Objective:To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province,Thailand.Methods:The snail specimens were collected f...Objective:To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province,Thailand.Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012.The prevalence of cercarial infection in snails was investigated using the crushing method.The drawing was done with the help of a camera lucida for the morphological study.Results:A total of 2479 snail individuals were collected and classified into 7 families,11 genera,and 14 species,Among them,8 snails species were found to be infected with an overall prevalence of 17.27%(428/2479),which infected with nine groups of cercariae;gymnocephalous cercaria,strigea cercaria,megalurous cercaria,monostome cercaria,parapleurolophocercous cercaria(Haplorchis cercaria),pleurolophocercous cercaria,furcocercous cercaria(Transversotrema cercaria),xiphidiocercaria,and virgulate cercaria.The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails(64.25%).Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals.This work will provide new information on both the distribution and first intermediate host of trematodes.展开更多
The Changning-Menglian suture in SW Yunnan has been accepted as the Paleotethyan main ocean. However, it has been a matter of debate as to its southerly extension in NW Thailand（the Chiang Mai-Chiang Rai vs. Nan-Utta...The Changning-Menglian suture in SW Yunnan has been accepted as the Paleotethyan main ocean. However, it has been a matter of debate as to its southerly extension in NW Thailand（the Chiang Mai-Chiang Rai vs. Nan-Uttaradit zone）. Our field investigation identified the high-iron basaltic rocks in the Chiang Dao Permian standard profile in NW Thailand. The high-iron rocks provide crucial records for understanding the controversy on the location of Paleotethyan main ocean in NW Thailand. The Early Permian high-iron samples show extremely high Fe Ot（20.96 wt.%–25.56 wt.%） and TiO2（6.07 wt.%–6.34 wt.%） and low SiO2（38.54 wt.%–43.46 wt.%） and Mg O（1.61 wt.%–2.40 wt.%） contents. Such characteristics are similar to those of the Fenner differentiation trend rarely observed in the natural system, distinct from those of the ＂normal＂ Bowen trend. Their chondrite- normalized REE and primitive mantle-normalized patterns are generally similar to those of typical OIB. The initial 87Sr/86 Sr ratios and εNd（t） values range from 0.704 677 to 0.705 103 and 3.16 to 3.48, respectively, falling near the field of typical OIB（oceanic-island basalt）. These data synthetically suggest that the Chiang Dao high-iron rocks are the products of high-degree partial melting of peridotite with Fe-rich eclogitic blobs/streaks in response to a seamount setting. In comparison with the Permian tectonic setting in SW Yunnan and NW Thailand, it is inferred that the Paleotethyan Ocean was located between the Shan-Thai terrane of Sibumasu and Sukhothai arc along the Inthanon zone of the Chiang Mai-Chiang Rai rather than Nan-Uttaradit zones.展开更多
An emission inventory containing emissions from traffic and other sources was complied. Based on the analysis, Carbon Monoxide （CO） emissions from traffic play a very important role in CO levels in Chiang Mai area. ...An emission inventory containing emissions from traffic and other sources was complied. Based on the analysis, Carbon Monoxide （CO） emissions from traffic play a very important role in CO levels in Chiang Mai area. Analysis showed that CO emissions from traffic during rush hours contributed approximately 90% of total CO emissions. Regional Atmospheric Modeling System （RAMS） was applied to simulate wind fields and temperatures in the Chiang Mai area, and eight ca^es were selected to study annual variations in wind fields and temperatures. Model results can reflect major features of wind fields and diurnal variations in temperatures. For evaluating the model performance, model results were compared with observed wind speed, wind direction and temperature, which were monitored at a meteorological tower. Comparison showed that model results are in good agreement with observations, and the model captured many of the observed features. HYbrid Particle And Concentration Transport model （HYPACT） was used to simulate CO concentration in the Chiang Mai area. Model results generally agree well with observed CO concentrations at the air quality monitoring stations, and can explain observed CO diurnal variations.展开更多
Objective:To investigate the infection of Fasciola gigantka(F.gigantka)in domestic cattle from Chiang Mai province and molecular confirmation using ITS-2 region.Methods:The liver and gall bladder of Bubalus bubalis(B....Objective:To investigate the infection of Fasciola gigantka(F.gigantka)in domestic cattle from Chiang Mai province and molecular confirmation using ITS-2 region.Methods:The liver and gall bladder of Bubalus bubalis(B.bubalis)and Bos taurus(B.taunts)from slaughterhouses were examined adult worms and prevalence investigation.The species confirmation with phylogenetic analysis using ITS-2 sequences was performed by maximum likelihood and UPGMA methods.Results:The total prevalences of infection in B.bubalis and Bubalus taurus(B.taurus)were67.27%and 52.94%respectively.The respective prevalence in both B.bubalis and B.taurus were acquired from Doi-Saket,Muang,and Sanpatong districts,with 81.25%,62.50%and 60.00%for B.bubalis and 62.50%,50.00%and 47.06%for Bos taunts respectively.The species confirmation of F.gigantka and some related species by basing on maximum likelihood and UPGMA methods used,4 groups of trematodes were generated,first F.gigantka group including specimen of Chiang Mai,second 2 samples of F.hepatica,third group of 3 rumen flukes;Orthocoelium streptocoelium,F.elongatus and Paramphistomum epliclitum and fourth group of 3 minute intestinal flukes:Haplorchis taichui,Stellantchasmu falcatus.Haplorchoides sp.and liver fluke;Opisthorchis civerrini respectively.Conclusions:These results can be confirmed the Giant liver fluke which mainly caused fascioliasis in Chiang Mai was identified as F.gigantka and specimens were the same as those of F.gigantka recorded in olher different countries.Nucleotide sequence of ITS-2 region has been proven as effective diagnostic tool for the identification of F.gigantka.展开更多
The main objective of this research was to study the pattern and suggestion in ICT usage of tourism business in Chiang Mai. One hundred ninety questionnaires, referred from ICT usage pattern in organization which was ...The main objective of this research was to study the pattern and suggestion in ICT usage of tourism business in Chiang Mai. One hundred ninety questionnaires, referred from ICT usage pattern in organization which was divided into three sections： office work, communication/contacts and public relation/advertising, were gathered from tourism business in four districts in Chiang Mai. Results showed that of the tourism business only 54.7% have their own websites. Using ICT for public relations and advertisement purpose, hotel/accommodation was the highest users with majority as 29.3%; followed by tour operator with majority as 26.3%; transportation and souvenir was the lowest number of users with minority as 50.0% and 25.0%. For communication purpose hotel/accommodation business and tour operator business were high users with majority as 56.1% and 43.4% followed by restaurant business as moderate user with majority as 50.0%; and transportation business as the lowest user with minority as 31.1%. The paper suggested to owners of tourism businesses the following： （1） training on ICT application; （2） setting up center of tourism information; （3） low cost of intemet requirement from small tourism business because they lack technical person on ICT usage. Both the local and national governments should have important roles in supporting the small and medium tourism enterprises by providing good public facilities, technical expertise and easy information access.展开更多
English is one of the most common languages in the world,and it has become one of the most important subjects in various countries.The native languages of China and Thailand are not English,and both countries are loca...English is one of the most common languages in the world,and it has become one of the most important subjects in various countries.The native languages of China and Thailand are not English,and both countries are located in Asia and have many similarities in geographical location and cultural background.The Ministries of Education of the two countries have successively put forward relevant policies to promote the development of English education in the country.The implementation of these policies has promoted the development of college English course teaching in the country.These factors determine that the two countries have similarities in college English course teaching for Non-English majors.However,there are differences in teaching mode and teaching staff in the two countries because of their different national conditions,which make many differences,exist in college English course teaching for non-English majors in the two countries.During the author’s career as an exchange student in Chiang Mai University,she experienced the difference of college English course teaching for non-English majors in Thai universities,so the author did some researches on the basis of the understanding of English course teaching in Thai universities.Therefore,this thesis takes Sino-Thai college English course teaching for non-English majors as the research object—takes Jiujiang University and Chiang Mai University as example,and analyses their present situation from the aspects of the development and evolution,the teaching mode,and teaching staff of college English course teaching for non-English majors.On this basis,the author makes a comparative analysis of the English course teaching for non-English majors in two selected universities,then find their respective advantages and disadvantages,and put forward some suggestions on the development of Sino-Thai college English course teaching.展开更多
The oceanic island volcanic rocks in the Chiang Mai zone, northern Thailand, are usually covered by Lower Carboniferous and Upper Permian shallow-water carbonate rocks, with the Hawaii rocks and potash trachybasalt be...The oceanic island volcanic rocks in the Chiang Mai zone, northern Thailand, are usually covered by Lower Carboniferous and Upper Permian shallow-water carbonate rocks, with the Hawaii rocks and potash trachybasalt being the main rock types. The alkaline series is dominant with sub-alkaline series occurring in few cases. The geochemical characteristics are described as follows: the major chemical compositions are characterized by high TiO2, high P2O5 and medium K2O; the rare-earth elements are characterized by right-inclined strong LREE-enrichment patterns; the trace element patterns are of the upward-bulging K-Ti enrichment type; multi-component plots falling within the fields of oceanic island basalts and alkali basalts, belonging to the oceanic island-type volcanic rocks, which are similar to the equivalents in Deqin and Gengma (the Changning-Menglian zone) of Yunnan Province, China.展开更多
On the basis of the petrographic characteristics, rock assemblages, petrochemistry, REEs, trace elements and geotectonic settings, the authors described the characteristics of continental marginal arc-volcanic rocks i...On the basis of the petrographic characteristics, rock assemblages, petrochemistry, REEs, trace elements and geotectonic settings, the authors described the characteristics of continental marginal arc-volcanic rocks in the Late Permian-Early Triassic (P2-T1) volcanic rocks distributed on the eastern side of the ocean-ridge/oceanic island basalts in the Chiang Mai belt. The volcanic rock assemblage is basaltic andesite-andesite-rhyolite. The volcanic series is dominated by the calc-alkaline series, with the tholeitic series coming next. The chemical composition of the volcanic rocks is characterized by high Al2O3; the REE distribution patterns are of the LREE-enrichment rightward incline type; the large cation elements are highly enriched, and the volcanic rocks are generally enriched in U and Th and depleted in Ti, Cr and P. The petrochemical plot falls within the field of island-arc volcanic rocks, in consistency with the projected points of continental marginal arc-volcanic rocks in the Lancangjiang belt. These continental mar-ginal arc-volcanic rocks, together with ocean-ridge/oceanic island-type volcanic rocks in the Chiang Mai belt, con-stitute the ocean-ridge volcanic rock-arc magmatic rock belts distributed in pairs, indicative of eastward subduction of the oceanic crust in the Chiang Mai belt. This result is of great importance in exploring the evolution of the paleo-Tethys in the Chiang Mai belt.展开更多
Suicide is a critical public health issue with rates varying across regions and demographic groups.Recent evidence suggests that ambient temperature may influence suicide risk.This study examines the association betwe...Suicide is a critical public health issue with rates varying across regions and demographic groups.Recent evidence suggests that ambient temperature may influence suicide risk.This study examines the association between temperature and suicide in Thailand’s tropical climate,focusing on Chiang Mai and Bangkok provinces,and quantifies the attributable burden.Daily suicide and meteorological data from 2002 to 2021 were analyzed using a time-stratified case-crossover approach with a distributed lag nonlinear model,adjusted for relative humidity.Province-specific estimates were pooled through a multivariate meta-regression model.The study found a positive,mostly linear association between temperature and suicide risk,with a relative risk(RR)of 1.70(95%CI:1.35,2.15)across the temperature range.Approximately 24.61%of suicides were attributable to temperature,with 12.05%due to hot temperatures above the 66th percentile.The pooled attributable fractions were higher in the 0−64 age group compared to those aged≥65,while differences between sexes were not statistically significant.This study highlights the significant association between higher ambient temperatures and increased suicide risks in Thailand,emphasizing the need to integrate climate considerations into mental health and suicide prevention policies.Further research across diverse climatic zones is essential for understanding climate influences on mental health globally.展开更多
Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tra...Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tracers.This study comprehensively investigates chemical composition of PM_(2.5),including both inorganic and organic compounds throughout haze and post-haze periods in 2019 at a rural site of Northern Thailand.Average PM_(2.5) concentrations during haze and post-haze period were 87±36 and 21±11μg/m^(3),respectively.Organic matter was the dominant contributor in PM_(2.5) mass,followed by water soluble inorganic ions and mineral dust.Molecular markers,including levoglucosan,dehydroabietic acid,and 4-nitrocatechol,and ions(Cl^(-),and K^(+)),were used to characterize low haze(PM_(2.5)<100μg/m^(3))and episodic haze(PM_(2.5)>100μg/m^(3)).Low haze is associated with local aerosols from agricultural waste burning,while episodic haze is linked to aged aerosols from mixed agricultural waste,softwood,and hardwood burning.Source apportionment incorporating these molecular markers in receptor modelling(Positive matrix factorization),identified three distinct biomass burning sources:mixed,local,and aged biomass burnings,contributing 31,19 and 13%of PM_(2.5) during haze period.During post-haze period,contributions shifted,with local biomass burning(32%)comparable to secondary sulfate(34%)and mixed dust and traffic sources(26%).These findings demonstrate that both regional and local sources con-tribute to severe haze,highlighting the need for integrated policies for cross-border cooperation as well as stricter regulations to reduce biomass burning in Northern Thailand and Southeast Asia.展开更多
Volcanic rocks in northwestern Thailand exposed dominantly in the Chiang Khong area, are commonly considered to be genetically linked to the tectonic evolution of the Paleo-Tethyan Ocean. The volcanic rocks consist ma...Volcanic rocks in northwestern Thailand exposed dominantly in the Chiang Khong area, are commonly considered to be genetically linked to the tectonic evolution of the Paleo-Tethyan Ocean. The volcanic rocks consist mainly of andesitic to rhyolitic rocks and are traditionally mapped as Permian-Triassic sequences. Our zircon U-Pb geochronological results show that two andesitic samples （TL-1-B and TL-31-B）, are representative of the Doi Yao volcanic zone, and give a mean weighted age of 241.2-＋-4.6 Ma and 241.7-＋-2.9 Ma, respectively. The rhyolitic sample （TL-32-B1） from the Doi Khun Ta Khuan volcanic zone erupted at 238.3＋3.8 Ma. Such ages indicate that Chiang Khong volcanic rocks erputed during the early Middle Triassic period. Seven samples from the Doi Yao and Doi Khun Ta Khuan zones exhibit an affinity to arc volcanics. Three rhyolitic samples from the Chiang Khong area have a geochemical affinity to both arc and syn-eollisional volcanic rocks. The Chiang Khong arc volcanic rocks can be geochemically compared with those in the Lampang area in northern Thailand, also consistent with those in Jinghong area of southwestern Yunnan. This indicates that the Chiang Rai arc-volcanic zone might northwardly link to the Lancangjiang volcanic zone in southwestern China.展开更多
When the Guomindang （GMD） took charge in 1927, it implemented the ＂political tutelage＂ system. Participation of other parties in politics was disallowed. But after the Anti-Japanese War （1937-45）, under the comb...When the Guomindang （GMD） took charge in 1927, it implemented the ＂political tutelage＂ system. Participation of other parties in politics was disallowed. But after the Anti-Japanese War （1937-45）, under the combined effect of internal and external pressure, the GMD needed to adopt a constitution, reorganize government and establish multi-party participation. The April 1947 governmental reorganization was the starting point of a transformation from a ＂political tutelage＂ system to a constitutional system. Though this reorganization introduced many non-GMD members into the government, it did not change the GMD＇s one-party dominance. Its desired transformation of China from one-party ＂political tutelage＂ into a constitutional democracy still remained limited.展开更多
基金Supported by National Research Council of Thailand(NRCT)(Grant No.2555A10402010)
文摘Objective:To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province,Thailand.Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012.The prevalence of cercarial infection in snails was investigated using the crushing method.The drawing was done with the help of a camera lucida for the morphological study.Results:A total of 2479 snail individuals were collected and classified into 7 families,11 genera,and 14 species,Among them,8 snails species were found to be infected with an overall prevalence of 17.27%(428/2479),which infected with nine groups of cercariae;gymnocephalous cercaria,strigea cercaria,megalurous cercaria,monostome cercaria,parapleurolophocercous cercaria(Haplorchis cercaria),pleurolophocercous cercaria,furcocercous cercaria(Transversotrema cercaria),xiphidiocercaria,and virgulate cercaria.The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails(64.25%).Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals.This work will provide new information on both the distribution and first intermediate host of trematodes.
基金Financial supports from the National Natural Science Foundation of China(Nos.41190073 and 41402165the Fundamental Research Funds for the Central Universities to SYSU are gratefully acknowledged
文摘The Changning-Menglian suture in SW Yunnan has been accepted as the Paleotethyan main ocean. However, it has been a matter of debate as to its southerly extension in NW Thailand（the Chiang Mai-Chiang Rai vs. Nan-Uttaradit zone）. Our field investigation identified the high-iron basaltic rocks in the Chiang Dao Permian standard profile in NW Thailand. The high-iron rocks provide crucial records for understanding the controversy on the location of Paleotethyan main ocean in NW Thailand. The Early Permian high-iron samples show extremely high Fe Ot（20.96 wt.%–25.56 wt.%） and TiO2（6.07 wt.%–6.34 wt.%） and low SiO2（38.54 wt.%–43.46 wt.%） and Mg O（1.61 wt.%–2.40 wt.%） contents. Such characteristics are similar to those of the Fenner differentiation trend rarely observed in the natural system, distinct from those of the ＂normal＂ Bowen trend. Their chondrite- normalized REE and primitive mantle-normalized patterns are generally similar to those of typical OIB. The initial 87Sr/86 Sr ratios and εNd（t） values range from 0.704 677 to 0.705 103 and 3.16 to 3.48, respectively, falling near the field of typical OIB（oceanic-island basalt）. These data synthetically suggest that the Chiang Dao high-iron rocks are the products of high-degree partial melting of peridotite with Fe-rich eclogitic blobs/streaks in response to a seamount setting. In comparison with the Permian tectonic setting in SW Yunnan and NW Thailand, it is inferred that the Paleotethyan Ocean was located between the Shan-Thai terrane of Sibumasu and Sukhothai arc along the Inthanon zone of the Chiang Mai-Chiang Rai rather than Nan-Uttaradit zones.
基金the Chinese Academy of Sciences （Grant No. KZCX3- SW-231） the National Natured Science Foundation of China （Grant No. 40533018）.
文摘An emission inventory containing emissions from traffic and other sources was complied. Based on the analysis, Carbon Monoxide （CO） emissions from traffic play a very important role in CO levels in Chiang Mai area. Analysis showed that CO emissions from traffic during rush hours contributed approximately 90% of total CO emissions. Regional Atmospheric Modeling System （RAMS） was applied to simulate wind fields and temperatures in the Chiang Mai area, and eight ca^es were selected to study annual variations in wind fields and temperatures. Model results can reflect major features of wind fields and diurnal variations in temperatures. For evaluating the model performance, model results were compared with observed wind speed, wind direction and temperature, which were monitored at a meteorological tower. Comparison showed that model results are in good agreement with observations, and the model captured many of the observed features. HYbrid Particle And Concentration Transport model （HYPACT） was used to simulate CO concentration in the Chiang Mai area. Model results generally agree well with observed CO concentrations at the air quality monitoring stations, and can explain observed CO diurnal variations.
文摘Objective:To investigate the infection of Fasciola gigantka(F.gigantka)in domestic cattle from Chiang Mai province and molecular confirmation using ITS-2 region.Methods:The liver and gall bladder of Bubalus bubalis(B.bubalis)and Bos taurus(B.taunts)from slaughterhouses were examined adult worms and prevalence investigation.The species confirmation with phylogenetic analysis using ITS-2 sequences was performed by maximum likelihood and UPGMA methods.Results:The total prevalences of infection in B.bubalis and Bubalus taurus(B.taurus)were67.27%and 52.94%respectively.The respective prevalence in both B.bubalis and B.taurus were acquired from Doi-Saket,Muang,and Sanpatong districts,with 81.25%,62.50%and 60.00%for B.bubalis and 62.50%,50.00%and 47.06%for Bos taunts respectively.The species confirmation of F.gigantka and some related species by basing on maximum likelihood and UPGMA methods used,4 groups of trematodes were generated,first F.gigantka group including specimen of Chiang Mai,second 2 samples of F.hepatica,third group of 3 rumen flukes;Orthocoelium streptocoelium,F.elongatus and Paramphistomum epliclitum and fourth group of 3 minute intestinal flukes:Haplorchis taichui,Stellantchasmu falcatus.Haplorchoides sp.and liver fluke;Opisthorchis civerrini respectively.Conclusions:These results can be confirmed the Giant liver fluke which mainly caused fascioliasis in Chiang Mai was identified as F.gigantka and specimens were the same as those of F.gigantka recorded in olher different countries.Nucleotide sequence of ITS-2 region has been proven as effective diagnostic tool for the identification of F.gigantka.
文摘The main objective of this research was to study the pattern and suggestion in ICT usage of tourism business in Chiang Mai. One hundred ninety questionnaires, referred from ICT usage pattern in organization which was divided into three sections： office work, communication/contacts and public relation/advertising, were gathered from tourism business in four districts in Chiang Mai. Results showed that of the tourism business only 54.7% have their own websites. Using ICT for public relations and advertisement purpose, hotel/accommodation was the highest users with majority as 29.3%; followed by tour operator with majority as 26.3%; transportation and souvenir was the lowest number of users with minority as 50.0% and 25.0%. For communication purpose hotel/accommodation business and tour operator business were high users with majority as 56.1% and 43.4% followed by restaurant business as moderate user with majority as 50.0%; and transportation business as the lowest user with minority as 31.1%. The paper suggested to owners of tourism businesses the following： （1） training on ICT application; （2） setting up center of tourism information; （3） low cost of intemet requirement from small tourism business because they lack technical person on ICT usage. Both the local and national governments should have important roles in supporting the small and medium tourism enterprises by providing good public facilities, technical expertise and easy information access.
文摘English is one of the most common languages in the world,and it has become one of the most important subjects in various countries.The native languages of China and Thailand are not English,and both countries are located in Asia and have many similarities in geographical location and cultural background.The Ministries of Education of the two countries have successively put forward relevant policies to promote the development of English education in the country.The implementation of these policies has promoted the development of college English course teaching in the country.These factors determine that the two countries have similarities in college English course teaching for Non-English majors.However,there are differences in teaching mode and teaching staff in the two countries because of their different national conditions,which make many differences,exist in college English course teaching for non-English majors in the two countries.During the author’s career as an exchange student in Chiang Mai University,she experienced the difference of college English course teaching for non-English majors in Thai universities,so the author did some researches on the basis of the understanding of English course teaching in Thai universities.Therefore,this thesis takes Sino-Thai college English course teaching for non-English majors as the research object—takes Jiujiang University and Chiang Mai University as example,and analyses their present situation from the aspects of the development and evolution,the teaching mode,and teaching staff of college English course teaching for non-English majors.On this basis,the author makes a comparative analysis of the English course teaching for non-English majors in two selected universities,then find their respective advantages and disadvantages,and put forward some suggestions on the development of Sino-Thai college English course teaching.
基金granted by the National Natural Science Foundation of China (Grant Nos. 40372105 and 40772143)
文摘The oceanic island volcanic rocks in the Chiang Mai zone, northern Thailand, are usually covered by Lower Carboniferous and Upper Permian shallow-water carbonate rocks, with the Hawaii rocks and potash trachybasalt being the main rock types. The alkaline series is dominant with sub-alkaline series occurring in few cases. The geochemical characteristics are described as follows: the major chemical compositions are characterized by high TiO2, high P2O5 and medium K2O; the rare-earth elements are characterized by right-inclined strong LREE-enrichment patterns; the trace element patterns are of the upward-bulging K-Ti enrichment type; multi-component plots falling within the fields of oceanic island basalts and alkali basalts, belonging to the oceanic island-type volcanic rocks, which are similar to the equivalents in Deqin and Gengma (the Changning-Menglian zone) of Yunnan Province, China.
基金the National Natural Science Foundation of China (Grant Nos. 40372105 and 40772143)
文摘On the basis of the petrographic characteristics, rock assemblages, petrochemistry, REEs, trace elements and geotectonic settings, the authors described the characteristics of continental marginal arc-volcanic rocks in the Late Permian-Early Triassic (P2-T1) volcanic rocks distributed on the eastern side of the ocean-ridge/oceanic island basalts in the Chiang Mai belt. The volcanic rock assemblage is basaltic andesite-andesite-rhyolite. The volcanic series is dominated by the calc-alkaline series, with the tholeitic series coming next. The chemical composition of the volcanic rocks is characterized by high Al2O3; the REE distribution patterns are of the LREE-enrichment rightward incline type; the large cation elements are highly enriched, and the volcanic rocks are generally enriched in U and Th and depleted in Ti, Cr and P. The petrochemical plot falls within the field of island-arc volcanic rocks, in consistency with the projected points of continental marginal arc-volcanic rocks in the Lancangjiang belt. These continental mar-ginal arc-volcanic rocks, together with ocean-ridge/oceanic island-type volcanic rocks in the Chiang Mai belt, con-stitute the ocean-ridge volcanic rock-arc magmatic rock belts distributed in pairs, indicative of eastward subduction of the oceanic crust in the Chiang Mai belt. This result is of great importance in exploring the evolution of the paleo-Tethys in the Chiang Mai belt.
文摘Suicide is a critical public health issue with rates varying across regions and demographic groups.Recent evidence suggests that ambient temperature may influence suicide risk.This study examines the association between temperature and suicide in Thailand’s tropical climate,focusing on Chiang Mai and Bangkok provinces,and quantifies the attributable burden.Daily suicide and meteorological data from 2002 to 2021 were analyzed using a time-stratified case-crossover approach with a distributed lag nonlinear model,adjusted for relative humidity.Province-specific estimates were pooled through a multivariate meta-regression model.The study found a positive,mostly linear association between temperature and suicide risk,with a relative risk(RR)of 1.70(95%CI:1.35,2.15)across the temperature range.Approximately 24.61%of suicides were attributable to temperature,with 12.05%due to hot temperatures above the 66th percentile.The pooled attributable fractions were higher in the 0−64 age group compared to those aged≥65,while differences between sexes were not statistically significant.This study highlights the significant association between higher ambient temperatures and increased suicide risks in Thailand,emphasizing the need to integrate climate considerations into mental health and suicide prevention policies.Further research across diverse climatic zones is essential for understanding climate influences on mental health globally.
文摘Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tracers.This study comprehensively investigates chemical composition of PM_(2.5),including both inorganic and organic compounds throughout haze and post-haze periods in 2019 at a rural site of Northern Thailand.Average PM_(2.5) concentrations during haze and post-haze period were 87±36 and 21±11μg/m^(3),respectively.Organic matter was the dominant contributor in PM_(2.5) mass,followed by water soluble inorganic ions and mineral dust.Molecular markers,including levoglucosan,dehydroabietic acid,and 4-nitrocatechol,and ions(Cl^(-),and K^(+)),were used to characterize low haze(PM_(2.5)<100μg/m^(3))and episodic haze(PM_(2.5)>100μg/m^(3)).Low haze is associated with local aerosols from agricultural waste burning,while episodic haze is linked to aged aerosols from mixed agricultural waste,softwood,and hardwood burning.Source apportionment incorporating these molecular markers in receptor modelling(Positive matrix factorization),identified three distinct biomass burning sources:mixed,local,and aged biomass burnings,contributing 31,19 and 13%of PM_(2.5) during haze period.During post-haze period,contributions shifted,with local biomass burning(32%)comparable to secondary sulfate(34%)and mixed dust and traffic sources(26%).These findings demonstrate that both regional and local sources con-tribute to severe haze,highlighting the need for integrated policies for cross-border cooperation as well as stricter regulations to reduce biomass burning in Northern Thailand and Southeast Asia.
文摘Volcanic rocks in northwestern Thailand exposed dominantly in the Chiang Khong area, are commonly considered to be genetically linked to the tectonic evolution of the Paleo-Tethyan Ocean. The volcanic rocks consist mainly of andesitic to rhyolitic rocks and are traditionally mapped as Permian-Triassic sequences. Our zircon U-Pb geochronological results show that two andesitic samples （TL-1-B and TL-31-B）, are representative of the Doi Yao volcanic zone, and give a mean weighted age of 241.2-＋-4.6 Ma and 241.7-＋-2.9 Ma, respectively. The rhyolitic sample （TL-32-B1） from the Doi Khun Ta Khuan volcanic zone erupted at 238.3＋3.8 Ma. Such ages indicate that Chiang Khong volcanic rocks erputed during the early Middle Triassic period. Seven samples from the Doi Yao and Doi Khun Ta Khuan zones exhibit an affinity to arc volcanics. Three rhyolitic samples from the Chiang Khong area have a geochemical affinity to both arc and syn-eollisional volcanic rocks. The Chiang Khong arc volcanic rocks can be geochemically compared with those in the Lampang area in northern Thailand, also consistent with those in Jinghong area of southwestern Yunnan. This indicates that the Chiang Rai arc-volcanic zone might northwardly link to the Lancangjiang volcanic zone in southwestern China.
文摘When the Guomindang （GMD） took charge in 1927, it implemented the ＂political tutelage＂ system. Participation of other parties in politics was disallowed. But after the Anti-Japanese War （1937-45）, under the combined effect of internal and external pressure, the GMD needed to adopt a constitution, reorganize government and establish multi-party participation. The April 1947 governmental reorganization was the starting point of a transformation from a ＂political tutelage＂ system to a constitutional system. Though this reorganization introduced many non-GMD members into the government, it did not change the GMD＇s one-party dominance. Its desired transformation of China from one-party ＂political tutelage＂ into a constitutional democracy still remained limited.
