配筋率对钢筋混凝土框架梁极限承载力的影响——拱效应试验研究

通过对9根不同纵筋配筋率的钢筋混凝土试验梁进行加载试验,研究了纵筋配筋率对钢筋混凝土框架梁拱效应的影响以及拱效应条件下钢筋混凝土框架梁的极限承载力.试验结果和理论分析表明,钢筋混凝土框架梁中的拱效应可以使构件的极限承载力提高1倍左右;纵筋配筋率越低,极限承载力提高的幅度越显著.为提高拱效应的作用,宜将钢筋混凝土框架梁的纵筋配筋率控制在1.5%以内.     

基于秩和比法的突发事件固有风险水平评估

建立突发事件固有风险指标框架,定量评估突发事件固有风险水平。选择自然灾害、事故灾难、公共卫生事件、社会安全事件等四大类突发事件造成的死亡人数和经济损失方面的量化指标,采用秩和比法计算全国31省市区的突发事件相对风险水平,经滑动平均处理后,得到各地突发事件固有风险指数。求解各地突发事件固有风险指数与其累积频率对应的概率单位值的回归方程,将其排序分档,可把全国分为高风险、较高风险、一般风险和低风险水平等四类地区。结果表明我国各地区突发事件固有风险水平存在一定的差异,总体呈西高东低分布。突发事件固有风险指数可定量评估各地区的突发事件固有风险水平,突发事件固有风险指标设置合理、方法可行。     

COD/SO42-值对硫酸盐废水厌氧消化的影响

采用间歇试验方式,研究了COD/SO₄^2-值对硫酸盐废水厌氧消化的影响.试验结果表明,COD/SO₄^2-值是影响厌氧消化处理效果的主要参数.本试验中,COD/SO₄^2->15,硫酸盐还原作用对厌氧反应器影响甚微;COD/SO₄^2-=5-15时,硫酸盐还原作用对厌氧反应器产生轻度抑制,相对产甲烷率为79.2%-94.7%;COD/SO₄^2-=0.5-5时,反应器受中度抑制,相对产甲烷率为61.6%-79.2%;COD/SO₄^2-<0.5时,反应器受严重抑制.COD/SO₄^2-≥1时,相对产甲烷率与COD/SO₄^2-值之间有很好的线性关系.     

Offspring sex ratio variation in the bridled nailtail wallaby, Onychogalea fraenata

The bridled nailtail wallaby is a sexually size dimorphic, promiscuous, solitary macropod. Sex ratios of pouch young were studied at two sites over 3 years, beginning with 14 months of severe drought. Females that were in better condition were more likely to have sons, and condition was dependent on body size. Females at one site were heavier, were consequently in better condition, and produced more sons than females at the other site. Females that declined in condition had more daughters during the most severe part of the drought than females that maintained condition, but endoparasite infection did not affect the pouch young sex ratio. Age also appeared to affect sex ratio adjustment, because weight was strongly influenced by age. Sex ratio bias was not caused by early offspring mortality, but occurred at conception. Mothers did not appear to bias energy expenditure on sons or daughters; males and females did not differ in condition at the end of pouch life. Pouch young sex ratio variation was most consistent with the Trivers-Willard hypothesis, but could also have been influenced by local resource competition, since sons dispersed further than daughters. Offspring condition was related to survival, and was correlated with maternal condition. Received: 14 April 1998 / Accepted after revision: 10 November 1998     

大熊猫肌肉氨基酸含量的初步研究

测定了３只大熊猫的头部、背部和腿部等１０个肌肉样品中１７种氨基酸（ＡＡ）含量,并分析了各样品ＡＡ与Ｌｙｓ含量的比值．结果表明：对同一只大熊猫,不同部位的肌肉样品中各ＡＡ含量无明显差异;对同一个肌肉样品,１７种ＡＡ含量比较,Ｇｌｕ含量最高,Ａｓｐ、Ａｒｇ、Ｌｙｓ、Ｌｅｕ、Ａｌａ、Ｇｌｙ、Ｖａｌ、Ｐｒｏ、Ｔｈｒ、Ｐｈｅ等含量较高;不同年龄大熊猫肌肉ＡＡ含量有差异,除极少数ＡＡ外,未成熟雄性大熊猫肌肉ＡＡ含量高于成熟和老龄雌性大熊猫,且有显著性差异（Ｐ＜０．０５或Ｐ＜０．０１）;成熟雌性大熊猫肌肉中,除Ｐｒｏ外,其余所有ＡＡ含量与其年龄无显著差异（Ｐ＞０．０５）;除极少数ＡＡ外,不同年龄、性别大熊猫肌肉样品中各ＡＡ与Ｌｙｓ含量的比值无明显差异     

部分亚硝化-厌氧氨氧化耦合工艺处理污泥脱水液

在缺氧滤床+好氧悬浮填料生物膜工艺中实现部分亚硝化,然后进行厌氧氨氧化(ANAMMOX),考察其对高含氮、低C/N污泥脱水液的处理能力.结果表明,亚硝化反应器在15~29℃、DO 6~9mg/L条件下,通过综合调控进水氨氮负荷(ALR)、进水碱度/氨氮、水力停留时间(HRT)等运行参数,可以调节出水(NO2--N)/(NH4+-N)的比率,能够较好地实现部分亚硝化反应以完成厌氧氨氧化.当进水ALR为1.16kg/(m3·d),进水碱度/氨氮为5.1时,出水(NO2--N)/(NH4+-N)在1.2左右,(NO2--N)/(NOx--N)大于90%,进入ANAMMOX反应器的氮物质去除率达到83.8%.     

水泥窑共处置危险废物过程中重金属的分配

以废弃农药、污染土壤和废白土为研究对象,在3个新型干法水泥厂开展了水泥窑共处置的工程试验,分析了共处置对13种重金属在不同相分配情况的影响.结果表明,重金属的分配不受危险废物投加的影响,不挥发和半挥发重金属在烟气中的分配率远低于在熟料中的分配率;尾气中Hg及部分重金属的排放浓度很小甚至低于检测限;As在烟气中分配率较高,与该金属在窑内的存在形态以及As的某些化合物具有挥发性等因素有关;为控制尾气中重金属含量满足相关标准的排放限值,根据本研究和相关研究数据预测了重金属允许的最大投加量和废物中允许的重金属最大含量.     

生活垃圾焚烧飞灰制陶瓷砖

分析了飞灰的性质,利用飞灰、黄陶土、缸砂及文石研制陶瓷砖,并进行正交配比试验。结果表明:飞灰主要矿物成分是硅酸盐及铝硅酸盐,可用作陶瓷砖的原材料;飞灰的掺加量对陶瓷砖表观质量起决定性影响,最佳配比方案为飞灰25%,黄陶土55%,缸砂10%,文石10%;最佳配比制品浸出毒性均达标。     

Pup production,sex ratios,and survivorship in African wild dogs, <Emphasis Type="Italic">Lycaon pictus</Emphasis>

The local resource enhancement (LRE) model predicts that in cooperatively breeding species, sex ratios will be biased in favor of the more helpful sex. In this study, we assess the assumptions underlying the LRE model in a population of cooperatively breeding wild dogs (Lycaon pictus) in Northern Botswana monitored over a 15-year period. In this population, litter size and pup survival to 1 year are strongly affected by pack size and the breeding female’s age, but adult males have a stronger and more linear effect on females’ reproductive performance than do adult females. This asymmetry in the benefits derived from male and female helpers is reflected in male-biased sex ratios in litters at the time pups emerge from the den. Sex ratio biases are most pronounced in the litters of the youngest mothers who live in significantly smaller packs than older females. The presence of potential rivals for the dominant female’s position depresses pup production at the time of emergence, suggesting that competition among females for breeding positions may also contribute to the selective forces affecting birth sex ratios.     

Sex allocation in a monomorphic seabird with a single-egg clutch: test of the environment, mate quality, and female condition hypotheses

Sex allocation theory posits that mothers should preferentially invest in sons when environmental conditions are favorable for breeding, their mates are of high quality, or they are in good body condition. We tested these three hypotheses in rhinoceros auklets (Cerorhinca monocerata), monomorphic seabirds that lay a single-egg clutch, in 2 years that differed in environmental conditions for breeding. Results supported the environment and mate quality hypotheses, but these effects were interactive: offspring sex was independent of paternal traits in the poor year for breeding, while females mated to larger and more ornamented males reared more sons in the better year. Conversely, offspring sex was unrelated to female condition, as indexed by hatching date. We propose that good rearing conditions enable females to rear sons possessing the desirable phenotypic attributes of their mates. Results also supported two critical assumptions of sex allocation theory: (1) dimorphism in offspring condition at independence: daughters fledged with higher baseline levels of corticosterone than sons and (2) differential costs of rearing sons versus daughters: mothers rearing sons when environmental conditions were poor completed parental care in poorer condition than mothers rearing daughters in the same year and mothers rearing either sex when conditions were better. These novel results may help to explain the disparate results of previous studies of avian sex allocation.