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71.
One-step disposal of Cr (Ⅵ)-bearing wastewater by natural pyrrhotite   总被引:3,自引:0,他引:3  
Cr(VI)-bearing wastewater can be treated by natural pyrrhotite which is used for reductant to reduce Cr(VI) and precipitant to precipitate Cr(III) simultaneously. The disposal products can be divided into three parts in the beakers, namely supernatant in the upper part, the yellowish colloidal precipitates in the middle part and the pyrrhotite in the lower part. The content of total Cr=Cr(VI)+Cr(III) in the supernatant liquid is 0.06 mg/L, which is lower than 1.5 mg/L of the discharge standard of China and near to 0.05 mg/L of the standard of potable water. This one-step disposal composing of both reduction and precipitation which is traditionally divided into two independent steps called reducing technology and precipitating technology respectively. The new method is of obvious economic advantage and favourable to decreasing surplus mud derived from adding Ca(OH)2 to precipitate Cr(III) traditionally so as to avoid recontamination. In fact, sodium sulfite (Na2SO3) used in disposal of Cr(VI) was traditionally produced from natural mineral of pyrrhotite (FeS). One molecule of FeS is 4 times more than that of Na2SO3 from a view point of rational use of mineral resources. Therefore the prospective of application of the one-step disposal of Cr(VI) method is full of promise.  相似文献   
72.
One-step disposal of Cr (Ⅵ)-bearing wastewater by natural pyrrhotite   总被引:1,自引:0,他引:1  
Cr(Ⅵ)-bearing wastewater can be treated by natural pyrrhotite which is used for reductant to reduce Cr(Ⅵ) and precipitant to precipitate Cr(Ⅲ) simultaneously. The disposal products can be divided into three parts in the beakers,namely supernatant in the upper part,the yellowish colloidal precipitates in the middle part and the pyrrhotite in the lower part. The content of total Cr=Cr(Ⅵ)+Cr(Ⅲ) in the supernatant liquid is 0.06 mg/L,which is lower than 1.5 mg/L of the discharge standard of China and near to 0.05 mg/L of the standard of potable water. This one-step disposal composing of both reduction and precipitation which is traditionally divided into two independent steps called reducing technology and precipitating technology respectively. The new method is of obvious economic advantage and favourable to decreasing surplus mud derived from adding Ca(OH)2 to precipitate Cr(Ⅲ) traditionally so as to avoid recontamination. In fact,sodium sulfite (Na2SO3) used in disposal of Cr(Ⅵ) was traditionally produced from natural mineral of pyrrhotite (FeS). One molecule of FeS is 4 times more than that of Na2SO3 from a view point of rational use of mineral resources. Therefore the prospective of application of the one-step disposal of Cr(Ⅵ) method is full of promise.  相似文献   
73.
对分形(fractal)思想的起源、发展和分形、分维(fractal dimension)的含义作了简略的介绍.鉴于物理学中对空间认识的改变而引起的物理学的发展,试探性地将分形、分维思想用来对物质世界的一些物质结构和物质运动现象作定性解释。  相似文献   
74.
预处理对小麦成熟胚愈伤组织形成的影响   总被引:15,自引:1,他引:14  
研究了种子预处理及生长素质量浓度对小麦成熟胚愈伤组织形成及种子碳水化合物和蛋白质降解的影响。结果表明:1)在2,4-D质量浓度为8mg/L时发芽率最低,出愈率最高。2)低温处理促进冀麦36种子萌发,抑制其愈伤组织的形成;而对河农326种子萌发及愈伤组织形成无明显影响;引起河农326种子淀粉酶、蛋白酶活性显著增加。3)CaCl2处理促进冀麦36、河农326种子萌发,但抑制其愈伤组织形成,使河农326种子淀粉酶活性显著增加。4)PEG处理促进冀麦36、河农326种子萌发,抑制河农326愈伤组织形成,但对冀麦36愈伤组织形成无明显影响,并明显引起河农326种子淀粉酶、蛋白酶活性升高。  相似文献   
75.
本文论述了知识经济的由来及主要特征及知识经济时代信息技术的重要性。  相似文献   
76.
为解决非线性光学活性有机分子透明性差及裂解温度低的问题,设计合成了2-乙酰氨基-4,5-对硝基二苯基噻唑和2-氨基-4.5-对硝基二苯基噻唑化合物,并研究了其热性能、光学性能.由于杂环的引人,较好地改善了其透明性能,并提高了其裂解温度.  相似文献   
77.
Gou  Kemian  Shang  Lijuan  An  Xiaorong  Deng  Jixian  Chen  Yongfu  Huang  Peitang 《科学通报(英文版)》1999,44(3):236-236
Western blot analysis revealed that one IgG1 monoclonal antibody (mAb) to sp18 family membrane proteins (Mr. 14, 16 and 18 ku) of bovine sperm reacted faintly with protein bands of 14, 18, 22, 30 and 60 ku (reducing) in samples of mouse sperm. The mAb also reacted to protein of egg lysozyme. Using a laser confocal microscope, indirect immunofluorescence (IIP) showed that the sp18 antigens were present in the posterior head of murine sperm. In murine in vitro fertilization (IVF) and embryo development trails, a total of 426 oocytes from C57BL/6 and F1 hybrid strain (CD1 × C57BL/6 cross) of 12 female mice were used in 3 independent trails. After preincubating capacitated sperm with 182 μg/mL of sp18 mAb in the modified TYH IVF medium for 15-20 min, cumulus-oocyte-complexes were introduced. The fertilization rate in sp18 mAb groups was 77.1 %, which was not significantly (P > 0.05) different from the nonspecific mouse IgG (79.2%) and non-IgG (80.3 %) control groups. Fertilized oocytes had been continuously cultured in modifed CZB medium. 100%, 100% and 97.9% of 1-cell embryos developed to 2-cell stage in sp18 mAb, nonspecific mouse IgG and non-IgG group 30 h after the start of fertilization, respectively. In the nonspecific mouse IgG and non-IgG groups, 64.1 % and 64.3% of embryos developed to the 4-cell stage, respectively, but all developing eggs in sp18 mAb groups arrested development in vitro at 2-cell stage. After zonae of 2-cell blocked embryos were enzy-matically removed with 0.5% pronase, detection of sp18 antigens by IIF indicated that the fluorescence scattered on two embryonic cells. For embryos fertilized in vivo and co-cultured with 182 μg/mL sp18 mAb, the numbers of 1-cell embryos reaching the 2-cell and 4-cell stage were 95. 2% and 70. 5%, which were not significantly (P>0.05) different from the control group (92.9% and 77.9%). These results indicate that the sp18 antigens on posterior head of mouse sperm were incorporated into the egg plasma membrane during fertilization, and played an active role in development of murine preimplanta-tion embryo.  相似文献   
78.
库车坳陷是一种新型的前陆盆地,其构造样式以类型Ⅱ三角带为特征。复杂构造区的层面在二维平面内可看作为一条曲线,从而可运用分形几何学方法由分数维来定量描述。运用平衡剖面技术和分形方法,以BC95-230 剖面为例,进行了缩短量和剖面应变计算。分析结果表明,N1 底界曲面的分维值为1.0491,缩短量达35.267 km ,表现出50.05% 的应变。由于受层间滑动等多种地质因素的影响,平衡剖面技术计算结果存在较大误差。因此,要正确平衡地质剖面,必须对小尺度范围的应变进行分析  相似文献   
79.
序列扩频UWB通信系统的Rake接收性能分析   总被引:1,自引:1,他引:0  
基于一个能较好描述超宽带(UWB)信号传播特性的S-V室内多径传播统计信道模型,对高速序列扩频的UWB系统Rake接收机设计中的若干关键问题进行了详细仿真和分析.结果表明,在该信道下,选择合并Rake(S-Rake)接收机或有限合并Rake(L-Rake)接收机的性能显著优于部分合并Rake(P-Rake)接收机.通过5~10个Rake接收支路的等增益合并(EGC)能够较好地克服符号间干扰(ISI)和码间干扰(ICI),而不需要使用复杂的均衡器.  相似文献   
80.
一种新的彩色图像边缘检测算法   总被引:15,自引:0,他引:15  
传统的边缘检测方法大都基于灰度图像,不能充分利用彩色图像的全部信息。针对已有算法中存在的像素点扩散、边缘定位不准确、边缘不连续等问题,提出了一种彩色图像边缘提取算法,基于图像自身梯度方向信息和多通道信息融合技术,将灰度边缘模板算子扩展应用到彩色图像的边缘检测中,在RGB空间中对原彩色图像进行多通道边缘检测;同时采用滤波来抑制噪声,依靠边缘生长保证检出边缘的连续性,并提出了自适应确定边缘提取门限值的方法。该文提出的彩色图像边缘检测算法计算量小,实验结果表明了其能充分利用图像的颜色和梯度信息,有效地消除噪声,提高边缘检测的准确性,保证边缘的连续性。  相似文献   
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