全连续冷连轧机开卷区自动控制系统

河北中钢全连续冷连轧机组中开卷区控制采用Siemens PLC,实现了逻辑控制、速度控制、张力控制和区域跟踪,取得了令人满意的控制效果。     

改进的活套控制技术开发与应用

活套控制是热连轧精轧热负荷调试过程中首先要投入的动态控制功能,是保证带钢宽度和厚度质量控制能否稳定的前提。在宝山钢铁股份有限公司某热轧生产线三电自主集成改造项目中,通过对原有活套控制系统的套量计算模型、力矩模型、起套过程控制、稳态控制等进行优化,保证了新的活套控制一次投入成功,从开轧到正式投产无废钢,活套角度和张力控制精度均较老系统有了较大提高。     

冷轧联机活套轮衬对张力波动的影响探讨

通过对冷轧酸轧联机入口活套张力波动的故障分析,找出了导致活套张力波动原因,提出了活套轮盘衬块磨损的解决措施,同时设计了控制程序参数的优化方案,为处理类似的设备问题提供了思路。     

Influence of trichome exudates from species ofLycopersicon on oviposition behavior ofHeliothis zea (Boddie)

Cage experiments revealed that accessions of the wild tomato speciesLycopersicon hirsutum were preferred sites for oviposition byHeliothis zea. Hexane extracts from the leaves ofL. hirsutum were also preferred sites of oviposition in choice experiments among extracts from severalLycopersicon species. Extracts ofL. hirsutum were still biologically active several days after application, indicating that the phytochemical(s) involved are relatively stable and of low volatility. Gas Chromatographic analysis of leaf hexane extracts from 12 different accessions of theL. hirsutum complex and three tomato cultivars revealed substantial qualitative and quantitative variation in the chemical composition of these extracts. Comparison of these results with extract oviposition studies implicate a group of structurally related compounds as the active agents. Mass spectroscopy has tentatively identified these compounds as sesquiterpenes with the chemical formula C₁₅H₂₂O₂. These compounds are apparently synthesized and secreted from glandular trichomes on the leaf surface. These phytochemicals did not stimulate ovipositional behavior in females of the cabbage looper,Trichoplusia ni. The existence of genetic variation for the presence and amount of kairomones that serve as cues for insect orientation and oviposition could be utilized in a breeding program to develop tomato cultivars with genetically modified allelochemic profiles that would disrupt the sequential behavioral processes of insect host-plant selection.     

Identification of female sex pheromone components of rice looper,Plusia festucae (L.), (Lepidoptera: Noctuidae)

The rice looper,Plusia festucae, is a defoliator of the rice plant. Chromatographic behavior, chemical reactions, and GC-MS analyses of the female sex pheromone revealed that the main component was (Z)-5-dodecenyl acetate (Z5–12: OAc, component I). The GC-MS analysis also indicated that the pheromone gland extract included another three monounsaturated components, (Z)-5-dodecen-l-ol (Z5–12: OH, component II), (Z)-7-tetradecenyl acetate (Z7–14: OAc, component III), and (Z)-7-tetradecen-l-ol (Z7–14: OH, component IV) in the following ratio: I:II:III:IV=100:6:15:1. In a paddy field, the mixture of synthetic I, II, and III in a ratio of 100:6:15 showed stronger attractancy than the virgin female, while the role of IV was unknown.     

Genetic aspects of interpopulational differences in pheromone blend of cabbage looper moth,Trichoplusia ni

The genetic basis of interpopulational differences in the pheromone blend emitted by the cabbage looper moth,Trichoplusia ni (Hübner), was examined by crossing individuals from a field-derived population (P₁) with individuals from a long-maintained laboratory colony (P₂). These colonies differed in the emission rate and relative proportions of four of the five known minor pheromone components, but not in the emission rate of the major component, (Z)-7-dodecenyl acetate (Z7-12Ac). These differences in pheromone blend were quantitatively small but biologically significant, because in the field, males responded preferentially to traps baited with a pheromone blend that is similar to that emitted by P₁ females relative to a blend similar to that emitted by P₂ females. In initial crosses, variation in the quantity and quality of pheromone blends among families of P₁, P₂, and F₁ hybrid females was examined. In F₁ females the relative proportions (quantity relative to the major component) of (Z)-5-dodecenyl acetate (Z5-12Ac) and (Z)-7-tetradecenyl acetate (Z7-14Ac) were intermediate to parental lines. In a second more extensive set of crosses, analyses included P₁, P₂, F₁, F₂, and selected backcrosses. The relative proportion of Z5-12Ac, Z7-14Ac, and Z9-14Ac emitted by F₁ females were intermediate to parental lines. The frequency distributions of relative proportions of these components emitted by females were not consistent with those expected under a single autosomal or sex-linked gene hypothesis, suggesting that more than one gene is involved in the quantitative differences in the pheromone blend.     

A high-efficiency collection device for quantifying sex pheromone volatilized from female glands and synthetic sources

A high-efficiency collection device for sex pheromones volatized from forcibly extruded female glands is described. Filtered nitrogen gas is the carrier and glass wool the adsorbent. Small quantities of distilled carbon disulfide are used to rinse the glass wool. Recovery efficiency of synthetic compounds was usually 90–100%, and a mean of 2.4 ± 0.65 SD ng/min of (Z)-7-dodecenyl acetate was recovered in emissions from individualTrichoplusia ni (Hubner) glands.     

热连轧液压活套压力控制的改进

以热连轧液压活套系统为研究对象,对活套的张力控制原理和电液控制系统进行了研究和分析,并且在液压缸的压力PI控制器中加入了补偿控制等改进措施,并以马钢2 250 mm热轧精轧产线为试验平台,投入功能以及对控制参数进行了校正,提升了活套张力控制的稳定性。     

轧机活套液压控制系统状态监测与故障诊断专家系统研究

在轧钢生产线中,活套液压系统是较重要的一个环节,其故障会直接影响产品质量,导致经济损失。根据轧机活套液压系统故障具有隐蔽性、复杂性及难排除等特点,开发了基于Visual Basic 6.0软件的故障诊断专家系统。该专家系统采用正向推理方式,且其知识库和推理机是相互独立的,将专家系统与模糊判定理论相结合,对活套液压系统进行故障排除,提高了准确性。并根据系统提供的故障系数,可以实现优先顺序排除故障的功能,节约了时间。本专家系统具有操作简便、实用性强等特点,具有良好的人机交流界面。     

Chemical basis of resistance in soya bean to cabbage looper,Trichoplusia ni

Thin layer chromatography resolved nine major compounds from the 60%-methanol extractables from PI 227687 soya bean (Glycine max (L) Merrill) leaves. The flavonoids, daidzein, an unidentified flavonoid X2 (R_f 0·19), glyceollins, sojagol and coumestrol exhibited antifeedant and/or antibiotic effects against the larvae of cabbage looper, Trichoplusia ni Hb. The results indicate that several compounds in PI 227687 soya beans contribute to its antifeedant and/or antibiotic effects against T ni. The role of these compounds in plant resistance to insects is discussed.