Partial Remelting of Thixotropic Magnesium-Rare Earth Alloy from Near Non-Equilibrium-Liquidus Casting

After the investigation on partial remelting of thixotropic magnesium serial alloys （ZK60） by near non-equilibrium liquidus casting （NNLC）, the primary solid grains of ZK60-2Ca alloy spheroidized notably during partial remelting processing, however, coarsening and polygonization as occurred holding time prolonged. The refining and globularity of the thixotropic alloys are promoted after further alloyed by Y, RE, Nd and/or Ag, and the results vary with those addition. The remelting structure of ZK60-2Ca-1Y alloy is finer than its base alloy. And the effect of RE, especially Ag, on the refinement of microstrueture is notable, but Nd does nothing on it. There is little impact of remelting temperature fluctuation on partial remelted microstrueture as holding time in general. On the contrary, it is more sensitive at longer holding time. The quality thixotropic silver-contained alloy can be achieved by remelted partially at 600℃ for 10 min.

Investigation of the Appropriate Partial Level Density Formula for Pre-Equilibrium Nuclear Exciton Model

Ericson formula represents the first formula, which was suggested to describe the partial level density (PLD) formula in pre-equilibrium region of the nuclear reactions. Then a number of corrections were added to this formula in order to make it more suitable to physical meaning. In this paper, there are two aims to be done: the first aim is to study the correspondence between one and two-components formulae in Ericson, Pauli, and pairing corrections;the second aim is to compare and study the results of Comprehensive formula, which contents with all corrections, with Ericson, Pauli, and pairing formulae. The Comprehensive formula was suggested to simulate the reality. To achieve these aims the 56Fe and 90Zr nuclei were chosen and the results showed that the difference between one and two-components formulae was too small which can be neglected. Furthermore, the results strongly recommended that for cross section calculations of the nuclear reaction, one must use Comprehensive formula rather than Pauli formula.

中国高新技术产品进口关税减让的经济效应

降低高新技术产品进口关税是中国践行扩大开放承诺的有力措施,对于以高新技术产业发展推动高水平科技自立自强具有重要意义。运用可计算局部均衡模型,从产业层面考察了中国高新技术产品进口关税减让的经济影响。研究发现:中国高新技术产品进口关税税率下调对进口的促进效应大于出口,其效应随降税幅度的提高而递增,且现有关税税率越高,降税的贸易效应越大;中国高新技术产品的内销额和消费者价格将减少,但生产者价格和产量变化不大;中国高新技术产业的消费者剩余大幅提高,生产者剩余变化幅度有限,但政府进口关税收入下降明显,所以高新技术产品的社会净福利将减少,其中广播、电视和通讯设备类产品的净福利损失最大,办公、会计和计算机器类产品与航空航天产品的净福利损失较小。研究结果可为中国高新技术产品关税政策调整提供依据,也能为中国主动扩大进口政策制定提供参考。

部分信息下带时滞的鲁棒资产负债博弈问题研究

研究了部分可观测信息下带时滞的鲁棒资产负债博弈问题,运用滤波理论,将不完全信息转化为完全信息,以终端相对财富的效用最大化为目标,构建了不完全信息带时滞的鲁棒资产负债博弈问题,借助动态规划原理,得到了均衡投资策略和值函数的显示表达式。最后,通过数值模拟验证了参数对均衡投资策略和值函数的影响,主要得出了不完全信息下投资者的效用低于完全信息。所以,投资者应尽可能的搜集与投资相关的更多信息,以便于做出更加明智的决策。

基于差示光谱及指纹图谱结合偏最小二乘回归分析法研究决明子提取物的平衡溶解度

目的:确定决明子提取物的最佳溶出介质,分析决明子提取物中主要成分在最佳溶出介质中对平衡溶解度的贡献程度,明确决明子提取物平衡溶解度的标志物。方法:以总蒽醌含量为指标,采用差示分光光度法测定决明子提取物在37℃时于水、0.1 moL/L盐酸和pH 6.8磷酸盐缓冲液中不同时间点的平衡浓度,确定最佳溶出介质。以决明子提取物总蒽醌指纹图谱为参照,采用HPLC法建立决明子提取物在最佳溶出介质中不同平衡时间点平衡浓度的指纹图谱,筛选决明子提取物平衡溶解度的标志物。结果:决明子提取物在37℃时于水、0.1 moL/L盐酸和pH 6.8磷酸盐缓冲液中平衡溶解度分别为10.344、10.910、11.099μg/mL,达到平衡时间点的时间分别为24 h、3 h和7 h。在最佳溶出介质中,VIP值>1的化学成分有22个,其中VIP值分别为1.13987、1.15565、1.12806、1.14825、1.14880的化学成分分别为已知成分橙黄决明素、大黄酸、大黄素、大黄酚和大黄素甲醚。结论:pH 6.8磷酸盐缓冲液为决明子提取物的最佳溶出介质,可以橙黄决明素、大黄酸、大黄素、大黄酚和大黄素甲醚为溶解度标志物考察决明子提取物的平衡溶解度。

On-node lattices construction using partial Gauss–Hermite quadrature for the lattice Boltzmann method

A concise theoretical framework,the partial Gauss–Hermite quadrature(pGHQ),is established to construct on-node lattices of the lattice Boltzmann(LB)method under a Cartesian coordinate system.Compared with the existing approaches,the pGHQ scheme has the following advantages:extremely concise algorithm,unifies the constructing procedure for symmetric and asymmetric on-node lattices,and covers a full-range quadrature degree of a given discrete velocity set.We employ the pGHQ scheme to search the local optimal and asymmetric lattices for{n=3,4,5,6,7}moment degree equilibrium distribution discretization on the range[-10,10].The search reveals a surprising abundance of available lattices.Through a brief analysis,the discrete velocity set shows a significant influence on the positivity of equilibrium distributions,which is considered as one of the major impacts of the numerical stability of the LB method.Hence,the results of the p GHQ scheme lay a foundation for further investigations to improve the numerical stability of the LB method by modifying the discrete velocity set.It is also worth noting that pGHQ can be extended into the entropic LB model,even though it was proposed for the Hermite polynomial expansion LB theory.

Partial melting of ultrahigh-pressure metamorphic rocks at convergent continental margins: Evidences, melt compositions and physical effects

Ultrahigh-pressure（UHP） metamorphic rocks are distinctive products of crustal deep subduction,and are mainly exposed in continental subduction-collision terranes. UHP slices of continental crust are usually involved in multistage exhumation and partial melting, which has obvious influence on the rheological features of the rocks, and thus significantly affect the dynamic behavior of subducted slices. Moreover,partial melting of UHP rocks have significant influence on element mobility and related isotope behavior within continental subduction zones, which is in turn crucial to chemical differentiation of the continental crust and to crust-mantle interaction.Partial melting can occur before, during or after the peak metamorphism of UHP rocks. Post-peak decompression melting has been better constrained by remelting experiments; however, because of multiple stages of decompression, retrogression and deformation, evidence of former melts in UHP rocks is often erased. Field evidence is among the most reliable criteria to infer partial melting. Glass and nanogranitoid inclusions are generally considered conclusive petrographic evidence. The residual assemblages after melt extraction are also significant to indicate partial melting in some cases. Besides field and petrographic evidence, bulk-rock and zircon trace-element geochemical features are also effective tools for recognizing partial melting of UHP rocks. Phase equilibrium modeling is an important petrological tool that is becoming more and more popular in P-T estimation of the evolution of metamorphic rocks; by taking into account the activity model of silicate melt, it can predict when partial melting occurred if the P-T path of a given rock is provided.UHP silicate melt is commonly leucogranitic and peraluminous in composition with high SiO_2,low MgO, FeO, MnO, TiO_2 and CaO, and variable K_2 O and Na_2 O contents. Mineralogy of nanogranites found in UHP rocks mainly consists of plagioclase ＋ K-feldspar ＋ quartz, plagioclase being commonly albite-rich.Trace element pattern of the melt is characterized by significant enrichment of large ion lithophile elements（LILE）, depletion of heavy rare earth elements（HREE） and high field strength elements（HFSE）,indicating garnet and rutile stability in the residual assemblage. In eclogites, significant Mg-isotope fractionation occurs between garnet and phengite; therefore, Mg isotopes may become an effective indicator for partial melting of eclogites.

Iterative algorithm of solutions for multivalued general mixed implicit equilibrium-like problems

The multivalued general mixed implicit equilibrium-like problems are introduced and studied. To solve these problems, a new predictor-corrector iterative algorithm is proposed and analyzed using the auxiliary principle technique. The convergence of the suggested algorithm is also proved in weaker conditions.

基于改进变分模态分解去噪的高频电应力下聚酰亚胺局部放电温-频特性研究

局部放电是导致高频电力变压器中聚酰亚胺(PI)绝缘劣化的重要原因。为研究高频电压下聚酰亚胺局部放电机理,探索温度、频率因素对局部放电特性的影响,建立了高频局部放电测试平台。针对使用脉冲电流传感器采集局部放电信号容易受噪声干扰的问题,采用变分模态分解(VMD)对局部放电原始信号进行去噪。其中,针对VMD难以自适应选取分解参数的问题,使用平衡优化器(EO)算法获得最优模态分解个数K与惩罚因子α。实验获取了25~100℃四个温度点与10~50kHz五个频率点下的聚酰亚胺局部放电情况,并分析其变化规律。实验结果表明,温度越大放电起始电压越小,而频率与局部放电起始电压无关;最大放电幅值、总放电幅值和单周波平均放电次数与温度、频率呈正相关;频率越高,温度对局部放电特征量的影响越大,而温度越高,频率对局部放电特征量的影响也更为显著,两者呈现一种耦合促进关系。

基于博弈的多用户部分卸载策略研究

部分卸载通过将任务进行拆分并行运行在不同计算节点以降低时延与能耗。现使用部分卸载的方案,同时将任务部分卸载在两个计算节点。由于每一移动用户计算任务时延与能耗受其他用户卸载决策影响,将系统卸载决策问题描述为一个多玩家博弈。此外证明了上述博弈纳什均衡存在,表明系统可以收敛到一个稳定的状态。为了达到纳什均衡,设计了一种基于博弈的多用户部分卸载方案。最大量仿真表明,在代价和效用两方面上述方案均能获得更好的表现效果。

MATHEMATICAL PROGRAMS WITH SYSTEM OF GENERALIZED VECTOR QUASI-EQUILIBRIUM CONSTRAINTS IN FC-SPACES

In this article, four new classes of systems of generalized vector quasi-equilibrium problems are introduced and studied in FC-spaces without convexity structure. The notions of Ci（x）-FC-partially diagonally quasiconvex, Ci（x）-FC-quasiconvex, and Ci（x）-FC- quasiconvex-like for set-valued mappings are also introduced in FC-spaces. By applying these notions and a maximal element theorem, the nonemptyness and compactness of solution sets for four classes of systems of generalized vector quasi-equilibrium problems are proved in noncompact FC-spaces. As applications, some new existence theorems of solutions for mathematical programs with system of generalized vector quasi-equilibrium constraints are obtained in FC-spaces. These results improve and generalize some recent known results in literature.

海洋蓝碳生态系统服务价值评估——以盐城市海洋蓝碳为例

根据经济学局部均衡理论,论文首先核算单位海洋蓝碳物质量,并利用碳交易价格作为海洋蓝碳的单位价格,将物质量与价值量相乘,得到单位海洋蓝碳经济价值,然后通过规模乘数效应,核算盐城市海洋蓝碳生态系统服务经济价值总量。由于生态系统服务功能指的是人类从生态系统提供的服务中获得的经济效益增加或减少的经济损失,因此,对海洋蓝碳服务功能的评估基于流量的概念,时间维度为一年。为避免重复计算,只考虑最终流向人类的海洋蓝碳服务效益,而不考虑支持性的服务过程。该研究不仅能够用于核算盐城市海洋蓝碳生态系统服务功能,而且能为其他生态系统服务价值评估提供借鉴。

PREDICTOR-CORRECTOR ALGORITHMS FOR SOLVING GENERALIZED MIXED IMPLICIT QUASI-EQUILIBRIUM PROBLEMS

A new class of generalized mixed implicit quasi-equilibrium problems （GMIQEP） with four-functions is introduced and studied. The new class of equilibrium problems includes many known generalized equilibrium problems and generalized mixed implicit quasi-variational inequality problems as many special cases. By employing the auxiliary principle technique, some predictor-corrector iterative algorithms for solving the GMIQEP are suggested and analyzed. The convergence of the suggested algorithm only requires the continuity and the partially relaxed implicit strong monotonicity of the mappings

基于Stackelberg博弈与深度强化学习的计算卸载策略

为使5G混合专网结构的2种用户能获得最优计算卸载策略,将2种用户竞争移动边缘计算(mobile edge computing,MEC)服务器资源的问题建模成Stackelberg博弈,并分别讨论了完全信息博弈和不完全信息博弈下的策略。完全信息博弈下,存在唯一纳什均衡解;不完全信息博弈下,将环境建模为部分可观测的马尔可夫决策过程(partially observable Markov decision process,POMDP),并提出一种基于二阶段深度强化学习(two-stage deep reinforcement learning,TSDRL)的最优卸载策略。仿真实验表明:该算法相较于D-DRL算法能减少20.81%的时延及3.38%的能耗,有效提高用户QoE(quality of experience)。

张家口市各区县用水结构时空演变及其驱动因素分析

以张家口市14个区县为研究区域,分析其用水量和用水结构时空演变特征并据此划分区县类型,运用偏最小二乘法(PLS)分析不同类型区县用水量和用水结构的驱动因素及其阈值。结果表明:2005—2025年间张家口各区县用水量和用水结构维持稳定,用水结构整体处于相对均衡状态;各区县间存在极显著差异,依据用水量和用水结构时空演变特征划分为用水状态最优组(用水量低、均衡度高)、良好组(用水量低、均衡度低)、中等组(用水量高、均衡度高)和及格组(用水量高、均衡度低);社会因素(总人口、城镇人口和农村人口数量)和经济因素(耕地面积)分别是所有类型区县用水量和用水结构的关键驱动因素,制定总体用水规划方案时通过政策引导用水量较高区县人口向较低区县流动,制定不同类型区县的用水定额,鼓励用水量较高区县种植低耗水的经济作物并推进节水技术的应用,可以优化人口数量和结构并调整耕地面积,实现用水量减少、均衡度提高的规划目标。

On Topics in Quantum Games

This work concentrates on simultaneous move non-cooperating quantum games. Part of it is evidently not new, but it is included for the sake self consistence, as it is devoted to introduction of the mathematical and physical grounds of the pertinent topics, and the way in which a simple classical game is modified to become a quantum game (a procedure referred to as a quantization of a classical game). The connection between game theory and information science is briefly stressed, and the role of quantum entanglement (that plays a central role in the theory of quantum games), is exposed. Armed with these tools, we investigate some basic concepts like the existence (or absence) of a pure strategy and mixed strategy Nash equilibrium and its relation with the degree of entanglement. The main results of this work are as follows: 1) Construction of a numerical algorithm based on the method of best response functions, designed to search for pure strategy Nash equilibrium in quantum games. The formalism is based on the discretization of a continuous variable into a mesh of points, and can be applied to quantum games that are built upon two-players two-strategies classical games, based on the method of best response functions. 2) Application of this algorithm to study the question of how the existence of pure strategy Nash equilibrium is related to the degree of entanglement (specified by a continuous parameter γ ). It is shown that when the classical game GC has a pure strategy Nash equilibrium that is not Pareto efficient, then the quantum game GQ with maximal entanglement (γ = π/2) has no pure strategy Nash equilibrium. By studying a non-symmetric prisoner dilemma game, it is found that there is a critical value 0γc such that for γγc there is a pure strategy Nash equilibrium and for γ≥γc there is no pure strategy Nash equilibrium. The behavior of the two payoffs as function of γ starts at that of the classical ones at (D, D) and approaches the cooperative classical ones at (C, C) (C = confess, D = don’t confess). 3) We then study Bayesian quantum games and show that under certain conditions, there is a pure strategy Nash equilibrium in such games even when entanglement is maximal. 4) We define the basic ingredients of a quantum game based on a two-player three strategies classical game. This requires the introduction of trits (instead of bits) and quantum trits (instead of quantum bits). It is proved that in this quantum game, there is no classical commensurability in the sense that the classical strategies are not obtained as a special case of the quantum strategies.

主合金成分对铝合金中析出相的影响

利用JMat-Pro软件包对Al-(6.0-8.0)Zn-(1.8-2.8)Mg-(1.4-2.6)Cu合金的热力学相关物理参数和平衡相析出进行了分析。结果表明:合金元素Zn、Mg、Cu、Fe、Si、Zr的偏摩尔吉布斯自由能均为负值。合金中Zn、Mg和Si活度的最大值分别为:0.2、0.061和0.069,Cu、Fe和Zr元素的活度都接近于0。平衡析出相η相、S相和T相的析出起始温度分别为407~443℃、405~473℃和111~176℃。η相析出量随Zn含量的增加而增加,随Cu含量的增加而减少。S相析出量随Cu含量的增加而增加,随Zn含量的增加而减少。T相析出量随Mg含量的增加而增加,随Zn、Cu含量的增加而减少。

序空间中的极大元定理及其在博弈中的应用

运用不动点定理及偏序集中归纳集的性质,获得了乘积序空间中集值映射的1个极大元定理。同时,将该定理应用于非合作非货币化博弈,得到1个广义Nash均衡点存在性定理,并用实例验证了该存在性定理的可行性。

生态资产评估静态部分平衡模型的分析与改进

静态部分平衡模型是目前生态资产价值评估中可操作性比较强的一种评估模型。由于生态资产评估领域中还存在很多争议,论文从对生态资产评估的目的、特点、模型假设、方法和途径等方面入手,对生态资产价值评估静态部分平衡模型进行了分析,指出传统模型中存在的一些缺陷,并尝试对模型进行改进。选择黄河皇甫川流域五分地沟小流域作为研究区,依据传统模型和改进模型分别对研究区进行生态资产评估,结果表明,改进模型估算的流域生态资产总价值比传统模型的计算结果高出约1/3,其中林地和草地的单位面积价值上升,灌木林的单位面积价值则下降。