Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to c...Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to carry pollen and spores, and to assess the contribution of the water-borne pollen to pollen assemblages in lake sediments at the end of the river system. Results indicate the pollen assemblages in water samples consist of both local and upland pollen. Percentages of upland pollen reach 30% - 60%, and pollen assemblages in water samples do not indicate the nature of local vegetation at the sampling sites. Fluvial currents have the capacity to transport large quantities of pollen long distances, and the contribution of this fluvial transported pollen is relatively high, For example, percentages of Picea Dietr. pollen in water samples at sampling sites 130 km and 145 km away from Picea forests reach 16.5% and 7.7%, respectively. Fluvial pollen transport occurs primarily during flood periods, and pollen concentrations from the flood samples are 17.1 - 12.5 times those from normal fluvial flow. Reservoirs affect pollen transportation since pollen is deposited at reservoir inlets and pollen concentrations are much reduced at reservoir outlets. Human activity can thus change natural features of pollen transportation and deposition. The main factors influencing pollen concentrations and assemblages are sampling time, sampling location, and rainfall intensity.展开更多
In context of building beautiful countryside nationwide, underdeveloped areas are confronted by many problems, such as monotonous industry structure, simi- lar rural landscape and loss of characteristics. With a case ...In context of building beautiful countryside nationwide, underdeveloped areas are confronted by many problems, such as monotonous industry structure, simi- lar rural landscape and loss of characteristics. With a case of Jiangjia Village, Jishui County, Jiangxi Province, the research explored rural pattern, cultural characteristics, building style, development value and potential and analyzed regional cooperation, urban-rural integration, and planning first, from the perspectives of economy, culture and building in order to protect traditional economy and highlight local characteristics.展开更多
The author described some new species and genera of the fossil woods from Mesozoic of Western Liaoning besides Xenoxylon latiporosum (Cramer) Gothan, X. hopeiense Chang, X. liaoningense Duan et Wang, X. yixia...The author described some new species and genera of the fossil woods from Mesozoic of Western Liaoning besides Xenoxylon latiporosum (Cramer) Gothan, X. hopeiense Chang, X. liaoningense Duan et Wang, X. yixianense Zhang et Shang, Protopiceoxylon yizhouense Duan et Cui. They are Protopiceoxylon chaoyangense Duan sp. nov., Araucarioxylon batuense Duan sp. nov., Taxoxylon liaoxiense Duan sp. nov. and an old species Araucarioxylon sidugawaense Shimakura.展开更多
Black bedded, nodular, and lenticular chert and silicified parts of stromatolites from the approximately 1 400 - 1 600 million year-old Gaoyuzhuang Formation, North China, contain remark-ably well prep served microflo...Black bedded, nodular, and lenticular chert and silicified parts of stromatolites from the approximately 1 400 - 1 600 million year-old Gaoyuzhuang Formation, North China, contain remark-ably well prep served microflora composed of diverse prokaryotic and possible eukaryotic microbes. Macroscopic algae have also been found. This Formation provides important paleobiological information from which to assess status of Mesoproterozoic life, and to evaluate paleoenvironmental conditions and pre-Phanerozoic biostratigraphy. The Gaoyuzhuang Formation has yielded over 100 taxa described by over 10 investigators. Most of the microbial taxa can be divided into three different assemblages according to their paleobiological and paleoenvironmental characteristics. I. The oscillatoriacean/chroococcacean assemblage which occurs in the first member of the Formation and this is interpreted to represent an assemblage from shallow water mat-building and mat-dwelling taxa with some possible planktonic taxa; 2. the nostocacean assemblage found only in the second member, and includes benthic mat-building or mat-dwelling taxa; and 3. the chroococcacean assemblage of the fourth member, which represents intertidal to supratidal mat-building and allochthonous taxa. Proterozoic microfossils found in chert, especially cyanobacteria, are possibly more valuable as paleoenvironmental indicators than as chronostratigraphic tools because of their morphological conservation, although trends in diversity appear to exist for cyanobacteria in the Proterozoic. The general characteristics of Gaoyuzhuang microfossils, and the fact that most nostocacean chains occur and are. preserved with the chain perpendicular to bedding indicate that: (1) the individual size of Gaoyuzhuang microfossils are part of a general trend of increase with time; (2) Gaoyuzhuang deposits are possibly in a fresh water environment and the rate of sedimentation might be equal to or less than the microbial growth rate; (3) the sedimentary model of Gaoyuzhuang might be from intertidal to subtidal or deep sea, and then to intertidal or supratidal; and (4) the eukaryotic organisms had densely occurred when Gaoyuzhuang Formation deposited.展开更多
The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicoti...The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.展开更多
Using monthly precipitation and monthly mean temperature, a surface humid index was proposed. According to the index, the distributed characteristics of extreme dryness has been fully analyzed. The results indicated t...Using monthly precipitation and monthly mean temperature, a surface humid index was proposed. According to the index, the distributed characteristics of extreme dryness has been fully analyzed. The results indicated that there is an obvious increasing trend of extreme dryness in the central part of northern China and northeastern China in the last 10 years, which shows a high frequency period of extreme dryness; while a low frequency period in the regions during the last 100 years. Compared with variation trend of the temperature in these regions, the region of high frequent extreme dryness is consistent with the warming trend in the same region.展开更多
Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply descr...Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.展开更多
In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we invest...In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we investi- gated the absolutely dated Holocene records in Zhuye Lake for detecting the Holocene climate cycles. Totally, 14 14C dates and 6 optically simulated luminescence (OSL) dates are obtained from the QTH01 and QTH02 sections. The proxies of grain-size, total organic carbon content (TOC), C/N and 813C are used for wavelet analysis, and the results show obvious -256, -512 and -1024-year climate cycles, which are consistent with the Holocene millennial and cen- tennial scale climate cycles in the typical Asian summer monsoon domain. In different parts of the Zhuye Lake, the Holocene sediments show variable climate cycles that are affected by the lake basin topography. In the Zhuye Lake, the Holocene climate cycles are mainly correlated with the solar-related Asian summer monsoon variability and the North Atlantic ice-rafting events.展开更多
The Western Development Strategy(WDS)is a key aspect of China’s coordinated regional development strategy and effort to build a modern country.The world is undergoing profound changes that have not been witnessed in ...The Western Development Strategy(WDS)is a key aspect of China’s coordinated regional development strategy and effort to build a modern country.The world is undergoing profound changes that have not been witnessed in a century.This paper discusses the WDS’s importance in regards to China’s modernization drive and the great rejuvenation of the Chinese nation.First,this paper identifies the WDS’s mission to improve people’s livelihood in China’s western regions,promote common prosperity for the Eurasian continent,and support the green transition of China’s and Eurasian energy economic and environmental systems,and safeguard ecological security in Asia at large.Second,this paper suggests that the key to the WDS is to reshape the geographical layout of economic activity in the western regions to avoid inefficiency.Specifically,China should develop a compact geographical layout of economic activity in the western regions,introduce a unique competition strategy,as well as find solutions for coordinated regional development based on key river basins.Finally,develop smart internet and inland free ports within the western regions.展开更多
The present study investigates the interdecadal variability of seasonal mean surface solar radiation over Northwest China using station observations from 1961-2003. Spring and summer surface solar radiation over North...The present study investigates the interdecadal variability of seasonal mean surface solar radiation over Northwest China using station observations from 1961-2003. Spring and summer surface solar radiation over Northwest China was lower in the late 1970s through 1990s than in the 1960s through the mid-1970s, and fall and winter surface solar radiation displayed similar patterns. These results indicate that the decrease in spring and summer surface solar radiation may be associated with increased low-cloud cover over Northwest China. Rainfall anomalies were closely related to the low-cloud cover over Northwest China and with the Northern Hemisphere circumglobal teleconnection in spring, summer, and winter.展开更多
Code review is an important process to reduce code defects and improve software quality. In social coding communities like GitHub, as everyone can submit Pull-Requests, code review plays a more important role than eve...Code review is an important process to reduce code defects and improve software quality. In social coding communities like GitHub, as everyone can submit Pull-Requests, code review plays a more important role than ever before, and the process is quite time-consuming. Therefore, finding and recommending proper reviewers for the emerging Pull-Requests becomes a vital task. However, most of the current studies mainly focus on recommending reviewers by checking whether they will participate or not without differentiating the participation types. In this paper, we develop a two-layer reviewer recommendation model to recommend reviewers for Pull-Requests (PRs) in GitHub projects from the technical and managerial perspectives. For the first layer, we recommend suitable developers to review the target PRs based on a hybrid recommendation method. For the second layer, after getting the recommendation results from the first layer, we specify whether the target developer will technically or managerially participate in the reviewing process. We conducted experiments on two popular projects in GitHub, and tested the approach using PRs created between February 2016 and February 2017. The results show that the first layer of our recommendation model performs better than the previous work, and the second layer can effectively differentiate the types of participation.展开更多
文摘Pollen analysis of 30 modem water samples from the Shivang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to carry pollen and spores, and to assess the contribution of the water-borne pollen to pollen assemblages in lake sediments at the end of the river system. Results indicate the pollen assemblages in water samples consist of both local and upland pollen. Percentages of upland pollen reach 30% - 60%, and pollen assemblages in water samples do not indicate the nature of local vegetation at the sampling sites. Fluvial currents have the capacity to transport large quantities of pollen long distances, and the contribution of this fluvial transported pollen is relatively high, For example, percentages of Picea Dietr. pollen in water samples at sampling sites 130 km and 145 km away from Picea forests reach 16.5% and 7.7%, respectively. Fluvial pollen transport occurs primarily during flood periods, and pollen concentrations from the flood samples are 17.1 - 12.5 times those from normal fluvial flow. Reservoirs affect pollen transportation since pollen is deposited at reservoir inlets and pollen concentrations are much reduced at reservoir outlets. Human activity can thus change natural features of pollen transportation and deposition. The main factors influencing pollen concentrations and assemblages are sampling time, sampling location, and rainfall intensity.
基金Supported by Jiangxi Social Science Program during the 12th Five-year Plan(14SH05)Jiangxi Social Science University Humanity(JC1434)Jiangxi Art Science Planning Program(YG2014113)~~
文摘In context of building beautiful countryside nationwide, underdeveloped areas are confronted by many problems, such as monotonous industry structure, simi- lar rural landscape and loss of characteristics. With a case of Jiangjia Village, Jishui County, Jiangxi Province, the research explored rural pattern, cultural characteristics, building style, development value and potential and analyzed regional cooperation, urban-rural integration, and planning first, from the perspectives of economy, culture and building in order to protect traditional economy and highlight local characteristics.
文摘The author described some new species and genera of the fossil woods from Mesozoic of Western Liaoning besides Xenoxylon latiporosum (Cramer) Gothan, X. hopeiense Chang, X. liaoningense Duan et Wang, X. yixianense Zhang et Shang, Protopiceoxylon yizhouense Duan et Cui. They are Protopiceoxylon chaoyangense Duan sp. nov., Araucarioxylon batuense Duan sp. nov., Taxoxylon liaoxiense Duan sp. nov. and an old species Araucarioxylon sidugawaense Shimakura.
文摘Black bedded, nodular, and lenticular chert and silicified parts of stromatolites from the approximately 1 400 - 1 600 million year-old Gaoyuzhuang Formation, North China, contain remark-ably well prep served microflora composed of diverse prokaryotic and possible eukaryotic microbes. Macroscopic algae have also been found. This Formation provides important paleobiological information from which to assess status of Mesoproterozoic life, and to evaluate paleoenvironmental conditions and pre-Phanerozoic biostratigraphy. The Gaoyuzhuang Formation has yielded over 100 taxa described by over 10 investigators. Most of the microbial taxa can be divided into three different assemblages according to their paleobiological and paleoenvironmental characteristics. I. The oscillatoriacean/chroococcacean assemblage which occurs in the first member of the Formation and this is interpreted to represent an assemblage from shallow water mat-building and mat-dwelling taxa with some possible planktonic taxa; 2. the nostocacean assemblage found only in the second member, and includes benthic mat-building or mat-dwelling taxa; and 3. the chroococcacean assemblage of the fourth member, which represents intertidal to supratidal mat-building and allochthonous taxa. Proterozoic microfossils found in chert, especially cyanobacteria, are possibly more valuable as paleoenvironmental indicators than as chronostratigraphic tools because of their morphological conservation, although trends in diversity appear to exist for cyanobacteria in the Proterozoic. The general characteristics of Gaoyuzhuang microfossils, and the fact that most nostocacean chains occur and are. preserved with the chain perpendicular to bedding indicate that: (1) the individual size of Gaoyuzhuang microfossils are part of a general trend of increase with time; (2) Gaoyuzhuang deposits are possibly in a fresh water environment and the rate of sedimentation might be equal to or less than the microbial growth rate; (3) the sedimentary model of Gaoyuzhuang might be from intertidal to subtidal or deep sea, and then to intertidal or supratidal; and (4) the eukaryotic organisms had densely occurred when Gaoyuzhuang Formation deposited.
文摘The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.
基金Major State Basic Research Development Program of China No.G1999043400+1 种基金 National Natural Science Foundation of China No.40375028
文摘Using monthly precipitation and monthly mean temperature, a surface humid index was proposed. According to the index, the distributed characteristics of extreme dryness has been fully analyzed. The results indicated that there is an obvious increasing trend of extreme dryness in the central part of northern China and northeastern China in the last 10 years, which shows a high frequency period of extreme dryness; while a low frequency period in the regions during the last 100 years. Compared with variation trend of the temperature in these regions, the region of high frequent extreme dryness is consistent with the warming trend in the same region.
基金Under the auspices of National Natural Science Foundation of China (No. 40635029, No. 40771014)
文摘Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.
基金Under the auspices of National Natural Science Foundation of China (No. 41001116)Fundamental Research Funds for the Central Universities (No. LZUJBKY-2010-99)
文摘In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we investi- gated the absolutely dated Holocene records in Zhuye Lake for detecting the Holocene climate cycles. Totally, 14 14C dates and 6 optically simulated luminescence (OSL) dates are obtained from the QTH01 and QTH02 sections. The proxies of grain-size, total organic carbon content (TOC), C/N and 813C are used for wavelet analysis, and the results show obvious -256, -512 and -1024-year climate cycles, which are consistent with the Holocene millennial and cen- tennial scale climate cycles in the typical Asian summer monsoon domain. In different parts of the Zhuye Lake, the Holocene sediments show variable climate cycles that are affected by the lake basin topography. In the Zhuye Lake, the Holocene climate cycles are mainly correlated with the solar-related Asian summer monsoon variability and the North Atlantic ice-rafting events.
文摘The Western Development Strategy(WDS)is a key aspect of China’s coordinated regional development strategy and effort to build a modern country.The world is undergoing profound changes that have not been witnessed in a century.This paper discusses the WDS’s importance in regards to China’s modernization drive and the great rejuvenation of the Chinese nation.First,this paper identifies the WDS’s mission to improve people’s livelihood in China’s western regions,promote common prosperity for the Eurasian continent,and support the green transition of China’s and Eurasian energy economic and environmental systems,and safeguard ecological security in Asia at large.Second,this paper suggests that the key to the WDS is to reshape the geographical layout of economic activity in the western regions to avoid inefficiency.Specifically,China should develop a compact geographical layout of economic activity in the western regions,introduce a unique competition strategy,as well as find solutions for coordinated regional development based on key river basins.Finally,develop smart internet and inland free ports within the western regions.
基金supported by the Special Scientific Research Project for Public Interest(Grant No.GYHY201006021)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX2-EW-QN204)+1 种基金the National Basic Research Program of China(Grant No.2009CB421405)the National Natural Science Foundation of China(Grant Nos.40905027 and 40730952)
文摘The present study investigates the interdecadal variability of seasonal mean surface solar radiation over Northwest China using station observations from 1961-2003. Spring and summer surface solar radiation over Northwest China was lower in the late 1970s through 1990s than in the 1960s through the mid-1970s, and fall and winter surface solar radiation displayed similar patterns. These results indicate that the decrease in spring and summer surface solar radiation may be associated with increased low-cloud cover over Northwest China. Rainfall anomalies were closely related to the low-cloud cover over Northwest China and with the Northern Hemisphere circumglobal teleconnection in spring, summer, and winter.
基金Project(2016-YFB1000805)supported by the National Grand R&D Plan,ChinaProjects(61502512,61432020,61472430,61532004)supported by the National Natural Science Foundation of China
文摘Code review is an important process to reduce code defects and improve software quality. In social coding communities like GitHub, as everyone can submit Pull-Requests, code review plays a more important role than ever before, and the process is quite time-consuming. Therefore, finding and recommending proper reviewers for the emerging Pull-Requests becomes a vital task. However, most of the current studies mainly focus on recommending reviewers by checking whether they will participate or not without differentiating the participation types. In this paper, we develop a two-layer reviewer recommendation model to recommend reviewers for Pull-Requests (PRs) in GitHub projects from the technical and managerial perspectives. For the first layer, we recommend suitable developers to review the target PRs based on a hybrid recommendation method. For the second layer, after getting the recommendation results from the first layer, we specify whether the target developer will technically or managerially participate in the reviewing process. We conducted experiments on two popular projects in GitHub, and tested the approach using PRs created between February 2016 and February 2017. The results show that the first layer of our recommendation model performs better than the previous work, and the second layer can effectively differentiate the types of participation.