习近平强流通促消费惠民生思想初探

习近平总书记一直高度重视内贸流通工作,围绕发展商品生产、运用市场规律、搞活创新流通、提升消费品质等方面,有过重要论述,形成流通惠民思想,进一步丰富和发展了马克思主义流通理论。系统梳理和深入研究习近平强流通促消费惠民生思想,将为新时代推动建设中国特色社会主义流通体系、更好迈向流通强国、增强人民幸福感获得感提供理论指导和实践遵循。

试论浙江现代商贸流通强省

改革开放以来,浙江作为市场大省,专业批发市场曾经并将继续在浙江经济体制改革、民间人才培养、民有资本聚集、个私经济发展等方面发挥极其巨大的作用。在当前新的国际、国内经济形势下,有必要针对存在的问题,引导专业市场进行整合、转型与提升,使之与现代商贸流通的业态、方式和组织相对接,努力把浙江由“市场大省”提升为“现代商贸流通强省”。

加快流通产业转型升级 更好地满足消费者美好需要

党的十九大结束后,笔者联系我国流通产业的实际认真研读了"十九大报告",回顾了我国流通业的发展,特别是转型升级的这五年,分析了流通业取得的10个方面的成绩,探讨了我国流通业发展8个不平衡不充分的问题,并且分析了导致不平衡不充分问题的7个方面的原因,探讨了中国特色社会主义流通产业发展道路的9个方面内容,分析了我国流通产业发展进入"新时代"的趋势,以及7个方面的路径选择。

Numerical analysis on forced convection enhancement in an annulus using porous ribs and nanoparticle addition to base fluid

Miniaturization of electronic equipment has forced researchers to devise more effective methods for dissipating the generated heat in these devices.In this study,two methods,including porous media inserting and adding nanoparticles to the base fluid,are used to improve heat transfer in an annulus heated on both walls.To study porous media insert,porous ribs are used on the outer and inner walls independently.The results show that when porous ribs are placed on the outer wall,although the heat transfer enhances,the pressure drop increment is so considerable that performance number (the ratio of heat transfer enhancement pressure increment,PN) is less than unity for all porous rib heights and porous media permeabilities that are studied.On the other hand,the PN of cases where porous ribs were placed on the inner wall depends on the Darcy number (Da).For example,for ribs with Da=0.1 and Da=0.0001,the maximum performance number,PN=4,occurs at the porous ribs height to hydraulic diameter ratios H/Dh=1 and H/Dh=0.25.Under these conditions,heat transfer is enhanced by two orders of magnitude.It is found that adding 5% nanoparticles to the base fluid in the two aforementioned cases improves the Nusselt number and PN by 10%–40%.

A Novel Non-Equidifferent Optical APPM Mapping Scheme for Strong Turbulent Atmospheric Channel

An optical Amplitude and Pulse Position Modulation(APPM) mapping scheme for strong turbulent atmospheric channel is proposed to optimize Bit Error Rate(BER) performance.In this scheme,a nonequidifferent amplitude series is designed based on quantitative BER analysis of the specific A×M APPM demapping procedures containing time slot selection and amplitude decision in selected time slot,which are different from traditional ones.Simulation results of 4×4,4×8 and 4×16 APPM show 4,3.4 and 6.9 d B SNR gain against traditional APPM scheme respectively.Thus significant BER performance improvement is achieved which helps to enhance reliability of freespace optical communication systems.

Forced Convective Heat Transfer Experiment of Supercritical Water in Different Diameter of Tubes

Forced convective experiment of supercritical water was performed in Inconel-625 tubes of 4.62 mm, 7.98 mm and 10.89 mm in diameter. The water flowed upward, covering the ranges of pressure of 23.4 MPa to 25.8 MPa, mass flux of 90 kg/m^2s to 3,281 kg/m^2s, local bulk temperature of 102-384 ℃, inner wall temperature of 167-669℃ and heat flux of up to 2.41 MW/m^2. The results exhibited severe deteriorated and enhancement heat transfer. The experimental results can be calculated by the Jackson＇s correlation and the Bishop＇s correlation mostly. But some data with strong effects of the buoyancy force and the variations of flow regimes can not be predicted properly.

Network traffic flow evolution with battery electric vehicles and conventional gasoline vehicles

In order to investigate the effect of the use of battery electric vehicles on traffic dynamics,the valid paths of electric battery vehicles are defined and a check-based method is proposed to obtain them.Then,assuming that travelers only focus on their past travel experience,a day-to-day traffic assignment model is established based on reinforcement learning and bounded rationality.In the proposed model,the Bush-Mosteller model,a reinforcement learning model,is modified to calculate path choice probability according to bounded rationality.The modified model updates the path choice probability only if the gap between expected travel time and perceived travel time is beyond the cognitive threshold.Numerical experiments validate the effectiveness of the model and show that traffic flows can converge to the equilibrium in any case of cognitive thresholds and penetration rates of battery electric vehicles.The cognitive threshold has a positive influence on the variation of traffic flows while it has a negative influence on the differences between traffic flows.The adaptation of battery electric vehicles leads to the poor performance of the traffic system.

Convective mass transfer enhancement in a membrane channel by delta winglets and their comparison with rectangular winglets

Numerical calculations were conducted to simulate the flow and mass transfer in narrow membrane channels equipped with delta winglets, which are often used as longitudinal vortex generators to enhance heat transfer in heat exchanger applications. The channel consists of an impermeable solid wall and a membrane. The delta winglets are attached to the solid wall surface to enhance the mass transfer near the membrane surface and suppress the concentration polarization. The winglet performance was evaluated in terms of concentration polarization factor versus consumed pumping power. Calculations were implemented for NaCl solution flow in a membrane channel having a height of 2.0 mm for Reynolds numbers ranging from 400 to 1000. The delta wing- lets were optimized under equal pumping power condition, and the results of optimization suggest winglet height of 5/6 of the channel height, aspect ratio of 2.0, attack angle of 30% and a winglet interval equal to the channel height The optimal delta winglets were compared with the optimal rectangular winglets we found previously, and it is shown that the rectangular winglets yield a somewhat better performance than the delta winglets. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.

Performance Enhancement and Utility Maximization for TCP in Wireless Mesh Networks

In Wireless Mesh Networks (WMNs),the performance of conventional TCP significantly deteriorates due to the unreliable wireless channel.To enhance TCP performance in WMNs,TCP/LT is proposed in this paper.It introduces fountain codes into packet reorganization in the protocol stack of mesh gateways and mesh clients.Furthermore,it is compatible with conventional TCP.Regarded as a Performance Enhancement Proxies (PEP),a mesh gateway buffers TCP packets into several blocks.It simultaneously processes them by using fountain encoders and then sends them to mesh clients.Apart from the improvement of the throughput of a unitary TCP flow,the entire network utility maximization can also be ensured by adjusting the scale of coding blocks for each TCP flow adaptively.Simulations show that TCP/LT presents high throughput gains over single TCP in lossy links of WMNs while preserving the fairness for multiple TCPs.As losses increase,the transmission delay of TCP/LT experiences a slow linear growth in contrast to the exponential growth of TCP.

Analysis of Internal Cooling Geometry Variations in Gas Turbine Blades

The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on theheat transfer. An experimental approach is performed with flow visualization via paint injection into water. Alsonumerical calculations are carried out in two sets, on the one hand water calculations accompanying the experimentsand on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculationsare still ongoing delivering preliminary results.Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leadingedge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modifiedgeometries the pressure ratio is held constant compared to the base.Among several investigated configurations one could be identified that leads to a heat transfer enhancement inone leading edge channel 7 % larger compared to the base.