探讨合理控制储罐加温温度降低原油储运能耗

在原油储运过程中，克服影响离心泵效率的一个主要因素就是原油黏度，通常对原油储罐进行加温或其他方式来降低原油黏度。固然原油黏度低对离心泵性能影响小，但原油加温需要更多的蒸汽，这就需要综合考虑储罐加温和离心泵运行经济能耗。

连续性血液净化上机血液加温温度对心脏术后患者血压影响观察

探究心脏术后患者在使用连续性血液净化(CRRT)上机时不同加温温度对患者生命体征的影响。方法:研究对象为2019年4月至2020年12月心外监护室收入的60例需要进行CRRT的患者为研究对象,根据患者入科时间采用随机数字法将患者分为观察组30例以及对照组30例。观察组采用CRRT不加温上机,对照组采用常规加温温度为43℃上机,记录并比较两组患者上机前,上机后5min、10min的中心温度、心率、平均动脉压。结果:两种不同的上机血液加温温度对患者中心温度、心率的影响不大,差异无统计学意义(p>0.05),但是上机5、10min后两组患者的平均动脉压较上机前都有所下降,差异有统计学意义(p<0.05)。结论:CRRT上机时两种不同血液加温温度对患者中心温度、心率均无影响。而不加温上机,能够减少患者血压波动,降低上机时患者低血压的发生。

Improvement of machining quality of copper-plated roll mold by controlling temperature variation

Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the quality of micro prism film. The main cause of the pitch error was investigated during machining large roll mold whose machined length was 1 200 mm. The temperature of machining system was elevated during machining roll mold, and this elevation induced thermal expansion of the system. The temperature variation around the roll mold also made thermal expansion of the roll mold. The amount of thermal expansion had strong relationship to the amount of pitch error. Therefore, the roll mold was machined after warming-up of machining system and precise temperature controller around copper-plated roll mold was installed, which minimized the temperature variation. Finally, precise micro prism patterns without pitch error were machined on the large roll mold.

Determining heating pipe temperature in greenhouse using proportional integral plus feedforward control and radial basic function neural-networks

Proportional integral plus feedforward (PI+FF) control was proposed for identifying the pipe temperature in hot water heating greenhouse. To get satisfying control result, ten coefficients must be adjusted properly. The data for training and testing the radial basic function (RBF) neural-networks model of greenhouse were collected in a 1028 m2 multi-span glasshouse. Based on this model, a method of coefficients adjustment is described in this article.

Algorithm of heating temperature for Chongqing's winter greenhouses

Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment, which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient (WEC) and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production.

Critical Temperature Characteristics of Layered High-Temperature Superconductor Under Pressure

We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pressure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature superconductor. If the pressure is not a constant, we have a relation of quadratic equation between the pressure and the temperature of layered high-temperature superconductor. In a special case, we find the critical temperature decreases with further increasing pressure. In another special ease, the critical temperature increases with further increasing pressure.

Square concrete columns strengthened with carbon fiber reinforced plastics sheets at low temperatures

Twenty-one square concrete columns were constructed and tested. The testing results indicate that bonded carbon fiber reinforced plastics(CFRP) sheets can be used to increase the strength and improve the serviceability of damaged concrete columns at low temperatures. The failure of the specimens,in most cases,takes place within the middle half of the columns. And the failure of strengthened columns is sudden and explosive. The CFRP sheets increase both the axial load capacity and the ultimate concrete compressive strain of the columns. The ultimate loads of strengthened columns at-10,0 and 10 ℃ increase averagely by 9.09%,6.63% and 17.83%,respectively,as compared with those of the control specimens. The axial compressive strength of strengthened columns is related to the curing temperatures. The improvement of axial compressive strength decreases with reducing temperature,and when the temperature drops to a certain value,the improvement increases with falling temperature.

Changes in Air Temperatures and Atmosphere Circulation in High Mountainous Parts of Bulgaria for the Period 1941-2008

Changes of air temperatures and atmosphere circulation at three high mountainous stations in Bulgaria are investigated for the period of 1941-2008.The three stations are located on peaks Musala,Cherni vrah and Botev,where air temperature data have good quality.Some missing data were recovered using the method of differences. A significant mean annual air temperature rise happened in high mountainous parts of Bulgaria- the warming is in the order of 0.7°C for the entire period.The increase is very prominent particularly in the last 30 years.Main contributors to this overall tendency are summer months-June,July and August.To some degree,January also could be included in this group.November trend shows temperature rise at the beginning of the investigated period.One of the causes for such a tendency is atmosphere circulation in respective months.It also shows signs of considerable reorganization in both winter and summer.There is an increase of the cases of warm atmosphere patterns typical for winter, summer and autumn seasons in Bulgaria.Meridional circulation has essential significance for air temperatures during the cold half of the year.In January and June atmosphere circulation has a substantial influence on the thermal regime of air in high mountains of Bulgaria.In July,August and November this influence is reduced.There are no cycles in air temperatures for the investigated period.

Investigation into the tribological behaviors of press hardening steels on the tailored conditions

There has been a growing demand for safety parts with tailored properties in automobile industry.However,the understanding of tribological behavior of press hardening steels(PHS)on the tailored conditions is highly inadequate.The present work aims at creating new knowledge about the tribological characteristics of PHS on the tailored conditions and bridging this existing gap.The paper proposes an improved hot drawing tribo-simulator to simulate the realistic experimental conditions industry.Investigations were carried out on the condition of different initial heating temperatures,tool temperatures,austenitizing temperatures,cooling rates and microstructures.The presented results show that the whole frictional process is divided into three stages for both coated and uncoated steels.The frictional factor changes a lot and the peak value of frictional factor occurs for serious adhesive wear.The frictional factor rises as the tool temperature and austenitizing temperature rise.The surface morphology of tools indicates that the coating adhering to tool gets thicker as the tool temperature increases.With the increase of cooling rate,the frictional factor declines firstly and then rises to some extent.Flat dies with different temperatures are used to form specimens with different microstructures,which also affects the frictional factor and wear.

A Meta-analysis of the Effects of Warming and Elevated CO_2 on Soil Microbes

Soil microbes play important roles in terrestrial ecosystem carbon and nitrogen cycling. Climatic warming and elevated CO2 are two aspects of climatic change. In this study, we used a meta-analysis approach to synthesise observations related to the effects of warming and elevated CO2 on soil microbial biomass and community structure. Ecosystem types were mainly grouped into forests and grasslands. Warming methods included open top chambers and infrared radiators. Experimental settings included all-day warming, daytime warming and nighttime warming. Warming increased soil actinomycetes and saprotrophic fungi, while elevated CO2 decreased soil gram-positive bacteria(G+). Mean annual temperature and mean annual precipitation were negatively correlated with warming effects on gram-negative bacteria(G–) and total phospholipid fatty acid(PLFA), respectively. Elevation was positively correlated with the warming effect on total PLFA, bacteria, G+ and G–. Grassland exhibited a positive response of total PLFA and actinomycetes to warming, while forest exhibited a positive response in the ratio of soil fungi to bacteria(F/B ratio) to warming. The open top chamber method increased G–, while the infrared radiator method decreased the F/B ratio. Daytime warming rather than all-day warming increased G–. Our findings indicated that the effects of warming on soil microbes differed with ecosystem types, warming methods, warming times, elevation and local climate conditions.

Observation of a bi-critical point between antiferromagnetic and superconducting phases in pressurized single crystal Ca0.73La0.27FeAs2

One of the most strikingly universal features of the high-temperature superconductors is that the super- conducting phase emerges in the close proximity of the antiferromagnetic phase, and the interplay between these two phases poses a long-standing challenge. It is commonly believed that, as the antifer- romagnetic transition temperature is continuously suppressed to zero, there appears a quantum critical point, around which the existence of antiferromagnetic fluctuation is responsible for the development of the superconductivity. In contrast to this scenario, we report the observation of a bi-critical point identified at 2,88 GPa and 26.02 K in the pressurized high-quality single crystal Cao.73Lao.27FeAs2 by com- plementary in-situ high pressure measurements. At the critical pressure, we find that the antiferromag- netism suddenly disappears and superconductivity simultaneously emerges at almost the same temperature, and that the external magnetic field suppresses the superconducting transition temperature but hardly affects the antiferromagnetic transition temperature.