The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,...The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,respectively.The caprocks have a cumulative thickness of 50-120 m in general,and a single-layer thickness of 20-50 m,interbedded with sandstone about 1-2 m thick.The large set of mudstone is distributed continuously,as pure mudstone caprock.Forty-three mudstone and tuff samples were taken to perform displacement pressure test with our independently developed displacement pressure tester.Test result shows that the displacement pressure is 0.04-10.00 MPa,which is equivalent to 0.09-20.01 MPa after being corrected to the actual burial depth.As the burial depth increases,the displacement pressure rises gradually,and is 1-10 times greater than that of oil-bearing sandstone or conglomerate reservoir at the same burial depth.The difference between displacement pressure of mudstone caprock and sandstone or conglomerate reservoir increases greatly if the burial depth exceeds 1000 m.Because of the displacement pressure difference between caprock and reservoir,the maximum height of hydrocarbon column sealed by the caprock ranges from 300 m to 2000 m,much higher than the height of the trap closure at the same burial depth.No hydrocarbons will leak through such caprocks.Analysis of the reservoir GOI,homogeneous temperature,and crude maturity of both deep and shallow reservoirs in Well Wu-20 in the Wuerxun Depression shows that Damoguaihe II Member reservoir is a secondary reservoir developed during adjustment of early reservoir.It is mainly distributed in inverted structures.Faulting is one of the main factors breaking the integrity of caprocks.Three kinds of faults are often related to the migration of hydrocarbons across regional caprocks:the first type refers to the positive inverted faults breaking the early sealing conditions and making the hydrocarbons accumulated in the early period re-migration;the second展开更多
Western Yunnan is a region with intensive tectonic activity and serious earthquake risk. It is of significant importance to study three dimensional crustal structure of this region to understand the tectonic setting a...Western Yunnan is a region with intensive tectonic activity and serious earthquake risk. It is of significant importance to study three dimensional crustal structure of this region to understand the tectonic setting and disaster mechanism. Densification and digitalization of seismic networks in this region provides an opportunity to study the velocity structure with bulletin data. In this study, we collect P-wave data of 10 403 regional earthquakes recorded by 79 seismic stations from January 2008 to December 2010. In addition to first arrivals data （Pg with epieentral distance less than 200 km and Pn）, the Pg （or P） data with epicentral distance more than 200 km are also considered as later direct arrivals in the tomographic inversion. We also compare the quantity and the quality of the seismic data before 2010 and after 2010. The test results show that adding the follow-up Pg phase can effectively improve the inversion ability of crustal imaging, and quantity and the data quality are significantly improved since 2010. The tomographie results show that： （1） The Honghe fault zone, which is the major fault systems in this region, may cut through the entire crust, and the velocity contrasts between two sides at lower crust beneath the Honghe fault are estimated at higher than 10%, while the velocity difference below Nujiang fault zone extends only in the upper crust; （2） Most of the earthquakes in the region occurred at the interface of high-velocity media and low-velocity media, i.e., the areas with high velocity gradient, which has been validated in other areas.展开更多
Type 2 diabetes mellitus and metabolic disorders have become an epidemic globally.However,the pathogenesis remains largely unclear and the prevention and treatment are still limited.In addition to environmental factor...Type 2 diabetes mellitus and metabolic disorders have become an epidemic globally.However,the pathogenesis remains largely unclear and the prevention and treatment are still limited.In addition to environmental factors during adulthood,early life is the critical developmental window with high tissue plasticity,which might be modified by external environmental cues.Substantial evidence has demonstrated the vital role of early-life nutrition in programming the metabolic disorders in later life.In this review,we aim to overview the concepts of fetal programming and investigate the effects of early-life nutrition on energy metabolism in later life and the potential epigenetic mechanism.The related studies published on PubMed database up to March 2020 were included.The results showed that both maternal overnutrition and undernutrition increased the riskes of metabolic disorders in offspring and epigenetic modifications,including DNA methylation,miRNAs,and histone modification,might be the vital mediators.The beneficial effects of early-life lifestyle modifications as well as dietary and nutritional interventions on these deleterious metabolic remolding were initially observed.Overall,characterizing the early-life malnutrition that reshapes metabolic disease trajectories may yield novel targets for early prevention and intervention and provide a new point of view to the energy metabolism.展开更多
After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in t...After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou Province, China, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-step process from the “ori展开更多
The Xiaolangdi Reservoir has entered the later sediment-retaining period, and new sediment transport phenomena and channel re-estab- lishing behaviors are appearing. A physical model test was used to forecast the scou...The Xiaolangdi Reservoir has entered the later sediment-retaining period, and new sediment transport phenomena and channel re-estab- lishing behaviors are appearing. A physical model test was used to forecast the scouring and silting trends of the lower Yellow River. Based on water and sediment data from the lower Yellow River during the period from 1960 to 2012, and using a statistical method, this paper analyzed the sediment transport in sediment-laden flows with different discharges and sediment concentrations in the lower Yellow River. The results show that rational water-sediment regulation is necessary to avoid silting in the later sediment-retaining period. The combination of 3 000 m^3/s 〈 Q 〈 4 000 m^3/s and 20 kg/m^3 〈 S 〈 60 kg/m^3 （where Q is the discharge and S is the sediment concentration） at the Huayuankou section is considered an optimal combination for equilibrium sediment transport in the lower Yellow River over a long period of time.展开更多
In recent years, Chinese scholars have made important progress in research on later Greek philosophy. Using current European and American work as a reference point, this article explores the differences and gaps betwe...In recent years, Chinese scholars have made important progress in research on later Greek philosophy. Using current European and American work as a reference point, this article explores the differences and gaps between foreign and Chinese scholars in this field of research. The author believes that on the question of the boundaries of later Greek philosophy, Chinese scholars have, through long years of exploration, come up with independent opinions and solutions that differ from those of their European and Ameriean counterparts, and that they have a better grasp of the distinctive features of later Greek philosophy. Their work, however, clearly falls short with regard to historical source material. As far as methodology is concerned, there is a clear tendency towards convergence between Chinese scholars and their foreign colleagues.展开更多
The phenomenon of marital dissolution in later life,also referred to as“gray divorce”,is described on the rise in contemporary Western societies.This article contributes to the study of marriage breakdown in older a...The phenomenon of marital dissolution in later life,also referred to as“gray divorce”,is described on the rise in contemporary Western societies.This article contributes to the study of marriage breakdown in older age,with a specific focus on Italian society.First,the temporal trends of this phenomenon are reconstructed using official statistics.The data reveal that,although still relatively rare,the dissolution of marriage in later life is expanding in Italy.The analysis of the period from 1974 to 2015 indicates a rise in the average age at separation,a higher percentage of spouses over 50 years on the total number of couples obtaining legal separation,and an increase in the proportion of Italian spouses separating after many years of marriage.Furthermore,data from the national survey“Family and Social Subjects”,conducted in 2016 by the Italian National Institute of Statistics,are utilized to explore the relationship between specific traits of those who separated and their tendency to dissolve marriages before or after the age of 50.The data suggest that individuals with characteristics such as lower educational attainment,residence in the South and Islands,and adherence to more traditional family models are more likely to experience separation in later life.展开更多
The paper presents a study of surface texture character-ization of knitted fabrics during simulated wear based onlaser-scanned profiles.The three-dimensional profilewas obtained by scanning the fabric surface using th...The paper presents a study of surface texture character-ization of knitted fabrics during simulated wear based onlaser-scanned profiles.The three-dimensional profilewas obtained by scanning the fabric surface using the la-ser trlangulation technique.The analytical techniquesused to derive quantitative parameters Included statisticalanalysis,fractal analysis,and Fourler analysis.展开更多
Background:As a structurally and functionally important component in forest ecosystems,plant debris plays a crucial role in the global carbon cycle.Although it is well known that plant debris stocks vary greatly with ...Background:As a structurally and functionally important component in forest ecosystems,plant debris plays a crucial role in the global carbon cycle.Although it is well known that plant debris stocks vary greatly with tree species composition,forest type,forest origin,and stand age,simultaneous investigation on the changes in woody and non-woody debris biomass and their carbon stock with forest succession has not been reported.Therefore,woody and non-woody debris and carbon stocks were investigated across a subalpine forest successional gradient in Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau.Results:Plant debris ranged from 25.19 to 82.89 Mg∙ha−1 and showed a global increasing tendency across the subalpine forest successional series except for decreasing at the S4 successional stage.Accordingly,the ratios of woody to non-woody debris stocks ranged from 26.58 to 208.89,and the highest and lowest ratios of woody to non-woody debris stocks were respectively observed in mid-successional coniferous forest and shrub forest,implying that woody debris dominates the plant debris.In particular,the ratios of coarse to fine woody debris stocks varied greatly with the successional stage,and the highest and lowest ratios were found in later and earlier successional subalpine forests,respectively.Furthermore,the woody debris stock varied greatly with diameter size,and larger diameter woody debris dominated the plant debris.Correspondingly,the carbon stock of plant debris ranged from 10.30 to 38.87 Mg∙ha−1 across the successional series,and the highest and lowest values were observed in the mid-coniferous stage and shrub forest stage,respectively.Most importantly,the carbon stored in coarse woody debris in later successional forests was four times higher than in earlier successional forests.Conclusions:The stock and role of woody debris,particularly coarse woody debris,varied greatly with the forest successional stage and dominated the carbon cycle in the subalpine forest ecosystem.Thus,preservin展开更多
The PL 19e3 Oilfield is the only super-large monolithic oilfield with oil and gas reserves up to 1×10^(9) t in the Bohai Bay Basin,and it has been successfully developed.Exploration and development practices have...The PL 19e3 Oilfield is the only super-large monolithic oilfield with oil and gas reserves up to 1×10^(9) t in the Bohai Bay Basin,and it has been successfully developed.Exploration and development practices have provided abundant data for analyzing formation conditions of this super-large oilfield.On the basis of the exploration and development history,fundamental reservoir features,and with available geological,geophysical and test data,the hydrocarbon accumulation conditions and key exploration&development technologies of the PL 19e3 Oilfield were discussed.The key conditions for forming the super-large Neogene oilfield include four aspects.Firstly,the oilfield is located at the high position of the uplift that contacts the brachy-axis of the multi-ridge slope in the biggest hydrocarbon-rich sag in the Bohai Bay Basin,thus it has sufficient hydrocarbon source and extremely superior hydrocarbon migration condition.Secondly,the large-scale torsional anticlines which formed in the Neogene under the control of the Tanlu strike-slipping movement provide sufficient storage spaces for oil and gas preservation.Thirdly,the“multiple sets of composite reservoir-caprock assemblages”developing in the special shallow-water delta further contributes greatly to the effective storage space for oil and gas preservation.Fourthly,due to the coupling of the uplift and strike slip in the neotectonic period,extensive faulting activities constantly released the pressure while the late period massive hydrocarbon expulsion of the Bozhong took place at the same time,which assures the constant and intense charging of oil and gas.The super-large PL 19e3 Oilfield was controlled by the coupling effects of all those special geologic factors.In view of this oilfield's features(e.g.violently reformation caused by strike slip,and the special sedimentary environment of shallow-water delta),some key practical technologies for exploration and development have been developed.Such technologies include:the special prestack depth migration proces展开更多
In order to contribute to the Apparent Polar Wander Path (APWP) of the North China Block (NCB) , we collected paleomagnetic samples of Late Paleozoic rocks from the northern and southern margins of the Alashan (Alxa) ...In order to contribute to the Apparent Polar Wander Path (APWP) of the North China Block (NCB) , we collected paleomagnetic samples of Late Paleozoic rocks from the northern and southern margins of the Alashan (Alxa) terrane (the western part of Inner Mongolia and northern parts of Gansu and Ningxia Provinces) and adjacent regions. Laboratory work revealed different types of demagnetization behavior and isolated a higher temperature characteristic component in most of the samples. Results of IRM experiments show high thermal stability and high coercivities for the magnetic carriers in these rocks. The characteristic component passed the fold and/or reversal tests, suggesting that the characteristic components were probably primary. On the basis of comparing the paleomagnetic results with the geologic evidence, we discuss the tectonic implications. In the Late Paleozoic, the Alashan region had been part of the NCB and was not connected with the northern and southern blocks. During the Carboniferous Alashan wandered around the equator, and then moved northerly during the Permian. During the Jurassic the Alashan region rotated anticlockwise about 25° relative to the NCB when the Helanshan geosyncline closed.展开更多
One of the environmental liabilities left by abandoned urban waste disposal sites, closed without the correct procedures, is the risk of exposure to their effluents, whose emissions may occur for many years. The purpo...One of the environmental liabilities left by abandoned urban waste disposal sites, closed without the correct procedures, is the risk of exposure to their effluents, whose emissions may occur for many years. The purpose of the proposed methodology, referred to as SISTAVAFE, an assessment system of a closed landfill, is to contribute in the risk assess- ment of exposure to leachate as well as to suggest procedures for site monitoring, according to different levels of care and urgency. The method is based on four matrices that help make an initial evaluation of the risk source, potential target and the surface and underground environmental paths. This paper only addresses the contamination caused by liquid effluents.展开更多
The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 s...The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 shows the highest catalytic activity and gives the polystyrene with high molecular weight(Mw=188800)and a syndio-rich microstructure.The catalytic behavior of transition metal acetylides is related to metal,phosphine,and alkynyl ligands bonded to the metal atoms.展开更多
Chengdu fault depression is an important Quaternary basin in the piedmont of Longmenshan mountain.Formation and evolution of the fault depression are entirely controlled by the Longmenshan piedmont fault and the Longq...Chengdu fault depression is an important Quaternary basin in the piedmont of Longmenshan mountain.Formation and evolution of the fault depression are entirely controlled by the Longmenshan piedmont fault and the Longquanshan fault.Since the late Quaternary,Chengdu fault depression has been subjected to an NW-SE oriented compression.Many NE or NNE trending faults inside the depression or near its margins show thrust slip,resulting in moderate and strong earthquakes along the piedmont Longmenshan fault,the western slop Longquanshan fault,and Pujiang-Xinjin-Chengdu-Deyang fault.It is indicated that three faults as mentioned above have the potential capability for the occurrence of moderate earthquakes.展开更多
In view of the increasing cement concrete pavement in China,the proportion of road non-slip surface layer is large,the winter slippery performance is insufficient and the later non-slip treatment is difficult. Through...In view of the increasing cement concrete pavement in China,the proportion of road non-slip surface layer is large,the winter slippery performance is insufficient and the later non-slip treatment is difficult. Through the concrete construction and post-application and development of the anti-skid sand in the road and bridge,the feasible anti-skid optimization measures are put forward.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 41072163,41172135)New Century Excellent Talents in Heilongjiang Provincial University (Grant No. 1251-NCET-015)National Oil and Gas Project (Grant No. 2008ZX05003-002)
文摘The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,respectively.The caprocks have a cumulative thickness of 50-120 m in general,and a single-layer thickness of 20-50 m,interbedded with sandstone about 1-2 m thick.The large set of mudstone is distributed continuously,as pure mudstone caprock.Forty-three mudstone and tuff samples were taken to perform displacement pressure test with our independently developed displacement pressure tester.Test result shows that the displacement pressure is 0.04-10.00 MPa,which is equivalent to 0.09-20.01 MPa after being corrected to the actual burial depth.As the burial depth increases,the displacement pressure rises gradually,and is 1-10 times greater than that of oil-bearing sandstone or conglomerate reservoir at the same burial depth.The difference between displacement pressure of mudstone caprock and sandstone or conglomerate reservoir increases greatly if the burial depth exceeds 1000 m.Because of the displacement pressure difference between caprock and reservoir,the maximum height of hydrocarbon column sealed by the caprock ranges from 300 m to 2000 m,much higher than the height of the trap closure at the same burial depth.No hydrocarbons will leak through such caprocks.Analysis of the reservoir GOI,homogeneous temperature,and crude maturity of both deep and shallow reservoirs in Well Wu-20 in the Wuerxun Depression shows that Damoguaihe II Member reservoir is a secondary reservoir developed during adjustment of early reservoir.It is mainly distributed in inverted structures.Faulting is one of the main factors breaking the integrity of caprocks.Three kinds of faults are often related to the migration of hydrocarbons across regional caprocks:the first type refers to the positive inverted faults breaking the early sealing conditions and making the hydrocarbons accumulated in the early period re-migration;the second
基金supported by China National Special Fund for Earthquake Scientific Research in Public Interest (Grant 201208004)National Natural Science Foundation of China (grant 41174040)Scientific Research Institutes’ Basic Research and Development Operations Special Fund of Institute of Geophysics,China Earthquake Administration (grant DQJB10A01)
文摘Western Yunnan is a region with intensive tectonic activity and serious earthquake risk. It is of significant importance to study three dimensional crustal structure of this region to understand the tectonic setting and disaster mechanism. Densification and digitalization of seismic networks in this region provides an opportunity to study the velocity structure with bulletin data. In this study, we collect P-wave data of 10 403 regional earthquakes recorded by 79 seismic stations from January 2008 to December 2010. In addition to first arrivals data （Pg with epieentral distance less than 200 km and Pn）, the Pg （or P） data with epicentral distance more than 200 km are also considered as later direct arrivals in the tomographic inversion. We also compare the quantity and the quality of the seismic data before 2010 and after 2010. The test results show that adding the follow-up Pg phase can effectively improve the inversion ability of crustal imaging, and quantity and the data quality are significantly improved since 2010. The tomographie results show that： （1） The Honghe fault zone, which is the major fault systems in this region, may cut through the entire crust, and the velocity contrasts between two sides at lower crust beneath the Honghe fault are estimated at higher than 10%, while the velocity difference below Nujiang fault zone extends only in the upper crust; （2） Most of the earthquakes in the region occurred at the interface of high-velocity media and low-velocity media, i.e., the areas with high velocity gradient, which has been validated in other areas.
基金Supported by the grants from the National Natural Science Foundation of China(Nos.81870579,81870545,81170736,81570715).
文摘Type 2 diabetes mellitus and metabolic disorders have become an epidemic globally.However,the pathogenesis remains largely unclear and the prevention and treatment are still limited.In addition to environmental factors during adulthood,early life is the critical developmental window with high tissue plasticity,which might be modified by external environmental cues.Substantial evidence has demonstrated the vital role of early-life nutrition in programming the metabolic disorders in later life.In this review,we aim to overview the concepts of fetal programming and investigate the effects of early-life nutrition on energy metabolism in later life and the potential epigenetic mechanism.The related studies published on PubMed database up to March 2020 were included.The results showed that both maternal overnutrition and undernutrition increased the riskes of metabolic disorders in offspring and epigenetic modifications,including DNA methylation,miRNAs,and histone modification,might be the vital mediators.The beneficial effects of early-life lifestyle modifications as well as dietary and nutritional interventions on these deleterious metabolic remolding were initially observed.Overall,characterizing the early-life malnutrition that reshapes metabolic disease trajectories may yield novel targets for early prevention and intervention and provide a new point of view to the energy metabolism.
基金supported by the National Natural Science F oundation of China(Grant No.40172014)the Guizhou University Foundation.
文摘After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou Province, China, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-step process from the “ori
基金supported by the National Natural Science Foundation of China(Grants No.51039004 and No.51079055)the High-Level Personnel Research Start-Up Funds of North China University of Water Resources and Electric Power(Grant No.201403)the Science and Technology Research Project of the Education Department of Henan Province(Grant No.14A570001)
文摘The Xiaolangdi Reservoir has entered the later sediment-retaining period, and new sediment transport phenomena and channel re-estab- lishing behaviors are appearing. A physical model test was used to forecast the scouring and silting trends of the lower Yellow River. Based on water and sediment data from the lower Yellow River during the period from 1960 to 2012, and using a statistical method, this paper analyzed the sediment transport in sediment-laden flows with different discharges and sediment concentrations in the lower Yellow River. The results show that rational water-sediment regulation is necessary to avoid silting in the later sediment-retaining period. The combination of 3 000 m^3/s 〈 Q 〈 4 000 m^3/s and 20 kg/m^3 〈 S 〈 60 kg/m^3 （where Q is the discharge and S is the sediment concentration） at the Huayuankou section is considered an optimal combination for equilibrium sediment transport in the lower Yellow River over a long period of time.
基金financed by the Distinguished Professor Project of Zhejiang University
文摘In recent years, Chinese scholars have made important progress in research on later Greek philosophy. Using current European and American work as a reference point, this article explores the differences and gaps between foreign and Chinese scholars in this field of research. The author believes that on the question of the boundaries of later Greek philosophy, Chinese scholars have, through long years of exploration, come up with independent opinions and solutions that differ from those of their European and Ameriean counterparts, and that they have a better grasp of the distinctive features of later Greek philosophy. Their work, however, clearly falls short with regard to historical source material. As far as methodology is concerned, there is a clear tendency towards convergence between Chinese scholars and their foreign colleagues.
文摘The phenomenon of marital dissolution in later life,also referred to as“gray divorce”,is described on the rise in contemporary Western societies.This article contributes to the study of marriage breakdown in older age,with a specific focus on Italian society.First,the temporal trends of this phenomenon are reconstructed using official statistics.The data reveal that,although still relatively rare,the dissolution of marriage in later life is expanding in Italy.The analysis of the period from 1974 to 2015 indicates a rise in the average age at separation,a higher percentage of spouses over 50 years on the total number of couples obtaining legal separation,and an increase in the proportion of Italian spouses separating after many years of marriage.Furthermore,data from the national survey“Family and Social Subjects”,conducted in 2016 by the Italian National Institute of Statistics,are utilized to explore the relationship between specific traits of those who separated and their tendency to dissolve marriages before or after the age of 50.The data suggest that individuals with characteristics such as lower educational attainment,residence in the South and Islands,and adherence to more traditional family models are more likely to experience separation in later life.
文摘The paper presents a study of surface texture character-ization of knitted fabrics during simulated wear based onlaser-scanned profiles.The three-dimensional profilewas obtained by scanning the fabric surface using the la-ser trlangulation technique.The analytical techniquesused to derive quantitative parameters Included statisticalanalysis,fractal analysis,and Fourler analysis.
基金supported by the National Nature Science Foundation of China(32071554,31570445).
文摘Background:As a structurally and functionally important component in forest ecosystems,plant debris plays a crucial role in the global carbon cycle.Although it is well known that plant debris stocks vary greatly with tree species composition,forest type,forest origin,and stand age,simultaneous investigation on the changes in woody and non-woody debris biomass and their carbon stock with forest succession has not been reported.Therefore,woody and non-woody debris and carbon stocks were investigated across a subalpine forest successional gradient in Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau.Results:Plant debris ranged from 25.19 to 82.89 Mg∙ha−1 and showed a global increasing tendency across the subalpine forest successional series except for decreasing at the S4 successional stage.Accordingly,the ratios of woody to non-woody debris stocks ranged from 26.58 to 208.89,and the highest and lowest ratios of woody to non-woody debris stocks were respectively observed in mid-successional coniferous forest and shrub forest,implying that woody debris dominates the plant debris.In particular,the ratios of coarse to fine woody debris stocks varied greatly with the successional stage,and the highest and lowest ratios were found in later and earlier successional subalpine forests,respectively.Furthermore,the woody debris stock varied greatly with diameter size,and larger diameter woody debris dominated the plant debris.Correspondingly,the carbon stock of plant debris ranged from 10.30 to 38.87 Mg∙ha−1 across the successional series,and the highest and lowest values were observed in the mid-coniferous stage and shrub forest stage,respectively.Most importantly,the carbon stored in coarse woody debris in later successional forests was four times higher than in earlier successional forests.Conclusions:The stock and role of woody debris,particularly coarse woody debris,varied greatly with the forest successional stage and dominated the carbon cycle in the subalpine forest ecosystem.Thus,preservin
基金The work was supported by the National Science and Technology Major Project of China(No.2016ZX05024-003).
文摘The PL 19e3 Oilfield is the only super-large monolithic oilfield with oil and gas reserves up to 1×10^(9) t in the Bohai Bay Basin,and it has been successfully developed.Exploration and development practices have provided abundant data for analyzing formation conditions of this super-large oilfield.On the basis of the exploration and development history,fundamental reservoir features,and with available geological,geophysical and test data,the hydrocarbon accumulation conditions and key exploration&development technologies of the PL 19e3 Oilfield were discussed.The key conditions for forming the super-large Neogene oilfield include four aspects.Firstly,the oilfield is located at the high position of the uplift that contacts the brachy-axis of the multi-ridge slope in the biggest hydrocarbon-rich sag in the Bohai Bay Basin,thus it has sufficient hydrocarbon source and extremely superior hydrocarbon migration condition.Secondly,the large-scale torsional anticlines which formed in the Neogene under the control of the Tanlu strike-slipping movement provide sufficient storage spaces for oil and gas preservation.Thirdly,the“multiple sets of composite reservoir-caprock assemblages”developing in the special shallow-water delta further contributes greatly to the effective storage space for oil and gas preservation.Fourthly,due to the coupling of the uplift and strike slip in the neotectonic period,extensive faulting activities constantly released the pressure while the late period massive hydrocarbon expulsion of the Bozhong took place at the same time,which assures the constant and intense charging of oil and gas.The super-large PL 19e3 Oilfield was controlled by the coupling effects of all those special geologic factors.In view of this oilfield's features(e.g.violently reformation caused by strike slip,and the special sedimentary environment of shallow-water delta),some key practical technologies for exploration and development have been developed.Such technologies include:the special prestack depth migration proces
基金Project supported by the National Natural Science Foundation of China.
文摘In order to contribute to the Apparent Polar Wander Path (APWP) of the North China Block (NCB) , we collected paleomagnetic samples of Late Paleozoic rocks from the northern and southern margins of the Alashan (Alxa) terrane (the western part of Inner Mongolia and northern parts of Gansu and Ningxia Provinces) and adjacent regions. Laboratory work revealed different types of demagnetization behavior and isolated a higher temperature characteristic component in most of the samples. Results of IRM experiments show high thermal stability and high coercivities for the magnetic carriers in these rocks. The characteristic component passed the fold and/or reversal tests, suggesting that the characteristic components were probably primary. On the basis of comparing the paleomagnetic results with the geologic evidence, we discuss the tectonic implications. In the Late Paleozoic, the Alashan region had been part of the NCB and was not connected with the northern and southern blocks. During the Carboniferous Alashan wandered around the equator, and then moved northerly during the Permian. During the Jurassic the Alashan region rotated anticlockwise about 25° relative to the NCB when the Helanshan geosyncline closed.
文摘One of the environmental liabilities left by abandoned urban waste disposal sites, closed without the correct procedures, is the risk of exposure to their effluents, whose emissions may occur for many years. The purpose of the proposed methodology, referred to as SISTAVAFE, an assessment system of a closed landfill, is to contribute in the risk assess- ment of exposure to leachate as well as to suggest procedures for site monitoring, according to different levels of care and urgency. The method is based on four matrices that help make an initial evaluation of the risk source, potential target and the surface and underground environmental paths. This paper only addresses the contamination caused by liquid effluents.
文摘The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 shows the highest catalytic activity and gives the polystyrene with high molecular weight(Mw=188800)and a syndio-rich microstructure.The catalytic behavior of transition metal acetylides is related to metal,phosphine,and alkynyl ligands bonded to the metal atoms.
文摘Chengdu fault depression is an important Quaternary basin in the piedmont of Longmenshan mountain.Formation and evolution of the fault depression are entirely controlled by the Longmenshan piedmont fault and the Longquanshan fault.Since the late Quaternary,Chengdu fault depression has been subjected to an NW-SE oriented compression.Many NE or NNE trending faults inside the depression or near its margins show thrust slip,resulting in moderate and strong earthquakes along the piedmont Longmenshan fault,the western slop Longquanshan fault,and Pujiang-Xinjin-Chengdu-Deyang fault.It is indicated that three faults as mentioned above have the potential capability for the occurrence of moderate earthquakes.
文摘In view of the increasing cement concrete pavement in China,the proportion of road non-slip surface layer is large,the winter slippery performance is insufficient and the later non-slip treatment is difficult. Through the concrete construction and post-application and development of the anti-skid sand in the road and bridge,the feasible anti-skid optimization measures are put forward.
