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Heisenberg Group and Energy-Momentum Conservative Law in de-Sitter Spaces—— In Memory of the 100th Anniversary of Einstein's Special Relativity and the 70th Anniversary of Dirac's de-Sitter Spaces 被引量:9
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作者 LU Qi-Keng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3X期389-392,共4页
In 1935 Dirac established the physical wave equations in the de-Sitter spaces but neither energy-momentum operators nor their conservative laws were given. In this article it is proved that in the de-Sitter group ther... In 1935 Dirac established the physical wave equations in the de-Sitter spaces but neither energy-momentum operators nor their conservative laws were given. In this article it is proved that in the de-Sitter group there is a subgroup group isomorphic to the Heisenberg group and the generators of this groups are the energy-momentum operators which obey a conservative law. 展开更多
关键词 energy-momentum conservation Heisenberg grup de-Sitter space
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Analysis of pH Value and Primary Nutrients in Blueberry Garden Soil
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作者 董克锋 刘方春 +1 位作者 姜惠铁 崔兴国 《Agricultural Science & Technology》 CAS 2016年第4期1028-1032,共5页
In order to explore the soil nutrient characteristics and put forward the improvement measures, a field experiment was arranged and performed. The experiment was conducted to evaluate the pH value and primary nutrient... In order to explore the soil nutrient characteristics and put forward the improvement measures, a field experiment was arranged and performed. The experiment was conducted to evaluate the pH value and primary nutrient status in blueberry garden soil by means of collecting 21 soil samples from the main production base of blueberries in Qingdao, according to the specific requirements of blueberries for soil pH and organic matter and the second national soil survey nutrient classification standard. Results showed that the blueberry garden soil had the following characteristics: acidic soil, low organic matter content with significant differences among different bases, moderate total nitrogen and alkaline hydrolysis nitrogen contents, high available phosphorus content and above moderate available potassium content. Then, it is found that the primary causes were the differences in soil basic fertility, excessive use of sulfur, inadequate inputs of organic matter, not thorough soil improvement, and imperfect fertilizer management in the blueberry gardens. Finally, the corresponding improvement measures were put forward, for example, increasing organic fertilizer and organic matter covering, as well as the application of CaCO_3 and formulated fertilization. 展开更多
关键词 Blueberry garden soil pH Primary nutrient Improvement measure
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Alignments, Topologies, Convex Geometries and Higgs Spaces 被引量:1
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作者 J. M. S. Simoes-Pereira 《Journal of Mathematics and System Science》 2014年第3期158-163,共6页
Aligned spaces generalize topological spaces and generate Higgs spaces. We give a necessary and sufficient condition for a finite aligned space to be a topological space, we prove the existence of two kinds of convex ... Aligned spaces generalize topological spaces and generate Higgs spaces. We give a necessary and sufficient condition for a finite aligned space to be a topological space, we prove the existence of two kinds of convex geometries, and we compare several concepts and results for arbitrary (that is, not necessarily finite) aligned, topological and Higgs spaces. 展开更多
关键词 Aligned space topological space convex geometry Higgs space.
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Using LSA and text segmentation to improve automatic Chinese dialogue text summarization 被引量:3
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作者 LIU Chuan-han WANG Yong-cheng +1 位作者 ZHENG Fei LIU De-rong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第1期79-87,共9页
Automatic Chinese text summarization for dialogue style is a relatively new research area. In this paper, Latent Semantic Analysis (LSA) is first used to extract semantic knowledge from a given document, all questio... Automatic Chinese text summarization for dialogue style is a relatively new research area. In this paper, Latent Semantic Analysis (LSA) is first used to extract semantic knowledge from a given document, all question paragraphs are identified, an automatic text segmentation approach analogous to Text'filing is exploited to improve the precision of correlating question paragraphs and answer paragraphs, and finally some "important" sentences are extracted from the generic content and the question-answer pairs to generate a complete summary. Experimental results showed that our approach is highly efficient and improves significantly the coherence of the summary while not compromising informativeness. 展开更多
关键词 Automatic text summarization Latent semantic analysis (LSA) Text segmentation Dialogue style COHERENCE Question-answer pairs
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Necessary and Sufficient Condition for Generalized Diagonal Dominance Matrices 被引量:1
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作者 杨益民 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第2期26-29,共4页
In the paper,a necessary and sufficeent condition for generalized diagonal domiance matrices is given.Further, the relations among all generalized positive definite matrices are shown, also,some flaws and mistakes in... In the paper,a necessary and sufficeent condition for generalized diagonal domiance matrices is given.Further, the relations among all generalized positive definite matrices are shown, also,some flaws and mistakes in the references are corrected. 展开更多
关键词 generalized diagonal dominance matrix generalized positive definite matrix M-MATRIX
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Analysis on the Elements of Theories of Economic Laws
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作者 Sun Wenguang Chen Xiaodong 《China's Foreign Trade》 2011年第7期66-68,共3页
Economic law is a marginal or interdisciplinary academic subject, given its object of study, theoretical elements and theoretical origins. The emergence and development of economic law builds on and transcends civil a... Economic law is a marginal or interdisciplinary academic subject, given its object of study, theoretical elements and theoretical origins. The emergence and development of economic law builds on and transcends civil and commercial laws, administrative laws and other traditional legal departments, making the modern laws cover many legal departments and academic disciplines. 展开更多
关键词 Economic law Object of study ELEMENT
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Criteria Conditions for Generalized Diagonally Dominant Matrices 被引量:3
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作者 TIAN Su-xia 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第1期63-67,共5页
In this paper, some new sufficient conditions for generalized dominant matrices are given, and some results in [1] are generalized and improved.
关键词 generalized diagonal dominant matrices α-diagonal dominant matrix criteria condition
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Improved Repetitive Control for High-Precision Satellite Rendezvous
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作者 ZHANG Yi QI Ruiyun 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第2期201-218,共18页
This paper is focused on control design for high-precision satellite rendezvous systems.A relative motion model of leader-follower satellites described by relative orbit elements(ROE)is adopted,which has clear geometr... This paper is focused on control design for high-precision satellite rendezvous systems.A relative motion model of leader-follower satellites described by relative orbit elements(ROE)is adopted,which has clear geometric meaning and high accuracy.An improved repetitive control(IRC)scheme is proposed to achieve high-precision position and velocity tracking,which utilizes the advantage of repetitive control to track the signal precisely and conquers the effects of aperiodic disturbances by adding a nonsingular terminal sliding mode(NSTSM)controller.In addition,the nonlinear state error feedback(NLSEF)is used to improve the dynamic performance of repetitive controller and the radial basis function(RBF)neural networks are employed to approximate the unknown nonlinearities.From rigorous Lyapunov analysis,the stability of the whole closed-loop control system is guaranteed.Finally,numerical simulations are carried out to assess the efficiency and demonstrate the advantages of the proposed control scheme. 展开更多
关键词 satellite rendezvous relative orbit elements repetitive control sliding mode control radial basis function(RBF)neural network
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Comparative regeneration status in a natural forest and enrichment plantations of Chittagong (south) forest division, Bangladesh
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作者 M. Kamal Hossain M. Lutfor Rahman +1 位作者 A. T. M. Rafiqul Hoque M. Khairul Alam 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第4期255-260,共6页
The natural regeneration of the tree species in pure natural forest stand and enrichment plantations of Baraitali Forest of Chittagong (South) Forest Division, Bangladesh was studied by stratified random quadrat metho... The natural regeneration of the tree species in pure natural forest stand and enrichment plantations of Baraitali Forest of Chittagong (South) Forest Division, Bangladesh was studied by stratified random quadrat method during April 2002 to November 2002. Totally 100 plots of 3 m X 3 m in size represents a total of 64 regenerating tree species from natural forest with an average seedlings of 24767/hm2, while only 40 regenerating tree species were recorded from enrichment plan-tations with an average seedlings of 18633/hm2. Maximum regeneration in natural forest was found with Castanopsis spp. (2200 seedlings/hm2) followed by Glochidion lanceolarium (2183 /hm2) whereas, in enrichment plantations maximum regen-eration was found with Dipterocarpus gracilis (2117/hm2) followed by Anogeissus acuminata (2000/hm2). For natural forest, highest relative density was found for Castanopsis spp (8.88%), relative frequency for Glochidion lanceolarium (7.36%), rela-tive abundance for Syzygium spp. (3.79%) and Importance Value Index were recorded with Glochidion lanceolarium (18.24%). The corresponding values for enrichment plantations were highest with Dipterocarpus gracilis (11.36%), Glochidion lanceo-larium (9.71%), Dipterocarpus gracilis (5.92%), Glochidion lanceolarium (23.32%) respectively. Stem per hectare of some common trees with their seedlings and saplings in both the natural stands and enrichment plantations showed that only Dip-terocarpus gracilis successfully recruited in both sites but recruitment was higher in natural forest. Like many other primary rain forests, the Baraitoli forest typically has both substantial seedlings and soil seed bank from which regeneration may occur. The naturally regenerated seedlings are quite dense but it could not reach the pole stage due to human interference. 展开更多
关键词 REGENERATION Natural forest Enrichment plantations Relative density Frequency ABUNDANCE Importance Value Index
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QoS Guaranteed Pre-Pushing Scheme in Peer-Assisted Streaming Network
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作者 LIN Fuhong LU Xing 《China Communications》 SCIE CSCD 2014年第A02期111-117,共7页
In peer-assisted streaming network, service provider needs to pre-pushing resources to some users for caching. This scheme can increase the resource availability. In traditional strategy, in order to guarantee the use... In peer-assisted streaming network, service provider needs to pre-pushing resources to some users for caching. This scheme can increase the resource availability. In traditional strategy, in order to guarantee the user's quality of service (QoS), the pre-pushing action can only start at the time point that the certain user has not used the computer for more than 20 minutes. If the user comes back, the pre-pushing action will be stopped. We claim that this is not an efficient scheme. In this paper, we propose a novel pre-pushing scheme to improve the pre-pushing efficiency, while meeting the user's QoS requirements. The basic idea is using the user's available bandwidth as much as possible in the condition of meeting the user's QoS requirements. Then we design an available bandwidth calculating strategy. The numerical simulation demonstrates that our proposed scheme outperforms the traditional one. 展开更多
关键词 peer-assisted streaming network downlink bandwidth pre-pushing available bandwidth
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Numerical Study of φ^4 Model by Potential Importance Sampling Method
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作者 YUAN Qing-Xin DING Guo-Hui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5期873-876,共4页
We investigate the phenomena of spontaneous symmetry breaking for φ^4 model on a square lattice in the parameter space by using the potential importance samplingmethod, which was proposed by Milchev, Heermann, and Bi... We investigate the phenomena of spontaneous symmetry breaking for φ^4 model on a square lattice in the parameter space by using the potential importance samplingmethod, which was proposed by Milchev, Heermann, and Binder [J. Star. Phys. 44 (1986) 749]. The critical values of the parameters allow us to determine the phase diagram of the model. At the same time, some relevant quantifies such as susceptibility and specific heat are also obtained. 展开更多
关键词 symmetry breaking potential importance sampling method φ4 model
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保健饮料银杏枣汁的生产工艺 被引量:5
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作者 马芳芳 《食品工业科技》 CAS CSCD 北大核心 2000年第3期57-58,共2页
具有保健作用的银杏叶提取物 ( EGB)、红枣、枸杞子和蜂蜜制成了枣香宜人、酸甜适口、对心脑血管疾病、老年痴呆症、降低血压等有保健作用的饮料。
关键词 EGB 红刺 枸杞子 蜂蜜 保健饮料 生产工艺
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多模态影像融合在颅底肿瘤的诊断、治疗中的应用价值 被引量:9
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作者 李成才 姚国杰 +6 位作者 杜威 胡亮平 韦可 伍杰 秦汉 王再贵 马廉亭 《中国临床神经外科杂志》 2018年第3期145-148,共4页
目的探讨多模态影像融合在颅底肿瘤的诊断、治疗中的应用价值。方法 9例颅底肿瘤术前均行DynaCTA检查及MRI薄层(2 mm)增强扫描检查,将多组影像数据输入工作站,采用"双容积重建"技术进行脑血管及MRI的影像融合,通过静态及动态... 目的探讨多模态影像融合在颅底肿瘤的诊断、治疗中的应用价值。方法 9例颅底肿瘤术前均行DynaCTA检查及MRI薄层(2 mm)增强扫描检查,将多组影像数据输入工作站,采用"双容积重建"技术进行脑血管及MRI的影像融合,通过静态及动态融合影像观察肿瘤与脑结构、血管及颅骨的毗邻关系,并对肿瘤的诊断、手术治疗及预防血管并发症进行分析。结果 9例均获得满意的影像融合、具有很好的空间一致性,在一张影像上可以清晰显示病变及其周围脑结构、血管及颅骨解剖关系,提高精准性诊断,并应用于指导治疗策略、设计手术划及预防并发症。9例均恢复满意出院。结论多模态影像融合对提高颅底肿瘤的诊断精准性、提高肿瘤全切除率、降低病死率和残疾率效果肯定,对血管损伤并发症治疗疗效肯定。 展开更多
关键词 颅底肿瘤 多模态影像融合 诊断 治疗 并发症
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乳化炸药线型切割器对薄壳弹药销毁效果的数值模拟研究 被引量:4
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作者 王敏 龙源 +1 位作者 钟明寿 谢兴博 《爆破器材》 CAS 北大核心 2018年第2期39-43,共5页
针对目前的弹药销毁状况,为了减轻直接爆破的环境压力,利用理论分析及数值模拟的方法,首先对设计的简易乳化炸药线型切割器的药型罩材料进行确定,数值模拟表明:铝质药型罩所形成的射流侵彻能力要比紫铜材质的提高28%,而后利用ANSYS数值... 针对目前的弹药销毁状况,为了减轻直接爆破的环境压力,利用理论分析及数值模拟的方法,首先对设计的简易乳化炸药线型切割器的药型罩材料进行确定,数值模拟表明:铝质药型罩所形成的射流侵彻能力要比紫铜材质的提高28%,而后利用ANSYS数值模拟得出该切割器最佳炸高为15 mm。最后对乳化炸药线型切割器切割薄壳弹药的过程进行数值模拟,证明该切割器可以达到切去弹药外壳而不产生剧烈爆轰及高速破片的效果。 展开更多
关键词 聚能射流 切割器设计 冲击起爆 数值模拟
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On Functions Meromorphically Starlike with Respect to Symmetric Points
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作者 邹中柱 吴卓人 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2003年第1期71-76,共6页
In this paper we introduce the notion of functions meromorphically starlike with respect to symmetric points. Some results obtained here include necessary and/or sufficient conditions for functions belonging to meromo... In this paper we introduce the notion of functions meromorphically starlike with respect to symmetric points. Some results obtained here include necessary and/or sufficient conditions for functions belonging to meromorphically starlike class and a structural formula is given. 展开更多
关键词 meromorphically starlike hadamard products(or convolution) operators.
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Search for gamma-ray spectral lines with the DArk Matter Particle Explorer 被引量:5
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作者 DAMPE Collaboration Yun-Feng Liang 《Science Bulletin》 SCIE EI CSCD 2022年第7期679-684,共6页
The DArk Matter Particle Explorer(DAMPE)is well suitable for searching for monochromatic and sharpγ-ray structures in the GeV-TeV range thanks to its unprecedented high energy resolution.In this work,we search forγ-... The DArk Matter Particle Explorer(DAMPE)is well suitable for searching for monochromatic and sharpγ-ray structures in the GeV-TeV range thanks to its unprecedented high energy resolution.In this work,we search forγ-ray line structures using five years of DAMPE data.To improve the sensitivity,we develop two types of dedicated data sets(including the BgoOnly data which is the first time to be used in the data analysis for the calorimeter-based gamma-ray observatories)and adopt the signal-to-noise ratio optimized regions of interest(ROIs)for different DM density profiles.No line signals or candidates are found between 10 and 300 GeV in the Galaxy.The constraints on the velocity-averaged cross section for xx→γγand the decay lifetime for x→γv,both at 95%confidence level,have been calculated and the systematic uncertainties have been taken into account.Comparing to the previous Fermi-LAT results,though DAMPE has an acceptance smaller by a factor of~10,similar constraints on the DM parameters are achieved and below 100 GeV the lower limits on the decay lifetime are even stronger by a factor of a few.Our results demonstrate the potential of high-energy-resolution observations on dark matter detection. 展开更多
关键词 DAMPE Dark matter GAMMA-RAY Line-like structure
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glmm.hp: an R package for computing individual effect of predictors in generalized linear mixed models 被引量:14
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作者 Jiangshan Lai Yi Zou +2 位作者 Shuang Zhang Xiaoguang Zhang Lingfeng Mao 《Journal of Plant Ecology》 SCIE CSCD 2022年第6期1302-1307,共6页
Generalized linear mixed models(GLMMs)have been widely used in contemporary ecology studies.However,determination of the relative importance of collinear predictors(i.e.fixed effects)to response variables is one of th... Generalized linear mixed models(GLMMs)have been widely used in contemporary ecology studies.However,determination of the relative importance of collinear predictors(i.e.fixed effects)to response variables is one of the challenges in GLMMs.Here,we developed a novel R package,glmm.hp,to decompose marginal R2^(2)explained by fixed effects in GLMMs.The algorithm of glmm.hp is based on the recently proposed approach‘average shared variance’i.e.used for multivariate analysis.We explained the principle and demonstrated the use of this package by simulated dataset.The output of glmm.hp shows individual marginal R2^(2)s that can be used to evaluate the relative importance of predictors,which sums up to the overall marginal R2^(2).Overall,we believe the glmm.hp package will be helpful in the interpretation of GLMM outcomes. 展开更多
关键词 coefficient of determination commonality analysis fixed effect GLMM hierarchical partitioning marginal R2^(2) relative importance variance partitioning
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Witnesses' Appearance in Court and Guarantees for the Defendant's Right to Confrontation
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《Social Sciences in China》 2010年第4期36-52,共17页
The main significance of witnesses' appearing in court to testify in criminal trials is that this practice guarantees the defendant's right to confrontation. The issue can thus be framed in another way, as the issue... The main significance of witnesses' appearing in court to testify in criminal trials is that this practice guarantees the defendant's right to confrontation. The issue can thus be framed in another way, as the issue of the appearance in court of the necessary witnesses. Here, the defendant's right to confront is the key point. Since neither China's criminal procedural law nor corresponding judicial interpretations have granted the defendant the right to confront, the rate of appearance of the necessary witnesses amounts in practice to only about twenty- five percent. Criminal trials conducted in the absence of the right to confrontation usually conform to the doctrine of positive substantive truth and manifest a lack of care in conviction and sentencing as well as reliance on a single source of legitimacy in reaching judgments. To correct this state of affairs, it is necessary to institute the right to confront and corresponding safeguards. 展开更多
关键词 witnesses' appearance in court rate of appearance of necessary witnesses in court right to confront legitimacy of judgments
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Characterization of the Bounded Symmetric Domain
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作者 ZHAO Zhen Gang 《Journal of Mathematical Research and Exposition》 CSCD 2009年第3期434-440,共7页
We give a necessary and sufficient condition for a domain to be biholomorphic to a bounded symmetric domain.
关键词 Caratheodory volume element Eisenmann-kobayashi volume element bounded symmetric domain
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