The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle m...The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle model. With the new model, the statistical correspondence between the production decline stage and the reserve-production imbalance is clarified,and the correlation of water cut with the recovery percent of recoverable reserves is discussed, providing quantitative basis of reservoir engineering for dividing development stages of oilfield and defining mature oilfields. According to the statistics of oilfields in eastern China, the time point corresponding to the reserve-production balance coefficient dropping to less than 1dramatically is well correlated the beginning point of production decline, thus the time when the reserve-production balance coefficient drops dramatically can be taken as the initiation point of production decline stage. The research results show that the water cut and the recovery percent of recoverable reserves have a good statistical match in the high water cut stage, and it is more rational to take both the start point of production decline stage and the water cut of 90%(or the recovery percent of recoverable reserves of 80%) as the critical criteria for defining a mature oilfield. Five production evolution patterns can be summarized as follows: growth–peak plateau–stepped decline, growth–stepped stabilizing–stepped decline, growth–stepped stabilizing–rapid decline, growth–peak plateau–rapid decline, and growth–continuous decline.展开更多
On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awa...On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awards of the National Textile Industry were held in Beijing.展开更多
Based on the statistics of 130 thesauri having been published in China so far,this article analyzes the development of thesauri in China from the origin,publication year,academic disciplines and quantity of entries co...Based on the statistics of 130 thesauri having been published in China so far,this article analyzes the development of thesauri in China from the origin,publication year,academic disciplines and quantity of entries collected,and re-defines the development stages.In addition,by collecting the 1,000 relevant research papers,the article also analyzes the theoretical studies from the aspects of the quantity of papers and research subjects in order to give a clear picture of the development and features of the researches on thesaurus in China.展开更多
Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The s...Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The succession patterns of methanotrophic communities and functions in Wudalianchi volcano forest soils could provide a basis for the study of evolutionary mechanisms between soil microorganisms,the environment,and carbon cycling of temperate forest ecosystems under climate change.In this study,the characteristics and drivers of methanotrophic community structure and function of two volcanic soils at different stages of development are analyzed,including an old volcano and a new volcano,which most recently erupted 300 years and 17-19×10^(5)years ago,respectively,and a non-volcano hills as control,based on space for time substitution and Miseq sequencing and bioinformation technology.The results showed that CH_(4) fluxes were significantly higher in old-stage volcano forest soils than new-stage forest soils and non-volcano forest soils.There were significant differences in the community composition and diversity of soil methanotrophs from different volcano forest soils.Methylococcus was the dominant genus in all soil samples.Additionally,the relative abundance of Methylococcus,along with Clonothrix,Methyloglobulus,Methylomagum,Methylomonas and Methylosarcina,were the important genera responsible for the differences in methanotrophic community structure in different volcano forest soils.The relative abundance of methanotroph belonging toγ-proteobacteria was significantly higher than that belonging toα-proteobacteria(P<0.05).Chao1,Shannon and Simpson indices of soil methanotrophic community were significantly lower in new-stage volcanos and were significantly affected by bulk density,total porosity,p H,nitrate,dissolved organic carbon and dissolved organic nitrogen.There were significant differences in community structure between new-stage and old-stage volcanoes.Bulk density and p H are important soil properties contributing to the divergence of methanotrophs community structure,and changes in soil properties due to soil development time are important factors driving differences in methanotrophs communities in Wudalianchi volcanic soils.展开更多
基金Supported by the National Natural Science Foundation of China (72088101)。
文摘The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle model. With the new model, the statistical correspondence between the production decline stage and the reserve-production imbalance is clarified,and the correlation of water cut with the recovery percent of recoverable reserves is discussed, providing quantitative basis of reservoir engineering for dividing development stages of oilfield and defining mature oilfields. According to the statistics of oilfields in eastern China, the time point corresponding to the reserve-production balance coefficient dropping to less than 1dramatically is well correlated the beginning point of production decline, thus the time when the reserve-production balance coefficient drops dramatically can be taken as the initiation point of production decline stage. The research results show that the water cut and the recovery percent of recoverable reserves have a good statistical match in the high water cut stage, and it is more rational to take both the start point of production decline stage and the water cut of 90%(or the recovery percent of recoverable reserves of 80%) as the critical criteria for defining a mature oilfield. Five production evolution patterns can be summarized as follows: growth–peak plateau–stepped decline, growth–stepped stabilizing–stepped decline, growth–stepped stabilizing–rapid decline, growth–peak plateau–rapid decline, and growth–continuous decline.
文摘On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awards of the National Textile Industry were held in Beijing.
基金supported by the National Nature Science Foundation of China(Grant No.70573103)
文摘Based on the statistics of 130 thesauri having been published in China so far,this article analyzes the development of thesauri in China from the origin,publication year,academic disciplines and quantity of entries collected,and re-defines the development stages.In addition,by collecting the 1,000 relevant research papers,the article also analyzes the theoretical studies from the aspects of the quantity of papers and research subjects in order to give a clear picture of the development and features of the researches on thesaurus in China.
基金the Special Projects for the Central Government to guide the development of local science and technology(ZY20B15)the Key Research&Development Program funding project of Heilongjiang Province(GA21C030)the Research Funds of Provincial Research Institutes of Heilongjiang Province(ZNBZ2022ZR07)。
文摘Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The succession patterns of methanotrophic communities and functions in Wudalianchi volcano forest soils could provide a basis for the study of evolutionary mechanisms between soil microorganisms,the environment,and carbon cycling of temperate forest ecosystems under climate change.In this study,the characteristics and drivers of methanotrophic community structure and function of two volcanic soils at different stages of development are analyzed,including an old volcano and a new volcano,which most recently erupted 300 years and 17-19×10^(5)years ago,respectively,and a non-volcano hills as control,based on space for time substitution and Miseq sequencing and bioinformation technology.The results showed that CH_(4) fluxes were significantly higher in old-stage volcano forest soils than new-stage forest soils and non-volcano forest soils.There were significant differences in the community composition and diversity of soil methanotrophs from different volcano forest soils.Methylococcus was the dominant genus in all soil samples.Additionally,the relative abundance of Methylococcus,along with Clonothrix,Methyloglobulus,Methylomagum,Methylomonas and Methylosarcina,were the important genera responsible for the differences in methanotrophic community structure in different volcano forest soils.The relative abundance of methanotroph belonging toγ-proteobacteria was significantly higher than that belonging toα-proteobacteria(P<0.05).Chao1,Shannon and Simpson indices of soil methanotrophic community were significantly lower in new-stage volcanos and were significantly affected by bulk density,total porosity,p H,nitrate,dissolved organic carbon and dissolved organic nitrogen.There were significant differences in community structure between new-stage and old-stage volcanoes.Bulk density and p H are important soil properties contributing to the divergence of methanotrophs community structure,and changes in soil properties due to soil development time are important factors driving differences in methanotrophs communities in Wudalianchi volcanic soils.
文摘目的探讨不同病因矮小症患儿血清生长激素释放肽(Ghrelin)、胰岛素样生长因子-1(insulinlike growth factor-1,IGF-1)水平变化及其临床意义。方法选取2016年1月至2022年1月南通大学附属医院如皋分院收治的212例矮小症患儿,根据不同病因分为生长激素缺乏症组(n=60)、特发性矮小症组(n=46)、Turner综合征组(n=38)、先天性甲状腺功能减退症组(n=32)和宫内发育迟缓组(n=36),另选取同期于本院行体检证实身高同性别、同年龄标准范围内的106例健康儿童作为对照组。比较不同病因矮小症患儿与对照组的人口学特征和骨龄年龄差(bone age difference,BAD)、身高标准差分值(heightstandard deviation score,Ht SDS)、年生长速率(growth velocity,GV)和生长激素(growth hormone,GH)峰值等生长发育指标及青春前期和青春期的血清Ghrelin、IGF-1水平。采用受试者操作特征(receiveroperating characteristic,ROC)曲线分析血清Ghrelin、IGF-1水平对特发性矮小症的鉴别诊断价值。统计学方法采用单因素方差分析、LSD-t检验及χ^(2)检验。结果特发性矮小症组青春期患儿比例为65.2%,明显高于其他4组(P值均<0.05),其中青春期患儿比例从高至低依次为宫内发育迟缓组(41.7%)、先天性甲状腺功能减退症组(40.6%)、生长激素缺乏症组(35.0%)和Turner综合征组(31.6%);特发性矮小症组BAD为(1.4±0.3)岁,明显高于其他4组(P值均<0.05),其中BAD值从高至低依次为生长激素缺乏症组[(1.2±0.2)岁]、先天性甲状腺功能减退症组[(1.1±0.2)岁]、Turner综合征组[(0.7±0.1)岁]和宫内发育迟缓组[(0.3±0.1)岁]。特发性矮小症组GV值为[(3.7±0.8)cm/年],明显高于其他4组(P值均<0.05),其中GV值从高至低依次为生长激素缺乏症组[(2.2±0.7)cm/年]、宫内发育迟缓组[(2.1±0.6)cm/年]、先天性甲状腺功能减退症组[(1.7±0.5)cm/年]和Turner综合征组[(1.2±0.4)cm/年]。生长激素缺乏症组GH峰值为[(6.4±0.3)μg/L],明显低于其他4组(P值均<0.05),其中GH峰值从低至高依次为宫内发育迟缓组[(13.4±3.2)μg/L]、Turner综合征组[(14.2±2.1)μg/L]、特发性矮小症组[(14.7±2.5)μg/L]和先天性甲状腺功能减退症组[(15.6±2.9)μg/L]。Turner综合征组Ghrelin水平显著高于生长激素缺乏症组、特发性矮小症组、先天性甲状腺功能减退症组和宫内发育迟缓组(P值均<0.05);先天性甲状腺功能减退症组IGF-1水平显著低于生长激素缺乏症组、特发性矮小症组、Turner综合征组和宫内发育迟缓组(P值均<0.05)。特发性矮小症组青春前期的血清Ghrelin、IGF-1水平均明显低于青春期(P值均<0.05)。ROC曲线分析结果显示,血清Ghrelin、IGF-1鉴别诊断特发性矮小症的曲线下面积(area under the curve,AUC)分别为0.776、0.733,联合检测鉴别诊断特发性矮小症的AUC为0.839,灵敏度为90.0%,特异性为65.6%(P<0.001)。结论不同病因矮小症患儿血清Ghrelin、IGF-1水平均存在异常表达,特发性矮小症患儿在青春前期和青春期的血清Ghrelin、IGF-1水平差异明显,血清Ghrelin、IGF-1联合检测对特发性矮小症的鉴别诊断具有较好的诊断效能。
