“双一流”建设中的组织合法性与制度趋同——对414位高校二级学院院长的调查分析

在推进"双一流"建设中,从组织合法性视角探讨二级学院如何协调自身与学校组织目标间的张力与关系、采取何种合法性逻辑服务"双一流"建设大局、不同二级学院又将面临怎样的共性与差异问题等具有重要的理论与实践意义。采用问卷调查法和深度访谈法,对414位"双一流"建设高校二级学院院长进行深入调研,结果显示:规制合法性、模拟合法性和规范合法性三种组织合法性机制在"双一流"建设中起着重要作用,并在大学和学院追求合法性的过程中,促使二级学院由竞争趋同演化为制度趋同。为了避免这种趋同,就必须建立规范科学的"双一流"评价机制;尊重学科发展规律,给予二级学院更多的自主空间;建立学科建设投入的均衡机制,并注重学科特色的打造。可以预见的是,在"双一流"建设的现在和未来一段时期内,规制合法性依然会保持一个较高的水平,或许会进一步提高;模拟合法性将逐渐下降;规范合法性将逐渐增强。

Strategy for Synthesis of Flexible Heat Exchanger Networks Embedded with System Reliability Analysis

System reliability can produce a strong influence on the performance of the heat exchanger network(HEN).In this paper,an optimization method with system reliability analysis for flexible HEN by genetic/simulated annealing algorithms(GA/SA) is presented.Initial flexible arrangements of HEN is received by pseudo-temperature enthalpy diagram.For determining system reliability of HEN,the connections of heat exchangers(HEXs) and independent subsystems in the HEN are analyzed by the connection sequence matrix(CSM),and the system reliability is measured by the independent subsystem including maximum number of HEXs in the HEN.As for the HEN that did not meet system reliability,HEN decoupling is applied and the independent subsystems in the HEN are changed by removing decoupling HEX,and thus the system reliability is elevated.After that,heat duty redistribution based on the relevant elements of the heat load loops and HEX areas are optimized in GA/SA.Then,the favorable network configuration,which matches both the most economical cost and system reliability criterion,is located.Moreover,particular features belonging to suitable decoupling HEX are extracted from calculations.Corresponding numerical example is presented to verify that the proposed strategy is effective to formulate optimal flexible HEN with system reliability measurement.

Simultaneous Optimization of Synthesis and Scheduling of Cleaning in Flexible Heat Exchanger Networks

A novel methodology is presented for simultaneously optimizing synthesis and cleaning schedule of flexible heat exchanger network(HEN)by genetic/simulated annealing algorithms(GA/SA).Through taking into account the effect of fouling process on optimal network topology,a preliminary network structure possessing two-fold oversynthesis is obtained by means of pseudo-temperature enthalpy(T-H)diagram approach prior to simultaneous optimization.Thus,the computational complexity of this problem classified as NP(Non-deterministic Polynomial)-complete can be significantly reduced.The promising matches resulting from preliminary synthesis stage are further optimized in parallel with their heat exchange areas and cleaning schedule.In addition,a novel continu- ous time representation is introduced to subdivide the given time horizon into several variable-size intervals according to operating periods of heat exchangers,and then flexible HEN synthesis can be implemented in dynamic manner.A numerical example is provided to demonstrate that the presented strategy is feasible to decrease the total annual cost(TAC)and further improve network flexibility,but even more important,it may be applied to solve large-scale flexible HEN synthesis problems.

Verification of Seismic Performance of Pile Foundation in Composite Ground through Experimental and Numerical Methods

A new construction method of pile foundation in composite ground, in which, prior to installing piles, the ground is improved around the heads of the piles in soft ground or ground subject to liquefaction, which is introduced in this paper. This construction method uses a combination of pile foundation construction together with common ground improvement methods, including deep mixing, preloading and sand compaction piling, and it is referred to as the composite ground pile method. Since an artificial ground with relatively high rigidity comparing with that of the original ground was formed around the pile in this method, and the seismic performance has not been made clear, thus the seismic performance of piles in composite ground was systematically analyzed through a series of centrifuge model tests and numerical analyses by using dynamic nonlinear finite element method, and a verification method for the seismic performance of piles in composite ground was proposed on the basis of the experimental and numerical results.

Ensemble Simulations of a Nonlinear Barotropic Model for the North Atlantic Oscillation

A numerical ensemble-mean approach was employed to solve a nonlinear barotropic model with chastic basic flows to analyze the nonlinear effects in the formation of the North Atlantic Oscillation （NAO）. The nonlinear response to external forcing was more similar to the NAO mode than the linear response was, indicating the importance of nonlinearity. With increasing external forcing and enhanced low-frequency anomalies, the effect of nonlinearity increased. Therefore, for strong NAO events, nonlinearity should be considered.