低压下不同新型清洁气体灭火剂抑灭21700型锂离子电池火研究

为探究在航空运输低压环境下Novec1230（全氟己酮）和2-BTP（2-溴-3,3,3三氟丙烯）2种新型清洁气体灭火剂扑灭和抑制空运锂离子电池火的效果,基于动压变温实验舱,自主设计了适用于气体灭火剂的实验灭火装置;在40,60,80 kPa 3种环境压力梯度下开展灭火实验,分析了施加2种灭火剂前后锂电池表面温度变化和灭火过程中的实验现象。结果表明:低压下2-BTP和Novec1230均能有效降低锂离子电池火焰中自由基浓度,快速扑灭明火;2-BTP的降温和抑制温升效果明显优于Novec1230,能更好地抑制锂电池之间的连锁热失控。研究结果可为新一代机载灭火剂的选择提供参考。     

化学法去除循环水排污水中的磷

研究了聚合氯化铝、硫酸铁、氯化铁及生石灰等除磷剂对循环水排污水的除磷效果,考察了反应温度、反应时间、污水p H和除磷剂投加方式对除磷效果的影响。实验结果表明:聚合氯化铝和硫酸铁的除磷效率相当,其次是氯化铁,生石灰的除磷效率最低;最终选用聚合氯化铝作为除磷剂,对循环水排污水进行除磷处理时无需调节其p H,反应可在室温下进行,反应时间需大于300 s;聚合氯化铝最佳投加量为40 mg/L,二次性投加聚合氯化铝的除磷效果明显好于一次性投加;二次性投加出水TP为0.37 mg/L。     

杀藻细菌色素Deinoxanthin的理化性质及其制剂研发

塔玛亚历山大藻(Alexandrium tamarense)是一种有毒甲藻,常引发赤潮,对海洋环境及人类健康造成极大的威胁.前期研究发现,耐辐射球菌属的一株细菌Y35能够通过分泌杀藻化合物Deinoxanthin达到控制塔玛亚历山大藻生长的效果.为了加强Deinoxanthin的应用效果,对其在不同条件下的稳定性进行了研究.结果表明,杀藻化合物Deinoxanthin有较高的热稳定性,且在中性和碱性条件下稳定,在光照和紫外线辐射下易分解.而通过壳聚糖和海藻酸钠对Deinoxanthin进行包埋固定化,从而构建缓释微球提高了Deinoxanthin的稳定性.杀藻制剂能够高效地表现出杀藻效果,杀藻制剂的研发为杀藻细菌色素应用于藻华治理奠定了基础.     

Hydrogeomorphic Reference Condition and Its Relationship with Macroinvertebrate Assemblages in Southeastern U.S. Sand Hills Streams

Defining stream reference conditions is integral to providing benchmarks to ecological perturbation. We quantified channel geometry, hydrologic and environmental variables, and macroinvertebrates in 62 low‐gradient, SE United States (U.S.) Sand Hills (Level IV ecoregion) sand‐bed streams. To identify hydrogeomorphic reference condition (HGM), we clustered channel geometry deviation from expectations given watershed area (Aws), resulting in two HGM groups discriminated by area at the top of bank (Atob) residuals <0.6 m² and >0.6 m² predicted to be HGM reference/nonreference streams, respectively. Two independent partial least squares discriminate analyses used (1) hydrologic/environmental variables and (2) macroinvertebrate mean trait values (mT) on 10 reference/nonreference stream pairs of similar Aws for classification validation. Nonreference streams had flashier hydrographs and altered flow magnitudes, lower organic matter, coarser substrate, higher pH/specific conductivity compared with reference streams. Macroinvertebrate assemblages corresponded to HGM groupings, with mT indicative of multivoltinism, collector‐gatherer functional feeding groups, fast current‐preference taxa, and lower Ephemeroptera, Plecoptera, and Trichoptera richness and biotic integrity in nonreference streams. HGM classifications in Sand Hills, sand‐bed streams were determined from channel geometry. This easily implemented classification is indicative of contemporary hydrologic disturbance resulting in contrasting macroinvertebrate assemblages.     

取样及样品前处理对制革废水中总铬的影响

通过利用火焰原子吸收分光光度法测定制革企业不同工艺流程产生废水的总铬,考察不同量具及取样量、不同消解方法和样品保存期限对测定结果的影响。结果表明水样中悬浮物造成的取样不均匀性导致测定结果差异明显,不同消解方法测定制革废水总铬,检测数据具有可比性,固定剂的加入能够使得水样检测数据保持稳定。     

Utilization of winery wastes for Trichoderma viride biocontrol agent production by solid state fermentation

Biocontrol agents are safe and environmental friendly alternatives for pesticides in agriculture application. Trichoderma viride WEBL0703 performed a high level of antagonistic activity toward a broad spectrum of phytopathogens and was determined as a biocontrol agent, which was produced by solid state fermentation using grape marc and wine lees. The maximum yield of T. viride conidia was up to 6.65 × 10^9 CFU/g initial dry substrate （IDS） after 10 d fermentation. As important enzymes for protecting plants from disease, chitinase, β-glucanase, and pectinase yields were 47.8 U/g IDS, 8.32 U/g IDS and 9.83 U/g IDS, respectively. These results show that it is feasible to convert winery wastes to a value-added and environmental friendly biocontrol agent.     

DCCH型澄清池的性能试验研究

文章通过现场试验和分析分别考察了混凝剂加药量,活性泥渣浓度,助凝剂,澄清池进水流量和机械搅拌力度因素对DCCH型澄清池出水残余浊度的影响。试验表明增加混凝剂加药量可改善出水水质,但药量过量会使残余浊度上升;在一定范围内增加反应区活性泥渣沉降比澄清池残余浊度降低,且残余浊度与活性泥渣浓度符合一级反应动力学规律;助凝剂可改善絮体结构使残余浊度降低,但从经济环保角度出发应尽量减少使用量;增加进水流量使残余浊度上升,上升幅度主要取决于澄清池形成絮体的结构;适当增加机械搅拌力度能有效的降低澄清池残余浊度。     

固氮蓝藻Nostoc commune和Anabaena azotica Ley耐盐性及机理研究

文章考察了两种固氮蓝藻Nostoc commune（地木耳）和Anabaena azotica Ley（固氮鱼腥藻）在不同浓度Na2CO3（0.2×10^-4～1.8×10^-4g/m l）的BG110培养基中的耐盐性。分别测定了两种固氮蓝藻在不同培养阶段的叶绿素a含量、胞外多糖含量、氨基酸含量和固氮酶活性的变化。研究结果表明两种固氮蓝藻都能在Na2CO3盐胁迫条件下生长,且随着Na2CO3盐胁迫性增加,两种蓝藻的叶绿素a含量、胞外多糖含量、氨基酸含量和固氮酶活性都呈现先增加后减少的趋势;而随着培养天数的增加,两种藻类叶绿素a的变化曲线与微生物的生长曲线很相似,胞外多糖和氨基酸的增长和叶绿素a的增长是同步的,其中,Anabaena azotica Ley的固氮酶活性在培养到21天时达到最大值,Nostoc commune的固氮酶活性在培养到28天时达到最大值;比较而言Anabaena azotica Ley的耐盐性好于Nostoc commune的耐盐性,固氮能力也高于Nostoc commune。     

型煤防水性能的研究

型煤的吸湿性影响型煤的性能和推广范围,型煤的防水剂技术是型煤清洁高效燃烧工艺的技术关键之一,本文论述了ＧＳ防水剂的防水性能和经济性,提出了提高型煤防水性能的三种不同技术途径。应用本文所述技术生产的型煤的防水率达到８０％以上,从而保证了型煤高效能清洁燃烧。     

Effects of sand movement by wind on nematodes and soil-borne fungi in coastal foredunes

In stabilized dunesAmmophila arenaria (marram grass) degenerates due to a process involving soil-borne pathogens and parasites. This leads to exposure of the sand surface so that wind erosion may create blowouts.Ammophila rejuvenates on the edges of the blowouts, where the sand has accumulated. We tested the hypothesis that such rejuvenation of plants may be related to a reduction of the plant-parasitic nematodes and fungal propagules during the process of wind-driven transport. Field measurements in blowouts during storm events indicated that the drifted sand contained relatively low numbers of plant pathogenic fungi and plant-parasitic nematodes. A wind tunnel experiment showed that drifting sand may indeed reduce the numbers of fungi and nematodes. Although most fungi were attached to sand particles, they were also affected by the wind-borne sand movement. Sand that had been deposited by wind was made up of a larger proportion of large-sized particles. In our experiment the relatively small particles were lost during transport. Stirring the soil (part of the forces of natural winds) by mixing for 15 min. with a propeller mixer at 1500 rpm significantly reduced the number of nematodes and fungi. Both sand movement in the wind tunnel and intensive stirring of the sand enhanced the growth ofAmmophila test plants in a bioassay. It was concluded that in wind-blown sand the pathogen inoculum is reduced. Therefore, serious consideration should be given to allowing controlled reactivation of blowouts to rejuvenate decliningAmmophila in stabilized foredunes. Implications for dune management are briefly discussed. Nomenclature: van der Meijden (1990) for vascular plants. Nematodes were identified to the genus level according to Bongers (1988). The allocation of nematodes to feeding groups was according to Yeates et al. (1993). Nomenclature of fungi according to Domsch et al. (1980) was used throughout this study except forFusarium. Species of the latter genus were identified according to Nelson et al. (1983).