The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better...The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models.展开更多
In the context of the continuous deepening of the“Double Reduction”policy and the growing demand for quality education,leveled mathematics readers,as an emerging form of publishing that integrates subject education ...In the context of the continuous deepening of the“Double Reduction”policy and the growing demand for quality education,leveled mathematics readers,as an emerging form of publishing that integrates subject education and reading experience,face challenges such as unclear leveling logic,insufficient functional support,and weak user engagement.This paper introduces the 4V marketing theory and constructs an analytical framework from four dimensions:differentiation,functionality,added value,and resonance.Two representative products,“Climbing Mathematics”and“Spark Mathematics,”are selected for a typical case comparison to identify their strengths and weaknesses in content design,service systems,and brand operation,and to extract transferable strategic elements.The study finds that the user-value-oriented strategy based on the 4V model can effectively address the core issues in the market promotion and user relationship building of leveled mathematics readers,providing practical paths and theoretical support for educational publishing institutions to achieve product innovation and brand upgrading in this niche field.展开更多
To better understand the community structure characteristics of zooplankton in the artificial reef area of Tianjin in the Bohai Bay and its relationship with major environmental factors,the project conducted three cru...To better understand the community structure characteristics of zooplankton in the artificial reef area of Tianjin in the Bohai Bay and its relationship with major environmental factors,the project conducted three cruise surveys in the spring(May),summer(July)and autumn(October)of 2016 and monitored conventional environmental factors.The results showed that there were 36 species of zooplankton,including 14 species of copepods,phytoplankton larvae 12 species;6 kinds of coelenterates;3 species of shrimp and 1 species of hairy shrimp in the artificial reef area of Tianjin in the three cruise surveys.The dominant species in spring,summer,and autumn have obvious changes,among which the dominant species in spring are Eurytemora pacifica,Clytia hemisphoerica,Clalnus sinicus,and Macruran larva;in summer are Oithona similis and Brachyura zoea larva;and autumn only the Clalnus sinicus.Correlation analysis shows that the diversity and uniformity of zooplankton in the artificial reef area have increased to varying degrees,indicating that the overall construction of artificial reefs in the Tianjin sea area has improved the marine ecological protection to some extent.The results of CCA showed that salinity and water temperature were the main environmental factors affecting the distribution of zooplankton communities in artificial reefs in Tianjin.展开更多
Predicting the deliverability change laws of a gas well in the early stage is one of the technical difficulties in natural gas development.The commonly used steady seepage analysis methods have relatively large errors...Predicting the deliverability change laws of a gas well in the early stage is one of the technical difficulties in natural gas development.The commonly used steady seepage analysis methods have relatively large errors.And this problem cannot be solved effectively by the classical methods of production decline analysis and pressure transient well test analysis.To solve this problem,this paper did calculation based on the well test model of constant-pressure production,changed the previous approximate method of simplifying the calculation of the exponential integral function,and accurately calculated the analytical solution of absolute openflow potential of a gas well.In addition,the deliverability instability characteristics of different types of gas wells were quantitatively described by taking vertical wells in homogeneous reservoirs as the reference benchmark.Then,combined with the deliverability evaluation needs of a new well,a new practical method focusing on solving the problems of gas formation testing analysis was researched and developed,and also applied on site at some key wells in the hot spots of natural gas development in the Sichuan Basin.And the following research results were obtained.First,the accurate formula for the analytical solution of well test model significantly enhances the adaptability to short-term test conditions.Second,the newly established chart briefly reveals the quantitative relationship between the unstable deliverability characteristics of a gas well and the main influencing factors.Third,if the char-acteristic parameter of turbulence effect is unknown,it is necessary to perform iterative calculation of the variable skin factor when the well test model of constant-pressure production is used to analyze the change trend of the absolute openflow potential of a gas well.Fourth,by con-ducting comparative analysis on the calculation results of typical cases,the decline laws of the absolute openflow potential of different types of gas wells can be understood further.It is concluded that this new method is capable of improving the prediction accuracy of the unstable deliverability of gas wells.Therefore,it can be widely applied to the deliverability evaluation of gas wells in the exploration stage,the evaluation stage of early development and the commissioning stage of new development and production wells,which is conducive to the formulation of natural gas exploration and development decision.展开更多
文摘The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models.
文摘In the context of the continuous deepening of the“Double Reduction”policy and the growing demand for quality education,leveled mathematics readers,as an emerging form of publishing that integrates subject education and reading experience,face challenges such as unclear leveling logic,insufficient functional support,and weak user engagement.This paper introduces the 4V marketing theory and constructs an analytical framework from four dimensions:differentiation,functionality,added value,and resonance.Two representative products,“Climbing Mathematics”and“Spark Mathematics,”are selected for a typical case comparison to identify their strengths and weaknesses in content design,service systems,and brand operation,and to extract transferable strategic elements.The study finds that the user-value-oriented strategy based on the 4V model can effectively address the core issues in the market promotion and user relationship building of leveled mathematics readers,providing practical paths and theoretical support for educational publishing institutions to achieve product innovation and brand upgrading in this niche field.
文摘To better understand the community structure characteristics of zooplankton in the artificial reef area of Tianjin in the Bohai Bay and its relationship with major environmental factors,the project conducted three cruise surveys in the spring(May),summer(July)and autumn(October)of 2016 and monitored conventional environmental factors.The results showed that there were 36 species of zooplankton,including 14 species of copepods,phytoplankton larvae 12 species;6 kinds of coelenterates;3 species of shrimp and 1 species of hairy shrimp in the artificial reef area of Tianjin in the three cruise surveys.The dominant species in spring,summer,and autumn have obvious changes,among which the dominant species in spring are Eurytemora pacifica,Clytia hemisphoerica,Clalnus sinicus,and Macruran larva;in summer are Oithona similis and Brachyura zoea larva;and autumn only the Clalnus sinicus.Correlation analysis shows that the diversity and uniformity of zooplankton in the artificial reef area have increased to varying degrees,indicating that the overall construction of artificial reefs in the Tianjin sea area has improved the marine ecological protection to some extent.The results of CCA showed that salinity and water temperature were the main environmental factors affecting the distribution of zooplankton communities in artificial reefs in Tianjin.
基金Project supported by the National Major Science and Technology Project“Demonstrative Project of Large Carbonate Gas Field Development in Sichuan Basin”(No.2016ZX05052).
文摘Predicting the deliverability change laws of a gas well in the early stage is one of the technical difficulties in natural gas development.The commonly used steady seepage analysis methods have relatively large errors.And this problem cannot be solved effectively by the classical methods of production decline analysis and pressure transient well test analysis.To solve this problem,this paper did calculation based on the well test model of constant-pressure production,changed the previous approximate method of simplifying the calculation of the exponential integral function,and accurately calculated the analytical solution of absolute openflow potential of a gas well.In addition,the deliverability instability characteristics of different types of gas wells were quantitatively described by taking vertical wells in homogeneous reservoirs as the reference benchmark.Then,combined with the deliverability evaluation needs of a new well,a new practical method focusing on solving the problems of gas formation testing analysis was researched and developed,and also applied on site at some key wells in the hot spots of natural gas development in the Sichuan Basin.And the following research results were obtained.First,the accurate formula for the analytical solution of well test model significantly enhances the adaptability to short-term test conditions.Second,the newly established chart briefly reveals the quantitative relationship between the unstable deliverability characteristics of a gas well and the main influencing factors.Third,if the char-acteristic parameter of turbulence effect is unknown,it is necessary to perform iterative calculation of the variable skin factor when the well test model of constant-pressure production is used to analyze the change trend of the absolute openflow potential of a gas well.Fourth,by con-ducting comparative analysis on the calculation results of typical cases,the decline laws of the absolute openflow potential of different types of gas wells can be understood further.It is concluded that this new method is capable of improving the prediction accuracy of the unstable deliverability of gas wells.Therefore,it can be widely applied to the deliverability evaluation of gas wells in the exploration stage,the evaluation stage of early development and the commissioning stage of new development and production wells,which is conducive to the formulation of natural gas exploration and development decision.
