硫化亚铁活化过一硫酸盐降解含表面活性剂水溶液中三氯乙烯的效果与机制

采用硫化亚铁(FeS)活化过一硫酸盐(PMS)降解含表面活性剂吐温-80(TW-80)水溶液中的三氯乙烯(TCE),考察了PMS和FeS投加量、TW-80浓度、溶液初始pH、无机阴离子(Cl^–和HCO₃^–)对TCE降解的影响,确定了PMS/FeS体系中的主导自由基及TCE降解机理,验证了PMS/FeS体系处理实际地下水中含TW-80的TCE效果。结果表明：增加PMS或FeS投加量有利于TCE的降解,但当其投加剂量分别超过0.8 mmol·L^–1和0.6 g·L^–1时,TCE降解反而受到抑制,且TCE的降解率随TW-80浓度的增加而下降;PMS/FeS体系对pH有较宽的适用范围,在pH=11时受到抑制,Cl^–和HCO₃^–对TCE降解有抑制作用;通过自由基淬灭实验和电子顺磁共振实验确定了SO₄^–·、HO·和O₂^–·是PMS/FeS体系中的主导自由基;相比于其他氯代烃,该体系对四氯乙烯和四氯化碳也有较好的降解效果;实际地下水的处理结果证实PMS/FeS体系在实际应用中具有潜力和优势。     

生物质灰结渣和腐蚀特性

针对目前生物质燃料燃烧过程中存在的灰结渣和受热面腐蚀问题,通过分析生物质灰的元素成分、矿物组成、理化特性及熔融特性等,探讨了灰结渣的形成过程和受热面腐蚀的机理。研究表明:生物质燃烧灰结渣的主要原因为碱金属硫酸盐及氯化物的形成降低了飞灰熔点,增加了飞灰的表面黏性,黏结在受热面表面形成结渣;此外,由于燃料中的氯化物在高温下参与氧化还原反应生成HCl和Cl₂,再与金属受热面发生化学反应,形成了受热面腐蚀。通过研究燃料成分、炉膛温度、过量空气系数、受热面材质等因素对结渣和受热面腐蚀的影响,得出可以采用生物质与煤混烧、加入添加剂、水洗及金属表面防腐等防治措施避免或减少结渣和腐蚀现象发生。     

GO-TiO2改性中空纤维膜的制备条件及抗污染性能研究

以氧化石墨烯(GO)与纳米二氧化钛(TiO_2)为改性剂,采用界面聚合法与抽滤吸附结合,对聚偏氟乙烯中空纤维超滤膜(简称原膜)进行表面改性,得到新型纳米改性膜(简称GO-TiO_2改性膜).研究改性膜的制备工艺条件及其对腐殖酸(HA)的吸附截留性能与抗污染特性.结果表明:(1)最佳制备工艺条件为:钛酸丁酯2 m L、GO 1 mg、间苯二胺1%(质量分数)、间苯二胺浸泡时间8 min、均苯三甲酰氯0.2%(质量分数)、均苯三甲酰氯浸泡时间10 min;(2)亲水性提高显著,亲水性表面为GO-聚酰胺-TiO_2复合结构,改性膜接触角由80.6°±1.8°下降到38.6°±1.2°;(3)抗污染性能提高明显.改性膜通量总衰减率由改性前的51.2%下降到35.6%,过滤周期约为原膜的2.5倍;反冲洗后膜通量恢复率由69%提高到96%.     

Preliminary shotgun glycoproteome analysis of N-glycosylation sites in serum proteins of ricin-intoxicated rats

In this study, the variations of serum glycoproteins after exposure to ricin toxin (RT) in Wistar albino rats are reported. For glycopeptide enrichment, Microcon YM-3 centrifugal filter device capture and micro-liquid chromatography (LC)–electrospray ionization (ESI)–tandem mass spectrometric (MS/MS) analysis were used; 74 trypsin-digested proteins were identified in the control group, and 58 in the RT-intoxication group. Additionally, 33 N-glycosides and 14 glycoproteins were identified in the control, and 50 and 21 in the RT-intoxication group.     

Denitrification and phosphorus uptake by DPAOs using nitrite as an electron acceptor by step-feed strategies

Denitrifying phosphorus accumulating organisms (DPAOs) using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In this study, the step-feed strategy was proposed to achieve low nitrite concentration, which can avoid or relieve nitrite inhibition. The results showed that denitrification rate, phosphorus uptake rate and the ratio of the phosphorus uptaken to nitrite denitrified (anoxic P/N ratio) increased when the nitrite concentration was 15 mg·L^-1 after step-feeding nitrite. The maximum denitrification rate and phosphorus uptake rate was 12.73 mg NO2-–N·g MLSS-1?h-1 and 18.75 mg PO43-–P·g MLSS-1?h-1, respectively. These rates were higher than that using nitrate (15 mg·L^-1) as an electron acceptor. The maximum anoxic P/N ratio was 1.55 mg PO43--P?mg NO2--N-1. When the nitrite concentration increased from 15 to 20 mg NO2--N?L-1 after addition of nitrite, the anoxic phosphorus uptake was inhibited by 64.85%, and the denitrification by DPAOs was inhibited by 61.25%. Denitrification rate by DPAOs decreased gradually when nitrite (about 20 mg·L^-1) was added in the step-feed SBR. These results indicated that the step-feed strategy can be used to achieve denitrifying phosphorus removal using nitrite as an electron acceptor, and nitrite concentration should be maintained at low level (<15 mg·L^-1 in this study).     

Factors influencing sexual cannibalism and its benefit to fecundity and offspring survival in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

Sexual cannibalism is hypothesized to have evolved as a way to obtain a high-quality meal, as an extreme mate choice or as a consequence of female aggressive spillover. Here, we examined underlying factors likely to influence sexual cannibalism in the wolf spider Pardosa pseudoannulata (Bösenberg & Strand, 1906) from China, including mating status, female egg-laid status, female hunger level, female adult age and mate size dimorphism. The results showed that about 10 % of P. pseudoannulata virgin females cannibalized the approaching males before mating and that 28 % of P. pseudoannulata virgin females immediately cannibalized the males after mating. No incidents of sexual cannibalism during copulation were observed. Before mating, previously mated females and starved females tended to engage in significantly higher rates of attacks compared to virgin and well-fed females. Females that had laid egg sacs tended to engage in a significantly higher rate of attacks and sexual cannibalism than virgin females before mating. Regardless of pre- or post-mating, there was a strong positive relationship between mate size dimorphism and the occurrence of sexual cannibalism. We also tested the effects of sexual cannibalism on the fecundity of cannibalistic females and the survival of their offspring. Our results indicated that sexual cannibalism affected positively the offspring survival of cannibalistic females, but not fecundity. Our findings support the hypothesis that sexual cannibalism has evolved as an adaptive component of female foraging strategy and that it benefits offspring survival as a result of paternal investment.     

基于加速度限控制策略的振动试验过载停机实验研究

西门子Simcenter Testlab振动控制采集分析系统在航天振动试验领域应用十分广泛,但是在实际工程应用中常常由于对软件工作机制理解不到位,参数设置不合理造成试验异常中断,这不仅给产品带来了巨大的安全隐患,而且也增加了试验时间和成本,严重影响研制进度。因此,本文针对某航天产品正弦振动试验的过载停机故障,从软件加速度限控制功能的角度分析了潜在原因,并且开展了实验验证。首先描述了振动试验过程和过载停机现象,排除了硬件原因,然后对可能的加速度限控制功能设置和通道量程过小等原因设计了三组实验进行分析验证,得出了此次试验过载停机①与加速度限控制(频域)设置无关,②而与通道量程(时域)设置有关,③通过忽略限幅通道过载设置可使试验正常进行的分析结论,最后针对Simcenter Testlab加速度限控制功能和通道量程设置提出了使用建议,为后续航天产品振动试验提供参考。     

Efficiency of mercapto flavor compounds in removing acrylamide under high temperature and low humidity conditions

Acrylamide (AA) is a potential human carcinogen, genotoxicant, and neurotoxicant. Thus, the aim of this study was to examine the ability of mercapto flavor compounds to remove AA released from consumer packaging into food products. Four mercapto flavor compounds including 1,2-ethanedithiol, 1-butanethiol, 2-methyl-3-furanthiol, and 2-furanmethanethiol were employed to extract AA in model system using high temperature and low humidity. Our study showed that mercaptans were effective in eliminating AA in our model system. In order to remove 0.2 μmol AA, the optimal conditions in the reaction system were mercaptan flavor chemicals at 5 μmol, temperature 180 °C, and reaction time 25 min. In the presence of a higher pH, the greater was the amount of AA eliminated. Evidence indicates that employment of mercapto flavor chemicals under certain temperature and pH conditions is a reliable method to remove any unwanted AA from food products.     

High zinc removal from water and soil using struvite-supported diatomite obtained by nitrogen and phosphate recovery from wastewater

Zinc is known as an essential element of human life. However, excessive zinc discharge into water and soil causes water pollution, leading to serious health issues such as septicemia, meningitis and iron-deficiency anemia. Here, a novel material made of struvite-supported diatomite was obtained from eutrophic water treated by mesoporous MgO-modified diatomite. This material was applied for zinc remediation in aqueous solutions and contaminated soils to test the reuse of P-containing products. Struvite-supported diatomite was characterized by field emission scanning electron microscopy and X-ray diffraction. Results show that the maximum removal efficiency of Zn(II) from wastewater streams reached 90.54% at an initial pH of 5 and struvite-supported diatomite dosage of 0.3 g/L. Moreover, the X-ray diffraction patterns of precipitates after Zn(II) sorption show that the combination between zinc and the phosphate group played a key role for zinc removal in solution. For Zn-contaminated soils amended with 10% struvite-supported diatomite, available Zn decreased by 65.38% and acid soluble Zn decreased by 56.9% after 56 days.