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New Vertex-Degree Condition for Pancyclic Graphs
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作者 顾国华 宋增民 徐新丽 《Journal of Southeast University(English Edition)》 EI CAS 1998年第2期117-120,共4页
Let G be a 2 connected graph with n vertices. In this paper, we prove that if there exist two vertices of any there independent vertices in G such that the sum of whose degree is at least n , then G ... Let G be a 2 connected graph with n vertices. In this paper, we prove that if there exist two vertices of any there independent vertices in G such that the sum of whose degree is at least n , then G is pancyclic, or G is K n/2,n/2 , or G is K n/2,n/2 -e , or G is a cycle of length 5. 展开更多
关键词 pancyclic graph vertex degree independent set bipartite graph
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竟·章·竞
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作者 周忠财 《语文知识》 2005年第8期26-27,共2页
查《现代汉语词典》时,发现“竟”“章”“竞”三个字都收在“立”部,“竟”和“章”,还收在“音”部,这是为什么呢?
关键词 “竟” “章” “竞” “立”部 “音”部 中学 语文 语言知识
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Discussion on Green Development of Fenlong for Yield Increase, Quality Enhancing, Water Retaining and Multiple Use of Natural Resources 被引量:7
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作者 韦本辉 《Agricultural Science & Technology》 CAS 2017年第9期1631-1637,共7页
Fenlong green ecological agriculture technology (Fenlong technology), a new smash ridging farming method developed by Guangxi Academy of Agdcultural Sciences, has been elected as the recommended cultivation techniqu... Fenlong green ecological agriculture technology (Fenlong technology), a new smash ridging farming method developed by Guangxi Academy of Agdcultural Sciences, has been elected as the recommended cultivation technique by the Ministry of Agriculture of China. It replaces the traditional plowshare with spiral drill, and its tilth depth is twice deeper than that by tractor tilthing. It also extends soil nutrient, moisture, oxygen and microorganism, the so-called "Four pools". Soil nutrient, oxygen, microorganism, light and rainfall use ratio is increased by 10%-100%, creating a platform for natural increase of more than 10% of crop yield. Its application to over 20 kinds of crops in 21 provinces has proved that the yield increases 10-30% with quality enhancing 5% and double water retaining capacity but no more input. When the application area of Fenlong could reach 67 million hm2, the amount of fertilizer can be reduced by 40-50 billion kg, saving 120-150 billion Yuan. In this paper, we put forward the strategy of "4+1" (arable, saline-alkali soil, grasslands, Sponge City + rivers) green development in China, and deepened the Fenlong cultivated tilled layer from 16.5 cm to 35 cm for 67 million hm2 arable land, ridged 13.3 million hm2 of saline-alkali soil for 35 cm, and also 35 cm for 67 million hm2 degraded steppe, which could have the following 3 effects: first, the 147 million hm2 of land with Fenlong cultivation could increase loosing soil to 315.491 billion m3, in* creasing by 159.26% for 120 million hm2 of arable land with the average tilled layer of 16.5 cm, which has loosing soil of only 198.1 billion m3, that is, the space of the land increases 1.6 times. Second, every hectare of plowland could store up to 450 m3/hm2 of natural rainfall, and the unused 60 m3 of saline-alkali soil and grasslands could store water of 102 billion m3, showing an increase of over 88.89% for the current plowland storage of 54 billion m3 at now, that is, double the natural rainfall storage capacity. Third, the two multiple increase of natural resources application can bring trillions of resource activation, environmental cleaning, food security, citizens, health, economic, ecological and social benefits, and makes the Chinese nation move forward in green development. Its application in "big scientific research" and "One Belt And One Road" will contribute Chinese strength to the world. 展开更多
关键词 Fenlong green development Multiple use of natural resource Increase three-dimensional land space Recommended cultivation technique by the Ministry of Agriculture of China Big scientific research
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Local inhomogeneity of mechanical properties in stir zone of friction stir welded AA1050 aluminum alloy 被引量:8
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作者 Xiao-chao LIU Yun-qian ZHEN +4 位作者 Yu-feng SUN Zhi-kang SHEN Hai-yan CHEN Wei GUO Wen-ya LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第9期2369-2380,共12页
The local inhomogeneity of the stir zone in friction stir welded face-centered cubic metal was investigated,which has multiple activated slip systems during plastic deformation,by selecting commercial AA1050 aluminum ... The local inhomogeneity of the stir zone in friction stir welded face-centered cubic metal was investigated,which has multiple activated slip systems during plastic deformation,by selecting commercial AA1050 aluminum alloy as an ideal experimental material.The local inhomogeneity was evaluated by uniaxial tensile tests using small samples with a 1 mm gauge length.The corresponding microstructural parameters such as grain size,misorientation angle distribution,and micro-texture,were quantified by the backscattered electron diffraction technique.A comprehensive model was used to reveal the microstructure−mechanical property relationship.The experimental results showed that the uniaxial tensile property changes significantly across the weld.The maximum ultimate tensile strength(UTS)occurred in the center of the stir zone,which was 99.0 MPa.The weakest regions were located at the two sides of the stir zone.The largest difference value in UTS reached 14.9 MPa,accounting for 15%of the maximum UTS.The analysis on the structure−mechanical property relationship suggests that the micro-texture change with the location formed during the rotational material flow is the main reason for the local inhomogeneity. 展开更多
关键词 friction stir welding face-centered cubic metal local inhomogeneity mechanical properties MICRO-TEXTURE
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A continuously stratified nonlinear model for internal solitary waves in the northern South China Sea 被引量:3
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作者 谢皆烁 蔡树群 何映晖 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第5期1040-1048,共9页
A continuously stratified nonlinear model is set up to study the impact of topographical character on the generation of internal solitary waves over a sill by tidal flow.One of the reasons why almost all of the genera... A continuously stratified nonlinear model is set up to study the impact of topographical character on the generation of internal solitary waves over a sill by tidal flow.One of the reasons why almost all of the generated internal solitary waves propagate westward in the northern South China Sea is explained.The model simulations describe the generation and propagation of internal waves well.When the strength of imposed barotropic tides and the water stratification stay unchanged,the steepness of the sill slope can control both(a) whether or not the waves induced over a sill by tidal flow are linear internal waves or nonlinear internal solitary waves,and(b) the amplitude of the internal solitary waves generated.If the steepness of the sill is asymmetric,the nonlinear internal solitary waves may be induced on the steeper side of the sill.These conclusions are supported by a numerical experiment with a monthly-mean stratification and an actual seafloor topography from the Luzon Strait. 展开更多
关键词 internal solitary waves numerical modeling SILL South China Sea
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Mental EEG Analysis Based on Infomax Algorithm
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作者 WUXiao-pei GuoXiao-jing ZANGDao-xin SHENQian 《Chinese Journal of Biomedical Engineering(English Edition)》 2004年第1期7-15,共9页
The patterns of EEG will change with mental tasks performed by the subject. In the field of EEG signal analysis and application, the study to get the patterns of mental EEG and then to use them to classify mental task... The patterns of EEG will change with mental tasks performed by the subject. In the field of EEG signal analysis and application, the study to get the patterns of mental EEG and then to use them to classify mental tasks has the significant scientific meaning and great application value. But for the reasons of different artifacts existing in EEG, the pattern detection of EEG under normal mental states is a very difficult problem. In this paper, Independent Component Analysis is applied to EEG signals collected from performing different mental tasks .The experiment results show that when one subject performs a single mental task in different trials, the independent components of EEG are very similar. It means that the independent components can be used as the mental EEG patterns to classify the different mental tasks. 展开更多
关键词 EEG Mental task Independent component analysis
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Nonlinear Analysis of Flexible and Steel Catenary Risers with Internal Flow and Seabed Interaction Effects 被引量:4
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作者 陈海飞 徐思朋 郭海燕 《Journal of Marine Science and Application》 2011年第2期156-162,共7页
Flexible risers and steel catenary risers often provide unique riser solutions for today’s deepwater field development. Accurate analysis of these slender structures, in which there are high-speed HP/HT internal flow... Flexible risers and steel catenary risers often provide unique riser solutions for today’s deepwater field development. Accurate analysis of these slender structures, in which there are high-speed HP/HT internal flows, is critical to ensure personnel and asset safety. In this study, a special global coordinate-based FEM rod model was adopted to identify and quantify the effects of internal flow and hydrostatic pressure on both flexible and deepwater steel catenary risers, with emphasis on the latter. By incorporating internal flow induced forces into the model, it was found that the internal flow contributes a new term to the effective tension expression. For flexible risers in shallow water, internal flow and hydrostatic pressure made virtually no change to effective tension by merely altering the riser wall tension. In deep water the internal pressure wielded a dominant role in governing the riser effective tension and furthering the static configuration, while the effect of inflow velocity was negligible. With respect to the riser seabed interaction, both the seabed support and friction effect were considered, with the former modeled by a nonlinear quadratic spring, allowing for a consistent derivation of the tangent stiffness matrix. The presented application examples show that the nonlinear quadratic spring is, when using the catenary solution as an initial static profile, an efficient way to model the quasi-Winkler-type elastic seabed foundation in this finite element scheme. 展开更多
关键词 flexible riser steel catenary riser (SCR) rod model internal flow effective tension seabed interaction
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Localized Excitations of (2+1)-Dimensional Korteweg-de Vries System Derived from a Periodic Wave Solution
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作者 QIANG Ji-Ye FEI Jin-Xi +1 位作者 CAI Gui-Ping ZHENG Chun-Long 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期275-281,共7页
With the aid of an improved projective approach and a linear variable separation method, new types of variable separation solutions (including solitary wave solutions, periodic wave solutions, and rational function s... With the aid of an improved projective approach and a linear variable separation method, new types of variable separation solutions (including solitary wave solutions, periodic wave solutions, and rational function solutions) with arbitrary functions for (2+1)-dimensional Korteweg-de Vries system are derived. Usually, in terms of solitary wave solutions and rational function solutions, one can find some important localized excitations. However, based on the derived periodic wave solution in this paper, we find that some novel and significant localized coherent excitations such as dromions, peakons, stochastic fractal patterns, regular fractal patterns, chaotic line soliton patterns as well as chaotic patterns exist in the KdV system as considering appropriate boundary conditions and/or initial qualifications. 展开更多
关键词 improved projective approach KdV system chaos SOLITON FRACTAL
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AN EVEN COMPONENT BASED FACE RECOGNITION METHOD
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作者 Pang Yanwei Liu Zhengkai 《Journal of Electronics(China)》 2005年第5期513-519,共7页
This paper presents a novel face recognition algorithm. To provide additional variations to training data set, even-odd decomposition is adopted, and only the even components (half-even face images) are used for furth... This paper presents a novel face recognition algorithm. To provide additional variations to training data set, even-odd decomposition is adopted, and only the even components (half-even face images) are used for further processing. To tackle with shift-variant problem,Fourier transform is applied to half-even face images. To reduce the dimension of an image,PCA (Principle Component Analysis) features are extracted from the amplitude spectrum of half-even face images. Finally, nearest neighbor classifier is employed for the task of classification. Experimental results on ORL database show that the proposed method outperforms in terms of accuracy the conventional eigenface method which applies PCA on original images and the eigenface method which uses both the original images and their mirror images as training set. 展开更多
关键词 Face recognition Pattern recognition EIGENFACE Fourier transform Half-even face
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Internal solitary waves on the southwest shelf of Dongsha Island observed from mooring ADCP
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作者 蔺飞龙 侯一筠 +2 位作者 刘亚豪 方泳 胡珀 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第5期1179-1187,共9页
Internal solitary waves (ISWs) are frequently observed in the area between Dongsha Island (DI) and Taiwan Island. However, there have been few in-situ observations southwest of DI. To improve our knowledge of ISWs... Internal solitary waves (ISWs) are frequently observed in the area between Dongsha Island (DI) and Taiwan Island. However, there have been few in-situ observations southwest of DI. To improve our knowledge of ISWs in this area, we observed the ISWs over the continental shelf (115.4°E, 20.3°N) from Aug. 29 to Oct. 10, 2011 with temperature sensors and an acoustic Doppler current profiler (ADCP). The observations showed that the a fully developed ISW produced a current whose maximum westward velocity was 0.92 rrds and maximum northward velocity was 0.47 m/s. During the 41-day observation period the ISWs appeared for three periods with about 7-day gaps between each period. During each day, two types of ISWs were observed. The first type of wave arrived regularly diurnally at the same time each day, with a similar pattern to that of the type-a wave identified by Ramp et al. (2004). The second type arrived about 12 h after the first type and was delayed about 1 hour each day; this wave type was related to the type-b wave. Thus, our observations confirmed that both type-a and type-b waves can reach the area southwest of the DI. Moreover, the waves observed by the mooring propagated toward the directions of 270°-315° clockwise from true north, indicating obvious refraction from uneven topography around DI. 展开更多
关键词 internal solitary wave (ISWs) South China Sea Dongsha Island REFRACTION
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Design and Analysis of Typical Buoyancy Tank Riser Tensioner Systems 被引量:1
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作者 Zhuang Kang Lusheng Jia Liping Sun Wenzhou Liang 《Journal of Marine Science and Application》 2012年第3期351-360,共10页
The method for design and analysis of a buoyancy tank riser tensioner system (BTRTS) was put forward in this paper, taking the free standing hybrid riser's top buoyancy tank as an example. The design procedure was ... The method for design and analysis of a buoyancy tank riser tensioner system (BTRTS) was put forward in this paper, taking the free standing hybrid riser's top buoyancy tank as an example. The design procedure was discussed and was also illustrated in a flowchart, after a short description of the global arrangement, structure configuration, and the function of different types of buoyancy tanks (BT). The objective of this paper is to describe a way of developing a BT with minimal hydro force, maximal net lift, and no redundancy of compartments. The method of determining the main dimensions of the BT, namely the length and the outer diameter, was outlined. A series of investigations was conducted for a West Africa FSHR BT design, and the effect of the ratio of the length to the outer diameter (L/D) on the hydrodynamics and the weight of the BT was discussed. The methodology of designing the internal structure of the BT was presented. The effects of the number of compartments and the dimension of the inner stem on the BT weight and strength were compared. The relationship between inner structure and the number one index of the BT as well as the riser's top tension factor (TTF) were illustrated for normal operating conditions and conditions with one or more compartments (or inner stem) damaged. A design instance was given in this paper, when L/D is 4-6, the BT weight and the drag force are compromised. When the BT is divided into 10 compartments, the riser TTF will reach the maximum value, and the ratio of the stem OD to shell OD is about 0.3. A global strength analysis method of the BT and the main load case matrix was also included in the paper, together with the local strength analysis of the buoyancy tank's pad-eye assembly. 展开更多
关键词 buoyancy tank (BT) buoyancy tank riser tensioner system (BTRTS) top tension factor (TTF) strength analysis
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Non-unitary Scattering Theory against Generalized Unitary Scattering Theory
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作者 Jacek A. Jakiel Wiestaw A. Kantor 《Computer Technology and Application》 2016年第6期287-299,共13页
Comparison of non-unitary and generalized unitary scattering theories is done by means of nuclear monodromy (equivalence of Schrodinger and Maxwell time-independent equations), tunneling and radioactivity. Radioacti... Comparison of non-unitary and generalized unitary scattering theories is done by means of nuclear monodromy (equivalence of Schrodinger and Maxwell time-independent equations), tunneling and radioactivity. Radioactivity is important part of physics and our life. Its importance stretches from medicine as far as to war strategies. We present theoretical approach to achieve better understanding of the radioactive decay when modified quantum theory is applied. It can be done by updating existing codes to understand better construction of the world and terms and conditions of our existence. The theory modifications are strictly connected with the unimodular M matrix and Wronskian matrices (i.e. their determinants named Wronskians) which create underpinning of so called monodromy being two track wave-function evolution. 展开更多
关键词 Nuclear monodromy RADIOACTIVITY scattering theory UNITARITY TUNNELING boundary condition.
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Legislative Impact on Significance of RES in the Latvian Energy Market
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作者 Peteris Shipkovs Galina Kashkarova +2 位作者 Lana Migla Ilze Purina Kristina Lebedeva 《Journal of Environmental Science and Engineering(B)》 2012年第5期611-619,共9页
Latvia is a new European Union country, with 20-year experience in the efforts to develop the energy policy that would favour reliable supply of the state with energy and promote its effective and rational utilization... Latvia is a new European Union country, with 20-year experience in the efforts to develop the energy policy that would favour reliable supply of the state with energy and promote its effective and rational utilization. The energy law should take into consideration the technological progress and increasing energy consumption as well as the poorly regulated sphere of production and utilization. At present, new regulations are needed, as the existent ones have become outdated and unable to ensure stable development of the energy sector. However, the lack of experience and sometimes external influence could lead to a situation when the new law would not be conducive to the industrial development but vice-versa-would slow it down. Since Latvia has been confronted by counterproductive laws, it is highly important to estimate beforehand the future impact of legislation on the state economy. On issue of for the country is now to guarantee-by force of law-the optimal share of renewable energy in the national energy mix. The objective set within the framework of European Union policy is to achieve a 40% share of renewable energy by 2020; therefore, it is necessary to work out a separate law concerning the RES (renewable energy sources). The new RES law is to regulate support and to promote increase in the share of renewable. However, there are many influencing factors--not clearly specified outlooks for the energy sector and national economy development, the interests of energy importers, lobbying, etc.; these factors can make the RES law not only ineffective but even negatively affecting the RES share stability in the state energy balance. It is therefore essential, before the law has been adopted, to thoroughly analyze it so that the optimal variant is accepted. 展开更多
关键词 Renewable energy sources energy market energy legislation.
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Double-Cropping Pinto Bean after Winter Barley in Western Colorado USA
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作者 C. H. Pearson R. L. Sharp 《Journal of Agricultural Science and Technology》 2010年第1期1-7,共7页
A double-cropping field study was conducted at the Colorado State University, Fruita. Colorado USA to evaluate an irrigated, double-cropping system of winter barley (Hordeum vulgare L.) followed by pinto bean (Phas... A double-cropping field study was conducted at the Colorado State University, Fruita. Colorado USA to evaluate an irrigated, double-cropping system of winter barley (Hordeum vulgare L.) followed by pinto bean (Phaseolus vutgaris L.) for the valley areas of western Colorado USA and other similar environments. Double-cropping pinto bean after winter barley was successful, but to use our double-cropping technology in commercial agriculture in adapted locations will likely require identifying or developing a winter barley cultivar that matures earlier than current cultivars but does not head and flower so early that it is susceptible to freeze damage. Double-cropping was more profitable in all three years than growing either pinto bean or winter barley as a sole crop. 展开更多
关键词 Double-cropping dry bean winter barley alternative cropping system.
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Scapular dislocation from trivial trauma: a rare case 被引量:2
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作者 LandgeVikrant VaishyaRaju AggarwalAnurag 《Chinese Journal of Traumatology》 CAS 2012年第1期62-64,共3页
Dislocation of the scapula between the ribs and into the thoracic cage is a very rare event.Scapulothoracic dissociation though has been reported,usually occurs after a severe injury and is often associated with other... Dislocation of the scapula between the ribs and into the thoracic cage is a very rare event.Scapulothoracic dissociation though has been reported,usually occurs after a severe injury and is often associated with other serious injuries like brachial plexus or chest injury,etc.Ainscow has described a rare type that may occur due to slight violence with a pre-existing condition.Cases of isolated scapular dislocation after minor trauma have not been reported frequently in the literature.It is a distinct clinical entity and needs to be differentiated from other similar conditions.Here,we present a case of painless scapular dislocation associated with trivial trauma followed by spontaneous reduction in a l0 years old girl.The patient had a recurrence of the dislocation before presenting to us.But she did not have any pre-existing condition for scapular dislocation. 展开更多
关键词 SCAPULA THORAX Shoulder dislocation
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Moderate deviations principle for products of sums of random variables
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作者 MIAO Yu MU JianYong 《Science China Mathematics》 SCIE 2011年第4期769-784,共16页
Let(Xn)n≥1 be a sequence of independent identically distributed(i.i.d.) positive random variables with EX1 = μ,Var(X1) = σ2.In the present paper,we establish the moderate deviations principle for the products of pa... Let(Xn)n≥1 be a sequence of independent identically distributed(i.i.d.) positive random variables with EX1 = μ,Var(X1) = σ2.In the present paper,we establish the moderate deviations principle for the products of partial sums(πnk=1Sk/n!μn)1/(γbn√(2n))1where γ = σ/μ denotes the coefficient of variation and(bn) is the moderate deviations scale. 展开更多
关键词 moderate deviations principle products of sums independent identically distribution positive random variables
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Cold Nuclear Matter Effects on Isolated Prompt Photon and Isolated Prompt Photon+Jet Productions in Relativistic Heavy-Ion Collisions
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作者 代巍 陈时勇 +1 位作者 张本威 王思科 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第3期349-355,共7页
We investigate the cold nuclear matter(CNM) effects on isolated prompt photon and isolated prompt photon associated jet productions in nuclear collisions at the NLO accuracy by using the EPS09 NLO nuclear parton distr... We investigate the cold nuclear matter(CNM) effects on isolated prompt photon and isolated prompt photon associated jet productions in nuclear collisions at the NLO accuracy by using the EPS09 NLO nuclear parton distribution functions and their error sets.Nuclear modification factors of isolated prompt photon and isolated prompt photon+jet productions due to CNM effects in p+A and A+A reactions at the RHIC and the LHC are provided with varying rapidity and transverse momentum of the final state photon.It is shown that the CNM effects on isolated prompt photon and photon+jet are modest,which give a small enhancement at low pT region and a more obvious suppression at large pT at central rapidity.At forward rapidity a pronounced suppression of γ as well as γ+jet is always observed. 展开更多
关键词 isolated photon prompt photon photon +jet cold nuclear matter effects heavy ion collisions EPS09 photon production
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