（Mn＋Zn）-LS螯合微肥的研制及肥效实验

以废碱锰电池和木质素为原料,采用＂焙烧-酸解-螯合＂工艺制成（Mn＋Zn）-LS螯合微肥,通过红外光谱分析改性前后木质素的结构变化,并利用盆栽试验验证其肥效。红外分析结果表明,微肥的红外光谱图在峰形、峰位和强度上都发生了较大的变化,木质素结构单元上引入了新的基团（-SO3H、-SO-O-）和金属离子的络合导致了芳环吸收峰的变化,而且其中的络合也与芳环有关。盆栽试验结果表明,螯合微肥施用效果较好、增产明显,具有一定的抗病能力和抗倒伏性,且施用量范围广、易控制,适用范围广;在本试验中,Mn以2mg·kg-1土的施用量为最佳,鲜重增加46.3%,干重增加28.5%;同时盆栽后可以改善土壤pH和有效Zn、Mn含量,为后期利用提供肥力保证。     

肉种蛋鸡啄羽行为在遮光笼中亮区和暗区的频次差异

通过比较盒式笼中肉种蛋鸡啄羽行为在遮光区和非遮光区的频次差异,旨在检验遮光、环境丰富度、啄羽和福利的关系。利用行为观测者摄像分析仪,对相同光周期下遮光的单鸡笼和双鸡笼每组各16只同日龄肉种产蛋鸡的活动同时摄录并分析。结果显示,单鸡笼啄羽频次(4.3±1.13)显著低于双鸡笼的(14.0±2.0)(P<0.01);单鸡笼暗区啄羽相比亮区减少了46%(P>0.05),而双鸡笼啄羽仅发生在亮区(P<0.05);亮区啄羽,单鸡笼较之双鸡笼则显著减小了80%(P<0.01),而暗区啄羽2者水平都很低(0~1.5),无显著差异。本研究中未见剧烈型啄羽,仅有温和型啄羽。本研究表明,虽然啄羽的密度效应大于啄羽的遮光效应,但遮光能够降低密度对啄羽的效应值。遮光提供分化的光环境,而被遮光的环境很可能以减弱视觉信号方式减小羽毛对啄羽行为的刺激作用。这提示对盒式鸡笼进行局部遮光以增大其环境丰富度从而提高动物福利,也有可取之处。     

Comparative genotoxicity testing of rhine river sediment extracts using the comet assay with permanent fish cell lines (rtg-2 and rtl-w1) and the ames test*

Goals, Scope and Background

Improved quality of surface waters and sediments requires advanced strategies for ecotoxicological assessment. Whilst at least in Germany assessment strategies on the basis of chemical analysis and acute toxicity data dominated the last decades, the development of more specific biological endpoints and biomarkers in ecotoxicology is required in order to arrive at a good ecological potential and good chemical status of surface waters in the European river basins until the year 2015, as required by the European Water Framework Directive. Since sediments have for long been known to function both as a sink and as a source of pollutants in aquatic systems, and since part of the particle-associated substances have frequently been demonstrated to cause mutagenic and carcinogenic effects in aquatic organisms, particularly in fish, there is, among other requirements, an urgent need to develop, standardize and implement integrated vertebrate-based test systems addressing genotoxicity into recent sediment investigation strategies. Thus, the present study was designed to compare the suitability of two commonly used test systems, the comet assay and the Ames test, for the evaluation of the ecotoxicological burden of surface and core sediment samples from the river Rhine.

Methods (or Main Features)

In order to determine the importance of inherent enzymatic activities, two permanent fish cell lines with different biotransformation capacities, RTL-W1 and RTG-2, were compared with respect to their capability of detecting genotoxic effects in 18 surface and core sediment samples from 9 locations along the River Rhine in the comet assay with and without exogenous bioactivation. For further comparison, as a prokaryotic mutagenicity assay, theSalmonella plate incorporation assay (Ames test) with the test strains TA98 and TA 100 with and without exogenous metabolic activation was used.

Results and Discussion

Whereas all sediment extracts induced genotoxic effects in the comet assay with RTL-W1 cells, only 12 out of 18 sediment extracts revealed significant genotoxicity in the tests with the less biotransformation-competent RTG-2 cells. Exogenous bioactivation by addition of ß-naphthoflavone /phenobarbital-induced S9 from rat liver resulted in both reduction or increase of genotoxicity in samples from different sites, however, without consistent reaction patterns. In general, the responses of RTL-W1 cells indicated higher biotransformation capacity than in RTG-2 cells without S9 complementation. In Ames tests using TA98 with S9, 16 out of 18 extracts induced significant mutagenicity with induction factors up to 4. Compared to TA98, the strain TA100 proved less sensitive, with maximum induction factors of 1.3, indicating the potential presence of substances inducing frarneshift mutations, which can only be detected in the strain TA98. Chemical analyses revealed particularly high levels of hexachlorbenzene (up to 860 µg/kg) and priority PAHs (up to 4.8 mg/kg); so far, however, no correlation could be found between compounds analyzed and the corresponding biotests.

Conclusions

Results document that both comet assay and Ames test are capable of detecting xenobiotic interaction with DNA in consequence of exposure to complex environmental samples. Whereas the alkaline version of the comet assay detects a broad range of interactions with the DNA, however without information about their eventual importance, the Ames test only reveals established mutations, but fails to detect transient (reparable) DNA alterations. However, even transient primary changes in the DNA structure might result in carcinogenic processes and, eventually, in implications at the population level. As a consequence, for hazard assessment purposes, a combination of both assays is required to avoid false negatives in genotoxicity evaluation. Poor correlation between data obtained by chemical analysis and results in bioassays is indicative of our limited understanding of the sources of genotoxicity. In fact, numerous studies combining chemical and biological approaches for hazard assessment of complex environmental mixtures indicate that priority pollutant concentrations are a poor indicator of toxicity.If compared to the cell line RTG-2, RTL-W1 proved more effective in detecting genotoxicity in surface sediment samples and, thus, indicated the importance of bioactivation of at least part of the compounds in superficial layers of sediments. Results further document that the common assumption may be wrong that, in comparison to deeper strata, surface layers carry a lower toxic burden in consequence of the current decrease in water pollution. This might at least in part be due to remobilization of more heavily polluted sediments from deeper layers during severe flood events followed by re-sedimentation in flood plains or upstream weirs, where they might cover less polluted younger sediment layers.

Recommendations and Perspectives

For a comprehensive assessment of genotoxicity in surface and core sediments, a combination of eukaryotic (comet assay) and prokaryotic assays (Ames test) with and without exogenous bioactivation is recommended. Since studies with organic sediments extracts simulate a worst-case scenario and fail to take into account bioavailability, there is broad consensus that whole-sediment exposure protocols represent the most realistic scenarios. Whereas more realistic solid phase exposure has frequently been applied in both microbial and invertebrate acute toxicity testing, there is an urgent need to develop corresponding whole sediment fish-based genotoxicity tests.

     

Size rank and growth potential in redclaw crayfish (Cherax quadricarinatus): are stunted juveniles suitable for grow‐out?

Considerable size variation emerges at an early stage among redclaw (Cherax quadricarinatus) juveniles. In order to explore whether juveniles from different size fractions of the same population differ in their growth potential, they were reared individually, in the absence of social effects. In the first experiment, post‐release siblings were reared for 5 weeks and then categorized into three size fractions: small, med‐sized and large. Subsequently, juveniles of each size fraction (n=24, 18, and 18, respectively) were reared in individual cells for 46 days and their moult increments and moult intervals were compared. In addition, the growth indices of the med‐ and large‐sized juveniles were compared with those of juveniles from other broods that were similar in age and size but belonged to a different size fraction, in order to separate the effect of absolute size from that of size rank. In a second experiment, juveniles from the small‐, med‐ and large‐size fractions (n=21) of a commercial nursery‐reared population were individually reared for 14 weeks and their growth indices were compared. Survival of individuals from the small‐size fraction was low, particularly in the first experiment, and increased with fraction size. However, small‐sized juveniles did not show reduced growth potential and even grew at a faster rate than large‐sized juveniles. The results indicate that social interactions plays an important role in the development of size variation, and that small juveniles have the potential to grow rapidly when reared in individual compartments. Overall, the size rank was a poor predictor of growth potential.     

SOC Definition of Battery Management System Used in Hybrid Vehicles

For the requirement of building up the battery management system (BMS) of hybrid vehicles(HEVs), the real time measurement and estimation of charge (SOC) of the Ni MH batteries are investigated, because the popular SOC definition is unsuitable under the condition of variable current discharge. The origin of this kind unsuitability are analyzed ,and the characteristics and existing problems of different kinds of SOC measuring methods are compared. On the basis of mentioned above, some corrections are given to the popular SOC definition, and the new conception of SOC is proposed. The corrected definition of SOC is suitable for the real time SOC estimation under the variable current condition of the batteries used in HEVs. Based on the corrected SOC definition, the computational model of the new SOC is built and simulated. Satisfactory result has been obtained from comparisons of the simulating results, which shows that the theoretical model provides a basis for optimizing the adaptation of power system to the hybrid vehicles (HEVs).     

基于数值模拟的微型溴化锂屏蔽泵的性能分析

针对现有单级溴化锂屏蔽泵存在效率低、能耗高的缺点,研究开发了两级叶轮微型溴化锂屏蔽泵。设计两级微型溴化锂屏蔽泵机泵一体结构以及两级屏蔽泵的水力部件,包括叶轮设计、径向导叶和螺旋形涡室组合设计等。利用CFD软件FLUENT,对两级屏蔽泵进行流场模拟,得到了内部流场的分布情况。由此分别以溴化锂和清水为介质进行了性能预测,与设计值进行比对,结果符合设计要求。经样机试验验证,在相同流量下,两级微型溴化锂屏蔽泵比现有单级微型溴化锂屏蔽泵扬程高约1 m,机组效率高约1.6%。设计的两级屏蔽泵的扬程和机组效率模拟值与试验值比较接近,初步验证了模拟可信,设计方法可行。     

免维护干荷蓄电池批量充电的若干技术问题

测试记录说明，经过５－８ｈ初充电，免维护干式蓄电池的容量要比不充电的增加３０％以上，而完全放电的免维护干荷蓄电池，要恢复其额定容量，其补充充电的时间却很长，在充电过程中的一些技术措施，实践证明是行之有效的。     

采用粉末微电极循环伏安法估测锂离子电池炭负极材料的循环性能

阐明了采用粉末微电极循环伏安法估测锂离子电池(LIB)炭负极材料的循环性能的原理．采用该法研究了经高温热处理后具有良好贮锂结构的石油焦试样在1mol／L LiClO4／EC DEC(1：1)电解液中的循环性能．实验结果表明，该试样是一种循环性能优越的LIB负极材料：充、放电到第500循环时，放电容量仍保持了最大放电容量的85．02％，充、放电效率为94．96％；同时也证明了粉末微电极循环伏安法用于估测LIB炭负极材料的循环性能的可行性．     

Interactive effect of lithium on concentration of alkali cations in sugar beet (Beta vulgaris L.) under saline conditions

Background and aims

Increasing demand for lithium (Li⁺) for portable energy storage is leading to a global risk of Li⁺ pollution from the manufacture, use, and disposal of Li⁺-containing products. Although Li⁺, a reactive alkali metal, has no essential function in plants, they readily take it up and accumulate it in large amounts in their tissues. The underlying mechanisms for this Li⁺ uptake and accumulation are, however, not well described. Our aim has been to investigate the effects of other alkali metals with similar physicochemical properties on the uptake, accumulation, and toxicity of Li⁺ at low and high osmolarity.

Methods

To determine the way in which Li⁺ affects the accumulation of other cations under saline conditions, sugar beet plants were grown in hydroponic culture with equimolar amounts of Li⁺, potassium (K⁺), and sodium (Na⁺) at low and high concentrations in various combinations.

Results

Sugar beet plants tolerated high Li⁺ concentrations in the leaf and petiole. Low Li⁺ concentrations had no impact on plant growth but induced stomata closure. The presence of other monovalent cations at equimolar concentrations did not affect Li⁺ accumulation, but Li⁺ application altered the ratio of monovalent and divalent cations in leaves. Plants treated with high Li⁺ in combination with Na⁺ or K⁺ showed reduced plant growth and leaf necrosis, indicating the severe stress caused by Li⁺ toxicity.

Conclusion

The presence of cations with similar physicochemical properties to those of Li⁺ cannot mitigate its toxicity.     

农用电动车蓄电池的正确使用

随着人们环保意识的增强及国家对相关产业的重视,电动车在我国农村生活与生产中的应用逐渐增多。蓄电池是农用电动车的核心部件,其正确使用与保养尤为重要。介绍农用电动车蓄电池的结构及其使用方法,为正确、安全使用农用电动车提供技术指导。