Wetlands play an important ecological role and provide many functions for people, yet wetlands are cur- rently decreasing and deteriorating. The ability to calculate an economic value for the loss of wetlands is becom...Wetlands play an important ecological role and provide many functions for people, yet wetlands are cur- rently decreasing and deteriorating. The ability to calculate an economic value for the loss of wetlands is becoming in- creasingly important for policy makers. In this study, remote sensing, field investigations, department visits, and other methods were used to survey wetland types, assess wetland area changes, and calculate wetland economic value. Mar- ket value loss and ecological ftmction value loss, caused by reduction of wetland area and environmental pollution were calculated using commonly accepted methods of market valuation, ecological valuation, environmental protection investment cost analysis, and outcome parameters. According to market value loss and ecological function value loss, preliminarily fund allocation for wetland and ecological compensation was calculated. This will provide an important reference for future Yellow River Delta eco-compensation studies.展开更多
Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a hig...Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a high degree of uncertainty to the reserve estimation, and in consequence to the whole mine planning procedure. Real option approach is an efficient method of decision making in the uncertain conditions. This approach has been used for evaluation of defined natural resources projects until now. This study considering the metal price uncertainty used real option approach to prepare a methodology for reserve estimation in open pit mines. This study was done on a copper cylindrical deposit, but the achieved methodology can be adjusted for all kinds of deposits. This methodology was comprehensively described through the examples in such a manner that can be used by the mine planners.展开更多
Crohn's disease and ulcerative colitis evolve with a relapsing and remitting course.Determination of inflammatory state is crucial for the assessment of disease activity and for tailoring therapy.However,no simple...Crohn's disease and ulcerative colitis evolve with a relapsing and remitting course.Determination of inflammatory state is crucial for the assessment of disease activity and for tailoring therapy.However,no simple diagnostic test for monitoring intestinal inflammation is available.Noninvasive markers give only indirect assessments of disease activity.Histopathological or endoscopical examinations accurately assess inflammatory activity,but they are invasive,time consuming and expensive and therefore are unsuitable for routine use.Imaging procedures are not applicable for ulcerative colitis.The usefulness of ultrasound and Doppler imag-ing in assessing disease activity is still a matter of discussion for Crohn's disease,and an increased interest in computed tomography enterograph (CTE) has been seen,mainly because it can delineate the extent and severity of bowel wall inflammation,besides detecting extraluminal findings.Until now,the available data concerning the accuracy of magnetic resonance enterography in detecting disease activity is less than CTE.Due to this,clinical activity indices are still commonly used for both diseases.展开更多
Five multiparameter empirical criteria were exclusively evaluated by comparing them with the strength data covering various stress conditions to find out which failure criterion best fits the test data and describes t...Five multiparameter empirical criteria were exclusively evaluated by comparing them with the strength data covering various stress conditions to find out which failure criterion best fits the test data and describes the mechanical behavior of the salt rock sequence (halite,bedded composite specimens and anhydrite interlayers).Full-scale comparison of all criteria for the three rock types was conducted based on five standard statistics calculated from least squares curve-fitting,which measures both the goodness of fitting and the quality of future prediction.The results indicate that all five nonlinear criteria with a basic power form are efficient in predicting the strength trend in the low tension area as well as in the high compression area of the soft rocks.The parameters obtained for the bedded rock salt are somewhat in the ones for the "pure" rocks and are even closer to those obtained for the halite.The generalized Hoek-Brown criterion is proven to perform best to two rock strength data followed by one for the Bieniawski empirical criterion,thus is the best candidate for the analysis of the salt rock.The Sheorey empirical criterion consistently achieves an intermediate performance for all the three rocks.It seems that the superiority of the poly-axial criteria (the Mogi 1967 criterion and the N-type criterion) over the former three triaxial criteria no longer exists when applied to the conventional triaxial strength data.Besides,the method of tension cut-off was proposed to solve the ambiguity problem of the two poly-axial criteria in the tension field in the plane of the major (σ1) andminor principal stress (σ3).展开更多
Based on the in-depth study on the theory of tourism carrying capacity at home and abroad, author of this paper defined the concept and connotation of tourism carrying capacity, and proposed the evaluation index syste...Based on the in-depth study on the theory of tourism carrying capacity at home and abroad, author of this paper defined the concept and connotation of tourism carrying capacity, and proposed the evaluation index system of tourism carrying capacity. He also conducted a systematic analysis of tourism resources in the Jokhang Temple scenic spot, constructed an evaluation index system of tourism carrying capacity of the Jokhang Temple scenic spot, pointed out the status quo of its carrying capacity and factors constraining the carrying capacity through quantitative calculation, and put forward suggestions to regulate its carrying capacity.展开更多
Leaving ditches between adjacent mining areas can effectively reduce re-stripping in the latter mining area and simultaneously lead to an increment in internal dumping costs in the former mining area. This paper estab...Leaving ditches between adjacent mining areas can effectively reduce re-stripping in the latter mining area and simultaneously lead to an increment in internal dumping costs in the former mining area. This paper establishes calculation models for these two marginal costs. The optimizing model for slope cover height can be determined by including marginal cost models in the objective function. The paper has two main contributions:(a) it fully considers redistribution of dumping space in the model;(b) it introduces price fluctuations and cash discounts in the model. We use the typical open-pit mine as an example to test and prove the model. We conclude that a completely covered slope is reasonable in Haerwusu open pit mine; in addition to an increasing price index, the slope cover height can be reduced; and that price changes are one of the most important influencing factors of slope cover height optimization in an open-pit mine.展开更多
基金Under the auspices of Scientific and Technological Projects of Shandong Province (No. 2006GG2206019, 2007 GG30006002)National Natural Science Foundation of China (No.40901065)
文摘Wetlands play an important ecological role and provide many functions for people, yet wetlands are cur- rently decreasing and deteriorating. The ability to calculate an economic value for the loss of wetlands is becoming in- creasingly important for policy makers. In this study, remote sensing, field investigations, department visits, and other methods were used to survey wetland types, assess wetland area changes, and calculate wetland economic value. Mar- ket value loss and ecological ftmction value loss, caused by reduction of wetland area and environmental pollution were calculated using commonly accepted methods of market valuation, ecological valuation, environmental protection investment cost analysis, and outcome parameters. According to market value loss and ecological function value loss, preliminarily fund allocation for wetland and ecological compensation was calculated. This will provide an important reference for future Yellow River Delta eco-compensation studies.
文摘Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a high degree of uncertainty to the reserve estimation, and in consequence to the whole mine planning procedure. Real option approach is an efficient method of decision making in the uncertain conditions. This approach has been used for evaluation of defined natural resources projects until now. This study considering the metal price uncertainty used real option approach to prepare a methodology for reserve estimation in open pit mines. This study was done on a copper cylindrical deposit, but the achieved methodology can be adjusted for all kinds of deposits. This methodology was comprehensively described through the examples in such a manner that can be used by the mine planners.
文摘Crohn's disease and ulcerative colitis evolve with a relapsing and remitting course.Determination of inflammatory state is crucial for the assessment of disease activity and for tailoring therapy.However,no simple diagnostic test for monitoring intestinal inflammation is available.Noninvasive markers give only indirect assessments of disease activity.Histopathological or endoscopical examinations accurately assess inflammatory activity,but they are invasive,time consuming and expensive and therefore are unsuitable for routine use.Imaging procedures are not applicable for ulcerative colitis.The usefulness of ultrasound and Doppler imag-ing in assessing disease activity is still a matter of discussion for Crohn's disease,and an increased interest in computed tomography enterograph (CTE) has been seen,mainly because it can delineate the extent and severity of bowel wall inflammation,besides detecting extraluminal findings.Until now,the available data concerning the accuracy of magnetic resonance enterography in detecting disease activity is less than CTE.Due to this,clinical activity indices are still commonly used for both diseases.
基金Project(2009CB724608) supported by the National Basic Research Program of China
文摘Five multiparameter empirical criteria were exclusively evaluated by comparing them with the strength data covering various stress conditions to find out which failure criterion best fits the test data and describes the mechanical behavior of the salt rock sequence (halite,bedded composite specimens and anhydrite interlayers).Full-scale comparison of all criteria for the three rock types was conducted based on five standard statistics calculated from least squares curve-fitting,which measures both the goodness of fitting and the quality of future prediction.The results indicate that all five nonlinear criteria with a basic power form are efficient in predicting the strength trend in the low tension area as well as in the high compression area of the soft rocks.The parameters obtained for the bedded rock salt are somewhat in the ones for the "pure" rocks and are even closer to those obtained for the halite.The generalized Hoek-Brown criterion is proven to perform best to two rock strength data followed by one for the Bieniawski empirical criterion,thus is the best candidate for the analysis of the salt rock.The Sheorey empirical criterion consistently achieves an intermediate performance for all the three rocks.It seems that the superiority of the poly-axial criteria (the Mogi 1967 criterion and the N-type criterion) over the former three triaxial criteria no longer exists when applied to the conventional triaxial strength data.Besides,the method of tension cut-off was proposed to solve the ambiguity problem of the two poly-axial criteria in the tension field in the plane of the major (σ1) andminor principal stress (σ3).
文摘Based on the in-depth study on the theory of tourism carrying capacity at home and abroad, author of this paper defined the concept and connotation of tourism carrying capacity, and proposed the evaluation index system of tourism carrying capacity. He also conducted a systematic analysis of tourism resources in the Jokhang Temple scenic spot, constructed an evaluation index system of tourism carrying capacity of the Jokhang Temple scenic spot, pointed out the status quo of its carrying capacity and factors constraining the carrying capacity through quantitative calculation, and put forward suggestions to regulate its carrying capacity.
基金the key project of the National Natural Science Foundation of China (No. 51034005)the Research Fund for the Doctoral Program of Higher Education of China(No.20100095110019)+1 种基金the National‘‘Twelfth Five-Year’’Plan for Science and Technology Support of China(No.2014BAC14B00)the National High Technology Research and Development Program of China(No.2012AA062004)
文摘Leaving ditches between adjacent mining areas can effectively reduce re-stripping in the latter mining area and simultaneously lead to an increment in internal dumping costs in the former mining area. This paper establishes calculation models for these two marginal costs. The optimizing model for slope cover height can be determined by including marginal cost models in the objective function. The paper has two main contributions:(a) it fully considers redistribution of dumping space in the model;(b) it introduces price fluctuations and cash discounts in the model. We use the typical open-pit mine as an example to test and prove the model. We conclude that a completely covered slope is reasonable in Haerwusu open pit mine; in addition to an increasing price index, the slope cover height can be reduced; and that price changes are one of the most important influencing factors of slope cover height optimization in an open-pit mine.
