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排序方式: 共有143条查询结果,搜索用时 15 毫秒
1.
植物对灰尘有吸附作用,但植物的哪些部分对灰尘有吸附作用值得研究。基于此,开展针对性的研究性学习,以期通过试验,探究对灰尘有吸附作用的植物器官及其影响。  相似文献   
2.
正巧喂。在鸡日粮中添加1%~2%的木炭渣,可使粪便干燥,臭味降低;添加2%~5%的沸石粉,可减少粪便含水量及臭味,并有利于提高饲料利用率。巧熏。用艾叶、苍术、大青叶或大蒜秸杆各等份、适量,在鸡舍内燃烧,既杀菌又除臭,特别是在空舍时使用效果更好。巧吸。木炭、活性炭、煤渣、生石灰等具有很强的  相似文献   
3.
硫酸盐对锌和镉在可变电荷土壤上吸附的影响   总被引:8,自引:1,他引:8  
SO4^2- and Zn^2 or Cd^2 were added to three variable charge soils in different sequences.In one sequence sulfate was added first ,and in the other,Zn^2 or Cd^2 first.The addition of sulfate to the system invariably caused an increase in adsorption of the heavy metal added,with the effect more remarkable whn the soil reacted with the sulfate prior to the metal.the shift in pH50 for both Zn and Cd adsorption was aslo comparatively larger in the first sequence of reactions .It was suggested that the increase in negative charge density and the resultant negative potential of the soil were the primary cause of the pronounced effect of sulfate on adsorption of Zn or Cd,and the formaiton of the ternary surface complex-S-SO4-M might also play a role in the effect.  相似文献   
4.
土壤中砷的吸附和砷对水稻的毒害效应与pH的关系   总被引:4,自引:0,他引:4  
  相似文献   
5.
粉砂壤土对铵离子的吸附特性   总被引:3,自引:0,他引:3  
平衡状态下粉砂壤土吸附铵离子的实验结果表明,土壤溶液中NH4+的质量浓度产ρ(NH4+)影响土壤对NH4+的吸附模式。当ρ(NH4+)低于某一数值ρk(NH4+)时土壤中的NH4+将被溶解到土壤溶液中;当ρ(NH4+)较大时土壤对NH4+的吸附作用可用Langmir吸附模式描述;当ρ(NH4+)较小(但大于ρk(NH4+)时,土壤对NH4+的吸附作用可用线性等温的Frundlich吸附公式描述。  相似文献   
6.
膨润土对土壤中有机氯农药吸附性能的测定   总被引:2,自引:0,他引:2  
在模拟DDT污染的土壤中加入不等量的膨润土作吸附剂,模拟自然降水过程,对其进行淋溶试验,以此来测定土样中吸附的DDT量与吸附剂用量和淋溶水量之间的相关性。试验结果表明,吸附是由土壤中原有的土壤胶体和加入的膨润土两者共同完成的。在试验条件下,当土壤中加入膨润土为0.50%时,土壤胶体和膨润土壤二者形成的具有吸附性的结构,使其具有更大的比表面积,吸附能力最强。  相似文献   
7.
1、二氧化氯 分子式:ClO2 它是氯的氧化物,以游离气体存在。常温常压下是一种带有辛辣气味的黄色气体。严格来讲二氧化氯不是氯制剂而是氧化剂。其氧化能力较氯酸强2.5倍。孔水中杀灭细菌、病毒较一般消毒剂强。因为二氧化氯分子与病毒的蛋白质之间有吸附作用,致使病毒颗粒表面有高浓度的消毒剂分子达到灭活作用。其治疗效果不受水体中有机物、  相似文献   
8.
Hygroexpansion of wood during moisture adsorption and desorption processes   总被引:1,自引:0,他引:1  
In order to investigate the shrinking and swelling behavior of wood at a non-equilibrium state, the moisture sorptlon processes of wood under constant and changing conditions were studied. For the static sorption experiment, Chinese fir (Cunninghamia lanceolata) specimens were subjected to the adsorption processes at 25℃, 10 different relative humidity environments and the moisture contents were measured at distinct time intervals of adsorption processes. For the dynamic sorption experiment, the specimens were exposed to periodically and linearly varying relative humidity between 45% and 75% at 25℃. Moisture content as well as radial and tangential dimensional changes in response to the changing relative humidity were measured. The main results from the experiments indicated that: the moisture sorption isotherms of Chinese fir at equilibrium state and different stages of adsorption processes could be characterized by S-shape curves. From the non-equilibrium state to the equilibrium state, the sigmoid moisture sorption isotherms changed from smooth, gradually increasing values to a steep rise at 100% humidity. Furthermore, under dynamic conditions with a constant temperature and a linearly and periodically varying relative humidity, the moisture content as well as radial and tangential dimensional changes of the specimens generally waved but lagged behind the relative humidity change.  相似文献   
9.
林玉锁  薛家骅 《土壤学报》1991,28(4):390-395
本文从溶质、溶剂与吸附剂表面三者之间相互作用的角度,阐明了Freundlich方程(x=kc^1/a)在固-液吸附中两个参数的物理意义,k是与吸附平衡常数成正比的特征参数,k值大小则表示吸附反应进行的程度;a与溶质和吸附剂表面脱落的溶剂分子数的比值有关,是表征吸附作用力性质的特征参数。由实验求得k和a值初步探讨了Zn在石灰性土壤中的吸附机制和迁移规律,结果是令人满意的。  相似文献   
10.
增硝营养对水稻不同生育时期生长及氮素吸收同化的影响   总被引:14,自引:0,他引:14  
The effect of nitrate (NO3^-) on rice (Oryza sativa L.) growth as well as N absorption and assimilation during different growth stages was examined using three typical rice cultivars. Dry weight, yield, N uptake, nitrate reductase activity (NRA) in leaves, and glutamine synthetase activity (GSA) in roots and leaves during their entire growth periods, as well as the kinetic parameters of ammonium (NH4^+) uptake at the seedling stage, were measured with solution culture experiments. Results indicated that addition of NH4^+-N and NO3^-N at a ratio of 75:25 (NH4^++NO3^- treatment) when compared with that of NH4^+-N alone (NH4^+ treatment) increased the dry weight of ‘Nanguang' cultivar by 30% and ‘Yunjing 38' cultivar by 31%, and also increased their grain yield by 21% and 17%, respectively. For the four growth stages, the total N accumulation in plants increased by an average of 36% for ‘Nanguang' and 31% for ‘Yunjing 38', whereas the increasing effect of NO3^- in the ‘4007' cultivar was only found at the seedling stage, in the NH4^++NO3^- treatment compared to the NH4^+ treatment, NRA in the leaves increased by 2.09 folds, and GSA increased by 92% in the roots and 52% in the leaves of the three cultivars. NO3^- supply increased the maximum uptake rate (Vmax) in the ‘Nanguang' and ‘Yunjing 38' cultivars, reflecting that the NO3^- itself, not the increasing N concentration, increased the uptake rate of NH4^+ by rice. There was no effect on the apparent Michaelis-Menten constant (Kin) of the three cultivars. Thus, some replacement of NH4^+ with NO3^-could greatly improve the growth of rice plants, mainly on account of the increased uptake of NH4^+ promoted by NO3^-, and future studies should focus on the molecular mechanism of the increased uptake of NH4^+ by NO3^-.  相似文献   
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