Selectivity in Mammalian Extinction Risk and Threat Types: a New Measure of Phylogenetic Signal Strength in Binary Traits

Abstract: The strength of phylogenetic signal in extinction risk can give insight into the mechanisms behind species’ declines. Nevertheless, no existing measure of phylogenetic pattern in a binary trait, such as extinction‐risk status, measures signal strength in a way that can be compared among data sets. We developed a new measure for phylogenetic signal of binary traits, D, which simulations show gives robust results with data sets of more than 50 species, even when the proportion of threatened species is low. We applied D to the red‐list status of British birds and the world's mammals and found that the threat status for both groups exhibited moderately strong phylogenetic clumping. We also tested the hypothesis that the phylogenetic pattern of species threatened by harvesting will be more strongly clumped than for those species threatened by either habitat loss or invasive species because the life‐history traits mediating the effects of harvesting show strong evolutionary pattern. For mammals, our results supported our hypothesis; there was significant but weaker phylogenetic signal in the risk caused by the other two drivers (habitat loss and invasive species). We conclude that D is likely to be a useful measure of the strength of phylogenetic pattern in many binary traits.     

Effects of tetrahydrofuran on dissolved oxygen,pH, culturable aerobic microbes and enzyme activity in wastewater

Tetrahydrofuran (THF) is easy to volatilize and hard to biodegrade. Little is known about the influence and fate of tetrahydrofuran in the environment. The effects of THF were examined on dissolved oxygen, pH, culturable aerobic microbes (bacteria, actinomycetes, and fungi) and four selected enzymes (protease, phosphatase, amylase, and lipase) in wastewater. The wastewater containing some activated sludge was taken from the aeration basin in Sibao sewage plant in Hangzhou, China. THF at lower concentrations of enhanced aerobic respiration and higher concentrations decreased utilization of oxygen in wastewater. The short-term influence of THF on pH was not obvious, but the long-term effect was apparent. Inhibition of THF on culturable aerobic microbes rose with increasing THF concentrations but decreased with prolongation of incubation time. No effect of THF on the activity of protease, phosphatase, amylase, and lipase was found. Data indicate that lower concentrations of THF exert no marked influence on wastewater in an urban sewage plant.     

Process development for recovery of copper and precious metals from waste printed circuit boards with emphasize on palladium and gold leaching and precipitation

A novel hydrometallurgical process was proposed for selective recovery of Cu, Ag, Au and Pd from waste printed circuit boards (PCBs). More than 99% of copper content was dissolved by using two consecutive sulfuric acid leaching steps in the presence of H₂O₂ as oxidizing agents. The solid residue of 2nd leaching step was treated by acidic thiourea in the presence of ferric iron as oxidizing agent and 85.76% Au and 71.36% Ag dissolution was achieved. The precipitation of Au and Ag from acidic thiourea leachate was investigated by using different amounts of sodium borohydride (SBH) as a reducing agent. The leaching of Pd and remained gold from the solid reside of 3rd leaching step was performed in NaClO-HCl-H₂O₂ leaching system and the effect of different parameters was investigated. The leaching of Pd and specially Au increased by increasing the NaClO concentration up to 10 V% and any further increasing the NaClO concentration has a negligible effect. The leaching of Pd and Au increased by increasing the HCl concentration from 2.5 to 5 M. The leaching of Pd and Au were endothermic and raising the temperature had a positive effect on leaching efficiency. The kinetics of Pd leaching was quite fast and after 30 min complete leaching of Pd was achieved, while the leaching of Au need a longer contact time. The best conditions for leaching of Pd and Au in NaClO-HCl-H₂O₂ leaching system were determined to be 5 M HCl, 1 V% H₂O₂, 10 V% NaClO at 336 K for 3 h with a solid/liquid ratio of 1/10. 100% of Pd and Au of what was in the chloride leachate were precipitated by using 2 g/L SBH. Finally, a process flow sheet for the recovery of Cu, Ag, Au and Pd from PCB was proposed.     

生物脱臭技术的现状与展望

生物脱臭技术是利用固定在载体上的微生物 ,分解H2 S、NH3、有机溶剂等有害、发臭气体 ,使之成为无害、无味气体 ,从而达到除臭的目的。生物脱臭法与活性炭吸附、药液吸收等物理化学脱臭法相比 ,具有维护管理简单、运行成本低等优点。指出生物脱臭技术是一种应用前景广泛的除臭技术     

Estimation of mercury content in tailings of the gold mine area of Poconé, Mato Grosso,Brazil

As in many other parts of the world, gold is produced in the surface mining region of Poconé, Mato Grosso, Brazil, using mercury. The goal of this investigation was to estimate the amount of mercury in certain tailings and to determine the area of the land that has been contaminated by the gold mining operations. Mercury concentrations from 2 to 495 ng/g (dw) were determined in the tailing materials. It was observed that only isolated sites were acting as central points of contamination. Using digital Landsat satellite data (The-matic Mapper) and aerial photos, the sites degraded by the mining were classified, and their total area was estimated to be 12.3 km² in the region of Poconé. It was estimated, that 4.9 km² were occupied by the contaminated tailings. The mean height of the pile slags was determined to be 4.5 m. From the experimentally calculated average density of the material in the tailings, 2.01 g/cm³, the total mercury content in the piles of tailings was estimated to be 1600 ± 350 kg.     

不同收获方式对粮食损失的影响——基于全国3251个农户粮食收获的实地调研

使用全国3251个农户的数据,通过两步法,比较不同收获方式和社会化服务（购买农机服务）对小麦、水稻、玉米三种主要粮食作物收获环节损失的影响。结果表明：相较于全人工收获方式,全程机械化收获总体上提高了收获环节损失。分品种而言,增加了水稻损失,但降低了小麦损失;半机械化收获显著降低了玉米的收获损失。深入研究发现：购买农机服务能够显著减少小麦的收获损失,稳健性检验反映结论仍然保持一致。基于此,对于小麦要进一步推动全程机械化,对于水稻和玉米,要研发适合农户规模的小型农机和专业农机,短期内进一步推进分段机械化。     

HEALTH RISKS ASSOCIATED WITH CONSUMPTION OF UNTREATED WATER FROM HOUSEHOLD ROOF CATCHMENT SYSTEMS1

ABSTRACT: Rainwater harvesting is receiving increased attention worldwide as an alternative source of drinking water. Although collected rainwater is typically consumed without any type of disinfection, the microbial quality of this type of water source can be poor. Around the world, consumers of collected and stored rainwater may be at considerable risk to a variety of infectious diseases. This review presents studies attributing specific risks of diseases to the consumption of contaminated rainwater. Diseases attributed to the consumption of untreated rainwater include bacterial diarrheas due to Salmonella and Campylobacter, bacterial pneumonia due to Legionella, botulism due to Clostridium, tissue helminths, and protozoal diarrheas from Giardia and Cryptosporidium. Simple indicator systems such as fecal coliform measurements may prove to be inadequate for determining microbial risks associated with consumption of water from rainwater catchment systems.     

黄铁矿晶体形态模拟实验研究

采用实验方法模拟金矿床成矿作用条件,研究水热体系黄铁矿各种晶体形态生成的物理化学条件,着重阐述黄铁矿的五角十二面体、八面体、立方体等晶形形成环境因素。实验成果有助于找矿矿物学、成因矿物学的发展和金矿的找矿和勘探。     

南亚热带不同植被根际微生物数量与根际土壤养分状况

研究了包括尾叶桉、广东凤丫蕨、柳叶竹、大叶相思、青皮、木荷、湿地松在内的7种南亚热带不同植物植被下土壤根际微生物与根际养分状况及其相关关系。结果表明,根际环境对细菌有明显的正效应,对放线菌和真菌有正、负两方面的影响,但对根际微生物总量具有根际效应明显;在南亚热带森林生态系统中.在植物的某些生长季节,微生物的根际效应与土壤养分的根际效应一致     

川西植被恢复过程中的土壤微生物评价及与土壤因子的关系

较系统地评价了川西植被恢复过程中的土壤微生物以及土壤因子对土壤微生物恢复的制约作用。结果表明:在自然恢复的前50 a,40 a群落的微生物数量恢复最佳,40~50 a会逐渐减少,其中微生物的生理类群数量在30 a到达最好,而微生物数量(细菌、真菌和放线菌)在40 a达到最好;采用桦木、刺楸和杉木对微生物及其生理类群群落的恢复效果差,建议恢复川西中亚热带森林生态系统重新选用合适的豆科植物;人工抚育可显著地促进微生物生理类群数量;土壤中的速效K和阳离子交换量是促进土壤微生物和3种生理类群恢复的主要决定因子,而pH、有机质、全K必须通过速效K或阳离子交换量才能对土壤微生物和生理类群起到较大的作用,速效N对微生物及其生理类群没有明显的作用。