared by laser melting deposition is reported in this paper. The results indicate that in-situ reaction occurred during laser melting deposition of coaxially fed mixed powders from TC4 and B4C with formation of form TiB and TiC reinforcement. For TiC/Ti60 composites, there are some un-melted TiC particles and re-solidified TiC particles appeared as discontinuous chain-like morphology. Reinforcements of TiB and TiC with fraction about 25 vol% were formed with feeding 5 wt% B4C. The morphology of TiB tended to be needle-like and prismatic, while TiC appeared as granular. Small amount of un-reacted B4C with reduced size remained within the composites. A thin skull of reaction product formed around the un-reacted B4C weakened its interface bonding with the titanium alloy matrix, thus resulting in less outstanding properties of the composites. Under 600 ℃, the ultimate tensile strength of the TiCP (5wt%)/Ti60 composites was 60 MPa higher than that of Ti60 alloy, following with decreased elongation.

关键词： titanium matrix composites in-situ reaction laser melting deposition microstructure properties

Construction and evaluation of a novel end-column amperometric detection system for electrophoresis microchips

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Science china Chemistry 2010年第1期53卷 250-256页

作者： CHEN ZhiFeng1,GAO YunHua2,WANG Li3,CHU XiaoGang1 1Chinese Academy of inspection and quarantine,beijing 100123,china 2Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,beijing 100190,china 3beijing Institute of Labour Protection,beijing 100054,china Chinese Academy of inspection and quarantine Beijing China Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing China beijing Institute of Labour Protection Beijing China

A set of integrated end-column amperometric detection system has been developed,onto which an electrophoresis microchip can be conveniently *** machined by a piece of transparent organic glass,the system consists of an electrophoresis microchip platform and an amperometric detection reservoir,in which the microchip can be fixed onto the platform by microchip grooves and with stainless steel *** detection electrode can be directly fixed in the amperometric detection reservoir by screws and *** dopamine as the model analyte,we take platinum disc electrodes with different diameters of 100 μm,300 μm and 500 μm and a carbon fiber electrode with the diameter of 240 μm as the working electrode,all of which accomplish sensitive *** detection parameters of the system are optimized with the carbon fiber *** detection results show that in the electrochemical cleaning procedure,the relative deviations of 3.2% and 0.5% for the peak current and retention time,respectively,can be obtained for the successive detections of 100 μM dopamine,and the limit of detection for dopamine can reach 0.4 μM(S/N = 3).This system is small,but its performance of detection is stable and sensitive,and the replacement of its working electrodes is convenient,so it is very suitable as a universal platform of end-column amperometric detection for electrophoresis microchips.

关键词： electrophoresis microchip amperometric detection dopamine evaluation

Detection of the urban heat island in beijing using HJ-1B satellite imagery

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Science china Earth Sciences 2010年第S1期53卷 67-73页

作者： YANG Jun1,GONG Peng2,ZHOU JinXing3,HUANG HuaBing2 & WANG Lei2 1 Key Laboratory of Silviculture and Conservation,Ministry of Education,beijing Forestry University,beijing 100083,china 2 State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute of Remote Sensing Applications,Chinese Academy of Sciences and beijing Normal University,beijing 100101,china 3 Institute of Desertification Studies,Chinese Academy of Forestry,beijing 100091 china Key Laboratory of Silviculture and Conservation Ministry of Education Beijing Forestry University Beijing China State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing China Institute of Desertification Studies Chinese Academy of Forestry Beijing China

Satellite images are used extensively in studying the urban heat island(UHI) *** evaluated the suitability of thermal infrared(TIR) data from the HJ-1B satellite for detecting UHI using a case study in *** modified algorithms for retrieving the land surface temperature(LST) from HJ-1B data were *** results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST *** spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS *** the two algorithms,the mono-window algorithm performed better but further tests are *** more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in china and neighboring countries.

关键词： surface temperature NDVI mono-window algorithm single-channel algorithm

Three industries and wastewater and COD discharge of beijing

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Journal of Environmental Sciences 2000年第4期12卷 474-477页

作者： WANG Yan 1, WANG Hong rui 2, NING Da tong 2 (1. beijing Municipal Research Institute of Environmental Protection, beijing 100037, china 2. Institute of Environmental Sciences, beijing Normal University, beijing 100875, china) 北京市环境保护所北京 1 0 0 0 3 北京师范大学北京 1 0 0 875

With the swift development of economy, the water quality of beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.

关键词： direct wastewater discharge coefficient (DWDC) complete wastewater discharge coefficient (CWDC) direct discharge coefficient of COD(DDC of COD) complete discharge coefficient of COD (CDC of COD)

Local and non-local sources of airborne particulate pollution at beijing——The ratio of Mg/Al as an element tracer for estimating the contributions of mineral aerosols from outside beijing

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Science china Chemistry 2005年第3期48卷 253-264页

作者： HAN Lihui1, ZHUANG Guoshun1,2,3, SUN Yele1 & WANG Zifa3 1. The Center for Atmospheric Environmental Study, Department of Chemistry, beijing Normal University, beijing 100875, china 2. Center for Atmospheric Chemistry Study, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, china 3. LAPC/NZC, Institute of Atmospheric Physics, CAS, beijing 100029, china The Center for Atmospheric Environmental Study Department of Chemistry Beijing Normal University Beijing China Center for Atmospheric Chemistry Study Department of Environmental Science & Engineering Fudan University Shanghai China Institute of Atmospheric Physics CAS LAPC/NZC Beijing China

A new element tracer technique has firstly been established to estimate the contri-butions of mineral aerosols from both inside and outside beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in beijing, of which mineral aerosol accounted for 32%―67% of total suspended particles （TSP）, 10%―70% of fine particles （PM2.5）, and as high as 74% and 90% of TSP and PM2.5, respectively, in dust storm. The sources from outside beijing contributed 62% （38%―86%） of the total mineral aerosols in TSP, 69% （52%―90%） in PM10, and 76% （59%―93%） in PM2.5 in spring, and 69% （52%―83%）, 79% （52%―93%）, and 45% （7%―79%） in TSP, PM10, and PM2.5, respectively, in winter, while only20% in summer and autumn. The sources from outside beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in beijing. The contributions from outside Bei-jing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.

关键词： mineral aerosol local sources non-local sources dust storm re-suspended dust element tracer technique.

Landscape patterns and their evolutions in　the suburban ecotone──A case study of the eastern suburb of beijing

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Journal of Environmental Sciences 1994年第3期6卷 277-286页

作者： Yang Jurong,Zhang Hongmei,Huang Yi Institute of Environmental Science,beijing Normal University,beijing 100875,china

The characteristics and evolutions of the landscape patterns in the suburban ecotone are studied on the basis of landscape-ecological maps of different years derived from the corresponding aerial photos The relationship between landscape patterns and urban economical development is ana- lyzed. The diversity index is used to characterize the features of the landscape patterns in the ecotone and define the location of Sharp change.

关键词： suburban ecotone landscape patterns diversity index.