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多次交配对雌性蛾类生殖适应性影响的Meta分析 被引量:3
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作者 张诗语 曾菊平 +2 位作者 吴先福 彭龙慧 刘兴平 《环境昆虫学报》 CSCD 北大核心 2015年第6期1272-1279,共8页
多次交配是昆虫中一种重要的交配行为,许多学者对此开展了大量的研究以解释雌性昆虫多次交配行为的适应性意义。在鳞翅目蛾类昆虫中存在两种典型的交配策略(单配制和多配制),但这两类交配策略的雌蛾进行多次交配获得哪些利益和代价目前... 多次交配是昆虫中一种重要的交配行为,许多学者对此开展了大量的研究以解释雌性昆虫多次交配行为的适应性意义。在鳞翅目蛾类昆虫中存在两种典型的交配策略(单配制和多配制),但这两类交配策略的雌蛾进行多次交配获得哪些利益和代价目前仍不清楚。本文采用Meta分析法对搜集到的24篇文献中来自8科25种蛾类进行分析,比较两种不同交配策略的雌蛾多次交配与其适应性参数之间的关系。结果表明,多次交配行为明显增加了雌蛾的产卵量和卵的孵化率,而导致寿命的下降。其中,多次交配导致多配制蛾类产卵量和卵的孵化率明显的增加,但寿命趋于延长却没有明显差异;而对单配制蛾类而言,多次交配对相应的适应性参数均没有明显的影响。 展开更多
关键词 多次交配 适应性参数 蛾类 配制 多配制 META分析
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Polygynous Mating System and Behavioural Reason of Black Crested Gibbon (Nomascus concolor jingdongensis) at Dazhaizi,Mt.Wuliang, Yunnan,China 被引量:12
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作者 范朋飞 蒋学龙 +1 位作者 刘长铭 罗文寿 《Zoological Research》 CAS CSCD 北大核心 2006年第2期216-220,共5页
The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females... The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2 - 5 sub-adults, juveniles and itfants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 (G3) and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3's territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3's territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi. 展开更多
关键词 Nomascus concolor jingdongensis Group size and composition Social structure Polygyny Local population Wuliang Mountain
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Improved reduced-complexity bit and power allocation algorithms for multicarrier systems
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作者 许威 赵春明 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期12-15,共4页
Based on the iterative bit-filling procedure, a computationally efficient bit and power allocation algorithm is presented. The algorithm improves the conventional bit-filling algorithms by maintaining only a subset of... Based on the iterative bit-filling procedure, a computationally efficient bit and power allocation algorithm is presented. The algorithm improves the conventional bit-filling algorithms by maintaining only a subset of subcarriers for computation in each iteration, which reduces the complexity without any performance degradation. Moreover, a modified algorithm with even lower complexity is developed, and equal power allocation is introduced as an initial allocation to accelerate its convergence. Simulation results show that the modified algorithm achieves a considerable complexity reduction while causing only a minor drop in performance. 展开更多
关键词 multicarrier modulation allocation algorithm bit loading computational complexity
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Novel consistency control strategy for jet dispensing
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作者 SHEN Ping LI Han-xiong 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第6期1418-1436,共19页
A new consistency control method for jet dispensing is proposed. First, the working parameters, namely, viscosity, supply pressure and supply time, are experimentally investigated. Then, the glue viscosity is approxim... A new consistency control method for jet dispensing is proposed. First, the working parameters, namely, viscosity, supply pressure and supply time, are experimentally investigated. Then, the glue viscosity is approximated by a polynomial model using the least square method. Based on this model and temperatme control implemented using the Dahlin principle, the viscosity of the glue can be maintained at a constant value. Then, the viscosity model of the glue is applied to deriving the droplet mass as the nominal model of the temperature controller. The robustness of the temperature controller is analyzed by applying the small gain theory. The glue supply pressure controller is designed using the consistency control strategy, and the robustness is analyzed. Finall), simulations and experiments are conducted using a jet dispensing control system. The results show that the proposed control strategy can significantly improve the droplet consistency. 展开更多
关键词 jet dispensing consistency control internal model control disturbance rejection jetting valve
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Development of Five-Finger Multi-DoF Myoelectric Hands with a Power Allocation Mechanism
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作者 Tatsuya Seki Tatsuhiro Nakamura Ryu Kato Soichiro Morishita Hiroshi Yokoi 《Journal of Mechanics Engineering and Automation》 2014年第2期97-105,共9页
To be used as five-fingered myoelectric hands in daily living, robotic hands must be lightweight with the size of human hands. In addition, they must possess the DoFs (degrees of freedom) and high grip force similar... To be used as five-fingered myoelectric hands in daily living, robotic hands must be lightweight with the size of human hands. In addition, they must possess the DoFs (degrees of freedom) and high grip force similar to those of human hands. Balancing these requirements involves a trade-off; ideal robotic hands have yet to sufficiently satisfy both requirements. Herein, a power allocation mechanism is proposed to improve the grip force without increasing the size or weight of robotic hands by using redundant DoFs during pinching motions. Additionally, this mechanism is applied to an actual five-fingered myoelectric hand, which produces seven types of motions necessary for activities of daily living and realizes a -60% improvement in fingertip force, allowing three fingers to pinch objects exceeding 1 kg. 展开更多
关键词 Five-finger multi-degree of freedom (DoF) robotic hand power allocation mechanism interference driven link based onwire mechanism.
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GRADIENT OF REFERENCE DIFFERENCE BASED MATCHING ALGORITHM FOR IMAGE FEATURE POINT
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作者 GuanYepeng GuWeikang YeXiuqing LiuJilin 《Journal of Electronics(China)》 2004年第2期163-169,共7页
During matching on feature point, gray correlation matching technology is utilized to extract multi-peaks as a coarse matching set. A pair of given corresponding reference points within the left and right images is us... During matching on feature point, gray correlation matching technology is utilized to extract multi-peaks as a coarse matching set. A pair of given corresponding reference points within the left and right images is used to calculate gradients of reference difference between the reference points and each feature point within the multi-peaks set. The unique correspondence is determined by criterion of minimal gradients of reference difference. The obtained correspondence is taken as a new pair of reference points to update the reference points continuously until all feature points in the left (or right) image being matched with the right (or left) image. The gradients of reference difference can be calculated easily by means of pre-setting a pair of obvious feature points in the left and right images as a pair of corresponding reference points. Besides, the efficiency of matching can be improved greatly by taking the obtained matching point as a new pair of reference points, and by updating the reference point continuously. It is proved that the proposed algorithm is valid and reliable by 3D reconstruction on two pairs of actual natural images with abundant and weak texture, respectively. 展开更多
关键词 Feature point Gray correlation Multi-peaks set MATCHING Reference point
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POWER ALLOCATION AND ADAPTIVE MODULATION STRATEGY FOR MIMO-OFDM SYSTEMS WITH IMPERFECT CSI
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作者 Liu Yi Zhang Hailin 《Journal of Electronics(China)》 2007年第4期443-447,共5页
The presented scheme named M-CAP (Maximum CAPacity) uses the CSI (Channel State Information) and its statistics to deduce an equivalent channel according to which the transmit power is allocated to the subchannels. An... The presented scheme named M-CAP (Maximum CAPacity) uses the CSI (Channel State Information) and its statistics to deduce an equivalent channel according to which the transmit power is allocated to the subchannels. And then modulation scheme is determined adaptively according to the power allocated to each subchannel. The advantage of the M-CAP scheme is that it combines power allocation and adaptive modulation while maintaining a large capacity. We demonstrate by computer simulations that the proposed M-CAP scheme can significantly improve system performance compared with the traditional schemes. 展开更多
关键词 Power allocation Adaptive modulation Multi-Input Multi-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) Singular Value Decomposition (SVD) Channel State Information (CSI)
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MULTICARRIER DS-CDMA WITH ADAPTIVE MODULATION AND POWER ALLOCATION
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作者 ZhaoYahong ZhangZhongpei WuWeiling 《Journal of Electronics(China)》 2003年第3期177-182,共6页
Adaptive modulation and power allocation is introduced into the multicarrier DS-CDMA system to improve the system performance and bandwidth efficiency. First, the systemdesign appropriate for adaptive modulation and p... Adaptive modulation and power allocation is introduced into the multicarrier DS-CDMA system to improve the system performance and bandwidth efficiency. First, the systemdesign appropriate for adaptive modulation and power allocation is given, then the algorithmof adaptive modulation and power allocation is applied. Simulation results demonstrate greatperformance improvement compared with the fixed modulated one. 展开更多
关键词 Multicarrier DS-CDMA Adaptive modulation and power allocation OPTIMIZATION
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