Nutritive Equilibrium in Rice Plant Populations for High Yield

The effects of nitrogen, phosphorus and potassium application level, seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization. There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations. The equilibrium index of nutrient amount, content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2. The optimum nutritive proportion of nitrogen: phosphorus: potassium assimilated by the plants was about 10: 2: 9 at the ripening stage. But the content and the proportion varied with the growth stages. Therefore, the nutrient in rice plant populations should be in a dynamic equilibrium, so as to achieve high yield.

Analysis of the Evolutionary Significance of Heterosis——taking the contribution of fitness to the genetic diversity in random mating population as an example

Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population （i. e. RR, Rr and rr） under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote＇s fithess so as not to wash out different types of genes. It deepens Darwin＇s thoughts of individual section by making the individual fitness consonant with population fitness.

Evolution Law by Generations of Genotype Entropy of the Inbred Population Based on Fitness

The study researched the inbred population which three genotypes of each pair heterozygous gene with different fitness. Change law by generations of genotype ratio was reflected by difference equations. The result showed that the genotype ratio that parents were all heterozygous population tended to balance, about needing 15 generations. The fitness of Rr was over or equal to two times of RR＇s or rr, which was the condition of Rr could be reserved for a long time.

Spatial Pattern of Long-term Residence in the Urban Floating Population of China and its Influencing Factors

Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial crisis.By using China Migrants Dynamic Survey data for 2012–2014,China Labor-force Dynamics Survey data for 2014–2016,and macroscale urban matched data,we analyzed the spatial pattern of long-term residential behavior in China’s urban floating population in 2012–2016 and developed an urban spatial utility equilibrium model containing‘macro’urban factors and‘micro’individual and household factors to explain the pattern.The results first revealed that long-term residence is defined as≥6 yr for the urban floating population in China.Second,members of this population are more likely to be long-term residents of the megacities in the three urban agglomerations in eastern China as well as of small and medium-sized cities in western and northeastern China,whereas short-term residence is more likely in cities in central China and near the three urban agglomerations.Third,urban population density and housing prices,both have a significant U-shaped effect,are main factors affecting the spatial pattern of long-term residence.

Stochastic evolutionary public goods game with first and second order costly punishments in finite populations

We study the stochastic evolutionary public goods game with punishment in a finite size population. Two kinds of costly punishments are considered, i.e., first-order punishment in which only the defectors are punished, and second-order punishment in which both the defectors and the cooperators who do not punish the defective behaviors are punished. We focus on the stochastic stable equilibrium of the system. In the population, the evolutionary process of strategies is described as a finite state Markov process. The evolutionary equilibrium of the system and its stochastic stability are analyzed by the limit distribution of the Markov process. By numerical experiments, our findings are as follows.（i） The first-order costly punishment can change the evolutionary dynamics and equilibrium of the public goods game, and it can promote cooperation only when both the intensity of punishment and the return on investment parameters are large enough.（ii）Under the first-order punishment, the further imposition of the second-order punishment cannot change the evolutionary dynamics of the system dramatically, but can only change the probability of the system to select the equilibrium points in the ＂C＋P＂ states, which refer to the co-existence states of cooperation and punishment. The second-order punishment has limited roles in promoting cooperation, except for some critical combinations of parameters.（iii） When the system chooses＂C＋P＂ states with probability one, the increase of the punishment probability under second-order punishment will further increase the proportion of the ＂P＂ strategy in the ＂C＋P＂ states.

Self-similarity of spanwise rotational motions’population trends in decelerating open-channel flow

Decelerating open-channel flow is a type of flow that gradually moves forward with decreasing velocity and increasing water depth.Although all flow parameters change along the streamwise direction,previous studies have revealed that these parameters’vertical distributions at different sections can be universally described with a single profile when being nondimensionalised by appropriate scales.This study focuses on the population trends of spanwise rotational motions at various sections along the main flow direction by particle imaging velocimetry(PIV)measurement.The wall-normal population distributions of density,radius,swirling strength,and convection velocity of the prograde and retrograde motions show similar trends in uniform open-channel flows.The dimensionless representation is invariant along the main flow direction.This study’s results indicate the self-similar characteristic of population trends of spanwise rotational motions prevails in decelerating open-channel flow.

Stability Analysis of a Deterministic Epidemic Model in Metapopulation Setting

We present in this article an epidemic model with saturated in metapopulation setting. We develop the mathematical modelling of HIV transmission among adults in Metapopulation setting. We discussed the positivity of the system. We calculated the reproduction number, If ?for , then each infectious individual in Sub-Population j infects on average less than one other person and the disease is likely to die out. Otherwise, if ?for , then each infectious individual in Sub-Population j infects on average more than one other person;the infection could therefore establish itself in the population and become endemic. An epidemic model, where the presence or absence of an epidemic wave is characterized by the value of ?both ideas of the inner equilibrium point of stability properties are discussed.

基于水资源空间均衡的“四水四定”调控模型构建

为实现未来不同时间尺度下的水资源空间均衡与动态调控,创建了一套完整严谨、可动态调控的“四水四定”模型体系。通过模糊信息粒化窗口的支持向量机模型预测区域未来总用水量,利用基于时间序列相似性分析的自回归支持向量机模型预测区域未来分用水量,并对两类数据进行不确定性分析;构建了复杂回归函数对各类用水指标进行情景预测,经统计检验后将其作为当前用水模式下未来用水指标;构建了“四水四定”水资源承载力模型和水资源空间均衡模型,基于未来总用水量、未来各分用水量、未来用水指标,选用水资源负载系数、用水效益和水土资源匹配系数3个指标,结合基尼系数量化水资源空间均衡度,分析当前用水模式下未来水资源均衡度;构建了最优化模型,以最小化基尼系数为目标函数调整未来用水模式,实现水资源动态调控。所创建的模型体系可以实现未来不同时间尺度下的水资源空间均衡与动态调控。

航天器姿态控制群体博弈分布式分配方法

针对由多个细胞星构成的组合卫星的姿态控制问题,提出了一种包含控制力矩计算层与冗余力矩分配层的双层姿态控制方法。将细胞星间的冗余力矩分配问题转化为群体博弈的策略选择问题,综合考虑能量消耗、飞轮输出力矩裕度和飞轮角动量裕度设计收益函数,以力矩分配系数作为群体质量,以细胞星作为策略建立群体博弈模型。考虑群体演化中模仿和比较形成的不同演化策略,分别采用Smith动力学以及复制器动力学修订协议求解博弈的Nash均衡解,并利用有限制策略的群体博弈理论形成分布式冗余力矩分配方式,得到各个细胞星的控制策略。最后通过仿真实验验证了此分配方式的有效性。

群体博弈理论的新进展

群体博弈理论是近三十年来发展起来的博弈论的新方向,源于1950年J.Nash在其博士学位论文中关于有限非合作博弈混合策略和平衡点的“Mass-Action”解释,建立了由众多个体组成的群体及社会中,个体的理性决策行为理论,在社会学、生物学、经济学、管理学、信息科学等领域有广泛和深入的应用。本文介绍近年来群体博弈理论的研究成果及新进展,探讨群体博弈理论的发展动向。

基于水资源空间均衡的“四水四定”调控模型的应用

将前期研究构建的基于水资源空间均衡的“四水四定”调控模型应用于山东省临沂市水资源空间均衡动态调控,在预测各区(县)用水量和用水指标的基础上,探究了各区(县)未来水资源空间均衡度,在不同时间尺度上对未来用水量进行了动态调控。结果表明:调控模型可靠性高且具备普适性;当前用水模式下临沂市未来水资源在空间上处于绝对均衡状态,仅水土匹配系数处于一般均衡状态;对各区(县)不同类型未来用水量进行动态调控,可在不同时间尺度上使临沂市水资源空间均衡的各项指标达到绝对均衡状态;在“四水四定”与水资源空间均衡的约束下,通过对未来长短期用水量的动态调控,临沂市预期用水量能够实现动态均衡。

改进平衡优化器算法求解柔性车间调度问题

针对原始平衡优化器算法(Equilibrium Optimizer,EO)求解车间调度问题时出现精度低、稳定性差的问题,提出一种基于单向多种群信息交流的量子改进平衡优化器算法(Improved Multipopulation Quantum Equilibrium Optimizer,IMQEO)。首先,将初始化平衡池分为三个子平衡池,一个平衡池主要肩负开发功能,其余平衡池主要用于空间探索,以高效搜寻最优解;然后分离最优浓度各分量,重建多个最优浓度,结合贪婪策略,个体依次包围收缩于各最优浓度,实现加速收敛;最后,利用量子旋转门策略更新浓度以跳出局部最优解。对比标准EO算法,经过车间调度算例测试,结果表明混合改进策略具有较好的优化效果。

Modelling of the populating development of the genome in the radiation condition of the environment

The existence of the genome population in condition of radiation environment has been considered. The differences between the laws of the allele frequencies for autosomal genes and genes linked to sex are described. Radiation conditions were found at maintenance of the balance of the Hardy-Weinberg genotype in the population, as well as conditions of complete elimination of the targeted allele by ionizing radiation. Conclusions about the nature of radiation resistance of the population are drawn.

群体博弈合作均衡的存在性和适定性研究

针对许多经济问题面临着大规模大群体之间的策略互动,且策略互动时,参与主体之间为寻求更高利益可能达成合作的行为,研究群体博弈合作均衡的存在性,为这些情况提供统一分析框架。首先,介绍群体博弈模型及群体博弈合作均衡的定义;其次,在群体状态函数为伪连续的条件下,构造辅助偏好映射,借助伪连续的性质,得到群体博弈问题合作均衡的存在性结果,并举例说明该存在性定理的优越性。针对求解群体博弈合作均衡时,原始数据收集可能会出现偏差,模型数据可能受到干扰,求解的近似解序列可能不可行的情形,研究群体博弈合作均衡的适定性,为数值计算提供理论依据。首先,分别引入该类群体博弈问题合作均衡的Hadamard适定性和Levitin-Polyak适定性概念;然后,借助合作均衡映射的半连续性和紧性结果,建立Hadamard适定性成立的充分性条件;最后,借助群体状态函数的伪连续性,建立Levitin-Polyak适定性成立的充分性条件。

渭河流域人口与经济空间分布一致性及影响因素分析

[目的]探究渭河流域人口与经济空间分布特征及协调关系,为缩小区域差距、促进区域协调发展相关政策制定提供理论依据。[方法]基于2000—2019年渭河流域88个县区人口和GDP数据,综合运用不均衡指数、地理集中度、不一致指数等方法,从总体和局域分析渭河流域人口与经济空间分布关系的动态演变特征,并基于面板数据对人口与经济空间分异的影响因素进行探析。[结果](1)渭河流域人口与经济不均衡程度经历了先减小再扩大的变化过程,不均衡指数由2000年的0.105上升至2019年的0.107,区域发展差异一直存在;(2)人口与经济空间分布均呈现“东南稠密,西北稀疏”的特点,但人口要素主要聚集在渭河干流沿线县区,经济要素则主要以各市辖区为聚集中心;(3)根据不一致指数,渭河流域人口与经济空间分布关系可划分为经济极化型、经济超前型、均衡发展型、人口超前型、人口极化型5种类型;(4)人口与经济分布的空间非均衡性不仅受市场机制和政府作用的影响,还与城市发展水平和区域发展战略明显关联,解释变量在不同时期影响作用也存在一定差异。[结论]渭河流域区域发展不协调形势严峻,推动流域西北部县区发展,缩小省际发展差距,促进人口与经济空间均衡仍然是未来需要解决的问题之一。

人口老龄化、资本价格扭曲与产业结构优化

资本要素价格的市场扭曲程度不仅决定着要素相对配置效率、影响着产业结构调整方向,同时资本和劳动之间的替代对地区老龄化程度和劳动力技能结构也造成深远影响。构建两地区一般均衡框架,通过数值模拟的方式发现地区间老龄化程度加深会促使地区产业结构向服务业倾斜,而劳动力的流入不仅能够改善地区劳动力技能结构、稀释老龄化程度,同时能够对资本产生引致效应,带来地区资本深化的同时,促进产业结构向第二产业倾斜。进一步对理论模型的关键结论进行中介效应检验发现,地区老龄化程度对产业结构优化存在促进作用,而资本价格负向扭曲和劳动价格负向扭曲则会造成要素配置的冗余,不利于产业结构优化,中介效应对产业结构优化的阻滞效应大约为6.1%。

机制与价值双重维度:人口空间均衡研究进展与展望

聚焦人口空间均衡,是根据现阶段中国人口均衡发展面临的突出问题,针对性地对人口均衡问题的复杂性作出有重点的简化。本研究主要包括以下几个方面:从宏观经济学的市场要素引申的人口空间均衡及社会经济结构的均衡、自然地理空间规定性影响下的人口及其他要素的空间均衡,以及城市化进程中居民点体系的人口空间均衡等方面探讨机制维度的人口空间均衡;从价值维度探讨中国语境下的人口空间均衡;从全国及各地人口空间均衡发展存在的主要问题、原因分析及界定与测量方法等方面探讨人口空间均衡在中国的实践探索。未来的人口空间均衡研究,应回归均衡本质,从微观个体迁移行为出发,将这一具有很强应用价值的概念进行学科化、学术化探索;应引入新的研究方法与分析工具,建构人口空间均衡的科学评价标准;应在价值与机制两种话语体系的人口空间均衡中搭建沟通的桥梁,建立一种能够将两种维度关联的、综合的人口空间均衡概念。

空间均衡视角下水-经济-人口要素匹配度评价方法

为响应水资源空间均衡发展战略,提出以行业用水量为轴,社会经济、人口、水资源为抓手的“一轴三维”区域空间均衡研究思路。构建总体空间均衡性评价与要素空间匹配度评价相结合的量化分析模型,研究各要素的时间演变规律和空间分布特征,并对匹配度算法进行改进,提出基于数列的累计排序占比算法。将该模型应用于1980~2019年长江流域农业、工业、生活用水与行业产值、区域人口和水资源量的空间均衡性分析。结果表明:近40 a间,长江流域各要素空间均衡性呈现总体波动向好态势,但各维度的差异明显,其中“水资源量-行业用水”呈现高度不均衡的状态。各要素空间匹配性方面,2019年长江流域行业用水与行业产值的匹配性较好,与区域人口的匹配性居中,与水资源量的匹配性不佳。通过对比不同匹配度算法,研究提出的累计排序占比法可以有效解决原有算法的不足,同时在不同的场景下均具有较高的稳定性和较好的可辨识度。通过构建总体空间均衡性指标评价与微观各要素空间匹配度分析相结合的“一轴三维”空间均衡评价体系,可为长江流域水资源调配、管理和区域均衡发展提供理论参考和技术支撑。

阶段性减免企业养老保险缴费政策的宏观稳定效应、机制与异质性影响研究

2020年我国首次使用阶段性减免企业养老保险缴费政策应对疫情带来的经济冲击,为实现“六稳”与“六保”发挥了积极作用,而本文进一步揭示了其政策效应与机制。本文通过构建一个包含社保部门的TANK-DSGE模型,对其政策的宏观稳定效应与作用机制进行了量化评估和检验,并在人口老龄化环境下对该政策进行了敏感度分析。本文主要结论为:阶段性减免企业养老保险缴费政策对经济有着较强的短期刺激作用,稳就业的政策精准性较好,但在中长期也存在抑制投资和扩大养老保险基金收支缺口等政策成本;其政策作用路径包括利率、通胀、工资和劳动力投入;虽然退休人员家庭对政策的反应存在异质性,但影响并不显著;老龄化环境下,政策刺激的短期效果增强,但其政策成本也更高,工资和劳动力投入的作用机制得到增强,通胀与利率的作用机制被弱化,退休人员政策反应的异质性更强;从政策乘数来看,在老龄化环境中,该政策的“稳增长”和“稳就业”效果均更好。当前我国经济正面临“三重压力”,阶段性减免企业养老保险缴费政策或可再度发挥稳定经济的重要作用。

欠发达地区发展的“低水平均衡”及其突破——川西B县乡村振兴的案例研究

乡村多样性现实和乡村振兴分类推进的政策要求,呼唤更为丰富的乡村类型研究。尽管“空心化”所导致的“乡村衰落”已经成为诸多乡村振兴研究的默认起点,但以B县为代表的“三区三州”地区可能会成为这一默认共识的“视野盲区”。这类地区在人口流动上呈现出明显的“域内流动”特征,而过往的区域发展阶段论或者“封闭说”无法很好地解释这种流动模式得以维持的原因及其对乡村发展的影响。B县乡村振兴的现实背景是以人口“域内流动”为表征的“低水平均衡”发展陷阱,使得在“空心化语境”基础上建立的政策议程与该类乡村面临的首要困难不匹配:与“空心化”议题中“人的流失”相比,“低水平均衡”面对的是人口域内流动和低人力资本带来的负反馈问题。然而,B县在合法性逻辑和内部效率的主导下,采取“情境性抽离”的做法推进乡村振兴,导致了“低水平均衡”的再生产。建议避免照搬“空心化”较强地区的做法,以嵌入性的政策实践来突破“低水平均衡”,并在充分考虑“人口在地化”优缺点的基础上统筹产业推进、公共服务和社会治理。