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Using a support vector machine method to predict the development indices of very high water cut oilfields 被引量:11
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作者 Zhong Yihua Zhao Lei +2 位作者 Liu Zhibin Xu Yao Li Rong 《Petroleum Science》 SCIE CAS CSCD 2010年第3期379-384,共6页
Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems ... Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems of the small number of samples collected for oilfield development indices, a new support vector regression prediction method for development indices is proposed in this paper. This method uses the principle of functional simulation to determine the input-output of a support vector machine prediction system based on historical oilfield development data. It chooses the kernel function of the support vector machine by analyzing time series characteristics of the development index; trains and tests the support vector machine network with historical data to construct the support vector regression prediction model of oilfield development indices; and predicts the development index. The case study shows that the proposed method is feasible, and predicted development indices agree well with the development performance of very high water cut oilfields. 展开更多
关键词 Oilfield development indices oilfield performance support vector regression high watercut time series
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Development and Reservation of Geographical Indication Products in China 被引量:2
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作者 Zhang Wen 《China Standardization》 2006年第2期31-35,共5页
With more than 5000-year civilization, China has gradually formed in its different regions hundreds of the geographic indication products, such as Longjing Tea, Maotai Liquor, Shaoxing Rice Wine, Jinghua Ham, Beijing ... With more than 5000-year civilization, China has gradually formed in its different regions hundreds of the geographic indication products, such as Longjing Tea, Maotai Liquor, Shaoxing Rice Wine, Jinghua Ham, Beijing Roast Duck, Xinjiang Honey Jelon, etc. They are the precious creatures of Chinese nation. 展开更多
关键词 In development and Reservation of Geographical Indication Products in China
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Is urban development an urban river killer? A case study of Yongding Diversion Channel in Beijing, China 被引量:8
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作者 Xi Wang Junqi Li +4 位作者 Yingxia Li Zhenyao Shen Xuan Wang Zhifeng Yang Inchio Lou 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第6期1232-1237,共6页
The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of... The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of the Yongding Diversion Channel in Beijing, China, and its relationship with rainfall and urban development. Monthly water quality data were obtained from April to October of 2004 at monitoring sites of Sanjiadian, Gaojing, Luodaozhuang, and Yuyuangtan. The monthly water quality grades from 2007 to 2011 were also investigated and compared with those of other rivers. Dissolved oxygen and pH showed greater decreases after one or two moderate rainfall events than several light rainfall events. The potassium permanganate index (CODMn), ammonia nitrogen (NH3-N) and total phosphorus (TP) increased more after several light rainfall events than after one or two moderate or heavy rainfall events. Pollutant concentrations (CODMn, NH3-N, TP) in downstream regions showed greater changes than those in upstream areas after heavy rainfall events. Intense human activities around the channel greatly influenced the water quality of the channel in rainy season because of runoff pollution; however, heavy rainfall had a strong dilution effect on the pollutant concentrations in rivers. Overall, urban development has obviously deteriorated the water quality of the Yongding Diversion Channel as indicated by an increase in the water quality index from 3.22 in 2008 to 4.55 in 2010. The Pearson correlation between monthly rainfall and water quality indices from 2007 to 2011 ranged from 0.1286 to 0.6968, generally becoming weaker as rainfall and rainfall runoff became more random and extreme. 展开更多
关键词 rainfallurban development water quality indices Yongding Diversion Channel
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A New Indicator for Modern Forestry Development: Forest Thickness
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作者 FAN Baomin LI Zhiyong CHEN Jie Research Institute of Forestry Policy and Information, Chinces Academy of Forestry, Beijing 100091, P. R. China 《Chinese Forestry Science and Technology》 2008年第4期53-60,共8页
Modern forestry focusing on ecological dimension needs some new indicators different from those designed for the traditional forestry. On the basis of the evaluation indicators for traditional forestry, such as forest... Modern forestry focusing on ecological dimension needs some new indicators different from those designed for the traditional forestry. On the basis of the evaluation indicators for traditional forestry, such as forest coverage, total standing stock volume and forest volume per unit area, the paper came up with a new indicator called "forest thickness" (FT). FT refers to the thickness which can be got if using total stock volume of forest and trees to cover the total land in a given area, and it is charged by mm. This indicator can be used to solve the long-term problem that the forest coverage can not reflect in a comprehensive way the level of forest ecological development, and provide the easy and clear approach to measuring and comparing the levels of forest ecological development in different periods at different regions. When the indicator value is over 9 mm, the ecosystem is indicated as excellent; when in 6-9 mm, the ecosystem is indicated as good; when in 3-6 mm, the ecosystem is indicated as moderately good; when below 3 mm, the ecosystem is indicated as bad. The indicator values of FT are calculated for the world, 17 countries, and different historic periods and different regions of China, based on which the forestry ecological status in these areas are compared and evaluated. 展开更多
关键词 modern forestry forest thickness forest coverage development indicator
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A global assessment of recent trends in gastrointestinal cancer and lifestyle-associated risk factors 被引量:14
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作者 Lili Lu Christina S.Mullins +2 位作者 Clemens Schafmayer Sebastian Zeißig Michael Linnebacher 《Cancer Communications》 SCIE 2021年第11期1137-1151,共15页
Background:Gastrointestinal(GI)cancers were responsible for 26.3%of cancer cases and 35.4%of deaths worldwide in 2018.This study aimed to analyze the global incidence,mortality,prevalence,and contributing risk factors... Background:Gastrointestinal(GI)cancers were responsible for 26.3%of cancer cases and 35.4%of deaths worldwide in 2018.This study aimed to analyze the global incidence,mortality,prevalence,and contributing risk factors of the 6 major GI cancer entities[esophageal cancer(EC),gastric cancer(GC),liver cancer(LC),pancreatic cancer(PC),colon cancer,and rectal cancer].Methods:Using the Global Cancer Observatory and the Global Health Observatory databases,we reviewed the current GI cancer incidence,prevalence,and mortality,analyzed the association of GI cancer prevalence with national human development indices(HDIs),identified the contributing risk factors,and estimated developing age-and sex-specific trends in incidence and mortality.Results:In 2020,the trend in age-standardized rate of incidence of GI cancers closely mirrored that of mortality,with the highest rates of LC,EC,and GC in Asia and of colorectal cancer(CRC)and PC mainly in Europe.Incidence and mortality were positively,but the mortality-to-incidence ratio(MIR)was inversely correlated with the national HDI levels.High MIRs in developing countries likely reflected the lack of preventive strategies and effective treatments.GI cancer prevalence was highest in Europe and was also positively correlated with HDIs and lifestyle-associated risk factors,such as alcohol consumption,smoking,obesity,insufficient physical activity,and high blood cholesterol level,but negatively correlated with hypertension and diabetes.Incidences of EC were consistently and those of GC mostly decreasing,whereas incidences of CRC were increasing in most countries/regions,especially in the younger populations.Incidences of LC and PC were also increasing in all age-gender populations except for younger males.Mortalities were decreasing for EC,GC,and CRC in most countries/regions, and age-specific trends were observed in PC and LC with adecrease in the younger but an increase in the older population.Conclusions: On the global scale, higher GI cancer burden was accompanied,for the most part, by factors associated with the so-called Western lifestylereflected by high and very high national HDI levels. In countries/regionswith very high HDI levels, patients survived longer, and increasing GI cancercases were observed with increasing national HDI levels. Optimizing GI cancer prevention and improving therapies, especially for patients with comorbidmetabolic diseases, are thus urgently recommended. 展开更多
关键词 annual percentage change(APC) diabetes gastrointestinal(GI)cancer high blood cholesterol human development indices(HDI) hypertension incidence LIFESTYLE mortality prevalence
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