STUDY ON MINE FIRE-RESISTANT OPTICAL FIBER CABLE KL5004

This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficiency mine.

Composites Based on GM(1,1)-Markov in the Salt Spray Corrosion Environment

This study was designed to solve the problem of magnesium hazards due to potash extraction in the salt lake region.Using basalt fiber(BF)as the reinforcement material and magnesium oxychloride cement(MOC)as the gelling material,a BF/MOC composite material was prepared.Firstly,the effect of BF addition content on the basic mechanical properties of the composites was investigated.Then,through the salt spray corrosion test,the durability damage deterioration evaluation analysis was carried out from both macroscopic and microscopic aspects using mass change,relative dynamic modulus of elasticity(RDME)change,SEM analysis and FT-IR analysis.Finally,a GM(1,1)-Markov model was established to predict the durability life of composite materials by using durability evaluation indicators.The results show that:when the BF content is 0.10%(by volumetric content),the composites have the best mechanical properties and resistance to salt spray corrosion.However,when the volume of BF content exceeds 0.10%,a large number of magnesium salt crystallization products are observed from the microscopic point of view,and the corrosion of the main strength phase of MOC is more serious.The prediction results of the GM(1,1)-Markov model are highly identical with the raw data.In addition,using the change of RDME as a predictor,RDME is more sensitive to environmental factor compared to the change of mass.Predictions using the change of RDME as a threshold indicate that MOC-BF0.10 has the longest durability life,which is 836 days.The model is important to promote the application of MOC composites in the salt lake region and to promote the healthy development of green building materials.

Biodegradable Polylactide-co-glycolide (PLGA) Thin Films Prepared by Electrospray and Pressurized Spray Deposition

PLGA thin films were prepared onto implantable devices by the electrospray and pressurized spray method. Thin films with structural gradients were obtained by controlling four parameters consisting of solution concentration, applied voltage, air pressure , and deposition time. The surface morphologies of the deposited films were observed using scanning electron microscopy （SEM）. The image analysis revealed the control factors on the preparation of PLGA thin films. The beaded structure is ensily formed with a decrease in polymer concentration while the fibrous structure is easily formed with an increuse in polymer concentration. With the increase in applied voltage, the surface morphologies changed continnously from a small amount of fibrous shape to a large fibrous one： a small amount of.fibrous shape at 10 kV, more fibers with non-uniform diameter at 20 kV, and most fibers with uniform diameter at 30 kV. Low air pressure（0.1 MPa ） corresponded to round particles while high air pressure （0.3 MPa ） corresponded to fiat particles. The change in thickness from 5.34 to 10.1μm was a result of deposition time increasing from 5 to 10 s. From our above work, films of the bead or fiber structures can be obtained by changing electrical parameters to impropvc tbe biocompntibility of the film.

High-temperature oxidation resistance of Si-coated C/SiC composites

In this paper,Si coatings were sprayed onto C/SiC composite substrates by atmospheric plasma spraying(APS).The high-temperature oxidation behavior of the substrate and coating at temperatures of 1100 and 1300℃was also studied.The C/SiC ceramic matrix composite will be damaged seriously and even failed due to the oxidation of carbon fibers in matrix.The Si coating effectively improved the oxidation resistance of the C/SiC substrate in the high-temperature oxidation test.The effect of the thickness of the Si coatings on the oxidation resistance was investigated.The 150-μm coating is proved to enable the substrate to have the lowest oxidation weight loss and the best oxidation resistance after static oxidation for 5 h.

Fire and Corrosion Resistances of Intumescent Nano-coating Containing Nano-SiO_2 in Salt Spray Condition

The nano-concentrates and flame retardant nano-coating were prepared in thhis study. The effect of nano-SiO2 on the corrosion resistance and fire resistance of ammonium polyphosphate-pentaerythritol-melamine （APP- PER-MEL） coating was investigated by differential thermal analysis （DTA）, scanning electron microscopy （SEM）, effective thermal conductivity （λ/d）, X-ray photoelectron spectroscopy （XPS） and fire protection test. The chemical action and endothermic effect of ammonium polyphosphate, pentaerythritol and melamine in traditional flame retardant coating were damaged by salt spray condition, whereas the flame-retardant additives in the nano-coating demonstrated the good chemical interaction in salt spray condition. The uniformly dispersed nano-SiO2 particles could improve corrosion resistance of the coating, and hence nano-coating could remain the good fire-resistant properties even after 500 h salt spray test.