基于FMS的高清视频服务器的研究

在当今网络视频发展的过程中。高清视频,多用户,大并发流是视频点播发展的必然趋势。该文从分析flash media server系统入手,提出了一种应用于高校内部高速网的高清视频服务的设计方案,并对该系统的体系机构和各个组成部分进行了改进,重点是针对用户的VCR操作,视频文件的内热度等。对视频文件进行分盘分区分段存储。从而大幅度降低了服务拒绝率,减少了用户等待时间[1]。

Questionnaire Research on Indoor Environment Quality i n China

With 1 185 pi eces of questionnaire, it is found that in China, people take fresh air, odor, e tc., as well as indoor air temperature, humidity, as the most important indoor a ir parameters. It is also found that there is a significant sensitivity differen ce in indoor environment between southerners and northerners in China. People fr om different regions have different demands for their working and living environ ment. Therefore, as a good design of air conditioning system, it is strongly rec ommended that the different demands of people from different regions should be t aken into consideration.

Effect of thermal storage performance of concrete radiant cooling room on indoor temperature

A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by TRNSYS. The comparative analysis of the characteristics of attenuation and delay proves that the operation of radiant cooling system increases the degree of temperature attenuation of the room and reduces the inner surface temperature of the wall significantly, but has little effect on the attenuation coefficient and delay time of wall heat transfer. The simulation results also show that the inner surface temperature of the walls in the radiant cooling room is much lower than that in non-cooling room in the day with the maximum cooling load, which reduces the indoor operation temperature largely, and improves the thermal comfort. Finally, according to the analysis of indoor temperature of the rooms with different operation schedules of cooling system, it can be derived that the indoor mean temperature changes with the working time of radiant cooling system, and the operation schedule can be adjusted in practice according to the actual indoor temperature to achieve the integration of energy efficiency and thermal comfort.

Spatial Distribution of Internal Temperatures in a LGR （Light Green Roof） for Brazilian Tropical Weather

This article aims to assess the spatial distribution of the IST （internal surface temperatures） in the ceiling and DBT （dry bulb temperatures） of a LGR （light green roof） in a test cell. Cover systems known as green roofs have the potential to retain rainwater and help reduce runoff. However, the characteristic considered in this work is the insulation capacity of this kind of coverage. To evaluate the spatial distribution of temperatures in an environment with light green roof, we proposed a new method for acquisition of series of climatological data and temperatures according to spatial and temporal approaches of dynamic climatology. Climatological data were provided by an automatic weather station and temperatures were collected in a test cell with light green roof. The spatial distribution of surface temperatures and internal air temperature （DBT） are based on the concepts of a climatic episode and typical experimental day from the study of the dynamic climatology. The results led to the conclusion that the light green roof has a balanced spatial distribution of the IST and of the internal air temperature （DBT）, i.e., without substantial variations over the day. The new methodology also showed the importance of specifying the location of the sensors and automatic weather station in experimental studies on the thermal behaviour of buildings.

Effects of air-sea coupling on the eastward propagating boreal winter intraseasonal oscillation over the tropical Indian Ocean

The effects of air-sea coupling over the tropical Indian Ocean（TIO） on the eastward propagating boreal winter intraseasonal oscillation（MJO） are investigated by comparing a fully coupled and a partially decoupled Indian Ocean experiment using the SINTEX-F coupled model.Air-sea coupling over the TIO significantly enhances the intensity of the eastward propagations of the MJO along the5°-10°S zonal areas.The zonal asymmetry of the SST anomaly（SSTA） is responsible for the enhanced eastward propagation.A positive SSTA appears to the east of the MJO convection,which results in the boundary layer moisture convergence and positively feeds back to the MJO convection.In addition,the air-sea interaction effect on the eastward propagation of the MJO is related to the interannual variations of the TIO.Air-sea coupling enhances（reduces） the eastward-propagating spectrum during the negative Indian Ocean dipole mode and positive Indian Ocean basin mode.Such phase dependence is attributed to the role of the background mean westerly in affecting the wind-evaporation-SST feedback.Air-sea coupling（decoupling） enhances（reduces） the zonal asymmetry of the low-level specific humidity,and thus the eastward propagation spectrum of the MJO.

Characteristics of Momentum and Heat Transfer over Semiarid Grasslands with Different Grazing Intensities in Inner Mongolia,China

The drag coefficient （Ca） and heat transfer coefficient （Ch） with the bulk transfer scheme are usually used to calculate the momentum and heat fluxes in meteorological models. The aerodynamic roughness length （z0m） and thermal roughness length （z0h） are two crucial parameters for bulk transfer equations. To improve the meteorological models, the seasonal and interannual variations of Z0m, Z0h, coefficient kB-1, Cd, and Ch were investigated based on eddy covariance data over different grazed semiarid grasslands of Inner Mongolia during the growing seasons （May to September） from 2005 to 2008. For an ungrazed Leymus chinensis grassland （ungrazed since 1979）, Z0m and z0h had significant seasonal and in- terannual variations. Zorn was affected by the amount and distribution of rainfall, kB 1 exhibited a relatively negative variation compared with z0h, which indicates that the seasonal variation of z0h cannot be described by kB 1. To parameterize Zorn and z0h, the linear regressions between ln（z0m）, ln（z0h）, and the leaf area index （LAI） were performed with R2=0.71 and 0.83. The monthly average kB-1 was found to decrease linearly with LAI. The four-year averaged values of Ca and Ch were 4.5 × 10^-3 and 3.9× 10^-3, respectively. The monthly average Cd only varied by 8% while the variation of Ch was 18%, which reflects the dif- ferent impacts of dead vegetation on momentum and heat transfer at this natural grassland. Moreover, with the removal of vegetation cover, grazing intensities reduced Z0m, Z0h, Cd, and Ch.

Effect of graphitization degree of fuel cell gas diffusion layers on their heat management:Modeling and experiments

Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP on its through plane thermal conductivity and in-plane thermal conductivity is investigated.The relationship between heat treatment temperatures(1800,2000,2200,2400 and 2500℃)and graphitization degree is also investigated by SEM,XRD and Raman measurements.A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix carbon.The experimental and simulation results are compared.The results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and in plane thermal conductivity.

Impact of cold indoor thermal environmental conditions on human thermal response

To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects were recorded at 10 min intervals for 90 min under air temperatures of 7.4,9.1,11 and 15 °C.The results show that both local skin temperatures and mean skin temperature decrease not only with the drop of ambient air temperature but also with the exposure time.Local thermal sensation and overall the thermal sensation have the similar temperature-varying and time-varying characteristics.Predicted mean vote(PMV) model cannot correctly predict the thermal sensation under non-thermal equilibrium cold environment.The correlation between local thermal sensation and local skin temperatures shows that thermal sensation is closely related to skin temperature.Skin temperature is an effective indicator of thermal sensation.A linear relationship model between overall thermal sensation and mean skin temperature,considering both ambient temperature and exposure time,was established in the non-thermal equilibrium cold environment,which makes the evaluation of thermal sensation more objective.

Improvement of thermal performance of envelopes for traditional wooden vernacular dwellings of Tujia Minority in Western Hunan,China

Thermal performance of envelopes and indoor thermal environment were technologically improved for traditional wooden vernacular dwellings of Tujia Minority in Western Hunan, China, on the premise of protecting their conventional styles. Thermal insulation boards and wooden boards were added to the interior side of external walls of vernacular dwellings to form two layers of air cavities, so as to gain excellent thermal performance. The indoor temperature of such dwellings after reconstruction was apparently improved compared with the data before reconstruction both in winter and summer, which verified the feasibility and the effectiveness of the reconstruction technologies proposed.

Intracellular temperature measurement by a dual-thermocouple difference method

A dual thermocouple difference technique is developed to determine the accuracy and anti-interference ability in the process of intracellular temperature measurement.First,two micro-nano thermocouples(TC)and a high-precision signal acquisition module are used to measure the temperature difference between the cell and the culture medium(separated about 10μm from the cell).The cold junctions of two TCs are connected to eliminate the setting of the reference temperature and enhance the anti-interference ability.Then,a low-noise voltage amplifier and digital acquisition card are used to sample signals.In order to verify the feasibility of the dual thermocouple difference method,the temperature changes of U251 cells are detected.The calibration results of two TCs show that the Seebeck coefficient is about 5μV/℃,and the signal acquisition accuracy is 0.5μV in a low voltage range(0-15μV).With the dual thermocouple difference method,errors due to the cold junctions can be removed and the interference caused by environmental temperature fluctuation can be reduced.The phenomenon of cellular temperature increase proves that the dual thermocouple difference method can detect the tiny temperature change of a single cell.The method potentially is a highly powerful technique for studying local thermogenesis of cells and helps to explore the relationship between cellular thermogenesis and cellular processes.

Calculation on inner wall temperature in oil-gas pipe flow

Based on the energy equation of gas-liquid flow in pipeline,the explicit temperature drop formula for gas-liquid steady state calculation was derived.This formula took into consideration the Joule-Thomson effect,impact of terrain undulation and heat transfer with the surroundings along the line.Elimination of temperature iteration loop and integration of the explicit temperature equation,instead of enthalpy energy equation,into the conjugated hydraulic and thermal computation have been found to improve the efficiency of algorithm.Then,the inner wall temperature of gas-liquid flow was calculated by using explicit temperature equation and inner wall convective heat transfer coefficient of mixed flow which can be obtained by liquid convective heat transfer coefficient and gas convective heat transfer coefficient on the basis of liquid holdup.The temperature results of gas-liquid flow and inner wall in the case example presented both agree well with those in professional multiphase computational software OLGA.

Dynamic thermal management by greedy scheduling algorithm

Chip multiprocessors(CMPs) allow thread level parallelism,thus increasing performance.However,this comes with the cost of temperature problem.CMPs require more power,creating non uniform power map and hotspots.Aiming at this problem,a thread scheduling algorithm,the greedy scheduling algorithm,was proposed to reduce the thermal emergencies and to improve the throughput.The greedy scheduling algorithm was implemented in the Linux kernel on Intel's Quad-Core system.The experimental results show that the greedy scheduling algorithm can reduce 9.6%-78.5% of the hardware dynamic thermal management(DTM) in various combinations of workloads,and has an average of 5.2% and up to 9.7% throughput higher than the Linux standard scheduler.

The Microclimatic Influence of a Water Body on an Urban Environment

The paper aims to investigate the potential of a water body to influence in lowering the warmth in the city of Sao Jose do Rio Preto, Brazil, due to the evaporative cooling effects. In order to verify its potential, three collecting points of temperature and humidity were placed in an urban area close to the municipal dam. The first one was placed on the dam margin, the second one, 50 m distant of the margin and, the third one, 100 m distant. The data were taken during December 2010 and then compared to the climate data of the Climate Station of CIIAGRO-Integrated Center of Agro Meteorological. The results show that the closer the collection point is to the water body, and the lower is the temperature variation. The humidity taxes verified at the closest point to the water body indicate values higher than those ones collected at the most distant point. The insertion of moisture through the water bodies in an urban environment demonstrated to be a strategy that improved the thermal conditions and has to be considered for urban planners to establish strategies of urban occupation.

Adaptive Thermal Comfort for Occupants of Low-Cost Dwellings in a Hot Dry Climate

Adaptive models are based on the observation that there are some actions that people can and actually do take to achieve thermal comfort. Studies regarding thermal comfort conditions in economical dwellings were carried out simultaneously in seven Mexican cities, corresponding to warm dry and warm humid climates. In this article, case studies of low-cost dwellings in the city of Hermosillo （in northwest Mexico）, are presented and analyzed. Field surveys were carried out to obtain information about the physical characteristics of the dwellings and their occupants, as well as the indoor thermal environment. Neutral temperature was obtained from the applied survey. The high neutral temperature reveals the effect of inhabitants＇ adaptation mechanism to extreme climates. Occupant comfort votes as a function of indoor air temperatures were analyzed, and different characteristics such as age, size and gender were evaluated separately. The results show the variability of the neutral temperature and the tolerance to temperature changes, depending on the population＇s specific characteristics. In many cases where the population does not have access to artificial acclimatization devices, the neutral temperature values for specific climates and people can inform architects when choosing the most suitable thermal strategies for building design.

基于智力城镇化的特色小镇产业培育探索——以辽宁通远堡镇为例

我国城镇化正处于劣势的体力城镇化阶段,特色小镇作为新型城镇化的主力军,体力化威胁仍不可避免。为缓解特色小镇体力化困境,文章基于智力城镇化的相关理论,以辽宁通远堡镇为例,围绕特色产业展开智力化培育的探索。结合链式产业思维,以智力投入、智力主体、智力产出三大环节为基础,以智力要素创新性地打造智力链条,构建可持续的特色产业,带动城镇化转型升级,以期为辽宁省乃至全国特色小镇培育提供借鉴。

Inverse Heat Conduction Estimation of Inner Wall Temperature Fluctuations under Turbulent Penetration

Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high frequency can lead to time-varying wall thermal stress and even thermal fatigue on the inner wall. Numerous cases, however, exist where inner wall temperatures cannot be measured and only outer wall temperature measurements are feasible. Therefore, it is one of the popular research areas in nuclear science and engineering to estimate temperature fluctuations on the inner wall from measurements of outer wall temperatures without damaging the structure of the pipe. In this study, both the one-dimensional(1D) and the two-dimensional(2D) inverse heat conduction problem(IHCP) were solved to estimate the temperature fluctuations on the inner wall. First, numerical models of both the 1D and the 2D direct heat conduction problem(DHCP) were structured in MATLAB, based on the finite difference method with an implicit scheme. Second, both the 1D IHCP and the 2D IHCP were solved by the steepest descent method(SDM), and the DHCP results of temperatures on the outer wall were used to estimate the temperature fluctuations on the inner wall. Third, we compared the temperature fluctuations on the inner wall estimated by the 1D IHCP with those estimated by the 2D IHCP in four cases:(1) when the maximum disturbance of temperature of fluid inside the pipe was 3℃,(2) when the maximum disturbance of temperature of fluid inside the pipe was 30℃,(3) when the maximum disturbance of temperature of fluid inside the pipe was 160℃, and(4) when the fluid temperatures inside the pipe were random from 50℃ to 210℃.

Intraseasonal oscillation features of the South China Sea summer monsoon and its response to abnormal Madden and Julian Oscillation in the tropical Indian Ocean

By applying the OLR and wind data, rainfall data and the Madden and Julian Oscillation （MJO） index, the paper deals with in traseasonal oscillation features and interannual differences of the South China Sea （SCS） summer monsoon, distribution of its LF circulation and convection fields and rainfall, and path of summer monsoon ISO spreading, as well as impact of tropical IndoMJO on SCS summer monsoon ISO during 19792008. It is found that （1） there are three intraseasonal oscillations of the SCS summer monsoon Intraseasonal Oscillation （ISO） in summer （from May to August） in the climate normal. The SCS summer monsoon ISO goes through six phases （exclusive of weak phase） at every complete fluctuation： developing, the strongest, weakening, restraining, the weakest, and recovering. Due to tropical LC convection spreading to the east and north, the LR convection and circulation fields in the lst3rd and 4th6th phases present the antiphase in the Arabian SeaWest Pa cific latitudinal band. Its corresponding rain bands in the lst3rd and 4th6th phases als present antiphase roughly. The rain band, mainly in tropical regions in the south of 20N, moves eastward with LR convection shifting eastward, while the rain band moves northward with LR convection shifting northward in East Asia （EA） subtropical regions in the north of 20N. （2） The SCS summer monsoon ISO presents significant interannual variations in intensity. There are three stronger monsoon in traseasonal oscillations in summer in the strong SCS monsoon ISO year. The first two oscillations from the tropical Indian Ocean ISO spread northward to the Bay of Bengal first, and then to the South China Sea （SCS） along the 10-20N latitudinal band. They are strengthened there and stimulate the ISO moving to the north to form the tropical IndoISO. Finally they spread to South China （SC） by relay way in the longitudelatitude direction. Moreover, in the weaker SCS summer monsoon ISO, the oscillation weakens greatly and irregularly in intensity with the weaker ISO spreading in the longitudelatitude direction. In average conditions, the tropical Indian ISO spreads to the SCS by about 20 days （one half ISO periods）. （3） MJO1 （the first modal of MJO index provided by the CPC） averaged value in the lst2nd pentads of April has the negative correlation with the SCS monsoon ISO intensity. The tropical IndoMJO is slightly stronger in the subsequent May to August when it is more ac tive in the lst2nd pentads of April, and the ISO also spreads strongly to the SCS, so that the SCS summer monsoon ISO strengthens. Conversely, the SCS summer monsoon ISO weakens. The abnormal MJO in the lst2nd pentads of April contrib utes to a certain theory basis for us to predict the subsequent SCS summer monsoon ISO intensity and analyze the related re gions＇ abnormal rainfall.

Sensitivity of simulated tropical intraseasonal oscillations to cumulus schemes

The sensitivity of simulated tropical intraseasonal oscillations (ISO) to different cumulus parameterization schemes was analyzed using an atmospheric general circulation model (latest version-SAMIL2.2.3) developed at the Laboratory for Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) at the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences.Results show that the basic features of tropical climatological intraseasonal oscillations (CISO) can be captured using all three cumulus schemes.The CISO simulated by the Tiedtke scheme was found to be more realistic than that of the Manabe and Zhang-McFarlane schemes.The results of simulated transient intraseasonal oscillations (TISO) indicate that although the Tiedtke and the Zhang-McFarlane schemes in the new version SAMIL2.2.3 have been adjusted according to different problems,only the latter can simulate the eastward propagation of the 27-50-day TISO mode.It may be associated with the more realistic diabatic heating profile simulated by the Zhang-McFarlane scheme.In addition,the Manabe scheme in SAMIL2.2.3 is the same as that in the prior version SAMIL2.08.However,some aspects of the physical process,such as the radiation scheme and aerosol condition,have been changed.Conversely the eastward propagation from 100°E to the west of the tropical 27-50-day TISO mode only can be simulated using the Manabe scheme of SAMIL 2.08.Consequently,not all the improvements of physical parameterization schemes work well in every respect.The coordinated developments between dynamic frame and physical processes,and among different physical processes,are important methods that may be used to improve the model.