Grasslands account for about a quarter of the Earth's land area and are one of the major terrestrial ecosystems,with significant ecological and economic values.The influence of environmental factors and management...Grasslands account for about a quarter of the Earth's land area and are one of the major terrestrial ecosystems,with significant ecological and economic values.The influence of environmental factors and management types on grassland biodiversity has garnered considerable attention.This study investigated how patterns of species richness are influenced by geographical distance,environmental gradients,and management type in the moist mountain grasslands of northeastern Yunnan,China.We used structural equation modeling to disentangle the impacts of environment and management on phylogenetic community structure,and using partial Mantel tests estimated the roles of dispersal limitation and environmental filtering on taxonomic and phylogenetic beta diversity of three types of grasslands.Our results show that taxonomic alpha diversity increased in grazed grasslands and decreased in mowed grasslands,compared with protected grasslands.However,the phylogenetic structure of both grazed and mowed grassland communities was clustered,whereas that of protected communities was random.Moreover,both grazing and mowing significantly reduced the taxonomic and phylogenetic beta diversity of grasslands,with the lowest values observed in mowed grasslands.Both taxonomic and phylogenetic beta diversity were dominated by species turnover under different management types.The taxonomic and phylogenetic beta diversities of protected and grazed grasslands were simultaneously affected by environmental filtering and dispersal limitation,with the later playing a stronger role.In addition,mowing and following management measures had a stronger filtering effect on grassland community structure,as reflected by changes in community composition.展开更多
In the context of deepening educational reforms,the significance of ideological and political education has become increasingly prominent,emerging as a crucial aspect of enhancing students’comprehensive qualities.To ...In the context of deepening educational reforms,the significance of ideological and political education has become increasingly prominent,emerging as a crucial aspect of enhancing students’comprehensive qualities.To ensure the orderly progress of ideological and political education in courses,it is essential to actively promote the integration of ideological and political elements within coursework.This integration aims to align professional course education with ideological and political education,fostering a collaborative educational model.Therefore,in the teaching of bidding and contract management courses,constructing a“micro-ideological and political”teaching model has emerged as a critical component.The implementation of this model facilitates the seamless integration of bidding and contract management coursework with ideological and political education,thereby elevating the teaching quality of these courses.Additionally,it leverages the synergistic role of coursework and ideology in educating students,ultimately enhancing the quality and level of talent cultivation.Hence,this paper proposes strategies for constructing a“microideological and political”model within the context of ideological and political teaching reforms in bidding and contract management courses,inviting discussion and exchange on this topic.展开更多
From the perspective of civil subject theory,law of value,comparative law and history of laws,the thesis expounds that the contract on the transfer of the contractual right of rural lands is in nature a civil contract...From the perspective of civil subject theory,law of value,comparative law and history of laws,the thesis expounds that the contract on the transfer of the contractual right of rural lands is in nature a civil contract instead of an administrative one.Then it explores the defects in the contract from the viewpoint of legal value goal,contract law and legal sociology,that is,the relevant provisions in Rural Land Contract Law and Explanations of Supreme People's Court about the Issues concerning the Laws Applicable to the Trial of Cases of Disputes over Rural Land Contracting go against the principle of free contracting and run counter to the legal value goal of justice,so they do not achieve good implementing effect.Finally,the thesis demonstrates and makes some practical legislative proposals to perfect the contract system for circulation of the right to operate constructed rural lands,aiming at improving the circulation rate through perfecting the contract of the right to rural land contractual management,solving the disputes in rural lands circulation and safeguarding the legitimate rights of the farmers.展开更多
The realty(real estate)management of ownership of buildings includes the owner(homeowner)entrust-management and the owner self-management,the former through the way of realty service contracts,the latter through the r...The realty(real estate)management of ownership of buildings includes the owner(homeowner)entrust-management and the owner self-management,the former through the way of realty service contracts,the latter through the resolution of the owners’assembly and the owners’committee.The legal disputes of realty service contracts involve balancing interests among the realty service enterprise,individual owner,and all the owners.We should use dynamic balancing of the interests of the three parties to implement the interests of the win-win cooperation rather than the interests of the trade-off of“all or nothing.”The realty service contract is similar to the entrustment contract,both of which are based on the owners’entrustment.The duty to provide realty service is not simply equivalent to fiduciary duty.The realty service contract has the essence of both behavior debt and result debt.For the former,the general provisions of the entrustment contract can be referred to,and for the latter,the general provisions of the contract for work can be referred to.In view of the group characteristics of the realty service contract,owners have no right to terminate the realty service contract at any time but should obey the principle of due process and take the majority mechanism to make a dismissal resolution resolution.The resolutions and management stipulations worked out by the owners’assembly in a majority mechanism,both of which belong to resolution behavior and are legal tools of the owners’autonomy,shall be binding on all the owners.The relationship between the owner,the owner’s assembly,and the owner’s committee is similar to the fiduciary relationship.If the decision made by the owners’assembly or the owners’committee and the management stipulation infringes upon the legal rights and interests of the owners,the injured owner has the right to revocation litigation.At present,residential commodity owners have a relatively low degree of autonomy in China,and legal disputes over realty services are frequent.In the future,we need to perfect the legal incentive and constraint measures,and stimulate the vitality of owner autonomy to promote better implementation of the owner self-management and owner entrust-management.展开更多
Effective cost control in the investment and design phases of highway construction is crucial for managing project expenses.However,current management practices often overlook pre-construction cost management,leading ...Effective cost control in the investment and design phases of highway construction is crucial for managing project expenses.However,current management practices often overlook pre-construction cost management,leading to budget overruns and project delays during later stages.To ensure the smooth execution and cost control of highway construction projects,this paper examines the significance of cost control,evaluates the current state and challenges of highway construction,and proposes strategies for cost management.These strategies aim to establish a robust foundation for cost management in highway projects.展开更多
To provide a much more resilient transport scheme for tractor and trailer transportation systems,this paper explores the generation method of tractor and trailer transport schemes considering the influence of disrupte...To provide a much more resilient transport scheme for tractor and trailer transportation systems,this paper explores the generation method of tractor and trailer transport schemes considering the influence of disrupted events.Three states of tractors including towing loaded trailers,towing empty trailers,and idle driving are taken into account.Based on the disruption management theory,a scheduling model is constructed to minimize the total deviation cost including transportation time,transportation path,and number of used vehicles under the three states of tractors.A heuristics based on the contract net and simulated annealing algorithm is designed to solve the proposed model.Through comparative analysis of examples with different numbers of newly added transportation tasks and different types of road networks,the performance of the contract net algorithm in terms of deviations in idle driving paths,empty trailer paths,loaded trailer paths,time,number of used vehicles,and total deviation cost are analyzed.The results demonstrate the effectiveness of the model and algorithm,highlighting the superiority of the disruption management model and the contract net annealing algorithm.The study provides a reference for handling unexpected events in the tractor and trailer transportation industry.展开更多
1. Introduction With the opening ceremony of the Gotthard Base Tunnel on 1 June 2016, a new world record was established: the commissioning of the longest railway tunnel in the world. Many challenges have been overcom...1. Introduction With the opening ceremony of the Gotthard Base Tunnel on 1 June 2016, a new world record was established: the commissioning of the longest railway tunnel in the world. Many challenges have been overcome and many technical innovations have been developed and considered in this project. As of 11 December 2016, the Gotthard Base Tunnel has been an integral part of the new timetable of the Swiss Federal Railways (SBB-CFF-FFS), and is in full operation. With a total length of 57 km and a cruising speed of 200 km·h^-1 for passenger trains, the Gotthard Base Tunnel reduces the journey time through the Alps by 40 min, significantly reducing the distance between the south and north of Europe.展开更多
The mortgage of land contract management rights has launched a pilot project in Ningxia,Hubei,Henan,Guizhou,Chongqing and other provinces,municipalities and autonomous regions,which provides a good solution to the pro...The mortgage of land contract management rights has launched a pilot project in Ningxia,Hubei,Henan,Guizhou,Chongqing and other provinces,municipalities and autonomous regions,which provides a good solution to the problem of funds for rural development and plays a huge role in promoting local rural economic development.In the mortgage financing of land contract management rights implemented in various regions,how to determine a scientific,accurate and reasonable mortgage rate of land contract management rights becomes a difficulty troubling the mortgage financing of land.On the basis of unified annual output value of land,this article uses survey method,income capitalization method,and comparison method to analyze the value of land contract management rights,and finally determine the mortgage rates of land contract management rights.展开更多
This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications mini...This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer (4-1-4), an initial herbicide (Pasture Gard, Dow Agro) application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza (L.) Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.展开更多
Four directions for grassland management are set out under the Common Agricultural Policy: the existing, environmental, productional and integrated. The aim of this work is to demonstrate the agreement of production ...Four directions for grassland management are set out under the Common Agricultural Policy: the existing, environmental, productional and integrated. The aim of this work is to demonstrate the agreement of production potential of grassland with the strategy of the CAP on the background of commodity milk production. This work is connected with randomly selected 1656 farms from the north-eastern part of the Lublin province remaining the dairy cattle. Source material for analysis was derived from the evaluation reports of dairy farms and the datas of Voivodeship Statistical Office. Taken the average annual milk production and surface of permanent grasslands, were divided into three groups of management direction: I- existing, II- integrated, III- productional In a separate II group of this management, three subgroups were identified dependent on the volume of milk production: A-(20-50), B-(50-100), C-(100-350) thousand of liters. In the studied farms the participation of grasslands in the structure of agriculture fanning lands was significantly higher than the average in the region as well as in the country. The largest research group accounted 49.5% of farms producing 20-50 thousand liters of milk with an average area of 21.23 ha and sustained an average of 9.8 cows. Large proportion of permanent grassland in the structure of agricultural lands and large stocking density per 100 ha of grasslands in northeast farms of Lublin province indicate significant intensification of feed production on the farmlands.展开更多
In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management ...In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management of the contract, can promote the reasonable and balanced investment cost allocation in the quality and safety and other aspects of the project, so that the construction project can obtain higher added value, and to further promote China' s economic construction and accelerate the pace of the city. This paper first briefly elaborates our construction project cost of the contract management on the present situation, and some problems are analyzed and discussed, and then puts forward some suggestions on the measures and countermeasures for cost management of construction engineering contract.展开更多
In the colleges and universities, the relationship between the instructors and the students is very close. The counselors carry out the scientific and reasonable management on the life and learning of the students, an...In the colleges and universities, the relationship between the instructors and the students is very close. The counselors carry out the scientific and reasonable management on the life and learning of the students, and the students meet with the problems in their life and learning and exchange and communicate timely with the counselors, which is the process to realize the functions of the counselors. Then the management of the instructors built on the psychological contract is the more perfect, comprehensive, and scientific management mode. This kind of the management mode is not only very conducive to the development of the students, but also conducive to the interaction and communication between the counselors and the students. In a relaxed and harmonious atmosphere, the student's development will be more healthy and positive. This paper elaborates and analyzes several aspects in view of the management of the psychological contract of the university counselors.展开更多
In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, bu...In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, but also has an important role in the coordination and stability of the whole system of public security colleges and universities. Based on the theory of Psychological Contract, this paper expounds the basic understanding and research value of Psychological Contract, and puts forward the measures to cultivate teachers' good character and understanding, and as well as coordinate teachers' needs, effectively change teachers' attitude and actively promote the establishment of good interpersonal relationship to explain the research on the Management Mechanism of Teachers in Public Security Colleges and Universities from the Perspective of Psychological Contract.展开更多
The psychological contract is a set of personal beliefs about the reciprocal obligations and rights established in an exchange relationship,and high-level fulfillment of psychological contract helps the development of...The psychological contract is a set of personal beliefs about the reciprocal obligations and rights established in an exchange relationship,and high-level fulfillment of psychological contract helps the development of a team.This study summarizes the concept and theoretical basis of psychological contract,the influencing factors and intervention status of nurse psychological contract,and constructs a psychological contract intervention model to provide reference and reference for better construction and management of nursing teams.展开更多
The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the ...The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the total land area (FAO,1990). Grassland can provide feed for herbivore and produce high-quality food,clothing,medicines and industrial materials for man.On the other hand,it also plays an important role in the fertility of the soil,the conservation of water, the improvement of the environment and maintaining the ecological balance of the Earth’s surface.展开更多
The main manufacturer and its suppliers' relationship management is very important for success of the large aircraft project. The study concentrates on analysis of the relationship management on a psychological con- ...The main manufacturer and its suppliers' relationship management is very important for success of the large aircraft project. The study concentrates on analysis of the relationship management on a psychological con- tract perspective, shows that constructing good psychological contract is useful to promote mutual trust, reduce the transaction cost caused by incompleteness of formal contract, avoid the risk of supplier management between the main manufacturer and suppliers of the large aircraft project. And with further understanding of the dynamic contracting process as well as formation framework of psychological contract between the main manufacturer and suppliers, we can better understand the relationship black-box and provide a new perspective for the study of the relationship management, then given some constructive suggestions to supplier relationship management.展开更多
Land change is a cause and consequence of global environmental change.Land use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major in...Land change is a cause and consequence of global environmental change.Land use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major international research projects.This study interprets land use and land cover status and the changes within the Koshi River Basin(KRB)using Landsat remote sensing(RS)image data,and employs logistic regression model to analyze the influence of natural and socioeconomic driving forces on major land cover changes.The results showed that the areas of built-up land,bare land and forest in KRB increased from 1990 to 2015,including the largest increases in forest and the highest growth rate in construction land.Areas of glacier,grassland,sparse vegetation,shrub land,cropland,and wetland all decreased over the study period.From the perspective of driving analysis,the role of human activities in land use and land cover change is significant than climate factors.Cropland expansion is the reclamation of cropland by farmers,mainly from early deforestation.However,labor force separation,geological disasters and drought are the main factors of cropland shrinkage.The increase of forest area in India and Nepal was attributed to the government’s forest protection policies,such as Nepal’s community forestry has achieved remarkable results.The expansion and contraction of grassland were both dominated by climatic factors.The probability of grassland expansion increases with temperature and precipitation,while the probability of grassland contraction decreases with temperature and precipitation.展开更多
The soil biological activity of mountain meadows is a significant factor that determines the health and utility of these regions. The climax stage of this area is forest, but to maintain semi-natural grassland, which ...The soil biological activity of mountain meadows is a significant factor that determines the health and utility of these regions. The climax stage of this area is forest, but to maintain semi-natural grassland, which is characterised by high biodiversity,low-intensity land use(mowing or grazing) is necessarily required. To understand the effect of various mowing regimes on the soil biological activity and plants, the soil microbial activity(microbial biomass carbon, dehydrogenase activity and number of the cultivable fraction of soil microbial community),annelids community(density and species composition earthworms and enchytraeids) and plant species composition were investigated. The study area was located in the Pieniny National Park in the Carpathian Mountains, in a meadow belonging to the association Dactylis glomerata-Poa trivialis. The investigated variants were divided according to mowing regime:traditional scything – hand mowing(HM), mechanical mowing(MM), or the abandonment of mowing – nonmowing(NM). The microbial activities(expressed by,e.g. microbial biomass carbon and the number of phosphorus bacteria) were affected by the mowing regime. The density of earthworms was higher in the HM and MM than in the NM variants. The largest changes in plant species composition were caused by the abandonment of mowing(NM). The mean number of plant species was positively correlated with soil moisture, earthworm density, and microbial activity(expressed indirectly by dehydrogenases activity). The soil microbial community, such as vegetative bacteria forms and ammonifying bacteria,were positively associated with pH value, and the microbial and total organic carbon content. The results presented here indicate that there is no single form of optimal management for all living organisms.Decisions about mowing regimes, or abandonment of use, should be preceded by multi-aspect studies,including plants and soil biota.展开更多
The status quo and significance of contract and management right transfer of rural land are analyzed,and major problems existed in contract and management right transfer of rural land in Anhui Province are studied,con...The status quo and significance of contract and management right transfer of rural land are analyzed,and major problems existed in contract and management right transfer of rural land in Anhui Province are studied,containing unsound transfer market,insufficient flow demand motion,single transfer form,non-standard register,right determination and certificate issuing. On this basis,several policies and suggestions are proposed,such as combining practical use with suitable use of land right determination and certificate issuing,establishing multilayer rural social security system and expanding land management range.展开更多
The sword lily Gladiolus palustris Gaudin is protected on European level and listed in Annexes II and IV of the EC Habitat Directive 92/43/EEC.It grows in nutrient-poor,calcareous meadows in central and eastern Europe...The sword lily Gladiolus palustris Gaudin is protected on European level and listed in Annexes II and IV of the EC Habitat Directive 92/43/EEC.It grows in nutrient-poor,calcareous meadows in central and eastern Europe.Tree encroachment in montane meadows of the European Alps as a result of recent land use changes and the abandonment of traditional farming practices threaten the survival of this species.Conservation-driven mowing is considered a feasible conservation measure for maintaining high species diversity in abandoned semi-natural grasslands.To assess the effects of tenyears of biennial mowing on a grassland community in the Dolomiti Bellunesi National Park,Italy(Site of Community Importance,Natura 2000 network),ten25 m2 plots were established whereby four plots were placed in the mowed area,four in the non-mowed area and two in a small non-mowed patch of grassland inside the mowed area.In each plot the following variables were recorded,total percentage of plant cover,percentage cover of woody species,percentage cover of herbaceous species,percentage cover and number of flowering ramets of G.palustris and a complete list of species and their percentage abundance.Mowed plots showed a higher species richness than non-mowed plots.The number of G.palustris flowering ramets and percentage cover increased manifold in mowed plots compared to nonmowed plots.The resumption of mowing forconservation purposes undertaken by the managing authority halted the process of tree encroachment and avoided a drastic change in plant composition.Periodic mowing(every second or third year)was demonstrated to be a cost-effective conservation measure in non-productive grasslands to keep grasses at bay in favour of forbs of high conversation value.展开更多
基金sponsored by the Strategic pilot project(type A)of the Chinese Academy of Sciences(Project No.XDA26020203-K207002210014)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0402).
文摘Grasslands account for about a quarter of the Earth's land area and are one of the major terrestrial ecosystems,with significant ecological and economic values.The influence of environmental factors and management types on grassland biodiversity has garnered considerable attention.This study investigated how patterns of species richness are influenced by geographical distance,environmental gradients,and management type in the moist mountain grasslands of northeastern Yunnan,China.We used structural equation modeling to disentangle the impacts of environment and management on phylogenetic community structure,and using partial Mantel tests estimated the roles of dispersal limitation and environmental filtering on taxonomic and phylogenetic beta diversity of three types of grasslands.Our results show that taxonomic alpha diversity increased in grazed grasslands and decreased in mowed grasslands,compared with protected grasslands.However,the phylogenetic structure of both grazed and mowed grassland communities was clustered,whereas that of protected communities was random.Moreover,both grazing and mowing significantly reduced the taxonomic and phylogenetic beta diversity of grasslands,with the lowest values observed in mowed grasslands.Both taxonomic and phylogenetic beta diversity were dominated by species turnover under different management types.The taxonomic and phylogenetic beta diversities of protected and grazed grasslands were simultaneously affected by environmental filtering and dispersal limitation,with the later playing a stronger role.In addition,mowing and following management measures had a stronger filtering effect on grassland community structure,as reflected by changes in community composition.
文摘In the context of deepening educational reforms,the significance of ideological and political education has become increasingly prominent,emerging as a crucial aspect of enhancing students’comprehensive qualities.To ensure the orderly progress of ideological and political education in courses,it is essential to actively promote the integration of ideological and political elements within coursework.This integration aims to align professional course education with ideological and political education,fostering a collaborative educational model.Therefore,in the teaching of bidding and contract management courses,constructing a“micro-ideological and political”teaching model has emerged as a critical component.The implementation of this model facilitates the seamless integration of bidding and contract management coursework with ideological and political education,thereby elevating the teaching quality of these courses.Additionally,it leverages the synergistic role of coursework and ideology in educating students,ultimately enhancing the quality and level of talent cultivation.Hence,this paper proposes strategies for constructing a“microideological and political”model within the context of ideological and political teaching reforms in bidding and contract management courses,inviting discussion and exchange on this topic.
基金Supported by the Research Project of Humanities and Social Sciencesat Universities(08KN020) launched by Guizhou Provincial Education Department
文摘From the perspective of civil subject theory,law of value,comparative law and history of laws,the thesis expounds that the contract on the transfer of the contractual right of rural lands is in nature a civil contract instead of an administrative one.Then it explores the defects in the contract from the viewpoint of legal value goal,contract law and legal sociology,that is,the relevant provisions in Rural Land Contract Law and Explanations of Supreme People's Court about the Issues concerning the Laws Applicable to the Trial of Cases of Disputes over Rural Land Contracting go against the principle of free contracting and run counter to the legal value goal of justice,so they do not achieve good implementing effect.Finally,the thesis demonstrates and makes some practical legislative proposals to perfect the contract system for circulation of the right to operate constructed rural lands,aiming at improving the circulation rate through perfecting the contract of the right to rural land contractual management,solving the disputes in rural lands circulation and safeguarding the legitimate rights of the farmers.
文摘The realty(real estate)management of ownership of buildings includes the owner(homeowner)entrust-management and the owner self-management,the former through the way of realty service contracts,the latter through the resolution of the owners’assembly and the owners’committee.The legal disputes of realty service contracts involve balancing interests among the realty service enterprise,individual owner,and all the owners.We should use dynamic balancing of the interests of the three parties to implement the interests of the win-win cooperation rather than the interests of the trade-off of“all or nothing.”The realty service contract is similar to the entrustment contract,both of which are based on the owners’entrustment.The duty to provide realty service is not simply equivalent to fiduciary duty.The realty service contract has the essence of both behavior debt and result debt.For the former,the general provisions of the entrustment contract can be referred to,and for the latter,the general provisions of the contract for work can be referred to.In view of the group characteristics of the realty service contract,owners have no right to terminate the realty service contract at any time but should obey the principle of due process and take the majority mechanism to make a dismissal resolution resolution.The resolutions and management stipulations worked out by the owners’assembly in a majority mechanism,both of which belong to resolution behavior and are legal tools of the owners’autonomy,shall be binding on all the owners.The relationship between the owner,the owner’s assembly,and the owner’s committee is similar to the fiduciary relationship.If the decision made by the owners’assembly or the owners’committee and the management stipulation infringes upon the legal rights and interests of the owners,the injured owner has the right to revocation litigation.At present,residential commodity owners have a relatively low degree of autonomy in China,and legal disputes over realty services are frequent.In the future,we need to perfect the legal incentive and constraint measures,and stimulate the vitality of owner autonomy to promote better implementation of the owner self-management and owner entrust-management.
文摘Effective cost control in the investment and design phases of highway construction is crucial for managing project expenses.However,current management practices often overlook pre-construction cost management,leading to budget overruns and project delays during later stages.To ensure the smooth execution and cost control of highway construction projects,this paper examines the significance of cost control,evaluates the current state and challenges of highway construction,and proposes strategies for cost management.These strategies aim to establish a robust foundation for cost management in highway projects.
基金support provided by the National Natural Science Foundation of China(Grant No.52362055)the Science and Technology Plan Project of Guangxi Zhuang Autonomous Region(Grant No.2021AC19334)Guangxi Science and Technology Major Program(Grant No.AA23062053).
文摘To provide a much more resilient transport scheme for tractor and trailer transportation systems,this paper explores the generation method of tractor and trailer transport schemes considering the influence of disrupted events.Three states of tractors including towing loaded trailers,towing empty trailers,and idle driving are taken into account.Based on the disruption management theory,a scheduling model is constructed to minimize the total deviation cost including transportation time,transportation path,and number of used vehicles under the three states of tractors.A heuristics based on the contract net and simulated annealing algorithm is designed to solve the proposed model.Through comparative analysis of examples with different numbers of newly added transportation tasks and different types of road networks,the performance of the contract net algorithm in terms of deviations in idle driving paths,empty trailer paths,loaded trailer paths,time,number of used vehicles,and total deviation cost are analyzed.The results demonstrate the effectiveness of the model and algorithm,highlighting the superiority of the disruption management model and the contract net annealing algorithm.The study provides a reference for handling unexpected events in the tractor and trailer transportation industry.
文摘1. Introduction With the opening ceremony of the Gotthard Base Tunnel on 1 June 2016, a new world record was established: the commissioning of the longest railway tunnel in the world. Many challenges have been overcome and many technical innovations have been developed and considered in this project. As of 11 December 2016, the Gotthard Base Tunnel has been an integral part of the new timetable of the Swiss Federal Railways (SBB-CFF-FFS), and is in full operation. With a total length of 57 km and a cruising speed of 200 km·h^-1 for passenger trains, the Gotthard Base Tunnel reduces the journey time through the Alps by 40 min, significantly reducing the distance between the south and north of Europe.
基金Supported by Guangxi Philosophy and Social Science Project in 2011(11CJY001)Research Project of Guangxi Department of Education(201106LX628)
文摘The mortgage of land contract management rights has launched a pilot project in Ningxia,Hubei,Henan,Guizhou,Chongqing and other provinces,municipalities and autonomous regions,which provides a good solution to the problem of funds for rural development and plays a huge role in promoting local rural economic development.In the mortgage financing of land contract management rights implemented in various regions,how to determine a scientific,accurate and reasonable mortgage rate of land contract management rights becomes a difficulty troubling the mortgage financing of land.On the basis of unified annual output value of land,this article uses survey method,income capitalization method,and comparison method to analyze the value of land contract management rights,and finally determine the mortgage rates of land contract management rights.
文摘This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer (4-1-4), an initial herbicide (Pasture Gard, Dow Agro) application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza (L.) Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.
文摘Four directions for grassland management are set out under the Common Agricultural Policy: the existing, environmental, productional and integrated. The aim of this work is to demonstrate the agreement of production potential of grassland with the strategy of the CAP on the background of commodity milk production. This work is connected with randomly selected 1656 farms from the north-eastern part of the Lublin province remaining the dairy cattle. Source material for analysis was derived from the evaluation reports of dairy farms and the datas of Voivodeship Statistical Office. Taken the average annual milk production and surface of permanent grasslands, were divided into three groups of management direction: I- existing, II- integrated, III- productional In a separate II group of this management, three subgroups were identified dependent on the volume of milk production: A-(20-50), B-(50-100), C-(100-350) thousand of liters. In the studied farms the participation of grasslands in the structure of agriculture fanning lands was significantly higher than the average in the region as well as in the country. The largest research group accounted 49.5% of farms producing 20-50 thousand liters of milk with an average area of 21.23 ha and sustained an average of 9.8 cows. Large proportion of permanent grassland in the structure of agricultural lands and large stocking density per 100 ha of grasslands in northeast farms of Lublin province indicate significant intensification of feed production on the farmlands.
文摘In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management of the contract, can promote the reasonable and balanced investment cost allocation in the quality and safety and other aspects of the project, so that the construction project can obtain higher added value, and to further promote China' s economic construction and accelerate the pace of the city. This paper first briefly elaborates our construction project cost of the contract management on the present situation, and some problems are analyzed and discussed, and then puts forward some suggestions on the measures and countermeasures for cost management of construction engineering contract.
文摘In the colleges and universities, the relationship between the instructors and the students is very close. The counselors carry out the scientific and reasonable management on the life and learning of the students, and the students meet with the problems in their life and learning and exchange and communicate timely with the counselors, which is the process to realize the functions of the counselors. Then the management of the instructors built on the psychological contract is the more perfect, comprehensive, and scientific management mode. This kind of the management mode is not only very conducive to the development of the students, but also conducive to the interaction and communication between the counselors and the students. In a relaxed and harmonious atmosphere, the student's development will be more healthy and positive. This paper elaborates and analyzes several aspects in view of the management of the psychological contract of the university counselors.
文摘In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, but also has an important role in the coordination and stability of the whole system of public security colleges and universities. Based on the theory of Psychological Contract, this paper expounds the basic understanding and research value of Psychological Contract, and puts forward the measures to cultivate teachers' good character and understanding, and as well as coordinate teachers' needs, effectively change teachers' attitude and actively promote the establishment of good interpersonal relationship to explain the research on the Management Mechanism of Teachers in Public Security Colleges and Universities from the Perspective of Psychological Contract.
文摘The psychological contract is a set of personal beliefs about the reciprocal obligations and rights established in an exchange relationship,and high-level fulfillment of psychological contract helps the development of a team.This study summarizes the concept and theoretical basis of psychological contract,the influencing factors and intervention status of nurse psychological contract,and constructs a psychological contract intervention model to provide reference and reference for better construction and management of nursing teams.
文摘The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the total land area (FAO,1990). Grassland can provide feed for herbivore and produce high-quality food,clothing,medicines and industrial materials for man.On the other hand,it also plays an important role in the fertility of the soil,the conservation of water, the improvement of the environment and maintaining the ecological balance of the Earth’s surface.
基金COMAC management system innovation model research(NAEK0001)Humanities and social sciences planning project of the Ministry of Education(12YJA630008)
文摘The main manufacturer and its suppliers' relationship management is very important for success of the large aircraft project. The study concentrates on analysis of the relationship management on a psychological con- tract perspective, shows that constructing good psychological contract is useful to promote mutual trust, reduce the transaction cost caused by incompleteness of formal contract, avoid the risk of supplier management between the main manufacturer and suppliers of the large aircraft project. And with further understanding of the dynamic contracting process as well as formation framework of psychological contract between the main manufacturer and suppliers, we can better understand the relationship black-box and provide a new perspective for the study of the relationship management, then given some constructive suggestions to supplier relationship management.
基金financially supported by the National Natural Science Foundation of China(Grant No.41761144081)Second Tibetan Plateau Scientific Expedition and Research(Grant No.2019QZKK0603)Strategic Priority Research Program of the ChineseAcademyofSciences(GrantNo.XDA20040201)。
文摘Land change is a cause and consequence of global environmental change.Land use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major international research projects.This study interprets land use and land cover status and the changes within the Koshi River Basin(KRB)using Landsat remote sensing(RS)image data,and employs logistic regression model to analyze the influence of natural and socioeconomic driving forces on major land cover changes.The results showed that the areas of built-up land,bare land and forest in KRB increased from 1990 to 2015,including the largest increases in forest and the highest growth rate in construction land.Areas of glacier,grassland,sparse vegetation,shrub land,cropland,and wetland all decreased over the study period.From the perspective of driving analysis,the role of human activities in land use and land cover change is significant than climate factors.Cropland expansion is the reclamation of cropland by farmers,mainly from early deforestation.However,labor force separation,geological disasters and drought are the main factors of cropland shrinkage.The increase of forest area in India and Nepal was attributed to the government’s forest protection policies,such as Nepal’s community forestry has achieved remarkable results.The expansion and contraction of grassland were both dominated by climatic factors.The probability of grassland expansion increases with temperature and precipitation,while the probability of grassland contraction decreases with temperature and precipitation.
基金financed by the Ministry of Science and High Education of the Republic of Poland(No.BM–4162/15,4175/17 and DS3337/KEKiOP)
文摘The soil biological activity of mountain meadows is a significant factor that determines the health and utility of these regions. The climax stage of this area is forest, but to maintain semi-natural grassland, which is characterised by high biodiversity,low-intensity land use(mowing or grazing) is necessarily required. To understand the effect of various mowing regimes on the soil biological activity and plants, the soil microbial activity(microbial biomass carbon, dehydrogenase activity and number of the cultivable fraction of soil microbial community),annelids community(density and species composition earthworms and enchytraeids) and plant species composition were investigated. The study area was located in the Pieniny National Park in the Carpathian Mountains, in a meadow belonging to the association Dactylis glomerata-Poa trivialis. The investigated variants were divided according to mowing regime:traditional scything – hand mowing(HM), mechanical mowing(MM), or the abandonment of mowing – nonmowing(NM). The microbial activities(expressed by,e.g. microbial biomass carbon and the number of phosphorus bacteria) were affected by the mowing regime. The density of earthworms was higher in the HM and MM than in the NM variants. The largest changes in plant species composition were caused by the abandonment of mowing(NM). The mean number of plant species was positively correlated with soil moisture, earthworm density, and microbial activity(expressed indirectly by dehydrogenases activity). The soil microbial community, such as vegetative bacteria forms and ammonifying bacteria,were positively associated with pH value, and the microbial and total organic carbon content. The results presented here indicate that there is no single form of optimal management for all living organisms.Decisions about mowing regimes, or abandonment of use, should be preceded by multi-aspect studies,including plants and soil biota.
文摘The status quo and significance of contract and management right transfer of rural land are analyzed,and major problems existed in contract and management right transfer of rural land in Anhui Province are studied,containing unsound transfer market,insufficient flow demand motion,single transfer form,non-standard register,right determination and certificate issuing. On this basis,several policies and suggestions are proposed,such as combining practical use with suitable use of land right determination and certificate issuing,establishing multilayer rural social security system and expanding land management range.
基金funded by Dolomiti Bellunesi National Park in the context of European‘Habitat’directive 92/43/CEE monitoringfunding provided by Universitàdegli Studi di Pavia within the CRUI-CARE Agreement。
文摘The sword lily Gladiolus palustris Gaudin is protected on European level and listed in Annexes II and IV of the EC Habitat Directive 92/43/EEC.It grows in nutrient-poor,calcareous meadows in central and eastern Europe.Tree encroachment in montane meadows of the European Alps as a result of recent land use changes and the abandonment of traditional farming practices threaten the survival of this species.Conservation-driven mowing is considered a feasible conservation measure for maintaining high species diversity in abandoned semi-natural grasslands.To assess the effects of tenyears of biennial mowing on a grassland community in the Dolomiti Bellunesi National Park,Italy(Site of Community Importance,Natura 2000 network),ten25 m2 plots were established whereby four plots were placed in the mowed area,four in the non-mowed area and two in a small non-mowed patch of grassland inside the mowed area.In each plot the following variables were recorded,total percentage of plant cover,percentage cover of woody species,percentage cover of herbaceous species,percentage cover and number of flowering ramets of G.palustris and a complete list of species and their percentage abundance.Mowed plots showed a higher species richness than non-mowed plots.The number of G.palustris flowering ramets and percentage cover increased manifold in mowed plots compared to nonmowed plots.The resumption of mowing forconservation purposes undertaken by the managing authority halted the process of tree encroachment and avoided a drastic change in plant composition.Periodic mowing(every second or third year)was demonstrated to be a cost-effective conservation measure in non-productive grasslands to keep grasses at bay in favour of forbs of high conversation value.