A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear so...A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear soil model, and they are described in the form of S-function to enhance the calculation efficiency and simulation accuracy. Finally, the interaction of truck and soil is simulated by Adams-Maflab co-simulation to study the influence of soft terrain on the ride comfort of vehicles. The co-simulation results reveal that the terrain properties have a great influence on the ride comfort of vehicles as well as driving speed, road roughness and cargo weight. This co-simulation model is convenient for adding the factor of terrain deformation to the analysis of vehicle ride comfort. It can also be used to optimize suspension system parameters especially for off-road vehicles.展开更多
The conventional long-offset nonhyperbolic moveout equation is derived for the transverse isotropic media with a vertical symmetric axis(VTI).It cannot be extended to the transverse isotropic media with an arbitrary...The conventional long-offset nonhyperbolic moveout equation is derived for the transverse isotropic media with a vertical symmetric axis(VTI).It cannot be extended to the transverse isotropic media with an arbitrary spatial orientation of symmetry axis(ATI).In this paper,we optimize a modified long-offset nonhyperbolic moveout equation for ATI media based on the conventional nonhyperbolic moveout equation and the exact analytical solution of the quartic moveout coefficient(A_4) and NMO velocity for ATI media that were derived in our previous work.Compared with the exact traveltimes of the ray-tracing algorithm for anisotropic media,this optimized equation can be used to calculate the traveltime varying with survey line azimuth in arbitrary strong or weak ATI media.It can replace the time-consuming, multi-offset,and multi-azimuth ray tracing method for forward modeling of long-offset reflection traveltimes in ATI media,which is useful to further anisotropic parameter inversion using long-offset nonhyperbolic moveout.展开更多
The importance of solving the employment problems by nongovernmental economy in China has aroused the concern of many scholars widely. However, few literatures could be found to deal with the impacts on nonagricultura...The importance of solving the employment problems by nongovernmental economy in China has aroused the concern of many scholars widely. However, few literatures could be found to deal with the impacts on nonagricultural employment growth in China by nongovernmental economy from several levels such as the whole nation, urban and rural. Based on the research accessed on the relationships between nongovernmental economy and em-ployment, the impacts of the development of nongovernmental economy on non-agricultural employment growth in China are emphasized in this paper. Taking time series data of non-agricultural employment in China’s different economy types in 1992–2005 as study objects, by establishing econometric re-gression models, some meaningful points are found as follows, the impacts of nongovernmental economy on the nonagricultural employment in either national or urban-rural level are rather sig-nificant although their impacts’ degrees are different. Based on the research findings above, some countermeasures are proposed to accelerate the nongovernmental economic development and im-prove its ability to absorb nonagricultural employment.展开更多
Based on long-term monitoring data, the relationships between permafrost degradation and embankment deformation are analyzed along the Qinghai-Tibet Highway(QTH). Due to heat absorbing effect of asphalt pavement and c...Based on long-term monitoring data, the relationships between permafrost degradation and embankment deformation are analyzed along the Qinghai-Tibet Highway(QTH). Due to heat absorbing effect of asphalt pavement and climate warming,permafrost beneath asphalt pavement experienced significant warming and degradation. During the monitoring period, warming amplitude of the soil at depth of 5 m under asphalt ranged from 0.21 °C at the XD1 site to 0.5 °C at the KL1 site. And at depth of 10 m, the increase amplitude of ground temperature ranged from 0.47 °C at the NA1 site to 0.07 °C at the XD1 site. Along with ground temperature increase, permafrost table beneath asphalt pavement decline considerably. Amplitude of permafrost table decline varied from 0.53 m at the KL1 site to 3.51 m at the NA1 site, with mean amplitude of 1.65 m for 8 monitoring sites during the monitoring period. Due to permafrost warming and degradation, the embankment deformation all performed as settlement at these sites. At present, those settlements still develop quickly and are expected to continue to increase in the future. The embankment deformations can be divided into homogeneous deformation and inhomogeneous deformation. Embankment longitudinal inhomogeneous deformation causes the wave deformations and has adverse effects on driving comfort and safety, while lateral inhomogeneous deformation causes longitudinal cracks and has an adverse effect on stability. Corresponding with permafrost degradation processes,embankment settlement can be divided into four stages. For QTH, embankment settlement is mainly comprised of thawing consolidation of ice-rich permafrost and creep of warming permafrost beneath permafrost table.展开更多
A complete geometric nonlinear formulation for rigid-flexible coupling dynamics of a flexible beam undergoing large overall motion was proposed based on virtual work principle, in which all the high-order terms relate...A complete geometric nonlinear formulation for rigid-flexible coupling dynamics of a flexible beam undergoing large overall motion was proposed based on virtual work principle, in which all the high-order terms related to coupling deformation were included in dynamic equations. Simulation examples of the flexible beam with prescribed rotation and free rotation were investigated. Numerical results show that the use of the first-order approximation coupling (FOAC) model may lead to a significant error when the flexible beam experiences large deformation or large deformation velocity. However, the correct solutions can always be obtained by using the present complete model. The difference in essence between this model and the FOAC model is revealed. These coupling high-order terms, which are ignored in FOAC model, have a remarkable effect on the dynamic behavior of the flexible body. Therefore, these terms should be included for the rigid-flexible dynamic modeling and analysis of flexible body undergoing motions with high speed.展开更多
This article analyzes the form and the mechanism of non-public forestry's institution obstacles by classical economies, institution economics', legal economics and economic theories of modern forestry. Regarding the...This article analyzes the form and the mechanism of non-public forestry's institution obstacles by classical economies, institution economics', legal economics and economic theories of modern forestry. Regarding the proprietary institution as the core, and cost-income as the main clewf-it defines the concept and eategory, of non-public forestry subsidy and compensation. And oecorrling to the relased control and efficiency principle of market econonf-this paper establishes a set of institution that accords with the development of non-public forestry, offers both theoretical supports and decision- making references to remove institution obstacles of nan-public forestry, and coordinates the policies of non-public forestry with those of the public-owned forestry.展开更多
Nonlinear modeling of a flexible beam with large deformation was investigated. Absolute nodal cooridnate formulation is employed to describe the motion, and Lagrange equations of motion of a flexible beam are derived ...Nonlinear modeling of a flexible beam with large deformation was investigated. Absolute nodal cooridnate formulation is employed to describe the motion, and Lagrange equations of motion of a flexible beam are derived based on the geometric nonlinear theory. Different from the previous nonlinear formulation with Euler-Bernoulli assumption, the shear strain and transverse normal strain are taken into account. Computational example of a flexible pendulum with a tip mass is given to show the effects of the shear strain and transverse normal strain. The constant total energy verifies the correctness of the present formulation.展开更多
The parameters are considered as normal random quantities in filtering and prediction, and the observation equations usually are nonlinear ones. The nonlinear equations should be deployed in Taylor抯 formula, adopting...The parameters are considered as normal random quantities in filtering and prediction, and the observation equations usually are nonlinear ones. The nonlinear equations should be deployed in Taylor抯 formula, adopting to first power of term, by linear static filtering and prediction, and transformed into linear equations, and then the tested estimating values and their variances according to some statistical methods such as maximum tested estimation. The formulas of nonlinear static filtering and prediction, adapting to quadratic and cross terms by Taylor抯 progression formula, and the compu-tation formulas were also deduced that filtering the corresponding function nonlinear sig-nals and predicting the signals with nonlinear function. Meanwhile, it is been testified that the formula of static filtering and prediction is a special case of nonlinear filtering formulas.展开更多
The objective of this study entails the review and assessment of the relevance of existing and draft policies and legislation that affects the Non-timber Forest Products (NTFP) sector in Swaziland. A hierarchical me...The objective of this study entails the review and assessment of the relevance of existing and draft policies and legislation that affects the Non-timber Forest Products (NTFP) sector in Swaziland. A hierarchical method of policy and legislation review and analysis was devised for this study. Findings indicated that most national policies and legislation are outdated and old-fashioned, with gaps and overlaps, and there is lack of collaboration between institutions implementing these. The present national forest policy does not adequately guide the development of NTFPs. As a consequence, whilst international policies and legislation capture an excellent spectrum of elements and issues on NTFPs they still remain difficult to implement. However, national level criteria and indicators have issues and elements that are relevant to the sustainable use of NTFPs. It was recommended that national strategies, action plans, policies and legislation be reviewed and updated. The study shows that there are no existing institutional networks or formal collaboration between the institutions involved in the implementation of local, national, regional, and international policies and legislation that affect NTFPs. Government, private sector, Non-Governmental Organizations (NGO's), communities, individuals, and all concerned agencies should jointly develop and implement policies and legislation to provide secure access and benefits to people whose livelihood depends on/is supplemented by NTFPs and further foster networking and collaboration. The immediate adoption and implementation of the 11 policy recommendations on the sustainable management of Non-timber Forest Resources compiled by the Secretariat of the Convention on Biodiversity (CBD) from the Convention on Biological Diversity is highly recommended. It is worthwhile to note that while some of the 11 recommendations were directly inherited from certain articles of the CBD some are general recommendations.展开更多
This paper first describes the importance of using location specific S-N curves for fatigue damage assessment of existing steel structures. It discusses the existing concepts and methods for developing S-N curves usin...This paper first describes the importance of using location specific S-N curves for fatigue damage assessment of existing steel structures. It discusses the existing concepts and methods for developing S-N curves using empirical formulae and monotonic strength parameters, such as the ultimate tensile strength and hardness. It also discusses relationships among these monotonic parameters. Then it presents formulae for developing hardness-based full range S-N curves for medium strength steels. The formulae are verified using experimental data obtained from both monotonic and cyclic testing. Finally, it describes the advantages of these hardness-based formulae for developing location specific S-N curves as hardness testing is a non-destructive test which can be carried out on specific locations in structures.展开更多
The assessment of the policy framework governing Invasive Alien Species(IAS) control is of critical importance in conservation. The undertaking of a SWOT analysis of such a framework is necessary because it enhances t...The assessment of the policy framework governing Invasive Alien Species(IAS) control is of critical importance in conservation. The undertaking of a SWOT analysis of such a framework is necessary because it enhances the efficacy of IAS control. The aim of this study is to carry out a SWOT analysis of the policy framework guiding the control of the spreading of Acacia mearnsii and other IAS in the Golden Gate Highlands National Park in South Africa,as well as the implementation of restorative measures in the park and adjacent communities in line with the recommendations of the Convention on Biodiversity. A comparative analysis of this framework and the hierarchical framework that was developed during the European Union Conference on Freshwater Invasives- Networking for Strategy in 2013 is undertaken. The results indicate the need to strengthen parkcommunity relations,upgrade existing legislation,and boost the technical capacity of South African national parks to identify,detect,monitor and predict IAS invasions,both within the parks and their surroundings. This knowledge is important for developing future policies on IAS control in South Africa.展开更多
The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was ...The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was analyzed and calculated in this paper.The temperature rise due to the heat leak along the transfer pipeline was calculated by the simplified equation and was modified by considering the negative Joule-Thomson effect.The modified results were compared with the temperature rise obtained by non-linear differential equations with consideration of the pressure gradient.The results show that the pressure gradient has strong effect on the temperature distribution.The modified results are in good agreement with the values calculated by the complicated equation,which verifies the effectiveness of the simplified equation in calculating the temperature rise when the negative JT effect of He Ⅱ is known.展开更多
The Albertine Graben is one of the most petroliferous onshore rifts in Africa. It forms the northemmost termination of the western arm of the East African Rift System. Its surface exposures were first studied by Wayla...The Albertine Graben is one of the most petroliferous onshore rifts in Africa. It forms the northemmost termination of the western arm of the East African Rift System. Its surface exposures were first studied by Wayland [1] and Pickford et al. [2] among others. Pickford et al. [2] especially developed the basic stratigraphic framework of the graben which was later modified by the government geoscientists and international oil companies using subsurface data. However, the stratigraphic units were not fully and formally described, and have been used informally in different and often confusing ways. The current study therefore aims to solve this challenge by establishing a coherent stratigraphic scheme for the entire graben through an integral study of surface and subsurface data. The study involves precise description of the type and reference sections for various formations both in exposure and wells; and has therefore led to the development of lithostratigraphic columns of different basins in the graben. The approach reveals that the Semliki area, south of Lake Albert, has the most complete sedimentary succession in the graben, spanning the period from middle Miocene (ca 15 Ma) to Recent. It also reveals that platform deposits, which form a small fraction of the thickness of the basinal succession, represent a highly condensed sequence which only saw deposition at times of Lake highstand.展开更多
For the last decade, discussions about who governs policy on prevention and treatment of HIV/AIDS have revolved around the controversial relationship between Western donors and the power they have over their recipient...For the last decade, discussions about who governs policy on prevention and treatment of HIV/AIDS have revolved around the controversial relationship between Western donors and the power they have over their recipient governments. While these debates were once politically germane, recent trends show a decline of donor funding, as well as an increase of financial ownership of the epidemic within Southern Africa. Commensurate with this shifting financial influence, some well-governed, wealthy African states are beginning to deviate from global M&E (monitoring and evaluation) indicators. These policy movements, away from global M&E indicators, also correlate with increases in HIV prevalence, which signals the need for further investigation into policy efficacy.展开更多
In general, it can be argued that institutional framework a country or region designs plays a significant role in crafting, applying or even success of public policy. Drawing lessons from how Asia exploited the develo...In general, it can be argued that institutional framework a country or region designs plays a significant role in crafting, applying or even success of public policy. Drawing lessons from how Asia exploited the developmental state's concept by designing institutions which targeted key public policy areas such as education, health, domestic savings, and rural development, or aligned infrastructures such as roads, transport and ports, to drive economic development. The paper explores how this approach can be applied in sub-Saharan Africa (or individual countries). The objective is to extricate constant factors impacting development both in ahistorical and atemporal terms. The investigation is guided by the key question: whether quality of institutions and institutional analysis can help explain development failures in Africa? Hence, on one part, it probes institutions, institution-making, public policy making and what uniquely the Asian developmental state did that can help illuminate institutional role in policymaking and application. In pursuing this objective, the paper is cognisant of the question by Brousseau et al. asked, regarding generalizability of institutional capabilities, "If growth-enhancing institutions are identified in a specific country, can other countries learn from and transplant these". The investigation concludes that in public policy and development strategy-making institutions do matter as they delimit or even help create possibilities necessary for development and its sustenance, and to a certain extent, they are the vital constant (factors) that explains development differentiations in different geographic spaces or time periods.展开更多
During the course of the last years the need for the increase in the electric energy production in Brazil as well as in the rest of the world, has raised the tone of the debate about the environment impact of such pro...During the course of the last years the need for the increase in the electric energy production in Brazil as well as in the rest of the world, has raised the tone of the debate about the environment impact of such production. As a result of these debates, both the several levels of government and some of the NGOs (Non-Governmental Organizations) have commissioned innumerous opinion researches aiming at measuring and evaluating the knowledge and perception of the public in relation of the best non-polluting energy sources. Prior to 2001 these researches would not make any sense in Brazil., however due to that year's drought, the competent authorities were faced with the necessity of developing a plan, the PNE2030 (Piano Nacional de Energia) aiming, among others objectives, at finalizing the construction of the Angra three plants and implementing new nuclear plants in places still to be determined. Allowing for the complexity of the subject, this paper presents a field research conducted from September 28th, 2010 to October 28th, 2010 assessing the current level of perception of the Brazilian population about the nuclear area, in particular of the residents of three cities of Rio de Janeiro. As a result of this work, the authors suggest how the competent authorities should proceed to reach in an efficient manner a greater understanding of the population about the proposed subject, through communication campaigns being both informative and educational.展开更多
基金The National Natural Science Foundation of China(No.50575040)the Natural Science Foundation of Jiangsu Province(No.BK2007112)
文摘A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear soil model, and they are described in the form of S-function to enhance the calculation efficiency and simulation accuracy. Finally, the interaction of truck and soil is simulated by Adams-Maflab co-simulation to study the influence of soft terrain on the ride comfort of vehicles. The co-simulation results reveal that the terrain properties have a great influence on the ride comfort of vehicles as well as driving speed, road roughness and cargo weight. This co-simulation model is convenient for adding the factor of terrain deformation to the analysis of vehicle ride comfort. It can also be used to optimize suspension system parameters especially for off-road vehicles.
基金the National Natural Science Foundation of China(Grant No.40874028)the Special Fund (Grant No.2008ZX05008-006-004).
文摘The conventional long-offset nonhyperbolic moveout equation is derived for the transverse isotropic media with a vertical symmetric axis(VTI).It cannot be extended to the transverse isotropic media with an arbitrary spatial orientation of symmetry axis(ATI).In this paper,we optimize a modified long-offset nonhyperbolic moveout equation for ATI media based on the conventional nonhyperbolic moveout equation and the exact analytical solution of the quartic moveout coefficient(A_4) and NMO velocity for ATI media that were derived in our previous work.Compared with the exact traveltimes of the ray-tracing algorithm for anisotropic media,this optimized equation can be used to calculate the traveltime varying with survey line azimuth in arbitrary strong or weak ATI media.It can replace the time-consuming, multi-offset,and multi-azimuth ray tracing method for forward modeling of long-offset reflection traveltimes in ATI media,which is useful to further anisotropic parameter inversion using long-offset nonhyperbolic moveout.
基金The paper was sponsored by the National Social Science Foundation for Key Projects (Grant No. 07&ZD011)EU INCO-DEV (SUSDEV-CHINA) (Grant No. ICA4-CT-2002- 10004).
文摘The importance of solving the employment problems by nongovernmental economy in China has aroused the concern of many scholars widely. However, few literatures could be found to deal with the impacts on nonagricultural employment growth in China by nongovernmental economy from several levels such as the whole nation, urban and rural. Based on the research accessed on the relationships between nongovernmental economy and em-ployment, the impacts of the development of nongovernmental economy on non-agricultural employment growth in China are emphasized in this paper. Taking time series data of non-agricultural employment in China’s different economy types in 1992–2005 as study objects, by establishing econometric re-gression models, some meaningful points are found as follows, the impacts of nongovernmental economy on the nonagricultural employment in either national or urban-rural level are rather sig-nificant although their impacts’ degrees are different. Based on the research findings above, some countermeasures are proposed to accelerate the nongovernmental economic development and im-prove its ability to absorb nonagricultural employment.
基金Project(2012CB026106) supported by National Basic Research Program of ChinaProject(2014BAG05B01) supported by National Key Technology Support Program China+1 种基金Project(51Y351211) supported by West Light Program for Talent Cultivation of Chinese Academy of SciencesProject(2013318490010) supported by Ministry of Transport Science and Technology Major Project,China
文摘Based on long-term monitoring data, the relationships between permafrost degradation and embankment deformation are analyzed along the Qinghai-Tibet Highway(QTH). Due to heat absorbing effect of asphalt pavement and climate warming,permafrost beneath asphalt pavement experienced significant warming and degradation. During the monitoring period, warming amplitude of the soil at depth of 5 m under asphalt ranged from 0.21 °C at the XD1 site to 0.5 °C at the KL1 site. And at depth of 10 m, the increase amplitude of ground temperature ranged from 0.47 °C at the NA1 site to 0.07 °C at the XD1 site. Along with ground temperature increase, permafrost table beneath asphalt pavement decline considerably. Amplitude of permafrost table decline varied from 0.53 m at the KL1 site to 3.51 m at the NA1 site, with mean amplitude of 1.65 m for 8 monitoring sites during the monitoring period. Due to permafrost warming and degradation, the embankment deformation all performed as settlement at these sites. At present, those settlements still develop quickly and are expected to continue to increase in the future. The embankment deformations can be divided into homogeneous deformation and inhomogeneous deformation. Embankment longitudinal inhomogeneous deformation causes the wave deformations and has adverse effects on driving comfort and safety, while lateral inhomogeneous deformation causes longitudinal cracks and has an adverse effect on stability. Corresponding with permafrost degradation processes,embankment settlement can be divided into four stages. For QTH, embankment settlement is mainly comprised of thawing consolidation of ice-rich permafrost and creep of warming permafrost beneath permafrost table.
基金Project(10772113) supported by the National Natural Science Foundation of China
文摘A complete geometric nonlinear formulation for rigid-flexible coupling dynamics of a flexible beam undergoing large overall motion was proposed based on virtual work principle, in which all the high-order terms related to coupling deformation were included in dynamic equations. Simulation examples of the flexible beam with prescribed rotation and free rotation were investigated. Numerical results show that the use of the first-order approximation coupling (FOAC) model may lead to a significant error when the flexible beam experiences large deformation or large deformation velocity. However, the correct solutions can always be obtained by using the present complete model. The difference in essence between this model and the FOAC model is revealed. These coupling high-order terms, which are ignored in FOAC model, have a remarkable effect on the dynamic behavior of the flexible body. Therefore, these terms should be included for the rigid-flexible dynamic modeling and analysis of flexible body undergoing motions with high speed.
基金Supported by Shanxi Provincial Soft Science (2004KR88)Shanxi Philosophical Social and Science Fund (04D023Z)
文摘This article analyzes the form and the mechanism of non-public forestry's institution obstacles by classical economies, institution economics', legal economics and economic theories of modern forestry. Regarding the proprietary institution as the core, and cost-income as the main clewf-it defines the concept and eategory, of non-public forestry subsidy and compensation. And oecorrling to the relased control and efficiency principle of market econonf-this paper establishes a set of institution that accords with the development of non-public forestry, offers both theoretical supports and decision- making references to remove institution obstacles of nan-public forestry, and coordinates the policies of non-public forestry with those of the public-owned forestry.
基金National Natural Science Foundation ofChina (No.10472066,10372057)
文摘Nonlinear modeling of a flexible beam with large deformation was investigated. Absolute nodal cooridnate formulation is employed to describe the motion, and Lagrange equations of motion of a flexible beam are derived based on the geometric nonlinear theory. Different from the previous nonlinear formulation with Euler-Bernoulli assumption, the shear strain and transverse normal strain are taken into account. Computational example of a flexible pendulum with a tip mass is given to show the effects of the shear strain and transverse normal strain. The constant total energy verifies the correctness of the present formulation.
文摘The parameters are considered as normal random quantities in filtering and prediction, and the observation equations usually are nonlinear ones. The nonlinear equations should be deployed in Taylor抯 formula, adopting to first power of term, by linear static filtering and prediction, and transformed into linear equations, and then the tested estimating values and their variances according to some statistical methods such as maximum tested estimation. The formulas of nonlinear static filtering and prediction, adapting to quadratic and cross terms by Taylor抯 progression formula, and the compu-tation formulas were also deduced that filtering the corresponding function nonlinear sig-nals and predicting the signals with nonlinear function. Meanwhile, it is been testified that the formula of static filtering and prediction is a special case of nonlinear filtering formulas.
文摘The objective of this study entails the review and assessment of the relevance of existing and draft policies and legislation that affects the Non-timber Forest Products (NTFP) sector in Swaziland. A hierarchical method of policy and legislation review and analysis was devised for this study. Findings indicated that most national policies and legislation are outdated and old-fashioned, with gaps and overlaps, and there is lack of collaboration between institutions implementing these. The present national forest policy does not adequately guide the development of NTFPs. As a consequence, whilst international policies and legislation capture an excellent spectrum of elements and issues on NTFPs they still remain difficult to implement. However, national level criteria and indicators have issues and elements that are relevant to the sustainable use of NTFPs. It was recommended that national strategies, action plans, policies and legislation be reviewed and updated. The study shows that there are no existing institutional networks or formal collaboration between the institutions involved in the implementation of local, national, regional, and international policies and legislation that affect NTFPs. Government, private sector, Non-Governmental Organizations (NGO's), communities, individuals, and all concerned agencies should jointly develop and implement policies and legislation to provide secure access and benefits to people whose livelihood depends on/is supplemented by NTFPs and further foster networking and collaboration. The immediate adoption and implementation of the 11 policy recommendations on the sustainable management of Non-timber Forest Resources compiled by the Secretariat of the Convention on Biodiversity (CBD) from the Convention on Biological Diversity is highly recommended. It is worthwhile to note that while some of the 11 recommendations were directly inherited from certain articles of the CBD some are general recommendations.
文摘This paper first describes the importance of using location specific S-N curves for fatigue damage assessment of existing steel structures. It discusses the existing concepts and methods for developing S-N curves using empirical formulae and monotonic strength parameters, such as the ultimate tensile strength and hardness. It also discusses relationships among these monotonic parameters. Then it presents formulae for developing hardness-based full range S-N curves for medium strength steels. The formulae are verified using experimental data obtained from both monotonic and cyclic testing. Finally, it describes the advantages of these hardness-based formulae for developing location specific S-N curves as hardness testing is a non-destructive test which can be carried out on specific locations in structures.
基金the Afromontane Research Unit (ARU) for providing financial support for this study
文摘The assessment of the policy framework governing Invasive Alien Species(IAS) control is of critical importance in conservation. The undertaking of a SWOT analysis of such a framework is necessary because it enhances the efficacy of IAS control. The aim of this study is to carry out a SWOT analysis of the policy framework guiding the control of the spreading of Acacia mearnsii and other IAS in the Golden Gate Highlands National Park in South Africa,as well as the implementation of restorative measures in the park and adjacent communities in line with the recommendations of the Convention on Biodiversity. A comparative analysis of this framework and the hierarchical framework that was developed during the European Union Conference on Freshwater Invasives- Networking for Strategy in 2013 is undertaken. The results indicate the need to strengthen parkcommunity relations,upgrade existing legislation,and boost the technical capacity of South African national parks to identify,detect,monitor and predict IAS invasions,both within the parks and their surroundings. This knowledge is important for developing future policies on IAS control in South Africa.
基金Sponsored by the National Natural Science Foundation of China(Grant No.10872152)the Ministries and Commissions of Science and Technology of Shanghai Government (Grant No. 03DZ 14014) for Shanghai Jiaotong University
文摘The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was analyzed and calculated in this paper.The temperature rise due to the heat leak along the transfer pipeline was calculated by the simplified equation and was modified by considering the negative Joule-Thomson effect.The modified results were compared with the temperature rise obtained by non-linear differential equations with consideration of the pressure gradient.The results show that the pressure gradient has strong effect on the temperature distribution.The modified results are in good agreement with the values calculated by the complicated equation,which verifies the effectiveness of the simplified equation in calculating the temperature rise when the negative JT effect of He Ⅱ is known.
文摘The Albertine Graben is one of the most petroliferous onshore rifts in Africa. It forms the northemmost termination of the western arm of the East African Rift System. Its surface exposures were first studied by Wayland [1] and Pickford et al. [2] among others. Pickford et al. [2] especially developed the basic stratigraphic framework of the graben which was later modified by the government geoscientists and international oil companies using subsurface data. However, the stratigraphic units were not fully and formally described, and have been used informally in different and often confusing ways. The current study therefore aims to solve this challenge by establishing a coherent stratigraphic scheme for the entire graben through an integral study of surface and subsurface data. The study involves precise description of the type and reference sections for various formations both in exposure and wells; and has therefore led to the development of lithostratigraphic columns of different basins in the graben. The approach reveals that the Semliki area, south of Lake Albert, has the most complete sedimentary succession in the graben, spanning the period from middle Miocene (ca 15 Ma) to Recent. It also reveals that platform deposits, which form a small fraction of the thickness of the basinal succession, represent a highly condensed sequence which only saw deposition at times of Lake highstand.
文摘For the last decade, discussions about who governs policy on prevention and treatment of HIV/AIDS have revolved around the controversial relationship between Western donors and the power they have over their recipient governments. While these debates were once politically germane, recent trends show a decline of donor funding, as well as an increase of financial ownership of the epidemic within Southern Africa. Commensurate with this shifting financial influence, some well-governed, wealthy African states are beginning to deviate from global M&E (monitoring and evaluation) indicators. These policy movements, away from global M&E indicators, also correlate with increases in HIV prevalence, which signals the need for further investigation into policy efficacy.
文摘In general, it can be argued that institutional framework a country or region designs plays a significant role in crafting, applying or even success of public policy. Drawing lessons from how Asia exploited the developmental state's concept by designing institutions which targeted key public policy areas such as education, health, domestic savings, and rural development, or aligned infrastructures such as roads, transport and ports, to drive economic development. The paper explores how this approach can be applied in sub-Saharan Africa (or individual countries). The objective is to extricate constant factors impacting development both in ahistorical and atemporal terms. The investigation is guided by the key question: whether quality of institutions and institutional analysis can help explain development failures in Africa? Hence, on one part, it probes institutions, institution-making, public policy making and what uniquely the Asian developmental state did that can help illuminate institutional role in policymaking and application. In pursuing this objective, the paper is cognisant of the question by Brousseau et al. asked, regarding generalizability of institutional capabilities, "If growth-enhancing institutions are identified in a specific country, can other countries learn from and transplant these". The investigation concludes that in public policy and development strategy-making institutions do matter as they delimit or even help create possibilities necessary for development and its sustenance, and to a certain extent, they are the vital constant (factors) that explains development differentiations in different geographic spaces or time periods.
文摘During the course of the last years the need for the increase in the electric energy production in Brazil as well as in the rest of the world, has raised the tone of the debate about the environment impact of such production. As a result of these debates, both the several levels of government and some of the NGOs (Non-Governmental Organizations) have commissioned innumerous opinion researches aiming at measuring and evaluating the knowledge and perception of the public in relation of the best non-polluting energy sources. Prior to 2001 these researches would not make any sense in Brazil., however due to that year's drought, the competent authorities were faced with the necessity of developing a plan, the PNE2030 (Piano Nacional de Energia) aiming, among others objectives, at finalizing the construction of the Angra three plants and implementing new nuclear plants in places still to be determined. Allowing for the complexity of the subject, this paper presents a field research conducted from September 28th, 2010 to October 28th, 2010 assessing the current level of perception of the Brazilian population about the nuclear area, in particular of the residents of three cities of Rio de Janeiro. As a result of this work, the authors suggest how the competent authorities should proceed to reach in an efficient manner a greater understanding of the population about the proposed subject, through communication campaigns being both informative and educational.