Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,...Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.展开更多
Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in rece...Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in recent years, the domestic democratic chaos in the United States has intensified, causing widespread doubts about the American political system and its democratic model.展开更多
BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To de...BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To determine the causes,document the symptoms,and determine factors predicting good yield of EUS-guided EMLN biopsy.METHODS All patients having EMLN(>10 mm)on thoracic imaging and referred for EUSguided biopsy were included in this retrospective observational study.Adequacy of the tissue specimen was assessed by the endoscopist with macroscopic on-site evaluation(MOSE)and then sent to a histopathologist for final diagnosis.Analysis for factors predicting good biopsy yield was then performed.RESULTS Of the total 243 patients with EMLN,131(53.9%)were males.The mean age was 47.6(±14.7)and range 14-86 years.Commonest causes of EMLN were tuberculosis 82(33.7%),anthracosis 53(21.8%),neoplastic disease 43(17.7%)and sarcoidosis 14(5.8%).Among the 43 patients with neoplastic diseases:40 had metastatic disease(breast 9,lung 7,pancreatobiliary 6,esophagus 5,kidney 5,hepatocellular 2,neuroendocrine 2,gastrointestinal stromal 1,undetermined 3)and 3 had primary malignancies(lymphoproliferative disorder 2,Kaposi sarcoma 1).Chest related clinical symptoms were absent in more than half the patients with tuberculosis 51/82(62.2%),anthracosis 31/53(58.5%)and neoplastic disease 28/43(65.1%).Factors associated with good biopsy yield were:Subcarinal location of MLN(P=0.026),MLN size>12 mm(P<0.0001),use of fine-needle biopsy(vs fine-needle aspiration)(P=0.049)and satisfactory MOSE(P<0.0001)on univariate analysis;while MLN size>12 mm(P=0.005)and satisfactory MOSE(P<0.0001)on multivariate analysis.CONCLUSION Tuberculosis,anthracosis and metastatic disease were the commonest causes of EMLN.More than half the cases with EMLN had no chest-related symptoms.Large MLN size and satisfactory MOSE observation predicted a good biopsy yield.展开更多
Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of...Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of changes in pollutant concentration,circulation background,and changes in various meteorological elements.The results show that this severe pollution weather process was a compound pollution process caused by accumulation of local pollutants and transportation of external pollutants,during which the primary pollutant was PM_(2.5).During the accumulation stage,the ground was controlled by a uniform pressure field,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the wind on the ground was from the northeast,which was conducive to the input of upstream pollution clusters into the city.Pollutant concentration was inversely correlated with daily average sea-level pressure,and positively correlated with daily average temperature.Wind speed and direction were closely related to PM_(2.5)concentration.During the accumulation stage,the ground was mainly dominated by weak winds,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the continuous northeastward wind continuously transported upstream pollutants to Shaoyang area.Local pollutants accumulated in the previous stable weather process and the terrain led to the outbreak of local pollution.展开更多
From 10 to 15 April 2025,China experienced a rare persistent extreme wind-dust compound disaster that swept from north to south.Based on observational data,historical disaster records,and situations of various exposed...From 10 to 15 April 2025,China experienced a rare persistent extreme wind-dust compound disaster that swept from north to south.Based on observational data,historical disaster records,and situations of various exposed elements,this study analyzed the formation mechanisms and evolution of this extreme event and conducted a rapid assessment of the associated loss and damage.The results indicate that the direct cause of this extreme wind-dust compound disaster was a strong cold vortex system generated in Mongolia,which moved eastward and southward,combined with the amplification effects of topography and urban structures,and the downward transmission of momentum from higher troposphere.The analysis revealed that approximately 697.47 million people were exposed to strong winds,while about 1,374.54 million people were exposed to high concentrations of PM10.The strong winds also caused varying degrees of damage to buildings,transportation networks,agricultural greenhouses,and forests.Based on vulnerability curves for wind-related loss and damage,it was estimated that the number of victims affected by this extreme wind-dust compound disaster ranged from 0.209 to 1.044 million,with casualties between 5 and 13 individuals.The number of damaged buildings was estimated to be between 2115 and 4607,and the area of affected crops was between 229 and 783 km2.The direct economic losses could reach as high as RMB 0.076–3.501 billion yuan.This study revealed the causes of this extreme wind-dust compound disaster and quantified the disaster loss and impact,providing new insights for the prevention of associated disasters.展开更多
A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting....A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.展开更多
Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.T...Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.The disease has diverse triggers,commonly including:lacrimal gland dysfunction;meibomian gland dysfunction accelerating tear evaporation;reduced blinking due to prolonged electronic device use;contact lens wear interfering with the tear film;medication side effects;environmental factors;hormonal fluctuations;certain ophthalmic surgeries,for example,LASIK.Treatment requires targeting specific pathogenic mechanisms,with the core focus on controlling inflammation,restoring tear film stability,and improving related gland function.展开更多
Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,s...Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.展开更多
First at all, it introduced the concept and the damages of continuous cropping obstacle. Then, it analyzed the causes of continuous cropping obstacles for Atractylodes macrocephala Koidz. In the end, in order to provi...First at all, it introduced the concept and the damages of continuous cropping obstacle. Then, it analyzed the causes of continuous cropping obstacles for Atractylodes macrocephala Koidz. In the end, in order to provide guidance for pro- moting sustainable development of Atractylodes macrocephala Koidz industry in Pingjiang County, it put forward some control methods for eliminating continuous cropping obstacles of Atractylodes macrocephala Koidz, including breeding varieties with high resistance; applying rotation cropping and intercropping reasonable; rational fertilization and soil disinfection; introducing antagonistic bacterial and eliminating au- tointoxication.展开更多
Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of t...Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of this process were analyzed in this article in terms of general circulation,character of physical quantity and tropical cyclone.The result showed that the precipitation process was a long wave adjustment process and it took place during the transformation process of general circulation turning from the zonal to the radial.During the cloudy-rainy weather process,the Ural mountain ridge and the Western Pacific subtropical high were more abnormally strong and in the further north than that in any other years.The tropical cyclone in the south of the subtropical cyclone activity was more frequent.There was more shortwave in middle latitudes of Asian.The cold air masses Siberia went down south.The cold air masses joined with the current of air in the Lower Yellow River.This led to the lasting cloudy-rainy weather for several days in Shandong.展开更多
Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Ti...Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.展开更多
After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room a...After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room at the back and with wing rooms on the left and right side.It has analyzed the formation,development,climax,damage and inheritance of quadrangle courtyard,and considered that it could manifest Chinese traditional humanistic idea and aesthetic idea,and is in possession of profound cultural connotation and regional feature.On this basis,causes for quadrangle courtyards have been studied.The primary cause at the initial stage lies in human body structure theory and the perfection of quadrangle courtyards at later stage depends on ethic order theory.展开更多
This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power ...This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power distance,connotation versus denotation,and orientation towards time,negative transfer of equivalent structures and behaviors,insufficient or improper teaching and the scarcity of universal knowledge for communication.展开更多
Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles ...Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles have their historical background which helped form his democratic ideas.展开更多
Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and it...Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and its main character Sister Carrie is a controversial person.Dreiser was criticized by critics and readers because he didn’t give any comment on her degener ation.This thesis tries to analyze the causes of this tragedy.In the end,the paper draws the conclusion:the American Dream looks beautiful,but to some extent it is not reliable,just like the foam of soap.It only gives people an illusion.So Carrie’s tragedy is in evitable.展开更多
The main causes of the vocational college students' oral fossilization summarized in the thesis are as follows:negative transfer of the native language,overgeneralization,communication strategies blockage.
This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global aver...This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global average. The country-averaged annual mean surface air temperature has increased by 1.1℃ over the past 50 years and 0.5-0.8℃ over the past 100 years, slightly higher than the global temperature increase for the same periods. Northern China and winter have experienced the greatest increases in surface air temperature. Although no significant trend has been found in country-averaged annual precipitation, interdecadal variability and obvious trends on regional scales are detectable, with northwestern China and the mid and lower Yangtze River basin having undergone an obvious increase, and North China a severe drought. Some analyses show that frequency and magnitude of extreme weather and climate events have also undergone significant changes in the past 50 years or so. Studies of the causes of regional climate change through the use of climate models and consideration of various forcings, show that the warming of the last 50 years could possibly be attributed to an increased atmospheric concentration of greenhouse gases, while the temperature change of the first half of the 20th century may be due to solar activity, volcanic eruptions and sea surface temperature change. A significant decline in sunshine duration and solar radiation at the surface in eastern China has been attributed to the increased emission of pollutants. Projections of future climate by models of the NCC （National Climate Center, China Meteorological Administration） and the IAP （Institute of Atmospheric Physics, Chinese Academy of Sciences）, as well as 40 models developed overseas, indicate a potential significant warming in China in the 21st century, with the largest warming set to occur in winter months and in northern China. Under varied emission scenarios, the country-averaged annual mean temperature is projected to increase by 1.5 2.1℃ by 2020, 2.3 3.3℃ by 2050, and by 3.9-6.0℃ by 2100, in comparison to the 30-year average of 1961-1990. Most models project a 10% 12% increase in annual precipitation in China by 2100, with the trend being particularly evident in Northeast and Northwest China, but with parts of central China probably undergoing a drying trend. Large uncertainty exists in the projection of precipitation, and further studies are needed. Furthermore, anthropogenic climate change will probably lead to a weaker winter monsoon and a stronger summer monsoon in eastern Asia.展开更多
Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic ...Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic abnormalities, remain largely unknown. Until recently, the only genetic tests used in the diagnosis of male infertility were aimed at detecting the presence of microdeletions of the long arm of the Y chromosome and/or chromosomal abnormalities. Various other single-gene or polygenic defects have been proposed to be involved in male fertility. However, their causative effects often remain unproven. The recent evolution in the development of whole-genome-based techniques and the large-scale analysis of mouse models might help in this process. Through knockout mouse models, at least 388 genes have been shown to be associated with spermatogenesis in mice. However, problems often arise when translating this information from mice to humans.展开更多
基金supported by the China Geological Survey Project(Nos.DD20220864 and DD20243077).
文摘Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.
文摘Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in recent years, the domestic democratic chaos in the United States has intensified, causing widespread doubts about the American political system and its democratic model.
文摘BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To determine the causes,document the symptoms,and determine factors predicting good yield of EUS-guided EMLN biopsy.METHODS All patients having EMLN(>10 mm)on thoracic imaging and referred for EUSguided biopsy were included in this retrospective observational study.Adequacy of the tissue specimen was assessed by the endoscopist with macroscopic on-site evaluation(MOSE)and then sent to a histopathologist for final diagnosis.Analysis for factors predicting good biopsy yield was then performed.RESULTS Of the total 243 patients with EMLN,131(53.9%)were males.The mean age was 47.6(±14.7)and range 14-86 years.Commonest causes of EMLN were tuberculosis 82(33.7%),anthracosis 53(21.8%),neoplastic disease 43(17.7%)and sarcoidosis 14(5.8%).Among the 43 patients with neoplastic diseases:40 had metastatic disease(breast 9,lung 7,pancreatobiliary 6,esophagus 5,kidney 5,hepatocellular 2,neuroendocrine 2,gastrointestinal stromal 1,undetermined 3)and 3 had primary malignancies(lymphoproliferative disorder 2,Kaposi sarcoma 1).Chest related clinical symptoms were absent in more than half the patients with tuberculosis 51/82(62.2%),anthracosis 31/53(58.5%)and neoplastic disease 28/43(65.1%).Factors associated with good biopsy yield were:Subcarinal location of MLN(P=0.026),MLN size>12 mm(P<0.0001),use of fine-needle biopsy(vs fine-needle aspiration)(P=0.049)and satisfactory MOSE(P<0.0001)on univariate analysis;while MLN size>12 mm(P=0.005)and satisfactory MOSE(P<0.0001)on multivariate analysis.CONCLUSION Tuberculosis,anthracosis and metastatic disease were the commonest causes of EMLN.More than half the cases with EMLN had no chest-related symptoms.Large MLN size and satisfactory MOSE observation predicted a good biopsy yield.
文摘Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of changes in pollutant concentration,circulation background,and changes in various meteorological elements.The results show that this severe pollution weather process was a compound pollution process caused by accumulation of local pollutants and transportation of external pollutants,during which the primary pollutant was PM_(2.5).During the accumulation stage,the ground was controlled by a uniform pressure field,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the wind on the ground was from the northeast,which was conducive to the input of upstream pollution clusters into the city.Pollutant concentration was inversely correlated with daily average sea-level pressure,and positively correlated with daily average temperature.Wind speed and direction were closely related to PM_(2.5)concentration.During the accumulation stage,the ground was mainly dominated by weak winds,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the continuous northeastward wind continuously transported upstream pollutants to Shaoyang area.Local pollutants accumulated in the previous stable weather process and the terrain led to the outbreak of local pollution.
基金supported by the National Natural Science Foundation of China(Grant No.42330502)the Central Government Guided Local Science and Technology Development Fund of Qinghai Province—Science and Technology Innovation Base Construction Project(Grant No.2025ZY017)。
文摘From 10 to 15 April 2025,China experienced a rare persistent extreme wind-dust compound disaster that swept from north to south.Based on observational data,historical disaster records,and situations of various exposed elements,this study analyzed the formation mechanisms and evolution of this extreme event and conducted a rapid assessment of the associated loss and damage.The results indicate that the direct cause of this extreme wind-dust compound disaster was a strong cold vortex system generated in Mongolia,which moved eastward and southward,combined with the amplification effects of topography and urban structures,and the downward transmission of momentum from higher troposphere.The analysis revealed that approximately 697.47 million people were exposed to strong winds,while about 1,374.54 million people were exposed to high concentrations of PM10.The strong winds also caused varying degrees of damage to buildings,transportation networks,agricultural greenhouses,and forests.Based on vulnerability curves for wind-related loss and damage,it was estimated that the number of victims affected by this extreme wind-dust compound disaster ranged from 0.209 to 1.044 million,with casualties between 5 and 13 individuals.The number of damaged buildings was estimated to be between 2115 and 4607,and the area of affected crops was between 229 and 783 km2.The direct economic losses could reach as high as RMB 0.076–3.501 billion yuan.This study revealed the causes of this extreme wind-dust compound disaster and quantified the disaster loss and impact,providing new insights for the prevention of associated disasters.
基金Supported by Key R&D Projects of Hunan Provincial Department of Science and Technology"Study on Key Modern Processing Techniques and Product Development of Huarong Mustard"(2023NK2039).
文摘A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.
文摘Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.The disease has diverse triggers,commonly including:lacrimal gland dysfunction;meibomian gland dysfunction accelerating tear evaporation;reduced blinking due to prolonged electronic device use;contact lens wear interfering with the tear film;medication side effects;environmental factors;hormonal fluctuations;certain ophthalmic surgeries,for example,LASIK.Treatment requires targeting specific pathogenic mechanisms,with the core focus on controlling inflammation,restoring tear film stability,and improving related gland function.
文摘Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.
文摘First at all, it introduced the concept and the damages of continuous cropping obstacle. Then, it analyzed the causes of continuous cropping obstacles for Atractylodes macrocephala Koidz. In the end, in order to provide guidance for pro- moting sustainable development of Atractylodes macrocephala Koidz industry in Pingjiang County, it put forward some control methods for eliminating continuous cropping obstacles of Atractylodes macrocephala Koidz, including breeding varieties with high resistance; applying rotation cropping and intercropping reasonable; rational fertilization and soil disinfection; introducing antagonistic bacterial and eliminating au- tointoxication.
文摘Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of this process were analyzed in this article in terms of general circulation,character of physical quantity and tropical cyclone.The result showed that the precipitation process was a long wave adjustment process and it took place during the transformation process of general circulation turning from the zonal to the radial.During the cloudy-rainy weather process,the Ural mountain ridge and the Western Pacific subtropical high were more abnormally strong and in the further north than that in any other years.The tropical cyclone in the south of the subtropical cyclone activity was more frequent.There was more shortwave in middle latitudes of Asian.The cold air masses Siberia went down south.The cold air masses joined with the current of air in the Lower Yellow River.This led to the lasting cloudy-rainy weather for several days in Shandong.
文摘Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.
文摘After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room at the back and with wing rooms on the left and right side.It has analyzed the formation,development,climax,damage and inheritance of quadrangle courtyard,and considered that it could manifest Chinese traditional humanistic idea and aesthetic idea,and is in possession of profound cultural connotation and regional feature.On this basis,causes for quadrangle courtyards have been studied.The primary cause at the initial stage lies in human body structure theory and the perfection of quadrangle courtyards at later stage depends on ethic order theory.
文摘This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power distance,connotation versus denotation,and orientation towards time,negative transfer of equivalent structures and behaviors,insufficient or improper teaching and the scarcity of universal knowledge for communication.
文摘Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles have their historical background which helped form his democratic ideas.
文摘Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and its main character Sister Carrie is a controversial person.Dreiser was criticized by critics and readers because he didn’t give any comment on her degener ation.This thesis tries to analyze the causes of this tragedy.In the end,the paper draws the conclusion:the American Dream looks beautiful,but to some extent it is not reliable,just like the foam of soap.It only gives people an illusion.So Carrie’s tragedy is in evitable.
文摘The main causes of the vocational college students' oral fossilization summarized in the thesis are as follows:negative transfer of the native language,overgeneralization,communication strategies blockage.
文摘This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global average. The country-averaged annual mean surface air temperature has increased by 1.1℃ over the past 50 years and 0.5-0.8℃ over the past 100 years, slightly higher than the global temperature increase for the same periods. Northern China and winter have experienced the greatest increases in surface air temperature. Although no significant trend has been found in country-averaged annual precipitation, interdecadal variability and obvious trends on regional scales are detectable, with northwestern China and the mid and lower Yangtze River basin having undergone an obvious increase, and North China a severe drought. Some analyses show that frequency and magnitude of extreme weather and climate events have also undergone significant changes in the past 50 years or so. Studies of the causes of regional climate change through the use of climate models and consideration of various forcings, show that the warming of the last 50 years could possibly be attributed to an increased atmospheric concentration of greenhouse gases, while the temperature change of the first half of the 20th century may be due to solar activity, volcanic eruptions and sea surface temperature change. A significant decline in sunshine duration and solar radiation at the surface in eastern China has been attributed to the increased emission of pollutants. Projections of future climate by models of the NCC （National Climate Center, China Meteorological Administration） and the IAP （Institute of Atmospheric Physics, Chinese Academy of Sciences）, as well as 40 models developed overseas, indicate a potential significant warming in China in the 21st century, with the largest warming set to occur in winter months and in northern China. Under varied emission scenarios, the country-averaged annual mean temperature is projected to increase by 1.5 2.1℃ by 2020, 2.3 3.3℃ by 2050, and by 3.9-6.0℃ by 2100, in comparison to the 30-year average of 1961-1990. Most models project a 10% 12% increase in annual precipitation in China by 2100, with the trend being particularly evident in Northeast and Northwest China, but with parts of central China probably undergoing a drying trend. Large uncertainty exists in the projection of precipitation, and further studies are needed. Furthermore, anthropogenic climate change will probably lead to a weaker winter monsoon and a stronger summer monsoon in eastern Asia.
文摘Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic abnormalities, remain largely unknown. Until recently, the only genetic tests used in the diagnosis of male infertility were aimed at detecting the presence of microdeletions of the long arm of the Y chromosome and/or chromosomal abnormalities. Various other single-gene or polygenic defects have been proposed to be involved in male fertility. However, their causative effects often remain unproven. The recent evolution in the development of whole-genome-based techniques and the large-scale analysis of mouse models might help in this process. Through knockout mouse models, at least 388 genes have been shown to be associated with spermatogenesis in mice. However, problems often arise when translating this information from mice to humans.
