Bee-hawking by the wasp, <Emphasis Type="BoldItalic">Vespa velutina</Emphasis>, on the honeybees <Emphasis Type="BoldItalic">Apis cerana</Emphasis> and <Emphasis Type="BoldItalic">A</Emphasis>. <Emphasis Type="BoldItalic">mellifera</Emphasis>

The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.     

上海市机动车环保检测机构管理模式构建及对策探讨

针对上海市机动车排放污染日趋严重的特点,以及提高机动车环保检测能力的迫切需求,以大量基础调研的基础为依据,客观剖析现阶段上海市机动车环保检测机构管理中存在的问题,提出构建分布合理、满足需求的标准化、规范化机动车环保检测体系的管理模式,从强化环检机构日常监管、优化检测资源、促进良性竞争、建设信息网络体系多个方面探讨管理对策,以保证环检机构的检测工作更加规范化和透明化,使检测数据更加具有公正性和权威性。     

稻田养鱼的生态防灾机制与效益分析—以湖南为例

以湖南为例从分散蓄水与扩容蓄水、即时蓄水与重复蓄水、分级截流与设阻截流等角度,分析了稻田养鱼的生态防灾机制,得出湖南宜鱼稻田87.0万hm^2,以蓄水30cm计算可蓄存107.9亿m^3。通过重复蓄水、设阻蓄水,接纳多次降雨洪水,调节水分时空分布,创造减灾避灾的人工生态防灾系统,形成多物种共生共存的农田湿地生态系统,提高农田生态经济效益。     

Characteristics of emissive spectrum and the removal of nitric oxide in N2/O2/NO plasma with argon additive

Although the approach using non-thermal plasma (NTP) for deNOx has been studied for over 15 years, how to achieve higher removal e ciency with lower cost is still a barrier for its industrial application. In order to investigate the impact of the argon additive on electron density, energy and nitric oxide reduction process in plasma, the spectrum of the dielectric barrier discharge at atmospheric pressure in a coaxial reactor was measured using the monochromater with high resolution. The comparative experiments for NO reduction were carried out simultaneously in N2/O2/NO plasma stream with and without argon, respectively. The nitrogen molecular spectrum which is attributed to the energy level transition (C3 u ! B3 g) was compared in the wavelength range 300–480 nm and the electron density and temperature were determined based on the relative intensities and Stark broadening width of spectral lines. The spectrum results indicated that the argon additive could enhance the intensity of emissive spectrum of plasma, thus the electron concentration as well as the energy was increased, and finally prompted the ionization rate to produce active N, O and O3. The results of NO reduction showed that NO conversion e ciency increased in the range of 10%–30% with 5% addition of argon in stream comparing with the condition without argon additive. This study will play a positive role in the industrial application of dielectric barrier discharge deNOx reactor.     

从抽提叶绿素后的蚕沙中提取叶蛋白

本文分析了从抽提叶绿素后的蚕沙中提取叶蛋白的工艺条件。结果表明：以０７％ＮａＯＨ作提取剂,料比１∶７,于６０℃搅拌提取６ｈ,叶蛋白的提取率为８４１２％;再用（１＋１）ＨＣｌ调ｐＨ值为３５,即得叶蛋白沉淀。按上述工艺条件,叶蛋白得率（以蚕沙干物计）为１００９％,蛋白质含量为７６６８％,提高了蚕沙的综合利用价值     

动力波洗涤器脱硫试验研究

采用动力波洗涤器冷模试验装置,在不加脱硫剂的情况下,考察各操作参数(液气比、pH值)及液柱喷射方式(逆喷、顺喷)对脱硫效率的影响,并对不同水质的清水(自来水、去离子水)的脱硫效率进行对比分析。结果表明:自来水的脱硫效率随液气比的增加而增大;逆喷时的脱硫效率明显高于顺喷;液气比>7时,逆喷的脱硫效率在75%以上;自来水的脱硫效率较去离子水要高;撞击流有强化吸收的特性。     

The adsorption of PCBs to Yangtse River sediment

The adsorption of six PCB congeners to natural sediments from the Yangtse River was investigated. Experiments were conducted at different PCB concentrations to get the adsorption isotherm for each compound. Analytical determinations were carried out using gas chromato‐graphy with ECD detector. Results showed that the adsorption mechanism of PCBs on Yangtse River sediment fitted the best to the Langmuir adsorption model. It was also found that the adsorption rate decreased as the solubility increased or the octanol‐water partition coefficient decreased for each compound.     

Organochlorine pesticides and PCBs in sediments from the Yangtse River,China

Organochlorine Pesticides and PCBs pollution levels were determined in sediment samples taken from three sites along the Yangtse River (Nanjing part). The concentrations of various pesticides were in the range of 1.42–8.06 ng/g (t‐HCH), and <0.01–4.12ng/g (t‐DDT), while the concentrations of PCBs were below detection limit at all three sites. The contamination by Organochlorine Pesticides and PCBs in sediments from the Yangtse River was not significant when compared with that reported in the literature from some other countries’ rivers, which may be due to the high flow velocity and water amount of the Yangtse River.     

ARTIFICIAL NEURAL NETWORKS FOR SUBSURFACE DRAINAGE AND SUBIRRIGATION SYSTEMS IN ONTARIO,CANADA1

ABSTRACT: Artificial neural network (ANN) models were developed to simulate fluctuations in midspan water table depths (WTD) given rainfall, potential evapotranspiration, and irrigation inputs on a Brookston clay loam in Woodslee, Ontario, having a dual‐purpose subsurface drainage/subirrigation setup. Water table depths and meteorologic data collected at this site from 1992 to 1994 and from 1996 to 1997 were used to train the ANNs. The ANNs were then used for real‐time control and time series simulations. The lowest root mean squared errors (RMSE) for the various ANNs were 60.6 mm for real‐time control simulation, and 88.4 mm for time‐series simulation of water table depths. It was possible to simulate WTD for the different modes of water table management in one network by incorporating an indicator for switching from one to the other. The ANN simulations were quite good even though the training data sets had irregular measurement intervals. With fewer input parameters and small network structures, ANNs still provided accurate results and required little time for training and execution. ANNs are therefore easier and faster to develop and run than conventional models and can contribute to the proper management of subsurface drainage and subirrigation systems.     

地理信息系统在累积影响评价中的应用

累积影响评价是在可持续发展目标要求下环境影响评价的一种新类型,但目前进行累积影响评价的方法和工具仍较缺乏。文章分析了利用地理信息系统进行累积影响评价的能力,结果表明：地理信息系统能改善对发展行为和环境状况的监测和跟踪,能较好地分析环境影响的时、空累积特征,是进行累积影响评价的有效工具;但是,其对环境影响累积过程的本质考虑有限,需要与能反映累积过程的子模式相结合。