Comparison of the Effect of a Hydrocarbon Oil and a Terpene Tackifier on the Autohesion of Styrene-Butadiene Rubber

Blends of uncrosslinked styrene-butadiene rubber (SBR) with a terpene tackifier resin or a naphthenic oil have been characterized, and their autohesion and cohesion determined using a T-peel geometry. SBR/oil blends are homogeneous at all proportions, while SBR/resin blends, based on DSC and DMA analysis, undergo bulk phase separation at about 50% resin. However, migration of tackifier to the surface region is proposed at much lower resin contents. Compositions diluted with oil have autohesion similar to the neat SBR. This is attributed to compensating effects; although oil hastens self-bond formation by increasing chain mobility, this is nearly equally balanced by more facile chain separation during bond rupture. In short, oil-diluted compositions are soft and weak. On the other hand, SBR compositions containing small amounts of resin have high autohesion. Resin-diluted specimens deform easily at low strain, just as those containing oil, but intertwined chains of the former have greater resistance to separation, due at least in part to higher glass transition temperatures. It is proposed that autohesion is further enhanced by migration of tackifier to the surface. This causes SBR/resin compositions to be both soft and strong-a necessary condition for high autohesion.     

导电高分子PEDOT／PSS保护银纳米颗粒的制备与表征

利用导电高分子聚（3，4-二氧乙基噻吩）／聚（对苯乙烯磺酸）（PEDOT／PSS）作保护剂，制备了银纳米颗粒，用UV-Vis和TEM对其进行了表征．结果表明，选择合适量的PEDOT／PSS保护剂可以得到大小分布较窄银纳米颗粒．     

化学气相沉积(CVD)炭/碳复合材料(C/C)研究现状

主要介绍了炭／炭复合材料（C／C）的化学气相沉积（CVD0制备方法及其影响因素，以及热解炭的组织与沉积机理。概括了VCD的基本方法，如等温法、压差法、热梯度法等。分析了温度、气流速率、气体浓度、预制体及孔隙的形状大小状况等对CVD过程的影响。列举了热解炭的组织，包括光滑层、粗糙层、各向同性体碳以及它们的变体，并对其生长特征及性能进行了较详细的描述。综述了热解炭的沉积机理，典型的有分子沉积、固态沉积、液滴沉积机理等。     

Characterization and Catalytic Properties of Combustion Synthesized Au/CeO2 Catalyst

Ceria-supported Au catalyst has been synthesized by the solution combustion method for the first time and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Au is dispersed as Au⁰ as well as Au³⁺ states on CeO₂ surface of 20-30 nm crystallites. On heating the as-prepared 1% Au/CeO₂ in air, the concentration of Au³⁺ ions on CeO₂ increases at the expense of Au⁰. Catalytic activities for CO and hydrocarbon oxidation and NO reduction over the as-prepared and the heat-treated 1% Au/CeO₂ have been carried out using a temperature-programmed reaction technique in a packed bed tubular reactor. The results are compared with nano-sized Au metal particles dispersed on -Al₂O₂ substrate prepared by the same method. All the reactions over heat-treated Au/CeO₂ occur at lower temperature in comparison with the as-prepared Au/CeO₂ and Au/Al₂O₂. The rate of NO + CO reaction over as-prepared and heat-treated 1% Au/CeO₂ are 28.3 and 54.0 mol g^-1 s^-1 at 250 and 300 °C respectively. Activation energy (E _a) values are 106 and 90 kJ mol^-1 for CO + O₂ reaction respectively over as-prepared and heat-treated 1% Au/CeO₂ respectively.     

SO2-4/La2O3-ZrO2催化合成亚油酸乙酯

将SO2-4/ZrO2负载镧制备了新型催化剂SO2-4/La2O3-ZrO2,以亚油酸和乙醇的酯化反应为探针,考察了不同制备条件对催化剂性能的影响,结果表明,La3+浸渍浓度为0.07 mol/L,经110℃烘干后于500℃焙烧3 h所得催化剂活性最好.采用正交实验法对影响酯化反应的因素进行考察,最佳实验条件为n(醇):n(酸)= 6:1,反应时间6 h,催化剂用量3%(亚油酸),酯化率可达93.7%.且该催化剂具有良好的重复使用和再生能力.     

线性多智能体系统一致性问题的部分稳定性方法（英文）

A linear transformation is proposed to deal with the consensus problem of high-order linear multi-agent systems(LMASs).In virtue of the linear transformation, the consensus problem is equivalently translated into a partial stability problem. We discuss three issues of the LMASs under a generalized linear protocol: 1) to find criteria of consensus convergence; 2) to calculate consensus function; 3) to design gain matrices in the linear consensus protocol. Precisely, we provide a necessary and sufficient criterion of consensus convergence in terms of Hurwitz stability of a matrix and give an analytical expression of the consensus function. In addition, we set up a relation between the gain matrices in the protocol and the convergence time and consensus accuracy of the agents, and then design the gain matrices with respect to a pre-specified convergence time and a required consensus accuracy.     

Single-phase gold/palladium catalyst: The nature of synergistic effect

The liquid phase oxidation of glycerol with oxygen has been studied using mono and bimetallic catalysts based on Au and Pd metals supported on activated carbon, in order to study the effect of the metal on the distribution of the products and on activity of catalysts. It was found that by using bimetallic catalysts (Au–Pd) a strong synergistic effect was shown. By using a preformed nucleating centre we were able to obtain a single alloyed phase, which allowed us to address the synergistic effect to the presence of alloyed Au/Pd. The advantage of using this latter catalyst lies not only in the high activity but also in a prolonged catalyst life. Although a partial leaching of palladium and assembling of the particles have been revealed by ICP and HRTEM respectively, activity after 10 re-cycles decreased less than expected (about 10%).     

硫氰酸钠法高吸湿(水)腈纶纺丝工艺及其性能的研究

采用丙烯酸和丙烯腈的共聚物与聚丙烯腈共混纺丝的方法,纺制了丙烯酸改性的聚丙烯腈纤维,研究了纺丝工艺条件与改性腈纶性能之间的关系。实验结果表明:随着共混纺丝所采用的丙烯酸共聚物的共聚比的增加,改性腈纶的断裂强度有所下降,吸湿性和保水性则不断提高;采用低温干燥致密化和较低的总拉伸倍数,有利于提高改性纤维的吸湿和保水性能;随着纤度的增大,改性腈纶的回潮率和保水率渐渐减小。     

Olefins polymerization on titania and titania-supported rhodium

The adsorption of ethene and propene on titania and titania-supported rhodium has been studied, observing a continuous adsorption even after 24 h. The samples have been reduced at 623 or 773 K, but no difference was observed, whichever the reduction temperature or the presence of rhodium, on the amount of gas adsorbed per unit of surface area of the solid. A study of the polymerization has been done following the equal reactivity hypothesis, and it has been concluded that the role played by the rhodium particles is to facilitate adsorption of the gaseous molecule, that is then transfered to the surface of the support, where it polymerizes.     

Effect of qualitative and quantitative variation in allelochemicals on a generalist insect: Iridoid glycosides and the southern armyworm

The behavioral and physiological effects of plant allelochemicals have been difficult to demonstrate; it is not often clear whether the compounds are deterrent, toxic, or both. In this study, we compared the qualitative and quantitative effects of several iridoid glycosides on a generalist lepidopteran herbivore,Spodoptera eridania (Noctuidae). Larval growth and survivorship and larval preference or avoidance were measured on artificial diets containing different iridoid glycosides at different concentrations. We also tested the toxicity/deterrence of these compounds. We found that iridoid glycosides retarded larval growth significantly at relatively low concentrations and that they were usually avoided in preference tests. The toxicity/ deterrence test did not always reflect the results of these other tests. The merits of using a variety of methods for determining deterrence and/or toxicity of plant allelochemicals are discussed.