二(巯基乙酸)钡的合成及其应用性能研究

以巯基乙酸和氢氧化钡等为原料合成了二 (巯基乙酸 )钡 ,试验选择了其优惠工艺条件。对产品进行了红外光谱分析及其物化常数的检测 ,并研究了它与有机锑复配时在聚氯乙烯 (PVC)塑料中的热稳定性能。     

风景园林科技"十五"计划及2015年发展规划

简要回顾、分析、总结近２０年来中国风景园林科技发展状况，提出行业科技“十五”及２０１５年发展目标。     

固体绝缘材料真空干燥的瞬态湿分迁移

固体绝缘材料是电气行业的主要原材料，真空处理工艺是改善其性能的关键技术之一。本文分析了真空干燥过程中湿分的非稳态迁移机理，为民工产品的真空处理工艺提供了理论依据。     

全自动石油油管（套管）静水压试验装置的改进

介绍了一种适用于石油油管、套管进行静水压试验的全自动试验装置。其适用管径为φ60－φ180mm（上至更大管径），长度8－11m（或8.5－11.5m及其他尺寸）；可试压力为0－100MPA，循环周期不大于150s；工作方式为单机单根或单机双根；密封方式为径向外抱式强制密封。介绍了其总体设计方案、配套情况及主要技术特点。     

The Effect of External Mass Transfer Resistance during Drying of Fermented Sausage

The drying mechanism of fermented sausages (sucuks) that were cylindrical rod shaped, 40 cm long and 4 cm diameter, during ripening under natural convection conditions at different temperatures (15 to 30°C) was examined. To simulate the experimental drying curves, three empirical models and a diffusional model assuming negligible external mass transfer resistance were evaluated. The drying rate curves of sucuk samples were also simulated taking into account the influence of the external mass transfer resistance. The equation was solved using the trial-and-error solution algorithm developed in this study and the mass transfer coefficient, k _c , and effective moisture diffusivity, D _eff , were simultaneously determined (1.44 × 10^?8 to 1.93 × 10^?8 m/s and 4.30 × 10^?10 to 6.85 × 10^?10 m²/s, respectively). The proposed model considering the effect of external resistance allowed the accurate simulation of the experimental drying data of sucuks at different temperatures.     

CR(III) removal by macroreticular chelating ion exchange resins

The poly(styrene-co-divinylbenzene) beads were synthesized by suspension polymerization using benzoylperoxide as an initiator and i -octane as a diluent. The copolymer beads with a particle size range of 32-60 mesh were selected. Chloromethylation was performed with chloromethylether at 0°C using tetrachloroethane as swelling agent and AlCl 3 as catalyst. The phosphorylation of copolymer beads (RS) and its chloromethylated derivative (RCS) was carried out using a mixture of PCl 3 and AlCl 3 under the reflux. The phosphorylated resins (RSP) were further oxidized using concentrated HNO 3 to obtain the oxidized form of RSP resins (RSPO). The removal of Cr(III) by the resins RSP, RSPO, and RCSP containing phosphinic, phosphonic, and methylenephosphonic groups, respectively, was investigated by batch and column methods. The results were compared with that of Diaion CRP-200 resin having methylenephosphonic functional groups. These resins exhibited a high affinity for Cr(III). The percent removal of Cr(III) reached a plateau with almost a 100% of removal at pH range between 2 and 2.5. The breakthrough capacity decreased in the order RCSP>RSPO>Diaion CRP-200>RSP.     

Comparative pyrolysis of polyolefins (PP and LDPE) and PET

In the present study, thermal degradation of polyolefins (PP and LDPE) and PET in a tubular reactor in an inert atmosphere was conducted. Each polymer was subjected to pyrolysis at the temperatures of 673, 773, 873, and 973 K. Yields of tar, residual coke and gas, and conversion degrees were calculated. Tars which include valuable chemicals were characterized by GC–MS, ¹H-NMR, FTIR, and GPC. Pyrolysis gases (C1 + C2, C3, C4, C5, and C6 + C7) were also analyzed by GC analysis. From the comparison of data, it can be said that pyrolysis of PP and LDPE leads to the formation of tar containing mainly paraffinic structures, while aromatic structures were produced by the pyrolysis of PET.     

Artificial neural network models for lot-sizing problem: a case study

Lot-sizing is one of the most difficult problems in production planning. The main purpose of this study is to propose a new lot-sizing based on artificial neural network (ANN), which may lead to a better performance than commonly used lot-sizing heuristics (SM, EOQ, PPB, LUC, and LTC). The data obtained are the results of years 2004 thru 2009 for 186 different types of stock items from the 2nd Air Supply and Maintenance Centre Command, a state-funded factory in Kayseri, Turkey. Factual data were applied under the coverage of the study, and the system from which the data have been obtained is still in live and active status. In the study, the purchasing costs, holding costs, and set-up costs were taken into consideration. These data were obtained from the administration data system of the enterprise. The solutions of this lot-sizing heuristics were found by WinQSB software accordingly. The ANN was constituted by using the NeuroSolutions software. The criterion of deviation from the optimum solution and the criterion of percentage of times obtaining the optimum order pattern were taken into account for the comparison purposes. The performance values of 400 ANNs were compared to lot-sizing methods. MS Excel and Visual Basic Macro were utilized for all calculations applied after this stage. The results showed that the proposed ANN-based method outperformed all lot-sizing methods taken into account in this study.     

钾碱对烧结型烃类蒸汽转化催化剂活性及稳定性的影响

利用常压微反-色谱装置,考察了烧结型烃类蒸汽转化催化剂钾碱加入方式和加入量对活性及稳定性的影响。结果表明,钾碱以钾的复盐(KAlSiO4)形式加入为好。它虽对活性有一定的抑制作用,但加入适量的钾,在对初活性影响不太大的情况下,有利于提高活性稳定性。     

Effect of Preharvest Deficit Irrigation on Second Crop Watermelon Grown in an Extremely Hot Climate

As a second crop, watermelons (Citrullus vulgaris, Crimson sweet) were grown in 2003 and 2004 in the Sanliurfa-Harran Plain in southeastern Turkey to determine the effect of preharvest water stress on fruit yield, quality (i.e., soluble solids contents and fruit size), leaf temperature, and some other physiological parameters. Preharvest drip irrigation treatments included (1) complete irrigation cutoff, dry (D); (2) full irrigation based on replenishment of soil water depleted from 0 to 90?cm soil profile (C); (3) 75% full irrigation (IR1); (4) 50% full irrigation (IR2); and (5) 25% full irrigation (IR3) with 3-day irrigation interval. Treatment plots received the same level of irrigation water until the fruit formation stage, except for Treatment D. Then, different water stress levels were imposed on treatment plots. Irrigation water applied to the five respective treatments were 636, 511, 395, 245, and 120?mm in 2003 and 648, 516, 403, 252, and 127?mm in 2004. Results indicated that fruit yield was significantly lowered by reduced water rates. The seasonal average yield response factor (ky) for both years was 1.0, but it was 0.97 for 2003 and 0.98 for 2004. The highest marketable fruit yield, obtained from treatment C, was 32.4?Mg?ha?1 in 2003 and 37.1?Mg?ha?1 in 2004. D, IR2, and IR3 treatments reduced most measured parameters, except for soluble solids contents (SSC). Both the fruit size and SSC were significantly affected by late-season irrigation management; individual fruit weights were significantly reduced, whereas SSC increased in the IR2 and IR3 treatments compared to the control values. The writers’ results clearly indicated that reduced preharvest irrigation was detrimental. Water use efficiency (WUE) was significantly affected by irrigation treatments. Even a 25% reduction in the irrigation amount caused a 15% reduction in marketable yield. This indicates that deficit irrigation in the ripening stage significantly increased water use efficiency. The study demonstrated that a moderate deficit irrigation, which is replenishment up to 50% of soil water depleted in the root zone, can be successfully used to improve WUE under semiarid climatic conditions.