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Review on Drought Disasters in the Five Provinces of Northern China in 1920
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作者 王鑫宏 《Meteorological and Environmental Research》 CAS 2010年第4期87-91,共5页
This paper analyzed the severe drought that took place in the five provinces of Northern China in 1920.Study suggested that the severe damage caused by the drought was resulted from many reasons,such as certain specif... This paper analyzed the severe drought that took place in the five provinces of Northern China in 1920.Study suggested that the severe damage caused by the drought was resulted from many reasons,such as certain specific natural conditions,deterioration of ecological environment,malformations of the rural economy and turbulence of domestic politics.However,some new phenomena took shapes during this time disaster relief activity. 展开更多
关键词 1920 Five provinces in northern China DROUGHT Characteristics Cause of formation Disaster relief China
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Modes of Occurrence and Cleaning Potential of Trace Elements in Coals from the Northern Ordos Basin and Shanxi Province, China 被引量:9
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作者 WANGWenfeng QINYong JIANGBo FUXuehai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第4期960-969,共10页
Based on the analyses of 43 elements in 16 samples of the raw coal and feed coal collected from the northern Ordos basin and Shanxi Province, the modes of occurrence of these elements were studied using the method of ... Based on the analyses of 43 elements in 16 samples of the raw coal and feed coal collected from the northern Ordos basin and Shanxi Province, the modes of occurrence of these elements were studied using the method of cluster analysis and factor analysis, and the cleaning potential of the hazardous elements relatively enriched in the coals was discussed by analyzing six samples of the cleaned coal from the coal-washing plants and coal cleaning simulation experiments. The results shows that the elements Br and Ba show a strong affinity to the organic matter, Cs, Cd, Pb, Zn and Hg partly to the organic matter, and the other trace elements are mainly associated with the mineral matter. Cs, Mo, P, Pb, Zn and S have positive correlations with the two principal factors, reflecting the complexity of their modes of occurrence. Some elements that were thought to show a faint relationship (Be with S and Sb with carbonates) in other rocks are found to have a strong interrelation in the coals. Clay minerals (mainly kaolinite) dominate in the coals, and Ta, Th, Ti, Sc, REE, Hf, U, Se, W, V, Nb, Mo, Al, P, Cr, Pb and Zn are distributed mostly in kaolinite, while K, Rb, Cs, and Na have much to do with illite. Conventional cleaning can reduce the concentrations of most hazardous elements in various degrees. The hazardous elements S, As, Sb, Se, Mo, Pb, Cd and Hg relatively enriched in some coals from the area studied have a relatively high potential of environmental risks. However, by physical coal cleaning processes, more than 60% of As and Hg were removed, showing a high degree of removal, more than 30% of Sb, as well as S, Pb and Cd partly associated with the inorganic matter were removed. Se and Mo showing a relatively low degree of removal could be further removed by deep crushing of the coal during physical cleaning processes, and the concentrations of S, Pb, Cd and Hg with a partial association with the organic matter could be decreased in such ways as the coal blending. Cluster analysis together with factor analysis is a rapid and effective way to deduce the mode of occurrence of an element from bulk samples, and the removability data of most hazardous elements are basically consistent with their modes of occurrence suggested, which indicates that the statistical analysis could predict the cleaning potential of hazardous elements during the physical coal cleaning. 展开更多
关键词 trace element mode of occurrence factor analysis cluster analysis cleaning potential northern Ordos basin Shanxi province
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Changes in Ecosystem Service Values on the Loess Plateau in Northern Shaanxi Province,China 被引量:9
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作者 LI Jing REN Zhi-yuan 《Agricultural Sciences in China》 CAS CSCD 2008年第5期606-614,共9页
The Loess Plateau in northern Shaanxi Province of China covers Yulin, Yan'an, and Tongchuan cities mainly. The kind of physiognomy is complicated and various, including the transitional region of the sand and wind, t... The Loess Plateau in northern Shaanxi Province of China covers Yulin, Yan'an, and Tongchuan cities mainly. The kind of physiognomy is complicated and various, including the transitional region of the sand and wind, the hilly-gully fragile region, the pimple mound region from North to South. Large-scale land reclamation projects that are severely affecting these ecosystems have been implemented. In this paper, we reported an investigation to the changes in land use and ecosystem services on the Loess Plateau in northern Shaanxi Province from 1978 to 2000. We used three LANDSAT TM and/or ETM data sets to estimate the changes in the size of five land-cover/land-use categories, and we also used previously published value coefficients to estimate the changes in the value of ecosystem services delivered by each land category. Finally, we ranked the contribution of various ecosystem functions to the overall value of the ecosystem services, we have estimated that the annual value of the ecosystem services is 56.95 billon RMB yuan in the Loess Plateau in northern Shaanxi Province in 2000. In the region, from 1978 to 2000, the economic value of the fixing carbon was higher, the economic value of water conservation was the lowest, but the economic value of the NPP, fixing carbon, and supplying oxygen accounted for above ninety percent of the total value, obviously the vegetation created the biggest ecosystem service value. We can conclude that future land-use policy formulation should give precedence to the conservation of these ecosystems over uncontrolled reclamation, and that further land reclamation should be based on rigorous environmental impact analyses. 展开更多
关键词 LANDUSE ecosystem services the value ecosystem functions the Loess Plateau northern Shaanxi province
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Quantitative analysis of the dynamic change and spatial differences of the ecological security: a case study of Loess Plateau in northern Shaanxi Province 被引量:5
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作者 LI Jing REN Zhiyuan ZHOU Zixiang 《Journal of Geographical Sciences》 SCIE CSCD 2006年第2期251-256,共6页
Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecologica... Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows: (1) the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; (2) the ecological footprint appears an increasing trend; (3) ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and (4) the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv. 展开更多
关键词 regional ecological security dynamic change spatial difference quantitative analysis the Loess Plateau in northern Shaanxi province
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Spatial-temporal Frame,Evolution and Mineralization of the Northern Qilian Metallogenic Province 被引量:2
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作者 Sun Haitian Wu Jieren and Li Jinping Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing Xi’an Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Xi’an, Shaanxi Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第2期204-216,共13页
Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed t... Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed the tectonic environment of crustal breakupcaused by mantle diapirism, in which ultramafic-mafic rocks were intruded along beep faultbelts and the superlarge Jinchuan magmatic Cu-Ni sulphide deposit was formed. In theMiddle-Late Proterozoic metallogenic epoch the crust was further broken to form anintracontinental rift, in which the Chenjiamiao style massive Cu-Fe sulphide deposits hosted bybasic volcanic tuff were formed in the lower volcano-sedimentary sequence, while the largesedex type Jingtieshan style Fe-Cu deposits were formed within the upper abyssal carbon-richargillaceous sedimentary sequence. The Early Palaeozoic saw the aulacogen environment, with-in which the Baiyinchang style superlarge massive base and precious metal sulphide depositshosted by quartz keratophyric tuff were formed in the Middle-Late Cambrian rifted island arcand the massive Cu-Zn sulphide deposits and magmatic chromite deposits associated with theophiolite suite were formed in the Early-Middle Ordovician, and the Honggou style massiveCu-Fe sulphide deposits hosted by spilite were formed in the Late Ordovician back-arc basinenvironment. In the Late Palaeozoic-Meso-Cenozoic, the metallogenic province went into anintracontinental orogenic stage characterized by compressive tectonic environment, in whichthere occurred carbonate-quartz vein type and tectono-alteration gold deposits associated withductile-shear structures. 展开更多
关键词 northern Qilian metallogenic province evolution and mineralization
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Change Characteristics and Cause Analysis of Summer Precipitation Anomaly in Loess Plateau of Northern Shaanxi Province 被引量:1
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作者 Qiang Li Zhicai Li +1 位作者 Xiaoli Li Tao Liu 《Meteorological and Environmental Research》 CAS 2013年第2期5-7,11,共4页
[ Objective] The research aimed to study change characteristics and formation cause of summer precipitation abnormality in Loess Plateau of northern Shaanxi Province. [ Method] Based on summer precipitation data at 15... [ Objective] The research aimed to study change characteristics and formation cause of summer precipitation abnormality in Loess Plateau of northern Shaanxi Province. [ Method] Based on summer precipitation data at 15 observation stations in Loess Plateau of northern Shaanxi Province and NCEP/NCAR dataset from 1961 to 2008, change characteristics of summer precipitation in the region were investigated by using linear trend estimation and composite analysis. [Result] Summer rainfall had decrease trend in most parts of northem Shaanxi Province, but had increase trend in western and southern regions. The interannual and interdecadal variations were obvious. It had a large amount of precipitation from the mid- 1970s to the mid-1990s, while summer rainfall had decrease trend after the mid-1990s and increase trend in recent years. In wet years, it was a large positive anomaly zone from western Ural Mountains to northem Lake Baikal at middle and high latitudes, indicating that there was a blocking high over the Ural Mountains, while it was negative anomaly zone from northern Okhotsk Sea to Lake Baikal. From Northwest Pacific Ocean to Bo- hal Sea Bay and North China, it was a wide range of significant positive anomaly zone, which was favorable for Westem Pacific subtropical high ex- tending westward and northward. The analysis in dry years showed opposite circulation configuration. It was " -, +, -" wave train distribution in middle and high latitudes and positive anomaly zone along the Sea of Okhotsk. Western Pacific subtropical high was also by south and east. Major water vapor was from southeast direction in wet years, and abundant water vapor caused more summer rainfall in northern Shaanxi. In dry years, water vapor was from westerly tuming southerly flow. It was weaker and by east. [ Conclusion] The research provided reference for reasonable utilization of summer precipitation in the zone. 展开更多
关键词 Loess Plateau northern Shaanxi province Summer precipitation ABNORMALITY China
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Distribution and Source of Main Contaminants in Surface Sediments of Tidal Flats in the Northern Shandong Province 被引量:1
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作者 LIU Zhijie LI Peiying +2 位作者 ZHANG Xiaolong LI Ping XU Yuanqin 《Journal of Ocean University of China》 SCIE CAS 2014年第5期842-850,共9页
Twenty-nine samples of surface sediments from tidal flats in the Northern Shandong Province were collected for grain size, heavy metal(Hg, Cu, Pb, Zn, Cd, and Cr), and oil pollution analyses. The geoaccumulation index... Twenty-nine samples of surface sediments from tidal flats in the Northern Shandong Province were collected for grain size, heavy metal(Hg, Cu, Pb, Zn, Cd, and Cr), and oil pollution analyses. The geoaccumulation index(Igeo) and factor analysis were introduced to evaluate sediment quality and source of contaminants. The mean concentrations of Hg, Cu, Pb, Zn, Cd, Cr, and oil in the surface sediments in the study area are 0.033, 17.756, 19.121, 55.700, 0.291, 59.563, and 14.213 μg g-1, respectively. The heavy metal contamination in the old delta lobe is slightly higher than that in the abandoned delta lobe; however, the opposite was observed for oil pollution. The Igeo results revealed that the overall quality of the surface sediments in the study area is in good condition. The heavy metal pollution levels show a descending order: Cd> Hg> Cr> Cu> Zn> Pb, Cd being the main pollutant. The contamination level for in the study area is relatively lower than those for China's other tidal flats. Heavy metals are mainly derived from natural sources of rock weathering and erosion, partly influenced by industrial and agricultural discharge. However, oil pollution is mainly from runoff input, motorized fishing boat sewage, and oil exploitation. 展开更多
关键词 tidal flat sediments heavy metals quality evaluation factor analysis source of contaminants northern Shandong province
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Genetic diversity of Leishmania donovani isolates from cutaneous lesions of military personnel in the Mullaitivu and Kilinochchi districts of the Northern Province,Sri Lanka
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作者 Tharaka Wijerathna Nayana Gunathilaka +3 位作者 Saveen Semege Nishantha Pathirana Wasana Rodrigo Deepika Fernando 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2022年第9期418-424,共7页
Objective:To compare the DNA sequences of Leishmania(L.)donovani isolated from individuals in two districts of the Northern Province with other parts of Sri Lanka and neighboring countries.Methods:Samples were collect... Objective:To compare the DNA sequences of Leishmania(L.)donovani isolated from individuals in two districts of the Northern Province with other parts of Sri Lanka and neighboring countries.Methods:Samples were collected from military personnel at the Army Hospital,Narahenpita,Sri Lanka from November 2018 to March 2020.A portion of the samples was fixed,stained with Giemsa and observed under the light microscope.The genomic The DNA was extracted from the remaining portion of the samples using DNEasy blood tissue kit(Qiagen,Germany)and amplified using Leishmania genus-specific primers for molecular diagnosis initially.DNA was amplified using L.donovani species-specific primers by PCR and the amplified product was sequenced for comparison of nucleotide sequences.Results:Out of 76 suspected patients,at least one biological sample of 45(59.2%)was positive for L.amastigotes upon microscopy.Overall,33(43.4%)were positive in Leishmania genus-specific PCR,but only 23(30.3%)were positive in L.donovani specific PCR.The dendrogram indicates that the current sequences clustered together with those from Nepal and Gampaha districts(Western Province),Sri Lanka,while the Indian and Eastern African sequences clustered separately.Conclusions:The genetic diversity was low among the isolates,indicating a single and possibly a local point of origin.However,the similarity of Sri Lankan and Nepal strains indicate a possibility of a shared point of origin,which needs more extensive evidence to confirm. 展开更多
关键词 LEISHMANIASIS Sri Lanka PHYLOGENETICS Kilinochchi Mullaitivu northern province
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Analysis on Hydrogeochemical Characteristics and Their Temporal and Spatial Variation in the Karst Catchment of Lianjiang River,Northern Guangdong Province
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作者 Zhou Chen Xizhi Wang +3 位作者 Baosheng Li Gongcou Guan Zhaoxiong Liang Jun Wang 《Meteorological and Environmental Research》 CAS 2013年第11期35-43,共9页
[ Objective] The study aimed to discuss the hydrogeochemical features and their temporal and spatial variation in the karst catchment of Lianjiang River, northem Guangdong Province. [ Method] Water samples were collec... [ Objective] The study aimed to discuss the hydrogeochemical features and their temporal and spatial variation in the karst catchment of Lianjiang River, northem Guangdong Province. [ Method] Water samples were collected from 10 sub-drainages of Lianjiang River in July of 2012 and January of 2013, and then major chemical ions in tributaries of Xingzi River and Tongguanshui River were analyzed in detail to discuss the hydrochemistry type, spatial and temporal distribution and its causes of formation in Lianjiang River basin. [ Result] Among chemical ions in the wa- ter samples, Ca2. and HCO^- were dominant in Lianjiang River, accounting for over 70% and 80% of total concentrations of cations and anions re- spectively, followed by Mg2+ and SO24-. The concentrations of most major ions were higher in winter than those in summer except SO4^2- concentra- tion was much higher in summer than that in winter, which was related to anthropogenic factors. From hydrochemical types, it is seen that HCO3-- Ca2+ type in summer and HCO3--Ca2+ ~ Mg2. type in winter were dominant in Lianjiang River, followed by the HCO3--SO4^2- · Ca2+ type, and only two samples of Xingzi River belonged to HCO3--Ca2+ Mg2· Na+ type in winter. The spatial distribution regularity of chemical ions was not obvi- ous in the 10 sub-drainages of Lianjiang River. The concentrations of chemical ions changed greatly in the upper reaches but slightly in the lower reaches of Xingzi River catchment. The concentrations of chemical ions were steady in Tongguanshui River catchment with a smaller area, and it was a little higher in the upper reaches than those in the lower reaches. [ Conclusion] Natural processes, such as lithological heterogeneities and at- mospheric precipitation, contributed to the chemical composition of Lianjiang River catchment, northem Guangdong Province. 展开更多
关键词 northern Guangdong province Uanjiang River Ion concentration Spatial and temporal variation Hydrochemical types
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The Origin of Pb-Zn Deposits in the Northern Kuandian Area, Liaoning Province
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作者 Qu Yajun and Wang Changfeng (Liaoning Institute of Ceological Survey, Shenyang, 110032. P. R. China) 《Global Geology》 2001年第1期45-51,共7页
Carbonates and clastic rocks are well developed in the second-order basins of an Paleoproterozoic aulacogen in the northern Kuandian area, Liaoning Province. The carbonates cousist of two parts, the upper and the lowe... Carbonates and clastic rocks are well developed in the second-order basins of an Paleoproterozoic aulacogen in the northern Kuandian area, Liaoning Province. The carbonates cousist of two parts, the upper and the lower carbonate forma- tions. The clastic rocks occured between the two formations. Two Pb-Zn ore belts exist in both of upper and lower carbo- nate formations and are called B and A-belt respectively. Several tens of Pb-Zn ore bodies are found in A-belt. Some Pb -Zn ore bodies are apparent in vertical zoning in a sequence of Fe-Zn-Pb-Ba from the lower to the upper. Geological and geochemical researches show that the ore components in the A-belt was exhalated from the liquid source bed deeply and was precipitated in a closed second-order basins. While those in the B-belt was derived from the upper crust and was de- opsited in a normal oceanic enviornment. The second-order basins in Liaodong-Ji’nan-North Korean Peninsular aulaco- gen at the margin of the Archean craton are promising sites for looking for the deposits formed by exhalation of the liquid source bed deeply under crust. 展开更多
关键词 LIAONING province northern Kuandian Paleoproterozoic CARBONATE rock lead- zinc ore deposit
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Reorganizing the Local Boy Scouts Associations in the Northern Province of the Gold Coast Colony
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作者 Doris Susannah Essah 《Cultural and Religious Studies》 2018年第7期417-425,共9页
Imperialist Robert Baden-Powell’s Boy Scouts Association started in the Gold Coast Colony during the First World War and schooled boys for nationality during the 1920s.This paper uses archival documents to discuss ho... Imperialist Robert Baden-Powell’s Boy Scouts Association started in the Gold Coast Colony during the First World War and schooled boys for nationality during the 1920s.This paper uses archival documents to discuss how Chief Scout Governor Gordon Guggisberg,who was brigadier general during the First World War,reorganized the Boy Scouts Association in the Northern Province of the Northern Territories Protectorate.The scout officers at the Local Boy Scouts Associations had the power to fashion desire but were not supposed to have consequences on political power.As government officers and scout officers they had warrants to work at the government schools at Gambaga,Wa,and Lawra to attain money locally for kits to instruct and invent the identity,customs and nationalist categories of schoolboys performing the British Empire. 展开更多
关键词 reorganizing the northern provincE LOCAL Boy Scouts Association the northern TERRITORIES Protectorate of the GOLD Coast Colony Governor GORDON Guggisberg imperialist Robert Baden-Powell
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Gender Equality in Northern Province Hospitality Sector in Sri Lanka
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作者 Ilangkeeran Bithushan Mathanki Jegathasan 《Journal of Tourism and Hospitality Management》 2017年第4期163-171,共9页
The term "gender equality" describes the equal valuing of the different characters assumed by male and female. At present in Northern part of Sri Lanka, there is huge improvement in the field of hospitality. Nowaday... The term "gender equality" describes the equal valuing of the different characters assumed by male and female. At present in Northern part of Sri Lanka, there is huge improvement in the field of hospitality. Nowadays, gender equality is very important in every workforce especially in the hospitality sector. Many countries are accepting the gender equality. After the ethnic war in Northern Province Tamil people without any discrimination, male and female are taking part in the field of hospitality. The main reasons for this change are economical breakdown and the interest of people towards hospitality field. There are more than 10 women staffs working in the hotel industry in the Northern part of Sri Lanka. The hospitality industry helps the women staffs to balance their families. Because Northern Province has many women leadership families. Most of the female workers (Captain of the families) are working as cleaning staff, front office assistance, assistance managers, managers, and training instructors in the Northern Province hotel sector. According to the authors' field visit, Northern Province hospitality sectors provide some security service for the female staffs such as hostel arrangements, no night shift works, and high security inside the hotel. The Northern Province hospitality outlet not only hotels but also catering service, self-employments such as sweets delivery for the fimctions and food cooking for the parties, house works are done by both genders because after the war, many families are affected by the economic poverty. According to the authors' data collection, more than 200 families are doing the self-employment jobs such as catering service for the parties, food issuing for the university students, sweets issuing for the functions. Female staffs are able to work with the good mentality as they come to the working field. Though there are educated people in Northern part of Sri Lanka, only a few are qualified in this particular field. Nevertheless, at present many Northern Province female students are studying hospitality degree at University College of Jaffna. They come from different districts, mostly from Northern Province. The women hoteliers are not only capable in front office but they are also able to work in human resource department, account department, kitchen department, housekeeping department and security service department. At last, it is noted that hospitality is the key factor in the long-lasting sustainability of the economic system of the Northern part of Sri Lanka. In the future, the Northern part of Sri Lanka hospitality sector will improve a lot without any gender discrimination, because at present, the students are studying hospitality degree for their great future. It is a sustainable activity for the Northern Province hospitality sector without gender discrimination. 展开更多
关键词 gender equality northern province hospitality sector rules of female staff economic poverty sustainable focus of hospitality sector SELF-EMPLOYMENT
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Effects of Different Modes of Returning Farmland to Forest on Physicochemical Properties of Soil in Bashang Area of Northern Hebei Province
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作者 Yue YANG Yitian YANG +2 位作者 Zhiyong WU Caiwu WU Yongjiao HAN 《Meteorological and Environmental Research》 CAS 2020年第4期98-102,共5页
[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three differe... [Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best. 展开更多
关键词 Returning farmland to forest Physicochemical properties of soil Bashang area of northern Hebei province
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黔北—滇东二叠纪锰矿主要成矿规律与成矿区带划分 被引量:1
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作者 刘志臣 周琦 +3 位作者 杨瑞东 杜远生 陈登 肖林 《矿产综合利用》 CAS 2024年第1期62-72,共11页
这是一篇地球科学领域的论文。锰矿为我国十分紧缺的战略矿产之一。黔北-滇东地区是我国二叠纪锰矿最典型的分布区,在全球晚古生代也较为少见,该区锰矿资源丰富,找矿潜力巨大,称为“遵义式锰矿”。研究表明,该区锰矿产于二叠纪茅口晚期... 这是一篇地球科学领域的论文。锰矿为我国十分紧缺的战略矿产之一。黔北-滇东地区是我国二叠纪锰矿最典型的分布区,在全球晚古生代也较为少见,该区锰矿资源丰富,找矿潜力巨大,称为“遵义式锰矿”。研究表明,该区锰矿产于二叠纪茅口晚期,分布严格受黔北裂谷盆地控制,锰矿在地堑盆地中心喷溢沉积成矿,在地垒区则无锰矿分布,矿体空间展布方向与盆地展布方向基本一致。其中,黔北遵义-黔西地区锰矿在空间上分布于盆地相区,并可分为中心相、过渡相、边缘相等三个锰矿相带,进一步指示了锰矿具体成矿位置,显示了锰矿受盆地中心控制非常明显的特点。在划分的遵义-宣威锰矿成矿带的基础上,详细划分出遵义-黔西锰矿成矿亚带中深溪—八里、龙坪—兴隆、团溪—尚稽、黔西4个锰矿矿集区,以及水城-宣威锰矿成矿亚带中水城—纳雍、格学2个锰矿矿集区。该研究成果对寻找黔北—滇东二叠纪隐伏锰矿床,开展成矿预测,具有重要的意义。 展开更多
关键词 地球科学 二叠纪锰矿 成矿规律 成矿区带 黔北—滇东
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豫北两熟区不同夏播作物对后茬冬小麦中后期群体微环境及产量的影响
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作者 邵云 杨俊华 +2 位作者 刘玘 王鹏飞 王岚 《麦类作物学报》 CAS CSCD 北大核心 2024年第4期485-495,共11页
为探讨不同夏播作物前茬对后茬冬小麦生长和产量的影响,在河南省新乡市获嘉县开展田间二因素试验,设置两个不同施肥水平(常规施肥和不施氮肥)和三种夏播作物前茬(玉米、大豆和花生),分析小麦拔节期至成熟期叶面积指数(LAI)、叶夹角(LA)... 为探讨不同夏播作物前茬对后茬冬小麦生长和产量的影响,在河南省新乡市获嘉县开展田间二因素试验,设置两个不同施肥水平(常规施肥和不施氮肥)和三种夏播作物前茬(玉米、大豆和花生),分析小麦拔节期至成熟期叶面积指数(LAI)、叶夹角(LA)、光合有效辐射(PAR)、叶片叶绿素含量(SPAD)、叶绿素荧光(F_(v)/F_(m)),以及土壤含水量(SWC)、土壤温度(Ts)和土壤呼吸速率(Rs)变化,并在成熟期测定小麦产量及其构成因素。结果表明,与常规施肥(CK)相比,不施氮肥条件下不同前茬的小麦LA略增,而LAI、IPAR、SPAD、F_(v)/F_(m)、SWC、Ts和Rs均有所降低。不施氮肥条件下,花生前茬的小麦LAI、IPAR、SPAD、F_(v)/F_(m)、SWC、Ts和Rs均显著低于其他两种前茬(P<0.05),其中花生、大豆和玉米前茬的SWC较CK的降幅分别为13.56%、13.39%和10.77%。与CK相比,不施氮肥条件下,花生前茬的小麦LA较CK的增幅在3种前茬中居中,小麦株型较为紧凑,有利于改善植株下层光合辐射,为群体生长创造良好的光合和土壤条件,其产量较玉米和大豆前茬分别高20.0%和21.9%;玉米前茬的整体表现不如大豆和花生前茬,但其和花生前茬的小麦千粒重和群体数均较高,因而产量居中;大豆前茬的小麦结实小穗数和干物质量较高,但其小麦千粒重较低,最终籽粒产量也较低。综合来看,在两熟种植模式中,选用花生作为冬小麦的前茬作物是豫北地区一年两熟区作物配置的一种较优选择。 展开更多
关键词 豫北地区 一年两熟制 冬小麦 前茬作物 产量 群体生长
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琼北东寨港桥头村大桥沉没于海时间考与1605年琼州大震后东寨港缓慢下沉速率及机理
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作者 徐起浩 《古地理学报》 CAS CSCD 北大核心 2024年第3期725-752,共28页
琼北东寨港桥头村大桥和大桥前面条石路面废墟,现今位于退潮后水面下并被淤泥覆盖,仅小部分出露。据家谱、墓碑考证和实地调查,该大桥在1605年琼州大震后45年、即公元1650年尚在使用,是琼州大震后,又经近百年才沉没于海的。1650年后至今... 琼北东寨港桥头村大桥和大桥前面条石路面废墟,现今位于退潮后水面下并被淤泥覆盖,仅小部分出露。据家谱、墓碑考证和实地调查,该大桥在1605年琼州大震后45年、即公元1650年尚在使用,是琼州大震后,又经近百年才沉没于海的。1650年后至今(截至调查年1984年),东寨港桥头村地区地面以不低于1.5 cm/a的速率下沉;近30~40年来东寨港中段和北段以不低于1 cm/a速率缓慢下沉,南端下沉速率小些。琼州大地震后的早期,东寨港的下沉速率可能更大些。本研究粗略估算了这次地震同震下沉幅度东寨港中部和北部可能达2~3 m。南部下沉幅度小些。对震后缓慢下沉机理进行了讨论,认为琼州大震是在新生代以来至震前各地质时期,琼北地幔柱隆起、地壳隆起拉张破裂、火山多次活动或喷发、地壳减薄表部下沉、壳下持续性强烈活动的背景下发生的。震前琼北特别是琼北东部地壳经历了数千年的隆起,积聚巨大能量形成壳下热点。震前因地下水向拉张断裂的贯入,降低断裂面摩擦力,震前陆地开始下沉,并终于全面突破断裂面摩擦阻力发生陆陷成海大地震。震时释放部分能量,震后剩余能量对断裂持续拉张,东寨港持续地堑型沉陷。地震时及震后相当长时间内海水对断裂快速和持续贯入降低了断裂面上的摩擦力,使震后断裂呈相对稳定滑动,这些可能是震后东寨港数百年来大速率缓慢下沉的主要原因。连接琼州大地震,晚更新世及可能迟至全新世早期以来,东寨港经历过由陆变海、由海变陆、又由陆变海的演变过程。 展开更多
关键词 琼北 地震事件 震后下沉速率 断裂拉张 海水沿断裂贯入 稳定滑动
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基于知觉体验的工业遗产更新策略研究——以豫北纱厂为例
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作者 郭苏琳 王思玮 《建筑与文化》 2024年第9期213-215,共3页
在存量时代背景下,工业遗产更新逐渐成为引领城市特色,推动城市高质量发展的重要抓手。本研究基于知觉体验的相关理念与方法,通过运用CiteSpace文献计量软件,对知觉体验的关键词进行可视化分析,总结出相应的研究方向。同时,通过解析豫... 在存量时代背景下,工业遗产更新逐渐成为引领城市特色,推动城市高质量发展的重要抓手。本研究基于知觉体验的相关理念与方法,通过运用CiteSpace文献计量软件,对知觉体验的关键词进行可视化分析,总结出相应的研究方向。同时,通过解析豫北棉纺织厂,构建了“工业遗产层级保护”为基础的虚拟评价体系,提炼出“审美感知”“精神引领”“感官联动”为路径的更新策略,旨在将知觉体验引入工业遗产保护,为其提供理论基础与参考依据,助推城市转型与可持续发展。 展开更多
关键词 知觉现象学 知觉体验 工业遗产 豫北棉纺织厂
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赣北彭山还原性S型花岗岩成因及其对Sn富集的启示:来自锆石微量元素的证据
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作者 尹青青 唐菊兴 +8 位作者 项新葵 赵晓彦 汪方跃 徐裕敏 郭虎 余振东 谢金玲 代晶晶 彭勃 《地学前缘》 EI CAS CSCD 北大核心 2024年第3期133-149,共17页
彭山锡多金属矿集区成矿区划位于长江中下游成矿带与江南钨多金属成矿带的过渡部位。以前研究认为与锡大规模成矿有关的花岗岩通常为高分异的过铝质岩浆,但是关于Sn在还原性岩浆中与矿物相的分配和迁移的氧逸度阈值犹未可知,锡与钨在赣... 彭山锡多金属矿集区成矿区划位于长江中下游成矿带与江南钨多金属成矿带的过渡部位。以前研究认为与锡大规模成矿有关的花岗岩通常为高分异的过铝质岩浆,但是关于Sn在还原性岩浆中与矿物相的分配和迁移的氧逸度阈值犹未可知,锡与钨在赣北地区成矿的分带分区(解耦)究竟是受岩浆源区特征的控制还是为氧逸度所制约,目前尚不清楚。本文对区内花岗岩岩石成因、锡的来源、岩浆演化早期的氧化还原条件,及其对锡在岩浆中的分配、萃取和迁移的控制过程开展了研究,即对彭山岩体进行了精细的锆石原位微区分析测试。结果显示,锆石P含量普遍较高,结合P(∑REE+Y)拟合的3条趋势线的斜率分别为0.91、0.85和0.81,与S型花岗岩(∑REE+Y)<1.15×P演变规律相符。在Eu/Eu^(*)Yb N/Gd N关系图解中未显示出与Ti分离曲线的同步协变关系,相反,各组岩石均显示为负相关关系,说明3组锆石Eu/Eu^(*)的比值受榍石与斜长石的共结晶的影响较为有限。依据Hf Ce^(4+)/Ce^(3+)zircon和Ti Ce^(4+)/Ce^(3+)zircon关系图,白云母花岗岩数据区域均位于趋势线末端,与黑云母二长花岗岩和花岗斑岩相比,显示出更低的氧逸度特点。Eu/Eu^(*)与Ce^(4+)/Ce^(3+)zircon比值在各岩石单元中所表现出的还原程度是相耦合的,即组成彭山岩体的3个岩石单元——成矿后花岗斑岩岩脉、黑云母二长花岗岩岩基和白云母花岗岩成矿岩株,其锆石Eu异常(Eu/Eu^(*))和Ce^(4+)与Ce^(3+)比值(Ce^(4+)/Ce^(3+)zircon)呈逐渐递减趋势。双桥山群中1.5~1.3 Ga砂泥质沉积岩与细碧角斑岩系组成的海相古火山喷发沉积建造,可能提供了本区Sn的初始来源。白云母花岗岩成矿岩株的氧逸度显著低于大湖塘石门寺矿床的花岗岩,锆石微量元素揭示了富锡岩浆演化比富钨岩浆具有更低的氧逸度。 展开更多
关键词 还原性 S型花岗岩 Sn富集 锆石 赣北 彭山
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基于DSSAT模型的未来晋北马铃薯最适播期和品种选择研究
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作者 张娜 马雅丽 +1 位作者 张建新 王大勇 《农学学报》 2024年第9期54-61,共8页
选取大同市云州区作为研究区,基于DSSAT模型,在基准年和未来气候变化情景(2个CO_(2)浓度:450、550μmol/mol;2个增温:1.5、2.0℃)下开展40个播期和7个温度敏感系数处理的模型模拟试验,其中认为450μmol/mol CO_(2)伴随1.5℃增温、550μm... 选取大同市云州区作为研究区,基于DSSAT模型,在基准年和未来气候变化情景(2个CO_(2)浓度:450、550μmol/mol;2个增温:1.5、2.0℃)下开展40个播期和7个温度敏感系数处理的模型模拟试验,其中认为450μmol/mol CO_(2)伴随1.5℃增温、550μmol/mol CO_(2)伴随2.0℃增温情景为未来最可能发生的气候变化,以此探讨未来晋北地区马铃薯最适播期以及品种耐热性的变化特征,并定量分析采取改变最适播期或改变品种措施的增产效应。结果表明:气温升高、CO_(2)浓度增加均使马铃薯最适播期提前,且未来最适播期变化主要源于气温的增加,其中450μmol/mol CO_(2)伴随1.5℃增温、550μmol/mol CO_(2)伴随2.0℃增温,最适播期分别提前4、5 d;采取最适播期管理措施后,通过改变播期将给450μmol/mol CO_(2)伴随1.5℃增温、550μmol/mol CO_(2)伴随2.0℃增温情景分别带来10.2%、20.7%的增产,此时的产量将比基准年产量分别增加12.3%和20.8%;采取改种温度敏感性高的品种,提高品种的耐热性,可以适当提高产量,但提高幅度有限。因此,未来晋北地区可采取播期提前或辅以培育温度敏感性高的新品种来降低未来气候变化的影响,保证马铃薯稳产高产。 展开更多
关键词 晋北地区 马铃薯 DSSAT模型 气候变化 适应性对策
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山西沁源枣林庄、柳湾摩崖造像调查简报
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作者 武夏(摄影) 徐晴(绘图) +4 位作者 姬凌飞(绘图) 刘亚楠(绘图) 马楠 李辉 冯鹏锦 《考古与文物》 CSSCI 北大核心 2024年第8期38-50,共13页
2021年1月和4月,山西大学考古系对山西长治沁源枣林庄、柳湾摩崖造像进行了两次调查。枣林庄摩崖造像开凿有3个主龛,龛下刻有供养人形象及题记,据造像题材与风格推断应开凿于北魏晚期。柳湾摩崖造像共有12龛,风化较为严重,根据造像题材... 2021年1月和4月,山西大学考古系对山西长治沁源枣林庄、柳湾摩崖造像进行了两次调查。枣林庄摩崖造像开凿有3个主龛,龛下刻有供养人形象及题记,据造像题材与风格推断应开凿于北魏晚期。柳湾摩崖造像共有12龛,风化较为严重,根据造像题材与风格推断应陆续开凿于东魏北齐时期。此次调查为研究晋东南地区北朝佛教遗存的年代序列以及佛教的传播路线等提供了重要资料。 展开更多
关键词 山西 枣林庄 柳湾 摩崖造像 北朝
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