Large quantities of ballast water discharge from ocean going ships in sea ports of China is one of the important factorswhich cause the spread of aquatic nonindigenous harmful species isolated geographically by waters...Large quantities of ballast water discharge from ocean going ships in sea ports of China is one of the important factorswhich cause the spread of aquatic nonindigenous harmful species isolated geographically by waters,the deteriorating environment of the near-shore water area and the frequent outbreaks of red tides.In this paper,the total amount of the ballast water input estimation model for entry ships in Chinese ports was established.The information of foreign trade shipping and the import and export goods released publicly by the State Department of Transportation and the State General Administration of Customs were investigated.And then,the input features and its ecological environment risk of ballast water in China's offshore entry ships from2007to2012were analyzed based on the established total input amounts of ballast water from entry ships to Chinese sea ports together with the ballast water input ratio of the five major port-groups in China.The results show that:the total ballast water input amounts from entry ships of the five major port-groups in China are extremely imbalanced.The most developed Yangtze River Delta in economy has the biggest total ballast water input amounts,103.61million tons in2012.The second is the Circum-Bohai Sea Region(73.66million tons)and the third is the Pearl River Delta(67.24million tons).The total ballast water input amounts of the northwest and the southwest coastal areas are less,only16.57and5.71million tons respectively.The large quantity of entry ships’ballast water discharge has been an enormous threat to ecological environment of our country's sea areas,especially to economically developed regions.展开更多
In this paper, a generalized three-dimensional(3D) scattering channel model for macrocellular land mobile environments is considered. This model simultaneously describes angular arrival of multi-path signals in the az...In this paper, a generalized three-dimensional(3D) scattering channel model for macrocellular land mobile environments is considered. This model simultaneously describes angular arrival of multi-path signals in the azimuth and elevation planes in an environment where uniformly distributed scatterers are assumed to be present in hemispheroids around the base station(BS) and mobile station(MS). Using this channel model, we first derive the closed-form expression for the joint and marginal probability density functions of the angle-of-arrival and time-of-arrival measured at the BS and the MS corresponding to the azimuth and elevation angles. Next, we derive an expression for the Doppler spectral distribution caused by motion of the MSs. Furthermore, we analyze the performance of multiple-input multiple-output antenna systems numerically. The results show that the proposed 3D scattering channel model performs better than previously proposed two-dimensional(2D) models for indoor and outdoor environments. We compare the results with previous scattering channel models and measurement results to validate the generalizability of our model.展开更多
Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have re...Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have reliable, incorporative area-based security-information networks to protect their environments. Plural （dual） surveillance which is rooted in biologic senses, e.g., from two-eyes, can have the feature of fault-tolerance, availability and maintainability in monitoring tasks. Further, it can fit the contemporary wireless communication methods being incorporated with MIMO （multi-in multi-out）, to prevent information loss, interference, unexpected changes caused by such as clogged water and chemical reactions. Consequently, network prototypes, including SW （spider-web）network and CCC （cube-connected cycle）, are proactively suggested. More reliable capabilities, including those encouraging local ferries and drones, for efficient logistic operation and mixed-use buildings with quality assured performance, can be good for smart urban growth, resource utilization in Taiwan, which is aimed as an aerotropolis--a means for placemaking.展开更多
Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Bas...Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Based on the field study result, by using the simulation sol, ware, THERB, the effectiveness of the crawlspace warm air heating system has been examined. The effect of the factors, such as the wind amount circulating between crawlspace and indoor space, foundation insulation condition, and heat amount into the crawlspace, on the indoor thermal environment has been analyzed. Based on these analyses, the measured crawlspace heating system can make the average temperature of the living room above 20℃. These two houses have excellent thermal environment. According to the simulating result, heat amount input into crawlspace, which can make comfortable indoor thermal environment, for every month in heating period has been roughly concluded, and they are 600 W in December and March and 800 W in February and January, respectively.展开更多
语言能力是人类的特征之一.人类语言具有极其复杂的结构,可以用有限的元素生成出无数的语句,用来表达思想、情感,传承人类文明.但人类是如何获得和学习语言的问题至今未解.Science杂志在2005年提出了125个需要探索的科学问题,"为...语言能力是人类的特征之一.人类语言具有极其复杂的结构,可以用有限的元素生成出无数的语句,用来表达思想、情感,传承人类文明.但人类是如何获得和学习语言的问题至今未解.Science杂志在2005年提出了125个需要探索的科学问题,"为什么存在语言学习的关键期"(Why are there critical periods for language learning?)即是其中之一.本文重点阐述控制或调节语言学习关键期运作的因素,以及影响关键期内语言学习的重要条件,并指出了未来可能的研究方向.展开更多
By reference of the δ18O and δ13C isotopic compositions of G.sacculifer and accelerator mass spectrometry (AMS)14C dates, the U K 37 , ∑C – 21 /∑C +- 22 and Pr/Pn in core DGKS9603 have been used to characterize t...By reference of the δ18O and δ13C isotopic compositions of G.sacculifer and accelerator mass spectrometry (AMS)14C dates, the U K 37 , ∑C – 21 /∑C +- 22 and Pr/Pn in core DGKS9603 have been used to characterize the changes of paleooceanographic environment occurring in the East China Sea (ECS) during the last 35000 years. The stratigraphic records of these proxies have shown that during the last 35 ka the Okinawa Trough has gone through 7 stronger cold-climate events (C1–C7) and 9 terrigenous matter-decreasing events (e2–e9), of which, the C1 corresponds to the cold episode occurring in the middle late Holocene, C2–C4 and C7 correspond to the H1–H4 events, respectively. e1 and e3–e8 correspond to the decrease of sea surface temperature (SST), respectively. The terrigenous inputs increased when Heinrich events occurred. Climate colding resulted in the decrease of terrigenous matter transported by rivers, and the increase of that transported by winter monsoon. Heinrich events are closely related to East Asia monsoon. During the Last Glacial Maximum (LGM, 15.5–25.8 Cal ka BP), reduction environment fluctuated strongly, bringing forth three stronger reduction events (R1–R3) and one weaker reduction event (O), of which, R1–R3 correspond to the decrease of SST and increase of terrigenous nutrient and O corresponds to the decrease of terrigenous nutrient. The fluctuation of reduction condition must be related to the change of sea surface productivity.展开更多
In this paper, a model of Beddington-DeAngelies chemostat involving two species of micro-organism competing for two perfectly complementary growth-limiting nutrients and pulsed input of toxicant in the polluted enviro...In this paper, a model of Beddington-DeAngelies chemostat involving two species of micro-organism competing for two perfectly complementary growth-limiting nutrients and pulsed input of toxicant in the polluted environment was studied. Using Floquet theory and small amplitude perturbation method, a conclusion was that there exists twomicro-organism eradication periodic solution and which is global asymptotical stability. At the same time, the condition of the permanence for system was obtained. From the biological point of view, the method for protecting species is to improve the amount of impulsive period, and control the amount of toxicant input to the chemostat. Finally, our results are illustrated by numerical simulations.展开更多
For the interaction of parasitoids and their insect hosts in the laboratory environment, a novel mathematical model with impulsive resource inputs, stage-structure, maturation delays and negative binomial distribution...For the interaction of parasitoids and their insect hosts in the laboratory environment, a novel mathematical model with impulsive resource inputs, stage-structure, maturation delays and negative binomial distribution is proposed. Based on the adaptability of the insect host to the environment, we study the permanence of the system in two cases and gain conditions under which the host and parasitoid species can coexist with impulsive resource inputs. We also discuss the existence of the positive periodic solution when the system is permanent by applying a fixed point theory. Besides, we perform numerical simulations which not only confirm but also further enhance our theoretical results. The simulations show that when total input of resource is fixed, smaller input amounts with shorter periods of impulsive delivery produce smaller oscillation amplitudes for both the host and parasitoid populations at the juvenile stage. However, both the densities of adult host and adult parasitoid are not affected by the resource management strategy. Furthermore, we also reconfirm that larger maturation delays, either the host or the parasitoid＇s delay, lead to any more individuals staying at the inmature stage of the species, while the adult populations decline dramatically at the same time. On the other hand, larger host maturation delays promote the parasitoid＇s population growth at both stages, and the impact of parasitoid maturation delay on the host population is almost the same but not as dramatic. These findings give us a deeper understanding about the host parasitoid interaction in laboratory environment.展开更多
文摘Large quantities of ballast water discharge from ocean going ships in sea ports of China is one of the important factorswhich cause the spread of aquatic nonindigenous harmful species isolated geographically by waters,the deteriorating environment of the near-shore water area and the frequent outbreaks of red tides.In this paper,the total amount of the ballast water input estimation model for entry ships in Chinese ports was established.The information of foreign trade shipping and the import and export goods released publicly by the State Department of Transportation and the State General Administration of Customs were investigated.And then,the input features and its ecological environment risk of ballast water in China's offshore entry ships from2007to2012were analyzed based on the established total input amounts of ballast water from entry ships to Chinese sea ports together with the ballast water input ratio of the five major port-groups in China.The results show that:the total ballast water input amounts from entry ships of the five major port-groups in China are extremely imbalanced.The most developed Yangtze River Delta in economy has the biggest total ballast water input amounts,103.61million tons in2012.The second is the Circum-Bohai Sea Region(73.66million tons)and the third is the Pearl River Delta(67.24million tons).The total ballast water input amounts of the northwest and the southwest coastal areas are less,only16.57and5.71million tons respectively.The large quantity of entry ships’ballast water discharge has been an enormous threat to ecological environment of our country's sea areas,especially to economically developed regions.
基金supported by the National Nature Science Foundation of China (No.61471153)the Scientific and Technological Support Project (Industry) of Jiangsu Province (No. BE2011195)the Major Program of the Natural Science Foundation of Institution of Higher Education of Jiangsu Province (No. 14KJA510001)
文摘In this paper, a generalized three-dimensional(3D) scattering channel model for macrocellular land mobile environments is considered. This model simultaneously describes angular arrival of multi-path signals in the azimuth and elevation planes in an environment where uniformly distributed scatterers are assumed to be present in hemispheroids around the base station(BS) and mobile station(MS). Using this channel model, we first derive the closed-form expression for the joint and marginal probability density functions of the angle-of-arrival and time-of-arrival measured at the BS and the MS corresponding to the azimuth and elevation angles. Next, we derive an expression for the Doppler spectral distribution caused by motion of the MSs. Furthermore, we analyze the performance of multiple-input multiple-output antenna systems numerically. The results show that the proposed 3D scattering channel model performs better than previously proposed two-dimensional(2D) models for indoor and outdoor environments. We compare the results with previous scattering channel models and measurement results to validate the generalizability of our model.
文摘Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have reliable, incorporative area-based security-information networks to protect their environments. Plural （dual） surveillance which is rooted in biologic senses, e.g., from two-eyes, can have the feature of fault-tolerance, availability and maintainability in monitoring tasks. Further, it can fit the contemporary wireless communication methods being incorporated with MIMO （multi-in multi-out）, to prevent information loss, interference, unexpected changes caused by such as clogged water and chemical reactions. Consequently, network prototypes, including SW （spider-web）network and CCC （cube-connected cycle）, are proactively suggested. More reliable capabilities, including those encouraging local ferries and drones, for efficient logistic operation and mixed-use buildings with quality assured performance, can be good for smart urban growth, resource utilization in Taiwan, which is aimed as an aerotropolis--a means for placemaking.
基金Project(10YZ156) supported by Innovation Program of Shanghai Municipal Education Commission, China Project(sdl09009) supported by Training Program for Outstanding Youth Teacher of Shanghai Municipal Education Commission, China Project(Z2010-103) supported by Shanghai Education Development Foundation, China
文摘Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Based on the field study result, by using the simulation sol, ware, THERB, the effectiveness of the crawlspace warm air heating system has been examined. The effect of the factors, such as the wind amount circulating between crawlspace and indoor space, foundation insulation condition, and heat amount into the crawlspace, on the indoor thermal environment has been analyzed. Based on these analyses, the measured crawlspace heating system can make the average temperature of the living room above 20℃. These two houses have excellent thermal environment. According to the simulating result, heat amount input into crawlspace, which can make comfortable indoor thermal environment, for every month in heating period has been roughly concluded, and they are 600 W in December and March and 800 W in February and January, respectively.
文摘语言能力是人类的特征之一.人类语言具有极其复杂的结构,可以用有限的元素生成出无数的语句,用来表达思想、情感,传承人类文明.但人类是如何获得和学习语言的问题至今未解.Science杂志在2005年提出了125个需要探索的科学问题,"为什么存在语言学习的关键期"(Why are there critical periods for language learning?)即是其中之一.本文重点阐述控制或调节语言学习关键期运作的因素,以及影响关键期内语言学习的重要条件,并指出了未来可能的研究方向.
基金This work was supported by the National Natural Science Foundation of China and National Bureau of Oceanography Foundation for Youth (Grant Nos. 49706068, 49736210 and 99506).
文摘By reference of the δ18O and δ13C isotopic compositions of G.sacculifer and accelerator mass spectrometry (AMS)14C dates, the U K 37 , ∑C – 21 /∑C +- 22 and Pr/Pn in core DGKS9603 have been used to characterize the changes of paleooceanographic environment occurring in the East China Sea (ECS) during the last 35000 years. The stratigraphic records of these proxies have shown that during the last 35 ka the Okinawa Trough has gone through 7 stronger cold-climate events (C1–C7) and 9 terrigenous matter-decreasing events (e2–e9), of which, the C1 corresponds to the cold episode occurring in the middle late Holocene, C2–C4 and C7 correspond to the H1–H4 events, respectively. e1 and e3–e8 correspond to the decrease of sea surface temperature (SST), respectively. The terrigenous inputs increased when Heinrich events occurred. Climate colding resulted in the decrease of terrigenous matter transported by rivers, and the increase of that transported by winter monsoon. Heinrich events are closely related to East Asia monsoon. During the Last Glacial Maximum (LGM, 15.5–25.8 Cal ka BP), reduction environment fluctuated strongly, bringing forth three stronger reduction events (R1–R3) and one weaker reduction event (O), of which, R1–R3 correspond to the decrease of SST and increase of terrigenous nutrient and O corresponds to the decrease of terrigenous nutrient. The fluctuation of reduction condition must be related to the change of sea surface productivity.
基金Acknowledgment This work is supported by Natural Science Foundation of Shanxi Province （2013011002-2）.
文摘In this paper, a model of Beddington-DeAngelies chemostat involving two species of micro-organism competing for two perfectly complementary growth-limiting nutrients and pulsed input of toxicant in the polluted environment was studied. Using Floquet theory and small amplitude perturbation method, a conclusion was that there exists twomicro-organism eradication periodic solution and which is global asymptotical stability. At the same time, the condition of the permanence for system was obtained. From the biological point of view, the method for protecting species is to improve the amount of impulsive period, and control the amount of toxicant input to the chemostat. Finally, our results are illustrated by numerical simulations.
基金Shouzong Liu would like to thank Professor John D. Reeve and Professor Dashun Xu for their valuable input. This work is supported by the National Natural Science Foundation of China （11501489, 11671346, 11371306 and 11601466）, Nanhu Scholars Program of XYNU, Nanhu Scholars Program for Young Scholars of XYNU, Foundation and frontier project of Henan Province （152300410019）, the sci-tech opening cooperation project of Henan Province （172106000071） and Youth Teacher Foundation of XYNU（2016GGJJ-14, 2011079）.
文摘For the interaction of parasitoids and their insect hosts in the laboratory environment, a novel mathematical model with impulsive resource inputs, stage-structure, maturation delays and negative binomial distribution is proposed. Based on the adaptability of the insect host to the environment, we study the permanence of the system in two cases and gain conditions under which the host and parasitoid species can coexist with impulsive resource inputs. We also discuss the existence of the positive periodic solution when the system is permanent by applying a fixed point theory. Besides, we perform numerical simulations which not only confirm but also further enhance our theoretical results. The simulations show that when total input of resource is fixed, smaller input amounts with shorter periods of impulsive delivery produce smaller oscillation amplitudes for both the host and parasitoid populations at the juvenile stage. However, both the densities of adult host and adult parasitoid are not affected by the resource management strategy. Furthermore, we also reconfirm that larger maturation delays, either the host or the parasitoid＇s delay, lead to any more individuals staying at the inmature stage of the species, while the adult populations decline dramatically at the same time. On the other hand, larger host maturation delays promote the parasitoid＇s population growth at both stages, and the impact of parasitoid maturation delay on the host population is almost the same but not as dramatic. These findings give us a deeper understanding about the host parasitoid interaction in laboratory environment.
