Premature senescence in Bacillus thuringiensis(Bt)cotton has emerged as a significant challenge to the formation and realization of fiber yield and quality since its commercialization in 1997.Initially,premature senes...Premature senescence in Bacillus thuringiensis(Bt)cotton has emerged as a significant challenge to the formation and realization of fiber yield and quality since its commercialization in 1997.Initially,premature senescence was thought to be an inherent trait associated with the Bt gene.However,subsequent research and practice have demonstrated that it is not directly linked to the Bt gene but rather results from a physiological imbalance between the sink and source,as well as between the root and shoot in Bt cotton.This short review provides an overview of the causes,mechanisms,and control measures for premature senescence in Bt cotton.It offers valuable insights for future research and the sustainable application of transgenic crops.展开更多
An improved genetic algorithm (GA) is proposed based on the analysis of population diversity within the framework of Markov chain. The chaos operator to combat premature convergence concerning two goals of maintaining...An improved genetic algorithm (GA) is proposed based on the analysis of population diversity within the framework of Markov chain. The chaos operator to combat premature convergence concerning two goals of maintaining diversity in the population and sustaining the convergence capacity of the GA is introduced. In the CHaos Genetic Algorithm (CHGA), the population is recycled dynamically whereas the most highly fit chromosome is intact so as to restore diversity and reserve the best schemata which may belong to the optimal solution. The characters of chaos as well as advanced operators and parameter settings can improve both exploration and exploitation capacities of the algorithm. The results of multimodal function optimization show that CHGA performs simple genetic algorithms and effectively alleviates the problem of premature convergence.展开更多
The somatic cell nuclear transfer （SCNT） technique has been applied successfully in a range of mammalian species giving rise to offspring, however, the efficiency of development to term has remained low. Oocyte meio...The somatic cell nuclear transfer （SCNT） technique has been applied successfully in a range of mammalian species giving rise to offspring, however, the efficiency of development to term has remained low. Oocyte meiotic arrest is an important option to make the SCNT more flexible and increase the number of cloned embryos produced. This paper showed that the use of butyrolactone I to arrest the meiotic division for 24 h prior to in vitro maturation （IVM） provided bovine oocytes capability of supporting development of blastocysts as efficiently as non arrested oocytes. In the SCNT group, cleavage rates were not affected by prematuration when adding butyrolactone I during IVM （57.9% vs. 62.4%; control vs. 10 μmol.L^-1 butyrolactone I）, developmental rates to biastocyst were unaffected （22.0% vs. 20.3%; control vs. 10 μmol.L^-1 butyrolactone I, p〉0.05） by the addition ofbutyrolactone I during IVM in cloned embryos. Moreover, the total cell numbers of blastocyst were not affected by butyrolactone I （total nucleus numbers, 132±16.5 vs. 128±19.4, p〉0.05）. In conclusion, the SCNT embryos from butyrolactone I- prematured bovine oocytes had the same developmental potential as the non treated one. The present study provided a method for laboratories of in vitro embryos production, mainly those working on the SCNT, where prematuration could be used to iiacrease the flexibility of the procedure.展开更多
提出了一种基于混沌遗传算法的计算圆度误差的新方法.它利用混沌优化方法的遍历性和随机性,通过混沌扰动操作可克服传统遗传算法中的早熟问题,确保算法的全局收敛性.该方法满足最小条件原理,其计算结果的精确度非常高,理论上可以获得全...提出了一种基于混沌遗传算法的计算圆度误差的新方法.它利用混沌优化方法的遍历性和随机性,通过混沌扰动操作可克服传统遗传算法中的早熟问题,确保算法的全局收敛性.该方法满足最小条件原理,其计算结果的精确度非常高,理论上可以获得全局最优解.实例计算表明,这种算法简单明确,具有精度高、收敛速度快、易于计算机程序实现和推广应用等特点.
Abstract：
A new method for calculating the roundness error based on chaos genetic algorithms is proposed. The system utilizes the ergodicity and randomness of chaos optimal method and by means of chaos stir operation, which can overcame the problem of premature convergence in traditional genetic algorithms and ensured an convergence of the algorithms. The method satisfies the principle of the least condition, the precision of calculating result is very high and can find .the global optimal solution. An actual calculated example showed that this method is simple and clear and it has features of high precision and fast convergent speed as well as using computer easily and popularizing application easily.展开更多
Considering premature convergence in the searching process of genetic algorithm, a chaotic migration-based pseudo parallel genetic algorithm (CMPPGA) is proposed, which applies the idea of isolated evolution and infor...Considering premature convergence in the searching process of genetic algorithm, a chaotic migration-based pseudo parallel genetic algorithm (CMPPGA) is proposed, which applies the idea of isolated evolution and information exchanging in distributed Parallel Genetic Algorithm by serial program structure to solve optimization problem of low real-time demand. In this algorithm, asynchronic migration of individuals during parallel evolution is guided by a chaotic migration sequence. Information exchanging among sub-populations is ensured to be efficient and sufficient due to that the sequence is ergodic and stochastic. Simulation study of CMPPGA shows its strong global search ability, superiority to standard genetic algorithm and high immunity against premature convergence. According to the practice of raw material supply, an inventory programming model is set up and solved by CMPPGA with satisfactory results returned.展开更多
The mechanism of particle swarm optimization algorithm is studied, and one can draw the conclusion that the best particle found by the swarm falling into local minima is one of the main reasons for premature convergen...The mechanism of particle swarm optimization algorithm is studied, and one can draw the conclusion that the best particle found by the swarm falling into local minima is one of the main reasons for premature convergence. Therefore, an improved particle swarm optimization algorithm is proposed. This algorithm selects the best particle with roulette wheel selection method, so premature converging to local optima is avoided. At last, the improved particle swarm optimization algorithm is applied to optimization of time-sharing power supply for zinc electrolytic process. Simulation and practical results show that the global search ability of IPSO is improved greatly and optimization of time-sharing power supply for zinc electrolytic process can bring about outstanding economic benefit for plant.展开更多
基金supported by National Key Research and Development Program of China(2024YFD2300221)China Agricultural Research System(CARS-15–15)+1 种基金Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2024D03)Dong Hezhong Studio for Popularization of Science and Technology in Salt Tolerant Industrial Crops(202228297).
文摘Premature senescence in Bacillus thuringiensis(Bt)cotton has emerged as a significant challenge to the formation and realization of fiber yield and quality since its commercialization in 1997.Initially,premature senescence was thought to be an inherent trait associated with the Bt gene.However,subsequent research and practice have demonstrated that it is not directly linked to the Bt gene but rather results from a physiological imbalance between the sink and source,as well as between the root and shoot in Bt cotton.This short review provides an overview of the causes,mechanisms,and control measures for premature senescence in Bt cotton.It offers valuable insights for future research and the sustainable application of transgenic crops.
基金The National Natural Science Foundation of China !(No .699740 43 )
文摘An improved genetic algorithm (GA) is proposed based on the analysis of population diversity within the framework of Markov chain. The chaos operator to combat premature convergence concerning two goals of maintaining diversity in the population and sustaining the convergence capacity of the GA is introduced. In the CHaos Genetic Algorithm (CHGA), the population is recycled dynamically whereas the most highly fit chromosome is intact so as to restore diversity and reserve the best schemata which may belong to the optimal solution. The characters of chaos as well as advanced operators and parameter settings can improve both exploration and exploitation capacities of the algorithm. The results of multimodal function optimization show that CHGA performs simple genetic algorithms and effectively alleviates the problem of premature convergence.
基金Supported by the Scientific Research Fund of Heilongjiang Provincial Education Department (11531028)Heilongjiang Postdoctoral Fund (LBH-Z11245)
文摘The somatic cell nuclear transfer （SCNT） technique has been applied successfully in a range of mammalian species giving rise to offspring, however, the efficiency of development to term has remained low. Oocyte meiotic arrest is an important option to make the SCNT more flexible and increase the number of cloned embryos produced. This paper showed that the use of butyrolactone I to arrest the meiotic division for 24 h prior to in vitro maturation （IVM） provided bovine oocytes capability of supporting development of blastocysts as efficiently as non arrested oocytes. In the SCNT group, cleavage rates were not affected by prematuration when adding butyrolactone I during IVM （57.9% vs. 62.4%; control vs. 10 μmol.L^-1 butyrolactone I）, developmental rates to biastocyst were unaffected （22.0% vs. 20.3%; control vs. 10 μmol.L^-1 butyrolactone I, p〉0.05） by the addition ofbutyrolactone I during IVM in cloned embryos. Moreover, the total cell numbers of blastocyst were not affected by butyrolactone I （total nucleus numbers, 132±16.5 vs. 128±19.4, p〉0.05）. In conclusion, the SCNT embryos from butyrolactone I- prematured bovine oocytes had the same developmental potential as the non treated one. The present study provided a method for laboratories of in vitro embryos production, mainly those working on the SCNT, where prematuration could be used to iiacrease the flexibility of the procedure.
文摘提出了一种基于混沌遗传算法的计算圆度误差的新方法.它利用混沌优化方法的遍历性和随机性,通过混沌扰动操作可克服传统遗传算法中的早熟问题,确保算法的全局收敛性.该方法满足最小条件原理,其计算结果的精确度非常高,理论上可以获得全局最优解.实例计算表明,这种算法简单明确,具有精度高、收敛速度快、易于计算机程序实现和推广应用等特点.
Abstract：
A new method for calculating the roundness error based on chaos genetic algorithms is proposed. The system utilizes the ergodicity and randomness of chaos optimal method and by means of chaos stir operation, which can overcame the problem of premature convergence in traditional genetic algorithms and ensured an convergence of the algorithms. The method satisfies the principle of the least condition, the precision of calculating result is very high and can find .the global optimal solution. An actual calculated example showed that this method is simple and clear and it has features of high precision and fast convergent speed as well as using computer easily and popularizing application easily.
文摘Considering premature convergence in the searching process of genetic algorithm, a chaotic migration-based pseudo parallel genetic algorithm (CMPPGA) is proposed, which applies the idea of isolated evolution and information exchanging in distributed Parallel Genetic Algorithm by serial program structure to solve optimization problem of low real-time demand. In this algorithm, asynchronic migration of individuals during parallel evolution is guided by a chaotic migration sequence. Information exchanging among sub-populations is ensured to be efficient and sufficient due to that the sequence is ergodic and stochastic. Simulation study of CMPPGA shows its strong global search ability, superiority to standard genetic algorithm and high immunity against premature convergence. According to the practice of raw material supply, an inventory programming model is set up and solved by CMPPGA with satisfactory results returned.
文摘The mechanism of particle swarm optimization algorithm is studied, and one can draw the conclusion that the best particle found by the swarm falling into local minima is one of the main reasons for premature convergence. Therefore, an improved particle swarm optimization algorithm is proposed. This algorithm selects the best particle with roulette wheel selection method, so premature converging to local optima is avoided. At last, the improved particle swarm optimization algorithm is applied to optimization of time-sharing power supply for zinc electrolytic process. Simulation and practical results show that the global search ability of IPSO is improved greatly and optimization of time-sharing power supply for zinc electrolytic process can bring about outstanding economic benefit for plant.
