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Reversing design methodology of investment casting die profile based on ProCAST

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China Foundry 2010年第2期7卷 132-137页

作者： Dou Yangqing bu kun Dou Yangliu Dong Yiwei The Key Laboratory of Contemporary Design and Integrated Manufacturing Technology Northwestern Polytechnical University Xi＇an710072 China

Turbine blade is one of the critical components of aircraft *** performance of the engine depends on the shape and dimensions of components,but superalloy blade material cannot be easily *** investment casting is an ideal process for such net-shape components,it requires an accurate determination of the casting-die *** this paper,a reversing design methodology for investment casting die using ProCAST is *** combining the methods of simplifying grid files and quick sorting,the efficiency of sorting and matching can be largely ***,the mould/die cavity anti-deformation system can be easily *** ProCAST,the optimized die profile for investment casting can be established.

关键词： investment casting reversing design methodology node matching numerical simulation ProCAST

Intelligent design of investment casting mold based on a hybrid reasoning method

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China Foundry 2009年第1期6卷 20-23页

作者： Jiang Ruisong Zhang Dinghua Wang Wenhu bu kun The Key Laboratory of Contemporary Design and Integrated Manufacturing Ministry of Education China Northwestern Polytechnical University Xi＇an 710072 China

A hybrid reasoning model was proposed in which CBR(case-based reasoning)was applied to the conceptual design and RBR(rule-based reasoning)was applied to the detailed design after research of the design process and domain knowledge of the aero-engine turbine blade investment casting mold design *** the conceptual design stage,the representation and retrieval technologies were researched which improve the retrieval ***,RBR was used to modify the retrieval *** experimentation shows that the approach in this study can be used to obtain a more satisfactory design result.

关键词： turbine blade investment casting mold intelligent design CBR RBR

Spatio-temporal Pattern and Spatial Heterogeneity of Ecotones Based on Land Use Types of Southeastern Da Hinggan Mountains in China

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Chinese Geographical Science 2015年第2期25卷 184-197页

作者： YU Lingxue ZHANG Shuwen LIU Tingxiang TANG Junmei bu kun YANG Jiuchun Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences bureau of Land and Resources of Linyi City Department of Geography and Environment Systems University of Maryland Baltimore County

Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial heterogeneity of the ecotones among agricultural land, forest land, and grassland of the southeastern Da Hinggan Mountains in the northeastern China. The change of these delineated ecotones under different slopes and aridity conditions was analyzed by two landscape indices, edge density(ED) and core area percentage of landscape(CPL), to explore the inter-linkage between spatial structure of ecotones and socioeconomic development and land management. Specifically, the ecotones such as agriculture-forest(AF) ecotone, forest-grassland(FG) ecotone, and agriculture-forestgrassland(AFG) ecotone moved from the arid southeast to the humid northwest. The flat area with small slope is more edge-fragmented than the steep area since the ED decreases as the slope increases. The AF ecotone mostly found in the humid region is moving to more humid areas while the agriculture-grassland(AG) ecotone mostly found in the dry region is moving towards the drier region.

关键词： ecotones core area percentage of landscape(CPL) edge density(ED) modified moving split window land use pattern spatial heterogeneity

A MODIS Time Series Data Based Algorithm for Mapping Forest Fire burned Area

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Chinese Geographical Science 2013年第3期23卷 344-352页

作者： YANG Wei ZHANG Shuwen TANG Junmei bu kun YANG Jiuchun CHANG Liping Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Geography and Environmental Systems University of Maryland Baltimore County

burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and cli- mate change and the effect of forest fire on carbon budgets. This study proposed an algorithm to map forest fire burned area using the Moderate-Resolution Imaging Spectroradiameter （MODIS） time series data in Heilongjiang Province, China. The algorithm is divided into two steps： Firstly, the ＇core＇ pixels were extracted to represent the most possible burned pixels based on the comparison of the tem- poral change of Global Environmental Monitoring Index （GEMI）, burned Area Index （BAI） and MODIS active fire products between pre- and post-fires. Secondly, a 15-km distance was set to extract the entire burned areas near the ＇core＇ pixels as more relaxed conditions were used to identify the fire pixels for reducing the omission error as much as possible. The algorithm comprehensively considered the thermal characteristics and the spectral change between pre- and post-fires, which are represented by the MODIS fire products and the spectral index, respectively. Tahe, Mohe and Huma counties of Heilongjiang Province, China were chosen as the study area for burned area mapping and a time series of burned maps were produced from 2000 to 2011. The results show that the algorithm can extract burned areas more accurately with the hiehest accuracy of 96.61%.

关键词： burned area mapping Moderate Resolution Imaging Spectroradiameter (MODIS) Global Environmental Monitoring Index(GEMI) burned Area Index (BAI)

High Resolution Land Cover Datasets Integration and Application Based on Landsat and GlobCover Data from 1975 to 2010 in Siberia

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Chinese Geographical Science 2016年第4期26卷 429-438页

作者： LIU Tingxiang ZHANG Shuwen XU Xinliang bu kun NING Jia CHANG Liping Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Land cover is recognized as one of the fundamental terrestrial datasets required in land system change and other ecosystem related researches across the globe. The regional differentiation and spatial-temporal variation of land cover has significant impact on regional natural environment and socio-economic sustainable development. Under this context, we reconstructed the history land cover data in Siberia to provide a comparable datasets to the land cover datasets in China and abroad. In this paper, the European Space Agency(ESA) Global Land Cover Map(GlobCover), Landsat Thematic Mapper(TM), Enhanced Thematic Mapper(ETM), Multispectral Scanner(MSS) images, Google Earth images and other additional data were used to produce the land cover datasets in 1975 and 2010 in Siberia. Data evaluation show that the total user′s accuracy of land cover data in 2010 was 86.96%, which was higher than ESA GlobCover data in Siberia. The analysis on the land cover changes found that there were no big land cover changes in Siberia from 1975 to 2010 with only a few conversions between different natural forest types. The mainly changes are the conversion from deciduous needleleaf forest to deciduous broadleaf forest, deciduous needleleaf forest to mixed forest, savannas to deciduous needleleaf forest etc., indicating that the dominant driving factor of land cover changes in Siberia was natural element rather than human activities at some extent, which was very different from China. However, our purpose was not just to produce the land cover datasets at two time period or explore the driving factors of land cover changes in Siberia, we also paid attention on the significance and application of the datasets in various fields such as global climate change, geopolitics, cross-border cooperation and so on.

关键词： land cover change Landsat data integration data application Siberia

Classification framework and semantic labeling for Big Earth Data

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Big Earth Data 2023年第3期7卷 886-903页

作者： Juanle Wang kun bu Dongmei Yan Jingyue Wang Bowen Duan Min Zhang Guojin He State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciencesand Natural Resources ResearchChinese Academy of SciencesBeijingChina Collaborative InnovationCenter for Development and Utilization of Geographic Information Resources in Jiangsu Province NanjingChina Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchunChina International Research Center of Big Data for Sustainable Development Goals BeijingChina Schoolof Civil and Architectural Engineering Shandong University of TechnologyZiboChina College of Resourceand Environment University of Chinese Academy of SciencesBeijingChina

Big Earth Data refers to the multidimensional integration and association of scientific data,including geography,resources,environment,ecology,and *** effective data classification system and label management strategy are important foundations for long-term management of data *** objective of this study was to construct a classification system and realize multidimensional semantic data label management for the Big Earth Data Science Engineering Program(CASEarth).This study constructed two sets of classification and coding systems that realize classification by mapping each other;namely,the geosphere-level and Sustainable Development Goals(SDGs)indicator *** technique was based on natural language processing technology and solved problems with subject-word segmentation,weight calculation,and dynamic matching.A prototype system for classification and label management was constructed based on existing CASEarth datasets of more than 1,***,we expect our study to provide the methodology and technical support for useroriented classification and label management services for Big Earth Data.

关键词： Big Earth Data CASEarth scientific engineering data classification data labeling data management

Dynamics of Saline-alkali Land and Its Ecological Regionalization in Western Songnen Plain, China

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Chinese Geographical Science 2010年第2期20卷 159-166页

作者： YANG Jiuchun ZHANG Shuwen LI Ying bu kun ZHANG Yubo CHANG Liping ZHANG Yangzhen Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Software College Jilin University Changchun 130012 China

As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one of main distribution regions of saline-alkali land in China,with great potential in agricultural development. In this study,the extent,transformation,spatial distribution and temporal change of saline-alkali land in the western Songnen Plain during 1954–2005 were investigated by using remote sensing and GIS spatial analysis methods. Saline-alkali land change was detected from a temporal series of topographic maps in 1954,satellite images of Landsat MSS in 1976,Landsat TM/ETM in 1988,2000 and 2005 through artificial visual interpretation. The results indicated a significant expansion in saline-alkali land area and aggravation in salinization. The area of saline-alkali land had increased from 401.48×103 ha in 1954 to 1 097.45×103 ha in 2005. While the ratio of light,moderate and serious salinized land areas changed from 6.72︰2.92︰1.00 to 1.25︰1.06︰1.00 in the study period. Grassland,cropland,swampland and water body were the major land use and land cover types from which saline-alkali land transformed. And the secondary salinization occured mainly in Da′an City,Tongyu County,Changling County,Daqing City,Dorbod Mongolian Autonomous County and Zhaoyuan County. Finally,seven large ecoregions and 14 corresponding sub-ecoregions were delineated out based on spatio-temopral dynamic characteristics of saline-alkali land and geo-relational environmental attributes. According to the results,measures of amelioration and ways of development of saline-alkali land in the western Songnen Plain were put forward.

关键词： saline-alkali land salinization ecological regionalization food security Songnen Plain

The role of statins in erectile dysfunction： a systematic review and meta-analysis

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Asian Journal of Andrology 2014年第3期16卷 461-466页

作者： Xiang Cai Ye Tian Tao Wu Chen-Xi Cao Si-Yuan bu kun-Jie Wang Department of Urology West China Hospital Sichuan University Chengdu China

To evaluate the effect of statins for erectile dysfunction （ED）, a systematic review of the literature was conducted in the Cochrane Library, Embase and PubMed from the inception of each database to June 2013. Only randomized controlled trials （RCTs） comparing treatment for ED with statins were identified. Placebo RCTs with the International Index of Erectile Function （IIEF） as the outcome measure were eligible for meta-analysis. A total of seven RCTs including two statins with a total of 586 patients strictly met our criteria for systematic review and five of them qualified for the meta-analysis. A meta-analysis using a random effects model showed that statins were associated with a significant increase in IIEF-5 scores （mean difference （MD）： 3.27; 95% confidential interval （CI）：1.51 to 5.02; P〈 0.01） and an overall improvement of lipid profiles including total cholesterol （MD： -1.08; 95% Ch -1.68 to -0.48; P 〈 0.01）, low-density lipoprotein （LDL） cholesterol （MD： -1.43; 95% Ch -2.07 to -0.79; P 〈 0.01）, high-density lipoprotein （HDL） cholesterol （MD： 0.24; 95% Ch 0.13 to 0.35; P〈 0.01） and triglycerides （TGs）（MD. -0.55; 95% Ch -0.61 to -0.48; P 〈 0.01）. In summary, our study revealed positive consequences of these lipid-lowering drugs on erectile function, especially for nonresponders to phosphodiesterase type 5 inhibitors （PDE51s）. However, it has been reported that statin therapy may reduce levels of testosterone and aggravate symptoms of ED. Therefore, larger, well-designed RCTs are needed to investigate the double-edged role of statins in the treatment of ED.

关键词： dyslipidemia endothelial dysfunction erectile dysfunction statins

Remote Sensing Monitoring of Gullies on a Regional Scale: A Case Study of Kebai Region in Heilongjiang Province, China

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Chinese Geographical Science 2015年第5期25卷 602-611页

作者： ZHANG Shuwen LI Fei LI Tianqi YANG Jiuchun bu kun CHANG Liping WANG Wenjuan YAN Yechao Northeast Institute of Geography and Agroecology Chinese Academy of Sciences College of Earth Science Jilin University Henan University

Gully erosion is one of the major causes of land degradation in most areas and attracts increasing attention from researchers. We monitored gullies in the Kebai region in Heilongjiang Province of China by using remote sensing data and found that gully density increased with the increase in slope when the slope was less than 3°. Gully density in sunny slopes or windward slopes was greater than in shady slopes or leeward slopes because of the impacts of freezing and thawing, wind and solar radiation. Specifically, the gully density in northeast slope was the greatest and in southwest was the smallest. Gully density was reduced with increasing slope length and the longer the slope length, the less the gully density changed between 1965 and 2005. Affected by runoff, gullies most easily to occur in concave slopes and the critical elevation for gully erosion was 250–275 m. Moreover, hilly regions had the greatest gully density, followed by tableland regions, whereas the gully density in flatlands was the lowest. However, the gully density of these three types of landforms all increased between 1945 and 2000, and the portion of increase was 57.45%(hill), 52.91%(mesa) and 25.32%(plain), respectively.

关键词： gully density gully erosion monitoring remote sensing Kebai region, China