两种定性分析验气装置的改进

利用验气装置连续鉴定砷和锡、或砷和锑、以及鉴定碳酸根等离子的方法快速简便、现象明显、干扰易于排除。如果用试管夹、纸卷、透明不干胶带、橡皮筋、细棉绳等仪器或生活日用品取代橡皮塞 ,对验气装置加以改进和简化 。

Simulation and experimental study of high pressure switching expansion reduction considering real gas effect

Switching expansion reduction(SER)uses a switch valve instead of the throttle valve to realize electronically controlled pressure reduction for high pressure pneumatics.A comprehensive and interactive pneumatic simulation model according to the experimental setup of SER has been built.The mathematical model considers heat exchanges,source air pressure and temperature,environmental temperatures and heat transfer coefficients variations.In addition,the compensation for real gas effect is used in the model building.The comparison between experiments and simulations of SER indicates that,to compensate the real gas effect in high pressure discharging process,the thermal capacity of air supply container in simulation should be less than the actual value.The higher the pressure range,the greater the deviation.Simulated and experimental results are highly consistent within pressure reduction ratios ranging from 1.4 to 20 and output air mass flow rates ranging from 3.5 to 132 g/s,which verifies the high adaptability of SER and the validity of the mathematic model and the compensation method.

Influence of Pore Size,Salinity and Gas Composition upon the Hydrate Formation Conditions

An experimental device was set up to study the hydrate formation conditions.Effects of pore size,salinity,and gas composition on the formation and dissociation of hydrates were investigated.The result indicates that the induction time for the formation of hydrates in porous media is shorter than that in pure water.The decrease in pore size,by decreasing the size of glass beads,increases the equilibrium pressure when the salinity and temperature are kept constant.In addition,higher salinity causes higher equilibrium pressure when the pore size and temperature are kept constant.It is found that the effects of pore size and salinity on the hydrate equilibrium are quite different.At lower methane concentration,the hydrate equilibrium is achieved at lower pressure and higher temperature.

Experimental study on gas permeability by adsorption under 3D-stress

Using self-developed gas-seepage experimental installation,under the sameeffective stress conditions,coal permeability experiments on different adsorption characteristicsof gases,different temperatures and different gas adsorption contents were performed,and the influence law of adsorption on coal permeability was studied.At the sametime,experimental analogy showed clearly that gas drawing plucks the permeability variationlaw.The results show that adsorption has a major impact on coal permeability.Thegreater the adsorption,the more the gas adsorption capacity and the coal permeabilitybecomes smaller.Permeability becomes smaller along with confining of pressure andtemperature,and this is in accord with local practice results.

Verification of Effective Stress for Unsaturated Clay by Collapse Test

Generally, a suction control apparatus is used to examine compression properties of unsaturated clay. This is usually carried out with a pore water pressure of 0 under condition of applying pore air pressure, which is positive pore air pressure in a triaxial compression test. It is known as the Axis Translation Technique. However in this study, the suction control apparatus does not employ a method of controlling initial degree of saturation of specimen. The method for making specimen using micro wave is used to ensure a uniform distribution of water content of specimen （microwave oven method）. Consequently, both compression properties are similar to each other. Collapse tests were carried out using specimens under the microwave oven method and air dry state. As a result, it was found that the former does not result in collapse but the latter results in a significant amount of collapse. Such occurrence of collapse is dependent on the soil structure. Therefore, the equation of effective stress for unsaturated soil proposed Bishop should not neglect as an occurrence of collapse for unsaturated soils.

Successful Commercial Test of Novel Desulfurizing Agent at SINOPEC Shanghai Gaoqiao Branch Company

The novel JX-7 jet fuel desulfurizing agent has been successful tested in commercial scale on the jet fuel hydrotreating unit at the SINOPEC Gaoqiao Branch Company,while delivering a jet fuel with its silver strip corrosion indicator meeting the military jet fuel standard.

Development and Test of an Experimental Apparatus to Study Thermal-Choking in Ideal Gases and Self-decomposition in Superheated N2O

N2O represents a popular oxidizer for hybrid rocket motors for a variety of reasons, including safety, ease of access and self-pressurization. It is often used as a saturated two-phase fluid in these applications to take advantage of self-pressurization. Recent interest in using this oxidizer in regeneratively cooled engines requires a detailed heat transfer process analysis to the coolant, in order to quantify performance. Since the injection of N2O typically takes place in the two-phase region, our study focuses on heat transfer rates in this region, and extends the region to include superheated vapor. This analysis is critical for these cooling applications, because the exothermic decomposition nature of N2O also means that unchecked heating in the superheated region may result in a runaway reaction in the cooling passages. Furthermore, provided that sufficient heat transfer rates are available, N2O is expected to accelerate in the cooling passages due to Rayleigh flow effects much like those of a calorically perfect gas. The proximity of superheated N2O to its saturated vapor curve, at the conditions studied here, makes the suitability of a perfect gas model questionable, but that benchmarks is still useful. This paper presents the development of an experimental apparatus （a ＂Rayleigh tube＂）, specifically designed to study this problem, and test the analytical methods developed to model it. Since we focus on the development of the apparatus, the data presented were uses primarily calorically perfect gas surrogates, but the goal is to apply the apparatus and method to N2O. The design and construction of the Rayleigh tube is presented, along with preliminary results with perfect gases. Finally, we present preliminary results on heated N2O flow. Using a simple model for predicted dry-out point, we investigate where superheating may be expected to occur. We present estimates of critical heating and compare them to the heat required to achieve self-decomposition.

A combined dynamic inhalation device designed for moxa-smoking toxicity testing

OBJECTIVE： To design a combined dynamic inhalation device for testing the toxicity induced by moxa smoking. METHODS： The new apparatus （Patent No. 201120101911.5） includes air renewal and recycling systems, a gas generating device, a gas control unit, and a device to measure and control tem- perature and humidity. Sprague-dawley rats were tested for acute and sub-chronic toxicity after exposure to moxa-burning smoke.METHODS： The new apparatus （Patent No. 201120101911.5） includes air renewal and recycling systems, a gas generating device, a gas control unit, and a device to measure and control tem- perature and humidity. Sprague-dawley rats were tested for acute and sub-chronic toxicity after exposure to moxa-burning smoke.RESULTS： We found an LQ0 of 1.2× 10^4 mg/m^3 in the acute toxicity assays. In sub-chronic toxicity tests the organ coefficients studied showed no sig-nificant differences within rats groups of the same gender after treatment with moxa smoke or a month of recovery. However, mean gray degree of lung 70 heat shock protein （HSP70） was significantly elevated in the high dose group in comparison with the low dose group （P 〈 0.05）, mean gray degree, mean optical density, gross area of HSP70 in other organs and caspase-9 parameters showed no significant differences between groups.CONCLUSION： These results suggest that moxa smoke had no overt toxicity in rats. This work pro- vides evidence and reference for the design of dy- namic inhalation exposure systems.

An Experimental Investigation of the Dissipation Mechanisms in the Suction Side Boundary Layer of a Turbine Blade

The present work is part of an extensive experimental activity carried out by the authors in recent years aimed at investigating the boundary layer transition phenomenon in turbine blades. The large scale of the cascade and the use of advanced LDV instrumentation and precision probe traversing mechanism resulted in high degree of spatial resolution and high accuracy of measurements. The main dissipation mechanism determining the profile losses in turbomachinery blades is the work of deformation of the mean motion within the boundary layer operated by both viscous and turbulent shear stresses. In the present paper, the local viscous and turbulent deformation works have been directly evaluated from the detailed measurements of boundary layer mean velocity and Reynolds shear stress. The results show the distributions and the relative importance of the viscous and turbulent contributions to the loss production, in relation with the boundary layer states occurring along the turbine profile.

Experimental Study of Twin Pulse Jet Engines for Power Plant Application

The total efficiency of power plants depends on the energy conversion in a combustor and a turbine .Considerably higher energy transfer rates can be obtained from a pulsed combustion.but unsteady flow of a single jet combustor reduces the turbine efficiency.Therefore.two pulse combustors were set in parallel and connected to a settling chamber that supplies a flow with constant pressure to the turbine.The aim of investigations presented here is a demonstration of technical feasibility for industrial applications and to show the benefits obtained from the pulse combustors.