Catalysis of Active Carbon Supporting Transition Metal Oxides for Pyrotechnical Reagent with Potassium Perchlorate

In order to improve the pyrotechnical reagent with potassium perchlorate,composite catalyst of active carbon supporting transition metal oxides (TMO),Fe2O3 and CuO,were prepared and added into pyrotechnical reagent with potassium perchlorate.Accelerating rate calorimeter (ARC) was used to study the catalysis of pyrotechnical reagent which is consisted of potassium perchlorate and composite catalyst.Composite catalyst of both Fe2O3 and CuO supported by active carbon can catalyze pyrotechnical reagent with potassium perchlorate.Furthermore,it can lower the apparent activation energy and accelerate the reaction with a smaller quantity than that with Fe2O3 and CuO.The maximal reaction rate of pyrotechnical reagent with potassium perchlorate mixed with Fe2O3/active carbon and CuO/active carbon is 8.31 min-1 and 9.13 min-1,which is 1.74 times and 1.91 times of pyrotechnical reagent mixed with no catalyst;time to maximal rate was 18.99 min and 1.96 min respectively,which is lower than pyrotechnical reagent mixed with no catalyst by 86.46% and 98.67% ;the apparent activation energy is 368.10 kJ·mol-1 and 325.29 kJ·mol-1,which is lower than pyrotechnical reagent mixed with no catalyst by 31.89% and 39.81% respectively.     

Synthesis of Li2Fe0.9Mn0.1SiO4/C composites using glucose as carbon source

Li2Fe0.9Mn0.1SiO4/C composites were synthesized by using glucose as carbon source. The samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and electrochemical measurements. All Li2Fe0.9Mn0.1SiO4/C composites are of the similar crystal structure. With increasing the carbon content in the range of 5%-20% (mass fraction), the diffraction peaks in XRD patterns broaden and the particle sizes and the tap density of samples decrease. The Li2Fe0.9Mn0.1SiO4/C composites with carbon content of 14.12% show excellent the capacity retention remains 92.2% after 30 cycles.     

Carbon spheres prepared via solvent-thermal reaction method and their microstructures after high temperature treatment

Carbon spheres with size of 50–300 nm were synthesized via a solvent-thermal reaction with calcium carbide and chloroform as reactants in a sealed autoclave. The morphologies and microstructures of carbon spheres before and after high temperature treatment (HTT) were characterized by X-ray diffractometry (XRD), scanning electronic microscopy (SEM), energy diffraction spectroscopy (EDS), and transmission electron microscopy (TEM). The formation mechanism of carbon spheres was discussed. The results indicate that the carbon spheres convert to hollow polyhedron through HTT. Carbon spheres are composed of entangled and curve graphitic layers with short range order similar to cotton structure, and carbon polyhedron with dimension of 50–250 nm and shell thickness of 15–30 nm. The change of solid spheres to hollow polyhedron with branches gives a new evidence for formation mechanism of hollow carbon spheres.     

载铜活性炭催化剂-微波法联用处理黄姜皂素废水

以硝酸铜为活性成分材料制备活性炭载体催化剂,采用载铜活性炭-微波联用的废水处理工艺,对黄姜皂素废水的COD降解效果进行了研究,并考察了催化剂用量、微波功率、微波处理时间、水样pH值、催化剂使用次数等影响因素。结果表明：在载铜活性炭的催化作用下,微波辐射处理能使黄姜生产皂素废水的COD迅速降低,去除率达到60%左右,明显优于单纯载铜活性炭或微波的处理效果。     

Longitudinal surface cracks of thin slabs

Based on the production practice of medium carbon thin slabs in the CSP plant,the reasons and influencing factors for the formation of longitudinal cracks were investigated,and some industrial measures were taken to eliminate the cracks.The results show that the efficient solutions to reduce longitudinal cracks are improving the performance of the mold powder,stabilizing the mold heat flux,and maintaining a proper taper of the mold during casting.Proper pouring temperature and secondary cooling also play...     

Decarburization rate of RH refining for ultra low carbon steel

The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operating conditions.According to the apparent decarburization rate constant (KC) calculated by the carbon content in the samples taken from the hot melt in a ladle at an interval of 1-2 min,it is observed that the total decarburization reaction period in RH can be divided into the quick decarburization period and the stagnant decarburization period,which is quite different from the tradit...     

Precipitation and stability of reversed austenite in 9Ni steel

A new method was used to analyze the factors affecting the precipitation of reversed austenite during tempering. The samples were kept at various tempering temperatures for 10 min and their length changes were recorded. Then, the precipitation of reversed austenite which led to the length reduction was shown by thermal expansion curves. The results show that the effects of process parameters on the precipitation of reversed austenite can be determined more accurately by this method than by X-ray diffraction...     

Removal characteristics of disinfection by-products formation potential by bioaugmentation activated carbon process

The high-active bacteria were screened from 8 dominant bacteria obtained from the natural water body,and then the bioaugmentation activated carbon was formed by hydraulic immobilization of the high-active bacteria. Plant-scale studies on removal characteristics of disinfection by-products formation potentials (DBPFP) by bioaugmentation activated carbon process were conducted for micro-polluted raw water treatment. The results show that the bioaugmentation activated carbon process has adopted better purification efficiency to THMFP and HAAFP than traditional biological activated carbon process,and that average removal efficiencies of THMFP and HAAFP can reach 35% and 39.7% during the test period,increasing by more than 10% compared with traditional biological activated carbon process. The removal efficiencies of THMFP and HAAFP are stable because of the biodegradation of the high-active bacteria and the adsorption of active carbon. The biodegradability of CHCl3 formation potential is better as compared with that of CHCl2Br and CHClBr2 formation potentials among THMFP,and high removal efficiency of CHCl3formation potential is obtained by bioaugmentation degradation of the high-active bacteria. The biodegradability of HAAFP is better in comparison with that of THMFP,and the chemical properties of HAAFP are propitious to adsorption of activated carbon. Thus,HAAFP is on predominance during the competitive removal process with THMFP.     

Si(111)上生长LiNbO_3薄膜的研究

利用射频磁控溅射的方法,在Si(111)衬底上制备了LiNbO3薄膜。采用X射线衍射(XRD)和扫描电子显微镜(SEM)研究了衬底温度、退火温度和溅射气体压强对LiNbO3薄膜结晶和表面形貌的影响,并用椭圆偏振仪测量了薄膜的厚度和折射率。结果表明:衬底温度为450℃时制备的薄膜,退火前后都没有LiNbO3相生成;衬底温度为500～600℃时,LiNbO3薄膜出现(012)、(104)和(116)面衍射峰,经600℃退火后3个衍射峰的强度加强;衬底温度为600℃时,经600～900℃退火得到的LiNbO3薄膜,除出现(012)、(104)和(116)面衍射峰外,还出现(006)面衍射峰;溅射气体压强从0.8 Pa增大到2.4 Pa时,经800℃退火后得到的LiNbO3薄膜表面晶粒团簇变小,而0.8 Pa制备的薄膜经800℃退火后LiNbO3相的结晶程度较其它压强下完善;900℃退火后得到的LiNbO3薄膜折射率为2.25,与LiNbO3晶体相当。     

纳米碳管的非线性热电传输

利用Landauer-Büttiker公式对金属导线/单臂纳米碳管/金属导线结构的热电传输进行理论计算.在有限温度梯度下,利用迭代法计算非线性热电势和热电导,研究表明,热电势和热电导与系统电子的传输行为密切相关,热电势随系统化学势的变化而振荡,且可为正也可为负值,这种行为完全依赖于电子电导的变化.研究结果对分子器件热传输的实际应用有意义.