福建省台风灾害时空变化分析

根据福建省灾害性气象年鉴和福建省气候影响评价资料,建立以县域为单元的福建省台风灾害数据库,运用Excel软件和M ap info技术,重建了1980~2005年福建台风灾害时空动态格局。研究表明:福建台风灾害年际变化总体呈波动上升趋势,年内80%左右集中在7~9月份,群发性强。空间上集中在沿海地区,灾情明显存在3个高值中心,即闽中的莆田、福清、长乐和平潭,闽南的漳浦、云霄和诏安,闽东北的霞浦和福鼎;致灾因子与灾情灾次比空间分布错位,体现承灾体脆弱性对台风灾害的影响。分阶段研究表明:台风灾害致灾因子变化不太明显,但灾情呈明显增强趋势,进一步反映环境不稳定性和承灾体脆弱性对台风灾害的影响机制。     

河北张家口地区雹灾区划研究

使用雹灾汇报资料,对本区的雹灾受灾频率、重灾频率和成灾面积比的分布做了区划分析。结果显示：受灾频率较大的地区基本与本区的坝头地带、坝上西部及复杂山地配合;较小的地区是海拔最低的洋河谷地。重灾频率和成灾面积比的分布与受灾频率基本相反。分析原因,主要是雹块大小与海拔高度呈反相关以及生长期的差异。     

苏南地区新近沉积土的动剪切模量比与阻尼比--试验研究

苏南地区的场地土主要为漫滩相、湖沼相或冲湖相新近沉积软弱土，结构松散，沉积零乱，成分复杂，饱水可液化粉细砂层及粉土层较为发育，在地震或动力荷载的作用下有可能发生软土震陷或砂土液化。通过对苏南地区淤泥质粉质粘土、粘土、粉质粘土、粉质粘土与粉细砂互层土、粉土、粉砂、细砂和中粗砂等8类新近沉积土155个原状土样历时4年的试验研究，给出了该地区上述8类新近沉积土的动剪切模量比G／Gmax和阻尼比D随剪应变幅值γ变化的平均拟合曲线及其参数的推荐值。为便于一般工程应用，给出了这8类新近沉积土的G/Gmax-γ，和D—γ关系曲线的推荐值及其标准差。     

Livestock excreta management through vermicomposting using an epigeic earthworm Eisenia foetida

In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost) at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and increase in nitrogen and phosphorus contents. Total K was lower in the final cast than in the initial feed. C:N ratios of the vermicomposts ranged from 16.2 ± 2.17 to 75.4 ± 6.84. Microbial activity measured as dehydrogenase activity in buffalo, donkey and camel wastes increased with time up to day 90. But in sheep and goat wastes, maximum dehydrogenase activity was recorded on day 60 and decreased thereafter. The cocoons and hatchlings production by Eisenia foetida in different excreta were also investigated. The greatest number and biomass of hatchlings was recorded in horse excreta followed by cow, goat and sheep excreta. Thus, cow, horse, sheep and goat excreta show potential as good substrates in vermicomposting using Eisenia foetida, although further research is required to explore the feasibility of use of buffalo, donkey and camel excreta in combination with cow/sheep/goat excreta.     

INCREASING WATER SUPPLY BY MIXING OF FRESH AND SALINE GROUND WATERS1

ABSTRACT: The quality of ground water in any aquifer takes its final form due to natural mixture of waters, which may originate from different sources. Water quality varies from one aquifer to another and even within the same aquifer itself. Different ground water quality is obtained from wells and is mixed in a common reservoir prior to any consumption. This artificial mixing enables an increase in available ground water of a desired quality for agricultural or residential purposes. The question remains as to what proportions of water from different wells should be mixed together to achieve a desired water quality for this artificial mixture. Two sets of laboratory experiments were carried out, namely, the addition of saline water to a fixed volume of fresh water. After each addition, the mixture volume and the electric conductivity value of the artificially mixed water were recorded. The experiments were carried out under the same laboratory temperature of 20°C. A standard curve was developed first experimentally and then confirmed theoretically. This curve is useful in determining either the volume or discharge ratio from two wells to achieve a predetermined electrical conductivity value of the artificial mixture. The application of the curve is given for two wells within the Quaternary deposits in the western part of the Kingdom of Saudi Arabia.     

Effect of the water–oil ratio on brine/surfactant/alcohol/oil systems optimized for soil remediation

The optimum middle-phase microemulsion used for remediation of oily contaminated soils is often obtained by mixing a certain amount of a surfactant/alcohol mixture with oil and adjusting the salinity concentrations at a constant water–oil ratio. Upon introduction to the subsurface, however, the system may not be in the optimum state throughout the remediation process owing to the change in the water–oil ratio. This research has attempted to investigate the effect of the water–oil ratio on the phase behavior of systems containing brine, anionic surfactant, alcohols, and different oils. By systematically changing the water–oil ratio, while keeping the others variables constant, the systems exhibited different phase behavior. The results revealed that the effect of the water–oil ratio on system behavior was significant, and analogous to that of salinity. Increasing the water–oil ratio led the system change from winsor I → winsor III → winsor II. The greater the water–oil ratio the lower the salinity required to produce the middle-phase microemulsion, but the narrower the salinity range of the three-phase region. An empirical correlation has been developed in order to predict the changes in phase behavior with the changes in water–oil ratio. This provides a useful tool for designing optimum formulations suitable for soil remediation. Received: October 5, 1999 / Accepted: March 27, 2000     

Cooperatively breeding superb fairy-wrens show no facultative manipulation of offspring sex ratio despite plausible benefits

We report a long-term study of offspring sex ratios in the cooperatively breeding superb fairy-wren Malurus cyaneus. Detailed study of this species had revealed a suite of potentially strong selection pressures on the sex ratio. First, females gain substantial fitness benefits from the presence of helpers; so females without male helpers would benefit from any strategy that increased the probability of recruiting help, such as overproduction of sons (local resource enhancement hypothesis), but large numbers of helper males compete among themselves, favouring the production of daughters (local resource competition). Second, daughters fledged early in the season have far greater chances of recruitment to the breeding population than late-fledged daughters, so mothers would benefit from production of daughters early in the breeding season (early bird hypothesis). Third, extra-group mate choice imposes strong sexual selection on males, suggesting that females mating with attractive sires could benefit from investing in sons (sexual selection hypothesis). However, the predictions from these and other sex ratio hypotheses were rejected. The only convincing evidence for manipulation of the sex ratio was a slight bias towards sons (11 sons to 10 daughters) that occurred regardless of context. This result does not support current theory.     

Contradictory results in sex ratio studies: populations do not necessarily differ

In avian sex ratio studies, results often differ between species and between populations within species. Some researchers argued that positive results were simply statistical artefacts and that sex ratio adjustment did not exist. However, many of the proposed mechanisms of sex ratio adjustment result in costly laying gaps. In these cases, females laying large clutches may restrict the sex manipulation to the first egg of the clutch. Consequently, detectability of sex ratio adjustment on the level of the clutch can be low. Though obvious, this fact is often neglected in the literature. Using simulations, I show that the proportion of undetected sex manipulation can be surprisingly high when the manipulation is restricted to the first egg. If the sample size is 50 broods, there is 47% and 71% chance in 6- and 12-egg clutches, respectively, that sex manipulation is undetected. Even with large samples (n = 100), the figures are 15% and 46%. These data suggest that nonsignificant results for clutch sex ratios do not necessarily mean that sex is not manipulated in a portion of the brood, e.g. in first-laid eggs. Hence, whenever possible, data on laying order-specific sex manipulation should also be collected. Without such data, contradictory results on brood sex ratios should be interpreted cautiously.     

Cofoundress relatedness and group productivity in colonies of social <Emphasis Type="Italic">Dunatothrips</Emphasis> (Insecta: Thysanoptera) on Australian <Emphasis Type="Italic">Acacia</Emphasis>

Facultative joint colony founding by social insects provides opportunities to analyze the roles of genetic and ecological factors in the evolution of cooperation. Although cooperative nesting is observed in range of social insect taxa, the most detailed studies of this behavior have been conducted with Hymenoptera (ants, bees, and wasps). Here, we show that foundress associations in the haplodiploid social thrips Dunatothrips aneurae (Insecta: Thysanoptera) are most often comprised of close relatives (sisters), though groups with unrelated foundresses are also found. Associations among relatives appear to be facilitated by limited female dispersal, which results in viscous population structure. In addition, we found that per capita productivity declined with increasing group size, sex ratios were female-biased, and some female offspring apparently remained in their natal domicile for some time following eclosion. D. aneurae thus exhibits a suite of similarities with eusocial Hymenoptera, providing evidence for the convergent evolution of associated social and life-history traits in Hymenoptera and Thysanoptera.     

气化熔融处理生活垃圾时灰渣的熔融特性

弄清垃圾灰渣的熔融特性对于保证生活垃圾的气化熔融与液态出渣具有重要作用。针对重庆生活垃圾灰与无烟煤灰形成的灰渣,实验研究了在不同的燃料添加量及添加剂条件下灰渣的熔点与粘度,并结合炉温的变化,分析了不同条件对灰渣熔融及液态出渣的影响。结果表明,灰渣的熔点与粘度均随燃料添加量的增加而升高;向燃料比为10%的灰渣中加入添加剂后,灰渣的熔点降低幅度较小,其粘度却随碱度的增加而增大以至熔渣流动性变差;燃料比为40%时,灰渣熔点与粘度均随添加剂的加入而显著降低,且向渣中加入CaO使得灰渣碱度为1.2时灰渣熔点较低且粘度较小,有利于其熔融与液态出渣。