The visual system of male scale insects

Animal eyes generally fall into two categories: (1) their photoreceptive array is convex, as is typical for camera eyes, including the human eye, or (2) their photoreceptive array is concave, as is typical for the compound eye of insects. There are a few rare examples of the latter eye type having secondarily evolved into the former one. When viewed in a phylogenetic framework, the head morphology of a variety of male scale insects suggests that this group could be one such example. In the Margarodidae (Hemiptera, Coccoidea), males have been described as having compound eyes, while males of some more derived groups only have two single-chamber eyes on each side of the head. Those eyes are situated in the place occupied by the compound eye of other insects. Since male scale insects tend to be rare, little is known about how their visual systems are organized, and what anatomical traits are associated with this evolutionary transition. In adult male Margarodidae, one single-chamber eye (stemmateran ocellus) is present in addition to a compound eye-like region. Our histological investigation reveals that the stemmateran ocellus has an extended retina which is formed by concrete clusters of receptor cells that connect to its own first-order neuropil. In addition, we find that the ommatidia of the compound eyes also share several anatomical characteristics with simple camera eyes. These include shallow units with extended retinas, each of which is connected by its own small nerve to the lamina. These anatomical changes suggest that the margarodid compound eye represents a transitional form to the giant unicornal eyes that have been described in more derived species.     

Modeling the current-voltage characteristics of thin-film silicon solar cells based on photo-induced electron transfer processes

Power conversion efficiency of p-i-n type macrocrystalline silicon (µc-Si:H) solar cells has been analyzed in terms of sequential processes of photo-induced electron transfer. The effect of the excitonic state on the charged carrier generation has been studied compared to a conventional scheme in which only charged carriers are taken into account for the operation of the solar cells. A numerical model has been developed to calculate current-voltage characteristics of solar cells on the basis of two types of charged carrier generation processes (exciton process and charged carrier process). The light trapping effect due to a textured back surface reflector (BSR) was embedded in the numerical model by using the effective medium theory in combination with the matrix method in the field of the electromagnetic theory of light. As an application of this modeling, it was found that the reported data of the power conversion efficiency were not explained by the conventional charged carrier process model and that the combined model of the charged carrier process with the exciton process well explains the performance of the p-i-n type μc-Si:H solar cells. In this way, the typical power conversion efficiencies were estimated to be 10.5% for the device (i-layer thickness: 1.8 μm) with the BSR (period: 600 nm; height: 250 nm) and 8.6% for the device with the flat reflector under the condition that the fractions of the exciton process and charged carrier process were 60% and 40%, respectively.     

Modeling the current-voltage characteristics of thin-film silicon solar cells based on photo-induced electron transfer processes

Power conversion efficiency of p-i-n type microcrystalline silicon (c-Si:H) solar cells has been analyzed in terms of sequential processes of photo-induced electron transfer. The effect of the excitonic state on the charged carrier generation has been studied compared to a conventional scheme in which only charged carriers are taken into account for the operation of the solar cells. A numerical model has been developed to calculate current-voltage characteristics of solar cells on the basis of two types of charged carrier generation processes (exciton process and charged carrier process). The light trapping effect due to a textured back surface reflector (BSR) was embedded in the numerical model by using the effective medium theory in combination with the matrix method in the field of the electromagnetic theory of light. As an application of this modeling, it was found that the reported data of the power conversion efficiency were not explained by the conventional charged carrier process model and that the combined model of the charged carrier process with the exciton process well explains the performance of the p-i-n type c-Si:H solar cells. In this way, the typical power conversion efficiencies were estimated to be 10.5% for the device (i-layer thickness: 1.8 m) with the BSR (period: 600 nm; height: 250 nm) and 8.6% for the device with the flat reflector under the condition that the fractions of the exciton process and charged carrier process were 60% and 40%, respectively.     

基于车载测试的轻型汽车排放特征

选择11辆轻型汽车作为研究对象,利用车载测试系统（portable emission measurement system,PEMS）研究了轻型汽车气态污染物排放和油耗特征。结果表明：轻型汽车一氧化碳（carbon monoxide,CO）、氮氧化物（nitrogen oxides,NO_x）和总碳氢化合物（total hydrocarbons,THC）的排放因子分别为（910.4±822.6）、（58.0±48.3）和（21.6±16.1）mg/km,且其排放速率随发动机比功率-速度（vehicle specific power-velocity,VSP-v）增大而增加,冷启动期间CO、NO_x和THC的排放量占排放总量的11.2%±2.1%、3.7%±5.4%和52.7%±4.6%。轻型汽车瞬态油耗速率随VSP-v的增大而增加,车辆相对油耗在平均车速低于15 km/h时显著上升,车速在40 km/h以上时油耗随车速变化呈平稳的趋势。20 ℃时CO、NO_x和THC排放速率高于1 ℃时的排放速率;1 ℃的环境温度使油耗速率增加,尤其在车辆高速行驶时,1 ℃时其油耗速率比20 ℃时高27.1%±24.5%。

     

水体中总有机卤化物的测定

研究一种测定水体中有冲有机卤化物（ＴＯＸ）含量的方法,分别通过气提和乙醚萃取并使用高温热解分光光度法测定挥发性有机卤（ＰＯＸ）和非挥发有机卤（ＮＰＯＸ）,方法检测限为１μｍｏｌ／Ｌ,变异系数〈３％,测得１０种不同类型的模拟化合物的平均回收率为８１％,自来水测定结果ＴＯＸ为２１７－４８３μｇ／Ｌ。     

生物反应器填埋场系统的特性研究

对生物反应器填埋场系统的运行特性进行研究。结果表明：生物反应器填埋场系统有助于渗滤液中有机物进行分相降解，在渗滤液的净化和填埋场垃圾的稳定化上优于渗滤液直接循环系统。并且提出了生物反应器填埋场的产气和基质降解过程的特性参数和动力学方程。     

Divergent mating patterns and a unique mode of external sperm transfer in Zoraptera: an enigmatic group of pterygote insects

A remarkable external sperm transfer is described for the first time in a species of a group of winged insects (Pterygota), the enigmatic Zoraptera. Mating and sperm transfer of two species of the order were examined in detail, documented, and compared with each other and with patterns described for other species belonging to the order. The behavior differs strikingly in Zorotypus impolitus and Zorotypus magnicaudelli. A copula is performed by males and females of the latter, as it is also the case in other zorapteran species and generally in pterygote insects. In striking contrast to this, males of Z. impolitus do not copulate but deposit small (100 μm in diameter) spermatophores externally on the abdomen of the female. Each spermatophore contains only one giant spermatozoon (3 mm long and 3 μm wide), a unique feature in the entire Hexapoda. External sperm transfer in Pterygota is a highly unusual case of evolutionary reversal. The very small relict group Zoraptera displays a uniform general morphology but exhibits very different reproductive structures and patterns of mating behavior. This may be an extreme form of a more general situation in insects, with a specific form of selection resulting in an accelerated rate of evolution in the reproductive system.     

Determination of hydroxyl radicals in TiO2/Ti photoelectrocatalytic oxidation system using Fe(phen)3 2+ spectrophotometry

A new method of determining the cumulate concentration of hydroxyl radicals in the TiO2/Ti photoelectrocatalytic(PEC)oxidation system was established by o-phenanthroline-Fe(Ⅱ)(Fe(phen)32+) spectrophotometry and using anion exchange membrane. Fe concentration of hydroxyl radicals can be calculated through determining the change of the Fe(phen)33+ absorbency at 509 nm. In addition, the research results showed the production rate of hydroxyl radicals was affected obviously by pH of solution, the cumulate concentration of hydroxyl radicals was the largest at nearby the initial pH 6.3 (isoelectric point), and the change direction of pH after illumination tended to nearby isoelectric point.     

Water quality characteristics along the course of the Huangpu River （China）

Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong,near the estuary of the Yangtze River.It plays a key role in supplying water for production,life,shipment and irrigation.With the industrial development,the pollution of the Huangpu River has become serious recently.The biological oxygen demand (BOD),total nitrogen (TN),total phosphorus (TP),oil,phenol and suspended solids (SS) were lower in the upstream sites than in the downstream sites,indicating pollutants being input along its course. Water quality was the worst in the Yangpu site,near the center of Shanghai City.Dissolved oxygen (DO) content was less than 2 mg/L in the site of Yangpu in July.Among relations between thirteen characteristics,relations between BOD,DO,TN,TP,NH_4~ -N, NO_3~--N and the count of total bacteria or Escherichia coli were significant and interdependent.Inner relationships between these main characteristics in the Huangpu River were studied.High nutrient concentration led to growth of microorganisms,including E.coli. Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body,and DO was a key factor for nitrification-denitrification process of nitrogen.In the Yangpu site,DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July.Low DO concentration will decrease nitrification rate.Nitrification need at higher DO value than other organic substrate oxidation.Consequently,river water contains low NO_3~--N values with high amounts of TN and NH_4~ -N there.This will block the self-purification of surface water,by decreasing the rate of nitrification-denitrification transformation process in the water body.     

给水厂浓缩污泥的稳态流变特征研究

针对给水厂浓缩污泥,采用旋转流变仪研究了其稳态流变特性,分别探讨了污泥的典型流变图、污泥浓度和温度对浓缩污泥极限粘度的影响.结果表明,污泥具有触变及剪切变稀的性质,其极限粘度(η∞)与污泥浓度(TSS)的关系符合指数关系,可用方程η∞=24.43-494.62e-0.14TSS描述.极限粘度与温度的关系服从于阿伦尼乌斯公式,相应的反应活化能为14.91J·mol-1.此外,宾汉模型可以描述污泥的流变性质,屈服应力随污泥浓度的升高而增加.     

ABR发酵产氢系统的控制运行及产氢效能

以稀释糖蜜为原料,通过分阶段提高进水COD的方法,考察了四格式、总有效容积为28.75L厌氧折流板反应器(ABR)的发酵产氢效能和运行特性.结果表明,以好氧和厌氧活性污泥的混合物接种,在水力停留时间(HRT)24h、进水pH为5.3～6.8和35℃等条件下,进水COD从500mg.L-1逐渐提高到6000mg.L-1左右,ABR可在63d内培育出具有产甲烷功能的微生物群落体系,并达到稳定运行状态.此时,4个格室中的液相末端产物以乙酸和丁酸为主,均呈现丁酸型发酵特征,系统的COD平均去除率为37.6%,平均产氢量为3.2L.d-1,去除单位COD的比产氢率平均为45.29L.kg-1(以COD计).随着进水COD的提高,ABR及各格室的运行特征也随之发生变化,在进水COD提高到8000mg.L-1并达到运行稳定状态时,后3个格室中仍有产甲烷活性的残留;前3个格室表现为乙醇型发酵,而最后1个格室的丁酸型发酵特征则得到加强;系统对COD的平均去除率降低为15.4%,平均产氢量和去除单位COD的产氢能力分别提高到12.85L.d-1和360.22L.kg-1(以COD计);由于诸如产甲烷菌和同型产乙酸菌的耗氢活性未被有效抑制,ABR的产氢效能受到了严重影响,虽然总产气速率和活性污泥的比产气率分别达到了61.54L.d-1和232L.kg-.1d-1(以MLVSS计),但总产氢速率和活性污泥的比产氢率分别仅为12.85L.d-1和48L.kg-1.d-1(以MLVSS计).