气相色谱法测定油墨中的六种溶剂

本文报道了用气相色谱法同时测定油墨中的正丁醇、丁酮、甲苯、乙酸丁酯、二甲苯、环己酮，这方法具有良好的精密度、回收率和线性关系，测定了四种油墨所含的溶剂。     

Heat transfer and fluid flow characteristics in flash desalination units

The present work investigates the effects of different operating and geometrical parameters on the flashing efficiency of water in a single stage flashing chamber. This chamber uses a submerged rectangular orifice as flow control area. Experiments were performed to investigate the effects of flow rate, liquid level in the flashing chamber, liquid inlet temperature and flashing range, on the flashing efficiency under various design conditions. These comprise flow with baffle placed in the flashing chamber, and wire meshes placed at the orifice to increase the turbulence level.It was found that the efficiency increased with the increase of the turbulence levels, flashing range and liquid inlet temperature; the efficiency deceased with the increase of the flow rate and liquid level in the flashing chamber. The application of numerical procedure to predict flow pattern and heat transfer in the flashing chamber is introduced as a powerful design tool.     

Relationships Between the Crystal Structures and the Multiple Melting Behaviors of Poly(ethylene 2,6‐naphthalate)

Summary: Poly(ethylene 2,6‐naphthalate) (PEN) can crystallize either from the glassy state or from the melt state. When crystallized from the glassy state, the sample was quenched from the melt in liquid nitrogen and then annealed at certain crystallization temperatures. When crystallized from the melt state, the sample was cooled to a preset temperature from the melt and then annealed for a certain time. The crystal modifications, morphologies and melting behaviors of PEN were investigated by means of wide‐angle X‐ray diffraction (WAXD), polarized optical microscopy (POM), small‐angle light scattering (SALS) and differential scanning calorimetry (DSC). The results show that an α crystal modification of PEN was obtained when PEN crystallized from the glassy state, whilst a β crystal modification was obtained when PEN crystallized from the melt state at a higher temperature. An hedritic morphology of PEN crystal was obtained with only one melting peak observed in DSC curves when PEN was crystallized at a higher temperature from either the glassy state or the melt state. The α crystal modification could also be obtained when PEN was crystallized at a lower temperature from the melt. Spherulitic or banded spherulitic morphologies of PEN crystals, exhibiting multiple melting peaks in DSC curves, were observed when PEN was crystallized at a lower temperature. The multiple melting behaviors of PEN crystals may be associated with spherulitic structures composed of lamellae of varying thickness.

WAXD patterns of PEN isothermally crystallized from different states.     

微晶纤维素增粘剂的研制

以棉浆为原料，废盐酸为水解催化剂，所得合成革用微晶纤锥素增粘剂的质量指标达到了德国和日本同类产品的标准。     

Dolomite brick with free lime

Conclusions Technology has been devised for the production of dolomite brick was free lime. To obtain parts, pure dolomite with a high content of free calcium oxide and sufficient free magnesium oxide and a low content of alumina and sesquioxides, the latter in sufficient quantity to ensure sintering, should be used.Anhydrous binder P can be used as the bond since it enables strong green material to be obtained after drying.The green material should be dried in a drier with an extracting fan at 250–300°. The heat transfer agent should not contain water vapor.The parts should be fired at 1600° for 5 hours; the temperature rises to 250° during the first hour.     

Nitrogen fertilizer in leucaena alley cropping. II. residual value of nitrogen fertilizer and leucaena residues

Legume residues have been credited with supplying mineral nitrogen (N) to the associated cereal crop and improving soil fertility in the long term. Few studies using¹⁵N have reported the fate of legume N and fertilizer N in the presence of legume residues in soil-plant systems over periods of two years or longer. A field experiment was conducted in microplots to evaluate: (1) the residual value of the¹⁵N added in leucaena residues; (2) the residual value of fertilizer¹⁵N applied in the presence of unlabelled leucaena residues in the first year to maize over three subsequent years; and (3) the long-term fate of residual fertilizer and leucaena¹⁵N in a leucaena alley cropping system.There was a significant increase in maize production over three subsequent years after addition of leucaena residues. The residual effect of fertilizer N increased maize yield in the second year when N fertilizer was applied at 36 kg N ha^–1 in the first year in the presence of leucaena residues. Of the leucaena¹⁵N applied in the first year, the second, third and fourth maize crop recovered 2.6%, 1.8% and 1.4%, respectively. The corresponding values for the residual fertilizer¹⁵N were 0.7%, 0.4% and 0.3%. About 12–14% of the fertilizer¹⁵N added in the first year was found in the 200 cm soil profile over the following three years. This differed from the 38–41% of leucaena¹⁵N detected in the soil over the same period. Most of the residual fertilizer and leucaena¹⁵N in the soil was immobilized in the top 25 cm with less than 1% leached below 100 cm. More than 36% of the leucaena¹⁵N and fertilizer¹⁵N added in the first year was apparently lost from the soil-plant system in the first two years. No further loss of the residual leucaena and fertilizer¹⁵N was detected after two years.     

Corrosion protection of aluminium in acidic chloride solutions with nontoxic inhibitors

Corrosion kinetics of 99.6% aluminium covered by a thin spontaneously formed oxide film in hydrochloric acid solution with and without the presence of substituted N-aryl pyrroles was studied using electrochemical impedance spectroscopy and quasi steady-state polarization. Measurements were performed on a rotating disc electrode in an argon-deaerated solution in the temperature range 20 to 50°C. The addition of inhibitor considerably increases overvoltage of the cathodic process (HER) and shifts Ecorr to negative potential values. The activation energy of the hydrogen evolution reaction was Ea=50±5kJmol–1 and was not affected by the presence of inhibitor. The inhibitory action occurs by -bonding between the adsorbed inhibitor molecules and the electrode surface. The electrode coverage follows the Langmuir adsorption isotherm with an adsorption equilibrium constant K=1.1–2.64×105dm3mol–1. The adsorption of organic compound prevents the adsorption of chloride ions and slow down the rate of corrosion.     

Preparation, characterization and mechanical properties of epoxidized soybean oil/clay nanocomposites

New epoxidized soybean oil (ESO)/clay nanocomposites have been prepared with triethylenetetramine (TETA) as a curing agent. The dispersion of the clay layers is investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM data reveal the intercalated structure of ESO/clay nanocomposites has been developed. The thermogravimetric analysis exhibits that the ESO/clay nanocomposites are thermally stable at temperatures lower than 180 °C, with the maximum weight loss rate after 325 °C. The glass transition temperature, T_g, about 7.5 °C measured by differential scanning calorimetry (DSC) and T_g about 20 °C measured by dynamic mechanical study have been obtained. The difference in the T_g between DSC and dynamic measurements may be caused by different heating rate. The nanocomposites with 5-10 wt% clay content possess storage modulus ranging from 2.0×10⁶ to 2.70×10⁶ Pa at 30 °C. The Young's modulus (E) of these materials varies from 1.20 to 3.64 MPa with clay content ranging from 0 to 10 wt%. The ratio of epoxy (ESO) to hydrogen (amino group of TETA) greatly affects dynamic and tensile mechanical properties. At higher amount of TETA, the nanocomposites exhibit stronger tensile and dynamic properties.     

Marginal operation field of existing MSF distillation plants

The capability of existing MSF distillation desalination plants to increase or decrease production by increase or decrease of top brine temperature and brine recirculating flow rate, is technologically limited. The factors which limit the process were analyzed and compared in a practical test carried out on a 4546 m³/d production plant. The brine levels in evaporator stages were calculated and measured to avoid the vapour blowthrough between the stages and to insure the dynamic stability of the plant. There was an increase of 20% in production at 94% of the design brine flow rate, and a top brine temperature 16.6°C greater than the design value before reaching the unsealing limit.     

Corrosion-resistant ceramics and polymer composites based on the BaO-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-SiO<Subscript>2</Subscript> system

This paper reports on the results of investigations aimed at synthesizing ceramic materials with a high mechanical strength, as well as with high thermal and chemical resistances to corrosive media. The methods used for one-stage preparation of barite-based ceramic and polymer composites with these properties are considered.