蚯蚓体表与土壤接触界面动态行为仿真

应用离散元软件PFC2D建立了蚯蚓波纹体表与土壤界面动态行为仿真模型,对比分析了光滑和波纹试样的接触界面、接触力场和接触颗粒数以及滑动阻力,得出:当波纹表面的摩擦力与土壤颗粒对波纹凸起处的向后推力之和小于光滑表面的摩擦力时,波纹表面起到减阻作用;如果土壤颗粒对波纹表面凸起处的向后推力过大,波纹会起到增加阻力的作用。另外,试样运动时,波纹表面比光滑表面对土壤的扰动大。随着垂直载荷的增加,波纹表面和光滑表面的滑动阻力均增加,且波纹表面的降阻效果减弱;随着前进速度的增加,2种试样滑动阻力的增加,但波纹表面的滑动阻力的增长小于光滑表面,即速度高时波纹表面降阻明显。结果表明:蚯蚓非光滑表面的减阻能力与接触界面特性和外部条件有关。研究结果可为揭示非光滑表面的减阻机制提供研究方法和参考。     

蚯蚓改善垂直潜流人工湿地处理农村污水效能的研究

通过引入赤子爱胜蚓,构建蚯蚓垂直潜流人工湿地,比较了蚯蚓人工湿地与对照人工湿地去除污染物的特性,并分析了投加蚯蚓对改善湿地内微生物量的空间分布及提高湿地防堵塞的效果.结果表明,蚯蚓的引入提高了垂直潜流人工湿地对污染物的去除效果,与对照人工湿地相比,蚯蚓人工湿地对COD、NH_4~+-N、TN、TP的去除率分别提高了15.8%、23.2%、20.6%、16.2%;同时,还增加了人工湿地各层的微生物量.在表层,蚯蚓人工湿地的细菌总数、亚硝酸菌数、硝酸菌数、反硝化菌数分别为对照人工湿地的2.3、2.9、2.0、2.1倍;并且蚯蚓的引入还在一定程度上缓解了垂直潜流人工湿地的堵塞.     

源于地龙蛋白的抗氧化肽鉴定与构效关系

为探究外源蛋白酶预酶解处理对地龙蛋白胃肠消化程度和胃肠消化后抗氧化活性的影响。该研究利用五种蛋白酶制备了不同的地龙蛋白酶解物,然后通过体外胃肠模拟消化探究这些酶解物的水解度、分子量分布和体外抗氧化活性的变化。五种蛋白酶酶解物中,碱性蛋白酶酶解物的水解度最高,为40.8%,其对DPPH、ABTS自由基的清除能力分别为27.36、175.46 μmol TE/g,ORAC值为0.70 μmol TE/mg。碱性蛋白酶酶解物经胃肠消化后的水解度、DPPH自由基清除率、ORAC值相比于地龙蛋白直接胃肠消化所得产物（EWP）分别提高了94.06%、72.21%及120.00%。GHEWP中鉴定出10 823条分子量<3 ku的肽,通过bioware.ucd.ie进行活性阈值评分筛选出活性评分最高的11个肽进行合成,验证活性,其中ATSGFFVY、HCFVLY、HLASGWY、HRYSDF、HYANMY的综合抗氧化能力较好,量子化学计算结果表明：ATSGFFVY、HCFVLY、HRYSDF、HYANMY的活性位点可能分别位于Tyr-8、Tyr-6、Tyr-3、Tyr-2上;HLASGWY的活性位点可能位于Trp-6上。该研究表明碱性蛋白酶预酶解可提高地龙蛋白的消化程度,增强其胃肠消化产物的抗氧化活性。     

Synthesis and biodegradability evaluation of 2‐methylene‐1,3‐dioxepane and styrene copolymers

Biodegradable copolymers of 2‐methylene‐1,3‐dioxepane (MDO) and styrene (ST) were synthesized by free‐radical copolymerization using di‐t‐butyl peroxide (DTBP) as the initiator. The copolymers containing ester units were characterized by Fourier transform infrared (FTIR), ¹H‐NMR, and ¹³C‐NMR spectroscopy. Their molecular weight and polydispersity index were determined by gel permeation chromatography (GPC). In vitro enzymatic degradation of poly(MDO‐co‐ST) was performed at 37°C in phosphate buffer solution (PBS, pH = 7.4) in the presence of Pseudomonas lipase or crude enzyme extracted from earthworm. The experiment showed that incorporating ester units into C? C backbone chain of polystyrene would result in a biodegradable copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1146–1151, 2007     

水蚯蚓在污水处理与污泥减量中的应用

微型动物污泥减量技术作为一种生态工程技术由于能耗低,不产生二次污染而受到关注,成为污水处理中研究的热点。该文介绍了水蚯蚓对污泥减量化的贡献及它所具有节约成本、环境友好的优势,同时也指出了水蚯蚓在污水处理中对出水水质的影响及存在的一些问题,并总结了污水处理中水蚯蚓的化学控制、物理控制、生物控制方法等措施。     

Effects of fluoride ion on the formation of earthworm‐like mesoporous silica

In a strong acidic environment, ordered earthworm‐like mesoporous silica has been synthesized with CTAB templating and fluoride ion (F^?) as a counterion. The synthesized products were characterized by small‐angle X‐ray diffraction (SXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ adsorption‐desorption isotherms, and Fourier‐transform infrared spectroscopy (FTIR). The effects of F/Si mole ratio on the morphology, surface area, and the pore size of the sample were discussed. It was found that a F/Si mole ratio at 0.083 induced the formation of 3D hexagonal mesophase, whereas higher F/Si mole ratios led to the formation of 2D hexagonal mesoporous silica, the optimum molar ratio of F/Si for the formation of delicate earthworm‐like mesoporous silica was observed at 0.250. The effects of the F/Si mole ratio, surfactant chain length, acid concentration, and shear flow on morphology were also studied.     

杀菌剂氟吗啉和多菌灵对蚯蚓的急性毒性

采用自然土和OECD标准人工土研究了氟吗啉和多菌灵对蚯蚓的急性毒性，并对试验过程中蚯蚓的中毒症状和形态、行为变化进行了观察。结果表明，氟吗啉在自然土壤中对蚯蚓的LC50为592．73mg／kg，95％置信区间为562．41～623．80mg／kg；氟吗啉在人工土壤中对蚯蚓的LC50为318．79mg／kg，95％置信区间为181．63-543．79mg／kg。多菌灵在自然土壤中对蚯蚓的LC50为26．53mg／kg，95％置信区间为15．98-42．93mg／kg；多菌灵在人工土壤中对蚯蚓的LC50为5．57mg／kg，95％置信区间为2．48～11．83mg／kg。依据农药对蚯蚓的毒性等级划分标准，氟吗啉在自然土壤和人工土壤中对蚯蚓的毒性均为低毒级；多菌灵在自然土壤中对蚯蚓的毒性为低毒级，而在人工土壤中对蚯蚓的毒性为中毒级。     

Decentralized control scheme for adaptive earthworm locomotion using continuum-model-based analysis

Crawling locomotion has been the focus of attention in the field of robotics because various applications of it are expected. However, the design methodologies for crawling robots, which can be applied in various environments, are not yet established. Therefore, we considered an earthworm as our model and employed an unconventional approach: we analyzed the motion of the earthworm with a continuum model and derived an optimal force distribution for its efficient propulsion, based on which we proposed an autonomous decentralized control scheme. The validity of the proposed control scheme was confirmed via simulations.     

3种地下害虫杀虫剂对蚯蚓和土壤微生物的影响

评价地下害虫杀虫剂二嗪磷、丁硫克百威和氟虫腈的生物安全性.利用滤纸接触法对赤子爱胜蚯蚓染毒,研究它们对蚯蚓的急性毒性.结果表明:二嗪磷、丁硫克百威、氟虫腈72 h的LC50值分别为0.55、141.94、137.47 mg/L,毒性大小为二嗪磷>氟虫腈>丁硫克百威.利用密闭法测定了二嗪磷、丁硫克百威和氟虫腈对土壤呼吸强度的影响,并对其使用的环境安全性进行了评价,3种农药对土壤微生物均属于尤实际危害性级农药,其中丁硫克百威安全性最好,其次为氟虫腈,二嗪磷最差.