A terminal course for psychology majors.

A special course for senior psychology majors "… in which one step has been taken in the direction away from the conservative tradition of lecturing and examining" is described. The students' first assignment is to list "… the ten most persistent and pressing problems of personal and social living… " and the second is to "… select the ten concepts, laws, or principles which you believe to be the most significant… ." From these the "… subject matter of the rest of the term is established." There is "… frequent and favorable reaction from students… ." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

尖晶石LiMn_2O_4高温电化学性能研究

通过熔融浸渍、分段烧结的方法用LiOH·H2 O和EMD制得尖晶石型LiMn2 O4 活性材料 ,对材料进行了元素分析和XRD结构表征 ,采用最小二乘法计算了样品的晶格常数 ,结果表明样品属于立方尖晶石结构 ,为缺锂型尖晶石锂锰氧。样品在高温下的充放电曲线和循环伏安曲线的测定结果表明样品的首次放电容量为 12 2 8mAh·g- 1,放电电压为 3 96V ,恒温充电电压为 4 0 7V ,二者差值仅为 0 11V ,说明以其为正极的电池的极化较小 ,在高温下具有良好的循环特性。     

Light Stability of Vanillin Solutions in Ethanol

Ethanolic solutions of vanillin, used as food flavouring are readily decomposed by the action of sunlight to 6,6'-dihydroxy-5,5'-dimethoxy-1,1'-biphenyl-3,3'-dicarbaldehyde (dehydrodi-vanillin). The decomposition is accompanied by the formation of a yellow colour and a slightly bitter taste. The U.S. Pharm-acopoeia (1975) spectroscopie assay of vanillin would be in-appropriate for samples contaminated with dehydrodivanillin, since the absorption maxima of vanillin are at 279 and 311 nm whereas the maxima for dehydrodivanillin are 279, 310nm with a shoulder at 337 nm.     

Polymers from renewable sources. III. Hydroxy-terminated myrcene polymers

A range of hydroxy-terminated polymyrcenes has been prepared using hydrogen peroxide initiated polymerization of pyroysate grade, β-myrcene in n-butanol solution at 100°C. An oligomeric fraction, containing a large proportion of dimeric material formed via the Diels–Alder reaction, always accompanies the major polymeric fraction. Procedures are described for the removal of this oligomeric material. Polyols so prepared and purified had number average molecular weights (M _n) between 4000 and 2000 g mol^?1 at low and high initiator concentrations, respectively, with corresponding number average functionalities (f _n) between 1.3 and 2.3 and polydispersities (M _w/M _n) of ～1.3. The microstructure of the polyols was investigated using NMR spectroscopy from which the main mode of propagation during polymerization of myrcene was deduced to be 1,4 addition across the conjugated double bonds. Glass transition temperatures of the polymyrcenes measured by differential scanning calorimetry were in the range ?50–60°C.     

Novel precursors suitable for RIM polyurethane networks

The synthesis and development of novel, furan-based diisocyanates (FDI) and myrcene-based polyols (PM) with potential for polyurethane production are presented. Pure FDI compounds, similar in structure to 4,4'-methylenediphenylene diisocyanate (MDI) were prepared unambiguously from fur-furylamine as liquids of low volatility, stable down to 0° C. making them particularly suitable for RIM. Comparative kinetics studies with n-butanol show the FDIs to behave as benzylic compounds with reactivities intermediate between those of aryl and alkyl diisocynates. Studies were made on segmented copolyurethanes prepared from FDI and polyol mixtures of 1,4-butane diol (BD) and polytetrahydrofuran (Mn. 1010). Hydroxyfunctional polymyrcenes were prepared from myrcene in n-butanol at 100° C using hydrogen peroxide as initiator. The liquid rubbers formed (M_n, 2000-4000; with f_n, 2.3-1.3 respectively) were shown by n.m.r. to comprise mainly substituted 1,4-butadiene units and are similar to the commercially available polybutadienes (PB). Copolyurethane elastomers were prepared from polyol blends of PM and 1,4-butane diol reacting with MDI. Both series of FDI-and PM-based copolyurethanes were shown by d.s.c. d.m.a. and tensile measurements to possess properties comparable to analogous materials formed from, respectively, MDI- and PB-based systems. In addition to their suitability for RIM, the results show the feasibility of deriving polyurethane feedstocks from naturally-occurring, non-oil based sources.     

Effects of alcohol ethoxylate and pluronic detergents on the development of pasture bloat in cattle and sheep

A series of studies was conducted to determine the efficacy and possible modes of action of a water-soluble mixture of alcohol ethoxylate and pluronic detergents (AEPD; Blocare 4511, ANCARE, Auckland, NZ) in preventing pasture bloat in ruminants grazing or fed freshly harvested alfalfa. Ten cannulated Suffolk wethers were offered freshly harvested alfalfa; five were given a daily intraruminal dose of 40 ml of 50% AEPD (vol/vol) 1 h before feeding, and five (controls) were dosed with water. Viscosity of ruminal fluid was reduced (P < 0.001) in AEPD-treated wethers, relative to the controls, for the first 2 h after feeding but not at 4 h after feeding and beyond. Treatment with AEPD did not affect dry matter (DM) intake, digestibility of DM, acid detergent fiber, or neutral detergent fiber, or N digestion and retention, implying that AEPD likely would not affect milk production. In a crossover grazing study, five of the wethers were given AEPD in drinking water (0.1%, vol/vol); treatment with AEPD was 100% effective for preventing bloat in sheep grazing early-bloom alfalfa for 4 h daily. Replicate grazing studies were conducted with cattle in Lethbridge, AB; Lacombe, AB; and Kamloops, BC. Treated animals received AEPD in the water (0.06%, vol/vol) and grazed vegetative alfalfa for 6 h daily. As it did with sheep, AEPD treatment effectively precluded the bloat observed in control animals. Consequently, AEPD may be a valuable tool for alfalfa pasture-based dairy production although further study is required to develop an integrated model for optimal administration under a variety of climatic conditions.     

The design and testing of a force feedback dental simulator

The Iowa Dental Surgical Simulator is a haptic simulator to train dental students in the haptic skills of dentistry. The initial design emphasizes the detection of carious lesions. This work describes the software and implementation of the prototype system, the design tradeoffs' and the technical issues associated with haptic and graphics subsystems. The work also describes the current system performance, including a formal evaluation by practicing dentists and performance measures. A discussion of the limitations of the current system is followed by an analysis of opportunities to improve the quality of the simulator. The results should be of interest to designers of medical haptic simulation systems and other simulation designers.     

The effects of hard segment content on microphase separation and physical properties of non-linear,segmented copolyureas formed by RIM

Summary The properties of RIM-copolyureas formed from a polyether triamine and containing 30 to 70% by weight of MDI/DETDA hard segments (HS) were investigated. As-moulded (mould temperature 115°C) and postcured (200°C/1h) materials were compared using DSC, DMTA and tensile stress-strain measurements. Phase separation ratios (PSR) of as-moulded materials increased from 47 to 56% with increasing HS content. Postcuring increased PSR to 70% for all materials resulting in significant intensification of HS glass transition at Tg^H (220 to 250°C), and reduced mechanical damping and modulus-temperature dependence between –40 and 200°C. Agreement between experimental tensile moduli and those predicted by appropriate two-phase composite theory has confirmed the co-continuous morphology of these RIM-copolyureas over the entire composition range studied.     

Li,Mn源对LiMn2O4尖晶石高温电化学性能的影响

采用熔盐浸渍法用LiNO3或LiOH·H2O作为Li源，以电解二氧化锰(EMD)或化学二氧化锰(CMD)作为Mn源，制备了4种尖晶石型LiMn2O4正极材料．对材料进行了XRD结构表征，采用最小二乘法计算了样品的晶格常数，以BET法测定了各样品的比表面积，测定了各样品的电导率；检测了各样品在高温下的贮藏和循环性能，在高温下作了循环伏安分析．结果表明，虽然各样品均属于立方尖晶石结构，但晶格常数、电导率和比表面积均不相同．以LiOH·H2O和EMD为原料制得的样品的极化最小，在高温下的贮藏性能和循环性能最好