[Objective] The objective of this study was to investigate the effects of different agricultural managements on soil microbial population,activity,functional diversity and soil enzyme activity in continuous mono-cropp...[Objective] The objective of this study was to investigate the effects of different agricultural managements on soil microbial population,activity,functional diversity and soil enzyme activity in continuous mono-cropping field of strawberry.[Method]A field plot experiment was carried out to evaluate characteristics of soil microbial community by soil enzyme analysis,microbial cultivation and Biolog analysis.[Result]The results showed that bacteria population proportion,the ration of bacteria to fungi,microorganism amount,AWCD,soil dehydrogenase activity,the Shannon,Simpson,and Mcintosh indices of soil microbial communities were obviously increased under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide(CaCN2)treatments,in addition,soil urease activity was significantly increased under strawberry-rice rotation and soil solarization with rice bran treatment,when compared with no fertilization.When compared with conventional fertilization treatment,strawberry-rice rotation and soil solarization with rice bran both significantly increased AWCD and Mcintosh index of soil microbial communities,meanwhile respectively increased soil urease and dehydrogenase activity.PCA analyses suggested that carbon utilization of soil microbial communities under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide treatment was obviously different from that of conventional fertilization and no fertilization treatment.[Conclusion] strawberry-rice rotation and soil solarization with rice bran were effective agricultural managements to control soil biological degradation under Continuous Cropped Strawberry.展开更多
Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area...Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area of Aba Prefecture. Within this region a total area of 26 000 ha have been identified through climate matching as suitable and a further 63 000 ha potentially suitable for environmental plantings of P. radiata. The plantations are being established in widely separated small patches on steep and degraded slopes along the dry river valley The newly introduced P. radiata are exposed to two kinds of forest health risks: they may be attacked by (a) indigenous pathogens and pests against which they may not possess any resistance or (b) by inadvertently introduced foreign pests or pathogens. This paper presents a survey of the potential damaging pests and a preliminary assessment of forest health risks facing the P. radiata plantations over a much longer timeframe than the initial phase of introduction and early plantation establishment. An empirical appmach was adopted to evaluate forest health risks by a combination of literature review, examination of historical records of pest and disease outbreaks in the surrounding conifemus forests, field surveys and inspections, specimen collection and identification, and most importantly, expert analysis of the likelihood of attack by specific pests and pathogens and the subsequent impact of such attacks. The assessment identified some specific forest health risks to the long-term success of P. radiata introduction in this area. These risks are closely associated with the indigenous pests and pathogens of the two native pine species, P. tabulaeformis and P. armondii since these pests and pathogens are considered more likely to establish on P. radiata over time. Exotic pests and pathogens are of a quarantine concern at present. Based on the results of assessment, recommendations are pmvided to improve forest vigour and to reduce the forest health risks posed by indigenous as well as exotic pests and pathogens to the introduced P. radiata. Ways to increase the ability to manage the forest health risks once a particular pest infestation and disease eventuates are also recommended. Although detrimental to the survival and growth of the introduced P. radiata, the impact of identified forest health risks are not considered to be fatal to the long term success ofP. radiata in this area.展开更多
[ Objective] Study on the photosynthesis and fluorescence characteristics in peony under water stress. [ Method ] The two peony varieties Huhong and Luoyanghong were treated by different water stress for determining t...[ Objective] Study on the photosynthesis and fluorescence characteristics in peony under water stress. [ Method ] The two peony varieties Huhong and Luoyanghong were treated by different water stress for determining the photosynthesis and fluorescence characteristics. [ Result ] With the aggravation of water stress, the net photosynthetic rate (Pn) and stomatal conductance (Gs) decreased, while the intercellular CO2 concentration (Ci) increased. Drought could decrease Pn, constrain gas exchange and change the daily photosynthesis. Fo of peony leaf increased and Fv/Fm decreased under water stress especially water logging, causing the inactivation of the PS II reaction center, and the chlorophyll fluorescence characters gradually recovered until afternoon. [ Conclusion] The 75% soil relative water content (SRWC) is the best condition for growth of peony. Compared with drought, water logging is more unfit for the growth of peony. For the two varieties, Huhong assumed more tolerance to drought, accordingly more adaptability.展开更多
The paper aims to study the impacts and countermeasures of climate change on animal husbandry in Qinghai plateau and its surrounding area,and evaluate the effect of countermeasures.Results showed that:First,the annua...The paper aims to study the impacts and countermeasures of climate change on animal husbandry in Qinghai plateau and its surrounding area,and evaluate the effect of countermeasures.Results showed that:First,the annual mean temperature,annual mean maximum temperature and annual mean minimum temperature showed an increasing trend in Qinghai plateau during the time from 1961 to 2008; the annual precipitation had not obvious change,but the obvious feature of seasonal change; wind speed and sunshine hours showed a decreasing trend during the time from 1961 to 2008.Secondly,under the current climate condition,grassland productivity showed a decreasing trend,and the grassland theoretical capacity affected by grassland productivity decreased too; warm winter was in favor of livestock overwintering safely,which resulted in a high level of the survival rate of young stock; temperature increasing and precipitation decreasing were beneficial to the fatness of livestock,but the meat yield of livestock was affected by some negative factors such as grassland degradation; livestock diseases had a close relationship with weather condition,and adverse weather condition may arose many diseases of livestock.Thirdly,in view of the current problems of livestock production,we took a series of countermeasures including grass industry construction,livestock improvement,developing new modes of animal husbandry,control and prevention of stockbreeding diseases and insect pests and recovery of meteorological disasters,which played a important role in promoting grassland productivity,solving the problem of the imbalances between livestock and forage,protecting the ecological environment and improving livestock performance.展开更多
Dovetree (Davidia involucrate), one of the first-class protective plants in China, is a relic species of paleotropical kingdom in Tertiary period, belonging toDavidiaceae with a single genus. In recent years, the incr...Dovetree (Davidia involucrate), one of the first-class protective plants in China, is a relic species of paleotropical kingdom in Tertiary period, belonging toDavidiaceae with a single genus. In recent years, the increase of regional developing projects has led to a sharp decrease of this ancient and rare plant in naturally distributed habitats and natural population. In this paper, the biological and ecological characteristics of Dovetree were described, and the geographically distributed condition of this species in different geologic periods as well as the major reasons for dynamic changes of its population were systematically analyzed in accordance with field researches and references. The investigations conducted in different years by setting up standard sample plots showed that the population number of Dovetree increased yearly in the areas without human interference but decreased yearly in the areas with human interference. With the increase of population density and human activities decreased as the logarithmic curve:Y=?100.7ln(x)+178.09, and it has turned from a dominant population into an endangered population. Based on the former and present studies on Dovetree, some protection strategies were put foreword for protecting this ancient and rare species. Keywords Davidia involucrate - Dovetree - Geographical Distribution - Biological Characteristics - Protection Policy CLC number S718.4 Document code A Article ID 1007-662X(2004)01-0039-06 Foundation Item: This research was coordinated by the National Natural Science Foundation of China (No. 39970591)Biography: Wu Gang (1965-), Male, Professor in Key Laboratory of Systems Ecology, Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.Responsible editor: Chai Ruihai展开更多
To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pav...To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pavement management system (PMS) are recorded and analyzed. Compared with the growth model, the linear model, the logarithm model and the exponential model, the cubic model has higher regression accuracy R2 and it can capture the sigmoid shape of the deterioration curve. So it is selected to simulate the pavement rotting development. The benefit over cost ratio is calculated to quantify the treatment cost- effectiveness. The analysis results show that thin hot mix asphalt (HMA) overlays and micro surfacing are more cost- effective than the. other two treatments on light and moderate traffic roads. Hot in-place recycling and thick HMA overlays have much longer service lives and greater cost-effectiveness under heavy or extra heavy traffic.展开更多
[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking...[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking an example of the artificial lakes in a campus in Xi'an, we comparatively analyzed the present pollution situation of Xiuyuan Lake and Mingyuan Lake, and provided controlling measures against eutrophication pollution, as well as restoration measures. [Result] All the indicators (TN, TP, Chl-a, NH3-N, CODMn) of the landscape water quality in both Xiuyuan Lake and Mingyuan Lake went severely beyond the Grade IV standards, presenting a state of heavy eutrophication. Nitrogen, phosphorus and other nutrient salts carried by atmospheric precipitation and its runoff, as well as domestic garbage generated by human activities were primary exogenous pollutants of the artificial lakes. And the release of sediment pollutants was endogenous substances causing deterioration of water quality. [Conclusion] This paper presents some measures to control the pollution of artificial lakes, and provides scientific references for the construction, operation and management of artificial lakes, as well as maintenance of aquatic environment.展开更多
Rammed earth wall technique is one of the local widespread traditional construction methods, and it has superior physical property and ecological protection characteristic. When contemporary raw-soil building is repla...Rammed earth wall technique is one of the local widespread traditional construction methods, and it has superior physical property and ecological protection characteristic. When contemporary raw-soil building is replaced by industry building, the hometown building culture is perishing gradually. In order to inherit and develop the Hanzhong local building, rammed earth wall in Taiyangling and Cangshe hometown is investigated, and the characteristics and construction techniques of the local rammed earth wall are concluded. According to the construction problems, the improvement suggestions are put forward, which establishes the foundation to investigate rammed earth wall further, and guide Rural House construction.展开更多
Mechanization is the future direction of rapeseed production in Sichuan. A series of technology tests for rapeseed mechanized production have been carried out in terms of variety selection, key agronomic measures and ...Mechanization is the future direction of rapeseed production in Sichuan. A series of technology tests for rapeseed mechanized production have been carried out in terms of variety selection, key agronomic measures and machinery in the main production area of Sichuan in recent years. In the research, the agronomic techniques, including variety selection for mechanical production, key agronomic measures and mechanical harvesting were analyzed. Based on the present condi- tions, strategy and suggestions for the development of mechanized rapeseed produc- tion in Sichuan also were presented.展开更多
With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Unio...With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.展开更多
Objective: To compare the functional outcomes of patients who had parotid masseter fascia reserved and unreserved flap elevating scheme in parotidectomy, especially the morbidity of Frey's syndrome. Methods: Twent...Objective: To compare the functional outcomes of patients who had parotid masseter fascia reserved and unreserved flap elevating scheme in parotidectomy, especially the morbidity of Frey's syndrome. Methods: Twenty-three patients (group A) had parotid masseter fascia reserved in the parotidectomy, 32 patients (group B) had parotid masseter fascia unreserved in the operation. Compare the morbidity of gustatory sweating syndrome of the two groups. Results: Follow-up after 6 months to 2.5 years, gustatory sweating syndrome occurred in 4 patients of group A (17%), 17 patients in group B (57%). Conclusion: Reservation technic of the parotid masseter fascial in parotidectomy could prevent regeneration of parasympathetic nerve and thus prevent Frey's syndrome post-operation.展开更多
In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper dep...In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper depicts the land degradation status and causes,through an integrated assessment,and some measures to alleviate the problem are proposed.展开更多
In recent years, the college English teaching reform has been increasingly deepened. The study of the relationship between cognitive approach and foreign language teaching is undoubtedly instructive not only to guaran...In recent years, the college English teaching reform has been increasingly deepened. The study of the relationship between cognitive approach and foreign language teaching is undoubtedly instructive not only to guarantee the quality of foreign language teaching but also to improve learners' foreign language proficiency. In this essay, the author expounds the development of cognitive approach and some relative teaching principles, on which basis the author puts forward some specific practices in foreign language teaching.展开更多
[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilize...[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.展开更多
A study was conducted to determine the influences of initial planting densities, thinning intensities, exposures and slope sites on physical property (wood density) and mechanical properties such as modulus of elast...A study was conducted to determine the influences of initial planting densities, thinning intensities, exposures and slope sites on physical property (wood density) and mechanical properties such as modulus of elasticity (MOE), bending strength, impact strength, compression strength along grain and hardness) of Pinus sylvestris var. mongolica plantation in Mao'ershan Forest Farm, Northeast China. Results show that the different initial planting densities (1.5 m×1.0 m, 1.5 m×2.0 m and 1.5 m×2.5 m) had significant effects on wood density and MOE, and the highest mean wood density and indexes of mechanical properties occurred in the stand with an initial planting density of 1.5 m×1.0 m. The indexes of mechanical properties such as hardness of end, bending strength, MOE and compression strength along grain of wood increased after mild thinning, but decreased after violent thinning. The exposures (sunny slope and shady slope) had a significant effect on MOE, and the highest mean MOE occurred on sunny slope. The slope sites (upper site and lower site) had a significant effect on wood density and main mechanical properties, except hardness. The highest mean wood density and mechanical properties occurred at lower site.展开更多
The situation of intercepted alien pests from imported hides in Hebei during 2013-2014 was systematically analyzed. The results showed that 163 batches of alien pests were intercepted, including 2 batches of quarantin...The situation of intercepted alien pests from imported hides in Hebei during 2013-2014 was systematically analyzed. The results showed that 163 batches of alien pests were intercepted, including 2 batches of quarantine weeds and they both were Italian cocklebur. According to the statistics of original countries, the intercepted hides from 21 countries all had alien pests, in which Australia was the largest number of batches and species of alien pests. The analysis results showed that there was severe risk in the imported hides carrying alien pests, thus to effectively prevent the invasion of alien pests to our country, several quarantine measures should be taken in the future, such as enhancing the quarantine inspection in ports, and promoting the personnel ability of interception and species identification of alien pests.展开更多
基金Supported by the National Science and Technology Funds for Agriculture(2009GB24910540)Special fund for National Public Service Sectors(Agriculture)Research(200903011)+1 种基金Natural Science Fund Project of Hohai University(2008429811)Central University Basic Research Operating Expenses Project(2010B05314)~~
文摘[Objective] The objective of this study was to investigate the effects of different agricultural managements on soil microbial population,activity,functional diversity and soil enzyme activity in continuous mono-cropping field of strawberry.[Method]A field plot experiment was carried out to evaluate characteristics of soil microbial community by soil enzyme analysis,microbial cultivation and Biolog analysis.[Result]The results showed that bacteria population proportion,the ration of bacteria to fungi,microorganism amount,AWCD,soil dehydrogenase activity,the Shannon,Simpson,and Mcintosh indices of soil microbial communities were obviously increased under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide(CaCN2)treatments,in addition,soil urease activity was significantly increased under strawberry-rice rotation and soil solarization with rice bran treatment,when compared with no fertilization.When compared with conventional fertilization treatment,strawberry-rice rotation and soil solarization with rice bran both significantly increased AWCD and Mcintosh index of soil microbial communities,meanwhile respectively increased soil urease and dehydrogenase activity.PCA analyses suggested that carbon utilization of soil microbial communities under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide treatment was obviously different from that of conventional fertilization and no fertilization treatment.[Conclusion] strawberry-rice rotation and soil solarization with rice bran were effective agricultural managements to control soil biological degradation under Continuous Cropped Strawberry.
文摘Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area of Aba Prefecture. Within this region a total area of 26 000 ha have been identified through climate matching as suitable and a further 63 000 ha potentially suitable for environmental plantings of P. radiata. The plantations are being established in widely separated small patches on steep and degraded slopes along the dry river valley The newly introduced P. radiata are exposed to two kinds of forest health risks: they may be attacked by (a) indigenous pathogens and pests against which they may not possess any resistance or (b) by inadvertently introduced foreign pests or pathogens. This paper presents a survey of the potential damaging pests and a preliminary assessment of forest health risks facing the P. radiata plantations over a much longer timeframe than the initial phase of introduction and early plantation establishment. An empirical appmach was adopted to evaluate forest health risks by a combination of literature review, examination of historical records of pest and disease outbreaks in the surrounding conifemus forests, field surveys and inspections, specimen collection and identification, and most importantly, expert analysis of the likelihood of attack by specific pests and pathogens and the subsequent impact of such attacks. The assessment identified some specific forest health risks to the long-term success of P. radiata introduction in this area. These risks are closely associated with the indigenous pests and pathogens of the two native pine species, P. tabulaeformis and P. armondii since these pests and pathogens are considered more likely to establish on P. radiata over time. Exotic pests and pathogens are of a quarantine concern at present. Based on the results of assessment, recommendations are pmvided to improve forest vigour and to reduce the forest health risks posed by indigenous as well as exotic pests and pathogens to the introduced P. radiata. Ways to increase the ability to manage the forest health risks once a particular pest infestation and disease eventuates are also recommended. Although detrimental to the survival and growth of the introduced P. radiata, the impact of identified forest health risks are not considered to be fatal to the long term success ofP. radiata in this area.
基金the Key Project Foundation of Henan Province (0122012400)the Key Project Foundation of Luoyang City (20011001)~~
文摘[ Objective] Study on the photosynthesis and fluorescence characteristics in peony under water stress. [ Method ] The two peony varieties Huhong and Luoyanghong were treated by different water stress for determining the photosynthesis and fluorescence characteristics. [ Result ] With the aggravation of water stress, the net photosynthetic rate (Pn) and stomatal conductance (Gs) decreased, while the intercellular CO2 concentration (Ci) increased. Drought could decrease Pn, constrain gas exchange and change the daily photosynthesis. Fo of peony leaf increased and Fv/Fm decreased under water stress especially water logging, causing the inactivation of the PS II reaction center, and the chlorophyll fluorescence characters gradually recovered until afternoon. [ Conclusion] The 75% soil relative water content (SRWC) is the best condition for growth of peony. Compared with drought, water logging is more unfit for the growth of peony. For the two varieties, Huhong assumed more tolerance to drought, accordingly more adaptability.
文摘The paper aims to study the impacts and countermeasures of climate change on animal husbandry in Qinghai plateau and its surrounding area,and evaluate the effect of countermeasures.Results showed that:First,the annual mean temperature,annual mean maximum temperature and annual mean minimum temperature showed an increasing trend in Qinghai plateau during the time from 1961 to 2008; the annual precipitation had not obvious change,but the obvious feature of seasonal change; wind speed and sunshine hours showed a decreasing trend during the time from 1961 to 2008.Secondly,under the current climate condition,grassland productivity showed a decreasing trend,and the grassland theoretical capacity affected by grassland productivity decreased too; warm winter was in favor of livestock overwintering safely,which resulted in a high level of the survival rate of young stock; temperature increasing and precipitation decreasing were beneficial to the fatness of livestock,but the meat yield of livestock was affected by some negative factors such as grassland degradation; livestock diseases had a close relationship with weather condition,and adverse weather condition may arose many diseases of livestock.Thirdly,in view of the current problems of livestock production,we took a series of countermeasures including grass industry construction,livestock improvement,developing new modes of animal husbandry,control and prevention of stockbreeding diseases and insect pests and recovery of meteorological disasters,which played a important role in promoting grassland productivity,solving the problem of the imbalances between livestock and forage,protecting the ecological environment and improving livestock performance.
基金The National Natural Science Foundation of China (No. 39970591)
文摘Dovetree (Davidia involucrate), one of the first-class protective plants in China, is a relic species of paleotropical kingdom in Tertiary period, belonging toDavidiaceae with a single genus. In recent years, the increase of regional developing projects has led to a sharp decrease of this ancient and rare plant in naturally distributed habitats and natural population. In this paper, the biological and ecological characteristics of Dovetree were described, and the geographically distributed condition of this species in different geologic periods as well as the major reasons for dynamic changes of its population were systematically analyzed in accordance with field researches and references. The investigations conducted in different years by setting up standard sample plots showed that the population number of Dovetree increased yearly in the areas without human interference but decreased yearly in the areas with human interference. With the increase of population density and human activities decreased as the logarithmic curve:Y=?100.7ln(x)+178.09, and it has turned from a dominant population into an endangered population. Based on the former and present studies on Dovetree, some protection strategies were put foreword for protecting this ancient and rare species. Keywords Davidia involucrate - Dovetree - Geographical Distribution - Biological Characteristics - Protection Policy CLC number S718.4 Document code A Article ID 1007-662X(2004)01-0039-06 Foundation Item: This research was coordinated by the National Natural Science Foundation of China (No. 39970591)Biography: Wu Gang (1965-), Male, Professor in Key Laboratory of Systems Ecology, Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.Responsible editor: Chai Ruihai
基金The Science and Technology Project of Jiangsu Provincial Communications Department(No.7621000078)
文摘To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pavement management system (PMS) are recorded and analyzed. Compared with the growth model, the linear model, the logarithm model and the exponential model, the cubic model has higher regression accuracy R2 and it can capture the sigmoid shape of the deterioration curve. So it is selected to simulate the pavement rotting development. The benefit over cost ratio is calculated to quantify the treatment cost- effectiveness. The analysis results show that thin hot mix asphalt (HMA) overlays and micro surfacing are more cost- effective than the. other two treatments on light and moderate traffic roads. Hot in-place recycling and thick HMA overlays have much longer service lives and greater cost-effectiveness under heavy or extra heavy traffic.
基金Supported by National Science Fund for Distinguished Young Scholars of China(41102107)Basic Research Program for Technology Innovation,Chang'an University(CHD2012JC080)~~
文摘[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking an example of the artificial lakes in a campus in Xi'an, we comparatively analyzed the present pollution situation of Xiuyuan Lake and Mingyuan Lake, and provided controlling measures against eutrophication pollution, as well as restoration measures. [Result] All the indicators (TN, TP, Chl-a, NH3-N, CODMn) of the landscape water quality in both Xiuyuan Lake and Mingyuan Lake went severely beyond the Grade IV standards, presenting a state of heavy eutrophication. Nitrogen, phosphorus and other nutrient salts carried by atmospheric precipitation and its runoff, as well as domestic garbage generated by human activities were primary exogenous pollutants of the artificial lakes. And the release of sediment pollutants was endogenous substances causing deterioration of water quality. [Conclusion] This paper presents some measures to control the pollution of artificial lakes, and provides scientific references for the construction, operation and management of artificial lakes, as well as maintenance of aquatic environment.
基金Supported by Fund for Scientific Research of Shaanxi University of Technology(SLG0811)~~
文摘Rammed earth wall technique is one of the local widespread traditional construction methods, and it has superior physical property and ecological protection characteristic. When contemporary raw-soil building is replaced by industry building, the hometown building culture is perishing gradually. In order to inherit and develop the Hanzhong local building, rammed earth wall in Taiyangling and Cangshe hometown is investigated, and the characteristics and construction techniques of the local rammed earth wall are concluded. According to the construction problems, the improvement suggestions are put forward, which establishes the foundation to investigate rammed earth wall further, and guide Rural House construction.
基金Supported by 863 Program(2011AA10A104)Special Funds of the Modern Agricultural Industry Technology System(CARS-13)+4 种基金National Technical Support Program(2010BAD01B08,2011BAD35B04)Sichuan Breeding Key Project(2011NZ0098-5)Financial Genetic Engineering Program of Sichuan Province(2011JYGC04013)Special Funds for Sichuan Agricultural Innovation Team ConstructionProgram for Sichuan Provincial Science Fund for Distinguished Young Scholars(No 2010JQ0054)~~
文摘Mechanization is the future direction of rapeseed production in Sichuan. A series of technology tests for rapeseed mechanized production have been carried out in terms of variety selection, key agronomic measures and machinery in the main production area of Sichuan in recent years. In the research, the agronomic techniques, including variety selection for mechanical production, key agronomic measures and mechanical harvesting were analyzed. Based on the present condi- tions, strategy and suggestions for the development of mechanized rapeseed produc- tion in Sichuan also were presented.
文摘With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.
文摘Objective: To compare the functional outcomes of patients who had parotid masseter fascia reserved and unreserved flap elevating scheme in parotidectomy, especially the morbidity of Frey's syndrome. Methods: Twenty-three patients (group A) had parotid masseter fascia reserved in the parotidectomy, 32 patients (group B) had parotid masseter fascia unreserved in the operation. Compare the morbidity of gustatory sweating syndrome of the two groups. Results: Follow-up after 6 months to 2.5 years, gustatory sweating syndrome occurred in 4 patients of group A (17%), 17 patients in group B (57%). Conclusion: Reservation technic of the parotid masseter fascial in parotidectomy could prevent regeneration of parasympathetic nerve and thus prevent Frey's syndrome post-operation.
文摘In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper depicts the land degradation status and causes,through an integrated assessment,and some measures to alleviate the problem are proposed.
文摘In recent years, the college English teaching reform has been increasingly deepened. The study of the relationship between cognitive approach and foreign language teaching is undoubtedly instructive not only to guarantee the quality of foreign language teaching but also to improve learners' foreign language proficiency. In this essay, the author expounds the development of cognitive approach and some relative teaching principles, on which basis the author puts forward some specific practices in foreign language teaching.
文摘[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.
基金This study was supported by National Natural Science Foundation of China (30471355) and the Key Technologies R&D Program of Heilongjiang Province (G99B5-3)
文摘A study was conducted to determine the influences of initial planting densities, thinning intensities, exposures and slope sites on physical property (wood density) and mechanical properties such as modulus of elasticity (MOE), bending strength, impact strength, compression strength along grain and hardness) of Pinus sylvestris var. mongolica plantation in Mao'ershan Forest Farm, Northeast China. Results show that the different initial planting densities (1.5 m×1.0 m, 1.5 m×2.0 m and 1.5 m×2.5 m) had significant effects on wood density and MOE, and the highest mean wood density and indexes of mechanical properties occurred in the stand with an initial planting density of 1.5 m×1.0 m. The indexes of mechanical properties such as hardness of end, bending strength, MOE and compression strength along grain of wood increased after mild thinning, but decreased after violent thinning. The exposures (sunny slope and shady slope) had a significant effect on MOE, and the highest mean MOE occurred on sunny slope. The slope sites (upper site and lower site) had a significant effect on wood density and main mechanical properties, except hardness. The highest mean wood density and mechanical properties occurred at lower site.
基金Supported by the Scientific Research Project of Hebei Entry-Exit Inspection and Quarantine Bureau(HE2013K030)~~
文摘The situation of intercepted alien pests from imported hides in Hebei during 2013-2014 was systematically analyzed. The results showed that 163 batches of alien pests were intercepted, including 2 batches of quarantine weeds and they both were Italian cocklebur. According to the statistics of original countries, the intercepted hides from 21 countries all had alien pests, in which Australia was the largest number of batches and species of alien pests. The analysis results showed that there was severe risk in the imported hides carrying alien pests, thus to effectively prevent the invasion of alien pests to our country, several quarantine measures should be taken in the future, such as enhancing the quarantine inspection in ports, and promoting the personnel ability of interception and species identification of alien pests.