Understanding the influence of HCl on the NH_(3)-selective catalytic reduction reaction mechanism is crucial for designing highly efficient denitrification catalysts.The formation of chlorate species on the surface of...Understanding the influence of HCl on the NH_(3)-selective catalytic reduction reaction mechanism is crucial for designing highly efficient denitrification catalysts.The formation of chlorate species on the surface of the synthesized SbCeO_(x)catalyst,induced by HCl,significantly enhances low-temperature activity,as evidenced by a 30%increase in NO conversion at 155℃.Furthermore,it improves N_(2)selectivity at high temperatures,with a notable 17%increase observed at 405℃.Both experimental results and density functional theory calculations confirm that chlorate species form at Ce sites.This formation facilitates the creation of oxygen vacancies,boosting the oxygen exchange capacity.It also increases NH_(3)adsorption at the Ce sites,promotes the formation of Sb-OH,and reduces competitive OH adsorption on these sites.Notably,compared with the reaction mechanism without HCl,the presence of chlorate species enhances NH_(3)adsorption and activation,which is vital for subsequent catalytic reactions.展开更多
China’s path to modernization,which embodies a unique developmental model characterized by high-quality development,common prosperity,harmony with nature,and peaceful coexistence,is a multifaceted process that advanc...China’s path to modernization,which embodies a unique developmental model characterized by high-quality development,common prosperity,harmony with nature,and peaceful coexistence,is a multifaceted process that advances progress on multiple fronts.This paper applies two analytical lenses to the study of intergovernmental fiscal relations:multi-level governance,where different levels of government interact,and multi-objective decision-making,where multiple goals are pursued simultaneously.From this perspective,it puts forward three core propositions.First,the evolution of fiscal relations is shaped primarily by the central government’s need to balance incentivization,coordination,and control.Second,these relations are constrained by objective factors such as the output elasticity of loacl government actions,cost coefficients,externalities,and uncertainty.Third,the effectiveness of both central and local governments depends on the design of fiscal relations,as well as on their objectives,the output elasticity of actions,and costs.In essence,effective intergovernmental fiscal relations require a balance between centralized leadership and local initiative.Using this framework,the paper examines how changes in China’s fiscal system have influenced modernization across different historical periods,offering a theoretical model tailored to China’s national context.展开更多
Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results i...Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results into the augmentation of environmental and social costs.For metropolis like Beijing under rapid development,there exist various possibilities and options for transport development policy instruments.But there is no guarantee that they will be suitable for Beijing,although they are effective in their local places.This article assesses what kind of policy can most effectively improve the traffic conditions in Beijing in the future.After literature reviews on the practices of foreign policy and we established several feasible scenarios.Then,we used the Long Range Energy Alternatives Planning System(LREAP) analyzed their corresponding results of reduced energy consumption and emissions.Finally,by simulating and computing the realistic Beijing transportation scenarios,this paper scientifically assesses what kind of policy can most effectively improve the traffic condition in Beijing in the coming decade.展开更多
As two main tools of macroeconomic policies,coordination and conflict between fiscal and monetary policies have been paid considerable attention by researchers.Under a structural vector autoregressive model that incor...As two main tools of macroeconomic policies,coordination and conflict between fiscal and monetary policies have been paid considerable attention by researchers.Under a structural vector autoregressive model that incorporates fiscal and monetary policies,this paper analyzes the monetary policy response to fiscal shocks.Our study finds that during the occurrence of a fiscal shock,the growth rate of broad money supply M2 substantially increased,indicating the adoption of an expansionary monetary policy by the monetary authority to fiscal policy expansion.Based on this empirical finding,this paper improves the dynamic stochastic general equilibrium model to investigate the fiscal policy effects under China’s monetary policy coordination.Our analysis shows that monetary policy coordination will significantly boost the economic stimulus effect of fiscal policy,generating a fiscal crowding-in effect.From the perspective of China’s institutional strength,this conclusion offers a theoretical explanation on the empirical fact of the fiscal crowdingin effect uncovered in the research literature,and offers a policy reference for making the proactive fiscal policy more efficient and effective.This paper suggests that China’s policymakers give full play to the country’s institutional strength by coordinating fiscal and monetary policies for high-quality economic development.展开更多
Objective: It is to determine the causes of invasive fungal sinusitis in patients of Shiraz University hospitals, Iran. Methods: This cross-sectional study was conducted during 18 months (from 21 March 2009 till 22 Se...Objective: It is to determine the causes of invasive fungal sinusitis in patients of Shiraz University hospitals, Iran. Methods: This cross-sectional study was conducted during 18 months (from 21 March 2009 till 22 September 2010) in three Shiraz University Hospitals. Thirty-six patients with sings of invasive fungal sinusitis were enrolled, and tissue samples were investigated for histopathology, culture and antifungal susceptibility test. The laboratory results with host factor and sinus computed tomography scan were evaluated for classification of patients as proven, probable and possible invasive fungal sinusitis. Results: Thirty-five patients have involved with at least one risk factor (immune compromised disease, diabetes mellitus, or use of immune suppressed drugs). Radiological findings of parasinus invasion or necrosis were present in 20 patients. By histopathology, 21 patients were considered as proven, from these, 17 samples had positive growth. The culture aetiology agents were 4 Candida, 8 Aspergillus, and 5 Mucor. All positive culture samples were matched with histopathology findings. Significant associations were considered for radiologic finding and histopathology and culture (p 0.05). From 8 patients with mucormycosis histopathology, 6 suffered from diabetes mellitus. None of the antifungal agents were effective on these three types of infections. Conclusion: DM is the most common predisposing factor for IFS followed by ALL and AML. The most common aetiology of IFS was found to be Aspergillus fumigant followed by Mucormycosis and Candida. None of antifungal agents could successfully cover all the species.展开更多
Dividing aggregate liabilities by GDP is not an appropriate method for calculating the leverage ratio, and may mislead deleveraging operations. In terms of an intrinsic mechanism, an appropriate measure of leverage ra...Dividing aggregate liabilities by GDP is not an appropriate method for calculating the leverage ratio, and may mislead deleveraging operations. In terms of an intrinsic mechanism, an appropriate measure of leverage ratio should be the liability/asset ratio. In their business operations, it is inevitable for real-economy enterprises to incur liabilities arising from business and financial transactions. Therefore, the significance of deleveraging operations is to reduce the leverage ratio below a certain threshold to effectively prevent risks arising from an excessive leverage ratio, rather than to reduce the liability ratio of real-economy enterprises to zero. For real-economy enterprises, a key question is how to adjust their debt structure by reducing current liabilities and increasing mid-and long-term liabilities. The debt structure of real-economy enterprises is primarily determined by their financial structure. Hence, it is essential to adjust the financial structure in order to improve the debt structure of real-economy enterprises and increase the share of direct finance. Various risks exist in the combination of shares and bonds within the banking system, investment-lending linkage and market-based debt-to-equity operations, which are options in reducing the leverage ratio for real-economy enterprises. From the standpoint of giving play to capital market functions, it is advisable to increase the issuance of midand long-term corporate bonds and preferred stock, restrict non-financial listed companies from engaging in financial operations and the shareholders of listed companies from selling shares, encourage equity investment institutions to enhance equity investment in realeconomy enterprises, and further develop the financing function of the stock market.展开更多
AIM:To investigate the efficacy of probiotics in irritable bowel syndrome(IBS) patients.METHODS:Pub Med,Cochrane library,Scopus,Google Scholar,and Clinicaltrial.gov databases were searched for literature published bet...AIM:To investigate the efficacy of probiotics in irritable bowel syndrome(IBS) patients.METHODS:Pub Med,Cochrane library,Scopus,Google Scholar,and Clinicaltrial.gov databases were searched for literature published between September 2007 and December 2013.The applied Mesh terms were "probiotics," "irritable bowel syndrome," and "irritable bowel syndrome treatment." The collected data contained24 clinical trials,of which 15 were eligible for meta-analysis and nine were reviewed systematically.All studies were randomized placebo-controlled trials in patients with IBS that investigated the efficacy of probiotics in IBS improvement.The Jadad score was used to assess the methodological quality of trials.The quality scale ranges from 0 to 5 points,with a score ≤ 2 indicating a low quality report,and a score of ≥3 indicating a high quality report.Relative risk(RR),standardized effect size,and 95%CI were calculated using the Der Simonian-Laird method.The Cochran Q test was used to test heterogeneity with P < 0.05.Funnel plots were constructed and Egger's and BeggMazumdar tests were performed to assess publication bias.RESULTS:A total of 1793 patients were included in the meta-analysis.The RR of responders to therapies based on abdominal pain score in IBS patients for two included trials comparing probiotics to placebo was 1.96(95%CI:1.14-3.36;P = 0.01).RR of responders to therapies based on a global symptom score in IBS patients for two included trials comparing probiotics with placebo was 2.43(95%CI:1.13-5.21;P = 0.02).For adequate improvement of general symptoms in IBS patients,the RR of seven included trials(six studies) comparing probiotics with placebo was 2.14(95%CI:1.08-4.26;P = 0.03).Distension,bloating,and flatulence were evaluated using an IBS severity scoring system in three trials(two studies) to compare the effect of probiotic therapy in IBS patients with placebo,the standardized effect size of mean differences for probiotics therapy was-2.57(95%CI:-13.05--7.92).CONCLUSION:Probiotics reduce pain and symptom severity scores.The results demonstrate the beneficial effects of probiotics in IBS patients in comparison with placebo.展开更多
In view of food affordability and the threshold for food security, this paper has established an integrated index for assessing the vulnerability of food security in China, which is composed mainly of the balance betw...In view of food affordability and the threshold for food security, this paper has established an integrated index for assessing the vulnerability of food security in China, which is composed mainly of the balance between food supply and demand, the reserve for food security and the economic capacity for offset food demand. Six types of food security regions are identified based on the data from county-level statistics. At regional scale, China＇s food security is not optimistic. Under normal conditions without the emergence of extreme disasters and decline of grain-sown areas, China＇s most vulnerable areas （Type Ⅵ） account for 30.3% of the total number of counties （cities）, which are unable to meet the ends by food productivity or market based measures at subsistence levels. In China, there are only 14.5% of the counties （cities） that could guarantee well-off food security through grain production （Type Ⅰ） or economic measures to meet the demand by themselves （Type Ⅲ）. According to the different vulnerable levels of food security and its dominant forming factors, vulnerable regions of food security in China could be classified into three categories： （1） Vulnerable regions of food security dominated by natural factors （including Type IV and Type Via）, which account for 39.4% of the total number of counties （cities）, mainly located in fragile ecologic zones, i.e., farming-grazing transitional zones in the marginal areas of summer monsoon, the poor hilly areas in southern China and so on; （2） Vulnerable regions of food security dominated by low ratio of grain-sown areas （including Type VIb and Type Ⅴ）, which account for 16.7% of the total number of counties （cities）, mostly located in the developed areas in the eastern coast of China; （3） Potential vulnerable regions of food security with underdeveloped local economies （Type Ⅱ）, of which 57% are the main grain-surplus regions in China, mainly located in the areas of plains and basins with favorable climate.展开更多
Based on the China high resolution emission gridded data （I km spatial resolution）, this article is aimed to create a Chinese city carbon dioxide （CO2） emission data set using consolidated data sources as well as ...Based on the China high resolution emission gridded data （I km spatial resolution）, this article is aimed to create a Chinese city carbon dioxide （CO2） emission data set using consolidated data sources as well as normalized and standardized data processing methods. Standard methods were used to calculate city CO2 emissions, including scope I and scope 2. Cities with higher CO2 emissions are mostly in north, northeast, and eastern coastal areas. Cities with lower CO2 emissions are in the western region. Cites with higher CO2 emissions are clustered in the Jing-Jin-Ji Region （such as Beijing, Tianjin, and Tangshan）, and the Yangtze River Delta region （such as Shanghai and Suzhou）. The city per capita CO2 emission is larger in the north than the south. There are obvious aggregations of cities with high per capita CO2 emission in the north. Four cities among the top 10 per capita emissions （Erdos, Wuhai, Shizuishan, and Yinchuan） cluster in the main coal production areas of northern China. This indicates the significant impact of coal resources endowment on city industry and CO2 emissions. The majority （77%） of cities have annual CO2 emissions below 50 million tons. The mean annual emission, among all cities, is 37 million tons. Emissions from service-based cities, which include the smallest number of cities, are the highest. Industrial cities are the largest category and the emission distribution from these cities is close to the normal distribution. Emissions and degree of dispersion, in the other cities （excluding industrial cities and service-based cities）, are in the lowest level. Per capita CO2 emissions in these cities are generally below 20 t/person （89%） with a mean value of 11 t/person. The distribution interval of per capita CO2 emission within industrial cities is the largest among the three city categories. This indicates greater differences among per capita CO2 emissions of industrial cities. The distribution interval of per capita CO2 emission of other cities is the lowest, indicating smaller differences of per capita CO2 emissions among this city category. Three policy suggestions are proposed： first, city CO2 emission inventory data in China should be increased, especially for prefecture level cities. Second, city responsibility for emission reduction, and partition- ing the national goal should be established, using a bottom-up approach based on specific CO2 emission levels and potential for emission reductions in each city. Third, comparative and bench- marking research on city CO2 emissions should be conducted, and a Top Runner system of city CO2 emission reduction should be established.展开更多
The Chinese economy has achieved remarkable development over the past 40 years of reform and opening-up.However,with the narrowing of potential for efficiency improvement from resources reallocation and changes in pop...The Chinese economy has achieved remarkable development over the past 40 years of reform and opening-up.However,with the narrowing of potential for efficiency improvement from resources reallocation and changes in population age structure,the Chinese economy has moved from high-speed growth to high-quality development.In this setting,understanding factor endowment and comparative advantages of the economy from a perspective of human capital structure so as to enhance industrial structure adaptability by riding the trend is of significance for cultivating new driving force for economic development.This paper,following a theoretical paradigm of new structural economics,demonstrates how human capital structure matches industrial structure and the presence of optimal human capital structure using mathematical deduction.On this basis,national level panel data and instrumental variables are adopted for generalized method of moments,the results of which shows that there are varied impacts on economic growth in light of different human capital structure characteristics.The proportions of high-level human capital and medium-level human capital boost economic development,while that of low-level human capital has an inhibitory effect on economic growth.The policy implication of this study is that large economies should diversify efforts as per different human capital structure characteristics in terms of development need of tapping growth impetus from human capital structure improvement.It is of equal importance to raise the proportion of high and medium human capital in order to stimulate economic growth and to cut the proportion of low human capital that hinders economic development.展开更多
Inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative colitis, not only affect the intestinal tract but also have an extraintestinal involvement within the oral cavity. These or...Inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative colitis, not only affect the intestinal tract but also have an extraintestinal involvement within the oral cavity. These oral manifestations may assist in the diagnosis and the monitoring of disease activity, whilst ignoring them may lead to an inaccurate diagnosis and useless and expensive workups. Indurated tag-like lesions, cobblestoning, and mucogingivitis are the most common specific oral findings encountered in CD cases. Aphthous stomatitis and pyostomatitis vegetans are among non-specific oral manifestations of IBD. In differential diagnosis, side effects of drugs, infections, nutritional deficiencies, and other inflammatory conditions should also be considered. Treatment usually involves managing the underlying intestinal disease. In severe cases with local symptoms, topical and/or systemic steroids and immunosuppressive drugs might be used.展开更多
The paper summarizes results of the China Energy Modeling Forum's(CEMF)first study.Carbon emissions peaking scenarios,consistent with China's Paris commitment,have been simulated with seven national and indust...The paper summarizes results of the China Energy Modeling Forum's(CEMF)first study.Carbon emissions peaking scenarios,consistent with China's Paris commitment,have been simulated with seven national and industry-level energy models and compared.The CO2 emission trends in the considered scenarios peak from 2015 to 2030 at the level of 9e11 Gt.Sector-level analysis suggests that total emissions pathways before 2030 will be determined mainly by dynamics of emissions in the electric power industry and transportation sector.Both sectors will experience significant increase in demand,but have low-carbon alternative options for development.Based on a side-by-side comparison of modeling input and results,conclusions have been drawn regarding the sources of emissions projections differences,which include data,views on economic perspectives,or models'structure and theoretical framework.Some suggestions have been made regarding energy models'development priorities for further research.展开更多
It is hypothesized that liver impairment caused by coronavirus disease 2019(COVID-19)infection might play a central role in severe clinical presentations.Liver injury is closely associated with severe disease and,even...It is hypothesized that liver impairment caused by coronavirus disease 2019(COVID-19)infection might play a central role in severe clinical presentations.Liver injury is closely associated with severe disease and,even with antiviral drugs,have a poor prognosis in COVID-19 patients.In addition to the common hepatobiliary disorders caused by COVID-19,patients with pre-existing liver diseases demand special considerations during the current pandemic.Thus,it is vital that upon clinical presentation,patients with concurrent pre-existing liver disease associated with metabolic dysfunction and COVID-19 be managed properly to prevent liver failure.Careful monitoring and early detection of liver damage through biomarkers after hospitalization for COVID-19 is underscored in all cases,particularly in those with pre-existing metabolic liver injury.The purpose of this study was to determine most recent evidence regarding causality,potential risk factors,and challenges,therapeutic options,and management of COVID-19 infection in vulnerable patients with pre-existing liver injury.This review aims to highlight the current frontier of COVID-19 infection and liver injury and the direction of liver injury in these patients.展开更多
Objective:To determine the temporal patterns of cumulative incidence of brucellosis using autoregressive integrated moving average models.Methods:This cross-sectional study employed yearly and monthly data of 1117 lab...Objective:To determine the temporal patterns of cumulative incidence of brucellosis using autoregressive integrated moving average models.Methods:This cross-sectional study employed yearly and monthly data of 1117 laboratory-confirmed human brucellosis cases from January 2013 to December 2018 using the Yazd brucellosis national surveillance system.The monthly incidences constructed a timeseries model.The trend of cumulative incidence was perceived by tracing a line plot,which displayed a seasonal trend with periodicity.Thus,the ARIMA models were selected.Thereafter,Akaike information criteria(AIC)and Bayesian information criterion(BIC)values among different models indicated a preferable model from models which were expanded by diverse lags[(3,0,3),(2,0,3),(3,0,2),(4,0,3)and(3,0,4)].Then,the achieved ARIMA model was applied to the forecasting cumulative incidence of monthly brucellosis incidences.All analyses were performed using Stata,version 11.2.Results:For the ARIMA(3,0,4)model,MAPE value was 56.20%with standard error 0.009–0.016,and white noise diagnostic check(Q=19.79,P=0.975)for the residuals of the selected model showed that the data were completely modelled.The monthly incidences that were fitted by the ARIMA(3,0,4)model,with AIC(25.7)and BIC(43.35)with a similar pattern of actual cases from 2013 to 2018 and forecasting incidences from January 2019 to December 2019 were,respectively,0.50,0.44,0.45,0.49,0.55,0.58,0.56,0.51,0.46,0.44,0.45 and 0.49 per 100000 people.Conclusions:In summary,the study showed that the ARIMA(3,0,4)model can be applied to forecast human brucellosis patterns in Yazd province,supplementing present surveillance systems,and may be better for health policy-makers and planners.展开更多
OBJECTIVE： There is increasing interest in complementary and alternative medicine generally, and especially by those affected by chronic diseases, such as diabetes mellitus. We aimed to determine the prevalence and p...OBJECTIVE： There is increasing interest in complementary and alternative medicine generally, and especially by those affected by chronic diseases, such as diabetes mellitus. We aimed to determine the prevalence and pattern of complementary and altemative medicine use among patients suffering from diabetes mellitus in Shiraz, southern Iran. Another objective was to explore associated factors for use of complementary and alternative medicine among patients with diabetes mellitus. METHODS： A 19-item semi-structured questionnaire （open- and close-ended） was administered to 239 patients with diabetes mellitus in this cross-sectional study. It was carried out in two outpatient diabetes clinics affiliated with the Shiraz University of Medical Sciences, Shiraz, Iran. RESULTS： One hundred and eighty patients （75.3%） used at least one type of complementary and alternative medicine in the last year prior to the interview. Patients with diabetes mellitus who were living in a large family （〉 5 members）, not taking insulin, and believed that complementary and alternative medicine have synergistic effects with conventional medicine, were independently and significantly （P values： 0.02, 0.04, and 0.01, respectively） more likely to use complementary and alternative medicine. Most of the users （97.7%） reported use of herbal preparations, and 89.4% of users did not change their medication, neither in medication schedule nor its dosage. CONCLUSION： The use of complementary and alternative medicine, especially herbal remedies, is popular among diabetes patients in Shiraz, Iran. This use is associated with patients＇ family size, type of conventional medications and their view about concomitant use of complementary and conventional medicine.展开更多
Based on the MAP-CGE model,this paper simulated the impacts on the output,energy consumption and pollutant emissions of different cement production processes when implementing a low carbon cement standard in China.It ...Based on the MAP-CGE model,this paper simulated the impacts on the output,energy consumption and pollutant emissions of different cement production processes when implementing a low carbon cement standard in China.It also calculated the impacts on the marginal abatement cost and equilibrium price of the cement industry,and analyzed the co-abatement effects of different pollutants.The results showed that implementing the low carbon cement standard will be beneficial in promoting an upgrading of cement production processes,and strengthening the energy conservation and emission reduction in the cement industry.If there is no change in the existing technology,the cement industry will reduce SO2emissions by 1.17 kg and NOxemissions by 4.44 kg per ton of CO2emission reduction.Implementing low carbon cement standard can also promote NOxabatement in the cement industry.However,the cement industry will bear the abatement costs,and their equilibrium price will increase slightly.展开更多
The coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern.In addition to affecting the respiratory system,COVID-19 can potentially damage other system...The coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern.In addition to affecting the respiratory system,COVID-19 can potentially damage other systems in the body,leading to extra-pulmonary manifestations.Hepatic manifestations are among the common consequences of COVID-19.Although the precise mechanism of liver injury is still questionable,several mechanisms have been hypothesized,including direct viral effect,cytokine storm,hypoxic-ischemic injury,hypoxiareperfusion injury,ferroptosis,and hepatotoxic medications.Risk factors of COVID-19-induced liver injury include severe COVID-19 infection,male gender,advanced age,obesity,and underlying diseases.The presentations of liver involvement comprise abnormalities in liver enzymes and radiologic findings,which can be utilized to predict the prognosis.Increased gamma-glutamyltransferase,aspartate aminotransferase,and alanine aminotransferase levels with hypoalbuminemia can indicate severe liver injury and anticipate the need for intensive care units’hospitalization.In imaging,a lower liver-to-spleen ratio and liver computed tomography attenuation may indicate a more severe illness.Furthermore,chronic liver disease patients are at a higher risk for severe disease and death from COVID-19.Nonalcoholic fatty liver disease had the highest risk of advanced COVID-19 disease and death,followed by metabolic-associated fatty liver disease and cirrhosis.In addition to COVID-19-induced liver injury,the pandemic has also altered the epidemiology and pattern of some hepatic diseases,such as alcoholic liver disease and hepatitis B.Therefore,it warrants special vigilance and awareness by healthcare professionals to screen and treat COVID-19-associated liver injury accordingly.展开更多
China has entered the middle-to-late stage of urbanization.The scale of urbanto-urban migrants,which more refers to the urban-to-urban floating population(UUFP)across China,has significantly increased.UUFP settlement ...China has entered the middle-to-late stage of urbanization.The scale of urbanto-urban migrants,which more refers to the urban-to-urban floating population(UUFP)across China,has significantly increased.UUFP settlement intention is a crucial issue for urbanization development.This study examines the spatial pattern and factors influencing the settlement intention of the UUFP in China based on data obtained through its dynamic monitoring in 2017 and the binary logistic model.The results show that most members of the UUFP were married,older,better educated,and had a higher income than the average person with extensive migration experience.We correlated a high settlement intention with developed economies,coastal areas,good environmental conditions,and more amenities in cities such as Beijing,Tianjin,Shanghai,and Zhuhai.Amenities were more impactful on settlement intention than economic factors,from individual and regional perspectives.The UUFP more often sought equality of education for children and social integration in its choices of destinations.However,the distance was not a hindrance to intention to settle but played a substantial role in influencing it.We suggest optimizing the stock of the UUFP in large cities,improving public education services,and promoting remote urbanization.Likewise,industrial transfer and enhanced public resources may ease the pressure of large UUFP flows into large cities.展开更多
Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian...Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian Mountain, where forest, shrubland and grassland consist of its main ecosystems, can provide fresh water and many other ecosystem services, through a series of eco-hydrological process such as precipitation interception, soil water storage, and fresh water provision. Thus, monitoring water regulation and assessing the hydrological service of the Qilian Mountain are meaningful and helpful for the healthy development of the lower reaches of arid and semi-arid areas. In recent 10 years, hydrological services have been widely researched in terms of scale and landscape pattern, including water conservation, hydrological responses to afforestation and their ecological effects. This study, after analyzing lots of current models and applications of geographical information system（GIS） in hydrological services, gave a scientific and reasonable evaluation of mountain ecosystem in eco-hydrological services, by employing the combination of international forefronts and contentious issues into the Qilian Mountain. Assessments of hydrological services at regional or larger scales are limited compared with studies within watershed scale in the Qilian Mountain. In our evaluation results of forest ecosystems, it is concluded that long-term observation and dynamic monitoring of different types of ecosystem are indispensable, and the hydrological services and the potential variation in water supplement on regional and large scales should be central issues in the future research.v展开更多
Although China was one of the countries with the fastest-growing aging population in the world,limited scholarly attention has been paid to migration among older adults in China.The full picture of their migration in ...Although China was one of the countries with the fastest-growing aging population in the world,limited scholarly attention has been paid to migration among older adults in China.The full picture of their migration in the entire country over time remains unknown.This study examines the spatial patterns of older interprovincial migration flows and their drivers in China over the period 1995 to 2015,using four waves of census data and intercensal population sample survey data.Results from eigenvector spatial filtering negative binomial regressions indicate that older adults tend to migrate away from low cost-of-living rural areas to high cost-of-living urban and rural areas,moving away from areas with extreme temperature differences.The location of their grandchildren is among the most important attractions.Our findings suggest that family-oriented migration is more common than amenity-led migration among retired Chinese older adults,and the cost-of-living is an indicator of economic opportunities for adult children and the quality of senior care services.展开更多
文摘Understanding the influence of HCl on the NH_(3)-selective catalytic reduction reaction mechanism is crucial for designing highly efficient denitrification catalysts.The formation of chlorate species on the surface of the synthesized SbCeO_(x)catalyst,induced by HCl,significantly enhances low-temperature activity,as evidenced by a 30%increase in NO conversion at 155℃.Furthermore,it improves N_(2)selectivity at high temperatures,with a notable 17%increase observed at 405℃.Both experimental results and density functional theory calculations confirm that chlorate species form at Ce sites.This formation facilitates the creation of oxygen vacancies,boosting the oxygen exchange capacity.It also increases NH_(3)adsorption at the Ce sites,promotes the formation of Sb-OH,and reduces competitive OH adsorption on these sites.Notably,compared with the reaction mechanism without HCl,the presence of chlorate species enhances NH_(3)adsorption and activation,which is vital for subsequent catalytic reactions.
基金supported by the General Program of the National Natural Science Foundation of China(NSFC)(Grant No.72373148).
文摘China’s path to modernization,which embodies a unique developmental model characterized by high-quality development,common prosperity,harmony with nature,and peaceful coexistence,is a multifaceted process that advances progress on multiple fronts.This paper applies two analytical lenses to the study of intergovernmental fiscal relations:multi-level governance,where different levels of government interact,and multi-objective decision-making,where multiple goals are pursued simultaneously.From this perspective,it puts forward three core propositions.First,the evolution of fiscal relations is shaped primarily by the central government’s need to balance incentivization,coordination,and control.Second,these relations are constrained by objective factors such as the output elasticity of loacl government actions,cost coefficients,externalities,and uncertainty.Third,the effectiveness of both central and local governments depends on the design of fiscal relations,as well as on their objectives,the output elasticity of actions,and costs.In essence,effective intergovernmental fiscal relations require a balance between centralized leadership and local initiative.Using this framework,the paper examines how changes in China’s fiscal system have influenced modernization across different historical periods,offering a theoretical model tailored to China’s national context.
文摘Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results into the augmentation of environmental and social costs.For metropolis like Beijing under rapid development,there exist various possibilities and options for transport development policy instruments.But there is no guarantee that they will be suitable for Beijing,although they are effective in their local places.This article assesses what kind of policy can most effectively improve the traffic conditions in Beijing in the future.After literature reviews on the practices of foreign policy and we established several feasible scenarios.Then,we used the Long Range Energy Alternatives Planning System(LREAP) analyzed their corresponding results of reduced energy consumption and emissions.Finally,by simulating and computing the realistic Beijing transportation scenarios,this paper scientifically assesses what kind of policy can most effectively improve the traffic condition in Beijing in the coming decade.
基金a result of the Major Project of the National Social Science Fund of China (NSSFC)“Study on Monetary Policy and Fiscal Policy Coordination under the Dual Economic Circulations”(Grant No.20&ZD104)
文摘As two main tools of macroeconomic policies,coordination and conflict between fiscal and monetary policies have been paid considerable attention by researchers.Under a structural vector autoregressive model that incorporates fiscal and monetary policies,this paper analyzes the monetary policy response to fiscal shocks.Our study finds that during the occurrence of a fiscal shock,the growth rate of broad money supply M2 substantially increased,indicating the adoption of an expansionary monetary policy by the monetary authority to fiscal policy expansion.Based on this empirical finding,this paper improves the dynamic stochastic general equilibrium model to investigate the fiscal policy effects under China’s monetary policy coordination.Our analysis shows that monetary policy coordination will significantly boost the economic stimulus effect of fiscal policy,generating a fiscal crowding-in effect.From the perspective of China’s institutional strength,this conclusion offers a theoretical explanation on the empirical fact of the fiscal crowdingin effect uncovered in the research literature,and offers a policy reference for making the proactive fiscal policy more efficient and effective.This paper suggests that China’s policymakers give full play to the country’s institutional strength by coordinating fiscal and monetary policies for high-quality economic development.
文摘Objective: It is to determine the causes of invasive fungal sinusitis in patients of Shiraz University hospitals, Iran. Methods: This cross-sectional study was conducted during 18 months (from 21 March 2009 till 22 September 2010) in three Shiraz University Hospitals. Thirty-six patients with sings of invasive fungal sinusitis were enrolled, and tissue samples were investigated for histopathology, culture and antifungal susceptibility test. The laboratory results with host factor and sinus computed tomography scan were evaluated for classification of patients as proven, probable and possible invasive fungal sinusitis. Results: Thirty-five patients have involved with at least one risk factor (immune compromised disease, diabetes mellitus, or use of immune suppressed drugs). Radiological findings of parasinus invasion or necrosis were present in 20 patients. By histopathology, 21 patients were considered as proven, from these, 17 samples had positive growth. The culture aetiology agents were 4 Candida, 8 Aspergillus, and 5 Mucor. All positive culture samples were matched with histopathology findings. Significant associations were considered for radiologic finding and histopathology and culture (p 0.05). From 8 patients with mucormycosis histopathology, 6 suffered from diabetes mellitus. None of the antifungal agents were effective on these three types of infections. Conclusion: DM is the most common predisposing factor for IFS followed by ALL and AML. The most common aetiology of IFS was found to be Aspergillus fumigant followed by Mucormycosis and Candida. None of antifungal agents could successfully cover all the species.
文摘Dividing aggregate liabilities by GDP is not an appropriate method for calculating the leverage ratio, and may mislead deleveraging operations. In terms of an intrinsic mechanism, an appropriate measure of leverage ratio should be the liability/asset ratio. In their business operations, it is inevitable for real-economy enterprises to incur liabilities arising from business and financial transactions. Therefore, the significance of deleveraging operations is to reduce the leverage ratio below a certain threshold to effectively prevent risks arising from an excessive leverage ratio, rather than to reduce the liability ratio of real-economy enterprises to zero. For real-economy enterprises, a key question is how to adjust their debt structure by reducing current liabilities and increasing mid-and long-term liabilities. The debt structure of real-economy enterprises is primarily determined by their financial structure. Hence, it is essential to adjust the financial structure in order to improve the debt structure of real-economy enterprises and increase the share of direct finance. Various risks exist in the combination of shares and bonds within the banking system, investment-lending linkage and market-based debt-to-equity operations, which are options in reducing the leverage ratio for real-economy enterprises. From the standpoint of giving play to capital market functions, it is advisable to increase the issuance of midand long-term corporate bonds and preferred stock, restrict non-financial listed companies from engaging in financial operations and the shareholders of listed companies from selling shares, encourage equity investment institutions to enhance equity investment in realeconomy enterprises, and further develop the financing function of the stock market.
文摘AIM:To investigate the efficacy of probiotics in irritable bowel syndrome(IBS) patients.METHODS:Pub Med,Cochrane library,Scopus,Google Scholar,and Clinicaltrial.gov databases were searched for literature published between September 2007 and December 2013.The applied Mesh terms were "probiotics," "irritable bowel syndrome," and "irritable bowel syndrome treatment." The collected data contained24 clinical trials,of which 15 were eligible for meta-analysis and nine were reviewed systematically.All studies were randomized placebo-controlled trials in patients with IBS that investigated the efficacy of probiotics in IBS improvement.The Jadad score was used to assess the methodological quality of trials.The quality scale ranges from 0 to 5 points,with a score ≤ 2 indicating a low quality report,and a score of ≥3 indicating a high quality report.Relative risk(RR),standardized effect size,and 95%CI were calculated using the Der Simonian-Laird method.The Cochran Q test was used to test heterogeneity with P < 0.05.Funnel plots were constructed and Egger's and BeggMazumdar tests were performed to assess publication bias.RESULTS:A total of 1793 patients were included in the meta-analysis.The RR of responders to therapies based on abdominal pain score in IBS patients for two included trials comparing probiotics to placebo was 1.96(95%CI:1.14-3.36;P = 0.01).RR of responders to therapies based on a global symptom score in IBS patients for two included trials comparing probiotics with placebo was 2.43(95%CI:1.13-5.21;P = 0.02).For adequate improvement of general symptoms in IBS patients,the RR of seven included trials(six studies) comparing probiotics with placebo was 2.14(95%CI:1.08-4.26;P = 0.03).Distension,bloating,and flatulence were evaluated using an IBS severity scoring system in three trials(two studies) to compare the effect of probiotic therapy in IBS patients with placebo,the standardized effect size of mean differences for probiotics therapy was-2.57(95%CI:-13.05--7.92).CONCLUSION:Probiotics reduce pain and symptom severity scores.The results demonstrate the beneficial effects of probiotics in IBS patients in comparison with placebo.
基金National Natural Science Foundation of China, No.40571165Key Project of National Scientific and Tech-nological Support Plan, No.2007BAC03A11
文摘In view of food affordability and the threshold for food security, this paper has established an integrated index for assessing the vulnerability of food security in China, which is composed mainly of the balance between food supply and demand, the reserve for food security and the economic capacity for offset food demand. Six types of food security regions are identified based on the data from county-level statistics. At regional scale, China＇s food security is not optimistic. Under normal conditions without the emergence of extreme disasters and decline of grain-sown areas, China＇s most vulnerable areas （Type Ⅵ） account for 30.3% of the total number of counties （cities）, which are unable to meet the ends by food productivity or market based measures at subsistence levels. In China, there are only 14.5% of the counties （cities） that could guarantee well-off food security through grain production （Type Ⅰ） or economic measures to meet the demand by themselves （Type Ⅲ）. According to the different vulnerable levels of food security and its dominant forming factors, vulnerable regions of food security in China could be classified into three categories： （1） Vulnerable regions of food security dominated by natural factors （including Type IV and Type Via）, which account for 39.4% of the total number of counties （cities）, mainly located in fragile ecologic zones, i.e., farming-grazing transitional zones in the marginal areas of summer monsoon, the poor hilly areas in southern China and so on; （2） Vulnerable regions of food security dominated by low ratio of grain-sown areas （including Type VIb and Type Ⅴ）, which account for 16.7% of the total number of counties （cities）, mostly located in the developed areas in the eastern coast of China; （3） Potential vulnerable regions of food security with underdeveloped local economies （Type Ⅱ）, of which 57% are the main grain-surplus regions in China, mainly located in the areas of plains and basins with favorable climate.
基金funded by the project entitled"An Emission-Transport-Exposure Model Based Study on the Evaluation of the Environmental Impact of Carbon Market"[grant number:71673107]supported by the National Natural Science Foundation of China
文摘Based on the China high resolution emission gridded data （I km spatial resolution）, this article is aimed to create a Chinese city carbon dioxide （CO2） emission data set using consolidated data sources as well as normalized and standardized data processing methods. Standard methods were used to calculate city CO2 emissions, including scope I and scope 2. Cities with higher CO2 emissions are mostly in north, northeast, and eastern coastal areas. Cities with lower CO2 emissions are in the western region. Cites with higher CO2 emissions are clustered in the Jing-Jin-Ji Region （such as Beijing, Tianjin, and Tangshan）, and the Yangtze River Delta region （such as Shanghai and Suzhou）. The city per capita CO2 emission is larger in the north than the south. There are obvious aggregations of cities with high per capita CO2 emission in the north. Four cities among the top 10 per capita emissions （Erdos, Wuhai, Shizuishan, and Yinchuan） cluster in the main coal production areas of northern China. This indicates the significant impact of coal resources endowment on city industry and CO2 emissions. The majority （77%） of cities have annual CO2 emissions below 50 million tons. The mean annual emission, among all cities, is 37 million tons. Emissions from service-based cities, which include the smallest number of cities, are the highest. Industrial cities are the largest category and the emission distribution from these cities is close to the normal distribution. Emissions and degree of dispersion, in the other cities （excluding industrial cities and service-based cities）, are in the lowest level. Per capita CO2 emissions in these cities are generally below 20 t/person （89%） with a mean value of 11 t/person. The distribution interval of per capita CO2 emission within industrial cities is the largest among the three city categories. This indicates greater differences among per capita CO2 emissions of industrial cities. The distribution interval of per capita CO2 emission of other cities is the lowest, indicating smaller differences of per capita CO2 emissions among this city category. Three policy suggestions are proposed： first, city CO2 emission inventory data in China should be increased, especially for prefecture level cities. Second, city responsibility for emission reduction, and partition- ing the national goal should be established, using a bottom-up approach based on specific CO2 emission levels and potential for emission reductions in each city. Third, comparative and bench- marking research on city CO2 emissions should be conducted, and a Top Runner system of city CO2 emission reduction should be established.
文摘The Chinese economy has achieved remarkable development over the past 40 years of reform and opening-up.However,with the narrowing of potential for efficiency improvement from resources reallocation and changes in population age structure,the Chinese economy has moved from high-speed growth to high-quality development.In this setting,understanding factor endowment and comparative advantages of the economy from a perspective of human capital structure so as to enhance industrial structure adaptability by riding the trend is of significance for cultivating new driving force for economic development.This paper,following a theoretical paradigm of new structural economics,demonstrates how human capital structure matches industrial structure and the presence of optimal human capital structure using mathematical deduction.On this basis,national level panel data and instrumental variables are adopted for generalized method of moments,the results of which shows that there are varied impacts on economic growth in light of different human capital structure characteristics.The proportions of high-level human capital and medium-level human capital boost economic development,while that of low-level human capital has an inhibitory effect on economic growth.The policy implication of this study is that large economies should diversify efforts as per different human capital structure characteristics in terms of development need of tapping growth impetus from human capital structure improvement.It is of equal importance to raise the proportion of high and medium human capital in order to stimulate economic growth and to cut the proportion of low human capital that hinders economic development.
文摘Inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative colitis, not only affect the intestinal tract but also have an extraintestinal involvement within the oral cavity. These oral manifestations may assist in the diagnosis and the monitoring of disease activity, whilst ignoring them may lead to an inaccurate diagnosis and useless and expensive workups. Indurated tag-like lesions, cobblestoning, and mucogingivitis are the most common specific oral findings encountered in CD cases. Aphthous stomatitis and pyostomatitis vegetans are among non-specific oral manifestations of IBD. In differential diagnosis, side effects of drugs, infections, nutritional deficiencies, and other inflammatory conditions should also be considered. Treatment usually involves managing the underlying intestinal disease. In severe cases with local symptoms, topical and/or systemic steroids and immunosuppressive drugs might be used.
文摘The paper summarizes results of the China Energy Modeling Forum's(CEMF)first study.Carbon emissions peaking scenarios,consistent with China's Paris commitment,have been simulated with seven national and industry-level energy models and compared.The CO2 emission trends in the considered scenarios peak from 2015 to 2030 at the level of 9e11 Gt.Sector-level analysis suggests that total emissions pathways before 2030 will be determined mainly by dynamics of emissions in the electric power industry and transportation sector.Both sectors will experience significant increase in demand,but have low-carbon alternative options for development.Based on a side-by-side comparison of modeling input and results,conclusions have been drawn regarding the sources of emissions projections differences,which include data,views on economic perspectives,or models'structure and theoretical framework.Some suggestions have been made regarding energy models'development priorities for further research.
文摘It is hypothesized that liver impairment caused by coronavirus disease 2019(COVID-19)infection might play a central role in severe clinical presentations.Liver injury is closely associated with severe disease and,even with antiviral drugs,have a poor prognosis in COVID-19 patients.In addition to the common hepatobiliary disorders caused by COVID-19,patients with pre-existing liver diseases demand special considerations during the current pandemic.Thus,it is vital that upon clinical presentation,patients with concurrent pre-existing liver disease associated with metabolic dysfunction and COVID-19 be managed properly to prevent liver failure.Careful monitoring and early detection of liver damage through biomarkers after hospitalization for COVID-19 is underscored in all cases,particularly in those with pre-existing metabolic liver injury.The purpose of this study was to determine most recent evidence regarding causality,potential risk factors,and challenges,therapeutic options,and management of COVID-19 infection in vulnerable patients with pre-existing liver injury.This review aims to highlight the current frontier of COVID-19 infection and liver injury and the direction of liver injury in these patients.
文摘Objective:To determine the temporal patterns of cumulative incidence of brucellosis using autoregressive integrated moving average models.Methods:This cross-sectional study employed yearly and monthly data of 1117 laboratory-confirmed human brucellosis cases from January 2013 to December 2018 using the Yazd brucellosis national surveillance system.The monthly incidences constructed a timeseries model.The trend of cumulative incidence was perceived by tracing a line plot,which displayed a seasonal trend with periodicity.Thus,the ARIMA models were selected.Thereafter,Akaike information criteria(AIC)and Bayesian information criterion(BIC)values among different models indicated a preferable model from models which were expanded by diverse lags[(3,0,3),(2,0,3),(3,0,2),(4,0,3)and(3,0,4)].Then,the achieved ARIMA model was applied to the forecasting cumulative incidence of monthly brucellosis incidences.All analyses were performed using Stata,version 11.2.Results:For the ARIMA(3,0,4)model,MAPE value was 56.20%with standard error 0.009–0.016,and white noise diagnostic check(Q=19.79,P=0.975)for the residuals of the selected model showed that the data were completely modelled.The monthly incidences that were fitted by the ARIMA(3,0,4)model,with AIC(25.7)and BIC(43.35)with a similar pattern of actual cases from 2013 to 2018 and forecasting incidences from January 2019 to December 2019 were,respectively,0.50,0.44,0.45,0.49,0.55,0.58,0.56,0.51,0.46,0.44,0.45 and 0.49 per 100000 people.Conclusions:In summary,the study showed that the ARIMA(3,0,4)model can be applied to forecast human brucellosis patterns in Yazd province,supplementing present surveillance systems,and may be better for health policy-makers and planners.
文摘OBJECTIVE： There is increasing interest in complementary and alternative medicine generally, and especially by those affected by chronic diseases, such as diabetes mellitus. We aimed to determine the prevalence and pattern of complementary and altemative medicine use among patients suffering from diabetes mellitus in Shiraz, southern Iran. Another objective was to explore associated factors for use of complementary and alternative medicine among patients with diabetes mellitus. METHODS： A 19-item semi-structured questionnaire （open- and close-ended） was administered to 239 patients with diabetes mellitus in this cross-sectional study. It was carried out in two outpatient diabetes clinics affiliated with the Shiraz University of Medical Sciences, Shiraz, Iran. RESULTS： One hundred and eighty patients （75.3%） used at least one type of complementary and alternative medicine in the last year prior to the interview. Patients with diabetes mellitus who were living in a large family （〉 5 members）, not taking insulin, and believed that complementary and alternative medicine have synergistic effects with conventional medicine, were independently and significantly （P values： 0.02, 0.04, and 0.01, respectively） more likely to use complementary and alternative medicine. Most of the users （97.7%） reported use of herbal preparations, and 89.4% of users did not change their medication, neither in medication schedule nor its dosage. CONCLUSION： The use of complementary and alternative medicine, especially herbal remedies, is popular among diabetes patients in Shiraz, Iran. This use is associated with patients＇ family size, type of conventional medications and their view about concomitant use of complementary and conventional medicine.
基金supported by the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China(No.14XNJ008)
文摘Based on the MAP-CGE model,this paper simulated the impacts on the output,energy consumption and pollutant emissions of different cement production processes when implementing a low carbon cement standard in China.It also calculated the impacts on the marginal abatement cost and equilibrium price of the cement industry,and analyzed the co-abatement effects of different pollutants.The results showed that implementing the low carbon cement standard will be beneficial in promoting an upgrading of cement production processes,and strengthening the energy conservation and emission reduction in the cement industry.If there is no change in the existing technology,the cement industry will reduce SO2emissions by 1.17 kg and NOxemissions by 4.44 kg per ton of CO2emission reduction.Implementing low carbon cement standard can also promote NOxabatement in the cement industry.However,the cement industry will bear the abatement costs,and their equilibrium price will increase slightly.
文摘The coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern.In addition to affecting the respiratory system,COVID-19 can potentially damage other systems in the body,leading to extra-pulmonary manifestations.Hepatic manifestations are among the common consequences of COVID-19.Although the precise mechanism of liver injury is still questionable,several mechanisms have been hypothesized,including direct viral effect,cytokine storm,hypoxic-ischemic injury,hypoxiareperfusion injury,ferroptosis,and hepatotoxic medications.Risk factors of COVID-19-induced liver injury include severe COVID-19 infection,male gender,advanced age,obesity,and underlying diseases.The presentations of liver involvement comprise abnormalities in liver enzymes and radiologic findings,which can be utilized to predict the prognosis.Increased gamma-glutamyltransferase,aspartate aminotransferase,and alanine aminotransferase levels with hypoalbuminemia can indicate severe liver injury and anticipate the need for intensive care units’hospitalization.In imaging,a lower liver-to-spleen ratio and liver computed tomography attenuation may indicate a more severe illness.Furthermore,chronic liver disease patients are at a higher risk for severe disease and death from COVID-19.Nonalcoholic fatty liver disease had the highest risk of advanced COVID-19 disease and death,followed by metabolic-associated fatty liver disease and cirrhosis.In addition to COVID-19-induced liver injury,the pandemic has also altered the epidemiology and pattern of some hepatic diseases,such as alcoholic liver disease and hepatitis B.Therefore,it warrants special vigilance and awareness by healthcare professionals to screen and treat COVID-19-associated liver injury accordingly.
基金National Natural Sciences Foundation of China,No.42171237。
文摘China has entered the middle-to-late stage of urbanization.The scale of urbanto-urban migrants,which more refers to the urban-to-urban floating population(UUFP)across China,has significantly increased.UUFP settlement intention is a crucial issue for urbanization development.This study examines the spatial pattern and factors influencing the settlement intention of the UUFP in China based on data obtained through its dynamic monitoring in 2017 and the binary logistic model.The results show that most members of the UUFP were married,older,better educated,and had a higher income than the average person with extensive migration experience.We correlated a high settlement intention with developed economies,coastal areas,good environmental conditions,and more amenities in cities such as Beijing,Tianjin,Shanghai,and Zhuhai.Amenities were more impactful on settlement intention than economic factors,from individual and regional perspectives.The UUFP more often sought equality of education for children and social integration in its choices of destinations.However,the distance was not a hindrance to intention to settle but played a substantial role in influencing it.We suggest optimizing the stock of the UUFP in large cities,improving public education services,and promoting remote urbanization.Likewise,industrial transfer and enhanced public resources may ease the pressure of large UUFP flows into large cities.
基金Under the auspices of Ministry of Science and Technology of China(No.2012BAC08B01)
文摘Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian Mountain, where forest, shrubland and grassland consist of its main ecosystems, can provide fresh water and many other ecosystem services, through a series of eco-hydrological process such as precipitation interception, soil water storage, and fresh water provision. Thus, monitoring water regulation and assessing the hydrological service of the Qilian Mountain are meaningful and helpful for the healthy development of the lower reaches of arid and semi-arid areas. In recent 10 years, hydrological services have been widely researched in terms of scale and landscape pattern, including water conservation, hydrological responses to afforestation and their ecological effects. This study, after analyzing lots of current models and applications of geographical information system（GIS） in hydrological services, gave a scientific and reasonable evaluation of mountain ecosystem in eco-hydrological services, by employing the combination of international forefronts and contentious issues into the Qilian Mountain. Assessments of hydrological services at regional or larger scales are limited compared with studies within watershed scale in the Qilian Mountain. In our evaluation results of forest ecosystems, it is concluded that long-term observation and dynamic monitoring of different types of ecosystem are indispensable, and the hydrological services and the potential variation in water supplement on regional and large scales should be central issues in the future research.v
基金National Natural Science Foundation of China,No.42001153,No.42001161。
文摘Although China was one of the countries with the fastest-growing aging population in the world,limited scholarly attention has been paid to migration among older adults in China.The full picture of their migration in the entire country over time remains unknown.This study examines the spatial patterns of older interprovincial migration flows and their drivers in China over the period 1995 to 2015,using four waves of census data and intercensal population sample survey data.Results from eigenvector spatial filtering negative binomial regressions indicate that older adults tend to migrate away from low cost-of-living rural areas to high cost-of-living urban and rural areas,moving away from areas with extreme temperature differences.The location of their grandchildren is among the most important attractions.Our findings suggest that family-oriented migration is more common than amenity-led migration among retired Chinese older adults,and the cost-of-living is an indicator of economic opportunities for adult children and the quality of senior care services.
