The United States passed the Better Utilization of Investment Leading to Development(BUILD Act),as a counterweight to China’s overseas development activities.Under the Act,the US established a new federal agency,the ...The United States passed the Better Utilization of Investment Leading to Development(BUILD Act),as a counterweight to China’s overseas development activities.Under the Act,the US established a new federal agency,the U.S.International Development Finance Corporation(DFC),to enhance U.S.development financing capabilities.To better understand the impact of the DFC on China’s development finance,this article analyzes the DFC’s purpose,functions,structure,and funding.Then it focuses on the purpose of establishing the DFC,providing a preliminary analysis of the potential motivation for its establishment.It also compares the China Development Bank(CDB)and the DFC based on their focused sectors.Finally,through an in-depth analysis of financial frictions in China-U.S.relations,this article argues that the DFC competes with China’s overseas development financing activities in the context of broader strategic competition between China and the U.S.展开更多
This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid gro...This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.展开更多
Objective:China and the United States(the U.S.)have the heaviest colorectal cancer(CRC)burden with considerable variations in temporal trends.This study aims to analyze the temporal patterns of CRC burden and its risk...Objective:China and the United States(the U.S.)have the heaviest colorectal cancer(CRC)burden with considerable variations in temporal trends.This study aims to analyze the temporal patterns of CRC burden and its risk factors in China and the U.S.across the past three decades.Methods:Data were extracted from the Global Burden of Disease(GBD)Study in 2019,including cases,deaths,disability-adjusted life-years(DALYs),age-standardized rate(ASR),and summary exposure value(SEV)of CRC in China and the U.S.between 1990 and 2019.Annual average percentage changes(AAPCs)of CRC burden were calculated using the Joinpoint regression model.The mortality in CRC attributable to potential risk factors was characterized by countries,gender,and age groups.Results:In 2019,there were 607,900 and 227,241 CRC cases,and 261,777 and 84,026 CRC deaths in China and the U.S.,respectively.The age-standardized incidence rate(ASIR)was 30.55 per 100,000 in China and 41.86 per100,000 in the U.S.,and the age-standardized mortality rate(ASMR)was 13.86 per 100,000 in China and 14.77 per100,000 in the U.S.CRC incidence,mortality,and DALY rate in the U.S.showed downward trends in the past three decades(AAPC=-0.47,-1.06,and-0.88,respectively),while upward trends were observed in China(AAPC=3.11,1.05,and 0.91,respectively).Among the cause of CRC,the leading risk factor contributing to CRC death was low milk in China and smoking in the U.S.,respectively.Conclusions:From 1990 to 2019,the burden of CRC in China increased dramatically,particularly for males and middle-aged and elderly people.The management of the major risk factors associated with the high burden of CRC should be enhanced.展开更多
This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade...This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade dispute and retaliations on the alfalfa markets and trade in both nations. China’s rapid transition toward larger-scale commercial dairy production, with enhanced feed and cost management as well as quality and safety control, and its limited resources for high-quality alfalfa production are key factors for the dramatic increase in its alfalfa imports, from 19 601 metric tons in 2008 to 1.38 million metric tons(mmt) in 2018. While the United States dominated China’s alfalfa imports with an average share of 97.01% from 2007 to 2017, the share dropped to 83.76% in 2018 and 63.28% in January 2019 due to the trade dispute and retaliations started in 2018. China will likely remain a large importer of alfalfa because of both its growing demand and the comparative advantages of imported alfalfa in quality and price, but the imports from the United States will be highly affected by the ongoing trade dispute and negotiations. China is also expected to make more efforts to reduce its dependence on U.S. alfalfa through increased investment in domestic alfalfa production and identification of alternative sources of alfalfa and other hay imports.展开更多
The Weiquan Ag-polymetallic deposit is located on the southern margin of the Central Asian Orogenic Belt and in the western segment of the Aqishan-Yamansu arc belt in East Tianshan,northwestern China. Its orebodies, c...The Weiquan Ag-polymetallic deposit is located on the southern margin of the Central Asian Orogenic Belt and in the western segment of the Aqishan-Yamansu arc belt in East Tianshan,northwestern China. Its orebodies, controlled by faults, occur in the lower Carboniferous volcanosedimentary rocks of the Yamansu Formation as irregular veins and lenses. Four stages of mineralization have been recognized on the basis of mineral assemblages, ore fabrics, and crosscutting relationships among the ore veins. Stage I is the skarn stage(garnet + pyroxene), Stage Ⅱ is the retrograde alteration stage(epidote + chlorite + magnetite ± hematite 士 actinolite ± quartz),Stage Ⅲ is the sulfide stage(Ag and Bi minerals + pyrite + chalcopyrite + galena + sphalerite + quartz ± calcite ± tetrahedrite),and Stage IV is the carbonate stage(quartz + calcite ± pyrite). Skarnization,silicification, carbonatization,epidotization,chloritization, sericitization, and actinolitization are the principal types of hydrothermal alteration. LAICP-MS U-Pb dating yielded ages of 326.5±4.5 and 298.5±1.5 Ma for zircons from the tuff and diorite porphyry, respectively. Given that the tuff is wall rock and that the orebodies are cut by a late diorite porphyry dike, the ages of the tuff and the diorite porphyry provide lower and upper time limits on the age of ore formation. The δ13C values of the calcite samples range from-2.5‰ to 2.3‰, the δ18OH2 Oand δDVSMOWvalues of the sulfide stage(Stage Ⅲ) vary from 1.1‰ to 5.2‰ and-111.7‰ to-66.1‰, respectively,and the δ13C, δ18OH2 Oand δDV-SMOWvalues of calcite in one Stage IV sample are 1.5‰,-0.3‰, and-115.6‰, respectively. Carbon, hydrogen, and oxygen isotopic compositions indicate that the ore-forming fluids evolved gradually from magmatic to meteoric sources. The δ34SV-CDTvalues of the sulfides have a large range from-6.9‰ to 1.4‰, with an average of-2.2‰, indicating a magmatic source, possibly with sedimentary contributions. The206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb ratios of the sulfides are 17.9848-18.2785,15.5188-15.6536, and 37.8125-38.4650, respectively, and one whole-rock sample at Weiquan yields206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb ratios of 18.2060, 15.5674, and 38.0511,respectively. Lead isotopic systems suggest that the ore-forming materials of the Weiquan deposit were derived from a mixed source involving mantle and crustal components. Based on geological features, zircon U-Pb dating, and C-H-OS-Pb isotopic data, it can be concluded that the Weiquan polymetallic deposit is a skarn type that formed in a tectonic setting spanning a period from subduction to post-collision. The ore materials were sourced from magmatic ore-forming fluids that mixed with components derived from host rocks during their ascent, and a gradual mixing with meteoric water took place in the later stages.展开更多
China and the United States are two key players in global climate governance.What about their relations in the field of climate change and how should we view these relations? An analysis of their relations in global c...China and the United States are two key players in global climate governance.What about their relations in the field of climate change and how should we view these relations? An analysis of their relations in global climate governance is of great significance both for global multinational negotiations and their bilateral relations. The two parties have enhanced their cooperation on climate change since 2009 in terms of increasing willingness, broader scale, more diverse mechanisms and higher effectiveness. With the U.N. Paris Climate Conference 2015 approaching, China-US cooperation will inject much momentum into the multilateral process of reaching an ambitious agreement. However, there are also sharp divergences between China and the U.S. regarding principles, rules, and legal means. These divergences might become prominent during the Paris Conference and need to be addressed at the bilateral level.展开更多
Applying qualitative and quantitative methods, this article explains the driving forces behind U.S. President Donald Trump's decision to withdraw from the Paris Agreement, assesses the impacts of this withdrawal o...Applying qualitative and quantitative methods, this article explains the driving forces behind U.S. President Donald Trump's decision to withdraw from the Paris Agreement, assesses the impacts of this withdrawal on the compliance prospects of the agreement, and proposes how China should respond. The withdrawal undercuts the foundation of global climate governance and upsets the process of climate cooperation, and the impacts are manifold. The withdrawal undermines the universality of the Paris Agreement and impairs states' confidence in climate cooperation; it aggravates the leadership deficit in addressing global climate issues and sets a bad precedent for international climate cooperation. The withdrawal reduces other countries' emission space and raises their emission costs, and refusal to contribute to climate aid makes it more difficult for developing countries to mitigate and adapt to climate change. Cutting climate research funding will compromise the quality of future IPCC reports and ultimately undermine the scientific authority of future climate negotiations. China faces mounting pressure from the international community to assume global climate leadership after the U.S. withdraws, and this article proposes that China should reach the high ends of its domestic climate targets under the current Nationally Determined Contributions; internationally, China should facilitate the rebuilding of shared climate leadership, replacing the G2 with C5. Meanwhile, China needs to keep the U.S. engaged in climate cooperation.展开更多
This text combines authors' visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates "three culture e...This text combines authors' visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates "three culture effects" of Park development in terms of cultural system emphatically, then proposes some suggestions of cultural innovation in the Park of China.展开更多
This paper compares the internal structures of the manufacturing industries in China and the U.S. from 1998 to 2005 and leads to three major discoveries: First, the gaps between China and the U.S.'s manufacturing ...This paper compares the internal structures of the manufacturing industries in China and the U.S. from 1998 to 2005 and leads to three major discoveries: First, the gaps between China and the U.S.'s manufacturing capacity have been narrowing at a high speed in the last seven years, during which the share of added value of China's manufacturing industry to that of the U.S. increased from 13% to 52%, and then reached 76% in 2007. Second, the labor force employed in China's manufacturing industry increased by 50%, of which the increase in capital and technology-intensive production sectors exceeded that in labor-intensive sectors. Meanwhile, the labor force employed in the U.S. manufacturing industry decreased. Third, labor productivity in China's manufacturing industry increased by 2.78 times, and profits increased by 2.21 times, much higher than the U.S. growth rates of 18.2% and 49.5%. Obviously, the narrowing gaps between China and the U.S.'s production capacities mean China's industrial progress and the hierarchy of world industrial powers will be rearranged.展开更多
At Grand Epoch City near Beijing on December 12 and 13, the United States and China held the third Strategic Economic Dialogue (SED).As special representatives of President George W. Bush and President Hu Jintao,T... At Grand Epoch City near Beijing on December 12 and 13, the United States and China held the third Strategic Economic Dialogue (SED).As special representatives of President George W. Bush and President Hu Jintao,Treasury Secretary Henry M. Pauslon,Jr. and Vice Premier Wu Yi served as cochairs of the SED.……展开更多
Distance higher education is an important component of the Chinese higher education.How to enhance the quality of distance higher education is one of the key issues to be addressed in the research areas of distance ed...Distance higher education is an important component of the Chinese higher education.How to enhance the quality of distance higher education is one of the key issues to be addressed in the research areas of distance education and higher education.As a crucial step to quality improvement,the constitution of accreditation system in distance higher education balances the benefits of all parties involved.This paper explores the American accreditation system of higher education and distance education and concludes with suggestions for the constitution of the Chinese quality assurance system:1)establishing third-party institutions to share part of the government roles;2)constituting the accreditation system;3)setting up appropriate standards;4)publicizing results of quality assurance work;and 5)building internal quality assurance mechanism.This paper is aimed to provide some reference to the constitution of accreditation system of distance higher education in China,facilitate the solution of quality problems in distance education,and promote the continuous improvement and development of distance education in China.展开更多
Africa can be"left behind"after other advanced continents recover from the coronavirus disease 2019(COVID-19)pandemic as reflected by the global pandemic of HIV/MDS.In this paper,we summarize potentially ada...Africa can be"left behind"after other advanced continents recover from the coronavirus disease 2019(COVID-19)pandemic as reflected by the global pandemic of HIV/MDS.In this paper,we summarize potentially adaptable,effective and innovative strategies from China,Italy,and the U.S.The purpose is to help African countries with weaker healthcare systems better respond to the COVID-19 pandemic.China,being the first to report COVID-19 infection swiftly swung into anti-epidemic actions by the use of innovative risk communication and epidemic containment strategies.Italy and U.S.,the next rapidly hit countries after China,however,experienced sustained infections and deaths due to delayed and ineffective response.Many African countries responded poorly to the COVID-19 pandemic as evidenced by the limited capacity for public health surveillance,poor leadership,low education and socioeconomic status,among others.Experience from China,Italy and U.S.suggests that a better response to the COVID-19 pandemic in Mrica needs a strong public health leadership,proactive strategies,innovative risk communication about the pandemic,massive tests and isolation,and scaling-up community engagement.Lastly,African countries must collaborate with other countries to facilitate real-time information and experience exchange with other countries to avoid being left behind.展开更多
EIGHT years ago in 2009,when President Barack Obama was in Beijing for his first China visit,U.S.media such as CNN covered the trip by focusing on"whether China will develop a sense of global responsibility"...EIGHT years ago in 2009,when President Barack Obama was in Beijing for his first China visit,U.S.media such as CNN covered the trip by focusing on"whether China will develop a sense of global responsibility"as it grows bigger and bigger.A CNN talk show host pressured her Chinese guest on tough topics like human rights and global responsibility.As his country was scrutinized,questioned,展开更多
AS the world enters a new year,its largest developed nation and developing nation approach the 40th anniversary of the start of normalization process of diplomatic relations. Defined by dramatic twists and turns,the C...AS the world enters a new year,its largest developed nation and developing nation approach the 40th anniversary of the start of normalization process of diplomatic relations. Defined by dramatic twists and turns,the China-U.S. relationship has bounced back and forth from such optimistic events as the tentative contact during the Ping Pong Diplomacy of 1971,President Nixon’s visit in 1972,展开更多
The paper tries to address the question of whether the smart grid solution can be transferred internationally, and explore the transferability of the smart grid across countries with three national comparisons: USA, ...The paper tries to address the question of whether the smart grid solution can be transferred internationally, and explore the transferability of the smart grid across countries with three national comparisons: USA, Europe and China. A qualitative content analysis in which data (the academic papers) are coded in preparation for comparison and interpretation is chosen to find the similarities and differences of smart grid development in different national contexts. Trough a comparative analysis of the smart grid development in USA, Europe and China, this paper conducts a transferable framework of smart grid solution with global and local features.展开更多
Although the Msisippi is nearly halfway across the planet from the Yellow River in China,Unita Blackwell,now in her 60s,has helped to build,through 20 years of hard work,a special friendship bridge between these two r...Although the Msisippi is nearly halfway across the planet from the Yellow River in China,Unita Blackwell,now in her 60s,has helped to build,through 20 years of hard work,a special friendship bridge between these two regions.She has won the respect and acclaim of not only many in the United States,but also of many people in China.展开更多
Epithermal gold deposits are typical precious metal deposits related to volcanic and subvolcanic magmatism.Due to the lack of direct geological and petrographic evidences,the origin of the ore-forming fluid is deduced...Epithermal gold deposits are typical precious metal deposits related to volcanic and subvolcanic magmatism.Due to the lack of direct geological and petrographic evidences,the origin of the ore-forming fluid is deduced from the spatial diagenesis-mineralization relationship,chronological data,physicochemical characteristics of mineral fluid inclusions,mineral or rock elements and isotopic geochemical characteristics.By objectively examining this scientific problem via a geological field survey and petrographic analysis of the Gaosongshan epithermal gold deposit,we recently discovered and verified the following points:(1) Pyrite-bearing spherical quartz aggregates (PSQA) occur in the rhyolitic porphyry;(2) the mineralization is structurally dominated by WNW- and ENE-trending systems and occurs mostly in hydrothermal breccias and pyrite-quartz veins,and the ore types are mainly hematite-crusted quartz,hydrothermal breccia,massive pyrite-quartz,etc.;(3) the alteration types consist of prevalent silicification,sericitization,propylitization and carbonation,with local adularization and illitization.The ore minerals are mainly pyrite,primary hematite,native gold,and electrum,with lesser amounts of chalcopyrite,magnetite,sphalerite,and galena,indicating a characteristic epithermal low-sulfidation deposit.The ore-forming fluid may have been primarily derived from magmatic fluid exsolved from a crystallizing rhyolitic porphyry magma.Further zircon U-Pb geochronology,fluid inclusion,physicochemical and isotopic geochemical analyses revealed that (1) rhyolitic porphyry magmatism occurred at 104.6 ± 1.0 Ma,whereas the crystallization of the PSQA occurred at 100.8 ± 2.1 Ma;(2) the hydrothermal fluid of the pre-ore stage was an exsolved CO2-bearing H2O-NaCl magmatic fluid that produced inclusions mainly composed of pure vapor (PV),vapor-rich (WV) and liquid-rich (WL) inclusions with a small number of melt-(M) and solid-bearing (S) inclusions;mineralization-stage quartz contains WL and rare PV,WV and pure liquid (PL) inclusions characterized by the H2O-NaCl system with low formation temperatures and low salinities;(3) the characteristics of hydrogen,oxygen,sulfur,and lead isotopes and those of rare earth elements (REEs) provide insight into the affinity between PSQA and orebodies resulting from juvenile crust or enriched mantle.Combined with previous research on the mineralogenetic epoch (99.32 ± 0.01 Ma),we further confirm that the mineralization of the deposit occurred in the late Early Cretaceous,which coincides with the extension of the continental margin induced by subduction of the Pacific Plate beneath the Eurasian Plate.The formation of the ore deposit was proceeded by a series of magmatic and hydrothermal events,including melting of enriched juvenile crust,upwelling,the eruption and emplacement of the rhyolitic magma,the exsolution and accumulation of magmatic hydrothermal fluid,decompression,the cooling and immiscibility/boiling of the fluid,and mixing of the magmatic fluid with meteoric water,in association with water-rock interaction.展开更多
It is of great significance to have a clear understanding of the international environment that China faces. But this is an uneasy job. Since September 11, the world situation has become so complicated that it is hard...It is of great significance to have a clear understanding of the international environment that China faces. But this is an uneasy job. Since September 11, the world situation has become so complicated that it is hard to grasp its essence even with painstaking efforts. To judge such an already complicated international environment from China’s perspective adds more difficulties, for different people usually have different views due to the different angles from which they see the situation and different methods they adopt. This, understandably, leads to hot debates within the Chinese academic circles. To provide a stage for exchange of views, at the invitation of the CIR Expert Forum, some well-known scholars and experts on international relations from Beijing gathered to hold a symposium on November 5, 2002, with the theme of "How to assess the international environment that China faces". The speeches at the symposium will be published in two installments. Following are the first half.展开更多
文摘The United States passed the Better Utilization of Investment Leading to Development(BUILD Act),as a counterweight to China’s overseas development activities.Under the Act,the US established a new federal agency,the U.S.International Development Finance Corporation(DFC),to enhance U.S.development financing capabilities.To better understand the impact of the DFC on China’s development finance,this article analyzes the DFC’s purpose,functions,structure,and funding.Then it focuses on the purpose of establishing the DFC,providing a preliminary analysis of the potential motivation for its establishment.It also compares the China Development Bank(CDB)and the DFC based on their focused sectors.Finally,through an in-depth analysis of financial frictions in China-U.S.relations,this article argues that the DFC competes with China’s overseas development financing activities in the context of broader strategic competition between China and the U.S.
文摘This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.
基金Sanming Project of Medicine in Shenzhen(No.SZSM201911015)。
文摘Objective:China and the United States(the U.S.)have the heaviest colorectal cancer(CRC)burden with considerable variations in temporal trends.This study aims to analyze the temporal patterns of CRC burden and its risk factors in China and the U.S.across the past three decades.Methods:Data were extracted from the Global Burden of Disease(GBD)Study in 2019,including cases,deaths,disability-adjusted life-years(DALYs),age-standardized rate(ASR),and summary exposure value(SEV)of CRC in China and the U.S.between 1990 and 2019.Annual average percentage changes(AAPCs)of CRC burden were calculated using the Joinpoint regression model.The mortality in CRC attributable to potential risk factors was characterized by countries,gender,and age groups.Results:In 2019,there were 607,900 and 227,241 CRC cases,and 261,777 and 84,026 CRC deaths in China and the U.S.,respectively.The age-standardized incidence rate(ASIR)was 30.55 per 100,000 in China and 41.86 per100,000 in the U.S.,and the age-standardized mortality rate(ASMR)was 13.86 per 100,000 in China and 14.77 per100,000 in the U.S.CRC incidence,mortality,and DALY rate in the U.S.showed downward trends in the past three decades(AAPC=-0.47,-1.06,and-0.88,respectively),while upward trends were observed in China(AAPC=3.11,1.05,and 0.91,respectively).Among the cause of CRC,the leading risk factor contributing to CRC death was low milk in China and smoking in the U.S.,respectively.Conclusions:From 1990 to 2019,the burden of CRC in China increased dramatically,particularly for males and middle-aged and elderly people.The management of the major risk factors associated with the high burden of CRC should be enhanced.
基金the Vermont Agricultural Experiment Station at the University Vermont,USA,and the National Social Science Fund of China(17ZDA067)for financial support of this project。
文摘This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade dispute and retaliations on the alfalfa markets and trade in both nations. China’s rapid transition toward larger-scale commercial dairy production, with enhanced feed and cost management as well as quality and safety control, and its limited resources for high-quality alfalfa production are key factors for the dramatic increase in its alfalfa imports, from 19 601 metric tons in 2008 to 1.38 million metric tons(mmt) in 2018. While the United States dominated China’s alfalfa imports with an average share of 97.01% from 2007 to 2017, the share dropped to 83.76% in 2018 and 63.28% in January 2019 due to the trade dispute and retaliations started in 2018. China will likely remain a large importer of alfalfa because of both its growing demand and the comparative advantages of imported alfalfa in quality and price, but the imports from the United States will be highly affected by the ongoing trade dispute and negotiations. China is also expected to make more efforts to reduce its dependence on U.S. alfalfa through increased investment in domestic alfalfa production and identification of alternative sources of alfalfa and other hay imports.
基金funded by the China Geological Survey (No. 1212011220731)
文摘The Weiquan Ag-polymetallic deposit is located on the southern margin of the Central Asian Orogenic Belt and in the western segment of the Aqishan-Yamansu arc belt in East Tianshan,northwestern China. Its orebodies, controlled by faults, occur in the lower Carboniferous volcanosedimentary rocks of the Yamansu Formation as irregular veins and lenses. Four stages of mineralization have been recognized on the basis of mineral assemblages, ore fabrics, and crosscutting relationships among the ore veins. Stage I is the skarn stage(garnet + pyroxene), Stage Ⅱ is the retrograde alteration stage(epidote + chlorite + magnetite ± hematite 士 actinolite ± quartz),Stage Ⅲ is the sulfide stage(Ag and Bi minerals + pyrite + chalcopyrite + galena + sphalerite + quartz ± calcite ± tetrahedrite),and Stage IV is the carbonate stage(quartz + calcite ± pyrite). Skarnization,silicification, carbonatization,epidotization,chloritization, sericitization, and actinolitization are the principal types of hydrothermal alteration. LAICP-MS U-Pb dating yielded ages of 326.5±4.5 and 298.5±1.5 Ma for zircons from the tuff and diorite porphyry, respectively. Given that the tuff is wall rock and that the orebodies are cut by a late diorite porphyry dike, the ages of the tuff and the diorite porphyry provide lower and upper time limits on the age of ore formation. The δ13C values of the calcite samples range from-2.5‰ to 2.3‰, the δ18OH2 Oand δDVSMOWvalues of the sulfide stage(Stage Ⅲ) vary from 1.1‰ to 5.2‰ and-111.7‰ to-66.1‰, respectively,and the δ13C, δ18OH2 Oand δDV-SMOWvalues of calcite in one Stage IV sample are 1.5‰,-0.3‰, and-115.6‰, respectively. Carbon, hydrogen, and oxygen isotopic compositions indicate that the ore-forming fluids evolved gradually from magmatic to meteoric sources. The δ34SV-CDTvalues of the sulfides have a large range from-6.9‰ to 1.4‰, with an average of-2.2‰, indicating a magmatic source, possibly with sedimentary contributions. The206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb ratios of the sulfides are 17.9848-18.2785,15.5188-15.6536, and 37.8125-38.4650, respectively, and one whole-rock sample at Weiquan yields206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb ratios of 18.2060, 15.5674, and 38.0511,respectively. Lead isotopic systems suggest that the ore-forming materials of the Weiquan deposit were derived from a mixed source involving mantle and crustal components. Based on geological features, zircon U-Pb dating, and C-H-OS-Pb isotopic data, it can be concluded that the Weiquan polymetallic deposit is a skarn type that formed in a tectonic setting spanning a period from subduction to post-collision. The ore materials were sourced from magmatic ore-forming fluids that mixed with components derived from host rocks during their ascent, and a gradual mixing with meteoric water took place in the later stages.
基金China Clean Development Mechanism Fund Grant Program(2013020)The Talents Program of Shanghai Pujiang of 2014(14PJC003)the Philosophy and Social Sciences Planning Program of Shanghai of 2012(2012BGJ003)
文摘China and the United States are two key players in global climate governance.What about their relations in the field of climate change and how should we view these relations? An analysis of their relations in global climate governance is of great significance both for global multinational negotiations and their bilateral relations. The two parties have enhanced their cooperation on climate change since 2009 in terms of increasing willingness, broader scale, more diverse mechanisms and higher effectiveness. With the U.N. Paris Climate Conference 2015 approaching, China-US cooperation will inject much momentum into the multilateral process of reaching an ambitious agreement. However, there are also sharp divergences between China and the U.S. regarding principles, rules, and legal means. These divergences might become prominent during the Paris Conference and need to be addressed at the bilateral level.
基金This study was supported by the 2017 National Natural Science Foundation Project “The Impacts of U.S. Withdrawal from the Paris Agreement on Global Climate Governance and China's Response”.
文摘Applying qualitative and quantitative methods, this article explains the driving forces behind U.S. President Donald Trump's decision to withdraw from the Paris Agreement, assesses the impacts of this withdrawal on the compliance prospects of the agreement, and proposes how China should respond. The withdrawal undercuts the foundation of global climate governance and upsets the process of climate cooperation, and the impacts are manifold. The withdrawal undermines the universality of the Paris Agreement and impairs states' confidence in climate cooperation; it aggravates the leadership deficit in addressing global climate issues and sets a bad precedent for international climate cooperation. The withdrawal reduces other countries' emission space and raises their emission costs, and refusal to contribute to climate aid makes it more difficult for developing countries to mitigate and adapt to climate change. Cutting climate research funding will compromise the quality of future IPCC reports and ultimately undermine the scientific authority of future climate negotiations. China faces mounting pressure from the international community to assume global climate leadership after the U.S. withdraws, and this article proposes that China should reach the high ends of its domestic climate targets under the current Nationally Determined Contributions; internationally, China should facilitate the rebuilding of shared climate leadership, replacing the G2 with C5. Meanwhile, China needs to keep the U.S. engaged in climate cooperation.
文摘This text combines authors' visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates "three culture effects" of Park development in terms of cultural system emphatically, then proposes some suggestions of cultural innovation in the Park of China.
基金sponsored by "Empirical Research Project on China's Industrial Innovation Strategies and Policy Options",which is a major project of a key humanities and social sciences research center of the Ministry of Educationfunded by the "regional" sub-project of China's International Economic Competitiveness Research and Innovation Center of Fudan University
文摘This paper compares the internal structures of the manufacturing industries in China and the U.S. from 1998 to 2005 and leads to three major discoveries: First, the gaps between China and the U.S.'s manufacturing capacity have been narrowing at a high speed in the last seven years, during which the share of added value of China's manufacturing industry to that of the U.S. increased from 13% to 52%, and then reached 76% in 2007. Second, the labor force employed in China's manufacturing industry increased by 50%, of which the increase in capital and technology-intensive production sectors exceeded that in labor-intensive sectors. Meanwhile, the labor force employed in the U.S. manufacturing industry decreased. Third, labor productivity in China's manufacturing industry increased by 2.78 times, and profits increased by 2.21 times, much higher than the U.S. growth rates of 18.2% and 49.5%. Obviously, the narrowing gaps between China and the U.S.'s production capacities mean China's industrial progress and the hierarchy of world industrial powers will be rearranged.
文摘 At Grand Epoch City near Beijing on December 12 and 13, the United States and China held the third Strategic Economic Dialogue (SED).As special representatives of President George W. Bush and President Hu Jintao,Treasury Secretary Henry M. Pauslon,Jr. and Vice Premier Wu Yi served as cochairs of the SED.……
文摘Distance higher education is an important component of the Chinese higher education.How to enhance the quality of distance higher education is one of the key issues to be addressed in the research areas of distance education and higher education.As a crucial step to quality improvement,the constitution of accreditation system in distance higher education balances the benefits of all parties involved.This paper explores the American accreditation system of higher education and distance education and concludes with suggestions for the constitution of the Chinese quality assurance system:1)establishing third-party institutions to share part of the government roles;2)constituting the accreditation system;3)setting up appropriate standards;4)publicizing results of quality assurance work;and 5)building internal quality assurance mechanism.This paper is aimed to provide some reference to the constitution of accreditation system of distance higher education in China,facilitate the solution of quality problems in distance education,and promote the continuous improvement and development of distance education in China.
文摘Africa can be"left behind"after other advanced continents recover from the coronavirus disease 2019(COVID-19)pandemic as reflected by the global pandemic of HIV/MDS.In this paper,we summarize potentially adaptable,effective and innovative strategies from China,Italy,and the U.S.The purpose is to help African countries with weaker healthcare systems better respond to the COVID-19 pandemic.China,being the first to report COVID-19 infection swiftly swung into anti-epidemic actions by the use of innovative risk communication and epidemic containment strategies.Italy and U.S.,the next rapidly hit countries after China,however,experienced sustained infections and deaths due to delayed and ineffective response.Many African countries responded poorly to the COVID-19 pandemic as evidenced by the limited capacity for public health surveillance,poor leadership,low education and socioeconomic status,among others.Experience from China,Italy and U.S.suggests that a better response to the COVID-19 pandemic in Mrica needs a strong public health leadership,proactive strategies,innovative risk communication about the pandemic,massive tests and isolation,and scaling-up community engagement.Lastly,African countries must collaborate with other countries to facilitate real-time information and experience exchange with other countries to avoid being left behind.
文摘EIGHT years ago in 2009,when President Barack Obama was in Beijing for his first China visit,U.S.media such as CNN covered the trip by focusing on"whether China will develop a sense of global responsibility"as it grows bigger and bigger.A CNN talk show host pressured her Chinese guest on tough topics like human rights and global responsibility.As his country was scrutinized,questioned,
文摘AS the world enters a new year,its largest developed nation and developing nation approach the 40th anniversary of the start of normalization process of diplomatic relations. Defined by dramatic twists and turns,the China-U.S. relationship has bounced back and forth from such optimistic events as the tentative contact during the Ping Pong Diplomacy of 1971,President Nixon’s visit in 1972,
文摘The paper tries to address the question of whether the smart grid solution can be transferred internationally, and explore the transferability of the smart grid across countries with three national comparisons: USA, Europe and China. A qualitative content analysis in which data (the academic papers) are coded in preparation for comparison and interpretation is chosen to find the similarities and differences of smart grid development in different national contexts. Trough a comparative analysis of the smart grid development in USA, Europe and China, this paper conducts a transferable framework of smart grid solution with global and local features.
文摘Although the Msisippi is nearly halfway across the planet from the Yellow River in China,Unita Blackwell,now in her 60s,has helped to build,through 20 years of hard work,a special friendship bridge between these two regions.She has won the respect and acclaim of not only many in the United States,but also of many people in China.
基金financially supported by the National Key Research and Development Program of China (Grant No.2017YFC0601306)the National Natural Science Foundation of China (Grant No.41390444)+1 种基金the Program of the China Geological Survey(Grant No.DD20160344)supported by Team 707, Heilongjiang Bureau of Geological Exploration for Nonferrous Metals
文摘Epithermal gold deposits are typical precious metal deposits related to volcanic and subvolcanic magmatism.Due to the lack of direct geological and petrographic evidences,the origin of the ore-forming fluid is deduced from the spatial diagenesis-mineralization relationship,chronological data,physicochemical characteristics of mineral fluid inclusions,mineral or rock elements and isotopic geochemical characteristics.By objectively examining this scientific problem via a geological field survey and petrographic analysis of the Gaosongshan epithermal gold deposit,we recently discovered and verified the following points:(1) Pyrite-bearing spherical quartz aggregates (PSQA) occur in the rhyolitic porphyry;(2) the mineralization is structurally dominated by WNW- and ENE-trending systems and occurs mostly in hydrothermal breccias and pyrite-quartz veins,and the ore types are mainly hematite-crusted quartz,hydrothermal breccia,massive pyrite-quartz,etc.;(3) the alteration types consist of prevalent silicification,sericitization,propylitization and carbonation,with local adularization and illitization.The ore minerals are mainly pyrite,primary hematite,native gold,and electrum,with lesser amounts of chalcopyrite,magnetite,sphalerite,and galena,indicating a characteristic epithermal low-sulfidation deposit.The ore-forming fluid may have been primarily derived from magmatic fluid exsolved from a crystallizing rhyolitic porphyry magma.Further zircon U-Pb geochronology,fluid inclusion,physicochemical and isotopic geochemical analyses revealed that (1) rhyolitic porphyry magmatism occurred at 104.6 ± 1.0 Ma,whereas the crystallization of the PSQA occurred at 100.8 ± 2.1 Ma;(2) the hydrothermal fluid of the pre-ore stage was an exsolved CO2-bearing H2O-NaCl magmatic fluid that produced inclusions mainly composed of pure vapor (PV),vapor-rich (WV) and liquid-rich (WL) inclusions with a small number of melt-(M) and solid-bearing (S) inclusions;mineralization-stage quartz contains WL and rare PV,WV and pure liquid (PL) inclusions characterized by the H2O-NaCl system with low formation temperatures and low salinities;(3) the characteristics of hydrogen,oxygen,sulfur,and lead isotopes and those of rare earth elements (REEs) provide insight into the affinity between PSQA and orebodies resulting from juvenile crust or enriched mantle.Combined with previous research on the mineralogenetic epoch (99.32 ± 0.01 Ma),we further confirm that the mineralization of the deposit occurred in the late Early Cretaceous,which coincides with the extension of the continental margin induced by subduction of the Pacific Plate beneath the Eurasian Plate.The formation of the ore deposit was proceeded by a series of magmatic and hydrothermal events,including melting of enriched juvenile crust,upwelling,the eruption and emplacement of the rhyolitic magma,the exsolution and accumulation of magmatic hydrothermal fluid,decompression,the cooling and immiscibility/boiling of the fluid,and mixing of the magmatic fluid with meteoric water,in association with water-rock interaction.
文摘It is of great significance to have a clear understanding of the international environment that China faces. But this is an uneasy job. Since September 11, the world situation has become so complicated that it is hard to grasp its essence even with painstaking efforts. To judge such an already complicated international environment from China’s perspective adds more difficulties, for different people usually have different views due to the different angles from which they see the situation and different methods they adopt. This, understandably, leads to hot debates within the Chinese academic circles. To provide a stage for exchange of views, at the invitation of the CIR Expert Forum, some well-known scholars and experts on international relations from Beijing gathered to hold a symposium on November 5, 2002, with the theme of "How to assess the international environment that China faces". The speeches at the symposium will be published in two installments. Following are the first half.