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“阴/阳”和“positive/negative”之多义现象的认知对比研究
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作者 刘臻 张珊珊 梅德明 《语言教育》 2014年第4期53-56,60,共5页
多义现象是当今语言学研究的一个重要方面,从认知语言学的视角对多义现象进行对比研究是当今语义研究的一个热点,已取得了不少的研究成果,但是对于"阴/阳"和"positive/negative"这两组具有独特民族特色的字词的语... 多义现象是当今语言学研究的一个重要方面,从认知语言学的视角对多义现象进行对比研究是当今语义研究的一个热点,已取得了不少的研究成果,但是对于"阴/阳"和"positive/negative"这两组具有独特民族特色的字词的语义研究尚鲜有关注。本文从原型范畴和认知隐喻的视角,详细地分析了这两组字词的语义发展特征,发现它们的语义已经形成错综复杂的语义网状结构,既有语义重合之处,也有自己的独特之处,体现了中西文化的独特文化特征和思维特征。 展开更多
关键词 阴/阳 positive/negative 认知 多义现象 语义网络
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Analysis of Positive and Negative Influence of Constructing Xianyang Lake
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作者 王德耀 《Journal of Landscape Research》 2009年第9期25-30,共6页
Xianyang Lake is the abbreviation of Weihe River(Xianyang Urban Area Section) Comprehensive Treatment Project,which is to build a partition wall in the middle of the 500 wide Weihe River Valley,then a 270 m wide water... Xianyang Lake is the abbreviation of Weihe River(Xianyang Urban Area Section) Comprehensive Treatment Project,which is to build a partition wall in the middle of the 500 wide Weihe River Valley,then a 270 m wide water storage channel on the north side and a 230 m wide muddy water floodway channel on the south side will be formed.Two rubber dams are constructed in the water storage channels to form a 'Xianyang Lake' with an area of 1.24×106 m2,meanwhile,along both sides of Weihe River in this section,slope protection and flood prevention as well as a series of greening and cultural landscape projects are to be constructed.This project,with flood prevention as the core,aims to improve the living environment and protect ecological environment,and realize the comprehensive treatment of river way flood-proofing,desilting,sewage purification,greening and beautification.The construction of Xianyang Lake greatly improves the image of Xianyang City and generates considerable economic,social and ecological benefits,however,it also has negative effects,such as insufficient lake water supply,original ecology being intervened by human activities,aggravating local fiscal burden,and potential threats to the flood-proofing in the lower reaches of Weihe River.The author puts forwards that 'creating a lake by damming the river' in the process of urbanization and solving the conflicts between sectional interests and integrated interests should follow natural laws and go along the track of sustainable development,which is also the orientation of future work,and the concrete reform scheme is to be further studied. 展开更多
关键词 Xianyang LAKE Weihe RIVER positive and negative INFLUENCE
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原型范畴观视角下的中英文多义现象认知对比研究——以“阴/阳”和“positive/negative”为例
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作者 刘臻 《外语与翻译》 2014年第2期42-46,共5页
多义现象是当今语言学研究的一个重要方面,从认知语言学的视角对多义现象进行对比研究是当今语义研究的一个热点并取得了不少的研究成果,但是对于“阴/阳”和“positive/negative”这两组具有独特民族特色的字词的语义研究尚鲜有关... 多义现象是当今语言学研究的一个重要方面,从认知语言学的视角对多义现象进行对比研究是当今语义研究的一个热点并取得了不少的研究成果,但是对于“阴/阳”和“positive/negative”这两组具有独特民族特色的字词的语义研究尚鲜有关注。通过原型范畴和认知隐喻的视角,本文分析了这两组字词的语义发展特征,发现它们的语义已经形成错综复杂的语义网状结构,既有语义重合之处,也有自己的独特之处,体现了中西文化的独特文化特征和思维特征。 展开更多
关键词 阴/阳 positive/negative 认知 多义现象 语义网络
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Positive and negative terrains on northern Shaanxi Loess Plateau 被引量:35
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作者 ZHOU Yi TANG Guo'an +3 位作者 YANG Xin XIAO Chenchao ZHANG Yuan LUO Mingliang 《Journal of Geographical Sciences》 SCIE CSCD 2010年第1期64-76,共13页
The Loess positive and negative terrains (P-N terrains), which are widely distributed on the Loess Plateau, are discussed for the first time by introducing its characteristic, demarcation as well as extraction metho... The Loess positive and negative terrains (P-N terrains), which are widely distributed on the Loess Plateau, are discussed for the first time by introducing its characteristic, demarcation as well as extraction method from high-resolution Digital Elevation Models. Using 5 m-resolution DEMs as original test data, P-N terrains of 48 geomorphological units in different parts of Shaanxi Loess Plateau are extracted accurately. Then six indicators for depicting the geomorphologic landscape and spatial configuration characteristic of P-N terrains are proposed. The spatial distribution rules of these indicators and the relationship between the P-N terrains and Loess relief are discussed for further understanding of Loess landforms. Finally, with the integration of P-N terrains and traditional terrain indices, a series of un-supervised classification methods are applied to make a proper landform classification in northern Shaanxi. Results show that P-N terrains are an effect clue to reveal energy and substance distribution rules on the Loess Plateau. A continuous change of P-N terrains from south to north in Shaanxi Loess Plateau shows an obvious spatial difference of Loess land-forms and the positive terrain area only accounted for 60.5% in this region. The P-N terrains participant landform classification method increases validity of the result, especially in the Loess tableland, Loess tableland-ridge and the Loess low-hill area. This research is significant on the study of Loess landforms with the Digital Terrains Analysis methods. 展开更多
关键词 Loess Plateau positive and negative terrains DEM shoulder-lines spatial differentiation
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Evidence for Positive Darwinian Selection of Vip Gene in Bacillus thuringiensis
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作者 吴金雨 赵方庆 +3 位作者 白洁 邓刚 秦松 包其郁 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第7期649-660,共12页
Vegetative insecticidal proteins (VIPs), produced during the vegetative stage of their growth in Bacillus thuringiensis, are a group of insecticidal proteins and represent the second generation of insecticidal trans... Vegetative insecticidal proteins (VIPs), produced during the vegetative stage of their growth in Bacillus thuringiensis, are a group of insecticidal proteins and represent the second generation of insecticidal trans-genes that will complement the novel δendotoxins in future. Fewer structural and functional relationships of Vip proteins are known in comparison with those of δ-endotoxins. In this study, both the maximum-likelihood methods and the maximum parsimony based sliding window analysis were used to evaluate the molecular evolution of Vip proteins. As a result, strong evidence was found that Vip proteins are subject to the high rates of positive selection, and 16 sites are identified to be under positive selection using the Bayes Empirical Bayesian method. Interestingly, all these positively selected sites are located from site-705 to site-809 in the C-terminus of the Vip proteins. Most of these sites are exposed and clustered in the loop regions when mapped onto its computational predicted secondary tertiary and a part of the tertiary structure. It has been postulated that the high divergence in the C-terminal of Vip proteins may not result from the lack of functional constraints, but rather from the rapid mutation to adapt their targeted insects, driven by positive selection. The potential positive selection pressures may be an attempt to adapt for the "arm race" between Vip proteins and the targeted insects, or to enlarge their target's host range. Sites identified to be under positive selection may be related to the insect host range, which may shed a light on the investigation of the Vip proteins' structural and functional relationships. 展开更多
关键词 Bacillus thuringiensis positive selection sliding window maximum likelihood Vip proteins
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Quantifying spatial scale of positive and negative terrains pattern at watershed-scale:Case in soil and water conservation region on Loess Plateau 被引量:7
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作者 YANG Feng ZHOU Yi 《Journal of Mountain Science》 SCIE CSCD 2017年第8期1642-1654,共13页
The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed sca... The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed scale can serve to elucidate the structural characteristics and spatial patterns of P-N terrains, which benefits a better understanding of watershed evolution and suitable scales for loess landform research. The Two-Term Local Quadrat Variance Analysis(TTLQV) is calculated as the average of the square of the difference between the block totals of all possible adjacent pairs of block size, which can be used to detect both the scale and the intensity of landscape patches(e.g., plant/animal communities and gully networks). In this study, we determined the latitudinal and longitudinal spatial scale of P-N terrain patterns within 104 uniformly distributed watersheds in our target soil and water conservation region. The results showed that TTLQV is very effective for examining the scale of P-N terrain patterns. There were apparently three types of P-N terrain pattern in latitudinal direction(i.e., Loess Tableland type, Loess Hill type, and Transitional Form between Sand and Loess type), whereas there were both lower and higher values for P-N terrain pattern scales in all loess landforms in the longitudinal direction. The P-N terrain pattern alsoclearly presented anisotropy, suggesting that gully networks in the main direction were well-developed while others were relatively undeveloped. In addition, the relationships between the first scales and controlling factors(i.e., gully density, nibble degree, watershed area, mean watershed slope, NDVI, precipitation, loess thickness, and loess landforms) revealed that the first scales are primarily controlled by watershed area and loess landforms. This may indicate that the current spatial pattern of P-N terrains is characterized by internal force. In selecting suitable study areas in China' Loess Plateau, it is crucial to understand four control variables: the spatial scale of the P-N terrain pattern, the watershed area, the main direction of the watershed, and the loess landforms. 展开更多
关键词 positive and negative terrains TTLQV Spatial PATTERN SCALE LOESS LANDFORMS LOESS Plateau
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Oscillation in a Class of Neutral Differential Equations with Positive and Negative Coefficients
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作者 单文锐 葛渭高 郭彦平 《Journal of Beijing Institute of Technology》 EI CAS 2002年第3期321-324,共4页
The oscillatory behavior of neutral differential equation with positive and negative coefficients is investigated by mathematics analysis technique and the fixed point principle. Some sufficient conditions for oscilla... The oscillatory behavior of neutral differential equation with positive and negative coefficients is investigated by mathematics analysis technique and the fixed point principle. Some sufficient conditions for oscillation of neutral differential equation with positive and negative coefficients are obtained. 展开更多
关键词 neutral differential equation OSCILLATION fixed point principle positive and negative coefficients
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Positive Selection Analysis of VP1 Genes of Worldwide Human Enterovirus 71 Viruses 被引量:8
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作者 Wei-feng SHI Zhong ZHANG +4 位作者 Ai-she DUN Yan-zhou ZHANG Guang-fu YU Dong-ming ZHUANG Chao-dong ZHU 《Virologica Sinica》 SCIE CAS CSCD 2009年第1期59-64,共6页
Human enterovirus 71 viruses have been long circulating throughout the world. In this study, we performed a positive selection analysis of the VP1 genes of capsid proteins from Enterovirus 71 viruses. Our results show... Human enterovirus 71 viruses have been long circulating throughout the world. In this study, we performed a positive selection analysis of the VP1 genes of capsid proteins from Enterovirus 71 viruses. Our results showed that although most sites were under negative or neutral evolution, four positions of the VP1 genes were under positive selection pressure. This might account for the spread and frequent outbreaks of the viruses and the enhanced neurovirulence. In particular, position 98 might be involved in neutralizing antibodies, modulating the virus-receptor interaction and enhancing the virulence of the viruses. Moreover, both positions 145 and 241 might correlate to determine the receptor specificity. However, these positions did not display much difference in amino acid polymorphism. In addition, no position in the VP1 genes of viruses isolated from China was under positive selection. 展开更多
关键词 Human enterovirus 71 positive selection pressure VP1
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A recognition method of vibration parameter image based on improved immune negative selection algorithm for rotating machinery 被引量:4
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作者 窦唯 刘占生 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期5-10,共6页
To overcome the limitations of traditional monitoring methods, based on vibration parameter image of rotating machinery, this paper presents an abnormality online monitoring method suitable for rotating machinery usin... To overcome the limitations of traditional monitoring methods, based on vibration parameter image of rotating machinery, this paper presents an abnormality online monitoring method suitable for rotating machinery using the negative selection mechanism of biology immune system. This method uses techniques of biology clone and learning mechanism to improve the negative selection algorithm to generate detectors possessing different monitoring radius, covers the abnormality space effectively, and avoids such problems as the low efficiency of generating detectors, etc. The result of an example applying the presented monitoring method shows that this method can solve the difficulty of obtaining fault samples preferably and extract the turbine state character effectively, it also can detect abnormality by causing various fault of the turbine and obtain the degree of abnormality accurately. The exact monitoring precision of abnormality indicates that this method is feasible and has better on-line quality, accuracy and robustness. 展开更多
关键词 artificial immune system negative selection algorithm abnormality monitor image recognition rotating machinery
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c-Fos enhances the survival of thymocytes during positive selection by upregulating Bcl-2 被引量:2
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作者 Xiaoming Wang Yafeng Zhang +2 位作者 Gang Xiao Xiang Gao Xiaolong Liu 《Cell Research》 SCIE CAS CSCD 2009年第3期340-347,共8页
T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for ... T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for posi- tive selection is survival. TCR signal-induced Bcl-2 expression is believed to play a dominant role in the survival of positively selecting thymocytes, but how Bcl-2 is directly regulated is unknown. Here we report that the immediate early gene (IEG) c-Fos can stimulate the expression of Bcl-2, depending on a specific AP-l-binding site in the Bcl-2 promoter. In c-Fos transgenic (Fos-Tg) mice, c-Fos binds to this site and promotes the expression of Bcl-2. As a result, Fos-Tg thymocytes exhibited enhanced survival, and more mature single-positive (SP) thymocytes were generated, even on a unique TCR background. The TCR repertoire remained normal in Fos-Tg mice. Our results identified c-Fos as the mediator of the stimulatory effect of TCR signaling on Bcl-2 expression. Therefore, c-Fos, as an IEG, because of its early response ability, can quickly rescue the survival of short-lived thymocytes during positive selection. Our results provide novel insight into the mechanism regulating the survival of positively selecting thymocytes. 展开更多
关键词 C-FOS BCL-2 SURVIVAL thymocyte development positive selection
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Propagation of positive, negative, and recoil leaders in upward lightning flashes 被引量:2
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作者 XiuShu Qie ShanFeng Yuan +9 位作者 HongBo Zhang RuBin Jiang ZhiJun Wu MingYuan Liu ZhuLing Sun YunJiao Pu JinLiang Li Abhay Srivastava ZiLong Ma GaoPeng Lu 《Earth and Planetary Physics》 CSCD 2019年第2期102-110,共9页
Leader propagation is a fundamental issue in lightning physics. The propagation characteristics of positive leaders and negative leaders are summarized and compared based on data from high-speed camera and electromagn... Leader propagation is a fundamental issue in lightning physics. The propagation characteristics of positive leaders and negative leaders are summarized and compared based on data from high-speed camera and electromagnetic field in rocket-triggered lightning and tower-initiated lightning discharges; available channel base current data recorded in rocket-triggered lightning are also used. The negative leaders propagate in a stepped fashion accompanied by many branches. The stems ahead of the negative leader tip determine the manner and direction of the leader propagation, and even the branching and winding of the lightning channel. The impulsive current, electromagnetic field, and related optical images suggest that the positive leader may develop in a step-like fashion at its initial stage of triggered lightning. However, the stepping processes of the positive leader are obviously different from those of the negative leader. Tower-initiated lightning revealed that the most conspicuous characteristics of the stepwise positive leader involve the intermittent brush-like corona zone in front of the leader tip and the luminosity enhancement of the channel behind the tip. In rockettriggered lightning flashes, the charge transferred during an individual step for the negative leader was nearly an order greater than for the positive counterpart. The successive streamers ahead of the leader tip are essential for both negative and positive leader propagation, and the stems could be formed from one or more streamers in the previous negative streamer zone with the main leader channel dim. High-resolution observation of tower lightning also revealed a new type of bidirectional recoil leader, with polarity contrary to the traditional one, traversing in negative channels associated with tower-initiated and rocket-triggered lightning. 展开更多
关键词 LIGHTNING PROPAGATION negative LEADER positive LEADER RECOIL LEADER
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GLOBAL ATTRACTIVITY OF NEUTRAL DIFFERENCE EQUATIONS WITH POSITIVE AND NEGATIVE COEFFICIENTS 被引量:2
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作者 Li Xiaoping Jiang Jianchu Gao PingDept. of Math., Loudi Teacher’s College, Loudi 417000,China. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第3期258-266,共9页
A neutral difference equation with positive and negative coefficientsΔ(x n-c nx n-k )+p nx n-l -q nx n-r =0, n=0,1,2,...,is considered and a sufficient condition for the global attractivity of the ze... A neutral difference equation with positive and negative coefficientsΔ(x n-c nx n-k )+p nx n-l -q nx n-r =0, n=0,1,2,...,is considered and a sufficient condition for the global attractivity of the zero solution of this equation is obtained, which improves and extends the all known results in the literature. 展开更多
关键词 global attractivity neutral difference equations positive and negative coefficients.
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EXISTENCE OF POSITIVE SOLUTIONS FOR NEUTRAL DIFFERENCE EQUATIONS WITH POSITIVE AND NEGATIVE COEFFICIENTS 被引量:1
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作者 Luo Zhiguo Shen JianhuaDept. of Math., Hunan Normal Univ., Changsha 410081,China. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第3期251-257,共7页
In this paper the sufficient conditions for the existence of positive solutions of the neutral difference equations with positive and negative coefficients are established. The results improve some known conclusions i... In this paper the sufficient conditions for the existence of positive solutions of the neutral difference equations with positive and negative coefficients are established. The results improve some known conclusions in the literature. 展开更多
关键词 positive solutions neutral difference equations positive and negative coefficients.
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Genes for the high life: New genetic variants point to positive selection for high altitude hypoxia in Tibetans 被引量:2
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作者 Nina G.Jabionski 《Zoological Research》 CAS CSCD 2017年第3期117-117,共1页
People living on the high plateaus of the world have long fascinated biological anthropologists and geneticists because they live in "thin air" and epitomize an extreme of human biological adaptation.
关键词 HIGH for Genes for the high life New genetic variants point to positive selection for high altitude hypoxia in Tibetans in
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A negative selection algorithm with neighborhood representation 被引量:1
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作者 张凤斌 王大伟 王胜文 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第3期74-78,共5页
This paper proposes a negative selection with neighborhood representation named as neighborhood negative selection algorithm.This algorithm employs a new representation method which uses the fully adjacent but mutuall... This paper proposes a negative selection with neighborhood representation named as neighborhood negative selection algorithm.This algorithm employs a new representation method which uses the fully adjacent but mutually disjoint neighborhoods to present the self samples and detectors.After normalizing the normal samples into neighborhood shape space,the algorithm uses a special matching rule similar as Hamming distance to train mature detectors at the training stage and detect anomaly at the detection stage.The neighborhood negative selection algorithm is tested using KDD CUP 1999 dataset.Experimental results show that the algorithm can prevent the negative effect of the dimension of shape space,and provide a more accuracy and stable detection performance. 展开更多
关键词 artificial immune negative selection NEIGHBORHOOD matching rule
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Forced Oscillation of Neutral Advanced Dynamic Equations with Positive and Negative Coeffcients on Time Scales 被引量:1
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作者 YANG Jun WU Hui-ning 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第3期466-469,共4页
In this paper,we consider the forced neutral advanced dynamic equations with positive and negative coeffcients[x(t)-R(t)x(t+r)]+P(t)x(t+τ)△Q(t)x(t+δ)= f(t),t≥t0 on a time scale T.Several suffcient conditions are o... In this paper,we consider the forced neutral advanced dynamic equations with positive and negative coeffcients[x(t)-R(t)x(t+r)]+P(t)x(t+τ)△Q(t)x(t+δ)= f(t),t≥t0 on a time scale T.Several suffcient conditions are obtained for the oscillation of the dynamic equations.The main result is illustrated by an example. 展开更多
关键词 time scales FORCED NEUTRAL ADVANCED oscillation positive and negative coeffcients
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A self region based real-valued negative selection algorithm 被引量:1
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作者 张凤斌 王大伟 王胜文 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第6期851-855,共5页
Point-wise negative selection algorithms,which generate their detector sets based on point of self data,have lower training efficiency and detection rate.To solve this problem,a self region based real-valued negative ... Point-wise negative selection algorithms,which generate their detector sets based on point of self data,have lower training efficiency and detection rate.To solve this problem,a self region based real-valued negative selection algorithm is presented.In this new approach,the continuous self region is defined by the collection of self data,the partial training takes place at the training stage according to both the radius of self region and the cosine distance between gravity of the self region and detector candidate,and variable detectors in the self region are deployed.The algorithm is tested using the triangle shape of self region in the 2-D complement space and KDD CUP 1999 data set.Results show that,more information can be provided when the training self points are used together as a whole,and compared with the point-wise negative selection algorithm,the new approach can improve the training efficiency of system and the detection rate significantly. 展开更多
关键词 artificial immune real-valued negative selection cluster analysis self region partial training
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Effects of an immunosuppressive active component of Periplocae Cortex (Periploca sepium Bge.) on positive selection of thymocytes in vitro 被引量:1
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作者 Huifang Deng Hong Yang +6 位作者 Dingnan Wang Baihui Zeng Shaohua Shi Han Yu Yunzhou Li Zongying Xu Xianggen Zhong 《Journal of Traditional Chinese Medical Sciences》 2018年第2期161-167,共7页
Objective:To determine the effect of an immunosuppressive active component (periploside A) isolated from the stem bark of Periplocae Cortex (Periploca sepium Bge.),a Chinese medicinal herb used in the treatment of rhe... Objective:To determine the effect of an immunosuppressive active component (periploside A) isolated from the stem bark of Periplocae Cortex (Periploca sepium Bge.),a Chinese medicinal herb used in the treatment of rheumatoid arthritis for centuries in China,on positive selection of thymocytes in vitro.Methods:Female C57BL/6 mice at 6 weeks of age were housed in specific pathogen-free conditions.Double-positive thymocytes from C57BL/6 mice were induced into positive selection in vitro with or without periploside A treatment.Cell viability and expression of CD69,CD4,and CD8 were analyzed by flow cytometry.Results:Flow cytometric examination of thymocyte populations revealed that the percentage of CD8+ single-positive thymocytes was decreased by periploside A upon differentiation induced by an anti-CD3 antibody.However,the percentage of CD4+ single-positive thymocytes was decreased by periploside A upon differentiation induced by phorbol 12-myristate 13-acetate/ionomycin.Expression of CD69 plays a major role in prohibiting differentiation of thymocytes.Treatment with periploside A decreased CD69 expression in thymocytes.Conclusion:These results demonstrate that periploside A influences positive selection of thymocytes in vitro. 展开更多
关键词 IMMUNOSUPPRESSIVE active COMPONENT positive selection THYMOCYTES
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Fault Detection Using Negative Selection and Genetic Algorithms 被引量:3
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作者 Anam ABID Zia Ul HAQ Muhammad Tahir KHAN 《Instrumentation》 2019年第3期39-51,共13页
In this paper,negative selection and genetic algorithms are combined and an improved bi-objective optimization scheme is presented to achieve optimized negative selection algorithm detectors.The main aim of the optima... In this paper,negative selection and genetic algorithms are combined and an improved bi-objective optimization scheme is presented to achieve optimized negative selection algorithm detectors.The main aim of the optimal detector generation technique is maximal nonself space coverage with reduced number of diversified detectors.Conventionally,researchers opted clonal selection based optimization methods to achieve the maximal nonself coverage milestone;however,detectors cloning process results in generation of redundant similar detectors and inefficient detector distribution in nonself space.In approach proposed in the present paper,the maximal nonself space coverage is associated with bi-objective optimization criteria including minimization of the detector overlap and maximization of the diversity factor of the detectors.In the proposed methodology,a novel diversity factorbased approach is presented to obtain diversified detector distribution in the nonself space.The concept of diversified detector distribution is studied for detector coverage with 2-dimensional pentagram and spiral self-patterns.Furthermore,the feasibility of the developed fault detection methodology is tested the fault detection of induction motor inner race and outer race bearings. 展开更多
关键词 Detector Coverage Diversity Factor Fault Detection Genetic Algorithm negative selection Algorithm
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Characteristics of water volatilization and oxides generation by using positive and negative corona
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作者 Ke CHEN Lianghao WAN +8 位作者 Bingyan CHEN Tao CHU Renyue GENG Deyu SONG Xiang HE Wei SU Cheng YIN Minglei SHAN Yongfeng JIANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第4期61-70,共10页
The physical and chemical properties have significant differences for the positive and negative charged particles generated by discharge.In this work,a positive and negative corona discharge system was established,and... The physical and chemical properties have significant differences for the positive and negative charged particles generated by discharge.In this work,a positive and negative corona discharge system was established,and two discharge reactors for charged particles restraining and acting were designed by a needle electrode covered with a quartz tube and a plate electrode filled with water.The corona discharges happened within the needle-plate electrodes were excited by a positive and negative high voltage source,and the characteristics of both water volatilization and oxides generation were examined within influence of the distances of both quartz tube inside and outside.The results show that the characteristics of both the water volatilization and oxides generation can be affected by the distances of both quartz tube inside and outside.When the distances of tube inside were increased from 5.00 to 13.00 mm,the water volatilizations decreased under negative corona,and increased firstly and declined immediately under positive corona.The maximum value of the water volatilization appeared in the distances of tube inside with 6.00–8.00 mm.In addition,the concentrations of the HNO_(x) and H_(2)O_(2)in treated water decreased with increasing the distances of tube inside.Moreover,with increasing the distances of tube outside from 4.00 to 14.00 mm,the change trends of both the water volatilizations and oxides presented the same as the distances of tube inside,and the maximum value of the water volatilization and oxides appeared in the distance of tube outside with about 9.00 mm.Overall,the positive corona can generate more water volatilizations and oxides in water than negative corona,and non H_(2)O_(2)can be produced by negative corona.The results reflect the difference between positive and negative corona interaction with water,which can provide reference for plasma application. 展开更多
关键词 positive corona negative corona water volatilization oxides generation
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