聚乙二醇/蒙脱石插层复合物的制备及结构表征

通过X射线衍射、傅里叶变换红外光谱和差热分析表征聚乙二醇(PEG)／蒙脱石复合物的结构结果表明,PEG以单层或双层平卧于蒙脱石层间;PEG通过转换部分层间水进入蒙脱石层间通道内;大分子量的PEG与蒙脱石层间表面有更强的相互作用．     

高压聚乙烯反应器的自增强处理效果分析

本文论述茂名三十万吨乙烯工程高压聚乙烯反应器的自增强处理通过分析计算得出，在自增强处理后反应器器壁操作应力水平大大降低，而器壁危险截面也由内表面转移到弹塑性界面，这有利于反应器强度的提高和疲劳寿命的延长.     

用辣根过氧化物酶催化降解海水中柴油污染的研究

为深入探索酶催化技术在海洋石油污染处理中的应用,以游离辣根过氧化物酶(HRP)催化降解海水中柴油污染,研究了酶用量、溶液p H值、柴油初始浓度和催化反应时间等因素对酶催化降解海水中柴油污染的影响,确定了HRP催化降解海水中柴油污染的优化工艺条件,同时考察了反应助剂对海水中柴油污染去除率的影响。结果表明:HRP能有效催化降解海水的柴油污染,当海水中柴油的质量浓度为1.2g/L时,在温度为25℃、HRP加入量为1.6 U/m L、H_2O_2为250 mg/L、溶液pH为5的条件下,催化降解3 h,柴油去除率可达90.77%;聚乙二醇(PEG)对HRP催化降解海水中的柴油污染有较显著的影响。     

一种双降解膜在北疆棉区降解性能评价

[目的]评价EPI双降解膜在北疆棉区的综合性能,为技术引进和生产应用提供依据.[方法](1)通过自然光照、表面积法、地温计法测定地膜的诱导期、光降解能力及增温保温效果;(2)通过地埋法测定生物降解性能;(3)通过小区生产试验对比降解地膜对棉花产量和纤维品质的影响.[结果]EPI双降解膜能提高早春地温,光降解能力较强,但生物降解性能均较差.[结论]光降解能力符合技术需求,但生物降解能力有待提高.     

表面活性剂增强Bi2S3纳米颗粒光催化活性的研究

为开发高效的光催化材料,以利用太阳能来分解有机污染物,采用化学水浴沉积法制备Bi2S3纳米光催化材料,并分析其形貌、结构和光催化降解有机污染物的能力。结果表明：所制备的Bi2S3为表面粗糙的纳米颗粒;Bi2S3纳米颗粒对亚甲基蓝有较好的光催化降解效果,添加表面活性剂聚乙二醇(PEG)有助于Bi2S3纳米颗粒尺寸减小,增大颗粒比表面积,促进光生电子与空穴的有效分离,进一步增强其光催化活性。     

Evaluation of the structural strength and failure for floating collar of a single-point mooring fish cage based on finite element method

Deep-water fish cage floating collar also referred to as float, bears a load in the form of waves, fishing nets, and moorings, in which the longitudinal wave force is the main type of loading. The long-term continuous effects caused by wave force could cause reduction in strength, or vibration failure in the floating collar. In this study, the peak responses of a single-point mooring (SPM) cage floating collar, due to either static or vibration loadings, were calculated by the finite element method (FEM) based on an elastic model. In this model, the float exhibited macro-plastic deformation when the stress of 26.1 MPa, generated under 100 kN load, was greater than the yield limit (25 MPa). With the increase in order modes from 1 to 18 (1.2–7.9 Hz), the stress increased. Moreover, the harmonic stress corresponding to 8 and 0.1 Hz was clearly higher than that for 0 Hz under 100 kN loads, due to structural resonance. The range of stress values due to the random vibration was 16.0–63.7 MPa, when the angular velocities (k) were in the range of 0.01–16 rad s^―1. Moreover, the transient response (34.4 MPa) was maximum when the angular velocity was 10 rad s^―1 (range 1–100 rad s^―1). The reliability rate of the entire body was 53.1% and 97.0% after 10⁸ loading cycles for 100 kN and 10 kN loads, respectively. Furthermore, the fatigue modes of the key components were determined from the outer triangular tops and inner hexagonal intersections. In short, static analysis, vibration analysis, and fatigue analysis of FEM could be used as reliable ways to evaluate structural strength and failure for floating system. Finally, the floating parts could be strengthened with partially double pipes or optimized by increasing the stiffness, and appropriate damping could be widely used.     

乙纶经编网片断裂强力特性研究

本研究以国家有关测试标准为依据，采用裂区模型实验设计方法对多种系列乙纶单丝经编网片测样进行测定，数据采用多元方差分析方法，分析了网片纵横向之间、干湿态之间的断裂强力和断裂伸长率的差异性，找出了影响网片断裂强力和断裂伸长率的主要因素，分析了各主要因素影响的程度和趋势，回归各因素与断裂强力和断裂伸长率间的关系。研究分析结果表明，乙纶经编网片的断裂强力和断裂伸长率均与目脚总丝数、编织密度和成圈丝数有高度显著的线性关系。     

Movement and biological activity of drip-applied 1,3-dichloropropene and chloropicrin in raised mulched beds in the southeastern USA

Movement and biological activity of 1,3-dichloropropene (1,3-D) and chloropicrin applied through drip irrigation in raised beds was investigated at three locations in the southeastern USA. Tests were conducted in fields with dense populations of nutsedge (Cyperus spp), with one location also having a high level of soil nematodes, both of which served as biological indicators of the distribution of effective concentrations of 1,3-D and chloropicrin. Objectives were (1) to gain a better understanding of 1,3-D and chloropicrin movement and the extent of biological activity outside of the wetted bed area, and (2) to examine the effect of application rate, application concentration and subsequent irrigation events on movement and activity of 1,3-D and chloropicrin. InLine, an emulsifiable concentrate containing 60.8% w/w 1,3-D and 33.3% w/w chloropicrin, was injected into polyethylene mulched beds through the drip tubes and water movement in the beds was visualized by adding a blue dye to the injection system. Gas concentrations of 1,3-D and chloropicrin in soil were measured using Gastec detection tubes at different positions relative to the drip tube at 1-4 days after InLine application. After one week, mulch was removed and nutsedge survival evaluated at different positions in the bed. High concentrations of 1,3-D and chloropicrin were measured at the bed center and midway between the bed center and the shoulder, but concentrations were low at the bed shoulder. Width of nutsedge control was significantly greater than width of water movement. Plant-parasitic nematodes were controlled over the entire bed width, but nutsedge re-emerged at the bed shoulders regardless of treatment. Higher application rates and concentrations of 1,3-D + chloropicrin resulted in higher fumigant concentrations in soil air. Irrigations subsequent to application reduced soil air concentrations of 1,3-D and chloropicrin and increased water movement, as did the use of two drip tubes instead of one. The data show that the pesticidal activity of 1,3-D + chloropicrin extends beyond the waterfront and indicate a significant degree of fumigant activity of emulsifiable 1,3-D + chloropicrin. However, unlike plant-parasitic nematodes, nutsedge could not be controlled over the entire bed width, regardless of rate, concentration and volume of water applied.     

气调包装对果蔬保鲜效果的影响因素

气调包装主要是使用低密度聚乙烯薄膜袋进行果蔬包装,可以延长果蔬的储存寿命,保持其商品性状。通过使用低密度聚乙烯薄膜气调包装果蔬时,影响果蔬品质主要有三个因素,分别为微生物、气体成分和气调包装材料,本文对其进行了详细的分析,并对果蔬气调包装技术的发展方向进行了展望。     

一年生黑麦草、高羊茅及杂交羊茅黑麦草种子萌发期抗旱性研究

用不同浓度的聚乙二醇(PEG6000)溶液对5种植物种子进行模拟干旱胁迫萌发研究,旨在了解在干旱胁迫下种子发芽的抗旱能力.结果表明,5种植物种子对低PEG浓度(5%、10%)有一定的抗性,且在5%浓度水平上有轻微的促进发芽作用;在较高浓度(15%、20%)下,除一年生黑麦草Angus1的胚根、胚芽高于对照外,其余4种植物的胚根、胚芽长、发芽率均低于对照;在高PEG浓度(25%)下种子不能萌发.5种植物种子的抗性强弱依次为:一年生黑麦草Angus1＞羊茅黑麦草(意大利黑麦草型)Perny＞高羊茅fawn＞羊茅黑麦草(羊茅型)Hykor＞一年生黑麦草(2倍体)Surrey.