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991.
应用了五种自由基清除剂——苯甲酸钠、二苯胺,2.6二叔丁基对羟甲苯、生育醇(维生素E)和没食子酸丙酯来喷洒植株或涂抹叶片,然后接触致害浓度的SO_2。供试植物为芝麻、烟草、小麦、紫花苜蓿和辣椒五种。试验结果表明,预先经过这些药剂处理的植物,伤害有所减轻,外渗K+减少,与此同时,乙烷、丙二醛和荧光物质的产生也相应降低。自由基清除剂对SO_2伤害的保护作用说明在伤害过程中有自由基参与,它们引起膜类脂的过氧化作用。这些结果对膜类脂的过氧化是SO_2伤害过程的一个重要环节的假设提供了又一个证据。  相似文献   
992.
通过盆栽、模拟箱和氧化塘中凤眼莲净化含酚污水的试验表明:放养凤眼莲能使除酚过程加快,在0.6—10mg/L酚浓度范围内,植物净化速率为一般自然净化速率的2—3倍。在温度17—37℃范围内,凤眼莲均能明显加速酚水的净化。光照强度对凤眼莲净化酚水速率无显著影响。平衡地提高水中矿质营养元素的浓度,能加速除酚的过程。 水中含酚量小于1mg/L不造成植株中酚的残留;6mg/L以下酚含量增加亦不明显;10mg/L以上则随酚浓度的提高,植株中酚含量成倍增加。  相似文献   
993.
本文结合4个典型实例,对生产中因受落枓、弯曲、拉深等其它冲压工序的影响而产生的冲孔件质量问题进行了分析。介绍了在生产现场解决问题的方法和防止这类废次品产生的措施。根据对具体实例的分析、文章总结出了有关冲孔件质量控制的一些要点。  相似文献   
994.
The objectives of this present study were to assess the effects of varying dilutions, pH, temperature and cations on spermatozoa motile parameters (SMPs) in fish Larimichthys polyactis. Optimal SMPs were observed when emen was diluted in artificial seawater (ASW) at a ratio of 1 to 100, with temperature of 10 degreesC and pH 8.0. The spermatozoa of L. polyactis were immotile in distilled water and motile in solution containing different cations. Maximum SMPs were obtained in each solution containing 0.4 mol NaCI, 0.4 mol KCI, 0.2 mol CaCI2 and 0.2 mol MgCl2. This study provides baseline knowledge of L. polyactis spermatozoa sensitivity of pH, temperature and cationic effects.  相似文献   
995.
Chiang HL  Tsai JH  Chang DH  Jeng FT 《Chemosphere》2000,41(8):1227-1232
Activated carbon kinetic studies show that both H2S and CH3SH yielded pore diffusion coefficients from 10(-6) to 10(-8) cm2/s. Results indicated that pore structures could influence effective diffusivity. Under the same adsorbate concentration, CH3SH exhibited a greater effective pore diffusion coefficient than H2S. This may be attributed to the fact that CH3SH has both polar (-SH) and non-polar (-CH3) functional groups and dissolves into water easier, thus providing more attraction for the activated carbon surface. In addition, the saturation vapor pressure of CH3SH is lower than that of H2S. Therefore, CH3SH is easier to adsorb onto activated carbon than H2S.  相似文献   
996.
Fang GC  Chang CN  Wang NP  Wu YS  Wang V  Fu PP  Cheng CD  Chen SC  Lin DY 《Chemosphere》2000,41(11):1727-1731
Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there were more than 20,000 aftershocks that followed the Taiwan Chi-Chi Earthquake within three months. Thus, the PM2.5, PM(2.5-10) particle concentrations were also collected then and compared with total suspended particle (TSP) in this study. The average PM(2.5-10), PM2.5 and TSP concentrations are 24.6, 58.0 and 106 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 70 and 127 microg/m3, respectively. It is clearly shown that the average concentration of TSP after Taiwan Chi-Chi Earthquake was about 1.8 times as that of TSP concentration before Taiwan Chi-Chi Earthquake in the traffic site of central Taiwan. And the ratios of PM2.5/PM(2.5-10), PM2.5/PM10 and PM2.5/TSP are 2.2%, 67.2%, 38.9%, respectively. The results also indicated about Chi-Chi fine particle concentration (PM25) and the TSP increases in the traffic site of central Taiwan after Taiwan Chi-Chi Earthquake.  相似文献   
997.
铬盐废渣解毒研究   总被引:4,自引:1,他引:4  
通过试验测定了长沙铬盐厂铬盐废渣的性质。正交试验研究得出了以硫酸铵[(NH4)2SO4]为解毒剂的铬渣干法解毒最佳工艺。即以粒径为75μm铬渣与加入量为13.3%(质量百分比)、粒径为427μm的硫酸铵混合均匀,于500℃急速加热30min、闭炉门冷却,解毒处理效率达96.41%。  相似文献   
998.
Lee CH  Park CY  Park KD  Jeon WT  Kim PJ 《Chemosphere》2004,56(3):299-304
The changes in total P accumulation and P compounds with time in the plough layer in a paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK+Compost) for 31 years. Continuous fertilization increased the total and inorganic P contents in plough layers. In NPK, inorganic P fraction did not change with time, but organic P content increased significantly. Long-term application of chemical fertilizer together with compost accelerated the decrease in the organic P fraction, presumably due to promoting microbial activity in the plow layer, and then increased significantly inorganic P fraction. Compost application decreased the residual P and Fe-P fractions and then increased inorganic P fraction, in spite of continuous compost application. Increase in total, inorganic and extractable P with time may be closely related to the increase in the availability of accumulated P for rice growth.  相似文献   
999.
以流化床为反应器 ,探讨了一些主要参数如 :反应器温度 ,水蒸气 ,当量比ER以及催化剂对气体成分、氢产率和潜在氢产率的影响。实验所用催化剂为白云石和镍基催化剂。在实验条件范围内 ,氢产率为 2 2— 83g/kg生物质 (湿基 ) ,潜在氢产率为 115— 2 2 3g/kg生物质 (湿基 )。结果表明 ,较高的反应器温度 ,适当的水蒸气添加量可以有效提高氢的产出 ;白云石和镍基催化剂可使产品气中的氢含量提高 10 %以上。  相似文献   
1000.
Modeling VOCs adsorption onto activated carbon   总被引:2,自引:0,他引:2  
The activated carbon adsorption process is affected by the characteristics of adsorbent, adsorbate and environmental conditions. In this study, both adsorption and desorption processes are assumed to occur simultaneously and a numerical model was developed with a non-linear driving force in conjunction with the Langmuir model for predicting the overall adsorption process. The numerical model provides both adsorption and desorption rate constants and activation energies. The resultant equilibrium constants are of the same order of magnitude as reported by other studies. Results show that the model could well predict the adsorption isotherms and breakthrough curves under various conditions.  相似文献   
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