基于PLC的火灾报警控制系统设计

随着我国社会经济的飞速发展,在石油生产装置建设的过程中,由于其规模数量巨大,所以易燃易爆化学产品引发火灾事件屡屡发生。所以需要对自动报警系统进行严格的管控,从而保证化工生产装置的安全性。因此,针对由PCL做核心控制器的火灾报警系统自动化做出描述,并与消防系统联动控制的同时对其组成部分工作原理及相关工作进行了详细介绍。     

马铃薯致病疫霉拮抗细菌研究进展

为了解决马铃薯致病疫霉侵染马铃薯导致其死亡,进而造成马铃薯单位种植产量低的问题。本文从拮抗菌入手,归纳分析细菌类拮抗菌中的主要拮抗菌中芽孢杆菌、假单胞菌和粘细菌对马铃薯致病疫霉的抑制作用。同时,在总结前人研究的基础上,笔者认为在拮抗菌应用方面,可以采用多对一的新型平板对峙筛菌模式来模拟复杂条件下拮抗菌的拮抗作用,以期得到稳定的拮抗菌;并指出应从定植能力和根际微生物影响方面对拮抗菌实际应用的可行性进行研究;此外,提出未来对拮抗菌抑制马铃薯致病疫霉的探究应从表型层面的研究深入到分子层面,以期能成功从源头找寻抑制马铃薯致病疫霉的答案。     

微生物菌剂对青椒生长、品质和土壤养分状况的影响

以"圣鼎一号"青椒为试验材料,采用田间试验的方法,研究了增施微生物菌剂对青椒生长、品质和土壤养分状况的影响,以期为青椒合理的增施微生物菌剂提供参考依据.结果表明:增施含有侧孢短芽孢杆菌的微生物菌剂A能更有效地促进青椒生长,提高青椒的果实品质产量和土壤养分;与其它处理相比,减量施肥+微生物菌剂A处理促进青椒生长,提高果实品质产量的效果最明显.与其它增施微生物菌剂的处理相比,青椒的株高、茎粗和叶绿素均有不同程度的提高,使青椒维生素C含量、可溶性蛋白质、可溶性固形物和总产量分别提高了 3.3％～15.1％、14.2％～25.2％、6.2％～8.8％和23.3％～36.2％,硝酸盐含量降低了 9.1％～11.8％;与其它处理相比,常规施肥+微生物菌剂A处理使土壤养分含量增加的效果最明显.与其它增施微生物菌剂的处理相比,使土壤的硝态氮、有效磷和速效钾含量分别提高了 3.5～9.4％、4.8～14.0％和3.5～9.6％.增施含有侧孢短芽孢杆菌的微生物菌剂A可以作为一种促进青椒生长、增加果实品质产量和提高土壤养分的方法.     

果园有机肥深施机分层变量排肥控制系统设计与试验

果园不同深度的土壤养分不同，果树根系分层吸肥能力不同，有机肥分层变量深施可以解决传统施肥存在的养分分布不均和肥料利用率低等问题。针对有机肥分层变量深施的排肥控制问题，本文设计了排肥控制系统，可以根据用户设置的各层理论排肥量和作业速度，实时计算液压马达的理论转速，并采用PID算法控制比例流量阀开度，调节马达转速驱动螺旋输送器排肥，实现分层变量排肥。将AMESim中建立的液压系统模型与在Matlab/Simulink中建立的控制模型进行联合仿真，整定PID参数。液压马达转速调节性能试验中最大超调量为14r/min，达到稳定转速的时间最大为6s，控制性能较好，表明通过AMESim-Matlab/Simulink联合仿真，能够快速便捷地整定PID参数，结果准确可靠。排肥控制性能试验中排肥量相对误差最大6.20%，变异系数最大8.69%，排肥量准确性和均匀性均达到要求。设计的控制系统具有较好的性能，能为果园有机肥分层变量深施提供技术支撑。     

Cf-2/Rcr3pim番茄品系对南方根结线虫的抗性测定

Cf-2/Rcr3~(pim)基因型番茄不仅能够抵御番茄叶霉菌的侵染,而且对马铃薯金线虫的寄生也有一定的抑制效果。为挖掘根结线虫的新抗性资源,本研究采用室内人工接种法测定了Cf-0/Rcr3~(pim)、Cf-2/Rcr3-3和Cf-2/Rcr3~(pim)基因型番茄品系对南方根结线虫的抗感性。抗性评价结果显示,Cf-0/Rcr3~(pim)品系对南方根结线虫表现高感,Cf-2/Rcr3-3品系为中感,而Cf-2/Rcr3~(pim)品系则为感病。与Cf-0/Rcr3~(pim)和Cf-2/Rcr3-3基因型相比,Cf-2/Rcr3~(pim)基因型番茄品系虽然对南方根结线虫侵染的敏感性略低,但是不能阻止线虫在根系上的大量繁殖,不适于根结线虫的防控应用。     

Fabrication of hydrophobic/oleophilic cotton fabric by mussel-inspired chemistry for oil/water separation

A straightforward approach was proposed to modify cotton fabric for oil/water separation based on musselinspired reaction. The poly(DMA-Octadecyl acrylate) was designed to contain key chemical constituents present in mussel adhesive proteins by free radical polymerization of dopamine hydrochloride and octadecyl acrylate, which strongly adsorbed to fabric substrates, providing a special surface for fabric. The chemical structure, surface topography, and surface wettability of the fabric were characterized. The results showed that as-prepared cotton fabric displayed a high CA of >150° when dripped water droplets were on the modified fabric surface, and the oil contact angle (OCA) was close to 0°, it had excellent potential to be used in practical applications and has created a new method of fabric modification for oil/water separation.     

Effects of elevated CO2 concentration on bulbil germination and early seedling growth in Chinese yam under different air temperatures

The present study investigated the effects of elevated carbon dioxide concentration ([CO₂]) and air temperature on the germination of seed bulbils and the seedling vigour of two Chinese yam lines. Plants were grown under two [CO₂] levels, ambient and elevated (ambient + 200 μmol mol^?1), and two mean air temperature regimes, 22.2 °C (ambient + 1.4 °C) and 25.6 °C (ambient + 5.2 °C). Elevated [CO₂] did not affect bulbil germination under both air temperature regimes. During the early growth stage, the dry weight (DW) of leaves, vines, shoots, roots, belowground parts (roots + tubers) and whole plants were higher under elevated [CO₂] than ambient [CO₂] for both lines under the low- and high-temperature regimes. The values of vigour indexes (index I = germination % × seedling length and index II = germination % × seedling DW) were also higher under elevated [CO₂] than ambient [CO₂] for both lines. These results indicated that Chinese yam seedlings respond positively to elevated [CO₂] during the early growth stage. The above:belowground DW ratios were lower under elevated [CO₂] than ambient [CO₂] in seedlings with very small new tubers for both yam lines, indicating that elevated [CO₂] strongly affected the root growth in the early growth stage. The DWs of post-treatment seed bulbils were higher in the elevated [CO₂] under both air temperature regimes. The results showed that Chinese yam used a smaller amount of the reserves in seed bulbils under elevated [CO₂] than under ambient [CO₂].     

Effects of blue shrimp Litopenaeus stylirostris and goldlined rabbitfish Siganus lineatus in mono‐ and polyculture on production and environmental conditions

This study was conducted to compare the effects of shrimp and rabbitfish in mono‐ and polyculture stocked at high biomass on production and environmental conditions in a mesocosm system. Shrimp (14 g) and/or rabbitfish (19 g) were stocked in four treatments with different density but with the same total biomass (236 g m^?2), including shrimp monoculture (SM) (17 shrimp m^?2), shrimp–fish polyculture (SF) (11 shrimp and 4 rabbitfish m^?2), fish–shrimp polyculture (FS) (6 shrimp and 8 rabbitfish m^?2) and fish monoculture (FM) (12 rabbitfish m^?2). After 10 weeks of experiment, shrimp survival and biomass were low in the treatments where shrimp were dominant (SM, SF), while rabbitfish survival and biomass were high in all the treatments. Shrimp mortality was assumed to be related to an excess of the system carrying capacity (CC). Results suggested that CC is linked to shrimp biomass/density rather than the system eutrophication level. The ecosystem became heterotrophic as daily feed supply was beyond 7 g m^?2 per day. This threshold corresponded to the environmental CC of the semi‐intensive shrimp culture system. Under these conditions, the combination of high fish biomass and low shrimp biomass appeared as the most valuable in terms of system performances.     

春大豆鼓粒期冠层翻叶原因及翻叶对叶片净光合速率和粒重的影响

为明确春大豆鼓粒期冠层翻叶原因及翻叶对粒重的影响。在大田条件下,以28份大豆品种为材料,采用随机区组试验设计,研究了鼓粒初期植株顶部4片叶的单叶面积、比叶重、叶型指数、叶片含水量与翻叶率的关系;比较了翻叶与对照叶片的净光合速率、百粒重及粒重的差异。结果表明,不同大豆品种间翻叶率在0~26.5%之间,且差异显著,其中以‘中黄313’、‘中黄42’和‘中黄13’最高;单叶面积在46~151 cm²之间,其中以‘中黄39’、‘中黄42’和‘中黄13’最大;比叶重在0.536~1.64 mg/cm²之间,其中以‘中黄322’、‘中黄313’和‘中黄13’最低;叶型指数在1.35~3.51之间,其中以‘中黄70’、‘中黄80’和‘中黄42’最低。供试大豆品种分为3个类群,第I类群品种单叶面积小,比叶重高,叶型指数大,翻叶率为1.03%;第III类群品种单叶面积大,比叶重小,翻叶率高达19.7%;第II类群共4个品种,单叶面积、比叶重、叶型指数、翻叶率介于第I类和第III类群之间。翻叶后显著降低叶片净光合速率,平均降幅31.7%,粒数较多的‘新大豆27号’百粒重降低10.38%~22.4%,而粒数少的‘吉育60’粒重没有降低。大豆上层叶片单叶面积大、比叶重小及叶型指数低的叶片翻叶率高,翻叶降低叶片净光合速率,进而降低同节位百粒重及单节粒重,不利于大豆高产。