In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite tra...In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation technique.The wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been proposed.The likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will occur.It is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation method.This study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency.展开更多
The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers...The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.展开更多
Weir crest must have the correct shape in the concave side of an ogee-shaped crest to diminish erosion. This shape can be obtained using an approximation of the fractional Reynolds equations when the water interacts w...Weir crest must have the correct shape in the concave side of an ogee-shaped crest to diminish erosion. This shape can be obtained using an approximation of the fractional Reynolds equations when the water interacts with the surface. A model is introduced for the Reynolds stresses complemented with a closure relation of fractional origin. A power type solution is obtained for the main velocity and stress. Velocity profile is found based on the assumption of a steady flow and the energy conservation equation. A Froude number and the cubic equation of the weir are built. The dimensionless upstream velocity head is also determined which allow graphically showing the exponent and coefficient of the water-profile over an ogee-shaped crest. It is possible to estimate the occupied-space index trough an exponents＇ ratio of profile over the velocity head.展开更多
The peripheral nerve injuries,representing some of the most common types of traumatic lesions affecting the nervous system,are highly invalidating for the patients besides being a huge social burden.Although periphera...The peripheral nerve injuries,representing some of the most common types of traumatic lesions affecting the nervous system,are highly invalidating for the patients besides being a huge social burden.Although peripheral nervous system owns a higher regenerative capacity than does central nervous system,mostly depending on Schwann cells intervention in injury repair,several factors determine the extent of functional outcome after healing.Based on the injury type,different therapeutic approaches have been investigated so far.Nerve grafting and Schwann cell transplantation have represented the gold standard treatment for peripheral nerve injuries,however these approaches own limitations,such as scarce donor nerve availability and donor site morbidity.Cell based therapies might provide a suitable tool for peripheral nerve regeneration,in fact,the ability of different stem cell types to differentiate towards Schwann cells in combination with the use of different scaffolds have been widely investigated in animal models of peripheral nerve injuries in the last decade.Dental pulp is a promising cell source for regenerative medicine,because of the ease of isolation procedures,stem cell proliferation and multipotency abilities,which are due to the embryological origin from neural crest.In this article we review the literature concerning the application of tooth derived stem cell populations combined with different conduits to peripheral nerve injuries animal models,highlighting their regenerative contribution exerted through either glial differentiation and neuroprotective/neurotrophic effects on the host tissue.展开更多
基金financially supported by the Chinese State Key Laboratory of Ocean Engineering(Grant No.GKZD010068/084).
文摘In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation technique.The wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been proposed.The likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will occur.It is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation method.This study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency.
基金supported by State Forestry Administration (China) Research and Development Plan(Grant NoSD0639)the Community Comanagement Project of WWF-China
文摘The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.
文摘Weir crest must have the correct shape in the concave side of an ogee-shaped crest to diminish erosion. This shape can be obtained using an approximation of the fractional Reynolds equations when the water interacts with the surface. A model is introduced for the Reynolds stresses complemented with a closure relation of fractional origin. A power type solution is obtained for the main velocity and stress. Velocity profile is found based on the assumption of a steady flow and the energy conservation equation. A Froude number and the cubic equation of the weir are built. The dimensionless upstream velocity head is also determined which allow graphically showing the exponent and coefficient of the water-profile over an ogee-shaped crest. It is possible to estimate the occupied-space index trough an exponents＇ ratio of profile over the velocity head.
文摘The peripheral nerve injuries,representing some of the most common types of traumatic lesions affecting the nervous system,are highly invalidating for the patients besides being a huge social burden.Although peripheral nervous system owns a higher regenerative capacity than does central nervous system,mostly depending on Schwann cells intervention in injury repair,several factors determine the extent of functional outcome after healing.Based on the injury type,different therapeutic approaches have been investigated so far.Nerve grafting and Schwann cell transplantation have represented the gold standard treatment for peripheral nerve injuries,however these approaches own limitations,such as scarce donor nerve availability and donor site morbidity.Cell based therapies might provide a suitable tool for peripheral nerve regeneration,in fact,the ability of different stem cell types to differentiate towards Schwann cells in combination with the use of different scaffolds have been widely investigated in animal models of peripheral nerve injuries in the last decade.Dental pulp is a promising cell source for regenerative medicine,because of the ease of isolation procedures,stem cell proliferation and multipotency abilities,which are due to the embryological origin from neural crest.In this article we review the literature concerning the application of tooth derived stem cell populations combined with different conduits to peripheral nerve injuries animal models,highlighting their regenerative contribution exerted through either glial differentiation and neuroprotective/neurotrophic effects on the host tissue.
