河北省经济抗周期波动能力分析

河北省经济抗周期波动能力分析·王婷婷经济波动是各国经济发展中普遍存在的现象。在我国理论界，虽然还没有“经济波动规律”的明确提法，但建国４０多年来，特别是改革开放后十几年的经济发展实践始终伴随着程度不同的周期性波动。因此，分析经济波动的原因，把握其规律...

空调器能力波动原因实验研究

通过对某款36000 Btu/h能力段家用定速空调器,批量生产后抽检过程中出现制冷量波动根据抽检结果判定不合格的情况,从蒸发器、冷凝器、压缩机等方面对空调器能力波动原因制定了6个优化方案进行实验研究。结果表明原型机蒸发器流路过热情况与蒸发器表面风速分布一致,将蒸发器流路由原9进9出优化为10进10出的方案对整机性能波动情况有较好改善作用,同时基于该方案更换某品牌26.5排量压缩机后显著改善了整机能力波动情况,能力提升高达4.7%,能效提升高达7.1%。本研究为整机能力波动的情况提供了有效的解决方案,同时为同行后续遇到类似问题提供了相关指导。

我国股票型基金的市场波动择时能力分析

市场波动择时能力分析弥补了传统的收益择时能力分析中对风险因素的考虑欠缺。通过引入时变贝塔因子和收益择时因子,对Busse模型进行修正,从波动时变性的角度对我国股票基金的择时能力进行实证分析。实证结果表明,我国股票型基金的市场波动择时能力比收益择时能力显著;多因素模型中基金的波动择时行为比单因素模型更显著。

我国开放式基金波动择时能力研究

基金的择时能力评价是基金业绩评价的重要组成部分。本文通过构造FF3框架下加入收益择时因子的波动择时能力模型，对2012年至2014年我国开放式基金的周度数据进行了实证分析。实证表明，我国开放式基金具备较为显著的波动择时能力，同时波动择时能力会在一定程度上提升基金业绩。

FOF择时能力评价研究

作为一种新的资产管理工具,基金中基金(FOF)的择时能力受到学者们的广泛关注。本文区分了两种择时能力:收益择时能力和波动择时能力,并且对券商系基金中的基金进行了实证研究。结果显示,基金中基金的择时能力主要体现为波动择时能力。

一种基于时钟抽取偏置电压技术的存储器位线

基于一种新型时钟延时单元,设计了一种片上存储器的位线。在不增加版图面积的前提下,通过周期性地改变保持管的衬底偏置电压,减小了短路功耗、泄漏功耗和延迟时间,同时增加了电路的抗工艺波动能力。在SMIC 65nm工艺下,完成了传统位线、改进后的位线以及静态随机存取存储器(SRAM)的设计。仿真结果表明,在1GHz时钟频率下,改进后的两种位线与传统位线相比,功耗延迟积分别减小了19.1%和15.9%。最后,通过蒙特卡洛分析可知,改进后的位线相比于传统位线具有较强的抗工艺波动能力,即功耗延迟积的方差减小了97.1%。

横向联合与县域市场经济

一、横向联合与县域市场经济体制的建立建立市场经济体制,对长期在传统计划经济体制下运转的县域经济,是一项艰世繁重的任务.发展横向联合,开展同县域外的经济技术合作,对县域市场经济体制的建立,有积极的推进作用.

企业风险承担会导致审计溢价吗?——基于产权性质和费用粘性视角的拓展性分析

企业风险承担水平对审计收费的影响显而易见,但是长期以来较少有文献对这一问题展开分析。鉴于此,本文以2009～2014年中国资本市场A股上市公司为样本,探讨企业风险承担是否会导致审计溢价以及这一现象将会呈现出何种特征。实证研究发现:企业风险承担显著提高了审计收费,即存在针对企业风险承担的审计溢价行为;相较非国有企业,国有企业因风险承担造成的审计溢价相对较弱;审计溢价具有一定的粘性特征,即当企业风险承担水平下降时,审计费用的下降速度要低于企业风险承担水平的下降速度。

Carburization of ferrochromium metals in chromium ore fines containing coal during voluminal reduction by microwave heating

Chromium ore fines containing coal (COFCC) can be rapidly heated by microwave to conduct the voluminal reduction, which lays a foundation of getting sponge ferrochromium powders with a lower content of C. Under the conditions of COFCC with n(O)-n(C) (molar ratio) as 1.00-0.84 and n(SiO2)-n(CaO) as 1.00-0.39, the samples were heated by 10 kW microwave power to reach the given temperatures and held for different times respectively. The results show that the low-C-Cr ferrochromium metal phase in the reduced materials forms before the high-C-Cr ferrochromium metal phase does. With increasing temperature the C content of ferrochromium metals is in a positive correlation with the content of Cr. The C content of ferrochromium metal in reduced materials is 0-10.07% with an average value of 4.68%. With the increase of holding time the Cr content in ferrochromium metals is in a negative correlation with the content of C, while the content of Fe changes in the contrary way. In the microwave field the kinetic conditions of carburization are closely related with the temperature of microwave heating, holding time and carbon fitting ratio.

Wave breaking on turbulent energy budget in the ocean surface mixed layer

As an important physical process at the air-sea interface, wave movement and breaking have a significant effect on the ocean surface mixed layer (OSML). When breaking waves occur at the ocean surface, turbulent kinetic energy (TKE) is input downwards, and a sublayer is formed near the surface and turbulence vertical mixing is intensively enhanced. A one-dimensional ocean model including the Mellor-Yamada level 2.5 turbulence closure equations was employed in our research on variations in turbulent energy budget within OSML. The influence of wave breaking could be introduced into the model by modifying an existing surface boundary condition of the TKE equation and specifying its input. The vertical diffusion and dissipation of TKE were effectively enhanced in the sublayer when wave breaking was considered. Turbulent energy dissipated in the sublayer was about 92.0% of the total depth-integrated dissipated TKE, which is twice higher than that of non-wave breaking. The shear production of TKE decreased by 3.5% because the mean flow fields tended to be uniform due to wave-enhanced turbulent mixing. As a result, a new local equilibrium between diffusion and dissipation of TKE was reached in the wave-enhanced layer. Below the sublayer, the local equilibrium between shear production and dissipation of TKE agreed with the conclusion drawn from the classical law-of-the-wall (Craig and Banner, 1994).

Comparison of the Performance of Two Direct Wave Energy Conversion Systems: Archimedes Wave Swing and Power Buoy

Many wave energy conversion devices have not been well received. The main reasons are that they are too complicated and not economical. However, in the last two decades direct conversion systems have drawn the attention of researchers to their widely distributed energy source due to their simple structure and low cost. The most well-known direct conversion systems presently in use include the Archimedes Wave Swing (AWS) and Power Buoy (PB). In this paper, these two systems were simulated in the same conditions and their behaviors were studied in different wave conditions. In order to verify the simulations, results of the generator of the finite element computations were followed. An attempt was made to determine the merits and drawbacks of each method under different wave conditions by comparing the performance of the two systems. The wave conditions suitable for each system were specified.

A Quantum Wavepacket Study of State-to-State Photodissociation Dynamics of HOBr/DOBr

Photodissociation of HOBr is an important step in the reaction network of the depletion of ozone in stratosphere.Here,we report the first three-dimensional potential energy surfaces for the lowest three singlet states for HOBr,based on high level multi reference configuration interaction calculations.Quantum dynamics calculations are performed with a real wavepacket method,yielding not only absorption spectra but also internal state and angular distributions of the photodissociation fragments.Our results agree quantitatively with the measured total absorption cross sections of HOBr in the ultraviolet region and reproduce well the observed vibrationally cold and rotationally hot OH/OD fragments via photodissociation of HOBr/DOBr at 266 nm.In addition,we predict that the recoil anisotropy parameters for OH/OD are close to the limiting value of a parallel transition,suggesting a rapid dissociation process at 266 nm following an in-plane transition from the ground state(1^1A')to the 21A'state.This is consistent with the experimental conclusion derived from the measured rotational alignment.However,spin and electronic angular momenta need to be taken into account in the future to achieve a more quantitative agreement with experiment.Our work is expected to motivate further experimental investigations for this benchmark system.

Drying Kinetics and Energy Consumption in Vacuum Drying Process with Microwave and Radiant Heating

The general objective of this work is to analyze energy input in a vacuum process with the incorporation of microwave heating. Thus, necessary criteria for designing an efficient freeze-drying operation are considered through the analysis of strategies based on the combination of different intensities of radiant and microwave heating.The other aim of this research topic is to study the kinetics of drying in relation to mass transfer parameters.Five freeze-drying strategies using both heating systems were used. Consequently, energy input could be related to diffusivity coefficients, temperature and pressure profiles during dehydration of the product and analyzed in comparison to a conventional freeze-drying process.

Study on pile drivability with one dimensional wave propagation theory

Pile drivability is a key problem during the stage of design and construction installation of pile foundations. The solution to the one dimensional wave equation was used to determine the impact force at the top of a concrete pile for a given ram mass, cushion stiffness, and pile impedance. The kinematic equation of pile toe was established and solved based on wave equation theory. The movements of the pile top and pile toe were presented, which clearly showed the dynamic displacement, including rebound and penetration of pile top and toe. A parametric study was made with a full range of practical values of ram weight, cushion stiffness, dropheight, and pile impedance. Suggestions for optimizing the parameters were also presented. Comparisons between the results obtained by the present solution and in-situ measurements indicated the reliability and validity of the method.

Response and energy dissipation of rock under stochastic stress waves

The response and energy dissipation of rock under stochastic stress waves were analyzed based on dynamic fracture criterion of brittle materials integrating with Fourier transform methods of spectral analysis. When the stochastic stress waves transmit through rocks, the frequency and energy ratio of harmonic components were calculated by analytical and discrete analysis methods. The stress waves in shale, malmstone and liparite were taken as examples to illustrate the proposed analysis methods. The results show the harder the rock, the less absorption of energy, the more the useless elastic waves transmitting through rock, and the narrower the cutoff frequency to fracture rock. When the whole stress energy doubles either by doubling the duration time or by increasing the amplitude of stress wave, ratio of the energy of elastic waves transmitting through rock to the whole stress energy (i.e. energy dissipation ratio) is decreased to 10%-15%. When doubling the duration time, the cutoff frequency to fracture rock remains constant. However, with the increase of the amplitude of stress wave, the cutoff frequency increases accordingly.

Longitudinal type-line optimization of high-speed train for low aerodynamic noise

The basic head shape of high-speed train is determined by its longitudinal type-line(LTL),so it is crucial to optimize its aerodynamic performance.Based on the parametric modeling of LTL constructed by non-uniform relational B-spline(NURBS)and the fluctuation pressure obtained by large eddy simulation(LES),the Kriging surrogate model(KSM)of LTL was constructed for low aerodynamic noise,and the accuracy of the KSM was improved gradually by adding the sample point with maximum expected improvement(EI)and the optimal point from optimization.The optimal objective was searched with genetic algorithm(GA).The results show that the total fluctuation pressure level(FPL)of the optimal LTL can be 8.7 dB less than that of original one,and the shape optimization method is feasible for low aerodynamic noise design.

Hydrodynamic Performance of Multiple-Row Slotted Breakwaters

This study examines the hydrodynamic performance of multiple-row vertical slotted breakwaters. We developed a mathematical model based on an eigenfunction expansion method and a least squares technique for Stokes second-order waves. The numerical results obtained for limiting cases of double-row and triple-row walls are in good agreement with results of previous studies and experimental results. Comparisons with experimental measurements of the reflection, transmission, and dissipation coefficients （CR, Cr, and CE） for double-row walls show that the proposed mathematical model adequately reproduces most of the important features. We found that for double-row walls, the CR increases with increasing wave number, kd, and with a decreasing permeable wall part, din. The Cr follows the opposite trend. The CE slowly increases with an increasing kd for lower kd values, reaches a maximum, and then decreases again. In addition, an increasing porosity of dm would significantly decrease the CR while increasing the Cr. At lower values of kd, a decreasing porosity increases the CE, but for high values of kd, a decreasing porosity reduces the Ce. The numerical results indicate that, for triple-row walls, the effect of the arrangement of the chamber widths on hydrodynamic characteristics is not significant, except when kd〈0.5 Double-row slotted breakwaters may exhibit a good wave-absorbing performance at kd〉0.5, where by the horizontal wave force may be smaller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is marginal.

Energy-Momentum Distribution of Gravitational Waves

This paper has been addressed to the well-known problem of energy in gravitational waves. We have investigated the energy of cylindrical gravitational waves in the context of General Relativity and teleparallel theory of gravity. For this purpose, the prescriptions of Einstein, Landau-Lifshitz, Bergmann-Thomson, and Moeller are used in both the theories. It is shown that these energy-momentum complexes do not provide equivalent results in the two theories. However, these turn out to be constant for all the prescriptions except Moeller in both the theories at large distances.