不同N、P水平对龙须菜生长及生理生化特性的影响

研究了海水N、P营养水平对龙须菜的生长、光合作用及生化特性的影响,结果表明:单独N、P加富对龙须菜的生长无显著影响,而N、P同时加富可以显著促进龙须菜的生长;其相对生长速率随着时间的增加而降低,P加富处理在培养后期相对生长速率显著增加;N加富促进了龙须菜的光合作用,使藻胆蛋白和可溶性蛋自含量显著提高,可溶性搪含量降低....     

亚热带丘陵区绿狐尾藻人工湿地处理养猪废水氮磷去向

以亚热带丘陵区为研究区,采取野外定位观测的研究方法,选取耐高氮（N）、磷（P）的绿狐尾藻为湿地植物,建立稻草基质池+6级绿狐尾藻表面流湿地系统,湿地总面积1597 m²,水力负荷0.06~0.14 m·d^-1,水力停留时间31 d,研究此湿地系统对养猪废水（NH₄⁺-N：535.4~591.09 mg·L^-1、TN：682.09~766.96 mg·L^-1、TP：57.73~82.29 mg·L^-1和COD：918.4~1940.43 mg·L^-1）的治理效果,旨在为亚热带高负荷猪废水的生态治理提供参数依据.结果表明,湿地系统对NH₄⁺-N、TN、TP和COD的平均去除率为97.4%、97.1%、91.0%和90.2%,其中以CW1累积贡献率最大（37.3%、38.4%、43.3%和27.4%）.植物N、P吸收量在23.87~79.96 g·m^-2和5.34~18.98 g·m^-2之间,占湿地N、P去除量的19.1%和20.2%;底泥N、P吸附量在19.17~56.62 g·m^-2和10.59~26.62 g·m^-2之间,占去除量的19.8%和61.7%.湿地N、P去除率与影响因子间的关系表明,环境因子解释了湿地N、P去除率的79.9%和70.1%.其中,DO是湿地系统N去除的主要因子,底泥P吸附是P去除的关键.     

Positive remediation on sedimentary P by combination of capping with calcium hydroxide and oxidation with perhydrol

The capping is called passive remediation because the sedimentary P was released and then immobilized by the capping materials. However, the release depends on the environmental conditions. Therefore, a hypothesis was proposed that the oxidant was used to accelerate sedimentary P release and the capping material was used to capture those released P. It is positive remediation to reduce sedimentary P amount. The results show that soluble reactive phosphorus（SRP） concentration in the overlying wat...     

UV-LED/P25-based photocatalysis for effective degradation of isothiazolone biocide

• UV-LED with shorter wavelength was beneficial for photocatalytic degradation. • SRNOM dramatically inhibit the degradation. • ·OH acts as the active radical in photocatalytic degradation. • Degradation mainly undergoes oxidation, hydrolysis and chain growth reactions. In this work, LED-based photocatalysis using mixed rutile and anatase phase TiO₂ (P25) as the photocatalyst could effectively remove 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and methylisothiazolone (MIT) simultaneously, with removal efficiencies above 80% within 20 min. The photocatalytic degradation of both CMIT and MIT could be modeled using a pseudo-first-order rate equation. The photocatalytic degradation rates of CMIT and MIT under LED280 illumination were higher than under LED310 or LED360 illumination. At concentrations below 100 mg/L, the degradation rate of CMIT and MIT under LED illumination significantly increased with increasing catalyst dosage. Additionally, the effects of the chloride ion concentration, alkalinity and dissolved organic matter on the photocatalytic degradation reaction were also investigated. The ·OH free radicals were determined to play the primary role in the photocatalytic degradation reaction, with a degradation contribution of >95%. The photocatalytic degradation of CMIT and MIT mainly occurred via oxidation, hydrolysis, and chain growth reactions. Finally, the possible photocatalytic degradation pathways of CMIT and MIT over LED/P25 are proposed.     

煤系页岩瓦斯吸附-解吸特性核磁共振实验研究

吸附态和游离态瓦斯变化规律能为煤系页岩瓦斯安全高效抽采提供技术参考,常规实验方法难以实现对吸附态和游离态瓦斯变化规律的独立表征。以阜新盆地清河门矿煤系页岩为例,采用低场核磁共振技术对煤系页岩粉试样进行瓦斯吸附-解吸实验,并提出以核磁共振T2（横向弛豫时间）谱幅值积分作为瓦斯含量定量表征指标。实验表明:吸附-解吸过程T2谱曲线有3个特性峰,对应3个横向弛豫时间截止阈值;吸附态瓦斯量与瓦斯压力符合朗格缪尔方程,而游离态瓦斯量与瓦斯压力呈线性关系;吸附态瓦斯解吸过程具有明显滞后性,且存在7.26 MPa临界滞后瓦斯压力,而游离态瓦斯吸附和解吸过程近似可逆,无明显滞后性。     

Palm oil biodiesel: An assessment of PAH emissions, oxidative potential and ecotoxicity of particulate matter

This work assessed the impact of fuelling an automotive engine with palm biodiesel (pure, and two blends of 10% and 20% with diesel, B100, B10 and B20, respectively) operating under representative urban driving conditions on 17 priority polycyclic aromatic hydrocarbon (PAH) compounds, oxidative potential of ascorbic acid (OP^AA), and ecotoxicity through Daphnia pulex mortality test. PM diluted with filtered fresh air (WD) gathered in a minitunel, and particulate matter (PM) collected directly from the exhaust gas stream (W/oD) were used for comparison. Results showed that PM collecting method significantly impact PAH concentration. Although all PAH appeared in both, WD and W/oD, higher concentrations were obtained in the last case. Increasing biodiesel concentration in the fuel blend decreased all PAH compounds, and those with 3 and 5 aromatic rings were the most abundant. Palm biodiesel affected both OP^AA and ecotoxicity. While B10 and B20 exhibited the same rate of ascorbic acid (AA) depletion, B100 showed significant faster oxidation rate during the first four minutes and oxidized 10% more AA at the end of the test. B100 and B20 were significantly more ecotoxic than B10. The lethal concentration LC50 for B10 was 6.13 mg/L. It was concluded that palm biodiesel decreased PAH compounds, but increased the oxidative potential and ecotoxicity.     

三江平原退化湿地和农田土壤养分的比较研究

三江平原农业开垦导致地表水位和土壤水分下降,原生湿地退化为沼泽化草甸和典型草甸,或者直接转化为水田和旱田.退化湿地与农田土壤养分的对比研究结果表明,4种样地类型0-30 cm土层土壤有机质含量为水田＞沼泽化草甸＞旱田＞典型草甸,全氮含量差异与有机质含量差异相一致,速效磷含量为水田＞旱田＞沼泽化草甸＞典型草甸.这说明在湿地退化为典型草甸的过程中土壤养分严重下降,水分状况是影响湿地土壤养分下降的关键因素;但是农田土壤养分仍然保持较高水平,主要是由于耕作、施肥等非水分因素的影响.由此可见,水分条件和人为干扰共同决定了退化湿地和农田土壤养分状况.     

Repeatability and heritability of sperm competition outcomes in males and females of <Emphasis Type="Italic">Tribolium castaneum</Emphasis>

Differences among males in their success in achieving fertilisations when females mate with more than one partner are now recognised as an important target of sexual selection. However, very few studies have attempted to determine whether particular males are consistently successful in sperm competition and whether success in sperm competition is a heritable trait. Additionally, the potential heritability of female traits that influence the outcome of sperm competition has received only limited attention. Using the polyandrous beetle Tribolium castaneum, we examined repeatability of male success in sperm competition by mating pairs of males carrying different visible genetic markers to a string of different females. Males showed consistency in their ability to successfully transfer sperm to females, but not in their success in sperm competition. Furthermore, when we independently compared success in sperm competition of fathers with their sons, we found no evidence for heritability of this trait. Similarly, females that exhibited high or low first male sperm precedence did not tend to have daughters that showed the same pattern. Our results suggest that we should be wary of assuming that success in sperm competition is heritable through either sex.     

二噁英降解酶的研究进展

二噁英是一类广泛分布于环境中的持久性有机污染物,它们能够在食物链中逐级积累,并可引发多种细胞毒性,严重影响生态系统和人类健康。在众多二噁英降解方法中,生物降解法以环境友好和低成本等优点一直受到国内外学者的青睐,而二噁英降解酶是生物降解法中的关键物质。简要综述了近年来二噁英典型降解酶的降解机制、效果和编码基因等方面研究进展,并对二噁英降解酶未来的研究和应用方向进行了展望。     

Chemical characterization of fatty acids,alkanes, n-diols and alkyl esters produced by a mixed culture of Trichoderma koningii and Penicillium janthinellum grown aerobically on undecanoic acid,potatoe dextrose and their mixture

Little is known about the mixed fungal synthesis of high-value aliphatics derived from the metabolism of simple and complex carbon substrates. Trichoderma koningii and Penicillium janthinellum were fed with undecanoic acid (UDA), potatoe dextrose broth (PDB), and their mixture. Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) together with ¹H and ¹³C Nuclear Magnetic Resonance (NMR) characterized CHCl₃ soluble aliphatics in the fungal cell culture. Data from NMR and Py-FIMS analysis were complementary to each other. On average, the mixed fungal species produced mostly fatty acids (28% of total ion intensity, TII) > alkanes (2% of TII) > n-diols (2% of TII) > and alkyl esters (0.8% of TII) when fed with UDA, PDB or UDA+PDB. The cell culture accumulated aliphatics extracellularly, although most of the identified compounds accumulated intracellularly. The mixed fungal culture produced high-value chemicals from the metabolic conversion of simple and complex carbon substrates.