两相厌氧反应器相分离实验研究

在两相上流式厌氧生物反应器(UASB)动力学启动成功的条件下,选用钼酸盐作为产甲烷菌抑制剂,进行进一步的分相实验。实验前3 d在产酸相反应器进水中投加2.0 mmol/L的钼酸钠溶液,出水不进入产甲烷反应器。然后停止投加钼酸钠溶液,再运行3 d,出水依然不进入产甲烷反应器。6 d后,产酸反应器出水开始进入产甲烷反应器。结果表明:在停止投加钼酸盐后产酸菌便迅速恢复,而钼酸盐对产甲烷菌的作用是杀灭性的;产酸相出水去除效果降低,但是其酸化率由50%左右上升并最终稳定在60%左右,同时两相厌氧反应器整体去除效率提高。     

Automobile exhaust gas as a source of aqueous phase OH radical in the atmosphere and its effects on physiological status of pine trees

Free radical generation potential of automobile exhaust gas was examined by measuring hydroxyl (OH) radical photo-formation rates in exhaust gas-scrubbing water. Effects of automobile exhausts on physiological status of Japanese red pine trees (Pinus densiflora Sieb. et Zucc.) were also investigated to elucidate the mechanism how the free radicals derived from exhaust gas damage higher plants. Gasoline and diesel exhaust gases were scrubbed into pure water. Potential photo-formation rates of OH radical in aqueous phase (normalized to sun light intensity of clear sky midday on May 1 at 34°N) for gasoline and diesel cars were ave. 51 and 107 μM h⁻¹ m⁻³ of exhaust gas, respectively. Nitrite was a dominant source (ca. 70-90%) of photochemical formation of OH radical in both gasoline and diesel car exhausts. The scrubbed solution of diesel car exhaust gas was sprayed for six times per week to needles of pine tree seedlings in open top chambers. Control, exhaust + mannitol (added as OH radical scavenger), and nitrite + nitrate standard solution (equivalent levels existed in the exhaust gas) were also sprayed. Two months sprays indicated that the sprayed solutions of diesel exhaust and nitrite + nitrate caused a decrease of maximum photosynthetic rate and stomata conductance in pine needles while the control and exhaust + mannitol solution showed no effects on photosynthetic activities of pine needles. These results indicated that OH radicals generated mainly from photolysis of nitrite occurring in the scrubbing solution of exhaust gas are responsible for the decrease of photosynthetic activities of pine needles.     

柴油机排放多环芳香烃气/颗粒相分配研究

为了对柴油机排放PAHs在气相和颗粒相中的分配进行研究,采用了滤膜串联＂PUF/XAD-2/PUF＂吸附柱的方法采集柴油机排气中的气相和颗粒相PAHs,使用程序升温挥发（PTV）技术结合气相色谱-质谱联用（GC-MS）方法对PAHs进行了定性和定量分析。所用分析方法重复性的相对标准偏差（RSD）低于6.1%,检出限范围...     

Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid

Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.     

固相萃取-高效液相色谱法测定水中磺酰脲类除草剂

建立了固相萃取-高效液相色谱测定水中7种磺酰脲类除草剂的方法,考察了降解作用及滤膜对测定的影响.方法在0.30 mg/L～5.00 mg/L之间线性关系良好,7种磺酰脲类除草剂的检出限为0.32 μg/L～0.62 μg/L,RSD为4.4%～7.6%,平均加标回收率为87.9%～102%.     

The dissolution of benzene, toluene, m-xylene and naphthalene from a residually trapped non-aqueous phase liquid under mass transfer limited conditions

The results of dissolution experiments for benzene, toluene, m-xylene and naphthalene (BTXN) from a relatively insoluble oil phase (tridecane), residually trapped in a non-sorbing porous medium, are described. This mixture was chosen to simulate dissolution of soluble aromatic compounds from a petroleum hydrocarbon mixture, e.g., crude oil, for which a large fraction of the mixture is relatively insoluble. The experiments were carried out at a small source length to interstitial velocity ratio, L/v, so that dissolution would be mass transfer limited (MTL). When fitted to data for toluene, a multiregion mass transfer model was found to predict the experimental data satisfactorily for the other components without adjustment of the mass transfer rate parameters. These results indicate that the dissolution process can be generalized for various hydrophobic organic compounds present in a multicomponent non-aqueous phase liquid (NAPL) when mass transfer limitations are present. This also suggests that dissolution data obtained for one compound can be useful for predicting the dissolution histories for other compounds from petroleum hydrocarbon mixtures.     

全期表达外源基因的重组杆状病毒

构建了含早期、晚期、极晚期启动子、全期表达ＨＢｓＡｇ 基因的重组杆状病毒ｖＴｎＮＰＶＰ３５ＨＢｓＯＣＣ＋ ．结果ＨＢｓＡｇ 表达时间由感染后１２ ｈ 提前到４ ｈ,而其表达量,特别是病毒感染早期的表达水平亦显著提高,其中２４ ｈ 和９６ ｈ 的表达量分别比对照提高１８０ ％ 和６０ ％ ． 转录起始位点分析结果显示,该重组毒株可在病毒感染的早、晚期形成多个转录本     

Implications of Heterogeneous Chemistry of Nitric Acid for Nitrogen Deposition to Marine Ecosystems: Observations and Modeling

Size resolved particle composition and nitric acid (HNO₃)measurements from the ASEPS'98 experiment conducted in the BalticSea are used to provide observational evidence of substantialgas-particle transfer of oxidized nitrogen (N) compounds in themarine boundary layer. We then focus on the importance ofHNO₃ reactions on sea salt particles in determining spatio-temporal patterns of N dry deposition to marine ecosystems.Modelling results obtained assuming no kinetic or chemical limiton HNO₃ uptake and horizontally homogeneous conditions withnear-neutral stability, indicate that for wind speeds 3.5 – 10 ms^-1 transfer of HNO₃ to the particle phase to formparticle nitrate (NO₃ ^-) may decrease the N depositionvelocity by 50%. We extend this research using the CHEM-COASTmodel to demonstrate that, in a sulphur poor environment undermoderate wind speeds with HNO₃ concentrations representativeof those found in the marine boundary layer, inclusion ofheterogeneous reactions on sea spray significantly reducesmodelled NO₃ ^- deposition in the near coastal zone.     

Synthesis and Extraction Study of Calix[4]arene Dinitrile Derivatives Incorporated in a Polymeric Backbone with Bisphenol-A

Two new copolymers containing pendant calix[4]arene units with nitrile functionalities at their lower rim have been synthesized via nucleophilic substitution reactions involving 5,11,17,23-tetra-tert-butyl-25,27-bis(cyanomethoxy)-26,28-dihydroxy-calix[4]arene (3) or 25,27-bis(cyanometh oxy)-26,28-dihydroxy-calix[4]arene (4) with 1,5-dibromopentane and bisphenol-A. The phase transfer studies were performed by using liquid–liquid extraction procedures. It has been deduced from the observations that both copolymers show a good phase transfer affinity toward selected alkali, alkaline earth, and transition metal cations, unlike their precursor (3).     

应急管理阶段理论新模型研究

本文回顾了应急管理阶段理论的发展过程,分析了传统应急管理阶段理论存在的一些不足。根据突发事件中危害因素、受灾体、应急管理的不同行为特征,提出了应急管理阶段的新模型。在该新模型中,应急管理的生命周期包括"预防-监测-响应-恢复-重建"五个前后相续的阶段,而"减灾"与"准备"则被提升为贯穿应急管理整个生命周期的两类基础性活动。