At present,natural gas accounts for a low proportion in China's primary energy consumption structure and is highly dependent on foreign sources.Changqing gas province of the Ordos Basin where PetroChina Changqing ...At present,natural gas accounts for a low proportion in China's primary energy consumption structure and is highly dependent on foreign sources.Changqing gas province of the Ordos Basin where PetroChina Changqing Oilfield Company(referred to as Changqing Oilfield)is located is one of China's four major natural gas production bases.It bears the important responsibility for ensuring people's livelihood and promoting the healthy development of society economy.In recent years,Changqing Oilfield actively implements national instructive spirit on vigorously promoting domestic oil and gas exploration and development strength and formulates the secondary acceleration development strategies.Its annual natural gas production in 2020 reaches 448.5×10^(8) m^(3) and oil and gas equivalent exceeds 6000×10^(4) t,tamping its important position of“Western Daqing”in this industry.In order to further promote the continuous stable production and realize the goal of quality and efficiency improvement in Changqing gas province,this paper analyzes the situations and challenges of natural gas development in this gas province,prepares the development technological countermeasures and forecast the natural gas development prospect.And the following research results are obtained.First,the natural gas exploration and development in Changqing gas province is divided into four stages and the main technologies for the development of low-permeability carbonate gas reservoir,low-permeability sandstone gas reservoir and tight sandstone gas reservoir are formed.Second,the natural gas development in Changqing gas province faces six challenges,such as low reserve production degree,sharp decline of production rates and complex distribution of remaining undeveloped reserves of developed gas fields.And twenty-six development technological countermeasures are put forward correspondingly,such as well pattern thickening,extension and reserve increase,secondary production layer potential tapping and fine gas well management.Third,the development direction and goal of natural gas development in Changqing gas province is to pay equal attention to the stable production of old gas fields and the production increase of new areas and carry out conventional gas and unconventional gas research simultaneously.In conclusion,the annual natural gas production of Changqing gas province will maintain a sound momentum of steady growth and will exceed 500×10^(8) m^(3) at the end of the 14th Five-Year Plan and maintain at a stable level for a long term,which is conducive to the optimization of domestic energy consumption structure and realization of“carbon peak and carbon neutrality”.展开更多
Guizhou is one of the concentration provinces for natural resources in China. Most outstanding of these, in particular, are energy resources, mineral resources, biological resources and tourism resources. They occupy ...Guizhou is one of the concentration provinces for natural resources in China. Most outstanding of these, in particular, are energy resources, mineral resources, biological resources and tourism resources. They occupy a very important position in the country. Guizhou’s natural resources are of multiple categories, high grade, huge re-展开更多
Strengthening the environmental protection, deepening rural reform, increasing agricultural input, and promoting a more stable and higher-speed growth of peasants＇ income, all of these are playing a very important ro...Strengthening the environmental protection, deepening rural reform, increasing agricultural input, and promoting a more stable and higher-speed growth of peasants＇ income, all of these are playing a very important role in the sustainable development of agriculture. The environment problems are not only economic problems, but also important political problems. And they constitute an urgent and arduous task that we meet, and need a long time to be conquered. Under the present new historical circumstances, we should establish a scientific development philosophy, strengthen the environment protection, and build up a harmonious society in which urban and rural areas are progressing coordinately.展开更多
The development of human society is a process of continuous evolution in which humankind learns to understand, make use of, renovate and adapt itself to nature. Invariably,the CAS always attaches great importance to t...The development of human society is a process of continuous evolution in which humankind learns to understand, make use of, renovate and adapt itself to nature. Invariably,the CAS always attaches great importance to the comprehensive study of the protection and upgrade of the ecosystem for human existence and the co-ordination of relations between humankind and nature,and considers it of strategic significance for the overall S&T development of the country.As a result of painstaking efforts by generations of CAS professionals, a comprehensive research contingent has展开更多
1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the co...1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the country are copies of foreign products.展开更多
The distinctions between L1 acquisition and L2 acquisition have always been one of the significant factors in the language acquisition field. we all know the fact that different learners in different situations learn ...The distinctions between L1 acquisition and L2 acquisition have always been one of the significant factors in the language acquisition field. we all know the fact that different learners in different situations learn L2 s in different ways. The paper compares the natural route of development between L1 and L2 and the result demonstrates the relation between L1 and L2, to be exact, the similarities and differences.展开更多
First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik C...First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik Chakrabarti writes in his introduction to Inscriptions of Nature.His ambitious work examines the development of the natural and anthropological sciences on the Indian subcontinent since the early 19th century,and the shaping of knowledge about Indian nature through the exploration of its deep past:an exploration that dug not only into the depths of the earth,but also into ancient history,texts,myths,legends,folklore and the genealogies of local populations.This in-depth study not only combines the history of geology,paleontology,anthropology and ethnography,it also finely analyzes the interactions between the theoretical framework of scientific knowledge imported from Europe and local history,mythologies and indigenous beliefs.展开更多
DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS...DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS DNA polymerases pursue replication by inserting a base opposite this lesion,correctly or incorrectly展开更多
基金Project supported by the National Science and Technology Major Project"Development Demonstration Engineeing of Large Low-Permability Lithologic and Stratigraphic Oil and Gas Reservoirs in the Ordos Basin"(No.2016ZX05050)the PetoChina's Science and Technology Major Project,"Study on Production Stabilization and EOR Technologics of Changqing Gas Field"(No.2016E-0509).
文摘At present,natural gas accounts for a low proportion in China's primary energy consumption structure and is highly dependent on foreign sources.Changqing gas province of the Ordos Basin where PetroChina Changqing Oilfield Company(referred to as Changqing Oilfield)is located is one of China's four major natural gas production bases.It bears the important responsibility for ensuring people's livelihood and promoting the healthy development of society economy.In recent years,Changqing Oilfield actively implements national instructive spirit on vigorously promoting domestic oil and gas exploration and development strength and formulates the secondary acceleration development strategies.Its annual natural gas production in 2020 reaches 448.5×10^(8) m^(3) and oil and gas equivalent exceeds 6000×10^(4) t,tamping its important position of“Western Daqing”in this industry.In order to further promote the continuous stable production and realize the goal of quality and efficiency improvement in Changqing gas province,this paper analyzes the situations and challenges of natural gas development in this gas province,prepares the development technological countermeasures and forecast the natural gas development prospect.And the following research results are obtained.First,the natural gas exploration and development in Changqing gas province is divided into four stages and the main technologies for the development of low-permeability carbonate gas reservoir,low-permeability sandstone gas reservoir and tight sandstone gas reservoir are formed.Second,the natural gas development in Changqing gas province faces six challenges,such as low reserve production degree,sharp decline of production rates and complex distribution of remaining undeveloped reserves of developed gas fields.And twenty-six development technological countermeasures are put forward correspondingly,such as well pattern thickening,extension and reserve increase,secondary production layer potential tapping and fine gas well management.Third,the development direction and goal of natural gas development in Changqing gas province is to pay equal attention to the stable production of old gas fields and the production increase of new areas and carry out conventional gas and unconventional gas research simultaneously.In conclusion,the annual natural gas production of Changqing gas province will maintain a sound momentum of steady growth and will exceed 500×10^(8) m^(3) at the end of the 14th Five-Year Plan and maintain at a stable level for a long term,which is conducive to the optimization of domestic energy consumption structure and realization of“carbon peak and carbon neutrality”.
文摘Guizhou is one of the concentration provinces for natural resources in China. Most outstanding of these, in particular, are energy resources, mineral resources, biological resources and tourism resources. They occupy a very important position in the country. Guizhou’s natural resources are of multiple categories, high grade, huge re-
文摘Strengthening the environmental protection, deepening rural reform, increasing agricultural input, and promoting a more stable and higher-speed growth of peasants＇ income, all of these are playing a very important role in the sustainable development of agriculture. The environment problems are not only economic problems, but also important political problems. And they constitute an urgent and arduous task that we meet, and need a long time to be conquered. Under the present new historical circumstances, we should establish a scientific development philosophy, strengthen the environment protection, and build up a harmonious society in which urban and rural areas are progressing coordinately.
文摘The development of human society is a process of continuous evolution in which humankind learns to understand, make use of, renovate and adapt itself to nature. Invariably,the CAS always attaches great importance to the comprehensive study of the protection and upgrade of the ecosystem for human existence and the co-ordination of relations between humankind and nature,and considers it of strategic significance for the overall S&T development of the country.As a result of painstaking efforts by generations of CAS professionals, a comprehensive research contingent has
文摘1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the country are copies of foreign products.
文摘The distinctions between L1 acquisition and L2 acquisition have always been one of the significant factors in the language acquisition field. we all know the fact that different learners in different situations learn L2 s in different ways. The paper compares the natural route of development between L1 and L2 and the result demonstrates the relation between L1 and L2, to be exact, the similarities and differences.
文摘First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik Chakrabarti writes in his introduction to Inscriptions of Nature.His ambitious work examines the development of the natural and anthropological sciences on the Indian subcontinent since the early 19th century,and the shaping of knowledge about Indian nature through the exploration of its deep past:an exploration that dug not only into the depths of the earth,but also into ancient history,texts,myths,legends,folklore and the genealogies of local populations.This in-depth study not only combines the history of geology,paleontology,anthropology and ethnography,it also finely analyzes the interactions between the theoretical framework of scientific knowledge imported from Europe and local history,mythologies and indigenous beliefs.
文摘DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS DNA polymerases pursue replication by inserting a base opposite this lesion,correctly or incorrectly
