粉煤灰和钢渣处理多种金属污染的酸性土壤，金属有效性的衰减研究

The objectives of this work were to determine the potential mineralization of various organic pollutants that are likely found in compostable materials during composting, and to evaluate the participation of the microflora of the thermophilic and maturation composting phases in pollutant mineralization. Four composts were used: a biowaste compost (BioW), a municipal solid waste compost (MSW), a green waste compost (GW) and a co-compost of green waste and sludge (GW+S). In each composting plant, two samples were withdrawn: one in the thermophilic phase (fresh compost) and one in the maturation phase (mature compost) to have the microflora of thermophilic and maturation phases active, respectively. The mineralization of 5 organic pollutants, 3 polycyclic aromatic hydrocarbons (PAHs) (i.e., phenanthrene, fluoranthene and benzo(a)pyrene), 1 herbicide (dicamba) and 1 polychlorinated biphenyl (PCB, congener 52), was measured in a laboratory setting during incubations at 60 ℃ in fresh composts and at 28 ℃ in mature composts. All molecules were 14 C-labeled, which allowed the mineralization of the molecules to be measured by trapping of produced 14CO2 in NaOH. Their volatilization was also measured by trapping molecules on glass wool impregnated with paraffin oil. Mineralization of the organic molecules was only observed when the maturation microflora was present in the mature composts or when it was inoculated into the fresh compost. Phenanthrene mineralization of up to 60% in the fresh GW+S compost was the only exception. Mineralization of PAH decreased when the complexity of the PAH molecules increased. Mineralization of phenanthrene and fluoranthene reached 50%-70% in all mature composts. Benzo(a)pyrene was mineralized (30%) only in the MSW mature compost. Dicamba was moderately mineralized (30%-40%). Finally, no PCB mineralization was detected, but 20% of the PCB had volatilized after 12 d at 60 ℃. No clear difference was observed in the degrading capacity of the different composts, and the major difference was the larger mineralizing capacity of the maturation microflora compared with the thermophilic microflora.     

多氯联苯(PCB153)对湛江叉鞭金藻生理生态和超微结构的影响

为研究多氯联苯对海洋微藻的生理生态毒性,以湛江叉鞭金藻(Dicrateria zhanjiangensis)为研究对象,进行7 d的六氯联苯(PCB153)胁迫实验,比较其生长、光合色素含量、谷胱甘肽S-转移酶(GST)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量以及藻细胞超微结构的变化情况。结果显示,PCB153胁迫对湛江叉鞭金藻的生长、光合色素含量及抗氧化和解毒相关指标均有显著影响(P<0.05)。随着PCB153浓度的增大,其对湛江叉鞭金藻生长抑制作用不断增大,250 μg/L胁迫组藻细胞在第5天全部死亡。PCB153胁迫后,湛江叉鞭金藻叶绿素a、叶绿素c、类胡萝卜素和总光合色素均显著下降(P<0.05),且随着PCB153浓度的增加,各实验组光合色素含量下降比例增大。PCB153胁迫后,各胁迫组藻细胞MDA含量显著增加;低浓度PCB153 (< 25 μg/L)胁迫显著诱导SOD和GST活性的提高;而高浓度PCB153(> 25 μg/L)胁迫则显著抑制2种酶活性。短期低浓度PCB153胁迫会改变金藻细胞超微结构,使细胞器形态改变、聚缩;高浓度PCB153胁迫则会直接破坏细胞膜的完整性,使细胞破裂,导致细胞自溶死亡。研究表明,PCB153抑制叉鞭金藻的生长和光合色素合成,低浓度PCB153激活抗氧化和解毒系统,提高其自我保护水平,高浓度PCB153加剧脂质过氧化,破坏抗氧化和解毒系统正常功能,导致细胞破裂死亡。     

植物间作下根际微生物和土壤酶与土壤多氯联苯（PCB）降解的关系

以大豆、黑麦草和南瓜为材料,采用盆栽实验,研究了3种植物的单作和相互间作的不同种植方式对多氯联苯污染土壤的根际修复效应与机理。结果表明：（1）PCB去除率与土壤蛋白酶和磷酸酶活性均呈极显著正相关关系,相关系数分别为0.878和0.929（P〈0.01）,推测这两类酶可能参与了PCB的生物降解过程;（2）PCB去除率与土壤真菌密度呈显著相关（r=0.797）,而PCB去除率与土壤细菌及放线菌密度相关不显著;（3）在本实验条件下,微生物因素对土壤PCB的降解起主导作用,非灭菌土处理的土壤PCB去除率比灭菌土相对应的对照高出17.7%~30.75%;（4）根系分泌物能显著强化微生物的降解功能,添加黑麦草和大豆根系分泌物处理的土壤PCB去除率分别比只加营养液的对照高出21.4%和24.9%。     

植物间作体系根际修复土壤多氯联苯的效应

以大豆、黑麦草和南瓜为材料,运用盆栽实验,通过3种植物的单作和间作对多氯联苯污染土壤的根际修复效应进行了研究。结果表明,植物不同种植方式均对根际土壤中PCB浓度的降解有促进作用,其中植物单作的去除率比CK提高了10.4%～17.0%,植物间作的去除率比CK提高18.4%～23.9%。南瓜-大豆体系中的大豆根的蓄积浓度显著差异高于其他处理,而与大豆南瓜间作方式下黑麦草根蓄积浓度均比其单作显著提高,大豆-南瓜和南瓜-黑麦草间作系统中的大豆和黑麦草根中PCB蓄积浓度也显著提高（P〈0.05）。各处理间根际土壤的pH、Eh、电导率的差异性规律性不大。相关分析结果表明,根际土壤PCB去除率与植物吸收量呈显著正相关,而与pH、Eh和电导率没有达到显著相关。     

汽车前照灯CAN总线系统的硬件设计

本文结合51系列单片机原理,对汽车前照灯传统的点对点控制电路进行改造,研究开发出了汽车前照灯CAN总线多路传输系统,制作出两个带有CAN总线节点的PCB电路板,实现了汽车前照灯CAN总线系统的硬件设计。     

基于印制绕组的电磁式自供电拖拉机轮速传感器研究

针对传统供电方式难以适应现代农业传感器网络使用需求的问题,设计了一种基于印制绕组和Halbach阵列的电磁式自供电拖拉机轮速传感器。装置采用中间定子、两侧转子的结构形式,基于法拉第电磁感应定律对装置的输出感应电动势进行理论推导,确定其影响参数。使用有限元仿真软件,对影响装置输出性能的磁体排列方式、线圈匝数和装置气隙等进行仿真分析,并结合实际工程经验确定了定子线圈形状和永磁体极对数等参数。设计了后端电路,其可对装置的输出电压进行整流、测量和传输,从而计算转速,并可由装置直接供电。制作了装置样机,分别开展台架标定测试和实车应用试验。试验结果表明,装置转速和电压线性拟合结果良好,决定系数R2为0.99991,在转速400r/min下整流后的直流电压输出约为3.16V,可以满足为后端电路供电的需求。与商用编码器相比,在台架测试中装置的转速测量精度保持在1%以内,实车测试中精度基本保持在5%以内,可以满足实际使用要求。     

Degradation of PCB Waste Stripping Liquid Using UV/Fenton

The study shows that there will be a good effect to degrade printed circuit board(PCB) waste stripping liquid using UV/Fenton homogeneous photochemical catalysis system.The removal rate of COD could reach 80% at the conditions with double dose of H_2O_2,1:20 mol ratio of Fe~(2+):H_2O_2 and 80min hydraulic retention time(HRT).In all influential factors the H_2O_2 dosing ratio is the most important by order,then follows the ratio of FeSO_4/H_2O_2,and at last the illumination time.     

Design on Auto-programming System for PCB Manufacturing

Considering the speciality of PCB programming object, this article presents a method of abstracting drill information and characteristic automatically with computing vision system, discusses the feature abstracting and analysis process, and designs the binary image based filter and barycenter based position recorgnition method. The format of output data is given.The system running effect shows that it is better in resolution, higher in control accuracy, lower in hardware requirement, faster than by hand in programming efficiency. Automation programming is twenty times as fast as by hand.     

Micro-coil array used for signal transcutaneous transmission of multichannel electrical stimulation

Micro-coil array and matching capacitors together can realize the parallel transmission of multichannel signal. In order to improve the accuracy and reliability of receiving information from each channel and to reduce the size of implant systems, two kinds of micro-coil arrays fabricated by using PCB (printed circuit board) and FPC (flexible printed circuit) technology respectively are presented. Then the two micro-coil arrays are used in multi-channel transmission device with a 2 * 2 array. The coupling efficiency of two kinds of process coils under ideal coupling, spatial mismatch as well as different load conditions are tested. The results show that two kinds of coils are affected by spatial mismatch. However, if the transverse mismatch is restricted less than 3 mm and the angular mismatch is less than 30°, the two kinds of coils can be used for signal transcutaneous transmission for implantable electrical stimulation devices at the laboratory stage, and the channel output signal can meet the requirements of electrical nerve stimulation. As for the reliability of the system, FPC coil shows more advantages, and it is more adapted to implantable system.      

The influence of dietary energy levels with and without PCB induction on the growth of tilapia,Oreochromis niloticos x O. aureus

The effects of three dietary energy levels, 323, 365 and 408 Kcal/100g diet, on the growth performance of hybrid tilapia, Oreochromis niloticus x O. aureus, were studied. The experiment was carried out for 3 months in a recirculating rearing system. Growth and feed conversion ratios were significantly reduced (p<0.05) in fish exposed to 100 ppm polychlorinated biphenyl (PCB), fed high energy diets (365 and 408 Kcal/100g diet). The hepatic cytochrome P-450 and NADPH-cytochrome c reductase activities were also significantly (p<0.05) lower in PCB-treated fish fed high energy diets (365 and 408 Kcal/100g diet) than fish fed lower energy diet (323 Kcal/100g diet). The malic enzyme activity and the body lipid content in fish generally increased as the dietary energy level increased.