电加热熨平板加热条报警原因与检测方法的探究

电加热条是沥青摊铺机电加热熨平板中的重要元件之一,介绍了加热条的组成及结构,分析了影响加热条的报警原因,提出改进加热条的检测方法,对今后加热条生产厂家及主机制造商提高加热条应用具有一定的借鉴作用。

Review on hot spinning for difficult-to-deform lightweight metals

Hot spinning process has attracted significant attention because it can be used to manufacture complex parts, extend the forming limit of materials, decrease forming forces and reduce process chains. In this paper, we review researches on lightweight metals spun at elevated temperatures since they are difficult to deform at room temperature. These metals include light alloys, such as titanium, magnesium and aluminum alloys, and metal composites. Then, the heating methods used in the hot spinning process and the treatment methods employed for the temperature boundary condition in finite element analyses for the process were discussed. Finally, the future development directions for the hot spinning process of lightweight but difficult-to-deform alloys were highlighted.

上加热式理条机加工九华佛茶的应用研究

采用上加热式理条机与不同的机器配合,进行九华佛茶加工试验。结果表明,该机具有杀青和理条的功能,采用该机杀青,再用连续理条机理条,名茶多用机做形,烘干、提香。成品茶外形扁直匀整,色泽翠绿,符合扁直型九华佛茶品质要求。

周环反应立体选择规则的简易判断方法

周环反应不同于一般类型的化学反应,这类反应不受溶剂极性的影响,也不受酸、碱催化剂或引发剂的影响,反应是借助于热或光将能量传递给反应物而发生的.在整个反应历程中,不产生离子或自由基中间体,反应中旧键和新键的轨道形成一个环状过渡态,然后同时发生旧键的破裂和新键的形成.周环反应包括:电环化反应、环加成反应、σ键迁移反应等.Woodward-Hoffmann在1965年创立了周环反应的立体选择规则,一般教科书都以π电子数和反应条件的关系来表示其立体选择规则.例如:电环化反应选择规则是:环加成反应选择规则是:在长期教学过程中,发现学生不易直接看出其中的关系,因而只是死记硬背,机械记忆.本文以π电子数与前线轨道(FMO)的HOMO(最高占有轨道)、LUMO(最低空轨道)的能量及对称性和反应条件三者的关系中得出一种较为直观的表示方法,易于判断和掌握.

Enhanced-hydrogen gas production through underground gasification of lignite

Underground coal gasification is one of the clean technologies of in-situ coal utilization.Hydrogen production from underground gasification of lignite was investigated in this study based on simulation experiments.Pyrolysis of lignite, gasification activity, oxygen-steam gasification and the effect of groundwater influx were studied.As well, the advantages of lignite for stable underground gasification were analyzed.The results indicate that lignite has a high activity for gasification.Coal pyrolysis is an important source of hydrogen emission.Under special heating conditions, hydrogen is released from coal seams at temperatures above 350 °C and reaches its maximum value between 725 and 825 °C.Gas with a hydrogen concentration of 40% to 50% can be continuously obtained by oxygen-steam injection at an optimum ratio of steam to oxygen, while lignite properties will ensure stable gasification.Groundwater influx can be utilized for hydrogen preparation under certain geological conditions through pressure control.Therefore, enhanced-hydrogen gas production through underground gasification of lignite has experimentally been proved.

Different Warming Patterns of Tropical Pacific Sea Surface Temperature Projected by FGOALS-g2 and FGOALS-s2 under RCP8.5

The different patterns of SST changes under the ＋8.5 W m 2 Representative Concentration Pathway （RCP8.5） projected by the latest two versions of the Flexible Global Ocean-Atmosphere-Land System model （FGOALS-g2 and FGOALS-s2; grid-point version 2 and spectral version 2, respectively）, and the potential mecha- nisms for their formation are studied in this paper. The results show that, although both FGOALS-g2 and FGOALS-s2 project global warming patterns, FGOALS-g2 （FGOALS-s2） projects a La Nifia-like （an E1 Nifio-like） mean warming pattern with weakest （strongest） warming over the central （eastern） equatorial Pacific for 2081-2100 relative to 1986-2005 under RCP8.5. A mixed layer heat budget analysis shows that the projected tropical Pacific Ocean warming in both models is primarily caused by atmos- pheric forcing. The main differences in the heating terms contributing to the SST changes between the two models are seen in the downward longwave radiation and ocean forcing. The minimum SST warming over the equatorial Pacific in FGOALS-g2 is attributed to the local minimum heating of downward longwave radiation and maximum cooling of ocean forcing. In contrast, the maximum SST warming over the equatorial Pacific in FGOALS-s2 is due to the maximum warming of downward longwave radia- tion, and the contribution of ocean forcing is minor. The minimum SST warming over the equatorial Pacific in FGOALS-g2 emerges around the 2050s, before when the SST over the equatorial Pacific is warmer than that over the extra-equatorial Pacific. In FGOALS-s2, the SST dif- ference shows a continuous increasing trend for 2006- 2100. Further examination of the oceanic and atmospheric circulation changes is needed to reveal the process responsible for the longwave radiation and ocean forcing difference between the two models.

Regeneration of waste activated carbon after extracting gold with steam under microwave heating:Optimization using response surface methodology

The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology （RSM） technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.

Measurements of Hydrate Equilibrium Conditions for CH4, CO2, and CH4＋C2H6＋C3H8 in Various Systems by Step-heating Method

Phase equilibrium conditions of gas hydrate in several systems were measured by the step-heating method using the cylindrical transparent sapphire cell device.The experimental data for pure CH4 or CO2+deionized water systems showed good agreement with those in the literatures.This kind of method was then applied to CH4/CO2+sodium dodecyl sulfate(SDS)aqueous solution,CH4/CO2+SDS aqueous solution+silica sand,and(CH4+C2H6+C3H8)gas mixture+SDS aqueous solution systems,where SDS was added to increase the hydrate formation rate without evident influence on the equilibrium conditions.The feasibility and reliability of the step-heating method,especially for porous media systems and gas mixtures systems were determined.The experimental data for CO2+silica sand data shows that the equilibrium pressure will change significantly when the particle size of silica sand is less than 96μm.The formation equilibrium pressure was also measured by the reformation of hydrate.

Rapid Microwave-accelerated Multi-step Synthesis of 2,6-di（naphthalene Thioureido Carbamino）Pyridine

A rapid and simple procedure for synthesis of 2,6-di（naphthalene thioureido carbamino）pyridine fluorescine anion acceptor by the reaction between pyridine-2,6-dicarbohydrazide obtained from 2,6-dimethylpyridine after three-step reaction and 1-napbthyl isothiocyanate is described, and all reactions could be carried out under microwave heating condition.

Experimental investigation on performance of intumescent coating for steel plate at elevated temperature

Twenty tests were conducted to investigate the efficiency of the intumescent coating designed to protect steel plate at the elevated temperature, by means of electrical furnace. And the factors of the initial thickness of coating and temperature of electrical furnace were considered. The high temperature response behavior of the intumescent coating was observed. And the expansion form of ultrathin intumescent coating and the temperature of the steel plate(TS) were obtained. Besides, the heat flux from expansion layer to steel plate versus time was analyzed in order to evaluate the heat transfer effect of intumescent coating on steel plate. The experimental results show that the response behaviors of the coating subjected to fire could be divided into four phases: stabilization phase, foaming expansion phase, carbonization-consumption phase and inorganic layer phase. And the net heat flux to the steel plate decreased observably in the foaming expansion phase, while the surplus white inorganic substance, which is the residue of the intumesced char layer in the inorganic layer phase under the condition of the temperature of the electrical furnace(TEF) beyond 700 °C over 1 h, has little effect on fire protection for the steel plate.

Thermo-chemical conversion of coal samples under high temperature

Exhaustion of profitable coal resources makes for need of innovation including underground coal gasification(UCG).One of the most important problems of UCG is evaluation of the combustion area in underground coal seams.Physicochemical parameters of coal,in a whole,and coal mineral substance are changed under heating and combusting.Thermo-chemical conversion of coal mineral components has an effect on magnetic characteristics of coal seam and can be used for real-time control of combusting area.To this guessing check laboratory experiments have been made as an activity of the Far Eastern Federal University.Our investigation based on a theoretical analysis and laboratory simulation tests.Typical results of the laboratory experiments are presented below.Under heating coal thermo-chemical magnetization is forming.Coal's magnetic parameters varieties from anti-ferromagnetiсto ferromagnetic.Anti-ferromagnetic pyrite and siderite presented into coal mass is transformed into magnetic hematite and magnetite under heating.Therefore,geomagnetic is expected to be a useful geophysical tool to for evaluation of combustion volume and its migration for underground coal gasification.

On the Significance and Use of the Generalized Moist Potential Vorticity Equation

In this paper,the continuity and thermodynamic equations including moisture forcings were derived.Using these two equations and the basic momentum equation of local Cartesian coordinates,the budget equation of generalized moist potential vorticity(GMPV) was derived.The GMPV equation is a good generalization of the Ertel potential vorticity(PV) and moist potential vorticity(MPV) equations.The GMPV equation is conserved under adiabatic,frictionless,barotropic,or saturated atmospheric conditions,and it is closely associated with the horizontal frontogenesis and stability of the real atmosphere.A real case study indicates that term diabatic heating could be a useful diagnostic tool for heavy rainfall events.

Utilization Starch of Avocado Seed （Persea Americana Mill.） as a Raw Material for Dextrin

Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.

DNA-assisted rational design of BaF_2 linear and erythrocyteshaped nanocrystals

The synthesis of inorganic materials with special morphologies with the assistance of biological molecules is a potential development in the field of controllable growth and assembly of nanomaterials. In this paper, BaF2 nanocrystals in patterns of well-defined linear and erythrocyte-shaped structure were synthesized with the assistance of Escherichia coil DNA. Morphology and the arrangement of BaF2 particles on DNA were controllable by altering the reaction condition. Square nanoparticles arranged in linear chains were gained with the assistance of normal DNA; while, erythrocyte-shaped BaF2 nanospheres were synthesized with the assistance of denatured DNA. Besides, the influences of solvent, reaction temperature, concentration of reactants and the heating time on the morphology of the BaF2 particles were studied.

Formation of copper oxide nanowires and nanoparticles via electrospinning

Copper oxide nanowires and nanoparticles were fabricated through electrospinning followed by calcinations in different heating conditions.It was found that the solution viscosity and environment humidity had great impact on the morphologies of precursor nanowires,and the parameters of heat treatment,including final temperature and heating rate,significantly affected the product morphologies.

Flow characteristics of hypersonic inlets with different cowl-lip blunting methods

Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall.

Darcy–Forchheimer Three-Dimensional Flow of Williamson Nanofluid over a Convectively Heated Nonlinear Stretching Surface

The present study elaborates three-dimensional flow of Williamson nanoliquid over a nonlinear stretchable surface. Fluid flow obeys Darcy–Forchheimer porous medium. A bidirectional nonlinear stretching surface generates the flow. Convective surface condition of heat transfer is taken into consideration. Further the zero nanoparticles mass flux condition is imposed at the boundary. Effects of thermophoresis and Brownian diffusion are considered. Assumption of boundary layer has been employed in the problem formulation. Convergent series solutions for the nonlinear governing system are established through the optimal homotopy analysis method(OHAM). Graphs have been sketched in order to analyze that how the velocity, temperature and concentration distributions are affected by distinct emerging flow parameters. Skin friction coefficients and local Nusselt number are also computed and discussed.

Influence of the heating rate on the critical Marangoni number of oscillatory thermocapillary convection in the floating half zone

In the present study, numerical simulations were conducted on thermocapillary convection in floating half zones of 5 cSt silicone oil of different scales in comparison with the experimental studies in the microgravity conditions. The effect of heating rate on the marginal instability boundaries is indicated as a possible explanation for the significant quantitative discrepancies between the experimental results in the terrestrial conditions and in the microgravity conditions.