英语课堂上“以教师为中心”的现象处处可见,为改变这一局面,本文对《大学英语》第三册第三课“The Land of the Lock”进行了设计。该设计主要以“top—down”阅读策略为主,用以提升学生把握篇章内容的能力和猜词能力,力争做到“...英语课堂上“以教师为中心”的现象处处可见,为改变这一局面,本文对《大学英语》第三册第三课“The Land of the Lock”进行了设计。该设计主要以“top—down”阅读策略为主,用以提升学生把握篇章内容的能力和猜词能力,力争做到“以学生为中心”。展开更多
In this paper, the early warning signals of abrupt temperature change in different regions of China are investigated. Seven regions are divided on the basis of different climate temperature patterns, obtained through ...In this paper, the early warning signals of abrupt temperature change in different regions of China are investigated. Seven regions are divided on the basis of different climate temperature patterns, obtained through the rotated empirical orthogonal function, and the signal-to-noise temperature ratios for each region are then calculated. Based on the concept of critical slowing down, the temperature data that contain noise in the different regions of China are preprocessed to study the early warning signals of abrupt climate change. First, the Mann-Kendall method is used to identify the instant of abrupt climate change in the temperature data. Second, autocorrelation coefficients that can identify critical slowing down are calculated. The results show that the critical slowing down phenomenon appeared in temperature data about 5-10 years before abrupt climate change occurred, which indicates that the critical slowing down phenomenon is a possible early warning signal for abrupt climate change, and that noise has less influence on the detection results of the early warning signals. Accordingly, this demonstrates that the model is reliable in identifying the early warning signals of abrupt climate change based on detecting the critical slowing down phenomenon, which provides an experimental basis for the actual application of the method.展开更多
In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific...In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific decadal oscillation(PDO) index has been made on the basis of the critical slowing down principle in order to analyze its early warning signal of abrupt change. The chaotic characteristics of the PDO index sequence at different times are determined by using the largest Lyapunov exponent(LLE). The relationship between the regional sea surface temperature(SST) background field and the early warning signal of the PDO abrupt change is further studied through calculating the variance of the SST in the PDO region and the spatial distribution of the autocorrelation coefficient, thereby providing the experimental foundation for the extensive application of the method of the critical slowing down phenomenon. Our results show that the phenomenon of critical slowing down, such as the increase of the variance and autocorrelation coefficient, will continue for six years before the abrupt change of the PDO index. This phenomenon of the critical slowing down can be regarded as one of the early warning signals of an abrupt change. Through calculating the LLE of the PDO index during different times, it is also found that the strongest chaotic characteristics of the system occurred between 1971 and 1975 in the early stages of an abrupt change(1976), and the system was at the stage of a critical slowing down, which proves the reliability of the early warning signal of abrupt change discovered in 1970 from the mechanism. In addition, the variance of the SST,along with the spatial distribution of the autocorrelation coefficient in the corresponding PDO region, also demonstrates the corresponding relationship between the change of the background field of the SST and the change of the PDO.展开更多
Supported by geographical information system,using Costanza method and referring to terrestrial ecosystem service value in China,the influence of land use and land cover change(LUCC)between 1980 and 2000 on ecosystem ...Supported by geographical information system,using Costanza method and referring to terrestrial ecosystem service value in China,the influence of land use and land cover change(LUCC)between 1980 and 2000 on ecosystem service value in the up and middle reaches of Dongting Lake basin was analyzed in this study.The results showed that the estimated value of ecosystem services decreased 8.416 9×108 CNY over a 21-year period,and the main reasons were that the land for forest use was exploited for cropland and construction land use in study area.Further analysis results showed that the value of single ecosystem service function such as gas regulation,climate regulation,soil formation and conservation,biodiversity conservation,raw materials as well as recreation decreased significantly;and that of provision of water conservation,waste treatment and food production increased obviously in the area.The results of coefficient sensitivity analysis indicated that these estimates were reliable.展开更多
Using 2. 5 ×2. 5 winds and pressure grid data, the angular momentum budgets are studied in this paper for TC 9012 (Yancy) which was kept active 65 hours after land fall. It is found that the inland TC 9012 moved ...Using 2. 5 ×2. 5 winds and pressure grid data, the angular momentum budgets are studied in this paper for TC 9012 (Yancy) which was kept active 65 hours after land fall. It is found that the inland TC 9012 moved into the center of a relatively stable saddle, in which large amount of humid air was entrained into the storm from the southerly jet at low level to bund up the energy of latent heat, the weak cold air coming from the north provided it with baroclinic energy, while the vorticity transfer of geostrophic angular momentum on the radius 4°-8°from the cyclone center at upper troposphere and the input of cyclonic angular momentum produced by the βterm are immediate factors maintaining the central pressure and maximum winds.展开更多
The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the...The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process.展开更多
This article reviews: 1) The role of natural and human-induced controls in influencing large herbivore populations;2) how human controls (i.e., policy instruments, incentives and provisions) influence human activities...This article reviews: 1) The role of natural and human-induced controls in influencing large herbivore populations;2) how human controls (i.e., policy instruments, incentives and provisions) influence human activities and wildlife conservation;and 3) media framing of wildlife conservation using Zimbabwe as a case study, in particular Gonarezhou National Park and adjacent areas. The review shows that droughts are important in influencing large herbivore populations in semi-arid ecosystems;political instability and economic collapse does not necessarily lead to increased illegal hunting in situations where policy instruments, such as laws, are enforced. A higher perceived effectiveness of Communal Areas Management Programme for Indigenous Resources was partly associated with a decline in human-wildlife conflicts and there was a spill-over effect of frames from the political domain into wildlife conservation following Zimbabwe’s land reforms in 2000. It is concluded that natural bottom-up processes (e.g., droughts) influence large herbivore population dynamics whereas policy instruments, incentives, provisions and societal frames mainly have a top-down effect on wild large herbivore populations in savanna ecosystems.展开更多
The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge s...The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge state or account for neutrino mass. This holographic analysis treats charged Standard Model fermions as spheres with mass 0.187 g/cm<sup>2</sup> times their surface area, using the proportionality constant in the holographic relation between mass of the observable universe and event horizon radius. The analysis requires three Standard Model fermions per charge state and relates up quark and down quark masses to electron mass. Holographic analysis specifies electron mass, to six significant figures, in terms of fundamental constants α,ℏ,G,Λ and Ω Λ . Treating neutrinos as spheres and equating electron neutrino energy density with cosmic vacuum energy density predicts neutrino masses consistent with experiment.展开更多
Traditional approach to evaluate the impacts of climate change on the water resources systems always begins with downscaling general circulation models( GCMs) and proceeding back to the hydrological model. This approa...Traditional approach to evaluate the impacts of climate change on the water resources systems always begins with downscaling general circulation models( GCMs) and proceeding back to the hydrological model. This approach has some distinct disadvantages: 1) GCM must be downscaled; 2) different GCMs are difficult to be reconciled for a given climate change scenario;3) the uncertainty of GCMs is far from the requirement of the evaluation of climate change impacts. To overcome these limits of the traditional method,a new method termed as "bottom-up"was used for climate risk assessment that linked vulnerability assessment with climate information to assess the risk of climate change impacts on the Quabbin Reservoir,and United States under A2 scenario.The result shows that the risks are around 20% in 2006-2035 and 2036-2055,50% in 2066-2095.展开更多
Purpose: To alert the medical community that whole exome sequencing can find accessory gene changes in well-known syndromes that alter preventive health care and management. Meaning: A collagen type VI gene change add...Purpose: To alert the medical community that whole exome sequencing can find accessory gene changes in well-known syndromes that alter preventive health care and management. Meaning: A collagen type VI gene change adds muscle weakness, hypermobility, and dysautonomia concerns to usual management considerations for Down syndrome. Methods: Commercial whole exome sequencing combined with clinical interpretation of DNA sequence change added new considerations to patient management and parental counsel. Results: An 11-year-old child with the trisomy 21 form of Down syndrome who was evaluated for extraordinary joint laxity had a heterozygous collagen type VI aspartic to glutamic acid (COL6A3 c.6360 C>G p.Asp2120Glu) gene change found by whole exome sequencing. The DNA variant was qualified as having strong relevance to the enhanced hypermobility due to prior association of collagen 6 gene changes with myopathy. Conclusions: Dual diagnosis of Ehlers-Danlos syndrome was not assigned because the patient lacked criteria like bruising, unusual scars, or selected dysautonomia symptoms. The concept of a hypermobility spectrum offers advantages for management of its constituent conditions if clinically guided ascertainment and DNA diagnostics are employed.展开更多
English reading has gained much attention among teachers and students and become one of the research heatpots in English pedagogy.The paper gives a brief introduction of the theories of reading and attempts to apply t...English reading has gained much attention among teachers and students and become one of the research heatpots in English pedagogy.The paper gives a brief introduction of the theories of reading and attempts to apply the schema theory of reading into the classroom teaching.The classroom practice reveals that English reading under the guidance of schema theory proves effective and raises students' awareness of strategies.展开更多
The explosive initiator is one kind of sensitivity products with long life and high reliability.In order to improve the storage reliability assessment,the method of storage reliability assessment for explosive initiat...The explosive initiator is one kind of sensitivity products with long life and high reliability.In order to improve the storage reliability assessment,the method of storage reliability assessment for explosive initiator was proposed based on time series model using the sensitivity test data.In the method,the up and down test was used to estimate the distribution parameters of threshold.And an approach to design the up and down test was present to draw better estimations.Furthermore,the method of shrinkage estimation was introduced to get a better estimation of scale parameter by combining the sample information with prior information.The simulation result shows that the shrinkage estimation is better than traditional estimation under certain conditions.With the distribution parameters estimations,the time series models were used to describe the changing trends of distribution parameters along with storage time.Then for a fixed storage time,the distribution parameters were predicted based on the models.Finally,the confidence interval of storage reliability was obtained by fiducial inference.The illustrative example shows that the method is available for storage reliability assessment of the explosive initiator with high reliability.展开更多
The rapid expansion of urban areas due to rise in population and economic growth is increasing additional demand on natural resources thereby causing land-use changes especially in megacities. Therefore, serious probl...The rapid expansion of urban areas due to rise in population and economic growth is increasing additional demand on natural resources thereby causing land-use changes especially in megacities. Therefore, serious problems associated with rapid development such as additional infrastructure, informal settlements, environmental pollution, destruction of ecological structure and scarcity of natural resources has been studied carefully using remote sensing and GIS technologies for a rapidly grown megacity namely, Delhi. The present work evaluates the land use/land cover (LULC) changes and urban expansion in Mega city Delhi and highlights the major impact of rapid urbanization and population growth on the land cover changes which needs immediate attention. The results indicate that the city is expanding towards its peripheral region with the conversion of rural regions in to urban expansions. Built-up area of Delhi witnessed an overall increment from 540.7 km2 to 791.96 km2 or 16.86% of the total city area (1,490 km2 ) during the study period 1997 to 2008 which mainly came from agriculture land, waste land, scrub-land, sandy areas and water bodies. The increment in forest cover of 0.5 % is very small when considering the increment in built up category to 17%. Total area of waterbodies has reduced by 52.9% in a ten year period (58.26 km2 in 1997 to 27.43 km2 in 2008) with shallow waterbodies now having a dismal presence. LULC changes are studied with the urban growth parameters such as population, vehicles, gross state domestic product etc. The results lay emphasis on the concepts of urban planning to be applied such that more consideration is towards the preservation and management of natural land use classes which will increase the quality of life in an urban environment.展开更多
Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory conditions mainly of the colon and small intestine. Crohn’s disease (CD) and ulcerative colitis (UC) are the most frequent types of IBD....Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory conditions mainly of the colon and small intestine. Crohn’s disease (CD) and ulcerative colitis (UC) are the most frequent types of IBD. IBD is a complex disease which arises as a result of the interaction of environmental, genetic and immunological factors. It is increasingly thought that alterations of immunological reactions of the patients to their own enterable bacteria (microfilm) may contribute to inflammation. It is characterized by mucosal and sub mucosal inflammation, perpetuated by infiltration of activated leukocytes. CD may affect the whole gastrointestinal tract while UC only attacks the large intestine. The therapeutic goal is to achieve a steroid-free long lasting remission in both entities. UC has the possibility to be cured by a total colectomy, while CD never can be cured by any operation. A lifelong intake of drugs is mostly necessary and essential. Medical treatment of IBD has to be individualized to each patient and usually starts with anti-inflammatory drugs. The choice what kind of drugs and what route administered (oral, rectal, intravenous) depends on factors including the type, the localization, and severity of the patient’s disease. IBD may require immune-suppression to control symptoms such as prednisolone, thiopurines, calcineurin or sometimes folic acid inhibitors or biologics like TNF-α inhibitors or anti-integrin antibodies. For both types of disease (CD, UC) the same drugs are available but they differ in their preference in efficacy between CD and UC as 5-aminosalicylic acid for UC or budesonide for ileocecal CD. As therapeutic alternative the main mediators of the disease, namely the activated pro-inflammatory cytokine producing leukocytes can be selectively removed via two apheresis systems (Adacolumn and Cellsorba) in steroid-refractory or dependent cases. Extracorporeal photopheresis results in an increase of regulatory B cells, regulatory CD8<sup>+</sup> T cells and T-regs Type 1. Both types of apheresis were able to induce clinical remission and mucosal healing accompanied by tapering of steroids.展开更多
The top-down and bottom-up are two main approaches used in teaching extensive reading and both of them should be used alternatively so that students can not only understand the details but also the main ideas of readi...The top-down and bottom-up are two main approaches used in teaching extensive reading and both of them should be used alternatively so that students can not only understand the details but also the main ideas of reading materials.The importance of using top-down approach is emphasized and some suggestions are given on the problem that students pay so much attention on vocabulary and grammar rather than main idea in reading.展开更多
This paper aims at making some research on spatial metaphor from cognitive angle.Spatial metaphor is a basic tool which can make us more familiar with our world,and lots of abstract concepts are based on it.Take "...This paper aims at making some research on spatial metaphor from cognitive angle.Spatial metaphor is a basic tool which can make us more familiar with our world,and lots of abstract concepts are based on it.Take "UP-DOWN" for example,this paper will mainly discuss the symmetry and dissymmetry of its extension in Chinese and English.展开更多
According to the traditional fatigue constant life curve, the concept and the universal expression of the generalized fatigue constant life curve were proposed. Then, on the basis of the optimization method of the cor...According to the traditional fatigue constant life curve, the concept and the universal expression of the generalized fatigue constant life curve were proposed. Then, on the basis of the optimization method of the correlation coefficient, the parameter estimation formulas were induced and the generalized fatigue constant life curve with the reliability level p was given. From P-S-a-S-m curve, the two-dimensional probability distribution of the fatigue limit was derived. After then, three se, of tests of LY11 CZ corresponding to the different average stress were carried out in terms of the two-dimensional up-down method. Finally, the methods are used to analyze the test results, and it is found that the analyzed results with the high precision may be obtained.展开更多
In recent years, much attention has been paid to software-defined radio (SDR) technologies for multimode wireless systems SDR can be defined as a radio communication system that uses software to modulate and demodul...In recent years, much attention has been paid to software-defined radio (SDR) technologies for multimode wireless systems SDR can be defined as a radio communication system that uses software to modulate and demodulate radio signals. This article describes concepts, theory, and design principles for SDR down-conversion and up-conversion. Design issues in SDR down-conversion are discussed, and two different architectures, super-heterodyne and direct-conversion, are proposed. Design issues in SDR up-conversion are also discussed, and trade-offs in the design of filters, mixers, NCO, DAC, and signal processing are highlighted.展开更多
基金Project supported by the National Basic Research Program of China(Grant Nos.2012CB955902 and 2013CB430204)the National Natural Science Foundation of China(Grant Nos.41175067,41275074,and 41105033)the Special Scientific Research Project for Public Interest,China(Grant No.GYHY201106015)
文摘In this paper, the early warning signals of abrupt temperature change in different regions of China are investigated. Seven regions are divided on the basis of different climate temperature patterns, obtained through the rotated empirical orthogonal function, and the signal-to-noise temperature ratios for each region are then calculated. Based on the concept of critical slowing down, the temperature data that contain noise in the different regions of China are preprocessed to study the early warning signals of abrupt climate change. First, the Mann-Kendall method is used to identify the instant of abrupt climate change in the temperature data. Second, autocorrelation coefficients that can identify critical slowing down are calculated. The results show that the critical slowing down phenomenon appeared in temperature data about 5-10 years before abrupt climate change occurred, which indicates that the critical slowing down phenomenon is a possible early warning signal for abrupt climate change, and that noise has less influence on the detection results of the early warning signals. Accordingly, this demonstrates that the model is reliable in identifying the early warning signals of abrupt climate change based on detecting the critical slowing down phenomenon, which provides an experimental basis for the actual application of the method.
基金supported by the National Natural Science Foundation of China(Grant Nos.41175067 and 41305056)the National Basic Research Program of China(Grant No.2012CB955901)+1 种基金the Special Scientific Research Project for Public Interest of China(Grant No.GYHY201506001)the Special Fund for Climate Change of China Meteorological Administration(Grant No.CCSF201525)
文摘In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific decadal oscillation(PDO) index has been made on the basis of the critical slowing down principle in order to analyze its early warning signal of abrupt change. The chaotic characteristics of the PDO index sequence at different times are determined by using the largest Lyapunov exponent(LLE). The relationship between the regional sea surface temperature(SST) background field and the early warning signal of the PDO abrupt change is further studied through calculating the variance of the SST in the PDO region and the spatial distribution of the autocorrelation coefficient, thereby providing the experimental foundation for the extensive application of the method of the critical slowing down phenomenon. Our results show that the phenomenon of critical slowing down, such as the increase of the variance and autocorrelation coefficient, will continue for six years before the abrupt change of the PDO index. This phenomenon of the critical slowing down can be regarded as one of the early warning signals of an abrupt change. Through calculating the LLE of the PDO index during different times, it is also found that the strongest chaotic characteristics of the system occurred between 1971 and 1975 in the early stages of an abrupt change(1976), and the system was at the stage of a critical slowing down, which proves the reliability of the early warning signal of abrupt change discovered in 1970 from the mechanism. In addition, the variance of the SST,along with the spatial distribution of the autocorrelation coefficient in the corresponding PDO region, also demonstrates the corresponding relationship between the change of the background field of the SST and the change of the PDO.
基金Under the auspices of Science and Technology Research Projects of Hunan Province(2009JT3005,2007ZK3094)Knowledge Innovation Project of Chinese Academy of Sciences(KZCX2-SW-415)Foundation of Key Laboratory for Agro-ecological Processes in Subtropical Region and Wetland Project of WWF
文摘Supported by geographical information system,using Costanza method and referring to terrestrial ecosystem service value in China,the influence of land use and land cover change(LUCC)between 1980 and 2000 on ecosystem service value in the up and middle reaches of Dongting Lake basin was analyzed in this study.The results showed that the estimated value of ecosystem services decreased 8.416 9×108 CNY over a 21-year period,and the main reasons were that the land for forest use was exploited for cropland and construction land use in study area.Further analysis results showed that the value of single ecosystem service function such as gas regulation,climate regulation,soil formation and conservation,biodiversity conservation,raw materials as well as recreation decreased significantly;and that of provision of water conservation,waste treatment and food production increased obviously in the area.The results of coefficient sensitivity analysis indicated that these estimates were reliable.
文摘Using 2. 5 ×2. 5 winds and pressure grid data, the angular momentum budgets are studied in this paper for TC 9012 (Yancy) which was kept active 65 hours after land fall. It is found that the inland TC 9012 moved into the center of a relatively stable saddle, in which large amount of humid air was entrained into the storm from the southerly jet at low level to bund up the energy of latent heat, the weak cold air coming from the north provided it with baroclinic energy, while the vorticity transfer of geostrophic angular momentum on the radius 4°-8°from the cyclone center at upper troposphere and the input of cyclonic angular momentum produced by the βterm are immediate factors maintaining the central pressure and maximum winds.
文摘The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process.
文摘This article reviews: 1) The role of natural and human-induced controls in influencing large herbivore populations;2) how human controls (i.e., policy instruments, incentives and provisions) influence human activities and wildlife conservation;and 3) media framing of wildlife conservation using Zimbabwe as a case study, in particular Gonarezhou National Park and adjacent areas. The review shows that droughts are important in influencing large herbivore populations in semi-arid ecosystems;political instability and economic collapse does not necessarily lead to increased illegal hunting in situations where policy instruments, such as laws, are enforced. A higher perceived effectiveness of Communal Areas Management Programme for Indigenous Resources was partly associated with a decline in human-wildlife conflicts and there was a spill-over effect of frames from the political domain into wildlife conservation following Zimbabwe’s land reforms in 2000. It is concluded that natural bottom-up processes (e.g., droughts) influence large herbivore population dynamics whereas policy instruments, incentives, provisions and societal frames mainly have a top-down effect on wild large herbivore populations in savanna ecosystems.
文摘The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge state or account for neutrino mass. This holographic analysis treats charged Standard Model fermions as spheres with mass 0.187 g/cm<sup>2</sup> times their surface area, using the proportionality constant in the holographic relation between mass of the observable universe and event horizon radius. The analysis requires three Standard Model fermions per charge state and relates up quark and down quark masses to electron mass. Holographic analysis specifies electron mass, to six significant figures, in terms of fundamental constants α,ℏ,G,Λ and Ω Λ . Treating neutrinos as spheres and equating electron neutrino energy density with cosmic vacuum energy density predicts neutrino masses consistent with experiment.
基金National Natural Science Foundation of China(No.40971026)Key State Lab of Urban Water Resource and Environment,China(No.ES201109)+1 种基金National Science and Technology Infrastructure Program,China(No.2012BAC19B05-4)Natural Science Foundation of Jilin Province,China(No.20130101085JC)
文摘Traditional approach to evaluate the impacts of climate change on the water resources systems always begins with downscaling general circulation models( GCMs) and proceeding back to the hydrological model. This approach has some distinct disadvantages: 1) GCM must be downscaled; 2) different GCMs are difficult to be reconciled for a given climate change scenario;3) the uncertainty of GCMs is far from the requirement of the evaluation of climate change impacts. To overcome these limits of the traditional method,a new method termed as "bottom-up"was used for climate risk assessment that linked vulnerability assessment with climate information to assess the risk of climate change impacts on the Quabbin Reservoir,and United States under A2 scenario.The result shows that the risks are around 20% in 2006-2035 and 2036-2055,50% in 2066-2095.
文摘Purpose: To alert the medical community that whole exome sequencing can find accessory gene changes in well-known syndromes that alter preventive health care and management. Meaning: A collagen type VI gene change adds muscle weakness, hypermobility, and dysautonomia concerns to usual management considerations for Down syndrome. Methods: Commercial whole exome sequencing combined with clinical interpretation of DNA sequence change added new considerations to patient management and parental counsel. Results: An 11-year-old child with the trisomy 21 form of Down syndrome who was evaluated for extraordinary joint laxity had a heterozygous collagen type VI aspartic to glutamic acid (COL6A3 c.6360 C>G p.Asp2120Glu) gene change found by whole exome sequencing. The DNA variant was qualified as having strong relevance to the enhanced hypermobility due to prior association of collagen 6 gene changes with myopathy. Conclusions: Dual diagnosis of Ehlers-Danlos syndrome was not assigned because the patient lacked criteria like bruising, unusual scars, or selected dysautonomia symptoms. The concept of a hypermobility spectrum offers advantages for management of its constituent conditions if clinically guided ascertainment and DNA diagnostics are employed.
文摘English reading has gained much attention among teachers and students and become one of the research heatpots in English pedagogy.The paper gives a brief introduction of the theories of reading and attempts to apply the schema theory of reading into the classroom teaching.The classroom practice reveals that English reading under the guidance of schema theory proves effective and raises students' awareness of strategies.
文摘The explosive initiator is one kind of sensitivity products with long life and high reliability.In order to improve the storage reliability assessment,the method of storage reliability assessment for explosive initiator was proposed based on time series model using the sensitivity test data.In the method,the up and down test was used to estimate the distribution parameters of threshold.And an approach to design the up and down test was present to draw better estimations.Furthermore,the method of shrinkage estimation was introduced to get a better estimation of scale parameter by combining the sample information with prior information.The simulation result shows that the shrinkage estimation is better than traditional estimation under certain conditions.With the distribution parameters estimations,the time series models were used to describe the changing trends of distribution parameters along with storage time.Then for a fixed storage time,the distribution parameters were predicted based on the models.Finally,the confidence interval of storage reliability was obtained by fiducial inference.The illustrative example shows that the method is available for storage reliability assessment of the explosive initiator with high reliability.
文摘The rapid expansion of urban areas due to rise in population and economic growth is increasing additional demand on natural resources thereby causing land-use changes especially in megacities. Therefore, serious problems associated with rapid development such as additional infrastructure, informal settlements, environmental pollution, destruction of ecological structure and scarcity of natural resources has been studied carefully using remote sensing and GIS technologies for a rapidly grown megacity namely, Delhi. The present work evaluates the land use/land cover (LULC) changes and urban expansion in Mega city Delhi and highlights the major impact of rapid urbanization and population growth on the land cover changes which needs immediate attention. The results indicate that the city is expanding towards its peripheral region with the conversion of rural regions in to urban expansions. Built-up area of Delhi witnessed an overall increment from 540.7 km2 to 791.96 km2 or 16.86% of the total city area (1,490 km2 ) during the study period 1997 to 2008 which mainly came from agriculture land, waste land, scrub-land, sandy areas and water bodies. The increment in forest cover of 0.5 % is very small when considering the increment in built up category to 17%. Total area of waterbodies has reduced by 52.9% in a ten year period (58.26 km2 in 1997 to 27.43 km2 in 2008) with shallow waterbodies now having a dismal presence. LULC changes are studied with the urban growth parameters such as population, vehicles, gross state domestic product etc. The results lay emphasis on the concepts of urban planning to be applied such that more consideration is towards the preservation and management of natural land use classes which will increase the quality of life in an urban environment.
文摘Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory conditions mainly of the colon and small intestine. Crohn’s disease (CD) and ulcerative colitis (UC) are the most frequent types of IBD. IBD is a complex disease which arises as a result of the interaction of environmental, genetic and immunological factors. It is increasingly thought that alterations of immunological reactions of the patients to their own enterable bacteria (microfilm) may contribute to inflammation. It is characterized by mucosal and sub mucosal inflammation, perpetuated by infiltration of activated leukocytes. CD may affect the whole gastrointestinal tract while UC only attacks the large intestine. The therapeutic goal is to achieve a steroid-free long lasting remission in both entities. UC has the possibility to be cured by a total colectomy, while CD never can be cured by any operation. A lifelong intake of drugs is mostly necessary and essential. Medical treatment of IBD has to be individualized to each patient and usually starts with anti-inflammatory drugs. The choice what kind of drugs and what route administered (oral, rectal, intravenous) depends on factors including the type, the localization, and severity of the patient’s disease. IBD may require immune-suppression to control symptoms such as prednisolone, thiopurines, calcineurin or sometimes folic acid inhibitors or biologics like TNF-α inhibitors or anti-integrin antibodies. For both types of disease (CD, UC) the same drugs are available but they differ in their preference in efficacy between CD and UC as 5-aminosalicylic acid for UC or budesonide for ileocecal CD. As therapeutic alternative the main mediators of the disease, namely the activated pro-inflammatory cytokine producing leukocytes can be selectively removed via two apheresis systems (Adacolumn and Cellsorba) in steroid-refractory or dependent cases. Extracorporeal photopheresis results in an increase of regulatory B cells, regulatory CD8<sup>+</sup> T cells and T-regs Type 1. Both types of apheresis were able to induce clinical remission and mucosal healing accompanied by tapering of steroids.
文摘The top-down and bottom-up are two main approaches used in teaching extensive reading and both of them should be used alternatively so that students can not only understand the details but also the main ideas of reading materials.The importance of using top-down approach is emphasized and some suggestions are given on the problem that students pay so much attention on vocabulary and grammar rather than main idea in reading.
文摘This paper aims at making some research on spatial metaphor from cognitive angle.Spatial metaphor is a basic tool which can make us more familiar with our world,and lots of abstract concepts are based on it.Take "UP-DOWN" for example,this paper will mainly discuss the symmetry and dissymmetry of its extension in Chinese and English.
文摘According to the traditional fatigue constant life curve, the concept and the universal expression of the generalized fatigue constant life curve were proposed. Then, on the basis of the optimization method of the correlation coefficient, the parameter estimation formulas were induced and the generalized fatigue constant life curve with the reliability level p was given. From P-S-a-S-m curve, the two-dimensional probability distribution of the fatigue limit was derived. After then, three se, of tests of LY11 CZ corresponding to the different average stress were carried out in terms of the two-dimensional up-down method. Finally, the methods are used to analyze the test results, and it is found that the analyzed results with the high precision may be obtained.
文摘In recent years, much attention has been paid to software-defined radio (SDR) technologies for multimode wireless systems SDR can be defined as a radio communication system that uses software to modulate and demodulate radio signals. This article describes concepts, theory, and design principles for SDR down-conversion and up-conversion. Design issues in SDR down-conversion are discussed, and two different architectures, super-heterodyne and direct-conversion, are proposed. Design issues in SDR up-conversion are also discussed, and trade-offs in the design of filters, mixers, NCO, DAC, and signal processing are highlighted.