Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to cha...The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to characterize the pore morphology,and α-region,β-region,and αβ-region were used to describe the characteristics of the pore regional distribution.The directional characteristics of macroscopic diffusion of liquid in nonwoven fabrics were characterized by the indicator of primary diffusion orientation angle(PDOA).Ten kinds of spunlaced nonwoven fabrics were selected.Firstly,the data of pore characteristic indices of each sample were obtained through scanning electron microscope(SEM) and the image processing technology as well,and the pore regional distribution map of each sample was further acquired.Then,the PDOA of each sample was obtained through the droplet method and image processing technology.Based on the data and statistical analysis,it was found that the PDOA of a certain volume of liquid in the nonwoven fabrics presented a significant linear relationship with the average POA of the nonwoven fabrics.And the characteristics of pore distribution affected the directionality of liquid diffusion in the nonwoven fabrics.The samples with a large proportion of α-region and good distribution had prominent liquid diffusion along the direction of laying-up,and the difference in liquid diffusion of the samples was more obvious between the directions of laying-up and vertical laying-up.展开更多
Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morph...Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morphine-dependent rats is altered after death. Methods: Solid-phase extraction was used to extract morphine from the samples, and morphine levels were measured at 0-96 h postmortem using gas chromatography. Results: The study of the morphine dependent rats showed a significant (P<0.05) increase of morphine concentration in postmortem cardiac blood, liver tissues and kidneys tissues. A significant increase was also observed at 72 h and 96 h postmortem in the brain, while morphine levels in cardiac tissues only increased at 24 h and 96 h postmortem. These changes were associated with an observed pH rapid decrease: pH of cardiac blood dropped from 7.36±0.15 to 6.86±0.09 (P<0.01), pH of liver tissues from 6.98±0.04 to 6.34±0.03 (P<0.05). Conclusion: The postmortem regional distribution of morphine occurs in dependent rats, but different from the change that occurs in acute poisoning rats. The morphine concentration in cardiac blood and tissues tends to increase during the period of 0-96 h postmortem in dependent rats. Morphine concentration increases with pH rapid decrease. The antemortem internal amount of morphine affects its postmortem regional distribution. It appears that several mechanisms are accountable for postmortem morphine distribution. The understanding of the mechanisms and patterns may eventually lead to better choices of samples which may better represent antemortem drug levels.展开更多
The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major ...The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major cotton production provinces between 2001 to 2005 were analyzed.Eight quality展开更多
Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are an...Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.展开更多
To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method ...To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method in ArcGIS. The results showed that:(1) the aroma quality of flue-cured tobacco from Henan Province tobacco-growing areas ranged from better to slightly better and aroma quantity ranged from just a little to much. The ability of diffusiveness expressed slight to a little strong and the raw green odour, immature odour and ligneous odour were tiny;(2) there were significant differences between the aroma quality and scorched odour and no statistical differences among the aroma quantity, diffusiveness, raw green odour, ligneous odour and immature odour from different counties;(3) there were trends that scale of aroma quality increased from southwest to both north and east, aroma quantity showed a patchy distribution in space, diffusiveness decreased from east to west, scorched odour increased from west to both north and south, ligneous odour increased from north to south and green odour increased from south to north.展开更多
This paper investigates the regional distribution and pollution of energyintensive industries in China. Through the analysis of provincial panel data collected during 1998-2008, this work estimates the drivers of poll...This paper investigates the regional distribution and pollution of energyintensive industries in China. Through the analysis of provincial panel data collected during 1998-2008, this work estimates the drivers of pollution in 30 of China's provincial-level divisions. The paper concludes that while China's energy-intensive industries are heavily distributed in eastern and central China, the speed of development toward central and western China has, in recent years, risen continuously. Industries located in eastern China do, however, remain the primary polluters in the country. Notably, regional agglomeration of energy-intensive industries plays a positive role in energy conservation and pollution control in China. This paper also finds that patterns of pollution in China follow the environmental Kuznets curve (EKC) with strong inter-provincial discrepancies.展开更多
Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheime...Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.展开更多
Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCS...Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCSs are defined by a 20 dBZ echo top extending 14 km.The spatial distribution of DCSs genesis is also discussed,with reference to the National Centers for Environmental Prediction(NCEP)reanalysis data.The results show that DCSs occur mainly over land.They concentrate in south of 20°N during the pre-monsoon season,and then move distinctly to mid-latitude regions,with the most active region on the south slope of the Himalayas during monsoon season.DCSs over the Tibetan Plateau are more frequent than those in central-eastern China,but smaller in horizontal scale and weaker in convective intensity.DCSs in central-eastern China have more robust updrafts and generate more lightning flashes than in other Asian monsoon regions.The horizontal scale of DCSs over the ocean is larger than that over the other regions,and the corresponding minimum infrared(IR)brightness temperature is lower,whereas the convective intensity is weaker.Continental DCSs are more common from noon through midnight,and DCSs over the Tibetan Plateau are more frequently from noon through evening.Oceanic DCSs frequency has a weaker diurnal cycle with dawn maximum,and diurnal variation of DCSs over the tropical maritime continent is consistent with that over the continent.展开更多
Understanding the soil taxonomy and distribution characteristics of the permafrost region in the Qinghai-Tibet Plateau(QTP) is very important. On the basis of extensive field surveys and experimental analysis, this st...Understanding the soil taxonomy and distribution characteristics of the permafrost region in the Qinghai-Tibet Plateau(QTP) is very important. On the basis of extensive field surveys and experimental analysis, this study carries out soil taxonomic classification of the permafrost region in the QTP. According to Chinese Soil Taxonomy, the soil of the permafrost region in the QTP can be divided into 6 Orders(Histosols, Aridosols, Gleyosols, Isohumosols, Cambosols, Primosols), 11 Suborders, 19 Groups and 24 Subgroups. Cambosols are the dominant soil type in the permafrost region, followed by Aridosols. From the east to the west of the permafrost region in the QTP, the soil type gradually changes from Cambosols to Aridosols, showing a meridional zonality. The eastern region is dominated by Cambosols, with no obvious latitudinal zonality. From the south to the northwest of the western region, the dominance of Aridosols and Cambosols gradually transited to Aridosols, presenting a latitudinal zonality. The soil in the western region shows a poor vertical zonality, while the distribution of suborders of Cambosols in the eastern region shows a more obvious vertical zonality. The result indicates that precipitation and vegetation are the main factors that influence the zonal distribution of soil. The permafrost in the east has some effect on the vertical soil zonality, but the effect is weakened in the west.展开更多
A distribution map of osier weevil (Crytorrynchus lapathi L.) was drown up based on widely collecting information and field survey. The results showed that Osier weevil has a widespread in China, stretching from 33...A distribution map of osier weevil (Crytorrynchus lapathi L.) was drown up based on widely collecting information and field survey. The results showed that Osier weevil has a widespread in China, stretching from 33°21' to 51°42' N latitude and 83°00' to 132°58' E longitude, and distributes in forms of big or small patches or sports uncontinously. According to the analysis of meteorological data, the temperature and humidity threshold for osier weevil's distribution were determined by methods of PCA (Principle Component Analysis) and RA(Relativity Analysis): January temperature is -30~ 0℃. Annual temperature -4~13℃, Annual precipitation from 411~ 1,136 min.The areas with January temperature under 0℃, annual temperature above 0℃ and annual precipitation of 400~ 800 mm are the optimum distributing places for osier weevil in China.展开更多
The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Fur...The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Further study has proved the normal distributions exist in both the east and west parts of Chinese mainland partitioned along meridian 105°E. The empirical two-dimensional normal distribution functions for the deviations are presented in the paper. The results are of significance in reducing uncertainty of losses assessment immediately after a destroyed earthquake.展开更多
The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification...The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification and discharge at the interface under certain condition. It is of significant importance to take an insight into the phenomenon occurring at the interface. Through experiment, the pressboard is found as a porous material. The interface changes abruptly from bulk pressboard to the bulk oil as a result of the porous structure. A new model is proposed which divides the interface into bulk oil region, transition region, and bulk pressboard region. The width of the transition region is decided according to the microtome figure. The effective permittivity of the transition region is calculated using a new model based on fractal theory. The model is validated and compared with previous calculation model. The effect of the existence of transition region on the electric field distribution is discussed.展开更多
The optimized strategy made a comprehensive consideration of resources, technology, market orientation, production scale, industry basis and layout based on the principle of crop security and farmers’ income increasi...The optimized strategy made a comprehensive consideration of resources, technology, market orientation, production scale, industry basis and layout based on the principle of crop security and farmers’ income increasing, and determined the general planning on layout and structure optimization of future crop production ar-eas, with present crop production, market outlook, future industry development, con-cluding crop production characteristics of the 4 crop regions, and proposing function orientation and highlights.展开更多
Based on Remote Sensing (RS) and Geographical Information System (GIS) technology,urban expansion of 75 cities in China from the 1970s to 2020 was reconstructed by visual-interpretation method,which described the grow...Based on Remote Sensing (RS) and Geographical Information System (GIS) technology,urban expansion of 75 cities in China from the 1970s to 2020 was reconstructed by visual-interpretation method,which described the growing process of urban lands and its influences on local land use structures synchronously.By employing annual expansion area per city and urban expansion density,spatial-temporal characteristics and macro patterns of urban expansion were analyzed from the aspects of regional-distributions,administrative-levels and population-sizes comprehensively.Results indicate that:1) urban expansion in China was universal,distinct,persistent,periodic and fluctuating.In the past five decades,urban lands of 75 monitored cities in China expanded dramatically from 3606.26 km2 to 30 521.13 km2.2) Though urban expansion presented significant differences from the aspects of regional distribution,administrative levels,and population sizes,it exhibited a deceleration trend in the 13th Five-Year Plan among all kinds of cities.3) Cultivated lands were the first land resource for urban expansion,and 55.17% of newly-expanded urban lands appeared by encroaching this land use type.China’s urban expansion has caused sustained pressure on cultivated land protection,especially in super megacities,and the contradiction between urban expansion and cultivated land protection will always exist.4) The compactness of urban lands in China increased before 1987 and reduced in the next three decades,which was consistent with the implementation of major policies and the deployment of national strategies,and is expected to become compact with a stopping declining or even rebounding after the 13th Five-Year Plan.展开更多
For the survival and development of‘One Belt,One Road’,the present work aimed to evaluate the current situation of wave energy resources around Sri Lankan(SL)waters.Thirty-year ERA-Interim wind data were used to dri...For the survival and development of‘One Belt,One Road’,the present work aimed to evaluate the current situation of wave energy resources around Sri Lankan(SL)waters.Thirty-year ERA-Interim wind data were used to drive the third-generation wave model WAVEWATCH-III,and the seasonal and regional distribution characteristics of wave energy resources in SL waters were analyzed.Furthermore,the optimal season and region that contribute most to wave power in the study area were determined.On the basis of 30-year hindcast wave data,the significant wave height and wave power density,the occurrence of available SWH and rich WPD,the effective storage of wave energy,and the contribution and stability of wave energy were also analyzed.Results show that extremely optimistic wave energy resources are found at the western,southern,and southeastern waters of SL;moreover,the period of June,July,August(JJA)has great advantages in terms of the overall level of WPD,wave energy effective storage,and the contribution rate of wave energy.In addition,the wave energy during JJA is more stable than that of other periods and thus is benefi-cial to the transformation and development of wave energy.This study also provides important guiding value for disaster prevention and reduction,coastal zone management,and coastal development in the crucial region of the 21st Century Maritime Silk Road.展开更多
Hydrogeological map is one of the important carriers of groundwater related information.It directly reflects the hydrogeological conditions and previous investigation and research results of a mapping area.The hydroge...Hydrogeological map is one of the important carriers of groundwater related information.It directly reflects the hydrogeological conditions and previous investigation and research results of a mapping area.The hydrogeological map of China is a map reflecting the characteristics of hydrogeology and groundwater dynamics on a national scale.On the basis of the hydrogeological map of China(1:4000000)compiled in 1988,this map compilation attempted to update and enhance the existing map,with the latest survey results from the project of National Investigation and Evaluation of Groundwater Resources and Environmental Problems led by China Geological Survey.Task of the mapping program included redefining groundwater types,quantifying the classification standard of the groundwater and adding the pore-fissure water in laterite layer of hilly basin.The multilayer structures for porous,karst and porous-fractured groundwater and their water-rich grades are reflected on the map.Based on the comprehensive summary of the latest hydrogeological data of China,this research conducts an in-depth analysis of the regional distribution characteristics of groundwater in China,utilizes a digital mapping process and establishes a cartographic database for the purpose of further use.With the enrichment of the content and the continuous improvement of cognitive level,mapping content can be updated quickly,which has practical significance for the concept of surveying and mapping and scientific popularization.展开更多
Objective:To investigate the epidemic characteristics of multidrug resistant tuberculosis in Hainan,China,to provide basic information and theories for the prevention and control of multidrug resistant tuberculosis.Me...Objective:To investigate the epidemic characteristics of multidrug resistant tuberculosis in Hainan,China,to provide basic information and theories for the prevention and control of multidrug resistant tuberculosis.Methods:A retrospective descriptive epidemiological study was conducted.Data of multidrug resistant tuberculosis in Hainan Island from January 1,2014 to December 31,2019 were collected for statistical analysis.The counting data were described by frequency(percentage),and the measurement data were described by mean±standard deviation.Chi square test was used to compare the differences between different groups.If P<0.05,the difference was statistically significant.Results:From 2014 to 2019,the multidrug resistant rate of tuberculosis in Hainan Island was 24.9%(369/1484),8.0%(63/791)in newly-treated tuberculosis,and 44.2%(306/693)in retreatedmultidrug resistant rate of tuberculosis in Hainan Island was 24.9%(369/1484),8.0%(63/791)in newly-treatedtuberculosis,and 44.2%(306/693)in retreated tuberculosis.The multidrug resistant rate of newly-treated tuberculosis decreased by 0.05%per year,while that of retreated tuberculosis increased by 0.03%per year.multidrug resistant tuberculosis was mainly distributed in the city of Haikou(83 cases),Danzhou(44 cases),Wenchang(42 cases),Wanning(37 cases)and Dongfang(32 cases),accounting for 64.5%of all multidrug resistant tuberculosis.Among 369 multidrug resistant tuberculosis,81.0%were male.The proportion of newly-treated cases was 17.1%(63/369),while the proportion of retreated cases was 82.9%(306/369),which was significantly higher than that of newly-treated cases.The multidrug resistant rate of tuberculosis in different years was different.Conclusion:The drug resistance rate of tuberculosis in Hainan Island is higher than the national average level,which needs attention.The epidemiological characteristics of multidrug resistant tuberculosis with different treatment history were different.展开更多
This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are genera...This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are generally as follows:(1) Constant decrease of groundwater level is mainly distributed in China(East Asia), India(South Asia), Tajikistan(Central Asia) and Saudi Arabia(West Asia);(2) land subsidence occurs mainly in eastern plains of East Asia and west Siberian Plain of North Asia;(3) seawater intrusion occurs mainly in China, Japan and South Korea in East Asia, Philippines and Indonesia in Southeast Asia, the Indian coastal areas in South Asia;(4) groundwater level decline caused by groundwater exploitation in oil fields;(5) mining collapse is mainly in 50° to 70° north latitude band;(6) the total area of karst collapse in China of East Asia is as much as 197.05 km^2; and(7) ground fracture is mainly distributed in the North China Plain, Fenwei Plain and the Yangtze River Delta. Asia can be divided into 6 zones in terms of the geological environment negative effect caused by groundwater exploitation. According to analysis, with the increasing intensity of human activities, geological environment issues become more and more serious, therefore it is vital to control the human activities within the scope of 5× 10~5 people/km^2 to 9.9× 10~5 people/km^2 for the effective control of the size of the affected area by geological environment problems.展开更多
This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and...This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and its constitution characteristics .The results indicate that ore-forming elements on ore types and their distribution in this area are strongly controlled by the upper mantle heterogeneity .展开更多
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
基金National Key R&D Program of China (No. 2017YFB0309100)。
文摘The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to characterize the pore morphology,and α-region,β-region,and αβ-region were used to describe the characteristics of the pore regional distribution.The directional characteristics of macroscopic diffusion of liquid in nonwoven fabrics were characterized by the indicator of primary diffusion orientation angle(PDOA).Ten kinds of spunlaced nonwoven fabrics were selected.Firstly,the data of pore characteristic indices of each sample were obtained through scanning electron microscope(SEM) and the image processing technology as well,and the pore regional distribution map of each sample was further acquired.Then,the PDOA of each sample was obtained through the droplet method and image processing technology.Based on the data and statistical analysis,it was found that the PDOA of a certain volume of liquid in the nonwoven fabrics presented a significant linear relationship with the average POA of the nonwoven fabrics.And the characteristics of pore distribution affected the directionality of liquid diffusion in the nonwoven fabrics.The samples with a large proportion of α-region and good distribution had prominent liquid diffusion along the direction of laying-up,and the difference in liquid diffusion of the samples was more obvious between the directions of laying-up and vertical laying-up.
文摘Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morphine-dependent rats is altered after death. Methods: Solid-phase extraction was used to extract morphine from the samples, and morphine levels were measured at 0-96 h postmortem using gas chromatography. Results: The study of the morphine dependent rats showed a significant (P<0.05) increase of morphine concentration in postmortem cardiac blood, liver tissues and kidneys tissues. A significant increase was also observed at 72 h and 96 h postmortem in the brain, while morphine levels in cardiac tissues only increased at 24 h and 96 h postmortem. These changes were associated with an observed pH rapid decrease: pH of cardiac blood dropped from 7.36±0.15 to 6.86±0.09 (P<0.01), pH of liver tissues from 6.98±0.04 to 6.34±0.03 (P<0.05). Conclusion: The postmortem regional distribution of morphine occurs in dependent rats, but different from the change that occurs in acute poisoning rats. The morphine concentration in cardiac blood and tissues tends to increase during the period of 0-96 h postmortem in dependent rats. Morphine concentration increases with pH rapid decrease. The antemortem internal amount of morphine affects its postmortem regional distribution. It appears that several mechanisms are accountable for postmortem morphine distribution. The understanding of the mechanisms and patterns may eventually lead to better choices of samples which may better represent antemortem drug levels.
文摘The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major cotton production provinces between 2001 to 2005 were analyzed.Eight quality
文摘Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.
基金Supported by Major Special Projects of Development of Strong Flavor Characteristic and High Quality Tobacco Leaf by China National Tobacco Corporation(110201101001 TS-01)Pingdingshan Tobacco Company Technology Projects(PDSKJ2017018)Tianchang International Tobacco Company Technology Projects(TCKJ201701)
文摘To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method in ArcGIS. The results showed that:(1) the aroma quality of flue-cured tobacco from Henan Province tobacco-growing areas ranged from better to slightly better and aroma quantity ranged from just a little to much. The ability of diffusiveness expressed slight to a little strong and the raw green odour, immature odour and ligneous odour were tiny;(2) there were significant differences between the aroma quality and scorched odour and no statistical differences among the aroma quantity, diffusiveness, raw green odour, ligneous odour and immature odour from different counties;(3) there were trends that scale of aroma quality increased from southwest to both north and east, aroma quantity showed a patchy distribution in space, diffusiveness decreased from east to west, scorched odour increased from west to both north and south, ligneous odour increased from north to south and green odour increased from south to north.
基金This paper was made possible by grants from the Modern Business Research Center of Zhejiang Gongshang University, Zhejiang Provincial Natural Science Foundation.
文摘This paper investigates the regional distribution and pollution of energyintensive industries in China. Through the analysis of provincial panel data collected during 1998-2008, this work estimates the drivers of pollution in 30 of China's provincial-level divisions. The paper concludes that while China's energy-intensive industries are heavily distributed in eastern and central China, the speed of development toward central and western China has, in recent years, risen continuously. Industries located in eastern China do, however, remain the primary polluters in the country. Notably, regional agglomeration of energy-intensive industries plays a positive role in energy conservation and pollution control in China. This paper also finds that patterns of pollution in China follow the environmental Kuznets curve (EKC) with strong inter-provincial discrepancies.
基金supported by the National Natural Science Foundation of China,Nos.82171194 and 81974155(both to JL)the Shanghai Municipal Science and Technology Commission Medical Guide Project,No.16411969200(to WZ)Shanghai Municipal Science and Technology Commission Biomedical Science and Technology Project,No.22S31902600(to JL)。
文摘Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.
基金supported jointly by the National Basic Research Program of China(Grant No.2010CB428601)the National Natural Science Foundation of China(Grant Nos. 40930949&40905008)
文摘Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCSs are defined by a 20 dBZ echo top extending 14 km.The spatial distribution of DCSs genesis is also discussed,with reference to the National Centers for Environmental Prediction(NCEP)reanalysis data.The results show that DCSs occur mainly over land.They concentrate in south of 20°N during the pre-monsoon season,and then move distinctly to mid-latitude regions,with the most active region on the south slope of the Himalayas during monsoon season.DCSs over the Tibetan Plateau are more frequent than those in central-eastern China,but smaller in horizontal scale and weaker in convective intensity.DCSs in central-eastern China have more robust updrafts and generate more lightning flashes than in other Asian monsoon regions.The horizontal scale of DCSs over the ocean is larger than that over the other regions,and the corresponding minimum infrared(IR)brightness temperature is lower,whereas the convective intensity is weaker.Continental DCSs are more common from noon through midnight,and DCSs over the Tibetan Plateau are more frequently from noon through evening.Oceanic DCSs frequency has a weaker diurnal cycle with dawn maximum,and diurnal variation of DCSs over the tropical maritime continent is consistent with that over the continent.
基金financially supported by the National Major Scientific Project of China "Cryospheric Change and Impacts Research" program "Research of permafrost hydrothermal process and its response to climate change" (Grant No. 2013CBA01803)Chinese Academy of Sciences (KJZD-EW-G03-02)
文摘Understanding the soil taxonomy and distribution characteristics of the permafrost region in the Qinghai-Tibet Plateau(QTP) is very important. On the basis of extensive field surveys and experimental analysis, this study carries out soil taxonomic classification of the permafrost region in the QTP. According to Chinese Soil Taxonomy, the soil of the permafrost region in the QTP can be divided into 6 Orders(Histosols, Aridosols, Gleyosols, Isohumosols, Cambosols, Primosols), 11 Suborders, 19 Groups and 24 Subgroups. Cambosols are the dominant soil type in the permafrost region, followed by Aridosols. From the east to the west of the permafrost region in the QTP, the soil type gradually changes from Cambosols to Aridosols, showing a meridional zonality. The eastern region is dominated by Cambosols, with no obvious latitudinal zonality. From the south to the northwest of the western region, the dominance of Aridosols and Cambosols gradually transited to Aridosols, presenting a latitudinal zonality. The soil in the western region shows a poor vertical zonality, while the distribution of suborders of Cambosols in the eastern region shows a more obvious vertical zonality. The result indicates that precipitation and vegetation are the main factors that influence the zonal distribution of soil. The permafrost in the east has some effect on the vertical soil zonality, but the effect is weakened in the west.
文摘A distribution map of osier weevil (Crytorrynchus lapathi L.) was drown up based on widely collecting information and field survey. The results showed that Osier weevil has a widespread in China, stretching from 33°21' to 51°42' N latitude and 83°00' to 132°58' E longitude, and distributes in forms of big or small patches or sports uncontinously. According to the analysis of meteorological data, the temperature and humidity threshold for osier weevil's distribution were determined by methods of PCA (Principle Component Analysis) and RA(Relativity Analysis): January temperature is -30~ 0℃. Annual temperature -4~13℃, Annual precipitation from 411~ 1,136 min.The areas with January temperature under 0℃, annual temperature above 0℃ and annual precipitation of 400~ 800 mm are the optimum distributing places for osier weevil in China.
基金National Natural Science Foundation of China (40474023).
文摘The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Further study has proved the normal distributions exist in both the east and west parts of Chinese mainland partitioned along meridian 105°E. The empirical two-dimensional normal distribution functions for the deviations are presented in the paper. The results are of significance in reducing uncertainty of losses assessment immediately after a destroyed earthquake.
基金Project(2009CB724504)supported by the National Basic Research Program of China
文摘The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification and discharge at the interface under certain condition. It is of significant importance to take an insight into the phenomenon occurring at the interface. Through experiment, the pressboard is found as a porous material. The interface changes abruptly from bulk pressboard to the bulk oil as a result of the porous structure. A new model is proposed which divides the interface into bulk oil region, transition region, and bulk pressboard region. The width of the transition region is decided according to the microtome figure. The effective permittivity of the transition region is calculated using a new model based on fractal theory. The model is validated and compared with previous calculation model. The effect of the existence of transition region on the electric field distribution is discussed.
基金Supported by S&T Innovation Foundation of Hunan Academy of Agricultural Sciences~~
文摘The optimized strategy made a comprehensive consideration of resources, technology, market orientation, production scale, industry basis and layout based on the principle of crop security and farmers’ income increasing, and determined the general planning on layout and structure optimization of future crop production ar-eas, with present crop production, market outlook, future industry development, con-cluding crop production characteristics of the 4 crop regions, and proposing function orientation and highlights.
基金Under the auspices of the National Key R&D Program of China (No. 2017YFE0104600)。
文摘Based on Remote Sensing (RS) and Geographical Information System (GIS) technology,urban expansion of 75 cities in China from the 1970s to 2020 was reconstructed by visual-interpretation method,which described the growing process of urban lands and its influences on local land use structures synchronously.By employing annual expansion area per city and urban expansion density,spatial-temporal characteristics and macro patterns of urban expansion were analyzed from the aspects of regional-distributions,administrative-levels and population-sizes comprehensively.Results indicate that:1) urban expansion in China was universal,distinct,persistent,periodic and fluctuating.In the past five decades,urban lands of 75 monitored cities in China expanded dramatically from 3606.26 km2 to 30 521.13 km2.2) Though urban expansion presented significant differences from the aspects of regional distribution,administrative levels,and population sizes,it exhibited a deceleration trend in the 13th Five-Year Plan among all kinds of cities.3) Cultivated lands were the first land resource for urban expansion,and 55.17% of newly-expanded urban lands appeared by encroaching this land use type.China’s urban expansion has caused sustained pressure on cultivated land protection,especially in super megacities,and the contradiction between urban expansion and cultivated land protection will always exist.4) The compactness of urban lands in China increased before 1987 and reduced in the next three decades,which was consistent with the implementation of major policies and the deployment of national strategies,and is expected to become compact with a stopping declining or even rebounding after the 13th Five-Year Plan.
基金The work was supported by the Key Technology Research and Development Pro-gram of Shandong(Nos.2019GHY112072,2019GHY112051)the State Key Laboratory of Precision Measur-ing Technology and Instruments(No.pilab 1906)We also got a grant from the Key Research and Development Pro-gram of Tianjin(Nos.18YFZCSF00620,18YFYSZC00120).
文摘For the survival and development of‘One Belt,One Road’,the present work aimed to evaluate the current situation of wave energy resources around Sri Lankan(SL)waters.Thirty-year ERA-Interim wind data were used to drive the third-generation wave model WAVEWATCH-III,and the seasonal and regional distribution characteristics of wave energy resources in SL waters were analyzed.Furthermore,the optimal season and region that contribute most to wave power in the study area were determined.On the basis of 30-year hindcast wave data,the significant wave height and wave power density,the occurrence of available SWH and rich WPD,the effective storage of wave energy,and the contribution and stability of wave energy were also analyzed.Results show that extremely optimistic wave energy resources are found at the western,southern,and southeastern waters of SL;moreover,the period of June,July,August(JJA)has great advantages in terms of the overall level of WPD,wave energy effective storage,and the contribution rate of wave energy.In addition,the wave energy during JJA is more stable than that of other periods and thus is benefi-cial to the transformation and development of wave energy.This study also provides important guiding value for disaster prevention and reduction,coastal zone management,and coastal development in the crucial region of the 21st Century Maritime Silk Road.
文摘Hydrogeological map is one of the important carriers of groundwater related information.It directly reflects the hydrogeological conditions and previous investigation and research results of a mapping area.The hydrogeological map of China is a map reflecting the characteristics of hydrogeology and groundwater dynamics on a national scale.On the basis of the hydrogeological map of China(1:4000000)compiled in 1988,this map compilation attempted to update and enhance the existing map,with the latest survey results from the project of National Investigation and Evaluation of Groundwater Resources and Environmental Problems led by China Geological Survey.Task of the mapping program included redefining groundwater types,quantifying the classification standard of the groundwater and adding the pore-fissure water in laterite layer of hilly basin.The multilayer structures for porous,karst and porous-fractured groundwater and their water-rich grades are reflected on the map.Based on the comprehensive summary of the latest hydrogeological data of China,this research conducts an in-depth analysis of the regional distribution characteristics of groundwater in China,utilizes a digital mapping process and establishes a cartographic database for the purpose of further use.With the enrichment of the content and the continuous improvement of cognitive level,mapping content can be updated quickly,which has practical significance for the concept of surveying and mapping and scientific popularization.
基金National Science and Technology Major Project(No.2018ZX10101003-001-009)theNational Natural Science Foundation of China(No.81960002,81860002)School of Tropical Medicine and Laboratory Medicine,Hainan Medical University/Research Cultivation Fund(No.1021/XPY180017)。
文摘Objective:To investigate the epidemic characteristics of multidrug resistant tuberculosis in Hainan,China,to provide basic information and theories for the prevention and control of multidrug resistant tuberculosis.Methods:A retrospective descriptive epidemiological study was conducted.Data of multidrug resistant tuberculosis in Hainan Island from January 1,2014 to December 31,2019 were collected for statistical analysis.The counting data were described by frequency(percentage),and the measurement data were described by mean±standard deviation.Chi square test was used to compare the differences between different groups.If P<0.05,the difference was statistically significant.Results:From 2014 to 2019,the multidrug resistant rate of tuberculosis in Hainan Island was 24.9%(369/1484),8.0%(63/791)in newly-treated tuberculosis,and 44.2%(306/693)in retreatedmultidrug resistant rate of tuberculosis in Hainan Island was 24.9%(369/1484),8.0%(63/791)in newly-treatedtuberculosis,and 44.2%(306/693)in retreated tuberculosis.The multidrug resistant rate of newly-treated tuberculosis decreased by 0.05%per year,while that of retreated tuberculosis increased by 0.03%per year.multidrug resistant tuberculosis was mainly distributed in the city of Haikou(83 cases),Danzhou(44 cases),Wenchang(42 cases),Wanning(37 cases)and Dongfang(32 cases),accounting for 64.5%of all multidrug resistant tuberculosis.Among 369 multidrug resistant tuberculosis,81.0%were male.The proportion of newly-treated cases was 17.1%(63/369),while the proportion of retreated cases was 82.9%(306/369),which was significantly higher than that of newly-treated cases.The multidrug resistant rate of tuberculosis in different years was different.Conclusion:The drug resistance rate of tuberculosis in Hainan Island is higher than the national average level,which needs attention.The epidemiological characteristics of multidrug resistant tuberculosis with different treatment history were different.
基金supported by Geological Map of Groundwater Resources and Environment of China and Surrounding Areas(12120113014200)Series Maps of Karst Environment Geology of China and South East Asia(12120114006401,12120114006301)
文摘This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are generally as follows:(1) Constant decrease of groundwater level is mainly distributed in China(East Asia), India(South Asia), Tajikistan(Central Asia) and Saudi Arabia(West Asia);(2) land subsidence occurs mainly in eastern plains of East Asia and west Siberian Plain of North Asia;(3) seawater intrusion occurs mainly in China, Japan and South Korea in East Asia, Philippines and Indonesia in Southeast Asia, the Indian coastal areas in South Asia;(4) groundwater level decline caused by groundwater exploitation in oil fields;(5) mining collapse is mainly in 50° to 70° north latitude band;(6) the total area of karst collapse in China of East Asia is as much as 197.05 km^2; and(7) ground fracture is mainly distributed in the North China Plain, Fenwei Plain and the Yangtze River Delta. Asia can be divided into 6 zones in terms of the geological environment negative effect caused by groundwater exploitation. According to analysis, with the increasing intensity of human activities, geological environment issues become more and more serious, therefore it is vital to control the human activities within the scope of 5× 10~5 people/km^2 to 9.9× 10~5 people/km^2 for the effective control of the size of the affected area by geological environment problems.
文摘This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and its constitution characteristics .The results indicate that ore-forming elements on ore types and their distribution in this area are strongly controlled by the upper mantle heterogeneity .