When artificial waterfalls are built in gardens,leaves from trees or vegetation often fall into the water storage pool and block the pipelines,requiring regular cleaning of pipelines.This not only increases the manpow...When artificial waterfalls are built in gardens,leaves from trees or vegetation often fall into the water storage pool and block the pipelines,requiring regular cleaning of pipelines.This not only increases the manpower needed for maintenance but also disrupts the use of the waterfalls.Therefore,it is necessary to design a new type of artificial waterfall that is suitable for gardens.The waterfall should incorporate features that make cleaning easier,including filter plates and water funnels to prevent clogging caused by fallen leaves and debris.展开更多
Many rivers in tropical and subtropical karst regions are supersaturated with respect to CaCO3 and have high water hardness. After flowing through waterfall sites, river water is usually softened, accompanied by tufa ...Many rivers in tropical and subtropical karst regions are supersaturated with respect to CaCO3 and have high water hardness. After flowing through waterfall sites, river water is usually softened, accompanied by tufa formation, which is simply described as a result of water turbulence in fast-flowing water. In this paper, a series of laboratory experiments are designed to simulate the hydrological conditions at waterfall sites. The influences of air-water interface, water flow velocity, aeration and solid-water interface on water softening are compared and evaluated on a quantitative basis. The results show that the enhanced inorganic CO2 outgassing due to sudden hydrological changes occurring at waterfall sites is the principal cause of water softening at waterfall sites. Both air-water interface area and water flow velocity increase as a result of the 'aeration effect', 'low pressure effect' and 'jet-flow effect' at waterfall sites, which greatly accelerates CO2 outgassing and therefore makes natural waters become highly supersaturated with respect to CaCO3, consequently resulting in much CaCO3 deposition and reduction of water hardness. Aeration, rapidly increasing air-water interface area and water flow velocity, proves to be effective in reducing water hardness. This study may provide a cheap, safe and effective way to soften water.展开更多
Previous work on the eastern side of Rocky Mountain National Park(RMNP),Colorado indicated correlations among waterfall location,waterfall morphology,and the characteristics of bedrock joints.Characteristics of waterf...Previous work on the eastern side of Rocky Mountain National Park(RMNP),Colorado indicated correlations among waterfall location,waterfall morphology,and the characteristics of bedrock joints.Characteristics of waterfalls on the western side of the national park do not correlate as strongly with joint geometry.Longitudinal river profiles on the western side are less concave and waterfalls account for a greater proportion of the total elevation loss.We interpret these differences to result from more widely spaced joints,lithological differences,and complex glacial history.These results demonstrate that waterfall shape and typology may change due to both local and regional controls operating in a mountain region.Both regions had alpine valley glaciers,but continued landscape evolution via fluvial erosion has developed waterfalls with diverse locations and morphologies that reflect the influences of glacial deposits,bedrock erosional resistance,and joint geometry.展开更多
Establishing geoparks is an effective approach to protect natural resources and promote local tourism industry. The national geopark of the Hukou Waterfall is an important geopark which attracts more than 2 million to...Establishing geoparks is an effective approach to protect natural resources and promote local tourism industry. The national geopark of the Hukou Waterfall is an important geopark which attracts more than 2 million tourists per year. The Hukou Waterfall is formed by combination of multiple knickpoints due to the longitudinal profile analysis. Like other waterfalls in the world, the Hukou Waterfall will disappear in the future. Considering the mechanisms of waterfall evolution, this paper suggests establishing control engineering, preserving the water and soil in nearby region, and reinforcing the structure of waterfall to preserve the landscape of waterfall.展开更多
Species richness and human activities in natural environments are among the most important recreational needs. Monthly studies of aquatic fauna, artisanal fisheries and tourism characteristics was conducted during wet...Species richness and human activities in natural environments are among the most important recreational needs. Monthly studies of aquatic fauna, artisanal fisheries and tourism characteristics was conducted during wet and dry seasons, over a two year period in the three landscapes along the 6817.7 m length of Agbokum waterfalls by using a close-ended pre-coded survey instrument. Through MANOVA analysis of the 1780 respondents we found strong positive association between peoples visits to the recreational areas and the type of landscape in which the respondents felt happy. People who felt happier in landscape dominated by waterfalls, visit the middle reaches of the river for outdoor recreation more often while people who feel happy in landscapes dominated by slow water current with an extensive wide area and floodplains, visit downstream reaches of the waterfalls more often. Activities performed more often along downstream reaches include fishing, bathing/swimming, boating and hunting while more frequent activities in the middle reaches (waterfalls) include taking photographs, picnics, enjoying nature, outing with family and friends, looking at view, resting and relaxing. A total of 5484 fish representing 22 species belonging to 16 genera from 9 families were sampled with 10 species being restricted to wet season and only 1 in the dry. The number of taxa and individuals present at upstream, midstream and downstream reaches were 16 (2003), 13 (1034), 17 (2447), respectively. Tilapia zillii, Clarias gariepinus and Labeo coubie dominated overall catch constituting 35.5%. Twenty five operational boats counted during the period of study, were only used downstream by 25 full-time fishermen, 87 part-time, 44 shoreline fishermen and 36 assistant fishermen. Common gears were the hook and line constituting 45.8%, cast and dip net (10.1%) bailing (8.7%), gill nets (7.3%), seine net (6.4%) Traps (5.5%), lift net (4.7%) Dip nets (0.9%), poisoning (2.8%), cutlass (3.3%) and spear (1%). Seasonally occurring aquatic fauna include crustaceans (Atya gaboneensis and Palaemon paucidens) (23.5%) oysters (Etheria elliptica) (15.4%), clams (Galacea paradoxa) (20.8%), Manatee (Trichechus senegalensis) (2.5), Hippopotamus amphibious (1.8%), Otter (Lutra macullicolis) (0.5%), Crocodyles (Crocodylus niloticus, Crocodylus cataphractus (Aligata) and Osteolaemus tetraspsis) (18.8%). The nile monitor (Varanus nilaticus), aquatic snake (Anoscopus sp), and three species of water turtle (Kimxys erosa, Pelumedusa sp and Peliosus sp) (21.6%). Relatively higher faunal densities and species richness in the upstream and downstream reaches coupled with waterfalls in middle reaches can makes Agbokum waterfalls a tourism destination if only management strategies include Legislation to conserve these natural resources.展开更多
Have you ever been to Huangguoshu Waterfall?It is said to be No.1 waterfall in Asia.It lies in Guizhou Province and is one of the most famous place1for sightseeing.Every year,millions of people will come2to visit it.T...Have you ever been to Huangguoshu Waterfall?It is said to be No.1 waterfall in Asia.It lies in Guizhou Province and is one of the most famous place1for sightseeing.Every year,millions of people will come2to visit it.The great waterfall is 77.8 meters high and 101 meters wide.But if you went to the waterfall in spring in 2010,you would find a different water-展开更多
The Great Bent in the lower reaches of the Yarlung Zangbo River in Tibet houses the largest fluvial gorge in the world. On October 18, 1998, the Chinese government named the gorge the Grand Canyon of the Yarlung Zangb...The Great Bent in the lower reaches of the Yarlung Zangbo River in Tibet houses the largest fluvial gorge in the world. On October 18, 1998, the Chinese government named the gorge the Grand Canyon of the Yarlung Zangbo. Later, from October to December, the first trekking exploration through the canyon was successfully conducted by a group of Chinese scientists. In the meantime, the scientists carfled out a multi-disciplinary and comprehensive survey and made many discoveries in the region.展开更多
In order to confirm which process is the most important in the blood coagulation cascade,a dynamic model on the function of platelets in blood coagulation is presented based on biochemical experiments.Based on qualita...In order to confirm which process is the most important in the blood coagulation cascade,a dynamic model on the function of platelets in blood coagulation is presented based on biochemical experiments.Based on qualitative analysis and mathematical simulation,a series of conclusions about the influence of the activation rate of factor VIII and factor IX on the generation of thrombin(IIa)are drawn.It is evident that the pro-coagulation stimulus must exceed a threshold value to initiate the coagulation cascade.The value is related to the binding constant d_2 of the platelet. The stability of the equilibrium value is also related to the pro-coagulation stimulus. This article also evaluates the influence of the stimulus strength and the activated rate parameter of platelets on thrombin.The proportion of platelets activated at any given time is designated c.To each c,we obtain a maximum concentration of thrombin.It is evident that when the level of factor IX is below 1% of the normal level,the rate of thrombin generation reduces dramatically,resulting in severe bleeding tendency.展开更多
For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalanc...For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.展开更多
A waterfall highlights the locus of active fluvial erosion of bedrock, and its mechanism has been the subject of several studies;however, erosional processes remain to be clarified for specific rock structures composi...A waterfall highlights the locus of active fluvial erosion of bedrock, and its mechanism has been the subject of several studies;however, erosional processes remain to be clarified for specific rock structures composing a waterfall. Herein, the detailed morphology of cliffs around a waterfall is examined by a terrestrial laser scanning (TLS) approach to analyze erosional processes occurring in the cliffs. The study site is Kegon Falls in Japan, which has a vertical drop of surface water from the top of its cliff and groundwater outflows from its lower portion. The entire cliff is mostly overhanging and minor rockfalls are often observed. The latest major rockfall occurred in 1986, causing an approximate 8-m upstream shift of the waterfall lip. From the point cloud obtained by TLS measurement, a digital elevation model on a vertical plane was generated, and cross-sectional profiles were extracted. A distinct 5- to 10-m depression was found at the bottom of the upper andesite layer of the waterfall cliff, which appears to have been formed by freeze-thaw and wet-dry weathering following the upstream shift of the surface water drop. Stability analysis of the waterfall cliff with an undercutting notch indicates that the igneous rock composing the cliff is sufficiently strong to maintain its current overhanging shape and that catastrophic collapse of the entire waterfall face rarely occurs. Following the formation of the depression, the upper cliff face appears to have been gradually eroded by gravitational collapses of relatively small blocks bounded by columnar and platy joints.展开更多
The tumor objective response rate(ORR)is an important parameter to demonstrate the efficacy of a treatment in oncology.The ORR is valuable for clinical decision making in routine practice and a significant end-point f...The tumor objective response rate(ORR)is an important parameter to demonstrate the efficacy of a treatment in oncology.The ORR is valuable for clinical decision making in routine practice and a significant end-point for reporting the results of clinical trials.World Health Organization and Response Evaluation Criteria in Solid Tumors(RECIST)are anatomic response criteria developed mainly for cytotoxic chemotherapy.These criteria are based on the visual assessment of tumor size in morphological images provided by computed tomography(CT)or magnetic resonance imaging.Anatomic response criteria may not be optimal for biologic agents,some disease sites,and some regional therapies.Consequently,modifications of RECIST,Choi criteria and Morphologic response criteria were developed based on the concept of the evaluation of viable tumors.Despite its limitations,RECIST v1.1 is validated in prospective studies,is widely accepted by regulatory agencies and has recently shown good performance for targeted cancer agents.Finally,some alternatives of RECIST were developed as immune-specific response criteria for checkpoint inhibitors.Immune RECIST criteria are based essentially on defining true progressive disease after a confirmatory imaging.Some graphical methods may be useful to show longitudinal change in the tumor burden over time.Tumor tissue is a tridimensional heterogenous mass,and tumor shrinkage is not always symmetrical;thus,metabolic response assessments using positron emission tomography(PET)or PET/CT may reflect the viability of cancer cells or functional changes evolving after anticancer treatments.The metabolic response can show the benefit of a treatment earlier than anatomic shrinkage,possibly preventing delays in drug approval.Computer-assisted automated volumetric assessments,quantitative multimodality imaging in radiology,new tracers in nuclear medicine and finally artificial intelligence have great potential in future evaluations.展开更多
Requirement gathering for software development project is the most crucial stage and thus requirement engineering (RE) occupies the chief position in the software development. Countless techniques concerning the RE pr...Requirement gathering for software development project is the most crucial stage and thus requirement engineering (RE) occupies the chief position in the software development. Countless techniques concerning the RE processes exist to make sure the requirements are coherent, compact and complete in all respects. In this way different aspects of RE are dissected and detailed upon. A comparison of RE in Agile and RE in Waterfall is expatiated and on the basis of the literature survey the overall Agile RE process is accumulated. Agile being a technique produces high quality software in relatively less time as compared to the conventional waterfall methodology. The paramount objective of this study is to take lessons from RE that Agile method may consider, if quality being the cardinal concern. The study is patterned on the survey of the previous research reported in the coexisting literature and the practices which are being pursued in the area.展开更多
The resonant flow of an incompressible, inviscid fluid with surface tension on varying bottoms was researched. The effects of different bottoms on the nonlinear surface waves were analyzed. The waterfall plots of the ...The resonant flow of an incompressible, inviscid fluid with surface tension on varying bottoms was researched. The effects of different bottoms on the nonlinear surface waves were analyzed. The waterfall plots of the wave were drawn with Matlab according to the numerical simulation of the fKdV equation with the pseudo-spectral method. From the waterfall plots, the results are obtained as follows: for the convex bottom, the waves system can be viewed as a combination of the effects of forward-step forcing and backwardstep forcing, and these two wave systems respectively radiate upstream and downstream without mutual interaction. Nevertheless, the result for the concave bottom is contrary to the convex one. For some combined bottoms, the wave systems can be considered as the combination of positive forcing and negative forcing.展开更多
This interest, first of all, was a result of Georgia's unique natural conditions with its mountainous sights or the sea, diverse herbs, animals, different traditions from people living in different comers of the coun...This interest, first of all, was a result of Georgia's unique natural conditions with its mountainous sights or the sea, diverse herbs, animals, different traditions from people living in different comers of the country, agriculture and historical-architectural monuments. By the final stage of the Soviet Union Georgia had a well-developed tourist-resort infrastructure; there were tens of particularly important resorts centers and several hundreds of tourist headquarters. Hundreds of thousands of astonished foreigners or soviet tourists used to visit country every year. They had an opportunity to enjoy pleasantness of each natural area from subtropics of the Black Sea to glaciers of the Caucasus, from Kolkheti Valley to Alazani Valley, Darially Valley to Vardzia--all the tourist routes were filled of natural sights or historical monuments. In 2015 the faculty of Natural Sciences of Ivane Javakhishvili State University conducted a research--Research and Popularization of Natural Monuments of Endogenous Origin in River Rioni Basin EN/15/2015. During research it was revealed very interesting and unique naturally remarkable places, which have a great potential of consumption allowing regions to develop tourist potential. Within frames of the project it was possible to search unique forms of relief, visit and evaluate on spot; in case of necessity include specialists for conducting further ground researches. Recommendations were made to grant status of natural monument to these forms. Meetings were held with the local population in order to notify them importance of the objects within their region and reveal new and unknown places which can be studied in the future.展开更多
Agile development has its origins and roots in practice rather than academia. Hence, in this research, we go to the practitioners’ world to explore what they want to know about Agile development. We conducted our stu...Agile development has its origins and roots in practice rather than academia. Hence, in this research, we go to the practitioners’ world to explore what they want to know about Agile development. We conducted our study using a multi-methodological approach, a combination of a survey and an interpretive case study. We learned that Agile development is yet to reach a mature phase with: a) relatively limited numbers of experienced Agile practitioners;b) a large number of software developers who were trained in plan-based Waterfall development trying to transition to Agile;c) some companies and practitioners continuing to be skeptical of the benefits of Agile development over plan-based development;and d) tools in the process of being developed to support Agile development. Based on those factors, we learned that practitioners are wanting to find answers to the following questions: a) What should good Agile practitioners and teams know and do? b) How to train developers and teams to become good Agile practitioners? c) How to transition from plan-driven Waterfall development to Agile development? d) What tools are available to practice Agile development? How to use them to support Agile practices? The following are the answers we derived from our interpretive case study for the above four questions: a) Good Agile practitioners define their job in terms of the client’s mission;they don’t define their jobs as analysts, designers, programmers, testers, or project managers;b) For training, Agile practices such as test-driven development and continuous integration are best understood not in theory but by the act of doing;for organizational adoption of Agile development, Agile practices should be used not only in software development but encouraged in all functional areas;c) The best way to introduce a plan-based Waterfall practitioner to Agile is to have him think of Agile in terms of something familiar, as a series of mini-waterfalls that have very quick iterations;d) Simple tools, even non-software tools, that help manage Agile practices intuitively are preferable to complex Agile management software.展开更多
文摘When artificial waterfalls are built in gardens,leaves from trees or vegetation often fall into the water storage pool and block the pipelines,requiring regular cleaning of pipelines.This not only increases the manpower needed for maintenance but also disrupts the use of the waterfalls.Therefore,it is necessary to design a new type of artificial waterfall that is suitable for gardens.The waterfall should incorporate features that make cleaning easier,including filter plates and water funnels to prevent clogging caused by fallen leaves and debris.
基金This research was supported jointly by the CRCG Seed Grant of the University of Hong Kongthe National Natural Science Foundation of China(Nos.90202003 and 40303014)
文摘Many rivers in tropical and subtropical karst regions are supersaturated with respect to CaCO3 and have high water hardness. After flowing through waterfall sites, river water is usually softened, accompanied by tufa formation, which is simply described as a result of water turbulence in fast-flowing water. In this paper, a series of laboratory experiments are designed to simulate the hydrological conditions at waterfall sites. The influences of air-water interface, water flow velocity, aeration and solid-water interface on water softening are compared and evaluated on a quantitative basis. The results show that the enhanced inorganic CO2 outgassing due to sudden hydrological changes occurring at waterfall sites is the principal cause of water softening at waterfall sites. Both air-water interface area and water flow velocity increase as a result of the 'aeration effect', 'low pressure effect' and 'jet-flow effect' at waterfall sites, which greatly accelerates CO2 outgassing and therefore makes natural waters become highly supersaturated with respect to CaCO3, consequently resulting in much CaCO3 deposition and reduction of water hardness. Aeration, rapidly increasing air-water interface area and water flow velocity, proves to be effective in reducing water hardness. This study may provide a cheap, safe and effective way to soften water.
基金supported by the Jose Castillejo Grant(CAS14/00073,Ministry of Education,Spain)。
文摘Previous work on the eastern side of Rocky Mountain National Park(RMNP),Colorado indicated correlations among waterfall location,waterfall morphology,and the characteristics of bedrock joints.Characteristics of waterfalls on the western side of the national park do not correlate as strongly with joint geometry.Longitudinal river profiles on the western side are less concave and waterfalls account for a greater proportion of the total elevation loss.We interpret these differences to result from more widely spaced joints,lithological differences,and complex glacial history.These results demonstrate that waterfall shape and typology may change due to both local and regional controls operating in a mountain region.Both regions had alpine valley glaciers,but continued landscape evolution via fluvial erosion has developed waterfalls with diverse locations and morphologies that reflect the influences of glacial deposits,bedrock erosional resistance,and joint geometry.
基金Sponsored by the National Natural Science Fund(41471003)
文摘Establishing geoparks is an effective approach to protect natural resources and promote local tourism industry. The national geopark of the Hukou Waterfall is an important geopark which attracts more than 2 million tourists per year. The Hukou Waterfall is formed by combination of multiple knickpoints due to the longitudinal profile analysis. Like other waterfalls in the world, the Hukou Waterfall will disappear in the future. Considering the mechanisms of waterfall evolution, this paper suggests establishing control engineering, preserving the water and soil in nearby region, and reinforcing the structure of waterfall to preserve the landscape of waterfall.
文摘Species richness and human activities in natural environments are among the most important recreational needs. Monthly studies of aquatic fauna, artisanal fisheries and tourism characteristics was conducted during wet and dry seasons, over a two year period in the three landscapes along the 6817.7 m length of Agbokum waterfalls by using a close-ended pre-coded survey instrument. Through MANOVA analysis of the 1780 respondents we found strong positive association between peoples visits to the recreational areas and the type of landscape in which the respondents felt happy. People who felt happier in landscape dominated by waterfalls, visit the middle reaches of the river for outdoor recreation more often while people who feel happy in landscapes dominated by slow water current with an extensive wide area and floodplains, visit downstream reaches of the waterfalls more often. Activities performed more often along downstream reaches include fishing, bathing/swimming, boating and hunting while more frequent activities in the middle reaches (waterfalls) include taking photographs, picnics, enjoying nature, outing with family and friends, looking at view, resting and relaxing. A total of 5484 fish representing 22 species belonging to 16 genera from 9 families were sampled with 10 species being restricted to wet season and only 1 in the dry. The number of taxa and individuals present at upstream, midstream and downstream reaches were 16 (2003), 13 (1034), 17 (2447), respectively. Tilapia zillii, Clarias gariepinus and Labeo coubie dominated overall catch constituting 35.5%. Twenty five operational boats counted during the period of study, were only used downstream by 25 full-time fishermen, 87 part-time, 44 shoreline fishermen and 36 assistant fishermen. Common gears were the hook and line constituting 45.8%, cast and dip net (10.1%) bailing (8.7%), gill nets (7.3%), seine net (6.4%) Traps (5.5%), lift net (4.7%) Dip nets (0.9%), poisoning (2.8%), cutlass (3.3%) and spear (1%). Seasonally occurring aquatic fauna include crustaceans (Atya gaboneensis and Palaemon paucidens) (23.5%) oysters (Etheria elliptica) (15.4%), clams (Galacea paradoxa) (20.8%), Manatee (Trichechus senegalensis) (2.5), Hippopotamus amphibious (1.8%), Otter (Lutra macullicolis) (0.5%), Crocodyles (Crocodylus niloticus, Crocodylus cataphractus (Aligata) and Osteolaemus tetraspsis) (18.8%). The nile monitor (Varanus nilaticus), aquatic snake (Anoscopus sp), and three species of water turtle (Kimxys erosa, Pelumedusa sp and Peliosus sp) (21.6%). Relatively higher faunal densities and species richness in the upstream and downstream reaches coupled with waterfalls in middle reaches can makes Agbokum waterfalls a tourism destination if only management strategies include Legislation to conserve these natural resources.
文摘Have you ever been to Huangguoshu Waterfall?It is said to be No.1 waterfall in Asia.It lies in Guizhou Province and is one of the most famous place1for sightseeing.Every year,millions of people will come2to visit it.The great waterfall is 77.8 meters high and 101 meters wide.But if you went to the waterfall in spring in 2010,you would find a different water-
文摘The Great Bent in the lower reaches of the Yarlung Zangbo River in Tibet houses the largest fluvial gorge in the world. On October 18, 1998, the Chinese government named the gorge the Grand Canyon of the Yarlung Zangbo. Later, from October to December, the first trekking exploration through the canyon was successfully conducted by a group of Chinese scientists. In the meantime, the scientists carfled out a multi-disciplinary and comprehensive survey and made many discoveries in the region.
基金The project supported by The Beijing Municipal Natural Sciences Foundation (3982005)
文摘In order to confirm which process is the most important in the blood coagulation cascade,a dynamic model on the function of platelets in blood coagulation is presented based on biochemical experiments.Based on qualitative analysis and mathematical simulation,a series of conclusions about the influence of the activation rate of factor VIII and factor IX on the generation of thrombin(IIa)are drawn.It is evident that the pro-coagulation stimulus must exceed a threshold value to initiate the coagulation cascade.The value is related to the binding constant d_2 of the platelet. The stability of the equilibrium value is also related to the pro-coagulation stimulus. This article also evaluates the influence of the stimulus strength and the activated rate parameter of platelets on thrombin.The proportion of platelets activated at any given time is designated c.To each c,we obtain a maximum concentration of thrombin.It is evident that when the level of factor IX is below 1% of the normal level,the rate of thrombin generation reduces dramatically,resulting in severe bleeding tendency.
基金Supported by National Natural Science Foundation of China(Grant Nos.51575176,51375162)Scientific Research Foundation of Hunan Provincial Education Department of China(Grant No.15B085)Postgraduate Innovation Foundation of Hunan University of Science and Technology,China(Grant No.S140020)
文摘For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.
文摘A waterfall highlights the locus of active fluvial erosion of bedrock, and its mechanism has been the subject of several studies;however, erosional processes remain to be clarified for specific rock structures composing a waterfall. Herein, the detailed morphology of cliffs around a waterfall is examined by a terrestrial laser scanning (TLS) approach to analyze erosional processes occurring in the cliffs. The study site is Kegon Falls in Japan, which has a vertical drop of surface water from the top of its cliff and groundwater outflows from its lower portion. The entire cliff is mostly overhanging and minor rockfalls are often observed. The latest major rockfall occurred in 1986, causing an approximate 8-m upstream shift of the waterfall lip. From the point cloud obtained by TLS measurement, a digital elevation model on a vertical plane was generated, and cross-sectional profiles were extracted. A distinct 5- to 10-m depression was found at the bottom of the upper andesite layer of the waterfall cliff, which appears to have been formed by freeze-thaw and wet-dry weathering following the upstream shift of the surface water drop. Stability analysis of the waterfall cliff with an undercutting notch indicates that the igneous rock composing the cliff is sufficiently strong to maintain its current overhanging shape and that catastrophic collapse of the entire waterfall face rarely occurs. Following the formation of the depression, the upper cliff face appears to have been gradually eroded by gravitational collapses of relatively small blocks bounded by columnar and platy joints.
文摘The tumor objective response rate(ORR)is an important parameter to demonstrate the efficacy of a treatment in oncology.The ORR is valuable for clinical decision making in routine practice and a significant end-point for reporting the results of clinical trials.World Health Organization and Response Evaluation Criteria in Solid Tumors(RECIST)are anatomic response criteria developed mainly for cytotoxic chemotherapy.These criteria are based on the visual assessment of tumor size in morphological images provided by computed tomography(CT)or magnetic resonance imaging.Anatomic response criteria may not be optimal for biologic agents,some disease sites,and some regional therapies.Consequently,modifications of RECIST,Choi criteria and Morphologic response criteria were developed based on the concept of the evaluation of viable tumors.Despite its limitations,RECIST v1.1 is validated in prospective studies,is widely accepted by regulatory agencies and has recently shown good performance for targeted cancer agents.Finally,some alternatives of RECIST were developed as immune-specific response criteria for checkpoint inhibitors.Immune RECIST criteria are based essentially on defining true progressive disease after a confirmatory imaging.Some graphical methods may be useful to show longitudinal change in the tumor burden over time.Tumor tissue is a tridimensional heterogenous mass,and tumor shrinkage is not always symmetrical;thus,metabolic response assessments using positron emission tomography(PET)or PET/CT may reflect the viability of cancer cells or functional changes evolving after anticancer treatments.The metabolic response can show the benefit of a treatment earlier than anatomic shrinkage,possibly preventing delays in drug approval.Computer-assisted automated volumetric assessments,quantitative multimodality imaging in radiology,new tracers in nuclear medicine and finally artificial intelligence have great potential in future evaluations.
文摘Requirement gathering for software development project is the most crucial stage and thus requirement engineering (RE) occupies the chief position in the software development. Countless techniques concerning the RE processes exist to make sure the requirements are coherent, compact and complete in all respects. In this way different aspects of RE are dissected and detailed upon. A comparison of RE in Agile and RE in Waterfall is expatiated and on the basis of the literature survey the overall Agile RE process is accumulated. Agile being a technique produces high quality software in relatively less time as compared to the conventional waterfall methodology. The paramount objective of this study is to take lessons from RE that Agile method may consider, if quality being the cardinal concern. The study is patterned on the survey of the previous research reported in the coexisting literature and the practices which are being pursued in the area.
基金Project supported by the National Natural Science Foundation of China(No.10272044)the Ph. D. Programs Foundation of Ministry of Education of China(No.20040079004)
文摘The resonant flow of an incompressible, inviscid fluid with surface tension on varying bottoms was researched. The effects of different bottoms on the nonlinear surface waves were analyzed. The waterfall plots of the wave were drawn with Matlab according to the numerical simulation of the fKdV equation with the pseudo-spectral method. From the waterfall plots, the results are obtained as follows: for the convex bottom, the waves system can be viewed as a combination of the effects of forward-step forcing and backwardstep forcing, and these two wave systems respectively radiate upstream and downstream without mutual interaction. Nevertheless, the result for the concave bottom is contrary to the convex one. For some combined bottoms, the wave systems can be considered as the combination of positive forcing and negative forcing.
文摘This interest, first of all, was a result of Georgia's unique natural conditions with its mountainous sights or the sea, diverse herbs, animals, different traditions from people living in different comers of the country, agriculture and historical-architectural monuments. By the final stage of the Soviet Union Georgia had a well-developed tourist-resort infrastructure; there were tens of particularly important resorts centers and several hundreds of tourist headquarters. Hundreds of thousands of astonished foreigners or soviet tourists used to visit country every year. They had an opportunity to enjoy pleasantness of each natural area from subtropics of the Black Sea to glaciers of the Caucasus, from Kolkheti Valley to Alazani Valley, Darially Valley to Vardzia--all the tourist routes were filled of natural sights or historical monuments. In 2015 the faculty of Natural Sciences of Ivane Javakhishvili State University conducted a research--Research and Popularization of Natural Monuments of Endogenous Origin in River Rioni Basin EN/15/2015. During research it was revealed very interesting and unique naturally remarkable places, which have a great potential of consumption allowing regions to develop tourist potential. Within frames of the project it was possible to search unique forms of relief, visit and evaluate on spot; in case of necessity include specialists for conducting further ground researches. Recommendations were made to grant status of natural monument to these forms. Meetings were held with the local population in order to notify them importance of the objects within their region and reveal new and unknown places which can be studied in the future.
文摘Agile development has its origins and roots in practice rather than academia. Hence, in this research, we go to the practitioners’ world to explore what they want to know about Agile development. We conducted our study using a multi-methodological approach, a combination of a survey and an interpretive case study. We learned that Agile development is yet to reach a mature phase with: a) relatively limited numbers of experienced Agile practitioners;b) a large number of software developers who were trained in plan-based Waterfall development trying to transition to Agile;c) some companies and practitioners continuing to be skeptical of the benefits of Agile development over plan-based development;and d) tools in the process of being developed to support Agile development. Based on those factors, we learned that practitioners are wanting to find answers to the following questions: a) What should good Agile practitioners and teams know and do? b) How to train developers and teams to become good Agile practitioners? c) How to transition from plan-driven Waterfall development to Agile development? d) What tools are available to practice Agile development? How to use them to support Agile practices? The following are the answers we derived from our interpretive case study for the above four questions: a) Good Agile practitioners define their job in terms of the client’s mission;they don’t define their jobs as analysts, designers, programmers, testers, or project managers;b) For training, Agile practices such as test-driven development and continuous integration are best understood not in theory but by the act of doing;for organizational adoption of Agile development, Agile practices should be used not only in software development but encouraged in all functional areas;c) The best way to introduce a plan-based Waterfall practitioner to Agile is to have him think of Agile in terms of something familiar, as a series of mini-waterfalls that have very quick iterations;d) Simple tools, even non-software tools, that help manage Agile practices intuitively are preferable to complex Agile management software.