A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

不同类型浊度仪对浊度的测试研究

采用福尔马肼和黄河泥两种标准物分别标定了透射—散射光浊度仪、散射光浊度仪和721分光光度计,对黄河高浊度水及工序水进行了测试研究,用多项式回归分析法,拟合出不同类浊度仪测定的浊度间换算的经验公式,使历史数据与现测结果有连续性。同时为控制生产过程中净水剂的投加量、保证出水水质提供了指导。     

Contribution to the study of mechanism of stabilizing action of esters of phosphorous acid

The rate of the reaction of a series of phosphites with cyclohexene hydroperoxide and cyclohexene peroxy radicals was studied. The results of the measurements were compared with the stabilization efficiency of the same compounds in isotactic and in atactic polypropylene at 160°C and 120°C respectively and during the course of atmospheric ageing. It was found the reverse relation between the stabilization efficiency and the reaction constants of the reaction of phosphites with hydroperoxides. The main stabilization reaction of the phosphorous stabilizers seems to be the reaction of phosphites or of their decomposition products with radicals. The possibility of splitting off of free phenol from phosphites as a result of the reaction of the esters with hydroperoxide groups was checked.     

旋流脱气性能影响因素的CFD模拟

液体脱气是工业生产环节不可缺少的部分。脱气式旋流器能够在线、快速地进行脱气工作, 但目前发展处于初期阶段, 对于其脱气性能影响因素的探究还不全面。本文采用计算流体动力学(CFD)的方法, 运用流体力学软件Fluent, 在H₂O-CO₂的两相体系、湍流模型采用Reynolds应力模型、多相流模型采用Mixture混合模型的条件下, 对不同柱径比的液体脱气式旋流器进行数值模拟, 利用旋流离心场的离心力和压力梯度对微小气泡进行分离, 获得了对5～50μm不同直径气泡的分离性能以及进口流速对气泡分离性能的影响关系。研究发现, 在一定条件下, 随着柱径比值的增大, 脱气效率总体上先逐渐增大, 超过一个极限值后迅速减小, 但柱径比越大, 越有利于小气泡颗粒的迁移分离;分离效率随着进口流速增加而增加, 到达极限之后效率降低。     

A study of the miscibility of blends of polybutadiene and styrene-butadiene copolymers

We investigated the miscibility of polybutadienes with butadiene-styrene copolymers of varying styrene content. The methods of optical microscopy, differential scanning calorimetry, and small angle light scattering (SALS) were used. All polymers/copolymers used in this study have equivalent butadiene microstructures. Copolymers with high styrene levels are immiscible with polybutadiene. The tendency to miscibility increases with decreasing styrene content. An upper critical solution temperature is observed with the 23 percent styrene copolymer.     

三株流行性出血热病毒免疫原性的比较研究

三株病毒用不同方法制备的疫苗，免疫家兔后都能诱导产生免疫荧光抗体（IF）。其中Z10和L99株用细胞冻融以β-丙内酯灭活制备的疫苗还可以测到HI抗体。以β-丙内酯灭活的疫苗所产生的中和抗体，以Z10株最高（1：80～1：160），L99株较低（1：10），而LR1株未测出。但三株病毒感染的细胞培养上清液，用两种灭活剂均未产生HI或NT抗体。     

固体酸催化剂的酸性对噻吩类硫化物转化的影响

在温度300 ℃、空速2.0 h－1条件下,以含有芳烃、烯烃的噻吩类硫化物为模型化合物,探索研究不同酸类型分子筛催化剂硫转化的机理。研究表明,具有不同酸类型的催化剂硫转化效果不同,同时有B酸和L酸的催化剂硫转化效果较好,带侧链的噻吩容易被转化,而且侧链越长、个数越多越容易被吸附脱出。不同酸类型的催化剂对模型化合物的组成影响不同,同时具有B酸和L酸的催化剂使模型化合物中芳烃和烯烃都大量减少,只有L酸的催化剂芳烃会大量减少,而烯烃变化不明显。     

Electrophoretic study of albumins and globulins of 4 genotypes of Canavalia ensiformis

Polyacrylamide gel electrophoresis (PAGE) and PAGE-SDS were used to study seed albumins and globulins of Canavalia ensiformis. In PAGE the concentration of acrylamide used in the upper gel was 4.0% with a pH of 6.7 and in the lower gel 7.5% and 10% of acrylamide were used with a pH of 8.9. In PAGE-SDS the concentration of acrylamide was 4.4% with a pH of 6.8 in the upper gel and 7.5% and 12.6% with a pH of 8.8 in the lower gel. The material used were the Venezuelan genotypes Tovar, Yaracuy, Original and U-02. The albumins and globulins were extracted with a 0.5 M NaCl solution and then separated by dialysis against water and lyophilized. These protein fractions represented 84.85% of the total amount of protein in seeds. The albumins were separated in PAGE with 7.5% acrylamide into five fractions and globulins into six, with similar electrophoretic patterns between genotypes. In a similar manner, the patterns obtained in PAGE with 10% acrylamide were the same for all genotypes, showing five bands for albumins and three bands for globulins. With PAGE-SDS containing 7.5% of acrylamide, albumins were separated into as many as eight components, and globulins into as many as seven bands with mobilities between 0.2981 and 0.9932, with different patterns for each genotype. Also the patterns PAGE-SDS at 12.6% of acrylamide were different for the genotypes, separating proteins into a greater number of bands. The albumins showed as many as twenty-one bands with mobilities between 0.2603 and 0.7398, and globulins as many as sixteen bands with mobilities between 0.2454 and 0.7390. The PAGE patterns of the genotypes analyzed did not show differences between them. However, with PAGE-SDS different electrophoretic patterns were obtained which varied in the number and intensity of the bands, making it possible to distinguish the genotypes studied. The molecular weight of the albumins varied between 76,000 and 12,000 daltons and of the globulins between 80,000 and 12,000 daltons.     

The kinetics of oxidation of sodium sulphite

The kinetics of the reaction of oxygen with sodium sulphite in aqueous solution without and with a catalyst of cobaltous sulphate have been studied by a flow thermal method. The rate of reaction of oxygen and sodium sulphite was found to be first-order with respect to oxygen and variable order with respect to sulphite, and the promoting effect of cobaltous catalyst was proportional to its concentration. A reaction mechanism has been proposed and a rate expression derived which is in good agreement with the experimental data.     

等电流电渗析模型脱盐试验

等电流操作电渗析比等电压操作电渗析更容易通过调整膜对数控制多段电渗析各段的脱盐率和极化点。通过不同方案试验对比，提出了合理的等电流操作电渗析的膜对数组合。通过试验验证了Ca(HCO3)2型井水在预处理中加酸酸化，再进行电渗析脱盐工艺比预处理中未加酸酸化工艺脱盐效果较明显。     

旋毛虫成虫与肌幼虫排泄分泌抗原蛋白组分的比较分析

目的比较大理猪源旋毛虫(Trichinela spiralis)成虫与肌幼虫排泄分泌抗原(Excretory-secretory antigens,ES)的蛋白组分差异,并进一步分析其反应原性,为分离筛选出免疫原性和反应原性强的旋毛虫抗原成分奠定基础。方法分别收集和纯化旋毛虫成虫、肌幼虫虫体,制备ES,采用SDS-PAGE分析成虫和肌幼虫ES蛋白成分,Western blot分析其反应原性。结果经SDS-PAGE分析,旋毛虫成虫ES显示17条蛋白条带,相对分子质量范围在120000～14000之间,其中主带6条,相对分子质量分别为120000、64000、43000、40000、35000、33000;旋毛虫肌幼虫ES显示20条蛋白条带,相对分子质量范围在112000～10000之间,其中主带11条,相对分子质量分别为112000、66000、56000、55000、53000、49000、45000、43000、25000、21000、10000。Westernblot分析表明,旋毛虫成虫ES抗原显示7条反应带,相对分子质量分别为43000、40000、35000、27000、19000、18000、14000,其中相对分子质量43000、40000、27000、18000的条带着色明显;旋毛虫肌幼虫ES抗原显示14条反应带,相对分子质量范围在74000～12000之间,其中相对分子质量53000、49000、45000、43000、35000、27000、18000、12000的条带显色明显。结论旋毛虫成虫和肌幼虫ES抗原蛋白组分均复杂,有共同组分,也有不同组分,旋毛虫ES抗原具有较强的反应原性,是旋毛虫病研究的重要候选抗原。     

Model of Cellular Instability of Flames of Ternary Mixtures

A simple phenomenological diffusive-thermal model of cellular instability of premixed flames of ternary mixtures is developed and presented. The model shows that preferential diffusion can alter stoichiometry of the mixture, i.e., the ratio of the fuel and oxidizer concentrations, and also its effective dilution by an inert. Key parameters of the model are estimated using numerical modeling of burning velocities. Laminar burning velocities are calculated for hydrogen-oxygen-nitrogen, methane-oxygen-nitrogen, and propane-oxygen-nitrogen mixtures. Conditions for the appearance of cellular instability in ternary mixtures are determined and compared with experiments. In good agreement with experimental observations, the diffusive-thermal instability is predicted in hydrogen flames with equivalence ratios φ ≲ 1.45, in lean methane flames with φ ≲ 1.02, and in rich propane flames with φ ≳ 1.03. The magnitude of the change in the local flame velocity due to preferential diffusion is evaluated. It is demonstrated that nitrogen diffuses faster than oxygen in hydrogen-air and methane-air flames, while oxygen diffuses faster than nitrogen in flames of propane and other heavier hydrocarbons. In mixtures of air with propane or heavier hydrocarbons, the transition between stable and unstable regimes is predicted in mixtures that are leaner than the mixture corresponding to the peak of the burning velocity curve, in agreement with experimental observations. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 14–22, September–October, 2005.     

Statistical investigations of the pitting of passive iron

The surface concentration of pits at passive pure iron in borate buffer solutions containing chloride grows at a maximum rate shortly after the appearance of the first pit. Later on, a steady state surface concentration of pits is established after some characteristic time decreasing with the electrode potential and with the chloride concentration. The steady state surface concentration of pits increases linearly with the difference of the electrode potential vs the critical pitting potential, with the concentration of chloride and with the activity of hydrogen ions, but also grows with the surface concentration of emerging dislocations.The probability of finding a pit was the same on any part of the iron surface with uniform mechanical preparation. The Poisson distribution for the probability of finding a certain surface concentration of pits in a given area was nearly symmetrical. The distribution of the nearest distances of pits around a central pit also was of the Poisson type, but with an exclusion zone in which no pits nucleated. The width of the exclusion zone was independent of the electrode potential, but decreased with the activities of chloride and hydrogen ions.     

PVC／ACR共混体系的相容性研究

用DSC和FT－IR研究了PVC／ACR共混体系的相容性。结果表明,随KM355P含量比增加塑料相的玻璃化温度Tgt向高温移动,橡胶相的转变温度Tg2向低温转移;不同品种的ACR和PVC具有不同的相容性;ACR中PMMA组分与PVC之间形成氢键;提高了PVC／ACR体系的相容性。     

Enhancement of Biocontrol Efficacy of Pichia carribbica to Postharvest Diseases of Strawberries by Addition of Trehalose to the Growth Medium

The effects of trehalose on the antagonistic activity of Pichia caribbica against Rhizopus decay and gray mold decay of strawberries and the possible mechanisms involved were investigated. The proteomic analysis and comparison of P. carribbica in response to trehalose was analyzed based on two-dimensional gel electrophoresis. The antagonistic activity of P. carribbica harvested from the culture media of NYDB amended with trehalose at 0.5% was improved greatly compared with that without trehalose. The PPO (Polyphenoloxidase) and POD (Peroxidase) activity of strawberries treated with P. carribbica cultured in the NYDB media amended with trehalose at 0.5% was higher than that of the strawberries treated with P. carribbica harvested from NYDB. The β-1, 3-glucanase activity of strawberries treated with P. carribbica cultured in the NYDB media amended with trehalose at 0.5% was also higher than that of the strawberries treated with P. carribbica harvested from NYDB and the control. Several differentially expressed proteins of P. carribbica in response to trehalose were identified in the cellular proteome, most of them were related to basic metabolism.     

Experimental determination of the enthalpy of formation of the pyrochlore rare-earth hafnates

In this study, enthalpies of formation of compounds RE₂Hf₂O₇ type (where RE = La, Pr, Nd, Sm, Eu, and Gd), with pyrochlore structure have been measured by high-temperature oxide melt solution calorimetry. Results were compared with literature data, and dependencies of enthalpies of the formation of compounds with the pyrochlore structure from the ionic radius of rare-earth element were analyzed. The enthalpy of formation becomes more positive with the increase in ionic radius, which is in conformity with the results earlier observed for titanates and zirconates.     

Mechanism of corrosion of tin-oxide electrodes

Conclusions The destruction of tin-oxide ceramic by glass takes place rapidly, despite the absence of marked penetration of molten glass into the pores of the material, i.e., the low impregnation is not an essential condition for high corrosion resistance.The corrosion is linked with the change in the structure of the material, expressed by the increase in its dispersion and the development of a large number of fine, weakly interbonded grains with subsequent penetration between them of glass, bloating, and breakdown into separate fragments.The least corrosion by lead glass is exhibited by tin oxide ceramic with clearly expressed crystals bonded by dense intergrain contacts, regardless of the total porosity.The most intense corrosion is typical of a material with badly formed intergrain faces, and a high open porosity. Even prolonged service at high temperatures in contact with glass does not lead to marked growth of the grains and their regular delimitation.The most resistant to corrosion turned out to be a material with a well-formed granular structure, with a pore volume of about 9.1 mm³/g, and pores measuring 10–20 m. In service it is completely impregnated with glass.Translated from Ogneupory, No. 2, pp. 24–29, February, 1989.     

杀菌剂噻菌灵在香菇上残留量测定

以丙酮作提取剂，经二氯甲烷萃取，用丙酮定容，然后用ＳＩＧＭＡ－３００型带ＮＰＤ检测器的气相色谱仪测定。其测定结果的准确度和精密均符合残留量测定的要求。     

管间支撑物的结构对横纹槽管管束传热强化性能的影响

通过对壳程流体纵向冲刷型管壳式换热器的传热与流体阻力实验,比较了横纹槽管管束在折流杆支撑和空心环支撑两种情况下的传热强化特性,发现空心环管间支撑物比拆流杯管间支撑物有较好的性能.此外,还报道了用激光测速测量壳程流体在管间支撑物条件下的流速分布,分析了管间支撑物结构对传热性能的影响.     

Kinetics of polymerisation of furfuryl alcohol in aqueous solution

Kinetic information on the polymerisation of furfuryl alcohol catalysed by Clark-Lubs' aqueous buffer in the pH range of 1.0–2.2 has been derived from the rate of increase of colour intensity measured with a photoelectric colorimeter. The polymerisation reaction is found to be of zero order, with the activation energy increasing exponentially with pH. The time required to reach the extent of reaction at which a resin layer separates out from the aqueous solution decreases with increasing temperature but increases with increasing pH. An exponential expression relating the time for phase separation with temperature and pH has been derived.