低毒防腐剂百菌清及铜制剂对木材尺寸稳定及力学性能的影响

百菌清（CTL）、氨浴季铵铜（ACQ）、氨溶柠檬酸铜（ACC）处理马尾松（Pinus massoniana)、毛白杨（Populus tomentosa)后对木材尺寸稳定性及MOE／MOR的影响本文进行了研究。结果表明，除剂量11．48kg/m^3的百菌清处理的毛白杨外，以上防腐剂处理试材后吸水至饱和时的尺寸稳定性与对照相比有不同程度的增加，幅度为3．9％－28．05；各处理对抗弯弹性模量（MOE）影响幅度不大，其中对于马尾松，MOE差异不明显，对于毛白杨，各处理对MOE稍有增加（百菌清乳剂处理除外），幅度6．3％－8．1之间。各制剂处理马尾松、毛白杨后对抗弯强度（MOR）影响不明显。     

Effect of temperature on copper toxicity and hematological responses in the neotropical fish Prochilodus scrofa at low and high pH

Copper sulfate has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in water but also on water quality. The susceptibility of the neotropical freshwater fish Prochilodus scrofa to copper was evaluated at two temperatures with low and high water pH. Juvenile fish were acclimated at 20 and 30 °C and exposed to copper (static bioassay system) in water with pH 4.5 and 8.0. The 96 h-LC₅₀ were determined at each temperature and pH, as were the hematological parameters. The 96 h-LC₅₀ for copper (98 and 88 μg Cu L^− 1 in water with pH 4.5 and 16 and 14 μg Cu L^− 1 in water with pH 8.0 for fish kept at 20 and 30 °C, respectively) was significantly dissimilar in pH 4.5 and 8.0, but no difference was found between 20 and 30 °C in the same water pH. At 20 °C, regardless of the water pH, the hematocrit (Hct) increased while the red blood cells (RBC) and hemoglobin (Hb) concentration decreased compared to control pH 7.0. Copper exposure in water pH 4.5 and 8.0 causes an increase on the Hct, RBC and Hb concentrations in relation to the controls pH 4.5 and 8.0. At 30 °C, the changes on the blood parameters depended on the water pH and, after copper exposure at low and high pH, the blood changes indicated more complex responses. The changes in hematological parameters of the fish, regardless of the pH and water temperature, indicate ionoregulatory or respiratory disturbances that imply an increase in energy consumption to restore homeostasis instead of other physiological functions such as weight gain and growth.     

壳聚糖-铜杀菌剂的合成工艺及其Cu^2＋的解吸性能研究

[目的]利用壳聚糖开发载体化铜制剂,既可避免铜离子浓度过高的药害,又可以延长药效期.[方法]探讨了壳聚糖对Cu^2＋吸附量的影响因素,最佳条件下合成壳聚糖-铜杀菌剂,研究其在水中Cu^2＋的释放动力学.[结果] CTS-Cu的最佳合成工艺：硫酸铜浓度20g/L,壳聚糖、硫酸铜质量体积比为1/40,反应温度40℃,吸附时间90 min.载铜壳聚糖在水中Cu^2＋的释放量随时间的延长而增加,8h即可达到较高浓度,在36 h后基本达到稳定释放.[结论]为其农业生产应用奠定基础.     

A single application of Cu to field soil has long-term effects on bacterial community structure, diversity, and soil processes

Long-term diversity-disturbance responses of soil bacterial communities to copper were determined from field-soils (Spalding; South Australia) exposed to Cu in doses ranging from 0 through to 4012 mg Cu kg⁻¹ soil. Nearly 6 years after application of Cu, the structure of the total bacterial community showed change over the Cu gradient (PCR-DGGE profiling). 16S rRNA clone libraries, generated from unexposed and exposed (1003 mg Cu added kg⁻¹ soil) treatments, had significantly different taxa composition. In particular, Acidobacteria were abundant in unexposed soil but were nearly absent from the Cu-exposed sample (P<0.05), which was dominated by Firmicute bacteria (P<0.05). Analysis of community profiles of Acidobacteria, Bacillus, Pseudomonas and Sphingomonas showed significant changes in structural composition with increasing soil Cu. The diversity (Simpsons index) of the Acidobacteria community was more sensitive to increasing concentrations of CaCl-extractable soil Cu (Cu_Ext) than other groups, with decline in diversity occurring at 0.13 Cu_Ext mg kg⁻¹ soil. In contrast, diversity in the Bacillus community increased until 10.4 Cu_Ext mg kg⁻¹ soil, showing that this group was 2 orders of magnitude more resistant to Cu than Acidobacteria. Sphingomonas was the most resistant to Cu; however, this group along with Pseudomonas represented only a small percentage of total soil bacteria. Changes in bacterial community structure, but not diversity, were concomitant with a decrease in catabolic function (BioLog). Reduction in function followed a dose-response pattern with Cu_Ext levels (R²=0.86). The EC₅₀ for functional loss was 0.21 Cu_Ext mg kg⁻¹ soil, which coincided with loss of Acidobacteria diversity. The microbial responses were confirmed as being due to Cu and not shifts in soil pH (from use of CuSO₄) as parallel Zn-based field plots (ZnSO₄) were dissimilar. Changes in the diversity of most bacterial groups with soil Cu followed a unimodal response - i.e. diversity initially increased with Cu addition until a critical value was reached, whereupon it sharply decreased. These responses are indicative of the intermediate-disturbance-hypothesis, a macroecological theory that has not been widely tested in environmental microbial ecosystems.     

Food choice and reproductive success of Folsomia candida feeding on copper-contaminated mycelium of the soil fungus Alternaria alternata

We examined collembolan food preference for fungal mycelium grown on copper-contaminated medium, and the relationship between copper content, food selectivity and collembolan fitness when fed contaminated mycelium.To clarify whether collembolan food selectivity is related to fitness parameters, Folsomia candida were fed mycelium of the dark-pigmented fungus Alternaria alternata grown on medium with different copper concentrations. Copper-contaminated food (fungus grown on 50, 125, 250 and 500 μg Cu g⁻¹ medium, fresh wt.) was offered together with untreated food for 4 weeks. F. candida fed selectively on the provided mycelium and discriminated clearly between mycelium grown on high and low levels of contamination, distinctly preferring fungus grown on medium with a total copper concentration of 50 and 125 μg g⁻¹. In contrast, fungus grown on highly contaminated medium (250 and 500 μg g⁻¹) was avoided. Collembolan food preference generally matched fitness parameters. Reproduction was significantly affected by the total copper concentration of the fungal growth medium. When fed their preferred mycelium, collembolan reproduction was enhanced, whereas a diet of highly contaminated mycelium (250 or 500 μg g⁻¹) resulted in a strong decrease in reproduction. Adult survival was affected only marginally. Even though heavy metal contamination is a potential stress factor for many soil microarthropods, F. candida is able to discriminate between high and low quality food sources, and even benefits from moderately elevated copper concentrations.     

溴酚兰—丁基罗丹明等色染料离子对萃取光度法测定微量铜（Ⅱ）

基于铜，邻二氮菲和溴酚兰形成Ｃｕ：ｐｈｅｎ：ＢＰＢ为１：３：１的三元配合物且丁基罗丹明Ｂ与溴酚兰形成经ＢＰＢ：ＢＲＢ为１：３的等色染料离子对，建立了等色染出子对萃取法测Ｃｕ的新方法，该法摩尔吸光系数为２．８６×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１线性９．４４×１０＾－７－８．６５×１０＾－５ｍｏｌ．Ｌ＾－１。     

红壤柑桔园硼铜镁营养失调的诊断

根据植株外部症状及叶片、土壤分析结果,确诊福建省长泰县岩溪果场椪柑和蕉柑出现的叶片黄化、早期落叶等现象,系硼、铜过量及缺镁综合诱发的植株营养失调。发病植株叶片硼、铜含量明显超过适宜值,分别达110～258ppm和26～41ppm;镁含量偏低,为0.22％～0.31％。初步认为连年喷布(或土施)硼肥和波尔多液,以及土壤酸度过高是导致柑桔植株硼、铜、镁营养失调的直接原因。     

一氧化氮对铜、镉胁迫下平邑甜茶幼苗活性氧代谢的影响

利用一氧化氮供体硝普纳（sodium nitroprusside,SNP）,研究了一氧化氮对铜、镉胁迫下平邑甜茶幼苗的活性氧代谢的影响。结果表明：在200μM的CuCl2或CdCl2处理下,25～200uM的SNP能够提高平邑甜茶幼苗根系和叶片的SOD,POD活性,降低根系和叶片的超氧阴离子（O-2）产生速率及丙二醛（MDA）含量,表明适当浓度的一氧化氮可以通过提高部分抗氧化酶活性来缓解铜、镉胁迫对平邑甜茶幼苗的伤害。     

铜对圆锯片热应力的影响与研究

通过锯切木材试验,分别对锯身槽上嵌铜和不嵌铜设计的同条件下木工圆锯片,进行定点温度、横向摆动量和噪声参数的测量;并结合有限元热应力场分布与计算,以及铜材理化试验分析等手段,得出其嵌铜锯片消除热应力性能好,振声性能较高,锯片使用寿命延长等结论,并提出减振降噪的措施与建议,为优化圆锯片的设计工作提供参考依据。     

Critical body residues (CBRs) for ecotoxicological soil quality assessment: copper in earthworms

The term ‘critical body residue’ (CBR) was defined as the lowest observed total body concentration of a contaminant in an organism, which is associated with the occurrence of adverse toxic effects in either individuals or populations of a defined age or stage of development. In this study, internal toxicity thresholds were determined for copper in the clitellated adult stage of earthworms (Lumbricus rubellus and Aporrectodea caliginosa). The objective was to assess the applicability of CBRs as a practical tool in soil quality assessment of contaminated sites and as a means of a sustainable protection of earthworm fauna. Laboratory studies showed that body concentrations of Cu were generally in agreement with the chemically available CaCl₂-extractable fraction in soil, but that there was also some evidence of internal pH-related homeostatic regulation. Toxicological correlates of body Cu concentrations with adverse effects on cocoon production (fecundity) suggested an approximate sublethal internal threshold of about 40 mg kg⁻¹, with mortality occurring at about 60 mg kg⁻¹. Adult L. rubellus sampled from areas with a wide range of metal pollution showed body Cu concentrations with a minimum of 8 mg kg⁻¹ and a maximum of 60 mg kg⁻¹. Beyond this apparent physiological tolerance range, environmental management directed at optimal earthworm population survival may not be sustainable in contaminated fields. Studies of L. rubellus colonizing a metal-contaminated experimental sludge-treated field showed that a reduced rate of colonization can already be associated with an average body Cu concentration of 25 mg kg⁻¹. However, in this particular field situation mixture effects of other metals that were also present in the soil and the occurrence of avoidance behaviour during colonization may have contributed to this low internal toxicity threshold. It is concluded that the CBR approach seems to be a feasible option for use as a tool in a bioavailability-based soil quality assessment, even for essential trace metals like copper, but that further insight may be needed to establish the uncertainty and reliability of the application in environmental quality assessment and decision making.