Urban construction land suitability evaluation (UCLSE) is a complex system engineering and the basis for rational use of the limited urban land resources in China. It has an important practical value on urban constr...Urban construction land suitability evaluation (UCLSE) is a complex system engineering and the basis for rational use of the limited urban land resources in China. It has an important practical value on urban construction land use planning and management from the angle of methodology. As a widely used technique, traditional multi-criteria evaluation based on GIS (MCE-GIS), is not suitable for UCLSE. This study develops an improved MCE-GIS method which could be more suitable for UCLSE based on urban complex ecological system theory and the summary of the shortcomings of traditional MCE-GIS. The improvements include three aspects: a composite evaluation index system rather than natural indexes alone, an index weight calculated by using fuzzy Analytic Hierarchy Process (AHP) method rather than the common AHP method, and the integrated overlay rule, which includes selecting the minimum value, weighted linear combination (WLC) and simple summation. The main advantage of this improved technique is that it can make UCLSE more comprehensive, more operational and more reasonable. It can provide a scientific basis for decision making in the planning and management of urban construction land use. The improved MCE-GIS system has been adopted in the New Hefei City, Anhui Province, China. Based on the results of UCLSE in New Hefei, three functional areas including construction-appropriate areas, construction-restricted areas and construction-forbidden areas could be worked out, in which 36.90% of the total study area could be developed as urban construction land and the remaining 63.10% should be protected as reserves land or as ecological land. Furthermore, the results can orovide scientific decision suooort for spatial planning and eco-environment nrotection in New Hefei.展开更多
Background The vasovagal reflex syndrome (VVRS) is common in the patiems undergoing percutaneous coronary intervemion (PCI) However, prediction and prevention of the risk for the VVRS have not been completely fulf...Background The vasovagal reflex syndrome (VVRS) is common in the patiems undergoing percutaneous coronary intervemion (PCI) However, prediction and prevention of the risk for the VVRS have not been completely fulfilled. This study was conducted to develop a Risk Prediction Score Model to identify the determinants of VVRS in a large Chinese population cohort receiving PCI. Methods From the hos- pital electronic medical database, we idemified 3550 patients who received PCI (78.0% males, mean age 60 years) in Chinese PLA General Hospital from January 1, 2000 to August 30, 2016. The multivariate analysis and receiver operating characteristic 01OC) analysis were performed. Results The adverse events of VVRS in the patients were significantly increased after PCI procedure than before the operation (all P 〈 0.001). The rate of VVRS [95% confidence interval (CI)] in patients receiving PCI was 4.5% (4.1%-5.6%). Compared to the patients suffering no VVRS, incidence of VVRS involved the following factors, namely female gender, primary PCI, hypertension, over two stems im- plantation in the left anterior descending (LAD), and the femoral puncture site. The multivariate analysis suggested that they were independ- ent risk factors for predicting the incidence of VVRS (all P 〈 0.001). We developed a risk prediction score model for VVRS. ROC analysis showed that the risk prediction score model was effectively predictive of the incidence of VVRS in patients receiving PCI (c-statistic 0.76, 95% CI: 0.72-0.79, P 〈 0.001). There were decreased evems of VVRS in the patients receiving PCI whose diastolic blood pressure dropped by more than 30 mmHg and heart rate reduced by 10 times per minute (AUC: 0.84, 95% CI: 0.81-0.87, P 〈 0.001). Conclusion The risk prediction score is quite efficient in predicting the incidence of VVRS in patients receiving PCI. In which, the following factors may be in- volved, the femoral puncture site, female gender, hypertension, primary PCI, and over 2 stents implanted in LAD.展开更多
Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composi...Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is strong from 1950s to the middle of 1980s but weak after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over the middle and lower reaches of the Changjiang River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weak but decrease when preceding winter monsoon is strong. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause for abnormal rainfall over the middle and lower reaches of the Changjiang River.展开更多
Extensive reading has long been applied in the English as a foreign language classroom in China,but the fundamental theories and practical instruction are not satisfactory. The study aims to synthesize and examine ext...Extensive reading has long been applied in the English as a foreign language classroom in China,but the fundamental theories and practical instruction are not satisfactory. The study aims to synthesize and examine extensive reading studies over the past fifty years(1962-2019) from a holistic perspective. By performing a qualitative meta-analysis, a total of 81 articles published in widely accepted journals were carefully coded and analyzed. Three latent problems emerged,including that 1) most extensive reading researchers misunderstand the inherent characteristic of extensive reading(i. e., pleasure reading) and less frequently follow the principles of extensive reading instruction;2) there are methodological weaknesses in empirical research designs, and;3)research scope is limited regarding participants and methodology. Suggestions for extensive reading research and instruction are included.展开更多
Sediment carbon sequestration plays an essential role in mitigating atmospheric CO2 increases and the subsequently global greenhouse effect. To clarify the late Quaternary strata and carbon burial records in YeUow Riv...Sediment carbon sequestration plays an essential role in mitigating atmospheric CO2 increases and the subsequently global greenhouse effect. To clarify the late Quaternary strata and carbon burial records in YeUow River delta (YRD), detailed analysis of benthic foraminifera, total carbon (TC), organic carbon (Corg), sedimentary characteristics and moisture contents of sediments, was performed on core ZK3, 30.3 m in length and obtained from YRD in 2007. Eight depositional units (designated U1-U8 in ascending order) were identified. A comprehensive analysis method of historical geography and sedimentary geology was used to de- termine the precise depositional ages of the modem Yellow River delta (MYRD), from which pre-MYRD ages were deduced. The results indicates that the maximum burial rates of TC, inorganic carbon (IC) and Corg occurred in the delta front (U5), and the mini- mum in the shallow sea (U3). Remarkable high sedimentation rates in the MYRD are responsible for burial efficiency of carbon, with an average rate of Corg burial reaching 2087±251 g(m2yr)-1, and that of IC reaching 13741±808g(m2yr)-1, which are much higher than those of other regions with high contents of Corg. Therefore, YRD has a significant burial efficiency for carbon sequestration.展开更多
High-quality and high-resolution precipitation data are the basis for mesoscale numerical weather forecasting,model verification,and hydrological monitoring,which play an important role in meteorological and hydrologi...High-quality and high-resolution precipitation data are the basis for mesoscale numerical weather forecasting,model verification,and hydrological monitoring,which play an important role in meteorological and hydrological disaster prevention and mitigation.In this study,high-density rain gauge data are used to evaluate the fusion accuracy of the China Meteorological Administration Multisource Precipitation Analysis System(CMPAS),and four CMPAS products with different spatial and temporal resolution and different data sources are compared,to derive the applicability of CMPAS.Results show that all the CMPAS products show high accuracy in the Sichuan Basin,followed by Panxi Area and the western Sichuan Plateau.The errors of the four products all rise with the increase in precipitation.CMPAS overestimates precipitation in summer and autumn and underestimates it in spring and winter.Overall,the applicability of these fused data in the Sichuan Basin is quite good.Due to the lack of observations and the influence of the terrain and meteorological conditions,the evaluation of CMPAS in the plateau area needs further analysis.展开更多
In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics...In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2(Nsp2) and glycoprotein 5(GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.展开更多
Land scarcity has become the prominent obstacle on the way to sustainable development for China. Under the constraints of land shortage, how to allocate the finite land resources to the multiple land users in China co...Land scarcity has become the prominent obstacle on the way to sustainable development for China. Under the constraints of land shortage, how to allocate the finite land resources to the multiple land users in China considering various political, environmental, ecological and economic conditions have become research topics with great significance. In this study, an interval fuzzy national-scale land-use model(IFNLM) was developed for optimizing land systems of China. IFNLM is based on an integration of existing interval linear programming(ILP), and fuzzy flexible programming(FFP) techniques. IFNLM allows uncertainties expressed as discrete interval values and fuzzy sets to be incorporated within a general optimization framework. It can also facilitate national-scale land-use planning under various environmental, ecological, social conditions within a multi-period and multi-option context. Then, IFNLM was applied to a real case study of land-use planning in China. The satisfaction degree of environmental constraints is between 0.69 and 0.97, the system benefit will between 198.25 × 1012 USD and 229.67 × 1012 USD. The results indicated that the hybrid model can help generate desired policies for land-use allocation with a maximized economic benefit and minimized environmental violation risk. Optimized land-use allocation patterns can be generated from the proposed IFNLM.展开更多
Based on comprehensive analysis of the impact of population aging to social and economic development,a comprehensive evaluation system including 18 indexes was constructed for evaluating regional pressure of populatio...Based on comprehensive analysis of the impact of population aging to social and economic development,a comprehensive evaluation system including 18 indexes was constructed for evaluating regional pressure of population aging on social and economic development.Using statistics data of 31 regions in China from 2004 to 2008,the pressure of population aging on social and economic development,was comprehensively evaluated by using the factor analysis method.The spatial distribution of population aging in China was also analyzed.This study is to provide scientific basis for government to make strategies of coping with population aging according to regional pressure of population aging on social and economic development in China.展开更多
For years, the US and China have cooperated closely on manufacturing programs, which helps China become the world manufacturing center. While they both have gained much from the cooperation, there are also increasing ...For years, the US and China have cooperated closely on manufacturing programs, which helps China become the world manufacturing center. While they both have gained much from the cooperation, there are also increasing frictions, disputes, complains and dissatisfaction with each other because of the huge trade unbalance problem and other significant issues. The US is eager to expand export to China, but China seems hesitating to decide what to import from the US. This paper presents an analysis about the benefits of the US-China cooperation with a primary focus on the service sector, which remains a large and untapped opportunity for China. The goal of the paper is to explore a new route to relieve the trade balance issues as they separately impact both nations. While focusing on analyzing several immediate opportunities, the paper also investigates several new ideas that rest on technology as well as entrepreneurial development.展开更多
The function of Green Technology Innovation (GTI) in the Eco-Industrial Management (ELM) appears more and more important, but the research on how much this function plays is scarce. The influence of Green Technolo...The function of Green Technology Innovation (GTI) in the Eco-Industrial Management (ELM) appears more and more important, but the research on how much this function plays is scarce. The influence of Green Technology Innovation to the Eco-Industrial Management has gradually received the academic and the industrial attention. In this article an empirical research was attempted to inspect whether such influence exists and to what value. The study attempts to empirically explore the influencing degree of GTI on EIM in China based on the double logarithmic regression equation.展开更多
Predicate-Argument (PA) structure anal- ysis is often divided into three subtasks: predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isol...Predicate-Argument (PA) structure anal- ysis is often divided into three subtasks: predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isolation. However, this approach neglects logical constraints between them. We therefore exploite integrating predicate sense disambiguation with the latter two subtasks respectively, which verifies that the automatic predicate sense disambiguation could help the se- mantic role labeling task. In addition, a dual de- composition algorithm is used to alleviate the er- ror propagation between argument identification subtask and argument classification subtask by benefitting the argument identification subtask greatly. Experiment results show that our ap- proach leads to a better performance with PA a- nalysis than other pipeline approaches.展开更多
This paper establishes the theoretical hypothesis of carbon intensity convergence, and through statistics to analyze and describe the whole country and the eastern and western regions with the use of mixed regression ...This paper establishes the theoretical hypothesis of carbon intensity convergence, and through statistics to analyze and describe the whole country and the eastern and western regions with the use of mixed regression model and fixed effects regression method, and test σ -convergence, absolute convergence and conditional convergence in order to have an empirical study on carbon convergence hypothesis.展开更多
In this research,the Factor Analysis model of measuring provincial low carbon development in China has been constructed.Based on data from 30 provinces,an empirical study was developed to measure comprehensive low car...In this research,the Factor Analysis model of measuring provincial low carbon development in China has been constructed.Based on data from 30 provinces,an empirical study was developed to measure comprehensive low carbon development using the Factor Analysis model(Principal Components method and Normalized Varimax Rotation).The results reveal that the provincial marks of low carbon development are generally low and only nine provinces have high marks(more than 0.80).The results also show significant regional disparity.The provincial marks of the eastern region are higher than both the middle and western provinces of China's Mainland.All of the provinces with high marks(more than 0.90) are located in the eastern region,and those with the lowest marks(0.60) are located in the middle region.Furthermore,regional disparity in low carbon development follows the same pattern as economic development in China.Finally,some suggestions for decision-makers are presented.展开更多
China's government statement recently reported the plan of constructing Xiong'an New Area, which aims to phase out some extra capital functions from Beijing and to explore an innovative urban development mode with t...China's government statement recently reported the plan of constructing Xiong'an New Area, which aims to phase out some extra capital functions from Beijing and to explore an innovative urban development mode with the priority in eco-environmental protection. The New Area is located in the semi-arid North China Plain (NCP) and is home to NCP's largest natural freshwater wetland, Baiyangdian Lake. A comprehensive realization of surface water dynamics would be crucial for policy-makers to outline a sustainable environment development strategy for New Area. In this study, we used a total of 245 time slices of cloud-free Landsat images to document the continuous changes of water bodies within Xiong'an City dur- ing 1984-2016 and to provide detailed evidence of water presence and persistency states and changes under the influences of climate change and human actions. Our results reveal that the New Area water body areas varied dramatically during the past 33 years, ranging from 0.44 km^2 in April 1988 to 317.85 km^2 in February 1989. The change of surface water area was not characterized by a monotonically decreasing tendency. The evolution processes can be divided into four sub-stages: the first extreme desiccation in mid-1980s, the wet stage with the most extensive inundation areas and strong inter-annual fluctuations from late-1988 to late 1999, another desiccation stage in early 2000s, and the overall recovering stage between 2007 and 2016. We also mapped the maximum water inundation extents and frequencies of all-season, pre-wet season (February-May) and post-wet season (September-December) for the 33 years and different sub-periods. Although there is good agreement between time series of surface water area evolution in the New Area and station-based precipitation and evaporation variations, multipie lines of evidences reviewed in previous research indicate that the degraded Baiyangdian Lake was also tightly associated with human activities from various aspects, including dam construction, ground-water extraction, agricultural irrigation, etc. We highlighted the current status of exploring the driving mechanism of surface water changes and existing problems, and then offer recommendations.展开更多
OBJECTIVE:To master the syndrome patterns characteristics and explore the effective therapy methods ofTraditional Chinese Medicine(TCM) for cardiac syndrome X(CSX).METHODS:The TCM syndrome characteristics were mastere...OBJECTIVE:To master the syndrome patterns characteristics and explore the effective therapy methods ofTraditional Chinese Medicine(TCM) for cardiac syndrome X(CSX).METHODS:The TCM syndrome characteristics were mastered and the TCM intervention programs were determined by clinical investigations for TCM syndrome patterns characteristics of CSX patients.Then,the clinical efficacy studies on TCM intervention for CSX were carried out through randomized controlled trials.RESULTS:CSX is a clinical syndrome with the main manifestations of chest pain and chest stuffiness,and Qi stagnation,phlegm retention and blood stasis are the basic symptoms of CSX.As a result,the Qi-regulating,chest-relaxing and blood-activating therapy integrated with some Western Medicines was adopted for treatment.The effect of Qi-regulating,chest-relaxing and blood-activating therapy can reduce the frequency and degree of angina,improve the symptoms and exercise the tolerance of patients,inhibit the inflammatory response of vascular walls and protect the function of vascular endothelial cells,which is better than that of the simple and conventionalWestern Medicine alone.CONCLUSION:A good effect was achieved in the integration of Chinese and Western Medicines for CSX.The therapy is worthy to be applied further in clinical practice.On the other hand,more long-term and randomised controlled studies with large samples are still required to further determine the clinical efficacy and safety of the therapy.展开更多
Understanding the characteristics of the dynamic relationship between the onshore Ren- minbi (CNY) and the offshore Renminbi (CNH) exchange rates considering the impact of some extreme events is very important and...Understanding the characteristics of the dynamic relationship between the onshore Ren- minbi (CNY) and the offshore Renminbi (CNH) exchange rates considering the impact of some extreme events is very important and it has wide implications in several areas such as hedging. For better esti- mating the dynamic relationship between CNY and CNH, the Granger-causality test and Bry-Boschan Business Cycle Dating Algorithm were employed in this paper. Due to the intrinsic complexity of the lead-lag relationships between CNY and CNH, the empirical mode decomposition (EMD) algorithm is used to decompose those time series data into several intrinsic mode function (IMF) components and a residual sequence, from high to low frequency. Based on the frequencies, the IMFs and a residual sequence are combined into three components, identified as short-term composition caused by some market activities, medium-term composition caused by some extreme events and the long-term trend.The empirical results indicate that when it only matters the short-term market activities, CNH always leads CNY; while the medium-term impact caused by those extreme events may alternate the lead-lag relationships between CNY and CNH.展开更多
Soil aggregate stability,an important index of the physical characteristics of a soil,can provide a good indication of a soil’s erodibility,and deserves special consideration in regions with cold climate.The objectiv...Soil aggregate stability,an important index of the physical characteristics of a soil,can provide a good indication of a soil’s erodibility,and deserves special consideration in regions with cold climate.The objective of this study was to study the effect of freeze-thaw on soil water-stable aggregates in the black soil region of Northeast China.Samples of a typical black soil in the region were collected to measure water-stable aggregates after freeze-thaw under different conditions(i.e.,initial moisture contents,freezethaw cycles and freezing temperatures)by wet-sieving into eight particle size groups(>10,10–6,6–5,5–3,3–2,2–1,1–0.5,and0.5–0.25 mm).Freeze-thaw had the most effect on aggregate stability when the samples had an initial moisture content of 400 g kg-1.The water-stable aggregates of the four larger particle size groups(>5,5–3,3–2,and 2–1 mm)reached a peak stability value,but those of the two smaller particle size groups(1–0.5 and 0.5–0.25 mm)reached a minimum value when the soil moisture content was 400 g kg-1.Water-stable aggregates of the four larger particle size groups decreased while those of the two smaller particle size groups increased with the increase of freeze-thaw cycles.As temperatures fell,the water-stable aggregates of the four larger particle size groups decreased while those of the two smaller particle size groups increased.展开更多
When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the f...When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the fuel can escape the vehicle through evaporation. Changes in alkanes, olefins and aromatics each affect emissions differently, which could complicate control strategies for air pollution. In this study, we collected 31 gasoline samples over five provinces and cities(Beijing, Tianjin, Hebei, Shandong, and Shaanxi) in North China between 2012 and 2013. The organic composition of the gasoline samples was analyzed using the gas chromatography-mass spectrometry(GC-MS) method, and the aniline compounds were analyzed by solvent extraction and the GC-MS method. The ratios of alkanes, aromatics, olefins and other organic compounds in gasoline were 40.6%, 38.1%, 12.9% and 8.4%, respectively. The aromatic and benzene exceedances were 15 and 8 based on the China's gasoline standards(III), and they accounted for 48.4% and 25.8% of all the gasoline samples, respectively. Strong carcinogen aniline compounds were detected in all 31 samples, and the content of aniline compounds in 3 samples exceeded 1%. The high proportion of aromatics and olefins in the gasoline increased the emissions of carbon monoxide(CO) and toxics, as well as the atmospheric photochemical reactivity of exhaust emissions, which could hasten the formation of secondary pollutants. Our results are helpful for redefining government strategies to control air pollution in North China and relevant for developing new refining technology throughout China.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41201168)Fundamental Research Funds for the Central Universities(No.2013HGXJ0207)
文摘Urban construction land suitability evaluation (UCLSE) is a complex system engineering and the basis for rational use of the limited urban land resources in China. It has an important practical value on urban construction land use planning and management from the angle of methodology. As a widely used technique, traditional multi-criteria evaluation based on GIS (MCE-GIS), is not suitable for UCLSE. This study develops an improved MCE-GIS method which could be more suitable for UCLSE based on urban complex ecological system theory and the summary of the shortcomings of traditional MCE-GIS. The improvements include three aspects: a composite evaluation index system rather than natural indexes alone, an index weight calculated by using fuzzy Analytic Hierarchy Process (AHP) method rather than the common AHP method, and the integrated overlay rule, which includes selecting the minimum value, weighted linear combination (WLC) and simple summation. The main advantage of this improved technique is that it can make UCLSE more comprehensive, more operational and more reasonable. It can provide a scientific basis for decision making in the planning and management of urban construction land use. The improved MCE-GIS system has been adopted in the New Hefei City, Anhui Province, China. Based on the results of UCLSE in New Hefei, three functional areas including construction-appropriate areas, construction-restricted areas and construction-forbidden areas could be worked out, in which 36.90% of the total study area could be developed as urban construction land and the remaining 63.10% should be protected as reserves land or as ecological land. Furthermore, the results can orovide scientific decision suooort for spatial planning and eco-environment nrotection in New Hefei.
文摘Background The vasovagal reflex syndrome (VVRS) is common in the patiems undergoing percutaneous coronary intervemion (PCI) However, prediction and prevention of the risk for the VVRS have not been completely fulfilled. This study was conducted to develop a Risk Prediction Score Model to identify the determinants of VVRS in a large Chinese population cohort receiving PCI. Methods From the hos- pital electronic medical database, we idemified 3550 patients who received PCI (78.0% males, mean age 60 years) in Chinese PLA General Hospital from January 1, 2000 to August 30, 2016. The multivariate analysis and receiver operating characteristic 01OC) analysis were performed. Results The adverse events of VVRS in the patients were significantly increased after PCI procedure than before the operation (all P 〈 0.001). The rate of VVRS [95% confidence interval (CI)] in patients receiving PCI was 4.5% (4.1%-5.6%). Compared to the patients suffering no VVRS, incidence of VVRS involved the following factors, namely female gender, primary PCI, hypertension, over two stems im- plantation in the left anterior descending (LAD), and the femoral puncture site. The multivariate analysis suggested that they were independ- ent risk factors for predicting the incidence of VVRS (all P 〈 0.001). We developed a risk prediction score model for VVRS. ROC analysis showed that the risk prediction score model was effectively predictive of the incidence of VVRS in patients receiving PCI (c-statistic 0.76, 95% CI: 0.72-0.79, P 〈 0.001). There were decreased evems of VVRS in the patients receiving PCI whose diastolic blood pressure dropped by more than 30 mmHg and heart rate reduced by 10 times per minute (AUC: 0.84, 95% CI: 0.81-0.87, P 〈 0.001). Conclusion The risk prediction score is quite efficient in predicting the incidence of VVRS in patients receiving PCI. In which, the following factors may be in- volved, the femoral puncture site, female gender, hypertension, primary PCI, and over 2 stents implanted in LAD.
基金East Asia winter monsoon and Yunnan summertime drought and floods and their interdecadal anomalies a project of the Yunnan Province Science Foundation a Yunnan Province Foundation project (97D022G)
文摘Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is strong from 1950s to the middle of 1980s but weak after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over the middle and lower reaches of the Changjiang River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weak but decrease when preceding winter monsoon is strong. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause for abnormal rainfall over the middle and lower reaches of the Changjiang River.
文摘Extensive reading has long been applied in the English as a foreign language classroom in China,but the fundamental theories and practical instruction are not satisfactory. The study aims to synthesize and examine extensive reading studies over the past fifty years(1962-2019) from a holistic perspective. By performing a qualitative meta-analysis, a total of 81 articles published in widely accepted journals were carefully coded and analyzed. Three latent problems emerged,including that 1) most extensive reading researchers misunderstand the inherent characteristic of extensive reading(i. e., pleasure reading) and less frequently follow the principles of extensive reading instruction;2) there are methodological weaknesses in empirical research designs, and;3)research scope is limited regarding participants and methodology. Suggestions for extensive reading research and instruction are included.
基金funded by the National Natural Science Foundation of China (Grant Nos. 41406082, ZR2014DQ010, 40872167 and 41240022)Governmental Public Research Funds of China (Grant Nos. 201111023, 1212010611402 and GZH201200503)
文摘Sediment carbon sequestration plays an essential role in mitigating atmospheric CO2 increases and the subsequently global greenhouse effect. To clarify the late Quaternary strata and carbon burial records in YeUow River delta (YRD), detailed analysis of benthic foraminifera, total carbon (TC), organic carbon (Corg), sedimentary characteristics and moisture contents of sediments, was performed on core ZK3, 30.3 m in length and obtained from YRD in 2007. Eight depositional units (designated U1-U8 in ascending order) were identified. A comprehensive analysis method of historical geography and sedimentary geology was used to de- termine the precise depositional ages of the modem Yellow River delta (MYRD), from which pre-MYRD ages were deduced. The results indicates that the maximum burial rates of TC, inorganic carbon (IC) and Corg occurred in the delta front (U5), and the mini- mum in the shallow sea (U3). Remarkable high sedimentation rates in the MYRD are responsible for burial efficiency of carbon, with an average rate of Corg burial reaching 2087±251 g(m2yr)-1, and that of IC reaching 13741±808g(m2yr)-1, which are much higher than those of other regions with high contents of Corg. Therefore, YRD has a significant burial efficiency for carbon sequestration.
基金supported by the Sichuan Meteorological Bureau,the Sichuan Meteorological Observation and Data Centerthe Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province[grant number SCQXKJQN202121]+1 种基金the Key Technology Development Project of Weather Forecasting[grant number YBGJXM(2020)1A-08]the Innovative Development Project of the China Meteorological Administration[grant number CXFZ2021Z007]。
文摘High-quality and high-resolution precipitation data are the basis for mesoscale numerical weather forecasting,model verification,and hydrological monitoring,which play an important role in meteorological and hydrological disaster prevention and mitigation.In this study,high-density rain gauge data are used to evaluate the fusion accuracy of the China Meteorological Administration Multisource Precipitation Analysis System(CMPAS),and four CMPAS products with different spatial and temporal resolution and different data sources are compared,to derive the applicability of CMPAS.Results show that all the CMPAS products show high accuracy in the Sichuan Basin,followed by Panxi Area and the western Sichuan Plateau.The errors of the four products all rise with the increase in precipitation.CMPAS overestimates precipitation in summer and autumn and underestimates it in spring and winter.Overall,the applicability of these fused data in the Sichuan Basin is quite good.Due to the lack of observations and the influence of the terrain and meteorological conditions,the evaluation of CMPAS in the plateau area needs further analysis.
基金supported by the Jilin Province Science and Technology Development Project(No.20140101123JC)the Fundamental Research Fund of Jilin Universitythe Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1248)
文摘In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2(Nsp2) and glycoprotein 5(GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.
基金Under the auspices of National Natural Science Foundation of China(No.41201164)Humanities and Social Science Research Planning Fund,Ministry of Education of China(No.12YJCZH299)
文摘Land scarcity has become the prominent obstacle on the way to sustainable development for China. Under the constraints of land shortage, how to allocate the finite land resources to the multiple land users in China considering various political, environmental, ecological and economic conditions have become research topics with great significance. In this study, an interval fuzzy national-scale land-use model(IFNLM) was developed for optimizing land systems of China. IFNLM is based on an integration of existing interval linear programming(ILP), and fuzzy flexible programming(FFP) techniques. IFNLM allows uncertainties expressed as discrete interval values and fuzzy sets to be incorporated within a general optimization framework. It can also facilitate national-scale land-use planning under various environmental, ecological, social conditions within a multi-period and multi-option context. Then, IFNLM was applied to a real case study of land-use planning in China. The satisfaction degree of environmental constraints is between 0.69 and 0.97, the system benefit will between 198.25 × 1012 USD and 229.67 × 1012 USD. The results indicated that the hybrid model can help generate desired policies for land-use allocation with a maximized economic benefit and minimized environmental violation risk. Optimized land-use allocation patterns can be generated from the proposed IFNLM.
基金supported by a grant from the Major Programs of Fundamental Special Work of National Science and Technology (Grand No.2007FY110300),which comes from Ministryof Science and Technology of the People’s Republic of China
文摘Based on comprehensive analysis of the impact of population aging to social and economic development,a comprehensive evaluation system including 18 indexes was constructed for evaluating regional pressure of population aging on social and economic development.Using statistics data of 31 regions in China from 2004 to 2008,the pressure of population aging on social and economic development,was comprehensively evaluated by using the factor analysis method.The spatial distribution of population aging in China was also analyzed.This study is to provide scientific basis for government to make strategies of coping with population aging according to regional pressure of population aging on social and economic development in China.
文摘For years, the US and China have cooperated closely on manufacturing programs, which helps China become the world manufacturing center. While they both have gained much from the cooperation, there are also increasing frictions, disputes, complains and dissatisfaction with each other because of the huge trade unbalance problem and other significant issues. The US is eager to expand export to China, but China seems hesitating to decide what to import from the US. This paper presents an analysis about the benefits of the US-China cooperation with a primary focus on the service sector, which remains a large and untapped opportunity for China. The goal of the paper is to explore a new route to relieve the trade balance issues as they separately impact both nations. While focusing on analyzing several immediate opportunities, the paper also investigates several new ideas that rest on technology as well as entrepreneurial development.
文摘The function of Green Technology Innovation (GTI) in the Eco-Industrial Management (ELM) appears more and more important, but the research on how much this function plays is scarce. The influence of Green Technology Innovation to the Eco-Industrial Management has gradually received the academic and the industrial attention. In this article an empirical research was attempted to inspect whether such influence exists and to what value. The study attempts to empirically explore the influencing degree of GTI on EIM in China based on the double logarithmic regression equation.
文摘Predicate-Argument (PA) structure anal- ysis is often divided into three subtasks: predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isolation. However, this approach neglects logical constraints between them. We therefore exploite integrating predicate sense disambiguation with the latter two subtasks respectively, which verifies that the automatic predicate sense disambiguation could help the se- mantic role labeling task. In addition, a dual de- composition algorithm is used to alleviate the er- ror propagation between argument identification subtask and argument classification subtask by benefitting the argument identification subtask greatly. Experiment results show that our ap- proach leads to a better performance with PA a- nalysis than other pipeline approaches.
文摘This paper establishes the theoretical hypothesis of carbon intensity convergence, and through statistics to analyze and describe the whole country and the eastern and western regions with the use of mixed regression model and fixed effects regression method, and test σ -convergence, absolute convergence and conditional convergence in order to have an empirical study on carbon convergence hypothesis.
基金supported by Chinese National Science & Technology Board (Grant No. 2009DFB90120)
文摘In this research,the Factor Analysis model of measuring provincial low carbon development in China has been constructed.Based on data from 30 provinces,an empirical study was developed to measure comprehensive low carbon development using the Factor Analysis model(Principal Components method and Normalized Varimax Rotation).The results reveal that the provincial marks of low carbon development are generally low and only nine provinces have high marks(more than 0.80).The results also show significant regional disparity.The provincial marks of the eastern region are higher than both the middle and western provinces of China's Mainland.All of the provinces with high marks(more than 0.90) are located in the eastern region,and those with the lowest marks(0.60) are located in the middle region.Furthermore,regional disparity in low carbon development follows the same pattern as economic development in China.Finally,some suggestions for decision-makers are presented.
基金funded by the Thousand Young Talents Program in China(Y7QR011001)National Natural Science Foundation of China(41501445,41771366)+2 种基金Program of Provincial Natural Science Foundation of Anhui(1608085QD77)Program of Nanjing Institute of Geography and Limnology(NIGLAS2016TD01)funded by the United States Geological Surveying(USGS)Landsat Science Team Program Grant(G12PC00071)
文摘China's government statement recently reported the plan of constructing Xiong'an New Area, which aims to phase out some extra capital functions from Beijing and to explore an innovative urban development mode with the priority in eco-environmental protection. The New Area is located in the semi-arid North China Plain (NCP) and is home to NCP's largest natural freshwater wetland, Baiyangdian Lake. A comprehensive realization of surface water dynamics would be crucial for policy-makers to outline a sustainable environment development strategy for New Area. In this study, we used a total of 245 time slices of cloud-free Landsat images to document the continuous changes of water bodies within Xiong'an City dur- ing 1984-2016 and to provide detailed evidence of water presence and persistency states and changes under the influences of climate change and human actions. Our results reveal that the New Area water body areas varied dramatically during the past 33 years, ranging from 0.44 km^2 in April 1988 to 317.85 km^2 in February 1989. The change of surface water area was not characterized by a monotonically decreasing tendency. The evolution processes can be divided into four sub-stages: the first extreme desiccation in mid-1980s, the wet stage with the most extensive inundation areas and strong inter-annual fluctuations from late-1988 to late 1999, another desiccation stage in early 2000s, and the overall recovering stage between 2007 and 2016. We also mapped the maximum water inundation extents and frequencies of all-season, pre-wet season (February-May) and post-wet season (September-December) for the 33 years and different sub-periods. Although there is good agreement between time series of surface water area evolution in the New Area and station-based precipitation and evaporation variations, multipie lines of evidences reviewed in previous research indicate that the degraded Baiyangdian Lake was also tightly associated with human activities from various aspects, including dam construction, ground-water extraction, agricultural irrigation, etc. We highlighted the current status of exploring the driving mechanism of surface water changes and existing problems, and then offer recommendations.
基金Supported by Special Project of National Clinical Research Base of TCM (No. JDZX2012140)Innovation Team Development Plan of the Ministry of Education (No. IRT1276)
文摘OBJECTIVE:To master the syndrome patterns characteristics and explore the effective therapy methods ofTraditional Chinese Medicine(TCM) for cardiac syndrome X(CSX).METHODS:The TCM syndrome characteristics were mastered and the TCM intervention programs were determined by clinical investigations for TCM syndrome patterns characteristics of CSX patients.Then,the clinical efficacy studies on TCM intervention for CSX were carried out through randomized controlled trials.RESULTS:CSX is a clinical syndrome with the main manifestations of chest pain and chest stuffiness,and Qi stagnation,phlegm retention and blood stasis are the basic symptoms of CSX.As a result,the Qi-regulating,chest-relaxing and blood-activating therapy integrated with some Western Medicines was adopted for treatment.The effect of Qi-regulating,chest-relaxing and blood-activating therapy can reduce the frequency and degree of angina,improve the symptoms and exercise the tolerance of patients,inhibit the inflammatory response of vascular walls and protect the function of vascular endothelial cells,which is better than that of the simple and conventionalWestern Medicine alone.CONCLUSION:A good effect was achieved in the integration of Chinese and Western Medicines for CSX.The therapy is worthy to be applied further in clinical practice.On the other hand,more long-term and randomised controlled studies with large samples are still required to further determine the clinical efficacy and safety of the therapy.
基金partially supported by the National Natural Science Foundation of China under Grant Nos.71390330,71390331,71390335the National Nature Science Foundation of China for financial support to this study+1 种基金supported by the Postdoctorate Programme of Centre University of Economics and Financethe Postodctorate Programme of China Great Wall Asset Management Corporation
文摘Understanding the characteristics of the dynamic relationship between the onshore Ren- minbi (CNY) and the offshore Renminbi (CNH) exchange rates considering the impact of some extreme events is very important and it has wide implications in several areas such as hedging. For better esti- mating the dynamic relationship between CNY and CNH, the Granger-causality test and Bry-Boschan Business Cycle Dating Algorithm were employed in this paper. Due to the intrinsic complexity of the lead-lag relationships between CNY and CNH, the empirical mode decomposition (EMD) algorithm is used to decompose those time series data into several intrinsic mode function (IMF) components and a residual sequence, from high to low frequency. Based on the frequencies, the IMFs and a residual sequence are combined into three components, identified as short-term composition caused by some market activities, medium-term composition caused by some extreme events and the long-term trend.The empirical results indicate that when it only matters the short-term market activities, CNH always leads CNY; while the medium-term impact caused by those extreme events may alternate the lead-lag relationships between CNY and CNH.
基金Supported by the National Natural Science Foundation of China(Nos.41071183 and 40601054)
文摘Soil aggregate stability,an important index of the physical characteristics of a soil,can provide a good indication of a soil’s erodibility,and deserves special consideration in regions with cold climate.The objective of this study was to study the effect of freeze-thaw on soil water-stable aggregates in the black soil region of Northeast China.Samples of a typical black soil in the region were collected to measure water-stable aggregates after freeze-thaw under different conditions(i.e.,initial moisture contents,freezethaw cycles and freezing temperatures)by wet-sieving into eight particle size groups(>10,10–6,6–5,5–3,3–2,2–1,1–0.5,and0.5–0.25 mm).Freeze-thaw had the most effect on aggregate stability when the samples had an initial moisture content of 400 g kg-1.The water-stable aggregates of the four larger particle size groups(>5,5–3,3–2,and 2–1 mm)reached a peak stability value,but those of the two smaller particle size groups(1–0.5 and 0.5–0.25 mm)reached a minimum value when the soil moisture content was 400 g kg-1.Water-stable aggregates of the four larger particle size groups decreased while those of the two smaller particle size groups increased with the increase of freeze-thaw cycles.As temperatures fell,the water-stable aggregates of the four larger particle size groups decreased while those of the two smaller particle size groups increased.
基金supported by Chinese Academy of Sciences Strategic Priority Research Program Grant(XDB05020000,XDA05100100)the National Natural Science Foundation of China(41230642,41021004,41203053)
文摘When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the fuel can escape the vehicle through evaporation. Changes in alkanes, olefins and aromatics each affect emissions differently, which could complicate control strategies for air pollution. In this study, we collected 31 gasoline samples over five provinces and cities(Beijing, Tianjin, Hebei, Shandong, and Shaanxi) in North China between 2012 and 2013. The organic composition of the gasoline samples was analyzed using the gas chromatography-mass spectrometry(GC-MS) method, and the aniline compounds were analyzed by solvent extraction and the GC-MS method. The ratios of alkanes, aromatics, olefins and other organic compounds in gasoline were 40.6%, 38.1%, 12.9% and 8.4%, respectively. The aromatic and benzene exceedances were 15 and 8 based on the China's gasoline standards(III), and they accounted for 48.4% and 25.8% of all the gasoline samples, respectively. Strong carcinogen aniline compounds were detected in all 31 samples, and the content of aniline compounds in 3 samples exceeded 1%. The high proportion of aromatics and olefins in the gasoline increased the emissions of carbon monoxide(CO) and toxics, as well as the atmospheric photochemical reactivity of exhaust emissions, which could hasten the formation of secondary pollutants. Our results are helpful for redefining government strategies to control air pollution in North China and relevant for developing new refining technology throughout China.