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341.
选取3种石油烃降解菌:假单胞菌(Pseudomonas sp.,DS-1)、铜绿色假单胞菌(Pseudomonas aeruginosa,DS-2)和无色杆菌(Achromobacter sp.,DS-3),研究其对石油烃的降解效果及其细胞表面疏水性。结果表明,经过6d的降解,3种石油烃降解菌对石油烃的降解率分别为99.08%、79.75%、84.34%。石油烃的黏附性测试和盐析聚集测试结果表明,3种石油烃降解菌均表现出较高的细胞表面疏水性,其规律为DS-1DS-3DS-2。其中DS-1的细胞表面疏水性最高,达65.90%。DS-1、DS-2和DS-3菌株发生盐析聚集所需最小(NH4)2SO4摩尔浓度分别为2.0、2.8、2.4 mol/L。菌株的细胞表面疏水性和降解有机物的能力有着较高的相关性。 相似文献
342.
目的实现平面场中主应变的测量不确定度评定。方法首先建立主应变的是非线性传播测量模型,然后应用基于二阶TAYLOR级数展开理论的不确定度传播方法(LPU方法),开展平面问题中主应变的测量不确定度评定。针对二种常用的应变花,建立以主应变为输出量、以应变花之三个方向测量应变为输入量的测量模型,并将二阶LPU方法应用于该模型。设计数值计算算例,以说明主应变不确定度的评定过程和方法,并与一阶LPU结果进行了比较。结果当应变花三个方向的应变测量结果相近时,文中方法与一阶LPU方法获得的主应变的不确定度评定结果存在明显的差异,主应变不确定度评定结果在数值上都大于应变花测量的不确定度。当应变花三个方向的应变测量结果相差较大时,文中方法和一阶LPU方法获得的主应变测量不确定度评定结果相差不大。结论特定情况下,主应变的测量不确定度值远大于应变花测量的不确定度,且与一阶LPU方法的评定结果有显著差异,二者可相差一倍。 相似文献
343.
Anna Marszałek Grażyna Grabowska Krzysztof Łężak The Secret Study Group 《International journal of occupational safety and ergonomics》2019,25(2):268-277
Research into newly developed ballistic vests to be worn by police officers under clothing was carried out with air temperature conditions of +20 °C. A ballistic vest should incorporate protective features, comfort and ergonomics. The thermal strain on users who wore the vests was evaluated as an average and individually, after they had been conditioned in high (+50 °C), low (?40 °C) or neutral (+20 °C) air temperatures, while performing various occupational activities. Research involved six police officers aged 36–42 years, who wore civilian clothing used in moderate environmental conditions. During the tests, physiological parameters (internal temperature, local skin temperatures and amount of sweat secreted) were determined. The ease of doing exercises while wearing the vests, vest service and level of discomfort in use were assessed. Research showed that the vests tested, both as an average and individually, meet the requirements of Standard No. PN-V-87000:2011 (clause 4.5). 相似文献
344.
S. Mazzoli 《Geologische Rundschau》1995,84(4):781-793
Analysis of strain in Jurassic argillites forming part of the folded and thrusted sedimentary succession of the Lagonegro basin (southern Italian Apennines) has been carried out using ellipsoid-shaped 'reduction' spots as strain markers. Most of the determined finite strain ellipsoids are of oblate type and show a peculiar distribution of the maximum extension direction ( X), with maxima either subparallel or subperpendicular to the local fold axes. Using the strain matrix method, two different deformation histories have been considered to assist the interpretation of the observed finite strain pattern. A first deformation history involved vertical compaction followed by horizontal shortening (occurring by a combination of true tectonic strain and volume loss), whereby all strain is coaxial and there is no change in the intermediate axis of the strain ellipsoid. By this type of deformation sequence, which produces a deformation path where total strain moves from the oblate to the prolate strain field and back to the oblate field, prolate strain ellipsoids can be generated and may be recorded where tectonic deformation has not been large enough to reverse pre-tectonic compaction. This type of deformation history may be of local importance within the study area (i.e. it may characterize some fold hinge regions) and, more generally, is probably of limited occurrence in deformed pelitic rocks. A second deformation sequence considered the superposition of pre-tectonic compaction and tectonic strain consisting of initial layer-parallel shortening followed by layer-parallel shear (related to flexural folding). Also in this instance, volume change during tectonic deformation and tectonic plane strain have been assumed. For geologically reasonable amounts of volume loss due to compaction and of initial layer-parallel shortening, this type of deformation history is capable of producing a deformation path entirely lying within the oblate strain field, but still characterized by a changeover, during deformation, of the maximum extension axis ( X) from a position parallel to the fold axis to one perpendicular to it. This type of deformation sequence may explain the main strain features observed in the study area, where most of the measured finite strain ellipsoids, determined from the limb regions of flexural folds, display an oblate shape, irrespective of the orientation of their maximum extension direction ( X) with respect to the local structural trends. More generally, this type of deformation history provides a mechanism to account for the predominance of oblate strains in deformed pelitic rocks. Key words Finite strain states · Compaction · Tectonic strain · Deformation gradient tensors · Deformation paths 相似文献
345.
346.
Ji Shulan Liu Zhipei Liu Zhipeng Ren Haiyan 《Frontiers of Environmental Science & Engineering in China》2007,1(3):325-328
A bacterial strain, ZY3, growing on sex steroid hormones as the sole source of carbon and energy was isolated from the sewage
treatment plant of a prophylactic steroids factory. ZY3 degrades the 3-methoxy-17β-hydroxy-1,3,5(10),8(9)-δ-4-estren (MHE).
This strain was preliminarily identified as Raoultella sp. ZY3 according to its morphology and its 16S rRNA gene sequence. During the experimental period (72 h), the optimum temperature,
pH and 3-MHE concentration for the degradation of hydride by the strain ZY3 were 35°C, 10 and 10 mg/L, respectively. The degradation
rate of the sex steroid hormones increased to 87% and 85% after the addition of maltose and peptone, respectively.
Translated from China Environmental Science, 2005, 25(5): 585–588 [译自: 中国环境科学] 相似文献
347.
348.
苯丙氨酸解氨酶的分子生物学研究进展 总被引:9,自引:0,他引:9
苯丙氨酸解氨酶 (Phenylalanineammonialyase ,PALE .C .4.3 .1.5 )是一种只存在于植物及微生物细胞内的酶 ,主要分布于高等植物如小麦、大豆、玉米、土豆及酵母[1] 、真菌[2 ] 、链霉菌[3]中 .在 pH 8.8时 ,PAL催化苯丙氨酸脱氨生成肉桂酸和氨 ,当过量的氨存在 ,如 pH 10时 ,PAL催化肉桂酸和氨 ,氨化加成生成L 苯丙氨酸 (L phenylalanine) .利用PAL这种逆向催化特性转化肉桂酸生产L Phe ,已在国内外投入商业规模开发 ,成为当前生物化工领域研究与开发的热点 .L Phe是人… 相似文献
349.
冷挤压组合凹模的失效主要是凹模内腔疲劳裂纹的出现,在模具设计的前期较为准确的估算出组合凹模的疲劳寿命是模具优化设计的前提。通过对组合凹模的应力分析后,采用Mises屈服准则的方法把凹模所受的多轴应力转化成单轴应力,再利用局部应力应变法找到了估算冷挤压组合凹模寿命的途径。 相似文献
350.
驯化筛选微生物对油制气废水的降解特性 总被引:6,自引:1,他引:6
从5个菌源分离到的16株菌中筛选出S-2、Y-3和XH-3为优势菌种,分别用它们及其混合菌M-3研究对油制气废水的降解,60h之后CODcr的去除率为38.4%-44.0%,酚类化合物的去除率为95.4%-97.0%,芳烃类化合物的去除率为47.1%-53.7%,但氨氮的去除率只有14.0%-17.6%。采用GC/MS分析了处理前后废水中的芳烃类化合物,所筛选的微生物对芳环数≤3的芳烃类化合物降解能力强,还可去除一定量芳环数为4-6的芳烃类化合物。加入共代谢基质葡萄糖,可使CODcr、氨氮及可萃取有机物的去除率分别提高13.1%-22.9%、18.4%-22.7%及13.1%-18.1%;加入乙醇,可使CODcr、氨氮及可萃取有机物的去除率分别提高12.5%-21.2%、29.7%-42.2%及6.7%-7.7%。废水中芳烃类化合物的总去除率分别比无葡萄糖和无乙醇时提高了17.7%-21.7%和15.4%-21.2%。所筛选驯化的菌种有效地提高了油制气废水的降解效率。 相似文献