硼系润滑油添加剂在线表层改性行为试验研究

通过对纳米硼酸镧及有机硼酸酯两种稀土润滑油添加剂摩擦学性能的试验研究 ,发现该类添加剂能诱发稀土金属渗入摩擦副表层中 ,形成一种同摩擦副机体性能、结构不同的摩擦学特性层即表面改性层 ,从而使得摩擦副的摩擦学性能得到提高。结合磨损表面能谱分析 ,对磨损表面表层结构作了进一步分析 ,并从理论上分析了该种改性层的形成机理。试验结果表明 :硼系润滑油添加剂能实现表面在线改性 。

Investigation on Modification of NaY Zeolite and Its Behaviors in Selective Adsorptive Desulfurization of FCC gasoline

NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase ion exchange between NaY zeolite and cerium nitrate. The performance of two Y zeolites [Ce(IV)Y(1) and Ce(IV)Y(2)] was compared through static selective adsorptive desulfurization of FCC gasoline at room temperature and normal pressure. The sulfur compounds and contents of the FCC gasoline were analyzed by microcoulometry and GC-SCD chromatogram. The results showed that the effect of adsorptive desulfurization of FCC gasoline achieved by Ce(IV)Y(1) zeolite was better than that of Ce(IV)Y(2) zeolite. The rate for adsorptive desulfurization of FCC gasoline by Ce(IV)Y(1) zeolite and Ce(IV)Y(2) zeolite was 85.0% and 62.4%, respectively. The Ce(IV)Y(1) zeolite could adsorb DMTs, which could not be adsorbed by Ce(IV)Y(2) zeolite. The rate of regeneration of extruded Ce(IV)Y(1)zeolite was 95.5%.

Adsorption Behavior of Methyl Orange onto Modified Ultrafine Coal Powder

The adsorption of methyl orange onto ultrafine coal powder （UCP） and modified ultrafine coal powder （MUCP） from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of △G^0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ·mol^-1 at 303, 313, and 323 K, respectively. The values of △H^0 and △S^0 are -3.74 kJ· mol^-1 and 61.99 J·mol^-1, respectively. The adsorption process is spontaneous and exothermic.

Behavior of phenol adsorption on thermal modified activated carbon

Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon （AC） samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.

Surface modification of ZrO_2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy （EIS）. Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.

Membrane behavior of bentonite-amended Fukakusa clay in K, Na and Ca solutions

Bentonite has been proven to be effective in enhancing the membrane property of clay, by which landfill liners can have better barrier performance with regard to the migration of contaminants. In this work, 5% sodium bentonite amended with locally available Fukakusa clay was utilized to evaluate the membrane behavior toward different kinds of ions： K, Na and Ca. The chemico-osmotic efficiency coefficient, co, was obtained in electrolyte solution with different concentrations of 0.5, 1, 5, 10, and 50 mmol/L. According to the results, solute type and ion valence have a significant effect on membrane behaviors. Additionally, co continually decreased as the Na and Ca concentrations increased, which is consistent with the Gouy-Chapman theory. The membrane behavior toward Na was similar to that toward K, according to the chemico-osmotic efficiency coefficient co. In the case of the divalent ion Ca, the membrane behavior was lower compared to monovalent ions Na and K at the same concentration. The mechanisms of the membrane performance change were discussed with the assistance of XRD patterns, free-swelling results and SEM images.

碳纳米管增强镍磷基复合镀层研究

对CVD方法制备的碳纳米管进行表面改性处理 ,然后在液相中分散 ,利用化学共沉积方法形成碳纳米管镍磷基复合镀层 ,研究了碳纳米管表面改性后的红外谱、碳纳米管复合镀层的表面形貌、硬度及摩擦学行为 .结果表明 :碳纳米管的加入明显地提高镍磷复合镀层的硬度和改善了镍磷复合镀层的摩擦性能 .硬度达到 94 6HV ,2 0N载荷时摩擦系数为 0 7,增至 80N时降为 0 6 ;相同条件下与传统耐磨材料SiC增强的镍磷基复合镀层相比 。

Simulation of triaxial response of granular materials by modified DEM

A modified discrete element method(DEM)with rolling effect taken into consideration is developed to examine macroscopic behavior of granular materials in this study.Dimensional analysis is firstly performed to establish the relationship between macroscopic mechanical behavior,mesoscale contact parameters at particle level and external loading rate.It is found that only four dimensionless parameters may govern the macroscopic mechanical behavior in bulk.The numerical triaxial apparatus was used to study their influence on the mechanical behavior of granular materials.The parametric study indicates that Poisson’s ratio only varies with stiffness ratio,while Young’s modulus is proportional to contact modulus and grows with stiffness ratio,both of which agree with the micromechanical model.The peak friction angle is dependent on both inter-particle friction angle and rolling resistance.The dilatancy angle relies on inter-particle friction angle if rolling stiffness coefficient is sufficiently large.Finally,we have recommended a calibration procedure for cohesionless soil,which was at once applied to the simulation of Chende sand using a series of triaxial compression tests.The responses of DEM model are shown in quantitative agreement with experiments.In addition,stress-strain response of triaxial extension was also obtained by numerical triaxial extension tests.

Cross-cultural adaption and psychometric properties of the Chinese version of the Diabetes Behavior Rating Scale: a pilot study

Self-care behavior plays a major role in diabetic management. However, in China, a satisfactory instrument has not yet been developed to evaluate the compliance of self-care behavior for young patients with type 1 diabetes mellitus （T 1DM）. The Diabetes Behavior Rating Scale （DBRS） has a potential to be the first mature instrument. The purpose of this study is to cross-culturally adapt the DBRS, and preliminarily evaluate its psychometric properties. The instrument translation included translation, back translation and culture adaptation. Psychometric properties were assessed in a sample of 116 young patients with T1DM adapting insulin injection therapy. The Chinese version of the DBRS was divided to four subscales. Cronbaeh＇s α for the total scale was 0.92. The mean inter-item and item-total correlations were 0.35 and 0.54 respectively. Test-retest reliability showed good temporal stability （r=0.81, P=0.001）. Negative correlations were found between DBRS scores with the Diabetes Distress Scale scores （r=-0.32, P=-0.003） and hemoglobin Ale （HbAlc） levels （r=-0.36, P=0.002）. Higher DBRS scores correlated with better glycemic control. The Chinese insulin injection therapy version of the DBRS is well translated and culturally adapted. It shows good overall reliability and validity and appears to be a valuable tool for assessing the diabetic self-care behaviors for young patients with T 1DM.

Bio-inspired smart gating nanochannels based on polymer films

In this review we have summarized some recent results mainly reported by our group that focused on the development of smart gating nanochannels based on polymer films. These nanochannels were prepared using a track-etch process. The responsive materials/molecules and modification methods/techniques have also been demonstrated, from which we have obtained a series of smart gating nanochannels that can respond to single/dual external stimuli, e.g., pH, ion, temperature, light, and so on. These studies utilize responsive behaviors to regulate ionic transport properties inside a single nanochannel and demonstrate the fea-sibility of designing other smart nanodevices in the future.

Mechanical and thermal properties of polypeptide modified hydroxyapatite/poly(L-lactide) nanocomposites

A new type of polypeptide(poly(-benzyl-L-glutamate)(PBLG))modified hydroxyapatite(HA)/poly(L-lactide)(PLLA)nanocomposites(PBLG-g-HA/PLLA)were prepared by the solvent-mixing method,and their mechanical and thermal properties were investigated.The tensile test showed that the mechanical properties of PBLG-g-HA/PLLA nanocomposites were better than that of PLLA,even a 0.3 wt%content of PBLG-g-HA in the nanocomposites could make the tensile strength 12%higher than that of the neat PLLA sample,and the tensile modulus was about 17%higher than that of the PLLA sample.The thermal gravimetric analysis(TGA)showed that the PBLG-g-HA/PLLA composites have better thermal stability than the PLLA sample.The differential scanning calorimetry(DSC)was used to characterize the effect of PBLG-g-HA on the crystallization of PLLA.The isothermal crystallization behavior showed that the half crystallization time(t1/2)of PBLG-g-HA/PLLA was much shorter than that of the PLLA sample.When the PBLG-g-HA content was 10%,t1/2 was only 18.7 min,while t1/2 of the PLLA sample was 61.4 min.The results showed that the PBLG-g-HA worked as a nucleating agent and enhanced the crystallization speed of PLLA.

Law, Ethics and Gender： China＇s Quest for a Modern Selfhood as Reflected in its Adaptations of Ibsen＇s A Doll＇s House

In this paper, I will discuss Chinese adaptations of A Doll＇s House as a point of departure to see how problems arise when the self and the behaviour of a person is defined in legal terms at the expense of moral motives and how men and women have different concepts of law and morality. Gender issues in the formation of selfhood and philosophical concepts of behavioural ＂performativity＂ will be examined in the context of China＇s experimentations in projecting new concepts of womanhood and the female self. As a context, I will also outline some of the changes in cultural values and ethical categories in China over the past century, so as to see why the individualist conception of the self has played such a paramount important role in China＇s quest for modernity.

Isothermal crystallization of polypropylene/surface modified silica nanocomposites

In the present work, 3-methacryloxypropyltrimethoxy-silane silanized silica （SiO2-WD70） and 9,10-dihydro-9-oxa-10-phospha- phenanthrene-10-oxide immobilized silica （SiO2-WD70-DOPO） nanoparticles were prepared. Silica, SiO2-WD70 and SiO2- WD70-DOPO were incorporated into polypropylene （PP） by melt compounding. Differential scanning calorimetry （DSC）, X-ray diffraction （XRD） and polarized optical microscopy （POM） were employed to investigate the isothermal crystallization behavior of PP and PP/silica composites. The kinetic constant （kn）, and half crystallization time （t1/2） were calculated by Avrami equation, while the surface free energy of folding was calculated by Lauritzen-Hoffman theory. The increased k,, decreased t1/2 and the surface free energy （ere） in the order ofPP, PP/SiO2, PP/SiO2-WD70 and PP/SiO2-WD70-DOPO nanocomposites were attributed to the surface modification of silica. XRD indicated that SiO2-WD70-DOPO addition had no effect on PP crystal structure but accelerated the crystallization rate. POM determined that SiO2-WD70-DOPO addition promoted the nucleation of PP by inducing a higher nucleation density during isothermal conditions. The surface modified nanoparticle SiO2-WD70-DOPO might find possible application as a new type of inorganic nano-sized nucleation agent for PP.