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强子碰撞过程中J/ψ粒子的产生
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作者 吕华庆 裘忠平 《华中师范大学学报(自然科学版)》 CAS CSCD 1989年第1期29-34,共6页
本文在对J/ψ粒子的物理性质进行分析的基础上,得到了描写J/ψ状态的波函数。然后考虑J/ψ是色单态及自旋、宇称、电荷共轭宇称对J/ψ强生过程的制约作用,运用QCD微扰论方法计算了J/ψ强生过程的横动量分布。与费米实验室提供的实验进... 本文在对J/ψ粒子的物理性质进行分析的基础上,得到了描写J/ψ状态的波函数。然后考虑J/ψ是色单态及自旋、宇称、电荷共轭宇称对J/ψ强生过程的制约作用,运用QCD微扰论方法计算了J/ψ强生过程的横动量分布。与费米实验室提供的实验进行比较后,我们认为gg→J/ψg是一个重要的J/ψ粒子的强生机制,但是为了使理论预言与实验更好地符合,还需要进一步考虑其它可能的J/ψ粒子的强生机制。 展开更多
关键词 J/Ψ粒子 碰撞过程 强子 强生过程
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Role of Nitrogen and Nutrients in Crop Nutrition 被引量:4
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作者 Vicente Torres-Olivar Oscar Gabriel Villegas-Torres +5 位作者 Martha Lilia Dominguez-Patifio Hoctor Sotelo-Nava Antonio Rodrlguez-Martme Rosa Maria Melgoza-Aleman Luis Alonso Valdez-Aguilar Irfin Alia-Tejacal 《Journal of Agricultural Science and Technology(B)》 2014年第1期29-37,共9页
Nutrition is an important factor for the growth and development of plants. Among the main nutritional elements, there are nitrogen (N) and calcium (Ca). The N comes from two forms of inorganic ions, ammonium (NH... Nutrition is an important factor for the growth and development of plants. Among the main nutritional elements, there are nitrogen (N) and calcium (Ca). The N comes from two forms of inorganic ions, ammonium (NH4+) and nitrate (NO3) whose functions in the plant are the increase in leaf area and improving the succulence of many crops, among other essential physiological processes. Both the deficit and excess NO3- have a negative impact on plants increasing susceptibility to insect pests and pathogens, while Ca as divalent ion absorbed Ca2+ plays an important role in control of physiological disorders and the resistance of plants to diseases to increase the mechanical strength. The N and Ca have a close relationship in the nutritional role of the plant, because the Ca absorption acting nitrates, so that a proper balance affects plants better growth and higher strength. 展开更多
关键词 IONS ABSORPTION NITRATE AMMONIUM concentration.
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Analysis on Refinery System as a Complex Task-resource Network 被引量:4
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作者 刘苏昱 荣冈 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第3期253-262,共10页
Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in wh... Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in which nodes represent various tasks and edges denote the resources exchanged among tasks. Using the properties of node degree distribution, strength distribution and other weighted quantities, we demonstrate the heterogeneity of the network and point out the relation between structural characters of vertices and the functionality of correspond- ing tasks. The above phenomena indicate that the design requirements and principles of production process contrib- ute to the heterogeneous features of the network. Besides, betweenness centrality of nodes can be used as an impor- tance indicator to provide additional information for decision making. The correlations between structure and weighted properties are investigated to further address the influence brought by production schemes in system con- nectivity patterns. Cascading failures model is employed to analyze the robustness of the network when targeted at- tack happens. Two capacity assignment strategies are compared in order to improve the robustness of the network at certain cost. The refinery system displays more reliable behavior when the protecting strategy considers heteroge- neous properties. This phenomenon further implies the structure-activity relationship of the refinery system and provides insightful suggestions for process system design. The results also indicate that robustness analysis is a _promising applicat!on of methodologies from complex networks to process system engineering.. 展开更多
关键词 zomplex network refinery system structure-activity relationship HETEROGENEITY robusmess
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Research on the mechanical property test of a new high-strength metal bolt
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作者 SHI Jian-jun MA Nian-jie 《Journal of Coal Science & Engineering(China)》 2011年第4期393-396,共4页
In order to study how to improve the overall performance of the operational metal bolt, based on the production process of an ordinary metal bolt used in understructure engineering, this paper focused on the existing ... In order to study how to improve the overall performance of the operational metal bolt, based on the production process of an ordinary metal bolt used in understructure engineering, this paper focused on the existing problems of ordinary metal bolts identified by some survey and analysis. The results show that the structure of operational metal bolts is so unrea- sonable that the bolt tail is easily fractured by low load capacity. Furthermore, a new type of strong big-end metal bolt and its heat treatment and roughing processing technology were introduced. Through bolt tensile and metallographic tests, the property of the new big-end bolt was analyzed. The new findings indicate that after a special processing, the overall strength and plasticity of the bolt is greatly improved, and the grain of the bolt tail structure is refined, which would help build up favorable working conditions for bolt tails. 展开更多
关键词 mechanical test big-end bolt processing technology microscopic test
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Heavy Quarks Production in Hadronic Processes: Qualitative Study of Higher-Order Fock States
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作者 N.Mebarki K.Benhizia +1 位作者 Z.Belghobsi D.Bouaziz 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期717-722,共6页
The contribution of the two particles Fock states for the production of a heavy quark in proton-pion and photon-pion collisions is studied. It is shown that the effect depends strongly on the produced heavy quark mass... The contribution of the two particles Fock states for the production of a heavy quark in proton-pion and photon-pion collisions is studied. It is shown that the effect depends strongly on the produced heavy quark mass, and the choice of the factorization scale. 展开更多
关键词 jets in large Q2 scattering higher twist effect heavy quarks
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Enhanced Performance of Denitrifying Sulfide Removal Process by 1,2-Naphthoquinone-4-Sulphonate 被引量:1
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作者 Liu Chunshuang Han Kang +4 位作者 Zhao Dongfeng Guo Yadonag Liu Lihong Liu Fang Zhao Chaocheng 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第1期22-28,共7页
The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elementa... The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elemental sulfur and carbon dioxide, respectively, at high loading rates. This study has determined that the reaction rate of sulfide oxidized into sulfur could be enhanced in the presence of 1,2-naphthoquinone-4-sulphonate(NQS). The presence of NQS mitigated the inhibition effects of sulfide species on denitrification. Furthermore, the reaction rates of nitrate and acetate to nitrogen gas and CO_2, respectively, were also promoted in the presence of NQS, thereby enhancing the performance of DSR granules. The advantages and disadvantages of applying the NQS-DSR process are discussed. 展开更多
关键词 denitrifying sulfide removal NQS inhibition bio-granules
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Markov branching processes with killing and resurrection
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作者 CHEN An Yue LU Ying +1 位作者 NG Kai Wang ZHANG Han Jun 《Science China Mathematics》 SCIE CSCD 2016年第3期573-588,共16页
In this paper, we consider Markov branching processes with killing and resurrection. We first show that the Markov branching process with killing and stable resurrection is just the Feller minimum process which is hon... In this paper, we consider Markov branching processes with killing and resurrection. We first show that the Markov branching process with killing and stable resurrection is just the Feller minimum process which is honest and thus unique. We then further show that this honest Feller minimum process is not only positive recurrent but also strongly ergodic. The generating function of the important stationary distribution is explicitly expressed. For the interest of comparison and completeness, the results of the Markov branching processes with killing and instantaneous resurrection are also briefly stated. A new result regarding strong ergodicity of this difficult case is presented. The birth and death process with killing and resurrection together with another example is also analyzed. 展开更多
关键词 Markov branching processes killing stable and instantaneous resurrections uniqueness existence limiting and stationary distributions ergodicity strong ergodicity
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