异丁烯两段催化氧化制甲基丙烯酸催化剂的研究 Ⅱ．甲基丙烯醛气相氧化制甲基丙烯酸的杂多酸盐催化剂的研究

本文报道用于甲基丙烯醛（ＭＡＬ）选择氧化制甲基丙烯酸（ＭＡＡ）的ＰＭｏＶ杂多酸盐催化剂的研究结果。ＩＲ和ＸＲＤ考察结果表明，本文所研究的催化剂均具有稳定的Ｋｅｇｇｉｎ结构，催化剂物相组成为Ｈ（４－２ｙ－２）ＰＯ４（ＭｏＯ３）（１２－ｘ）（ＶＯ３）ｘＣＵｙＣｓｚ。在３００℃，原料气组成ＭＡＬ：Ｈ２Ｏ：Ｏ２：Ｎ２＝１：１０：３：３２．体积空速１２００ｈ（－１）的条件下，最佳催化剂的ＭＡＬ转化率为９４．１％，ＭＡＡ选择性达８８．７％。     

Effect of qualitatively varying nutrition on several parameters of aflatoxin B1 metabolism and toxicokinetics

The influence of qualitatively different nutrition (physiological and that with lysine, methionine, threonine and vitamins A, B, C deficiencies) on certain toxicokinetic parameters of 3H-aflatoxin B1, after single and multiple (every day, during 5 days) intraperitoneal injections of this agent in a dose of 25 micrograms/animal, was studied in two series of experiments on growing male WAG rats with the initial bw 40-50 g. It has been proved that the main parameters of aflatoxin B1 toxicokinetics depend on the injection multiplicity and the nutrition character. It has been established that the qualitative differences in the nutrition character essentially influence the stages of aflatoxin B1 distribution in the body, the sorption and metabolic transformation in the liver, enterohepatic recirculation, the rate and correlation of the main elimination routes. The nutrition character influences the level of persistence and cumulation of firmly bound aflatoxin B1 adducts in the liver and hepatocytic DNA. Possible mechanisms of such effects of different providing of the body with essential nutrients have been discussed. A conclusion has been made that the modifying effect of nutrition on the key stages of aflatoxin B1 toxicokinetics is realized, ultimately, in varying degree of the animal resistance to mutagenic and carcinogenic action of this agent.     

Formulas relating stability estimates of discrete-time and sampled-data nonlinear systems

We provide an explicit stability or input-to-state stability (ISS) estimate for a sampled-data nonlinear system in terms of the estimate for the corresponding discrete-time system and a function describing inter-sample growth. It is quite obvious that a uniform inter-sample growth condition, plus an ISS property for the exact discrete-time model of a closed-loop system, implies uniform ISS of the sampled-data nonlinear system. Our results serve to quantify these facts by means of comparison functions. Our results can be used as an alternative to prove and extend results in [[Reference to 1]] or extend some results in [[Reference to 4]] to a class of nonlinear systems. Finally, the formulas we establish can be used as a tool for some other problems which we indicate.     

VVER-440 fuel cycles with inert matrices for burning plutonium

The possibility of forming special fuel loads for VVER-440 that would make it possible to reduce the amount of transuranium elements in spent nuclear fuel by burning transuranium actinides is examined. Preliminary calculations are performed using the HELIOS spectral code to assess the effectiveness of the transmutation. Transmutation is modeled for two load variants: mixed uranium–plutonium oxide fuel and fuel with inert diluents. The main criterion for effective transmutation is a decrease of the mass of the transuranium elements as compared with an open fuel cycle.     

SPUTTERING BEHAVIOUR OF IRON SILICIDES UNDER LOW ENERGY Ar~+ ION BOMBARDMENT

1.IntroductionSputtering0fmulticomponentsolidsisaNioripreferentialbecause0fdifferenceinbindingenergy,atthesurfaceaswellasinthebulk,andenergytransferringefficiencybothbetweenaspecificat0micspecieswiththepr0jectileandwiththeenvir0nmentalat0msintargetl',']-C0nsequently,thepreferentialsputteringeffectisi0nenergyandtar-getcomp0sitiondependent.Thetransientc0mp0sitionchangeinthetargetandofthesputteredparticlesduringi0nbombardmentcanbemonit0redwithsurfacesensitiveanal-ysismethods,suchasAES,ISS,etc.…     

Effect of different drying methods on the essential oil yield,composition and antioxidant activity of <Emphasis Type="Italic">Origanum vulgare</Emphasis> L. and <Emphasis Type="Italic">Origanum onites</Emphasis> L.

Origanum onites and Origanum vulgare are important medicinal plants because of their flavoring, therapeutic, and preservative properties. Drying methods are important for obtaining high quality essential oil from spices. In this study, the effects of different drying processes on the essential oil yield, composition, and antiradical activity were evaluated. Plants were dried under sun light, in a ventilated shady place and in laboratory-type oven, and the oils were extracted with Clevenger type apparatus. Carvacrol and thymol were the major compounds in the essential oils of O. vulgare and O. onites, respectively. The highest oil yield and the highest antioxidant activity values were obtained from shade dried Origanum species followed by oven dried plants. The lowest essential oil yield and the lowest antioxidant activity for O. vulgare were found in fresh plants. The lowest essential oil yield, and the lowest antioxidant activity for O. onites belonged to sun dried plants. It could be concluded that essential oil yield, oil composition and antioxidant activity of both plants were greatly affected by the drying method.     

Determination of the geographical origin of Slovenian black locust,lime and chestnut honey

The geographical origin of three Slovenian unifloral honey types (black locust, lime and chestnut) was investigated by analysis of some physico-chemical parameters, the elemental content using total reflection X-ray fluorescence spectrometry (TXRF) and the stable carbon and nitrogen isotope ratios using isotope ratio mass spectrometry (IRMS). The results were interpreted by chemometric methods. A total of 122 samples of Slovenian black locust, lime and chestnut honeys were collected from domestic beekeepers all over Slovenia for three years. Slovenia is a small country by area, but paedologically and climatically diverse, therefore offering interesting possibilities for studying geographical influences. The combination of the investigated parameters offers the possibility of distinguishing among samples of specific honey types from the four different Slovenian natural-geographical macroregions, namely the Alpine, Dinaric, Pannonnian and Mediterranean regions. Lime honey samples were 100% correctly classified, while the success rates for black locust and chestnut honeys were slightly lower at 98.2% and 94.6%, respectively.     

Numerical study of electrical behavior of P3HT/PCBM bulk heterojunction solar cell

In this work the program AMPS-1D was used to optimize the performance of the organic solar cells. The cells considered consist of poly(3-HexylThiophène) [P3HT] as electron donors, and (6,6)-phenyl- C61-butyric acid methyl ester [PCBM] as electron acceptor, (P3HT/PCBM) is used as photo-active material, sandwiched between a transparent indium tin oxide (ITO) and layer of poly(3,4 ethylenedioxythiophene)/ poly(styrenesulfonate) (PEDOT/PSS) on top of the ITO electrode and an AL backside contact. The results showed that the optimum thickness of the solar cell is about 400 nm, V_oc = 0.61 at T = 300 K. This is in the good agreement with the corresponding computer simulation value of 0.63 V. The maximum limit for the organic solar cell efficiency is about 8%, provided that the band-gap of the cell is about 1.5 eV.     

新型受电弓滑板的设计与实现

针对某电气化铁路接触网导线磨耗严重问题,分析了磨耗原因,研制了一种新型双润滑铜基粉末冶金滑板。在铜基粉末冶金滑板内部加入锡、石墨、铅等合金元素,其中石墨和铅都起到自润滑作用,同时外部采用铝包双润滑结构,将高强石墨润滑剂与粉末冶金滑板整体结合,进一步提高润滑效果。经磨耗试验和现场装车运行试验结果表明该滑板与铝包钢接触网导线能形成良好配合,滑板使用寿命为4．4542万机车km,接触网导线的使用寿命大于15年以上。     

Enzymatic production of human milk fat analogues containing stearidonic acid and optimization of reactions by response surface methodology

Human milk fat analogues containing stearidonic acid (SDA) were produced by enzymatic acidolysis reactions between tripalmitin and free fatty acids (FFA) obtained from hazelnut oil and commercial oil mixture containing Echium oil. Lipozyme^® TL IM, immobilized sn-1,3 specific lipase was used in the enzymatic reactions. Response surface methodology (RSM) was applied by using central composite circumscribed design with five levels and three factors. The factors chosen were: Reaction temperature [55–65 °C], reaction time [4–12 h] and substrate molar ratio [3–5 mol/mol (total FFA/tripalmitin)]. Good quadratic models were obtained for the incorporation of SDA and oleic acid. Optimal conditions generated from the models were determined as 60 °C; 8 h, 4 mol/mol for temperature, time and substrate molar ratio, respectively. The models were verified at optimum conditions and furthermore scale-up synthesis of structured lipids (SLs) was performed. Stearidonic and oleic acid contents of the SL from scale-up production were found to be 2.0 and 22.9 mol/100 mol total FA respectively, with 46.2 mol/100 mol total FA of palmitic acid content located at sn-2 position. Besides, oxidative stability and melting profile of final SL were determined for characterization. SL had 6.1 h of induction time, and also had a wider melting range compared with tripalmitin.