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1.
分析了ABS树脂生产装置丁二烯缓冲罐中丁二烯自聚物的生成原因,提出了预防措施,避免丁二烯自聚物的生成,保证装置的安全平稳运行。 相似文献
2.
亚麻废水是一种较难降解的废水,采用气浮-完全推流曝气工艺和UASB法处理亚麻加工厂废水,从能耗、工艺特点、运行管理上进行对比。结果表明,采用气浮-完全推流曝气工艺在处理此类废水中可收到良好成效,且废水处理成本为0.6-0.7元/m3。 相似文献
3.
Copulatory plugs do not assure high first male fertilisation success: sperm displacement in a lizard
Pedro L. Moreira Vera L. Nunes José Martín Octávio S. Paulo 《Behavioral ecology and sociobiology》2007,62(2):281-288
Sperm competition selects for opposing male defensive and offensive reproductive traits, and its outcome may be determined
by the effectiveness to which one trait has evolved to out-compete the other. We tested the effectiveness of a first male
plug physical interference with a second male insemination (defence) vs the effectiveness of plug and associated sperm displacement
by a second male (offence) on the outcome of sperm competition in Iberian rock lizards. We conducted a double mating experiment
where we compared the proportion of eggs per clutch fertilised by the same second males (against the same first males) when
they copulated with females 30 min (first male plug adhered firmly inside the female cloaca) and 4 h (first male plug loosely
adhered or shed from the female cloaca) after first males. We found that second males fertilised the majority of the eggs
per clutch in the 30-min treatment, whereas fertilisations were equally shared between the two males in the 4-h treatment.
These results show that plugs have little defensive effectiveness, and thus, do not assure high first male fertilisation success.
Instead, sperm displacement appears to be associated with plug displacement. That is, because sperm embedded in first male
plugs, and displaced from competition for fertilisations by second males, is expected to increase in number with decreasing
time allowed for female sperm transport, second males thus enjoy higher fertilisation success. This study shows that offensive
plug displacement out-competes plug defensive role in Iberian rock lizards. Moreover, it reveals sperm displacement as a novel
sperm competition mechanism in reptiles. 相似文献
4.
低能耗污水处理技术的应用 总被引:1,自引:1,他引:0
以蚌埠市第三污水处理厂为例,详细介绍工程中所应用的一体化技术、低溶氧技术、同时硝化/反硝化技术、微孔软管曝气技术、新型推流技术等低能耗污水处理技术,并从反应机理、处理效果、节能效果等方面加以分析和比较,为相关技术人员选择污水处理工艺提供了新的思路。 相似文献
5.
在油田井下作业过程中,常对油井的高含水层或报废井实施封堵,这种传统的施工工艺存在一些不足之处。引入清洁生产理念,提出了用钢丝绳将水泥浆送入井筒中预定位置的施工工艺,即无管柱注水泥塞工艺。该工艺不需要水泥车等特种车辆的配合,不会发生井下开关操作失误造成的事故,比传统注灰工艺节约作业周期3/4以上。另外,该工艺从源头上实施了清洁生产措施,操作简单,经济效益较高,在油田修井作业系统有推广价值。 相似文献
6.
Tho Dinh Son Van Nghia Phan Trung Vu Nguyen Anh Huong Nguyen Lan Anh To Kim 《International Journal of Green Energy》2016,13(7):720-729
To date, non-food vegetable oil has been considered as the primary source for biodiesel production. Rubber seed oil has high acid value (34 mgKOH/g) and can be used for biodiesel synthesis. The purpose of this study was to investigate esterification of fatty acid, which derived from rubber seed oil, in a plug flow reactor system at high temperature and low methanol consumption. Response surface methodology was applied for design experiment and optimization of esterification reaction. Temperature, methanol consumption, and sulfuric acid were chosen as variables to examine their influence in a conversion to methyl ester. At 140°C, at 5:1 methanol to fatty acid ratio (by mole), H2SO4 1.5 (%v/w), and space time 20 min, the conversion to methyl ester attained 98.2%. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-Mass spectrometry (GC-MS) were used for analysis and to confirm the formation of methyl ester. Methyl ester was characterized for biodiesel fuel properties in accordance to ASTM standard. 相似文献
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8.
Stefan H. Nessler Gabriele Uhl Jutta M. Schneider 《Behavioral ecology and sociobiology》2009,63(3):355-362
Sperm competition is a potent driving force in evolution leading to a remarkable variety of male adaptations that prevent
or reduce fertilization by rivals. An extraordinary defensive strategy against sperm competition has evolved in a number of
web spiders where males break off parts of their paired genitalia in order to obstruct the copulatory openings of females
(mating plug). A recent comparative analysis on the family level reports that genital damage is most frequent in species with
sexual cannibalism although, as yet, a functional association between sexual cannibalism and genital damage has not been found.
Using the moderately sexually cannibalistic orb-web spider Argiope lobata, we show for the first time that males cannibalized during their first copulation damaged their pedipalps with significantly
higher probability (74%) than males that escaped (15%). Of all males that damaged their genitalia, 44% were able to place
a genital fragment inside the copulatory opening of the female, resulting in a relatively low total plugging rate of 14%.
Successful obstruction of the female copulatory opening reduced the share of paternity of subsequent males (P
2 = 0.06%), thus, indicating that genital damage may have evolved as a response to sperm competition in this species as well.
However, the low incidence of successful plugging and the strong relationship between sexual cannibalism and genital damage
suggest that apart from paternity protection, the nature of genital damage in A. lobata is further shaped by sexual conflict or cryptic female choice. 相似文献
9.
李玉军 《安全.健康和环境》2012,(10):5-7
分析了立式罐冷却喷水管喷水孔经常堵塞的原因:管道中有杂质、缺少放空阀、喷水管内壁有毛刺、油漆堵塞喷水孔等,找出了对应的解决办法。进一步说明了采用膜式喷头的益处。 相似文献
10.
螺旋升流式反应器脱氮除磷效果及其特性的研究 总被引:17,自引:2,他引:17
利用螺旋升流式反应器 (SpiralUp FlowReactor,SUFR)系统进行了生物脱氮除磷的试验研究 ,该系统连续稳定运行两个月的结果表明 ,对TN、TP和COD的去除率分别达 86 %、96 %和 94 %以上 .对SUFR系统的反应特性进行了分析 :(1)螺旋流动特征使本反应器的形式接近于活塞流反应器 ,有利于在空间上形成有机物的浓度梯度分布 ;(2 )SUFR系统表现出了较好的有机底物和氧气的传质特性 ;(3)SUFR系统中的微生物种群具有多样化 ,所形成的微生物生态系统更稳定 ,抗外界干扰及恢复调节能力强 相似文献