A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports through the four main straits in the South China Sea. The results show that the annua...A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports through the four main straits in the South China Sea. The results show that the annual transports through the four straits Luzon Strait, Taiwan Strait, Sunda Shelf and Mindoro Strait are -4.5, 2.3, 0.5 and 1.7 Sv (1 Sv=106 m3s-1), respectively. The Mindoro Strait has an important outflow that accounts for over one third of the total inflow through the Luzon Strait. Furthermore, it indicates that there are strong seasonal variations of water transport in the four straits. The water transport through the Luzon Strait (Taiwan Strait, Sunda Shelf, Mindoro Strait) has a maximum value of -7.6 Sv in December (3.1 Sv in July, 2.1S v in January, 4.5Sv in November), a minimum value of -2.1 Sv in June (1.5 Sv in October, -1.0 Sv in June, -0.2 Sv in May), respectively.展开更多
In this work, 23 black soil profiles were surveyed and 113 soil samples were collected to determine the field capacity (FC) of the black soil in Northeast China. The effectiveness of three methods measuring FC, the Wi...In this work, 23 black soil profiles were surveyed and 113 soil samples were collected to determine the field capacity (FC) of the black soil in Northeast China. The effectiveness of three methods measuring FC, the Wilcox method (WM), the undisturbed soil pressure plate method (PUM) and the air-dried sieved soil pressure plate method (PDM) were compared to select a suitable laboratory measurement method. Results show that the FC values measured by PDM are greater than those measured by PUM, and the values measured by PUM are greater than those measured by WM. PUM is more suitable for the determination of FC in the study area. One regression equation between PUM and PDM has been established through which undisturbed soil can be replaced by air-dried sieved soil, which is easier to get, to measure FC. FCs vary from 23.50% to 37.00%, with an average of 31.65%, which differ greatly among the 23 black soil profiles. FC is found to be significantly positively correlated with the silt content, clay content and bulk density of the soil, but significantly negatively correlated with the sand content. An empirical pedotransfer function is established to estimate the FC using available soil physical and chemical properties.展开更多
AIM: To identity the factors influencing colorectal cancer (CRC) screening behavior and willingness among Chinese outpatients.METHODS: An outpatient-based face-to-face survey was conducted from August 18 to Septem...AIM: To identity the factors influencing colorectal cancer (CRC) screening behavior and willingness among Chinese outpatients.METHODS: An outpatient-based face-to-face survey was conducted from August 18 to September 7, 2010 in Changhai Hospital. A total of 1200 consecutive patients aged ≥ 18 years were recruited for interview. The patient's knowledge about CRC and screening was pre-measured as a predictor variable, and other pre- dictors included age, gender, educational level, month- ly household income and health insurance status. The relationship between these predictors and screening behavior, screening willingness and screening approach were examined using Pearson's 2 test and logistic regression analyses.RESULTS: Of these outpatients, 22.5% had undergone CRC screening prior to this study. Patients who had participated in the screening were more likely to have good knowledge about CRC and screening (OR: 5.299, 95% CI: 3.415-8.223), have health insurance (OR: 1.996, 95% CI: 1.426-2.794) and older in age. Higher income, however, was found to be a barrier to the screening (OR: 0.633, 95% CI: 0.467-0.858). An analysis of screening willingness showed that 37.5% of the patients would voluntarily participated in a screen at the recommended age, but 41.3% would do so under doctor's advice. Screening willingness was positively correlated with the patient's knowledge sta- tus. Patients with higher knowledge levels would like to participate in the screening (OR: 4.352, 95% CI: 3.008-6.298), and they would select colonoscopy as a screening approach (OR: 3.513, 95% CI: 2.290-5.389). However, higher income level was, again, a bar- rier to colonoscopic screening (OR: 0.667, 95% CI: 0.505-0.908). CONCLUSION: Patient's level of knowledge and in-ome should be taken into consideration when conducting a feasible CRC screening.展开更多
With the development of science and technology, the researches and application of water resources including the gas water have been constantly developed. Through an analysis on the flaws of the water right theory, and...With the development of science and technology, the researches and application of water resources including the gas water have been constantly developed. Through an analysis on the flaws of the water right theory, and by executing reconstruction and renewal of the theory and system of water right in modem society, the water right position of the gas water will be established, leading to the maturity of the whole law effectiveness and substantial results of water right.展开更多
The Luzon Strait is the only deep channel that connects the South China Sea(SCS) with the Pacific.The transport through the Luzon Strait is an important process influencing the circulation,heat and water budgets of th...The Luzon Strait is the only deep channel that connects the South China Sea(SCS) with the Pacific.The transport through the Luzon Strait is an important process influencing the circulation,heat and water budgets of the SCS.Early observations have suggested that water enters the SCS in winter but water inflow or outflow in summer is quite controversial.On the basis of hydrographic measurements from CTD along 120° E in the Luzon Strait during the period from September 18 to 20 in 2006,the characteristics of temperature,salinity and density distributions are analyzed.The velocity and volume transport through the Luzon Strait are calculated using the method of dynamic calculation.The major observed results show that water exchanges are mainly from the Pacific to the South China Sea in the upper layer,and the flow is relatively weak and eastward in the deeper layer.The net volume transport of the Luzon Strait during the observation period is westward,amounts to about 3.25 Sv.This result is consistent with historical observations.展开更多
We examined regional empirical equations for estimating the surface concentration of particulate organic carbon (POC) in the South China Sea. These algorithms are based on the direct relationships between POC and th...We examined regional empirical equations for estimating the surface concentration of particulate organic carbon (POC) in the South China Sea. These algorithms are based on the direct relationships between POC and the blue-to-green band ratios of spectral remotely sensed reflectance, Rrs(λB)/Rrs(555). The best error statistics among the considered formulas were produced using the power function POC (rag/ m3)=262.173 [Rrs(443)/Rrs(555)]^-0.940. This formula resulted in a small mean bias of approximately -2.52%, a normalized root mean square error of 31.1%, and a determination coefficient of 0.91. This regional empirical equation is different to the results of similar studies in other oceanic regions. Our validation results suggest that our regional empirical formula performs better than the global algorithm, in the South China Sea. The feasibility of this band ratio algorithm is primarily due to the relationship between POC and the green-to- blue ratio of the particle absorption coefficient. Colored dissolved organic matter can be an important source of noise in the band ratio formula. Finally, we applied the empirical algorithm to investigate POC changes in the southwest of Luzon Strait.展开更多
The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater...The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater samples and fi ve sediment samples sourced in May 2011. A total of 22 phyla, 34 classes, 74 orders, 146 families, and 333 genera were identifi ed in this study. Some of them were detected for the fi rst time from the East China Sea. The estimated richness and diversity indices were both higher in the sediment samples compared with in the seawater samples. All the samples were divided by their diversity indices into four regions. Similarity analysis showed that the seawater samples could be classifi ed into six groups. The groups differed from each other and had unique community structure characteristics. It was found that different water masses in the sampling areas may have had some infl uence on the bacterial community structure. A canonical correspondence analysis revealed that seawater samples in different areas and at different depths were affected by different environmental parameters. This study will lay the foundation for future research on microbiology in the East China Sea.展开更多
With the development of economy and society, our country is on the road of rule by law, the legal system is progressing constantly. At the same time, we should also see that the administration according to law is not ...With the development of economy and society, our country is on the road of rule by law, the legal system is progressing constantly. At the same time, we should also see that the administration according to law is not perfect, and its shortcomings exist in different degree and need to be further improved. Based on the analysis of the status quo of grass-roots administrative law enforcement in China, this paper tries to put forward corresponding countermeasures, so as to promote the work of law-based administration for the corresponding study.展开更多
Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery, and analyze the influencing factors of BLLs in healthy pregnant women. Methods Pregnant women were r...Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery, and analyze the influencing factors of BLLs in healthy pregnant women. Methods Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital. Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group, and 120 healthy non-pregnant women as the control group. BLLs during pregnancy were determined by flame atomic absorption spectroscopy. Results BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3, 55.4±20.1, 55.9±19.7, and 67.6±17.4 μ/L, respectively, and the mean BLL in control group was 67.5±21.3 μg/L. BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043, 0.021, and 0.028). Furthermore, occupations, nutrients supplementation, and time of house/apartment painted were associated with BLLs in pregnant women. Lead-related occupations, cosmetics use, and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women, while calcium, iron, zinc, and milk supplements are protective factors. Conclusion Supplementing calcium, iron, zinc, and milk, or avoiding contact with risk factors may help people, especially pregnant women, to reduce lead exposure.展开更多
The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as ec...The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as economic output.This paper considers the overall process of energy consumption and constructs an evaluation indication system of energy consumption level combined with endogenous pollutants based on entropytopsis method,then makes empirical research.The results show that China's energy consumption level presents a fluctuant rise in the premise of emission.Energy consumption level depends on the relationship among energy input,pollutants and economic output.The raise of energy consumption level should not increase economic output and reduce pollutant emission at the expense of environment.Finally,the whole paper puts forward the countermeasures to improve the overall level of energy consumption.展开更多
The efficient use of water resources directly affects environmental, social, and economic development; therefore, it has a significant impact on urban populations. A slacks-based measure for data envelopment analysis ...The efficient use of water resources directly affects environmental, social, and economic development; therefore, it has a significant impact on urban populations. A slacks-based measure for data envelopment analysis (SBM-DEA) has been widely used in energy efficiency and environmental efficiency analyses in recent years. Based on this model, data from 316 cities were examined and a category method was employed involving three different sorting techniques to empirically evaluate the efficiency of urban water re- source utilization in China between 2000 and 2012. The overall efficiency (OE) of urban water resource utilization in China was initially low, but has improved over the past decade. The scale efficiency (SE) was higher than the pure technological efficiency (PTE); PTE is a major determining factor of OE, and has had an increasingly significant effect. The efficiency of water resource utilization varied ac- cording to the region, urban scale, and economic function. The OE score for the eastern China was higher than for the rest of the region, and the OE score for the western China was higher than for the central China. The OE score for urban water resource utilization has improved with urban expansion, except in the case of small cities. The SE showed an inverted U-shaped' trend with increasing urban expansion. The OE of urban water utilization in comprehensive functional cities was greater than in economic specialization cities, and was greater in heavy industry specialization cities than in other specialization cities. This study contributes to the field of urban water resource management by examining variations in efficiency with urban ~ezle展开更多
To analyze China’s actual urbanization level, we iden- tified two statistical approaches: using the population living within the administrative boundaries ("administrative-based" method) and within the urba...To analyze China’s actual urbanization level, we iden- tified two statistical approaches: using the population living within the administrative boundaries ("administrative-based" method) and within the urbanized or built-up areas ("infrastructure-based" method) of cities and towns as urban population. To illustrate the two approaches and the associated problems, we used data for Tangshan City as a case study. The estimates on the "administrative-based" method were unreliable and the "infrastructurebased" method provided a 29.4% urbanization rate for Tangshan City in 2002, which is lower than the mean of 36.1% for China as a whole published after the fifth national census in 2000. Given the city’s geographic location, comprehensive urban construction and economic development indicators, its urbanization rate should be higher than the average level. Thus, our results indicate that the value of 36.1% was higher than the actual status as a result of poor statistical quality and overestimation of the floating population.展开更多
Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipmen...Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.展开更多
To the issue on the superiority and inferiority of the "product approach" and the "process approach" writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify...To the issue on the superiority and inferiority of the "product approach" and the "process approach" writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify the relationship between these different approaches and the different writing levels. The results are the "product approach" is more helpful to the learners with lower writing level; whereas, the "process approach" is more effective to ones with higher level. Furthermore, the teaching approach itself cannot affirm the superiority and inferiority, and it would not be at work unless is applied for corresponding learners.展开更多
The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980 s, especially after the year 2000. The annual average sediment yield was 1.2 billion ...The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980 s, especially after the year 2000. The annual average sediment yield was 1.2 billion tons before 2000, but has significantly decreased to 0.3 billion tons over the last 10 years. Changes in discharge and sediment yield for the Yellow River have attracted the attention of both the Central Government and local communities. This study aimed to identify the individual contributions of changes in precipitation and human activities(e.g. water conservancy projects, terracing, silt dams, socio-economic and needs, and soil and water conservation measures) to the decrease in discharge and sediment yield of the Yellow River. The study used both improved the hydrological method and the soil and water conservation method. The study focused on discharge analysis for the upper reaches and the investigation of sediments for the middle reaches of the river. The results showed that discharge and sediment yield have both presented significant decreasing trends over the past 50 years. Precipitation showed an insignificant decreasing trend over the same period. The annual average discharge decreased by 5.68 billion m3 above Lanzhou reach of the Yellow River from 2000 to 2012; human activities(e.g. socio-economic water use) contributed 43.4% of the total reduction, whereas natural factors(e.g. evaporation from lakes, wetlands and reservoirs) accounted for 56.6%. The decrease in annual discharge and sediment yield of the section between Hekouzhen station and Tongguan station were 12.4 billion m3 and 1.24 billion tons, respectively. Human activities contributed 76.5% and 72.2% of the total reduction in discharge and sediment yield, respectively, and were therefore the dominant factors in the changes in discharge and sediment yield of the Yellow River.展开更多
基金国家自然科学基金"九五"重点项目 (49631020) (Supported by the Key Project of the National National Science Foundation of China No.49631020) 云南省自然科学基金"九五"重点项目 (96D012Z) (Supported by me key Project of the Provincial Natural Science Foun
基金Supported by National Natural Science Foundation of China (No. 40806012, 40876013)Open Fund of the Key Laboratory of Ocean Circulation and Waves, Chinese Academy of Sciences (No. KLOCAW0803)Scientific Research Foundation for talent, Guangdong Ocean University (No. E06118)
文摘A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports through the four main straits in the South China Sea. The results show that the annual transports through the four straits Luzon Strait, Taiwan Strait, Sunda Shelf and Mindoro Strait are -4.5, 2.3, 0.5 and 1.7 Sv (1 Sv=106 m3s-1), respectively. The Mindoro Strait has an important outflow that accounts for over one third of the total inflow through the Luzon Strait. Furthermore, it indicates that there are strong seasonal variations of water transport in the four straits. The water transport through the Luzon Strait (Taiwan Strait, Sunda Shelf, Mindoro Strait) has a maximum value of -7.6 Sv in December (3.1 Sv in July, 2.1S v in January, 4.5Sv in November), a minimum value of -2.1 Sv in June (1.5 Sv in October, -1.0 Sv in June, -0.2 Sv in May), respectively.
基金Under the auspices of National Natural Science Foundation of China(No.40671111)Major State Basic Research Development Program of China(No.2007CB407203)
文摘In this work, 23 black soil profiles were surveyed and 113 soil samples were collected to determine the field capacity (FC) of the black soil in Northeast China. The effectiveness of three methods measuring FC, the Wilcox method (WM), the undisturbed soil pressure plate method (PUM) and the air-dried sieved soil pressure plate method (PDM) were compared to select a suitable laboratory measurement method. Results show that the FC values measured by PDM are greater than those measured by PUM, and the values measured by PUM are greater than those measured by WM. PUM is more suitable for the determination of FC in the study area. One regression equation between PUM and PDM has been established through which undisturbed soil can be replaced by air-dried sieved soil, which is easier to get, to measure FC. FCs vary from 23.50% to 37.00%, with an average of 31.65%, which differ greatly among the 23 black soil profiles. FC is found to be significantly positively correlated with the silt content, clay content and bulk density of the soil, but significantly negatively correlated with the sand content. An empirical pedotransfer function is established to estimate the FC using available soil physical and chemical properties.
文摘AIM: To identity the factors influencing colorectal cancer (CRC) screening behavior and willingness among Chinese outpatients.METHODS: An outpatient-based face-to-face survey was conducted from August 18 to September 7, 2010 in Changhai Hospital. A total of 1200 consecutive patients aged ≥ 18 years were recruited for interview. The patient's knowledge about CRC and screening was pre-measured as a predictor variable, and other pre- dictors included age, gender, educational level, month- ly household income and health insurance status. The relationship between these predictors and screening behavior, screening willingness and screening approach were examined using Pearson's 2 test and logistic regression analyses.RESULTS: Of these outpatients, 22.5% had undergone CRC screening prior to this study. Patients who had participated in the screening were more likely to have good knowledge about CRC and screening (OR: 5.299, 95% CI: 3.415-8.223), have health insurance (OR: 1.996, 95% CI: 1.426-2.794) and older in age. Higher income, however, was found to be a barrier to the screening (OR: 0.633, 95% CI: 0.467-0.858). An analysis of screening willingness showed that 37.5% of the patients would voluntarily participated in a screen at the recommended age, but 41.3% would do so under doctor's advice. Screening willingness was positively correlated with the patient's knowledge sta- tus. Patients with higher knowledge levels would like to participate in the screening (OR: 4.352, 95% CI: 3.008-6.298), and they would select colonoscopy as a screening approach (OR: 3.513, 95% CI: 2.290-5.389). However, higher income level was, again, a bar- rier to colonoscopic screening (OR: 0.667, 95% CI: 0.505-0.908). CONCLUSION: Patient's level of knowledge and in-ome should be taken into consideration when conducting a feasible CRC screening.
文摘With the development of science and technology, the researches and application of water resources including the gas water have been constantly developed. Through an analysis on the flaws of the water right theory, and by executing reconstruction and renewal of the theory and system of water right in modem society, the water right position of the gas water will be established, leading to the maturity of the whole law effectiveness and substantial results of water right.
基金Supported by the Knowledge Innovation Project of CAS (No KZCX2-YW-214,the NSFC (No 40806010)the National Basic Research Program of China (973 Program) (No 403603)
文摘The Luzon Strait is the only deep channel that connects the South China Sea(SCS) with the Pacific.The transport through the Luzon Strait is an important process influencing the circulation,heat and water budgets of the SCS.Early observations have suggested that water enters the SCS in winter but water inflow or outflow in summer is quite controversial.On the basis of hydrographic measurements from CTD along 120° E in the Luzon Strait during the period from September 18 to 20 in 2006,the characteristics of temperature,salinity and density distributions are analyzed.The velocity and volume transport through the Luzon Strait are calculated using the method of dynamic calculation.The major observed results show that water exchanges are mainly from the Pacific to the South China Sea in the upper layer,and the flow is relatively weak and eastward in the deeper layer.The net volume transport of the Luzon Strait during the observation period is westward,amounts to about 3.25 Sv.This result is consistent with historical observations.
基金Supported by the National Natural Science Foundation of China(Nos.41376042,41176035)the Natural Science for Youth Foundation(No.41206029)+2 种基金the Youth Foundation by South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.SQ201102)the Open Research Fund of State Key Laboratory of Estuarine and Coastal Research(No.SKLEC-KF201302)the Open Project Program of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LTOZZ1201)
文摘We examined regional empirical equations for estimating the surface concentration of particulate organic carbon (POC) in the South China Sea. These algorithms are based on the direct relationships between POC and the blue-to-green band ratios of spectral remotely sensed reflectance, Rrs(λB)/Rrs(555). The best error statistics among the considered formulas were produced using the power function POC (rag/ m3)=262.173 [Rrs(443)/Rrs(555)]^-0.940. This formula resulted in a small mean bias of approximately -2.52%, a normalized root mean square error of 31.1%, and a determination coefficient of 0.91. This regional empirical equation is different to the results of similar studies in other oceanic regions. Our validation results suggest that our regional empirical formula performs better than the global algorithm, in the South China Sea. The feasibility of this band ratio algorithm is primarily due to the relationship between POC and the green-to- blue ratio of the particle absorption coefficient. Colored dissolved organic matter can be an important source of noise in the band ratio formula. Finally, we applied the empirical algorithm to investigate POC changes in the southwest of Luzon Strait.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB409804)the National Natural Science Foundation of China(No.41121064)
文摘The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater samples and fi ve sediment samples sourced in May 2011. A total of 22 phyla, 34 classes, 74 orders, 146 families, and 333 genera were identifi ed in this study. Some of them were detected for the fi rst time from the East China Sea. The estimated richness and diversity indices were both higher in the sediment samples compared with in the seawater samples. All the samples were divided by their diversity indices into four regions. Similarity analysis showed that the seawater samples could be classifi ed into six groups. The groups differed from each other and had unique community structure characteristics. It was found that different water masses in the sampling areas may have had some infl uence on the bacterial community structure. A canonical correspondence analysis revealed that seawater samples in different areas and at different depths were affected by different environmental parameters. This study will lay the foundation for future research on microbiology in the East China Sea.
文摘With the development of economy and society, our country is on the road of rule by law, the legal system is progressing constantly. At the same time, we should also see that the administration according to law is not perfect, and its shortcomings exist in different degree and need to be further improved. Based on the analysis of the status quo of grass-roots administrative law enforcement in China, this paper tries to put forward corresponding countermeasures, so as to promote the work of law-based administration for the corresponding study.
基金supported by Nanjing Maternity and Child Health Care Hospital
文摘Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery, and analyze the influencing factors of BLLs in healthy pregnant women. Methods Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital. Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group, and 120 healthy non-pregnant women as the control group. BLLs during pregnancy were determined by flame atomic absorption spectroscopy. Results BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3, 55.4±20.1, 55.9±19.7, and 67.6±17.4 μ/L, respectively, and the mean BLL in control group was 67.5±21.3 μg/L. BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043, 0.021, and 0.028). Furthermore, occupations, nutrients supplementation, and time of house/apartment painted were associated with BLLs in pregnant women. Lead-related occupations, cosmetics use, and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women, while calcium, iron, zinc, and milk supplements are protective factors. Conclusion Supplementing calcium, iron, zinc, and milk, or avoiding contact with risk factors may help people, especially pregnant women, to reduce lead exposure.
文摘The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as economic output.This paper considers the overall process of energy consumption and constructs an evaluation indication system of energy consumption level combined with endogenous pollutants based on entropytopsis method,then makes empirical research.The results show that China's energy consumption level presents a fluctuant rise in the premise of emission.Energy consumption level depends on the relationship among energy input,pollutants and economic output.The raise of energy consumption level should not increase economic output and reduce pollutant emission at the expense of environment.Finally,the whole paper puts forward the countermeasures to improve the overall level of energy consumption.
基金Key Research Program of Chinese Academy of Sciences(No.KZZD-EW-06-03-03)
文摘The efficient use of water resources directly affects environmental, social, and economic development; therefore, it has a significant impact on urban populations. A slacks-based measure for data envelopment analysis (SBM-DEA) has been widely used in energy efficiency and environmental efficiency analyses in recent years. Based on this model, data from 316 cities were examined and a category method was employed involving three different sorting techniques to empirically evaluate the efficiency of urban water re- source utilization in China between 2000 and 2012. The overall efficiency (OE) of urban water resource utilization in China was initially low, but has improved over the past decade. The scale efficiency (SE) was higher than the pure technological efficiency (PTE); PTE is a major determining factor of OE, and has had an increasingly significant effect. The efficiency of water resource utilization varied ac- cording to the region, urban scale, and economic function. The OE score for the eastern China was higher than for the rest of the region, and the OE score for the western China was higher than for the central China. The OE score for urban water resource utilization has improved with urban expansion, except in the case of small cities. The SE showed an inverted U-shaped' trend with increasing urban expansion. The OE of urban water utilization in comprehensive functional cities was greater than in economic specialization cities, and was greater in heavy industry specialization cities than in other specialization cities. This study contributes to the field of urban water resource management by examining variations in efficiency with urban ~ezle
基金supported by the National Basic Research Program of China (Grant no. 2005CB724206)the project of Master Plan of Yutian xian 2003–2020
文摘To analyze China’s actual urbanization level, we iden- tified two statistical approaches: using the population living within the administrative boundaries ("administrative-based" method) and within the urbanized or built-up areas ("infrastructure-based" method) of cities and towns as urban population. To illustrate the two approaches and the associated problems, we used data for Tangshan City as a case study. The estimates on the "administrative-based" method were unreliable and the "infrastructurebased" method provided a 29.4% urbanization rate for Tangshan City in 2002, which is lower than the mean of 36.1% for China as a whole published after the fifth national census in 2000. Given the city’s geographic location, comprehensive urban construction and economic development indicators, its urbanization rate should be higher than the average level. Thus, our results indicate that the value of 36.1% was higher than the actual status as a result of poor statistical quality and overestimation of the floating population.
基金Project(2011B061200043)supported by the Guangdong Provincial Department of Science and Technology,China
文摘Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.
文摘To the issue on the superiority and inferiority of the "product approach" and the "process approach" writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify the relationship between these different approaches and the different writing levels. The results are the "product approach" is more helpful to the learners with lower writing level; whereas, the "process approach" is more effective to ones with higher level. Furthermore, the teaching approach itself cannot affirm the superiority and inferiority, and it would not be at work unless is applied for corresponding learners.
基金National Basic Research Program of China,No.2011CB403303National Key Technology R&D Program,No.2013BAC05B04National Natural Science Foundation of China,No.41571276
文摘The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980 s, especially after the year 2000. The annual average sediment yield was 1.2 billion tons before 2000, but has significantly decreased to 0.3 billion tons over the last 10 years. Changes in discharge and sediment yield for the Yellow River have attracted the attention of both the Central Government and local communities. This study aimed to identify the individual contributions of changes in precipitation and human activities(e.g. water conservancy projects, terracing, silt dams, socio-economic and needs, and soil and water conservation measures) to the decrease in discharge and sediment yield of the Yellow River. The study used both improved the hydrological method and the soil and water conservation method. The study focused on discharge analysis for the upper reaches and the investigation of sediments for the middle reaches of the river. The results showed that discharge and sediment yield have both presented significant decreasing trends over the past 50 years. Precipitation showed an insignificant decreasing trend over the same period. The annual average discharge decreased by 5.68 billion m3 above Lanzhou reach of the Yellow River from 2000 to 2012; human activities(e.g. socio-economic water use) contributed 43.4% of the total reduction, whereas natural factors(e.g. evaporation from lakes, wetlands and reservoirs) accounted for 56.6%. The decrease in annual discharge and sediment yield of the section between Hekouzhen station and Tongguan station were 12.4 billion m3 and 1.24 billion tons, respectively. Human activities contributed 76.5% and 72.2% of the total reduction in discharge and sediment yield, respectively, and were therefore the dominant factors in the changes in discharge and sediment yield of the Yellow River.