Ivory Coast is a country rich in base metals and precious minerals: gold, manganese, diamond, iron, bauxite, cobalt and nickel. These natural resources are exposed to destruction and fragmentation by mining activities...Ivory Coast is a country rich in base metals and precious minerals: gold, manganese, diamond, iron, bauxite, cobalt and nickel. These natural resources are exposed to destruction and fragmentation by mining activities. The artisanal and small-scale exploitation of gold are increasingly practiced in our rural areas. These activities escape often in the control and monitoring of the mining administration. In order to better constrain these activities on the environment, the present work used remote sensing imageries to see its spatio-temporal impacts in the rural world in central Ivory Coast. The results show that gold artisanal activities have been practiced since 2013 and are experiencing an increasingly important growth. We note a devastation of forests and savannahs, a pollution of surface water, as well as an increase in poverty in rural areas. These activities are practiced near habited areas (villages). This creates a reduction of cultivatable soil. Remote sensing imageries make it possible to quickly map areas at large-scale gold mining in time and space.展开更多
Aesthetic Modernity is a western concept.It was based on the development of the historical view.This article focuses on the aesthetic modernity pursuits of modern and contemporary Chinese art and compares it with the ...Aesthetic Modernity is a western concept.It was based on the development of the historical view.This article focuses on the aesthetic modernity pursuits of modern and contemporary Chinese art and compares it with the western culture and modern art under the concept of aesthetics.It also analyses the problems and causes in the process of modernity of Chinese modern and con⁃temporary art,and presents the advice to the further development of Chinese art.展开更多
Nowadays human rights diplomacy is nothing new. This is because in recent years it often comes into relations between China and countries in the West and becomes hot issues. Countries in the West are the creator of hu...Nowadays human rights diplomacy is nothing new. This is because in recent years it often comes into relations between China and countries in the West and becomes hot issues. Countries in the West are the creator of human rights diplomacy. During the administration of President Jimmy Carter in the 1970s, the United States for the first time asserted that human fights are central to U.S. foreign policy, and the Carter administration has been known for its human fights diplomacy. Much earlier, in fact, the concept of human fights diplomacy had appeared in the thinking and views of some statesmen in the West.展开更多
In view of the disadvantage that the absolute difference of time-lapse seismic(the difference between monitoring data and base data) is not only related to the change of oil saturation, but also closely related to the...In view of the disadvantage that the absolute difference of time-lapse seismic(the difference between monitoring data and base data) is not only related to the change of oil saturation, but also closely related to the thickness of reservoir, a time-lapse seismic "relative difference method"(the ratio of monitoring data to base data) not affected by the thickness of reservoir but only related to the change of fluid saturation, is proposed through seismic forward modeling after fluid displacement simulation. Given the same change of fluid saturation, the absolute difference of time-lapse seismic conforms to the law of "tuning effect" and seismic reflection of "thin bed", and the remaining oil prediction method based on absolute difference of time-lapse seismic is only applicable to the reservoirs with uniform thickness smaller than the tuning thickness or with thickness greater than the tuning thickness. The relative difference of time-lapse seismic is not affected by reservoir thickness, but only related to the change of fluid saturation. It is applicable to all the deep-sea unconsolidated sandstone reservoirs which can exclude the effect of pressure, temperature, pore type and porosity on seismic. Therefore, the relation between the relative difference of time-lapse seismic and the change of fluid saturation, which is obtained from seismic forward modeling after Gassmann fluid displacement simulation, can be used to quantitatively predict the change of reservoir water saturation and then the distribution of the remaining oil. The application of this method in deep sea Zeta oil field in west Africa shows that it is reasonable and effective.展开更多
The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected b...The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected by high geogenic arsenic (As) concentrations (>10 μg/L) stemming from the oxidation of sulphide minerals (pyrite,arsenopyrite) in mineralised zones.These aquifers are still little investigated,especially concerning groundwater residence times and the influence of the annual monsoon season on groundwater chemistry.To gain insights on the temporal aspects of As contamination,we have used isotope tracers (noble gases,3H,stable water isotopes (2H,18O)) and performed hydrochemical analyses on groundwater abstracted from tube wells and dug wells in a small study area in southwestern Burkina Faso.Results revealed a great variability in groundwater properties (e.g.redox conditions,As concentrations,water level,residence time) over spatial scales of only a few hundred metres,characteristic of the highly heterogeneous fractured underground.Elevated As levels are found in oxic groundwater of circum-neutral pH and show little relation with any of the measured parameters.Arsenic concentrations are relatively stable over the course of the year,with little effect seen by the monsoon.Groundwater residence time does not seem to have an influence on As concentrations,as elevated As can be found both in groundwater with short (<50 a) and long (>10^3 a) residence times as indicated by 3He/4He ratios spanning three orders of magnitude.These results support the hypothesis that the proximity to mineralised zones is the most crucial factor controlling As concentrations in the observed redox/pH conditions.The existence of very old water portions with residence times >10^3 years already at depths of <50 m b.g.l.is a new finding for the shallow fractured bedrock aquifers of Burkina Faso,suggesting that overexploitation of these relatively low-yielding aquifers may be an issue in the future.展开更多
The Daerbute fault zone, located in the northwestern margin of the Junggar basin, in the Central Asian Orogenic Belt, is a regional strike-slip fault with a length of 400 km. The NE-SW trending Daerbute fault zone pr...The Daerbute fault zone, located in the northwestern margin of the Junggar basin, in the Central Asian Orogenic Belt, is a regional strike-slip fault with a length of 400 km. The NE-SW trending Daerbute fault zone presents a distinct linear trend in plain view, cutting through both the Zair Mountain and the Hala＇alate Mountain. Because of the intense contraction and shearing, the rocks within the fault zone experienced high degree of cataclasis, schistosity, and mylonization, resulting in rocks that are easily eroded to form a valley with a width of 300- 500 m and a depth of 50-100 m after weathering and erosion. The well-exposed outcrops along the Daerbute fault zone present sub-horizontal striations and sub-vertical fault steps, indicating sub-horizontal shearing along the observed fault planes. Flower structures and horizontal drag folds are also observed in both the well-exposed outcrops and high-resolution satellite images. The distribution of accommodating strike-slip splay faults, e.g., the 973-pluton fault and the Great Jurassic Trough fault, are in accordance with the Riedel model of simple shear. The seismic and time-frequency electromagnetic （TFEM） sections also demonstrate the typical strike-slip characteristics of the Daerbute fault zone. Based on detailed field observations of well-exposed outcrops and seismic sections, the Daerbute fault can be subdivided into two segments： the western segment presents multiple fault cores and damage zones, whereas the eastern segment only presents a single fault core, in which the rocks experienced a higher degree of rock cataclasis, schistosity, and mylonization. In the central overlapping portion between the two segments, the sediments within the fault zone are primarily reddish sandstones, conglomerates, and some mudstones, of which the palynological tests suggest middle Permian as the timing of deposition. The deformation timing of the Daerbute fault was estimated by integrating the depocenters＇ basinward migration and initiation of the splay faults （e.g., the Great Jurassic Trough fault and the 973-pluton fault）. These results indicate that there were probably two periods of faulting deformation for the Daerbute fault. By integrating our study with previous studies, we speculate that the Daerbute fault experienced a two-phase strike-slip faulting deformation, commencing with the initial dextral strike-slip faulting in mid-late Permian, and then being inversed to sinistral strike-slip faulting since the Triassic. The results of this study can provide useful insights for the regional tectonics and local hydrocarbon exploration.展开更多
In a Chinese language article in 2013,the New York Times likened Xiamen and its fashion designers to the Antwerp Six,labeling them the"Xiamen Gang."Last June,WWD reported on Xiamen's intentions to become...In a Chinese language article in 2013,the New York Times likened Xiamen and its fashion designers to the Antwerp Six,labeling them the"Xiamen Gang."Last June,WWD reported on Xiamen's intentions to become"China's New Fashion Hub"and in July;the Business of Fashion introduced us yet again to the idea of a"Xiamen Fashion Gang."展开更多
2015年8月3日秦岭北麓突发短时强降水,强度之大近年少有,并引发山洪造成人员伤亡。应用高空观测资料、地面加密资料、NCEP再分析资料,并结合风廓线雷达和多普勒天气雷达资料分析发现,此次降水过程具备较好的对流潜势及湿度条件,由冷锋...2015年8月3日秦岭北麓突发短时强降水,强度之大近年少有,并引发山洪造成人员伤亡。应用高空观测资料、地面加密资料、NCEP再分析资料,并结合风廓线雷达和多普勒天气雷达资料分析发现,此次降水过程具备较好的对流潜势及湿度条件,由冷锋系统触发,冷锋系统结构特点包括:锋区前近地面水汽含量>18 g·kg^(-1),锋面上升运动处于下沉运动之上、自由对流高度以下,850 h Pa以下强冷平流造成该层浅薄逆温,锋前出现显著对流不稳定,均为对流性强降水发生创造有利条件。强冷平流带来水平锋生,对流不稳定产生垂直锋生,总体强锋生主要出现在对流层中下层,达到20×10^(-10)K·s^(-1)·m^(-1)。秦岭的阻挡作用使得冷锋过境转为偏西风,并与强降水正反馈形成超低空强西风带。偏西风与迎面山体配合对降水产生增幅作用,并为降水区带来水汽输送,但超低空西风较强容易破坏雷暴单体的垂直结构,又使得降水不能长时间维持。风廓线雷达能够探测到冷锋系统的精细化垂直风场结构,反映了冷锋的垂直结构信息,并较其他气象要素更能提前预判系统发展,具有较强的预报指示意义。展开更多
文摘Ivory Coast is a country rich in base metals and precious minerals: gold, manganese, diamond, iron, bauxite, cobalt and nickel. These natural resources are exposed to destruction and fragmentation by mining activities. The artisanal and small-scale exploitation of gold are increasingly practiced in our rural areas. These activities escape often in the control and monitoring of the mining administration. In order to better constrain these activities on the environment, the present work used remote sensing imageries to see its spatio-temporal impacts in the rural world in central Ivory Coast. The results show that gold artisanal activities have been practiced since 2013 and are experiencing an increasingly important growth. We note a devastation of forests and savannahs, a pollution of surface water, as well as an increase in poverty in rural areas. These activities are practiced near habited areas (villages). This creates a reduction of cultivatable soil. Remote sensing imageries make it possible to quickly map areas at large-scale gold mining in time and space.
文摘Aesthetic Modernity is a western concept.It was based on the development of the historical view.This article focuses on the aesthetic modernity pursuits of modern and contemporary Chinese art and compares it with the western culture and modern art under the concept of aesthetics.It also analyses the problems and causes in the process of modernity of Chinese modern and con⁃temporary art,and presents the advice to the further development of Chinese art.
文摘Nowadays human rights diplomacy is nothing new. This is because in recent years it often comes into relations between China and countries in the West and becomes hot issues. Countries in the West are the creator of human rights diplomacy. During the administration of President Jimmy Carter in the 1970s, the United States for the first time asserted that human fights are central to U.S. foreign policy, and the Carter administration has been known for its human fights diplomacy. Much earlier, in fact, the concept of human fights diplomacy had appeared in the thinking and views of some statesmen in the West.
基金Supported by the China National Science and Technology Major Project(2017ZX05005-001)
文摘In view of the disadvantage that the absolute difference of time-lapse seismic(the difference between monitoring data and base data) is not only related to the change of oil saturation, but also closely related to the thickness of reservoir, a time-lapse seismic "relative difference method"(the ratio of monitoring data to base data) not affected by the thickness of reservoir but only related to the change of fluid saturation, is proposed through seismic forward modeling after fluid displacement simulation. Given the same change of fluid saturation, the absolute difference of time-lapse seismic conforms to the law of "tuning effect" and seismic reflection of "thin bed", and the remaining oil prediction method based on absolute difference of time-lapse seismic is only applicable to the reservoirs with uniform thickness smaller than the tuning thickness or with thickness greater than the tuning thickness. The relative difference of time-lapse seismic is not affected by reservoir thickness, but only related to the change of fluid saturation. It is applicable to all the deep-sea unconsolidated sandstone reservoirs which can exclude the effect of pressure, temperature, pore type and porosity on seismic. Therefore, the relation between the relative difference of time-lapse seismic and the change of fluid saturation, which is obtained from seismic forward modeling after Gassmann fluid displacement simulation, can be used to quantitatively predict the change of reservoir water saturation and then the distribution of the remaining oil. The application of this method in deep sea Zeta oil field in west Africa shows that it is reasonable and effective.
基金provided by the Swiss Agency for Development and Cooperation (SDC) through the "Programme 3E" (contract no.81016359)the Information Management System on Geogenic Contaminants, GAP (contract no.81025383)
文摘The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected by high geogenic arsenic (As) concentrations (>10 μg/L) stemming from the oxidation of sulphide minerals (pyrite,arsenopyrite) in mineralised zones.These aquifers are still little investigated,especially concerning groundwater residence times and the influence of the annual monsoon season on groundwater chemistry.To gain insights on the temporal aspects of As contamination,we have used isotope tracers (noble gases,3H,stable water isotopes (2H,18O)) and performed hydrochemical analyses on groundwater abstracted from tube wells and dug wells in a small study area in southwestern Burkina Faso.Results revealed a great variability in groundwater properties (e.g.redox conditions,As concentrations,water level,residence time) over spatial scales of only a few hundred metres,characteristic of the highly heterogeneous fractured underground.Elevated As levels are found in oxic groundwater of circum-neutral pH and show little relation with any of the measured parameters.Arsenic concentrations are relatively stable over the course of the year,with little effect seen by the monsoon.Groundwater residence time does not seem to have an influence on As concentrations,as elevated As can be found both in groundwater with short (<50 a) and long (>10^3 a) residence times as indicated by 3He/4He ratios spanning three orders of magnitude.These results support the hypothesis that the proximity to mineralised zones is the most crucial factor controlling As concentrations in the observed redox/pH conditions.The existence of very old water portions with residence times >10^3 years already at depths of <50 m b.g.l.is a new finding for the shallow fractured bedrock aquifers of Burkina Faso,suggesting that overexploitation of these relatively low-yielding aquifers may be an issue in the future.
基金We would like to thank the Xinjiang Oil Field Company of PetroChina for their permission to use the relevant geological and geophysical data. The constructive comments from the three anonymous reviewers are highly appreciated. This research has been financially supported by： the National Natural Science Foundation of China （Grant Nos. 41272142, 41502192, and 41702138）, the National Science and Technology Major Project （2017ZX0500101）3）, Strategic Priority Research Program of Chinese Acdemy of Sciences （XDA14010301）, the Provincial Science Foundation of Shandong Province （No. ZR2012DM011）, and the Open Funding of the Key Laboratory of Tectonics and Petroleum Resources （No. TPR-2016-02）.
文摘The Daerbute fault zone, located in the northwestern margin of the Junggar basin, in the Central Asian Orogenic Belt, is a regional strike-slip fault with a length of 400 km. The NE-SW trending Daerbute fault zone presents a distinct linear trend in plain view, cutting through both the Zair Mountain and the Hala＇alate Mountain. Because of the intense contraction and shearing, the rocks within the fault zone experienced high degree of cataclasis, schistosity, and mylonization, resulting in rocks that are easily eroded to form a valley with a width of 300- 500 m and a depth of 50-100 m after weathering and erosion. The well-exposed outcrops along the Daerbute fault zone present sub-horizontal striations and sub-vertical fault steps, indicating sub-horizontal shearing along the observed fault planes. Flower structures and horizontal drag folds are also observed in both the well-exposed outcrops and high-resolution satellite images. The distribution of accommodating strike-slip splay faults, e.g., the 973-pluton fault and the Great Jurassic Trough fault, are in accordance with the Riedel model of simple shear. The seismic and time-frequency electromagnetic （TFEM） sections also demonstrate the typical strike-slip characteristics of the Daerbute fault zone. Based on detailed field observations of well-exposed outcrops and seismic sections, the Daerbute fault can be subdivided into two segments： the western segment presents multiple fault cores and damage zones, whereas the eastern segment only presents a single fault core, in which the rocks experienced a higher degree of rock cataclasis, schistosity, and mylonization. In the central overlapping portion between the two segments, the sediments within the fault zone are primarily reddish sandstones, conglomerates, and some mudstones, of which the palynological tests suggest middle Permian as the timing of deposition. The deformation timing of the Daerbute fault was estimated by integrating the depocenters＇ basinward migration and initiation of the splay faults （e.g., the Great Jurassic Trough fault and the 973-pluton fault）. These results indicate that there were probably two periods of faulting deformation for the Daerbute fault. By integrating our study with previous studies, we speculate that the Daerbute fault experienced a two-phase strike-slip faulting deformation, commencing with the initial dextral strike-slip faulting in mid-late Permian, and then being inversed to sinistral strike-slip faulting since the Triassic. The results of this study can provide useful insights for the regional tectonics and local hydrocarbon exploration.
文摘In a Chinese language article in 2013,the New York Times likened Xiamen and its fashion designers to the Antwerp Six,labeling them the"Xiamen Gang."Last June,WWD reported on Xiamen's intentions to become"China's New Fashion Hub"and in July;the Business of Fashion introduced us yet again to the idea of a"Xiamen Fashion Gang."
文摘2015年8月3日秦岭北麓突发短时强降水,强度之大近年少有,并引发山洪造成人员伤亡。应用高空观测资料、地面加密资料、NCEP再分析资料,并结合风廓线雷达和多普勒天气雷达资料分析发现,此次降水过程具备较好的对流潜势及湿度条件,由冷锋系统触发,冷锋系统结构特点包括:锋区前近地面水汽含量>18 g·kg^(-1),锋面上升运动处于下沉运动之上、自由对流高度以下,850 h Pa以下强冷平流造成该层浅薄逆温,锋前出现显著对流不稳定,均为对流性强降水发生创造有利条件。强冷平流带来水平锋生,对流不稳定产生垂直锋生,总体强锋生主要出现在对流层中下层,达到20×10^(-10)K·s^(-1)·m^(-1)。秦岭的阻挡作用使得冷锋过境转为偏西风,并与强降水正反馈形成超低空强西风带。偏西风与迎面山体配合对降水产生增幅作用,并为降水区带来水汽输送,但超低空西风较强容易破坏雷暴单体的垂直结构,又使得降水不能长时间维持。风廓线雷达能够探测到冷锋系统的精细化垂直风场结构,反映了冷锋的垂直结构信息,并较其他气象要素更能提前预判系统发展,具有较强的预报指示意义。
