The business environment is an important index for measuring the international competitiveness of a country or region.Improving the business environment not only helps the logistics industry reduce costs and increase ...The business environment is an important index for measuring the international competitiveness of a country or region.Improving the business environment not only helps the logistics industry reduce costs and increase efficiency but also promotes the transformation and upgrading of the logistics sector.This paper focuses on the business environment of cross-border logistics enterprises in Harbin New District as the research object.It constructs the business environment index system of logistics enterprises in Harbin New District through empirical research using the subjective weighting method.The research data are then analyzed to identify the shortcomings in optimizing the business environment of cross-border logistics in Harbin New District.The paper proposes countermeasures and suggestions,aiming to provide a decision-making reference for promoting the high-quality development and all-round revitalization of Harbin New District.展开更多
This paper investigates the spatial effect of environmental regulation measures on the upgrading of industrial structure in the integrated development strategy of Beijing-Tianjin-Hebei region and its surrounding areas...This paper investigates the spatial effect of environmental regulation measures on the upgrading of industrial structure in the integrated development strategy of Beijing-Tianjin-Hebei region and its surrounding areas.In order to reflect the effect of the environmental regulation and different regulation measures more truly,this paper constructs indices of the environmental regulation measures through the results of policy texts quantification.On the basis of the previous research,this paper divides environmental regulation into the following types:personnel and administrative measures of command and control;market-oriented fiscal,taxation,financial and other economic measures;guidance measures.Spatial panel regression results show that administrative measures of command control and market-oriented fiscal measures have a significant role in promoting regional industrial structure upgrading,but not conducive to the advancement of the industrial structure of adjacent areas.Their roles in promoting and inhibition are counteracted,which causes the total effect of industrial structure upgrading of Beijing-Tianjin-Hebei and the surrounding areas are not significant.Personnel measures,financial measures,other economic measures and guidance measures do not have the short-term effect and spatial effect on the upgrading of industrial structure.展开更多
Accounting, being an integrated information system, is not merely influenced by its environment, but also affects environment as well, due to its crucial role in generating the necessary information to decision-makers...Accounting, being an integrated information system, is not merely influenced by its environment, but also affects environment as well, due to its crucial role in generating the necessary information to decision-makers. It has two main pillars： measuring and declaring the costs that result from the activities of companies, especially industrial companies because they affect the environment. Therefore, the objective of this research is to investigate how well industrial companies are committed to measuring their environmental duties and declaring them in their balance sheets. This topic will be developed over two parts： scientific basis of environmental costs and accounting; environmental measuring and disclosure.展开更多
In this paper, we present simultaneous multiple pollutant gases （CO2, CO, and NO） measurements by using the non-dispersive infrared （NDIR） technique. A cross-correlation correction method is proposed and used to c...In this paper, we present simultaneous multiple pollutant gases （CO2, CO, and NO） measurements by using the non-dispersive infrared （NDIR） technique. A cross-correlation correction method is proposed and used to correct the cross-interferences among the target gases. The calculation of calibration curves is based on least-square fittings with third-order polynomials, and the interference functions are approximated by linear curves. The pure absorbance of each gas is obtained by solving three simultaneous equations using the fitted interference functions. Through the interference correction, the signal created at each filter channel only depends on the absorption of the intended gas. Gas mixture samples with different concentrations of CO2, CO, and NO are pumped into the sample cell for analysis. The results show that the measurement error of each gas is less than 4.5%.展开更多
We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers＇ route choice and the resultant system performance in a signal controlled network with overlapped rou...We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers＇ route choice and the resultant system performance in a signal controlled network with overlapped routes. Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers＇ travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity.展开更多
Due to the urban and town development, it is common to see historical buildings and new buildings intermingled with one and another inside historical regions in Taiwan. With the increase of new buildings, natural vent...Due to the urban and town development, it is common to see historical buildings and new buildings intermingled with one and another inside historical regions in Taiwan. With the increase of new buildings, natural ventilation becomes harder, which leads to the impact on the preservation of historical building and the reduction of thermal comfort for residents. Besides, problems of new buildings＇ construction and design affect the developments of cities and towns in historical district, which has existed for hundreds of years. The Wugoushui Settlement is located in Pingtung County, the southernmost part of Taiwan, and its hot season of a year is pretty long and belongs to warm and humid tropical climate. In 2008, the Pingtung County Government officially registered and announced Wugoushui as traditional settlement and meanwhile, provided the maintenance and preservation for buildings in this region on government subsidies. This paper is based on one-year-long field experiments of Wugoushui Settlement. Residents in Wugoushui Settlement continue constructing new buildings near by the traditional buildings. With the fact that constructions of new buildings result in huge impact on the circumstances of natural ventilation and thermal comfort, which have been for hundreds of years, the simple weather station is set up to collect the data of local microclimate. In addition, four representative traditional architectures were selected to be measured their indoor and outdoor temperature, humidity, wind speed, wind direction and thermal radiation both in winter （December to February） and in summer （May to September）. The measurement time of each building is one week and every data record is kept every minute. Besides, residents were asked to fill out the comfort survey. Based on these data, the distributions of indoor and outdoor thermal environment as well as the thermal comfort of living space under the condition of the natural ventilation are assessed. Finally, focused on the indoor living space of historical districts in southern Taiwan, there are two main suggestions given in the essay： first, a provisional comfort zone in summer is planned and proposed; second, the preliminary suggestions for the design and norms of new buildings in historical district are provided.展开更多
Aiming at acute characteristics of flammability,explosibility,causticity and leakiness of high sour natural gas,giving full consideration to local natural conditions in Sichuan Province and starting with purification ...Aiming at acute characteristics of flammability,explosibility,causticity and leakiness of high sour natural gas,giving full consideration to local natural conditions in Sichuan Province and starting with purification process,the paper analyzed process configurations,energy utilization and conservation,safety and environment protection measures. The integrated technology and engineering scheme for high sour natural gas purification was established and successfully used in industrial application.展开更多
Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West ...Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West Frontier Province of Pakistan. For the detection, analysis and data acquisition, a high purity germanium detector was used. Associated external doses were calculated using a Monte Carlo neutron photon transport code. A theoretical model to determine the gamma dose rate at 1 m height from the floor, made of bricks, was employed for the calculation of mass attenuation coefficient and self-absorption in the floor for the gamma energies of these radionuclides and their progeny. Monte Carlo simulation shows that in this study the floor, having more than an effective thickness of 15 cm, contributes very little to the external gamma dose rate. The values of the external dose rate and annual effective dose are found to be much lower than the world average as well as from other countries of the world.展开更多
The analysis of naturally occurring radionuclides （226Ra, 232 Th and 40 K） and an anthropogenic radionuclide 13r Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. （Pakistan）, usin...The analysis of naturally occurring radionuclides （226Ra, 232 Th and 40 K） and an anthropogenic radionuclide 13r Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. （Pakistan）, using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium （HPGe） detector coupled with a computer based high resolution multi channel analyzer. The specific activity in soil ranges from 24.72 to 78.48Bq.kg-1 for 22TRa, 21.73 to 75.28Bq.kg- 1 for 232Th, 7.06 to 14.9Bq.kg 1 for 1arcs and 298.46 to 570.77Bq.kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq.kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report （370 Bq.kg-1）. Man-made radionuclide 13r Cs is also present in detectable amount in all sell samples. Presence of 13r Us indicates that the samples in this renlote area also recelvo some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.展开更多
An instrument to detect atmospheric HO_(2) radicals using fluorescence assay by gas expansion(FAGE)technique has been developed.HO_(2) is measured by reaction with NO to form OH and subsequent detection of OH by laser...An instrument to detect atmospheric HO_(2) radicals using fluorescence assay by gas expansion(FAGE)technique has been developed.HO_(2) is measured by reaction with NO to form OH and subsequent detection of OH by laser-induced fluorescence at low pressure.The system performance has been improved by optimizing the expansion distance and pressure,the influence factors of HO_(2) conversion efficiency are also studied.The interferences of RO_(2) radicals were investigated by determining the conversion efficiency of RO_(2) to OH during the measurement of HO_(2).The dependence of the conversion of HO_(2) on NO concentration was investigated,and low HO_(2) conversion efficiency was selected to realize the ambient HO_(2) measurement,where the conversion efficiency of RO_(2) derived by propane,ethene,isoprene and methanol to OH has been reduced to less than 6%in the atmosphere.Furthermore,no significant interferences from PM_(2.5) and NO were found in the ambient HO_(2) measurement.The detection limits for HO_(2)(S/N=2)are estimated to 4.8×10^5 cm^-3 and 1.1×10^6 cm^-3(ρHO_(2)=20%)under night and noon conditions,with 60 sec signal integration time.The instrument was successfully deployed during STORM-2018 field campaign at Shenzhen graduate school of Peking University.The concentration of atmospheric HOx radical and the good correlation of OH with j(O1D)was obtained here.The diurnal variation of HOx concentration shows that the OH maximum concentration of those days is about 5.3×10^6 cm^-3 appearing around 12:00,while the HO_(2) maximum concentration is about 4.2×10^8 cm^-3 appearing around 13:30.展开更多
Various environmental factors affect net primary productivity （NPP） of grassland ecosystem. Extensive reports on the effects of environmental variables on NPP can be found in literature. However, the agreement on th...Various environmental factors affect net primary productivity （NPP） of grassland ecosystem. Extensive reports on the effects of environmental variables on NPP can be found in literature. However, the agreement on the relative importance of various factors in shaping the spatial pattern of grassland NPP has not yet been reached. Here a grassland in situ NPP database comprising 602 samples in northern China for 1980-1999 was developed based on a literature review of published biomass and forage yield field measurements. Correlation analyses and dominance analysis were used to quantify the separate and combined effects of environmental variables （climate topography and soil） on spatial variation in NPP separately. Grassland NPP ranged from 4.76 g C m-2a-1 to 975.94gCm-2a-1, showing significant variations in space. NPP increased with annual precipitation and declined with annual mean temperature significantly. Specifically, precipitation had the greatest impact on deserts, followed by steppes and meadows. Grassland NPP decreased with increasing altitude because of water limitation, and positively correlated with slope, but weakly correlated with aspect. Soil quality showed positive effects on NPP. Annual precipitation was the dominant factor affecting the spatial variability of net primary productivity, followed by elevation.展开更多
The successful application of differential mobility analysis for the characterization and manipulation of nanoparticles at atmospheric pressure has given rise to further development of this technique. The parallel dif...The successful application of differential mobility analysis for the characterization and manipulation of nanoparticles at atmospheric pressure has given rise to further development of this technique. The parallel differential mobility analyzer provides the possibility to simultaneously measure a size spec- trum of nanoparticles and select a particular set of nanoparticles with a defined size for collection （as well as enrichment） and further orthogonal analysis （as for example electron microscopy, atomic force microscopy or mass spectrometry）. Performing a high resolution measurement of electrical mobility diameters allows molecular weight determination of species with ultrahigh molecular masses in the mega Dalton range （e.g. protein complexes）. The precise size measurement of the human rhinovirus has confirmed the potential of this technique to analyze even intact infectious human-pathogenic viruses. Moreover, the real-time measurement of nanoparticle occurrence in an urban environment confirms the versatility of the method presented here and its applicability also in other areas of importance.展开更多
Human exposures to pesticides can occur in the workplace,in the household and through the ambient environment.While several articles have reviewed the impact of pesticide exposures on human respiratory health in occup...Human exposures to pesticides can occur in the workplace,in the household and through the ambient environment.While several articles have reviewed the impact of pesticide exposures on human respiratory health in occupational settings,to the best of our knowledge,this article is the first one to review published studies on the association between pesticide exposures and human respiratory health in the general populations.In this article,we critically reviewed evidences up to date studying the associations between non-occupational pesticide exposures and respiratory health in general populations.This article also highlighted questions arising from these studies,including our recent analyses using the data from the Canadian Health Measures Survey（CHMS）,for future research.We found few studies have addressed the impact of environmental pesticide exposures on respiratory health,especially on lung function,in general populations.In the studies using the data from CHMS Cycle 1,exposures to OP insecticides,pyrethroid insecticides,and the organochlorine pesticide DDT were associated with impaired lung function in the Canadian general population,but no significant associations were observed for the herbicide 2,4-D.Future research should focus on the potential age-specific and pesticide-specific effect on respiratory health in the general population,and repeated longitudinal study design is critical for assessing the temporal variations in pesticide exposures.Research findings from current studies of non-occupational pesticide exposures and their health impact in general population will help to improve the role of regulatory policies in mitigating pesticide-related public health problems,and thereafter providing greater benefit to the general population.展开更多
Due to heavy energy consumption and low technical efficiency, China＇s iron and steel industry is trapped in the dilemma ＂large but not strong＂. This situation not only exerts enormous pressure on energy security bu...Due to heavy energy consumption and low technical efficiency, China＇s iron and steel industry is trapped in the dilemma ＂large but not strong＂. This situation not only exerts enormous pressure on energy security but also on increased carbon emission and environmental pollution. The contribution of this study is to calculate the energy and environment efficiency of China＇s iron and steel industry and to analyze the factors affecting this efficiency. An index of energy and environment efficiency is introduced based on Directional Slacks-based Distance Measure Model. This index is adopted to measure the energy and environment efficiency of China＇s iron and steel industry using 2,382 firm observations during 2001 to 2005. In addition, Hierarchy Linear Model （HLM） is applied to analyze the factors which can influence the efficiency with both firm-level and province-level data. The conclusions are as follows： The energy and environment efficiency of China＇s iron and steel industry did not have a significant change during the research period. A firm＇s age, size, ownership, product category and the economy of its province have significant influence on its energy and environment efficiency.展开更多
基金Heilongjiang Province Philosophy and Social Science Planning Project“Study on the Construction and Operation of Government Credit Evaluation System to Optimize the Business Legal Environment”(Project Number 21FXD260)。
文摘The business environment is an important index for measuring the international competitiveness of a country or region.Improving the business environment not only helps the logistics industry reduce costs and increase efficiency but also promotes the transformation and upgrading of the logistics sector.This paper focuses on the business environment of cross-border logistics enterprises in Harbin New District as the research object.It constructs the business environment index system of logistics enterprises in Harbin New District through empirical research using the subjective weighting method.The research data are then analyzed to identify the shortcomings in optimizing the business environment of cross-border logistics in Harbin New District.The paper proposes countermeasures and suggestions,aiming to provide a decision-making reference for promoting the high-quality development and all-round revitalization of Harbin New District.
基金We are grateful to the financial support from the National Natural Science Foundation of China[Grant number:71874074,Grant number:71433005,Grant number:71804063]Humanities and Social Science Fund of Ministry of Education of China[Grant number:18YJC630208,Grant number:19YJC810007]。
文摘This paper investigates the spatial effect of environmental regulation measures on the upgrading of industrial structure in the integrated development strategy of Beijing-Tianjin-Hebei region and its surrounding areas.In order to reflect the effect of the environmental regulation and different regulation measures more truly,this paper constructs indices of the environmental regulation measures through the results of policy texts quantification.On the basis of the previous research,this paper divides environmental regulation into the following types:personnel and administrative measures of command and control;market-oriented fiscal,taxation,financial and other economic measures;guidance measures.Spatial panel regression results show that administrative measures of command control and market-oriented fiscal measures have a significant role in promoting regional industrial structure upgrading,but not conducive to the advancement of the industrial structure of adjacent areas.Their roles in promoting and inhibition are counteracted,which causes the total effect of industrial structure upgrading of Beijing-Tianjin-Hebei and the surrounding areas are not significant.Personnel measures,financial measures,other economic measures and guidance measures do not have the short-term effect and spatial effect on the upgrading of industrial structure.
文摘Accounting, being an integrated information system, is not merely influenced by its environment, but also affects environment as well, due to its crucial role in generating the necessary information to decision-makers. It has two main pillars： measuring and declaring the costs that result from the activities of companies, especially industrial companies because they affect the environment. Therefore, the objective of this research is to investigate how well industrial companies are committed to measuring their environmental duties and declaring them in their balance sheets. This topic will be developed over two parts： scientific basis of environmental costs and accounting; environmental measuring and disclosure.
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA063006)the National Natural Science Foundation of China (Grant No. 40805015)the Excellent Youth Scientific Foundation of Anhui Province, China (Grant No. 10040606Y28)
文摘In this paper, we present simultaneous multiple pollutant gases （CO2, CO, and NO） measurements by using the non-dispersive infrared （NDIR） technique. A cross-correlation correction method is proposed and used to correct the cross-interferences among the target gases. The calculation of calibration curves is based on least-square fittings with third-order polynomials, and the interference functions are approximated by linear curves. The pure absorbance of each gas is obtained by solving three simultaneous equations using the fitted interference functions. Through the interference correction, the signal created at each filter channel only depends on the absorption of the intended gas. Gas mixture samples with different concentrations of CO2, CO, and NO are pumped into the sample cell for analysis. The results show that the measurement error of each gas is less than 4.5%.
基金Supported by the National Natural Science Foundation of China under Grant No 70521001, and the National Basic Research Program of China under Crant No 2006CB705503.
文摘We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers＇ route choice and the resultant system performance in a signal controlled network with overlapped routes. Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers＇ travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity.
文摘Due to the urban and town development, it is common to see historical buildings and new buildings intermingled with one and another inside historical regions in Taiwan. With the increase of new buildings, natural ventilation becomes harder, which leads to the impact on the preservation of historical building and the reduction of thermal comfort for residents. Besides, problems of new buildings＇ construction and design affect the developments of cities and towns in historical district, which has existed for hundreds of years. The Wugoushui Settlement is located in Pingtung County, the southernmost part of Taiwan, and its hot season of a year is pretty long and belongs to warm and humid tropical climate. In 2008, the Pingtung County Government officially registered and announced Wugoushui as traditional settlement and meanwhile, provided the maintenance and preservation for buildings in this region on government subsidies. This paper is based on one-year-long field experiments of Wugoushui Settlement. Residents in Wugoushui Settlement continue constructing new buildings near by the traditional buildings. With the fact that constructions of new buildings result in huge impact on the circumstances of natural ventilation and thermal comfort, which have been for hundreds of years, the simple weather station is set up to collect the data of local microclimate. In addition, four representative traditional architectures were selected to be measured their indoor and outdoor temperature, humidity, wind speed, wind direction and thermal radiation both in winter （December to February） and in summer （May to September）. The measurement time of each building is one week and every data record is kept every minute. Besides, residents were asked to fill out the comfort survey. Based on these data, the distributions of indoor and outdoor thermal environment as well as the thermal comfort of living space under the condition of the natural ventilation are assessed. Finally, focused on the indoor living space of historical districts in southern Taiwan, there are two main suggestions given in the essay： first, a provisional comfort zone in summer is planned and proposed; second, the preliminary suggestions for the design and norms of new buildings in historical district are provided.
文摘Aiming at acute characteristics of flammability,explosibility,causticity and leakiness of high sour natural gas,giving full consideration to local natural conditions in Sichuan Province and starting with purification process,the paper analyzed process configurations,energy utilization and conservation,safety and environment protection measures. The integrated technology and engineering scheme for high sour natural gas purification was established and successfully used in industrial application.
文摘Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West Frontier Province of Pakistan. For the detection, analysis and data acquisition, a high purity germanium detector was used. Associated external doses were calculated using a Monte Carlo neutron photon transport code. A theoretical model to determine the gamma dose rate at 1 m height from the floor, made of bricks, was employed for the calculation of mass attenuation coefficient and self-absorption in the floor for the gamma energies of these radionuclides and their progeny. Monte Carlo simulation shows that in this study the floor, having more than an effective thickness of 15 cm, contributes very little to the external gamma dose rate. The values of the external dose rate and annual effective dose are found to be much lower than the world average as well as from other countries of the world.
文摘The analysis of naturally occurring radionuclides （226Ra, 232 Th and 40 K） and an anthropogenic radionuclide 13r Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. （Pakistan）, using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium （HPGe） detector coupled with a computer based high resolution multi channel analyzer. The specific activity in soil ranges from 24.72 to 78.48Bq.kg-1 for 22TRa, 21.73 to 75.28Bq.kg- 1 for 232Th, 7.06 to 14.9Bq.kg 1 for 1arcs and 298.46 to 570.77Bq.kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq.kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report （370 Bq.kg-1）. Man-made radionuclide 13r Cs is also present in detectable amount in all sell samples. Presence of 13r Us indicates that the samples in this renlote area also recelvo some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.
基金The National Key Research and Development Program of China(Nos.2017YFC0209401,2017YFC0209403)the National Natural Science Foundation of China(Nos.61905003,61805257,91644107,and 61575206)+1 种基金the Natural Science Foundation of Anhui Province(No.2008085J20)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB05040200)。
文摘An instrument to detect atmospheric HO_(2) radicals using fluorescence assay by gas expansion(FAGE)technique has been developed.HO_(2) is measured by reaction with NO to form OH and subsequent detection of OH by laser-induced fluorescence at low pressure.The system performance has been improved by optimizing the expansion distance and pressure,the influence factors of HO_(2) conversion efficiency are also studied.The interferences of RO_(2) radicals were investigated by determining the conversion efficiency of RO_(2) to OH during the measurement of HO_(2).The dependence of the conversion of HO_(2) on NO concentration was investigated,and low HO_(2) conversion efficiency was selected to realize the ambient HO_(2) measurement,where the conversion efficiency of RO_(2) derived by propane,ethene,isoprene and methanol to OH has been reduced to less than 6%in the atmosphere.Furthermore,no significant interferences from PM_(2.5) and NO were found in the ambient HO_(2) measurement.The detection limits for HO_(2)(S/N=2)are estimated to 4.8×10^5 cm^-3 and 1.1×10^6 cm^-3(ρHO_(2)=20%)under night and noon conditions,with 60 sec signal integration time.The instrument was successfully deployed during STORM-2018 field campaign at Shenzhen graduate school of Peking University.The concentration of atmospheric HOx radical and the good correlation of OH with j(O1D)was obtained here.The diurnal variation of HOx concentration shows that the OH maximum concentration of those days is about 5.3×10^6 cm^-3 appearing around 12:00,while the HO_(2) maximum concentration is about 4.2×10^8 cm^-3 appearing around 13:30.
基金"Strategic Priority Research Program-Climate Change:Carbon Budget and Relevant Issues" of the Chinese Academy of Sciences(Project Number XDA05090305)
文摘Various environmental factors affect net primary productivity （NPP） of grassland ecosystem. Extensive reports on the effects of environmental variables on NPP can be found in literature. However, the agreement on the relative importance of various factors in shaping the spatial pattern of grassland NPP has not yet been reached. Here a grassland in situ NPP database comprising 602 samples in northern China for 1980-1999 was developed based on a literature review of published biomass and forage yield field measurements. Correlation analyses and dominance analysis were used to quantify the separate and combined effects of environmental variables （climate topography and soil） on spatial variation in NPP separately. Grassland NPP ranged from 4.76 g C m-2a-1 to 975.94gCm-2a-1, showing significant variations in space. NPP increased with annual precipitation and declined with annual mean temperature significantly. Specifically, precipitation had the greatest impact on deserts, followed by steppes and meadows. Grassland NPP decreased with increasing altitude because of water limitation, and positively correlated with slope, but weakly correlated with aspect. Soil quality showed positive effects on NPP. Annual precipitation was the dominant factor affecting the spatial variability of net primary productivity, followed by elevation.
基金supported by grant of the Austrian Science Foundation (TRP29-N20 to W.W.S and G.A)
文摘The successful application of differential mobility analysis for the characterization and manipulation of nanoparticles at atmospheric pressure has given rise to further development of this technique. The parallel differential mobility analyzer provides the possibility to simultaneously measure a size spec- trum of nanoparticles and select a particular set of nanoparticles with a defined size for collection （as well as enrichment） and further orthogonal analysis （as for example electron microscopy, atomic force microscopy or mass spectrometry）. Performing a high resolution measurement of electrical mobility diameters allows molecular weight determination of species with ultrahigh molecular masses in the mega Dalton range （e.g. protein complexes）. The precise size measurement of the human rhinovirus has confirmed the potential of this technique to analyze even intact infectious human-pathogenic viruses. Moreover, the real-time measurement of nanoparticle occurrence in an urban environment confirms the versatility of the method presented here and its applicability also in other areas of importance.
文摘Human exposures to pesticides can occur in the workplace,in the household and through the ambient environment.While several articles have reviewed the impact of pesticide exposures on human respiratory health in occupational settings,to the best of our knowledge,this article is the first one to review published studies on the association between pesticide exposures and human respiratory health in the general populations.In this article,we critically reviewed evidences up to date studying the associations between non-occupational pesticide exposures and respiratory health in general populations.This article also highlighted questions arising from these studies,including our recent analyses using the data from the Canadian Health Measures Survey（CHMS）,for future research.We found few studies have addressed the impact of environmental pesticide exposures on respiratory health,especially on lung function,in general populations.In the studies using the data from CHMS Cycle 1,exposures to OP insecticides,pyrethroid insecticides,and the organochlorine pesticide DDT were associated with impaired lung function in the Canadian general population,but no significant associations were observed for the herbicide 2,4-D.Future research should focus on the potential age-specific and pesticide-specific effect on respiratory health in the general population,and repeated longitudinal study design is critical for assessing the temporal variations in pesticide exposures.Research findings from current studies of non-occupational pesticide exposures and their health impact in general population will help to improve the role of regulatory policies in mitigating pesticide-related public health problems,and thereafter providing greater benefit to the general population.
文摘Due to heavy energy consumption and low technical efficiency, China＇s iron and steel industry is trapped in the dilemma ＂large but not strong＂. This situation not only exerts enormous pressure on energy security but also on increased carbon emission and environmental pollution. The contribution of this study is to calculate the energy and environment efficiency of China＇s iron and steel industry and to analyze the factors affecting this efficiency. An index of energy and environment efficiency is introduced based on Directional Slacks-based Distance Measure Model. This index is adopted to measure the energy and environment efficiency of China＇s iron and steel industry using 2,382 firm observations during 2001 to 2005. In addition, Hierarchy Linear Model （HLM） is applied to analyze the factors which can influence the efficiency with both firm-level and province-level data. The conclusions are as follows： The energy and environment efficiency of China＇s iron and steel industry did not have a significant change during the research period. A firm＇s age, size, ownership, product category and the economy of its province have significant influence on its energy and environment efficiency.
