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81.
We have used a Y-chromosome specific DNA probe in a controlled study to determine the presence of Y-chromosome material and to detect numerical abnormalities in uncultured amniotic fluid cells by fluorescent hybridization. Using this non-radioactive method, we correctly predicted fetal sex within 48 h in all but 3 of 54 cases and identified an XYY syndrome. The technique was previously tested with no false-positive or false-negative results on cultured interphase or metaphase nuclei of fetal fibroblasts and adult T-lymphocytes. Fluorescent in situ hybridization was applied to long-term fixed cytogenetic preparations up to 44 months old and was shown to be reliable.  相似文献   
82.
催化铁内电解-混凝-生物膜法处理荧光增白剂生产废水   总被引:2,自引:0,他引:2  
利用"催化铁内电解-混凝-生物膜法(A/O)"组合工艺成功处理了荧光增白剂生产废水,并系统阐述了各个处理单元的运行参数和处理效果.经检验,出水水质达到GB8978-96三级排放标准.  相似文献   
83.
The authors compare the diagnostic possibilities of fetal transabdominal echocardiography versus transvaginal echocardiography. A larger diagnostic capacity is verified in different gestation ages with transvaginal probe between the 11th and 14th week of gestation. The results are emphasized by colour Doppler.  相似文献   
84.
1 IntroductionOpticalfiberchemicalsensor,whichisdevelopedfromthecombinationofoptical fiberwave guidetechniqueandhighlysensitivemolecularluminescentanalyticalmethod ,hasshownagoodapplicationprospectinenvironmentalauto monitoring .Thefabricationofsensingprobeisthekeytechniqueforopticalfiberchemicalsensor.Althoughconventionalopticalfiberprobes,suchassensingmembraneetal.[1 ]hadbeengreatlydevelopedrecently ,therearestillmanyvitalproblemsneedstobesolved .Suchas (1)theamountofphotosensitiveindicator…  相似文献   
85.
本文讨论了角膜电极测定生化需氧量(BOD5)方法与传统碘量法的比较。两家实验室的验证结果表明,对于地表水和废水的测定,两种方法测得结果没有明显差异,用膜电极法测定BOD5方法的精密度和准确度可以满足实际样品的测定。  相似文献   
86.
Total OH reactivity was observed by use of the laser-induced pump and probe technique, and the urban air quality in Tokyo was diagnosed comprehensively. The concentrations of NOx, CO, O3, non-methane hydrocarbons (NMHCs) and oxygenated volatile organic compounds (OVOCs) were observed simultaneously. The observations were conducted in July and August 2003, and in January, February, May, and November 2004. Generally, the observed OH reactivity was higher than the calculated values derived using the observed concentrations of the trace species. The differences between the observed and calculated values in summer, spring, and autumn were approximately 30%. However, the difference in winter was smaller than those in the other seasons. In addition, while the differences observed in summer, spring, and autumn correlated with the total reactivity of the OVOCs (Σi kOVOCi[OVOCi](s−1), ki is rate constant of its compounds with OH), the correlations were not confirmed in the case of winter because atmospheric oxidation was less active and OVOCs levels were low in winter. These results suggest that the secondary products of the photochemical reactions in the atmosphere would be a missing sink for the OH loss process in the urban area.  相似文献   
87.
旋风静电除尘器流场分布测试研究   总被引:2,自引:0,他引:2  
利用五孔探针系统对直筒式旋风静电除尘器模型的三维流场进行了测定与分析。结果表明:随着入口风速、供电电压增加,旋风静电除尘器内气流的切向和径向速度分别增加,各截面轴向速度沿半径的分布基本相似;与旋风除尘器相比,旋风静电除尘器内气流的切向速度和径向速度的变化更为平缓,入口风速为8.5m/s时,在0.3~0.5倍简体直径时,切向速度达最大。  相似文献   
88.
A laboratory-scale intermittent aeration bioreactor was investigated to treat biologically pretreated coal gasification wastewater that was mainly composed of NH_3-N and phenol.The results showed that increasing phenol loading had an adverse effect on NH_3-N removal;the concentration in effluent at phenol loading of 40 mg phenol/(L·day) was 7.3 mg/L, 36.3%of that at 200 mg phenol/(L·day). The enzyme ammonia monooxygenase showed more sensitivity than hydroxylamine oxidoreductase to the inhibitory effect of phenol, with32.2% and 10.5% activity inhibition, respectively at 200 mg phenol/(L·day). Owing to intermittent aeration conditions, nitritation-type nitrification and simultaneous nitrification and denitrification(SND) were observed, giving a maximum SND efficiency of 30.5%.Additionally, ammonia oxidizing bacteria(AOB) and denitrifying bacteria were the main group identified by fluorescent in situ hybridization. However, their relative abundance represented opposite variations as phenol loading increased, ranging from 30.1% to 17.5%and 7.6% to 18.2% for AOB and denitrifying bacteria, respectively.  相似文献   
89.
岷江上游生态环境治理对策探讨   总被引:21,自引:1,他引:20  
鲁晓阳 《四川环境》1999,18(1):72-74
本文对岷江上游地区生态环境现状及面临危机进行了分析,提出对该地区生态环境保护与资源开发的基本思路。  相似文献   
90.
利用电子探针对水泥净浆中Cr、As、Pb分布特征的研究   总被引:4,自引:1,他引:3  
通过在模拟水泥窑中高温煅烧含Cr、As、Pb的水泥生料,制取水泥熟料,进而制备水泥净浆片.然后利用电子探针的点、线、面分析,研究了水泥净浆中Cr、As、Pb的整体分布特征及在不同矿物相中的具体分布特征,以揭示Cr、As、Pb在其中的微观物理化学形态,为建立Cr、As、Pb的释放机制提供理论基础.结果表明,Cr在水化硅酸...  相似文献   
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