Effect of additives on properties of aluminium titanate ceramics

The influence of some additives on bulk density,phase composition,mechanical strength and thermal shock resistance of aluminium titanate （AT） ceramics was investigated.AT ceramics with different additives of MgO,SiO2 and Fe2O3 were prepared by reaction sintering.Properties of AT ceramics were tested by using Archimedes,three-point bending and thermal cycling tests.It was found that additives of MgO,SiO2 and Fe2O3 or their compound additives are favorable to reduce the porosities of AT,enhance mechanical strength and thermal shock resistance.The role of additives can be rationalized in terms of promotion of sintering process,formation of new phases and influence on lattice constant c of AT ceramics.

Microstructure and mechanical properties of ceramic coatings formed on 6063 aluminium alloy by micro-arc oxidation

The microstructure and mechanical properties of ceramic coatings formed on 6063 aluminium alloy obtained in silicate-,borate- and aluminate-based electrolyte without and with nanoadditive Al2O3 and TiO2 by micro-arc oxidation（MAO） were studied by scanning electron microscopy（SEM）,energy-dispersive X-ray spectroscopy（EDS）,X-ray diffraction（XRD）,microhardness and friction-abrasion tests,respectively.SEM results show that coatings with nanoadditive have less porosities than those without nanoadditive.XRD results reveal that nanoadditive-containing coatings contain more oxides compared with nanoadditive-free coatings in all cases,which are consistent with the EDS analysis.Mechanical properties tests show that nanoadditive Al2O3-containing coatings have higher microhardness values compared with the other coatings obtained in silicate-,borate- and aluminate-based electrolyte.On the other hand,nanoadditive has a positive effect on improving the wearing-resistance of MAO coatings in all cases.Furthermore,the borate-MAO coatings present an inferior anti-wearing property compared with the silicate- and aluminate-MAO coatings for both the nanoadditive-free and nanoadditive-containing coatings.

其它书讯

联合国环境规划署:地中海海洋环境现状;MAP技术报告系列No.28,联合国环境规划署,雅典（1989）;225页 联系地址:Co-ordinating Unit for the MediteranenAction an,UNEP,Leoforos Vassileos Konstantinou48,P.O.Box 18019,1161O Athens,Greece经济合作与发展组织（OECD）环境专著No.27:化学品环境接触评价方法大纲OECD环境局（1989年7月）,350页。 联系地址（英语和法语）:Environment Directora- te,OECD,2 rue André-Pascal,75775 Paris cedex 16,France工业与发展:全球发展1989/90联合国工业发展组织（1989）;323页 联系地址:The Documents Unit F-335N,UNIDO,P.O.Box 300,A-1400 Vienna。

Effects of Ti-based additives on Mg_2FeH_6 dehydrogenation properties

Mg2FeH6 doped with and without Ti and its alloys (TiMn2, TiAl) were prepared combing ball milling and heat treatment. The effects of these additives on the dehydrogenation performance of Mg2FeH6 were studied systematically. The results show that all additives have favor influence on improving the hydrogen desorption property of Mg2FeH6. Especially, TiMn2 exhibits prominent effect on enhancing the dehydrogenation kinetics of Mg2FeH6. Moreover, the activation energy of TiMn2-doped Mg2FeH6 calculated by Kissinger equation is 94.87 kJ/mol, which is 28 kJ/mol lower than that of the undoped Mg2FeH6. The cycling tests suggest that the improved dehydrogenation kinetics of Mg2FeH6 doped by TiMn2 can maintain in the second cycle.

Effects of La-Ce addition on microstructure and mechanical properties of Al-18Si-4Cu-0.5Mg alloy

The microstructural evolution and mechanical properties of Al-18 Si-4 Cu-0.5 Mg alloy modified by the addition of La-Ce rare earth elements through OM,SEM,EPMA and tensile tests were investigated.The results of OM and SEM analyses indicated that primary Si particles were significantly refined from coarse block-like and irregular polygonal shapes into fine flaky shapes,while eutectic Si particles were modified from coarse and needle-like into fine and rod-or coral-like shapes with increase of La-Ce addition.The alloy exhibited the minimum primary Si particle size and the best mechanical properties with the addition of 0.3 wt.%La-Ce.The average particle size decreased from 61 to 28 μm,the ultimate tensile strength increased from 222 to 242 MPa and the elongation increased from 3.2% to 6.3%.In addition,modification mechanisms and fracture modes were explored by the means of SEM and EPMA.

Mechanical behavior and microstructural mechanism of improved disintegrated carbonaceous mudstone

This study aims to improve the mechanical behavior of disintegrated carbonaceous mudstone, which is used as road embankment filler in southwestern China. Triaxial tests were performed on disintegrated carbonaceous mudstone modified by fly ash, cement, and red clay. Then the stress-strain relationships and shear strength parameters were analyzed. The microstructure and mineral composition of the materials were identified via scanning electron microscopy and X-ray diffraction. The results show that the stress-strain relationships changed from strain-hardening to strain-softening when disintegrated carbonaceous mudstone was modified with cement. By contrast, the addition of fly ash and red clay did not change the type of stress-strain relationships. The order of these three additives is cement, red clay and fly ash according to their influences on the cohesion. Disintegrated carbonaceous mudstone without cement all showed bulging failures, and that modified with cement exhibited shear failures or bulging-shear failures. The soil particles of the improved soil were well bonded by cementitious substances, so the microstructure was denser and more stable, which highly enhanced the mechanical behavior of disintegrated carbonaceous mudstone. The findings could offer references for the use of carbonaceous mudstone in embankment engineering.

Synergistic effect of additives on electrodeposition of copper from cyanide-free electrolytes and its structural and morphological characteristics

Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction ofcopper on mild steel.This can be avoided by using a proper complexing agent,because the complexing agent tuned the potential ofnoble direction to less noble direction by complex formation.In this paper,environment friendly electrodeposition of copper fromnon-cyanide electrolyte using sodium gluconate as complexing agent was investigated in alkaline medium.The effects of additivessuch as1,2,3-benzotriazole,sodium lauryl sulphate,PEG8000and saccharin were studied.These additives are found to reduce thegrain size,grain boundaries and improve surface morphology of the copper deposits.Also they improve the throwing power of thedepositing electrolytes and hardness of deposits.The electrodeposited copper coatings were characterized by X-ray diffractiontechnique.XRD results indicate that the electrodeposited copper shows polycrystalline and face centered cubic structure.The crystalsize was calculated by XRD and AFM analysis.Among these additives studied,the mixture of benzotriazole and sodium laurylsulphate acts as the best additive.A uniform pore-free surface observed under SEM and AFM results reveal the grain refining broughtabout by the additives.

PREPARATION OF ACTIVATED CARBON FROM TWO CHINESE ANTHRACITES IN THE PRESENCE OF OXIDATIVE ADDITIVES

This paper broke with the conventional ways of oxidizing and catalyzing. It researched a new way to prepare activated carbon from anthracites which employed oxidative additives. It investigated the effects of the additive on adsorption and activation rate of the resultant activated carbon. The results showed that the new additives not only improved the adsorptivity but also increased the activation rate greatly, which is able to decrease the preparation cost.

Effect of different additives on the phase separation behavior and thermodynamics of p-tert-alkylphenoxy poly (oxyethylene) ether in absence and presence of drug

Cloud point （CP） determinations of 4-（1,1,3,3-tetramethylbutyl）phenyl-polyethylene glycol （TX-100 （nonionic surfactant）） was carried out in aqueous as well as in the attendance of drug （ceftriaxone sodium trihydrate （CFT））/（CFT ＋ different inorganic salts） and discussed thoroughly. Nonionic surfactants are employed exten- sively in different formulations. In aqueous solution, the values of CP of TX-100 are obtained to increase by means of enhancing of their concentration in the solution. The CP values of TX-100 solutions were found to de- crease in the presence of drug and their values decrease more with rising concentrations of the drug. The values of CP of CFT and TX-100 mixtures were found to further decrease in the attendance of inorganic salts in compar- ison to their absence. The effect of different sodium salts in decreasing CP values of TX-100 was achieved in the following order： NaCO3 〉 Na2SO4 〉 NaCl. However, in the case of potassium and ammonium salts, the decreasing order obtained is K2SO4 〉 KCO3 〉 KCI and （NH4）2SO4 〉 Na2CO3 〉 NH4Cl respectively. Various thermodynamic pa- rameters for example standard free energy （△G c）, standard enthalpy （△H c） as well as standard entropy （△S c） changes of phase separation were also evaluated and discussed in detail on the basis of their behavior.

A study on abnormal temperature variation of the earthquake in Jiujiang, China （2005） according＇to additive tectonics stress

A variation model of additive tectonics stress caused by celestial tide-generating force is put forward to explain its relationship with seismic fault sliding. Based on the model, the temperature data from National Center for Environmental Prediction （NCEP） before and after the earthquake in Jiujiang （China） on Nov.26, 2005 are studied. The figure of the temperature variation describes the effect of celestial tide-generating force on fault plane. The variation＇of temperature is not only associated with the seismic deformation but also in step with the evolution of fi＇iction of rock under the stress. The abnormal change of temperature can be used in the studies of short- impending earthquakes.

Extraction of Dietary Fiber from Wheat Bran and Effects of Its Additives on Viscosity-elasticity of Noodle Dough

[ Objective] The aim was to study the optimum extraction condition of dietary fiber of wheat bran and to discuss its influence on viscosity-elasticity of noodle dough with added extracts. [ Methed] Influences of a-amylase, alkaline concentration, alkaline hydrolysis time and temperature on water holding capability and swelling capacity of dietary fiber were evaluated using single-factor test and orthogonal test. Effects of added dietary fiber from wheat bran on dough absorption ratio, rupture stress of dough and creep resistance were studied. [ Result] When the hydrolysis condi-tions of wheat bran were 0.4% a-amylase at 75 ℃ for 60 rain, further alkaline conditions were 5% sodium hydroxide for 60 min at 65 ℃, dietary fi-ber exhibited fine water holding capability and swelling capacity. The addition of 3%-5% dietary fiber from wheat bran into dough had little influence on the water absorption ratio of noodle, rupture stress of dough, creep resistance and can make functional noodle with rich dietary fiber from wheat bran. [Coonclusion] The study provided reference for the comprehensive utilization of wheat bran and development of functional product.

Sorbitol Hydrogenolysis to Glycols over Baisic Additive Promoted Ni-based Catalysts

A series of Ni based catalysts with different supports and basic additives were prepared by sequential impregnation method. The catalysts were characterized by XRD, BET, H2-TPR and CO2-TPD techniques. It was found that the introduction of basic additives enhanced the basicities of catalyats and promoted the dispersities of Ni particles by strong interaction between Ni2＋ and basic additives. Among the Ni based catalysts, 10%Ni/10%La203/ZrO2 showed the superior performance in sorbitol hydrogenolysis. The synergistic effect of Ni and La203 was proven to play an essential role in selective synthesis of EG and 1,2-PG. In the optimal reaction condition, the catalyst presented 100% sorbitol conversion and over 48% glycols （EG and 1,2-PG） yield. The kinetics study of polyols （sorbitol, xylitol and glycerol） hydrogenolysis showed that polyols with more hydroxyl number have higher activity and products distribution was final results of kinetic balance, which could give us some inspiration abeut how to change the products selectivity.

Lubricant Biodegradation Enhancers: Designed Chemistry and Engineered Technology

In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a specific field of green chemistry and green engineering. Enhancement of biodegradability of unreadily biodegradable petroleum-based lubricants has as such become an urgent must. For over a decade the authors have been focusing on the improvement of biodegradability of unreadily biodegradable lubricants such as petroleum-based lubricating oils and greases. A new idea of lubricant biodegradation enhancer was put forward by the authors with the aim to stimulate the biodegradation of unreadily biodegradable lubricants by incorporating the enhancer into the lubricants in order to turn the lubricants into greener biodegradable ones and to help in situ bioremediation of lubricant-contaminated environment. This manuscript summarizes our recent efforts relating to the chemistry and technology of biodegradation enhancers for lubricants. Firstly, the chemistry of lubricant biodegradation enhancers was designed based on the principles of bioremediation for the treatment of hydrocarbon contaminated environment. Secondly, the ability of the designed biodegradation enhancers for increasing the biodegradability of unreadily biodegradable industrial lubricants was investigated through biodegradability evaluation tests, microbial population analysis, and biodegradation kinetics modeling. Finally, the impact of biodegradation enhancers on some crucial performance characteristics of lubricants such as lubricity and oxidation stability was tested via tribological evaluation and oxidation determinations. Our results have shown that the designed chemistry of nitrogenous and/or phosphorous compounds such as lauroyl glutamine, oleoyl glycine, oleic diethanolamide phosphate and lauric diethanolamide borate was outstanding in boosting biodegradation of petroleum-based lubricants which was ascribed to increase the microbial population and decrease the oil-water interfacial tension during the biodegradation process. Lubricants doped with the biodegradation enhancers exhibited much better biodegradability and higher biodegradation rate in the surrounding soils which could be well modeled by the exponential biodegradation kinetics. Furthermore, as lubricant dopants, the biodegradation enhancers also provided excellent capability in reducing friction and wear and in retarding oxidation of lubricants. In the nature of things, lubricant biodegradation enhancers, which are multi-functional not only in the improvement of biodegradability, but also in the fortification of lubricity and in the inhibition of oxidation of lubricants, are expected to be promising as a new category of lubricant additives.

Digital Manufacturing： What Are We Able to Print？

In a rational exercise, in the present paper it is extrapolated how the development of ICTs （information and communication technologies） and the incipient technological development of additive manufacturing has the potential to change our society. In the following, it is analyzing the evolution of man over physical matter and how this has shaped our society. The main milestones or key stages in history that have marked a transcendental change in the human-machine-environment relationship have been identified and consequently have led us to ask ourselves： What is next, how far are we, and what are we capable of printing？ In an attempt to identify the current state of the art, highlighting the possibilities those additive technologies can offer.

Thermal Analysis of Composite Cements

The hydration of cement compounds gives hydrated compounds, which allow linking together, the different particles and aggregate of cement, and gives the concrete the required qualities. The dynamics of hydration reactions will depend on many factors, such as the fineness of cement, the ratio w/c during hydration, temperature, mixing technique, and the presence of additives in blended cement, as pozzolan, tuff and slag from blast furnaces. We studied the thermal and kinetic reactions of Portland cement hydration, and its variants with different additions using a differential scanning calorimetric analysis. The parameters from these models of curves allow us to evaluate the enthalpies, and the degree of progression of this blended cement, and finally determine their activation energies. We can say that the hydration of Portland cement is due to a series of reactions as （ C3S,C2S,C3A and C4AF reactions with water） and each of them, has its own kinetic, the experimental measurement of the heat of hydration, allows us to represent the overall kinetics of these reactions values of activation energy, they are therefore apparent and global energy. In our experiments, significant differences in these physicochemical parameters were observed, depending on the additive used.

Pricing and Inventory Control Strategy for a Periodic-Review Energy Buy-Back System

Along with the rapid development of economics and enhancement of industrialization, the power demand keeps rising and frequently creates mismatch between demand and supply in electricity.This provides miscellaneous energy buy-back programs with great opportunities. Such programs, when activated, offer certain amount of financial compensations to participants for reducing their energy consumption during peak time. They aim at encouraging participants to shift their electricity usage from peak to non-peak time, and thereby release the demand pressure during peak time. This paper considers a periodic-review joint pricing and inventory decision model under an energy buy-back program over finite planning horizons, in which the compensation levels, setup cost and additive random demand function are incorporated. The objective is to maximize a manufacturer's expected total profit.By using Veinott's conditions, it is shown that the manufacturer's optimal decision is a state dependent(s, S, P) policy under a peak market condition, or partly an(s, S, A, P) policy under the normal market condition.

Car capacity near bus stops with mixed traffic derived by additive-conflict-flows procedure

To determinate car capacity at bus stops with mixed traffic, a new theoretical approach was developed on the basis of additive-conflict-flows procedure. The procedure was extended from homogeneous traffic flow to mixed traffic flow. The conflicts among cars, buses and bicycles near the stop can be described by the extended procedure. The procedure can be understood more easily than the theory of gap acceptance. Car capacity near the stop is the function of both bus stream and bicycle stream. The proposed model can also analyze the cases of pedestrian effects and limited priority of bicyclists. Numerical results show that the car capacity decreases with the increasing flow rates of other streams. In addition, pedestrian effects and bicyclist's limited priority have negative effects on car capacity near bus stops with mixed traffic flow.