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什么是可繁殖的宇宙论?
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《太空探索》 2004年第9期F003-F003,共1页
关键词 可繁殖 宇宙论 广义相对论 多宇宙理论 黑洞
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Differences in functional traits and reproductive allocations between native and invasive plants 被引量:6
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作者 WANG Cong-yan ZHOU Jia-wei +2 位作者 LIU Jun XIAO Hong-guang WANG Lei 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第3期516-525,共10页
Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants... Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions. 展开更多
关键词 functional trait specific leaf area reproductive allocation strategy phenotypic plasticity invasive plant
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The Research on Social Networks Public Opinion Propagation Influence Models and Its Controllability 被引量:9
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作者 Lejun Zhang Tong Wang +3 位作者 Zilong Jin Nan Su Chunhui Zhao Yongjun He 《China Communications》 SCIE CSCD 2018年第7期98-110,共13页
Public opinion propagation control is one of the hot topics in contemporary social network research. With the rapid dissemination of information over the Internet, the traditional isolation and vaccination strategies ... Public opinion propagation control is one of the hot topics in contemporary social network research. With the rapid dissemination of information over the Internet, the traditional isolation and vaccination strategies can no longer achieve satisfactory results. A positive guidance technology for public opinion diffusion is urgently needed. First, based on the analysis of influence network controllability and public opinion diffusion, a positive guidance technology is proposed and a new model that supports external control is established. Second, in combination with the influence network, a public opinion propagation influence network model is designed and a public opinion control point selection algorithm(POCDNSA) is proposed. Finally, An experiment verified that this algorithm can lead to users receiving the correct guidance quickly and accurately, reducing the impact of false public opinion information; the effect of CELF is no better than that of the POCDNSA algorithm. The main reason is that the former is completely based on the diffusion cascade information contained in the training data, but does not consider the specific situation of the network structure and the diffusion of public opinion information in the closed set. thus, the effectiveness and feasibility of the algorithm is proven. The findings of this article therefore provide useful insights for the implementation of public opinion control. 展开更多
关键词 social network public opinion propagation control influence network
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Effect of Dietary Nitrogen Corrected-True Metabolism Energy and Digestible Amino Acids on Broiler Breeder Reproductive Performance
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作者 J. Nasr A. Yaghobfar +1 位作者 Y. Ebrahimnezhad K. Nazeradl 《Journal of Agricultural Science and Technology(A)》 2011年第8期1137-1140,共4页
A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 fe... A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 females and 20 males broiler breeders in 4 treatments with 5 replicates (7 females with a male) were used in the form of a completely randomized trial design 2 ~ 2 factorial. Four experimental diets were formulation based on two factors, first factor was included, two types of Apparent and True Metabolizable Energy corrected for Nitrogen (AMEn and TMEn) and the second factor was included, two types of Total Amino Acids (TAA) and Digestible (DAA) of feedstuffs. The result showed that egg weight, egg production (%) and egg mass (g/hen/day) was significantly different which was affected by diets formulation based on energy and interaction between energy and amino acids (P 〈 0.01). Treatment 2 (AMEn + DAA) was at the highest level significantly different (P 〈 0.01) in egg weight 68.97 g, egg production 62.45%, and egg mass 43. i g/hen/day. Hatching eggs were significantly different which was affected by diet formulation based on amino acids. Fertility, hatchability and number of chicks per hen were significant different, that were affected by diet formulation based on energy (P 〈 0.05). Interaction between two factors, were significantly different in two reproductive traits fertility and hatchability (P 〈 0.05). This experiment showed that diet formulation based on AMEn and DAA for broiler breeder was better and significant on performance. 展开更多
关键词 Broiler breeders performance digestible amino acids TMEn AMEn
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Fish genome manipulation and directional breeding 被引量:12
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作者 YE Ding ZHU ZuoYan SUN YongHua 《Science China(Life Sciences)》 SCIE CAS CSCD 2015年第2期170-177,共8页
Aquaculture is one of the fastest developing agricultural industries worldwide.One of the most important factors for sustainable aquaculture is the development of high performing culture strains.Genome manipulation of... Aquaculture is one of the fastest developing agricultural industries worldwide.One of the most important factors for sustainable aquaculture is the development of high performing culture strains.Genome manipulation offers a powerful method to achieve rapid and directional breeding in fish.We review the history of fish breeding methods based on classical genome manipulation,including polyploidy breeding and nuclear transfer.Then,we discuss the advances and applications of fish directional breeding based on transgenic technology and recently developed genome editing technologies.These methods offer increased efficiency,precision and predictability in genetic improvement over traditional methods. 展开更多
关键词 fish directional breeding polyploidy breeding nuclear transfer transgenic fish genome editing
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Complex courtship success and plasticity environments displays facilitate in signaling across male reproductive variable
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作者 Dustin J. WILGERS Eileen A. HEBETS 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第2期175-186,共12页
Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, ... Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, to maintain effective communication. Male Rabidosa rabida wolf spiders produce complex courtship signals, consisting of both visual and seismic components. We test the hypothesis that the complex signaling of R. rabida contributes to male reproductive success in variable signaling environments. We first examine the condition-dependence of foreleg ornamentation (a presumed visual signal) and seismic signal components and find that both may provide potentially redundant information on foraging history. Next, we assessed reproductive success across manipulated signaling environments that varied in the effectiveness of visual and/or seismic signal transmission. In environments where only one signal could be successfully transmitted (e.g., visual or seismic), pairs were still able to successfully copulate. Additionally, we found that males altered their courtship display depending on the current signaling environment. Specifically, males reduced their use of a visual display component in signaling environments where visual signal transmission was ablated. Incorporating signals in multiple modalities not only enables R. rabida males to maintain copulation success across variable signaling environments, but it also enables males to adjust their composite courtship display to current signaling conditions . 展开更多
关键词 Communication Multimodal Signal evolution Condition-dependent LYCOSIDAE Rabidosa rabida Efficacy back-up Redundant signals
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