调频液体阻尼器(TLD)的等效力学模型研究

本文根据流体力学理论，建立了圆柱形ＴＬＤ中晃动液体的势流场，并从液体晃动的动力效应等效原则出发，导出了晃动液体的等效力学模型，并阐明其适用范围。文量计算的结果表明，在工程应用中，仅用ＴＬＤ的一阶晃动等效力学模型就能满足工程需要。

劳动规章制度效力模型研究

用人单位劳动规章制度的效力原则主要有明确性原则、比例原则和除外原则。明确性原则应当摒弃,比例原则应当借鉴,除外原则需要甄别。劳动规章制度效力阶位可以分为"效力模型"和"基准模型"两大体系。一般"效力模型"是指法律(劳动法或基准法)效力最高、集体合同第二、劳动合同次之、劳动规章制度(含劳动纪律)最低;"基准模型"指劳动规章制度的基准最高、劳动合同基准第二、集体合同次之、法律(劳动法或基准法)最低即为兜底条款或底线。

有效性——现代企业管理中效力模型诠释

没有任何一个企业会不认同管理的重要性。 但在中国，尤其是新兴领域内的企业（特别是互联网企业）又很少在企业管理，尤其是企业组织效力等方面加大自己的投入，其实，这种投入不是仅仅指资金的投入，更多地还是指战略、管理方面的投入。

操纵性应计模型的一个改进——基于动态面板估计的实证分析

使用动态面板对操纵性应计模型进行估计可以克服截面数据模型的内生性估计偏误。采用1999—2011年中国A股市场相关数据,对动态面板模型和其他模型的检测能力进行比较,结果表明:在对第Ⅱ类错误进行检验时,动态面板模型检测能力显著优于其他模型;在对第Ⅰ类错误、审计师意见检验时,动态面板模型检测能力与其他模型接近。

我国高校心理健康教育政策发展历程与主题演进分析

以1987—2023年国家层面颁布的高校心理健康教育政策文本为研究对象,综合政策效力量化模型和LDA主题模型分别对我国高校心理健康教育政策的演进历程、主题识别及强度演化情况进行分析。研究结果表明:我国高校心理健康教育政策演进历程分为萌芽扎根期、成长探索期、深化发展期等三个阶段,政策体系经历了从无到有的发展过程;政策主题涵盖“思想健康与品德教育”“心理健康知识与技能教学”“青年人才择业心理疏导与服务”“心理咨询服务与队伍建设”“心理健康教育环境与体系构建”“心理卫生工作保健与服务”等六个方面,各主题强度随着政策演进阶段的发展而趋于平衡,政府愈加重视高校心理健康教育工作建设并统筹兼顾其各方面发展。

取样大小对不同因果推理问题强度估计的影响研究

使用纸笔测验探讨表格集中呈现信息条件下取样大小对单一因果关系强度推理的影响，并比较五种模型：△P、效力PC、SS效力、Support和χ2的预测与实验数据的相关。结果显示：（1）取样大小对不同的问题有不同的影响，高取样在△P=0时导致了低估汁值，在0〈｜△P｜=PPC时没有效果，在｜△P｜〈PPC时有不一致的效果，4倍取样比2倍取样有更明显的取样大小效应；（2）取样大小效应更一致地出现在PPC与｜△P｜不相等且PPC值较高的问题中；（3）虽然Suppoa模型和ss效力模型都能预测取样大小因素在所有问题上的作用方式，但取样大小效应并不如因果支持模型所预测的那么强大，在两种因果方向条件下SS效力模型都能最好地预测被试的反应。

Creep mechanism and creep constitutive model of aluminum silicate short-fiber-reinforced magnesium matrix composite

By the constant stress tensile creep test method, creep tests were performed on aluminum silicate short fiber-reinforced AZ91D magnesium matrix composite with volume fraction of 30% and its matrix alloy AZ91D under different temperatures and stresses. The results indicate that the composite and the matrix have the same true stress exponent and true activation energy for creep, which are 3 and 144.63 kJ/mol, respectively. The creep of the composite is controlled by the creep of its matrix, which is mainly the controlling of viscous slip of dislocation, and the controlling of grain boundary slippage as a supplement. The creep constitutive model obtained from the experiment data can well describe the creep deformation pattern of the composite.

HYBRID APPROACH FOR ESTIMATING COUPLING EFFECT BETWEEN PROPELLANT SLOSHING DYNAMIC AND SPACECRAFT GNC

An approach based on equivalent mechanics theory and computational fluid dynamics （CFD） technology is proposed to estimate dynamical influence of propellant sloshing on the spacecraft. A mechanical model is estab- lished by using CFD technique and packed as a ＂sloshing＂ block used in spacecraft guidance navigation and control （GNC） simulation loop. The block takes motion characteristics of the spacecraft as inputs and outputs of pertur- bative force and torques induced by propellant sloshing, thus it is more convenient for analyzing coupling effect between propellant sloshing dynamic and spacecraft GNC than using CFD packages. An example demonstrates the accuracy and the superiority of the approach. Then, the deducing process is applied to practical cases, and simulation results validate that the proposed approach is efficient for identifying the problems induced by sloshing and evaluating effectiveness of several typical designs of sloshing suppression.

样例学习条件下的因果力估计

在逐个呈现因果样例的条件下 ,考察单一因果关系因果力估计的特点 ,同时检验联想解释 ,概率对比模型 ,权重ΔP模型 ,效力PC理论和pCI规则。实验让 6 5名大学生被试估计不同化学药物影响动物基因变异的能力。实验结果表明 :(1)对产生原因的因果力估计符合权重ΔP模型 ;(2 )对预防原因的因果力估计较多符合效力PC理论 ;(3)因果力估计具有复杂多样性 。

Bayesian analysis for mixed-effects model defined by stochastic differential equations

The nonlinear mixed-effects model with stochastic differential equations （SDEs） is used to model the population pharmacokinetic （PPK） data that are extended from ordinary differential equations （ODEs） by adding a stochastic term to the state equation. Compared with the ODEs, the SDEs can model correlated residuals which are ubiquitous in actual pharmacokinetic problems. The Bayesian estimation is provided for nonlinear mixed-effects models based on stochastic differential equations. Combining the Gibbs and the Metropolis-Hastings algorithms, the population and individual parameter values are given through the parameter posterior predictive distributions. The analysis and simulation results show that the performance of the Bayesian estimation for mixed-effects SDEs model and analysis of population pharmacokinetic data is reliable. The results suggest that the proposed method is feasible for population pharmacokinetic data.

Simulation of astronomical solar radiation over Yellow River Basin based on DEM

Based on the developed distributed model for calculating astronomical solar radiation (ASR), monthly ASR with a resolution of 1 km×1 km for the rugged terrains of Yellow River Basin was calculated, with DEM data as the general characterization of terrain. This model gives an all-sided consideration on factors that influence the ASR. Results suggest that (1) Annual ASR has a progressive decrease trend from south to north; (2) the magnitude order of seasonal ASR is: summer>spring>autumn>winter; (3) topographical factors have robust effect on the spatial distribution of ASR, particularly in winter when a lower sun elevation angle exists; (4) the ASR of slopes with a sunny exposure is generally 2 or 3 times that of slopes with a shading exposure and the extreme difference of ASR for different terrains is over 10 times in January; (5) the spatial differences of ASR are relatively small in summer when a higher sun elevation angle exists and the extreme difference of ASR for different terrains is only 16% in July; and (6) the sequence of topographical influence strength is: winter>autumn>spring>summer.

Numerical method of slope failure probability based on Bishop model

Based on Bishop's model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced according to numerical analysis theory. After complicated multi-independent variables implicit functional function was simplified to be a single independent variable implicit function and rule of calculating derivative for composite function was combined with principle of the mean deviations method, an approximative solution format of implicit functional function was established through Taylor expansion series and iterative solution approach of reliability degree index was given synchronously. An engineering example was analyzed by the method. The result shows its absolute error is only 0.78% as compared with accurate solution.

Numerical Investigation on 1,3-Butadiene/Propyne Co-pyrolysis and Insight into Synergistic Effect on Aromatic Hydrocarbon Formation

A numerical investigation on the co-pyrolysis of 1,3-butadiene and propyne is performed to explore the synergistic effect between fuel components on aromatic hydrocarbon formation. A detailed kinetic model of 1,3-butadiene/propyne co-pyrolysis with the sub-mechanism of aromatic hydrocarbon formation is developed and validated on previous 1,3-butadiene and propyne pyrolysis experiments. The model is able to reproduce both the single component pyrolysis and the co-pyrolysis experiments, as well as the synergistic effect between 1,3- butadiene and propyne on the formation of a series of aromatic hydrocarbons. Based on the rate of production and sensitivity analyses, key reaction pathways in the fuel decomposition and aromatic hydrocarbon formation processes are revealed and insight into the synergistic effect on aromatic hydrocarbon formation is also achieved. The synergistic effect results from the interaction between 1,3-butadiene and propyne. The easily happened chain initiation in the 1,3-butadiene decomposition provides an abundant radical pool for propyne to undergo the H-atom abstraction and produce propargyl radical which plays key roles in the formation of aromatic hydrocarbons. Besides, the 1,3-butadiene/propyne co-pyrolysis includes high concentration levels of C3 and C4 precursors simultaneously, which stimulates the formation of key aromatic hydrocarbons such as toluene and naphthalene.

论党内法规的政策性及其识别

党内法规基本属性的二重性是党内法规研究的重要内容。在党政体制中,规范体系、权力运行体系和政权结构体系以一种特殊的连结形式存在着,党内法规作为中国共产党治国理政规范化的产物,是这种连结的核心与关键。在党政体制框架下观察党内法规二重性,可以发现作为内部规范的党内法规因中国共产党的领导和长期执政地位而肩负的国家建设职能转化成了党政体制治理的重要工具。在党内法规制度体系的运作过程中,更多依靠效力发挥作用的党内法规更倾向于法属性;而更多依靠影响力发挥作用和功能的党内法规则倾向于政策性。此外,可以在执行层面按照效力—影响力标准区分四种不同的党内法规。

Failure load prediction of adhesive joints under different stress states over the service temperature range of automobiles

To predict the failure loads of adhesive joints under different stress states over the service temperature range of automobiles,adhesively bonded carbon fiber reinforced plastic( CFRP)/aluminum alloy joints under shear stress state( thickadherend shear joints,TSJ),normal stress state( butt joints,BJ) and combined shear and normal stress states( scarf joints with scarf angle 45°,SJ45°) were manufactured and tested at-40,-20,0,20,40,60 and 80 ℃,respectively. The glass transition temperature Tgof the adhesive and CFRP,failure loads and fracture surfaces were used to analyze the failure mechanism of CFRP/aluminum alloy joints at different temperatures. A response surface,describing the variations of quadratic stress criteria with temperature,was established and introduced into the cohesive zone model( CZM) to carry out a simulation analysis. Results show that the failure of CFRP/aluminum alloy joints was determined collectively by the mechanical performances of adhesive and CFRP. Besides,reducing temperature or increasing the proportion of normal stress of adhesive layer was more likely to cause fibre tear or delamination of CFRP,resulting in a more obvious effect of CFRP. The validity of the prediction method was verified by the test of scarf joints with the scarf angle of 30°( SJ30°) and 60°( SJ60°) at-10 and 50 ℃.

Constitutive modeling and springback prediction of stress relaxation age forming of pre-deformed 2219 aluminum alloy

Stress relaxation ageing behavior of pre-deformed AA2219 is studied through stress relaxation age experiments and finite element(FE) simulation. The results show that the stress can promote the process of ageing precipitation, and shorten the time to reach the peak strength. Meanwhile,the residual stress and yield strength increase along with the increase in the initial stress. Based on microstructure evolution and ageing strengthening theory,a unified constitutive model is established and incorporated into the FE simulation model through a user subroutine. It is found that the relative error of the radius is 3.6% compared with the experimental result and the springback is 16.8%. This indicates that the proposed stress relaxation ageing constitutive model provides a good prediction on the springback of such stiffened panel during its ageing process.

Compression behavior and constitutive model establishment of fly ash cenosphere/polyurethane aluminum alloy syntactic foam

The aluminum matrix syntactic foam was fabricated by pressure infiltration technique,and the filling material is syntactic foam material with fly ash cenosphere as the main component and polyurethane foam as the binder.Split Hopkinson pressure bar(SHPB)dynamic compression and quasi-static tests were carried out to examine the compressive response of syntactic foam in this study.Then the dynamic constitutive model was established.Results show that the compressive stress-strain curve of syntactic aluminum foam is similar to that of other metallic foam materials:both kinds of aluminum matrix syntactic foams have strain rate effect,and the syntactic foam has higher compressive strength and energy absorption than the same density aluminum foams.However,due to the different sizes of cenospheres,the dynamic compression results of two kinds of syntactic foams are different,and the energy absorption effect of syntactic foam with small size under dynamic impact is the best.In the range of strain rate and density studied experimentally,the curves of constitutive model fit well with the curves of experimental data.

Radiofrequency ablation vs hepatic resection for solitary colorectal liver metastasis:A meta-analysis

AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM.Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.RESULTS:Seven nonrandomized controlled trials studies were included in this analysis.These studies included a total of 847 patients:273 treated with RFA and 574 treated with HR.The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR:0.41,95% CI:0.22-0.90,P=0.008).RFA had a higher rate of local intrahe-patic recurrence compared to HR (OR:4.89,95% CI:1.73-13.87,P=0.003).No differences were found between the two groups with respect to postoperative morbidity and mortality.CONCLUSION:HR was superior to RFA in the treatment of patients with solitary CLM.However,the findings have to be carefully interpreted due to the lower level of evidence.

Finite element analysis of high-pressure hose for radial horizontal wells in coalbed methane extraction

Based on the serial-parallel model of single-layer board and the lamination theory, the forces exerted on different layers of the high-pressure hose and the resulting deformations were analyzed when the hose was radially stretched. An equation was proposed to calculate the anisotropic elastic constant of the composite layer with the wound steel wires. Furthermore, the finite element analysis （FEA） model of the high-pressure hose was established, followed by a simulation of the forces that act on different layers, and their deformations. The simulation results show that the stress imposed on the inner reinforced layer and external reinforced layer of the high-pressure hose are approximately 150 MPa and 115 MPa, respectively, in the presence of inner pressure. The stress of the rubber coating and polyethylene coating is lower. The lowest stress occurs on the inner surface of the high-pressure hose and the rubber coating between the two composite layers. The deformation of the rubber layer in the inner surface of the high-pressure hose decreases gradually along the radial direction from the inner surface to the external surface. The deformation of the reinforced composite layer is less than that of the external surface of the rubber coating. The equivalent stress of the reinforced composite layer is higher than that caused by the inner pressure, due to the presence of both inner pressure and axial tension.

A new approach for time effect analysis of settlement for single pile based on virtual soil-pile model

A new approach is proposed to analyze the settlement behavior for single pile embedded in layered soils. Firstly, soil layers surrounding pile shaft are simulated by using distributed Voigt model, and finite soil layers under the pile end are assumed to be virtual soil-pile whose cross-section area is the same as that of the pile shaft. Then, by means of Laplace transform and impedance function transfer method to solve the static equilibrium equation of pile, the analytical solution of the displacement impedance fimction at the pile head is derived. Furthermore, the analytical solution of the settlement at the head of single pile is theoretically derived by virtue of convolution theorem. Based on these solutions, the influences of parameters of soil-pile system on the settlement behavior for single pile are analyzed. Also, comparison of the load-settlement response for two well-instrumented field tests in multilayered soils is given to demonstrate the effectiveness and accuracy of the proposed approach. It can be noted that the presented solution can be used to calculate the settlement of single pile for the preliminary design of pile foundation.