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961.
利用遥感及多元信息复合处理技术,解译了由大量南北向线性体组成的南北向构造带以及其它构造信息,分析了它的控岩控矿特性,建立了5种成矿模式。为开辟找矿新区打下良好的基础。  相似文献   
962.
长链烷基化物与牛血清白蛋白相互作用的共振光散射研究   总被引:9,自引:0,他引:9  
奉萍  黄承志  舒为群 《环境化学》2001,20(5):497-502
应用荧光分光度计进行共振光散射测定,研究了水相介质中长链烷基化物十二烷基硫酸钠(SLS)与牛血清白蛋白(BSA)的结合平衡。实验表明,在微酸性条件下,SLS与BSA形成的复合物引起共振散射增强,根据470mm的光散射增强信号建立了一定酸度下SLS与BSA结合的数学关系式,随着pH值的变化,二者相互作用的结合平衡常数(Kf)及每分子BSA所结合的SLS个数(n)均不相同。  相似文献   
963.
以简并引物PCR获得的Cat酶基因片段探针,结合生物信息学方法,探明了耐辐射奇球菌(D.radiodu-rans)基因组中存在两个编码过氧化氢酶(Catalase,Cat)的基因:katA和B.katA和katB基因长2277bp和1611bp,各编码758和536个氨基酸,用pKK223-3表达载体连接katB基因,转入Cat酶缺陷型大肠杆菌(E. coliUM2)进行表达.katB基因表达产物具有Cat酶活性,电泳迁移位置与D.radiodurans CatB酶位置相符,并可重建E.coliUM2对低浓度H2O2损伤的耐受力。  相似文献   
964.
浙江省梅汛期洪涝灾情分析和预测   总被引:1,自引:0,他引:1  
通过所构设的雨涝强度、雨涝影响面积等统计量来估计浙江省梅汛期的灾情,有较高的准确率,能估计出极端情况,为灾害评估工作提供了新的思路。  相似文献   
965.
The contributions of deposited particles (P) to polycyclic aromatic hydrocarbon (PAH) levels in pine (Cedrus deodar) needles sampled from the Dalian region were evaluated by washing off the particles from pine needle surfaces. P values ranged from 4.4 +/- 2.2% for fluorene to 69.9 +/- 4.0% for indeno(1,2,3-cd)pyrene, and positively correlated with the logarithm of octanol-air partition coefficients (log K OA) of each PAH significantly. P and the total levels of 14 PAHs under study ( summation PAHs), that ranged from 490 to 3241 ng g(-1) dw (dry weight) with median value of 1521 ng g(-1) dw, were high for traffic areas, and low for residential or park areas, implying the significant contributions of PAHs in both gas and particle phases emitted by vehicles. However, PAH profiles in pine needles were not significantly altered by the washing, due to the low fractions (2-5%) of the 5- and 6-ring PAHs in summation PAHs. The high wind speed and frequently alternating wind directions in the Dalian spring could quicken the depuration processes of pine needle PAHs. Thus, the local meteorological conditions and source variations should be taken into account when using pine needles to implicate seasonal variations of atmospheric semi-volatile organic compounds.  相似文献   
966.
Zeng P  Zhuang WQ  Tay ST  Tay JH 《Chemosphere》2007,69(11):1751-1757
The precultured aerobic granules with special degradabilities could be used as a feasible bioseed for enhancement of aerobic granulation systems. In practice, the storage stability, physicochemical characteristics, and recovering efficiency of granules are crucial for a long-distance transportation and successful application. In this study, phthalic acid (PA)-degrading aerobic granules were cultivated and stored for 8 wk at 4 °C. The granular size, settling ability as well as structure integrity was found stable during the storage period. It was observed that the upper 1/3 part of granules stored in the reagent bottle turned to black color, while the lower 2/3 part granules did not significantly change color (brown–yellow) after the 8-wk storage. The black and brown–yellow color PA-degrading granules were manually separated and re-inoculated into two identical sequencing batch reactors for reviving the PA degradation capability. After a 7 d operation, both black and yellow granules restored their activities to the levels before storage, in terms of total organic carbon removal efficiency (100%), specific oxygen uptake rate (59 mg g VSS−1 h−1), and adenosine triphosphate content (0.016 mg g VSS−1). This study demonstrated that aerobic granules grown on a complex substrate could tolerate storage conditions and rapidly restored their bioactivities toward the target pollutant. The results also shed the light on the future application of precultured aerobic granules with unique functions for biodegradation and bioremediation purpose.  相似文献   
967.
Xu J  Yu Y  Wang P  Guo W  Dai S  Sun H 《Chemosphere》2007,67(7):1408-1414
Fourteen surface sediment samples were collected from Lanzhou Reach of Yellow River, China in July 2005. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector (GC-MS). Total concentrations of the PAHs ranged from 464 to 2621 ng/g dry weight. Sediment samples with the highest PAH concentrations appeared at the downstream of Lanzhou City, where there was the biggest wastewater discharge pipeline from Lanzhou Oil Refinery Factory and Lanzhou Chemical Industry Company. Municipal sewage also contributed to the PAH contamination in the sediments. A correlation existed between the sediment organic carbon content (f(oc)) and the total PAH concentrations (r(2)=0.57), suggesting that sediment organic carbon content played an important role in controlling the PAHs levels in the sediments. According to the observed molecular indices, PAHs contamination in Lanzhou Reach of Yellow River originated both from the high-temperature pyrolytic processes and from the petrogenic source, showing a mixed PAH input pattern, which was also confirmed by the results of a principal component analysis (PCA). According to the numerical effect-based sediment quality guidelines (SQGs) of the United States, the levels of PAHs at most studied sites in Lanzhou Reach of Yellow River should not exert adverse biological effects. Although at some sites (such as S10, S12, etc.) one PAH may exceed the effects range low (ERL), individual PAH did not exceed the effects range median (ERM). The results indicated that sediments in all sites should have potential biological impact, but should have no impairment.  相似文献   
968.
为了有效去除苯甲酸重副产物中含有的交联大分子和碳化物等有色杂质,降低有用组分资源化处理的难度,分别采用吸附和蒸馏两种方法对苯甲酸重副产物进行脱色处理。实验结果表明:大孔树脂、硅藻土、活性炭等作脱色剂不能有效去除苯甲酸重副产物中的有色杂质;在真空度0.093~0.095MPa、蒸馏温度220~240℃条件下进行蒸馏脱色,当温度出现回落时停止蒸馏,平均馏出率为66.99%;蒸馏脱色得到的轻组分颜色呈黄色,可满足中和、酸化、结晶、回收苯甲酸的要求;釜残物可作为燃料通过焚烧利用其热能。  相似文献   
969.
四个工艺结构完全相同的活性污泥法反应系统由于添加五氯苯酚的浓度不同,在稳定运行期,其总有机污染物COD及目标污染物五氯苯酚的去除率也不相同。BIOLOG方法分析各活性污泥系统中细菌的功能结构及镜检观察分析污泥中原生动物的种群结构后发现:五氯苯酚降低活性污泥污染物去除效率的根源在于,不同浓度的五氯苯酚对活性污泥中的微生物种群结构的定向选择,在不同程度上改变了活性污泥中微生物种群的功能结构,使微生物种群对污染物的降解速率和程度发生了改变。  相似文献   
970.
医疗废物焚烧过程脱硫机理和试验   总被引:1,自引:1,他引:0  
医疗废物中包括含有硫分的橡胶,焚烧时会产生SO2从而污染环境,因此医疗废物在焚烧处理时需要进行脱硫。应用HSC热力学软件计算可知,医疗废物焚烧炉内喷入脱硫剂在燃烧过程脱硫,脱硫效果最好的脱硫剂是CaO,然后是Ca(OH)2,CaCO3。综合各种因素,选用CaCO3做脱硫剂进行焚烧过程脱硫试验。试验结果表明:温度对脱硫有着重要的影响,最佳脱硫温度为830~870℃左右;随着Ca/S摩尔比的增大脱硫率增大,但增加的速度却趋于平缓,所得最佳Ca/S摩尔比为2.5。  相似文献   
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