How should international oil and gas enterprises realize energy transformation through green financial instrumentsØrsted located in Denmark is taken as an example to elaborate the methods with which international...How should international oil and gas enterprises realize energy transformation through green financial instrumentsØrsted located in Denmark is taken as an example to elaborate the methods with which international oil and gas enterprises realize energy transformation by green financial instruments.Ørsted has transformed from fossil energy to clean energy since 2009,and has now become a wind power giant in Denmark,with an annual income of DKK 67.8 billion(USD 9.8 billion).During the whole transformation process,the company comprehensively applied internal and external green financial instruments to assist the transformation.展开更多
The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond （UNCD） fihns grown from focused microwave Ar/CHa/H2 （argon- rich） plasma were systematically stud...The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond （UNCD） fihns grown from focused microwave Ar/CHa/H2 （argon- rich） plasma were systematically studied. The surface roughness, nucleation density, mierostruc- ture, and crystallinity of the obtained UNCD films were characterized by atomic force microscope （AFM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and Raman spectroscopy. The results indicate that the nucleation enhancement was found to be sensitive to the different sur- face pretreatment methods, and a higher initial nucleation density leads to highly smooth UNCD films. When the silicon substrate was pretreated by a two-step method, i.e., plasma treatment followed by ultrasonic vibration with diamond nanopowder, the grain size of the UNCD films was greatly decreased： about 7.5 nm can be achieved. In addition, the grain size of UNCD films depends on the substrate pretreatment methods and roughness, which indicates that the surface of substrate profile has a ＂genetic characteristic＂.展开更多
In this paper we prove a central limit theorem and a moderate deviation principle for a class of semilinear stochastic partial differential equations, which contain the stochastic Burgers’ equation and the stochastic...In this paper we prove a central limit theorem and a moderate deviation principle for a class of semilinear stochastic partial differential equations, which contain the stochastic Burgers’ equation and the stochastic reaction-diffusion equation. The weak convergence method plays an important role.展开更多
In 2020,China announced that it will strive to achieve carbon peak by 2030 and carbon neutrality by 2060.The time from carbon peak to carbon neutrality promised by China is far shorter than that of developed countries...In 2020,China announced that it will strive to achieve carbon peak by 2030 and carbon neutrality by 2060.The time from carbon peak to carbon neutrality promised by China is far shorter than that of developed countries,which requires hard work.Under the trend of carbon neutrality,Chinese oil and gas enterprises need to accelerate the pace of adjusting to the change in energy consumption structure.It is urgent to formulate energy transformation strategy in line with the trend of“carbon neutrality”.In the future,China’s oil and gas enterprises should improve the low-carbon level in the production process,reduce their own production and operation carbon emissions,increase the supply proportion of natural gas and renewable energy,reduce the emission level of energy consumption side,develop the technology of carbon capture,utilization and storage,offset unavoidable greenhouse gas emissions,play an active role in international cooperation,and use reasonable green financial tools to promote the realization of China’s carbon neutrality goal.展开更多
Under the instruction of the author's own confession in the preface of The House of the Seven Gables, it's easy for readers and critics to take the theme of this novel as past and present, stasis and change, a...Under the instruction of the author's own confession in the preface of The House of the Seven Gables, it's easy for readers and critics to take the theme of this novel as past and present, stasis and change, aristocracy and democracy, and then to unfavor?ably judge Pycheon siblings, the representatives of the former, by Holgrave, that of the latter. However, by using two narrative voic?es simultaneously in the novel, an intradiegeitic one and an extradeigetic one, Hawthorne actually reveals his equal disapproval of both the Pycheon siblings and Holgrave. In the intradiegetic narrative, the narrative voice as a whole takes its side with Holgrave and reveals Pycheon siblings'isolation from the united struggle of mankind. In the extradiegetic narrative where the narrator ad?dresses directly to his readers, the narrator expresses a similar disapproval of Holgrave, who is equally isolated from the chain of hu?manity for lacking sympathy for his fellow beings. With the co-existence of two narrative voices, Hawthorne's true concern lies in calling attention to the equally dangerous situations of isolation from the chain of humanity:an isolation from the chain of progress and that of human sympathy.展开更多
Advertising becomes indispensable in modern times due to its wide influence on consumers and it is presented in formsof various media including newspapers, radio and television, etc. Advertisement, with its visual and...Advertising becomes indispensable in modern times due to its wide influence on consumers and it is presented in formsof various media including newspapers, radio and television, etc. Advertisement, with its visual and verbal features, is often studiedby many scholars from a linguistic perspective. This article will compare two print advertisements in magazines targeting males andfemales respectively in terms of gendered social actors regarding multimodality and intertextuality.展开更多
In this thesis,compared with pioneer ladies,Alexandra and Antonia,the lost ladies Mrs.Forrest and Myra Henshawe worshipped mammonism as its slaves,hypocritical Christians rather than devoted disciples,unbuttoned hedon...In this thesis,compared with pioneer ladies,Alexandra and Antonia,the lost ladies Mrs.Forrest and Myra Henshawe worshipped mammonism as its slaves,hypocritical Christians rather than devoted disciples,unbuttoned hedonists rather than weather-beaten and down-to-earth innovators.Cynically fear of poverty,those depraved ladies elegized the previous ostenta tious years contrasted to those industrious pioneers of anti-temptation,immune to hedonism and materialism,and died nameless ly,a symbol of decadence of the pioneering age.展开更多
Focusing on pioneers'valiancy and innovation in frontiers'depersonalize life,this thesis applauds their down-toearth spirit and life-to-death struggle against its depressive desperation,its handicapped hardshi...Focusing on pioneers'valiancy and innovation in frontiers'depersonalize life,this thesis applauds their down-toearth spirit and life-to-death struggle against its depressive desperation,its handicapped hardship and miserable misfortunes in Willa Cather's writings--"A Wagner Matinee","The Bohemian Girl",O Pioneers! and My Antonia.Dull and monotonous though pioneers'routines were,the barren land firmly magnetized their escaping feet and instead,invoked their creativity,fear lessness,and self-sacrifice towards it.Hardworking year after year and endeavors arduously,the infertile homesteads had given up to prosperous and productive homelands,a miracle created with industrious hands of courageous and innovative pioneers.展开更多
The objective of this paper is to study the issue of uniformity on asymmetrical designs with two and three mixed levels in terms of Lee discrepancy. Based on the known formulation, we present a new lower bound of Lee ...The objective of this paper is to study the issue of uniformity on asymmetrical designs with two and three mixed levels in terms of Lee discrepancy. Based on the known formulation, we present a new lower bound of Lee discrepancy of fractional factorial designs with two and three mixed levels. Our new lower bound is sharper and more valid than other existing lower bounds in literature, which is a useful complement to the lower bound theory of discrepancies.展开更多
Purpose: Online reviews on tourism attractions provide important references for potential tourists to choose tourism spots. The main goal of this study is conducting sentiment analysis to facilitate users comprehendin...Purpose: Online reviews on tourism attractions provide important references for potential tourists to choose tourism spots. The main goal of this study is conducting sentiment analysis to facilitate users comprehending the large scale of the reviews, based on the comments about Chinese attractions from Japanese tourism website 4 Travel.Design/methodology/approach: Different statistics-and rule-based methods are used to analyze the sentiment of the reviews. Three groups of novel statistics-based methods combining feature selection functions and the traditional term frequency-inverse document frequency(TF-IDF) method are proposed. We also make seven groups of different rulesbased methods. The macro-average and micro-average values for the best classification results of the methods are calculated respectively and the performance of the methods are shown.Findings: We compare the statistics-based and rule-based methods separately and compare the overall performance of the two method. According to the results, it is concluded that the combination of feature selection functions and weightings can strongly improve the overall performance. The emotional vocabulary in the field of tourism(EVT), kaomojis, negative and transitional words can notably improve the performance in all of three categories. The rule-based methods outperform the statistics-based ones with a narrow advantage.Research limitation: Two limitations can be addressed: 1) the empirical studies to verify the validity of the proposed methods are only conducted on Japanese languages; and 2) the deep learning technology is not been incorporated in the methods.Practical implications: The results help to elucidate the intrinsic characteristics of the Japanese language and the influence on sentiment analysis. These findings also provide practical usage guidelines within the field of sentiment analysis of Japanese online tourism reviews.Originality/value: Our research is of practicability. Currently, there are no studies that focus on the sentiment analysis of Japanese reviews about Chinese attractions.展开更多
The asymptotic normality of the fixed number of the maximum likelihood estimators(MLEs)in the directed finite weighted network models with an increasing bi-degree sequence has been established recently.In this article...The asymptotic normality of the fixed number of the maximum likelihood estimators(MLEs)in the directed finite weighted network models with an increasing bi-degree sequence has been established recently.In this article,we further derive the central limit theorem for linear combinations of all the MLEs with an increasing dimension when the edges take finite discrete weight.Simulation studies are provided to illustrate the asymptotic results.展开更多
As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are ...As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are valuable for malware analysis,but how to exploit those permission patterns for malware detection remains an open issue.In this paper,we introduce the contrasting permission patterns to characterize the essential differences between malwares and clean applications from the permission aspect Then a framework based on contrasting permission patterns is presented for Android malware detection.According to the proposed framework,an ensemble classifier,Enclamald,is further developed to detect whether an application is potentially malicious.Every contrasting permission pattern is acting as a weak classifier in Enclamald,and the weighted predictions of involved weak classifiers are aggregated to the final result.Experiments on real-world applications validate that the proposed Enclamald classifier outperforms commonly used classifiers for Android Malware Detection.展开更多
Doubling is a simple but powerful method of constructing two-level tractional factorial designs with high resolution. This article studies uniformity in terms of Lee discrepancy of double designs. We give some linkage...Doubling is a simple but powerful method of constructing two-level tractional factorial designs with high resolution. This article studies uniformity in terms of Lee discrepancy of double designs. We give some linkages between the uniformity of double design and the aberration case of the original one under different criteria. Furthermore, some analytic linkages between the generalized wordlength pattern of double design and that of the original one are firstly provided here, which extend the existing findings. The lower bound of Lee discrepancy for double designs is also given.展开更多
Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gros...Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gross-Pitaevskii energy functional in the mean- field regime, as the particle number N → ∞ and however the scattering length → 0. By fixing N｜k｜, this leads to the mean-field approximation of Bose-Einstein condensates with attractive interactions in R^2.展开更多
A scheme of setting a limit to the TCP sending window size is proposed to improve the TCP fairness between upload and/or download flows in wired-cum-wireless networks. The goodput and delay of the upload and download ...A scheme of setting a limit to the TCP sending window size is proposed to improve the TCP fairness between upload and/or download flows in wired-cum-wireless networks. The goodput and delay of the upload and download TCP flows arc compared to evaluate the TCP fairness for different schemes, which are the different combinations of setting a limit （64 or 4） to the sending window size and using the delayed acknowledgement （ACK） scheme or not. Extensive simulation results and analysis show that （ 1 ） for TCP download flows, setting the limit of sending window size to 4 can improve the fairness; （2） for TCP upload flows, limiting the sending window size and using the delayed ACK strategy are both beneficial to fairness; （3） for TCP download and upload mixture flows, limiting the sending window size to a small value （ e. g. , 4） rather than using the delayed ACK strategy, is the solution to improvement of the fairness ; （4） a large delay interval （200 ms or 300 ms） does not result in improvement in fairness and performance; （ 5 ） a larger TCP packet size （ 1400 B） can improve the TCP upload goodput and decrease the download goodput; in contrast, a smaller TCP packet size （560 B） can increase the download goodput and decrease the upload goodput.展开更多
Chinese immigrants lived a hard life in the United States before 1949.Based on the analysis of their remarkable contributions to the American progress in its economy,society,culture,science,and many other fields,the i...Chinese immigrants lived a hard life in the United States before 1949.Based on the analysis of their remarkable contributions to the American progress in its economy,society,culture,science,and many other fields,the indication is given that the United States should thank the Chinese for their contributions and take active steps to develop friendly relations with China.展开更多
At the end of pioneering age, the women pioneers were substituted by lost ladies from whom the innovation, self-reliance, tolerance and endurance yielded to nihilism, reliant affinity, mammonism and hedonism. To remin...At the end of pioneering age, the women pioneers were substituted by lost ladies from whom the innovation, self-reliance, tolerance and endurance yielded to nihilism, reliant affinity, mammonism and hedonism. To reminisce the glory of pioneering splendors in the integration with the waste west land spiritually and alienation to the materialized modern society, Cather regressed to the memorable bygones in"The Best Years", The Professor's House and elegized the spiritual pioneering by means of infusing Christianity into the uncultivated indigenous inhabitants in Death Comes for the Archbishop.展开更多
By comparison between pioneering ladies in O Pioneers! and My Antonia and lost ladies in A Lost Lady and My Mor tal Enemy,this thesis aims at presenting the independent formers'wholesome loyalty to love and the re...By comparison between pioneering ladies in O Pioneers! and My Antonia and lost ladies in A Lost Lady and My Mor tal Enemy,this thesis aims at presenting the independent formers'wholesome loyalty to love and the reliant latters'marital be trayal.Nihilistic,cynic and despaired,the lost ladies had depraved from romantic love to self-destruction based on material hedo nism;diligent,enterprising and persistent,the pioneering ladies,from innocent girlhood to weather-beaten middle age,had real ized self-fulfillment both in spiritualization and prosperous homesteads.展开更多
This thesis aims at the elaboration of Willa Cather's pioneering themes based on her major works spanning over the prologue and epilogue of American pioneering age. Among which, O Pioneers! and My Antonia applause...This thesis aims at the elaboration of Willa Cather's pioneering themes based on her major works spanning over the prologue and epilogue of American pioneering age. Among which, O Pioneers! and My Antonia applause for the transcendent glory of innovative and enterprising pioneer ladies, declined in A Lost Lady and My Mortal Enemy and substituted with hedonism, affinity reliance and mammonism. In her late years, Cather resurrected her pioneering themes through the recollection of the best bygone time spent in waste west land.展开更多
For a long time, educators and researchers have been searching for the most proper ways for teaching and learning. The concept of'task'has been introduced into educational field in 1980s. InNunan (1989)'s ...For a long time, educators and researchers have been searching for the most proper ways for teaching and learning. The concept of'task'has been introduced into educational field in 1980s. InNunan (1989)'s model of task, there are five phases in-cluding goal, input, activity, teacher role, learner role and settings.With regard to activities, it is essential for teachers to encourage their students to engage in them through interaction. This article will study the impact of interaction on TBLT though a sample.展开更多
文摘How should international oil and gas enterprises realize energy transformation through green financial instrumentsØrsted located in Denmark is taken as an example to elaborate the methods with which international oil and gas enterprises realize energy transformation by green financial instruments.Ørsted has transformed from fossil energy to clean energy since 2009,and has now become a wind power giant in Denmark,with an annual income of DKK 67.8 billion(USD 9.8 billion).During the whole transformation process,the company comprehensively applied internal and external green financial instruments to assist the transformation.
基金supported by National Natural Science Foundation of China(No.11175137)the Research Fund of Wuhan Institute of Technology,China(No.11111051)
文摘The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond （UNCD） fihns grown from focused microwave Ar/CHa/H2 （argon- rich） plasma were systematically studied. The surface roughness, nucleation density, mierostruc- ture, and crystallinity of the obtained UNCD films were characterized by atomic force microscope （AFM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and Raman spectroscopy. The results indicate that the nucleation enhancement was found to be sensitive to the different sur- face pretreatment methods, and a higher initial nucleation density leads to highly smooth UNCD films. When the silicon substrate was pretreated by a two-step method, i.e., plasma treatment followed by ultrasonic vibration with diamond nanopowder, the grain size of the UNCD films was greatly decreased： about 7.5 nm can be achieved. In addition, the grain size of UNCD films depends on the substrate pretreatment methods and roughness, which indicates that the surface of substrate profile has a ＂genetic characteristic＂.
基金supported by NSFF(17BTJ034)The research of WANG was supported by NSFC(11871382,11771161).
文摘In this paper we prove a central limit theorem and a moderate deviation principle for a class of semilinear stochastic partial differential equations, which contain the stochastic Burgers’ equation and the stochastic reaction-diffusion equation. The weak convergence method plays an important role.
文摘In 2020,China announced that it will strive to achieve carbon peak by 2030 and carbon neutrality by 2060.The time from carbon peak to carbon neutrality promised by China is far shorter than that of developed countries,which requires hard work.Under the trend of carbon neutrality,Chinese oil and gas enterprises need to accelerate the pace of adjusting to the change in energy consumption structure.It is urgent to formulate energy transformation strategy in line with the trend of“carbon neutrality”.In the future,China’s oil and gas enterprises should improve the low-carbon level in the production process,reduce their own production and operation carbon emissions,increase the supply proportion of natural gas and renewable energy,reduce the emission level of energy consumption side,develop the technology of carbon capture,utilization and storage,offset unavoidable greenhouse gas emissions,play an active role in international cooperation,and use reasonable green financial tools to promote the realization of China’s carbon neutrality goal.
文摘Under the instruction of the author's own confession in the preface of The House of the Seven Gables, it's easy for readers and critics to take the theme of this novel as past and present, stasis and change, aristocracy and democracy, and then to unfavor?ably judge Pycheon siblings, the representatives of the former, by Holgrave, that of the latter. However, by using two narrative voic?es simultaneously in the novel, an intradiegeitic one and an extradeigetic one, Hawthorne actually reveals his equal disapproval of both the Pycheon siblings and Holgrave. In the intradiegetic narrative, the narrative voice as a whole takes its side with Holgrave and reveals Pycheon siblings'isolation from the united struggle of mankind. In the extradiegetic narrative where the narrator ad?dresses directly to his readers, the narrator expresses a similar disapproval of Holgrave, who is equally isolated from the chain of hu?manity for lacking sympathy for his fellow beings. With the co-existence of two narrative voices, Hawthorne's true concern lies in calling attention to the equally dangerous situations of isolation from the chain of humanity:an isolation from the chain of progress and that of human sympathy.
文摘Advertising becomes indispensable in modern times due to its wide influence on consumers and it is presented in formsof various media including newspapers, radio and television, etc. Advertisement, with its visual and verbal features, is often studiedby many scholars from a linguistic perspective. This article will compare two print advertisements in magazines targeting males andfemales respectively in terms of gendered social actors regarding multimodality and intertextuality.
文摘In this thesis,compared with pioneer ladies,Alexandra and Antonia,the lost ladies Mrs.Forrest and Myra Henshawe worshipped mammonism as its slaves,hypocritical Christians rather than devoted disciples,unbuttoned hedonists rather than weather-beaten and down-to-earth innovators.Cynically fear of poverty,those depraved ladies elegized the previous ostenta tious years contrasted to those industrious pioneers of anti-temptation,immune to hedonism and materialism,and died nameless ly,a symbol of decadence of the pioneering age.
文摘Focusing on pioneers'valiancy and innovation in frontiers'depersonalize life,this thesis applauds their down-toearth spirit and life-to-death struggle against its depressive desperation,its handicapped hardship and miserable misfortunes in Willa Cather's writings--"A Wagner Matinee","The Bohemian Girl",O Pioneers! and My Antonia.Dull and monotonous though pioneers'routines were,the barren land firmly magnetized their escaping feet and instead,invoked their creativity,fear lessness,and self-sacrifice towards it.Hardworking year after year and endeavors arduously,the infertile homesteads had given up to prosperous and productive homelands,a miracle created with industrious hands of courageous and innovative pioneers.
基金supported by the National Natural Science Foundation of China(11301546).supported by the National Natural Science Foundation of China(11271147,11471136)
文摘The objective of this paper is to study the issue of uniformity on asymmetrical designs with two and three mixed levels in terms of Lee discrepancy. Based on the known formulation, we present a new lower bound of Lee discrepancy of fractional factorial designs with two and three mixed levels. Our new lower bound is sharper and more valid than other existing lower bounds in literature, which is a useful complement to the lower bound theory of discrepancies.
基金supported by the National Natural Science Foundation of China under the grant #71373286 and # 71603189the Major Project of the Ministry of Education of China (Grant No. 17JZD034)
文摘Purpose: Online reviews on tourism attractions provide important references for potential tourists to choose tourism spots. The main goal of this study is conducting sentiment analysis to facilitate users comprehending the large scale of the reviews, based on the comments about Chinese attractions from Japanese tourism website 4 Travel.Design/methodology/approach: Different statistics-and rule-based methods are used to analyze the sentiment of the reviews. Three groups of novel statistics-based methods combining feature selection functions and the traditional term frequency-inverse document frequency(TF-IDF) method are proposed. We also make seven groups of different rulesbased methods. The macro-average and micro-average values for the best classification results of the methods are calculated respectively and the performance of the methods are shown.Findings: We compare the statistics-based and rule-based methods separately and compare the overall performance of the two method. According to the results, it is concluded that the combination of feature selection functions and weightings can strongly improve the overall performance. The emotional vocabulary in the field of tourism(EVT), kaomojis, negative and transitional words can notably improve the performance in all of three categories. The rule-based methods outperform the statistics-based ones with a narrow advantage.Research limitation: Two limitations can be addressed: 1) the empirical studies to verify the validity of the proposed methods are only conducted on Japanese languages; and 2) the deep learning technology is not been incorporated in the methods.Practical implications: The results help to elucidate the intrinsic characteristics of the Japanese language and the influence on sentiment analysis. These findings also provide practical usage guidelines within the field of sentiment analysis of Japanese online tourism reviews.Originality/value: Our research is of practicability. Currently, there are no studies that focus on the sentiment analysis of Japanese reviews about Chinese attractions.
基金Luo's research is partially supported by the Fundamental Research Funds for the Central Universities(South-Central University for Nationalities(CZQ19010))National Natural Science Foundation of China(11801576)+2 种基金the Scientific Research Funds of South-Central University For Nationalities(YZZ17007)Qin's research is partially supported by National Natural Science Foundation of China(11871237)Wang's research is partially supported by the Fundamental Research Funds for the Central Universities(South-Central University for Nationalities(CZQ18017)).
文摘The asymptotic normality of the fixed number of the maximum likelihood estimators(MLEs)in the directed finite weighted network models with an increasing bi-degree sequence has been established recently.In this article,we further derive the central limit theorem for linear combinations of all the MLEs with an increasing dimension when the edges take finite discrete weight.Simulation studies are provided to illustrate the asymptotic results.
基金This work was supported by Deakin Cyber Security Research Cluster National Natural Science Foundation of China under Grant Nos. 61304067 and 61202211 +1 种基金 Guangxi Key Laboratory of Trusted Software No. kx201325 the Fundamental Research Funds for the Central Universities under Grant No 31541311314.
文摘As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are valuable for malware analysis,but how to exploit those permission patterns for malware detection remains an open issue.In this paper,we introduce the contrasting permission patterns to characterize the essential differences between malwares and clean applications from the permission aspect Then a framework based on contrasting permission patterns is presented for Android malware detection.According to the proposed framework,an ensemble classifier,Enclamald,is further developed to detect whether an application is potentially malicious.Every contrasting permission pattern is acting as a weak classifier in Enclamald,and the weighted predictions of involved weak classifiers are aggregated to the final result.Experiments on real-world applications validate that the proposed Enclamald classifier outperforms commonly used classifiers for Android Malware Detection.
基金supported by NSFC(11271147,11301546,and 11401596)supported by NSFC(11271147 and 11471136)the Financially supported by self-determined research funds of CCNU from the colleges basic research and operation of MOE(CCNU16A02012)
文摘Doubling is a simple but powerful method of constructing two-level tractional factorial designs with high resolution. This article studies uniformity in terms of Lee discrepancy of double designs. We give some linkages between the uniformity of double design and the aberration case of the original one under different criteria. Furthermore, some analytic linkages between the generalized wordlength pattern of double design and that of the original one are firstly provided here, which extend the existing findings. The lower bound of Lee discrepancy for double designs is also given.
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China,National Center for Mathematics and Interdisciplinary Sciences in China
文摘Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gross-Pitaevskii energy functional in the mean- field regime, as the particle number N → ∞ and however the scattering length → 0. By fixing N｜k｜, this leads to the mean-field approximation of Bose-Einstein condensates with attractive interactions in R^2.
基金The National Science Foundation of Chi-na (No.90412010)the Major State Basic Research Devel-opment Program of China(973 Proguam) (No.2003CB317003)
文摘A scheme of setting a limit to the TCP sending window size is proposed to improve the TCP fairness between upload and/or download flows in wired-cum-wireless networks. The goodput and delay of the upload and download TCP flows arc compared to evaluate the TCP fairness for different schemes, which are the different combinations of setting a limit （64 or 4） to the sending window size and using the delayed acknowledgement （ACK） scheme or not. Extensive simulation results and analysis show that （ 1 ） for TCP download flows, setting the limit of sending window size to 4 can improve the fairness; （2） for TCP upload flows, limiting the sending window size and using the delayed ACK strategy are both beneficial to fairness; （3） for TCP download and upload mixture flows, limiting the sending window size to a small value （ e. g. , 4） rather than using the delayed ACK strategy, is the solution to improvement of the fairness ; （4） a large delay interval （200 ms or 300 ms） does not result in improvement in fairness and performance; （ 5 ） a larger TCP packet size （ 1400 B） can improve the TCP upload goodput and decrease the download goodput; in contrast, a smaller TCP packet size （560 B） can increase the download goodput and decrease the upload goodput.
文摘Chinese immigrants lived a hard life in the United States before 1949.Based on the analysis of their remarkable contributions to the American progress in its economy,society,culture,science,and many other fields,the indication is given that the United States should thank the Chinese for their contributions and take active steps to develop friendly relations with China.
文摘At the end of pioneering age, the women pioneers were substituted by lost ladies from whom the innovation, self-reliance, tolerance and endurance yielded to nihilism, reliant affinity, mammonism and hedonism. To reminisce the glory of pioneering splendors in the integration with the waste west land spiritually and alienation to the materialized modern society, Cather regressed to the memorable bygones in"The Best Years", The Professor's House and elegized the spiritual pioneering by means of infusing Christianity into the uncultivated indigenous inhabitants in Death Comes for the Archbishop.
文摘By comparison between pioneering ladies in O Pioneers! and My Antonia and lost ladies in A Lost Lady and My Mor tal Enemy,this thesis aims at presenting the independent formers'wholesome loyalty to love and the reliant latters'marital be trayal.Nihilistic,cynic and despaired,the lost ladies had depraved from romantic love to self-destruction based on material hedo nism;diligent,enterprising and persistent,the pioneering ladies,from innocent girlhood to weather-beaten middle age,had real ized self-fulfillment both in spiritualization and prosperous homesteads.
文摘This thesis aims at the elaboration of Willa Cather's pioneering themes based on her major works spanning over the prologue and epilogue of American pioneering age. Among which, O Pioneers! and My Antonia applause for the transcendent glory of innovative and enterprising pioneer ladies, declined in A Lost Lady and My Mortal Enemy and substituted with hedonism, affinity reliance and mammonism. In her late years, Cather resurrected her pioneering themes through the recollection of the best bygone time spent in waste west land.
文摘For a long time, educators and researchers have been searching for the most proper ways for teaching and learning. The concept of'task'has been introduced into educational field in 1980s. InNunan (1989)'s model of task, there are five phases in-cluding goal, input, activity, teacher role, learner role and settings.With regard to activities, it is essential for teachers to encourage their students to engage in them through interaction. This article will study the impact of interaction on TBLT though a sample.
