The relationship between ecology and the incidence of cooperative breeding in Australian birds

Summary Australia has many cooperatively breeding species of birds. These tend to occur in eucalypt and semi-arid woodlands rather than in rainforests or deserts. They tend to be insectivores that pursue rather than sit and wait for their prey, and tend to forage on the ground rather than above it. We propose that environments where resources do not show marked seasonal fluctuations are those in which cooperative breeding is most likely to evolve. Under these conditions birds might experience difficulty acquiring the extra food necessary to breed, especially if inexperienced. When adult survival was high, young and inexperienced birds could delay breeding. Unpredictable environments may also favor cooperative breeding, but our data do not strongly support this. Groupliving would be favored further if young birds are particularly vulnerable to predators when alone. They should therefore remain in the family group and delay their dispersal unitl a suitable breeding vacancy becomes available. These hypotheses are not mutually exclusive, but are complementary. Both may be required to ensure that at least some year-old birds do not breed and also do not disperse. We believe that they give rise to predictions, which can be tested in future field studies.     

Earthworms and radionuclides, with experimental investigations on the uptake and exchangeability of radiocaesium

The potential influence of earthworm activity on the mobility of radionuclides in soils and their subsequent availability for uptake by plants and transfer to higher trophic levels is briefly reviewed. The accumulation of caesium by the earthworm Aporrectodea longa from soil and from plant litter was investigated in laboratory experiments, as was the effect of reworking (through burrowing and ingestion) soil and soil with added organic material, on the extractability of caesium (ammonium acetate extraction). Soil was spiked with (134)Cs, organic matter with (137)Cs. In soil-fed worms, most of the radioactivity measured was eliminated with the gut contents; 5-25% of the ingested radioactivity was retained or assimilated. Loss of caesium from soil-fed worms followed a two component curve, with an initial rapid loss due to gut clearance (half-life of loss (Tb1/2) of about 0.2-0.6 days) and a slower loss of assimilated caesium (Tb1/2 of 15-26 days). Loss rates of assimilated caesium from worms fed on fragmented apple leaves were found to have half-lives of 18-54 days. Assimilation of caesium from apple leaves was higher than from soil, ranging from 55-100% of the activity measured before gut clearance. Dry weight transfer factors (concentration in worm tissue/concentration in substrate) for worms cleared of their gut contents were similar for the two substrates 0.04 and 0.04 for two loss experiments with worms fed on radioactive soil, and 0.03 and 0.05 for worms fed on apple leaves. After three months of reworking soil and soil/organic mixtures, A. longa was found to have no measurable effect on the extractable fraction of caesium. If earthworms have any subtle effects they were masked by changes in availability that occurred when the spiked soil and organic substrates were mixed together. Only about half of the extractable fraction in soil was recovered when soil was mixed with organic material suggesting that some of the labile fraction in soil had become complexed with organic material. This exchange occurred in substrate mixtures with and without worms. The limitation of chemical extraction procedures is discussed and suggestions for further work are presented.     

对交通建设项目环境影响评价中几个问题的思考

目前，交通建设项目环境影响评价在促进区域经济发展，提高环境意识等方面发挥了重要作用，但仍存在许多不足之处。文中分别从相关法律法规、评价程序、清洁生产和总量控制、环境影响评价层次和公众参与等方面对其存在的问题加以论述分析。     

某高边坡变形破坏机制及整治对策探讨

反倾边坡的稳定性通常较好,但砂窝子高边坡因气候条件恶劣、地质条件复杂、人类工程活动剧烈而发生了大面积的浅表部变形,和一定规模的深部变形,对都江堰至汶川拟建公路的建设构成严重威胁。作者结合现场调查和地质勘察资料,分析了该高边坡的工程地质条件、水文地质条件、岩土体结构特征、以及边坡的变形破坏迹象,归纳出该边坡的变形破坏模式为压缩—倾倒弯曲—错动型,并在此基础上提出了合理的边坡整治方案建议。     

造纸黑液固化技术及有机复合肥肥效试验研究

研究包括两项发明：黑液固化工艺和黑液固化物生产有机NPK复合肥。黑液固化采用交联技术，在常温常压下，向黑液中投加一定量的胶凝剂和交联剂，经搅拌、使黑液在短时间内由液变为固态；通过对固化物成份的分析，以黑液固化物为原料生产有机NPK复合肥，并与一般NPK复混肥进行水稻、花生的肥效对比试验，得出了以黑液固化物生产的有机NPK复合肥肥效优于一般NPK复混肥的结论。     

Fenton氧化法的影响因素及其在废水处理中的应用

阐述了Fenton试剂的氧化机理,介绍了Fenton法的应用以及发展趋势,讨论了各项因素如pH值,Fe2 与H2O2投加量的比、温度和反应时间等对氧化效果的影响.Fenton法在处理难降解有机污染物时具有独特的优势,是一种很有应用前景的废水处理技术.     

一种动胶杆菌的固定化及其降解土壤中菲、芘的研究

 对一株经筛选后能高效降解菲、芘污染土壤的动胶杆菌进行固定化，实验结果表明，采用聚乙烯醇（PVA）100p/（g·L），海藻酸钠5p/（g·L），活性炭50p/（g·L）制得的固定化载体，机械强度好，对菲、芘的降解率10d分别可达87.48％和75.34％，明显高于游离菌对菲芘的降解率66.2％和54.49％.     

上海乡镇工业废气污染状况及防治

上海乡镇工业能源消耗以燃料煤为主，燃烧废气排放量占废气排放总量的９０％，二氧化硫排放量最大的行业是纺织业；烟尘、工业粉尘排放量最大的行业均为非金属矿物制品业。控制乡镇工业废气污染必须采取节约能源，调整能源消耗结构，加强行业整改等措施。     

城市公共交通规划环境影响评价的替代方案分析

城市交通的可持续发展战略要求在交迎规划的制定过程引入战略环境评价。文中结合发展实际，就城市公共交通规划的环境影响评价中的4种替代方案进行了环境影响分析。     

基于甘肃省卫星遥感的对流层NO2时空变化

基于OMI卫星遥感反演的NO₂柱浓度数据,分析了近11a甘肃省对流层NO₂柱浓度的时空变化及相关影响因素,同时利用HYSPLIT模型探究了大气污染物的来源.结果表明：从空间上,NO₂柱浓度呈现出由甘肃东北区向西南区递减趋势,最高值主要分布于庆阳市全境和平凉市少部分地区.从2008~2014年NO₂柱浓度值不断增长至最高值,高值区逐步扩大;2015~2018年NO₂柱浓度值波动变化,呈现出向周围区域递减的趋势,高值区范围缩小;从时间上,2008~2018年对流层NO₂柱浓度整体呈上升趋势,对流层NO₂柱浓度四季均值分布为：夏季>春季>秋季>冬季;NO₂柱浓度每年在6~8月达峰值,9月后开始下降,年内谷值出现在12月份~次年2月份;对研究区NO₂柱浓度的贡献最大的是自然要素.高温、降水有利于土壤排放NO₂,植被覆盖率对NO₂起到一定的消减作用.利用HYSPLIT得出2009~2018年每年7月庆阳市NO₂的外部输送路径,其中主要路径以陕西地区为主.